JP2011194899A - Wheel bearing device with built-in in-wheel type motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel bearing device with a built-in type in-wheel motor attaining enhancement of sealing performance and enhancing durability in an electric vehicle.SOLUTION: In the wheel bearing device with a built-in type in-wheel motor, a wheel bearing 1, a speed reducer 3 and a motor 2 are arranged on a coaxial axis to a central axis of the wheel. The wheel bearing 1 includes an outer member 27 fixed to a speed reducer casing 12 and formed with a double row of outer rolling traveling surfaces 27a on an inner periphery; an inner member 25 comprising a hub wheel 23 having a wheel mounting flange 28 on one end part and formed with an inner rolling traveling surface 23a and a small diameter step part extending from this in an axial direction on an outer periphery and an inner ring 24 pressed into the small diameter step part and formed with an inner rolling traveling surface 24a on an outer periphery; a double row of rolling elements 26 stored between both rolling traveling surfaces; and a seal 34 attached to an outer side of the outer member 27. Recessed grooves 40, 43, 38 are formed on the speed reducer casing 12, a motor casing 41 and the outer periphery of the outer member 27.

Description

  The present invention relates to an in-wheel motor built-in wheel bearing device in which a wheel bearing, a reducer, and a motor are combined, and more particularly, to improve sealing performance in an electric vehicle and to improve durability. The present invention relates to a wheel bearing device.

  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, as a wheel bearing device for an electric vehicle, an in-wheel motor built-in wheel bearing device in which a wheel bearing, a speed reducer, and a motor are combined is attracting attention. 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 built-in wheel bearing device, a device as shown in FIG. 8 is known. The in-wheel motor-equipped wheel bearing device includes a wheel bearing A that rotatably supports the hub of the drive wheel 100, a motor B as a rotational drive source, and the rotation of the motor B that is decelerated and transmitted to the hub. A reduction gear C that performs braking and a brake D that applies braking force to the hub are arranged on the central axis O of the drive wheel 100. Here, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as an outer side (left side in FIG. 8), and the side closer to the center is referred to as an inner side (right side in FIG. 8).

  The wheel bearing A includes an outer member 101 having a double row outer raceway surface 101a formed on the inner periphery, and a double row inner raceway surfaces 103a and 104a facing the double row outer raceway surface 101a. The inner member 102 is formed, and a double row of balls 105 accommodated between the rolling surfaces of the inner member 102 and the outer member 101 so as to roll freely. A seal 106 is attached and sealed in an opening on the outer side of the annular space formed between the outer member 101 and the inner member 102.

  The outer member 101 serving as a stationary side race ring integrally has a vehicle body attachment flange 101b attached to the outer casing 107 of the reduction gear C on the outer periphery, and is fixed via an attachment bolt (not shown). .

  The inward member 102 serving as the rotation-side raceway includes a hub wheel 103 and an inner ring member 104 fitted to the hub wheel 103. The hub wheel 103 integrally has a wheel mounting flange 108 for mounting the drive wheel 100 on the outer side end portion, and an outer side inner rolling surface 103a is formed on the outer periphery. A hub bolt 108a for mounting the wheel mounting flange 108 driving wheel 100 is implanted. On the other hand, the inner ring member 104 has an inner-side inner rolling surface 104a formed on the outer periphery, and is fixed integrally with the hub ring 103 by plastic coupling such as enlarged diameter caulking.

  The motor B is an axial gap type in which an axial gap is provided between a stator 110 fixed to a cylindrical casing 109 and a rotor 112 attached to an output shaft 111. The output shaft 111 is cantilevered by a pair of bearings 114 on the inner casing 113 of the reduction gear C. The inner side end of the clearance between the output shaft 111 and the casing 113 is sealed with a seal 115, and the opening on the inner side of the bottom 116 of the casing 109 is closed with a cap 117.

  The reducer C is a cycloid reducer, and includes an input shaft 119 having an eccentric shaft 118, an outer pin 120 passed between the casings 107 and 113, an inner pin 121 attached to the inner ring member 104, and each pin. And two curved plates 124 and 125 which are rotatably supported via bearings 122 and 123 and have a undulating trochoidal curve. The input shaft 119 is spline-coupled with the output shaft 111 of the motor B and is integrally rotated. When the output shaft 111 of the motor B rotates, the curved plates 124 and 125 attached to the input shaft 119 that rotates integrally with the motor B perform an eccentric motion, and are transmitted as a rotational motion of the inner member 102 (for example, Patent Documents). 1).

  In such a conventional in-wheel type motor-equipped wheel bearing device, the outer diameter of the wheel bearing A is smaller than the outer diameter of the casing 107 of the reduction gear C and the casing 109 of the motor B. When entering a water pool, rainwater and muddy water are more likely to collect at the outer diameter portion of the outer member 101 than in a conventional wheel bearing. Although the wheel bearing A is sealed by a seal 106 mounted on the outer side, when foreign matter such as rainwater enters the inside through the seal 106, the wheel bearing A is directly connected to the speed reducer C or the motor B. Therefore, not only the bearing portion but also the speed reducer C and the motor B may be damaged.

  Conventionally, various seal structures with improved sealing performance have been proposed. A typical example of a wheel bearing device having such a seal structure is shown in FIG. This wheel bearing device has an outer member 150 that is non-rotatably attached to the vehicle body side via a knuckle and has outer rows 150a and 150a of double rows formed on the inner periphery. A hub wheel 153 and an outer joint member of a constant velocity universal joint (not shown) attached integrally to the hub wheel 153 via double rows of balls 152, 152 held at circumferentially equidistant positions on the cage 151. It is supported so as to be rotatable around its axis.

