JP2008086130A - Electric motor - Google Patents

Abstract

An electric motor capable of improving the upper limit of the rotational speed of a rotor is provided.
A rotor 12 includes a first member 21 and a second member having different shapes, and a cooling oil supply oil passage 41 through which cooling oil supplied from the center side flows to the first member 21. Are formed outward in the radial direction, and the permanent magnet 18 is disposed only on the second member of the first member 21 and the second member.
[Selection] Figure 2

Description

  The present invention relates to an electric motor, and more particularly to a cooling structure thereof.

The electric motor includes a so-called IPM (Interior Permanent Magnetic) motor in which a permanent magnet is embedded in the rotor. It is formed by inserting a permanent magnet. In such an electric motor, a cooling oil supply oil passage for flowing the cooling oil supplied through the central shaft of the rotor to the slot is formed in each steel plate of the same shape, and the position of each cooling oil supply oil passage There is a technique of cooling each permanent magnet with cooling oil so that the cooling oil can be supplied to each slot by laminating each steel plate while shifting in the circumferential direction (see, for example, Patent Document 1).
JP 2006-67777 A

  By the way, in the case of the above structure, since the cooling oil supply oil passage is formed in communication with all the steel plates, the strength of the peripheral portion of the slots is insufficient, and the steel plates receive a large force from the permanent magnets when the rotor rotates. In some cases, the durability may be problematic. For this reason, the upper limit of the rotational speed of the rotor must be limited to a low level.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electric motor capable of improving the upper limit of the rotational speed of the rotor.

  In order to achieve the above object, the invention according to claim 1 is characterized in that the rotor (for example, the rotor 12 in the embodiment) is different from the first member (for example, the supply oil passage forming member 21 in the embodiment) and the second in different shapes. A cooling oil supply oil passage (for example, the cooling oil supply oil passage in the embodiment) that flows the cooling oil supplied from the center side to the first member. 41) is formed radially outward, and a permanent magnet (for example, the permanent magnet 18 in the embodiment) is disposed only on the second member of the first member and the second member. It is characterized by being.

  The invention according to claim 2 is the invention according to claim 1, wherein the second member has a cooling oil passage (for example, the cooling oil passage 31 in the embodiment) through which the cooling oil flows, and the slot into which the permanent magnet is inserted. (For example, the magnet insertion slot 19 in the embodiment) is formed at a circumferential end, and the first member and the second member so that the cooling oil supply oil passage communicates with the cooling oil passage. Are laminated in the axial direction.

  The invention according to claim 3 is the invention according to claim 2, wherein the first member discharges the cooling oil supplied from the cooling oil passage of the second member toward the stator (for example, A discharge port 52) according to the embodiment is provided.

  The invention according to claim 4 is the invention according to claim 2 or 3, wherein the rotor includes end face plates (for example, end face plate 56 in the embodiment) that are disposed at both ends in the axial direction and abut against the second member. The end face plate is configured to press down the permanent magnet disposed on the second member and to discharge cooling oil from the cooling oil passage of the second member to the outside. And

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the cooling oil supply oil passage formed in the first member is radially outward in a main rotation direction of the rotor. Is formed so as to be inclined rearward of the inner side in the radial direction.

  The invention according to claim 6 is the invention according to any one of claims 1 to 4, wherein the cooling oil supply oil passage formed in the first member is formed toward a center of the permanent magnet. It is characterized by.

  The invention according to claim 7 is the invention according to any one of claims 1 to 4, wherein the permanent magnet is configured by dividing the same magnetic pole into a plurality of parts in the circumferential direction, and the same in the second member A center rib (for example, the center rib 29 in the embodiment) is formed between the permanent magnets adjacent to each other in the circumferential direction with magnetic poles, and the cooling oil supply oil passage formed in the first member is formed toward the center rib. It is characterized by.

