JP2015064048A - In-wheel motor driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an in-wheel motor driving device in which the temperature state of a deceleration part can be known more accurately than before.SOLUTION: An in-wheel motor driving device comprises: a motor part; a wheel hub bearing part; a deceleration part that decelerates the output rotation of the motor part and transmits it to the wheel hub bearing part; and a lubricating oil circuit that passes lubricating oil into the deceleration part. The lubricating oil circuit comprises: a lubricating oil tank 53; an oil supply passage that supplies the lubricating oil from the lubricating oil tank to the deceleration part; oil discharge passages 61 and 62 that discharge the lubricating oil from the deceleration part to the lubricating oil tank; and a temperature sensor 63 that is arranged in the oil discharge passages or the lubricating oil tank and detects the temperature of the lubricating oil.

Description

  The present invention relates to a technique for preventing an overload operation of a deceleration unit provided in an in-wheel motor drive device.

  An in-wheel motor drive device includes, for example, a high-rotation type motor unit and a speed reduction unit including a cycloid speed reduction mechanism capable of obtaining a large reduction ratio of 1/10 or more, as shown in Japanese Patent No. 5072370 (Patent Document 1). And a wheel hub bearing portion, and are combined into a compact shape so as to be disposed inside the drive wheel.

  Moreover, the in-wheel motor drive device of patent document 1 is further provided with a temperature corresponding | compatible motor control means. The temperature-corresponding motor control means estimates the heat generation amount of the motor unit based on the temperature measured by the temperature sensor, and reduces the drive current of the motor unit or the speed command of the motor unit when the heat generation amount exceeds a specified value. It is to perform processing.

  The temperature sensor is installed in the motor stator, installed in the speed reduction unit casing, or installed in the cooling medium flow path flowing through the motor unit casing to measure the temperature of the cooling medium.

Japanese Patent No. 5072370

  However, the present inventor has found that there is a further improvement in the conventional in-wheel motor drive device. First, even if the temperature of the motor stator or the speed reduction part casing is measured, the temperature inside the speed reduction part cannot be obtained accurately. Since the rotating elements (gears and shafts) of the speed reducing unit, particularly the speed reducing unit input shaft, rotate at a high speed, the bearings and sliding parts that support the rotating elements become hot. Therefore, it is necessary to prevent seizure of the bearings and sliding parts of the speed reduction unit. However, since the rotating element always rotates, it is difficult to directly attach the temperature sensor.

  An object of the present invention is to provide an in-wheel motor drive device that can know the temperature state of the speed reduction unit more accurately than before and can prevent the overload operation of the speed reduction unit in view of the above situation. To do.

  For this purpose, an in-wheel motor drive device according to the present invention includes a motor unit, a wheel hub bearing unit, a speed reduction unit that decelerates the output rotation of the motor unit and transmits the output rotation to the wheel hub bearing unit, and a lubricating oil inside the speed reduction unit. A lubricating oil circuit. The lubricating oil circuit includes a lubricating oil tank, a supply oil passage that supplies the lubricating oil from the lubricating oil tank to the speed reducing portion, a discharge oil passage that discharges the lubricating oil from the speed reducing portion to the lubricating oil tank, and a discharged oil passage or lubrication. And a temperature sensor that is disposed in the oil tank and detects the temperature of the lubricating oil.

  According to the present invention, since the temperature of the lubricating oil flowing inside the speed reduction portion is measured, the temperature state of the speed reduction portion can be known more accurately than before. Therefore, the overload operation of the deceleration unit can be prevented.

  As one embodiment of the present invention, the lubricating oil tank is provided below the speed reducing portion, the drain oil passage is a through hole that vertically penetrates the boundary wall between the speed reducing portion and the lubricating oil tank, and the temperature sensor is a through hole. Or it is arranged in the lubricating oil tank. According to this embodiment, since the temperature of the lubricating oil is detected just after flowing down from the speed reduction part through the through hole, the temperature state of the speed reduction part can be known more accurately than in the past.

  As a preferred embodiment of the present invention, the through-hole has an opening-shaped receiving portion whose lower end side is smaller in diameter than the upper end side, and a horizontal hole that extends across the lower end side of the receiving portion. A temperature sensor support member that houses the temperature sensor may be provided. According to this embodiment, since the temperature sensor is installed at the lower end side of the receiving portion in the opening-shaped receiving portion whose diameter decreases from the upper end side toward the lower end side, the lubricating oil flowing down the receiving portion. Can be applied to the temperature sensor without any unevenness, and the temperature state of the deceleration unit can be known more accurately.

  As a preferred embodiment of the present invention, the in-wheel motor drive device further includes a temperature-responsive motor control unit that limits the output of the motor unit when the lubricant temperature detected by the temperature sensor is equal to or higher than a predetermined specified value. According to this embodiment, regardless of the driver's accelerator operation, the overload operation of the deceleration unit can be automatically prevented. In addition, the output here is at least one of the rotation speed and drive torque which a motor part outputs to a deceleration part. The temperature-responsive motor control means is provided outside the in-wheel motor driving device, but may be provided inside the in-wheel motor driving device. As another embodiment, it may be displayed on the driver's seat of the vehicle equipped with the in-wheel motor drive device that the deceleration unit is in an overload operation when the lubricating oil temperature detected by the temperature sensor is equal to or higher than a predetermined specified value.