  Inner rolling surfaces 153a facing the outer rolling surfaces 150a and 150a of the double row of the outer member 150 are formed on the outer periphery of the hub wheel 153, and a wheel mounting flange for mounting a brake disk and a wheel (not shown) at one end. 154 protrudes radially outward.

  The seal structure 155 includes a side surface 154 a on the outer member 150 side of the wheel mounting flange 154, a core metal 156 fitted to the inner peripheral surface of the outer member 150, and an elastic seal body 157 fixed to the core metal 156. It consists of and. The elastic seal body 157 includes two axial lip portions 158 that contact the side surface 154a of the wheel mounting flange 154 in the axial direction, and a radial lip portion 159 that contacts the outer peripheral surface of the hub wheel 153 in the radial direction. Yes.

  Further, the cored bar 156 has a circular arc shape (a crescent shape) that is partially extended along the side surface 154 a of the wheel mounting flange 154 so as to protrude radially outward from the outer peripheral surface 150 b of the outer member 150. A dam member 156a is formed, and the dam member 156a is in close contact with the end surface of the outer member 150 on the side surface 154a side. Further, the dam member 156a is formed only above the axis.

  Such a seal structure 155 is, for example, when the muddy water is applied to the outer member 150 during traveling of the vehicle, a part of the cored bar 156 has a radially outwardly upward direction from the outer peripheral surface 150b of the outer member 150. Since the dam member 156a extended so as to protrude is formed, the muddy water is prevented from flowing to the outer member 150 and the side surface 154a of the wheel mounting flange 154 by the dam member 156a. Therefore, the muddy water of the outer member 150 does not flow and collect in the axial lip portion 158, and the sealing performance can be maintained (see, for example, Patent Document 2).

JP 2008-74135 A JP 2003-49852 A

  However, in such a conventional seal structure 155, in order to maintain a desired contact surface pressure of the axial lip portion 158, it is necessary to narrow a gap between the cored bar 156 and the side surface 154a of the wheel mounting flange 154. was there. In addition, since a dam member 156a extended so as to protrude radially outward is formed on a part of the core metal 156, the core metal 156 is fitted to the outer member 150 in a state in which the phases are matched at the time of assembly. As a result, the number of assembling steps is increased and the cost reduction is hindered. Furthermore, there is a possibility that the dam member 156a may interfere with other parts at the time of assembling, or a stepping stone or the like may collide and plastically deform during traveling.

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an in-wheel motor-equipped wheel bearing device with improved durability and improved durability in an electric vehicle. .

  In order to achieve the object, the invention according to claim 1 of the present invention is an in-wheel motor built-in wheel bearing in which a wheel bearing, a speed reducer, and a motor are arranged coaxially with respect to the center axis of the wheel. The wheel bearing is attached to the casing of the speed reducer on the outer periphery, the outer member integrally formed with the double row outer rolling surface on the inner periphery, and the wheel is attached to one end. And a hub ring 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 row is formed, and a double row accommodated in a freely rollable manner between both rolling surfaces of the inner member and the outer member An annular space formed between the rolling element and the outer member and the inner member And a seal attached to an opening portion of the outer side groove on the outer periphery of the casing of the reduction gear is formed.

  An in-wheel type motor-equipped wheel bearing device in which a wheel bearing, a speed reducer, and a motor are coaxially arranged with respect to the center axis of the wheel as described above, and the wheel bearing is disposed on the outer periphery of the speed reducer casing. A small-diameter step having an outer member integrally formed with a double row outer raceway on the inner periphery and a wheel mounting flange for attaching a wheel to one end and extending in the axial direction on the outer periphery. A hub wheel formed with a portion, and at least one inner ring press-fitted into a small-diameter step portion of the hub wheel, and a double-row inner rolling surface facing the double-row outer rolling surface is formed on the outer periphery. An annular space formed between the inner member, 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 attached to the opening on the outer side of the Since a concave groove is formed in the vehicle, even if rain water or muddy water is applied to the casing of the speed reducer during traveling of the vehicle, it can be prevented from flowing between the wheel mounting flange and the outer peripheral surface. It is possible to provide an in-wheel motor-equipped wheel bearing device that improves the sealing performance of the seal in an electric vehicle over a period of time and has improved durability.

  Further, as in the second aspect of the present invention, if a concave groove is formed on the outer periphery of the motor casing, even if rain water or muddy water is applied to the motor casing while the vehicle is traveling, the outer peripheral surface is transmitted. It can prevent flowing between the wheel mounting flanges, improve the sealing performance of the seal in the electric vehicle over a long period of time, and enhance the durability.

  According to a third aspect of the present invention, the outer member integrally has a vehicle body mounting flange for mounting on the outer periphery of the speed reducer casing, and the double wheel is mounted on the outer periphery of the hub wheel. If the inner rolling surface opposite to one of the outer rolling surfaces is directly formed and a concave groove is formed on the outer periphery of the outer side end of the outer member, the outer member can be used while the vehicle is running. Even if rainwater or muddy water is applied, it can be prevented from flowing between the wheel mounting flange and the outer peripheral surface.

  Further, as in the invention described in claim 4, if the concave groove is formed at least in the range of 180 ° on the side opposite to the road surface, rainwater and muddy water that has traveled along the outer peripheral surface are lowered along the concave groove. Easily discharged.

  Further, as in the invention according to claim 5, the pitch circle diameter of the outer rolling element row of the double row rolling element rows is set larger than the pitch circle diameter of the inner rolling element row. In addition, if the number of rolling elements in the outer rolling element row is set to be larger than the number of rolling elements in the inner rolling element row, the bearing rigidity of the outer side portion can be increased compared to the inner side. The life of the bearing can be extended.