  According to the first aspect of the present invention, the cooling oil supply oil passage for flowing the cooling oil supplied from the center side to one of the first member and the second member constituting the rotor is provided. Since the permanent magnet is disposed only on the other second member excluding the first member, the force from the permanent magnet during the rotation of the rotor is basically applied to the second member. It acts and does not act on the first member whose strength is insufficient due to the formation of the cooling oil supply oil passage. Therefore, the upper limit of the rotational speed of the rotor can be improved.

  According to the second aspect of the present invention, the cooling oil supply passage is communicated with the cooling oil passage with respect to the second member formed at the circumferential end of the slot for inserting the permanent magnet. Since the first member is laminated in the axial direction, the permanent magnet can be directly cooled by flowing the cooling oil supplied from the cooling oil supply oil passage to the cooling oil passage. In addition, since the cooling oil passage is formed at the circumferential end of the slot for inserting the permanent magnet, it can be formed at the same time as the slot, so there is no need to separately form the cooling oil passage, reducing costs and reducing the strength of the rotor. Can also be suppressed.

  According to the third aspect of the invention, the discharge port provided in the first member discharges the cooling oil supplied from the cooling oil passage of the second member toward the stator, so that the stator is cooled. Can do.

  According to the invention which concerns on Claim 4, although an end surface plate will hold | suppress the permanent magnet arrange | positioned at the 2nd member and aim at retaining, this end surface plate is from the cooling oil path of the 2nd member. Since the cooling oil is configured to be discharged to the outside, the cooling oil in the cooling oil passage can be discharged toward the stator, and the coil end of the stator can be cooled.

  According to the fifth aspect of the present invention, the cooling oil supply oil passage is formed so as to be inclined so that the radial outer side is the rear side of the radial inner side in the main rotational direction of the rotor. The cooling oil can be satisfactorily sent radially outward in the cooling oil supply oil passage by using the rotational force in the rotation direction. Therefore, a separate drive source for sending the cooling oil is not necessary, and the cost can be reduced.

  According to the sixth aspect of the present invention, since the cooling oil supply oil passage is formed toward the center of the permanent magnet in the first member, the magnetic flux generated between the permanent magnets having different magnetic poles on the inner diameter side from the permanent magnet. For this exchange, the cooling oil supply oil passage can be arranged so as not to block the magnetic flux, and the rotor can be cooled without reducing the torque.

  According to the seventh aspect of the present invention, the permanent magnet is configured by dividing the same magnetic pole into a plurality of parts in the circumferential direction, so that the centrifugal force applied when the rotor rotates at a high speed can be reduced. In addition, a magnetic flux short circuit occurs at the center rib between the divided permanent magnets. However, since the cooling oil supply oil passage is formed toward the center rib in the first member, the magnetic flux short circuit generated near the center rib is cooled. It can be suppressed by the oil supply oil passage.

An electric motor according to an embodiment of the present invention will be described below with reference to the drawings.
1 and 2 are both cross-sectional views showing an electric motor 10 according to the present embodiment. The electric motor 10 is an IPM motor, and includes a stator 11 and a rotor 12 disposed inside the stator 11. This electric motor 10 is used as one of the drive sources of a hybrid vehicle, for example.

  The stator 11 has a substantially annular shape, and a plurality of stator magnetic poles 14 are provided on the inner periphery thereof so as to project toward the center of the stator 11 at equal intervals in the circumferential direction. A coil 16 is wound around each of the stator magnetic poles 14 via an interposed member 15. The stator 11 is fixed to a housing (not shown) of the electric motor 10.

  The rotor core 17 of the rotor 12 is the same as the permanent magnet holding member (second member) 20 shown in FIG. 1 in which a magnet insertion slot 19 for inserting the permanent magnet 18 is formed. It has the supply oil path formation member (1st member) 21 shown in FIG. 2 from which thickness and shape differ by a diameter.

