JP2015027820A - In-wheel motor driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent failures caused by deterioration and impurity contamination of a lubrication oil, which lubricates and cools an electric motor and a speed reducer of an in-wheel motor driving device.SOLUTION: An in-wheel motor driving device includes: an electric motor A which generates a driving force; a speed reducer B which reduces a speed of rotations of the electric motor A and outputs the rotations; and a wheel hub C which transmits the output from the speed reducer B to a wheel. The electric motor A and the speed reducer B are housed in a housing 22. The in-wheel motor driving device is provided with a lubrication oil passage 22e for lubricating and cooling the electric motor A and the speed reducer B. In the in-wheel motor driving device, a lubrication oil monitoring device 65 which detects deterioration and impurity contamination of a lubrication oil is installed in the lubrication oil passage 22e.

Description

  The present invention relates to an in-wheel motor drive device, and more particularly to an in-wheel motor drive device incorporating an oil pump that supplies lubricating oil using the rotation of a motor as a drive source.

  The in-wheel motor drive device 101 is installed in an inner space portion of a wheel of an automobile, and as shown in FIG. 14, an electric motor 103 that generates a driving force inside a housing 102 attached to a vehicle body, and a wheel And a speed reducer 105 that decelerates the rotation of the electric motor 103 and transmits it to the wheel hub 104.

  In the in-wheel motor drive device 101 having the above-described configuration, a low torque and high rotation motor is adopted as the electric motor 103 from the viewpoint of compactness of the device. On the other hand, the wheel hub 104 requires a large torque to drive the wheels. For this reason, a cycloid reduction gear that is compact and provides a high reduction ratio is often adopted as the reduction gear 105.

  A speed reducer 105 to which a cycloid speed reducer is applied includes an input shaft 106 having eccentric portions 106 a and 106 b, curved plates 107 a and 107 b arranged on the eccentric portions 106 a and 106 b, and curved plates 107 a and 107 b with respect to the input shaft 106. Rolling bearings 106c that are rotatably supported, a plurality of outer peripheral engagement members 108 that engage with the outer peripheral surfaces of the curved plates 107a and 107b to cause the curved plates 107a and 107b to rotate, and the curved plates 107a and 107b. And a plurality of inner pins 109 that transmit the rotation motion to the wheel-side rotation member 110.

    In the in-wheel motor drive device 101 configured as described above, an oil tank 102d for lubricating oil is provided at the lower portion of the housing 102, and the lubricating oil in the oil tank 102d is sucked by the rotary pump 113 from the suction passage 102f, and the electric motor 103 and the reduction gear A lubricating device is provided that supplies lubricating oil to 105 to perform lubrication and cooling (Patent Document 1).

    The lubricating device is provided in the housing 102 with a lubricating oil path 112 a provided in the motor-side rotating member 112, a lubricating oil supply port 112 b extending from the lubricating oil path 112 a toward the outer diameter surface of the motor-side rotating member 112, and the housing 102. The lubricating oil discharge port 102b for discharging the lubricating oil from the speed reducer 105, the lubricating oil discharging port 102b, and the lubricating oil passage 112a are connected, and the lubricating oil discharged from the lubricating oil discharging port 102b is returned to the lubricating oil passage 112a. A circulating oil path 102c that is disposed in the housing 102, and a rotary pump 113 that circulates the lubricating oil using the rotation of the wheel-side rotating member 110.

  Between the lubricating oil discharge port 102b and the rotary pump 113, an oil tank 102d for temporarily storing lubricating oil is provided at a lower portion of the speed reduction unit housing 102e of the reduction gear 105.

  In the in-wheel motor drive device 101 of FIG. 14, the lubricating oil sucked in by the rotary pump 113 is passed through the motor-side rotating member 112 of the electric motor 103 from the circulating oil passage 102 c provided on the upper and rear sides of the housing 102, and the speed reducer 105. It is circulated to. The lubricating oil lubricates and cools the inside of the speed reducer 105 from the lubricating oil supply port 112b of the motor side rotating member 112, and further lubricates and cools the inside of the electric motor 103 from the lubricating oil supply port 112c. The flow of the lubricating oil is indicated by broken arrows.

JP 2009-63043 A

  By the way, the lubricating oil used for the in-wheel motor drive device 101 has a function of cooling the electric motor 103.

