JP7744894B2 - salient pole rotating motor - Google Patents

Description

The present invention relates to a salient-pole rotating electric machine.

Conventionally, salient-pole rotating electric machines equipped with salient-pole rotors are known. Windings are wound around the salient poles of the rotor. The windings are held to the salient poles by brackets. When current flows through the windings, they generate magnetic force and heat. The windings can be cooled, for example, by airflow generated inside the salient-pole rotating electric machine as the rotor rotates, or by an internal fan attached to the shaft.

JP 2017-85829 A

Air flows along the surfaces of the salient poles and windings, cooling them. However, ventilation separation is likely to occur on the back side of the salient poles in the direction of rotation. Furthermore, brackets can obstruct axial airflow, reducing the rotor's cooling efficiency.

One example of the problem solved by this invention is to provide a salient-pole rotating electric machine that can improve rotor cooling efficiency.

An embodiment of the salient-pole rotating electric machine of the present invention comprises a housing, a stator housed in the housing, a shaft surrounded by the stator and rotatable about a rotation axis, multiple salient poles extending radially of the rotation axis between the stator and the shaft, multiple windings wound around the multiple salient poles, a bracket positioned between two adjacent ones of the multiple windings in the circumferential direction about the rotation axis and supporting those two windings, and two insulating plates positioned between the bracket and the two windings in the circumferential direction, and a rotor attached to the shaft, wherein each of the two insulating plates has a groove opening to both ends of the insulating plate in the radial direction, and the grooves are inclined with respect to the radial direction.

The salient-pole rotating electric machine of the present invention can improve rotor cooling efficiency.

FIG. 1 is a cross-sectional view of a salient-pole rotating electric machine according to this embodiment. FIG. 2 is a cross-sectional view of the rotor of this embodiment. FIG. 3 is an enlarged cross-sectional view of a portion of the rotor of this embodiment. FIG. 4 is a plan view of the bracket and insulating plate of this embodiment. FIG. 5 is a plan view of the insulating plate of this embodiment.

The salient-pole rotating electric machine 1 according to this embodiment will now be described with reference to the drawings. The configuration of the embodiment described below, as well as the actions and results (effects) brought about by this configuration, are merely examples and are not limited to the following description. Note that in this specification, ordinal numbers are used only to distinguish between parts and components, and do not indicate order or priority.

<Embodiment>
1 is a cross-sectional view of a salient-pole rotating electric machine 1 according to this embodiment. As shown in FIG. 1, the salient-pole rotating electric machine 1 includes a housing 2, a stator 3, a shaft 4, a rotor 5, and two bearings 6.

In the following figures, for convenience, three mutually orthogonal directions are defined. The X direction is the direction along the longitudinal direction of the housing 2 and may also be referred to as the front-to-back direction. The Y direction is the direction along the lateral direction of the housing 2 and may also be referred to as the left-to-right direction. The Z direction is the direction along the vertical direction of the housing 2 and may also be referred to as the up-to-down direction. Note that the expressions indicating directions such as front-to-back, left-to-right, up-to-down, etc. in this embodiment are used for convenience and do not limit the position, posture, or usage of the salient-pole rotating electric machine 1.

The salient-pole rotating electric machine 1 of this embodiment is, for example, a totally enclosed rotating electric machine. Therefore, a closed space that is separated from the outside of the housing 2 is provided inside the housing 2. However, the salient-pole rotating electric machine 1 is not limited to this example. For example, the salient-pole rotating electric machine 1 may be an open-type rotating electric machine.

The housing 2 is formed into a box shape from metal or the like. The housing 2 houses the stator 3 and rotor 5. Openings 21 that open in the X direction are provided at both ends of the housing 2 in the front-to-rear direction (X direction).

The stator 3 has a stator core 31 and a stator winding 32. The stator core 31 is fixed to the housing 2. The stator core 31 is located radially outside the rotor 5 and is formed in a cylindrical shape surrounding the rotor 5. The stator winding 32 is fixed to the stator core 31 by passing through multiple slots (not shown) formed in the inner periphery 31a of the stator core 31 so as to extend in the axial direction.

The shaft 4 is partially surrounded by the stator 3. The shaft 4 is supported by the housing 2 via two bearings 6 so that it can rotate around a rotation axis Ax. In other words, the two bearings 6 support the shaft 4 so that it can rotate relative to the housing 2. The rotation axis Ax is, for example, the central axis (center line) of the shaft 4. Note that the rotation axis Ax may be different from the central axis of the shaft 4.

