JP2008189188A - In-wheel motor driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-wheel motor driving device for improving the separation service life, by securing a bearing space, without being influenced by cleanliness of lubricating oil. <P>SOLUTION: A bearing device C for a wheel has an outer member 22 forming outside rolling traveling surfaces 32a and 33a of double rows on the inner periphery, a hub wheel 25 having a wheel installing flange 26 in one end part and forming an inside rolling traveling surface 25a and a small diameter step part 25b, an inner member 24 fitted in this hub wheel 25 and composed of a wheel side rotary member 11 pressing in and fixing an inner ring 34, a rolling body 23 of double rows stored between both rolling traveling surfaces, and seals 30 and 31 sealing an opening part between the outer member 22 and the inner member 24. The outer side seal 30 has a pair of side lips 36a and 36b and a grease lip 36c slidingly contacting with a base part 26b of the wheel installing flange 26. The seal 31 with a speed reduction part B is composed an oil seal. The lubricating oil is cut off thereby, and a bearing part is lubricated by grease. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an in-wheel motor drive device used in a vehicle having a direct drive wheel as a drive wheel, such as an automobile, and more particularly, an output shaft of an electric motor and a wheel hub are coaxially connected via a reduction gear. The present invention relates to an in-wheel motor drive device.

  In recent years, in-wheel motor systems in which a motor is built in a wheel are being adopted in a vehicle driven by a motor such as an electric vehicle. Here, the conventional in-wheel motor drive device 50 is described in Unexamined-Japanese-Patent No. 2006-258289 (patent document 1), for example. As shown in FIG. 6, the in-wheel motor driving device 50 includes a motor unit 53 that generates a driving force inside a casing 52 that is attached to a vehicle body 51, a wheel bearing device 55 to which a wheel 54 is attached, and a motor unit. And a speed reducer 57 that decelerates the rotation of 53 and transmits it to the hub wheel 56 of the wheel bearing device 55.

  Here, in order to reduce the weight and size of the apparatus, a low torque and high rotation motor is adopted for the motor unit 53 and a large torque is required to drive the wheels 54. A cycloid reducer that is compact and provides a high reduction ratio is employed.

  The speed reducer 57 includes a motor-side rotating member 58 having eccentric portions 58a and 58b, curved plates 59a and 59b disposed on the eccentric portions 56a and 58b, and curved plates 59a and 59b with respect to the motor-side rotating member 58. Rolling bearings 60a, 60b that are rotatably supported, a plurality of outer pins 61 that engage with the outer peripheral surfaces of the curved plates 59a, 59b to cause the curved plate curved plates 59a, 59b to rotate, and the curved plates 59a, A plurality of inner pins 63 that transmit the rotational motion of 59b to the inner member (wheel-side rotating member) 62 are provided.

Further, the wheel bearing device 55 is integrally provided with an outer flange 64b integrally attached to the casing 52 on the outer periphery, and the double-row outer rolling surfaces 64a and 64a are integrally formed on the inner periphery. A wheel mounting flange 67 for attaching the wheel 54 to one end, and an inner rolling surface 56a facing one of the double row outer rolling surfaces 64a, 64a on the outer periphery, and the inner rolling surface. A hub wheel 56 formed with a cylindrical small-diameter step 56b extending in the axial direction from 56a, and the other of the double-row outer rolling surfaces 64a and 64a are press-fitted and fixed to the small-diameter step 56b of the hub wheel 56 An inner member 62 formed of an inner ring 65 formed with an inner rolling surface 65a opposite to the inner ring 65, and a double row of balls accommodated in a freely rolling manner between the rolling surfaces of the inner member 62 and the outer member 64 66.
JP 2006-258289 A

  In such a conventional in-wheel motor drive device 50, since the lubrication of the wheel bearing device 55 is made common with the speed reduction portion 57, foreign matter such as wear powder generated in the speed reduction portion 57 is mixed in the lubricating oil. The bearing portion is lubricated with the lubricating oil. In this case, there is a concern that the peeling life may be reduced due to the problem of cleanliness of the lubricating oil.

  The present invention has been made in view of such a conventional problem, and provides an in-wheel motor drive device that is not affected by the cleanliness of the lubricating oil, secures a bearing space, and improves the peeling life. With the goal.

