JP5490169B2 - Rotating electric machine and rotor position detection sensor - Google Patents

Description

  The present invention relates to a rotating electrical machine having a magnetic rotor position detection sensor and a rotor position detection sensor.

  As a conventional technique, in Japanese Patent No. 3073086 (Patent Document 1), a highly magnetic permeable magnetic bypass member is provided so as to be sandwiched back and forth in the axial direction with respect to the rotation angle detector, and the leakage field magnet flowing through the rotation shaft. There has been proposed a structure that reduces the leakage field magnetic flux flowing through the rotor position detection sensor by passing the magnetic flux through these magnetic bypass members. In Japanese Patent No. 4341402 (Patent Document 2), a rotor position detection sensor (magnetic sensor) is disposed between a slip ring provided at one end of the rotary shaft and a bearing that supports the rotor. The rotation angle of the rotor is detected.

Japanese Patent No. 3573086 Japanese Patent No. 4341402

As a problem in the conventional rotating electric machine, in Patent Document 1, among the magnetic bypasses sandwiching the magnetic sensor, the magnetic bypass member extending in the radial direction in the vicinity of the back surface of the magnetic sensor is between the rotating shaft and the magnetic bypass member. Since there is a gap in the gap, the effect of bypassing the leakage magnetic flux flowing through the rotating shaft is insufficient. The magnetic bypass member fixed to the non-magnetic retainer is fixed to the shaft end of the rotating shaft. The magnetic bypass member attached to this retainer is also insufficient in the effect of bypassing the leakage magnetic flux. In Patent Document 2, the rotor position detection sensor is not disposed at the end of the shaft but between the slip ring and the rotor, and a slip ring terminal for supplying a field current is provided in the rotation shaft. As a result, the magnetic field generated around the terminal when a field current flows to the rotor causes noise components other than the magnetic field component effective as a sensor to be superimposed on the rotor of the rotor position detection sensor, increasing the angle detection error. Was.
In order to solve the above problems, the present invention relates to a rotating electric machine having a rotor position detection sensor, and provides a magnetic ring around a rotation axis and a non-magnetic ring between a rotor core and a magnetic ring, thereby allowing slippage. The combined magnetic field generated when a field current is passed through the ring terminal is returned to the magnetic ring around the rotation axis and shielded by the non-magnetic ring, thereby reducing the angle detection error of the resolver. is there.

A rotating electrical machine according to the present invention includes a stator and a rotor , a rotating shaft wired with a terminal for supplying power to the field winding of the rotor via a slip ring, and a rotor position detection sensor disposed on the rotating shaft. the rotating electric machine having the above-mentioned rotor position detection sensor includes a stator assembly having an output coil and the excitation coil, together constituted by the rotor assembly having opposed rotor core at a inner peripheral surface and the gap of the stator assembly the rotor assembly is composed of a magnetic ring and a non-magnetic ring and the rotor core, these magnetic ring, non-magnetic ring, and laminated rotor core outwardly across sequential concentric and innermost the magnetic ring, attached between the slip ring and the rotor in the rotation axis outer peripheral portion of the wiring portion of the terminal Than is.

According to the rotating electrical machine of the present invention, the combined magnetic field generated when a field current is passed through the slip ring terminal is circulated by the magnetic ring around the rotation axis and further shielded by the non-magnetic ring. The noise component superimposed on the signal component of the position detection sensor can be reduced, and the angle detection error of the rotor position detection sensor can be reduced.