  As described above, according to the present invention, the temperature state inside the speed reduction unit can be detected more accurately than before, and the speed reduction unit can be protected accurately.

It is a schematic longitudinal cross-sectional view which shows the in-wheel motor drive device which becomes one Embodiment of this invention. It is a cross-sectional view which shows the deceleration part of the embodiment. It is a longitudinal cross-sectional view which expands and shows the part enclosed with the dashed-two dotted line of FIG. It is a perspective view which shows a temperature sensor support member with a temperature sensor. It is a top view which shows a temperature sensor support member with a temperature sensor. It is a longitudinal cross-sectional view which shows a temperature sensor support member with a temperature sensor. It is a cross-sectional view showing a temperature sensor support member. It is a flowchart which shows the control performed with a motor control unit.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic longitudinal sectional view showing an in-wheel motor driving apparatus according to an embodiment of the present invention. FIG. 2 is a transverse cross-sectional view showing the speed reduction portion of the same embodiment. 3 is an enlarged longitudinal sectional view showing a portion surrounded by a two-dot chain line in FIG.

  The in-wheel motor drive device 21 includes a motor unit A that generates a driving force, a deceleration unit B that decelerates and outputs the rotation of the motor unit A, and a wheel hub bearing that transmits an output from the deceleration unit B to driving wheels (not shown). It consists of part C. And about the axial direction of the in-wheel motor drive device 21, it arranges coaxially in order of the motor part A, the deceleration part B, and the wheel hub bearing part C. The casing 22 forms an outline of the in-wheel motor drive device 21, and is a combination of the motor casing member 22a, the speed reduction casing member 22b, and the motor cover 22d.

  The motor part A includes a cylindrical motor part casing member 22a, and is arranged at a position facing the stator 23 fixed to the inner peripheral surface of the motor part casing member 22a with a radial gap inside the stator 23. And a motor rotating shaft 35 that is fixedly connected to the inner side of the rotor 24 and rotates integrally with the rotor 24. A coil 23 c is wound around the stator 23. The rotor 24 is formed so as to protrude radially outward from the outer periphery of the motor rotating shaft 35 and the rotor main body 24a having a hollow cylindrical shape in which a plurality of discs having a through hole in the center are stacked. A cylindrical rotor support 24b that is fixed to the inner periphery and supports the rotor main body 24a at the axial center of the motor rotation shaft 35 is provided. One end of the motor rotating shaft 35 located on the side opposite to the speed reduction portion B is rotatably supported by the central portion of the motor cover 22d via a rolling bearing 36a. The other end of the motor rotating shaft 35 on the side close to the speed reduction portion B is passed through the center hole of the inward flange portion 22e of the motor portion casing member 22a, and the center hole of the inward flange portion 22e via the rolling bearing 36b. Is supported rotatably.

  Since the motor rotation shaft 35 of the motor part A and the input shaft 25 of the speed reduction part B extend along a substantially horizontal axis O and rotate integrally, the assembly of the motor rotation shaft 35 and the input shaft 25 is a motor side rotation member. Called. One end of the input shaft 25 is inserted into and fixed to a motor rotation shaft oil passage 58a that becomes a central hole of the motor rotation shaft 35, and serrations are fitted, for example, at both ends of the motor rotation shaft 35 on the side close to the speed reduction portion B. They are connected and fixed together. The other end of the input shaft 25 is rotatably supported by one end of the output shaft 28 via a rolling bearing 36d.

  The speed reduction part B includes a cylindrical speed reduction part casing member 22b. The deceleration unit B includes an input shaft 25, an output shaft 28, and a cycloid reduction mechanism that transmits rotation between the input shaft 25 and the output shaft 28. Specifically, out of both ends of the input shaft 25, eccentric portions 25a and 25b provided eccentric to the end of the input shaft 25 on the side far from the motor rotation shaft 35, and the inner periphery of the eccentric portions 25a and 25b. Curved plates 26a and 26b as revolving members which are attached to the outer periphery so as to be relatively rotatable and perform a revolving motion around the rotation axis along with the rotation of the input shaft 25, and the outer peripheries of the corrugated plates 26a and 26b which are wave shaped A plurality of outer pins 27 as outer peripheral engagement members that engage with the portions to cause the rotation of the curved plates 26a and 26b, and a motion conversion mechanism that extracts only the rotation of the curved plates 26a and 26b and transmits it to the output shaft 28. Have Moreover, the deceleration part B is supplied with lubricating oil by the lubricating oil circuit mentioned later.