  In order to achieve such an object, the invention according to claim 1 of the present invention includes a casing, and a motor portion that is disposed in the casing and that rotationally drives a motor-side rotating member that is integrally formed with an eccentric portion. An in-wheel motor drive device comprising: a speed reducing portion that decelerates the rotation of the motor side rotating member and transmits it to the wheel side rotating member; and a wheel bearing device connected to the wheel side rotating member. The bearing device has a mounting flange for mounting on the casing on the outer periphery, an outer member having a double row outer raceway formed on the inner periphery, and a wheel mounting flange for mounting the wheel on one end. A hub ring integrally formed and formed with a cylindrical small-diameter step portion extending in the axial direction on the outer periphery, and an inner ring fitted to the small-diameter step portion of the hub ring and having an inner rolling surface formed on the outer periphery, or Wheel side rotating member Formed between the outer member and the inner member, a double row rolling element housed in a freely rolling manner between the rolling surfaces of the inner member and the outer member. A seal that seals the opening of the annular space, and a seal located between the annular space and the speed reduction portion among these seals is constituted by an oil seal, and the lubricant for the speed reduction portion is provided by this seal. It is blocked and the bearing is grease lubricated.

  Thus, in the in-wheel motor drive device including the motor portion and the speed reduction portion disposed in the casing and the wheel bearing device connected to the speed reduction portion, the wheel bearing device is disposed on the casing on the outer periphery. It has a mounting flange for mounting, an outer member with a double row outer raceway formed on the inner periphery, and a wheel mounting flange for mounting a wheel on one end, and an axial direction on the outer periphery. A hub ring formed with a cylindrical small-diameter step portion extending inward, and an inner member formed of an inner ring or a wheel-side rotating member that is fitted to the small-diameter step portion of the hub ring and has an inner rolling surface formed on the outer periphery thereof. A double row rolling element accommodated between the rolling surfaces of the inner member and the outer member, and an opening in an annular space formed between the outer member and the inner member. A seal for sealing, and of these seals The seal located between the cylindrical space and the speed reduction part is composed of an oil seal, and the lubricating oil in the speed reduction part is blocked by this seal and the bearing part is grease-lubricated. It is possible to prevent foreign matter such as the like from entering the inside of the bearing and reduce the peeling life, and a desired peeling life can be secured without being affected by the cleanliness of the lubricating oil.

  Preferably, as in the invention described in claim 2, an inner rolling surface facing one of the double row outer rolling surfaces is directly formed on the outer periphery of the hub wheel, and the inner base portion of the wheel mounting flange is formed. Is formed in a circular arc shape, and the seal on the outer side of the seals has a pair of side lips that are in sliding contact with the base portion and a grease lip that is inclined toward the bearing inward side. Since a highly compact seal can be obtained, the bearing span can be maximized and the durability of the wheel bearing device can be improved.

  If the wheel side rotating member is fitted in the hub wheel and the wheel side rotating member and the hub wheel are integrally plastically coupled as in the invention according to claim 3, it is light and compact. In addition, the joint can be prevented from loosening, the preload set initially can be maintained over a long period of time, and the durability can be improved.

  According to a fourth aspect of the present invention, the outer member includes a first outer member in which an outer rolling surface on the outer side is formed on the inner periphery, and an inner portion of the first outer member. A second outer member which is press-fitted and fixed to the inner side and has an inner-side outer rolling surface formed on the inner periphery, and a separate inner ring is press-fitted and fixed to the wheel-side rotating member. If the second outer member is made of high carbon chrome bearing steel or carburized steel, the inner bearing portion, which is stricter in terms of load load than the outer side, is advantageous in terms of peeling life, and durability of the wheel bearing device is improved. Can be improved.

  According to a fifth aspect of the present invention, the speed reduction portion has a plurality of waveforms formed of a trochoidal curve on an outer periphery, and a plurality of through holes that pass through the eccentric portion are formed. A curved plate that performs a revolving motion around its rotational axis as the side rotating member rotates, and a plurality of external members that are brought into rolling contact with the outer peripheral portion of the curved plate via needle roller bearings to generate a rotational motion. A pin and an inner pin that is in rolling contact with the inner periphery of the through-hole via a needle roller bearing, and the rotational movement of the curved plate is converted into a rotational movement around the rotational axis of the motor-side rotating member. If it is configured with a cycloid reduction mechanism that transmits to the wheel side rotation member, an extremely large reduction ratio can be obtained even with a compact configuration without using a multi-stage configuration. Even when the motor is used It can be transmitted a sufficient rotational torque to the wheels.