  Since the electric motor 103 is also interposed in the conductive portion, in addition to the performance required for the engine oil used in the reciprocating engine, electrical non-conductivity is also an important performance.

  However, if the lubricating oil itself is oxidized or if the lubricating oil contains sludge (metal powder) or the like, a short circuit occurs in the coil of the electric motor 103, which may lead to a vehicle failure.

  Therefore, an object of the present invention is to prevent a failure of an in-wheel motor drive device caused by a problem caused by deterioration of lubricating oil or contamination of impurities.

  In order to solve the above-described problems, the present invention includes an electric motor that generates a driving force, a speed reducer that decelerates and outputs the rotation of the electric motor, and a wheel hub that transmits the output from the speed reducer to the wheel. In the in-wheel motor drive device in which the electric motor and the speed reducer are accommodated in the housing and provided with a lubricating oil path for lubricating and cooling the electric motor and the speed reducer, the lubricating oil is deteriorated in the lubricating oil path. A lubricating oil monitoring device that detects contamination by impurities is installed.

    As the lubricant monitoring device, an electromagnetic flow meter or a two-electrode conductivity measuring device can be used.

  Moreover, a flowmeter and a pressure gauge can also be used as the lubricating oil monitoring device.

  An oil filter may be installed upstream or downstream of the lubricating oil monitoring device.

  As described above, according to the present invention, since the conductivity of the lubricating oil can be monitored, a short circuit of the coil of the electric motor can be prevented in advance.

  By installing the oil filter, sludge mixed in the lubricating oil can be removed.

Moreover, it is possible to detect clogging of lubricating oil by installing an anemometer.
Moreover, deterioration of the lubricating oil can be detected by installing a pressure gauge.

It is a schematic sectional drawing of the in-wheel motor drive device concerning one Embodiment of this invention. It is an enlarged view of the electric motor of FIG. It is an enlarged view of the reduction gear of FIG. It is an enlarged view of the wheel hub of FIG. It is sectional drawing of the VV line of FIG. It is an enlarged view of the eccentric part periphery of FIG. It is the figure which looked at the rotary pump of FIG. 1 from the axial direction. It is a schematic plan view of the electric vehicle which has the in-wheel motor drive device of FIG. It is the figure which looked at the electric vehicle of FIG. 8 from back. It is the schematic which shows an example of a lubricating oil monitoring apparatus. It is the schematic which shows the other example of a lubricating oil monitoring apparatus. It is the schematic which shows the other example of a lubricating oil monitoring apparatus. It is the schematic which shows the other example of a lubricating oil monitoring apparatus. It is sectional drawing of the in-wheel motor drive device of a prior art example.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  As shown in FIG. 8, an electric vehicle 11 equipped with an in-wheel motor drive device according to an embodiment of the present invention includes a chassis 12, front wheels 13 as steering wheels, drive wheels 14, and left and right drive wheels 14. And an in-wheel motor drive device 21 for transmitting the drive force to each. As shown in FIG. 9, the drive wheel 14 is accommodated in the wheel housing 12a of the chassis 12, and is fixed to the lower portion of the chassis 12 via a suspension device (suspension) 12b.

  The suspension device 12b supports the drive wheel 14 by a suspension arm that extends to the left and right, and suppresses vibration of the chassis 12 by absorbing vibration received by the drive wheel 14 from the ground by a strut including a coil spring and a shock absorber. Furthermore, a stabilizer that suppresses the inclination of the vehicle body when turning or the like is provided at a connecting portion of the left and right suspension arms. The suspension device 12b is an independent suspension type in which the left and right wheels can be moved up and down independently in order to improve the followability to the road surface unevenness and efficiently transmit the driving force of the driving wheels to the road surface. Is desirable.

  In this electric vehicle 11, it is necessary to provide a motor, a drive shaft, a differential gear mechanism, and the like on the chassis 12 by providing an in-wheel motor drive device 21 that drives the left and right drive wheels 14 inside the wheel housing 12a. This eliminates the need to secure a wide cabin space and control the rotation of the left and right drive wheels.

  As shown in FIG. 1, the in-wheel motor drive device 21 includes an electric motor A that generates a driving force, a speed reducer B that decelerates and outputs the rotation of the electric motor A, and an output from the speed reducer B as driving wheels. The electric motor A and the speed reducer are housed in the housing 22 and are mounted in the wheel housing 12a of the electric vehicle 11 as shown in FIG.

