JP3835474B2 - Rolling bearing unit with rotational speed detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adopt a structure coupling and fixing a sensor unit 45 to a cover 18a by a screw, to secure sufficient sealability in a screw coupling portion throughout a long period of time, and to improve assembly workability of the sensor unit 45. <P>SOLUTION: A body 34 of the cover 18a is made of synthetic resin, a through hole 44 and a second through hole 56 are provided in a bottom plate part 43 of the body 34, and a non-circular recessed part 57 is provided in a one end side opening circumferential rim part of the second through hole 56. In a head of a bolt 58 passed through the second through hole 56 and a third through hole 62 provided in the sensor unit 45, rotation prevention is carried out on the basis of engagement between an outer circumferential face of the head and an inner circumferential face of the recessed part 57. An O-ring 61 attached to a lock groove 60 provided in an inner face of the recessed part 57 is elastically abutted on the head of the bolt 58 throughout a whole circumference to seal a space between the bolt 58 and the bottom plate part 43. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The rolling bearing unit with a rotational speed detection device according to the present invention supports the wheel of an automobile so as to be rotatable with respect to the suspension device, and is used for 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. For this reason, the rolling bearing unit with a rotational speed detection device incorporating the rotational speed detection device in the rolling bearing unit can support the wheel rotatably with respect to the suspension device and detect the rotational speed of the wheel. In recent years, it has been widely performed.

  5-6 shows what was described in patent document 1 as an example of the conventional structure of the rolling bearing unit with a rotational speed detection apparatus used for such a purpose. This rolling bearing unit with a rotational speed detection device rotatably supports a hub 2 that is an inner ring equivalent member that rotates during use on the inner diameter side of an outer ring 1 that is an outer ring equivalent member that does not rotate even when used. The rotational speed of the encoder 3 fixed to a part of the hub 2 can be detected by the sensor 4 supported on the outer ring 1. That is, the double-row outer ring raceways 5 and 5 are provided on the inner peripheral surface of the outer ring 1. Further, an inner ring raceway is formed on the outer circumferential surface of the hub 2 and on the outer circumferential surface of the inner ring 7 constituting the inner ring equivalent member together with the hub 2 in a state of being coupled and fixed to the hub 2 by a nut 6 fitted on the hub 2. 8 and 8 are provided. A plurality of rolling elements 9 and 9 are provided between the inner ring raceways 8 and 8 and the outer ring raceways 5 and 5, respectively, so as to be freely rollable while being held by the cages 10 and 10, respectively. The hub 2 and the inner ring 7 are rotatably supported inside the outer ring 1.

Further, the hub 2 protrudes outward in the axial direction from the outer end portion of the outer ring 1 at the outer end portion in the axial direction of the hub 2 (referred to as an end portion on the outer side in the width direction in the assembled state in the automobile, the right end portion in FIG. 5) The flange 11 for attaching a wheel is provided in the part. Further, an attachment portion 12 for attaching the outer ring 1 to the suspension device at the inner end portion in the axial direction of the outer ring 1 (the end portion on the center side in the width direction in the assembled state in the automobile, which is the left end portion in FIG. 5). Is provided. Further, a gap between the axially outer end opening of the outer ring 1 and the outer peripheral surface of the intermediate portion of the hub 2 is closed by a seal ring 13. In the case of a rolling bearing unit for automobiles that is heavy, tapered rollers may be used as the plurality of rolling elements 9, 9, instead of balls as shown.

In order to incorporate the rotational speed detection device into the rolling bearing unit as described above, the encoder 3 is fitted and fixed to the outer peripheral surface of the inner ring 7 at the inner end portion in the axial direction and away from the inner ring raceway 8. . The encoder 3 is formed by subjecting a magnetic metal plate such as a mild steel plate to plastic working so as to be formed into an annular shape as a whole with an L-shaped cross section, and includes a cylindrical portion 15 and an annular portion 16. The portion 15 is fixed to the inner end portion in the axial direction of the inner ring 7 by fitting the portion 15 to the inner end portion in the axial direction of the inner ring 7 with an interference fit. Further, the annular portion 16 is formed with a large number of slit-like through holes 17 and 17 that are long in the diameter direction of the annular portion 16 in a radial manner at equal intervals in the circumferential direction. The magnetic characteristics of the annular ring portion 16 are changed alternately at equal intervals over the circumferential direction.

