JP4692879B2 - Hub unit - Google Patents

Description

  The present invention relates to a hub unit.

JP 2001-315503 A

  Conventionally, a hub unit for attaching a tire wheel and a brake disk is used in an automobile. The hub unit is provided so as to be rotatable integrally with the axle, and fixes a tire wheel and a brake disk, an outer ring disposed non-rotatingly via a rolling element on a radially outer side of the hub body, and a rolling element. And a waterproof / dustproof seal portion disposed on both sides of the battery. As a structure for attaching the hub unit to the automobile side, for example, Patent Document 1 discloses a structure in which an outer ring is fitted into a knuckle (vehicle side assembly member) provided on the automobile side.

  In the above structure, since the vehicle outer side is closed, there is not much intrusion of water etc., but since the vehicle inner side is open, water enters the gap between the axle and the knuckle (or outer ring) from the open side, Moreover, there is a problem that the water cannot easily escape to the outside. Therefore, there is a problem that water enters the rolling element side through the seal portion, and the rolling element is easily rusted.

  The present invention has been made in the background as described above. In particular, it is an object of the present invention to provide a hub unit that easily discharges water entering from the vehicle inner side to the outside.

Means for Solving the Problems and Effects of the Invention

The present invention
A hub main body having a wheel mounting portion that is attached to the outer peripheral surface of the axle so as to be integrally rotatable, and that protrudes radially outward from an end of the outer peripheral surface of the vehicle outer side;
A bearing portion attached to the outer peripheral surface of the hub main body, the inner ring rotating integrally with the axle and the hub main body, the outer ring disposed non-rotatingly on the radially outer side of the inner ring, the inner ring and the outer ring Between the inner ring and the outer ring at a vehicle inner side end portion in the axial direction of the annular space for the rolling element arrangement, and a rolling element that rotatably supports the inner ring with respect to the outer ring. A bearing portion having a seal portion that seals between the inner ring and the outer ring in a state in which relative rotation between the inner ring and the outer ring is allowed.
The outer ring is assembled to the vehicle by fitting from the inside to the opening of the vehicle side assembly member provided on the vehicle side at the end on the vehicle inner side,
A drain hole that opens to an inner peripheral surface of the end portion at a position closer to the vehicle inner side than the seal portion is provided at the end portion of the outer ring that is fitted to the vehicle-side assembly member. The hub unit is characterized in that it is formed in a form that penetrates the portion in the radial direction.

  According to the present invention, the end of the outer ring on the vehicle inner side is formed with a drain hole that opens to the inner peripheral surface of the end at a position closer to the vehicle inner side than the seal portion in a form that penetrates the end in the radial direction. Has been. This drain hole is made to face downward when the vehicle is assembled. Therefore, even if water or the like enters from the vehicle inner side, the water is naturally discharged through the drain hole, so that it is difficult for water to collect inside the outer ring. Therefore, it becomes difficult for water to enter from the seal portion, and the rusting of the rolling elements can be prevented.

  More specifically, the vehicle-side assembly member is formed in a cylindrical shape having both ends opened. In the vehicle assembly state, the outer ring is fitted into the opening on the vehicle outer side, and the vehicle-side assembly member The vehicle-side assembly member is positioned so as to form an inner-side open space in which an end on the vehicle inner side is opened between the peripheral surface and the outer peripheral surface of the axle. That is, for example, on the driven wheel side, the axle can be configured to be short and the vehicle inner side end of the vehicle side assembly member can be closed. In this case, water enters from the vehicle inner side. There is nothing. That is, the drainage hole according to the present invention is particularly effective when the end on the vehicle inner side of the vehicle side assembly member opens as described above.

On the other hand, when a through hole is formed in the radial direction and the drain hole is formed only by the through hole, the drain hole needs to be formed at a position that is not blocked by the vehicle side assembly member. For this reason, it may not be possible to open at the optimum position (immediately inside the seal portion). Such a problem can be solved by adopting the following configuration. That is,
In the vehicle assembly state, the drain hole has an inner opening that opens on the inner space side of the outer ring, opens at a position overlapping the vehicle assembly member, and an outer opening that opens on the outer space side A hub unit that opens to a position that is disengaged toward the vehicle outer side in the axial direction relative to the side assembly member.

