JP2013070579A - End plate for rotary electric machine and rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the manufacturing cost with a structure having a coolant passage for realizing a shaft center cooling structure in an end plate for a rotary electric machine.SOLUTION: An end plate 34 fits into the outer diameter side of a rotor shaft 16, which is rotatably provided, with a rotor core 32 and restricts the axial displacement of the rotor core 32. The end plate 34 is formed by performing circular bending on a metal plate, and a plate side coolant passage 50 is formed in the radial direction by a gap between both end edges in the circumferential direction.

Description

  The present invention relates to an end plate for a rotating electrical machine and a rotating electrical machine that are fitted together with a rotor core on the outer diameter side of a rotor shaft that is rotatably provided, and restrict axial displacement of the rotor core.

  2. Description of the Related Art Conventionally known rotary electric machines such as vehicular electric motors have a configuration including a rotor fixed on the outer diameter side of a rotor shaft and a stator arranged to face the outer diameter side of the rotor, for example. Moreover, a rotor may provide a permanent magnet inside the rotor core made from a magnetic material. In such a rotating electrical machine, the rotor is cooled in order to suppress the heat generation of the rotor during use and maintain the performance of the rotor. For example, a shaft-side refrigerant passage is formed inside the rotor shaft, a coolant (for example, cooling oil) that is a refrigerant is supplied to the shaft-side refrigerant passage, and the rotor is cooled by flowing cooling oil radially outward to the rotor. A so-called axial center cooling structure is conceivable. On the other hand, the rotor may include an end plate that is fitted to the outer diameter side of the rotor shaft together with the rotor core and restricts the axial displacement of the rotor core. In addition, when the end plate is included in the shaft cooling structure, a coolant passage may be formed in the end plate.

  For example, in Patent Document 1, a rotating electrical machine is provided that includes a rotor provided on the outer diameter side of a rotating shaft and a stator disposed to face the outer diameter side of the rotor, and a shaft channel is formed inside the rotating shaft. A cooling structure is described. In addition, the rotor core is fitted and arranged on the outer periphery of the rotating shaft, and the end plate is fitted on the outer peripheral surface of the rotating shaft so as to face both ends of the rotor core in the axial direction. Furthermore, a radial hole formed in the rotating shaft passing through the shaft flow path and the outer peripheral surface, a refrigerant passage formed in the rotor core side surface of the end plate, and a first discharge hole formed in the end plate It is said that oil is discharged through and sprayed to the coil end of the stator. Further, by providing the discharge groove and the second discharge hole on the outer peripheral side of the refrigerant passage, oil leaks from the gap between the end surface of the outermost peripheral portion of the end plate and the end surface of the outermost peripheral portion of the rotor core. It is said that drag loss caused by oil entering the gap with the rotor is suppressed.

JP 2011-142788 A

  When an annular end plate is manufactured by punching from a sheet-like metal plate with the configuration described in Patent Document 1, a lot of waste material is generated by punching the center portion of the end plate and the end plate and the rotation. There is a possibility that the yield of electric machines will deteriorate and the manufacturing cost will increase. Further, if a process for forming a coolant passage in the end plate is performed after the metal plate is punched, the manufacturing cost is likely to increase further. In particular, when the inner diameter of the rotor is increased, the inner diameter of the end plate is also increased, so that the amount of waste material due to the punching process is increased and the manufacturing cost is likely to further increase.

  An object of the present invention is to reduce the manufacturing cost of a rotating electrical machine end plate and a rotating electrical machine having a refrigerant passage for realizing a shaft center cooling structure.

  An end plate for a rotating electrical machine according to the present invention is an end plate for a rotating electrical machine that is fitted together with a rotor core on the outer diameter side of a rotor shaft that is rotatably provided and restricts axial displacement of the rotor core. An end plate for a rotating electrical machine, characterized in that a plate-side refrigerant passage in a radial direction is formed by a gap between circumferential end edges formed by circular bending.