Further, a cover 18 is fitted and fixed to the axially inner end opening of the outer ring 1 so as to face the inner side surface in the axial direction of the circular ring part 16 of the encoder 3. The axial inner end opening is closed. The cover 18, which is formed by plastic processing of a metal plate, includes a fitting tube portion 19 that can be fitted and fixed to the inner end opening in the axial direction of the outer ring 1, and a closing plate portion 20 that closes the inner end opening in the axial direction . And have. A bottomed cylindrical bulged portion 21 is formed at the center of the closing plate portion 20 to prevent interference between the closing plate portion 20 and the nut 6. In addition, a through hole 22 is formed in a portion near the outer periphery of the closing plate portion 20 in a diametrically outer portion than the bulging portion 21, and the detection portion 24 of the sensor 4 is connected to the cover 18 through the through hole 22. Inserted inside. Further, a mounting flange 25 is fixed on the outer peripheral surface of the intermediate portion of the sensor 4, and the mounting flange 25 is fixed to the closing plate portion 20 of the cover 18 with set screws 26, 26. 4 is coupled and fixed to the cover 18 in a predetermined positional relationship. In this state where the sensor 4 is coupled and fixed to the cover 18, the front end surface of the detection unit 24 faces the inner side surface in the axial direction of the annular ring part 16 constituting the encoder 3 with a minute gap.

  When the rolling bearing unit with a rotational speed detecting device as described above is used, the mounting portion 12 fixed to the outer peripheral surface of the outer ring 1 is coupled and fixed to the suspension device with a bolt (not shown) and the outer periphery of the hub 2 is fixed. By fixing the wheel to the flange 11 fixed to the surface by the studs 27, 27 provided on the flange 11, the wheel is supported rotatably with respect to the suspension device. When the wheel rotates in this state, the vicinity of the end surface of the detection unit 24 of the sensor 4 is located between the through holes 17 and 17 formed in the ring portion 16 and the through holes 17 and 17 adjacent to each other in the circumferential direction. The existing pillars pass alternately. As a result, the density of the magnetic flux flowing through the sensor 4 changes, and the output of the sensor 4 changes. The frequency at which the output of the sensor 4 changes in this way is proportional to the rotational speed of the wheel. Therefore, if the output of the sensor 4 is sent to a controller (not shown), the ABS and TCS can be controlled appropriately.

Japanese Utility Model Publication No. 7-31539

The present invention relates to an improvement of a rolling bearing unit with a rotational speed detection device as described above.

The rolling bearing unit with a rotational speed detection device of the present invention has an outer ring raceway on the inner peripheral surface, and has an outer ring equivalent member that does not rotate even when used in a state of being coupled and fixed to a suspension device, and an inner ring raceway on the outer peripheral surface. An inner ring equivalent member that rotates when in use, a plurality of rolling elements provided between the outer ring raceway and the inner ring raceway, and a cylindrical wall portion that adheres to one end opening of the outer ring equivalent member; In the part having the bottom plate part and the part corresponding to the inner ring corresponding to the part of the inner ring equivalent member, the characteristic extending in the circumferential direction, which is supported concentrically with the inner ring equivalent member, is changed alternately and at equal intervals. An encoder, a through hole provided in a part of the cover that faces the encoder, and a support hole that is inserted into the cover so that the output is changed as the encoder rotates. Sensor.

In particular, in the rolling bearing unit with a rotational speed detection device of the present invention, at least the portion of the cover in which the through hole is formed is the bottom plate portion made of synthetic resin , The thickness in the axial direction is larger than the thickness of the other part, and a second through hole parallel to the through hole is formed in a part of the bottom plate part away from the through hole. The sensor is supported by a holder, and the holder includes an insertion portion that is inserted into the through hole in a state where the sensor is supported, and a mounting flange portion in which the base end portion is coupled to the end portion of the insertion portion. And a third through-hole formed in a portion aligned with the opening of the second through-hole in a state where the insertion portion is inserted into the through-hole at the distal end portion of the mounting flange portion, In the state where the holder inserts the insertion portion into the through hole, the second, The bolts and nuts inserted through the three holes are screwed together and tightened, and then they are joined and fixed to the cover. The bolt head or nut is screwed onto the cover. The detected portion of the encoder and the detecting portion of the sensor are opposed to each other in the axial direction of the outer ring equivalent member and the inner ring equivalent member, and are part of the axial inner side surface of the cover. The portion in which the through hole is opened and the portion in which the second through hole is opened are present on the same plane, and in the width direction in the assembled state to the automobile rather than the remaining portion on the inner side surface in the axial direction of the cover. It protrudes inward in the axial direction, which is the center side.