  Preferably, as in the invention according to claim 6, if the rolling element diameter of the outer rolling element row is set smaller than the rolling element diameter of the inner rolling element row, the outer member The expansion of the outer diameter of the tube can be suppressed, and the weight and size can be reduced.

  According to a seventh aspect of the present invention, the seal includes a cylindrical portion that is press-fitted into the inner periphery of the outer side end of the outer member, and an inner diameter that is bent and extends radially inward from the cylindrical portion. And a seal member integrally formed by vulcanization and adhesion to the inner diameter portion of the core metal, the seal member extending in a radially outward direction, A side lip that is slidably contacted with an inner base portion of the wheel mounting flange via an axial shimiro, a dust lip that extends radially inwardly toward the inner diameter side of the side lip, and an inward bearing side And a base portion on the inner side of the wheel mounting flange is formed in a curved surface having an arc-shaped cross section, and the side lip and dust lip are slidably contacted with the base portion via a predetermined axial squeeze. As The outer peripheral end inner circumference of the outer member is formed in a step portion from the end surface to the vicinity of the position where the seal is fitted, and the inner diameter of the step portion is fitted to the seal. A stepped portion is formed between the base and the inner side surface of the wheel mounting flange, and the stepped portion of the outer member has a slight radial clearance in the stepped portion. If a substantially L-shaped labyrinth seal is formed, it is possible to prevent foreign matters such as rainwater and muddy water from entering the sliding contact portion of the seal, and to improve the sealing performance.

  Further, as in the invention described in claim 8, the sealing member integrally includes a covering portion that covers the exposed surface of the core metal, and the covering portion is formed from the inner diameter portion of the core metal to the cylindrical portion. If it is formed over the end and is set to be slightly larger than the outer diameter of the cylindrical portion, the airtightness between the seal and the outer member can be improved.

  According to a ninth aspect of the present invention, the outer member is fitted into a knuckle, and a mounting flange for being attached to a casing of the speed reducer is integrally provided on the outer periphery of the knuckle. The member is composed of the hub wheel and a pair of inner rings press-fitted into a small-diameter step portion of the hub wheel, and a groove is formed in a 180 ° range at least on the opposite road surface side of the outer periphery of the outer end of the knuckle. Thus, even if rain or muddy water is applied to the knuckle during traveling of the vehicle, it can be prevented from flowing between the wheel mounting flange and the outer peripheral surface.

  Further, as in the invention described in claim 10, if a plurality of the concave grooves are formed, the sealing performance can be further improved.

  Further, as in the invention according to claim 11, a drive shaft constituting the speed reducer is connected to the hub wheel of the wheel bearing so as to transmit torque, and the speed reducer comprises a cycloid speed reducer, and is eccentric. An input shaft having a shaft, a plurality of outer pins passed between the reducer casing and the motor casing, a plurality of inner pins attached to the drive shaft, and a rolling bearing on each pin Two curved plates that are rotatably supported, and these curved plates are formed in a wavy trochoidal curve with a gentle outer shape and mounted on the eccentric shaft, and the outer pin is mounted by a rolling bearing. If it is supported rotatably and the eccentric movement of the curved plate is guided on the outer peripheral side by this outer pin, the rotation of the motor is transmitted smoothly and efficiently with a large reduction ratio as the rotational movement of the drive shaft. .

  An in-wheel motor built-in wheel bearing device according to the present invention is an in-wheel motor built-in wheel bearing device in which a wheel bearing, a reducer, and a motor are arranged coaxially with respect to a central axis of a wheel, An outer member in which the wheel bearing is attached to the casing of the speed reducer on the outer periphery, a double row outer rolling surface is integrally formed on the inner periphery, and a wheel mounting flange for attaching the wheel to one end And at least one inner ring press-fitted into the small-diameter step portion of the hub ring, and the outer circumferential rolling of the double row on the outer periphery. An inner member in which a double-row inner rolling surface facing the surface is formed, and a double-row rolling element housed so as to be freely rollable between both rolling surfaces of the inner member and the outer member; An annular space formed between the outer member and the inner member. And a groove mounted on the outer periphery of the speed reducer casing, so that even if rain water or muddy water is applied to the speed reducer casing while the vehicle is running, In-wheel motor built-in wheel bearing with improved durability and improved sealing performance in electric vehicles over a long period of time An apparatus can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing an embodiment of an in-wheel motor-equipped wheel bearing device according to the present invention. It is a principal part enlarged view which shows the wheel bearing part of FIG. (A) is an enlarged view of the main part showing the outer seal part of FIG. 2, (b) is an enlarged view of the main part showing the casing part of the reducer of FIG. 1, and (c) is the motor of FIG. It is a principal part enlarged view which shows a casing part. It is a principal part enlarged 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 seal part of the wheel bearing of FIG. It is a longitudinal cross-sectional view which shows 3rd 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 wheel bearing part of FIG. It is a longitudinal cross-sectional view which shows the conventional bearing apparatus for in-wheel type motor built-in wheels. It is a principal part enlarged view which shows the conventional seal structure.

