JP2008267557A - Bearing unit for supporting wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing unit for supporting a wheel whereby a production cost and an administration cost can be reduced by making it commonly usable in right and left wheels while protecting an encoder. <P>SOLUTION: In this bearing unit 10 for supporting the wheel, a plurality of window parts 44a, 44b in which a sensor 35 to detect rotation of the encoder 34 can be inserted are formed in a cover member 40 fixed to the inboard side end part of an outer ring 12, and the window part 44b in which the sensor 35 is not inserted is closed by a plug member 50. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wheel support bearing unit, and more particularly, to a wheel support bearing unit for rotatably supporting a wheel of an automobile or the like with respect to a suspension device, the wheel support having a sensor for detecting the rotation speed of the wheel. The present invention relates to a bearing unit.

  2. Description of the Related Art In recent years, anti-lock brake systems (ABS) that control so that wheels do not lock during braking and traction control systems that control so that wheels do not slip when starting have been adopted as techniques for improving the safety of automobiles. In these systems, in order to control the lock or slip of the wheel, a rotation sensor that accurately measures the rotation speed of the wheel is provided. For this reason, various types have been devised in which a rotation sensor is incorporated in a wheel support bearing unit that rotatably supports a wheel with respect to a suspension device (for example, see Patent Document 1).

  In order for the rotation sensor to obtain a reliable rotation signal from the encoder, it is necessary to stabilize the air gap between the sensor and the encoder. However, in the wheel support bearing unit, different moment loads are always applied depending on the traveling conditions, and therefore the relative inclination and relative displacement of the outer and inner rings always change. As a result, the inclination of the encoder fixed to the inner ring also changes constantly, and the air gap with the sensor fixed to the outer ring or knuckle always changes.

For this reason, in the wheel support bearing unit described in Patent Document 1, the rotation sensor is arranged at a position slightly above the axis where the relative inclination and relative displacement of the outer and inner rings are small.
Japanese Patent Laid-Open No. 11-183492 (FIG. 1)

  By the way, the left and right axle structure of an automobile is often designed symmetrically with the longitudinal direction as an axis. For this reason, when the rotation sensors are arranged on the left and right wheels as described in Patent Document 1, the sensors on the left and right wheels are located at different positions when viewed from the respective bearings. In such cases, the separate production, management, and delivery of the right-wheel bearing unit and the left-wheel bearing unit for the bearing manufacturer leads to an increase in production cost and management cost, and for the automobile manufacturer, separate management. This is undesirable because it causes two types of repair parts and increases the management cost.

  For this reason, when providing a window portion for inserting a rotation sensor in the cover member of the bearing unit, a window portion is formed at each position where each rotation sensor of the right wheel bearing unit and the left wheel bearing unit is disposed. However, it is conceivable to use the cover member in common for both the right wheel bearing unit and the left wheel bearing unit. However, the window portion into which the sensor is not inserted remains open, and dust easily enters from this opening portion. In particular, when the encoder is molded with magnetized rubber magnetized with multiple poles, magnetic dust may stick to the encoder, or hard dust may get caught in the space between the sensor and the encoder. As a result, the encoder may be worn, and the rotational speed signal may be significantly degraded.

  The present invention has been made to eliminate such inconveniences, and an object of the present invention is to provide a wheel support bearing unit that can be shared by the left and right wheels to reduce production and management costs while protecting the encoder. It is to provide.

The above object of the present invention is achieved by the following configurations.
(1) a stationary wheel having a stationary raceway surface on the peripheral surface and connectable to a suspension device;
A rotating wheel having a rotation side raceway surface on a circumferential surface facing the stationary side raceway surface, and a wheel mounting flange for supporting a wheel on the outer circumferential surface;
A plurality of rolling elements provided between the stationary side raceway and the rotation side raceway;
An encoder fixed concentrically with the rotating wheel at an inboard side end of the rotating wheel;
A cover member that is fixed to an inboard side end portion of the stationary wheel and has a plurality of window portions into which a sensor that detects rotation of the encoder can be inserted;
A closing member that closes the window where the sensor is not inserted;
A wheel-supporting bearing unit comprising:
(2) A drain window is formed below the fixed cover member,
The plurality of window portions are a pair of window portions arranged symmetrically with respect to a vertical line passing through a central axis of the stationary wheel and the rotating wheel, and
The closing member is an inner door that is slidable along the circumferential direction inside the cover member,
When the wheel is a right wheel, the sensor is inserted into one of the pair of windows, and the other of the pair of windows is blocked by the inner door,
The one of the pair of window portions is closed by the inner door when the wheel is a left wheel, and the sensor is inserted into the other of the pair of window portions. Wheel support bearing unit.