More specifically, the hub unit has the following structure. That is,
The outer ring is
An outer ring main body in contact with the rolling element;
A flange portion projecting radially outward from an outer peripheral surface of the outer ring main body, and in contact with a vehicle outer side end portion of the vehicle side assembly member in the vehicle assembly state;
An inlay portion that protrudes inward in the axial direction from the vehicle inner side main surface of the flange portion and fits into the vehicle side assembly member in the vehicle assembly state, and forms an end on the vehicle inner side;
The drain hole is
A through hole formed through the inlay portion in a radial direction in the vehicle assembled state;
An axial groove formed in the axial direction on the outer circumferential surface of the inlay portion and reaching the vehicle inner side main surface of the flange portion;
A radial groove formed in a radial direction on the vehicle inner side main surface of the flange portion, an end portion on the inner side in the radial direction communicating with the axial groove, and an end portion on the outer side in the radial direction open to an outer peripheral surface of the flange portion Hub unit with.

  According to the present invention, since the drain hole is constituted by the through hole, the axial groove, and the radial groove, even if the through hole is formed at a position overlapping the vehicle side assembly member at the end of the outer ring, The outer opening can be formed at a position away from the vehicle outer side with respect to the vehicle side assembly member.

  In addition, the first inclined surface for drainage is formed in a portion of the outer ring that is located closer to the vehicle inner side than the drainage hole so that the inner peripheral surface of the outer ring expands toward the vehicle inner side. It is good. As a result, water can be allowed to flow naturally toward the vehicle inner side, and the efficiency of preventing water from entering the seal portion can be increased.

  Further, a second inclined surface for drainage is formed in a portion of the outer ring located between the seal portion and the drainage hole so that an inner peripheral surface thereof is expanded toward the drainage hole. It is good also as composition which has. Thereby, the water that has entered from the vehicle inner side can be allowed to flow down naturally and be discharged from the drainage hole, and the efficiency of preventing water from entering the seal portion can be increased.

  In addition, a rotation detection sensor may be provided on the vehicle inner side of the outer ring so as to partially close a radial gap between the vehicle-side assembly member and the axle. In other words, a rotation detection sensor (such as a pulsar ring) is attached to the hub unit, and the number of rotations detected by this sensor is used for ABS control. The radial gap may be partially narrowed. In such a structure, it is difficult for water that has entered to flow down to the vehicle inner side. Therefore, when the drain hole is provided as in the present invention, the effect becomes more prominent.

  On the other hand, the outer peripheral surface of the axle has a shape that gradually increases in diameter toward the vehicle inner side, and the inner peripheral surface of the mounting member gradually increases in diameter toward the vehicle inner side corresponding to the outer peripheral surface shape of the axle. It is in the shape to be. In the case of such a shape, it is difficult for water entering from the vehicle inner side to be discharged. Therefore, when the drain hole is provided as in the present invention, the effect is particularly remarkable.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an example of a hub unit 1 according to the present invention in a sectional structure. The hub unit 1 includes a cylindrical hub body 3a attached to the outer peripheral surface of the front end portion of the axle 2, a wheel mounting portion 3b projecting radially outward from the outer peripheral surface of the hub main body 3a, and an outer periphery of the hub main body 3a. And a bearing portion 4 attached to the surface. The bearing portion 4 is disposed between an inner ring 4a attached to the axle 2 so as to be integrally rotatable, an outer ring 4b non-rotatably arranged radially outward of the inner ring 4a, and the inner ring 4a and the outer ring 4b. A rolling element 4c that rotatably supports 4a with respect to the outer ring 4b, and seal portions 4e and 4f are included. The seal portions 4e and 4f are disposed between the inner ring 4a and the outer ring 4b at the vehicle outer side end or the vehicle inner side end in the axial direction of the annular space for disposing the rolling elements 4c. It is sealed in a state that allows relative rotation. The outer ring 4b is assembled to the vehicle by fitting from the inside to the opening of the vehicle side assembly member 5 (knuckle) at the end on the vehicle inner side.

  The axle tip portion 2t has a diameter smaller than that of the axle body portion 2m adjacent to the rear end side, and the hub body 3a is extrapolated to the axle tip portion 2t. A stepped portion 2a that contacts the rear end surface of the hub main body 3a is formed at the boundary position between the axle front end 2t and the axle main body 2m.

