JP2005344901A - Wheel supporting rolling bearing unit with encoder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide a structure capable of preventing leaking of grease existing in a space 10 provided with a rolling body 3, by preventing delay breaking of an inner race 12 and a calking part 15, in the structure for joining and fixing a hub body 11 and the inner race 12 by the calking part 15 formed in an inner end part of this hub body 11. <P>SOLUTION: The inner race 12 and the calking part 15 are cut off from an external space by a blocking-up plate part 26. This blocking-up plate part 26 is integrated with a slinger 19 for constituting a combination seal ring 20 for blocking up a shaft directional inner end part of the space 10. This constitution prevents sticking of foreign matter such as rainwater to the inner race 12 and the caulking part 15, and prevents the occurrence of corrosion becoming the cause of the delay breaking. Cost is reduced by minimizing the number of part items. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to an improvement in a rolling bearing unit with a wheel support with an encoder, which is used for rotatably supporting a vehicle wheel with respect to a suspension device and detecting the rotational speed of the wheel.

  A rolling bearing unit is used to rotatably support the wheels of the automobile with respect to the suspension system. Further, in order to control the anti-lock brake system (ABS) and the traction control system (TCS), it is necessary to detect the rotational speed of the wheel. As a wheel bearing rolling bearing unit with an encoder used for this purpose, for example, the one described in Patent Document 1 has been known. Further, in order to reduce the weight and cost of the wheel bearing rolling bearing unit, a structure in which the hub main body constituting the hub and the inner ring are fixed by caulking instead of the nut is also disclosed in Patent Document 1 above. Have been widely known in the past. First, the structure in which the hub body and the inner ring are coupled and fixed by caulking will be described with reference to FIG.

  This wheel-supporting rolling bearing unit is composed of an outer ring 1 and a hub 2 arranged concentrically with each other via a plurality of rolling elements 3 and 3 so that relative rotation can be freely performed. Out of these, the outer ring 1 has double-row outer ring raceways 4 and 4 on the inner peripheral surface and mounting portions 5 for coupling and fixing to the suspension device on the outer peripheral surface, and does not rotate during use. The hub 2 is the outer end of the outer peripheral surface (outside in the axial direction means outside in the width direction when assembled to the vehicle. On the contrary, the center side in the width direction is axially aligned when assembled to the vehicle. The same is applied throughout this specification and claims.) A flange 6 for supporting and fixing a wheel is provided, and double row inner ring raceways 7 and 7 are provided at an intermediate portion in the axial direction and an inner end portion in the axial direction. Respectively. Such a hub 2 rotates with a wheel supported and fixed to the flange 6 during use. The rolling elements 3 and 3 are divided into double rows between the inner ring raceways 7 and 7 and the outer ring raceways 4 and 4, and a plurality of rolling elements are provided in the cages 8 and 8 for each row. It is provided so as to be able to roll while being held. In the illustrated example, balls are used as the rolling elements 3 and 3, but in the case of a rolling bearing unit for a heavy vehicle, tapered rollers may be used.

  Further, seal members 9a and 9b are provided between the inner peripheral surface of both ends in the axial direction of the outer ring 1 and the outer peripheral surface of the axial intermediate portion and the axial inner end portion of the hub 2, respectively. Between the inner peripheral surface and the outer peripheral surface of the hub 2, both axial opening portions of the space 10 in which the rolling elements 3 and 3 are installed are closed. The hub 2 is formed by coupling and fixing a hub body 11 and an inner ring 12. Of these, the hub body 11 has a small-diameter step portion 13 formed on the inner end portion in the axial direction in addition to the flange 6 and the inner ring raceway 7 in the axial direction intermediate portion on the outer peripheral surface thereof. The inner ring 12 is fitted to the small-diameter step portion 13, and a cylindrical portion 14 provided at the inner end in the axial direction of the hub body 11 is radially deformed by a caulking portion 15 formed by plastic deformation. The inner end face in the axial direction is held down and coupled and fixed to the hub body 11.

