JP2006337381A - Rolling bearing unit having rotational speed sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate a sealing member, to reduce costs, and to improve the assembly working efficiency of a sensor unit 42, when fastening the sensor unit 42 to a cover 18a by screws. <P>SOLUTION: The cover 18a supported by an outer ring 1 that does not rotate also in use is provided with a stepped recess 49 without any penetration. A nut 52 is welded and fixed into the stepped recess 49, a bolt 53 is screwed to the nut 52 via a passage hole 59 provided at one portion of the sensor unit 42 to be composed by including a detection section for clamping, thus connecting the sensor unit 42 to the cover 18a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The rolling bearing unit with a rotational speed detecting 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.

9 to 10 show one described in Patent Document 1 as an example of a conventional structure of a rolling bearing unit with a rotational speed detection device used for such a purpose. This rolling bearing unit with a rotational speed detection device rotatably supports a hub 2 that rotates during use on the inner diameter side of an outer ring 1 that does not rotate during use. 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, double row outer ring raceways 5 and 5 are provided on the inner peripheral surface of the outer ring 1. Inner ring raceways 8 and 8 are provided on the outer peripheral surface of the hub 2 and the outer peripheral surface of the inner ring 7 coupled and fixed to the hub 2 by a nut 6 fitted on the hub 2. 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, at the outer end of the hub 2 (the end that is on the outer side in the width direction when assembled to the automobile, the right end in FIG. 9), the portion that protrudes axially outward from the outer end of the outer ring 1 Has a flange 11 for attaching a wheel. Further, an attachment portion 12 for attaching the outer ring 1 to a suspension device is provided at the inner end portion of the outer ring 1 (the end portion on the center side in the width direction in the assembled state to the automobile, which is the left end portion in FIG. 9). Provided. Further, a gap between the outer end opening of the outer ring 1 and the outer peripheral surface of the intermediate part 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 end portion of the inner ring 7 which is 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 of the inner ring 7 by fitting the portion 15 to the inner end portion of the inner ring 7 with an interference fit. Further, the annular portion 16 is formed with a plurality 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 portion 16 are changed alternately and at equal intervals over the circumferential direction.

  Further, a cover 18 is fitted and fixed to the inner end opening of the outer ring 1 so as to face the inner surface of the annular portion 16 of the encoder 3, and the inner end opening of the outer ring 1 is covered by the cover 18. Is blocking. The cover 18 formed by plastic processing of a metal plate has a fitting cylinder portion 19 that can be fitted and fixed to the inner end opening of the outer ring 1 and a closing plate portion 20 that closes the inner end opening. 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 of the annular portion 16 constituting the encoder 3 via 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.

  In the case of the conventional structure shown in FIGS. 9 to 10, the sensor 4 is coupled and fixed to the cover 18 with set screws 26 and 26 in order to reduce the trouble of repairing and replacing the sensor. That is, the bolts 28 and 28 are inserted into the mounting flange 25 fixed to the sensor 4 and the through holes 54 and 56 respectively provided in the cover 18, and the bolts 28 and 28 and the nuts 29 and 29 are screwed together. Further, the sensor 4 is coupled and fixed to the cover 18 by further tightening. When removing the sensor 4 from the cover 18 for repair or the like, the nuts 29 and 29 are loosened and the sensor 4 is removed from the cover 18.

In the case of the conventional structure shown in FIGS. 9 to 10 described above, the encoder 3 is formed by bending a magnetic metal plate, and the through holes 17 and 17 are formed in the annular portion 16, whereby the magnetic characteristics of the annular portion 16 are obtained. Are changed alternately and at equal intervals over the circumferential direction. On the other hand, a structure using a permanent magnet with alternating magnetic poles in the circumferential direction as an encoder has been conventionally known. However, when a permanent magnet is used as the encoder, it is required to increase the magnetization area of each magnetic pole in order to improve the detection capability of the sensor.

Japanese Utility Model Publication No. 7-31539

The rolling bearing unit with a rotational speed detection device of the present invention has been invented to realize a structure in which a permanent magnet is used as an encoder and a structure in which a magnetized area can be increased in view of the above-described circumstances.