The rolling bearing unit with the rotational speed detection device of the present invention configured as described above supports the wheel rotatably with respect to the suspension system of the automobile, and the operation when detecting the rotational speed of the wheel is described above. This is the same as in the case of the conventional structure.
In particular, in the case of the rolling bearing unit with a rotational speed detection device according to the present invention, a structure in which the sensor is screwed to the cover is employed and the sensor for the cover is employed in order to reduce the trouble of repairing and replacing the sensor. Assembling workability can be improved. That is, when the sensor is screwed and fixed to the cover, first, the insertion portion of the holder that supports the sensor is inserted into a through-hole provided in the synthetic resin bottom plate portion of the cover. Then, in a state where the second through hole provided in the cover and the third through hole provided in the mounting flange portion constituting the holder are aligned, the one surface of the holder and the one surface of the cover are brought into contact with each other Let Next, the bolts and nuts inserted through the second and third through holes are screwed together and further tightened to bond and fix the sensor to the cover. Such a sensor coupling and fixing operation can be performed while the cover is attached to the outer ring equivalent member, and it is possible to save the trouble of removing the cover from the outer ring equivalent member when the sensor is assembled to the cover. As described above, according to the rolling bearing unit with a rotational speed detection device of the present invention, the labor of coupling and fixing the sensor to the cover can be reduced, and the workability of assembling the rolling bearing unit with the rotational speed detection device can be improved. And the improvement of this assembly workability | operativity can attain cost reduction of the rolling bearing unit with a rotational speed detection apparatus.

Furthermore , the weight of the entire rolling bearing unit with a rotational speed detection device can be reduced.

  1-3 show Example 1 of the present invention. The feature of the present invention lies in the structure of the portion where the sensor unit formed by supporting the sensor in the holder is coupled to the cover fixed to the end of the outer ring equivalent member constituting the rolling bearing unit. The structure and operation of the rolling bearing unit formed by rotatably supporting the inner ring equivalent member with respect to the outer ring equivalent member are basically the same as those of the conventional structure shown in FIGS. The same reference numerals are assigned to the components, and overlapping descriptions are omitted or simplified. The following description will focus on the features of the present invention and portions different from the conventional structure described above. In addition, the figure showing the Example of this invention has the inside-and-outside direction regarding the width direction of a vehicle reversed right and left with FIG. 5 showing the above-mentioned conventional structure. In this embodiment, unlike the above-described conventional structure, the nut 6 (see FIG. 5) is not used to fix the inner ring 7 to the hub 2a. Instead, the front end portion (right end portion in FIG. 1) of the hub 2a is a cylindrical portion 33, and the portion protruding from the inner end surface of the inner ring 7 at the front end portion of the cylindrical portion 33 is caulked outward in the diametrical direction. The inner ring 7 is fixedly coupled to the hub 2a. Thereby, not only can the cost be reduced by eliminating the need for the nut 6, but also the space can be effectively utilized as much as the volume of the nut 6 is omitted.

A cover 18a is attached to the opening in the axial inner end (right end in FIG. 1) of the outer ring 1, which is a member corresponding to the outer ring that does not rotate even when in use, and the axial inner end opening of the outer ring 1 is blocked. . The cover 18a includes a main body 34 having a bottomed cylindrical shape formed by injection molding of a synthetic resin and provided with a cylindrical wall portion 39 and a bottom plate portion 43, and a fitting cylinder 35 coupled to an opening of the main body 34. . The fitting cylinder 35 is formed by plastically deforming a corrosion-resistant metal plate such as a stainless steel plate, and has an L-shaped cross section as a whole. The fitting cylinder 35 and a base of the fitting cylinder 36 are provided. And an inward flange 37 bent inward in the diameter direction from the end edge (the right end edge in FIG. 1). Such a fitting cylinder 35 is joined to the opening of the main body 34 by molding the inward flange 37 on the opening end of the main body 34 at the time of injection molding of the main body 34. In the inward flange portion 37, a large number of through holes 38 are formed intermittently along the circumferential direction. The synthetic resin constituting the main body 34 flows into the inside of each of the through holes 38, 38 when the main body 34 is injection-molded to increase the bonding strength between the main body 34 and the fitting cylinder 36.

