JP4984142B2 - Hub unit - Google Patents

Description

  The present invention relates to a hub unit, for example, a hub unit including a rotational speed detection device.

  Generally, a rotation speed detection device (rotation detection device) for detecting the rotation speed of a wheel is attached to a hub unit of an automobile. The rotation detection device is used, for example, as information input means for an anti-lock brake system (ABS) of an automobile. For example, the rotation detection device has a pulse generator (pulsar ring) fixed to the inner ring side of the hub unit and a sensor held by a sensor holder (annular cover body) fixed to the outer ring side. A configuration is known in which a rotational change of the accompanying pulsar ring is detected by a sensor (see Patent Documents 1 and 2).

JP 2005-241351 A JP 2005-315632 A

  In the technique described in Patent Document 1, the sensor head can be attached to the accommodation pocket (holding portion) in a clip-on manner by the elastic force of the clip portion, and the annular ring portion of the sensor holder is an outer member (outer ring). ) Is fitted and attached to the outer peripheral surface of the inner end. Further, the technique described in Patent Document 2 defines the length of the claw portion that comes into contact with the lower end (front end) of the front surface of the sensor with the sensor inserted in the accommodation pocket. The annular ring portion is fitted and attached to the outer peripheral surface of the inner side end portion of the outer member (outer ring).

  By the way, on the structure of the axle, the bearing width is reduced by regulating the shaft dimension of the bearing in the hub unit. However, as in the technique described in the above-mentioned patent document, in the rotational speed detection device, the annular ring part of the sensor holder is fitted and attached to the outer peripheral surface of the inner side end of the outer member (outer ring). In order to securely fix the sensor holder, it is necessary to provide a certain fitting dimension in the axial direction to ensure a sufficient fitting force, but the fitting dimension between the outer member and the sensor holder (annular cover body) In order to ensure sufficient, a gap with the vehicle body must be formed on the outer peripheral surface of the outer member, which may affect the mounting of the outer member itself.

  The present invention has been made in view of the above circumstances, and a hub capable of stably mounting a rotational speed detection device even when the bearing width is reduced by the restriction of the shaft dimension of the bearing in the hub unit. To provide a unit.

Means for Solving the Problems and Effects of the Invention

In order to solve the above problems, the hub unit of the present invention is
In order to rotatably support the wheel on the vehicle body, an outer ring that is press-fitted and fitted non-rotatably into the inner periphery of the axle case on the vehicle body side, is arranged concentrically with the outer ring, and tracks on the inner peripheral surface of the outer ring. An inner ring attached to the wheel side so as to rotate integrally with the wheel via a rolling element as a surface, and a rotation speed that is mounted on a vehicle inner side end of the inner ring and the outer ring to detect a change in the rotation speed of the wheel A hub unit having a detection device,
The rotational speed detection device is
A pulsar ring that rotates integrally with the inner ring, including a cylindrical inner ring fixing portion that is fitted and fixed to the outer peripheral surface of the inner ring, and a detected portion that protrudes in a radial manner outwardly from the inner ring fixing portion in a flange shape. When,
A head portion of a sensor for detecting a change in rotational speed of the wheel via a detected portion of the pulsar ring;
An annular cover portion provided opposite to the vehicle inner side in the axial direction to the detected portion of the pulsar ring and provided with a holding portion for holding and fixing the head portion on the opposite side of the detected portion in the axial direction; An annular cover body including a cylindrical outer ring fixing portion extending in an axial direction from the outer peripheral edge of the cover portion, and the outer ring fixing portion being fitted and fixed to the inner peripheral surface of the outer ring,
While being fixed to the vehicle outer side of the detected portion of the pulsar ring, the outer diameter end portion is elastically deformed to the inner peripheral portion of the outer ring fixing portion of the annular cover body that is fitted and fixed to the inner peripheral surface of the outer ring. A first seal member to be pressed;
A second seal member fixed to the vehicle outer side of the cover portion of the annular cover body and having an inner diameter end portion elastically deformed and pressed against the pulsar ring or the inner ring ,
The second seal member closes an opening formed in order to make the head portion of the sensor and the detected portion opposed to the annular cover body,
The second seal member seals between the pulsar ring and the annular cover body in the axial direction of the rolling element arrangement space formed between the outer ring and the inner ring .

