JP7306846B2 - Stators, motors, magnetic bearing units, and vacuum pumps - Google Patents

Description

The present invention relates to stators. The present invention also relates to a motor and a vacuum pump that rotates a rotor blade by the motor. Further, it relates to a magnetic bearing unit that supports a rotor.

A vacuum pump in which a rotor blade is rotated by a motor is described in Patent Document 1. The motor of the document includes a rotor to which rotary blades are connected, a stator for rotating the rotor, a first magnetic bearing unit arranged on one side of the stator in the axial direction of the rotor, and a magnetic bearing unit arranged on the other side of the stator. A second magnetic bearing unit is provided. The first magnetic bearing unit includes a first electromagnet that radially supports the rotor by magnetic force without contact, and a first sensor that is superimposed in the axial direction of the first electromagnet and detects radial displacement of the rotor. The second magnetic bearing unit includes a second electromagnet that radially supports the rotor without contact by magnetic force, and a second sensor that is superimposed in the axial direction of the second electromagnet and detects radial displacement of the rotor. In the first magnetic bearing unit, the first sensor is axially superimposed on one side of the first electromagnet. In the second magnetic bearing unit, the second sensor is axially superimposed on the other side of the second electromagnet.

JP 2018-145803 A

When assembling the motor, the first member (first magnetic bearing unit) located on one side of the stator and the stator are brought into contact with each other in the axial direction, and the second member (second magnetic bearing unit) located on the other side of the stator is brought into contact with each other. If the bearing unit) and the stator are brought into contact with each other in the axial direction, the position of the first member and the position of the second member in the axial direction can be defined with reference to the stator. However, in general, the stator of the motor has a symmetrical shape with respect to an imaginary plane perpendicular to the axis. Therefore, when the first member and the stator are brought into contact with each other in the axial direction, and the second member and the stator are brought into contact with each other in the axial direction, the distance from the center of the stator to the first member in the axial direction and , and the distance from the center of the stator to the second member are limited to a single distance, which impairs the degree of freedom in arranging the first member and the second member.

In view of the above problems, it is an object of the present invention to provide a stator in which members can be positioned while securing the degree of freedom in the arrangement of members arranged next to the stator in the axial direction. Another object of the present invention is to provide a motor and a vacuum pump having such a stator. Another object of the present invention is to provide a magnetic bearing unit that supports the rotor of the motor without contact.

In order to solve the above problems, the present invention provides a stator core including an annular portion and a salient pole portion projecting inwardly from the annular portion, an insulator including a tubular portion through which the salient pole portion penetrates, and the tubular portion. and a coil wound around a portion, wherein the direction along the axis of the annular portion is the axial direction, the direction perpendicular to the axial direction is the radial direction, one side of the axial direction is the first direction, and the other side is the first direction. The insulator is provided with a core covering portion on the outer side of the cylindrical portion in the radial direction when the side is the second direction, and the core covering portion is a first abutment member with which a member can abut from the axial direction. either the first contact portion or the second contact portion is selectively used as a positioning portion that includes a contact portion and a second contact portion and positions the member by contacting the member; A first distance between the center of the stator core and the first contact portion in the axial direction is longer than a second distance between the center of the stator core and the second contact portion in the axial direction. Characterized by being short.

The stator of the present invention includes the first contacted portion and the second contacted portion that are different in distance from the center of the stator core in the insulator. Therefore, by bringing a member arranged next to the stator in the axial direction into contact with the first contacted portion, the member can be positioned using the distance from the center of the stator to the member as the first distance. Further, by bringing a member arranged next to the stator in the axial direction into contact with the second abutted portion, the member can be positioned using the distance from the center of the stator to the member as the second distance. Therefore, according to the present invention, it is possible to position the member while ensuring the degree of freedom of arrangement of the member arranged next to the stator in the axial direction.

In the present invention, the insulator is composed of a first insulator member and a second insulator member made of resin that are divided into two in the axial direction, and the first insulator member and the second insulator member are the same member. can be assumed to be By dividing the insulator into two insulator members, each insulator member can be easily molded by injection molding even when the insulator has a complicated shape. Further, in this way, even if the insulator is composed of two insulator members, the number of parts does not increase.

Next, a motor according to the present invention includes the above stator, a rotor arranged on the inner peripheral side of the stator, a first electromagnet that supports the rotor in the radial direction without contact by magnetic force, and the first electromagnet. a first magnetic bearing unit including a first sensor that is superimposed in the axial direction of the rotor and detects the radial displacement of the rotor; a second electromagnet that supports the rotor in the radial direction by magnetic force without contact; a second magnetic bearing unit including a second sensor that is stacked in the axial direction of the second electromagnet and detects the radial displacement of the rotor; The second magnetic bearing unit is stacked in the first direction and contacts the first contact portion or the second contact portion of the core cover portion , and the second magnetic bearing unit is stacked in the second direction of the stator. and is brought into contact with the first contacted portion or the second contacted portion of the core cover portion.

A motor according to the present invention includes a stator having a first abutted portion and a second abutted portion that are different from each other in distance from the center of the stator core. Therefore, if the first magnetic bearing unit is brought into contact with the first contact portion and the second magnetic bearing unit is brought into contact with the second contact portion, the distance from the center of the stator to the first magnetic bearing unit is the first magnetic bearing unit. 1 distance and a second distance from the center of the stator to the second magnetic bearing unit. Also, if the first magnetic bearing unit is brought into contact with the second contact portion and the second magnetic bearing unit is brought into contact with the first contact portion, then the distance from the center of the stator to the first magnetic bearing unit is the first magnetic bearing unit. There may be two distances and the first distance may be from the center of the stator to the second magnetic bearing unit. Therefore, it is possible to position the first magnetic bearing unit and the second magnetic bearing unit while securing the degree of freedom of arrangement of the first magnetic bearing unit and the second magnetic bearing unit arranged on both sides of the stator in the axial direction.

Next, a vacuum pump of the present invention comprises a motor including the above stator and a rotor arranged on the inner peripheral side of the stator, a pump case, fixed wings fixed inside the pump case, and a rotary blade that is attached to the rotor and rotates inside the pump case.

According to the vacuum pump of the present invention, the stator, the first magnetic bearing unit, and the second magnetic bearing unit, which are laminated in the axial direction, are arranged in a motor with a high degree of freedom. Therefore, the degree of freedom in designing the vacuum pump is improved.

Further, a vacuum pump of the present invention comprises the above motor, a pump case, fixed blades fixed inside the pump case, and rotary blades attached to a rotor of the motor and rotating inside the pump case. , is characterized by having

According to the vacuum pump of the present invention, the stator, the first magnetic bearing unit, and the second magnetic bearing unit, which are laminated in the axial direction, are arranged in a motor with a high degree of freedom. Therefore, the degree of freedom in designing the vacuum pump is improved.

Next, another aspect of the present invention includes a stator core including an annular portion and a salient pole portion projecting inwardly from the annular portion; an insulator including a tubular portion through which the salient pole portion penetrates; and a wound coil, wherein the direction along the axis of the annular portion is the axial direction, the direction orthogonal to the axial direction is the radial direction, one side of the axial direction is the first direction, and the other side is the When the second direction is assumed to be the second direction, the insulator includes a first core cover portion superimposed in the first direction of the annular portion outside the cylindrical portion in the radial direction and a second core cover portion superimposed in the second direction of the annular portion. A core covering portion is provided, and each of the first core covering portion and the second core covering portion includes the first abutted portion and the second abutted portion, and is aligned with the center of the stator core in the axial direction. A first distance between the first contact portion is shorter than a second distance between the center of the stator core and the second contact portion in the axial direction, and the first contact portion and the second abutted portion are arranged side by side in a radial direction.

The stator of the present invention includes an insulator and a first core cover portion stacked in a first direction and a second core cover portion stacked in a second direction on the annular portion of the stator core. Also, the first core covering portion and the second core covering portion each include a first contact portion and the second contact portion having different distances from the center of the stator core. Therefore, for example, the first member arranged in the first direction of the stator is brought into contact with the first contacted portion of the first core cover portion, and the second member arranged in the second direction of the stator is brought into contact with the second core. By contacting the second contacted portion of the cover portion, the distance from the center of the stator to the first member (first distance) and the distance from the center of the stator to the second member (second distance) can be different. Also, the first member arranged in the first direction of the stator is brought into contact with the first contacted portion of the first core cover portion, and the second member arranged in the second direction of the stator is brought into contact with the second core cover portion. , the distance from the center of the stator to the first member and the distance from the center of the stator to the second member can be the same first distance. Further, the first member arranged in the first direction of the stator is brought into contact with the second contacted portion of the first core cover portion, and the second member arranged in the second direction of the stator is brought into contact with the second core cover portion. , the distance from the center of the stator to the first member and the distance from the center of the stator to the second member can be the same second distance. Therefore, according to the present invention, the two members arranged on both sides of the stator in the axial direction can be positioned while securing the degree of freedom of arrangement of these two members.

In the present invention, the first contact portion may be located inside the second contact portion in the radial direction. With this configuration, when an external member arranged on one side or the other side in the axial direction of the stator is brought into contact with the second contacted portion, the external member interferes with the first contacted portion. easy to avoid.