  A permanent magnet holding member 20 shown in FIG. 1 is formed by laminating a predetermined number of disc-shaped silicon steel plates 20A in the axial direction and joining them, and a substantially cylindrical rotor shaft 23 is formed at the center thereof. A shaft insertion hole 24 is formed for inserting the. Here, positioning grooves 25 extending along the axial direction are formed in the rotor shaft 23 at a plurality of locations (four locations) at equal intervals in the circumferential direction, and are formed in the shaft insertion holes 24 of the permanent magnet holding member 20. Is provided with a positioning projection 26 for positioning in the rotor circumferential direction with respect to the rotor shaft 23 by fitting into a predetermined positioning groove 25 of the rotor shaft 23.

  Further, in the permanent magnet holding member 20, a plurality of (eight) thinning holes 27 are formed at equal intervals in the circumferential direction around the shaft insertion hole 24, and a plurality of (eight) on the outer peripheral side. The magnet holding portions 28 are formed at equal intervals in the circumferential direction. Here, each magnet holding portion 28 has a pair of magnet insertion slots 19 formed so as to be adjacent to both sides via the rotor radius line on the same straight line orthogonal to the rotor radius line. It is configured. The pair of magnet insertion slots 19 are partitioned by a center rib 29, and an oil passage forming recess 30 that is recessed along the rotor circumferential direction on the opposite end of the rotor rib in the circumferential direction of the rotor. Is formed to be biased toward the outer periphery of the rotor.

  And the permanent magnet 18 is inserted in the magnet insertion slot 19 so that the direction of the magnetic pole is aligned in the magnet insertion slot 19 that makes a pair, and the direction of the magnetic pole is reversed between the adjacent magnet holding portions 28. That is, in one magnet holding portion 28, the permanent magnet 18 is provided in the pair of magnet insertion slots 19 so that the N pole is disposed on the inner side in the rotor radial direction and the S pole is disposed on the outer side in the rotor radial direction. In the magnet holding portion 28 adjacent to each other, the permanent magnets 18 are provided in the paired magnet insertion slots 19 so that the south pole is arranged on the inner side in the rotor radial direction and the north pole is arranged on the outer side in the rotor radial direction. In other words, the permanent magnet is configured by dividing the same magnetic pole into a plurality of pieces in the circumferential direction, and the center rib 29 is formed between the permanent magnets 18 adjacent to each other in the circumferential direction with the same magnetic pole. Here, the length of the permanent magnet 18 in the rotor axial direction is equal to the length of the permanent magnet holding member 20 in the rotor axial direction. With the permanent magnets 18 inserted into the magnet insertion slots 19 in this way, the permanent magnet holding member 20 has all the cooling oil passages 31 along the rotor axial direction between the oil passage forming recesses 30 and the permanent magnets 18. The permanent magnet 18 is formed on one side in the rotor circumferential direction.

  A supply oil passage forming member 21 shown in FIG. 2 is made of a disk-shaped silicon steel plate, and a shaft insertion hole 34 for inserting a cylindrical rotor shaft 23 is formed at the center thereof. The shaft insertion hole 34 is also provided with a positioning projection 36 for positioning in the circumferential direction of the rotor by fitting into a predetermined positioning groove 25 of the rotor shaft 23.

  Further, the supply oil passage forming member 21 is formed with a plurality of (eight) thinning holes 37 around the shaft insertion hole 34 at equal intervals in the circumferential direction. The protrusion 36 is formed so as to be aligned with the lightening hole 37 of the permanent magnet holding member 20 regardless of which positioning groove 25 is fitted.