  According to the end plate for a rotating electrical machine of the present invention, unlike the case where the end plate is formed by punching a plate material, no waste material is generated by the punching process, so that the yield can be improved and the manufacturing cost can be reduced. In addition, since the radial plate-side refrigerant passage can be formed by the gap between the circumferential edges of the end plate, the plate-side refrigerant passage becomes a refrigerant passage for realizing the shaft center cooling structure, and the end plate is rotated. A coolant such as a coolant can be sent radially outward by the action of centrifugal force. Moreover, it is not necessary to perform grooving on one side of the end plate after punching, and further cost reduction can be achieved.

  The rotating electrical machine according to the present invention includes a rotor shaft rotatably provided, a rotor core fixed to the outer diameter side of the rotor shaft, and fixed to at least one axial direction of the rotor core on the outer diameter side of the rotor shaft. A rotary electric machine comprising one or more end plates for a rotary electric machine that regulate axial displacement of the rotor core and a stator that is arranged opposite to the outer diameter side of the rotor core, Each of the plurality of rotating electric machine end plates is the rotating electric machine end plate according to claim 1.

  According to the rotating electrical machine of the present invention, unlike the case where the end plate is formed by punching a plate material, it is not necessary to generate a waste material by punching, so that the yield can be improved and the manufacturing cost can be reduced. In addition, since the radial plate-side refrigerant passage can be formed by the gap between the circumferential edges of the end plate, the plate-side refrigerant passage becomes a refrigerant passage for realizing the shaft center cooling structure, and the end plate is rotated. A coolant such as a coolant can be sent radially outward by the action of centrifugal force. Moreover, it is not necessary to perform grooving on one side of the end plate after punching, and further cost reduction can be achieved.

  Also, in the rotating electrical machine according to the present invention, preferably, the plurality of rotating electrical machine end plates are fixed to at least one axial side of the rotor core on the outer diameter side of the rotor shaft, The plates are stacked with the phases of the plate-side refrigerant passages shifted from each other.

  According to the above configuration, the thickness of each end plate is made by making the total thickness of a plurality of end plates required for strength equal to the thickness of one end plate required for a conventional product. Can be reduced. For this reason, it is possible to reduce the force required for processing in bending each end plate into a circle. Furthermore, since the plate-side refrigerant passages are formed at a plurality of locations where the circumferential phases of the plurality of end plates are shifted, the cooling performance of the rotating electrical machine can be improved.

  In the rotating electrical machine according to the present invention, preferably, the rotor shaft includes an axial refrigerant passage that is provided inside and communicates with an outer peripheral surface, and the axial refrigerant passage is provided directly or on a core side provided in the rotor core. The plate-side refrigerant passage communicates with the refrigerant passage.

  According to the end plate for a rotating electrical machine and the rotating electrical machine according to the present invention, in the end plate for the rotating electrical machine and the rotating electrical machine, the manufacturing cost can be reduced by the configuration having the refrigerant passage for realizing the shaft center cooling structure.

It is a fragmentary sectional view of the rotary electric machine containing an example of the end plate for rotary electric machines of embodiment of this invention. It is the figure which took out one end plate from FIG. 1 and looked at the axial direction. It is a figure which shows a mode that an end plate is formed from a metal plate at the time of manufacture of the end plate of FIG. It is a figure which shows a mode that a useless waste material arises at the time of manufacture of the end plate of a comparative example. In another example of the rotary electric machine of embodiment of this invention, it is a fragmentary sectional view of a rotor and a rotor shaft. It is AA sectional drawing of FIG. 5 regarding the perimeter of a rotor.

  Hereinafter, an embodiment according to the present invention will be described with reference to FIGS. The rotating electrical machine of the present embodiment including the end plate for the rotating electrical machine of the present embodiment is, for example, an electric vehicle, a fuel cell vehicle, and a motor for driving a hybrid vehicle in which an engine and a motor are mounted as a vehicle driving source. Or as a generator, or as a motor generator having both functions. For example, when the rotating electrical machine is used as a motor generator, this embodiment is applied to both the first motor generator (MG1) used mainly as a generator and the second motor generator (MG2) used mainly as a running motor. it can. In addition, the rotating electrical machine can be incorporated into a vehicle drive device that changes the output of the rotating electrical machine with a single-stage or multi-stage transmission.