In the present invention, each of the first core cover portion and the second core cover portion includes a first wall portion extending in the axial direction and a second wall portion extending in the axial direction outside the first wall portion in the radial direction. and two wall portions, wherein the thickness of the first wall portion in the radial direction is greater than the thickness of the second wall portion in the radial direction, and is different from the annular portion of the first wall portion. The end on the opposite side may be the first abutted portion, and the end of the second wall opposite to the annular portion may be the second abutted portion. . In this way, the radial width of the first abutted portion can be increased. Therefore, even if the first contacted portion is located on the inner peripheral side of the stator, it becomes easy to bring an external member into contact with the first contacted portion.

In the present invention, the first dimension of the first wall portion in the circumferential direction is longer than the length dimension of the coil in the circumferential direction, and the first wall portion is and a groove penetrating from the inner peripheral side to the outer peripheral side may be provided in the end portion opposite to the annular portion. If the first dimension of the first wall is longer than the length dimension of the coil in the circumferential direction, the coil can be protected from the outer peripheral side by the first wall. Further, if the groove is provided in the first wall portion, the coil wire of the coil wound around the cylindrical portion can be pulled out to the outer peripheral side through the groove portion.

In the present invention, each of the first core cover portion and the second core cover portion is a connecting portion that extends in the radial direction along the annular portion and connects the first wall portion and the second wall portion. wherein the coil wire pulled out from the coil is passed through the groove and routed through a second groove partitioned by the first wall, the second wall and the connecting portion can be With this configuration, when the coil wire pulled out from the coil is routed in the circumferential direction, it is not necessary to route the outside of the insulator. Therefore, disconnection of the coil wire can be prevented or suppressed. In addition, when the coil wire drawn out from the coil is routed in the circumferential direction, it is not necessary to route the outside of the insulator.

In the present invention, the second wall portion includes a reinforcing portion at the end portion on the side of the connection portion, the thickness of which in the radial direction increases toward the first wall portion as the thickness approaches the connection portion. can be With such a reinforcing portion, even if a load that bends the distal end portion of the second wall portion toward the outer circumference is applied when the coil wire is routed in the second groove, the second wall portion can It is possible to prevent or suppress breakage from a portion near the connecting portion.

In the present invention, a second dimension of the second wall portion in the circumferential direction may be shorter than the first dimension. Between two insulators adjacent in the circumferential direction, a gap is provided between the second wall portion of one insulator and the second wall portion of the other insulator. Therefore, the coil wire or the like routed through the second groove can be pulled out of the stator through the lateral gap of the second wall portion.

In the present invention, the second wall may be provided with a notch that penetrates in the radial direction. With this configuration, the coil wire or the like routed through the second groove can be pulled out of the stator through the notch portion provided in the second wall portion.

In the present invention, the insulator is composed of a first insulator member and a second insulator member made of resin that are divided into two in the axial direction, and the first insulator member and the second insulator member are the same member. can be assumed to be By dividing the insulator into two insulator members, each insulator member can be easily molded by injection molding even when the insulator has a complicated shape. Further, in this way, even if the insulator is composed of two insulator members, the number of parts does not increase.

A motor according to another aspect of the present invention includes the above-described stator, a rotor arranged on the inner peripheral side of the stator, a first electromagnet that supports the rotor in the radial direction without contact by magnetic force, and the first electromagnet. a first magnetic bearing unit including a first sensor that is stacked in the axial direction of the electromagnets and detects displacement of the rotor in the radial direction; and a second electromagnet that supports the rotor in the radial direction without contact by magnetic force; and a second magnetic bearing unit including a second sensor that is superimposed in the axial direction of the second electromagnet and detects displacement of the rotor in the radial direction, wherein the first magnetic bearing unit includes the stator are stacked in the first direction and abut against the first abutted portion or the second abutted portion of the first core cover portion , and the second magnetic bearing unit is the second magnetic bearing unit of the stator. It is stacked in the direction and contacts the first contacted portion or the second contacted portion of the second core cover portion.

A motor according to the present invention includes a stator having a first abutted portion and a second abutted portion that are different from each other in distance from the center of the stator core. Therefore, for example, the first magnetic bearing unit located in the first direction of the stator is brought into contact with the first abutted portion of the first core cover portion, and the second magnetic bearing unit located in the second direction of the stator is brought into contact with the first contact portion. The distance from the center of the stator to the first magnetic bearing unit is made different from the distance from the center of the stator to the second magnetic bearing unit by contacting the second abutted portion of the two-core cover portion. be able to. Further, if the first magnetic bearing unit is brought into contact with the second contacted portion of the first core cover portion and the second magnetic bearing unit is brought into contact with the first contacted portion of the second core cover portion, The distance from the center of the stator to the first magnetic bearing unit can be different from the distance from the center of the stator to the second magnetic bearing unit. Further, if the first magnetic bearing unit is brought into contact with the first contacted portion of the first core cover portion and the second magnetic bearing unit is brought into contact with the first contacted portion of the second core cover portion, The distance from the center of the stator to the first magnetic bearing unit and the distance from the center of the stator to the second magnetic bearing unit can be the same first distance. Further, if the first magnetic bearing unit is brought into contact with the second contacted portion of the first core cover portion and the second magnetic bearing unit is brought into contact with the second contacted portion of the second core cover portion, The distance from the center of the stator to the first magnetic bearing unit and the distance from the center of the stator to the second magnetic bearing unit can be the same second distance. Therefore, it is possible to position the first magnetic bearing unit and the second magnetic bearing unit while securing the degree of freedom of arrangement of the first magnetic bearing unit and the second magnetic bearing unit arranged on both sides of the stator in the axial direction.

In the present invention, the first sensor is stacked in the first direction of the first electromagnet, and the first electromagnet abuts on the first abutted portion of the first core covering portion of the stator. can be

In the present invention, the first electromagnet includes an electromagnet core having a core annular portion arranged to surround the axis and a core salient pole portion projecting inwardly from the core annular portion, an electromagnet insulator, and the electromagnet insulator. and an electromagnet coil wound around the core salient pole portion via the electromagnet insulator. and an outer flange projecting from an outer edge of the insulator cylinder in the radial direction, and the electromagnetic coil is disposed between the inner collar and the outer collar. An end portion of the outer collar portion in the second direction, which is wound around the insulator cylindrical portion, may abut against the first abutted portion from the axial direction. That is, the outer collar portion of the electromagnet insulator of the first electromagnet can be brought into contact with the first abutted portion provided on the insulator of the stator.

In the present invention, there is provided a resin sealing member that seals the stator, the first magnetic bearing unit, and the second magnetic bearing unit on the outer peripheral side of the rotor when the circumference of the axis is taken as the circumferential direction. , the first wall portion has an arc shape when viewed from the axial direction, the outer collar portion extends linearly in the circumferential direction when viewed from the axial direction, and the A thickness in a radial direction may be thinner than a thickness of the first wall portion, and a portion in the circumferential direction may protrude from the first wall portion to the outer peripheral side. In this way, a gap is likely to be formed between the stator and the first electromagnet. Therefore, it is easy to infiltrate the resin into these gaps and provide the resin sealing member.

In the present invention, the first sensor includes a sensor core having a sensor core annular portion arranged to surround the axis and a sensor core salient pole portion projecting inwardly from the sensor core annular portion, and attached to the sensor core salient pole portion. and a sensor coil wound around the sensor core salient pole portion via the coil bobbin. It is desirable to provide an abutting portion that abuts from the . With this configuration, the first center can be positioned in the axial direction with the first electromagnet as a reference due to the contact between the contact portion of the electromagnet insulator and the sensor core. Here, the electromagnet insulator abuts on the first abutted portion of the stator. Therefore, by contacting the electromagnet insulator and the sensor core, the distance from the center of the stator to the first sensor can be defined with high accuracy.

In the present invention, the sensor core includes a sensor core cutout portion on the outer peripheral edge of the sensor core annular portion, and the contact portion includes a contact surface that contacts the sensor core annular portion and a contact surface that contacts the sensor core annular portion in the first direction from the contact surface. and a protrusion that protrudes into the sensor core cutout and is inserted into the sensor core cutout. In this way, it is possible to define the position of the sensor around the axis by inserting the projection into the notch.

In the present invention, the second sensor is stacked in the first direction of the second electromagnet, and the second sensor contacts the second contacted portion of the second core cover portion of the stator. can be

Next, a vacuum pump of the present invention comprises a motor including the above stator and a rotor arranged on the inner peripheral side of the stator, a pump case, fixed wings fixed inside the pump case, and a rotary blade that is attached to the rotor and rotates inside the pump case.

According to the vacuum pump of the present invention, the stator, the first magnetic bearing unit, and the second magnetic bearing unit, which are laminated in the axial direction, are arranged in a motor with a high degree of freedom. Therefore, the degree of freedom in designing the vacuum pump is improved.

Further, a vacuum pump of the present invention comprises the above motor, a pump case, fixed blades fixed inside the pump case, and rotary blades attached to a rotor of the motor and rotating inside the pump case. , is characterized by having

According to the vacuum pump of the present invention, the stator, the first magnetic bearing unit, and the second magnetic bearing unit, which are laminated in the axial direction, are arranged in a motor with a high degree of freedom. Therefore, the degree of freedom in designing the vacuum pump is improved.