  Furthermore, the supply oil passage forming member 21 has a plurality of window portions 38 on the outer periphery so as to overlap the magnet insertion slots 19 of the permanent magnet holding member 20 regardless of which positioning groove 36 is fitted in any positioning groove 25. Formed on the side. As in the magnet insertion slot 19, these window portions 38 are formed on the same straight line perpendicular to the rotor radius line so as to be adjacent to each other on both sides via the rotor radius line, and are paired with each other. The magnet holding member 20 has an opening with a smaller cross-sectional area than the permanent magnet 18 inserted into each magnet insertion slot 19. The pair of window portions 38 are partitioned by a center rib 39, and a predetermined portion of the window portion 38 is an end portion in the rotor circumferential direction and is recessed along the rotor circumferential direction on the side opposite to the center rib 39. An oil passage forming recess 40 is formed.

  The oil passage described above is provided between one of the windows 38 that form a predetermined pair and one of the windows 38 that forms another pair adjacent to the window 38 in the circumferential direction of the rotor. The formation recess 40 is not formed, and a cooling oil supply oil passage 41 that passes through the shaft insertion hole 34 is formed between them. That is, in a state where the supply oil passage forming member 21 is overlapped with the permanent magnet holding member 20, the cooling oil supply oil passage 41 is located at a position between the permanent magnets 16 having different magnetic pole directions in the circumferential direction of the rotor. Is formed. The cooling oil supply oil passage 41 is a communication port 43 having a substantially circular shape on the outer periphery of the rotor, and a portion other than the communication port 43 is a groove portion 44 having a substantially constant width smaller than the diameter of the communication port 43. ing. The groove portion 44 of the cooling oil supply oil passage 41 is located slightly in the middle portion on the inner side in the rotor radial direction, and the outer side in the rotor radial direction in the main rotation direction of the rotor 12 (the direction indicated by the arrow R in FIG. An inclined portion 45 that is inclined so as to be on the side is formed, and an inlet channel portion 46 that passes through the shaft insertion hole 34 along the substantially radial direction is formed on the inner side of the inclined portion 45 in the rotor radial direction. An outlet channel portion 47 connected to the communication port 43 along the substantially radial direction is formed on the outer side in the rotor radial direction.

  Here, at the position where the supply oil passage forming member 21 of the rotor shaft 23 is arranged in the rotor axial direction, the cooling of the supply oil passage forming member 21 in a state where the positioning protrusion 36 is fitted in the predetermined positioning groove 25. A flow path hole 50 is formed along the radial direction so as to open facing the end of the oil supply oil path 41 on the shaft insertion hole 34 side.

  In addition, one of the windows 38 forming a predetermined pair different from the above and one of the windows 38 of another pair of windows 38 adjacent to each other in the circumferential direction of the rotor, The oil passage forming recess 40 described above is not formed, and a discharge port 52 is formed between the oil passage forming recesses 40. That is, in the state where the supply oil passage forming member 21 is overlapped with the permanent magnet holding member 20, the discharge port 52 is formed at a position that is a gap between the permanent magnets 16 having different magnetic pole directions in the circumferential direction of the rotor. ing. The discharge port 52 has a symmetrical shape around the rotor radial line, and the rotor radial inner portion is a communication port 53 having a semicircular shape, and the rotor radial outer portion is larger than the diameter of the communication port 53. The discharge port body 54 has a small substantially integral width.

  When the rotor 12 is assembled, as shown in FIG. 3, one end face plate 56 (details will be described later) is attached to the rotor shaft 23, and then the permanent magnet 18 is inserted into each magnet insertion slot 19 in advance. The permanent magnet holding member 20 in the state of being attached is attached to the rotor shaft 23 so as to contact one end face plate 56. Next, the supply oil passage forming member 21 is attached to the rotor shaft 23 so as to be in contact with the permanent magnet holding member 20, and another permanent magnet holding member 20 in a state where the permanent magnet 18 is inserted in each magnet insertion slot 19 in advance. The operation of attaching to the rotor shaft 23 so as to be in contact with the supply oil passage forming member 21 is repeated as appropriate.

