JP5067787B2 - In-wheel motor drive device - Google Patents

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. 7, 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 58a 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 and cause the curved plates 59a, 59b to rotate, and the curved plates 59a, 59b. A plurality of inner pins 63 that transmit the rotation motion 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 that 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, one end portion of the motor side rotation member 58 is rotatably supported on the inner diameter portion of the wheel side rotation member 62. That is, when the wheel-side rotating member 62 is tilted by a radial load or moment load applied from the wheel 54 via the wheel mounting flange 67, the motor-side rotating member 58 is also tilted. As a result, the gaps between the component parts of the speed reducing portion 57 are changed, and an excessive load acts between the component parts or damages the component parts.

  In order to solve such a problem, the wheel bearing device 55 is required to have a load capacity capable of appropriately supporting the load received from the wheel 54. However, generally increasing the load capacity of the bearing is not preferable because problems such as an increase in the size of the bearing and an increase in weight and cost occur.

  The present invention has been made in view of such a conventional problem, and improves the space efficiency of the bearing and increases the load capacity to improve the durability, and also improves the assembling and disassembling performance and is excellent in maintainability. Another object of the present invention is to provide an in-wheel motor drive device.

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 reduction portion that reduces the rotation of the motor side rotation member; and a wheel bearing device that is connected to the speed reduction portion and rotatably supports the wheel. Coupled to the speed reduction part via a connecting member, the wheel bearing device integrally has a mounting flange for mounting on the casing on the outer periphery, and a double row outer rolling surface is integrally formed on the inner periphery. An outer rolling member formed integrally with a wheel mounting flange for mounting a wheel at one end portion, an inner rolling surface facing one of the outer rolling surfaces of the double row on the outer periphery, and the inner rolling surface Extends axially from A hub wheel formed with a cylindrical small-diameter step portion and a cylindrical shaft portion fitted to the small-diameter step portion of the hub wheel are integrally formed on the other outer side of the double row outer rolling surface. An inner member formed of an inner ring member formed with opposing inner rolling surfaces, a double row rolling element housed in a freely rollable manner between both rolling surfaces of the inner member and the outer member, and A seal attached to an opening of an annular space formed between the outer member and the inner member, and the wheel bearing device is blocked from the speed reduction portion by an oil seal attached to the casing, By being lubricated by the grease sealed inside the bearing and forming a hardened uneven portion on the inner circumference of the hub wheel, the diameter of the fitting portion of the shaft portion is expanded, and it is cut into the uneven portion and caulked. the wheel hub and the inner ring member is plastically coupled together, the coupling member and the inner ring portion But the torque can be transmitted through the serration formed on each end and are detachably coupled, at least one of the tooth surface of the tooth surfaces of the serrations are formed in a crowning shape.

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 interposed via the connecting member. An outer member coupled to the speed reduction portion, the wheel bearing device integrally having a mounting flange for being attached to the casing on the outer periphery, and a double row outer rolling surface formed integrally on the inner periphery; A wheel mounting flange for mounting the wheel at one end is integrally formed, and an inner rolling surface facing one of the double row outer rolling surfaces on the outer periphery, and a cylindrical shape extending in the axial direction from the inner rolling surface A hub ring having a small-diameter step portion and a cylindrical shaft portion that is fitted to the small-diameter step portion of the hub ring are integrally formed, and the inner ring facing the other of the double-row outer rolling surfaces on the outer periphery. An inner member made of an inner ring member formed with a running surface, and this Mounted on the opening of the annular space formed between the outer member and the inner member, and the double row rolling elements accommodated between the rolling surfaces of the outer member and the outer member. The wheel bearing device is shut off from the speed reduction portion by an oil seal mounted on the casing, and is lubricated by grease sealed inside the bearing, and a hardened uneven portion is formed on the inner periphery of the hub wheel. The hub ring and the inner ring member are integrally plastically bonded by expanding the diameter of the fitting portion of the shaft portion and biting into the concavo-convex portion, and the serrations formed at the end portions of the connecting member and the inner ring member , respectively. Since it is connected so as to be able to transmit torque through and separable, and at least one tooth surface of the serrations is formed in a crowning shape, metal wear powder mixed in the lubricating oil of the speed reduction part, etc. Foreign matter inside the bearing This prevents intrusion and decreases the peeling life, ensures the desired peeling life without being affected by the cleanliness of the lubricating oil, improves the assembly and disassembly, and improves the maintenance. A wheel motor drive device can be provided. Further, even if the inner ring member is inclined by a radial load or moment load applied from the wheel via the wheel mounting flange, the inclination is allowed by this serration, and it is possible to prevent the connecting members from being inclined together. Therefore, it is possible to prevent an excessive load from acting between the constituent parts of the speed reduction portion or to damage the constituent parts, thereby improving durability and reliability.