  The electric motor A includes a stator 23 fixed to the housing 22, a rotor 24 disposed at a position facing the inner side of the stator 23 with a radial gap, and a rotor 24 fixedly connected to the inner side of the rotor 24. It is a radial gap motor provided with the motor side rotation member 25 which rotates integrally. The rotor 24 includes a flange-shaped rotor portion 24a and a cylindrical hollow portion 24b, and is rotatably supported with respect to the housing 22 by rolling bearings 36a and 36b.

  The motor-side rotating member 25 is arranged from the electric motor A to the speed reducer B in order to transmit the driving force of the electric motor A to the speed reducer B, and has eccentric portions 25 a and 25 b in the speed reducer B. One end of the motor-side rotating member 25 is spline-fitted with the hollow portion 24b of the rotor 24 and is supported by the rolling bearings 36c and 36d in the speed reducer B. Further, the two eccentric portions 25a and 25b are provided with a 180 ° phase change in order to cancel out the centrifugal force due to the eccentric motion.

  The speed reducer B is held at a fixed position on the housing 22 and curved plates 26a and 26b as revolving members that are rotatably held by the eccentric portions 25a and 25b, and engages with the outer peripheral portions of the curved plates 26a and 26b. A plurality of outer pins 27 as outer peripheral engagement members, a motion conversion mechanism that transmits the rotation of the curved plates 26a and 26b to the wheel-side rotation member 28, and a pair of counterweights 29 at positions adjacent to the eccentric portions 25a and 25b With. The reduction gear B is provided with a lubrication device that supplies lubricating oil to the reduction gear B.

  The wheel side rotation member 28 includes a flange portion 28a and a shaft portion 28b. Holes for fixing the inner pins 31 are formed on the end face of the flange portion 28a at equal intervals on the circumference around the rotation axis of the wheel side rotation member 28. The shaft portion 28 b is fitted and fixed to the hub member 32, and transmits the output of the speed reducer B to the drive wheel 14. The flange portion 28a of the wheel side rotation member 28 and the motor side rotation member 25 are rotatably supported by rolling bearings 36c and 36d.

  As shown in FIG. 5, the curved plates 26a and 26b have a plurality of corrugated waves composed of trochoidal curves such as epitrochoids on the outer periphery, and a plurality of through holes 30a 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 centering on the rotation axis of the curved plates 26a, 26b, and receive inner pins 31 described later. Further, the through hole 30b is provided at the center of the curved plates 26a and 26b and is fitted to the eccentric portions 25a and 25b.

  The curved plate 26a is rotatably supported by the rolling bearing 41 with respect to the eccentric portion 25a. As shown in FIG. 6, the rolling bearing 41 is fitted to the outer diameter surface of the eccentric portion 25a, the inner ring member 42 having an inner raceway surface 42a on the outer diameter surface, and the inner diameter of the through hole 30b of the curved plate 26a. The outer raceway surface 43 formed directly on the surface, a plurality of cylindrical rollers 44 disposed between the inner raceway surface 42a and the outer raceway surface 43, and a retainer (not shown) that keeps an interval between the adjacent cylindrical rollers 44 It is a cylindrical roller bearing provided with. Similarly, the curved plate 26a is supported by the rolling bearing 41 so as to be rotatable with respect to the eccentric portion 26a.

  As shown in FIG. 3, the outer pins 27 are provided at equal intervals on a circumferential track centering on the rotation axis of the motor-side rotation member 25. When the curved plates 26a and 26b revolve, the curved waveform and the outer pin 27 engage with each other to cause the curved plates 26a and 26b to rotate. Further, in order to reduce the frictional resistance with the curved plates 26a, 26b, needle roller bearings 27a are provided at the positions of both ends of the outer pin 27.

  The counterweight 29 has a disc shape and has a through-hole that fits with the motor-side rotation member 25 at a position off the center, in order to cancel out the unbalanced inertia couple caused by the rotation of the curved plates 26a and 26b. It is arranged at a position adjacent to each eccentric part 25a, 25b with a 180 ° phase change from the eccentric part.

