JP2014117080A - Cooling structure for rotary electric machine - Google Patents

Abstract

To provide a cooling structure for a rotating electrical machine capable of preventing a coolant from entering between a rotor and a stator and causing a power loss due to drag resistance.
A stator 50 includes an overlap portion 52 that overlaps the rotor 18 in the axial direction, and the overlap portion 52 has a different shape on the inner peripheral surface and does not overlap the rotor 18 in the axial direction. And an opposing wall surface 51c facing the outside in the axial direction and having an angle of 90 degrees or less with the inner peripheral surface of the non-overlap portion 51. It is composed of things.
[Selection] Figure 3

Description

  The present invention relates to a cooling structure for a rotating electrical machine that cools a stator with a coolant supplied from above the stator.

  Conventionally, as a cooling structure of this type of rotating electrical machine, the inner peripheral surface of the axial end portion of the stator is configured to be inclined so that the inner diameter increases toward the outer side in the axial direction. The coolant discharged from above and flowing down along the inner peripheral surface of the stator is prevented from staying in the lower part of the stator and entering between the stator and the rotor, and dragging of the rotor by the coolant is generated. A technique for preventing this is known. The device described in Patent Document 1 is configured such that the inner peripheral surface of the coil end at the axial end portion of the stator is inclined.

JP 2011-166951 A

  However, in the technique described in Patent Document 1, the coolant is allowed to enter between the stator and the rotor by discharging the coolant to the outside in the axial direction of the stator along the inclined surface at the lower portion of the stator. Although it is possible to prevent the coolant from flowing inwardly in the axial direction of the stator along the inclined surface in the upper part of the stator, the coolant may intrude between the stator and the rotor.

  And there existed a problem that the power loss by the drag resistance of a cooling fluid will generate | occur | produce with the rotation of a rotor with the cooling fluid which penetrate | invaded between the rotor and the stator.

  The present invention has been made in order to solve the above-described conventional problems, and is capable of preventing a coolant from entering between the rotor and the stator and generating a power loss due to drag resistance. An object of the present invention is to provide a cooling structure.

  In order to achieve the above object, the cooling structure for a rotating electrical machine according to the present invention includes (1) a rotatable rotor, a stator provided on the outer peripheral side of the rotor so as to surround the rotor, and cooling the stator from above. A cooling structure for a rotating electric machine including a coolant supply pipe for supplying a liquid, wherein the stator overlaps the rotor in the axial direction, and the overlap portion A non-overlap portion that is different in shape of the peripheral surface and does not overlap with the rotor in the axial direction, and an angle formed between an inner peripheral surface of the non-overlap portion and an inner peripheral surface of the non-overlap portion is It is composed of one having an opposing wall surface that is 90 degrees or less and that faces the outside in the axial direction.

  With this configuration, the coolant supplied to the stator from the coolant supply pipe is blocked from moving inward in the axial direction by the opposing wall surface at the upper portion of the non-overlap portion of the stator, and flows downward, so that the non-overlap portion of the stator In the lower part of the casing, the movement toward the inner side in the axial direction is blocked by the opposing wall surface and is discharged from the stator. For this reason, in any part including the upper part and the lower part of the stator, the coolant does not enter between the stator and the rotor.

  Therefore, it is possible to prevent the coolant from entering between the rotor and the stator and causing power loss due to drag resistance.

  In the rotating electrical machine cooling structure described in (1) above, (2) the opposing wall surface is provided on the upper half circumference on the inner circumference side of the non-overlap portion, and the lower side on the inner circumference side of the non-overlap portion. It is preferable to provide an inclined wall surface whose inner diameter increases toward the outer side in the axial direction on the side half circumference.

  With this configuration, it is possible to further prevent power loss due to drag resistance caused by the coolant entering between the rotor and the stator.

  In the rotating electrical machine cooling structure according to the above (1) or (2), (3) the non-overlap portion is preferably covered with a resin mold made of resin.

  With this configuration, since the opposing wall surface and the inclined wall surface are formed in the resin mold made of resin, the degree of freedom of the shape of the opposing wall surface and the inclined wall surface can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the cooling structure of the rotary electric machine which can prevent that a cooling fluid penetrate | invades between a rotor and a stator and a power loss by drag resistance generate | occur | produces can be provided.