  The bearing portion 4 is composed of a double-row outward angular ball bearing, and has two single-row inner rings 4a that are press-fitted and fitted in the form adjacent to the axial direction on the outer periphery of the hub body 3a, and two rows of raceway grooves. A single outer ring 4b, a plurality of balls (rolling elements) 4c arranged in two rows, and two crown-shaped cages 4d and 4d are provided. The bearing 4 is used in a form in which the outer ring 4b is not rotated and the inner ring 4a is rotated. The wheel mounting portion 3b is formed in a flange shape projecting outward from the outer peripheral surface of the hub body 3a, and the brake disc 9 and the tire wheel (with the bolt 8 projecting from the vehicle outer side main surface of the wheel mounting portion 9) (Not shown) is attached.

  On the outer peripheral surface of the hub body 3a, a step portion 3c that contacts the inner ring 4a on the vehicle outer side and a step portion 3d that contacts the inner ring 4a on the vehicle inner side are formed. Further, the axle main body 2m is formed with a step portion 2b that contacts the inner ring 4a on the vehicle inner side. On the other hand, a male thread portion protruding toward the vehicle outer side from the wheel mounting portion 3b is formed at the tip end portion of the axle shaft 2 inserted into the hub body 3a, and a hub for fastening the hub body 3a to the axle shaft 2 is formed here. The fastening nut 2v is screwed.

  The vehicle-side assembly member 5 is formed in a cylindrical shape with both ends opened. In the vehicle assembly state, the outer ring 4b is fitted into the opening on the vehicle outer side, and the inner peripheral surface of the vehicle-side assembly member 5 and the axle The vehicle-side assembly member 5 is positioned so as to form an inner-side open space S in which an end on the vehicle inner side is opened between the outer peripheral surface of the main body 2m. When the vehicle travels, rainwater or the like rolls up due to the rotation of the tire, and the rainwater easily enters the inner side open space S from the vehicle inner side opening of the vehicle side assembly member 5. As a result, there was a problem that water entered the rolling element 4c side through the seal part 4f, and the rolling element 4c was likely to rust, but in the present invention, the drain hole 6 was provided in the outer ring 4b inside the seal part 4f. Water could be discharged to the outside, and the above problem could be solved. More specifically, the drain hole 6 is formed at an end portion of the outer ring 4b fitted to the vehicle-side assembly member 5, and opens to the inner peripheral surface of the end portion at a position closer to the vehicle inner side than the seal portion 4f. The end is penetrated in the radial direction.

  As shown in FIG. 1, the vehicle outer side end portion of the vehicle side assembly member 5 fitted to the outer ring 4 b can be placed substantially at the same position or positioned outside the seal portion 4 f in the axial direction. Thereby, the length by which the vehicle side assembly | attachment part 5 press-fits with respect to the outer ring 4b can fully be ensured, and the outer ring 4b can be fixed firmly. In such a structure, the drain hole 6 may be formed as follows. That is, the inner opening 6d that opens to the inner space side of the outer ring 4b opens at a position that overlaps the vehicle-side assembly member 5 in the radial direction, and the outer opening 6e that opens to the outer space side has a vehicle-side assembly member. With respect to 5, it opens to the position which deviated to the vehicle outer side in the axial direction. Accordingly, the inner opening 6d can be formed at an optimal position (immediately inside the seal portion 4f), and the drainage path can be prevented from being blocked by the vehicle-side assembly member 5. More specifically, the drain hole 6 is configured by a through hole 6a formed at the vehicle inner side end of the outer ring 4b, an axial groove 6b, and a radial groove 6c described later. That is, as shown in FIG. 4A, if the drain hole 6 is configured using only the through hole 6a, the through hole 6a is blocked by the vehicle side assembly member 5. Due to design restrictions, there are many cases where a through hole (drainage hole) cannot be formed in the vehicle-side assembly member 5, so that drainage cannot be performed. As shown in FIG. 4B, if the vehicle side assembly member 5 is to be bypassed, the inner opening 6e is not positioned on the vehicle inner side of the seal portion 4f, and the effect of the present invention cannot be obtained.