  An in-wheel type motor-equipped wheel bearing device in which a wheel bearing, a reducer, and a motor are arranged coaxially with respect to a central axis of the wheel, wherein the wheel bearing is attached to a casing of the reducer on an outer periphery. A vehicle body mounting flange integrally formed, an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and a wheel mounting flange for mounting the wheel on one end portion. A hub wheel having an inner rolling surface facing one of the outer rolling surfaces of the double row on the outer periphery, a small-diameter step portion extending in the axial direction from the inner rolling surface, and a small-diameter step portion of the hub ring An inner member formed of an inner ring that is press-fitted into the inner ring and has an inner rolling surface facing the other of the outer rolling surfaces of the double row on the outer periphery, and between the rolling surfaces of the inner member and the outer member. Double row rolling elements housed in a freely rollable manner, the outer member and the inner part And a seal mounted on the outer opening of the annular space formed between the outer casing and the outer casing of the speed reducer, the motor casing, and the outer member. Grooves are formed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing a first embodiment of a wheel bearing device with a built-in in-wheel motor according to the present invention, FIG. 2 is an enlarged view of a main part showing a wheel bearing portion of FIG. 2A is an enlarged view of the main part showing the outer seal part of FIG. 2, FIG. 2B is an enlarged view of the main part showing the casing part of the reduction gear of FIG. 1, and FIG. It is a principal part enlarged view which shows a part. In the following description, the side closer to the outer side of the vehicle 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).

  This in-wheel type motor-equipped wheel bearing device includes a wheel bearing 1 that rotatably supports a wheel (not shown), a motor 2 as a rotational drive source, and a motor that decelerates the rotation of the motor 2 to a hub. The speed reducer 3 for transmission is arranged on the central axis O of the wheel.

  The motor 2 is configured by a radial gap type motor in which a radial gap is provided between a stator 5 fixed to a cylindrical motor casing 4 and a rotor 7 attached to an output shaft 6. The output shaft 6 is rotatably supported with respect to the motor casing 4 by rolling bearings 8 and 8 including a pair of deep groove ball bearings. The opening on the inner side of the motor casing 4 is closed with a cap 9.

  The speed reducer 3 is a cycloid speed reducer, and is attached to an input shaft 11 having an eccentric shaft 10, a plurality of outer pins 13 passed between the speed reducer casing 12 and the motor casing 4, and a drive shaft 14. A plurality of inner pins 15, and two curved plates 18 and 19 that are rotatably supported by the pins 13 and 15 via rolling bearings 16 and 17 made of cylindrical roller bearings. These curved plates 18 and 19 are formed in a wavy trochoid curve having a gentle outer shape, and are mounted on the eccentric shaft 10. The outer pin 13 is rotatably supported by rolling bearings 20 and 20 including a pair of needle roller bearings, and the eccentric motion of the curved plates 18 and 19 is guided on the outer peripheral side by the outer pin 13.

  The input shaft 11 is coupled to the output shaft 6 of the motor 2 via a spline (or serration) 11a and is rotationally driven integrally. When the output shaft 6 of the motor 2 rotates, the eccentric shaft 10 attached to the input shaft 11 that rotates integrally therewith rotates, and the curved plates 18 and 19 that engage with the eccentric shaft 10 perform eccentric motion. The rotation of the rotor 7 is smoothly and efficiently transmitted as a rotational movement of the drive shaft 14 with a large reduction ratio.

  The two curved plates 18 and 19 are mounted on the eccentric shaft 10 of the input shaft 11 with a phase difference of 180 ° so that the eccentric motion is canceled out. The curved plates 18 and 19 are disposed on both sides of the eccentric shaft 10. Counterweights 21 and 21 that are eccentric in the direction opposite to the eccentric direction of the eccentric shaft 10 are mounted so as to cancel the vibration caused by the eccentric movement of the eccentric shaft 10. The input shaft 11 is rotatably supported by a rolling bearing 22 formed of a deep groove ball bearing with respect to a drive shaft 14 described later.

  The wheel bearing 1 is referred to as a third generation for driving wheels, and as shown in an enlarged view in FIG. 2, an inner member 25 including a hub wheel 23 and an inner ring 24 press-fitted into the hub wheel 23, The inner member 25 is provided with an outer member 27 which is externally inserted through double-row rolling elements (balls) 26 and 26.

  The hub wheel 23 integrally has a wheel mounting flange 28 for mounting a wheel (not shown) at an end portion on the outer side, one (outer side) inner rolling surface 23a on the outer periphery, and this inner rolling. A small diameter step portion 23b extending in the axial direction from the surface 23a is formed, and a serration (or spline) 23c for torque transmission is formed on the inner periphery. The inner ring 24 is formed with the other (inner side) inner rolling surface 24a on the outer periphery, and is press-fitted into the small-diameter step portion 23b of the hub ring 23 through a predetermined scissors. Further, hub bolts 28 a are implanted at equidistant positions in the circumferential direction of the wheel mounting flanges 28.

  The hub wheel 23 is made of medium and high carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and includes an inner rolling surface 23a and an inner side of a wheel mounting flange 28 serving as a seal land portion of a seal 34 described later. The surface is hardened in the range of 58 to 64 HRC by induction hardening from the base 28b to the small diameter step 23b. On the other hand, the inner ring 24 and the rolling element 26 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core part by quenching.

  The outer member 27 integrally has a vehicle body mounting flange 27b attached to the reduction gear casing 12 via a fixing bolt 12a on the outer periphery, and a plurality of outer members 27 facing the inner rolling surfaces 23a, 24a of the inner member 25 on the inner periphery. The outer rolling surfaces 27a, 27a of the rows are integrally formed. Between these rolling surfaces 27a, 23a and 27a, 24a, double row rolling elements 26, 26 are accommodated via a cage 29 so as to be freely rollable.

  The outer member 27 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 27a and 27a are hardened in the range of 58 to 64HRC by induction hardening. Has been processed.