The cover 18a configured as described above is configured such that the fitting tube portion 36 of the fitting tube 35 is fitted onto the inner end portion in the axial direction of the outer ring 1 with an interference fit, whereby the inner end portion in the axial direction of the outer ring 1 is secured. The opening is blocked. In this state, the end face of the opening of the main body 34, that is, the front end face of the cylindrical wall 39 formed on the outer peripheral edge of the main body 34 is brought into contact with the inner end face in the axial direction of the outer ring 1. A locking groove is formed over the entire periphery of the distal end surface of the cylindrical wall portion 39, and an O-ring 40 is locked in the locking groove. In a state where the tip end surface of the cylindrical wall portion 39 and the axial inner end surface of the outer ring 1 are in contact with each other, the O-ring 40 is elastically formed between the axial inner end surface and the bottom surface of the locking groove. Compressed to seal the joint between the cover 18a and the outer ring 1, and prevent foreign matter such as muddy water from entering the cover 18a.

On the other hand, the axially inner end of the inner ring 7 constituting the inner ring member with the hub 2a (right end in FIG. 1) is fixedly fitted onto an encoder 3a. The encoder 3 a includes a support ring 41 and a permanent magnet 42. Of these, the support ring 41 is formed by bending a magnetic metal plate such as SPCC to form an overall ring shape with a substantially T-shaped cross section, and is fitted and fixed to the axial inner end of the inner ring 7 by an interference fit. Yes. The permanent magnet 42 is formed by, for example, attaching rubber mixed with ferrite powder to the inner side surface in the axial direction of the annular portion constituting the support ring 41 by baking or the like. The permanent magnet 42 is magnetized in the axial direction (left-right direction in FIG. 1), and the magnetization direction is changed alternately and at equal intervals in the circumferential direction. Therefore, the south pole and the north pole are alternately arranged at equal intervals on the inner side surface in the axial direction of the encoder 3a. The encoder 3a has a substantially T-shaped cross section as described above, because the inner diameter of the permanent magnet 42 attached to the annular portion constituting the support ring 41 of the encoder 3a is set to the shoulder portion of the inner ring 7. This is because the magnetized area of each magnetic pole (N pole or S pole) of the permanent magnet 42 is increased by making it smaller than the outer diameter. In this manner, by increasing the magnetization area of each magnetic pole of the permanent magnet 42, it is possible to improve the detection capability of the sensor having the encoder 3a as the detected portion.

In addition, a part of the inner side surface (the right side surface in FIG. 1) of the bottom plate portion 43 of the main body 34 constituting the cover 18a is shifted to the outer part in the diametrical direction (upper part in FIG. 1). Is provided with a protrusion 49 protruding inward in the axial direction. A recess 53 is formed in a portion corresponding to the protrusion 49 on the outer side in the axial direction of the bottom plate 43 (the left side in FIG. 1). In addition, a part of the protrusion 49 that faces the axial inner surface of the permanent magnet 42 that constitutes the encoder 3 a has a through-hole 44 that passes through the bottom plate 43, and the outer ring 1. It is formed in the axial direction. As is clear from FIG. 1, the thickness of the portion of the bottom plate 43 where the through hole 44 is formed in the axial direction of the through hole 44 is larger than the thickness of the other portion. Then, an insertion portion 46 provided near the tip (left end in FIG. 1, front end in FIG. 3) of the sensor unit 45 that supports the sensor in the holder is inserted into the through hole 44 without rattling. is doing. The detection part of a sensor exists in the front end surface part of this insertion part 46. FIG. This sensor unit 45 incorporates a magnetic detection element such as a Hall element, a magnetoresistive element (MR element), etc. that changes its characteristics in accordance with the flow direction of magnetic flux, and a waveform shaping circuit for adjusting the output waveform of this magnetic detection element. A sensor made of a magnetic material, such as a pole piece made of a magnetic material, for guiding the magnetic flux from the permanent magnet 42 (or flowing into the permanent magnet 42) to the magnetic detection element is wrapped in a synthetic resin holder. It is buried. Further, the end of a harness 47 for sending an output signal output as a waveform shaped from the IC to a controller (not shown) is directly connected to the sensor unit 45 (without using a connector or the like). Accordingly, the connector can be omitted, and the cost of the rolling bearing unit with the rotational speed detection device can be reduced accordingly.

  In addition, a part of the insertion portion 46 of the sensor unit 45, the tip half including the detection portion, has a prismatic shape as shown in FIG. Thereby, while preventing interference between the front half part and the fitting cylinder 35 and the O-ring 40, the detection part provided on the front end surface of the front half part is positioned as far as possible in the diametrical direction, The opposing encoder 3a can be increased in diameter. Therefore, the detection capability of the sensor can be improved by increasing the magnetization width of each magnetic pole (N pole or S pole) of the permanent magnet 42 attached to the encoder 3a.