  Here, as shown in FIG. 6, when the center point between the two curved plates 26a and 26b is G, the distance between the central point G and the center of the curved plate 26a is the right side of the central point G in FIG. L1, the sum of the mass of the curved plate 26a, the rolling bearing 41, and the eccentric portion 25a is m1, the amount of eccentricity of the center of gravity of the curved plate 26a from the rotational axis is ε1, and the distance between the center point G and the counterweight 29 is L2. Assuming that the mass of the counterweight 29 is m2 and the amount of eccentricity from the rotational axis of the center of gravity of the counterweight 29 is ε2, the relationship satisfies L1 × m1 × ε1 = L2 × m2 × ε2. A similar relationship is also established between the curved plate 26b on the left side of the center point G in FIG.

  As shown in FIG. 3, the motion conversion mechanism includes a plurality of inner pins 31 held by the wheel-side rotating member 28 and through holes 30a provided in the curved plates 26a and 26b. The inner pins 31 are provided at equal intervals on a circumferential track centering on the rotational axis of the wheel side rotation member 28, and one axial end thereof is fixed to the wheel side rotation member 28. Further, in order to reduce the frictional resistance with the curved plates 26a, 26b, a needle roller bearing 31a is provided at a position where the curved plates 26a, 26b come into contact with the inner wall surface of the through hole 30a.

  On the other hand, the through hole 30a is provided at a position corresponding to each of the plurality of inner pins 31, and the inner diameter of the through hole 30a is the outer diameter of the inner pin 31 ("the maximum outer diameter including the needle roller bearing 31a"). The same shall apply hereinafter).

  The lubricating device supplies lubricating oil to the electric motor A and the speed reducer B, and includes a lubricating oil passage 25c, a lubricating oil supply port 25d, a lubricating oil discharge port 22b, an oil tank 22d, and a rotary pump 51. And a circulating oil passage 22e.

  The lubricating oil passage 25c extends along the axial direction inside the motor-side rotating member 25. The lubricating oil supply port 25d extends from the lubricating oil passage 25c toward the outer diameter surface of the motor-side rotating member 25. In this embodiment, the lubricating oil supply port 25d is provided in each of the eccentric portions 25a and 25b.

  In addition, a lubricating oil discharge port 22b for discharging the lubricating oil inside the reduction gear B is provided at at least one position below the housing 22f that holds the reduction gear B. The lubricating oil discharge port 22b is in communication with an oil tank 22d provided at the lower part of the housing 22f that holds the reduction gear B.

  The oil tank 22d is connected to the rotary pump 51 via a feedback oil passage 22c provided between the housing 22f of the reduction gear B and the housing 22g of the electric motor A, and the lubricating oil in the oil tank 22d is sucked up by the rotary pump 51. Thus, the lubricating oil passage 25c is forcibly recirculated through the circulating oil passage 22e.

  Here, as shown in FIG. 7, the rotary pump 51 includes an inner rotor 52 that rotates using the rotation of the wheel-side rotating member 28, an outer rotor 53 that rotates following the rotation of the inner rotor 52, and a pump The cycloid pump includes a chamber 54, a suction port 55 that communicates with the return oil passage 22c, and a discharge port 56 that communicates with the circulation oil passage 22e.

  Inner rotor 52 has a tooth profile formed of a cycloid curve on the outer diameter surface. Specifically, the shape of the tooth tip portion 52a is an epicycloid curve, and the shape of the tooth gap portion 52b is a hypocycloid curve. The inner rotor 52 is fitted to the outer diameter surface of the cylindrical portion 31d of the stabilizer 31b and rotates integrally with the inner pin 31 (wheel-side rotating member 28) (see FIG. 1).

  The outer rotor 53 has a tooth profile constituted by a cycloid curve on the inner diameter surface. Specifically, the shape of the tooth tip portion 53a is a hypocycloid curve, and the shape of the tooth gap portion 53b is an epicycloid curve. The outer rotor 53 is rotatably supported by the housing 22.

  The inner rotor 52 rotates about the rotation center c1. On the other hand, the outer rotor 53 rotates around a rotation center c2 different from the rotation center c1 of the inner rotor. Further, when the number of teeth of the inner rotor 52 is n, the number of teeth of the outer rotor 53 is (n + 1). In this embodiment, n = 5.

  A plurality of pump chambers 54 are provided in the space between the inner rotor 52 and the outer rotor 53. When the inner rotor 52 rotates using the rotation of the wheel side rotation member 28, the outer rotor 53 rotates in a driven manner. At this time, since the inner rotor 52 and the outer rotor 53 rotate about different rotation centers c1 and c2, respectively, the volume of the pump chamber 54 changes continuously. As a result, the lubricating oil flowing in from the suction port 55 is pumped from the discharge port 56 to the circulating oil path 22e.

