JP2010172069A - Motor driving device, in-wheel motor driving device, and motor driving device for vehicles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor driving device wherein a stator can be evenly cooled. <P>SOLUTION: The motor driving device 21 includes a rotating shaft 35, a rotor 24 coupled with the outer circumference of the rotating shaft 35, a stator 23 positioned outside the rotor 24 in the radial direction; a pump casing 22p and a motor cover 22t that rotatably support an end of the rotating shaft 35 in the direction of the axis O. The rotating shaft 35 includes an axial oil passage 57 extended in the direction of the axis O. The rotor 24 includes an oil groove 59 and an oil hole 60 that are extended at least in the radial direction with the radial inside ends connected to the axial oil passage 57 and the radial outside ends directed to the pump casing 22p and the motor cover 22t. The inner walls of the pump casing 22p and motor cover 22t opposed to an end of the stator 23 in the direction of the axis O include a curved surface 22r for guiding oil discharged from the oil hole 60 to the stator 23. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a motor drive device for driving a vehicle, and more particularly to cooling of a stator and a rotor.

  As a motor drive device used for a drive source of a vehicle, a technique as described in, for example, Japanese Patent No. 3968333 (Patent Document 1) is conventionally known. In the in-wheel motor described in Patent Document 1, an oil pump is driven by a rotation shaft of the motor to circulate oil inside the motor. And the oil discharged from an oil pump is supplied to the stator core of a motor, and a motor is cooled.

Japanese Patent No. 3968333

  However, the conventional in-wheel motor has problems as described below. In other words, oil is supplied to the stator core and the stator coil by gravity drop from the highest position of the stator core and the stator coil to cool them, so that the oil does not reach the stator core and the stator coil evenly, and the stator is evenly distributed. It cannot be cooled. For this reason, a part of the stator rises in temperature exceeding the allowable range, and there is a concern that the function of the motor is deteriorated. The objective of this invention is providing the motor drive device which can cool a stator uniformly.

  For this purpose, the motor drive device according to the present invention rotatably supports a rotating shaft, a rotor coupled to the outer periphery of the rotating shaft, a stator positioned radially outward from the rotor, and an axial end of the rotating shaft. The rotor includes an axial oil passage extending in the axial direction, and the rotor extends at least in the radial direction, the radially inner end is connected to the axial oil passage, and the radially outer end is directed to the casing. The inner wall of the casing that includes the oil passage and faces the axial end of the stator has a guide surface that guides oil discharged from the radially outer end of the rotor oil passage to the stator.

  According to the present invention, the rotor includes a rotor oil passage that extends at least in the radial direction and has a radially inner end connected to the axial oil passage and a radially outer end directed to the casing, and is opposed to the axial end of the stator. Since the inner wall of the casing has a guide surface that guides the oil discharged from the radially outer end of the rotor oil passage to the stator, the oil discharged from the radially outer end of the rotor oil passage hits the casing inner wall and repels radially outward. And uniformly scattered on the outer diameter side of the stator. Therefore, oil can be supplied uniformly to the stator, and the stator can be uniformly cooled.

  The present invention is not limited to one embodiment, and the guide surface may be a convex curved surface or a combination of flat surfaces, but is preferably a concave curved surface. More preferably, the casing includes a first casing disposed at one end in the axial direction and a second casing disposed at the other end in the axial direction. The first casing forms a concave curved surface and is centered on the axis. The second casing has a first ring-shaped recess extending in a ring shape, the second casing forms a concave curved surface and has a second ring-shaped recess extending in a ring shape around the axis, and the stator has a first ring-shaped recess and It is located in the space between the second ring-shaped recesses. According to such an embodiment, the stator can be efficiently cooled from both axial ends.

  Any arrangement layout of the rotor oil passages in the rotor may be used. As a preferred embodiment, the rotor includes a rotor core positioned at the axial center and a pair of rotor pressing members positioned at both ends in the axial direction and sandwiching the rotor core, and the rotor pressing member contacts the rotor core as a rotor oil passage. A radially extending oil groove formed on the inner surface, and an oil hole extending from the radially outer end of the oil groove to the outer surface facing the casing in an oblique outer diameter direction with respect to the axial direction and penetrating the rotor pressing member And have. According to this embodiment, when the rotor core is formed of laminated steel plates, the rotor oil passage can be disposed on the rotor pressing member that holds and presses the rotor core from both ends in the axial direction, and the rotor oil passage is suitably assembled. be able to.

  There may be one or more rotor oil passages, and the oil holes extend toward the casing. Preferably, however, the rotor oil passages have an oil hole extending direction angle with respect to the axis at a predetermined first angle. A certain 1st rotor oil path and the 2nd rotor oil path whose extension direction angle of the oil hole with respect to an axis line is a 2nd angle different from a 1st angle are included. According to such an embodiment, oil can be discharged from the rotor at different angles, and the cooling effect is improved by supplying oil uniformly to the stator.

  Alternatively, the rotor oil passage has a first inner distance oil passage whose distance from the axial line to the radially outer end of the rotor oil passage is a predetermined first distance, and a first distance from the axis to the radially outer end of the rotor oil passage. And an outer diameter side oil passage that is a second distance larger than the distance. According to this embodiment, it becomes possible to scatter oil from different radial positions of the rotor, and the oil is evenly supplied to the stator to improve the cooling effect.

  Preferably, the thickness of the portion having the oil hole in the rotor pressing member is larger than the thickness near the axis. According to this embodiment, since the path of the oil hole becomes long, the direction of the oil discharged from the oil hole can be stabilized.

  Here, it is preferable to further include an oil cooler connected to the axial oil passage. According to this embodiment, it becomes possible to supply the oil cooled by the oil cooler to the axial oil passage, and the cooling efficiency of the motor is improved.

