JP2013103672A - Bearing apparatus for wheel including in-wheel electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight and compact bearing apparatus for wheel including an in-wheel electric motor, configured to ensure rigidity of the bearing apparatus for wheel and to improve rotational accuracy of an input shaft.SOLUTION: A reduction gear 3 includes: a sun gear 26 provided on an outer circumference of an input shaft 5; a ring gear 27 fixed to a housing 4; and pinion gears 28 which are equally spaced in the circumferential direction. An output member 6 includes: a coupling shaft part 31 formed on its outer circumference to be inserted in a hub wheel 13; an annular base part 33 formed on the inner side thereof to have a large diameter; a pair of flanges 34, 35 which are projected radially outward and arranged opposite to each other in the axial direction, while housing the pinion gears 28; and a holding part 50 formed of bridges 36 for connecting the components in the axial direction. A side face 50a of the holding part is brought into contact with a large end face of the inner ring 14 in an abutting state. The output member 6 is fixed to the hub wheel 13 by fixing nuts 32 so as to transmit torque.

Description

  The present invention relates to a wheel bearing device for rotatably supporting a wheel, and an in-wheel motor built-in wheel bearing device in an electric vehicle in which the wheel bearing device, a speed reducer, and a motor are combined.

  In recent years, as a countermeasure for reducing the environmental load of automobiles, a shift from a conventional driving type using an engine to a driving type using a motor has been studied. Under such circumstances, an in-wheel type motor-integrated wheel bearing device in which a wheel bearing, a reduction gear, and a motor are combined is attracting attention as a wheel bearing device for an electric vehicle. When the in-wheel type motor-equipped wheel bearing device is used as a driving wheel of an electric vehicle, each wheel can be individually driven to rotate, so that a large-scale power transmission mechanism such as a conventional propeller shaft or a differential is not required. Can be made lighter and more compact.

  As an example of this in-wheel type motor-equipped wheel bearing device, one shown in FIG. 11 is known. This in-wheel type motor-equipped wheel bearing device includes a wheel bearing device 101 that rotatably supports a wheel (not shown), a motor 102 as a rotation drive source, and a hub that decelerates the rotation of the motor 102 to reduce the rotation of the motor 102. The speed reducer 103 that transmits to the wheel is disposed on the central axis O of the wheel.

  The motor 102 is configured by a radial gap type motor in which a radial gap is provided between a stator 105 fixed to a cylindrical motor casing 104 and a rotor 107 attached to an output shaft 106. The output shaft 106 is rotatably supported by the rolling bearings 108 and 108 including a pair of deep groove ball bearings with respect to the motor casing 104. The opening on the inner side of the motor casing 104 is closed with a cap 109.

  The reduction gear 103 is a cycloid reduction gear, and includes an input shaft 111 having an eccentric shaft 110, a plurality of outer pins 113 passed between the reduction gear casing 112 and the motor casing 104, and a drive shaft (output member). 114 includes a plurality of inner pins 115 and two curved plates 118 and 119 that are rotatably supported on the eccentric shaft 110 via rolling bearings 116 and 117 formed of cylindrical roller bearings. The curved plates 118 and 119 are formed in a wavy trochoid curve having a gentle outer shape, and are attached to the eccentric shaft 110. The outer pin 113 is rotatably supported by rolling bearings 120 and 120 including a pair of needle roller bearings, and the outer pin 113 guides the eccentric motion of the curved plates 118 and 119 on the outer peripheral side.

  The input shaft 111 is coupled to the output shaft 106 of the motor 102 via a spline 111a and is integrally rotated. When the output shaft 106 of the motor 102 rotates, the eccentric shaft 110 attached to the input shaft 111 that rotates integrally therewith rotates, and the curved plates 118 and 119 engaged with the eccentric shaft 110 perform an eccentric motion. The rotation of the rotor 107 is smoothly and efficiently transmitted as a rotational movement of the drive shaft 114 with a large reduction ratio.

  The two curved plates 118 and 119 are mounted on the eccentric shaft 110 of the input shaft 111 with a phase difference of 180 ° so that the eccentric motion is canceled out, and on each side of the eccentric shaft 110, the curved plates 118 and 119 are mounted. Counterweights 121 and 121 that are eccentric in the direction opposite to the eccentric direction of the eccentric shaft 110 are mounted so as to cancel the vibration caused by the eccentric motion. The input shaft 111 is rotatably supported by a rolling bearing 122 formed of a deep groove ball bearing with respect to a drive shaft 114 described later.

  The wheel bearing device 101 is externally inserted through an inner member 125 including a hub wheel 123 and an inner ring 124 press-fitted into the hub wheel 123, and the inner member 125 via double rows of balls 126 and 126. The outer member 127 is provided.

  The hub wheel 123 integrally has a wheel mounting flange 128 for mounting a wheel at one end, and has an inner rolling surface 123a on the outer periphery and a small-diameter stepped portion 123b extending in the axial direction from the inner rolling surface 123a. A serration 123c for torque transmission is formed on the inner periphery. The inner ring 124 is formed with the other inner rolling surface 124a on the outer periphery, and is press-fitted into the small-diameter step portion 123b of the hub ring 123 via a predetermined squeeze.

  The outer member 127 integrally has a vehicle body mounting flange 127b attached to the reduction gear casing 112 via a fixing bolt 112a on the outer periphery, and a plurality of outer members 127 facing the inner rolling surfaces 123a and 124a of the inner member 125 on the inner periphery. The outer rolling surfaces 127a and 127a of the row are integrally formed. Between these rolling surfaces 127a, 123a and 127a, 124a, double rows of balls 126, 126 held in a cage 129 are accommodated so as to roll freely.

  The drive shaft 114 constituting the speed reducer 103 includes a flange portion 130 to which the inner pin 115 is attached, a cylindrical shoulder portion 131 extending in the axial direction from the flange portion 130, and a shaft extending in the axial direction from the shoulder portion 131. The part 132 is integrally formed. A serration 132a meshing with the serration 123c of the hub wheel 123 is formed on the outer periphery of the shaft portion 132, and a male screw is formed at this end portion. The drive shaft 114 is brought into contact with the hub wheel 123 until the shoulder portion 131 abuts the end surface of the inner ring 124. The drive shaft 114 and the hub wheel 123 are coupled to each other in the axial direction so as to transmit torque (fixed torque 133 is fixed by a fixed nut 133 fitted inside and screwed to the male screw) (see, for example, Patent Document 1). ).

JP 2011-117529 A

  In such a conventional structure, an oil seal 134 is mounted in an annular space formed between the outer member 127 of the wheel bearing device 101 and the shoulder 131 of the drive shaft 114, and the gear sealed in the speed reducer 103. Sealed so that oil does not leak into the bearing. However, in order to install this oil seal 134, a mounting space is required in the axial direction. For this reason, the whole apparatus enlarges and a weight increases. In order to avoid this, it is conceivable to reduce the size of the wheel bearing device 101. However, in this case, when the bearing rigidity is reduced and a moment load is applied, the curved plate 118 constituting the speed reducer 103, The displacement of 119 increases, and the contact state between the curved plates 118 and 119 and the outer pin 113 may be poor.