It is sectional drawing which shows the structure of the rotary electric machine in Embodiment 1 of this invention. It is sectional drawing which shows the modification of the rotary electric machine in Embodiment 1 of this invention. In the rotary electric machine according to Embodiment 1 of the present invention, it is a cross-sectional view showing an energization path when a current is passed between slip ring 15 and rotor 7. FIG. In the rotary electric machine in Embodiment 1 of this invention, it is sectional drawing of the rotating shaft 6 which shows the flow of the magnetic flux at the time of energizing the field winding 8 through the terminal 18 wired to the rotating shaft 6. FIG. In the conventional rotary electric machine, it is sectional drawing of the rotating shaft 6 in the rotor position detection sensor 22 part which shows the flow of the magnetic flux when the field winding 8 is energized through the terminal 18 wired to the rotating shaft 6. In the rotary electric machine according to Embodiment 1 of the present invention, it is a cross-sectional view showing a flow of magnetic flux generated by passing a current through field winding 8. It is sectional drawing of the rotor assembly 21 in Embodiment 1 (Embodiment 4) of this invention. FIG. 3 is a front view of the rotor position detection sensor showing the flow of magnetic flux between the rotor assembly 21 of the rotor position detection sensor 22 and the stator assembly 20 in the rotary electric machine according to Embodiment 1 of the present invention. It is a front sectional view showing a press-fitting shape of a rotor assembly 21 in Embodiment 2 of the present invention. FIG. 10 is a side cross-sectional view of the rotor assembly 21 as viewed in the direction of the arrows along the line XX in FIG. 9, schematically showing a configuration of integral molding of the rotor assembly 21. It is a front view of the rotor assembly 21 in Embodiment 3 of this invention. It is a front view which shows only the rotor assembly 21 in Embodiment 4 of this invention. 4 shows a rotor assembly 21 according to a fourth embodiment of the present invention, in which (a) is a front view of the rotor assembly 21 showing the rotary shaft 6 in cross section, and (b) is an enlarged cross-sectional view of portion A in FIG. is there.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In addition, the same code | symbol shows the same or an equivalent part between each figure.

Embodiment 1
A rotating electrical machine according to Embodiment 1 of the present invention will be described below with reference to FIG.

In FIG. 1, the main body of the rotating electrical machine 1 according to the first embodiment is provided with an aluminum front bracket 2 and a rear bracket 3 and inside thereof, and a pulley 11 is fixed to a tip by a nut 12. A rotating shaft 6 rotatably supported by the front bearing 4 and the rear bearing 5, a rotor 7 fixed to the rotating shaft 6 and having a field winding 8, and attached to both side surfaces of the rotor 7. The front fan 13 and the rear fan 14, the stator 9 which is sandwiched and fixed between the front bracket 2 and the rear bracket 3, and includes the stator core and the stator winding 10, and the shaft end of the outer rotary shaft 6 by the rear bearing 5. A slip ring 15 that is attached to the rotor and supplies current to the rotor 7, and is housed in the brush holder 16 and is attached to the slip ring 15. A brush 16 but to power contact, a slip ring 15
And a terminal 18 wired in a terminal wiring groove 6a provided in the axial direction on the rotary shaft 6 in order to electrically connect the field winding 8 to each other.

The rotating electrical machine 1 further includes a rotor position detection sensor 22 for detecting the rotation angle of the rotor 7 on the rotation shaft 6 between the rotor 7 and the slip ring 15.
The rotor position detection sensor 22 includes a ring-shaped rotor assembly 21 (described later) fixed to the rotary shaft 6 and a ring-shaped stator assembly 20 (described later) whose inner periphery faces the rotor assembly 21. A rotary shaft 6 wired with a terminal 18 for supplying power to the field winding 8 of the child 7 is attached to the outer peripheral portion of the wiring portion of the terminal 18.

  The rotating electrical machine 1 includes a ring 19 that holds the rotor assembly 21, a power circuit unit (not shown) that supplies current to the field winding 8 through the brush 16, and a control that controls driving of the power circuit unit. Circuit portion (not shown), and the power circuit portion is connected to the stator winding 10 and the DC / AC interconversion circuit electrically connected to the stator winding 10 and the brush 16 to be connected to the field. A field current switching circuit (not shown) that is electrically connected to the magnetic winding 8 and controls the current to the field winding 8 is provided.

Next, the flow of current and magnetic flux in the rotating electrical machine 1 will be described with reference to FIGS.
FIG. 3 shows an energization path when a current flows between the slip ring 15 and the rotor 7, and FIG. 4 shows a magnetic flux generated when the field winding 8 is energized through the terminal 18 wired to the rotating shaft 6. FIG. 5 shows the flow of magnetic flux to the rotor position detection sensor in the conventional rotating electrical machine 1, and FIG. 6 shows the flow of magnetic flux generated by passing a current through the field winding 8. Yes.