Speed sensing rolling bearing unit of the present invention has outer ring raceway on an inner peripheral surface having an outer ring does not rotate even during use, the inner ring raceway on an outer peripheral surface opposite to the inner circumferential surface, rotates during use a hub, a plurality of rolling elements disposed rollably between the outer ring raceway and inner ring raceway, a part of the hub which is fixed to the hub concentric to over characteristics in the circumferential direction And encoders that are changed alternately and at equal intervals .

The encoder includes a support ring and a permanent magnet. Of these, the support ring is an annular shape as a whole, a circular ring part and a cylinder which is folded back 180 degrees on the outer peripheral edge side of the circular ring part, and the distal end side thereof is bent axially outward with respect to the circular ring part. It consists of parts. Of these, the cylindrical portion is fitted and fixed to the inner end of the hub by an interference fit, and the permanent magnet is attached to the inner surface of the annular portion. The permanent magnet is magnetized in the axial direction, and the magnetization direction is changed alternately and at equal intervals over the circumferential direction. The inner diameter of the permanent magnet attached to the inner surface of the ring portion is fitted between the cylindrical portion and the inner end portion of the hub while the cylindrical portion is fitted and fixed to the inner end portion of the hub. The outer diameter of the permanent magnet is set to be larger than the diameter of the fitting portion between the cylindrical portion and the inner end portion of the hub.

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 of the present invention, the magnetization area of each magnetic pole of the permanent magnet can be increased, and the detection capability of the sensor using the encoder as the detected portion can be improved.

[First example of reference example of the present invention ]
1-3 have shown the 1st example of the reference example regarding this invention . The feature of this reference example 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 a part of the outer ring constituting the rolling bearing unit. Since the structure and operation of the rolling bearing unit formed by rotatably supporting the hub with respect to the outer ring are basically the same as those of the conventional structure shown in FIGS. The description will be omitted or simplified, and the following description will focus on the features of the present reference example and portions different from the conventional structure described above. In addition, the reference example regarding this invention and the figure showing embodiment of this invention are right-and-left reverse about the width direction of a vehicle with respect to FIG. 9 showing the above-mentioned conventional structure. In the case of this reference example , unlike the conventional structure described above, the nut 6 (see FIG. 9) 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 31, and the portion protruding from the inner end surface of the inner ring 7 at the front end portion of the cylindrical portion 31 is caulked outward in the diametrical direction. The inner ring 7 is fixedly coupled to the hub 2a. By adopting such a structure, 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 nut 6 is omitted.

A cover 18a is attached to the inner end (right end in FIG. 1) opening of the outer ring 1 that does not rotate even when in use, and the inner end opening of the outer ring 1 is closed. The cover 18a is formed by plastically deforming a corrosion-resistant metal plate such as a stainless steel plate, and has a bottomed cylindrical main portion 32 and a state protruding outward in the diameter direction from the opening peripheral edge of the main portion 32. And a flange portion 33 having an L-shaped cross section. The flange portion 33 includes an abutting portion 34 having a shape that can be abutted against the inner end opening of the outer ring 1, and a fitting portion 35 having a shape that can be externally fitted to the opening of the outer ring 1. .

  The cover 18a configured as described above closes the inner end opening of the outer ring 1 by fixing the fitting portion 35 to the inner end portion of the outer ring 1 with an interference fit. In this state, the end face of the opening of the flange 33, that is, the outer face of the abutting portion 34 of the flange 33 is brought into contact with the inner end face of the outer ring 1.

On the other hand, the encoder 3a is fitted and fixed to the inner end portion (the right end portion in FIG. 1) of the inner ring 7 constituting the hub 2a . The encoder 3 a includes a support ring 36 and a permanent magnet 37. Of these, the support ring 36 is formed by bending a magnetic metal plate such as SPCC so as to have a substantially T-shaped cross section, and is formed into an annular shape as a whole, and is fitted and fixed to the inner end of the inner ring 7 by an interference fit. The permanent magnet 37 is formed by, for example, attaching rubber mixed with ferrite powder to the inner side surface of the annular portion constituting the support ring 36 by baking or the like. The permanent magnet 37 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, S poles and N poles are alternately arranged at equal intervals on the inner side surface of the encoder 3a in the circumferential direction. The encoder 3a has a substantially T-shaped cross section as described above. The reason why the inner diameter of the permanent magnet 37 attached to the annular portion constituting the support ring 36 of the encoder 3a is set to the shoulder portion of the inner ring 7 is as follows. This is because it is smaller than the outer diameter and the magnetized area of each magnetic pole (N pole or S pole) of the permanent magnet 37 is increased. Further, by increasing the magnetization area of each magnetic pole of the permanent magnet 37 in this way, it is possible to improve the detection capability of a sensor using the encoder 3a as a detected portion.