  In addition, since the wheel bearing device 101 that supports the drive shaft 114 of the speed reducer 103 is elastically deformed by the load from the road surface to the wheels, the rolling bearing 122 becomes the original axis of the input shaft 111 and the output shaft 106. However, the motor casing 104 is hardly affected by the load from the wheels, and the coaxiality of the two rolling bearings 108 and 122 is deteriorated and tilted. For this reason, an uneven load is likely to act on these rolling bearings 108 and 122, not only lowering the durability and noise of the rolling bearings 108 and 122 but also lowering the rotational accuracy of the input shaft 111 and the output shaft 106. There was a problem such as.

  The present invention has been made in view of such a conventional problem, and while ensuring the rigidity of the wheel bearing device, it is lightweight and compact, and the rotational accuracy of the input shaft and the durability of the bearing that supports the input shaft are achieved. It is an object of the present invention to provide an in-wheel type motor-equipped wheel bearing device with improved performance.

  In order to achieve such an object, the invention according to claim 1 of the present invention includes a wheel bearing device for rotatably supporting a wheel, a motor arranged coaxially with respect to the central axis of the wheel, The planetary gear reducer having an input shaft driven by the output of the motor, a cylindrical portion, and a front end portion whose central portion is opened at an outer end portion thereof, the planetary gear reducer and the motor And an outer member of the wheel bearing device is fitted into the opening of the front end of the housing, fastened to the front end by a fixing bolt, and the input shaft is connected to the planet. An in-wheel motor-equipped wheel bearing device supported by a pair of rolling bearings on both axial sides of a gear reducer, the wheel bearing device having a vehicle body mounting flange integrally on an outer periphery and an inner periphery Double row inversion A hub wheel having an outer member integrally formed with a surface, a wheel mounting flange for mounting the wheel on one end, and a small-diameter step portion extending in the axial direction on the outer periphery, and the hub wheel An inner member formed of at least one inner ring press-fitted into the small-diameter step portion, and formed with a double-row inner rolling surface facing the double-row outer rolling surface on the outer periphery, the inner member and the inner member An in-wheel type motor-integrated wheel bearing device comprising a double-row rolling element that is rotatably accommodated between both rolling surfaces of the outer member, wherein the large end surface of the inner ring has the planetary gear reducer It contacts with the side of the holding part of the output member which constitutes the planetary gear reducer so as to overlap with the insertion hole of the pinion pin which constitutes.

  Thus, a planetary gear reducer provided with a wheel bearing device for rotatably supporting a wheel, a motor arranged coaxially with respect to the central axis of the wheel, and an input shaft driven by the output of the motor And a cylindrical portion, and a front end portion whose central portion is open at an end portion on the outer side thereof, and a planetary gear reducer and a housing that accommodates a motor, the opening portion of the front end portion of the housing An in-wheel motor built-in wheel in which an outer member of a wheel bearing device is fitted and fastened to a front end portion by a fixing bolt, and an input shaft is supported by a pair of rolling bearings on both axial sides of a planetary gear reducer A bearing device for a wheel, wherein the wheel bearing device has a body mounting flange integrally on the outer periphery, an outer member integrally formed with a double row outer rolling surface on the inner periphery, and a wheel on one end. Wheel mounting frame for mounting A hub wheel having a small diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small diameter step portion of the hub wheel, and outer rows of double rows on the outer periphery. An inner member formed with a double-row inner rolling surface facing the surface, and a double-row rolling element accommodated in a freely rolling manner between the rolling surfaces of the inner member and the outer member. In the in-wheel type motor-equipped wheel bearing device, the side surface of the holding portion of the output member constituting the planetary gear speed reducer is configured such that the large end surface of the inner ring overlaps with the insertion hole of the pinion pin constituting the planetary gear speed reducer. Compared with conventional devices, the inner ring diameter can be increased and abutted against the output member at a one-step larger diameter position, effectively ensuring the rigidity of the wheel bearing device. Use space to reduce axial space With wear, it is possible to provide an in-wheel type motor built wheel bearing apparatus with improved rotational accuracy and durability of the bearing for supporting the input shaft of the input shaft.

  Preferably, as in the invention according to claim 2, the output member constituting the planetary gear speed reducer has a coupling shaft portion fitted into the hub wheel on the outer periphery and a large diameter on the inner side of the coupling shaft portion. The pair of rolling bearings supported by the output member, and the holding member. The annular base portion formed on the annular base portion and the holding portion that protrudes radially outward from the annular base portion and holds the reduction gear. The portion includes a pair of flanges that are opposed to each other in the axial direction at a predetermined interval and accommodates the pinion gear, and a bridge that connects the pair of flanges in the axial direction, and the pinion is connected to the pair of flanges. If the pin is fixed and the pinion gear is rotatably supported by the pinion pin via the needle roller bearing, the output member can be smoothly rotated, and the input shaft and the pin can be fixedly fitted to the input shaft. Motor rotor rotational accuracy of which is improved.

  Further, as in the third aspect of the invention, an axial hole coaxial with the coupling shaft portion is formed on the inner end surface of the holding portion, and the shaft hole has a depth reaching the annular base portion. In addition, if the input shaft is inserted into the shaft hole and supported by a pair of rolling bearings, the input shaft is cantilevered by the output member, so that the support structure can be simplified and the wheel Since the vibrations and impacts transmitted to the output member are simultaneously applied to both rolling bearings in the same manner, it is possible to prevent an unbalanced load from acting on either rolling bearing.

  Further, as in the invention according to claim 4, if the annular base portion of the output member is fitted and inserted into the small diameter step portion of the hub wheel via an elastic member, leakage of lubricating oil in the speed reducer to the outside It is possible to prevent the surrounding environment from being contaminated.

  Further, as in the invention described in claim 5, if the outer member is fitted and inserted into the front end portion of the housing via an elastic member, rain water and the like can be prevented from entering from the outside, and in the speed reducer Leakage of lubricating oil can be prevented.

  Further, as in the invention described in claim 6, it is effective if the pitch circle diameter of one of the rolling elements in the double row is set larger than the pitch circle diameter of the other rolling element. In addition, it is possible to extend the life of the bearing by utilizing the bearing space. Further, the diameter of the inner ring can be increased and abutted against the output member at the position of one step larger diameter, and the axial space can be shortened while ensuring the rigidity of the wheel bearing device.

  In addition, if the diameter of the one rolling element is set larger than the diameter of the other rolling element as in the invention described in claim 7, the bearing life can be increased.

  Further, as in the invention according to claim 8, if the number of the one rolling elements is set larger than the number of the other rolling elements, the bearing rigidity can be increased, and the rigidity of the bearing can be increased. Can be achieved.

  If the rolling element is made of ceramic as in the ninth aspect of the invention, it is possible to reduce the weight, increase the rigidity, and improve the wear resistance. The area of the contact ellipse in contact with the inner raceway and the inner raceway of the inner ring is reduced, and torque loss and dynamic friction that occur when the rolling element rolls between each raceway can be suppressed. This can reduce the rotational torque of the bearing.

  According to a tenth aspect of the present invention, a bolt hole is formed at a circumferentially equidistant position of the wheel mounting flange of the hub wheel, and the wheel mounting flange is connected to the wheel mounting flange by a wheel bolt screwed into the bolt hole. If the wheel is fixed, it will not only be possible to replace it easily in the market if a defect such as a scratch occurs on the threaded part of the wheel bolt. Therefore, it is not necessary to secure the space on the inner side of the wheel mounting flange, and the repairability is improved, and the axial space can be reduced by that amount, and the weight and the size can be reduced while ensuring the rigidity. it can.