  FIG. 1 is a partial cross-sectional view of the rotating electrical machine of the present embodiment. As shown in FIG. 1, the rotating electrical machine 10 is rotatably supported on a casing 14 by a bearing (not shown), that is, is rotatably provided, and is fitted to the outer diameter side of the intermediate portion of the rotor shaft 16. The rotor 18 is fixed, and the stator 20 is disposed on the outer diameter side of the rotor 18 so as to be opposed to each other via an air gap 19 that is a radial gap. The stator 20 is fixed to the inner peripheral surface of the casing 14, for example. Such a rotating electrical machine 10 is a so-called axial cooling structure in which a cooling oil such as ATF that is a coolant flows through the rotor shaft 16 and a cooling oil flows through the rotor 18 radially outward. The rotor 18 and the stator 20 are cooled.

  The stator 20 includes a stator core 24 formed of a magnetic material such as a laminate formed by laminating a plurality of electromagnetic steel plates in the axial direction, and is formed to project radially at a plurality of locations in the circumferential direction of the inner peripheral surface of the stator core 24. Teeth 26 and a plurality of (for example, three-phase) stator coils 28 wound around the teeth 26. In the stator coil 28, a pair of coil ends 30 are formed by portions protruding outward from both axial side surfaces of the stator core 24. The stator core 24 is fixed to the inner surface of the casing 14. The multi-phase stator coil 28 is wound around the stator core 24 by concentrated winding, distributed winding, wave winding, or the like.

  The casing 14 accommodates the stator 20 and the rotor 18. The rotor 18 is embedded in a substantially cylindrical rotor core 32 formed of a magnetic material such as a laminate formed by laminating a plurality of electromagnetic steel plates in the axial direction, and embedded in a plurality of locations in the circumferential direction inside the rotor core 32. And a permanent magnet (not shown). The plurality of permanent magnets are respectively magnetized in the radial direction of the rotor 18, and magnetic characteristics at a plurality of circumferential positions on the outer peripheral portion of the rotor 18 are alternately varied in the circumferential direction. Note that a plurality of permanent magnets can be arranged in a V shape extending outward in the radial direction at a plurality of locations in the circumferential direction of the rotor core 32 as a set of two permanent magnets.

  Further, a pair of end plates for rotating electrical machines (hereinafter simply referred to as “end plates”) 34 made of a disk-shaped nonmagnetic material are disposed on both sides of the rotor core 32 in the axial direction. 32 is clamped from both axial sides. The detailed configuration of each end plate 34 will be described later.

  Further, the rotor shaft 16 has an outward flange 36 formed on the outer peripheral surface of one end portion (left end portion in FIG. 1), and the two end plates 34 and the rotor core 32 are fitted to the outer diameter side of the rotor shaft 16. In this state, the other end portion (the right end portion in FIG. 1) of the rotor shaft 16 is caulked to the outer side in the radial direction, so that the caulking portion 38 is formed. The outward flange 36 and the caulking portion 38 sandwich the pair of end plates 34 and the rotor core 32. For this reason, each end plate 34 regulates the axial displacement of the rotor core 32. Further, an axial passage 40 for flowing cooling oil in the axial direction and a radial passage 42 for flowing cooling oil in the radial direction are formed inside the rotor shaft 16. The radial passage 42 passes through the axial passage 40 and the outer peripheral surface of the rotor shaft 16. The axial passage 40 and the radial passage 42 form an axial refrigerant passage 44 that is provided inside the rotor shaft 16 and communicates with the outer peripheral surface of the rotor shaft 16.

  In addition, the radial direction of the radial passage 42 (“radial direction” means the radial direction of the rotor unless otherwise specified) in a part of the inner circumferential surface of the rotor core 32. In the entire specification and claims The axial inner circumferential groove 46, which is the core-side refrigerant passage that extends over the entire length in the axial direction of the rotor core 32, is formed in the portion facing the outer end.