Further, as in the second aspect of the invention, the basic load rating of the inner rolling element row of the double row rolling element rows is set to be larger than the basic load rating of the outer rolling element row. For example, even if the load applied to the inner side rolling element row portion becomes larger than the load applied to the outer side rolling element row portion, the life can be increased and the strength and durability can be improved.

According to a third aspect of the present invention, a pitch circle diameter of the inner rolling element is set larger than a pitch circle diameter of the outer rolling element, and the inner rolling element If the number of rolling elements in the row is set to be larger than the number of rolling elements in the outer side rolling element row, the rigidity of the inner side rolling element row portion is increased and the basic load rating is set on the outer side rolling element row. It becomes larger than the basic load rating of the part, can improve the space efficiency of the bearing and can realize a lean design, and can improve the strength and durability.

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 reducing portion and a wheel bearing device connected to the speed reducing portion and rotatably supporting a wheel, the wheel bearing device is connected to the speed reducing portion via a connecting member. And an outer member integrally formed with a double-row outer rolling surface on the inner periphery, the wheel bearing device being combined and having an attachment flange for being attached to the casing on the outer periphery. A wheel mounting flange for mounting a wheel on the inner side, an inner rolling surface facing one of the outer rolling surfaces of the double row on the outer periphery, and a small cylindrical diameter extending in the axial direction from the inner rolling surface Step The formed hub wheel and a cylindrical shaft portion fitted to the small diameter step portion of the hub wheel are integrally formed, and an inner rolling surface facing the other of the outer rolling surfaces of the double row is provided on the outer periphery. An inner member formed of an inner ring member formed, a double row rolling element that is rotatably accommodated between both rolling surfaces of the inner member and the outer member, and the outer member and the inner member And a seal mounted on the opening of the annular space formed between the wheel bearing device and the oil seal mounted on the casing. The hub wheel and the inner ring member are formed by forming a hardened uneven portion on the inner periphery of the hub wheel and enlarging the fitting portion of the shaft portion to bite into the uneven portion and caulking. There are plastic bonded together, the connecting member and the inner ring member, respectively end Possible torque transmission through the formed serrations, and is detachably coupled, at least one of the tooth surface of the tooth surfaces of the serrations are formed in a crowning shape, in the lubricating oil of the speed reduction portion Prevents foreign matter such as mixed metal wear powder from entering the bearings and shortening the peeling life, ensuring the desired peeling life without being affected by the cleanliness of the lubricating oil. It is possible to provide an in-wheel motor drive device with improved decomposability and excellent maintainability. Further, even if the inner ring member is inclined by a radial load or moment load applied from the wheel via the wheel mounting flange, the inclination is allowed by this serration, and it is possible to prevent the connecting members from being inclined together. Therefore, it is possible to prevent an excessive load from acting between the constituent parts of the speed reduction portion or to damage the constituent parts, thereby improving durability and reliability.

A casing, a motor unit disposed in the casing, and a motor-side rotating member integrally formed with an eccentric portion, and a motor-side rotating member, a speed-reducing unit that decelerates the rotation of the motor-side rotating member, and the speed-reducing unit An in-wheel motor drive device including a wheel bearing device for rotatably supporting a wheel, wherein the wheel bearing device is coupled to the speed reduction portion via a connecting member, and the wheel bearing device is And an outer member integrally formed with a double row outer rolling surface on the inner periphery, and a wheel mounting flange for mounting a wheel on one end. A hub ring having an inner rolling surface facing one of the outer rolling surfaces of the double row on the outer periphery, and a cylindrical small-diameter step portion extending in an axial direction from the inner rolling surface, and Small diameter of hub ring An inner member composed of an inner ring member integrally formed with a cylindrical shaft portion fitted to the portion, and formed with an inner rolling surface facing the other of the outer rolling surfaces of the double row on the outer periphery; A double row rolling element housed in a freely rollable manner between both 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 An oil seal mounted on the casing, the wheel bearing device is cut off from the speed reduction portion, and is lubricated by grease enclosed in the bearing, and is disposed on the inner periphery of the hub wheel. A hardened concavo-convex portion is formed, and the hub ring and the inner ring member are integrally plastically bonded by expanding the diameter of the fitting portion of the shaft portion and biting into the concavo-convex portion, and the connecting member and the inner ring member. but torque Den via the serration formed on each end Capable, and are detachably coupled, the tooth surfaces of the serrations are formed in a crowning shape.