  The rotary pump 51 may be driven at the rotation speed of the electric motor A instead of the rotation speed after deceleration.

  As described above, when the oil tank 22d is provided, the lubricating oil that cannot be completely discharged by the rotary pump 51 can be temporarily stored in the oil tank 22d during high-speed rotation. As a result, an increase in torque loss of the reducer B can be prevented. On the other hand, during low-speed rotation, the lubricating oil stored in the oil tank 22d can be returned to the lubricating oil passage 25c even if the amount of lubricating oil reaching the lubricating oil discharge port 22b decreases. As a result, the lubricating oil can be stably supplied to the reduction gear B.

  The housing 22f of the speed reducer B is provided with an oil tank 22d for lubricating oil at the lower portion. The lubricating oil in the oil tank 22d is sucked by the rotary pump 51, and the lubricating oil is supplied to the electric motor A and the speed reducer B for lubrication. And cooling.

  A lubricating oil passage 25c for supplying lubricating oil to the inside of the speed reducer B is provided from the discharge port of the rotary pump 51 driven in synchronization with the rotation of the wheel-side rotating member 28 that has reduced the speed of the electric motor A by the speed reducer. It extends rearward along the inner side of the housing 22g of the electric motor A, passes through the lubricating oil passage 25c from the rear end portion of the hollow portion 24b of the rotor 24, and is supplied by the lubricating oil supply port 25d of the motor side rotating member 25 of the reduction gear B. Composed. Further, as shown in FIG. 2, an oil supply hole 25 e for supplying lubricating oil to the electric motor A is provided in the hollow portion 24 b of the rotor 24 of the electric motor A.

  The return oil passage 22c for the lubricating oil is configured by a passage that reaches the suction port of the rotary pump 51 through the lubricant discharge port 22b and the oil tank 22d provided at the bottom of the housing 22f of the speed reducer B. The flow of the lubricating oil is as indicated by the dashed arrows.

  In the in-wheel motor drive device according to the present invention, a lubricating oil monitoring device 65 for detecting the mixing or deterioration of impurities in the lubricating oil is installed inside the circulating oil passage 22e of the rear cover 22h portion of the housing 22g of the electric motor A. ing.

  As the lubricant monitoring device 65, for example, an electromagnetic flow meter 65a can be used.

  The electromagnetic flow meter 65a measures the flow rate of a conductive fluid using Faraday's law regarding electromagnetic induction. A non-conductive fluid cannot detect the flow rate, but impurities (metal powder) are When mixed, the flow rate is detected, so that the mixed state of conductive impurities (metal powder) into the lubricating oil can be detected by the electromagnetic flow meter 65a. In addition, by using a capacitance type as the electromagnetic flow meter 65a, it is possible to detect a slight amount of impurities mixed in the lubricating oil.

  As the lubricant monitoring device 65, for example, a two-electrode conductivity measuring device 65b can be used.

  FIG. 10 is a schematic configuration diagram of a two-electrode type conductivity measuring device 65b, in which two electrodes 65c are separated from each other in the circulating oil passage 22e, and the current between the two electrodes 65c is measured by an ammeter 68. By measuring the change in the conductivity of the lubricating oil, it is possible to detect the mixing of impurities (metal powder) into the lubricating oil. As a result of detection, when the lubricating oil needs to be replaced, a vehicle failure is prevented by displaying it on the driver and informing the driver.

  Moreover, as the lubricating oil monitoring device 65, for example, a device that detects the flow velocity by using an electrode 65d with a strain gauge 65e attached, as shown in FIG. 11, can be used.

  By detecting the flow rate of the lubricating oil, it is possible to detect clogging of the lubricating oil.

  As shown in FIGS. 1 and 2, an oil filter 66 may be provided in the lubricating oil monitoring device 65, and impurities contained in the lubricating oil may be removed by the oil filter 66.

  As shown in FIG. 12, the lubricating oil monitoring device 65 and the oil filter 66 may be installed on the upstream side of the lubricating oil monitoring device 65, as shown in FIG. As shown, the oil filter 66 may be installed downstream of the lubricating oil monitoring device 65.