  At this time, each permanent magnet holding member 20 is attached to the rotor shaft 23 while the positioning projection 26 is fitted in the predetermined positioning groove 25. Each supply oil passage forming member 21 is also attached to the rotor shaft 23 while the positioning projection 36 is fitted in the predetermined positioning groove 25. As shown in FIG. 4, when the supply oil passage forming member 21 is attached to the rotor shaft 23, a position where a predetermined flow passage hole 50 of the rotor shaft 23 can communicate with the cooling oil supply oil passage 41 of the supply oil passage forming member 21. Will be placed. Here, one or a plurality of supply oil passage forming members 21 are attached in a stacked manner. When a plurality of supply oil passage forming members 21 are attached in a stacked manner, the respective positioning projections 36 are fitted in the same positioning groove 25 so that the cooling oil The supply oil passage 41 is overlapped and the discharge port 52 is overlapped.

  In this state, the communication port 43 on the rotor outer periphery side of the cooling oil supply oil passage 41 of the supply oil passage forming member 21 that communicates with the flow passage hole 50 of the rotor shaft 23 is, as shown in FIG. The permanent magnet holding member 20 adjacent to the 56 side communicates with two cooling oil passages 31 adjacent to each other in the rotor circumferential direction. Moreover, as shown in FIG. 6, the discharge port 52 of the supply oil path formation member 21 has two other cooling oils close to the circumferential direction of the rotor of the permanent magnet holding member 20 adjacent to the one end face plate 56 side. The supply oil passage forming member 21 and the permanent magnet holding member 20 are laminated in the axial direction so that the cooling oil supply oil passage 41 communicates with the cooling oil passage 31. ) Further, all the oil passage forming recesses 40 of the supply oil passage forming member 21 are individually communicated with the cooling oil passages 31 in which the positions of the permanent magnet holding members 20 adjacent to the one end face plate 56 are aligned in the rotor circumferential direction. Will do.

  Then, as shown in FIG. 7, the rotor shaft of another permanent magnet holding member 20 is brought into contact with the supply oil passage forming member 21 while the positioning projection 36 is fitted in the predetermined positioning groove 25. 23 is attached. Then, the communication port 43 on the rotor outer peripheral side of the cooling oil supply oil passage 41 of the supply oil passage forming member 21 is close to the rotor circumferential direction of the permanent magnet holding member 20 adjacent to the side opposite to the one end face plate 56. The two cooling oil passages 31 communicate with each other. Further, the discharge port 52 of the supply oil passage forming member 21 is also provided in the other two cooling oil passages 31 adjacent to the circumferential direction of the rotor of the permanent magnet holding member 20 adjacent to the one end face plate 56 on the opposite side. You will communicate. Further, all the oil passage forming recesses 40 of the supply oil passage forming member 21 are respectively connected to the cooling oil passages 31 in which the positions of the permanent magnet holding members 20 adjacent to the opposite side of the one end face plate 56 are aligned in the rotor circumferential direction. You will communicate individually.

  Next, as shown in FIG. 8, the phase of the circumferential direction of another supply oil passage forming member 21 is changed from that of the already attached oil passage forming member 21. The discharge port 52 is attached to the rotor shaft 23 so as to communicate with two adjacent cooling oil passages 31 communicating with the cooling oil supply oil passage 41.

  As described above, the predetermined number of permanent magnet holding members 20 and the predetermined number of supply oil passage forming members 21 are arranged between the adjacent permanent magnet holding members 20 with the permanent magnet holding members 20 on both ends in the rotor axial direction. Are superposed while sequentially changing the circumferential phase of the supply oil passage forming member 21 so that the supply oil passage forming member 21 is disposed on the surface. Then, as shown in FIG. 9, the other end face plate 56 is attached to the rotor shaft 23 so as to come into contact with the permanent magnet holding member 20 on the rotor axial direction end side.