  According to the wheel support bearing unit of the present invention, the cover member fixed to the inboard side end portion of the stationary wheel is formed with a plurality of window portions into which sensors for detecting the rotation of the encoder can be inserted, Since the window portion that is not inserted is closed by the closing member, the bearing unit including the cover member can be shared by the left and right wheels while protecting the encoder disposed inside the cover member, thereby reducing production and management costs. it can.

  Hereinafter, a sensor-equipped wheel support bearing unit according to each embodiment of the present invention will be described in detail with reference to the drawings.

(First embodiment)
The sensor-supported wheel support bearing unit 10 of the present embodiment is for a drive wheel. As shown in FIG. 1, a hub 11 that is a rotating wheel, an outer ring 12 that is a stationary wheel, and a ball that is a plurality of rolling elements. 13. The hub 11 includes a hollow hub wheel 15, and the hub wheel 15 is an end portion on the outboard side (an end portion on the outer side in the vehicle width direction in an assembled state in an automobile) that is a portion of the outer peripheral surface near one end in the axial direction. : The left end of FIG. 1) has a wheel mounting flange 16 extending radially outward. On the wheel mounting flange 16, a plurality of studs 17 for mounting a wheel, a brake rotor, and the like (not shown) constituting the wheel are planted on the outboard side side surface at substantially equal intervals in the circumferential direction. Furthermore, a spline groove 18 that engages with a spline shaft of a constant velocity joint (not shown) is formed on the inner peripheral surface of the hub wheel 15.

  A small-diameter step portion 19 is formed at the axial end of the hub wheel 15 on the inboard side, and an inner ring 20 is fitted on the small-diameter step portion 19. Then, the inner ring 20 is coupled and fixed to the hub wheel 15 by caulking and expanding a portion protruding from the inner end surface of the inner ring 20 of the small-diameter stepped portion 19 in the diametrically outward direction. The inner ring 20 may be fixed to the hub wheel 15 at the same time as the constant velocity joint is fixed to the hub wheel 15. Further, a first inner ring raceway surface 21 which is a rotation side raceway surface is formed on the outer peripheral surface of the hub ring 15 in the axial direction, and a second inner ring raceway surface 22 which is a rotation side raceway surface is formed on the outer peripheral surface of the inner ring 20. Is formed.

  On the inner peripheral surface of the outer ring 12, a stationary side track corresponding to the first outer ring raceway surface 23 corresponding to the first inner ring raceway surface 21 of the hub wheel 15 and the second inner ring raceway surface 22 of the inner ring 20. A second outer ring raceway surface 24 that is a surface is formed. Further, a suspension device attachment flange 25 extending radially outward is provided on the outer peripheral portion of the outer ring 12 on the side away from the wheel attachment flange 16, and is fixed to the suspension device 26 via this flange 25. .

  A plurality of balls 13 are respectively provided in the circumferential direction via the cage 14 between the double-row first and second inner ring raceway surfaces 21 and 22 and the double-row first and second outer ring raceway surfaces 23 and 24. It is arranged so that it can roll. In the illustrated example, the balls 13 are used as the rolling elements. However, in the case of a wheel support bearing unit that is heavy, tapered rollers may be used as the rolling elements.

  A plurality of balls 13 are arranged between the inner peripheral surface of both ends of the outer ring 12 and the outer peripheral surfaces of the hub ring 15 and the inner ring 20 facing the inner peripheral surface. The outer ring 12, the hub ring 15 and the inner ring are arranged. Sealing devices 27 and 28 for sealing the annular space between them are disposed, and leakage of grease filled inside and entry of water and foreign matters from the outside are prevented.

  The inboard-side sealing device 27 is configured by sliding a sealing member 30 fixed to a core metal 29 fitted in the outer ring 12 to a slinger 31 fitted to the inner ring 20, and outboard. The side seal device 28 is configured by sliding a seal member 33 fixed to a cored bar 32 fitted in the outer ring 12 to the outer peripheral surface of the hub ring 15.