  As a preferred embodiment, the above-described motor drive device further includes a speed reduction unit that decelerates the rotation of the rotation shaft and transmits it to the wheel side rotation member. The speed reducer includes a motor-side rotating member that is coupled to the rotating shaft, a disk-shaped eccentric member that is eccentric from the axis of the motor-side rotating member and is coupled to one end of the motor-side rotating member, and an inner circumference that rotates relative to the outer circumference of the eccentric member. A curved plate having a plurality of curved concave portions that are attached in a circumferential direction and have a plurality of curved concave portions that are recessed in the radial direction, and a plurality of circumferentially spaced intervals around the axis of the motor side rotating member. An outer engagement member that engages with the curved recess as the eccentric member rotates and revolves and rotates the curved plate; and an inner engagement that engages with a hole provided between the outer periphery and the axis of the curved plate. A wheel-side rotating member that is coupled to the inner engaging member and extracts the rotation of the curved plate, the motor-side rotating member includes an axial oil passage, and the eccentric member extends from the axial oil passage to the outer periphery of the eccentric member. Including a lubricating oil passage that lubricates the curved plate. .

  According to this embodiment, it is possible to lubricate the speed reduction unit using common oil and to cool the stator of the motor drive device.

  Moreover, the in-wheel motor drive device of this invention is equipped with the motor drive device of this invention, and the wheel hub fixedly connected by the wheel side rotation member. Thereby, the cooling efficiency of an in-wheel motor drive device improves.

  The vehicle motor drive device of the present invention includes the motor drive device of the present invention and a differential device that distributes the rotation of the wheel side rotation member to a plurality of wheels, and is mounted on the vehicle body of the vehicle. Thereby, the cooling efficiency of the vehicle motor drive device is improved.

  As described above, the present invention includes the rotor oil passage that extends at least in the radial direction and has the radially inner end connected to the axial oil passage and the radially outer end directed to the casing, so that the rotor can be cooled uniformly. . In addition, the inner wall of the casing facing the axial end of the stator has a guide surface that guides the oil discharged from the radially outer end of the rotor oil passage to the stator, so that the oil discharged from the radially outer end of the rotor oil passage Hits the inner wall of the casing and is repelled outward in the radial direction and scattered uniformly on the outer diameter side of the stator. Therefore, even if the stator coil protrudes from the stator core toward both ends in the axial direction, the stator core can be directly cooled from the outer diameter side of the stator, and the stator coil and the stator core can be efficiently cooled. Therefore, according to the present invention, the rotor and the stator can be uniformly cooled.

It is a longitudinal cross-sectional view which shows the motor drive device which becomes one Example of this invention. It is sectional drawing in II-II of FIG. It is explanatory drawing which shows typically the state which looked at the pump casing of the Example from the axial direction. It is a rear view which shows the state which took out the rotor pressing member of the Example and saw it from the axial direction inner side. It is a front view which shows the state which took out the rotor pressing member of the Example and saw it from the axial direction outer side. It is a longitudinal cross-sectional view of the rotor pressing member of the same Example. It is a figure which expands and shows the range shown with the dashed-two dotted line of FIG. It is a rear view which shows the state which took out the rotor pressing member which becomes another Example, and was seen from the axial direction inner side. It is a front view which shows the state which took out the rotor pressing member of the other Example, and was seen from the axial direction outer side. It is a longitudinal cross-sectional view of the rotor pressing member of another Example. Furthermore, it is a figure which expands and shows the range shown with the dashed-two dotted line of FIG. 10 about the rotor pressing member of another Example. It is a longitudinal cross-sectional view which shows the motor drive device which becomes further another Example of this invention. It is a longitudinal cross-sectional view of the rotor pressing member of the same Example. It is the front view which looked at the rotor pressing member of the Example from the axial direction outer side. It is a top view which shows the arrangement layout of the in-wheel motor drive device provided with the motor drive device of this invention. It is a top view which shows the arrangement layout of the motor drive device for vehicles provided with the motor drive device of this invention. It is an expanded sectional view showing the motor drive device for vehicles of the example.

  Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings. FIG. 1 is a longitudinal cross-sectional view showing an in-wheel motor drive device provided with the motor drive device of this embodiment. 2 is a cross-sectional view taken along the line II-II in FIG.

  The in-wheel motor drive device 21 includes a motor unit A as a motor drive device that generates a driving force, a deceleration unit B that decelerates and outputs the rotation of the motor unit A, and a drive wheel (not shown) that outputs from the deceleration unit B And a wheel hub bearing portion C for transmitting to the wheel. The motor part A is housed in a motor casing 22a, a pump casing 22p, and a motor cover 22t that form the outer part of the motor part, and the speed reducing part B is housed in a speed reducing part casing 22b that forms the outer part of the speed reducing part. C is rotatably supported by a bearing section casing 22c fixed to the speed reduction section casing 22b, and is mounted, for example, in a wheel housing of an electric vehicle. Or it is attached to the bogie of a railway vehicle. The motor casing 22a, the pump casing 22p, the motor cover 22t, the speed reduction portion casing 22b, and the bearing portion casing 22c are connected to each other to form one casing 22.

  The motor part A includes a stator 23 fixed to the inner periphery of a cylindrical motor casing 22a, a rotor 24 disposed at a position facing the inside of the stator 23 via a gap opened in the radial direction, It is a radial gap motor provided with a rotating shaft 35 that is fixedly connected to the inside and rotates integrally with the rotor 24.

  One end of the rotating shaft 35 is rotatably supported by the motor cover 22t via a rolling bearing 63. The other end of the rotating shaft 35 is rotatably supported by the pump casing 22p via a rolling bearing 62 and is coupled to one end of the speed reducing portion input shaft 25. The motor cover 22t is a disk-shaped member that closes the opening at one end of the motor casing 22a, and is an end portion of the motor portion A and also an end portion of the in-wheel motor drive device 21. The pump casing 22p is a disk-shaped member that closes the opening at one end of the motor casing 22a, and includes an oil pump 51 described later.

  The rotor 24 coupled to the outer periphery of the rotary shaft 35 at the central portion in the axis O direction of the rotary shaft 35 includes a rotor core 24b made of a magnetic material such as a laminated steel plate, and a pair of rotor pressers attached to both ends of the rotor core 24b in the axis O direction. It has member 24c. The pair of rotor pressing members 24 c sandwich the rotor core 24 b and prevent the rotor core 24 b from coming out of the rotating shaft 35. The rotor core 24b may include a permanent magnet.