  When the rolling bearing unit for supporting a wheel as described above is used, the outer ring 1 is coupled and fixed to the suspension device by the mounting portion 5, and the wheel is supported and fixed to the flange 6 of the hub 2. This wheel is supported rotatably. In addition, the encoder is supported by a part of the hub 2 and the detection portion of the sensor supported by the outer ring 1 or a part of the suspension device is opposed to the detection surface of the encoder, thereby rotating the hub 2. Speed can be detected.

  By the way, in the case where the hub main body 11 and the inner ring 12 are coupled and fixed by the caulking portion 15 to form the hub 2 as described above, it is possible to prevent the inner ring 12 and the caulking portion 15 from being corroded. This is important in terms of ensuring the reliability and durability of the bearing unit. That is, tensile stress tends to remain in the portion near the outer diameter of the caulking portion 15 and the portion near the outer diameter of the inner ring 12 located in the vicinity of the caulking portion 15 due to the force applied during processing. If the offset part rusts, delayed fracture may occur. In order to prevent the occurrence of such delayed fracture, it is possible to prevent foreign matter such as rainwater from adhering to rust on the caulking portion 15 where the tensile stress is likely to remain and the portion near the outer diameter of the inner ring 12. Thus, it is preferable to prevent the caulking portion 15 and the inner ring 12 from being corroded to cause delayed fracture.

  For this reason, a structure as shown in FIG. 4 as described in Patent Documents 1 and 2 is conventionally known. In the case of this conventional structure, the caulking portion 15 and the inner ring 12 are blocked from the external space by the cover 16 attached to the inner end opening of the outer ring 1, and foreign matter such as rainwater is placed on the caulking portion 15 and the inner ring 12. I try not to stick.

  However, in the case of the conventional structure shown in FIG. 4 described above, the space 10 in which the rolling elements 3 and 3 are installed and the space 17 in which encoders and sensors are to be installed are not blocked. Therefore, grease existing in the space 10 in which the rolling elements 3 and 3 are installed may enter (leak out) the space 17 in which the encoder and sensor are to be installed. If this grease enters the space 17, the grease existing in the space 10 in which the rolling elements 3 and 3 are installed may be insufficient, resulting in a problem that the rolling fatigue life of the wheel bearing rolling bearing unit is reduced. There is sex.

  Such an inconvenience is caused by the structure shown in FIG. 4 between the inner circumferential surface of the inner ring 12 in the axial direction and the outer circumferential surface of the inner ring 12 in the axial direction. It can be solved by attaching 9b. However, if such a structure is adopted, the number of parts constituting the wheel bearing rolling bearing unit with an encoder increases, which complicates parts production, parts management, and assembly work. This wheel bearing rolling bearing unit with an encoder is troublesome. This is not preferable because the cost increases.

Japanese Patent Laid-Open No. 11-183493 JP-A-10-95203

  The present invention has been made in view of the above circumstances. Specifically, with regard to a rolling bearing unit with a wheel support with an encoder, in which the hub main body and the inner ring constituting the hub are coupled and fixed by a caulking portion formed at the inner end portion of the hub main body, the inner ring and the caulking portion are delayed. The present invention has been invented to realize a structure capable of preventing breakage and preventing leakage of grease existing in a space where rolling elements are installed at low cost.

The wheel support rolling bearing unit with an encoder according to the present invention includes an outer ring, a hub, a plurality of rolling elements, and a pair of seal members, similarly to the conventionally known wheel support rolling bearing unit with an encoder. And an encoder.
Among these, the outer ring has a double row outer ring raceway on the inner peripheral surface, and does not rotate during use.
The hub has a double-row inner ring raceway on the outer peripheral surface, and rotates with the wheel when in use.
In addition, the hub is divided into a plurality of rows between the inner ring raceways and the outer ring raceways, and a plurality of hubs are provided so as to roll freely in each row.
The both seal members are provided between the inner peripheral surface of both ends in the axial direction of the outer ring and the outer peripheral surface of the hub, respectively, and between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub. Close both axial ends of the space where the moving body is installed.
The encoder is supported concentrically with the hub at a portion that rotates together with the hub, and alternately changes the characteristics of the surface to be detected in the circumferential direction.
The hub is formed by plastically deforming the axially inner end surface of the inner ring that is fitted around the axially inner end portion of the hub body, and the cylindrical portion provided at the axially inner end portion of the hub body radially outward. It is held down by the caulking part.