Next, the present invention provides a magnetic bearing unit for rotatably supporting a rotor, wherein the direction along the central axis of rotation of the rotor is the axial direction, the direction orthogonal to the central axis of rotation is the radial direction, and one side of the axial direction is a first direction and the other side is a second direction, an electromagnet that supports the rotor in the radial direction without contact by magnetic force; a sensor for detecting the displacement of the electromagnet, wherein the electromagnet core has a core annular portion disposed surrounding the rotation center axis and a core salient pole portion protruding inwardly from the core annular portion; , an electromagnet insulator, and an electromagnet coil wound around the core salient pole via the electromagnet insulator, wherein the sensor includes a sensor core annular portion arranged around the rotation center axis and the sensor core annular portion a sensor core having a sensor core salient pole portion projecting inwardly from a sensor core, a coil bobbin attached to the sensor core salient pole portion, and a sensor coil wound around the sensor core salient pole portion via the coil bobbin; The electromagnet insulator includes an insulator tubular portion through which the core salient pole portion penetrates, an inner collar portion projecting from an inner end of the insulator tubular portion in the radial direction, and an outer portion of the insulator tubular portion in the radial direction. It is characterized by having an outer brim portion that protrudes from an end, and a contact portion that contacts the sensor core annular portion from the second direction on the outer peripheral side of the insulator cylindrical portion.

According to the magnetic bearing unit of the present invention, the electromagnet insulator of the electromagnet has the abutting portion that abuts against the sensor core of the sensor from the axial direction. Therefore, by stacking the sensor in the axial direction of the electromagnet, the position of the sensor in the axial direction can be defined on the basis of the electromagnet.

In the present invention, the sensor core includes a sensor core cutout portion on the outer peripheral edge of the sensor core annular portion, and the contact portion includes a contact surface that contacts the sensor core annular portion and a contact surface that contacts the sensor core annular portion in the first direction from the contact surface. and a protrusion that protrudes into the sensor core cutout and is inserted into the sensor core cutout. With this configuration, it is possible to define the position of the sensor around the axis by inserting the protrusion into the core-side notch.

Next, a vacuum pump of the present invention has the above magnetic bearing unit and a rotor to which rotor blades are attached, and the rotor is rotatably supported by the magnetic bearing unit. do.

According to the present invention, it is possible to position a member arranged next to the stator in the axial direction while securing the degree of freedom of arrangement of this member.

According to the magnetic bearing unit of the present invention, it is easy to position the sensor with respect to the electromagnet.

1 is a cross-sectional view of a vacuum pump to which the present invention is applied; FIG. It is a side view of a stator unit. It is a perspective view of a stator. It is a top view of a stator. It is a perspective view of an insulator. It is a top view of an insulator. 4 is a partially enlarged view of an insulator; FIG. 4 is a perspective view of a first magnetic bearing unit; FIG. It is a perspective view of a first sensor. 4 is a perspective view of a first electromagnet; FIG. It is a perspective view of an electromagnet insulator. FIG. 4 is a perspective view of a second magnetic bearing unit; FIG. 5 is an explanatory diagram of a contact state between the stator and the first magnetic bearing unit; FIG. 8 is a side view of a stator unit of Modification 1; FIG. 11 is a side view of a stator unit of Modification 2; FIG. 11 is an explanatory diagram of a stator unit of Modified Example 3;

Embodiments of a stator, a magnetic bearing unit, a motor, and a vacuum pump to which the present invention is applied will be described below with reference to the drawings. FIG. 1 is a sectional view of a vacuum pump to which the present invention is applied. FIG. 2 is a side view of the stator unit. In the following description, the direction along the axis L of the stator and the motor is the axial direction X, one side of the axial direction X is the first direction X1, and the other side is the second direction X2. A direction orthogonal to the axis LX is defined as a radial direction Y, and a circumference around the axis L is defined as a circumferential direction. Note that the axis L is the rotation center axis of the rotor. Also, the first direction X1 is the output side of the motor, and the second direction X2 is the anti-output side of the motor.

(Vacuum pump)
As shown in FIG. 1 , the vacuum pump 1 includes a pump case 2 , fixed blades 3 and rotary blades 4 arranged in the pump case 2 , and a motor 7 that rotates the rotary blades 4 .

The motor 7 includes an annular stator 9 and a rotor 10 arranged at the center in the radial direction Y of the stator 9 . The motor 7 also includes a first magnetic bearing unit 11 and a second magnetic bearing unit 12 that support the rotor 10 in the radial direction Y in a non-contact manner, and a third magnetic bearing unit that supports the rotor 10 in the axial direction X in a non-contact manner. 13 and.

Stator 9 , first magnetic bearing unit 11 , and second magnetic bearing unit 12 constitute stator unit 8 . As shown in FIG. 2, the stator unit 8 is cylindrical as a whole and surrounds the rotor 10 from the outer peripheral side. In the stator unit 8, the first magnetic bearing unit 11, the stator 9, and the second magnetic bearing unit 12 are arranged in the axial direction X in this order. Therefore, the stator 9 surrounds the central portion of the rotor 10 in the axial direction X from the outer peripheral side. The first magnetic bearing unit 11 surrounds the rotor 10 from the outer peripheral side in the first direction X1 of the stator 9 . The second magnetic bearing unit 12 surrounds the rotor 10 from the outer peripheral side in the second direction X2 of the stator 9 .

As shown in FIG. 1, the third magnetic bearing unit 13 is positioned on the side of the rotor 10 in the second direction X2. The third magnetic bearing unit 13 includes an axial sensor 15 that detects the position of the rotor 10 in the axial direction X, and two sets of electromagnets 16 that support the rotor 10 in a floating state in the axial direction X. The two sets of electromagnets 16 are arranged with a metal plate 17 fixed to the end of the rotor 10 in the second direction X<b>2 sandwiched in the axial direction X. The two sets of electromagnets 16 are excited based on the output of the axial sensor 15 and attract the metal plate 17 in the first direction X1 and the second direction X2. That is, the output of the axial sensor 15 is transmitted to a control device (not shown). The controller energizes the two sets of electromagnets 16 based on the position of the rotor 10 in the axial direction X. As shown in FIG. Thereby, the third magnetic bearing unit 13 adjusts the position of the rotor 10 in the axial direction X. As shown in FIG.

The motor 7 also includes a stator column 19 that houses the stator unit 8 and a resin sealing member 20 that seals the stator unit 8 inside the stator column 19 . The stator column 19 is tubular, and the stator unit 8 is fixed to the inner peripheral surface of the stator column 19 . The resin sealing member 20 is positioned on the outer peripheral side of the rotor 10 . When sealing with the resin sealing member 20, after a cylindrical member having a shape corresponding to the arrangement space of the rotor 10 is arranged in the stator column 19, the space between the stator unit 8 and the stator column 19 is is filled with resin.

The rotor 10 extends in the axial direction X. As shown in FIG. The rotor 10 has an output shaft 23 protruding from the stator column 19 in the first direction X1. The rotor blades 4 are fixed to the output shaft 23 (rotor 10 ) via the rotor flange 24 .

The pump case 2 includes an annular base 26 fixed to the stator column 19 from the second direction X2. The third magnetic bearing unit 13 is positioned inside the center hole 26 a of the base 26 . The pump case 2 also includes a tubular case 27 fixed to the base 26 . The cylindrical case 27 extends from the outer peripheral portion of the base 26 in the first direction X1. The cylindrical case 27 surrounds the stator column 19 from the outer peripheral side. A stationary blade 3 is fixed to the inner peripheral surface of the cylindrical case 27 . The rotor blades 4 and the fixed blades 3 are alternately arranged along the axial direction X. As shown in FIG.

An air inlet 28 is formed at the end of the tubular case 27 in the first direction X1. An exhaust port forming portion 29 is attached between the cylindrical case 27 and the base 26 . The pump case 2 communicates with an auxiliary pump (not shown) via an exhaust port 30 passing through the exhaust port forming portion 29 .

The vacuum pump 1 rotates the rotor blades 4 by the motor 7 , transfers the gas sucked from the intake port 28 in the second direction X<b>2 , and discharges the gas from the exhaust port 30 .

(stator)
FIG. 3 is a perspective view of the stator 9 viewed from the first direction X1. FIG. 4 is a plan view of the stator 9 viewed from the first direction X1. FIG. 5 is a perspective view of an insulator. FIG. 5(a) shows the insulator viewed from the inner peripheral side, FIG. 5(b) shows the insulator viewed from the circumferential direction, and FIG. 5(c) shows the insulator viewed from the outer peripheral side. is the case. FIG. 6 is a plan view of the insulator viewed from the first direction X1. FIG. 7 is a partially enlarged view of the insulator.

As shown in FIGS. 3 and 4, the stator 9 includes a stator core 33 having an annular portion 31 and salient pole portions 32 projecting inward from the annular portion 31, and an insulator 34 attached to each salient pole portion 32. , and a coil 35 wound around each salient pole portion 32 via an insulator 34 . The stator core 33 is a laminated core in which plate-shaped base materials are stacked in the axial direction X. As shown in FIG. In this example, the number of salient pole portions 32 is six. Therefore, six insulators 34 are attached to the stator core 33 . Six coils 35 are wound around the stator core 33 via six insulators 34 . Here, the magnet (not shown) provided on the outer peripheral surface of the rotor 10 has four magnetic poles. The number of coils 35 and the number of magnetic poles of the magnets provided on the rotor 10 are not limited to the numbers described above, and may be other numbers.