  Next, the configuration of the present invention will be described in more detail. First, regarding the structure of the outer ring 4b, as shown in the cross-sectional view of FIG. 1 and the schematic perspective view of FIG. 2, a flange portion 4h protrudes radially outward from the outer peripheral surface of the outer ring main body 4b. The vehicle outer side end of the attachment member 5 is in contact. In addition, an inlay portion 4 g protrudes inward in the axial direction from the vehicle inner side main surface of the flange portion 4 h and is fitted into the vehicle side assembly member 5. On the other hand, the drain hole 6 includes a through hole 6a, an axial groove 6b, and a radial groove 6c. The through hole 6a is formed through the inlay portion 4g in the radial direction, the axial groove 6b is formed in the axial direction on the outer peripheral surface of the inlay portion 4g, and the end on the vehicle inner side communicates with the through hole 6a. The end portion on the vehicle outer side reaches the vehicle inner side main surface of the flange portion 4h. The radial groove 6c is formed in the radial direction on the vehicle inner side main surface of the flange portion 4h, the radially inner end communicates with the axial groove 6b, and the radially outer end is the outer periphery of the flange portion 4h. To be released to the surface. The hub unit 1 is attached to the vehicle so that the through hole 6a and the radial groove 6c face downward. By adopting such a structure, the vehicle-side assembly member 5 can be press-fitted and fitted until the vehicle outer side end is located on the vehicle outer side with respect to the seal portion 4f, and the outer ring can be firmly fixed, The inner opening 6d can be formed on the vehicle inner side of the seal portion 4f, and the drain hole 6 can be formed so as to bypass the vehicle-side assembly member 5.

  On the other hand, on the outer peripheral surface of the axle main body 2m, step portions 2c to 2e are formed which gradually increase in diameter toward the vehicle inner side. Further, on the inner peripheral surface of the vehicle-side assembly member 5, step portions 5 a and 5 b are formed which gradually increase in diameter toward the vehicle inner side corresponding to the outer peripheral surface shape of the axle body 2 m. In such a shape, when the water which entered the inner side open space S becomes a ball shape, it may not be easily discharged. Therefore, when the drain hole 6 is formed, the effect is particularly noticeable.

  A sensor 7 (pulsar ring) for detecting the rotational speed is provided on the outer peripheral surface of the axle body 2m. Since the radial gap between the axle main body 2m and the vehicle-side assembly member 5 is locally narrowed by the sensor 7, the water once entering the inner-side open space S is hardly discharged. Therefore, when the drain hole 6 is provided, the effect appears more remarkably.

  Next, another embodiment of the present invention is shown in FIG. In this embodiment, the first inclined surface 10 for drainage is formed in a portion of the outer ring 4b that is located closer to the vehicle inner side than the drainage hole 6 so that the inner peripheral surface of the outer ring 4b expands toward the vehicle inner side. It is. By this first inclined surface 10, the water that has entered the inner side open space S can flow down to the vehicle inner side and be discharged. The first inclined surface 10 is preferably formed only in the vicinity of the drainage hole 6 rather than being formed so as to make one round of the inner peripheral surface of the outer ring 4b. If the outer ring 4b is formed so as to go around the inner circumferential surface, the thickness of the outer ring 4b may be reduced, so that the strength may decrease. In addition, water actually flows down only at the lower part of the outer ring 4b. It is better to form the first inclined surface 10 only in the vicinity of the drain hole 6.

  Further, in the portion of the outer ring 4b located between the seal member 4f and the drain hole 6, the inner peripheral surface of the outer ring 4b expands toward the inner opening 6d side of the drain hole 6, so that the second drain An inclined surface 11 is formed. Therefore, even if water enters just inside the seal portion 4f, the second inclined surface 11 allows the water to flow down to the inner opening 6d. Therefore, the inside of the seal part 4f can always be kept dry. The second inclined surface 11 is also preferably formed only in the vicinity of the drain hole 6 for the same reason as the first inclined surface 10.