3 to 6, when the rotor position detection sensor 22 is disposed between the slip ring 15 and the rotor 7, a current is passed through the field winding 8 at a position close to the rotor position detection sensor 22. Members such as the terminal 18 are arranged, and a current flows as shown by a path A in FIG.
FIG. 4 shows the flow of current, assuming that the terminal 18R on the right side flows toward the back and the terminal 18L on the left side flows toward the front side, but according to Ampere's law, Since a clockwise magnetic field is generated with respect to the energization direction of the terminal 18, a magnetic field is generated clockwise for the right terminal 18R and counterclockwise for the left terminal 18L as in the path B. .

  In FIG. 3, the slip ring 15, the rotor position detection sensor 22, the rear bearing 5, and the rotor 7 are arranged in this order. In this arrangement, the rotor position detection sensor 22 is arranged between the slip ring 15 and the rotor 7. If it is done, the position of the rear bearing 5 may be arranged anywhere on the rotating shaft 6. 3 and 4, two terminals 18 are arranged so as to face the rotation shaft 6 (in the radial direction). For example, a tangential rotating electric machine having two rotors 7 is provided. 1 may have two or more terminals 18 and may have two or more terminals.

  Further, in the conventional rotating electric machine, the magnetic flux passes through the rotor assembly 21 as shown in the path C and passes through the core back of the stator core 26 as shown in the path C as shown by the path B in FIG. Since the circulating magnetic flux is also generated, these are superimposed as noise components on the sensor signal component, which causes a decrease in rotation angle detection accuracy.

Further, as shown in FIG. 6, most of the magnetic flux generated by the current in the field winding 8 flows between the rotor 7 and the stator 9 as shown in the path D. However, a part of the magnetic flux passes through the rotor shaft 6 as in the path E and passes through the rotor position detection sensor 22. Those leakage magnetic flux flows into the rotor position detection sensor 22 and a noise component is superimposed on a signal component,
The rotational angle detection accuracy is reduced.

The rotating electrical machine according to the first embodiment is configured as shown in FIGS. 7 and 8 in order to solve the above-described problems.
FIG. 7 is a cross-sectional view of the rotor assembly 21, and FIG. 8 is a front view of the rotor position detection sensor showing the flow of magnetic flux between the rotor assembly 21 and the stator assembly 20 of the rotor position detection sensor 22.

Hereinafter, the rotor position detection sensor 22 according to the first embodiment will be described in detail with reference to FIGS.
When the rotor position detection sensor 22 is a resolver in particular, the stator assembly 20 includes an annular stator core 26 that is a laminate of thin silicon steel plates and a plurality of radially extending inwardly from the stator core 26. Teeth 27 is provided, and an insulator 28 made of a resin material such as polybutylene terephthalate (PBT) or nylon (PA) is provided on the stator core 26, and the insulator 28 has a circumferential surface of each tooth 27 and the stator core 26. It covers the both ends. A sensor winding 29 that is an exciting coil or an output coil is wound on each tooth 27 via an insulator 28.

As will be described later, the rotor assembly 21 is fixed on the rotary shaft 6 so as to be coaxially rotated, and is configured by a protruding pole having a protruding shape whose gap permeance changes in a sine wave shape with respect to the rotation angle.
That is, the rotor assembly 21 is provided with a magnetic ring 23 fixed to the outer periphery of the rotary shaft 6 at the innermost peripheral portion, as shown in FIG. 7, in order to reduce noise due to terminal current and noise due to leakage magnetic flux. A non-magnetic ring 24 is disposed on the outer periphery, and a rotor core 25 is disposed on the outermost periphery in a concentric manner so as to be stacked outward.

  The rotor assembly 21 and the rotating shaft 6 are fixed by press-fitting the rotating shaft 6 into the rotating shaft mounting hole 23a of the magnetic ring 23, and the inner diameter of the rotor assembly 21, that is, the rotating shaft mounting hole 23a of the magnetic ring 23 is fixed. Protrusions (not shown) are provided on the inner peripheral surface side, and the tightening allowance of the protrusions and the shape of the escape portion are sufficient for the specifications of the rotational torque and press-fit load related to the rotating shaft 6 having the rotor assembly 21 and the rotor 7. The parameters are determined in consideration of the above.