  Referring to FIG. 2, the curved plate 26 a has a plurality of corrugations composed of trochoidal curves such as epitrochoids on the outer peripheral portion, and a plurality of through holes 30 a and 30 b penetrating from one end face to the other end face. Have A plurality of through holes 30a are provided at equal intervals on the circumference centered on the rotation axis of the curved plate 26a, and receive an inner pin 31 described later. The through hole 30b is provided at the center (rotation axis) of the curved plate 26a, and holds the outer peripheral surface of the eccentric portion 25a so as to be concentric. The same applies to the curved plate 26b.

  The curved plate 26a which is a rotating element is supported by the rolling bearing 41 so as to be rotatable with respect to the eccentric portion 25a. The rolling bearing 41 serving as a rotating element is formed directly on the inner peripheral surface of the inner ring member 42 having the inner raceway surface 42a fitted on the outer peripheral surface of the eccentric portion 25a and the through hole 30b of the curved plate 26a. A cylindrical roller provided with an outer raceway surface 43, a plurality of cylindrical rollers 44 disposed between the inner raceway surface 42 a and the outer raceway surface 43, and a cage (not shown) that holds the spacing between adjacent cylindrical rollers 44. It is a bearing. Alternatively, it may be a deep groove ball bearing. The inner ring member 42 further has a pair of flanges facing each other across the inner raceway surface 42a of the inner ring member 42 on which the cylindrical rollers 44 that are rolling elements roll, and the cylindrical rollers 44 are paired with a pair of flanges. Hold in between.

  As shown in FIG. 3, the outer pin 27 extends in parallel with the axis O, and both ends thereof are supported by the outer pin holding member 45 via the needle roller bearings 27a. The outer pin holding member 45 has a cylindrical portion and inward flange portions 45f formed at both axial ends of the cylindrical portion. And the hole for supporting the edge part of the outer pin 27 is formed in the inward flange part 45f of the outer pin holding member 45 at the circumferential direction equal intervals. The outer pin holding member 45 is attached and fixed to the inner surface of the speed reduction unit casing member 22b. A through hole 61 is formed in the lower portion of the outer pin holding member 45. The through hole 61 is a long hole that is long in the circumferential direction of the outer pin holding member 45 as shown in FIG. 2 and narrow in the axial direction as shown in FIG. The central portion in the circumferential direction of the through hole 61 is at a position lower than both sides in the circumferential direction of the through hole 61. As will be described later, the lubricating oil flows along the inner peripheral surface of the curved outer pin holding member 45 and is guided to the central portion in the circumferential direction of the through hole 61.

  As shown in FIG. 1, the motion conversion mechanism includes a plurality of inner pins 31 as inner engagement members implanted in the flange portion 28 a of the output shaft 28, and through holes 30 a provided in the curved plates 26 a and 26 b. Consists of. The inner pins 31 are provided at equal intervals (see FIG. 2) on a circumferential track centering on the axis O serving as the rotation axis of the output shaft 28, and extend in parallel with the axis O of the output shaft 28. The base end of 31 is fixed to the output shaft 28. On the outer periphery of the inner pin 31, a hollow cylindrical body 31a and a needle roller bearing including a plurality of rollers 31e arranged in an annular gap between the hollow cylindrical body 31a and the inner pin 31 are provided. This needle roller bearing is a part of the inner pin 31.

  The output shaft 28 arranged coaxially with the input shaft 25 takes out the rotation of the curved plates 26a and 26b as the output of the speed reduction unit B through the motion conversion mechanism described above. As a result, the rotation of the input shaft 25 is decelerated by the deceleration unit B and transmitted to the output shaft 28. Therefore, even when the low torque, high rotation type motor unit A is employed, it is possible to transmit the necessary torque to the drive wheels.

  The wheel hub bearing portion C includes a hub wheel 32 fixedly connected to the output shaft 28 and a wheel hub bearing 33 that holds the hub wheel 32 rotatably with respect to the casing 22. The wheel hub bearing 33 is a double-row angular ball bearing, and an inner ring member 33 n is fitted and fixed to the outer peripheral surface of the hub ring 32. A plurality of balls 33b are arranged in the annular gap between the outer ring member 33g and the inner ring member 33n. Further, a plurality of balls 33 b are arranged in the annular gap between the outer ring member 33 g and the hub ring 32.

  The outer ring member 33g of the wheel hub bearing 33 is fixed to the axial end of the speed reduction unit casing member 22b. The hub wheel 32 includes a cylindrical hollow portion 32 a that is coupled to the shaft portion 28 b of the output shaft 28, and a flange portion 32 b that is formed at an end portion on the side farther from the speed reduction portion B. A driving wheel (not shown) is fixedly connected to the flange portion 32b by a bolt 32c. Since the output shaft 28 of the speed reduction part B and the hub wheel 32 of the wheel hub bearing part C extend along the substantially horizontal axis O and rotate together, the assembly of the output shaft 28 and the hub wheel 32 is a wheel-side rotating member. Called.