Each insulator 34 is made of resin. As shown in FIG. 5, each insulator 34 has a tubular portion 37 through which the salient pole portion 32 penetrates. In addition, each insulator 34 includes an inner brim portion 38 that protrudes from the inner end in the radial direction Y of the cylindrical portion 37 . The inner collar portion 38 extends in the axial direction X and in the circumferential direction. As shown in FIGS. 4 and 6, the shape of the inner collar portion 38 when viewed from the axial direction X is an arc shape centered on the axis L. As shown in FIGS. Furthermore, each insulator 34 includes an outer collar portion 39 that protrudes from the outer end in the radial direction Y of the tubular portion 37 . As shown in FIG. 5, the outer collar portion 39 extends in the axial direction X and the circumferential direction. The shape of the outer flange portion 39 when viewed from the axial direction X is an arc shape with the axis L as the center. As shown in FIGS. 3 and 4 , the six insulators 34 are annularly arranged with the salient pole portions 32 inserted into the cylindrical portions 37 . Circumferentially adjacent insulators 34 contact each other in the circumferential direction.

As shown in FIG. 3 , the outer collar portion 39 includes a first core cover portion 41 and the annular portion 31 that are superimposed in the first direction X1 of the annular portion 31 of the stator core 33 outside the cylindrical portion 37 in the radial direction Y. and a second core covering portion 42 stacked in the second direction X2. Each of the first core covering portion 41 and the second core covering portion 42 includes a first contacted portion 43 and a second contacted portion 44 with which a member can contact from the axial direction X. As shown in FIG. The first contact portion 43 is located inside in the radial direction Y of the second contact portion 44 . As shown in FIG. 2, the first distance D1 between the center H of the stator core 33 and the first contact portion 43 in the axial direction X is the distance between the center H of the stator core 33 and the second contact portion 43 in the axial direction X. 44 is shorter than the second distance D2. Note that the center H of the stator core 33 is the center of the stator 9 in the axial direction X. As shown in FIG.

More specifically, as shown in FIG. 5, each of the first core covering portion 41 and the second core covering portion 42 includes a first wall portion 47 extending in the axial direction X and a radial direction of the first wall portion 47. A second wall portion 48 extending in the axial direction X outside Y, and a connecting portion 49 extending in the radial direction Y along the annular portion 31 of the stator core 33 and connecting the first wall portion 47 and the second wall portion 48 . , provided.

As shown in FIG. 6 , the shape of the first wall portion 47 when viewed from the axial direction X is an arc shape curved in the circumferential direction along the annular portion 31 . The first dimension E1 of the first wall portion 47 in the circumferential direction is longer than the length dimension C1 (see FIG. 4) of the coil 35 in the circumferential direction. A first thickness F1 of the first wall portion 47 in the radial direction Y is thicker than a second thickness F2 of the second wall portion 48 in the radial direction Y. The height of the first wall portion 47 in the axial direction X is shorter than the height of the second wall portion 48 in the axial direction X. The first walls 47 of the insulators 34 adjacent to each other in the circumferential direction abut each other.

A first end surface 47 a of the first wall portion 47 in the axial direction X (the end portion of the first wall portion 47 opposite to the annular portion 31 ) is the first contacted portion 43 . The first end surface 47a is provided with two grooves 51 penetrating from the inner peripheral side to the outer peripheral side. Each groove 51 extends linearly. One groove 51 of the two grooves 51 is deeper in the axial direction X than the other groove 51 . Each groove 51 is positioned outside in the radial direction Y of the winding start position and the winding end position of the coil 35 wound around the body.

The shape of the second wall portion 48 when viewed from the axial direction X is an arc shape. The second wall portion 48 extends circumferentially along the annular portion 31 on the outer peripheral side of the first wall portion 47 . As shown in FIG. 6, the second dimension E2 of the second wall portion 48 in the circumferential direction is shorter than the first dimension E1 of the first wall portion 47 in the circumferential direction. Therefore, as shown in FIGS. 3 and 4, the second wall portions 48 of the two insulators 34 adjacent in the circumferential direction are not in contact with each other, and the one second wall portion 48 and the other second wall portion 48 are not in contact with each other. A gap 50 is formed between them.

A second end surface of the second wall portion 48 in the axial direction X (the end portion opposite to the annular portion 31 ) is the second contacted portion 44 . The second wall portion 48 has two grooves 52 penetrating the second end face from the inner peripheral side to the outer peripheral side. Each groove 52 extends linearly. Each groove 52 is positioned on an extension line of each groove 51 of the first wall portion 47 . One of the two grooves 52 is deeper in the axial direction X than the other groove 52 . Here, as shown in FIGS. 5(b), 6 and 7, the second wall portion 48 has an end portion on the side of the connection portion 49 so that the thickness in the radial direction Y approaches the connection portion 49. A reinforcing portion 53 is provided that increases along with the first wall portion 47 side. Further, the second wall portion 48 is provided with a notch portion 54 penetrating in the radial direction Y at an intermediate position in the circumferential direction, as shown in FIG. 5(c).

The connecting portion 49 connects the circumferential central portion of the first wall portion 47 and the circumferential central portion of the second wall portion 48 . Therefore, between the first wall portion 47 and the second wall portion 48, openings penetrating in the axial direction X are provided on both sides of the connecting portion 49 in the circumferential direction.

Here, as shown in FIGS. 5( a ) and 5 ( b ), the first wall portion 47 , the second wall portion 48 and the connecting wall portion 47 and the connection wall portion 47 are provided on the first core cover portion 41 and the second core cover portion 42 , respectively. A wiring routing groove 55 (second groove) is defined by the portion 49 . As shown in FIG. 6 , the planar shape of the wire routing groove 55 when viewed from the axial direction X is an arc shape that curves along the annular portion 31 . As illustrated in FIG. 4 , the coil wire 35 a drawn out from the coil 35 to the outer peripheral side through the groove 51 of the first wall portion 47 is routed in the wire routing groove 55 in the circumferential direction.

5, the insulator 34 is composed of a first insulator member 57 and a second insulator member 58 divided into two in the axial direction X. As shown in FIG. The first insulator member 57 and the second insulator member 58 are the same member. That is, if the first insulator member 57 is reversed in the axial direction X, it can be used as the second insulator member 58 . Also, if the second insulator member 58 is inverted in the axial direction X, it can be used as the first insulator member 57 .

Here, the coil wire 35a routed through the wiring route groove 55 is pulled out of the stator 9 through the gap 50 on the side of the second wall portion 48 in the circumferential direction, as shown in FIG. Alternatively, the coil wire 35 a is pulled out of the stator 9 through the cutout portion 54 provided in the second wall portion 48 . Alternatively, the coil wire 35 a is pulled out of the stator 9 through a groove 52 provided in the second wall portion 48 . The coil wire 35a is connected to the control device via lead wires. In some cases, the coil wire 35 a is connected to a lead wire in the wiring routing groove 55 and drawn out of the stator 9 .

The control device rotates the rotor 10 around the axis L by supplying power to each coil 35 through lead wires.

(First magnetic bearing unit and second magnetic bearing unit)
FIG. 8 is a perspective view of the first magnetic bearing unit 11 viewed from the first direction X1. FIG. 9 is a perspective view of the first sensor that constitutes the first magnetic bearing unit 11 when viewed from the first direction X1. FIG. 10 is a perspective view of the first electromagnet that constitutes the first magnetic bearing unit 11. FIG. 10A shows the first electromagnet viewed from the first direction X1, and FIG. 10B shows the first electromagnet viewed from the second direction X2. FIG. 11 is a perspective view of an electromagnet insulator. FIG. 12 is a perspective view of the second magnetic bearing unit 12 viewed from the first direction X1.

As shown in FIG. 8, the first magnetic bearing unit 11 includes a first sensor 61 that detects displacement of the rotor 10 in the radial direction Y, and a first electromagnet 62 that supports the rotor 10 in the radial direction Y without contact by magnetic force. And prepare. The first sensor 61 is superimposed on the first electromagnet 62 in the first direction X1. The first electromagnet 62 is excited based on the output from the first sensor 61 .

As shown in FIG. 9 , the first sensor 61 includes a sensor core 66 having a sensor core annular portion 64 , a sensor core salient pole portion 65 projecting inward from the sensor core annular portion 64 , and a sensor substrate 67 . The sensor core salient pole portions 65 are provided at angular positions spaced apart from each other by 90° in the circumferential direction. Therefore, there are four sensor core salient pole portions 65 .

The sensor core annular portion 64 has eight core-side cutouts 68 (sensor core cutouts) on the outer peripheral edge. The eight core-side notch portions 68 include four sets of two core-side notch portions 68 sandwiching each sensor core salient pole portion 65 from both sides in the circumferential direction. Each core-side notch 68 penetrates in the axial direction X. As shown in FIG.

Each sensor core salient pole portion 65 has a pair of branched portions 70 branched into two in the circumferential direction at the end portion on the inner peripheral side. A coil bobbin 71 is attached to each branch portion 70 . A sensor coil 72 is wound around each branch portion 70 via a coil bobbin 71 . Accordingly, the first sensor 61 has eight sensor coils 72 .

Here, the eight sensor coils 72 are provided with four coil groups 73 ( 1 ) to ( 4 ) of a pair of sensor coils 72 wound around each branch portion 70 of one sensor core salient pole portion 65 . The four coil sets 73(1)-(4) are arranged around the axis L at angular intervals of 90°. One of the four coil sets 73(1) to 73(4), which are arranged at an angular interval of 180°, faces the other two coil sets 73(1) and 73(3). The facing direction in which the sets 73(2) and 73(4) face each other is orthogonal. Here, the first sensor 61 detects the position of the rotor 10 based on the current flowing through the sensor coil 72 . The first sensor 61 is a displacement sensor that detects displacement in the radial direction Y of the rotor 10 .