  Next, the end plate 34 of this embodiment is demonstrated using FIGS. FIG. 2 is a view of one end plate 34 taken out from FIG. 1 and viewed in the axial direction. As shown in FIG. 2, each end plate 34 is made of a metal plate (for example, a plate material such as copper, stainless steel, or aluminum material) that is a non-magnetic plate material, and a circular circumferential part thereof is cut. Have a different shape. Such an end plate 34 is formed by processing as shown in the order of (a), (b), and (c) in FIG. 3A shows a rectangular metal plate 48 which is a material forming the end plate 34, and FIG. 3B shows a state in the middle of bending the metal plate 48, FIG. 3C shows the end plate 34. That is, the rectangular metal plate 48 of FIG. 3A is subjected to a bending process using a bending apparatus (not shown), that is, a process of bending the circular shape so that both ends in the circumferential direction are separated from each other. After the state of b), the end plate 34 shown in FIG. 3C is formed. In the end plate 34, a radial plate-side refrigerant passage 50 is formed by a gap between both circumferential edges.

  As shown in FIG. 1, the circumferential direction of the plate-side refrigerant passage 50 (“circumferential direction” refers to the circumferential direction of the rotor unless otherwise specified. The same applies to the entire specification and claims). Each end plate 34 is fitted and fixed to the outer diameter side of the rotor shaft 16 together with the rotor core 32 so that the phase matches the phase in the circumferential direction of the axially inner circumferential groove 46 of the rotor core 32. For this reason, the plate-side refrigerant passages 50 provided in the end plates 34 communicate with each other via the axial inner circumferential groove 46. Further, the shaft side refrigerant passage 44 communicates with each plate side refrigerant passage 50 via an axial inner circumferential groove 46. By inserting a pin member such as a rivet pin in the axial direction where the rotor core 32 and each end plate 34 are aligned, or by pressing a plurality of circumferentially aligned locations in the axial direction to form a caulking portion, The rotor core 32 and each end plate 34 may be integrated. This caulking portion may be formed only on the rotor core 32, and a plurality of steel plates may be integrated.

  In the example of FIG. 1, the axial length of the stator 20 including each coil end 30 is smaller than the axial length of the rotor 18 including each end plate 34. However, the axial length of the stator 20 may be the same as the axial length of the rotor 18, and may be slightly larger than the axial length of the rotor 18. Further, the cooling oil sprayed to the outside from the plate-side refrigerant passage 50 of each end plate 34 is blown toward each coil end 30 by the action of centrifugal force when the rotor 18 rotates. Further, in the illustrated example, an axial passage 52 that extends over the entire length of the stator core 24 is formed in a part in the circumferential direction between the inner circumferential surface of the casing 14 and the outer circumferential surface of the stator core 24 or in a plurality of circumferential directions. Although it is possible for oil to enter, this axial passage 52 can also be omitted.

  In such a rotating electrical machine 10, a rotating magnetic field is generated in the stator 20 by causing a plurality of phases of alternating current to flow through the plurality of stator coils 28, and the rotor 18 can be rotated together with the rotor shaft 16.

  In such a rotating electrical machine cooling structure including the rotating electrical machine 10, as indicated by an arrow α in FIG. 1, the cooling oil is supplied to the axial passage 40 of the rotor shaft 16 from a cooling oil supply device constituted by a pump or the like (not shown). When supplied, the cooling oil is supplied from the axial inner circumferential groove 46 to the plate-side refrigerant passages 50 of the end plates 34 on both sides via the radial passage 42. The cooling oil supplied to each plate-side refrigerant passage 50 is blown to the outer diameter side as indicated by an arrow β in FIG. 1 while cooling the rotor 18 by the action of centrifugal force when the rotor 18 rotates, and the stator The coil 28 and the stator core 24 are cooled.

  According to the end plate 34 and the rotating electrical machine 10, unlike the conventional structure in which the end plate is formed by punching a metal plate, it is not necessary to generate waste material by punching, so that the yield is improved and the manufacturing is performed. Cost can be reduced. That is, FIG. 4 is a diagram showing a state in which useless waste material is generated when the end plate 54 of the comparative example that is out of the present invention is manufactured. In the comparative example of FIG. 4, a plurality of annular end plates 54 are formed by punching a plurality of portions of a long sheet-like metal plate 56 made of a non-magnetic material into a donut shape by pressing a white portion of FIG. 4. doing. For this reason, in the comparative example, during the punching process, many waste materials are easily generated at the outer peripheral portion of the metal plate 56 and the central portion of the end plate 34, which are indicated by the hatched portion in FIG. Therefore, the yield of the end plate 34 is deteriorated, which causes the manufacturing cost to increase. On the other hand, according to the present embodiment, it is not necessary to generate such waste material, so that the cost can be reduced. In particular, when the inner diameter of the end plate 34 (FIG. 2 and the like) is increased, the amount of waste material is increased in the comparative example, so that the effect of the present invention is remarkable with respect to the comparative example.