  An in-wheel motor-equipped wheel bearing device according to the present invention includes a wheel bearing device for rotatably supporting a wheel, a motor arranged coaxially with respect to the central axis of the wheel, and an output of the motor. A planetary gear speed reducer having an input shaft to be driven, a cylindrical portion, and a housing that houses the planetary gear speed reducer and a motor, having a front end portion whose central portion is opened at an outer end portion thereof. And an outer member of the wheel bearing device is fitted into the opening of the front end of the housing and fastened to the front end by a fixing bolt, and the input shaft is the shaft of the planetary gear reducer. An in-wheel motor-equipped wheel bearing device supported by a pair of rolling bearings on both sides in the direction, the wheel bearing device having a vehicle body mounting flange integrally on the outer periphery and a double-row outer rolling device on the inner periphery Running surface A hub wheel integrally formed with an outer member, a wheel mounting flange for mounting the wheel at one end, and a small-diameter step portion extending in the axial direction on the outer periphery, and a small diameter of the hub wheel An inner member formed of at least one inner ring press-fitted into a stepped portion, and formed with a double-row inner rolling surface opposed to the double-row outer rolling surface on the outer periphery, and the inner member and the outer In a wheel bearing device with a built-in in-wheel type motor including a double-row rolling element that is rotatably accommodated between both rolling surfaces of a member, a large end surface of the inner ring constitutes the planetary gear reducer. Since it is in contact with the side surface of the holding portion of the output member that constitutes the planetary gear speed reducer so as to overlap with the insertion hole of the pinion pin, the inner ring has a larger diameter than the conventional device and is further Butting it against the output member at the large diameter position It is possible to effectively use the space while ensuring the rigidity of the wheel bearing device and reduce the axial space, and improve the rotational accuracy of the input shaft and the durability of the bearing supporting the input shaft. An in-wheel type motor-equipped wheel bearing device can be provided.

It is a longitudinal section showing a 1st embodiment of a bearing device for wheels with a built-in in-wheel type motor concerning the present invention. (A) is the principal part enlarged view which shows the wheel bearing apparatus and reduction gear of FIG. 1, (b) is the principal part enlarged view which shows one seal part of (a), (c) is (a). It is a principal part enlarged view which shows the other seal part of this. (A) is a principal part enlarged view which shows the motor part of FIG. 1, (b) is a principal part enlarged view which shows the seal part of (a). It is a principal part enlarged view which shows the wheel bearing apparatus and output member of FIG. It is a principal part enlarged view which shows the modification of FIG. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the bearing apparatus for in-wheel type motor built-in wheels which concerns on this invention. It is a principal part enlarged view which shows the modification of the reduction gear of FIG. It is a principal part enlarged view which shows the modification of the wheel bearing apparatus of FIG. It is a principal part enlarged view which shows the modification of the wheel bearing apparatus of FIG. It is a principal part enlarged view which shows the modification of the wheel bearing apparatus of FIG. It is a longitudinal cross-sectional view which shows the conventional bearing apparatus for in-wheel type motor built-in wheels.

  A wheel bearing device for rotatably supporting a wheel, a motor arranged coaxially with respect to the central axis of the wheel, a planetary gear reducer having an input shaft driven by the output of the motor, and a cylinder And an outer end of the front end of which the central portion is opened, and a housing that houses the planetary gear reducer and a motor. The wheel is provided at the opening of the front end of the housing. An in-wheel type motor in which an outer member of a bearing device is fitted and fastened to the front end portion by a fixing bolt, and the input shaft is supported by a pair of rolling bearings on both axial sides of the planetary gear reducer An internal wheel bearing device, wherein the wheel bearing device has a body mounting flange integrally on the outer periphery, and an outer member integrally formed with a double row outer rolling surface on the inner periphery, and one end portion Attach the wheel to A wheel mounting flange for integrally forming an inner rolling surface facing one of the double row outer rolling surfaces and a small-diameter step portion extending in the axial direction from the inner rolling surface. A hub ring, an inner member formed of an inner ring press-fitted into a small-diameter step portion of the hub ring and formed with an inner rolling surface facing the other of the double-row outer rolling surfaces, and the inner member and the A double row rolling element housed between both rolling surfaces of the outer member so as to be freely rollable, and a seal attached to both end openings of an annular space formed between the outer member and the inner member The planetary gear speed reducer is fixed to the housing and arranged coaxially with the sun gear. Ring gear and circumferentially between these ring gear and sun gear It is composed of planetary gears composed of pinion gears that are equally arranged via pinion pins at a plurality of intervals, and an output member that constitutes the planetary gear speed reducer is fitted on the outer periphery of the hub wheel via serrations. A coupling shaft portion, an annular base portion having a large diameter on the inner side of the coupling shaft portion, a radially outward projecting projecting from the annular base portion, and disposed opposite to each other in the axial direction at a predetermined interval. A pair of flanges in which the pinion gears are housed, and a holding portion formed of a bridge that connects the pair of flanges in the axial direction, and the pair of rolling bearings are supported by the output member, and the inner ring The large end surface is in contact with the side surface of the holding portion of the output member so as to overlap with the insertion hole of the pinion pin, and is fixed to the end of the coupling shaft portion. The output member is fixed to the hub wheel so as to transmit torque.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a first embodiment of an in-wheel motor-equipped wheel bearing device according to the present invention, and FIG. 2A is a main portion showing the wheel bearing device and the speed reducer of FIG. (B) is an enlarged view of the main part showing one seal part of (a), (c) is an enlarged view of the main part showing the other seal part of (a), and FIG. 1 is an enlarged view of the main part showing the motor part of FIG. 1, FIG. 4B is an enlarged view of the main part showing the seal part of FIG. 1, and FIG. 4 is an enlarged view of the main part showing the wheel bearing device and output member of FIG. FIG. 5 is an enlarged view of a main part showing a modification of FIG. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  The in-wheel motor-equipped wheel bearing device includes a wheel bearing device 1 that rotatably supports a wheel (not shown), a motor 2 that serves as a rotational drive source, and a motor 2 that decelerates rotation of the motor 2 to be described later. The reduction gear 3 that transmits to the hub wheel 13 and the housing 4 that accommodates the reduction gear 3 and the motor 2 are the main components and are arranged on the central axis O of the wheel. The hub wheel 13 of the wheel bearing device 1 is rotated by an output member 6 coaxial with the input shaft 5 of the speed reducer 3.

  The housing 4 includes a cylindrical portion 7 and a front end portion 8 at an end on the outer side thereof, the center portion is opened, and an outer member 17 of the wheel bearing device 1 is fitted into the opening portion 9 so that the vehicle body is attached. A flange 17b is fastened to the front end 8 by a fixing bolt 17c.

  A partition base 8a having a larger diameter is formed coaxially with the opening 9 inside the front end 8 of the housing 4, and a cup-shaped partition member 10 is fixed to the partition base 8a with bolts (not shown). ing. A center hole 11 is formed at the center of the partition wall member 10, and this center hole 11 faces an outer diameter surface of a rotor support member 41 described later via an annular space. A partition wall 12 is configured by the partition wall base portion 8a and the partition wall member 10 connected to the partition wall base portion 8a. The partition wall 12 has a function of partitioning the housing 4 into a housing space for the motor 2 on the outer diameter side and a housing space for the reduction gear 3 on the inner diameter side.