  An in-wheel motor drive device according to the present invention includes a casing, a motor unit that is disposed in the casing and that rotationally drives a motor-side rotating member integrally formed with an eccentric portion, and rotates the motor-side rotating member. In an in-wheel motor drive device comprising a speed reduction portion that decelerates and transmits to a wheel-side rotating member, and a wheel bearing device connected to the wheel-side rotating member, the wheel bearing device is disposed on the casing on the outer periphery. It has a mounting flange for mounting, an outer member with a double row outer raceway formed on the inner periphery, and a wheel mounting flange for mounting a wheel on one end, and an axial direction on the outer periphery. A hub ring formed with a cylindrical small-diameter step portion extending inward, and an inner member that is fitted to the small-diameter step portion of the hub ring and has an inner rolling surface formed on the outer periphery or the wheel-side rotating member A double-row rolling element accommodated between the rolling surfaces of the inner member and the outer member, and an opening in an annular space formed between the outer member and the inner member. And a seal positioned between the annular space and the speed reduction part is constituted by an oil seal, and the lubricant oil of the speed reduction part is blocked by the seal so that the bearing part is Because it is grease-lubricated, it can prevent foreign matter such as metal wear powder mixed in the lubricating oil from entering the inside of the bearing and shortening the peeling life, and the desired peeling without being affected by the cleanliness of the lubricating oil. A lifetime can be secured.

  A casing, a motor unit disposed in the casing, and a motor-side rotating member integrally formed with an eccentric part, and a speed reducer that decelerates the rotation of the motor-side rotating member and transmits it to the wheel-side rotating member And an in-wheel motor drive device comprising a wheel bearing device coupled to the wheel-side rotating member, wherein the wheel bearing device integrally has an attachment flange for being attached to the casing on the outer periphery. The outer member having a double row outer raceway formed on the inner circumference and the wheel mounting flange for attaching the wheel to one end are integrally provided on one of the outer raceways of the double row on the outer circumference. A hub wheel formed with an opposing inner rolling surface, a cylindrical small-diameter stepped portion extending in the axial direction from the inner rolling surface, and an inner rolling facing the other outer rolling surface of the double row on the outer periphery. The inner ring on which the surface is formed An inner member composed of the wheel-side rotating member fixed and fitted into the small-diameter step portion of the hub wheel, and accommodated in a freely rollable manner between both rolling surfaces of the inner member and the outer member. A double row rolling element, and a seal that seals an opening of an annular space formed between the outer member and the inner member, and an outer seal among these seals is provided on the wheel mounting flange. The seal includes a pair of side lips that are in sliding contact with the base and a grease lip that is inclined toward the bearing inward side, and a seal that is positioned between the annular space and the speed reduction portion is configured by an oil seal. The lubricating oil is cut off and the bearing is grease lubricated.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing an embodiment of an in-wheel motor drive device according to the present invention, FIG. 2 is a transverse sectional view taken along line II-II in FIG. 1, and FIG. 3 is a main portion of FIG. FIG. 4 is an enlarged view of the main part showing the eccentric part of FIG. 1, FIG. 5A is an enlarged view showing the wheel bearing device of FIG. 1, and FIG. 4B is a seal on the outer side of FIG. It is a principal part enlarged view which shows a part. In the following description, the side closer to the outer side of the vehicle in a state assembled to the vehicle is referred to as the outer side (left side in the drawing), and the side closer to the center is referred to as the inner side (right side in the drawing).

  The in-wheel motor drive device 1 transmits a motor unit A that generates a driving force, a deceleration unit B that decelerates and outputs rotation of the motor unit A, and an output from the deceleration unit B to wheels (not shown). Wheel bearing device C.

  The motor part A includes a stator 3 fixed to the casing 2, a rotor 4 provided with a radial gap (radial clearance) on the inner side of the stator 3, an opposed arrangement, and a rotor 4 fitted to the inner side of the rotor 4. It is comprised by the radial gap motor provided with the motor side rotating member 5 which rotates integrally. Further, an end cap 6 for preventing dust from entering the inside of the motor unit A is attached to the opening on the inner side of the motor unit A.