  The stator 23 located radially outside the rotor 24 includes a stator core 23b that is fixed to the inner periphery of the cylindrical motor casing 22a, and a stator coil 23c that is wound around the stator core 23b. Part of the stator coil 23c protrudes from the stator core 23b to both ends in the axis O direction, and the radially outer portion 23cg is separated from the motor casing 22a via a gap 23s.

  The speed reduction part B is a curve as a speed reduction part input shaft 25 coupled to the rotation shaft 35, eccentric members 25a and 25b coupled to the speed reduction part input shaft 25, and a revolution member held rotatably by the eccentric members 25a and 25b. Plates 26a, 26b, a plurality of outer pins 27 as outer peripheral engagement members that engage with the outer peripheral portions of the curved plates 26a, 26b, a cylindrical outer pin holding portion 45 that supports both ends of the outer pins 27, and an outer The speed reduction part casing 22b that supports the outer periphery of the pin holding part 45, the inner pin 31 as an inner engagement member that takes out the rotation of the curved plates 26a and 26b, the wheel-side rotating member 28 that is coupled to the inner pin 31, and the curve A center collar 29 that is attached to a gap between the plates 26a and 26b and abuts against the end surfaces of the curved plates 26a and 26b to prevent the curved plate from tilting, and a reinforcing member 61 that prevents the inner pin 31 from bending. Having.

  One end of the speed reduction part input shaft 25 on the side far from the motor part A is rotatably supported by an end part of a wheel side rotation member 28 described later via a bearing 64. Further, the other end of the speed reducer input shaft 25 on the side close to the motor part A is coupled to one end of the rotating shaft 35. In the middle between these two ends, eccentric members 25a and 25b are formed on the outer periphery of the speed reducing portion input shaft 25. The two disc-shaped eccentric members 25a and 25b are provided with a 180 ° phase change in the circumferential direction in order to cancel each other the vibrations generated by the centrifugal force due to the eccentric motion. The rotation shaft 35 and the speed reduction part input shaft 25 constitute a motor side rotation member that transmits the driving force of the motor part A to the speed reduction part B.

  Referring to FIG. 2, a curved plate 26b is coaxially attached to the outer periphery of the eccentric member 25b. The curved plate 26b has a plurality of curved concave portions that are formed of a trochoidal curve such as epitrochoid on the outer peripheral portion and are recessed in the radial direction, and these curved concave portions engage with an outer pin 27 described later. The curved plate 26b has a plurality of through holes 30a and 30b penetrating from one end face to the other end face.

  A plurality of through holes 30a are provided at equal intervals on the circumference centering on the rotation axis X of the curved plate 26b, and receive the inner pins 31 respectively. A cylindrical inner pin collar 31b is coaxially attached to the outer periphery of the inner pin 31, and the inner pin collar 31b is rotatably supported by the inner pin 31 via a needle roller bearing 31a. Thereby, the inner pin collar 31b rolls along the hole wall surface of the through hole 30a, and the inner engagement member rolls and contacts the inner periphery of the through hole 30a. The through hole 30b is provided at the center X of the curved plate 26b, and is the inner periphery of the curved plate 26b. The curved plate 26b is attached to the outer periphery of the eccentric member 25b via the rolling bearing 41 so as to be relatively rotatable.

  The rolling bearing 41 includes an inner ring member 42 that fits on the outer peripheral surface of the eccentric member 25b, a plurality of rollers 44, and a cage (not shown) that holds a gap between the rollers 44 adjacent in the circumferential direction. This is a cylindrical roller bearing in which the hole wall surface of the hole 30b is the outer raceway surface. Alternatively, it may be a deep groove ball bearing. The inner ring member 42 further includes a pair of flange portions facing each other with the inner raceway surface 42a of the inner ring member 42 on which the rollers 44 roll, and holds the rollers 44 between the pair of flange portions. The same applies to the curved plate 26a.

  The plurality of inner pins 31 extend in parallel with the axis O, and are commonly supported by the wheel-side rotating member 28 at the base end on the side far from the motor part A. The wheel-side rotation member 28 includes a shaft portion 28 b extending along the axis O, and a flange portion 28 a that is formed at the end portion of the shaft portion 28 b and is coupled to the base end of the inner pin 31. Holes for fixing the inner pins 31 at equal intervals on the circumference centering on the rotation axis O of the wheel side rotation member 28 are formed in the end face of the flange portion 28a. A wheel hub 32 of a wheel hub bearing portion C described later is fixed to the outer peripheral surface of the shaft portion 28b.

  A reinforcing member 61 is provided at the tip of the inner pin 31 on the side away from the flange portion 28a. The reinforcing member 61 includes a flange-shaped annular portion 61b coupled to the tips of the plurality of inner pins 31, and a cylindrical portion 61c extending from the inner diameter portion of the annular portion 61b to the motor portion A in the direction of the axis O. Since the load applied to some of the inner pins 31 from the curved plates 26a and 26b is supported by all the inner pins 31 via the annular portion 61b, the stress acting on the inner pins 31 is reduced and the durability is improved. Can be made. The tip of the cylindrical portion 61 c is drivingly coupled to the oil pump 51.

  A plurality of outer pins 27 that engage with the outer peripheries of the curved plates 26 a and 26 b are provided at equal intervals on a circumferential track centering on the rotation axis O of the speed reducing portion input shaft 25. When the curved plates 26a, 26b are rotated by the eccentric members 25a, 25b and revolved, the curved concave portions on the outer periphery of the curved plates 26a, 26b and the outer pin 27 are engaged, and the curved plates 26a, 26b rotate. Give rise to

  The outer pin 27 disposed inside the speed reduction part casing 22b may be directly held by the speed reduction part casing 22b, but preferably is an outer pin holding part fitted and fixed to the inner wall of the speed reduction part casing 22b. 45. More specifically, both end portions in the axial direction of the outer pin 27 are rotatably supported by needle roller bearings 27 a attached to the outer pin holding portion 45. Thus, by attaching the outer pin 27 to the outer pin holding portion 45 so as to be rotatable, the contact resistance due to the engagement with the curved plates 26a, 26b can be reduced.