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

  The motor unit A is supplied with a motor drive current from the battery 48 via the inverter 49, receives an electromagnetic force generated by supplying an AC motor drive current to the coil 23c of the stator 23, and is configured by a permanent magnet or a magnetic material. The rotor 24 is rotated. The motor drive current is controlled by a motor control unit 50 that is electrically connected to the inverter 49. The motor control unit 50, the battery 48, and the inverter 49 are mounted on the vehicle body.

  As a result, the motor rotating shaft 35 connected to the rotor 24 outputs rotation, and when the motor rotating shaft 35 and the input shaft 25 rotate, the curved plates 26 a and 26 b revolve around the axis O of the input shaft 25. At this time, the outer pin 27 is engaged so as to be in rolling contact with the curved waveform of the curved plates 26 a and 26 b to rotate the curved plates 26 a and 26 b in the direction opposite to the rotation of the input shaft 25.

  The hollow cylindrical body 31a of the inner pin 31 inserted through the through hole 30a is sufficiently thinner than the inner diameter of the through hole 30a, and is a rotating element that contacts the hole wall surface of the through hole 30a as the curved plates 26a and 26b rotate. It is. As a result, the revolving motion of the curved plates 26 a and 26 b is not transmitted to the inner pin 31, and only the rotational motion of the curved plates 26 a and 26 b is transmitted to the wheel hub bearing portion C via the output shaft 28. Thus, the through hole 30a and the inner pin 31 serve as a motion conversion mechanism.

  Through this motion conversion mechanism, the output shaft 28 arranged coaxially with the input shaft 25 takes out the rotation of the curved plates 26a, 26b as the output of the deceleration unit B. As a result, the rotation of the input shaft 25 is decelerated by the deceleration unit B and transmitted to the output shaft 28. Therefore, even when the low torque, high rotation type motor unit A is employed, it is possible to transmit the necessary torque to the drive wheels.

Note that the reduction ratio of the speed reduction unit B having the above-described configuration 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. The In the embodiment shown in FIG. 2, because Z _A = 12 and Z _B = 11, the reduction ratio is 1/11, and a very large reduction ratio can be obtained.

  Thus, by adopting the cycloid reduction mechanism that can obtain a large reduction ratio without using a multistage configuration in the reduction part B, a compact and high reduction ratio in-wheel motor drive device 21 can be obtained.

  Next, a mechanism for circulating the lubricating oil in the in-wheel motor drive device 21 will be described. The lubricating oil circuit is described with reference to FIGS. 1 and 2. The lubricating oil pump 51, the discharge oil passage 54, and the casing oil passage 55. A communication oil passage 56, an output shaft cover oil passage 57, a motor rotation shaft oil passage 58a, a speed reducing portion input shaft oil passage 58b, radial oil passages 59a and 59b, an annular groove 60g, and an oil supply hole tip. The end port 60h, the through holes 61 and 62, the lubricating oil tank 53, and the suction oil passage 52 are provided, and the lubricating oil is circulated in this order. As a result, the lubricating oil circuit lubricates rotating elements such as the input shaft 25, the output shaft 28, the inner pin 31, the eccentric portions 25a and 25b, the curved plates 26a and 26b, and various needle roller bearings that constitute the speed reduction portion B. Cool down.

  A lubricating oil tank 53 is attached to the lower part of the speed reduction unit casing member 22b. The space of the speed reduction part B that houses the outer pin 27, the inner pin 31, the eccentric parts 25a and 25b, the curved plates 26a and 26b, and the outer pin holding member 45, and the lubricating oil tank 53 are the hollow cylinders of the speed reduction part casing member 22b. A wall is defined as a boundary wall. The boundary wall is provided with a through hole 62. The through holes 61 and 62 communicating in the vertical direction are discharge oil passages for discharging the lubricating oil from the speed reduction portion B to the lubricating oil tank 53. The lubricating oil that has lubricated the cycloid reduction mechanism of the reduction part B gathers under its own weight as indicated by the arrow in FIG. 2 and flows down through the through holes 61 and 62 sequentially as indicated by the arrow in FIG. And stored in the lubricating oil tank 53.

  A temperature sensor 63 is disposed between the through-holes 61 and 62 that are the lowermost part of the deceleration unit B. As shown in the enlarged view of FIG. 3, the temperature sensor 63 is a cylindrical thermistor and has a sensing unit 63s at the center in the longitudinal direction. One end of the temperature sensor 63 is connected to the motor control unit 50 via the signal line 65, detects the temperature of the lubricating oil flowing down the through holes 61 and 62, and transmits the detection signal to the motor control unit 50. The motor control unit 50 includes a motor drive current control unit 50a that controls a motor drive current supplied to the motor unit A, and a temperature-responsive motor control unit 50b that prevents an overload operation of the deceleration unit B. The temperature corresponding motor control means 50b will be described later.