The sensor substrate 67 is annular. The sensor substrate is arranged on the side where the first electromagnet 62 is located with respect to the sensor core 66 and the sensor coil 72 and fixed to the coil bobbin 71 . The sensor substrate 67 has eight substrate-side cutouts 75 on its outer peripheral edge. The eight board-side notch portions 75 overlap each of the core-side notch portions 68 when viewed from the axial direction X. As shown in FIG. Therefore, the eight board-side cutouts 75 include four sets of two board-side cutouts 75 sandwiching each sensor core salient pole part 65 from both sides in the circumferential direction when viewed from the axial direction X. Although the reason will be described later, the circumferential width of the board-side notch portion 75 is wider than the circumferential width of the core-side notch portion 68 .

As shown in FIG. 10 , the first electromagnet 62 includes an electromagnet core 83 having a core annular portion 81 and a core salient pole portion 82 protruding inward from the core annular portion 81 , and an electromagnet attached to the core salient pole portion 82 . An insulator 84 and an electromagnet coil 85 wound around the core salient pole portion 82 via the electromagnet insulator 84 are provided. In this example, the electromagnet core 83 includes eight core salient pole portions 82 arranged at equal angular intervals. Therefore, the first electromagnet 62 includes eight electromagnet insulators 84 and eight electromagnet coils 85 .

As shown in FIG. 11, each electromagnet insulator 84 includes an insulator tube portion 87 through which the core salient pole portion 82 penetrates. Each electromagnet insulator 84 also includes an insulator inner collar portion 88 that protrudes from the inner end of the insulator cylinder portion 87 in the radial direction Y. As shown in FIG. The insulator inner collar portion 88 spreads in the axial direction X and the circumferential direction. The shape of the insulator inner collar portion 88 when viewed from the axial direction X is linear. Further, each electromagnet insulator 84 includes an insulator outer collar portion 89 that protrudes from the outer end in the radial direction Y of the insulator tubular portion 87 . The insulator outer collar portion 89 spreads in the axial direction X and the circumferential direction. The shape of the insulator outer collar portion 89 when viewed from the axial direction X is linear. The thickness of the insulator outer collar portion 89 in the radial direction Y is thinner than the first wall portion 47 of the insulator 34 of the stator 9 .

The electromagnet insulator 84 includes a sensor support portion 91 that overlaps the core annular portion 81 of the electromagnet core 83 in the first direction X1 outside the insulator cylindrical portion 87 in the radial direction Y. As shown in FIG. The sensor support portion 91 includes an extension portion 92 extending from the insulator outer collar portion 89 along the end face of the core annular portion 81 in the first direction X1, and an extension portion 92 extending from the outer end portion in the radial direction Y of the extension portion 92 in the first direction. and a wall portion 93 (contact portion) extending in X1. The wall portion 93 includes a thick portion 94 extending from the extending portion 92 in the first direction X1 and a thin portion 95 having a thickness in the radial direction Y smaller than that of the thick portion 94 . The outer surface of the wall portion 93 in the radial direction Y is flat, and the thick portion 94 protrudes from the thin portion 95 to the inner peripheral side. Between the thick portion 94 and the thin portion 95, a stepped portion 96 having an end face 96a facing the first direction X1 is provided. Also, the thin portion 95 includes a first width portion 97 and a second width portion 98 extending from the thick portion 94 toward the first direction X1. The circumferential width of the first width portion 97 is the same as the circumferential width of the thick portion 94 . The circumferential width of the second width portion 98 is narrower than the first width portion 97 and the thick portion 94 . The second width portion 98 extends in the first direction X1 from one end portion of the first width portion 97 in the circumferential direction.

The thin portion 95 has a substrate support groove 99 and a core support groove 100 on one edge in the circumferential direction. A substrate support groove 99 is provided in the first width portion 97 . The substrate support groove 99 extends along the end surface 96 a of the stepped portion 96 to the other side in the circumferential direction. The substrate support groove 99 includes a pair of opposing inner wall surfaces 99a and 99b that face each other in the axial direction X, and a connection inner wall surface 99c that connects the other circumferential ends of the pair of opposing inner wall surfaces 99a and 99b. The width dimension of the substrate support groove 99 in the axial direction X, that is, the distance between the pair of opposing inner wall surfaces 99 a and 99 b corresponds to the thickness dimension of the sensor substrate 67 of the first sensor 61 . The connection inner wall surface 99c extends in the axial direction X. As shown in FIG. The connection inner wall surface 99c faces one side in the circumferential direction.

The core support groove 100 is positioned in the first direction X1 of the substrate support groove 99 . The core support groove 100 is provided in the second width portion 98 (projection). The core support groove 100 includes a pair of opposed inner wall surfaces 100a and 100b facing each other in the axial direction X, and a connection inner wall surface 100c connecting the other ends of the pair of opposed inner wall surfaces 100a and 100b in the circumferential direction. The width dimension of the core support groove 100 in the axial direction X, that is, the distance between the pair of opposed inner wall surfaces 100 a and 100 b corresponds to the thickness dimension of the sensor core 66 of the first sensor 61 . The connection inner wall surface 100c extends in the axial direction X. As shown in FIG. The connection inner wall surface 100c faces one side in the circumferential direction.

As shown in FIG. 10 , each electromagnet coil 85 is wound around the outer peripheral side of the insulator tubular portion 87 between the insulator inner flange portion 88 and the insulator outer flange portion 89 . The eight electromagnet coils 85 wound around the core salient pole portion 82 via the electromagnet insulator 84 include four coil sets 86(1) to (4) of two electromagnet coils 85 adjacent in the circumferential direction. Two electromagnet coils 85 adjacent in the circumferential direction in each coil set 86(1) to (4) have winding directions opposite to each other, and magnetic poles of different polarities are paired. The four coil sets 86(1)-(4) are arranged around the axis L at angular intervals of 90°. Of the four coil sets 86(1)-(4), one two coil sets 86(1) and 86(3) arranged at an angular interval of 180° face each other. It is orthogonal to the facing direction in which the coil sets 86(2) and 86(4) face each other.

Next, the first sensor 61 is supported by the electromagnet insulator 84 of the first electromagnet 62 .

More specifically, as shown in FIG. 8, the wall portion 93 of each sensor support portion 91 of the electromagnet insulator 84 extends from the second direction X2 to each substrate-side notch portion 75 of the sensor substrate 67 and each core of the sensor core 66. It is inserted into the side notch 68 . By rotating the sensor substrate 67 and the first electromagnet 62 in opposite directions about the axis L, the opening edges of the substrate-side notches 75 of the sensor substrate 67 support the sensors from one side in the circumferential direction. It is inserted into the substrate support groove 99 of the portion 91, and the sensor substrate 67 is supported at a predetermined position in the axial direction X and the circumferential direction. Further, by rotating the sensor core 66 and the first electromagnet 62 in opposite directions about the axis L, the opening edges of the core-side notch portions 68 of the sensor core 66 are moved from one side in the circumferential direction to the sensor support portions 91. , and the sensor core 66 is supported at predetermined positions in the axial direction X and the circumferential direction. The reason why the circumferential width of the board-side notch portion 75 is wider than the circumferential width of the core-side notch portion 68 is that when the sensor support portion 91 is inserted, it is necessary as a relief. This is because the circumferential dimensions are different.

As a result, the sensor substrate 67 is located on the second direction X2 side of the end surface 96a of the stepped portion 96 of the sensor support portion 91 and the pair of opposed inner wall surfaces 99a and 99b of the substrate support groove 99 facing the first direction X1. It is supported by the inner wall surface 99b. That is, the opposing inner wall surface 99b of the substrate support groove 99 facing the first direction X1 serves as a substrate contact portion that contacts the sensor substrate 67 from the second direction X2 and supports the sensor substrate 67. As shown in FIG. Further, the sensor core 66 is supported by the opposing inner wall surface 99b facing the first direction X1 on the second direction X2 side of the pair of opposing inner wall surfaces 99a and 99b of the core support groove 100. As shown in FIG. That is, the opposed inner wall surface 100b of the core support groove 100 facing the first direction X1 serves as a contact portion (contact surface) that contacts the sensor core 66 from the second direction X2 and supports the sensor core 66. As shown in FIG. Therefore, the first sensor 61 is supported by the first electromagnet 62 while being positioned in the axial direction X by the electromagnet insulator 84 .

Furthermore, when the opening edge portion of each board-side notch 75 in the sensor board 67 is inserted into the board support groove 99, the sensor board 67 is positioned on the other side in the circumferential direction of the two board-side notches 75 forming the set. At the board-side notch 75 , the opening edge portion of the board-side notch 75 abuts the connection inner wall surface 99 c of the board support groove 99 . Further, when the opening edge portion of each core side notch portion 68 in the core annular portion 81 is inserted into the core support groove 100, each core side notch portion 68 has an opening edge portion of the core side notch portion 68. contacts the connection inner wall surface 100c of the core support groove 100. As shown in FIG. Thereby, the first sensor 61 is supported by the first electromagnet 62 while being positioned in the circumferential direction by the electromagnet insulator 84 . When the state in which the first sensor 61 is positioned in the circumferential direction is viewed from the axial direction X, each of the four coil groups 73(1) to (4) of the first sensor 61 is connected to the first electromagnet It overlaps each of the 62 four coil sets 86(1)-(4).