  In order to assemble the wheel support bearing unit 10 as described above to an automobile, the suspension device mounting flange 25 of the outer ring 12 is fixed to the suspension device 26, and the stud 17 and the nut are attached to the wheel mounting flange 16 of the hub wheel 15 on the rotating wheel side. The brake rotor and the wheel are fixed via a not shown. Thereby, the wheel can be rotatably supported with respect to the suspension device 26.

  Further, in the wheel support bearing unit 10, an encoder 34 is fixed to the side surface in the axial direction of the slinger 31 of the seal device 27 in order to detect the rotational speed of the hub 11. In addition, a sensor 35 having a detection unit in the vicinity of the encoder 34 is attached to the suspension device 26 via a sensor hole 36, and a rotational speed signal detected by the detection unit is sent to the outside via a harness 37. .

  The encoder 34 is disposed opposite to the detection unit in the axial direction via a predetermined air gap, and changes the magnetic characteristics alternately and at equal intervals in the circumferential direction. The encoder 34 is formed by mixing a ferromagnetic material in rubber or synthetic resin, and is formed with a rubber magnet or plastic magnet alternately magnetized in the circumferential direction. It is composed of a magnetic metal plate such as a mild steel plate to be changed.

  The detection unit is an IC incorporating a magnetic detecting element such as a Hall element or a magnetoresistive element (MR element) that changes its characteristics according to the flow direction of magnetic flux, and a waveform shaping circuit for adjusting the output waveform of the magnetic detecting element. Consists of. In addition, when the encoder 34 having a permanent magnet is used, the detection unit does not need to incorporate a permanent magnet. However, when the encoder 34 made of a simple magnetic material is used, a magnetic flux generation source is connected to the sensor side. It is necessary to incorporate a permanent magnet.

  A cover member 40 is fitted and fixed to the outer peripheral surface of the inboard side end portion of the outer ring 12. The cover member 40 includes a first cylindrical portion 41 fitted to the outer peripheral surface of the inboard side end portion of the outer ring 12, a second cylindrical portion 42 having a smaller diameter than the first cylindrical portion 41, and a radial direction from the second cylindrical portion 42. And an inward flange portion 43 extending inward. The tip peripheral surface of the inward flange portion forms a sliding contact with a constant velocity joint (not shown) or a labyrinth seal, and the cover member 40 partitions the space where the encoder 34 is installed from the external space, It prevents foreign objects from entering the space.

  As shown in FIG. 2, a drainage window 45 opened across the second cylindrical portion 42 and the inward flange portion 43 is formed below the cover member 40, and in the space where the end cap 34 is disposed. Drain the water that has entered

  Further, the cover member 40 has a small change in the air gap between the encoder 34 and the sensor 35, at a position obliquely above the horizontal line h passing through the central axis of the hub 11 and the outer ring 12, and the central axis. A pair of window portions 44a and 44b are formed at positions symmetrical with respect to the passing vertical line v. The pair of window portions 44 a and 44 b are opened across the second cylindrical portion 42 and the inward flange portion 43.

  As shown in FIG. 2, when the wheel is a right wheel, the sensor 35 attached to the suspension device 26 is inserted into one window portion 44a, and the other window portion 44b into which the sensor is not inserted is closed. The plug member 50 which is a member is closed. Although not shown, when the wheel is a left wheel, the sensor 35 attached to the suspension device 26 is inserted into the other window portion 44b, and the one window portion 44a into which the sensor is not inserted is blocked by the plug member 50. Can be removed. For this reason, when the bearing unit 10 applied to the right wheel and the bearing unit 10 applied to the left wheel are attached to the suspension device 26, the sensor 35 is arranged in the same phase as viewed from one side of the vehicle body.

  As shown in FIG. 3, the plug member 50 is a substantially L-shaped resin part, and sandwiches the edge portion of the second cylindrical portion 42 and the edge portion of the inward flange portion 43 that define the window portion 44 b. 1 and second engaging portions 51 and 52. In order to prevent the first and second engaging portions 51 and 52 from falling into the cover member 40, the outer portions 51a and 52a are formed longer than the inner portions 51b and 52b. The plug member 50 deforms the inner portions 51b and 52b, and engages and disengages the first and second engaging portions 51 and 52 with the edge of the second cylindrical portion 42 and the edge of the inward flange portion 43, The cover member 40 can be easily attached and detached.