1 is a diagram showing a first embodiment of a cooling structure for a rotating electric machine according to the present invention, and is a schematic configuration diagram of a transaxle of a hybrid vehicle. FIG. It is a figure which shows 1st Embodiment of the cooling structure of the rotary electric machine which concerns on this invention, and is a principal part schematic sectional drawing of the transaxle provided with the rotary electric machine. It is a figure which shows 1st Embodiment of the cooling structure of the rotary electric machine which concerns on this invention, and is AA direction arrow sectional drawing of FIG. It is a figure which shows 1st Embodiment of the cooling structure of the rotary electric machine which concerns on this invention, and is the side view which looked at the rotary electric machine from the axial direction. (A)-(c) is a figure which shows 1st Embodiment of the cooling structure of the rotary electric machine which concerns on this invention, and is an enlarged view of the non-overlap part of a stator. It is a figure which shows 2nd Embodiment of the cooling structure of the rotary electric machine which concerns on this invention, and is AA direction arrow sectional drawing of FIG. It is a figure which shows 2nd Embodiment of the cooling structure of the rotary electric machine which concerns on this invention, and is the side view which looked at the rotary electric machine from the axial direction. (A)-(c) is a figure which shows 2nd Embodiment of the cooling structure of the rotary electric machine which concerns on this invention, and is an enlarged view of the non-overlap part of a stator.

  Embodiments of a cooling structure for a rotating electrical machine according to the present invention will be described below with reference to the drawings.

  FIGS. 1-5 is a figure which shows 1st Embodiment of the cooling structure of the rotary electric machine which concerns on this invention.

  First, the configuration will be described.

  In FIG. 1, a transaxle 11 constituting a driving device for a vehicle such as an automobile includes a motor generator MG2 as a rotating electric machine and a speed reducer 13 connected to a rotating shaft 12 of the motor generator MG2.

  The transaxle 11 rotates in accordance with the rotation of the rotating shaft 12 decelerated by the speed reducer 13, and the axle 14 connected to the wheels, the internal combustion engine 15, the motor generator MG1 as a rotating electrical machine, and the speed reducer. 13, a power distribution mechanism 16 that distributes power among the internal combustion engine 15 and the motor generator MG <b> 1.

  In the reduction gear 13, the reduction ratio from the motor generator MG2 to the power distribution mechanism 16 is, for example, twice or more. In addition, the crankshaft 17 of the internal combustion engine 15, the rotor 18 of the motor generator MG1, and the rotor 19 of the motor generator MG2 rotate about the same axis.

  The power distribution mechanism 16 is constituted by a planetary gear, and is supported so as to be rotatable coaxially with the sun gear 21 coupled to a hollow sun gear shaft 20 penetrating the crankshaft 17 through the shaft center. The ring gear 22 is included.

  The power distribution mechanism 16 is disposed between the sun gear 21 and the ring gear 22, and is coupled to a pinion gear 23 that revolves while rotating on the outer periphery of the sun gear 21, and an end portion of the crankshaft 17, and a rotation shaft of each pinion gear 23. And the planetary carrier 24 that supports the structure.

  In the power distribution mechanism 16, the sun gear shaft 20 coupled to the sun gear 21, the ring gear case 16 a coupled to the ring gear 22, and the crankshaft 17 coupled to the planetary carrier 24 serve as power input / output shafts.

  When the power input / output to / from any two of these three axes is determined, the power input / output to the remaining one axis is determined based on the power input / output to the other two axes. .

  A counter drive gear 25 for taking out power is attached to the ring gear case 16 a, and the counter drive gear 25 rotates integrally with the ring gear 22.

  The counter drive gear 25 is connected to a power transmission reduction gear 26, and power is transmitted between the counter drive gear 25 and the power transmission reduction gear 26.

  That is, the power transmission reduction gear 26 includes a counter driven gear 39 connected to the counter drive gear 25 and a final drive gear 40 connected to the counter driven gear 39.

  The final drive gear 40 of the power transmission reduction gear 26 is connected to a differential gear 27, and the power transmission reduction gear 26 transmits power to the differential gear 27.