  From the viewpoint of reducing the weight of the in-wheel motor drive device 21, the casing 22 is formed of a light metal such as an aluminum alloy or a magnesium alloy. On the other hand, it is desirable to form the outer pin holding part 45, which requires high strength, from carbon steel.

  The wheel hub bearing portion C includes a wheel hub 32 fixedly connected to the wheel-side rotating member 28, a wheel hub bearing 33 that rotatably holds the wheel hub 32, and a bearing portion casing 22c that supports the wheel hub bearing 33. Prepare. The wheel hub bearing 33 is a double-row angular ball bearing, and its outer ring is fitted and fixed to the inner periphery of the cylindrical bearing portion casing 22 c, and the inner ring is fitted and fixed to the outer diameter surface of the wheel hub 32. The wheel hub 32 includes a cylindrical hollow portion 32a that receives the shaft portion 28b of the wheel-side rotating member 28, and a flange portion 32b that is formed at the end of the hollow portion 32a on the side farther from the speed reduction portion B in the axis O direction. A drive wheel road wheel (not shown) is connected and fixed to the flange portion 32b by a bolt 32c.

  The operation principle of the in-wheel motor drive device 21 having the above configuration will be described in detail.

  For example, the motor unit A receives an electromagnetic force generated by supplying an alternating current to the stator coil 23c, and the rotor 24 including a magnetic body or a permanent magnet rotates. As a result, when the rotating shaft 35 connected to the rotor 24 rotates, the speed reducing portion input shaft 25 rotates together with the rotating shaft 35, and the eccentric members 25a and 25b coupled to the speed reducing portion input shaft 25 move eccentrically about the axis O. To do.

  Then, the curved plates 26a and 26b revolve around the rotation axis O of the motor side rotating member. At this time, the outer pin 27 is engaged with the curved concave portions formed on the outer circumferences of the curved plates 26a and 26b while being in rolling contact with each other, so that the curved plates 26a and 26b rotate in the direction opposite to the rotation of the motor side rotating member. Let

  The outer periphery of the inner pin collar 31b inserted through the through hole 30a is sufficiently thinner than the inner diameter of the through hole 30a, and abuts against the hole wall surface of the through hole 30a as the curved plates 26a and 26b rotate. As a result, the revolving motion of the curved plates 26 a and 26 b is not transmitted to the inner pin 31, but only the rotational motion of the curved plates 26 a and 26 b is transmitted to the wheel hub bearing portion C via the wheel-side rotating member 28.

At this time, the wheel-side rotating member 28 disposed coaxially with the axis O takes out the rotation of the curved plates 26 a and 26 b as the output shaft of the speed reduction unit B. The reduction ratio of the reduction part B is calculated as (Z _A −Z _B ) / Z _B where Z _{A is} the number of outer pins 27 and Z _B is the number of waveforms of the curved plates 26a and 26b. In the embodiment shown in FIG. 2, since Z _A = 12 and Z _B = 11, the reduction ratio is 1/11, and a very large reduction ratio can be obtained. As a result, the rotation of the speed reduction unit input shaft 25 is decelerated by the speed reduction unit B and transmitted to the wheel side rotation member 28. Therefore, even when the low torque, high rotation type motor unit A is employed, it is necessary for the drive wheels. Torque can be transmitted.

  In this way, by adopting the speed reduction unit B that can obtain a large speed reduction ratio without using a multi-stage configuration, the in-wheel motor drive device 21 having a compact and high speed reduction ratio can be obtained. Since the outer pin 27 is rotatable with respect to the outer pin holding portion 45 and the needle roller bearing 31a is provided at a position where the outer pin 27 comes into contact with the curved plates 26a and 26b of the inner pin 31, the frictional resistance is reduced. The transmission efficiency of the deceleration part B is improved.

  By employing the in-wheel motor drive device 21 according to this embodiment in an electric vehicle, the unsprung weight can be suppressed. As a result, an electric vehicle with excellent running stability can be obtained.

  In the present embodiment, two curved plates 26a and 26b of the speed reduction portion B are provided with 180 ° phase shifts. However, the number of the curved plates can be arbitrarily set. In the case of providing a sheet, it is preferable to change the phase by 120 °.

  In this embodiment, an example is shown in which the inner pin 31 is fixed to the wheel-side rotating member 28 and the through hole 30a is provided in the curved plates 26a and 26b. However, the present invention is not limited to this. The rotation of the speed reduction unit B can be any configuration that can be transmitted to the wheel hub 32. For example, it may be a motion conversion mechanism composed of an inner pin fixed to a curved plate and a hole formed in the wheel side rotation member.

  The description of the operation in the present embodiment has been made by paying attention to the rotation of each member, but in reality, power including torque is transmitted from the motor unit A to the drive wheels. Therefore, the power decelerated as described above is converted into high torque.

  In the description of the operation in the present embodiment, power is supplied to the motor unit A to drive the motor unit A, and the power from the motor unit A is transmitted to the drive wheels. When decelerating or going down a hill, the power from the driving wheel side may be converted into high-rotation and low-torque rotation by the deceleration unit B and transmitted to the motor unit A, and the motor unit A may generate power. . Furthermore, the electric power generated here may be stored in a battery, and the motor unit A may be driven later, or may be used for the operation of other electric devices provided in the vehicle.

  Next, the lubrication structure of the deceleration part B will be described in detail.

  A suction oil passage 52 provided in the pump casing 22p and extending in the vertical direction connects the suction port of the oil pump 51 and an oil reservoir 53 provided in the lower part of the speed reduction unit B. The discharge oil passage 54 provided in the pump casing 22p and extending in the vertical direction is connected to the discharge port of the oil pump 51 at the lower end and connected to one end of the cooling oil passage 55 provided in the motor casing 22a at the upper end. The cooling oil passage 55 intersects with a water jacket 65 provided in the motor casing 22a. The water jacket 65 includes a cooling water inlet 65i, a cooling water inlet / outlet 65o, and a cooling water passage 65w disposed around the motor portion A. The water jacket 65 functions as an oil cooler connected to the axial oil passage 57, and the cooling water flowing in from the cooling water inlet 65i cools the lubricating oil flowing through the motor section A and the cooling oil passage 55 in the course of flowing through the cooling water passage 65w. And flows out from the cooling water inlet / outlet 65o.