  The drive shaft 14 constituting the speed reducer 3 includes a flange portion 30 to which the inner pin 15 is attached, a cylindrical shoulder portion 31 extending in the axial direction from the flange portion 30, and a shaft extending in the axial direction from the shoulder portion 31. The part 32 is integrally formed (see FIG. 1). A serration (or spline) 32a that meshes with the serration 23c of the hub wheel 23 and an external thread 32b are formed at the end of the outer periphery of the shaft portion 32. The drive shaft 14 is fitted into the hub wheel 23 until the shoulder 31 abuts the end surface of the inner ring 24, and is tightened with a predetermined tightening torque by the fixing nut 33 screwed to the male screw 32b. The hub wheel 23 is coupled in the axial direction so that torque can be transmitted.

  In addition, a seal 34 is attached to an opening on the outer side of the annular space formed between the outer member 27 and the inner member 25, and leakage of the lubricating grease sealed inside the bearing to the outside and from the outside In addition to preventing rainwater, dust and the like from entering the bearing, an oil seal 35 that is in sliding contact with the outer periphery of the drive shaft 14 is attached to the opening on the inner side, and the lubricating grease enclosed in the bearing is exposed to the outside. And leakage of lubricating oil and contaminants from the reduction gear 3 side is prevented.

  As shown in an enlarged view in FIG. 3A, the seal 34 is an integrated seal composed of a core metal 36 fitted in the outer member 27 and a seal member 37 joined to the core metal 36. It is configured. The core metal 36 is formed by press working from a steel plate having rust prevention ability such as an austenitic stainless steel plate (JIS standard SUS304 type) or a rust-proof cold rolled steel plate (JIS standard SPCC type). A cylindrical portion 36a that is press-fitted into the inner periphery of the outer side end portion of the outer member 27 via a predetermined shimiro and an inner diameter portion 36b that is bent and extends radially inward from the cylindrical portion 36a are integrally formed. ing.

  On the other hand, the seal member 37 is made of synthetic rubber such as NBR (acrylonitrile-butadiene rubber) and is integrally joined to the cored bar 36 by vulcanization adhesion. The seal member 37 includes a side lip 37a extending obliquely outward in the radial direction, a dust lip 37b extending obliquely outward in the radial direction on the inner diameter side of the side lip 37a, and a bearing inner side (inner side). ) And a grease lip 37c extending in an inclined manner and a covering portion 37d that covers the exposed surface of the cored bar 36. The covering portion 37d is formed from the inner diameter portion 36b of the cored bar 36 to the end portion of the cylindrical portion 36a, and is set to be slightly larger in diameter than the outer diameter of the cylindrical portion 36a. It is press-fitted into the inner periphery of the end of the Thereby, the airtightness of the seal 34 and the outer member 27 can be improved.

  A base portion 28b on the inner side of the wheel mounting flange 28 is formed in a curved surface having an arc-shaped cross section, and a side lip 37a and a dust lip 37b are slidably contacted with the base portion 28b with a predetermined axial squeeze, and a grease lip 37c is predetermined. Are in sliding contact with each other through a radial shimoshiro. In addition to NBR, the material of the seal member 37 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.

  Here, in the present embodiment, an annular groove 38 is formed on the outer periphery of the outer end of the outer member 27. As a result, even when rain water or muddy water is applied to the outer member 27 during traveling of the vehicle and travels along the outer peripheral surface, it flows under the concave groove 38 by the so-called soot action and can be easily discharged. It can prevent flowing between the wheel mounting flange 28. Accordingly, it is possible to provide an in-wheel type motor-integrated wheel bearing device that improves the sealing performance of the seal 34 in an electric vehicle over a long period of time and has improved durability. The above-described concave groove 38 may be formed over the entire circumference. However, if it is formed at least in the range of 180 ° on the side opposite to the road surface, rainwater and muddy water that has traveled on the outer circumferential surface of the outer member 27 are formed. It is discharged downward along the concave groove 38.

  In addition, although the wheel bearing comprised by the double row angular contact ball bearing which used the ball for the rolling element 26 was illustrated here, it was not restricted to this but what was comprised by the double row tapered roller bearing using a tapered roller It may be.

  FIG.3 (b) is a principal part enlarged view which shows the reduction gear casing 12 of the reduction gear 3 of FIG. The reduction gear casing 12 is in contact with an inner side surface of the vehicle body mounting flange 27b of the outer member 27 via an elastic member 39 such as an O-ring, and an annular concave groove 40 is formed on the outer periphery. The concave groove 40 can prevent rainwater or muddy water from flowing to the outer member 27 along the outer peripheral surface of the speed reducer casing 12, and can further improve the sealing performance. In addition, although the ditch | groove 40 may be formed over a perimeter, if it is formed in the range of 180 degrees at least on the anti-road surface side, the rainwater and muddy water which were transmitted along the outer peripheral surface of the reduction gear casing 12 will be sufficient as it. It is discharged downward along the concave groove 40. Further, by forming a plurality of concave grooves 40 instead of a single one, it is possible to prevent rainwater and muddy water from flowing to the outer member 27 along the outer peripheral surface of the speed reducer casing 12, and to further improve the sealing performance. Improvements can be made.

  FIG.3 (c) is a principal part enlarged view which shows the motor casing 4 of the motor 2 of FIG. A cylindrical cover 41 is attached via an elastic member 42 such as an O-ring so as to cover the outer periphery of the motor casing 4, and an annular concave groove 43 is formed on the outer periphery. This concave groove 43 can prevent rainwater and muddy water from flowing through the outer peripheral surface of the cover 41 to the speed reducer casing 12 and the outer member 27, and can further improve the sealing performance. The concave groove 43 may be formed over the entire circumference, but if it is formed at least in the range of 180 ° on the side opposite to the road surface, rainwater and muddy water that has traveled along the outer peripheral surface of the cover 41 are formed in the concave groove 43. It accumulates in the groove 43 and is discharged downward. Further, the groove 43 may be formed in a plural number instead of a single one.