Although the distance between the pair of opposed inner wall surfaces 99a and 99b corresponds to the thickness dimension of the sensor substrate 67 of the first sensor 61, the distance should be less than the thickness of the sensor substrate 67 in consideration of variations in component dimensions. It may be set large, or a stepped structure having only the opposing inner wall surface 99b instead of the groove shape may be used. Furthermore, an adhesive may be used for fixing.

Also, the distance between the pair of opposed inner wall surfaces 100a and 100b corresponds to the thickness dimension of the sensor core 66 of the first sensor 61, but is set to be greater than the thickness of the sensor core 66 in consideration of variations in component dimensions. Alternatively, a stepped structure having only the opposing inner wall surface 100b instead of the groove shape may be used. Furthermore, an adhesive may be used for fixing.

The output of the first sensor 61, like the output of the axial sensor 15, is transmitted to a control device (not shown). The control device energizes each electromagnet coil 85 based on the output of the first sensor 61 to adjust the position of the rotor 10 in the radial direction Y at the position of the first electromagnet 62 . That is, of the four coil sets 86(1) to (4) of the first electromagnet 62, one of the two coil sets 86(1) and 86(3) arranged at an angular interval of 180° has the electromagnet coils By controlling the energization of 85, the position of rotor 10 in the facing direction of the two coil sets 86(1) and 86(3) is adjusted. In addition, by controlling the energization of each of the electromagnetic coils 85 of the other two coil sets 86(2) and 86(4), the rotor rotation in the opposing direction of the two coil sets 86(2) and 86(4) is controlled. Adjust 10 positions.

As shown in FIG. 12, the second magnetic bearing unit 12 includes a second sensor 101 that detects displacement of the rotor 10 in the radial direction Y, and a second electromagnet 102 that supports the rotor 10 in the radial direction Y without contact by magnetic force. And prepare. The second sensor 101 is superimposed on the first electromagnet 62 in the first direction X1. A second electromagnet 102 is excited based on the output from the second sensor 101 . Here, the second magnetic bearing unit 12 has the same configuration as the first magnetic bearing unit 11 except that the size of the second electromagnet 102 in the axial direction X is shorter than that of the first electromagnet 62 . Therefore, description of the second magnetic bearing unit 12 is omitted.

Here, by the first magnetic bearing unit 11 and the second magnetic bearing unit 12, the rotor 10 is supported in the radial direction Y without contact at two points in the first direction X1 and the second direction X2 of the stator 9. As shown in FIG. The control device drives the first electromagnet 62 based on the output from the first sensor 61 . Similarly, the output from the second sensor 101 drives the second electromagnet 102 . Thereby, the control device controls the position of the rotor 10 in the direction perpendicular to the axial direction X to adjust the inclination of the rotor 10 .

(stator unit)
As shown in FIG. 2 , the first magnetic bearing unit 11 is stacked on the stator 9 in the first direction X<b>1 and contacts the first contacted portion 43 of the stator 9 . More specifically, in the first magnetic bearing unit 11, the insulator outer collar portion 89 of the electromagnet insulator 84 of the first electromagnet 62 is axially aligned with the first wall portion 47 of the first core cover portion 41 of the insulator 34 of the stator 9. Abut from X. Therefore, the distance from the center H of the stator 9 (the center H of the stator core 33) to the first magnetic bearing unit 11 in the axial direction X is the first distance D1.

On the other hand, the second magnetic bearing unit 12 is overlapped in the second direction X2 of the stator 9 and contacts the second contacted portion 44 of the stator 9, as shown in FIG. That is, as shown in FIG. 12, in the second magnetic bearing unit 12, the outer peripheral edge portion of the sensor core 66 of the second sensor 101 is axially aligned with the second wall portion 48 of the second core cover portion 42 of the insulator 34 of the stator 9. Abut from X. Therefore, the distance from the center H of the stator 9 (the center H of the stator core 33) to the second magnetic bearing unit 12 in the axial direction X is the second distance D2.

13A and 13B are explanatory diagrams of the contact state between the stator 9 and the first magnetic bearing unit 11. FIG. As shown in FIG. 13, the first wall portion 47 of the insulator 34 of the stator 9 has an arc shape when viewed from the axial direction X. As shown in FIG. On the other hand, the insulator outer collar portion 89 of the first electromagnet 62 that contacts the first end face 47a (the first contacted portion 43) of the first wall portion 47 extends linearly when viewed from the axial direction X. In addition, the insulator outer collar portion 89 is thinner than the first wall portion 47 and contacts the outer peripheral end portion of the first end surface 47 a of the first wall portion 47 . Furthermore, a portion of the insulator outer collar portion 89 in the circumferential direction protrudes from the first wall portion 47 to the outer peripheral side.

Here, the insulator outer collar portion 89 contacts the outer peripheral end portion of the first end surface 47 a of the first wall portion 47 . Therefore, due to the load from the first electromagnet 62 , a moment is generated in the first wall portion 47 in the direction of bending the first wall portion 47 to the outer peripheral side. The first wall portion 47 is thicker in the radial direction Y than the second wall portion 48 against such a moment. Therefore, even if such a moment occurs, the first wall portion 47 will not be distorted and the insulator 34 will not be damaged.

In addition, the insulator outer collar portion 89 of the first electromagnet 62 and the first wall portion 47 of the stator 9, which are in contact with each other in the axial direction X, are different in shape and thickness when viewed from the axial direction X, and are different in shape and thickness when viewed from the axial direction X. A portion of the portion 89 in the circumferential direction protrudes from the first wall portion 47 to the outer peripheral side. As a result, a gap is formed between the stator 9 and the first electromagnet 62, so that the resin sealing member 20 can be provided by infiltrating resin between the first magnetic bearing unit 11 and the stator 9. Easy.

(Effect)
In the stator 9 of this example, the insulator 34 is provided with the first contacted portion 43 and the second contacted portion 44 that are different in distance from the center H of the stator core 33 . Therefore, the first magnetic bearing unit 11 arranged in the first direction X1 of the stator 9 is brought into contact with the first contacted portion 43, and the second magnetic bearing unit 12 arranged in the second direction X2 of the stator 9 is brought into contact with the first contact portion 43. By contacting the second contacted portion 44, the distance from the center H of the stator 9 to the first magnetic bearing unit 11 (first distance D1) and the distance from the center H of the stator 9 to the second magnetic bearing unit 12 (second distance D2) can be different.

Further, in this example, the first contact portion 43 having a short distance from the center H of the stator core 33 to the first contact portion 43 is positioned inside the second contact portion 44 in the radial direction Y. As shown in FIG. Therefore, when the second magnetic bearing unit 12 is brought into contact with the second contact portion 44 from the axial direction X, the second magnetic bearing unit 12 and the first contact portion 43 do not interfere with each other.

Furthermore, in this example, the first thickness F1 of the first wall portion 47 in the radial direction Y is thicker than the second thickness F2 of the second wall portion 48 in the radial direction Y. Therefore, the width in the radial direction Y of the first abutted portion 43 (the first end surface 47a of the first wall portion 47) can be increased. Therefore, even if the first contacted portion 43 is located on the inner peripheral side of the stator 9 , it is easy to bring an external member into contact with the first contacted portion 43 .

Also, the first dimension E1 of the first wall portion 47 in the circumferential direction is longer than the length dimension C1 of the coil 35 in the circumferential direction. Therefore, the first wall portion 47 can protect the coil 35 from the outer peripheral side. Further, the first wall portion 47 has a groove 51 penetrating from the inner peripheral side to the outer peripheral side at the end portion opposite to the annular portion 31 . Therefore, the coil wire 35a of the coil 35 wound around the cylindrical portion 37 of the insulator 34 can be pulled out to the outer peripheral side through the groove 51 portion.

Furthermore, in this example, each of the first core cover portion 41 and the second core cover portion 42 includes a wiring routing groove 55 partitioned by the first wall portion 47 , the second wall portion 48 and the connection portion 49 . Also, the coil wire 35 a drawn out from the coil 35 is routed through the wiring routing groove 55 via the groove 51 of the first wall portion 47 . Therefore, when the coil wire 35a pulled out from the coil 35 is routed in the circumferential direction, it is not necessary to route the insulator 34 outside. Therefore, disconnection of the coil wire 35a can be prevented or suppressed. In addition, when the coil wire 35a pulled out from the coil 35 is routed in the circumferential direction, it is not necessary to route the outside of the insulator 34, so that the stator 9 can be prevented from becoming large in the radial direction Y.

Further, in this example, the second wall portion 48 includes, at the end portion on the connecting portion 49 side, a reinforcing portion 53 whose thickness in the radial direction Y increases as it approaches the connecting portion 49 . Therefore, even when a load is applied to bend the second width portion 98 of the second wall portion 48 to the outer peripheral side when the coil wire 35a is routed in the wire routing groove 55, the second wall portion 48 is not connected to the connecting portion. It is possible to prevent or suppress breakage from the proximal portion near 49 .

Furthermore, in this example, the second dimension E2 of the second wall portion 48 in the circumferential direction is shorter than the first dimension E1. Thereby, a lateral gap 50 of the second wall portion 48 is formed between the adjacent insulators 34 . Therefore, the coil wire 35 a routed through the wire routing groove 55 can be pulled out of the stator 9 through the gap 50 on the side of the second wall portion 48 .