  The other end of the cooling oil passage 55 is connected to one end of a communication oil passage 56 provided in the motor cover 22t. The other end of the communication oil passage 56 is connected to an axial oil passage 57 that is provided inside the tubular rotary shaft 35 and the speed reduction portion input shaft 25 and extends along the axis O. The axial oil passage 57 branches from the axis O into a lubricating oil passage 58a extending radially outward in the eccentric member 25a and a lubricating oil passage 58b extending radially outward in the eccentric member 25b from the axis O. . The radially outer ends of the lubricating oil passages 58 a and 58 b are connected to a hole 43 provided in the inner raceway surface 42 a so as to penetrate the inner ring member 42 of the rolling bearing 41.

  FIG. 3 is an explanatory view schematically showing a state in which the pump casing 22p is viewed from the direction of the axis O. The oil pump 51 attached to the center of the pump casing 22p and driven by the cylindrical portion 61c of the reinforcing member 61 is constituted by, for example, a cycloid pump, and the lubricating oil stored in the oil reservoir 53 is supplied from the inlet 52i at the lower end of the intake oil passage 52. Inhalation is performed, and lubricating oil is discharged into the discharge oil passage 54. A hole 53i that communicates the internal space of the motor casing 22a and the oil reservoir 53 is provided in the lower portion of the pump casing 22p. The hole 53i is provided above the inlet 52i so that the lubricating oil flows from the hole 53i to the oil reservoir 53.

  The lubricating oil sequentially passes through the discharge oil passage 54 and the cooling oil passage 55 and is cooled in the cooling oil passage 55. Next, the lubricating oil sequentially passes through the communication oil passage 56 and the axial oil passage 57, branches into the lubricating oil passages 58a and 58b at the speed reduction portion B, flows outward in the radial direction, and is provided in the eccentric member 25a. The rolling bearing 41 and the rolling bearing 41 provided on the eccentric member 25b are lubricated. Further, since the lubricating oil flows radially outward by the action of centrifugal force, the curved plates 26a and 26b and the outer pin 27 are lubricated. Thereafter, the lubricating oil falls and is stored in an oil reservoir 53 provided at the lower portion of the speed reduction portion B. The lubricating oil circulation path is configured as described above.

  Next, the cooling structure of the motor part A will be described in detail.

  An oil hole 35 h that connects the axial oil passage 57 and the outer periphery of the rotation shaft 35 is formed at the center of the rotation shaft 35. A portion of the outer periphery of the rotating shaft 35 where the oil hole 35 h is provided faces the rotor core 24 b via a gap, and the gap forms an oil chamber 84. The oil chamber 84 extends to the rotor pressing member 24c.

  4 is a rear view showing a state in which the rotor pressing member 24c is taken out and viewed from the inside in the axis O direction, FIG. 5 is a front view of the rotor pressing member 24c as viewed from the outside in the axis O direction, and FIG. 6 is a rotor pressing member 24c. FIG. 7 is an enlarged view of a range indicated by a two-dot chain line in FIG. 6. Each of the rotor pressing members 24c has a disk shape having a thickness in the direction of the axis O, and the rotor pressing member 24c disposed on the side closer to the pump casing 22p faces the inner side surface 86 that contacts the rotor core 24b and the pump casing 22p. And has an outer surface 87 which The outer surface 87 of the rotor pressing member 24c disposed on the side close to the motor cover 22t faces the motor cover 22t.

  A through hole 85 through which the rotary shaft 35 passes is formed at the center of the rotor pressing member 24c. Further, an annular step 88 that surrounds the through hole 85 is formed on the inner surface 86 that contacts the rotor core 24b of both surfaces of the rotor pressing member 24c. The annular step 88 is recessed from the inner surface 86 and forms the end of the oil chamber 84 in the axis O direction.

  The inner side surface 86 is further provided with oil grooves 59 extending in the radial direction at equal intervals in the circumferential direction. The length of the oil groove 59 is different between the oil groove 59l and the oil groove 59s adjacent to each other in the circumferential direction as shown in FIG.

As shown in FIG. 7, an oil hole 60 that penetrates the rotor pressing member 24 c is formed in the outer diameter end 59 o of each oil groove 59. The oil hole 60 extends from the outer diameter end 59o toward the oblique outer diameter direction. All of the oil holes 60 extend from the radially outer end 59 o of the oil groove 59 to the outer surface 87 at a first angle θ ₁ in the oblique outer diameter direction with respect to the axis O direction.

  As shown in FIG. 5, the outlets of the oil holes 60 connected to the shorter oil groove 59s are arranged at equal intervals on a virtual circle γ indicated by a one-dot chain line. On the other hand, the outlets of the oil holes 60 connected to the longer oil groove 59l are arranged at equal intervals on a virtual circle δ which is indicated by a dashed line and which is larger than the virtual circle γ. Thus, in the oil groove 59s and the oil groove 59l that become rotor oil paths adjacent in the circumferential direction, the distance from the outlet of the oil hole 60 connected to the shorter oil groove 59s to the axis O is short (first distance). The distance from the outlet of the oil hole 60 connected to the longer oil groove 59l to the axis O is long (second distance).

  When the inner surface 86 is in close contact with the rotor core 24 b, the oil groove 59 becomes a pipe line, and together with the oil chamber 84 and the oil hole 60, the rotor oil path is configured.

  The inner wall of the pump casing 22p and the inner wall of the motor cover 22t facing the end of the stator 23 in the axis O direction are respectively formed on curved surfaces 22r recessed in the axis O direction as shown in FIG. The curved surface 22r is a guide surface that guides the lubricating oil discharged from the outlet of the oil hole 60 to the radially outer portion 23cg of the stator coil 23c. The curved surface 22r is a ring-shaped recess centered on the axis O, and the outer diameter portion of the curved surface 22r faces the stator coil 23c.