  The wheel bearing device 1 is called the third generation for driving wheels, and as shown in an enlarged view in FIG. 2 (a), an inner side composed of a hub wheel 13 and an inner ring 14 press-fitted into the hub wheel 13. A member 15 and an outer member 17 externally inserted into the inner member 15 via double-row rolling elements (balls) 16 and 16 are provided.

  The hub wheel 13 integrally has a wheel mounting flange 18 for mounting a wheel (not shown) at an end portion on the outer side, one (outer side) inner rolling surface 13a on the outer periphery, and this inner rolling. A small diameter step portion 13b extending in the axial direction from the surface 13a is formed, and a serration (or spline) 13c for torque transmission is formed on the inner periphery. The inner ring 14 is formed with the other (inner side) inner rolling surface 14a on the outer periphery, and is press-fitted into the small-diameter step portion 13b of the hub ring 13 through a predetermined squeeze. Further, hub bolts 18 a are implanted at equidistant positions in the circumferential direction of the wheel mounting flanges 18.

  The hub wheel 13 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 13a and an inner side of a wheel mounting flange 18 serving as a seal land portion of a seal 20 described later. The surface is hardened in the range of 58 to 64 HRC by induction hardening from the base 18b to the small diameter step 13b. On the other hand, the inner ring 14 is made of a high carbon chrome steel such as SUJ2, and is hardened in the range of 58 to 64 HRC up to the core by quenching.

  The outer member 17 integrally has a vehicle body mounting flange 17b attached to the front end 8 of the housing 4 via a fixing bolt 17c on the outer periphery, and is opposed to the inner rolling surfaces 13a and 14a of the inner member 15 on the inner periphery. Double row outer rolling surfaces 17a, 17a are integrally formed. Between these rolling surfaces 17a, 13a and 17a, 14a, double row rolling elements 16, 16 are accommodated in a cage 19 so as to roll freely.

  The outer member 17 is formed of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and at least the double row outer rolling surfaces 17a and 17a are hardened in the range of 58 to 64 HRC by induction hardening. Has been processed.

  In this embodiment, the rolling element 16 is formed of a ceramic made of silicon nitride. Since the rolling element 16 is made of ceramics having a Young's modulus approximately 1.5 times that of steel, the amount of deformation due to load is reduced. For this reason, high rigidity can be achieved, and the area of the contact ellipse that contacts the outer rolling surface 17a of the outer member 17 and the inner rolling surface 14a of the inner ring 14 can be reduced. Torque loss (hysteresis loss) and dynamic friction that occur when rolling between the rolling surfaces can be suppressed, and the rotational torque of the bearing can be reduced.

  In addition, seals 20 and 21 are attached to the opening of the annular space formed between the outer member 17 and the inner member 15, and leakage of the lubricating grease sealed inside the bearing to the outside is reduced. Prevents lubricating oil, contamination, etc. from entering the bearing from the side.

  As shown in an enlarged view in FIG. 2 (b), the outer seal 20 is an integral type comprising a cored bar 22 fitted in the outer member 17 and a seal member 23 joined to the cored bar 22. It is composed of a seal. The cored bar 22 is formed by pressing a steel plate such as an austenitic stainless steel plate (JIS standard SUS304) or a cold rolled steel plate (JIS standard SPCC), and has an inner peripheral end on the outer side of the outer member 17. It is press-fitted through a predetermined scissors.

  On the other hand, the seal member 23 is made of synthetic rubber such as NBR (acrylonitrile-butadiene rubber) and is integrally joined to the cored bar 22 by vulcanization adhesion. The seal member 23 includes a side lip 23a extending obliquely outward in the radial direction, a dust lip 23b extending obliquely outward in the radial direction on the inner diameter side of the side lip 23a, and a bearing inner side (inner side). And a grease lip 23c extending in an inclined manner.

  A base portion 18b on the inner side of the wheel mounting flange 18 is formed in a curved surface having an arc-shaped cross section, and a side lip 23a and a dust lip 23b are slidably contacted with the base portion 18b with a predetermined axial squeeze, and a grease lip 23c is predetermined. Are in sliding contact with each other through a radial shimoshiro. In addition to NBR, the material of the seal member 23 is excellent in heat resistance and chemical resistance, such as HNBR (hydrogenated acrylonitrile butadiene rubber), EPDM (ethylene propylene rubber), etc., which are excellent in heat resistance. Examples thereof include ACM (polyacrylic rubber), FKM (fluororubber), and silicon rubber.

  As shown in an enlarged view in FIG. 2 (c), the inner-side seal 21 is an integral type comprising a cored bar 24 fitted into the outer member 17 and a seal member 25 joined to the cored bar 24. It is composed of a seal. The core metal 24 is formed by pressing from a steel plate such as an austenitic stainless steel plate or a cold rolled steel plate, and is press-fitted into the inner periphery of the outer side end portion of the outer member 17 via a predetermined squeeze.

  On the other hand, the seal member 25 is made of synthetic rubber such as ACM and is integrally joined to the cored bar 24 by vulcanization adhesion. The seal member 25 integrally includes a main lip 25a that is slidably contacted with the outer diameter surface of the inner ring 14 and a grease lip 25b that is inclined and extended toward the bearing inner side (outer side). A garter spring 25c is externally fitted to ensure a predetermined lip tension. Here, since synthetic rubber such as ACM having excellent heat resistance and chemical resistance is used for the seal member 25, compatibility with the lubricating oil is good and oil leakage can be prevented over a long period of time. Examples of the material of the seal member 25 include HNBR, EPDM, and the like having excellent heat resistance, FKM, silicon rubber, and the like other than ACM.

  In addition, although the 3rd generation structure was illustrated here as the wheel bearing apparatus 1, this invention is not restricted to this, The 1st generation structure in which the bearing which consists of a double row angular ball bearing etc. is externally fitted to the hub ring, The second generation structure may be formed of a pair of inner rings in which the inner member is fitted onto the hub ring. In addition, although the wheel bearing device constituted by the double row angular contact ball bearing using balls as the rolling elements 16 is exemplified, the present invention is not limited to this, and it is constituted by a double row tapered roller bearing using tapered rollers. May be.

  The reduction gear 3 is of a planetary gear type. As shown in FIG. 2A, the input shaft 5 and the output member 6, a sun gear 26 integrally formed on the outer diameter surface of the input shaft 5, and the sun gear 26 On the outer periphery, the ring gear 27 is disposed along the inner diameter surface of the boundary portion between the partition wall base 8a and the partition wall member 10 and is fixed via the knock pin 27a. And the pinion gear 28 arranged in the same manner. The pinion gear 28 is supported by a pinion pin 30 via a needle roller bearing 29.

  The output member 6 is integrally provided with a coupling shaft portion 31 at an end portion on the outer side. The coupling shaft portion 31 has a serration (or spline) 31 a engaged with the serration 13 c of the hub wheel 13 on the outer periphery, and a male screw 31 b formed at an end portion of the serration 31 a and is fastened by a fixing nut 32.

  On the inner side of the coupling shaft portion 31, an annular base portion 33 having a one-step larger diameter than this is formed, and a pair of flanges 34 and 35 project from the annular base portion 33 radially outward. The pair of flanges 34 and 35 are arranged to face each other in the axial direction with a space slightly larger than the width dimension of the pinion gear 28, and a bridge 36 for connecting the pair of flanges 34 and 35 in the axial direction is a circumference. It is provided in the direction equidistant position. The pair of flanges 34 and 35 have a carrier function in the planetary gear type reduction gear 3.