In the following description, for convenience, the axial direction, radial direction, and circumferential direction of the rotation axis Ax are defined. The axial direction is the direction along the rotation axis Ax. The radial direction is the direction perpendicular to the rotation axis Ax. The circumferential direction is the direction around the rotation axis Ax. Note that in the following description, unless otherwise specified, the axial direction, radial direction, and circumferential direction refer to the axial direction, radial direction, and circumferential direction of the rotation axis Ax.

The shaft 4 extends axially along the rotation axis Ax, passing through the opening 21 of the housing 2. The portion of the shaft 4 between its two axial ends 4a, 4b is housed within the housing 2. Meanwhile, the two axial ends 4a, 4b of the shaft 4 protrude from the housing 2 to the outside.

One end 4a can be connected to various connecting objects, for example. An external fan is fixed to the other end 4b. The external fan is covered, for example, by an external fan cover, and rotates integrally with the shaft 4.

An internal fan 41 is fixed to the shaft 4 between each of the two bearings 6 and the rotor 5. The internal fan 41 rotates integrally with the shaft 4, generating an airflow that flows in the axial direction, circulating cooling gas in the enclosed space. In Figure 1, the internal fan 41 generates an airflow that flows, for example, from right to left on the page, to cool the rotor 5 and stator 3. In the following explanation, unless otherwise specified, the direction of the airflow generated within the housing 2 by the internal fan 41 will be described as the direction described above.

Figure 2 is a cross-sectional view of the rotor 5 according to this embodiment. As shown in Figure 2, the rotor 5 has a rotor core 51, multiple rotor windings 52, multiple pole heads 53, multiple insulating layers 54, multiple brackets 55, and multiple insulating plates 56. Note that the rotor windings 52 are an example of a winding.

As shown in Figure 1, the rotor core 51 is attached to the shaft 4 between its axial ends 4a, 4b. As a result, the rotor core 51 is housed in the housing 2 and rotates integrally with the shaft 4. In the following explanation, unless otherwise specified, the rotation direction of the rotor 5 in Figure 2 will be described as clockwise.

The two bearings 6 are provided in the opening 21 of the housing 2. That is, the rotor core 51 is located axially between the two bearings 6. The two bearings 6 are, for example, plain bearings.

As shown in FIG. 2, the rotor core 51 has a central portion 510 and multiple salient poles 511. The central portion 510 is attached to the shaft 4. The salient poles 511 protrude radially outward from the central portion 510 toward the inner periphery 31a of the stator core 31. In other words, the salient poles 511 extend radially about the rotation axis Ax between the stator 3 and the shaft 4. The inner periphery 31a is, for example, the inner periphery surface of the stator core 31 or the radially inner end of the stator core 31.

The rotor winding 52 is wound around the side surface 511a of the salient pole 511 of the rotor core 51. In other words, the rotor winding 52 surrounds the salient pole 511. The side surface 511a is the outer surface of the salient pole 511 that faces in a direction (e.g., the axial direction and circumferential direction) that intersects the direction in which the salient pole 511 extends.

Each pole head 53 is attached to the end of the corresponding salient pole 511 on the radially outer side of the rotation axis Ax. Each pole head 53 protrudes axially and circumferentially from the side surface 511a of the salient pole 511. As a result, each pole head 53 presses against the rotor winding 52 from the radially outer side. Therefore, the pole head 53 is located radially between the salient pole 511 and the inner periphery 31a of the stator core 31.

The pole head 53 has an end face 53a and a bottom face 53b. The end face 53a is an arc-shaped curved surface that faces radially outward and extends approximately circumferentially. The radius of the end face 53a is shorter than the radius of the inner periphery 31a of the stator core 31. As a result, the end face 53a is spaced from the inner periphery 31a, forming a gap 18 between the end face 53a and the inner periphery 31a through which airflow can pass. The center of the end face 53a may differ from the center of the inner periphery 31a of the stator core 31. The bottom face 53b is located on the opposite side of the end face 53a and faces the salient pole 511.

The insulating layer 54 is a layer formed, for example, from a synthetic resin. The insulating layer 54 has a portion extending radially between the salient pole 511 and the rotor winding 52, and a portion extending approximately circumferentially between the rotor winding 52 and the pole head 53. In other words, the insulating layer 54 has an L-shaped cross section.