  The lubricating oil discharged from the oil pump 51 sequentially passes through the discharge oil passage 54 and the cooling oil passage 55 and is cooled in the cooling oil passage 55. Next, the lubricating oil sequentially passes through the communication oil passage 56 and the axial oil passage 57, branches to the oil hole 35h, and flows radially outward. Next, the lubricating oil flows into the oil chamber 84, passes through the oil groove 59 and the oil hole 60 sequentially from both ends of the oil chamber 84 in the axis O direction, and is discharged from the oil hole 60. Thus, the rotor 24 is suitably cooled.

  Then, the lubricating oil discharged from the oil hole 60 connected to the shorter oil groove 59s advances along the arrow α, hits the curved surface 22r, is repelled radially outward along the arrow β, and the diameter of the stator coil 23c. It scatters uniformly in the direction outer side part 23cg. Then, the lubricating oil flows into the central portion of the stator 23 in the axis O direction along the gap 23s, and the stator core 23b can be directly cooled from the outer diameter side of the stator 23.

  Further, the lubricating oil discharged from the oil hole 60 connected to the longer oil groove 59l advances along the arrow α, hits the curved surface 22r, is repelled radially outward along the arrow β, and the diameter of the stator coil 23c. It scatters uniformly in the direction outer side part 23cg. Then, the lubricating oil flows into the central portion of the stator 23 in the direction of the axis O along the gap 23s, and the stator core 23b can be directly cooled from the outer diameter side of the stator 23.

  Therefore, it becomes possible to supply lubricating oil uniformly to the stator 23, and the stator 23 can be cooled uniformly. Alternatively, the lubricating oil may be directly applied to the inner diameter side of the stator coil 23c from the oil hole 60 connected to the longer oil groove 59l to uniformly cool the inner diameter side of the stator 23.

  The lubricating oil uniformly supplied to the stator 23 gathers at the lower part of the motor part A and flows down from the hole 53i to the oil reservoir 53 of the speed reducing part B. The lubricating oil is again drawn into the oil pump 51 to circulate and cool the motor part A.

  According to the present embodiment, the pump casing 22p corresponding to the first casing disposed at one end in the axial direction and the motor cover 22t corresponding to the second casing disposed at the other end in the axial direction are included. The first casing forms a concave curved surface and has a curved surface 22r as a first ring-shaped concave portion extending in a ring shape around the axis O, and the second casing forms a concave curved surface and centers around the axis O. It has a curved surface 22r as a second ring-shaped recess extending in a ring shape. The stator 23 is located in a space between the first ring-shaped recess and the second ring-shaped recess. As a result, the lubricating oil hits the first ring-shaped concave portion and the second ring-shaped concave portion and is repelled outward in the radial direction, and is uniformly scattered on the outer diameter side of the stator 23. Therefore, the stator 23 can be efficiently cooled from both ends of the axis O direction.

  Next, a motor driving apparatus according to another embodiment of the present invention will be described. In the other embodiments, the lengths of the oil grooves 59 of the rotor pressing member 24c are all the same, and the configurations of the other portions are all in common with the above-described embodiment. 8 is a rear view showing a state in which the rotor pressing member 24c of another embodiment is taken out and viewed from the inside of the axis O direction, and FIG. 9 is a front view of the rotor pressing member 24c viewed from the outside of the axis O direction. These are the longitudinal cross-sectional views of the rotor pressing member 24c.

  All the outlets of the oil holes 60 are arranged at equal intervals on the virtual circle γ as shown in FIG. Even in an embodiment in which the lengths of the oil grooves 59 are all equal, the rotor 24 is preferably cooled. Further, the lubricating oil discharged from the outlet of the oil hole 60 proceeds along the arrow α, hits the curved surface 22r, is repelled radially outward along the arrow β, and is uniformly formed on the radially outer portion 23cg of the stator coil 23c. Scatter. Therefore, it becomes possible to supply lubricating oil uniformly to the stator 23, and the stator 23 can be cooled uniformly.

Next, a motor driving apparatus according to still another embodiment of the present invention will be described. In still another embodiment, the lengths of the oil grooves 59 of the rotor pressing member 24c are all the same, the extending directions of the oil holes 60 adjacent in the circumferential direction are different from each other, and the configuration of other portions is the same as that of the above-described embodiment. To do. That is, one of the oil holes 60 adjacent in the circumferential direction, extend at an angle theta ₁ to the oblique outer diameter direction with respect to the axis O direction from the inner surface 86 to the outer surface 87 as shown in FIG. The other oil hole 60 adjacent in the circumferential direction, extend at an angle theta ₂ to the oblique outer diameter direction from the inner surface 86 as shown in FIG. 11 to the outer surface 87. The angle θ ₂ is smaller than the angle θ ₁ .

If the angle theta ₁ specifically described per oil hole 60 extending at a small angle theta ₂ than lubricating oil discharged from the oil hole 60 directed into the pump casing 22p proceeds along arrow alpha, curved surface of the pump casing 22p inner wall It hits 22r and is repelled radially outward along the arrow β and is uniformly scattered on the radially outer portion 23cg of the stator coil 23c. Similarly, the lubricating oil discharged from the oil hole 60 directed to the motor cover 22t also proceeds along the arrow α, hits the curved surface 22r of the inner wall of the motor cover 22t, and is repelled radially outward along the arrow β, so that the stator coil 23c It scatters uniformly in the radially outer portion 23cg. Incidentally, the lubricating oil from the oil hole 60 extending at an angle theta ₂ directly against the stator coil 23c may be uniformly cooled inner diameter side of the stator 23.

Further, concretely describing per oil hole 60 extending at an angle greater theta ₁ than the angle theta _2, the lubricating oil discharged from the oil hole 60 also passes along the arrow α in the same manner, motor cover 22t inner wall and the pump casing 22p Each of them hits the curved surface 22r of the inner wall and is repelled radially outward along the arrow β to be uniformly scattered on the radially outer portion 23cg of the stator coil 23c. Therefore, it becomes possible to supply lubricating oil uniformly to the stator 23, and the stator 23 can be cooled uniformly.