A large-diameter portion 50 is formed near the base end of the insertion portion 46 (near the right end in FIG. 1, near the back end in FIG. 3). An O-ring 52, which is a kind of seal ring, is formed between the axially outer side surface of the large-diameter portion 50 and a locking groove 51 formed in a closed annular shape at the peripheral edge of the axially inner end opening of the through hole 44. Is pinched. In a state where the insertion portion 46 is inserted into the through hole 44, the O-ring 52 is elastically compressed between the outer peripheral surface of the insertion portion 46 and the locking groove 51, and the cover 18a and the sensor The space between the insertion portion 46 of the unit 45 is sealed. That is, the O-ring 52 prevents foreign matter such as muddy water from entering the cover 18 a and the outer ring 1 through the through hole 44. As a result, the durability of the rolling bearing unit itself is ensured, and foreign matter such as magnetic powder is prevented from adhering to the side surface of the permanent magnet 42 constituting the encoder 3a, and the accuracy of rotational speed detection is deteriorated. Can be prevented. As a seal ring for sealing the insertion portion 46 of the sensor unit 45 with respect to the cover 18a, other seal rings such as an X ring having an X-shaped cross section may be used instead of the O ring 52 as described above. If used, the force required to insert the insertion portion 46 of the sensor unit 45 into the through hole 44 can be reduced, and the mounting work of the sensor unit 45 can be facilitated.

Further, a portion near the base end of the sensor unit 45 (near the right end in FIG. 1 and near the back end in FIG. 3) is connected to the end of the insertion portion 46 constituting the sensor unit 45 (FIG. 1, 3 is provided with a mounting flange portion 48. The mounting flange portion 48 has an axially outer surface (the left end surface in FIG. 1 and the front end surface in FIG. 3) that can be brought into contact with a part of the end surface of the protrusion 49 provided on the cover 18a. The surfaces 48 and 49 that are in contact with each other are flat surfaces.

In the vicinity of the center of the bottom plate 43 of the cover 18a in the diametrical direction, a portion facing the concave portion 55 existing inside the cylindrical portion 33 provided in the hub 2a has a second parallel to the through hole 44. The through hole 56 is provided in a state of penetrating the bottom plate portion 43. In addition, a concave portion 57 whose inner peripheral surface shape is a non-cylindrical shape is formed at one end side (the left side in FIG. 1) opening peripheral portion of the second through hole 56. And the head part of the volt | bolt 58 whose outer peripheral surface is a hexagonal cylinder shape is press-fit in this recessed part 57. FIG. With the head portion of the bolt 58 thus press-fitted into the recess 57, the peripheral portion of the end surface of the head portion of the bolt 58 on the outer surface in the axial direction of the cover 18a faces the head portion in the diametrical direction. By caulking inward, the head of the bolt 58 is prevented from coming out of the recess 57.

  In such a state, the outer peripheral surface of the head of the bolt 58 is engaged with the inner peripheral surface of the concave portion 57 to prevent the bolt 58 from rotating with respect to the cover 18a. Further, the outer diameter of the threaded portion of the bolt 58 is slightly smaller than the inner diameter of the second through hole 56, and the space between the outer peripheral surface of the threaded portion and the inner peripheral surface of the second through hole 56 is set. A cylindrical gap is formed. A cylindrical sleeve 59, which will be described later, provided in a part of the sensor unit 45 can be inserted into the cylindrical gap. In addition, when tightening the nut 63 described later, a rotational force is applied to the bolt 58, and when the outer peripheral surface of the head of the bolt 58 is pressed against the inner peripheral surface of the concave portion 57, the concave portion 57 is formed. In order to prevent damage from being caused by the head of the bolt 58, the outer diameter of the head of the bolt 58 is made larger than the outer diameter of the head of a bolt that is generally used.

  Further, a closed annular locking groove 60 is formed in the periphery of the opening of the second through hole 56 on the bottom surface of the recess 57. An O-ring 61 that is a seal member is attached to the locking groove 60. In a state in which the head of the bolt 58 is press-fitted into the recess 57, the O-ring 61 is elastically contacted with a part of the inner surface of the head of the bolt 58 over the entire circumference. 58 and the bottom plate portion 43 are sealed. This prevents foreign matter such as muddy water from entering the cover 18a through the second through hole 56.

  A plurality of deep grooves 54 and 54 are formed in the axial direction on the inner surface of the protrusion 49 provided on the cover 18a. By forming such a plurality of grooves 54, 54, a thick protrusion 49 portion of the cover 18a is thinned, and distortion is prevented when the cover 18a is molded by synthetic resin injection molding. I am trying.