Sectional drawing which shows one Embodiment of the hub unit which concerns on this invention. The perspective view of the outer ring | wheel 4b. The embodiment in which the first inclined surface 10 and the second inclined surface 11 are formed. The figure which shows the state at the time of comprising a drain hole only by the through-hole 6a.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hub unit 2 Axle 2m Axle main body 2t Axle tip part 3 Hub 3a Hub main body 3b Wheel mounting part 4 Bearing part 4a Inner ring 4b Outer ring 4c Rolling body 4f Seal part 4g Inlay part 4h Flange part 5 Vehicle side assembly member 6 Drain hole 6a Through hole 6b Axial groove 6c Radial groove 6d Inner opening 6e Outer opening 7 Sensor

Claims (8)

A hub main body having a wheel mounting portion that is attached to the outer peripheral surface of the axle so as to be integrally rotatable, and that protrudes radially outward from an end of the outer peripheral surface of the vehicle outer side;
A bearing portion attached to the outer peripheral surface of the hub main body, the inner ring rotating integrally with the axle and the hub main body, the outer ring disposed non-rotatingly on the radially outer side of the inner ring, the inner ring and the outer ring Between the inner ring and the outer ring at a vehicle inner side end portion in the axial direction of the annular space for the rolling element arrangement, and a rolling element that rotatably supports the inner ring with respect to the outer ring. A bearing portion having a seal portion that seals between the inner ring and the outer ring in a state that allows relative rotation between the
The outer ring is assembled to the vehicle by fitting from the inside to the opening of the vehicle side assembly member provided on the vehicle side at the end on the vehicle inner side,
A drain hole that opens to an inner peripheral surface of the end portion at a position closer to the vehicle inner side than the seal portion is provided at the end portion of the outer ring that is fitted to the vehicle-side assembly member. A hub unit, characterized in that the hub unit is formed so as to penetrate the portion in the radial direction.   The vehicle-side assembly member is formed in a cylindrical shape having both ends opened. In the vehicle assembly state, the outer ring is fitted into an opening on the vehicle outer side, and the inner peripheral surface of the vehicle-side assembly member The hub unit according to claim 1, wherein the vehicle-side assembly member is positioned so as to form an inner-side open space in which an end portion on the vehicle inner side is opened between the outer peripheral surface of the axle.   In the vehicle assembly state, the drain hole has an inner opening that opens on the inner space side of the outer ring, opens at a position overlapping the vehicle assembly member, and an outer opening that opens on the outer space side The hub unit according to claim 1 or 2, wherein the hub unit is opened at a position deviating toward the vehicle outer side in the axial direction with respect to the side assembly member. The outer ring is
An outer ring main body in contact with the rolling element;
A flange portion projecting radially outward from an outer peripheral surface of the outer ring main body, and in contact with a vehicle outer side end portion of the vehicle side assembly member in the vehicle assembly state;
An inlay portion that protrudes inward in the axial direction from the vehicle inner side main surface of the flange portion and fits into the vehicle side assembly member in the vehicle assembly state, and forms an end on the vehicle inner side;
The drain hole is
A through hole formed through the inlay portion in a radial direction in the vehicle assembled state;
An axial groove formed in the axial direction on the outer circumferential surface of the inlay portion and reaching the vehicle inner side main surface of the flange portion;
A radial groove formed in a radial direction on the vehicle inner side main surface of the flange portion, an end portion on the inner side in the radial direction communicating with the axial groove, and an end portion on the outer side in the radial direction open to an outer peripheral surface of the flange portion The hub unit according to any one of claims 1 to 3, comprising:   2. A first inclined surface for drainage is formed in a portion of the outer ring located closer to the vehicle inner side than the drainage hole so that the inner peripheral surface of the outer ring expands toward the vehicle inner side. The hub unit of any one of thru | or 4.   A second inclined surface for drainage is formed in a portion of the outer ring located between the seal portion and the drainage hole so that an inner peripheral surface thereof is expanded in diameter toward the drainage hole. The hub unit according to any one of claims 1 to 5.   7. A rotation detection sensor is provided on a vehicle inner side of the outer ring so as to partially close a radial gap between the vehicle side assembly member and the axle. The hub unit according to claim 1.   The outer peripheral surface of the axle is shaped to gradually increase in diameter toward the vehicle inner side, and the inner peripheral surface of the mounting member is shaped to gradually increase in diameter toward the vehicle inner side corresponding to the outer peripheral surface shape of the axle. The hub unit according to any one of claims 1 to 7, wherein:

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