  The temperature sensor 63 is fixedly supported by the temperature sensor support member 66. FIG. 4 is a perspective view showing the temperature sensor support member together with the temperature sensor. FIG. 5 is a plan view showing the temperature sensor support member together with the temperature sensor. FIG. 6 is a longitudinal sectional view showing the temperature sensor support member together with the temperature sensor, and represents a VI-VI section in FIG. 5. FIG. 7 is a transverse sectional view showing the temperature sensor support member, and represents a VII-VII section in FIG. 5. As shown in FIG. 5, the temperature sensor support member 66 is H-shaped, and a receiving portion 66a is formed at the center thereof. The receiving portion 66a has a circular opening cross section extending in the vertical direction, and has an opening shape in which the lower end side has a smaller diameter than the upper end side like a funnel. The lower end opening 66d of the receiving portion 66a is a circular opening having the same diameter as the lower end of the receiving portion 66a having the smallest diameter, and extends in the vertical direction. That is, the lower end opening 66d is a circular opening section having a constant diameter that does not change in the vertical direction from the upper end side to the lower end side of the lower end opening 66d.

  The H-shaped temperature sensor support member 66 has two arm portions 66b extending in parallel with each other on both sides of the receiving portion 66a. The arm portion 66b draws a gentle arc along the outer peripheral surface of the outer pin holding member 45. At both ends of each arm portion 66b, a hole 66h penetrating in the vertical direction is formed. As shown in FIG. 2, a bolt 67 is passed from below into each hole 66 h, and the temperature sensor support member 66 allows the through hole 61 to pass through by screwing the upper end of the bolt 67 into the lower part of the outer pin holding member 45. It is fixed so as to straddle. The two arm portions 66b are attached to both sides of the through-hole 61 so as to be separated from each other in the axial direction, and the receiving portion 66a is held in the circumferential center of the through-hole 61, that is, the outer pin is held It is arranged at the lowermost part of the member 45. Thereby, the opening of the through hole 61 is formed between the hole edge on one side in the circumferential direction of the through hole 61 and the receiving part 66a and between the hole edge on the other side in the circumferential direction of the through hole 61 and the receiving part 66a. Is left behind.

  The temperature sensor support member 66 is further formed with a lateral hole 66c. The horizontal hole 66c has a circular opening cross section and extends from one arm portion 66b to the other arm portion 66b across a lower end opening 66d connected to the lower end of the receiving portion 66a. The horizontal hole 66c receives the cylindrical temperature sensor 63. Both ends of the temperature sensor 63 are fixed to the horizontal holes 66c by appropriate fixing means. Thereby, the sensing part 63s located at the center of the temperature sensor 63 is arranged in the receiving part 66a.

  As shown in FIG. 1, a lubricating oil pump 51 and a discharge extending upward from the lubricating oil pump 51 are formed on an inward flange portion 22 e that becomes a boundary wall between the motor portion A and the speed reducing portion B of the motor portion casing member 22 a. An oil passage 54 and a suction oil passage 52 extending downward from the lubricating oil pump 51 are provided. The lower end of the suction oil passage 52 is connected to the lubricating oil tank 53. The lubricating oil pump 51 draws lubricating oil from the lubricating oil tank 53 and discharges it to the discharge oil passage 54.

  The drive mechanism of the lubricating oil pump 51 will be described. With reference to FIG. 1, an inner pin support member 31 b that supports the inner pin 31 is connected and fixed to the tip of each inner pin 31 by press-fitting. The inner pin support member 31b is connected to the inner flange portion 31c of the annular flange portion 31c connecting the tips of the inner pins 31, and the cylindrical cylindrical shape extending in the axial direction so as to be separated from the inner pin 31. Part 31d. The inner pin support member 31 b that supports the plurality of inner pins 31 uniformly distributes the load applied to some of the inner pins 31 from the curved plates 26 a and 26 b to all the inner pins 31. The cylindrical portion 31d supports the needle roller bearing 36c on its inner peripheral surface, and engages with the lubricating oil pump 51 on its outer peripheral surface.

  When the plurality of inner pins 31 rotate together with the output shaft 28, the cylindrical portion 31 d that is rotated by the inner pins 31 drives the lubricating oil pump 51. The lubricating oil pump 51 provided at the inner peripheral edge of the inward flange portion 22 e is driven by the output of the motor part A, and circulates the lubricating oil inside the in-wheel motor driving device 21.

  The lubricating oil pump 51 is disposed coaxially with the axis O, and is driven by the inner pin support member 31b. The suction oil passage 52 formed inside the wall of the inward flange portion 22e extends in the vertical direction, and its upper end is connected to the suction port of the lubricating oil pump 51, and its lower end is provided at the lower part of the speed reduction part B. Connected to the lubricating oil tank 53. The discharge oil passage 54 formed inside the wall of the inward flange portion 22e extends in the vertical direction, is connected to the discharge port of the lubricating oil pump 51 at the lower end, and is formed in the motor casing member 22a at the upper end. Connected to one end of the casing oil passage 55.

  The casing oil passage 55 is formed inside the hollow cylindrical wall that constitutes the motor part casing member 22a, and extends in the axial direction. The end of the casing oil passage 55 on the motor cover 22 d side is connected to the outer diameter side end of the communication oil passage 56. The communication oil passage 56 is formed inside the wall of the motor cover 22d of the casing 22 and extends in the radial direction. An inner diameter side end of the communication oil passage 56 is connected to a motor rotation shaft oil passage 58 a provided in the motor rotation shaft 35 via an output shaft cover oil passage 57.