  Further, each outer portion 51a, 52a is provided with a claw 53, and the plug member 50 is firmly fixed by the cover member 40 by being engaged with a hole 46 formed on the surface of the cover member 40. The Note that a recess may be formed in the cover member 40 instead of the hole 46. further. A handle 54 is formed on the outer surface of the plug member 50 to facilitate attachment / detachment.

  Therefore, according to the wheel support bearing unit 10 of the present embodiment, the pair of windows 44a and 44b into which the sensor 35 can be inserted into the cover member 40 fixed to the inboard side end of the outer ring 12 are the hub 11 and It is formed symmetrically with respect to the vertical line V passing through the central axis of the outer ring 12. As a result, the sensors 35 are respectively inserted into the pair of windows 44a and 44b formed at positions where the change in the air gap becomes small according to the left and right wheels, and the bearing unit 10 including the cover member 40 is shared by the left and right wheels. This can reduce the production and management costs of bearing manufacturers and automobile manufacturers. In addition, the other of the pair of windows 44a and 44b into which the sensor is not inserted is closed by the plug member 50, so that dust or the like is prevented from entering the space where the encoder 34 is disposed from the windows 44a and 44b. The encoder 34 can be protected.

(Second Embodiment)
Next, a wheel support bearing unit with a sensor according to a second embodiment of the present invention will be described in detail with reference to FIG. This embodiment is different from the first embodiment in the structure of the closing member, and the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  In the second embodiment, a crescent-shaped inner door 60 that is slidable in the circumferential direction is provided inside the second cylindrical portion 42 of the cover member 40 as the closing member. The inner door 60 is an elastic member made of metal or resin, the entire length of which is 1/2 or more of the arc length of the second cylindrical portion 42. In addition, the inner door 60 has a radius of curvature of the outer peripheral surface equal to or greater than the radius of curvature of the inner peripheral surface of the second cylindrical portion 42 in a free state before being fitted to the cover member 40, and the second cylinder due to its own elasticity. It arrange | positions so that the internal peripheral surface of the part 42 may be followed.

  The inner door 60 has two inner windows 61a at a position separated by a substantially shorter arc distance than the short arc distance between the windows 44a and 44b of the second cylindrical section 42 by the circumferential width of the windows 44a and 44b. , 61b are formed. Thereby, when the wheel is a right wheel, the one window 44a and the inner window 61a are communicated with each other so that the sensor 35 can be inserted therein, and the other window 44b and the inner window 61b are connected to each other. The position is shifted in the circumferential direction, and the other window portion 44 b is closed by the inner door 60. When the wheel is a left wheel, the other window 44b and the inner window 61b are communicated with each other so that the sensor 35 can be inserted therein, and the one window 44a is closed by the inner door 60. . Further, by making the opening dimensions of the inner windows 61a and 61b and the diameter of the sensor 35 substantially equal, the inner door 60 is fixed by the sensor 35, and the inner door 60 is prevented from moving due to the influence of vibration or the like. it can.

  Further, a handle 62 is attached to one end portion in the circumferential direction of the inner windows 61 a and 61 b of the inner door 60. The handle 62 protrudes from the window portions 44a and 44b of the cover member 40, and the inner door 60 is regulated by the handle 62 and slides by the circumferential width of the inner windows 61a and 61b. When the inner door 60 is slid and the sensor 35 is inserted into the windows 44a and 44b communicating with the inner windows 61a and 61b, the handle 62 is positioned in the windows 44a and 44b by the sensor 35. The inner door 60 is also positioned with respect to the cover member 40. When the inner door 60 is formed by pressing a metal material, the handle 62 may be formed by bending the plates of the inner windows 61a and 61b outward.

Further, as shown in FIG. 4, the window portions 44 a and 44 b of the cover member 40 of the present embodiment are formed only on the second cylindrical portion 42, but the first shape can be obtained by changing the shape of the inner door 60. Similarly to the embodiment, it may be formed across the second cylindrical portion 42 and the inward flange portion 43.
Other configurations and operations are the same as those in the first embodiment.

  Therefore, according to the wheel support bearing unit 10 of the present embodiment, as in the first embodiment, the bearing unit 10 including the cover member 40 is shared by the left and right wheels, thereby reducing the production and management costs of bearing manufacturers and automobile manufacturers. The other window portions 44a and 44b into which the sensor can not be inserted are closed by sliding the inner door 60, so that dust or the like enters the space where the encoder 34 is disposed from the window portion 44b. This prevents the encoder 34 from being protected.