Further, in this example, the second wall portion 48 includes a notch portion 54 penetrating in the radial direction Y. As shown in FIG. Therefore, the coil wire 35a routed through the wire routing groove 55 can be pulled out of the stator 9 through the provided notch portion 54. As shown in FIG.

Furthermore, in this example, the second wall portion 48 is provided with two grooves 52 . Each groove 52 is located on an extension line of each groove 51 provided in the first wall portion 47 . Therefore, the coil wire 35a drawn out from the coil 35 to the outer peripheral side through each groove 51 can be further drawn out to the outer peripheral side of the stator 9 through each groove 52 .

The insulator 34 is composed of a first insulator member 57 and a second insulator member 58 which are divided in the axial direction X, and the first insulator member 57 and the second insulator member 58 are the same member. Here, if the insulator is divided into two insulator members 57 and 58, even if the insulator 34 has a complicated shape, each insulator member 57 and 58 can be easily formed by injection molding. Further, since the first insulator member 57 and the second insulator member 58 are the same member, even if the insulator 34 is composed of the two insulator members 57 and 58, the number of parts does not increase.

Furthermore, in this example, the first sensor 61 is moved in the axial direction with the first electromagnet 62 as a reference by contact between the opposing inner wall surface 100b (contact surface) of the core support groove 100 of the electromagnet insulator 84 and the sensor core 66. Positioned at X. Also, the electromagnet insulator 84 is in contact with the first contacted portion 43 of the stator 9 . Therefore, by bringing the electromagnet insulator 84 and the sensor core 66 into contact with each other, the distance from the center H of the stator 9 to the first sensor 61 can be defined with high accuracy.

Further, in this example, the sensor core 66 has a core-side notch 68 on the outer peripheral edge of the sensor core annular portion 64 , and the electromagnet insulator 84 has a second width portion 98 inserted into the core-side notch 68 . Also, the connection inner wall surface 100c of the core support groove 100 provided in the second width portion 98 abuts the opening edge portion of the core-side notch portion 68 in the sensor core 66 from the other side in the circumferential direction. Accordingly, the position of the first sensor 61 around the axis L can thus be defined.

(Modification)
14 is a side view of the stator unit of Modification 1. FIG. FIG. 15 is a side view of a stator unit of Modification 2. FIG. FIG. 16 is an explanatory diagram of a stator unit of Modification 3. FIG. In the above example, the first magnetic bearing unit 11 can be reversed in the axial direction X and arranged. That is, the first magnetic bearing unit 11 can be in a state in which the first electromagnet 62 is superimposed on the first sensor 61 in the first direction X1. Similarly, the second magnetic bearing unit 12 can be reversed in the axial direction X and arranged. That is, the second magnetic bearing unit 12 can be in a state in which the second electromagnet 102 is superimposed on the second sensor 101 in the first direction X1.

A stator unit 8A of Modification 1 shown in FIG. 14 is a case where only the second magnetic bearing unit 12 is reversed in the axial direction X in the stator unit 8 described above. In the stator unit 8A, the insulator outer collar portion 89 of the electromagnet insulator 84 of the second electromagnet 102 positioned on the stator 9 side in the second magnetic bearing unit 12 and the first abutted portion of the second core cover portion 42 of the stator 9 The second magnetic bearing unit 12 is positioned in the axial direction X by contacting the portion 43 . In this example, the distance from the center H of the stator 9 to the first magnetic bearing unit 11 and the distance from the center H of the stator 9 to the second magnetic bearing unit 12 can be the same first distance D1. can.

A stator unit 8B of Modified Example 2 shown in FIG. 15 is a case where only the first magnetic bearing unit 11 is reversed in the axial direction X in the stator unit 8 described above. In the stator unit 8B, the sensor core 66 of the first sensor 61 located on the side of the stator 9 in the first magnetic bearing unit 11 is brought into contact with the second contacted portion 44 of the first core covering portion 41 of the stator 9, Position the first magnetic bearing unit 11 in the axial direction X. In this example, the distance from the center H of the stator 9 to the first magnetic bearing unit 11 and the distance from the center H of the stator 9 to the second magnetic bearing unit 12 can be the same second distance D2. can.

A stator unit 8C of Modified Example 3 shown in FIG. 16 is a case where both of the second magnetic bearing units 12 are reversed in the axial direction X in the stator unit 8 described above. The stator unit 8C brings the sensor core 66 of the first sensor 61 located on the stator 9 side in the first magnetic bearing unit 11 into contact with the second contacted portion 44 of the first core covering portion 41 of the stator 9, The first magnetic bearing unit 11 is positioned in the axial direction X. In addition, the insulator outer collar portion 89 of the electromagnet insulator 84 of the second electromagnet 102 located on the stator 9 side in the second magnetic bearing unit 12 is attached to the first abutted portion 43 of the second core cover portion 42 of the stator 9 . The second magnetic bearing unit 12 is positioned in the axial direction X by abutting. In this case, the distance from the center H of the stator 9 to the first magnetic bearing unit 11 is the second distance D2. On the other hand, the distance from the center H of the stator 9 to the second magnetic bearing unit 12 is the first distance D1.

Therefore, with the stator 9 of the present invention, the first magnetic bearing unit 11 and the second magnetic bearing unit 12, which are arranged on both sides of the stator 9 in the axial direction X, can be arranged freely while securing the first magnetic bearing unit 11 and the second magnetic bearing unit 12. The magnetic bearing unit 11 and the second magnetic bearing unit 12 can be positioned in the axial direction X.

DESCRIPTION OF SYMBOLS 1... Vacuum pump, 2... Pump case, 3... Fixed blade, 4... Rotor blade, 7... Motor, 8... Stator unit, 9... Stator, 10... Rotor, 11... First magnetic bearing unit, 12... Second magnetic Bearing unit 13 Third magnetic bearing unit 15 Axial sensor 16 Electromagnet 17 Metal plate 19 Stator column 20 Resin sealing member 23 Output shaft 24 Rotor flange 26 Base 26a...Center hole of base 27...Cylindrical case 28...Air intake port 29...Exhaust port forming part 30...Exhaust port 31...Annular part 32...Salient pole part 33...Stator core 34...Insulator , 35... Coil 35a... Coil wire 37... Cylindrical part 38... Inner flange part 39... Outer flange part 41... First core cover part 42... Second core cover part 43... First abutted part Part 44... Second contacted part 47... First wall part 47a... First end surface 48... Second wall part 49... Connection part 50... Gap 51... Groove 52... Groove 53... Reinforcement part 54 Notch part 55 Wire routing groove (second groove) 57 First insulator member 58 Second insulator member 61 First sensor 62 First electromagnet 64 Sensor core Annular portion 65 Sensor core salient pole portion 66 Sensor core 67 Sensor substrate 68 Core side notch (sensor core notch) 70 Branch portion 71 Coil bobbin 72 Sensor coil 73 (1 ) to (4)... Coil set of sensor coil, 75... Substrate-side notch, 81... Core annular part, 82... Core salient pole part, 83... Electromagnet core, 84... Electromagnet insulator, 85... Electromagnet coil, 86 ( 1) to (4)... Coil group of electromagnet coils, 87... Insulator cylindrical part, 88... Inner insulator flange part, 89... Outer insulator flange part, 91... Sensor support part, 92... Extension part, 93... Wall part ( Contact portion) 94 Thick portion 95 Thin portion 96 Stepped portion 96a End surface (contact surface) 97 First width portion 98 Second width portion (projection) 99 Substrate support groove 99a Opposing inner wall surface 99b Opposing inner wall surface 99c Connecting inner wall surface 100 Core supporting groove 100a Opposing inner wall surface 100b Opposing inner wall surface 100c Connecting inner wall surface 101 Second Sensor 102 Second electromagnet C1 Circumferential length dimension of coil D1 First distance from center of stator core D2 Second distance from center of stator core E1 Circumferential direction of first wall E2: second dimension in the circumferential direction of the second wall portion; F1: first thickness in the radial direction of the first wall portion; E2: second thickness in the radial direction of the second wall portion; direction, Y...radial direction

Claims (26)