The bracket 55 is a component made of a metal such as aluminum. The bracket 55 is positioned between two circumferentially adjacent salient poles 511 and is fixed to the rotor core 51 by a bolt A that passes through the bracket 55. In this embodiment, at least two of the multiple brackets 55 are arranged axially with a gap between them.

Each bracket 55 secures the rotor winding 52 and insulating plate 56 to the salient pole 511 in the circumferential direction. In other words, each bracket 55 supports two rotor windings 52 and insulating plates 56 that are adjacent to each other in the circumferential direction.

Figure 3 is an enlarged cross-sectional view of a portion of the rotor 5 according to this embodiment. As shown in Figure 3, at least one barrier 551 is provided on each bracket 55. The barrier 551 is formed integrally with the bracket 55 and protrudes from at least one of the two end portions 55a of the bracket 55 in the circumferential direction toward the inner periphery 31a of the stator 3.

The barrier 551 extends, for example, in a direction along the side surface 511a of the salient pole 511. As shown in Figure 2, the tip 551a of the barrier 551 on the radially outer side is located between the stator 3 and the rotor 5 in the radial direction.

In this embodiment, the tip 551a of the barrier 551 is located between the end face 53a of the pole head 53 and the vertex 53a1 of the end face 53a that is farthest from the rotation axis Ax. Therefore, the barrier 551 is spaced apart from the inner periphery 31a of the stator core 31. Note that the length of the barrier 551 may be changed as appropriate, as long as the tip 551a is located between the end face 53a of the pole head 53 and the vertex 53a1.

The insulating plates 56 are plates made of synthetic resin, such as epoxy resin. The multiple insulating plates 56 have the same shape. However, the multiple insulating plates 56 may also have different shapes.

Figure 4 is a plan view of the bracket 55 and insulating plate 56 of this embodiment. As shown in Figure 4, each insulating plate 56 is positioned between the rotor winding 52 and the bracket 55 in an inverted state in the circumferential direction. In Figure 4, the axial flow direction of the cooling gas is from top to bottom on the page, and the rotation direction is from left to right on the page.

The width of the insulating plate 56 in the axial direction is slightly larger than the width of the bracket 55 in the axial direction. The length of the insulating plate 56 in the radial direction is slightly longer than the creepage distance of the rotor winding 52 wound around the salient pole 511. As a result, the insulating plate 56 prevents electrical conduction between the rotor winding 52 and the bracket 55.

Figure 5 is a plan view of the insulating plate 56 according to this embodiment. As shown in Figure 5, the insulating plate 56 has multiple recesses 561 and multiple grooves 562. Furthermore, the insulating plate 56 has an engaging portion 563.

The multiple recesses 561 are recessed from the end 56b on the inner side of the insulating plate 56 in the radial direction toward the end 56a on the outer side of the insulating plate 56 in the radial direction. Furthermore, the recesses 561 are provided on the surface of the insulating plate 56 that contacts the rotor winding 52. Each recess 561 is a portion that comes into contact with bolt A when the insulating plate 56 is placed between the rotor winding 52 and the bracket 55. In other words, each recess 561 is a portion that fits with bolt A when the insulating plate 56 is placed between the rotor winding 52 and the bracket 55.

The radially outer end 562a of the groove 562 opens to the end 56a of the insulating plate 56. The radially inner end 562b of the groove 562 opens to the end 56b of the insulating plate 56. In other words, each of the multiple grooves 562 opens to both radial ends 56a, 56b of the insulating plate 56. Each of the multiple grooves 562 is inclined with respect to the radial direction.

As shown in Figure 4, in the insulating plate 56 (insulating plate 56 on the right side in Figure 4) that contacts the rotor winding 52 portion that is the rear surface of the salient pole 511 in the direction of rotation of the rotor 5, the inclination direction of the multiple grooves 562 is configured so that end 562a is located on the upwind side in the direction of axial cooling gas flow, and end 562b or the opening on end 56c (described below) is located on the downwind side.

Furthermore, in the insulating plate 56 (insulating plate 56 on the left side in Figure 4) that contacts the portion of the rotor winding 52 that forms the front surface of the salient pole 511 in the direction of rotation of the rotor 5, the inclination direction of the multiple grooves 562 is configured so that the opening on end 562b or end 56c (described below) is located on the upwind side in the direction of axial cooling gas flow, and end 562a is located on the downwind side. This allows the rotation of the rotor 5 to promote the flow of cooling gas in the axial direction.