  Next, a motor driving apparatus according to still another embodiment of the present invention will be described. In still another embodiment, the thickness of the rotor pressing member 24c is different between the inner diameter side and the outer diameter side. Moreover, the filter which filters lubricating oil is provided. All other configurations are the same as those in the above-described embodiment. FIG. 12 is a longitudinal sectional view showing a motor driving apparatus according to still another embodiment of the present invention. FIG. 13 is a longitudinal sectional view of the rotor pressing member 24c. FIG. 14 is a front view of the rotor pressing member 24c as viewed from the outside in the axis O direction. As shown in FIG. 13, the thickness of the portion having the oil hole 60 in the rotor pressing member 24 c is larger than the thickness in the vicinity of the axis O.

  The outer surface 87 of the rotor pressing member 24c has a shape in which a ring-shaped inner diameter portion 87i is recessed from the ring-shaped outer diameter portion 87o, and an annular step 89 centering on the axis O is formed. A chamfer 90 is provided over the entire circumference at the boundary portion between the annular step 89 and the outer diameter portion 87o.

  In a state where the rotor 24 is attached to the rotating shaft 35, the protruding portion 35t formed on the outer periphery of the rotating shaft 35 supports the inner diameter portion 87i of one rotor pressing member 24c, and the outer diameter portion 87o is more than the protruding portion 35t. Projects outward in the direction of the axis O. Further, with the rotor 24 attached to the rotating shaft 35, the retaining member 35r connected and fixed to the outer periphery of the rotating shaft 35 comes into contact with the inner diameter portion 87i of the other rotor pressing member 24c, so that the rotor 24 is separated from the rotating shaft 35. While preventing from coming off, the outer diameter portion 87o projects outward in the direction of the axis O from the retaining member 35r.

  As described above, according to another embodiment, the portion of the rotor pressing member 24c having the oil hole 60 is large in thickness and the path of the oil hole 60 is long, so that the direction of the lubricating oil discharged from the oil hole 60 is stabilized. Can be made. In addition, the outlet of the oil hole 60 can be arranged in the vicinity of the curved surface 22r to effectively cool the stator coil radial outer portion 23cg.

  In another embodiment, as shown in FIG. 12, a through hole 68 is formed in the center of the motor cover 22t. The through hole 68 is connected to the axial oil passage 57, but is sealed by a lid member 67 that is detachably attached to the outside of the motor cover 22t.

  A filter member 66 is inserted and fixed in the axial oil passage 57 in the motor part A. Since the filter member 66 filters the lubricating oil flowing through the axial oil passage 57, it is possible to supply clean lubricating oil to the speed reduction unit B. In addition, the filter member 66 can be easily replaced by removing the lid member 67, and the maintenance of the in-wheel motor drive device 21 is facilitated.

  FIG. 15 is a plan view showing an arrangement layout of the in-wheel motor drive device 21. The vehicle body 11 includes four wheels on the front, rear, left and right. Of these, the left wheel 12L and the right wheel 12R are drive wheels. The left wheel 12L is coupled to the wheel hub 32 of the in-wheel motor drive device 21L disposed on the left side of the vehicle. The in-wheel motor drive device 21L is suspended under the floor of the vehicle body 11 by a suspension device (not shown). Similarly, the right wheel 12R is coupled to the wheel hub 32 of the in-wheel motor drive device 21R disposed on the right side of the vehicle. The in-wheel motor drive device 21R is also suspended below the floor of the vehicle body 11 by a suspension device (not shown). The in-wheel motor drive devices 21L and 21R are both the in-wheel motor drive device 21 described above, and are arranged symmetrically with respect to the center line of the vehicle body 11 extending in the vehicle front-rear direction.

  According to this arrangement layout, since the motor part A of the in-wheel motor drive devices 21L and 21R has the oil groove 59, the oil hole 60, and the curved surface 22r, the cooling efficiency of the left and right in-wheel motor drive devices 21L and 21R is improved. Both improve.

  The motor part A described so far can be applied to the in-wheel motor drive device 21 that is directly attached to the wheel, and also to a vehicle motor drive device that is mounted on the vehicle body and is drive-coupled via the wheel and the drive shaft. Applicable.

  FIG. 16 is a plan view showing an arrangement layout of the vehicle motor drive device 71 provided with the motor section A described above. FIG. 17 is a developed cross-sectional view showing the vehicle motor drive device 71 of the same embodiment. In this embodiment, the same components as those in the above-described embodiment are denoted by the same reference numerals, description thereof is omitted, and different configurations will be described below.

  The left wheel 12L is suspended under the floor of the vehicle body 11 by a suspension device (not shown). The inner side in the vehicle width direction of the left wheel 12L is coupled to the outer end in the vehicle width direction of the drive shaft 13L extending in the vehicle width direction. The inner end of the drive shaft 13L in the vehicle width direction is drivingly coupled to the vehicle motor drive device 71. The right wheel 12R is the same as the left wheel 12L and is arranged symmetrically with respect to the center line of the vehicle body 11 extending in the vehicle front-rear direction. Although not shown in the drawing, the left drive shaft 13L and the right drive shaft 13R may be arranged asymmetrically with different lengths.

  The vehicle motor drive device 71 includes one motor part A and one speed reduction part B serving as a cycloid reduction gear, and further includes a differential gear device 72 disposed adjacent to the speed reduction part B.

  The differential gear device 72 includes a ring gear 75, a differential gear case 76, a pinion mate shaft 77, a pair of pinion mate gears 78 and 79, and two side gears 82 and 83. This is a differential device that transmits driving force to the left and right wheels 12L, 12R.

  The shaft portion 28b of the wheel side rotation member 28 extending along the axis O is rotatably supported on the casing 22 by the bearing 73a on the flange portion 28a side and rotatably supported on the casing 22 by the bearing 73b. Both the bearing 73a and the bearing 73b are rolling bearings. The outer periphery of the shaft portion 28b is coupled to the center of the gear 74 between the bearing 73a and the bearing 73b, and the gear 74 rotates integrally with the wheel-side rotating member 28.