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. 4 is an enlarged view of a main part showing the eccentric part of FIG. 1, FIG. 5 is an enlarged view showing the wheel bearing device of FIG. 1, and FIG. 6 is an enlarged view of the main part showing the connecting part of FIG. is there. 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 disposed with an axial gap (axial gap) provided inside the stator 3, and a rotor 4 fitted inside the rotor 4 It is comprised by the axial 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 disk-shaped flange portion 4b extending radially outward from the cylindrical portion 4a. The double row rolling bearings 7 and 7 are rotatably supported with respect to the casing 2. 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 what used the axial gap motor for the motor part A was illustrated here, not only this but the motor of arbitrary structures is applicable, for example, although not shown in figure, it fixes to the inner periphery of a casing A radial gap motor may be provided that includes a stator and a rotor opposed to the inner diameter side of the stator via a radial 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. And it is rotatably supported with respect to the connecting member 11. 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 connecting member 11, and two counterweights 15 attached to the motor side rotating member 5 , 15. 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 connecting member 11 has a plurality of inner pins 18, 18 fixed to the inner side end at equal intervals on the circumference centering on the rotation axis of the connecting member 11, and the outer side end. A female serration (or spline) 11a that is detachably connected to an inner member 24 that constitutes a wheel bearing device C that will be described later is formed. The connecting member 11 is made of carburized steel such as SCR430, and the surface of the connecting member 11 including the female serration 11a is hardened in a range of 58 to 64 HRC. For example, the connecting member 11 may be formed of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and a hardened layer may be formed on the surface by induction hardening. .

  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, 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 connecting member 11 and through holes 19 provided in the curved plates 12 a and 12 b. In order to reduce the frictional resistance with the through hole 19, the inner pin 18 is mounted with a needle roller bearing 18 a at a position where it comes into rolling contact with the inner peripheral surface of the through hole 19. 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. (See FIG. 3).

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 flange part 4b rotates. At this time, the rotor 4 rotates at a higher speed as a higher 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 rotational movement of the curved plates 12 a and 12 b is transmitted to the hub wheel 25 via the connecting 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 connecting member 11, even when the low torque, high rotation type motor unit A is adopted, the torque necessary for the wheels can be obtained. It is possible to communicate.

  The speed reduction ratio of the speed reduction portion 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 22c for attaching to the casing 2 on the outer periphery, and double row outer rolling surfaces 22a and 22b are formed on the inner periphery. The outer member 22 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and at least the double row outer rolling surfaces 22a and 22b have a surface hardness in the range of 58 to 64HRC by induction hardening. Is cured.

  The inner member 24 includes a hub ring 25 and an inner ring member 16 plastically coupled to the hub ring 25. 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 arranged on one (outer side) of the double row outer rolling surfaces 22a and 22b 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. Hub bolts 26a for fixing the wheels to the circumference of the wheel mounting flange 26 are equally planted. 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 a wheel mounting flange that serves as a seal land portion of the outer seal 30 described later, including the inner rolling surface 25a. The surface hardness is set to a range of 58 to 64 HRC by induction hardening from the base portion 26b of the 26 to the small diameter step portion 25b.

  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 inner ring member 16 is formed in a cylindrical shape, and an inner rolling surface 16a facing the other (inner side) of the double row outer rolling surfaces 22a and 22b of the outer member 22 on the outer periphery, and the inner rolling surface 16a. A shaft portion 17 extending in the axial direction from is integrally formed. The shaft portion 17 is formed with 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 is formed at the end of the in-row portion 17a. A male serration (or spline) 16 b that engages with the serration 11 a of the connecting member 11 is formed at the inner end of the inner ring member 16.

  The inner ring member 16 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the surface hardness is in the range of 58 to 64 HRC by induction quenching from the outer peripheral surface of the male serration 16b to the inrow portion 17a. Is cured. In addition, the fitting part 17b is made into the surface hardness after forging.