  On the downhill or the like, wheel rotation is transmitted to the differential gear 27, and the power transmission reduction gear 26 is driven by the differential gear 27.

  On the other hand, motor generator MG1 includes rotor 18 in which a plurality of permanent magnets are embedded, and stator 50 that is provided on the outer periphery of rotor 18 so as to surround rotor 18 and forms a rotating magnetic field. Yes.

  The stator 50 includes a stator core 29 and a three-phase coil 30 as a stator coil wound around the stator core 29.

  The rotor 18 is coupled to a sun gear shaft 20 that rotates integrally with the sun gear 21 of the power distribution mechanism 16, and the stator core 29 is formed by laminating thin sheets of electromagnetic steel plates, and the case is fixed by a fixing means such as a bolt (not shown). 31 (see FIG. 2).

  The crankshaft 17 and the sun gear shaft 20 are rotatably supported by a case 31 (see FIG. 2) via a bearing (not shown).

  Motor generator MG1 operates as an electric motor that rotationally drives rotor 18 by the interaction between the magnetic field generated by the permanent magnet embedded in rotor 18 and the magnetic field formed by three-phase coil 30.

  Motor generator MG1 also operates as a generator that generates electromotive force at both ends of three-phase coil 30 due to the interaction between the magnetic field generated by the permanent magnet and the rotation of rotor 18.

  Motor generator MG2 includes a rotor 19 in which a plurality of permanent magnets are embedded, and a stator 32 that is provided on the outer periphery of rotor 19 so as to surround rotor 19 and forms a rotating magnetic field.

  The stator 32 includes a stator core 33 and a three-phase coil 34 as a stator coil wound around the stator core 33.

  The rotor 19 is coupled to the ring gear case 16 a that rotates integrally with the ring gear 22 of the power distribution mechanism 16 by the speed reducer 13. Further, the stator core 33 is formed by laminating thin electromagnetic steel plates, for example, and is fixed to the case 31 (see FIG. 2) by fixing means such as bolts (not shown).

  Motor generator MG2 also operates as a generator that generates an electromotive force at both ends of three-phase coil 34 due to the interaction between the magnetic field of the permanent magnet and the rotation of rotor 19.

  Motor generator MG2 operates as an electric motor that rotates rotor 19 by the interaction between the magnetic field generated by the permanent magnet and the magnetic field formed by three-phase coil 34. In the present embodiment, motor generator MG1 mainly functions as a generator, and motor generator MG2 mainly functions as an electric motor.

  The speed reducer 13 performs speed reduction by a structure in which a planetary carrier 35 that is one of the rotating elements of the planetary gear is fixed to the case 31 of the transaxle 11.

  That is, the speed reducer 13 includes a sun gear 36 coupled to the shaft of the rotor 19, a ring gear 37 that rotates integrally with the ring gear 22, and a pinion gear 38 that meshes with the ring gear 37 and the sun gear 36 and transmits the rotation of the sun gear 36 to the ring gear 37. It is comprised including.

  For example, the speed reducer 13 can double the speed reduction ratio by doubling the number of teeth of the ring gear 37 with respect to the number of teeth of the sun gear 36.

  FIG. 2 is a diagram showing a cooling structure of motor generator MG1. The motor generator MG1 is housed in a case 31, and a metal or resin oil pipe 41 through which oil as a coolant flows is provided between the upper side of the motor generator MG1 and the upper surface 31A of the case 31. Yes.

  Since the cooling structure of motor generator MG2 is the same as that of motor generator MG1, in the present embodiment, only the cooling structure of motor generator MG1 will be described with reference to the drawings.

  In FIG. 2, an oil pipe 41 as a coolant supply pipe has an upstream end connected to an oil passage 43 formed in the case 31, and a downstream end of the oil pipe 41 is closed by a closing member 42.

  For this reason, the oil pipe 41 extends along the axial direction of the sun gear shaft 20, that is, along the axial direction of the rotor 18.

  Oil is supplied to the oil passage 43 from an oil pump (not shown) through an oil passage 31 b formed in the case 31. The oil pump is driven by the internal combustion engine 15 and increases the amount of oil supplied as the rotational speed of the internal combustion engine 15 increases.