  According to the present invention, the annular cover body that holds and fixes the head portion of the sensor in the rotational speed detection device is fitted and fixed to the inner peripheral surface of the outer ring. According to this, compared with the case where the annular cover body is fitted and fixed to the outer peripheral surface of the outer ring, it is possible to mount the downsized rotation speed detection device, and it is possible to reduce the cost. Even when the bearing width is reduced by the restriction of the shaft dimension of the bearing in the hub unit, it is possible to sufficiently secure the axial dimension of the outer ring fixing portion fitted to the inner peripheral surface of the outer ring. Therefore, the rotational speed detection device can be stably attached.

  Further, the rotational speed detection device may be provided with a seal member that seals between the pulsar ring and the annular cover body at the vehicle inner side end portion in the axial direction of the rolling element arrangement space formed between the outer ring and the inner ring. it can. That is, since the annular cover body is fitted and fixed to the inner peripheral surface of the outer ring, the pulsar ring and the annular cover body are arranged in a shape facing each other in the rolling element arrangement space. By integrally forming the sealing member, the rolling element arrangement space can be rationally sealed without interposing the inner ring and the outer ring. As a result, space saving can be achieved in the rolling element arrangement space, and the number of parts can be reduced and the assemblability can be improved to further reduce the cost.

  As a specific aspect of the seal member, the outer portion of the pulsar ring is fixed to the vehicle outer side of the detected portion, and the outer diameter end portion is incorporated in the seal groove formed in the inner peripheral portion of the outer ring fixing portion of the annular cover body. And a second seal member fixed to the vehicle outer side of the cover portion of the annular cover body and having an inner diameter end portion incorporated in a seal groove formed in the pulsar ring or the inner ring. it can. Usually, since the lubricant (for example, grease) is applied to the rolling element arrangement space, the first seal member encloses the lubricant inside the detected part of the pulsar ring, and the second seal member is detected. It is possible to effectively prevent foreign matter from entering the rolling element arrangement space outside the section.

  The annular cover body in the rotational speed detection device can be configured such that the vehicle inner side end surface in the axial direction of the cover portion forms the same plane as the vehicle inner side end surface in the axial direction of the outer ring. Usually, the head portion of the sensor is fixed by being pushed into the holding portion of the annular cover body from the radial direction. At this time, since the cover portion and the vehicle inner side end surface of the outer ring form the same plane, the head portion can be easily pushed into the holding portion without being obstructed by the outer ring end portion.

  And it is preferable that the holding | maintenance part of a cyclic | annular cover body is provided with the elastic piece which engages the engaging part formed in the head part by pressing the head part of a sensor from the vehicle inner side in an axial direction. According to this, since the bullet piece presses from the vehicle inner side, the head portion can be received also at the vehicle inner side end portion of the outer ring, and the head portion can be stably held and fixed to the holding portion. . As a result, since the sensor is stably fixed, reliable detection can be performed.

  Embodiments of a hub unit according to the present invention will be described below with reference to the drawings. 1 is a diagram showing an example of a cross-sectional structure of a hub unit according to an embodiment of the present invention, FIG. 2 is an exploded perspective view showing an example of a rotational speed detection device, FIG. 3 is an enlarged view of a portion A in FIG. 2 is an enlarged view of a portion B in FIG. 2, and FIG. 5 is an enlarged view of a portion C in FIG. In FIG. 1, the left side in the figure is the vehicle outer side, and the right side in the figure is the vehicle inner side.

  As shown in FIG. 1, the hub unit 1 is interposed between a drive axle 2 and an axle case 3, and rotatably supports a wheel (drive axle 2) (not shown) with respect to the vehicle body (axle case 3). ing. The hub unit 1 includes a hub wheel 4, a rolling bearing 5, and a rotation speed detection device 6 that is mounted on the inner side and outer ring ends of the rolling bearing 5 and detects a change in the rotation speed of the wheel. Yes.

  The hub wheel 4 has a shaft portion 41 that is spline-fitted to the drive axle 2, and a hub flange 42 that fixes a wheel (not shown) to the vehicle outer side end portion of the shaft portion 41. A bolt insertion hole 43 a through which the bolt 43 is inserted is formed in the hub flange 42, and the wheel is fixed through the bolt 43.

  The rolling bearing 5 is formed of a double-row outward angular ball bearing. Further, the rolling bearing 5 includes an outer ring 52 that is non-rotatably attached to the vehicle body side, a rolling element 53 that is concentrically arranged with the outer ring 52 and that has an inner peripheral surface 52a of the outer ring 52 as a raceway surface (hereinafter also referred to as the “tama 53”). And an inner ring 51 attached to the wheel side so as to rotate integrally with the wheel. Specifically, the rolling bearing 5 uses a part of the outer peripheral surface of the shaft portion 41 of the hub wheel 4 as an inner ring on the vehicle outer side, and is a single unit on the vehicle inner side that is press-fitted and fitted to the outer periphery of the shaft portion 41. An inner ring 51 for a row, an outer ring 52 that is press-fitted into the inner periphery of the axle case 3 and has a double-row (two rows) raceway groove, a plurality of eggs 53 arranged in a double row, and two And crown-shaped cages 54, 54. Therefore, in this embodiment, the outer ring 52 is not rotated and the inner ring 51 (hub wheel 4) is rotated.