  The rotor 4 includes a hollow cylindrical portion 4a having a spline (or serration) formed on the inner periphery, and a flange-shaped rotor portion 4b extending radially outward from the cylindrical portion 4a, and is formed of an angular ball bearing. It is rotatably supported with respect to the casing 2 by double row rolling bearings 7 and 7. An oil seal 8 is installed between the casing 2 and the rotor 4 to prevent the lubricating oil sealed in the speed reduction part B from entering the motor part A.

  In addition, although the thing which employ | adopted the radial gap motor as the motor part A was illustrated here, the motor of arbitrary structures is applicable not only to this, For example, although not shown in figure, it fixes to the inner periphery of a casing An axial gap motor may be provided that includes a stator and a rotor that is opposed to the inner diameter side of the stator via an axial gap.

  The motor-side rotating member 5 is arranged from the motor part A to the speed reduction part B in order to transmit the driving force of the motor part A to the speed reduction part B, and the eccentric parts 5a and 5b are integrated in the speed reduction part B. Is formed. The motor-side rotating member 5 has an inner end that is spline-fitted to the cylindrical portion 4a of the rotor 4 and a rolling bearing 9 and 10 that includes a pair of angular ball bearings on both sides of the speed reduction portion B. The wheel side rotating member 11 is rotatably supported. Further, the two eccentric portions 5a and 5b are formed by changing the phase by 180 ° so that the centrifugal forces due to the eccentric motion cancel each other.

  The deceleration part B is held at a fixed position on the casing 2 and curved plates 12a and 12b that are revolving members that are rotatably held by the eccentric parts 5a and 5b, and engages with the outer peripheral parts of the curved plates 12a and 12b. A plurality of outer pins 13, 13 serving as outer peripheral engagement members, a motion conversion mechanism 14 for transmitting the rotational motion of the curved plates 12 a, 12 b to the wheel side rotation member 11, and two counters mounted on the motor side rotation member 5 Weights 15 and 15 are provided. These counterweights 15 and 15 are formed in a disc shape, and in order to cancel out the unbalanced inertia couple generated by the rotation of the curved plates 12a and 12b, the eccentric portions 5a and 5b are positioned at positions adjacent to the eccentric portions 5a and 5b. 5b and 180 ° phase are changed.

  The wheel-side rotating member 11 has a flange portion 16 extending radially outward at an end portion on the inner side, and a hollow shaft portion 17 projecting integrally from the flange portion 16 via a small-diameter step portion 16a. . A plurality of inner pins 18, 18 are fixed to the flange portion 16 at equal intervals on the circumference around the rotation axis of the wheel side rotation member 11.

  Next, the motion conversion mechanism 14 will be described with reference to FIG. The curved plate 12a has a plurality of corrugations composed of a trochoidal curve such as epitrochoid on the outer peripheral portion, and a plurality of through holes 19 and 19 and a bearing hole 20 are formed. A plurality of through holes 19 are formed at equal intervals on a circumference centered on the rotation axis of the curved plate 12a, and an inner pin 18 to be described later is fitted therein. The bearing hole 20 is formed at the center of the curved plate 12a and is fitted to the eccentric portion 5a. The curved plate 12a is rotatably supported with respect to the eccentric portion 5a by a rolling bearing 21 formed of a deep groove ball bearing.

  The outer pins 13 are provided at equal intervals on a circumferential track centering on the rotation axis of the motor-side rotating member 5. Since these outer pins 13 coincide with the revolution trajectories of the curved plates 12a and 12b, when the curved plates 12a and 12b revolve, the curved waveform and the outer pin 13 are engaged, and the curved plates 12a and 12b A rotation motion is caused in 12b. Further, in order to reduce the frictional resistance with the curved plates 12a and 12b, needle roller bearings 13a are mounted at positions where they are in rolling contact with the outer peripheral surfaces of the curved plates 12a and 12b (see FIG. 3).