  FIG. 4 is an enlarged view of a main part showing a second embodiment of a wheel bearing device with a built-in in-wheel motor according to the present invention, and FIG. 5 is an enlarged view of a main part showing a seal part of the wheel bearing of FIG. is there. Note that this embodiment is basically different from the above-described embodiment only in the configuration of the bearing portion, and other detailed explanations are given by attaching the same reference numerals to the same parts or parts having the same function. Omitted.

  The wheel bearing 44 is referred to as a third generation for the drive wheel, and includes an inner member 46 including a hub wheel 45 and an inner ring 24 press-fitted into the hub wheel 45, and a double row of rolling on the inner member 46. And an outer member 47 inserted through the moving bodies 26, 26.

  The hub wheel 45 integrally has a wheel mounting flange 28 at an end portion on the outer side, one (outer side) inner rolling surface 45a on the outer periphery, and a small diameter step portion extending in the axial direction from the inner rolling surface 45a. 23b is formed, and a serration (or spline) 23c for torque transmission is formed on the inner periphery. The inner ring 24 is formed with the other (inner side) inner rolling surface 24a on the outer periphery, and is press-fitted into the small-diameter step portion 23b of the hub ring 23 through a predetermined scissors.

  The hub wheel 45 is made of medium and high carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and includes an inner rolling surface 45a and a base portion on the inner side of the wheel mounting flange 28 which becomes a seal land portion of the seal 34. The surface is hardened in the range of 58 to 64 HRC by induction hardening from 28b to the small diameter step portion 23b.

  The outer member 47 integrally has a vehicle body mounting flange 27b attached to the speed reducer casing 12 via the fixing bolt 12a on the outer periphery, and a plurality of outer members 47 facing the inner rolling surfaces 45a and 24a of the inner member 46 on the inner periphery. The outer rolling surfaces 47a and 27a of the row are integrally formed. Between these rolling surfaces 47a, 45a and 27a, 24a, double-row rolling elements 26, 26 are accommodated via rollers 48, 29 so as to roll freely.

  The outer member 47 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 47a and 27a are hardened in the range of 58 to 64HRC by induction hardening. Has been processed.

  Here, in the present embodiment, the pitch circle diameter PCDo of the outer side rolling elements 26 rows is set larger than the pitch circle diameter PCDi of the inner side rolling elements 26 rows, and the outer side rolling elements 26 rows. The rolling element diameter do of the inner side and the rolling element diameter di of the inner side rolling element 3b row (do = di), but due to the difference in pitch circle diameters PCDo and PCDi, the outer side rolling element 26 row rolling element The number Zo is set to be larger than the number of rolling elements Zi of the inner-side rolling elements 26 row (Zo> Zi). Thereby, the bearing rigidity of an outer side part can be increased compared with an inner side, and lifetime improvement of a bearing can be achieved. Here, the outer side rolling element 26 and the inner side rolling element 26 are exemplified as having the same size. However, the present invention is not limited to this, and the outer side rolling element 26 row has a rolling element diameter do that is the inner side rolling element 26. It may be set to a smaller diameter (do <di) than the rolling element diameter di of the row of moving bodies 3b. Thereby, the expansion of the outer diameter of the outer member 47 can be suppressed, and light weight and compactness can be achieved.

  Furthermore, in the present embodiment, as shown in an enlarged view in FIG. 5, the inner periphery of the outer end of the outer member 47 extends from the end surface to the vicinity of the position where the seal 34 is fitted. The step 47b is formed with an inner diameter larger than the fitting surface of the seal 34. On the other hand, a step 49 is formed between the inner side base portion 28 b of the wheel mounting flange 28 and the inner side surface 28 c of the wheel mounting flange 28. Then, the stepped portion 47b of the outer member 47 is engaged with the stepped portion 49 through a slight radial clearance, and a substantially L-shaped labyrinth seal 50 is formed. The labyrinth seal 50 can prevent foreign matters such as rainwater and muddy water from entering the sliding contact portion of the seal 34 and improve the sealing performance.

  FIG. 6 is a longitudinal sectional view showing a third embodiment of the in-wheel type motor-equipped wheel bearing device according to the present invention, and FIG. 7 is an enlarged view of a main part showing the wheel bearing portion of FIG. Note that this embodiment is basically different from the first embodiment described above only in the configuration of the bearing portion, 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.

  This in-wheel type motor-equipped wheel bearing device includes a wheel bearing 51 that rotatably supports a wheel (not shown), a motor 2 as a rotation drive source, and a motor that decelerates the rotation of the motor 2 to a hub. The speed reducer 3 for transmission is arranged on the central axis O of the wheel.

  The motor 2 is configured by a radial gap type motor in which a radial gap is provided between a stator 5 fixed to a cylindrical motor casing 4 and a rotor 7 attached to an output shaft 6. The output shaft 6 is rotatably supported with respect to the motor casing 4 by rolling bearings 8 and 8 including a pair of deep groove ball bearings. The opening on the inner side of the motor casing 4 is closed with a cap 9.