  Further, the outer surface of the bottom plate portion 38 constituting the central portion of the main portion 32 constituting the cover 18a (on the side opposite to the space 30 in which the rolling elements 9, 9 are to be closed by the cover 18a, A protruding portion 39 that protrudes in the axial direction is provided in a part of the portion (right side surface of 2) that is offset outward in the diameter direction (upward in FIG. 1). In addition, a part of the outer peripheral wall portion of the protrusion 39 protrudes outward in the diameter direction from the outer peripheral surface of the bottom plate portion 38 and is continuous with the outer peripheral surface of the fitting portion 35 constituting the flange portion 33. The bulging portion 58 is used. Accordingly, the abutting portion 34 of the flange portion 33 is discontinuous at this portion. In addition, an insertion hole 40 penetrating in the axial direction is provided in a portion facing the inner side surface of the permanent magnet 37 constituting the encoder 3a in a portion of the bottom portion 38 of the projecting portion 39 that is close to the diameter direction. . The insertion hole 40 is formed by burring, and a short cylindrical portion 41 formed along with the burring is projected to the side facing the encoder 3a. For this reason, the burring process for providing the insertion hole 40 is performed by abutting a die (not shown) on the outer surface of the projection 39 (the left side surface in FIG. 1) around the portion where the insertion hole 40 is to be provided. . By forming the short cylindrical portion 41 in this way, an operation of inserting an insertion portion 43 of the sensor unit 42 described later into the short cylindrical portion 41 and temporarily fixing the sensor unit 42 to the cover 18a. Can be done easily.

  And the insertion part 43 provided in the part near the front-end | tip (left end of FIG. 1, 3) of the said sensor unit 42 which supports a sensor in a holder is inserted in the said insertion hole 40 without shakiness. . The detection part of the sensor is present at the distal end surface part of the insertion part 43. This sensor unit 42 incorporates a magnetic detecting 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 detecting 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 37 (or flowing into the permanent magnet 37) to the magnetic detection element is wrapped in a synthetic resin holder. It is buried. Further, the end of the harness 44 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 42 (without 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.

  A locking groove 46 is formed on the outer peripheral surface of the intermediate portion of the insertion portion 43, and an O-ring 47 is locked in the locking groove 46. In a state where the insertion portion 43 is inserted inside the insertion hole 40 and the short cylindrical portion 41, the O-ring 47 is elastic between the inner peripheral surface of the short cylindrical portion 41 and the bottom surface of the locking groove 46. And the gap between the outer peripheral surface of the insertion portion 43 and the inner peripheral surface of the insertion hole 40 is sealed. That is, the O-ring 47 prevents foreign matters such as muddy water from entering the cover 18 a and the outer ring 1 through the insertion hole 40. And while ensuring the durability of a rolling bearing unit itself, it prevents that foreign materials, such as magnetic powder, adhere to the side surface of the permanent magnet 37 which comprises the said encoder 3a, and prevents that the precision of a rotational speed detection deteriorates. To do. As a seal ring for sealing the insertion portion 43 of the sensor unit 42 with respect to the cover 18a, another seal ring such as an X ring having an X-shaped cross section may be used instead of the O ring 47 as described above. If used, the force required to insert the insertion portion 43 of the sensor unit 42 into the insertion hole 40 can be reduced, and the mounting operation of the sensor unit 42 can be facilitated.

  Further, a mounting flange portion 45 is provided near the base end of the sensor unit 42 (near the right end in FIGS. 1 and 3), and the base end portion is coupled to the end portion of the insertion portion 43 constituting the sensor unit 42. ing. The mounting flange portion 45 has a shape in which the outer surface can be in contact with the end surface of the protrusion 39 provided on the cover 18a, and the surfaces of the both portions 45 and 39 that are in contact with each other are smooth surfaces.