In particular, in the wheel bearing rolling bearing unit with an encoder according to the present invention, of the pair of seal members, a seal member provided between the inner peripheral surface of the inner end in the axial direction of the outer ring and the outer peripheral surface of the inner ring. Is a combination seal ring comprising a seal ring and a slinger.
Among these, the seal ring is fitted and fixed to the inner peripheral surface of the inner end portion in the axial direction of the outer ring, and has a seal lip made of an elastic material.
The slinger is externally fitted and fixed to the outer peripheral surface of the inner end of the inner ring in the axial direction. The slinger is integrally formed of a metal plate, and a cylindrical portion that is fitted and fixed to the inner end portion of the inner ring is fitted to a portion closer to the outer diameter of the slinger at a radially outer portion than the cylindrical portion. The cylindrical portion is provided with a ring portion that is bent radially outward from the axially inner end portion, and a blocking plate portion that closes the radially inner portion in the radially inner portion of the cylindrical portion. is there.
Then, in the state where the cylindrical portion is fitted and fixed to the inner end portion in the axial direction of the inner ring, the closing plate portion blocks the inner end portion in the axial direction of the inner ring and the caulking portion from the external space.
Furthermore, an encoder, in which the characteristics of the inner side surface in the axial direction are alternately changed in the circumferential direction, is attached and fixed to the inner side surface of the slinger concentrically with the rotation center of the hub.

According to the rolling bearing unit with a wheel support with an encoder of the present invention configured as described above, delayed destruction of the inner ring and the caulking portion can be prevented, and leakage of grease existing in the space where the rolling elements are installed can be prevented. The structure can be realized at low cost.
That is, since the inner ring and the caulking portion are blocked from the external space by the closing plate portion, it is possible to prevent foreign matters such as rainwater from adhering to the inner ring and the caulking portion. Then, corrosion of the inner ring and the caulking portion can be prevented, and the delayed fracture due to the corrosion can be prevented from occurring in the inner ring and the caulking portion.
Further, since the seal ring and slinger block the space between the inner peripheral surface of the inner end of the outer ring in the axial direction and the outer peripheral surface of the inner ring, the leakage of the grease is prevented, and the wheel bearing rolling bearing unit is rolled. A decrease in fatigue life can be prevented.
Moreover, since the slinger constituting the combination seal ring and the closing plate portion for blocking the inner ring and the caulking portion from the external space are integrally formed, parts production, parts management, and assembly work can be easily performed. The manufacturing cost of the wheel bearing rolling bearing unit with encoder can be reduced.

When carrying out the present invention, for example, as described in claim 2, the metal plate constituting the slinger is folded back 180 degrees at the outer peripheral edge of the annular portion so that the axial direction of the annular portion is increased. The thickness is about two sheets of the thickness of the metal plate. Then, an encoder is attached and fixed to the inner side surface in the axial direction of the annular portion.
With this configuration, it is possible to secure the rigidity of the annular portion to which the encoder is attached and fixed, to ensure the flatness of the encoder, and to improve the reliability of detecting the rotational speed of the hub using the encoder.
Alternatively, as described in claim 3, an encoder having an outer diameter smaller than the outer diameter of the inner end portion in the axial direction of the inner ring is fixedly attached to the inner side surface in the axial direction of the closing plate portion.
Since the entire outer peripheral edge portion of the closing plate portion is supported by the inner ring via the cylindrical portion, the rigidity is high even if the thickness dimension is small (even for one metal plate). Therefore, the flatness of the encoder can be ensured, and the reliability of detecting the rotational speed of the hub using this encoder can be improved.

  FIG. 1 shows a first embodiment of the present invention corresponding to claims 1 and 2. The feature of the present embodiment is that a space in which the rolling elements 3 are installed is prevented while foreign matter such as rain water is prevented from adhering to the caulking portion 15 and the inner ring 12 formed at the inner end of the hub body 11 in the axial direction. 10 is to realize a structure capable of preventing the grease existing in the space 10 from leaking out of the space 10 at a low cost. Since the structure and operation of other parts are the same as the structure shown in FIG. 3 including the entire structure of the wheel support rolling bearing unit, the illustration and explanation of the equivalent parts are omitted or simplified. Hereinafter, the characteristic part of the present embodiment will be mainly described.