  In the present embodiment, the radial plate-side refrigerant passage 50 (FIG. 2 and the like) can be formed by the gap between the circumferential edges of each end plate 34, so that the plate-side refrigerant passage 50 has the shaft center cooling structure. Thus, the cooling oil can be sent radially outward by the action of the centrifugal force when the end plate 34 rotates. In addition, since the plate-side refrigerant passage 50 is formed, it is not necessary to perform groove processing on one side of the end plate 34 after punching, and further cost reduction can be achieved. As a result, in the end plate 34 and the rotating electrical machine 10, the manufacturing cost can be reduced by the configuration having the plate-side refrigerant passage 50 for realizing the shaft center cooling structure.

  In the example of FIG. 1, the coolant is caused to flow into the plate-side refrigerant passage 50 of the end plate 34 via the axial-side refrigerant passage 44 of the rotor shaft 16 and the axially inner circumferential groove 46 of the rotor core 32. Yes. However, it is also possible to cause the coolant to flow directly from the shaft-side refrigerant passage 44 of the rotor shaft 16 to the plate-side refrigerant passage 50 of each end plate 34 without going through the inner peripheral portion of the rotor core 32. For example, radial passages that communicate with the axial passage 40 can be formed at a plurality of locations that are aligned with the radial inner ends of the plate-side refrigerant passages 50 of the end plates 34 in the axial direction of the rotor shaft 16.

  Further, a cylindrical refrigerant passage can be formed over the entire circumference between the inner peripheral surface of the rotor core 32 and the outer peripheral surface of the rotor shaft 16. In this case, for example, a pair of end plates in which the inner diameter of the rotor core 32 is slightly larger than the outer diameter of the rotor shaft 16 and the rotor core 32 is fitted to the outer peripheral surface of the rotor shaft 16 with a clearance fit and fixed with an interference fit from both sides. At 34, the rotor core 32 is fixed to the rotor shaft 16.

  In the example of FIG. 1 (the same applies to another example of FIG. 5 described later), a pair of end plates 34 are disposed on both sides in the axial direction of the rotor core 32. However, the end plates are disposed only on one axial side of the rotor core 32. 34 can also be arranged. In this case, for example, the end plate 34 disposed on the left side of the rotor core 32 in FIG. 1 is omitted, and the rotor core 32 is sandwiched between the end plate 34 disposed on the right side of the rotor core 32 in FIG. To do.

  FIG. 5 is a partial cross-sectional view of a rotor and a rotor shaft in another example of the rotating electrical machine according to the embodiment of the present invention. 6 is a cross-sectional view taken along the line AA of FIG. 5 with respect to the entire circumference of the rotor. In the case of the other examples shown in FIGS. 5 to 6, instead of the end plates 34 (see FIG. 1 etc.) arranged on both sides of the rotor core 32 in the embodiment shown in FIGS. In this case, three end plates 58 are used. That is, on the outer diameter side of the rotor shaft 16, a plurality of end plates 58 are fixed to both sides of the rotor core 32 in the axial direction. Further, the configuration of each end plate 58 is the same as that in which the axial thickness of each end plate 34 constituting the embodiment shown in FIGS. That is, each end plate 58 is formed by subjecting a metal plate made of a non-magnetic material, which is a plate material, to a circular bending process, and a radial plate-side refrigerant passage 50 is formed by a gap between both circumferential edges. Has been. It should be noted that the number of end plates 58 disposed on both axial sides of the rotor core 32 may be two or more, and the number is not limited.