Further, in the vicinity of the center in the diameter direction of the end surface of the protrusion 39 provided on the cover 18a, the portion facing the concave portion 48 existing inside the cylindrical portion 31 provided on the hub 2a does not penetrate in the axial direction. A bottomed stepped recess 49 is provided. The stepped recess 49 includes a large-diameter portion 50 on the opening side and a small-diameter portion 51 on the back side, and a nut 52 is fixed in the large-diameter portion 50 by welding or bonding. For example, when fixing by welding, a pair of electrodes for welding are brought into contact with the nut 52 and the cover 18a in a state where the nut 52 is fitted in the large diameter portion 50. Thereby, the contact part of the outer surface of the said nut 52 and the inner surface of the said large diameter part 50 is welded. In this state, the nut 52 does not rotate in the stepped recess 49 or shift in the axial direction. The large-diameter portion 50 has a depth at which the nut 52 does not protrude from the end face of the protrusion 39 in a state where the nut 52 is fixed by welding or adhesion. The small-diameter portion 51 has such a size that a tip of a threaded portion of a bolt 53 described later, which is screwed with a nut 52 welded and fixed in the large-diameter portion 50, can enter and exit.

  On the other hand, the stepped portion provided in the cover 18a with the insertion portion 43 inserted into the insertion hole 40 at the tip end portion (the lower end portion in FIGS. 1 and 3) of the mounting flange portion 45 provided in the sensor unit 42. A through hole 59 penetrating in the axial direction is provided in a portion facing the recess 49. A cylindrical metal core 55 is inserted inside the through hole 59. The metal core 55 is molded inside the through hole 59 when the mounting flange 45 is injection molded. Further, a threaded portion of a bolt 53 that can be screwed into a nut 52 fixed in the stepped concave portion 49 by welding or adhesion can be inserted into the cored bar 55. Further, the total length of the core metal 55 is substantially equal to the thickness of the mounting flange portion 45, and when the bolt 53 and the nut 52 are screwed and tightened through the mounting flange portion 45, the bolt 53 The head and the nut 52 prevent the mounting flange 45 made of synthetic resin from being crushed.

The operation of mounting the sensor unit 42 on the cover 18a in order to form the rolling bearing unit with the rotational speed detection device of the present reference example by combining the members each configured as described above is as follows. To do. First, the insertion portion 43 of the sensor unit 42 is inserted into the insertion hole 40 and the short cylindrical portion 41 provided in the cover 18a, and the through hole 59 provided in the sensor unit 42 and the step provided in the cover 18a. The outer surface of the mounting flange 45 is brought into contact with one surface of the protrusion 39 in a state where the nut 52 fixed in the recess 49 is aligned. 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 43 and the inner surface of the permanent magnet 37 constituting the encoder 3a. The size of each part is regulated so that there exists.

  Next, the threaded portion of the bolt 53 is inserted inside the cored bar 55 inserted into the through hole 59 of the mounting flange portion 45. Then, the screw portion is screwed into a nut 52 fixed by welding or adhesion in the stepped recess 49 and tightened. Accordingly, the sensor unit 42 is sandwiched between the head of the bolt 53 and the nut 52, and the sensor unit 42 is coupled and fixed to the cover 18a. As described above, when the total length of the core metal 55 is made substantially equal to the thickness of the mounting flange portion 45 and the bolt 53 and the nut 52 are screwed and tightened through the mounting flange portion 45, The metal core 55 is stretched between the head of the bolt 53 and the nut 52. Therefore, the mounting flange portion 45 does not sag due to a compressive load based on the tightening of the bolt 53.

As described above, according to the rolling bearing unit with the rotational speed detection device of the present reference example , the structure in which the sensor is screwed and fixed to the cover 18a is employed, so that the labor of repairing and replacing the sensor can be reduced. In addition, it is possible to ensure the sealing performance at the screwed joint portion at a low cost and improve the workability of assembling the sensor to the cover 18a. That is, in order to screw this sensor to the cover 18a by screwing, the projection 39 provided on the cover 18a passes through both sides of the cover as in the conventional structure described above except for the insertion hole 40. There are no holes. Therefore, foreign matter such as muddy water does not enter from the outside into the space 30 where the rolling elements 9 and 9 exist through the screwed joint portion. As a result, it is not necessary to provide a seal member at the portion where the sensor is screwed to the cover 18a in order to ensure the sealing performance between the sensor and the cover 18a, and the rolling bearing unit with a rotational speed detector is provided. The overall cost can be reduced.