  By providing the bridges 36 at equidistant positions in the circumferential direction, the output member 6 can be smoothly rotated. As a result, the rotation accuracy of the rotor 42 of the motor 2 described later can be improved through the output member 6 and the input shaft 5. .

  A shaft hole 37 coaxial with the coupling shaft portion 31 is formed on the end face of the inner flange 35 of the pair of flanges 34 and 35. The shaft hole 37 has a depth that reaches the annular base 33. The input shaft 5 is inserted into the shaft hole 37 and is supported by a pair of rolling bearings 39 and 39 made of deep groove ball bearings.

  A pair of flanges 34 and 35 and a bridge 36 are provided with pinion gear accommodating portions partitioned in the circumferential direction. The pinion gear 28 is accommodated in these accommodating portions and is integrated with the pair of flanges 34 and 35 via the pinion pin 30. Are combined. A locking hole 30a that penetrates in the radial direction is formed at the end of the pinion pin 30, and is fixed by a set screw (not shown) that is screwed into a screw hole 35a formed in the flange 35 on the inner side. Yes.

  Thrust plates 38 and 38 are interposed between both side surfaces of each pinion gear 28 and the pair of flanges 34 and 35 in order to ensure smooth rotation of the pinion gear 28. A pair of rolling bearings 39 and 39 are mounted in an annular space formed between the inner diameter surfaces of the pair of flanges 34 and 35 and the outer diameter surface of the input shaft 5 facing the inner diameter surfaces. It is supported by the member 6. Thus, since the input shaft 5 is cantilevered by the output member 6, the support structure can be simplified, and vibrations and impacts transmitted from the wheel to the output member 6 can be detected by both rolling bearings 39. , 39 are simultaneously loaded in the same manner, so that it is possible to prevent an unbalanced load from acting on either of the rolling bearings 39, 39, and to improve rotational accuracy and durability. In addition, the generation of rotating noise can be suppressed.

  As shown in FIG. 3A, the motor 2 is a radial gap type in which a radial gap is provided between a stator 40 fixed to the cylindrical portion 7 of the housing 4 and a rotor 42 attached by a rotor support member 41. This is a brushless DC motor.

  The rotor support member 41 includes a cylindrical support portion 41a fitted to the inner diameter portion of the rotor 42, a disk portion 41b extending radially inward from the cylindrical support portion 41a along the partition wall 12, and the disk portion 41b. A cylindrical fixing portion 41c formed at the inner end of the cylinder is provided. The rotor support member 41 is fixed to the input shaft 5 via a key 41d locked to the cylindrical fixing portion 41c.

  An oil seal 43 is mounted in an annular space formed between the center hole 11 of the partition member 10 and the cylindrical fixing portion 41 c of the rotor support member 41. As shown in an enlarged view in FIG. 3B, the oil seal 43 is constituted by an integral oil seal including a cored bar 44 and a seal member 45 joined to the cored bar 44. The core metal 44 is formed by pressing from a steel plate such as an austenitic stainless steel plate or a cold rolled steel plate.

  On the other hand, the seal member 45 is made of synthetic rubber such as ACM, and is integrally joined to the cored bar 44 by vulcanization adhesion. The seal member 45 integrally includes a main lip 45a slidably in contact with the outer diameter surface of the cylindrical fixing portion 41c, and a sub lip 45b extending obliquely toward the inner side. The main lip 45a includes a predetermined lip tightness. A garter spring 45c is externally fitted to ensure the force. The oil seal 43 prevents the lubricating oil on the speed reducer 3 side from moving to the motor 2 side, and the motor 2 side is maintained in a dry state, so that the lubricating oil may hinder the rotation of the rotor 42. Avoided. In addition to ACM, examples of the material of the seal member 45 include HNBR, EPDM, and the like that are excellent in heat resistance, FKM, silicon rubber, and the like.

  As shown in FIG. 3A, the motor 2 and the speed reducer 3 are within the range of the axial length of the cylindrical portion 7 of the housing 4 except for the rear end portion (end portion on the inner side) of the input shaft 5. Therefore, it is closed by a cover 47 attached to the rear end portion of the cylindrical portion 7 via an O-ring 46. The O-ring 46 is made of a synthetic rubber such as ACM.

  A rotation sensor 48 is disposed at the center of the cover 47. The rotation sensor 48 is a resolver, the sensor stator 48 a is fixed to the cover 47, and the sensor rotor 48 b is attached to the input shaft 5.

  A lead wire (not shown) of the sensor stator 48a is connected to a connector insertion portion (not shown) provided outside. As the rotation sensor 48, a Hall element or the like can be used in addition to the resolver. The rotation angle of the input shaft 5 detected by the rotation sensor 48 is input to a control circuit via a signal line cable (not shown) and used for rotation control of the motor 2.

  Here, in this embodiment, as shown in FIG. 2A, the output member 6 has a coupling shaft portion 31 formed on the outer end portion and a large diameter on the inner side of the coupling shaft portion 31. An annular base 33 formed and a pair of flanges 34 and 35 projecting radially outward from the annular base 33 are provided. As shown in an enlarged view in FIG. 4, the annular base 33 of the output member 6 is an ACM. The hub ring 13 is fitted into the small-diameter step portion 13b through an O-ring 49 made of synthetic rubber or the like. And the side surface 50a of the holding part 50 which consists of a pair of flanges 34 and 35 and the bridge 36 which connects the pair of flanges 34 and 35 in the axial direction is brought into contact with the large end surface 14b of the inner ring 14 in abutment. Yes. Specifically, the large end surface 14 b of the inner ring 14 is in contact with the side surface 50 a of the holding portion 50 of the output member 6 so as to overlap with the insertion hole of the pinion pin 30. Thereby, compared with the conventional apparatus, the diameter of the inner ring 14 can be increased and abutted against the output member 6 at a position where the diameter of the inner ring 14 is one step larger, and the space is effectively utilized while ensuring the rigidity of the wheel bearing apparatus 1. In addition, it is possible to provide an in-wheel motor-equipped wheel bearing device that can shorten the axial space and improve the rotational accuracy of the input shaft 5 and the durability of the bearing that supports the input shaft 5. .

  The pinion pin 30 that supports the pinion gear 28 is fitted on the same surface or slightly recessed so as not to protrude from the end surface of the flange 34. Thereby, the contact | abutting with the inner ring | wheel 14, the large end surface 14b, and the side surface 50a of the holding | maintenance part 50 is not prevented, but a proper butting state can be maintained.

  Unlike the conventional device in which an oil seal is mounted between the outer member of the wheel bearing device and the shoulder of the drive shaft (output member), the seal 21 is slidably contacted with the outer diameter of the inner ring 14. As a result, the axial space can be further shortened, and the lubricating grease sealed inside the bearing by the single seal 21 can be leaked to the outside. Can be prevented from entering, so that the rotational torque due to the seal sliding contact can be reduced.

  Further, the annular base portion 33 of the output member 6 is fitted and inserted into the small diameter step portion 13 b of the hub wheel 13 through the O-ring 49, and the outer member 17 is attached to the front end portion 8 of the housing 4 through the O-ring 51. Since it is inserted, it is possible to prevent rainwater and the like from entering from the outside, to prevent the lubricating oil in the speed reducer 3 from leaking to the outside, and to prevent the surrounding environment from being contaminated. These O-rings 49 and 51 are made of synthetic rubber such as ACM.