  A combination seal ring 20 including a seal ring 18 and a slinger 19 is closed between the inner peripheral surface of the inner end portion in the axial direction of the outer ring 1 and the outer peripheral surface of the inner end portion in the axial direction of the inner ring 12. Of these, the seal ring 18 is formed in an annular shape as a whole by combining the metal core 21 and the elastic material 22. Of these, the elastic member 22 includes a plurality (three in the illustrated example) of seal lips 23a, 23b, and 23c. The structure of such a seal ring 18 is the same as that of a seal ring constituting a combination seal ring that has been widely known.

  The slinger 19 is integrally made of a metal plate such as a stainless steel plate or a galvanized steel plate, and is formed in a round bowl shape. Such a slinger 19 includes a cylindrical portion 24, an annular portion 25, and a closing plate portion 26. Of these, the cylindrical portion 24 is formed at a portion near the outer diameter of the slinger 19 and is fitted and fixed to the inner end portion of the inner ring 12 by an interference fit. The annular portion 25 is provided at a radially outer portion than the cylindrical portion 24 in a state of being bent radially outward from an axially inner end portion of the cylindrical portion 24. Further, the metal plate is folded back 180 degrees at the outer peripheral edge of the annular portion 25, so that the thickness of the annular portion 25 in the axial direction is equal to the thickness of the metal plate. . Further, the closing plate portion 26 is provided in a state continuously inward in the radial direction from the inner peripheral edge of the annular ring portion 25, and is present in a radially inner portion of the cylindrical portion 24. The entire inner part is closed.

  The slinger 19 as described above is fixed to the inner end portion of the hub 2 in the axial direction by fixing the cylindrical portion 24 to the inner end portion of the inner ring 12 in the axial direction. In this state, the closing plate portion 26 blocks the axially inner end portion of the inner ring 12 and the caulking portion 15 from the external space. Of the three seal lips 23 a, 23 b, 23 c provided on the seal ring 18, the seal lip 23 a closest to the outer diameter is on the outer surface in the axial direction of the annular portion 25, and the remaining two seal lips 23 b 23c are in sliding contact with the outer peripheral surface of the cylindrical portion 24 over the entire circumference.

  Further, a ring-shaped encoder 27 is attached and fixed to the inner side surface in the axial direction of the ring portion 25 of the slinger 19 over the entire circumference by baking, bonding or the like. The encoder 27 is made of a rubber magnet in which powder made of a magnetic material is mixed in rubber, and is magnetized in the axial direction (left-right direction in FIG. 1). And it is changed at equal intervals. Therefore, N poles and S poles are alternately arranged at equal intervals on the inner side surface in the axial direction of the encoder 27, which is the detected surface. A sensor (not shown) is supported by the outer ring 1 or the suspension device, and its detection portion is opposed to the detected surface of the encoder 27.

  According to the rolling bearing unit with a wheel support with an encoder of the present embodiment configured as described above, the closing plate portion 26 blocks the inner ring 12 and the caulking portion 15 from the external space. It is possible to prevent foreign matter such as rainwater from adhering to the portion 15. Therefore, it is possible to prevent the inner ring 12 and the caulking portion 15 from being corroded by these foreign substances, and it is possible to prevent the inner ring 12 and the caulking portion 15 from being delayed and broken. Further, the seal ring 18 and the cylindrical portion 24 and the circular ring portion 25 of the slinger 19 block the space between the inner peripheral surface of the axially inner end portion of the outer ring 1 and the outer peripheral surface of the inner ring 12. The grease existing in the space 10 can be prevented from leaking out of the space 10. For this reason, a sufficient amount of the grease present in the space 10 can be secured to prevent a reduction in the rolling fatigue life of the wheel bearing rolling bearing unit. In addition, since the closing plate portion 26 is formed integrally with the slinger 19, the manufacture of parts, the management of parts, and the assembly work become easy, and the manufacturing cost of the wheel bearing rolling bearing unit with encoder can be reduced. .