  In the example shown in FIG. 12, a two-electrode conductivity measuring device 65 b and an electromagnetic flow meter 65 a constituting the lubricating oil monitoring device 65 are installed downstream of the oil filter 66, and a pressure gauge 67 is further installed. Yes. By installing the pressure gauge 67, deterioration of the lubricating oil can be detected.

  In the example shown in FIG. 13, a two-electrode conductivity measuring device 65 b, an electromagnetic flow meter 65 a, and a pressure gauge 67 constituting the lubricating oil monitoring device 65 are installed upstream of the oil filter 66.

  In the embodiment shown in FIG. 12 or FIG. 13, the oil filter 66, the lubricating oil monitoring device 65, the pressure gauge 67, etc. are unitized so that they can be installed in the circulating oil passage 22e in a replaceable manner.

  As shown in FIG. 4, the wheel hub C includes a hub member 32 fixedly connected to the wheel-side rotation member 28, and a wheel hub bearing 33 that holds the hub member 32 rotatably with respect to the housing 22 f of the speed reducer B. Is provided. The hub member 32 has a cylindrical hollow portion 32a and a flange portion 32b. The drive wheel 14 is fixedly connected to the flange portion 32b by a bolt 32c. A spline and a male screw are formed on the outer diameter surface of the shaft portion 28b of the wheel side rotation member 28. A spline hole is formed in the inner diameter surface of the hollow portion 32 a of the hub member 32. Then, the wheel-side rotating member 28 is fitted to the inner diameter surface of the hub member 32, and the both ends are fastened by being screwed to the female screw at the tip thereof by the nut 32d.

  The wheel hub bearing 33 is fitted to the outer raceway surface formed integrally with the outer diameter surface of the hollow portion 32a of the hub member 32 and the outer diameter surface of the inner side of the hollow portion 32a of the hub member 32. An inner member 33a comprising an inner ring 33b having an inner raceway surface on the outer surface, a double row ball 33c disposed on the outer raceway surface and the inner raceway surface of the inner member 33a, and an inner member 33a. An outer member 33d having inner and outer raceways facing the outer raceway surface and the inner raceway surface on the inner peripheral surface, a retainer 33e that holds a gap between adjacent balls 33c, and a wheel hub It is a double row angular contact ball bearing provided with sealing members 33f and 33g for sealing both axial ends of the bearing 33.

  The outer member 33d of the wheel hub bearing 33 is fixed to the housing 22f by fastening bolts 37.

The operation of the in-wheel motor drive device 21 configured as described above will be described.
The electric motor A receives, for example, electromagnetic force generated by supplying an alternating current to the coil of the stator 23, and the rotor 24 composed of a permanent magnet or a magnetic material rotates. At this time, the rotor 24 rotates at a higher speed as a higher frequency voltage is applied to the coil.

  Thereby, when the motor side rotation member 25 connected to the rotor 24 rotates, the curved plates 26 a and 26 b revolve around the rotation axis of the motor side rotation member 25. At this time, the outer pin 27 engages with the curved waveform of the curved plates 26 a and 26 b to cause the curved plates 26 a and 26 b to rotate in the direction opposite to the rotation of the motor-side rotating member 25.

  The inner pin 31 inserted through the through hole 30a comes into contact with the inner 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 C via the wheel-side rotating member 28.

  At this time, since the rotation of the motor-side rotating member 25 is decelerated by the reduction gear B and transmitted to the wheel-side rotating member 28, it is necessary for the drive wheel 14 even when the low-torque, high-rotation type electric motor A is adopted. It is possible to transmit an appropriate torque.

  Note that the reduction ratio of the reduction gear B configured as described above is calculated as (ZA−ZB) / ZB, where ZA is the number of outer pins 27 and ZB is the number of waveforms of the curved plates 26a and 26b. In the embodiment shown in FIG. 5, since ZA = 12, ZB = 11, the reduction ratio is 1/11, and a very large reduction ratio can be obtained.

  Thus, by adopting the reduction gear B that can obtain a large reduction ratio without using a multi-stage configuration, a compact and high reduction ratio in-wheel motor drive device 21 can be obtained. Moreover, since the frictional resistance is reduced by providing the needle roller bearings 27a and 31a at the positions where they contact the curved plates 26a and 26b of the outer pin 27 and the inner pin 31, the transmission efficiency of the speed reducer B is improved. .