  Next, the rotation speed detection device 6 will be described. As shown in FIG. 2, the rotational speed detection device 6 detects an annular pulsar ring 60 in which magnetic poles (N pole, S pole) having different polarities are alternately arranged in the circumferential direction, and changes in the rotation of the pulsar ring 60. A sensor head portion 70 and an annular cover body 80 for holding the head portion 70 are provided. That is, the head portion 70 of the sensor detects the rotational change of the wheel by detecting the rotational change of the pulsar ring 60.

  As shown in FIGS. 2 and 3, the pulsar ring 60 has a cylindrical inner ring fixing portion 62a that is externally fitted and fixed to the outer peripheral surface 51a of the inner ring 51, and a flange-like protrusion that protrudes radially outward from the inner ring fixing portion 62a. A pulsar ring main body as a detected portion that is composed of a pulsar ring support portion 62 that includes a flange portion 62b and an N pole and an S pole that are alternately magnetized and is bonded and fixed to the end face of the flange portion 62b. 61. The pulsar ring 60 is press-fitted onto the outer periphery of the inner ring 51 of the rolling bearing 5 and fixed at the vehicle inner side end in the axial direction, and rotates integrally with the inner ring 51 (see FIG. 1).

  Returning to FIG. 2, the head unit 70 is formed of a polymer material such as resin, and is formed by molding a sensor 71 (see FIG. 3) such as an IC (Integrated Circuit) chip having a magnetic circuit. The sensor 71 can detect the rotation of the pulsar ring 60 when a voltage is generated in the magnetic circuit due to a change in magnetic flux density caused by the rotation of the pulsar ring 60. A lead wire 79 is drawn out from the head unit 70.

  The annular cover body 80 includes a cylindrical outer ring fixing portion 81 and an annular cover portion 82 that extends radially inward from the vehicle inner side end portion of the outer ring fixing portion 81. An opening 82a penetrating in the thickness direction is formed in the cover portion 82 at a predetermined position in the circumferential direction, and a holding portion 83 that holds the head portion 70 on the vehicle inner side corresponding to the opening 82a. Is provided.

  Specifically, as shown in FIG. 3, the annular cover body 80 includes an outer ring fixing portion 81 extending in the axial direction (vehicle outer side) from the outer peripheral edge of the cover portion 82, and the inner peripheral surface of the outer ring 52. The inner fitting is fixed to 52a. The cover portion 82 is disposed opposite to the vehicle inner side in the axial direction on the pulsar ring main body 61 (detected portion) of the pulsar ring 60 and sandwiches the cover portion 82 with the pulsar ring main body 61 (detected portion) in the axial direction. A holding portion 83 for holding and fixing the head portion 70 is provided on the opposite side.

  Thereby, when the head part 70 is hold | maintained at the holding | maintenance part 83, rotation of the pulsar ring 60 is detected through the opening part 82a. Further, since the outer ring fixing portion 81 is fixed by being fitted into the inner peripheral surface 52a of the outer ring 52, a constant fitting dimension in the axial direction can be easily secured, and a sufficient fitting force can be secured. it can. In addition, when attaching the head part 70 to the holding | maintenance part 83, it has the structure which pushes and fixes the head part 70 to the holding | maintenance part 83 from the radial direction (arrow P direction in FIG. 2) of the cyclic | annular cover body 80.

  Here, in the rotational speed detection device 6 according to the present embodiment, the pulsar ring 60 and the annular cover body 80 at the vehicle inner side end portion in the axial direction of the rolling element arrangement space 53 a formed between the outer ring 52 and the inner ring 51. A sealing member 90 is provided for sealing between the two.

  Specifically, the seal member 90 is formed as an elastic seal body such as a rubber material, and is attached to the first seal member 91 and the annular cover body 80 side that are adhesively fixed (for example, vulcanized and bonded) to the pulsar ring 60 side. And a second seal member 92 that is bonded and fixed (for example, vulcanized and bonded).