(Third embodiment)
Next, a wheel support bearing unit with a sensor according to a third embodiment of the present invention will be described in detail with reference to FIG. The present embodiment is different from the second embodiment in the structure of the inner door of the closing member, and the same parts as those in the second embodiment are denoted by the same reference numerals and the description thereof is omitted or simplified.

  The inner door 60a of the third embodiment is formed in an annular shape having an outer diameter equal to the inner diameter of the second cylindrical portion 42, and has inner windows 61a and 61b and a handle 62 as in the second embodiment, A drainage inner window 63 is also provided at a position corresponding to the drainage window 45 of the cover member 40. The drainage inner window 63 has a circumferential width larger than the circumferential width of the drainage window 45 by a sliding distance so that the drainage window 45 is not blocked when the inner door 60a slides.

Further, as shown in FIG. 5A, the window portions 44 a and 44 b of the cover member 40 prevent the handle 62 of the inner door 60 from interfering with the cover member 40 when the inner door 60 is inserted and fixed to the cover member 40. In addition, a notch 47 having an inner diameter B larger than the outer diameter A of the handle 62 is provided. Therefore, the annular inner door 60a can improve the rigidity as compared with that of the second embodiment, and can more reliably prevent entry of dust having a large momentum such as a stepping stone. It should be noted that the width of the cutout portion 47 may be equal to or greater than the plate thickness of the handle 62 so that the handle 62 passes through.
Other configurations and operations are the same as those in the first embodiment.

In addition, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.
In the above embodiment, the sensor detection unit and the encoder are arranged to face each other in the axial direction via a predetermined air gap, but may be arranged to face each other in the radial direction.

  Moreover, in the said embodiment, although it is the structure inserted from a radial direction outer side, the structure inserted from an axial direction side may be sufficient. The sensor may be configured to be bolted to the suspension device as in the above embodiment, or may be configured to be fixed to the cover member itself.

It is sectional drawing for demonstrating the wheel support bearing unit which concerns on 1st Embodiment of this invention. It is a right view of FIG. (A) is a perspective view of the closure member attached to the cover member of 1st Embodiment, (b) is a perspective view of the closure member, (c) is the closure member attached to the cover member FIG. The closing member of the bearing unit for wheel support concerning a 2nd embodiment of the present invention is shown, (a) is a sectional view near a sensor, and (b) is a sectional view along the IV-IV line of (a). is there. The closing member of the wheel support bearing unit which concerns on 3rd Embodiment of this invention is shown, (a) is sectional drawing of the sensor vicinity, (b) is sectional drawing along the VV line of (a). is there.

Explanation of symbols

10 Wheel Support Bearing Unit 11 Hub (Rotating Wheel)
12 Outer ring (stationary ring)
13 balls (rolling elements)
15 Hub wheel 19 Small diameter step portion 20 Inner ring 21 First inner ring raceway surface (rotating side raceway)
22 Second inner ring raceway (rotating raceway)
23 First outer ring raceway (stationary raceway)
24 Second outer ring raceway (stationary raceway)
27, 28 Sealing device 34 Encoder 40 Cover members 44a, 44b Window portion 50 Plug member (blocking member)
60, 60a Inner door (closing member)

Claims (2)

A stationary wheel having a stationary raceway surface on the peripheral surface and connectable to a suspension device;
A rotating wheel having a rotation side raceway surface on a circumferential surface facing the stationary side raceway surface, and a wheel mounting flange for supporting a wheel on the outer circumferential surface;
A plurality of rolling elements provided between the stationary side raceway and the rotation side raceway;
An encoder fixed concentrically with the rotating wheel at an inboard side end of the rotating wheel;
A cover member formed with a plurality of windows fixed to the inboard side end of the stationary wheel and capable of inserting a sensor for detecting rotation of the encoder;
A closing member that closes the window where the sensor is not inserted;
A wheel-supporting bearing unit comprising: A drainage window is formed below the fixed cover member,
The plurality of windows are a pair of windows arranged symmetrically with respect to a vertical line passing through the central axis of the stationary wheel and the rotating wheel, and
The closing member is an inner door that is slidable along the circumferential direction inside the cover member,
When the wheel is a right wheel, the sensor is inserted into one of the pair of window portions, and the other of the pair of window portions is blocked by the inner door,
The one of the pair of window portions is closed by the inner door when the wheel is a left wheel, and the sensor is inserted into the other of the pair of window portions. Wheel support bearing unit.

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