  The output shaft cover oil passage 57 is provided in the output shaft cover 22 f that becomes a part of the casing 22. The output shaft cover 22 f is a substantially disk-shaped wall member positioned opposite to one end of the motor rotation shaft 35. The output shaft cover oil passage 57 is formed inside the wall of the output shaft cover 22f.

  The motor rotation shaft oil passage 58 a is an oil passage that is provided inside the motor rotation shaft 35 and extends along the axis O to supply the center of the shaft. One end of the motor rotation shaft oil passage 58a on the side close to the speed reduction portion B is connected to a speed reduction portion input shaft oil passage 58b provided on the input shaft 25 and extending along the axis O. Further, one end of the motor rotation shaft oil passage 58a on the side farther from the speed reduction portion B is connected to the output shaft cover oil passage 57 described above. Further, the motor rotation shaft oil passage 58a is connected to the inner diameter side end of the rotor oil passage 64 at the middle in the axial direction.

  The speed reducer input shaft oil passage 58b is an oil passage provided inside the input shaft 25 and extending along the axis O between both ends of the input shaft 25. An oil supply hole 59c is provided at one end of the output shaft 28 facing the flange portion 28a. The oil supply hole 59c is a hole having a smaller diameter than the cross section of the speed reduction part input shaft oil path 58b, and regulates the flow rate of the lubricating oil passing therethrough so as to communicate one end of the speed reduction part input shaft oil path 58b with the rolling bearing 36d. . Since the motor rotation shaft oil passage 58a and the speed reducer input shaft oil passage 58b continuously extend to form one straight line, they are also referred to as an axial oil passage.

  The speed reducer input shaft oil passage 58b is branched into a radial oil passage 59a extending radially outward in the eccentric portion 25a and a radial oil passage 59b extending radially outward in the eccentric portion 25b. To do. Since the radial oil passages 59a and 59b have the same configuration, the radial oil passage 59a will be described. Referring to FIG. 2, the radial oil passage 59a is in the anti-eccentric direction of the eccentric portion 25a, that is, the eccentric portion from the axis O. It extends linearly in the direction closest to the outer peripheral surface of 25a. The outer diameter side end of the radial oil passage 59a is connected to an annular groove 60g formed along the outer peripheral surface of the eccentric portion 25a. The annular groove 60g is disposed between the outer peripheral surface of the eccentric portion 25a and the inner peripheral surface of the inner ring member 42, and is connected to a plurality of oil supply hole tip ports 60h drilled in the inner ring member 42. The oil supply hole front end port 60h penetrates from the inner peripheral surface of the inner ring member 42 to the inner raceway surface 42a.

  Explaining the operation of the lubricating oil circuit, the lubricating oil pump 51 driven by the output shaft 28 via the inner pin support member 31b sucks the lubricating oil stored in the lubricating oil tank 53 via the suction oil passage 52, Lubricating oil is discharged into the discharge oil passage 54. The lubricating oil is pressurized by the lubricating oil pump 51 and flows from the discharge oil passage 54 through the casing oil passage 55, the communication oil passage 56, the output shaft cover oil passage 57, and the motor rotation shaft oil passage 58a.

  A part of the lubricating oil flowing through the motor rotating shaft oil passage 58a flows into the rotor oil passage 64, and is jetted from the outer peripheral surface of the rotor 24 in the outer diameter direction toward the stator 23 to cool the rotor 24 and the stator 23. . Next, the lubricating oil goes to the lower part of the motor part A and returns to the lubricating oil tank 53 through the discharge hole 68.

  Further, the remaining portion of the lubricating oil flowing through the motor rotating shaft oil passage 58a flows into the speed reducer input shaft oil passage 58b. A part of the lubricating oil flowing through the speed reducing portion input shaft oil passage 58b branches and flows into the radial oil passages 59a and 59b, respectively, and is injected from the oil supply hole front end port 60h to the inner raceway surface 42a via the annular groove 60g. Is done. Such lubricating oil lubricates the rolling bearing 41 provided in the eccentric portion 25a and the rolling bearing 41 provided in the eccentric portion 25b. The lubricating oil flows in the direction of the outer diameter of the speed reduction portion B by the action of centrifugal force. In the speed reduction portion B, the surface of the curved plates 26a and 26b, the contact location between the inner pin 31 and the hole wall surface of the through hole 30a, and the hollow cylinder The body 31a, the roller 31e, the engaging portion of the outer pin 27 and the waved outer peripheral surfaces of the curved plates 26a and 26b, and the surface of the outer pin 27 are lubricated sequentially. Lubricating oil lubricates and cools the speed reduction part B suitably by this axial center oil supply system.