  The gear 74 meshes with the ring gear 75 of the differential gear device 72. The ring gear 75 is fixed to the outside of a differential gear case 76 that is rotatably supported by the casing 22 via bearings 80 and 81. In the differential gear case 76, a pinion mate shaft 77 is installed so as to be orthogonal to the rotation axis P, and a pair of pinion mate gears 78 and 79 are rotatably supported on the shaft 77 so that the inside of the differential gear case 76. Provided.

  Further, in the differential gear case 76, a pair of side gears 82 and 83 which are between the pinion mate gears 78 and 79 and mesh with the pinion mate gears 78 and 79 are rotatably arranged. The left side gear 82 is coupled to the left drive shaft 13L and rotates integrally. Further, the right side gear 83 is coupled to the right drive shaft 13R and rotates integrally.

  According to the vehicle motor drive device 71, the motor portion A of the vehicle motor drive device 71 has the oil groove 59, the oil hole 60, and the curved surface 22r, so that the cooling efficiency of the vehicle motor drive device 71 is improved. . The left wheel 12L and the right wheel 12R may be either front wheels or rear wheels.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  11 Body, 12L Left wheel, 12R Right wheel, 13L, 13R Drive shaft, 21, 21L, 21R In-wheel motor drive device, 22 casing, 22a motor casing, 22p pump casing, 22t motor cover, 22r curved surface, 23 stator, 23b stator core , 23c Stator coil, 24 rotor, 24b rotor core, 24c rotor pressing member, 25 reduction part input shaft, 25a, 25b eccentric member, 26a, 26b curved plate, 27 outer pin, 28 wheel side rotating member, 31 inner pin, 32 wheel Hub, 33 Wheel hub bearing, 35 Rotating shaft, 35h Oil hole, 51 Oil pump, 53 Oil pool, 53i hole, 55 Cooling oil passage, 57 Axis oil passage, 59 Oil groove, 60 Oil hole, 61 Reinforcement member, 65 Water Jacket, 6 6 Filter member, 67 Cover member, 68 Through hole, 71 Motor drive device for vehicle, 72 Differential gear device, 84 Oil chamber, 85 Through hole, 86 Inner surface, 87 Outer surface, 87i Inner surface, 87o Outer surface, 88 , 89 Annular steps, 90 chamfers.

Claims (11)

A rotating shaft, a rotor coupled to the outer periphery of the rotating shaft, a stator positioned radially outward from the rotor, and a casing that rotatably supports an axial end of the rotating shaft;
The rotating shaft includes an axial oil passage extending in the axial direction,
The rotor includes a rotor oil passage extending at least in the radial direction and having a radially inner end connected to the axial oil passage and a radially outer end directed to the casing;
The motor driving device, wherein an inner wall of the casing facing an axial end of the stator has a guide surface that guides oil discharged from a radially outer end of the rotor oil passage to the stator.   The motor driving device according to claim 1, wherein the guide surface is a concave curved surface. The casing includes a first casing disposed at one end in the axial direction, and a second casing disposed at the other end in the axial direction,
The first casing has a first ring-shaped recess that forms the concave curved surface and extends in a ring shape around an axis.
The second casing has a second ring-shaped recess that forms the concave curved surface and extends in a ring shape around an axis.
The motor driving apparatus according to claim 2, wherein the stator is located in a space between the first ring-shaped recess and the second ring-shaped recess. The rotor includes a rotor core positioned at a central portion in the axial direction, and a pair of rotor pressing members positioned at both ends in the axial direction and sandwiching the rotor core,
The rotor pressing member serves as the rotor oil passage in the axial direction from a radially extending oil groove formed on an inner surface that contacts the rotor core and from the radially outer end of the oil groove to the outer surface facing the casing. The motor drive device according to claim 1, further comprising an oil hole extending in an oblique outer diameter direction and penetrating the rotor pressing member.   The rotor oil passage includes a first rotor oil passage in which an extending direction angle of the oil hole with respect to an axis is a predetermined first angle, and a second angle in which the extending direction angle of the oil hole with respect to the axis is different from the first angle. The motor drive device according to claim 4, including a second rotor oil passage that is an angle.   The rotor oil passage has an inner diameter side oil passage whose distance from the axis to the radially outer end of the rotor oil passage is a predetermined first distance, and a distance from the axis to the radially outer end of the rotor oil passage is the first distance. The motor drive device according to claim 4, further comprising an outer diameter side oil passage that is a second distance larger than the distance.   The motor driving device according to claim 4, wherein a thickness of the portion having the oil hole in the rotor pressing member is larger than a thickness in the vicinity of the axis.   The motor driving device according to claim 1, further comprising an oil cooler connected to the axial oil passage. A speed reducer that decelerates the rotation of the rotation shaft and transmits the rotation to the wheel side rotation member;
The speed reduction unit includes a motor-side rotation member coupled to the rotation shaft, a disc-shaped eccentric member that is eccentric from the axis of the motor-side rotation member and coupled to one end of the motor-side rotation member,
A curved plate having an inner periphery attached to the outer periphery of the eccentric member so as to be relatively rotatable, an outer periphery formed of a wavy curve, and having a plurality of curved concave portions recessed in the radial direction;
A plurality of outer circumferentially arranged members arranged at equal intervals in the circumferential direction around the axis of the motor-side rotating member, and engaged with the curved recess as the eccentric member rotates and revolves and rotates the curved plate;
An inner engagement member that engages with a hole provided between the outer periphery of the curved plate and the axis;
A wheel-side rotating member that is coupled to the inner engagement member and takes out the rotation of the curved plate;
The motor side rotating member includes the axial oil passage,
The motor drive device according to claim 1, wherein the eccentric member includes a lubricating oil passage that extends from the axial oil passage to an outer periphery of the eccentric member and lubricates the curved plate.   An in-wheel motor drive device comprising: the motor drive device according to claim 9; and a wheel hub fixedly connected to the wheel-side rotating member.   A motor drive device for a vehicle mounted on a vehicle body of the vehicle, comprising: the motor drive device according to claim 9; and a differential device that drives and transmits the rotation of the wheel side rotation member to a plurality of wheels.

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