The rotor assembly 21 may be fixed by welding by fitting the rotary shaft attachment hole 23a to the rotary shaft 6.
Furthermore, the positioning of the rotor assembly 21 in the axial direction is determined by the ring 19 disposed on the pulley 11 side on the rotary shaft 6 from the rotor assembly 21. Thus, by performing the positioning in the axial direction by the ring 19, it becomes possible to reduce the processing cost and improve the assemblability.
Further, as shown in FIG. 2, the rotor assembly 21 may be fixed in the axial direction by providing a step 6 b on the rotating shaft 6 and positioning in the axial direction by the step 6 b. In this way, the rotor assembly 21 is press-fitted into the rotating shaft 6 and the rotating shaft 6 is provided with the step 6b to perform the axial positioning, whereby the cost can be reduced and the assemblability can be improved by reducing the number of steps.
In addition, the rotor assembly 21 can be fixed to the rotary shaft 6 by welding after being pressed into the rotary shaft 6 and positioned in the axial direction by the ring 19.
The rotor assembly 21 can also be fixed to the rotary shaft 6 by welding after being positioned on the rotary shaft 6 and positioned in the axial direction by the step 6b provided on the rotary shaft 6.

In the rotor position detection sensor 22 according to the first embodiment configured as described above, the magnetic flux generated by energization of the terminal 18 is magnetic along the magnetic ring 23 as shown in the path F as shown in FIG. Since the path is formed and the magnetic flux is blocked by the nonmagnetic ring 24, it is possible to prevent the magnetic flux of the signal component of the rotor position detection sensor 22 shown in the path G from being superimposed.
Further, the leakage magnetic flux E (FIG. 6) that passes through the rotation shaft 6 and penetrates the rotor position detection sensor 22 can be shielded, and it is possible to prevent a decrease in rotation angle detection accuracy.
1 and 2, the slip ring 15, the rotor position detection sensor 22, the rear bearing 5, and the rotor 7 are arranged in this order from the outer side to the inner side of the rotary electric machine 1. The position detection sensor 22 can reduce the leakage magnetic flux that travels along the path F regardless of the position of the rotor 7 on the rotating shaft 6 in the direction opposite to the pulley.

Embodiment 2
The rotor position detection sensor 22 of the rotating electrical machine according to the second embodiment is configured as shown in FIGS.
FIG. 9 is a front sectional view showing the press-fitting shape of the rotor assembly 21 in the second embodiment, and FIG. 10 is a side sectional view of the rotor assembly 21 taken along line XX in FIG. The structure of this integral molding is shown.
Hereinafter, the rotor position detection sensor 22 of the rotating electrical machine according to the second embodiment will be described in detail with reference to FIGS. 9 and 10.
As described in the first embodiment, the rotor assembly 21 includes the magnetic ring 23 having the rotation shaft mounting hole 23a fitted and fixed to the outer periphery of the rotation shaft 6 on the innermost side, and the non-magnetic ring 24 and the outermost ring on the outer periphery. The rotor core 25 is arranged on the outer periphery. As the material of the magnetic ring 23, a material such as iron or ferrite is used, and as the material of the non-magnetic ring 24, austenitic stainless steel or aluminum, an epoxy resin having high hardness, or the like is used.

Each member constituting the rotor assembly 21 is fixed by press-fitting or integration with a molding resin, as shown in FIGS.
In the case of fixing by press-fitting, a groove 30 for press-fitting is provided on the inner diameter of the non-magnetic ring 24 and the inner diameter of the rotor core 25 as shown in FIG. 9, and the non-magnetic ring 24 is press-fitted into the magnetic ring 23, and the rotor core 25 Press fit. The tightening allowance and the shape of the relief portion of these press-fitting groove portions 30 fully take into account the rotational torque and press-fit load standards calculated from the rotor assembly 21 and the inertia of the rotor 7 and the maximum angular acceleration of the rotating electrical machine 1. Since the amount of deformation of the outer diameter of the rotor assembly at the time of press-fitting is minimized, the influence on the rotational angle detection accuracy is small. Moreover, since each member can be firmly fixed in press-fitting, it leads to an improvement in reliability.