  On the other hand, a second end provided on the cover 18a in a state where the insertion portion 46 is inserted into the through hole 44 at the tip end portion (lower end portion in FIGS. 1 and 3) of the mounting flange portion 48 provided on the sensor unit 45. A third through hole 62 penetrating in the axial direction is formed in a portion aligned with the opening on the other end side (right side in FIG. 1) of the through hole 56. The inner half of the cylindrical sleeve 59 is inserted inside the third through hole 62. The sleeve 59 is molded inside the third through hole 62 when the mounting flange portion 48 is injection molded. Inside the sleeve 59, a threaded portion of a bolt 58 having its head engaged with the concave portion 57 can be inserted. The total length of the sleeve 59 is substantially equal to the total length of the third through hole 62 plus the total length of the second through hole 56, and the outer half of the sleeve 59 is connected to the mounting flange portion 48. It protrudes from the outer surface of the. When the bolts 58 and the nuts 63 are screwed and tightened through the second and third through holes 56 and 63, the heads of the bolts 58 and the nuts 63 are made of synthetic resin. A certain mounting flange portion 48 and the cover 18a are prevented from being crushed.

The operation of mounting the sensor unit 45 on the cover 18a in order to form the rolling bearing unit with the rotational speed detection device of the present invention by combining the members each configured as described above is as follows. Do. First, the insertion portion 46 of the sensor unit 45 is inserted into the through hole 44 provided in the cover 18a. Then, the second through hole 56 provided in the cover 18a and the third through hole 62 provided in the sensor unit 45 are aligned. Next, the sleeve 59 is inserted into the second through hole 56, and the axially outer surface of the mounting flange portion 48 is brought into contact with the inner surface of the protrusion 49 provided on the cover 18a. In this state, a minute gap having a desired thickness (for example, about 0.5 mm) is provided between the detection unit provided on the distal end surface of the insertion unit 46 and the inner surface of the permanent magnet 42 constituting the encoder 3a. The size of each part is regulated so that there exists.

  Then, the nut 63 is screwed into the threaded portion of the bolt 58 inserted through the sleeve 59 and protruded from the inner surface of the mounting flange portion 48, and further tightened, whereby the head of the bolt 58 and the nut are secured. The sensor unit 45 and the cover 18a are held between the sensor unit 45 and the sensor unit 45, and the sensor unit 45 is coupled and fixed to the cover 18a. Since the overall length of the sleeve 59 is restricted as described above, when the bolt 58 and the nut 63 are screwed and tightened via the mounting flange portion 48 and the cover 18a, the sleeve 59 is not attached to the sleeve 59. It is stretched between the head of the bolt 58 and the nut 63. Therefore, it is possible to prevent the sensor unit 45 and a part of the cover 18a from being sag due to a compressive load based on the tightening of the nut 63.

  According to the rolling bearing unit with a rotation speed detection device of the present embodiment configured as described above, the structure in which the sensor is screwed and fixed to the cover 18a is adopted, so that the labor for sensor repair and replacement can be reduced. . In addition, the workability of assembling the sensor with respect to the cover 18a can be improved. That is, the head of the bolt 58 is brought into contact with the cover 18a based on the engagement between the outer peripheral surface of the bolt 58 and the inner peripheral surface of the recess 57 having a non-cylindrical inner peripheral surface shape provided on the cover 18a. There is no rotation. Accordingly, when the sensor unit 45 is screwed and coupled to the cover 18a, the bolt 58 and the nut 63 inserted through the second through hole 56 and the third through hole 62 are screwed together and further tightened. In particular, it is sufficient to tighten only the nut 63 without suppressing the bolt 58. Such a coupling and fixing operation of the sensor unit 45 can be performed while the cover 18a is attached to the outer ring 1, and it is troublesome to remove the cover 18a from the outer ring 1 when the sensor unit 45 is assembled to the cover 18a. Can be omitted. As described above, according to the rolling bearing unit with a rotational speed detection device of the present embodiment, the labor of coupling and fixing the sensor to the cover can be reduced, and the assembly workability of the rolling bearing unit with the rotational speed detection device can be improved. By improving the assembly workability, the cost of the rolling bearing unit with a rotation speed detecting device can be reduced.