  Double-row rolling elements 23, 23 are accommodated between the rolling surfaces 22a, 25a, 22b, 16a of the outer member 22 and the inner member 24, and these double-row rolling elements 23 are held by the cages 28, 28a. , 23 are movably held respectively. The hub wheel 25 and the inner ring member 16 are integrated by pressing the shaft portion 17 of the inner ring member 16 into the hub wheel 25 with a predetermined squeezing force, and the shoulder portion 16c of the inner ring member 16 abuts the end surface of the small-diameter step portion 25b. In this state, the diameter of the fitting portion 17b is increased by pushing a diameter expanding jig such as a mandrel into the outer diameter of the fitting portion 17b. That is, the hub wheel 25 and the inner ring member 16 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, in this embodiment, the pitch circle diameter of the inner side rolling elements 23 of the double row rolling elements 23 is set larger than the pitch circle diameter of the outer side rolling elements 23. Further, with the difference in pitch circle diameter, the number of rolling elements in the inner side rolling element 23 row is set larger than the number of rolling elements in the outer side rolling element 23 row. Accordingly, the rigidity of the inner side rolling element 23 row portion is increased, the basic load rating is larger than the basic rated load of the outer rolling element 23 row portion, and the load applied to the inner side rolling element 23 row portion is increased. Even if it becomes larger than the load applied to the outer rolling element 23 row portion, the life can be extended. That is, it is possible to provide a wheel bearing device C that can improve the space efficiency of the bearing, realize a lean design, and have improved strength and durability.

  Here, the pitch circle diameter of the inner-side rolling elements 23 is set to be larger than the pitch circle diameter of the outer-side rolling elements 23, and the number of rolling elements in the inner-side rolling elements 23 row is set to the outer-side rolling elements 23 row. Although the load capacity of the inner side rolling element 23 row portion is increased by setting more than the number of rolling elements of the rolling element 23 row, this is not restrictive. For example, although not illustrated, the inner side rolling element is increased. The load capacity may be increased by making the size of the moving body larger than the size of the outer side rolling element, and the outer side rolling element of the double row rolling elements is a ball, and the inner side rolling element It is also possible to increase the load capacity of the rolling element row portion on the inner side by using tapered rollers.

  Further, seals 30 and 31 for sealing an opening of an annular space formed between the outer member 22 and the inner member 24 are mounted. Further, an oil seal 32 is attached to the outer end of the casing 2, and the opening of the annular space formed between the casing 2 and the connecting member 11 is sealed. This oil seal 32 has a garter spring 32a, shuts off the bearing portion and the speed reduction portion B, and prevents the lubricating oil that lubricates the speed reduction portion B from entering the inside of the bearing. That is, foreign matter such as metal wear powder mixed in the lubricating oil of the deceleration portion B is prevented from entering the bearing and deteriorating the peeling life. The bearing portion is lubricated by grease sealed inside by seals 30 and 31. Thereby, the bearing part can ensure a desired peeling life without being affected by the cleanliness of the lubricating oil that lubricates the inside of the speed reduction part B.

Next, the connection structure of the connection member 11 and the inner ring member 16 will be described with reference to FIG.
The connecting member 11 and the inner ring member 16 are connected via serrations 11a and 16b so that torque can be transmitted. Thereby, the deceleration part B and the wheel bearing device C can be separated, and an in-wheel motor drive device with improved assembly and disassembly and excellent maintainability can be provided.

  Further, at least one tooth surface of the female serration 11a of the connecting member 11 and the male serration 16b of the inner ring member 16 is formed in a drum-shaped crowning shape. Thereby, even if the inner ring member 16 is inclined by a radial load or a moment load applied from the wheel via the wheel mounting flange 26, the inclination is allowed by these serrations 11a and 16b, and the connecting member 11 is prevented from being inclined together. can do. Therefore, it is possible to prevent an excessive load from acting between the component parts of the speed reduction portion B or damage the component parts, thereby improving durability and reliability.

  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 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 the rotation to the wheel bearing device. The present invention can be applied to an in-wheel motor drive device arranged in a shape.