  Here, as shown in FIG. 4, when the center point between the two curved plates 12a and 12b is G, the distance between the central point G and the center of the curved plate 12a is L1 for the inner side of the central point G. The mass of the curved plate 12a is m1, the amount of eccentricity of the center of gravity of the curved plate 12a from the rotational axis is ε1, the distance between the center point G and the counterweight 15 is L2, the mass of the counterweight 15 is m2, and the counterweight 15 Assuming that the amount of eccentricity of the center of gravity from the rotation axis is ε2, L1 × m1 × ε1 = L2 × m2 × ε2 is satisfied. A similar relationship is established between the curved plate 12 b on the outer side of the center point G and the counterweight 15.

  As shown in FIG. 2, the motion conversion mechanism 14 includes a plurality of inner pins 18 and 18 held by the wheel-side rotating member 11 and through holes 19 provided in the curved plates 12 a and 12 b. The inner pin 18 is provided with a needle roller bearing 18a at a position where it comes into rolling contact with the inner peripheral surface of the through hole 19 in order to reduce frictional resistance with the through hole 19 (see FIG. 3). On the other hand, the through hole 19 is formed at a position corresponding to each of the plurality of inner pins 18, and the inner diameter dimension of the through hole 19 is set to a predetermined amount larger than the outer diameter dimension of the inner pin 18 including the needle roller bearing 18a. Has been.

Next, the operation principle of the in-wheel motor drive device 1 according to the present invention will be described with reference to FIG.
The motor part A receives an electromagnetic force generated by supplying an alternating current to the coil 3a of the stator 3, and the rotor 4 having the permanent magnet (or magnetic body) 4c fixed to the rotor part 4b rotates. At this time, the rotor 4 rotates at a higher speed as a high frequency voltage is applied to the coil 3a. As a result, the motor-side rotating member 5 connected to the rotor 4 rotates, and the curved plates 12 a and 12 b revolve around the rotation axis of the motor-side rotating member 5. At this time, the outer pin 13 engages with the curved waveform of the curved plates 12 a and 12 b to cause the curved plates 12 a and 12 b to rotate in the direction opposite to the rotation of the motor-side rotating member 5.

  The inner pin 18 inserted through the through hole 19 rolls into contact with the inner peripheral surface of the through hole 19 as the curved plates 12a and 12b rotate, and the revolving motion of the curved plates 12a and 12b is not transmitted to the inner pin 18. In addition, only the rotation of the curved plates 12 a and 12 b is transmitted to the hub wheel 25 via the wheel-side rotating member 11. As described above, since the rotation of the motor-side rotating member 5 is decelerated by the deceleration unit B and transmitted to the wheel-side rotating member 11, even when the low-torque, high-rotation type motor unit A is employed, it is necessary for the wheels. Torque can be transmitted.

  The speed reduction ratio of the speed reduction part B is calculated as (Za−Zb) / Zb, where Za is the number of outer pins 13 and Zb is the number of waveforms of the curved plates 12a and 12b. For example, when Za = 12, Zb = 11, the reduction ratio is 1/11, and an extremely large reduction ratio can be obtained even with a compact configuration without using a multistage configuration.

  As shown in an enlarged view in FIG. 5, the wheel bearing device C includes an outer member 22 and an inner member inserted into the outer member 22 via double-row rolling elements (balls) 23 and 23. 24. The outer member 22 integrally has an attachment flange 32a to be attached to the casing 2 on the outer periphery, and one (outer side) outer rolling surface 32a of the double row outer rolling surfaces 32a and 33a on the inner periphery. Is formed by press-fitting and fixing to the inner periphery of the inner end of the first outer member 32, and the other (inner side) outer rolling surface 33a is formed on the inner periphery. And a second outer member 33.

  The first outer member 32 is made of medium-high carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and at least the outer rolling surface 32a is hardened by induction hardening to a surface hardness of 58 to 64 HRC. Is given. The second outer member 33 is made of high carbon chrome bearing steel such as SUJ2 or carburized steel such as SCR430. In the case of high carbon chrome bearing steel, the second outer member 33 is quenched at 820 to 860 ° C. It is tempered at 200 ° C. and cured to the core in the range of 58 to 64 HRC. In the case of carburized steel, the surface is hardened in the range of 58 to 64 HRC.