  Here, as shown in FIG. 10, the end face plate 56 has an outer diameter that is smaller than the outer diameter of the permanent magnet holding member 20, and the outer diameter is arranged in the abutting permanent magnet holding member 20. All the permanent magnets 18 are pressed from one side in the rotor axial direction, and the cooling oil passages 31 on both ends of the pair of magnet insertion slots 19 arranged on the same straight line of the permanent magnet holding member 20 are protruded to the outside. The size is set to open. That is, the end face plate 56 is configured to be able to discharge the cooling oil from the cooling oil passage 31 of the permanent magnet holding member 20 to the outside. Further, since the window 38 of each supply oil passage forming member 21 has a smaller cross-sectional area than the permanent magnet 18, each supply oil passage forming member 21 also presses the permanent magnet 18 disposed on the permanent magnet holding member 20. As a result, the permanent magnet 18 is arranged only in the permanent magnet holding member 20 of the permanent magnet holding member 20 and the supply oil passage forming member 21. Further, a balance hole 57 for adjusting an unbalance amount when the rotor 12 rotates is formed in the end face plate 56.

  In such a rotor 12 of the electric motor 10, the cooling oil supplied from the inside of the rotor shaft 23 is rotated from the center side of the rotor shaft 23 by a centrifugal force through a predetermined flow path hole 50 during the rotation of the rotor. It is introduced into a cooling oil supply oil passage 41 formed toward the outer side in the rotor radial direction of the supply oil passage forming member 21, flows to the rotor outer diameter side in the cooling oil supply oil passage 41, and all the permanent magnet holding members 20 It is introduced into two adjacent cooling oil passages 31 that are aligned in the circumferential direction of the rotor, flows in the rotor axial direction, and from the discharge port body 54 of the discharge port 52 formed in another appropriate supply oil passage forming member 21. While a part is discharged toward the stator 11, it is further discharged toward the stator 11 from the cooling oil passage 31 of the permanent magnet holding member 20 at both ends in the rotor axial direction. The cooling oil discharged from the discharge port 52 toward the stator 11 enters between the stator magnetic poles 14 to cool the coil 16 and is discharged toward the stator 11 from the position of the end face plate 56 of the cooling oil passage 31. The cooled cooling oil cools the end of the coil 16.

  Here, it is preferable to set the number of the flow passage holes 50 and the supply oil passage forming members 21 so that the cooling oil can be supplied to all the cooling oil passages 31, but from the relationship with the rotor axial length. You may thin out suitably. However, the numbers and positions of the flow path holes 50, the cooling oil supply oil paths 41, and the discharge ports 52 are set so that the cooling oil flows as evenly as possible.

According to the electric motor 10 according to the present embodiment described above, the supply oil passage forming member 21 constituting the rotor 12 and the permanent magnet holding member 20 are supplied from the center side to the supply oil passage forming member 21. In order to arrange the permanent magnet 18 only in the permanent magnet holding member 20 which is the other side excluding the supply oil passage forming member 21, the cooling oil supply oil passage 41 through which the cooling oil to flow is formed is formed facing outward in the radial direction. The force from the permanent magnet 18 during rotation basically acts on the permanent magnet holding member 20 and does not act on the supply oil passage forming member 21 whose strength is insufficient due to the formation of the cooling oil supply oil passage 41. Therefore, the upper limit of the rotational speed of the rotor 12 can be improved.
Further, since the permanent magnet is configured by dividing the same magnetic pole into a plurality of parts in the circumferential direction, the centrifugal force applied when the rotor 12 rotates at a high speed can be reduced.

  In addition, since the cooling oil supply oil passage 41 and the discharge port 52 serving as slits are formed at the interpolar portions between the permanent magnets 16 having different magnetic pole directions in the rotor circumferential direction, the magnetic flux passes through the interpolar portions. Thus, the magnetic flux that passes through the stator 11 from the surface of the permanent magnet 16 and returns to the adjacent permanent magnet 16 can be increased. Therefore, the torque and output of the electric motor 10 can be increased.