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. It is an enlarged view which shows the wheel bearing apparatus of FIG. It is a principal part enlarged view which shows the connection part of FIG. 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 ..... Flange part 4c ... ......... Permanent magnet 5 ......... Motor side rotating members 5a, 5b ......... Eccentric parts 6, 29 ......... End cap 7, 9, 10, 21 ... Rolling bearings 8, 32 ... Oil seal 11 ... Connecting member 11a ... Female serration 12a, 12b ··· Curved plate 13 ················································································· ... ··························································································································· • · ... Shoulder 17 ...... Shaft 17a ... In-row 17b ... Fitting 18 ...・ ・ ・ ・ Inner pin 19 ・ ・ ・ ・ ・ ・ Through hole 20 ・ ・ ・ ・ ・ ・ Bearing hole 22 ・ ・ ・ ・ ・ ・ Outer member 22a, 22b · · · Outer rolling surface 22c · · · mounting flange 23 · · · rolling element 24 · · · inner member 25 · · · ... hub wheel 25b ... small diameter step 26 ... wheel mounting flange 26a ... hub bolt 27 ... .... concave Portions 28, 28a ... Retainer 30 ... Outer side seal 31 ... Inner side seal 32a ... ..Garter spring 50 ... In-wheel motor drive device 51 ... Car body 52 ... Case 53 ... ...... Motor 54 ... Wheel 55 ... Wheel bearing device 56 ... Hub wheels 56a, 65a・ ・ ・ ・ ・ Inner rolling surface 56b ......... Small diameter step 57 ......... Speed reduction part 58 ......... Motor side rotating member 58a, 58b ... eccentric parts 59a, 59b ... curved plates 60a, 60b ... rolling bearings 61 ... outer pins 62 ... ..... Inner member 63 ..... Inner pin 64 ..... Outer member 64a ..... Outward rolling Surface 64b ... Mounting flange 65 ... Inner ring 66 ... Ball 67 ... Wheel mounting Flange A ········ Motor B ······· Deceleration C · ·········· Wheel Bearing G ··· ········· Center point L1 between curved plates ········· Distance L2 between the center point and the center of the curved plate ··········· Center point and counterweight The distance m1 from the center of the plate ·························································· Zb: Number of corrugated plate waveforms ε Eccentricity from the center of gravity of the rotary axis of the eccentric weight .epsilon.2 .......... counterweight from rotation axis of the center of gravity of .......... curved plates

Claims (3)

A casing (2);
A motor part (A) for rotating and driving a motor side rotating member (5) disposed in the casing (2) and integrally formed with eccentric parts (5a) and (5b);
A decelerating portion (B) for decelerating the rotation of the motor side rotating member (5);
In-wheel motor drive device (1) provided with wheel bearing device (C) connected to this reduction part (B) and rotatably supporting a wheel,
The wheel bearing device (C) is connected to the speed reduction part (B) via a connecting member (11), and the wheel bearing device (C) is attached to the casing (2) on the outer periphery. An outer member (22) having a flange (22c) integrally and having a double row of outer rolling surfaces (22a), (22b) integrally formed on the inner periphery;
A wheel mounting flange (26) for mounting a wheel at one end, and an inner rolling surface (25a) facing one of the double row outer rolling surfaces (22a) and (22b) on the outer periphery; A hub wheel (25) having a cylindrical small diameter step portion (25b) extending in the axial direction from the inner rolling surface (25a), and a small diameter step portion (25b) of the hub wheel (25) are fitted. An inner ring having a cylindrical shaft portion (17) integrally formed, and having an inner raceway surface (16a) facing the other of the double row outer raceway surfaces (22a) and (22b) on the outer periphery. An inner member (24) comprising a member (16);
A double row rolling element (23) accommodated so as to roll between both rolling surfaces of the inner member (24) and the outer member (22);
A seal (30), (31) attached to an opening of an annular space formed between the outer member (22) and the inner member (24);
The wheel bearing device (C) is cut off from the speed reduction portion (B) by an oil seal (32) attached to the casing (2), and is lubricated by grease enclosed in the bearing.
A hardened concave and convex portion (27) is formed on the inner periphery of the hub wheel (25), and the fitting portion (17b) of the shaft portion (17) is enlarged to bite into the concave and convex portion (27) and crimped. Thus, the hub ring (25) and the inner ring member (16) are integrally plastically coupled,
The connecting member (11) and the inner ring member (16) are coupled to each other so as to be able to transmit torque and to be separated through serrations (11a) and (16b) formed at end portions thereof, and the serration (11a). , (16b) At least one tooth surface of the tooth surfaces is formed in a crowning shape . 2. The in-wheel motor drive device according to claim 1, wherein a basic load rating of an inner side rolling element row of the double row rolling element rows is set larger than a basic load rating of an outer side rolling element row. A pitch circle diameter of the inner side rolling elements is set to be larger than a pitch circle diameter of the outer side rolling elements, and the number of rolling elements in the inner side rolling element row is the outer side rolling element row. The in-wheel motor drive device according to claim 2 , wherein the in-wheel motor drive device is set to be larger than the number of rolling elements.

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