  For this reason, when the oil pump is driven, oil is supplied to the oil pipe 41 through the oil passages 31b and 31a.

  Although not shown, oil passage 31b extends to an oil pipe provided above motor generator MG2, and supplies oil to an oil pipe provided above motor generator MG2. ing.

  Therefore, the oil pump can supply oil to an oil pipe 41 provided above motor generator MG1 and an oil pump provided above motor generator MG2.

  In addition, an oil passage 43 serving as a passage through which oil flows is defined inside the oil pipe 41, and discharge holes 44 and 45 for discharging oil flowing through the oil passage 43 are formed below the oil pipe 41. Is formed.

  Further, in the three-phase coil 30, an end portion protruding from the stator core 29 in the axial direction of the sun gear shaft 20 forms a coil end 30a. The coil end 30 a is covered with a resin mold 48. A gap (air gap) having a predetermined size is formed between the stator 50 and the rotor 18.

  The discharge holes 44 are provided so as to face the coil ends 30a located at both axial ends of the three-phase coil 30, and oil is discharged to the resin mold 48 that covers the coil ends 30a. Further, the discharge hole 45 is provided to face the central portion in the axial direction of the three-phase coil 30, and discharges oil to the central portion in the axial direction of the three-phase coil 30.

  In motor generator MG1, stator 50 and rotor 18 overlap (overlap) in the axial direction and stator 50 and rotor 18 do not overlap (do not overlap) in the axial direction. It is divided.

  In other words, the overlap region is a region where the stator 50 and the rotor 18 face each other in the radial direction, and the non-overlap region is a region where the stator 50 and the rotor 18 do not face each other in the radial direction. This is an area where the coil end 30a at the end of the coil exists.

  In the following description, a portion of the stator 50 that overlaps the rotor 18 in the axial direction is referred to as an overlap portion 52 (see FIGS. 3 and 4), and a portion that does not overlap the rotor 18 in the axial direction is non-overlapping. This is referred to as a section 51 (see FIGS. 3 and 4).

  That is, the stator 50 includes an overlap portion 52 that overlaps the rotor 18 in the axial direction and a non-overlap portion 51 that does not overlap the rotor 18 in the axial direction.

  Next, the stator 50 of the motor generator MG1 will be described in detail with reference to FIGS.

  As shown in FIGS. 3 and 4, the stator 50 includes an overlap portion 52 and a non-overlap portion 51, and the non-overlap portion 51 is intermediate between the end surface 51 a and the inner peripheral surface 51 d. It has a wall surface 51b and an opposing wall surface 51c.

  Here, the end surface 51a is an annular surface that constitutes the outermost end portion in the axial direction of the non-overlap portion 51 and extends in the substantially vertical direction at the end portion in the axial direction. The end surface 51a is connected to the intermediate wall surface 51b at the connection portion 51ab. The inner peripheral surface 51 d is a cylindrical surface that forms the inner peripheral portion of the non-overlap portion 51.

  The intermediate wall surface 51b is an annular surface provided between the end surface 51a and the opposing wall surface 51c, and is inclined at an angle α with respect to the inner peripheral surface 51d so that the oil supplied from the oil pipe 41 is transmitted through the surface. ing.

  The intermediate wall surface 51b is connected to the opposing wall surface 51c at the connection portion 51bc. 3 and 4, the intermediate wall surface 51b is inclined so that the inner diameter increases as it goes outward in the axial direction.

  The angle α formed by the intermediate wall surface 51b with respect to the inner peripheral surface 51d is set to be larger than the angle β formed by the opposing wall surface 51c with respect to the inner peripheral surface 51d at the connection portion 51cd.

  The opposing wall surface 51c is an annular surface provided so that an angle β formed with the inner peripheral surface 51d at the connecting portion 51cd with the inner peripheral surface 51d is 90 degrees or less, and is outside in the axial direction (on the end surface 51a side). Opposite to.

  Specifically, as shown in FIG. 5A, the opposing wall surface 51c is provided such that an angle β formed with the inner peripheral surface 51d is 90 degrees (right angle), or FIG. As shown, the angle β formed with the inner peripheral surface 51d is set to be less than 90 degrees (acute angle).