  The first seal member 91 is bonded and fixed to the vehicle outer side of the pulsar ring main body 61 (detected portion) of the pulsar ring 60, that is, to the flange portion 62 b, and the outer diameter end portion is the inner side of the outer ring fixing portion 81 of the annular cover body 80. It is incorporated in a seal groove 81d formed in the peripheral portion 81a. Further, the seal member 91 is also incorporated in another seal groove 81d formed in the inner peripheral portion 81a of the outer ring fixing portion 81 at the inner diameter end portion. Accordingly, the first seal member 91 fixed to the pulsar ring 60 comes into close contact with the annular cover body 80 while being elastically deformed, and the lubricant such as grease enclosed in the rolling element arrangement space 53a flows out to the outside. It has a function to prevent.

  The second seal member 92 is bonded and fixed to the vehicle outer side of the cover portion 82 of the annular cover body 80, and the inner diameter end portion is incorporated in a seal groove 51 d formed in the inner ring 51. However, the second seal member 92 is not provided in the opening 82a for making the detected portion and the sensor 71 face each other (the second seal member 92 is penetrated so as to match the shape of the opening 82a). However, even if the second seal member 92 is not cut out according to the shape of the opening 82a, the detection accuracy is small. That is, the second seal member 92 fixed to the annular cover body 80 is in close contact with the inner ring 51 while being elastically deformed, and has a function of preventing water and dust from entering the rolling element arrangement space 53a from the external space. The intrusion prevention effect is greater when the opening 82 a is blocked by the second seal member 92. In this embodiment, the seal groove into which the second seal member 92 is incorporated is formed in the inner ring 51, but the seal groove may be formed in the pulsar ring 60. Moreover, it is good also as a structure which abbreviate | omitted each seal grooves 51d and 81d by elastically deforming each seal member and pressing the seal member against the opposing member.

  Next, detailed aspects of the head unit 70 and the holding unit 83 will be described with reference to FIGS. 4 and 5. As shown in FIG. 4, the head portion 70 includes groove-shaped guide rail portions 72 and 72 extending in the longitudinal direction (pushing direction) on the side portions 70a and 70a on both sides, and a bellows-like uneven shape on the upper portion 70b. And a joint part 73.

  Subsequently, as shown in FIG. 5, the holding portion 83 of the annular cover body 80 guides the head portion 70 of the sensor 71 that is pushed in along the pushing direction described above on the vehicle inner side in the axial direction. It has guide pieces 84 and 84, and a resilient piece 85 that engages with an engaging portion 73 formed in the head portion 70 by pressing from the vehicle inner side. Thereby, the head part 70 can be hold | maintained so that it may be pinched | interposed from an axial direction.

  Specifically, the pair of guide pieces 84 and 84 rise in a shape that sandwiches the opening 82a of the cover portion 82 from the circumferential direction, and the opposing end surfaces 84a and 84a are formed in a longitudinal shape extending in the radial direction. ing.

  The bullet piece 85 includes a bullet base 85a that rises from the inner peripheral edge of the cover portion 82, and a bullet action portion 85b that bends in the radial direction (radially outward) from the upper end of the bullet base 85a. Yes. The elastic action portion 85b includes a pressing portion 85c that presses and engages the engaging portion 73 of the head portion 70. That is, the bullet piece 85 is formed so as to go around from the tip of the head unit 70 to the upper part when the head unit 70 is attached to the holding unit 83.

  Next, returning to FIG. 3, a structure for attaching the head unit 70 to the holding unit 83 will be described. As described above, the head unit 70 is fixed at a predetermined position of the holding unit 83 by pushing the head unit 70 toward the holding unit 83 in the radial direction (see FIG. 2). Specifically, the guide rail portion 72 of the head portion 70 is held so that the end portion of the guide piece 84 of the holding portion 83 is fitted. At this time, the end surfaces 84a and 84a of the guide pieces 84 are in contact with or close to the bottoms of the guide rail portions 72 and 72, and the head portion 70 is positioned in the circumferential direction. At the same time, since the end portion of the guide piece 84 enters the groove-shaped guide rail portion 72, positioning in the axial direction is also performed. Thereby, when the head part 70 is pushed into the holding part 83, it is guided in the pushing direction through the guide rail part 72 and the guide piece 84 (see FIGS. 4 and 5).

  Further, the pressing portion 85 c of the elastic piece 85 of the holding portion 83 is engaged with the engaging portion 73 of the head portion 70 so as to press. At this time, the pressing portion 85c is engaged with a predetermined recess position of the engaging portion 73, whereby the radial positioning of the head portion 70 with respect to the holding portion 83 is performed. As a result, the guide piece 84 and the bullet piece 85 sandwich the head portion 70, thereby preventing the head portion 70 from coming off.