  The inner member 24 includes a hub wheel 25 and a wheel-side rotating member 11 that is fitted into the hub wheel 25 and in which a separate inner ring 34 is press-fitted and fixed to the small-diameter step portion 11a. The hub wheel 25 integrally has a wheel mounting flange 26 for mounting a wheel (not shown) at an end portion on the outer side, and is on one side (outer side) of the double-row outer rolling surfaces 32a and 33a on the outer periphery. An opposed inner rolling surface 25a and a cylindrical small diameter step portion 25b extending in the axial direction from the inner rolling surface 25a are formed. Further, the inner ring 34 is formed with an inner rolling surface 34a facing the other (inner side) of the double row outer rolling surfaces 32a, 33a on the outer periphery. A hub bolt 26a for fixing the wheel is planted on the circumference of the circumference of the wheel mounting flange 26.

  The hub wheel 25 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and includes an inner rolling surface 25a and a wheel mounting flange 26 that serves as a seal land portion of an outer seal 30 described later. The surface 26 is hardened in a range of 58 to 64 HRC by induction hardening from the base portion 26b to the small diameter step portion 25b. On the other hand, the inner ring 34 is made of high carbon chrome bearing steel such as SUJ2 or carburized steel such as SCR 430. In the case of high carbon chrome bearing steel, the inner ring 34 is quenched at 820 to 860 ° C. and then tempered at 160 to 200 ° C. The core is hardened in the range of 58 to 64 HRC. In the case of carburized steel, the surface is hardened in the range of 58 to 64 HRC.

  Here, an uneven portion 27 hardened by induction hardening is formed on the inner periphery of the hub wheel 25. The concavo-convex portion 27 is formed in the shape of an iris knurl, and a plurality of annular grooves formed independently by turning or the like and a plurality of axial grooves formed by broaching or the like are crossed grooves configured to be substantially orthogonal, Or it consists of the crossing groove | channel comprised by the helical groove | channel inclined mutually. Further, in order to ensure good biting property, the tip of the concavo-convex portion 27 is formed in a spire shape such as a triangular shape.

  The shaft portion 17 of the wheel-side rotating member 11 has an in-row portion 17a that is cylindrically fitted to the small-diameter step portion 25b of the hub wheel 25 via a predetermined shimiro, and a fitting portion 17b at the end of the in-row portion 17a. Is formed. The wheel-side rotating member 11 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and is formed from the outer periphery of the flange portion 16 serving as a seal land portion of the inner-side seal 31 described later to the in-row portion 17a. Thus, the surface is hardened in a range of 58 to 64 HRC by induction hardening. In addition, the fitting part 17b is made into the surface hardness after forging.

  Double-row rolling elements 23 and 23 are accommodated between the rolling surfaces 32a, 25a and 33a and 34a of the outer member 22 and the inner member 24, and these double-row rolling elements 23 are held by the cages 28 and 28. , 23 are movably held respectively. In the present embodiment, the second outer member 33 and the inner ring 34, that is, the inner bearing portion that is stricter in terms of load compared to the outer side is made of high carbon chrome bearing steel or carburized steel. Compared with carbon steel, it is advantageous in terms of peeling life, and durability of the wheel bearing device C is improved.

  Integration of the hub wheel 25 and the wheel-side rotating member 11 is achieved by pressing the shaft portion 17 of the wheel-side rotating member 11 into the hub wheel 25 with a predetermined squeeze, and the front-side end surface of the inner ring 34 on the end surface of the small-diameter step portion 25b. In the abutted state, the fitting portion 17b is expanded by pushing a diameter expanding jig such as a mandrel into the outer diameter side of the fitting portion 17b. That is, the hub wheel 25 and the wheel-side rotating member 11 are plastically coupled and integrated by plastically deforming the fitting portion 17b and biting into the uneven portion 27 of the hub wheel 25 and caulking. As a result, the weight and size can be reduced, the loosening of the coupling portion can be prevented, the preload set initially can be maintained over a long period of time, and the durability can be improved. Reference numeral 29 denotes an end cap attached to the opening of the hub wheel 25 to prevent foreign matters such as rainwater and dust from entering the inner member 24 from the outside.