  The intermediate wall surface 51 b and the opposing wall surface 51 c are formed over the entire circumference on the inner circumference side of the non-overlap portion 51.

  In addition, the angle β formed between the opposing wall surface 51c and the inner peripheral surface 51d in the connecting portion 51cd with the inner peripheral surface 51d may be 90 degrees or less, and the opposing wall surface 51c is as shown in FIG. Further, it may be a curved surface that gently leads from the intermediate wall surface 51b.

  Thus, the non-overlap portion 51 has the intermediate wall surface 51b and the opposing wall surface 51c, and the inner diameter shape is different from the overlap portion 52. In addition, an angle β formed by the opposing wall surface 51c with respect to the inner peripheral surface 51d in the connection portion 51cd is an obtuse angle or an acute angle.

  Next, the operation will be described.

  When the stator 50 is cooled, oil is supplied from the oil pump to the oil pipe 41 through the oil passages 31 b and 31 a of the case 31.

  The oil pumped by the oil pump is discharged from discharge holes 44 and 45 formed in the lower part of the oil pipe 41, supplied to the stator 50, and flows downward while taking heat of the stator 50, and the three-phase coil 30 and The coil end 30a is efficiently cooled.

  Specifically, the oil discharged from the discharge holes 45 flows down along the outer peripheral surface of the stator 50 in the region including the central portion in the axial direction where the three-phase coil 30 of the stator 50 is disposed, and the three-phase The coil 30 is cooled.

  On the other hand, the oil discharged from the discharge holes 44 flows down along the outer peripheral surface of the stator 50 and the end surface 51a in the axial end region where the coil end 30a of the stator 50 is disposed, and flows through the coil end 30a. Cooling.

  At this time, as shown in FIGS. 3 and 4, the oil discharged from the discharge hole 44 flows down to the intermediate wall surface 51 b along the end surface 51 a in the upper part of the non-overlap portion 51 of the stator 50, and then to the opposing wall surface. The movement toward the inner side in the axial direction (overlap portion 52 side) is blocked by 51c, and flows downward through the intermediate wall surface 51b and the opposing wall surface 51c.

  Then, the oil that has flowed downward along the intermediate wall surface 51 b and the opposing wall surface 51 c moves from the intermediate wall surface 51 b to the end surface 51 a side and is discharged from the stator 50 at the lower part of the non-overlap portion 51 of the stator 50.

  For this reason, oil does not enter between the stator 50 and the rotor 18 in any part including the upper part and the lower part of the stator 50. Further, the oil discharged from the discharge holes 44 contacts the end surface 51a, the intermediate wall surface 51b, and the opposing wall surface 51c of the non-overlap portion 51 provided with the coil end 30a and takes heat from these surfaces, so that the stator 50 Can be cooled satisfactorily.

  That is, in order to prevent oil from entering between the stator 50 and the rotor 18, if the oil flow path is separated from the non-overlap portion 51 of the stator 50, the cooling of the stator 50 is performed. In this embodiment, since the oil contacts not only the end surface 51a of the non-overlap portion 51 but also the intermediate wall surface 51b and the opposing wall surface 51c, the cooling performance of the stator 50 is not impaired.

  In this embodiment, the example in which the cooling structure of the rotating electrical machine is applied to the stator 50 of the motor generator MG1 has been described. However, the same cooling structure of the rotating electrical machine may be applied to the stator 32 of the motor generator MG2. .

  In the present embodiment, the rotating electrical machine cooling structure is applied to a hybrid vehicle. However, the rotating electrical machine cooling structure may be applied to a vehicle using only a motor as a drive source. In addition, the cooling structure of the rotating electric machine may be applied to other apparatuses as long as the apparatus includes the rotating electric machine, not limited to the vehicle.

  Thus, in the cooling structure of the rotating electrical machine of the present embodiment, the stator 50 has an overlap portion 52 that overlaps the rotor 18 in the axial direction, and the overlap portion 52 has a different inner peripheral surface shape and a rotor. 18 and a non-overlap portion 51 that does not overlap in the axial direction, and an angle formed between the inner peripheral surface of the non-overlap portion 51 and the inner peripheral surface of the non-overlap portion 51 is 90 degrees or less. It is comprised from what provided the opposing wall surface 51c which opposes an axial direction outer side.