FIG. 2 shows a second embodiment of the present invention corresponding to claims 1 and 3. In this embodiment, the outer diameter D ₂₇ of the encoder 27a is smaller than the outer diameter D ₁₂ of the inner end portion in the axial direction of the inner ring 12 (D ₂₇ <D ₁₂ ). Such a small-diameter encoder 27a is attached and fixed to the inner side surface in the axial direction of the closing plate portion 26 by baking, bonding or the like.
Since the structure and operation of the other parts are the same as those of the first embodiment described above, a duplicate description is omitted.

The fragmentary sectional view which shows Example 1 of this invention. The fragmentary sectional view which shows the same Example 2. FIG. Sectional drawing which shows the 1st example of a conventional structure. Sectional drawing which shows the 2nd example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer ring 2 Hub 3 Rolling element 4 Outer ring raceway 5 Mounting part 6 Flange 7 Inner ring raceway 8 Cage 9a, 9b Seal member 10 Space 11 Hub body 12 Inner ring 13 Small diameter step part 14 Cylindrical part 15 Caulking part 16 Cover 17 Space 18 Seal ring 19 Slinger 20 Combination seal ring 21 Core metal 22 Elastic material 23a, 23b, 23c Seal lip 24 Cylindrical part 25 Circular ring part 26 Closing plate part 27, 27a Encoder

Claims (3)

  An outer ring having a double row outer ring raceway on the inner peripheral surface and not rotating even when used, a hub having a double row inner ring raceway on the outer peripheral surface and rotating together with the wheels during use, both the inner ring raceways and the both outer rings A plurality of rolling elements are provided for each row, and are provided between the raceway and the outer peripheral surface of the hub, and the outer peripheral surface of the hub. Provided between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub, a pair of seal members that closes both axial opening portions of the space where the rolling elements are installed, and a portion that rotates together with the hub. An encoder that is supported concentrically with the hub and has the characteristics of the surface to be detected alternately changed with respect to the circumferential direction. The cylindrical part provided on the inner end of the hub body in the axial direction is plastically deformed radially outward. In the rolling bearing unit with an encoder-supported wheel supported by the caulking portion, the inner peripheral surface of the inner end of the outer ring in the axial direction and the outer peripheral surface of the inner ring of the pair of seal members. The seal member provided between the inner ring and the outer ring has a seal ring having a sealing lip made of an elastic material, which is fitted and fixed to the inner circumferential surface of the outer ring in the axial direction, and the outer circumferential surface of the inner ring in the axial direction. It is a combination seal ring consisting of slingers that are externally fitted and fixed, and this slinger is integrally formed of a metal plate, and is fitted and fixed to the outer diameter portion of the inner ring by an interference fit at the axial inner end of the inner ring. A cylindrical portion that is radially outward from the cylindrical portion, and an annular portion that is bent radially outward from the axially inner end of the cylindrical portion. Blocking plate that closes the inner part in the direction The clogging plate portion cuts off the axially inner end portion and the caulking portion of the inner ring from the external space in a state where the cylindrical portion is fitted and fixed to the axially inner end portion of the inner ring. The encoder, in which the characteristics of the inner surface in the axial direction are alternately changed with respect to the circumferential direction, is attached and fixed concentrically with the center of rotation of the hub on the inner surface in the axial direction of the slinger. Rolling bearing unit for wheel support with encoder.   The metal plate constituting the slinger is folded back 180 degrees at the outer peripheral edge of the annular portion, thereby making the thickness in the axial direction of the annular portion equal to two of the thickness of the metal plate, The rolling bearing unit with a wheel support with an encoder according to claim 1, wherein an encoder is attached and fixed to an inner side surface in the axial direction of the annular portion.   The rolling bearing unit with a wheel support with an encoder according to claim 1, wherein an encoder having an outer diameter smaller than the outer diameter of the inner end portion in the axial direction of the inner ring is attached and fixed to the inner side surface in the axial direction of the closing plate portion.

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