  The speed reducer 3 is a cycloid speed reducer, and includes an input shaft 11 having an eccentric shaft 10, a plurality of outer pins (not shown) passed between the speed reducer casing 12 and the motor casing 4, and a drive shaft. 14 includes a plurality of inner pins 15, and two curved plates 18 and 19 that are rotatably supported on each pin via rolling bearings 16 and 17 formed of cylindrical roller bearings. These curved plates 18 and 19 are formed in a wavy trochoid curve having a gentle outer shape, and are mounted on the eccentric shaft 10.

  The input shaft 11 is coupled to the output shaft 6 of the motor 2 via a spline (or serration) 11a and is rotationally driven integrally. When the output shaft 6 of the motor 2 rotates, the eccentric shaft 10 attached to the input shaft 11 that rotates integrally therewith rotates, and the curved plates 18 and 19 that engage with the eccentric shaft 10 perform eccentric motion. The rotation of the rotor 7 is smoothly and efficiently transmitted as a rotational movement of the drive shaft 14 with a large reduction ratio.

  The two curved plates 18 and 19 are mounted on the eccentric shaft 10 of the input shaft 11 with a phase difference of 180 ° so that the eccentric motion is canceled out. The curved plates 18 and 19 are disposed on both sides of the eccentric shaft 10. Counterweights 21 and 21 that are eccentric in the direction opposite to the eccentric direction of the eccentric shaft 10 are mounted so as to cancel the vibration due to the eccentric movement of the eccentric shaft 10. The input shaft 11 is rotatably supported by a rolling bearing 22 formed of a deep groove ball bearing with respect to a drive shaft 14 described later.

  The wheel bearing 51 is referred to as a second generation, and as shown in an enlarged view in FIG. 7, an inner member 53 including a hub ring 52 and a pair of inner rings 24 and 24 press-fitted into the hub ring 52, An outer ring (outer member) 54 is provided on the pair of inner rings 34, 34.

  The hub wheel 52 integrally has a wheel mounting flange 28 at an end portion on the outer side, a small diameter step portion 52b extending in the axial direction from the wheel mounting flange 28 is formed, and a serration (or spline for torque transmission) is formed on the inner periphery. ) 23c is formed. The pair of inner rings 24, 24 are press-fitted into the small-diameter stepped portion 52b of the hub wheel 52 through a predetermined squeeze.

  The hub wheel 52 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and 50 by induction quenching from the shoulder 52a where the inner ring 24 on the outer side abuts to the small diameter step 52b. The surface is hardened in the range of ~ 64HRC.

  The outer ring 54 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. Then, it is press-fitted into the knuckle 55 via a predetermined squeeze and is positioned and fixed in the axial direction via a retaining ring 56. The knuckle 55 has an attachment flange 55a integrally attached to the reduction gear casing 12 via a fixing bolt 12a on the outer periphery.

  Seals 57 and 58 are attached to both end openings of an annular space formed between the outer ring 54 and the pair of inner rings 24 and 24, and leakage of lubricating grease sealed inside the bearing and rainwater and dust from the outside. Or the like, or lubricating oil, contamination and the like from the inside of the bearing are prevented from entering from the reduction gear 3 side.

  Here, in the present embodiment, an annular groove 59 is formed on the outer periphery of the outer end of the knuckle 55. As a result, even if rain water or muddy water is applied to the knuckle 55 during traveling of the vehicle and flows along the outer peripheral surface, it flows under the groove 59 and can be easily discharged. It can be prevented from flowing. Therefore, it is possible to provide an in-wheel type motor-integrated wheel bearing device that improves the sealing performance of the seal 57 in the electric vehicle over a long period of time and has improved durability. The concave groove 59 described above may be formed over the entire circumference, but may be formed at least in a range of 180 ° on the opposite road surface side.

  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 type motor according to the present invention is a combination of a wheel bearing, a speed reducer, and a motor, and the wheel bearing is an inner member serving as a rotating member and an outer member serving as a stationary member. The present invention can be applied to a first generation to a third generation structure in which a seal is attached to an opening on the outer side of an annular space formed between the members.

1, 44, 51 Wheel bearing 2 Motor 3 Reducer 4 Motor casing 5 Stator 6 Output shaft 7, 8, 16, 17, 20, 21 Rolling bearing 9 Cap 10 Eccentric shaft 11 Input shaft 11a Spline 12 Reducer casing 13 Outside Pin 14 Drive shaft 15 Inner pins 18, 19 Curved plate 22 Counterweights 23, 45, 52 Hub wheels 23a, 24a, 45a Inner rolling surface 23b, 52b Small diameter step 23c, 32a Serration 24 Inner rings 25, 46, 53 Inner Member 26 Rolling elements 27, 47, 54 Outer members 27a, 47a Outer rolling surface 27b Car body mounting flange 27c Outer member outer side end surface 28 Wheel mounting flange 28a Hub bolt 28b Inner side base 28c of wheel mounting flange Side surfaces 29 and 48 on the inner side of the flange Cage 30 Flange part 3 DESCRIPTION OF SYMBOLS 1 Shoulder part 32 Shaft part 32b Male screw 33 Fixing nuts 34 and 57 Outer side seal 35 Oil seal 36 Core metal 36a Cylindrical part 36b Inner diameter part 37 Seal member 37a Side lip 37b Dustrip 37c Grease lip 37d Cover part 38, 40, 43 , 59 Groove 39, 42 Elastic member 41 Cover 47b, 49 Step portion 50 Labyrinth seal 52a Shoulder portion 55 Knuckle 55a Mounting flange 56 Retaining ring 58 Inner side seal 100 Driving wheel 101 Outer member 101a Outer rolling surface 101b Car body mounting Flange 102 Inner member 103 Hub wheel 103a, 104a Inner rolling surface 104 Inner ring member 105 Ball 106, 115 Seal 107, 109, 113 Casing 108 Wheel mounting flange 108a Hub bolt 110 Stator 111 Output shaft 112 Rotor 1 14, 122, 123 Bearing 116 Casing bottom 117 Cap 118 Eccentric shaft 119 Output shaft 120 Outer pin 121 Inner pin 124, 125 Curved plate 150 Outer member 150a Outer rolling surface 150b Outer surface 151 Cage 152 Ball 153 Hub wheel 153a Inner rolling surface 154 Wheel mounting flange 154a Wheel mounting flange side surface 155 Seal structure 156 Core metal 156a Weir member 157 Elastic seal body 158 Axial lip portion 159 Radial lip portion A Wheel bearing B Motor C Reducer D Brake di Inner side Outer diameter of rolling element do Outer diameter of outer rolling element O Driving wheel central axis PCDi Pitch circle diameter of inner rolling element row PCDo Pitch diameter of outer rolling element row Zi Number of inner rolling element Zo Number of outer rolling elements