  With this configuration, the oil supplied to the stator 50 from the oil pipe 41 is blocked from moving inward in the axial direction (on the overlap portion 52 side) by the opposing wall surface 51c in the upper portion of the non-overlap portion 51 of the stator 50. Even in the lower part of the non-overlap portion 51 of the stator 50, the movement toward the inner side in the axial direction is blocked by the opposing wall surface 51c and the stator 50 is discharged.

  For this reason, oil does not enter between the stator 50 and the rotor 18 in any part including the upper part and the lower part of the stator 50. Therefore, it is possible to prevent oil from entering between the rotor 18 and the stator 50 and causing power loss due to drag resistance.

  In the cooling structure of the rotating electrical machine of the present embodiment, the non-overlap portion 51 is covered with a resin mold 48 made of resin.

  With this configuration, since the opposing wall surface 51c is formed in the resin mold 48, the degree of freedom of the shape of the opposing wall surface 51c can be improved.

  6-8 is a figure which shows 2nd Embodiment of the cooling structure of the rotary electric machine which concerns on this invention. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment, and description is abbreviate | omitted.

  Here, in the present embodiment, the shape of the upper half circumference and the lower half circumference on the inner circumference side of the non-overlap portion 51 of the stator 50 is different, and the inclined wall surface that discharges oil to the outside in the axial direction on the lower half circumference. Is provided.

  As shown in FIGS. 6 and 7, the stator 50 has an inclined wall surface 51 e whose inner diameter increases toward the outer side in the axial direction on the lower half circumference on the inner circumference side of the non-overlap portion 51. That is, an inclined wall surface 51e that is inclined downward toward the outer side in the axial direction is provided on the lower half of the inner periphery of the non-overlap portion 51.

  The inclined wall surface 51e is provided between the end surface 51a and the inner peripheral surface 51d, and is connected to the end surface 51a at the connection portion 51ae and to the inner peripheral surface 51d at the connection portion 51de.

  Thus, by providing the inclined wall surface 51e whose inner diameter increases toward the outer side in the axial direction on the lower half circumference of the inner peripheral side of the non-overlap portion 51, the lower portion of the non-overlap portion 51 is viewed from above. The oil that has flowed down is moved outward in the axial direction by the inclination of the inclined wall surface 51e and discharged from the stator 50.

  Further, as shown in FIGS. 8B and 8C, the upper half circumference on the inner peripheral side of the non-overlap portion 51 has an intermediate wall surface 51b and an opposing wall surface 51c between the end surface 51a and the inner peripheral surface 51d. However, as shown in FIGS. 6, 7, and 8 (a), the intermediate wall surface 51 b and the opposing wall surface 51 c are not provided, but the end surface 51 a and the inner peripheral surface are provided. A configuration having only 51d may also be used.

  Specifically, as shown in FIG. 8B, an intermediate wall surface 51b and an opposing wall surface 51c are provided on the upper half circumference on the inner circumference side of the non-overlap portion 51, as in the first embodiment. The angle α formed by the intermediate wall surface 51b with respect to the inner peripheral surface 51d is preferably set to 180 degrees, and the angle β formed by the opposing wall surface 51c with respect to the inner peripheral surface 51d at the connection portion 51cd is preferably set to 90 degrees.

  In this case, in the upper part on the inner peripheral side of the non-overlap portion 51, when the oil reaches the opposing wall surface 51c through the end surface 51a and the intermediate wall surface 51b, the movement toward the inner side in the axial direction is blocked by the opposing wall surface 51c. To flow down. For this reason, oil does not enter between the stator 50 and the rotor 18 above the stator 50.

  Further, as shown in FIG. 8C, an intermediate wall surface 51b and an opposing wall surface 51c are provided on the upper half circumference on the inner peripheral side of the non-overlap portion 51, as in the first embodiment, and the intermediate wall surface 51b is provided. Is set to 180 ° or more, and the angle β formed by the opposing wall surface 51c to the inner peripheral surface 51d at the connecting portion 51cd is preferably set to 90 °.