  As shown in FIG. 5, an O-ring 49 may be interposed between the corner of the annular base 33 of the output member 6 and the end of the small diameter step 13 b of the hub wheel 13. Thereby, the process of the annular groove which mounts the O-ring 49 on the outer peripheral surface of the annular base 33 can be omitted, and the assembly process can be simplified and the cost can be reduced along with the simplification of the process process. it can.

  The in-wheel type motor-equipped wheel bearing device according to the present invention is configured as described above, and the operation thereof will be described with reference to FIG.

  When the accelerator of the driver's seat is operated to drive the motor 2, the input shaft 5 is rotated integrally with the rotation of the rotor 42, and the motor output is input to the speed reducer 3. When the sun gear 26 rotates integrally with the input shaft 5, the speed reducer 3 revolves while the pinion gear 28 rotates. When the pinion gear 28 rotates at a reduced speed at this revolution speed, the output member 6 is rotated at a deceleration output having a predetermined reduction ratio. Then, the inner member 15 of the wheel bearing device 1 is rotated integrally with the coupling shaft portion 31 of the output member 6, and the wheel attached to the hub wheel 13 is driven.

  The input shaft 5 is supported by a pair of rolling bearings 39 and 39 on both sides of the pinion gear 28 and rotates. Since these rolling bearings 39 and 39 are both attached to the flanges 34 and 35 integral with the output member 6, as described above, the radial transmission from the wheel to the output member 6 through the wheel bearing device 1 is performed. Directional vibrations and shocks are simultaneously applied to both rolling bearings 39 and 39 in the same manner, and any rolling bearings 39 and 39 can be prevented from applying an unbalanced load.

  Further, since both ends of the pinion pin 30 of the pinion gear 28 are supported by the pair of flanges 34 and 35, the support rigidity becomes high, and good engagement between the pinion gear 28, the ring gear 27, and the sun gear 26 can be obtained. And durability can be improved.

  FIG. 6 is a longitudinal sectional view showing a second embodiment of the in-wheel motor-equipped wheel bearing device according to the present invention, FIG. 7 is an enlarged view of a main part showing a modification of the speed reducer in FIG. FIG. 9 is an enlarged view of a main part showing a modification of the wheel bearing device in FIG. 6, FIG. 9 is an enlarged view of a main part showing a modification of the wheel bearing device in FIG. 8, and FIG. 10 is a wheel bearing in FIG. It is a principal part enlarged view which shows the modification of an apparatus. In this embodiment, the wheel bearing device and the housing are basically partially different from the embodiment described above, and the same reference numerals are given to the same parts or parts having the same function. Detailed description will be omitted.

  This in-wheel type motor-equipped wheel bearing device includes a wheel bearing device 52 that rotatably supports a wheel (not shown), a motor 2 as a rotational drive source, and a motor 2 that decelerates rotation of the motor 2 to be described later. The reduction gear 3 that transmits to the hub wheel 13 and the housing 53 that accommodates the reduction gear 3 and the motor 2 are the main constituent elements, and are arranged on the central axis O of the wheel. The hub wheel 13 of the wheel bearing device 52 is rotated by the output member 6 coaxial with the input shaft 5 of the speed reducer 3.

  The housing 53 includes a cylindrical portion 7 and a front end portion 54 at an outer end portion thereof, a center portion thereof is opened, and an outer member 56 of the wheel bearing device 52 is fitted into the opening portion 55 so that the vehicle body is attached. The flange 56a is fastened to the front end portion 54 by the fixing bolt 17c.

  A partition wall base 54 a is formed coaxially with the opening 55 inside the front end portion 54 of the housing 53, and the cup-shaped partition wall member 10 is integrally formed with the partition base 54 a. Thereby, the number of parts can be reduced, the assembly process can be simplified, and the cost can be reduced. A center hole 11 is formed at the center of the partition member 10, and this center hole 11 faces the outer diameter surface of the support cylindrical portion 41 c of the rotor support member 41 through an annular space. A partition wall 12 ′ is configured by the partition base 54 a and the partition member 10 formed integrally with the partition base 54 a. The partition wall 12 ′ has a function of dividing the inside of the housing 53 into an accommodation space for the motor 2 on the outer diameter side and an accommodation space for the reduction gear 3 on the inner diameter side.

  The wheel bearing device 52 is referred to as a third generation for driving wheels, and includes an inner member 15 including a hub wheel 13 and an inner ring 14 press-fitted into the hub wheel 13. And an outer member 56 inserted through the rolling elements 16 and 16.

  The outer member 56 integrally has a vehicle body mounting flange 56a attached to the front end portion 54 of the housing 53 via a fixing bolt 17c on the outer periphery, and double row outer rolling surfaces 17a and 17a are integrally formed on the inner periphery. Has been. The outer member 56 is formed 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 17a and 17a have a surface in the range of 58 to 64HRC by induction hardening. It has been cured.

  In addition, seals 20 and 21 are attached to the opening of the annular space formed between the outer member 56 and the inner member 15, and leakage of the lubricating grease sealed inside the bearing to the outside is reduced. Prevents lubricating oil, contamination, etc. from entering the bearing from the side.

  In this embodiment, the speed reducer 3 is of a planetary gear type, and includes an input shaft 5 and an output member 6, a sun gear 26 integrally formed on the outer diameter surface of the input shaft 5, and a partition wall base portion on the outer periphery of the sun gear 26. The ring gear 27 is disposed along the inner diameter surface of the boundary portion between the ring member 54 a and the partition wall member 10, and is fixed by a knock pin (not shown) and a retaining ring 57. The ring gear 27 and the sun gear 26 are equally spaced in the circumferential direction. And the pinion gear 28 arranged in the above.

  Here, the outer member 56 constituting the wheel bearing device 52 is different from that of the above-described embodiment in that the vehicle body mounting flange 56a is increased in diameter radially outward, and the pilot portion 58 is provided at the outer diameter portion. Is formed. The outer diameter d0 of the pilot portion 58 is set larger than the inner diameter d1 of the partition wall base portion 54a of the front end portion 54 in the housing 53 or the outer diameter of the ring gear 27. Then, the opening portion 55 of the front end portion 54 of the housing 53 is fitted to the pilot portion 58 via the O-ring 51. Thereby, when assembling the ring gear 27 of the speed reducer 3 from the outer side of the vehicle, the required gear oil bath lid is not required, the number of parts can be reduced, and the work efficiency can be improved and the cost can be reduced. As well as axial space can be shortened.

  FIG. 7 shows a modification of the speed reducer 3 of FIG. Similar to the above-described embodiment, a pilot portion 58 is formed on the outer diameter portion of the vehicle body mounting flange 56 a, and the opening portion 55 of the front end portion 54 of the housing 53 is fitted to the pilot portion 58 via the O-ring 51. . The retaining ring 57 for preventing the ring gear 27 from coming off is abolished, and the ring gear 27 is in contact with the inner side surface 59 of the vehicle body mounting flange 56a of the outer member 56. As a result, when the ring gear 27 or the pinion gear 28 is twisted, the ring gear 27 can be prevented from being pulled out by the side surface 59 of the vehicle body mounting flange 56a when the ring gear 27 is pulled out by the thrust component force. Therefore, at the time of assembly, the side surface 59 of the vehicle body mounting flange 56a does not necessarily have to contact the ring gear 27, and may face each other through a slight gap.