  By adopting the in-wheel motor drive device 21 according to the above embodiment in the electric vehicle 11 shown in FIGS. 8 and 9, the unsprung weight can be suppressed. As a result, the electric vehicle 11 having excellent running stability can be obtained.

  In the above embodiment, the example in which the circulating oil path 22e is provided inside the housing 22 has been described. However, the present invention is not limited to this. For example, a circulating oil path is provided outside the in-wheel motor drive device 21. Also good.

  In the above-described embodiment, the example in which the lubricating oil supply port 25d is provided in the eccentric portions 25a and 25b has been described. However, the present invention is not limited to this, and the lubricating oil supply port 25d can be provided at an arbitrary position. However, from the viewpoint of stably supplying the lubricating oil to the rolling bearing 41, the lubricating oil supply port 25d is preferably provided in the eccentric portions 25a and 25b.

  In the above-described embodiment, the example in which the rotary pump 51 is driven by using the rotation of the wheel-side rotary member 28 is shown. However, the rotary pump 51 is driven by using the rotation of the motor-side rotary member 25. You can also. However, since the rotation speed of the motor side rotation member 25 is larger than that of the wheel side rotation member 28 (11 times in the above embodiment), the durability of the rotary pump 51 may be reduced. Further, even when connected to the wheel-side rotating member 28, a sufficient discharge amount can be ensured. From these viewpoints, the rotary pump 51 is preferably driven by utilizing the rotation of the wheel-side rotary member 28.

  Moreover, in said embodiment, although the example of the cycloid pump was shown as the rotary pump 51, it is not restricted to this, All the rotary pumps driven using the rotation of the wheel side rotation member 28 are employable. it can.

  In the above embodiment, the two curved plates 26a and 26b of the speed reducer B are provided with a 180 ° phase change, but the number of the curved plates can be arbitrarily set. When three are provided, it is preferable to change the phase by 120 °.

  In addition, although the motion conversion mechanism in the above-described embodiment has been shown as an example including the inner pin 31 fixed to the wheel side rotation member 28 and the through hole 30a provided in the curved plates 26a and 26b, However, the present invention is not limited to this, and any configuration that can transmit the rotation of the reduction gear B to the hub member 32 can be adopted. 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.

  In addition, although description of the operation | movement in said embodiment was performed paying attention to rotation of each member, the motive power containing a torque is actually transmitted from the electric motor A to a driving wheel. Therefore, the power decelerated as described above is converted into high torque.

  In the description of the operation in the above embodiment, electric power is supplied to the electric motor A to drive the electric motor A, and the motive power from the electric motor A is transmitted to the drive wheels 14. When the vehicle decelerates or goes down a hill, the power from the drive wheel 14 side is converted into high-rotation and low-torque rotation by the speed reducer B and transmitted to the electric motor A, and the electric motor A generates electric power. May be. Furthermore, the electric power generated here may be stored in a battery, and the electric motor A may be driven later, or used for the operation of other electric devices provided in the vehicle.

  Further, a brake can be added to the configuration of the above embodiment. For example, in the configuration of FIG. 1, the housing 22 is extended in the axial direction to form a space on the right side of the rotor 24 in the drawing, a rotating member that rotates integrally with the rotor 24, and the housing 22 cannot rotate and is axially A parking brake that locks the rotor 24 by disposing a movable piston and a cylinder that operates the piston and fitting the piston and the rotating member when the vehicle is stopped may be used.

  Alternatively, it may be a disc brake that sandwiches a flange formed on a part of a rotating member that rotates integrally with the rotor 24 and a friction plate installed on the housing 22 side with a cylinder installed on the housing 22 side. Furthermore, a drum brake can be used in which a drum is formed on a part of the rotating member, a brake shoe is fixed to the housing 22 side, and the rotating member is locked by friction engagement and self-engagement.

  In the above embodiment, an example of a cylindrical roller bearing is shown as a bearing for supporting the curved plates 26a and 26b. However, the present invention is not limited to this, and for example, a plain bearing, a cylindrical roller bearing, a tapered roller bearing, and a needle roller Regardless of whether it is a plain bearing or a rolling bearing, such as a bearing, a self-aligning roller bearing, a deep groove ball bearing, an angular contact ball bearing, or a four-point contact ball bearing, whether the rolling element is a roller or a ball Furthermore, any bearing can be applied regardless of whether it is a double row or a single row. Similarly, any type of bearing can be adopted for bearings arranged in other locations.