As shown in FIG. 10, when fixing each member (magnetic body ring 23, nonmagnetic body ring 24, rotor core 25) by integral molding, a decrease in detection accuracy due to outer diameter deformation of the rotor assembly 21 is prevented. Can do. In addition, as an advantage of integral molding, it is possible to reduce the number of processing steps and simplify the assembly step by fixing the members together.
Further, by integrating the magnetic body ring 23, the non-magnetic body ring 24, and the rotor core 25 with a molding resin, the manufacturing cost can be reduced and the assembly process can be simplified.
Further, by using stainless steel having hardness as the material of the nonmagnetic ring 24, the processing accuracy can be increased, and the rotating shaft 6 and the rotor assembly 21 can be fixed with high accuracy. The detection accuracy can be improved by improving the relative position accuracy of 20. Further, by using a resin for the material of the magnetic ring 23, the material cost and the manufacturing cost can be reduced.

Embodiment 3
In the rotor assembly 21 of the rotor position detection sensor 22 according to the third embodiment, the rotor core 25 is provided with a detent mechanism.
FIG. 11 is a front view of the rotor assembly 21 according to Embodiment 3 of the present invention.
Hereinafter, the rotor position detection sensor 22 of the rotating electrical machine according to the third embodiment will be described in detail with reference to FIG.
In the second embodiment, the fixing method of each member (the magnetic body ring 23, the non-magnetic body ring 24, and the rotor core 25) has been described. However, it is exposed to an environment beyond the scope of the intended use and the assumed use environment. In this case, the diameter due to a decrease in the fixing force between the rotary shaft 6 and the magnetic ring 23, the non-magnetic ring 24, and the rotor core 25 due to deterioration or external force due to a difference in linear expansion of each material, temperature change of the molding resin, chemical change, etc There is concern about misalignment of directions.

In this case, the relative position between the rotor core 25 and the rotor 7 is shifted, so that the position of the rotor 7 is erroneously detected, and in the worst case, the rotating machine main body may be damaged.
As a countermeasure in such a case, in the third embodiment, the rotation preventing projections 31 are provided on the outer peripheral surface of the magnetic ring 23 and the inner peripheral surface of the rotor core 25.
The non-magnetic ring 24 uses austenitic stainless steel or a resin material having a relatively low hardness, but a magnetic body using a high-hardness iron-based material for the non-magnetic ring 24 having a relatively low hardness. Anti-rotation protrusions 31 as described above are disposed on the outer peripheral surface of the ring 23 and the inner peripheral surface of the rotor core 25 to prevent rotation. As a result, the reliability is improved, and the magnetic ring 23, the non-magnetic ring 24, and the rotor core 25 can be easily positioned in the rotational direction during assembly, so that the assemblability can be improved.

  In FIG. 11, four anti-rotation protrusions 31 are provided for each member (magnetic body ring 23, rotor core 25), but the maximum angle required for the inertia relating to the rotor 7 and the rotating electrical machine 1. The number of anti-rotation protrusions 31 is determined based on the necessary rotational torque calculated from the acceleration.

Embodiment 4
The rotor assembly 21 of the rotor position detection sensor 22 according to the fourth embodiment is obtained by providing a rotation prevention mechanism for the rotor core 25 between the rotary shaft 6 and the magnetic ring 23.
FIG. 12 is a front view showing only the rotor assembly 21 in the fourth embodiment, FIG. 13 shows the rotor assembly 21 in the fourth embodiment, and FIG. 12A shows the rotor assembly 21 in which the rotary shaft 6 is shown in cross section. FIG. 5B is an enlarged cross-sectional view of a portion A in FIG.
Hereinafter, the rotor position detection sensor of the rotating electrical machine according to the fourth embodiment will be described in detail based on FIG. 12, FIG. 13, and FIG.

7 and 12, the rotation prevention mechanism of the rotor core 25 is constituted by a rotation prevention protrusion 32 and a terminal wiring groove 6a.
That is, the rotation preventing projection 32 is provided on the inner peripheral surface of the rotation shaft mounting hole 23 a of the rotor assembly 21, and the recess of the rotation shaft 6 that is engaged with the rotation prevention projection 32 is a terminal provided on the rotation shaft 6. It is formed by using the wiring groove 6a.

  As described above, the rotation prevention of the rotor assembly 21 is performed by using the terminal wiring groove 6 a, and has an effect of preventing the rotor assembly 21 from rotating with respect to the rotating shaft 6. Moreover, since positioning in the rotation direction during assembly can be easily performed, productivity, reliability, and assembly can be improved. Needless to say, the number of rotation-preventing protrusions 32 varies depending on the number of terminal wiring grooves 6 a of the rotating shaft 6.