  Further, the remaining portion of the lubricating oil flowing through the speed reduction portion input shaft oil passage 58b is injected from the oil supply hole 59c toward the flange portion 28a, lubricates the rolling bearing 36d, and flows into the speed reduction portion B. The lubricating oil flowing into the speed reduction part B from the radial oil passages 59a and 59b and the oil supply hole 59c flows toward the lower part of the speed reduction part B and flows down along the inner peripheral surface of the cylindrical part of the outer pin holding member 45. As shown by the arrows in FIG. At this time, the lubricating oil is guided to the receiving portion 66a arranged at the center in the circumferential direction of the through hole 61, that is, the lowermost portion of the outer pin holding member 45. Then, the lubricating oil enters the receiving port 66a, and is uniformly applied to the sensing unit 63s of the temperature sensor 63 by the funnel-shaped receiving port 66a as indicated by an arrow in FIG. The lubricating oil overflowing from the receiving port 66a flows down the opening between the opening 66a and the hole edge of the through hole 61. The lubricating oil that has flowed down through the through hole 61 in this manner then flows down through the through hole 62 and returns to the lubricating oil tank 53.

  Thus, the lubricating oil circuit supplies the lubricating oil from the lubricating oil tank 53 to the speed reducing unit B, and discharges the lubricating oil from the speed reducing unit B to the lubricating oil tank 53. As described above, in the in-wheel motor drive device 21 of the present embodiment, the temperature of the lubricating oil B is detected by the temperature sensor 63 as a means for preventing the overload operation of the deceleration unit B, and according to the detection result, The output of the motor part A is limited.

  In addition, according to the present embodiment, the lubricating oil that has just lubricated the speed reducing portion B flows through the through holes 61 and 62, and the temperature of the lubricating oil flowing down through the through holes 61 and 62 is measured by the temperature sensor 63. Thereby, even if it does not provide a temperature sensor directly in the rotation element of the deceleration part B, the temperature state of the deceleration part B can be known correctly.

  The detection signal of the lubricating oil temperature detected by the temperature sensor 63 is transmitted to the motor control unit 50 that controls the output of the in-wheel motor drive device 21, and the temperature corresponding motor control means 50b provided in the motor control unit 50 is used. Receive a detection signal of the lubricant temperature. The motor control unit 50 is installed outside the in-wheel motor drive device 21, for example, the vehicle body, but may be attached inside the in-wheel motor drive device 21. The control executed by the motor control unit 50 is shown in a flowchart in FIG.

  When the main key of the vehicle equipped with the in-wheel motor drive device is turned from OFF to ON, the motor control of the motor part A is started. First, in step S10, a normal motor driving torque is input from the motor unit A to the deceleration unit B. The normal motor driving torque is calculated from the opening degree of the accelerator operator operated by the driver of the vehicle. The motor drive current control unit 50a instructs the inverter 49 to energize the motor unit A with a motor drive current corresponding to a normal motor drive torque. Here, the temperature-corresponding motor control means 50b does not transmit any decrease command to the motor drive current control unit 50a.

  In the next step S <b> 20, the temperature corresponding motor control unit 50 b reads the lubricating oil temperature of the speed reduction unit detected by the temperature sensor 63. In the next step S30, the temperature-corresponding motor control means 50b determines whether or not the read lubricating oil temperature of the deceleration unit B is equal to or higher than a predetermined specified value. If it is less than the specified value (No), the deceleration unit B determines that it is not an overload operation, returns to step S20, and then monitors the lubricating oil temperature of the deceleration unit B. On the other hand, when it is more than a regulation value (Yes), it judges that deceleration part B is overload operation, and progresses to Step S40. Note that the predetermined specified value is obtained by confirming the correlation between the temperature of the rotating element of the speed reduction unit B and the temperature of the lubricating oil discharged from the speed reduction unit B by a test or the like in advance. Substitute as the temperature of the rotating element.

  Alternatively, in step S30, instead of the above-described determination, a change (temperature gradient) in the lubricating oil temperature per unit time is calculated, and the temperature increase in the lubricating oil temperature per unit time is more rapid than a predetermined specified value. Yes may be set to No. Otherwise, No may be set.

  In step S <b> 40, the temperature corresponding motor control unit 50 b limits the output of the in-wheel motor drive device 21. That is, the motor drive torque input from the motor unit A to the speed reduction unit B is made smaller than the normal motor drive torque to protect the speed reduction unit B. Specifically, the temperature-corresponding motor control means 50b commands the motor drive current control unit 50a, and the motor drive current control unit 50a commands the inverter 49 to energize the motor unit A with a motor drive current that is reduced than usual. To do. Thereby, the motor drive torque of the motor part A decreases. And the rotation speed of the motor rotating shaft 35 decreases.

  After exiting step S40, the process returns to step S10, and the above-described flow is repeated every predetermined unit time (for example, 10 to 1000 msec). When the main key of the vehicle equipped with the in-wheel motor drive device turns from ON to OFF, the motor control of the motor unit A is terminated.

  In the present embodiment, the determination result of step S30 described above may be displayed on the driver's seat. As a result, the driver can be urged to reduce the opening of the accelerator operator.