  However, the deep groove ball bearing has a higher allowable limit speed than the cylindrical roller bearing, but has a low load capacity. Therefore, in order to obtain a necessary load capacity, a large deep groove ball bearing must be employed. Therefore, from the viewpoint of making the in-wheel motor drive device 21 compact, a cylindrical roller bearing is suitable for the rolling bearing 41.

  In each of the above-described embodiments, an example in which a radial gap motor is adopted as the electric motor A has been described. However, the present invention is not limited to this, and a motor having an arbitrary configuration can be applied. For example, it may be an axial gap motor including a stator fixed to the housing and a rotor disposed at a position facing the inner side of the stator with a gap in the axial direction.

  Moreover, in each said embodiment, although the example of the in-wheel motor drive device 21 which employ | adopted the cycloid deceleration mechanism as the reduction gear B was shown, it is not restricted to this but arbitrary deceleration mechanisms are employable. For example, a planetary gear reduction mechanism, a parallel shaft gear reduction mechanism, or the like is applicable.

  Furthermore, although the electric vehicle 11 shown in FIG. 8 has shown the example which used the rear wheel as the driving wheel 14, it is not restricted to this, The front wheel 13 may be made into a driving wheel and may be a four-wheel drive vehicle. . In the present specification, “electric vehicle” is a concept including all vehicles that obtain driving force from electric power, and should be understood as including, for example, a hybrid vehicle.

  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.

DESCRIPTION OF SYMBOLS 11 Electric vehicle 12 Chassis 12a Wheel housing 12b Suspension device 13 Front wheel 14 Drive wheel 21 In-wheel motor drive device 22 Housing 22b Lubricating oil discharge port 22c Return oil path 22d Oil tank 22e Circulation oil path 22f Housing 22g Housing 23 Stator 24 Rotor 24a Rotor Portion 24b hollow portion 25 motor side rotating member 25a eccentric portion 25b eccentric portion 25c lubricating oil passage 25d lubricating oil supply port 25e oil supply hole 26a curved plate 26b curved plate 27 outer pin 27a bearing 28 wheel side rotating member 28a flange portion 28b shaft portion 29 Counterweight 30a Through hole 30b Through hole 31 Inner pin 31a Bearing 31b Stabilizer 31d Cylindrical part 32 Hub member 32a Hollow part 32b Flange part 32c Bolt 32d Nut 33 Wheel hub bearing 33a Inner member 3 b Inner ring 33c Ball 33d Outer member 33e Cage 33f Sealing member 33g Sealing member 36a Rolling bearing 36b Rolling bearing 36c Rolling bearing 37 Fastening bolt 41 Rolling bearing 42 Inner ring member 42a Inner raceway surface 43 Outer raceway surface 51 Rotary pump 52 Inner rotor 52a Tooth tip portion 52b Tooth groove portion 53 Outer rotor 53a Tooth tip portion 53b Tooth groove portion 54 Pump chamber 55 Suction port 56 Discharge port 65 Lubricating oil monitoring device 65a Electromagnetic flow meter 65b Conductivity measuring device 65c Electrode 65d Electrode 65e Strain gauge 66 Oil Filter 67 Pressure gauge 68 Ammeter A Electric motor B Reducer C Wheel hub

Claims (6)

  An electric motor that generates a driving force, a speed reducer that decelerates and outputs the rotation of the electric motor, and a wheel hub that transmits the output from the speed reducer to the wheel, the electric motor and the speed reducer are housed in the housing, In the in-wheel motor drive device provided with a lubricating oil passage for lubricating and cooling the electric motor and the speed reducer, a lubricating oil monitoring device for detecting deterioration of the lubricating oil and contamination of impurities is installed inside the lubricating oil passage. In-wheel motor drive device   The in-wheel motor drive device according to claim 1, wherein an electromagnetic flow meter is used as the lubricating oil monitoring device.   The in-wheel motor drive device according to claim 1, wherein a two-electrode conductivity measuring device is used as the lubricant monitoring device.   The in-wheel motor drive device according to claim 1, wherein a current meter is used as the lubricant monitoring device.   The in-wheel motor drive device in any one of Claims 1-4 which provided the pressure gauge in the inside of the said lubricating oil path. The in-wheel motor drive device according to any one of claims 1 to 5, wherein an oil filter is installed upstream or downstream of the lubricating oil monitoring device.

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