  It should be noted that within the scope of the present invention, the embodiments can be combined, or the embodiments can be appropriately modified and omitted.

DESCRIPTION OF SYMBOLS 1 Rotating electrical machine 2 Front bracket 3 Rear bracket 4 Front bearing 5 Rear bearing 6 Rotating shaft 6a Terminal wiring groove 6b Step 7 Rotor 8 Field winding 9 Stator 10 Stator winding 11 Pulley 12 Nut 13 Front fan 14 Rear fan 15 Slip ring 16 Brush 17 Brush holder 18 (18L) (18R) Terminal 19 Ring 20 Stator assembly 21 Rotor assembly 22 Rotor position detection sensor 23 Magnetic ring 23a Rotating shaft mounting hole 24 Nonmagnetic ring 25 Rotor core (resolver rotor core)
26 Stator core (resolver stator core)
27 Teeth 28 Insulator 29 Sensor winding 30 Press-fit groove 31, 32 Non-rotating protrusion.

Claims (13)

In a rotating electrical machine having a stator and a rotor, a rotating shaft wired with a terminal that feeds power to the field winding of the rotor via a slip ring, and a rotor position detection sensor disposed on the rotating shaft ,
The rotor position detection sensor includes a stator assembly having an output coil and an exciting coil, and a rotor assembly having a rotor core facing the inner peripheral surface of the stator assembly with a gap therebetween. It is composed of a body ring and the non-magnetic ring and the rotor core, these magnetic ring, non-magnetic ring, and laminated rotor core outwardly across sequential concentric the innermost magnetic ring and said A rotating electrical machine, wherein the rotating electrical machine is attached between the slip ring and the rotor on an outer peripheral portion of a rotating shaft of a wiring portion of a terminal . The rotating electrical machine according to claim 1, wherein the rotor core, the non-magnetic ring, and the magnetic ring are integrally fixed by press-fitting . The rotating electrical machine according to claim 1 or 2, wherein the magnetic ring and the non-magnetic ring are integrally formed with the rotor core . The rotating electrical machine according to any one of claims 1 to 3, wherein the non-magnetic ring is made of a stainless steel material . The rotating electrical machine according to any one of claims 1 to 3 , wherein the non-magnetic ring is made of a resin material . The rotating electrical machine according to claim 2 , wherein a rotation- preventing protrusion is provided on each of the magnetic ring outer peripheral surface and the rotor core inner peripheral surface . The rotating electrical machine according to claim 2 , wherein press-fitting grooves are provided on the inner peripheral surface of the nonmagnetic ring and the inner peripheral surface of the rotor core, respectively . 8. The rotor assembly is prevented from rotating by providing a protrusion on an inner peripheral surface of the magnetic ring and engaging the protrusion with a terminal wiring groove provided on the rotating shaft. The rotating electrical machine according to any one of the above. The rotating electrical machine according to any one of claims 1 to 8, wherein the rotor assembly is press-fitted into the rotating shaft, and is positioned in an axial direction by a ring provided on the rotating shaft . The rotating electrical machine according to any one of claims 1 to 8 , wherein the rotor assembly is press-fitted into the rotating shaft and is positioned in an axial direction by a step provided on the rotating shaft. The rotating electrical machine according to claim 9 , wherein the rotor assembly is press-fitted into the rotating shaft, and after being positioned in the axial direction by the ring, the rotor assembly is fixed to the rotating shaft by welding . The rotor assembly is mounted to the rotating shaft, after the axial positioning is performed by a step provided on said rotary shaft, to claim 10, characterized in that fixed to the rotary shaft by welding The rotating electrical machine described. The rotor position detection sensor attached to the rotating shaft of the rotating electrical machine according to claim 1,
A stator assembly having an output coil and an exciting coil, and a rotor assembly having a rotor core facing the inner peripheral surface of the stator assembly with a gap therebetween, the rotor assembly comprising a magnetic ring, a non-magnetic ring, and the rotor core Rotor position detection, characterized in that the magnetic ring, non-magnetic ring, and rotor core are sequentially stacked concentrically outward and attached to the rotary shaft with the innermost magnetic ring. Sensor.

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