  According to the lubricating oil circuit of the present embodiment, the lubricating oil tank 53, the oil supply hole front end port 60h as a supply oil passage for supplying the lubricating oil from the lubricating oil tank 53 to the speed reducing portion B, and the lubricating oil tank from the speed reducing portion B are provided. 53 has through holes 61 and 62 as discharge oil passages for discharging the lubricating oil, and a temperature sensor 63 that is disposed in the through holes 61 and 62 and detects the temperature of the lubricating oil. The closest lubricating oil temperature can be detected by the temperature sensor 63. Therefore, when the speed reduction part B becomes high temperature, the overload operation of the speed reduction part B can be accurately determined and the overload operation can be prevented accurately.

  In addition, according to the present embodiment, the lubricating oil tank 53 is provided below the speed reduction unit B, and the discharge oil passage for discharging the lubricating oil from the speed reduction unit B extends in the vertical direction on the boundary wall between the speed reduction unit B and the lubricating oil tank 53. The temperature sensor 63 is disposed between the through hole 61 and the through hole 62. As a result, the temperature of the lubricating oil just discharged from the speed reduction part B can be detected in the vicinity of the speed reduction part B. Therefore, the temperature of the deceleration part B can be detected more accurately.

  According to the present embodiment, the temperature sensor support member 66 is provided below the through hole 61 and above the through hole 62. The temperature sensor support member 66 has an opening-shaped receiving portion 66a whose lower end side is smaller in diameter than the upper end side, and a horizontal hole 66c extending across the lower end side of the receiving portion 66a, and the temperature sensor in the horizontal hole 66c. 63 is accommodated. As a result, the lubricating oil that has just been discharged from the deceleration portion B can be collected in the temperature sensor 63, and the lubricating oil can be applied to the temperature sensor 63 without unevenness. Therefore, the detection accuracy of the lubricating oil temperature is improved.

  Further, according to the present embodiment, the motor controller 50b corresponding to the temperature is further provided for limiting the output of the motor unit A when the lubricating oil temperature detected by the temperature sensor 63 is equal to or higher than a predetermined specified value. Thereby, the overload driving | operation of the deceleration part B can be prevented.

  Although the embodiments of the present invention have been described with reference to the drawings, the present invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The in-wheel motor drive device according to the present invention is advantageously used in electric vehicles and hybrid vehicles.

21 in-wheel motor drive device, 22 casing,
22a motor part casing member, 22b reduction part casing member,
22f output shaft cover, 23 stator, 23c coil, 24 rotor,
25 input shaft, 25a, 25b eccentric part, 26a, 26b curved plate,
27 outer pin, 28 output shaft, 61, 62 through hole, 31 inner pin,
31a hollow cylindrical body, 31b inner pin support member, 32 hub ring,
33 wheel hub bearing, 35 motor rotating shaft, 41 rolling bearing,
45 outer pin holding member, 48 battery, 49 inverter,
50 motor control unit, 50a motor drive current control unit,
50b motor controller corresponding to temperature, 51 lubricating oil pump, 52 suction oil passage,
53 lubricating oil tank, 54 discharge oil passage, 55 casing oil passage,
56 communication oil passage, 57 output shaft cover oil passage, 58a motor rotation shaft oil passage,
58b Speed reducer input shaft oil passage, 59a, 59b Radial oil passage, 59c Oil supply hole,
60g annular groove, 60h oil supply hole tip, 63 temperature sensor,
65 signal line, 66 temperature sensor support member, 66a receiving part, 66c side hole, A motor part, B speed reducing part, C wheel hub bearing part, O axis line.

Claims (4)

A motor part, a wheel hub bearing part, a speed reduction part that decelerates the output rotation of the motor part and transmits it to the wheel hub bearing part, and a lubricating oil circuit that flows lubricating oil inside the speed reduction part,
The lubricating oil circuit includes a lubricating oil tank, a supply oil path for supplying lubricating oil from the lubricating oil tank to the speed reducing part, a discharge oil path for discharging lubricating oil from the speed reducing part to the lubricating oil tank, An in-wheel motor drive device comprising: a temperature sensor that is disposed in a discharge oil passage or the lubricating oil tank and detects a temperature of the lubricating oil. The lubricating oil tank is provided below the speed reduction unit,
The drain oil passage is a through-hole penetrating a boundary wall between the speed reduction portion and the lubricating oil tank in the vertical direction,
The in-wheel motor drive device according to claim 1, wherein the temperature sensor is disposed in the through hole or the lubricating oil tank.   The through hole has an opening-shaped receiving portion whose lower end side is smaller in diameter than the upper end side, and a horizontal hole extending across the lower end side of the receiving portion, and the temperature sensor is accommodated in the horizontal hole The in-wheel motor drive device according to claim 2, wherein a temperature sensor support member is provided.   The in-wheel motor according to any one of claims 1 to 3, further comprising temperature-responsive motor control means for restricting the output of the motor unit when the lubricating oil temperature detected by the temperature sensor is equal to or higher than a predetermined specified value. Drive device.

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