  Here, seals 30 and 31 for sealing the opening of the annular space formed between the outer member 22 and the inner member 24 are mounted. The bearings are shut off from the speed reduction part B by these seals 30 and 31, and are lubricated by grease sealed inside. The seal 31 positioned between the annular space and the speed reduction part B is constituted by an oil seal having a garter spring 31a, and prevents the lubricating oil that lubricates the speed reduction part B from entering the bearing. As a result, foreign matter such as metal wear powder mixed in the lubricating oil can be prevented from entering the inside of the bearing to reduce the peeling life, and the desired peeling life can be secured without being affected by the cleanliness of the lubricating oil. be able to.

  As shown in an enlarged view in FIG. 6, the outer-side seal 30 includes a core bar 35 having a substantially L-shaped cross section fitted to the inner periphery of the end portion of the first outer member 32, and the core bar 35. The seal member 36 is integrally joined by vulcanization adhesion or the like. The core bar 35 is formed by pressing from a corrosion-resistant steel plate such as an austenitic stainless steel plate (JIS standard SUS304 type) or a rust-proof cold rolled steel plate (JIS standard SPCC type). Is formed.

  On the other hand, the seal member 36 is made of an elastic member such as nitrile rubber, and has a pair of side lips 36a and 36b slidably in contact with the base portion 6b of the wheel mounting flange 26 formed in an arc shape, and an inner diameter portion inclined toward the bearing inward side. And a grease lip 36c extending in this manner. Note that a slight radial clearance is formed between the grease lip 36 and the base portion 26b, and a labyrinth seal is formed, so that a reduction in torque of the bearing can be achieved.

  Thus, in the present embodiment, the bearing portion in the wheel bearing device C is blocked by the seal 31 positioned between the speed reduction portion B and the bearing portion is grease-lubricated. The oil seal can be changed to a compact seal composed of three lips with high sealing performance. Therefore, the bearing span can be maximized, and the durability of the wheel bearing device C can be further improved.

  Here, as the wheel bearing device C, a hub wheel 25 having an outer side inner rolling surface 25a formed on the outer periphery and an inner ring 34 having an inner side inner rolling surface 34a formed on the outer periphery are fixed. Although the wheel bearing device C having a so-called fourth generation structure in which the hub wheel 25 and the wheel-side rotating member 11 are integrally plastically coupled is illustrated as an example. However, a so-called second generation or third generation structure in which a separate inner ring is press-fitted and fixed to the small-diameter step portion of the hub ring may be used.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  An in-wheel motor drive device according to the present invention includes an in-wheel motor including a motor unit, a wheel bearing device to which a wheel is attached, and a speed reducing unit that decelerates the rotation of the motor unit and transmits it to the wheel bearing device. It can be applied to a drive device.

It is a longitudinal section showing one embodiment of the in-wheel motor drive concerning the present invention. It is a cross-sectional view along the II-II line of FIG. FIG. 3 is an enlarged view of a main part of FIG. 2. It is a principal part enlarged view which shows the eccentric part of FIG. (A) is an enlarged view which shows the wheel bearing apparatus of FIG. (B) is a principal part enlarged view which shows the seal | sticker part of the outer side of (a). It is a longitudinal cross-sectional view which shows the conventional in-wheel motor drive device.