  FIG. 8 is a modification of the wheel bearing device 52 of FIG. Note that this embodiment is basically different from the above-described embodiment only in the specifications of the left and right rolling elements, and other parts and parts having the same parts or parts having the same functions are denoted by the same reference numerals. The detailed explanation is omitted.

  The wheel bearing device 60 is referred to as a third generation for driving wheels. An inner member 62 including a hub wheel 13 and an inner ring 61 press-fitted into the hub wheel 13, and the inner member 62 are arranged in a double row. And an outward member 63 inserted through the rolling elements 16 and 16a.

  The hub wheel 13 integrally has a wheel mounting flange 18 at an end portion on the outer side, and has one inner rolling surface 13a and a small-diameter step portion 13b extending in the axial direction from the inner rolling surface 13a on the outer periphery. A serration 13c for torque transmission is formed on the inner periphery. The inner ring 61 is formed with the other inner rolling surface 61a on the outer periphery, and is press-fitted into the small-diameter step portion 13b of the hub ring 13 via a predetermined shimiro. The inner ring 61 is made of high carbon chrome steel such as SUJ2, and is hardened in the range of 58 to 64 HRC up to the core part by quenching.

  The outer member 63 integrally has a vehicle body mounting flange 56a attached to the front end 54 of the housing 53 via a fixing bolt 17c on the outer periphery, and faces the inner rolling surfaces 13a and 61a of the inner member 62 on the inner periphery. Double row outer rolling surfaces 17a and 63a are integrally formed. Between these rolling surfaces 17a, 13a and 63a, 61a, double-row rolling elements 16, 16a are accommodated in the cages 19, 19a so as to roll freely.

  The outer member 63 is formed of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and at least the double row outer rolling surfaces 17a and 63a are hardened in the range of 58 to 64 HRC by induction hardening. Has been processed.

  Further, seals 20 and 21 ′ are attached to the opening portion of the annular space formed between the outer member 63 and the inner member 62, and leakage of the lubricating grease sealed inside the bearing is reduced. Lubricating oil, contamination, and the like are prevented from entering the bearing from the third side. The inner-side seal 21 'basically has the same specifications as the internal structure and the like, except that the above-described seal 21 has a large diameter.

  Here, in this embodiment, the pitch circle diameter PCDi of the inner side rolling elements 16a among the double row rolling elements 16, 16a is set larger than the pitch circle diameter PCDo of the outer side rolling elements 16. (PCDi> PCDo). Due to the difference in pitch circle diameter PCDo, PCDi, the number of the left and right rolling elements 16, 16a is the same, but the diameter di of the inner rolling element 16a is larger than the diameter do of the outer rolling element 16. The diameter is set.

  In the wheel bearing device 60 having such a configuration, the pitch circle diameter PCDi of the inner side rolling element 16a is set to be larger than the pitch circle diameter PCDo of the outer side rolling element 16, and the rolling elements 16, 16a are correspondingly increased. The diameter di of the inner side rolling element 16a is set to be larger than the diameter do of the outer side rolling element 16, so that the bearing space is effectively utilized compared to the outer side. The bearing life on the inner side can be increased, and the life of the bearing can be extended. Further, the diameter of the inner ring 61 can be increased and abutted against the output member 6 at a position where the diameter is one step larger, and the axial space can be shortened while ensuring the rigidity of the wheel bearing device 60.

  FIG. 9 is a modification of the wheel bearing device 60 of FIG. The wheel bearing device 64 is referred to as a third generation for driving wheels, and includes an inner member 66 composed of a hub wheel 13, an inner ring 65 press-fitted into the hub wheel 13, and a double row on the inner member 66. And an outer member 67 inserted through the rolling elements 16 and 16.

  The hub wheel 13 integrally has a wheel mounting flange 18 at an end portion on the outer side, and has one inner rolling surface 13a and a small-diameter step portion 13b extending in the axial direction from the inner rolling surface 13a on the outer periphery. A serration 13c for torque transmission is formed on the inner periphery. The inner ring 65 is formed with the other inner rolling surface 65a on the outer periphery, and is press-fitted into the small-diameter step portion 13b of the hub ring 13 through a predetermined shimiro. The inner ring 65 is made of high carbon chrome steel such as SUJ2, and is hardened in the range of 58 to 64 HRC up to the core part by quenching.

  The outer member 67 integrally has a vehicle body mounting flange 56a attached to the front end 54 of the housing 53 via a fixing bolt 17c on the outer periphery, and faces the inner rolling surfaces 13a and 65a of the inner member 66 on the inner periphery. Double row outer rolling surfaces 17a and 67a are integrally formed. Between these rolling surfaces 17a, 13a and 67a, 65a, double-row rolling elements 16, 16 are accommodated in the cages 19, 19b so as to roll freely.

  The outer member 67 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and at least the double row outer rolling surfaces 17a and 67a are hardened in the range of 58 to 64 HRC by induction hardening. Has been processed.

  Further, seals 20 and 21 ′ are attached to the opening of the annular space formed between the outer member 67 and the inner member 66, leakage of the lubricating grease enclosed in the bearing inside, and reduction gears. Lubricating oil, contamination, and the like are prevented from entering the bearing from the third side.

  Here, in the present embodiment, the pitch circle diameter PCDi of the inner side rolling elements 16 of the double row rolling elements 16 and 16 is set to be larger than the pitch circle diameter PCDo of the outer side rolling elements 16. (PCDi> PCDo). Due to the difference in pitch circle diameters PCDo and PCDi, the size of the left and right rolling elements 16 and 16 is the same, but the number of inner side rolling elements 16 is set to be larger than the number of outer side rolling elements 16. ing.

  In the wheel bearing device 64 having such a configuration, the pitch circle diameter PCDi of the inner side rolling element 16 is set to be larger than the pitch circle diameter PCDo of the outer side rolling element 16, and the rolling elements 16, 16 correspondingly. However, since the number of rolling elements 16 on the inner side is set to be larger than the number of rolling elements 16 on the outer side, the bearing space is effectively utilized to make the inner side portion of the inner side portion larger than the outer side. The bearing rigidity can be increased, and the rigidity of the bearing can be increased.

  FIG. 10 is a modification of the wheel bearing device 64 of FIG. The wheel bearing device 68 is referred to as a third generation for driving wheels, and includes an inner member 70 including a hub wheel 69, an inner ring 65 press-fitted into the hub wheel 69, and a double row of the inner member 70. And an outer member 67 inserted through the rolling elements 16 and 16.

  The hub wheel 69 integrally has a wheel mounting flange 18 at an end portion on the outer side, and an inner rolling surface 13a and a small-diameter step portion 13b extending in the axial direction from the inner rolling surface 13a are formed on the outer periphery. A serration 13c for torque transmission is formed on the inner periphery. The hub wheel 69 is made of medium and high carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and includes the inner rolling surface 13a and the base portion 18b on the inner side of the wheel mounting flange 18 to the small diameter step portion 13b. As a result, the surface is hardened in the range of 58 to 64 HRC by induction hardening.