  Here, the annular cover body 80 is arranged such that the vehicle inner side end surface 82 p in the axial direction of the cover portion 82 forms the same plane as the vehicle inner side end surface 52 b in the axial direction of the outer ring 52. Thereby, the head part 70 can be fixed so that the lower part 70c of the head part 70 contacts (contacts) the vehicle inner side end face 52b of the outer ring 52. Therefore, it becomes possible to receive the pressure from the bullet piece 85 by the outer ring 52, and the stability can be further improved. As shown in FIG. 3, it may be formed at a position (offset position) separated from the head portion 70, as in the vehicle inner side end surface 52b ′ of the outer ring 52 represented by a broken line. Improves.

  Even when the bearing width is reduced by the restriction of the shaft dimension of the bearing in the hub unit 1 with the above structure, the rotational speed detecting device 6 can be stably attached.

  In addition, in this invention, it is not limited to the said Example, It can also be set as the Example variously changed within the range of this invention according to the objective and the use. For example, in the above embodiment, the example in which the rotational speed detection device 6 is used for the hub unit 1 for a driving axle of an automobile has been described. However, the rotational speed detection device 6 may be used for a hub unit for a driven axle.

The figure which shows an example of the cross-section of the hub unit which concerns on embodiment of this invention. The disassembled perspective view which shows an example of a rotational speed detection apparatus. The A partial enlarged view in FIG. The B partial enlarged view in FIG. The C partial enlarged view in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hub unit 2 Drive axle 3 Axle case 4 Hub wheel 5 Rolling bearing 6 Rotational speed detection apparatus 60 Pulsar ring 61 Pulsar ring main body (detected part)
62 Pulsar ring support part 62a Inner ring fixing part 62b Flange part 70 Head part 71 Sensor 72 Guide rail part 73 Engaging part 80 Annular cover body 81 Outer ring fixing part 82 Cover part 82a Opening part 83 Holding part 84 Guide part 85 Projection piece 90 Seal Member 91 First seal member 92 Second seal member

Claims (3)

In order to rotatably support the wheel on the vehicle body, an outer ring that is press-fitted and fitted non-rotatably into the inner periphery of the axle case on the vehicle body side, is arranged concentrically with the outer ring, and tracks on the inner peripheral surface of the outer ring. An inner ring attached to the wheel side so as to rotate integrally with the wheel via a rolling element as a surface, and a rotation speed that is mounted on a vehicle inner side end of the inner ring and the outer ring to detect a change in the rotation speed of the wheel A hub unit having a detection device,
The rotational speed detection device is
A pulsar ring that rotates integrally with the inner ring, including a cylindrical inner ring fixing portion that is externally fitted and fixed to the outer peripheral surface of the inner ring, and a detected portion that protrudes radially outward from the inner ring fixing portion in a flange shape. When,
A head portion of a sensor for detecting a change in rotational speed of the wheel via a detected portion of the pulsar ring;
An annular cover portion provided opposite to the vehicle inner side in the axial direction to the detected portion of the pulsar ring and provided with a holding portion for holding and fixing the head portion on the opposite side of the detected portion in the axial direction; An annular cover body including a cylindrical outer ring fixing portion extending in an axial direction from the outer peripheral edge of the cover portion, and the outer ring fixing portion being fitted and fixed to the inner peripheral surface of the outer ring,
While being fixed to the vehicle outer side of the detected portion of the pulsar ring, the outer diameter end portion is elastically deformed to the inner peripheral portion of the outer ring fixing portion of the annular cover body that is fitted and fixed to the inner peripheral surface of the outer ring. A first seal member to be pressed;
A second seal member fixed to the vehicle outer side of the cover portion of the annular cover body and having an inner diameter end portion elastically deformed and pressed against the pulsar ring or the inner ring ,
The second seal member closes an opening formed in order to make the head portion of the sensor and the detected portion opposed to the annular cover body,
The hub unit characterized in that the second seal member seals between the pulsar ring and the annular cover body in the axial direction of the rolling element arrangement space formed between the outer ring and the inner ring . The outer diameter end portion of the first seal member is incorporated in a seal groove formed in the inner peripheral portion of the outer ring fixing portion of the annular cover body, and the inner diameter end portion of the second seal member is connected to the pulsar ring or the inner ring. The hub unit according to claim 1, wherein the hub unit is configured to be incorporated in a seal groove to be formed . 3. The hub unit according to claim 1, wherein the annular cover body is disposed such that a vehicle inner side end surface in an axial direction of the cover portion is flush with a vehicle inner side end surface in an axial direction of the outer ring. .

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