  Further, in the case of the rolling bearing unit with the rotational speed detection device of this embodiment, a part of the bottom plate portion 43 constituting the synthetic resin main body 34 is formed in a closed annular locking groove 60 formed on the inner surface of the recess 57. An O-ring 61 is attached. The O-ring 61 is elastically brought into contact with a part of the head of the bolt 58 over the entire circumference, thereby sealing between the bolt 58 and the bottom plate portion 43. Thus, the locking groove 60 can be formed by making at least the bottom plate portion 43 portion made of synthetic resin. Further, since the O-ring 61 is mounted in the locking groove 60, a large compressive force is applied to the O-ring 61 based on the tightening between the head of the bolt 58 and the bottom plate portion 43. It will not be done. That is, even if a compressive force is applied to the O-ring 61 based on the tightening, the O-ring 61 escapes into the locking groove 60, so that the durability of the O-ring 61 is impaired by the O-ring 61. A large compressive force is not added. Therefore, the durability of the O-ring 61 can be improved, and a sufficient sealing performance at the screwed joint portion can be ensured over a long period of time. Further, by making the main body 34 of the cover 18a made of synthetic resin, it is possible to reduce the weight of the entire rolling bearing unit with a rotational speed detection device.

  FIG. 4 shows a second embodiment of the present invention. In the case of the present embodiment, unlike the case of the first embodiment described above, a hexagonal nut 63 is press-fitted into the non-circular recess 57 provided in the cover 18b instead of the head of the bolt 58a. Yes. Then, the nut 63 is prevented from coming out of the recess 57 by heat caulking the peripheral portion of the end surface of the nut 63 with the outer surface of the cover 18b. Then, the bolts 58a inserted through the third through holes 62a provided in the mounting flange portion 48 constituting the sensor unit 45 and the second through holes 56 provided in the cover 18b and the nut 63 are screwed together, Further, the sensor unit 45 is coupled and fixed to the cover 18b by tightening only the bolt 58a.

  In the case of this embodiment, unlike the case of the first embodiment described above, the cylindrical sleeve 59 (see FIGS. 1 and 3) is not inserted into the third through hole 62a. Instead, the inner diameter of the third through hole 62 a is made larger than the inner diameter of the second through hole 56, and the bolt 58 a is inserted into the third through hole 62 a and the second through hole 56. Yes. For this reason, the bolt 58a has a stepped shape including a large-diameter portion 64 near the proximal end and a small-diameter portion 65 near the distal end, and a screw portion is formed in the small-diameter portion 65. The outer diameter of the head of the bolt 58a and the outer diameter of the nut 63 screwed with the bolt 58a are sufficiently larger than the outer diameter of the small diameter portion 65 of the bolt 58a. This prevents the sensor unit 45 or a part of the cover 18b from being sag due to a compressive load based on the tightening of the bolt 58a and the nut 63.

  Further, a closed annular locking groove is formed on the peripheral edge of the opening on the other end side (right side in FIG. 4) of the second through hole 56. In addition, an O-ring 66 that is a seal ring is attached to the locking groove. In a state where the bolt 58a and the nut 63 are screwed together and further tightened, the O-ring 66 is elastically brought into contact with a part of the bolt 58a over the entire circumference so that the bolt 58a and the bottom plate portion are in contact with each other. 43 is sealed. Therefore, a compressive load based on the tightening of the bolt 58a does not apply a large compressive force to the O-ring 66 so as to impair durability. For this reason, the durability of the O-ring 66 can be improved, and a sufficient sealing performance at the screw joint can be secured over a long period of time.

A ring-shaped elastic washer 67 made of an elastic material such as rubber or Hytrel is baked on a part of the head of the bolt 58a facing the sensor unit 45 and attached or fixed by bonding or the like. Yes. The elastic washer 67 is elastically clamped between the side surface of the head of the bolt 58a and the side surface of the sensor unit 45 in a state where the bolt 58a and the nut 63 are screwed together. Yes. In this way, by sandwiching the elastic washer 67 made of an elastic material between the bolt 58a and the sensor unit 45 made of synthetic resin, the bolt 58a, the cover 18b, and the sensor unit 45, which are made of different materials as the temperature changes, are sandwiched. Even if there is a difference in thermal expansion between the bolt 58a, the bolt 58a is loosened, or the bolt 58a and the nut 63 cause excessive compression of the sensor unit 45 and part of the cover 18b to cause sag. Can be prevented.
Since other configurations and operations are the same as those in the first embodiment described above, the same parts are denoted by the same reference numerals, and redundant description is omitted.

  In each of the embodiments described above, the shape of the inner peripheral surface of the non-circular recess provided in the cover is not necessarily hexagonal. In short, it is preferable to prevent rotation of the bolt or nut based on the engagement between the inner peripheral surface of the recess and the head of the bolt or the outer peripheral surface of the nut. For example, the shape of the concave portion can be a circular cylinder or a square cylinder in which only the bolt head or a part of the side surface of the nut is engaged.