As shown in FIG. 3, the end 562b of the groove 562 provided in one insulating plate 56 communicates with the end 562b of the groove 562 provided in the other insulating plate 56 via a space S formed between the side surfaces 511a of two adjacent salient poles 511 and between the end surface 52a of the rotor winding 52 on the radially inner side and the central portion 510. As shown in FIG. 5, the end 562b of at least one of the multiple grooves 562 opens to one end 56c of the insulating plate 56 in the axial direction.

As shown in FIG. 3, each groove 562 is recessed from the surface 56d of the insulating plate 56 facing the rotor winding 52. This allows the airflow passing through the groove 562 to directly cool the rotor winding 52.

In this embodiment, the insulating plate 56 has multiple grooves 562 that are inclined relative to the radial direction, but this is not limited to this. For example, the width, shape, and number of the grooves 562 may be changed as appropriate within the allowable range in terms of the strength of the insulating plate 56.

The engagement portion 563 is a recessed portion in the thickness direction of the insulating plate 56. The engagement portion 563 engages with the insulating layer 54. This prevents the insulating plate 56 from being scattered radially outward due to the centrifugal force generated when the rotor 5 rotates.

When the salient-pole rotating electric machine 1 is operating, the rotor 5 and the inner fan 41 attached to the shaft 4 rotate in conjunction with the rotation of the shaft 4. The rotation of the inner fan 41 generates an airflow that flows axially in the closed space of the housing 2. Furthermore, the rotation of the rotor 5 causes an airflow to flow along the surface of the rotor 5.

The airflow flowing along the surface of the rotor 5 flows toward the opposite side of the rotation direction (the rear side), for example, along the end face 53a of the pole head 53. After passing through the pole head 53, the airflow flowing along the surface of the rotor 5 collides with the barrier 551.

The airflow that collides with the barrier 551 is guided by the barrier 551 and flows into the end 562a of the groove 562 of one of the insulating plates 56. The airflow passes through the groove 562 of that insulating plate 56 while cooling the rotor winding 52. The airflow that passes through the groove 562 of one of the insulating plates 56 flows through the space S into the end 562b of the groove 562 of the other insulating plate 56.

The airflow passes through the groove 562 in the other insulating plate 56, cooling the rotor winding 52 wound around the other salient pole 511. After passing through the groove 562 in the other insulating plate 56, the airflow flows along the end face 53a of the other pole head 53. The airflow then cools the entire rotor 5 in a similar manner.

On the other hand, the airflow flowing in the axial direction flows, for example, along the surface of the shaft 4, through the outer surface of the bracket 55 and the space S. At least one end 562b of the multiple grooves 562 opens to one end 56c in the axial direction. Furthermore, as described above, the grooves 562 are inclined relative to the radial direction. Therefore, the airflow flowing in the axial direction passes through the grooves 562 in the insulating plate 56 while cooling the rotor winding 52, and is guided to the end face 53a of the pole head 53. This allows the grooves 562 to guide the cooling gas circulated by the internal fan 41 to the surface of the rotor 5.

Because the grooves 562 are inclined relative to the radial direction, the cooling gas that passes through the grooves 562 is essentially sent in the axial direction. Therefore, even if the axially flowing airflow collides with the bracket 55, the insulating plate 56 can send the airflow in the axial direction.

In the salient-pole rotating electric machine 1 of this embodiment, the barriers 551 are provided at both ends 55a of the bracket 55 in the circumferential direction. However, it is sufficient if the barriers 551 are provided at least on the inflow side of the airflow in the circumferential direction.

As described above, the salient-pole rotating electric machine 1 of this embodiment comprises a housing 2, a stator 3, a shaft 4, and a rotor 5. The stator 3 is housed in the housing 2. The shaft 4 is surrounded by the stator 3 and is rotatable about the rotation axis Ax. The rotor 5 is attached to the shaft 4 and has multiple salient poles 511, multiple rotor windings 52, a bracket 55, and two insulating plates 56. The multiple salient poles 511 extend radially about the rotation axis Ax between the stator 3 and the shaft 4. The multiple rotor windings 52 are wound around the multiple salient poles 511. The bracket 55 is located between two of the multiple rotor windings 52 that are adjacent in the circumferential direction about the rotation axis Ax and supports those two of the multiple rotor windings 52. The two insulating plates 56 are located circumferentially between the bracket 55 and two of the multiple rotor windings 52. Each of the two insulating plates 56 has a groove 562 that opens to both ends 56a, 56b of the insulating plate 56 in the radial direction. The groove 562 is inclined relative to the radial direction.