  In this case, in the upper part on the inner peripheral side of the non-overlap portion 51, most of the oil flows down along the connection portion 51ab between the end surface 51a and the intermediate wall surface 51b, or is dropped downward from the connection portion 51ab. Part of the oil that has traveled along the wall surface 51b also flows downward when it reaches the opposing wall surface 51c. For this reason, oil does not enter between the stator 50 and the rotor 18 above the stator 50.

  Moreover, as shown to Fig.8 (a), the structure which the upper half circumference of the inner peripheral side of the non-overlap part 51 has only the end surface 51a and the inner peripheral surface 51d may be sufficient.

  In this case, since the inner peripheral surface 51 d is horizontal, the oil transmitted from the end surface 51 a to the inner peripheral surface 51 d in the upper portion on the inner peripheral side of the non-overlap portion 51 does not reach the overlap portion 52. It flows down along the surface 51d. For this reason, oil does not enter between the stator 50 and the rotor 18 above the stator 50.

  That is, as shown in FIG. 8A, by providing an inclined wall surface 51e whose inner diameter increases toward the outer side in the axial direction on the lower half circumference of the inner peripheral side of the non-overlap portion 51, the non-overlap Even if the shape of the upper half circumference on the inner circumference side of the portion 51 is any of FIGS. 8A to 8C, the stator 50 and the lower portion of both the upper and lower sides on the inner circumference side of the non-overlap portion 51 Oil can be prevented from entering between the rotor 18 and the rotor 18.

  As described above, in the rotating electrical machine cooling structure of the present embodiment, as shown in FIGS. 8B and 8C, the opposing wall surface 51 c is provided on the upper half circumference on the inner circumference side of the non-overlap portion 51. At the same time, the lower half of the inner periphery of the non-overlap portion 51 is provided with an inclined wall surface 51e whose inner diameter increases toward the outside in the axial direction.

  With this configuration, it is possible to further prevent the oil from entering between the rotor 18 and the stator 50 and causing power loss due to drag resistance.

  In the cooling structure of the rotating electrical machine of the present embodiment, the non-overlap portion 51 is covered with a resin mold 48 made of resin.

  With this configuration, since the inclined wall surface 51e is formed in the resin mold 48, the degree of freedom of the shape of the inclined wall surface 51e can be improved.

  As described above, the cooling structure for a rotating electrical machine according to the present invention has an effect that it is possible to prevent a coolant from entering between the rotor and the stator and generating a power loss due to drag resistance. It is useful as a cooling structure for a rotating electrical machine that cools the stator with coolant supplied from above the stator.

  DESCRIPTION OF SYMBOLS 18 ... Rotor, 30a ... Coil end, 41 ... Oil pipe (coolant supply pipe), 48 ... Resin mold, 50 ... Stator, 51 ... Non-overlap part, 51a ... End surface, 51b ... Intermediate wall surface, 51c ... Opposite wall surface, 51d ... Inner peripheral surface, 51e ... Inclined wall surface, 52 ... Overlap part, MG1 ... Motor generator (rotary electric machine)

Claims (3)

Cooling of a rotating electrical machine configured to include a rotatable rotor, a stator provided on the outer peripheral side of the rotor so as to surround the rotor, and a coolant supply pipe for supplying coolant to the stator from above. Structure,
The stator includes an overlap portion that overlaps the rotor in the axial direction, and a non-overlap portion that has an inner peripheral surface shape different from the overlap portion and does not overlap the rotor in the axial direction. ,
2. The opposed wall surface facing the outside in the axial direction and having an angle of 90 degrees or less with the inner circumferential surface of the non-overlapping portion is provided on the inner circumferential side of the non-overlapping portion. Cooling structure for rotating electrical machines. The opposing wall surface is provided on the upper half circumference on the inner circumference side of the non-overlap portion,
A cooling structure for a rotating electrical machine, wherein an inclined wall surface whose inner diameter increases toward the outer side in the axial direction is provided on the lower half circumference on the inner peripheral side of the non-overlap portion.   The cooling structure for a rotating electrical machine according to claim 1, wherein the non-overlap portion is covered with a resin mold made of resin.

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