  Further, the structure of the rotational speed detection device itself composed of the sensor and the encoder is not limited to the one using the illustrated magnetic sensor, and an eddy current type or photoelectric type sensor can also be used. Even when a magnetic sensor is used, a permanent magnet is not provided in the encoder which is a detected part, and a plurality of through holes are provided at equal intervals in the circumferential direction in the annular part constituting the encoder. An annular part can also be formed in a gear shape.

Sectional drawing which shows Example 1 of this invention. The figure which took out only the cover and was seen from the left of FIG. The perspective view which takes out and shows only the edge part and sensor unit of a harness. Sectional drawing which shows Example 2 of this invention. FIG. 7 is a cross-sectional view taken along line A-O-B in FIG. 6, showing an example of a conventional structure. The figure seen from the left of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer ring 2, 2a Hub 3, 3a Encoder 4 Sensor 5 Outer ring raceway 6 Nut 7 Inner ring 8 Inner ring raceway 9 Rolling element 10 Cage 11 Flange 12 Mounting part 13 Seal ring 15 Cylindrical part 16 Circular ring part 17 Through hole 18, 18a, 18b cover 19 fitting cylinder part 20 closing plate part 21 bulging part 22 through hole 24 detection part 25 mounting flange 26 set screw 27 stud 28 bolt 29 nut 30 space 31 through hole 32 through hole 33 cylindrical part 34 main body 35 fitting cylinder 36 fitting cylinder part 37 inward flange part 38 through-hole 39 cylindrical wall part 40 O-ring 41 support ring 42 permanent magnet 43 bottom plate part 44 through-hole 45 sensor unit 46 insertion part 47 harness 48 attachment flange part 49 protrusion part 50 large diameter part 51 Locking groove 52 O-ring 53 Recessed portion 54 Groove 55 Recessed portion 56 Second through hole 57 Recessed portion 5 , 58a bolt 59 the sleeve 60 engaging groove 61 O-ring 62,62a third hole 63 nut 64 of the large diameter portion 65 small diameter portion 66 O-ring 67 elastomeric washer

Claims (2)

An outer ring equivalent member that has an outer ring track on the inner peripheral surface and does not rotate when used in a state of being coupled and fixed to a suspension device, an inner ring equivalent member that has an inner ring track on the outer peripheral surface and rotates during use, and the outer ring track A plurality of rolling elements provided between the inner ring raceway and the inner ring raceway, a cover having a cylindrical wall portion and a bottom plate portion, which is attached to one end opening of the outer ring equivalent member, and the inner ring equivalent member. An encoder that is supported concentrically with the inner ring equivalent member in a part facing the cover in part, and whose circumferential characteristics are changed alternately and at equal intervals, and a part of the cover that faces the encoder A rolling bearing with a rotational speed detection device comprising: a through hole provided in a portion to be mounted; and a sensor that is supported and fixed to a part of the cover in a state in which the through hole is inserted, and that changes an output as the encoder rotates. In the unit above cover Portion formed at least the through hole of the out is the above bottom plate portion made of a synthetic resin, the axial thickness of the hole of this part is larger than the thickness of the other portions, the bottom plate portion A second through-hole parallel to the through-hole is formed in a part of the part away from the through-hole, and the sensor is supported by a holder, and the holder supports the sensor. The insertion portion is inserted into the through hole at the insertion portion to be inserted into the through hole in a state, a mounting flange portion whose base end portion is coupled to the end portion of the insertion portion, and a distal end portion of the mounting flange portion. A third through-hole formed in a portion aligned with the opening of the second through-hole in a state, and the holder has the insertion portion inserted into the through-hole, and the second and second The bolts and nuts inserted through the three holes are screwed and tightened to The bolt head or nut is attached to the cover before the bolt and nut are screwed together, and the detected portion of the encoder and the detection portion of the sensor are connected to each other. The outer ring equivalent member and the inner ring equivalent member are opposed to each other in the axial direction, and the part where the through hole is opened and the part where the second hole is opened are the same on a part of the inner side surface in the axial direction of the cover. With a rotational speed detection device, which exists on a plane and protrudes inward in the axial direction, which is the center side in the width direction in the assembled state to the automobile, from the remainder of the axially inner side surface of the cover. Rolling bearing unit. The rotational speed detection according to claim 1, wherein a groove that is recessed in the axial direction of the outer ring equivalent member and the inner ring equivalent member is formed in a part of the cover where the through hole and the second through hole are formed. Rolling bearing unit with device.

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