When the rotor 5 begins to rotate, an airflow is generated that flows over the surface of the rotor 5 in the direction opposite to the direction of rotation. Furthermore, an airflow is generated in the axial direction from the internal fan 41 attached to the shaft 4. The insulating plate 56, located circumferentially between the bracket 55 and the rotor winding 52, has grooves 562 that are inclined radially. Therefore, the airflow generated by the rotation of the rotor 5 and the airflow generated by the internal fan 41 pass through the grooves 562 and flow over the surface of the rotor 5 while being sent in the axial direction.

As a result, the insulating plate 56 guides the airflow generated by the internal fan 41 and the airflow generated by the rotation of the rotor 5 to the rotor winding 52. Therefore, the salient-pole rotating electric machine 1 of this embodiment can improve the cooling efficiency of the rotor 5.

The salient-pole rotating electric machine 1 of this embodiment also includes a barrier 551 that protrudes toward the stator 3 from at least one of the circumferential end portions 55a of the bracket 55. The tip 551a of the barrier 551 is located between the stator 3 and the rotor 5 in the radial direction. As a result, airflow generated by the rotation of the rotor 5 collides with the barrier 551 and is guided into the groove 562. Therefore, the salient-pole rotating electric machine 1 can further improve the cooling efficiency of the rotor 5.

In addition, in this embodiment, the radially inner end 562b of the groove 562 opens to the radially inner end 56b of the insulating plate 56 and also opens to one end 56c of the insulating plate 56 in the axial direction along the rotation axis Ax. This makes it easier for the groove 562 to direct the airflow flowing in the axial direction.

Furthermore, in this embodiment, the two insulating plates 56 have the same shape. This allows the salient-pole rotating electric machine 1 to reduce costs.

The above describes an embodiment of the present invention, but the above embodiment is merely an example and is not intended to limit the scope of the invention. The above embodiment can be implemented in a variety of other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, the specifications of each configuration, shape, and the like (structure, type, direction, format, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be modified as appropriate.

1... salient pole rotating electric machine, 2... housing, 3... stator, 4... shaft, 5... rotor, 51... rotor core, 511... salient pole, 52... rotor winding (winding), 55... bracket, 55a... end, 551... barrier, 551a... tip, 56... insulating plate, 56a... radially outer end, 56b... radially inner end, 56c... one axial end, 562... groove, 562b... radially inner end of groove, Ax... rotating shaft.

Claims (5)

The housing and
a stator housed in the housing;
a shaft surrounded by the stator and rotatable about a rotation axis;
a rotor attached to the shaft, the rotor including: a plurality of salient poles extending in a radial direction of the rotating shaft between the stator and the shaft; a plurality of windings wound around the plurality of salient poles; a bracket positioned between two adjacent ones of the plurality of windings in a circumferential direction around the rotating shaft and supporting the two windings; and two insulating plates positioned between the bracket and the two windings in the circumferential direction;
Equipped with
each of the two insulating plates is provided with a groove that opens to both ends of the insulating plate in the radial direction;
The groove is inclined with respect to the radial direction.
Salient pole rotating electric machine. a barrier protruding from at least one of both end portions of the bracket in the circumferential direction toward the stator;
Furthermore,
a tip of the barrier wall is located between the stator and the rotor in the radial direction;
2. A salient pole rotating electric machine according to claim 1. an end of the groove on the inner side in the radial direction opens to an end of the insulating plate on the inner side in the radial direction and also opens to one end of the insulating plate in the axial direction along the rotation shaft;
3. A salient-pole rotating electric machine according to claim 1 or 2. The two insulating plates have the same shape.
3. A salient-pole rotating electric machine according to claim 1 or 2. The housing and
a stator housed in the housing;
a shaft surrounded by the stator and rotatable about a rotation axis;
a rotor attached to the shaft, the rotor including: a plurality of salient poles extending in a radial direction of the rotating shaft between the stator and the shaft; a plurality of windings wound around the plurality of salient poles; a bracket positioned between two adjacent ones of the plurality of windings in a circumferential direction around the rotating shaft and supporting the two windings; and two insulating plates positioned between the bracket and the two windings in the circumferential direction;
a barrier wall extending from at least one of both end portions of the bracket in the circumferential direction toward the stator;
Equipped with
a tip of the barrier wall is located between the stator and the rotor in the radial direction;
Salient pole rotating electric machine.