A stator having a stator core including an annular portion and a salient pole portion projecting inwardly from the annular portion, an insulator including a tubular portion through which the salient pole portion penetrates, and a coil wound around the tubular portion ,
When a direction along the axis of the annular portion is defined as an axial direction, a direction perpendicular to the axial direction is defined as a radial direction, one side of the axial direction is defined as a first direction, and the other side is defined as a second direction,
The insulator includes a core covering portion outside the cylindrical portion in the radial direction,
The core covering portion includes a first contacted portion and a second contacted portion that can be contacted by the member from the axial direction,
either the first contacted portion or the second contacted portion is selectively used as a positioning portion for positioning the member in the axial direction;
A first distance between the center of the stator core and the first contact portion in the axial direction is longer than a second distance between the center of the stator core and the second contact portion in the axial direction. A stator characterized by being short. The insulator is composed of a first insulator member and a second insulator member divided into two in the axial direction,
2. The stator according to claim 1, wherein the first insulator member and the second insulator member are the same member. A stator according to claim 1 or 2;
a rotor arranged on the inner peripheral side of the stator;
A first magnetic field that includes a first electromagnet that supports the rotor in the radial direction by magnetic force without contact, and a first sensor that is stacked in the axial direction of the first electromagnet and detects displacement of the rotor in the radial direction. a bearing unit;
A second magnet comprising: a second electromagnet that supports the rotor in the radial direction by magnetic force without contact; and a second sensor that is stacked in the axial direction of the second electromagnet and detects displacement of the rotor in the radial direction. a bearing unit;
the first magnetic bearing unit is stacked in the first direction of the stator and contacts the first contacted portion or the second contacted portion of the core cover portion ;
The motor according to claim 1, wherein the second magnetic bearing unit is stacked in the second direction of the stator and contacts the first contacted portion or the second contacted portion of the core cover portion. A motor comprising the stator according to claim 1 or 2 and a rotor arranged on the inner peripheral side of the stator;
a pump case,
a fixed wing fixed inside the pump case;
and a rotary blade attached to the rotor and rotating inside the pump case. a motor according to claim 3;
a pump case,
a fixed wing fixed inside the pump case;
and a rotary blade attached to the rotor of the motor and rotating inside the pump case. A stator having a stator core including an annular portion and a salient pole portion projecting inwardly from the annular portion, an insulator including a tubular portion through which the salient pole portion penetrates, and a coil wound around the tubular portion ,
When a direction along the axis of the annular portion is defined as an axial direction, a direction perpendicular to the axial direction is defined as a radial direction, one side of the axial direction is defined as a first direction, and the other side is defined as a second direction,
The insulator includes a first core cover portion stacked in the first direction and a second core cover portion stacked in the second direction of the annular portion outside the cylindrical portion in the radial direction,
each of the first core cover portion and the second core cover portion includes a first contact portion and a second contact portion that can be contacted by members from the axial direction;
A first distance between the center of the stator core and the first contact portion in the axial direction is longer than a second distance between the center of the stator core and the second contact portion in the axial direction. short,
A stator, wherein the first contact portion and the second contact portion are arranged side by side in a radial direction. 7. The stator according to claim 6, wherein the first contacted portion is located radially inward of the second contacted portion. Each of the first core cover portion and the second core cover portion includes a first wall portion extending in the axial direction and a second wall portion extending in the axial direction outside the first wall portion in the radial direction. , and
the thickness of the first wall portion in the radial direction is thicker than the thickness of the second wall portion in the radial direction,
an end portion of the first wall portion opposite to the annular portion is the first abutted portion;
8. The stator according to claim 7, wherein the end portion of the second wall portion opposite to the annular portion is the second abutted portion. When the circumference of the axis is taken as the circumferential direction,
A first dimension of the first wall portion in the circumferential direction is longer than a length dimension of the coil in the circumferential direction,
9. The stator according to claim 8, wherein the first wall portion has a groove penetrating from the inner peripheral side to the outer peripheral side at the end portion opposite to the annular portion. each of the first core cover portion and the second core cover portion includes a connection portion extending in the radial direction along the annular portion and connecting the first wall portion and the second wall portion;
The coil wire pulled out from the coil is routed through the groove and through a second groove partitioned by the first wall, the second wall and the connecting portion. 10. The stator according to claim 9. The second wall portion is provided with a reinforcing portion at an end portion on the side of the connection portion, the thickness of which in the radial direction increases toward the first wall portion as the thickness approaches the connection portion. 11. The stator according to claim 10. 12. A stator according to claim 10 or 11, wherein a second dimension of said second wall portion in said circumferential direction is shorter than said first dimension. 13. The stator according to any one of claims 9 to 12, wherein the second wall comprises a notch extending radially therethrough. The insulator is composed of a first insulator member and a second insulator member divided into two in the axial direction,
The stator according to any one of claims 6 to 13, wherein the first insulator member and the second insulator member are the same member. a stator according to any one of claims 6 to 14;
a rotor arranged on the inner peripheral side of the stator;
A first magnetic field that includes a first electromagnet that supports the rotor in the radial direction without contact by magnetic force, and a first sensor that is superimposed in the axial direction of the first electromagnet and detects displacement of the rotor in the radial direction. a bearing unit;
A second magnet comprising: a second electromagnet that supports the rotor in the radial direction without contact by magnetic force; and a second sensor that is stacked in the axial direction of the second electromagnet and detects displacement of the rotor in the radial direction. a bearing unit;
the first magnetic bearing unit is stacked in the first direction of the stator and contacts the first contacted portion or the second contacted portion of the first core cover portion ;
The second magnetic bearing unit is stacked in the second direction of the stator and contacts the first contacted portion or the second contacted portion of the second core cover portion. motor. the first sensor is stacked in the first direction of the first electromagnet;
16. The motor according to claim 15, wherein the first electromagnet abuts on the first abutted portion of the first core cover portion of the stator. The first electromagnet includes an electromagnet core having a core annular portion arranged to surround the axis and a core salient pole portion projecting inwardly from the core annular portion, an electromagnet insulator, and the electromagnet insulator through the electromagnet insulator. and an electromagnet coil wound around the core salient pole,
The electromagnet insulator includes an insulator tubular portion through which the core salient pole portion penetrates, an insulator inner collar portion projecting from an inner end of the insulator tubular portion in the radial direction, and an insulator tubular portion projecting from an inner end of the insulator tubular portion in the radial direction. and an insulator outer flange projecting from the end,
The electromagnetic coil is wound around the insulator tubular portion between the insulator inner flange portion and the insulator outer flange portion,
17. The motor according to claim 16, wherein the end portion of the insulator outer collar portion in the second direction abuts the first abutted portion from the axial direction. Each of the first core cover portion and the second core cover portion includes a first wall portion extending in the axial direction and a second wall portion extending in the axial direction outside the first wall portion in the radial direction. , and
an end portion of the first wall portion opposite to the annular portion is the first abutted portion;
an end portion of the second wall portion opposite to the annular portion is the second abutted portion;
a resin sealing member that seals the stator, the first magnetic bearing unit, and the second magnetic bearing unit on the outer peripheral side of the rotor;
The first wall portion has an arc shape when viewed from the axial direction,
When the circumference of the axis is taken as the circumferential direction,
The outer collar portion extends linearly in the circumferential direction when viewed from the axial direction, has a thickness in the radial direction that is thinner than the thickness of the first wall portion, and has a portion in the circumferential direction that is less than the thickness of the first wall portion. 18. The motor according to claim 17, wherein the motor protrudes outwardly from the first wall. The first sensor includes a sensor core having a sensor core annular portion arranged to surround the axis and a sensor core salient pole portion projecting inwardly from the sensor core annular portion; a coil bobbin attached to the sensor core salient pole portion; a sensor coil wound around the sensor core salient pole via the coil bobbin;
19. The motor according to claim 17, wherein the electromagnet insulator has a contact portion that contacts the sensor core annular portion from the second direction on the outer peripheral side of the insulator cylindrical portion. The sensor core includes a sensor core notch on the outer peripheral edge of the sensor core annular portion,
The contact portion includes a contact surface that contacts the sensor core annular portion, and a projecting portion that projects from the contact surface in the first direction and is inserted into the sensor core notch. 20. Motor according to claim 19. the second sensor is superimposed in the first direction of the second electromagnet;
21. The motor according to any one of claims 15 to 20, wherein the second sensor contacts the second contacted portion of the second core cover portion of the stator. a motor comprising the stator according to any one of claims 6 to 14 and a rotor arranged on the inner peripheral side of the stator;
a pump case,
a fixed wing fixed inside the pump case;
and a rotary blade attached to the rotor and rotating inside the pump case. a motor according to any one of claims 15 to 21;
a pump case,
a fixed wing fixed inside the pump case;
and a rotary blade attached to the rotor of the motor and rotating inside the pump case. In a magnetic bearing unit that rotatably supports a rotor,
When the direction along the rotation center axis of the rotor is defined as the axial direction, the direction orthogonal to the rotation center axis is defined as the radial direction, one side of the axial direction is defined as the first direction, and the other side is defined as the second direction,
an electromagnet that supports the rotor in the radial direction without contact by magnetic force;
a sensor that is stacked in the first direction of the electromagnet and detects displacement of the rotor in the radial direction;
The electromagnet includes an electromagnet core having a core annular portion arranged around the rotation center axis and a core salient pole portion protruding inwardly from the core annular portion, an electromagnet insulator, and the electromagnet insulator through the electromagnet insulator. and an electromagnet coil wound around the core salient pole,
The sensor includes a sensor core having a sensor core annular portion arranged around the rotation center axis and a sensor core salient pole portion protruding inwardly from the sensor core annular portion; a coil bobbin attached to the sensor core salient pole portion; a sensor coil wound around the sensor core salient pole via the coil bobbin;
The electromagnet insulator includes an insulator tubular portion through which the core salient pole portion penetrates, an insulator inner collar portion projecting from an inner end of the insulator tubular portion in the radial direction, and an insulator tubular portion projecting from an inner end of the insulator tubular portion in the radial direction. A magnetic bearing unit, comprising: an insulator outer flange projecting from an end thereof; and an abutting portion abutting against the sensor core annular portion from the second direction on the outer peripheral side of the insulator cylindrical portion. The sensor core includes a sensor core notch on the outer peripheral edge of the sensor core annular portion,
The contact portion includes a contact surface that contacts the sensor core annular portion, and a projecting portion that projects from the contact surface in the first direction and is inserted into the sensor core notch. 25. A magnetic bearing unit according to claim 24. a magnetic bearing unit according to claim 24 or 25;
a rotor to which the rotor blades are attached;
A vacuum pump, wherein the rotor is rotatably supported by the magnetic bearing unit.

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