  Further, the supply oil passage forming member is arranged such that the cooling oil supply oil passage 41 communicates with the cooling oil passage 31 with respect to the permanent magnet holding member 20 in which the cooling oil passage 31 is formed at the circumferential end of the magnet insertion slot 19. Since 21 is laminated in the axial direction, the cooling oil supplied from the cooling oil supply oil passage 41 can be passed through the cooling oil passage 31 to directly cool the permanent magnet 18. Further, since the cooling oil passage 31 is formed at the circumferential end of the magnet insertion slot 19, it can be formed at the same time as the magnet insertion slot 19, and it is not necessary to separately form the cooling oil passage 31, reducing the cost and the rotor. 12 strength reduction can also be suppressed.

  Furthermore, since the discharge port 52 provided in the supply oil passage forming member 21 discharges the cooling oil supplied from the cooling oil passage 31 of the permanent magnet holding member 20 toward the stator 11, the stator 11 can be cooled. it can. Further, the discharge port 52 serves as a pressure adjusting air hole, and the cooling oil easily enters the cooling oil supply oil passage 41 and the cooling oil passage 31 from the rotor shaft 23.

  In addition, the end face plates 56 at both ends press the permanent magnet 18 disposed on the permanent magnet holding member 20 to prevent the end plate 56 from coming off, but these end face plates 56 are used as cooling oil passages for the permanent magnet holding member 20. By leaving the opening so that the cooling oil can be discharged to the outside from 31, the cooling oil in the cooling oil passage 31 can be discharged toward the stator 11 from both outer sides in the rotor axial direction of the permanent magnet holding members 20 at both ends in the rotor axial direction. The ends of the eleven coils 16 can be cooled. Further, this opening serves as a pressure adjusting air hole, and the cooling oil easily enters the cooling oil supply oil passage 41 and the cooling oil passage 31 from the rotor shaft 23.

  Further, since the cooling oil supply oil passage 41 is formed so as to be inclined so that the radially outer side is the rear side of the radially inner side in the main rotational direction of the rotor 12, the rotational force in the main rotational direction of the rotor 12. The cooling oil can be satisfactorily sent radially outward in the cooling oil supply oil passage 41 using Therefore, a separate drive source for sending the cooling oil is not necessary, and the cost can be reduced.

  In addition, as shown in FIG. 11, the window part 38 which makes the pair of supply oil path formation member 21 is connected, and the cooling oil supply oil path 41 is formed along a rotor radial direction so that it may open to the center part. May be. In such a supply oil passage forming member 21, the cooling oil supply oil passage 41 is formed toward the center rib 29 at the center of the permanent magnets 18 forming a pair of the permanent magnet holding members 20.

  With this configuration, in order to reduce the centrifugal force applied when the rotor 12 rotates at a high speed, as described above, when the permanent magnet is configured by dividing the same magnetic pole into a plurality of parts in the circumferential direction, the supply oil Even in the path forming member 21, a magnetic flux short circuit occurs at the position of the center rib 29 between the divided permanent magnets 18. However, since the cooling oil supply oil path 41 serving as a slit is formed toward the center rib 29, The magnetic flux short-circuit generated near 29 can be suppressed by the cooling oil supply oil passage 41.

  Furthermore, as shown in FIG. 12, a cutout portion 60 that extends from the end portion of the window portion 38 in the circumferential direction of the rotor to the outer peripheral side of the supply oil passage formation member 21 may be formed in the supply oil passage formation member 21. If comprised in this way, discharge of the cooling oil from the notch part 60 to the stator 11 will be attained, and the further cooling efficiency improvement can be aimed at. The notch 60 also serves as a pressure adjusting air hole, and the cooling oil easily enters the cooling oil supply oil passage 41 and the cooling oil passage 31 from the rotor shaft 23.