Explanation of symbols

1. In-wheel motor drive device 2 ... Casing 3 ... Stator 3a ... .... Coil 4 ..... Rotor 4a ..... Cylindrical part 4b ..... Rotor part 4c ... ......... Permanent magnet 5 ......... Motor side rotating members 5a, 5b ......... Eccentric parts 6, 29 ......... End cap 7, 9, 10, 21 ... Rolling bearing 8 ... Oil seal 11 ... Wheel side rotating members 11a, 25b ... Small diameter step 12a, 12b ... Curve plate 13 ... Outer pins 13a, 18a ... Needle roller bearing 14 ... Motion conversion mechanism 15・ ・ ・ ・ ・ ・・ ・ ・ Counter weight 16 ... Flange 17 ... Shaft 17a ... Inrow 17b ... ... Fitting part 18 ... Inner pin 19 ... Through hole 20 ... Bearing hole 22 ... ··· Outer member 23 ··· Rolling element 24 ··· Inner member 25 ··················· Hub wheel 25a , 34a... Inner rolling surface 26... Wheel mounting flange 26a... Hub bolt 26b. ... Uneven part 28 ... Retainer 30, 31 ... Seal 31a ... Garter spring 32 ... ........ First outer part 32a, 33a, outer rolling surface 32b, mounting flange 33, second outer member 34, ... .... Inner ring 35 ... Core 36 ... Seal members 36a, 36b ... Side lip 36c ... Glee Slip 50 ... In-wheel motor drive 51 ... Car body 52 ... Casing 53 ... ..Motor section 54 ..... Wheel 55 ..... Wheel bearing device 56 ..... Hub wheel 56a, 65a .. .... Inner rolling surface 56b ... Small diameter step 57 ... Deceleration part 58a, 58b ... Eccentric part 59a, 59b ... curve Plates 60a, 60b Rolling bearing 61 Outer pin 62 Inner member 63 Inner Pin 64 ... Outer member 64a ... Outer rolling surface 64b ... Mounting flange 65 ... .... Inner ring 66 ... Ball 67 ... Wheel mounting flange A ... Motor part B ...・ ・ ・ ・ ・ Deceleration part C ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel bearing device G ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Center point L1 between curved plates ・ ・ ・ ・ ・ ・ ・ ・..Distance L2 between the center point and the center of the curved plate ................... Distance m1 between the center point and the center of the counterweight .......... Mass of the curved plate m2. ..... Counterweight mass Z ... Number of outer pins Zb ... Number of corrugated plate waveforms ε1 ... Center of rotation of the center of gravity of the curved plate Eccentricity ε2 from the center of gravity of the counterweight from the rotational axis

Claims (5)

A casing,
A motor unit that is disposed in the casing and rotationally drives a motor-side rotating member in which an eccentric portion is integrally formed; and
A speed reducer that decelerates the rotation of the motor side rotating member and transmits it to the wheel side rotating member;
In an in-wheel motor drive device comprising a wheel bearing device connected to the wheel side rotating member,
The wheel bearing device has an outer flange having a mounting flange for mounting to the casing on the outer periphery, and a double row outer rolling surface formed on the inner periphery;
A hub wheel integrally having a wheel mounting flange for mounting a wheel at one end and having a cylindrical small-diameter step portion extending in the axial direction on the outer periphery, and a small-diameter step portion of the hub wheel fitted to the outer periphery An inner ring formed with an inner raceway or an inner member formed of the wheel-side rotating member,
A double row rolling element housed so as to be freely rollable between both rolling surfaces of the inner member and the outer member;
A seal for sealing an opening of an annular space formed between the outer member and the inner member;
Among these seals, a seal located between the annular space and the speed reduction part is constituted by an oil seal, and the lubricating oil of the speed reduction part is blocked by this seal, and the bearing part is grease lubricated. In-wheel motor drive device.   An inner rolling surface facing one of the double-row outer rolling surfaces is directly formed on the outer periphery of the hub wheel, and an inner side base portion of the wheel mounting flange is formed in an arc shape, and an outer portion of the seal is 2. The in-wheel motor drive device according to claim 1, wherein the side seal has a pair of side lips that are in sliding contact with the base portion and a grease lip that is inclined inward of the bearing.   The in-wheel motor drive device according to claim 1 or 2, wherein the wheel-side rotating member is fitted into the hub wheel, and the wheel-side rotating member and the hub wheel are integrally plastically coupled.   The outer member is press-fitted and fixed to the inner side of the first outer member having an outer outer rolling surface formed on the inner periphery, and the inner side outer side to the inner periphery. A separate outer ring is press-fitted and fixed to the wheel-side rotating member, and the inner ring and the second outer member are made of high-carbon chromium bearing steel or The in-wheel motor drive device of Claim 2 or 3 comprised by carburized steel.   The speed reduction part has a plurality of waveforms composed of trochoidal curves on the outer periphery, a plurality of through holes are formed through the eccentric part, and the rotation axis of the motor side rotation member is rotated. A curved plate that performs a revolving motion at the center, a plurality of outer pins that are brought into rolling contact with the outer peripheral portion of the curved plate via needle roller bearings to generate a rotational motion, and a needle roller bearing on the inner periphery of the through hole A cycloid reduction mechanism that converts the rotational motion of the curved plate into a rotational motion centered on the rotational axis of the motor-side rotational member and transmits the rotational motion to the wheel-side rotational member. The in-wheel motor drive device in any one of Claims 1 thru | or 4 comprised by these.

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