  Then, a plurality of end plates 58 on each side of the rotor core 32 in the axial direction are stacked so as to be shifted from each other in the circumferential direction of the plate-side refrigerant passage 50 as shown in FIG. Further, the plate-side refrigerant passages 50 are arranged at a plurality of equally spaced locations (three locations in FIG. 6) in the circumferential direction of the end plate 58. Further, the inner circumferential surface of the rotor core 32 is not formed with the axial inner circumferential groove 46 (see FIG. 1), and the inner circumferential surface of the rotor core 32 is a cylindrical surface. Instead, radial passages 60 communicating with the axial passage 40 are formed at a plurality of circumferential locations (three locations in FIG. 6) that are in phase with the plate-side refrigerant passage 50 at both axial portions of the rotor shaft 16. Has been. Each radial passage 60 allows the corresponding plate-side refrigerant passage 50 to communicate with the axial passage 40.

  In such a rotating electrical machine including a plurality of end plates 58, when cooling oil is supplied to the axial passage 40 of the rotor shaft 16 from a cooling oil supply device (not shown) during use, the cooling oil is indicated by an arrow in FIG. As indicated by γ, it is supplied to the plate-side refrigerant passages 50 of the plurality of end plates 58 via the corresponding radial passages 60. The cooling oil supplied to each plate-side refrigerant passage 50 is blown to the outer diameter side as shown by an arrow δ in FIG. 6 while cooling the rotor 18 by the action of the centrifugal force during the rotation of the rotor 18. The coil 28 (see FIG. 1) and the stator core 24 (see FIG. 1) are cooled.

  According to such another example of the rotating electric machine, the overall thickness of the plurality of end plates 58 required for strength is set to be approximately the same as the thickness of one end plate required for the conventional product. Thus, the thickness of each end plate 58 can be reduced. For this reason, it is possible to reduce the force required for processing in bending each end plate 58 into a circle. Further, since the plate-side refrigerant passages 50 are formed at a plurality of locations where the circumferential phases of the plurality of end plates 58 on the respective axial sides of the rotor 18 are shifted, the cooling performance of the rotor 18 in the circumferential direction is reduced. The uniformity can be improved and the cooling performance of the rotating electrical machine can be improved. Other configurations and operations are the same as those of the embodiment shown in FIGS.

  In each of the above-described embodiments, the rotor core 32 can be configured by a powder magnetic core formed by press-molding magnetic powder, in addition to a stacked body formed by stacking a plurality of steel plates. In addition to the oil, for example, cooling water or the like can be used as the cooling liquid.

  DESCRIPTION OF SYMBOLS 10 Rotating electrical machine, 14 Casing, 16 Rotor shaft, 18 Rotor, 19 Air gap, 20 Stator, 24 Stator core, 26 Teeth, 28 Stator coil, 30 Coil end, 32 Rotor core, 34 End plate, 36 Outward flange, 38 Caulking part, 40 axial passage, 42 radial passage, 44 axial refrigerant passage, 46 axial inner circumferential groove, 48 metal plate, 50 plate side refrigerant passage, 52 axial passage, 54 end plate, 56 metal plate, 58 end plate, 60 radial passage.

Claims (4)

An end plate for a rotating electrical machine that is fitted together with a rotor core on the outer diameter side of a rotor shaft that is rotatably provided and restricts axial displacement of the rotor core,
An end plate for a rotating electrical machine, which is formed by subjecting a plate material to circular bending, and a radial plate-side refrigerant passage is formed by a gap between circumferential edges. A rotor shaft provided rotatably,
A rotor core fixed to the outer diameter side of the rotor shaft;
One or more end plates for a rotating electrical machine fixed to at least one axial side of the rotor core on the outer diameter side of the rotor shaft and restricting axial displacement of the rotor core;
A rotating electrical machine comprising a stator disposed opposite to the outer diameter side of the rotor core,
2. The rotating electrical machine according to claim 1, wherein each of the one or more rotating electrical machine end plates is the rotating electrical machine end plate according to claim 1. The rotating electrical machine according to claim 2,
The plurality of rotating electric machine end plates are fixed to at least one axial side of the rotor core on the outer diameter side of the rotor shaft,
The rotating electrical machine end plates are laminated such that the phase of the plate-side refrigerant passage is shifted from each other. In the rotating electrical machine according to claim 2 or claim 3,
The rotor shaft includes an axial refrigerant passage that is provided inside and communicates with an outer peripheral surface;
The rotating electrical machine characterized in that the shaft-side refrigerant passage communicates with the plate-side refrigerant passage directly or through a core-side refrigerant passage provided in the rotor core.

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