  Here, in the present embodiment, bolt holes 71 a to which the wheel bolts 71 are fastened are formed at equal circumferential positions of the wheel mounting flanges 18. Then, after the brake rotor 72 and the wheel 73 are mounted on the wheel mounting flange 18 of the hub wheel 69, they are fixed by the wheel bolts 71. As a result, when a defect such as a scratch is generated in the threaded portion of the wheel bolt 71, not only can it be easily replaced on the market, but the wheel can be replaced for bolt replacement on the market as in the past. It is no longer necessary to secure a space on the inner side of the mounting flange 18, and repairability is improved, and the axial space can be reduced by that amount, and a lightweight and compact design can be achieved while securing rigidity.

  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.

  The wheel bearing device with a built-in in-wheel motor according to the present invention is a combination of a wheel bearing device, a speed reducer, and a motor, and the wheel bearing device becomes an inner member serving as a rotating member and a stationary member. The present invention can be applied to first generation to third generation structures provided with outer members.

1, 52, 60, 64, 68 Wheel bearing device 2 Motor 3 Reducer 4, 53 Housing 5 Input shaft 6 Output member 7 Cylindrical portion 8, 54 Housing front end 8a, 54a Bulkhead base 9, 55 Housing opening 10 Bulkhead member 11 Center hole 12, 12 'of bulkhead member Bulkhead 13, 69 Hub wheel 13a, 14a, 61a, 65a Inner rolling surface 13b Small diameter step 13c, 31a Serration 14, 61, 65 Inner ring 14b Large end surface 15, 62 , 66, 70 Inner member 16, 16a Rolling elements 17, 56, 63, 67 Outer member 17a, 63a, 67a Outer rolling surface 17b, 56a Car body mounting flange 17c Fixing bolt 18 Wheel mounting flange 18a Hub bolt 18b Wheel mounting flange Base portion 19, 19a, 19b on the inner side of the cage 20 Seal 20 on the outer side, 21 ' -Side seal 22, 24, 44 Core 23, 25, 45 Seal member 23a Side lip 23b Dustrip 23c, 25b Grease lip 25a, 45a Main lip 25c, 45c Garter spring 26 Sun gear 27 Ring gear 27a Knock pin 28 Pinion gear 29 Needle-shaped Roller bearing 30 Pinion pin 30a Locking hole 31 Coupling shaft portion 31b Male screw 32 Fixing nut 33 Annular base 34, 35 Flange 35a Screw hole 36 Bridge 37 Shaft hole 38 Thrust plate 39 Rolling bearing 40 Stator 41 Rotor support member 41a Cylindrical support portion 41b Disk part 41c Cylindrical fixing part 41d Key 42 Rotor 43 Oil seal 45b Sub lip 46, 49, 51 O-ring 47 Cover 48 Rotation sensor 48a Sensor stator 48b Sensor rotor 50 Holding part 50a Side surface 57 of retaining portion Retaining ring 58 Pilot portion 59 of outer member Side surface 71 on the inner side of the vehicle body mounting flange Wheel bolt 71a Bolt hole 72 Brake rotor 73 Wheel 101 Wheel bearing device 102 Motor 103 Reduction gear 104 Motor casing 105 Stator 106 Output shaft 107 Rotor 108 Rolling bearing 109 Cap 110 Eccentric shaft 111 Input shaft 111a Spline 112 Reducer casing 112a Fixing bolt 113 Outer pin 114 Drive shaft 115 Inner pins 116, 117, 120, 122 Rolling bearing 118, 119 Curved plate 121 Counterweight 123 Hub wheel 123a, 124a Inner rolling surface 123b Small diameter step portion 123c, 132a Serration 124 Inner ring 125 Inner member 126 Ball 127 Outer member 127a Outer rolling surface 12 b Car body mounting flange 128 Wheel mounting flange 129 Cage 130 Flange portion 131 Shoulder portion 132 Shaft portion 133 Fixing nut 134 Oil seal d0 Outer member pilot portion outer diameter d1 Housing partition wall base inner diameter di Inner side rolling element Diameter do Diameter of outer rolling element O Driving wheel central axis PCDi Pitch circle diameter of inner rolling element PCDo Pitch diameter of outer rolling element

Claims (10)

A wheel bearing device for rotatably supporting the wheel;
A motor disposed coaxially with respect to the central axis of the wheel;
A planetary gear reducer having an input shaft driven by the output of the motor;
A cylindrical portion, and a front end portion whose central portion is opened at an end portion on an outer side thereof, and a housing in which the planetary gear reducer and a motor are accommodated,
An outer member of the wheel bearing device is fitted into the opening of the front end portion of the housing and fastened to the front end portion by a fixing bolt,
The in-wheel type motor-integrated wheel bearing device in which the input shaft is supported by a pair of rolling bearings on both axial sides of the planetary gear reducer,
The wheel bearing device has an outer member integrally formed with a vehicle body mounting flange on the outer periphery, and a double row outer rolling surface is integrally formed on the inner periphery;
A hub wheel integrally having a wheel mounting flange for mounting the wheel at one end and having a small-diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter step portion of the hub ring An inner member in which a double row inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery,
In the in-wheel type motor built-in wheel bearing device comprising this inner member and a double row rolling element accommodated between both rolling surfaces of the inner member and the outer member,
The large end surface of the inner ring is in contact with the side surface of the holding portion of the output member constituting the planetary gear speed reducer so as to overlap with the insertion hole of the pinion pin constituting the planetary gear speed reducer. An in-wheel motor-equipped wheel bearing device characterized by the above.   An output member constituting the planetary gear speed reducer includes a coupling shaft portion that is fitted on the outer periphery of the hub wheel, an annular base portion having a large diameter on the inner side of the coupling shaft portion, and a radial direction from the annular base portion. The holding portion that protrudes outward and holds the reduction gear, and the pair of rolling bearings are supported by the output member, and the holding portions are disposed opposite to each other in the axial direction at a predetermined interval. A pair of flanges in which the pinion gears are housed and a bridge that connects the pair of flanges in the axial direction. The pinion pins are fixed to the pair of flanges, and the pinion gears are connected to the pinion pins. The in-wheel type motor-integrated wheel bearing device according to claim 1, which is rotatably supported via a needle roller bearing.   A shaft hole coaxial with the coupling shaft portion is formed on an end surface on the inner side of the holding portion. The shaft hole has a depth reaching the annular base portion, and the input shaft is inserted into the shaft hole. The in-wheel motor-equipped wheel bearing device according to claim 1 or 2, supported by a pair of rolling bearings.   The in-wheel type motor-integrated wheel bearing device according to claim 1, wherein the annular base portion of the output member is fitted and inserted into the small-diameter step portion of the hub wheel via an elastic member.   The in-wheel motor-equipped wheel bearing device according to claim 1, wherein the outer member is fitted and inserted into a front end portion of the housing via an elastic member.   2. The in-wheel motor-equipped wheel bearing device according to claim 1, wherein a pitch circle diameter of one of the double row rolling elements is set to be larger than a pitch circle diameter of the other rolling element.   The in-wheel type motor-integrated wheel bearing device according to claim 6, wherein a diameter of the one rolling element is set larger than a diameter of the other rolling element.   The in-wheel type motor-integrated wheel bearing device according to claim 6, wherein the number of the one rolling elements is set larger than the number of the other rolling elements.   The in-wheel motor-equipped wheel bearing device according to claim 1, wherein the rolling element is made of ceramic.   The bolt hole is formed in the circumferentially equidistant position of the wheel mounting flange of the hub wheel, and the wheel is fixed to the wheel mounting flange by a wheel bolt screwed into the bolt hole. Bearing device for wheels with built-in in-wheel motor.

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