  In addition, as shown in FIG. 13, a magnet insertion slot 19 is formed in each of the magnet holding portions 28 for the supply oil passage forming member 21 shown in FIG. 11 or FIG. 12, and the permanent magnet 18 has the same magnetic pole. You may combine the permanent magnet holding member 20 of the type which is not divided | segmented into plurality in the rotor circumferential direction (that is, the type in which the adjacent permanent magnets 18 are all arranged with different magnetic poles).

  With this configuration, the cooling oil supply oil passage 41 is formed toward the center of the permanent magnet 18 in the supply oil passage forming member 21. The cooling oil supply oil passage 41 can be arranged so as not to block the magnetic flux against the exchange of magnetic flux performed on the inner diameter side, and the rotor can be cooled without reducing the torque.

It is a front sectional view of the electric motor concerning one embodiment of the present invention. It is a front sectional view of the electric motor concerning one embodiment of the present invention. It is a perspective view which shows the state in the middle of the assembly of the rotor of the electric motor which concerns on one Embodiment of this invention. It is a perspective view which shows the state in the middle of the assembly of the rotor of the electric motor which concerns on one Embodiment of this invention. It is an expanded perspective view of the principal part which shows the state in the middle of the assembly of the rotor of the electric motor which concerns on one Embodiment of this invention. It is an expanded perspective view of the principal part which shows the state in the middle of the assembly of the rotor of the electric motor which concerns on one Embodiment of this invention. It is a perspective view which shows the state in the middle of the assembly of the rotor of the electric motor which concerns on one Embodiment of this invention. It is a perspective view which shows the state in the middle of the assembly of the rotor of the electric motor which concerns on one Embodiment of this invention. It is a perspective view which shows the state after the assembly of the rotor of the electric motor which concerns on one Embodiment of this invention. It is a front view of the rotor of the electric motor which concerns on one Embodiment of this invention. It is a front sectional view of another example of the supply oil passage formation member of the electric motor concerning one embodiment of the present invention. It is a front sectional view of another example of the supply oil passage formation member of the electric motor concerning one embodiment of the present invention. It is a front sectional view of another example of the electric motor according to one embodiment of the present invention.

Explanation of symbols

12 Rotor 18 Permanent magnet 19 Magnet insertion slot (slot)
20 Permanent magnet holding member (second member)
21 Supply oil passage forming member (first member)
29 Center rib 31 Cooling oil passage 41 Cooling oil supply oil passage 52 Discharge port 56 End face plate

Claims (7)

The rotor has a first member and a second member having different shapes,
In the first member, a cooling oil supply oil passage for flowing cooling oil supplied from the center side is formed facing radially outward,
A permanent magnet is disposed only on the second member of the first member and the second member. In the second member, a cooling oil passage for flowing cooling oil is formed at an end in a circumferential direction of a slot into which the permanent magnet is inserted,
2. The electric motor according to claim 1, wherein the first member and the second member are stacked in an axial direction so that the cooling oil supply oil passage communicates with the cooling oil passage.   The electric motor according to claim 2, wherein the first member includes a discharge port that discharges the cooling oil supplied from the cooling oil passage of the second member toward the stator. The rotor includes end plates arranged at both ends in the axial direction and in contact with the second member;
The end face plate is configured to press down the permanent magnet disposed on the second member and to discharge cooling oil from the cooling oil passage of the second member to the outside. Item 4. The electric motor according to Item 2 or 3.   The cooling oil supply oil passage formed in the first member is formed so as to be inclined so that a radially outer side is a rear side of a radially inner side in a main rotation direction of the rotor. The electric motor according to any one of claims 1 to 4.   5. The electric motor according to claim 1, wherein the cooling oil supply oil passage formed in the first member is formed toward a center of the permanent magnet. 6. The permanent magnet is configured by dividing the same magnetic pole into a plurality in the circumferential direction,
A center rib is formed between the permanent magnets adjacent in the circumferential direction with the same magnetic pole in the second member,
5. The electric motor according to claim 1, wherein the cooling oil supply oil passage formed in the first member is formed toward the center rib. 6.

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