Claims (11)

An in-wheel type motor built-in wheel bearing device in which a wheel bearing, a reducer, and a motor are arranged coaxially with respect to the central axis of the wheel,
The wheel bearing is attached to the casing of the speed reducer on the outer periphery, and an outer member in which 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,
A double row rolling element housed so as to be freely rollable between both rolling surfaces of the inner member and the outer member;
A seal mounted on the outer opening of the annular space formed between the outer member and the inner member;
A bearing device for an in-wheel type motor built-in wheel, wherein a concave groove is formed on an outer periphery of a casing of the speed reducer.   The in-wheel type motor-integrated wheel bearing device according to claim 1, wherein a concave groove is formed on an outer periphery of a casing of the motor.   The outer member integrally has a vehicle body mounting flange to be attached to the casing of the speed reducer on the outer periphery, and is an inner rolling surface facing one of the outer rolling surfaces of the double row on the outer periphery of the hub wheel. The in-wheel type motor-equipped wheel bearing device according to claim 1, wherein a groove is formed in an outer periphery of an outer end of the outer member.   The in-wheel type motor-integrated wheel bearing device according to any one of claims 1 to 3, wherein the concave groove is formed in a range of 180 ° at least on the side opposite to the road surface.   The pitch circle diameter of the outer side rolling element row of the double row rolling element row is set to be larger than the pitch circle diameter of the inner side rolling element row, and the outer rolling element row rolling element. The in-wheel type motor-integrated wheel bearing device according to claim 3, wherein the number is set to be larger than the number of rolling elements in the inner-side rolling element row.   The in-wheel type motor-integrated wheel bearing device according to claim 5, wherein a rolling element diameter of the outer rolling element row is set to be smaller than a rolling element diameter of the inner rolling element row. A core part provided with a cylindrical part press-fitted into the inner periphery of the outer side end of the outer member, and an inner diameter part bent and extended radially inward from the cylindrical part; It is composed of an integral seal composed of a seal member integrally vulcanized and bonded to the inner diameter part,
The seal member extends obliquely outward in a radial direction, and a side lip that is slidably contacted with an inner side base portion of the wheel mounting flange via an axial shimoshiro and radially outward on an inner diameter side of the side lip Incorporating a dust lip that extends at an angle and a grease lip that extends at an angle toward the inner side of the bearing,
A base portion on the inner side of the wheel mounting flange is formed in a curved surface having an arcuate cross section, and the side lip and dust lip are slidably contacted to the base portion via a predetermined axial direction shimiro,
The outer periphery of the outer member on the outer side is formed in a stepped portion from the end surface to the vicinity of the position where the seal is fitted, and the inner diameter of the stepped portion is fitted to the seal. The diameter is set to be larger than the surface, and a step is formed between the base and the side surface on the inner side of the wheel mounting flange.
The in-wheel type motor built-in wheel bearing according to claim 1, wherein the stepped portion of the outer member is engaged with the stepped portion through a slight radial clearance to form a substantially L-shaped labyrinth seal. apparatus.   The sealing member integrally includes a covering portion that covers the exposed surface of the core metal, and the covering portion is formed from an inner diameter portion of the core metal to an end portion of the cylindrical portion. The in-wheel type motor-integrated wheel bearing device according to claim 7, wherein the wheel device is set to be slightly larger than the outer diameter.   The outer member is fitted into a knuckle, and a mounting flange for being attached to the casing of the speed reducer is integrally formed on the outer periphery of the knuckle, and the inner member includes the hub wheel and a small diameter of the hub wheel. 3. The in-wheel according to claim 1, comprising a pair of inner rings press-fitted into a stepped portion, wherein a concave groove is formed in a range of 180 ° on at least the opposite road surface side of the outer periphery of the outer side end of the knuckle. Type wheel bearing device with built-in motor.   The in-wheel type motor-integrated wheel bearing device according to any one of claims 1 to 4 and 9, wherein a plurality of the concave grooves are formed.   A drive shaft constituting the speed reducer is connected to a hub wheel of the wheel bearing so as to transmit torque, the speed reducer is a cycloid speed reducer, an input shaft having an eccentric shaft, and a casing of the speed reducer And a plurality of outer pins passed between the motor casing, a plurality of inner pins attached to the drive shaft, and two curved plates rotatably supported by each pin via a rolling bearing These curved plates are formed in a wavy trochoidal curve having a gentle outer shape, and are mounted on the eccentric shaft, and the outer pin is rotatably supported by a rolling bearing, and the curved plate is supported by the outer pin. The in-wheel type motor-integrated wheel bearing device according to claim 1, wherein the eccentric motion is guided on the outer peripheral side.

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