  As described above, the outer peripheral surface portion of the protrusion 39 and the outer peripheral surface of the flange portion 33 constituting the cover 18a are continuously connected by the bulging portion 58. This is for the purpose of positioning the insertion hole 40 penetrating in the outermost diametrical direction as much as possible. With such a configuration, the diameter of the permanent magnet 37 attached to the annular portion of the encoder 3a is increased, the magnetization width of each magnetic pole (N pole or S pole) of the permanent magnet 37 is increased, and the sensor The detection ability can be improved.

[Second Example of Reference Example of the Present Invention ]
Next, FIGS. 4 to 5 show a second example of the reference example related to the present invention . In the case of this reference example , the cover 18b includes a fitting portion 35a that can be fitted to the inner end portion of the outer ring 1 and a bottom plate portion 38a continuous from the fitting portion 35a. And in the state which protrudes in the axial direction the short cylindrical part 41a in the part near the outer periphery, the protrusion 39a in the part near the center on the inner side (the right side in FIG. 4, the front side in FIG. 5) of the bottom plate part 38a. Provided. Further, the inner edge of the outer ring 1 can be abutted against the outer peripheral portion of the outer surface of the bottom plate portion 38a. The short cylindrical portion 41 a has an insertion hole 40 on the inner side, and an insertion portion 43 constituting the sensor unit 42 can be freely inserted into the insertion hole 40.

In particular, in the case of this reference example , unlike the case of the first example described above, the short cylindrical portion 41a is formed toward the opposite side of the encoder 3a with respect to the bottom plate portion 38a. The short cylindrical portion 41a and the protruding portion 39a have the same height in the axial direction (the amount of protrusion from the inner surface of the bottom plate portion 38a), and the leading edge of the short cylindrical portion 41a and the protruding portion 39a. The tip surface is located on the same plane. And the outer side surface (of FIG. 4) of the mounting flange part 45 which comprises the sensor unit 42 to the opening edge of these short cylindrical parts 41a and the single side | surface (right side surface of FIG. 4, the front side surface of FIG. 5) of the protrusion 39a. A part of the left side) can be freely contacted.

  Further, a concave portion 57 that does not penetrate in the axial direction is provided in a portion facing the concave portion 48 that exists inside the cylindrical portion 31 provided in the hub 2a near the center of the end surface of the protrusion 39a in the diameter direction. Unlike the stepped recess 49 in the case of the first example described above, the recess 57 is formed in a simple bottomed cylindrical shape that is not stepped. In the recess 57, the head of the bolt 53 is fixed by welding by spot welding or adhesively fixed by an adhesive.

The operation of mounting the sensor unit 42 on the cover 18b is performed as follows in order to configure the rolling bearing unit with the rotational speed detection device of the present reference example by combining the respective members configured as described above. . First, the insertion portion 43 constituting the sensor unit 42 is inserted inside the short cylindrical portion 41a provided on the cover 18b. At the same time, the threaded portion of the bolt 53 fixed in the recess 57 provided in the protrusion 39 a of the cover 18 b is inserted into the through hole 59 provided in the mounting flange portion 45 constituting the sensor unit 42. Then, the outer side surface of the mounting flange portion 45 is brought into contact with one side of the protrusion 39a (the right side surface in FIG. 4 and the front side surface in FIG. 5). Next, the nut 52 is screwed into the threaded portion of the bolt 53, and further tightened, whereby the sensor unit 42 is coupled and fixed to the cover 18b. Also in this example, since the sensor is screwed to the cover 18b and no through-hole is provided in the cover 18b, the inside of the space 30 where the rolling elements 9 and 9 are present from the outside through the screwed joint portion. Foreign matter such as muddy water will not enter. As a result, a structure in which the sensor is screwed and coupled to the cover 18b is employed, and in order to ensure the sealing performance of the screwed coupling portion, there is no need to provide a seal member, and the rolling with a rotational speed detection device is eliminated. The overall cost of the bearing unit can be reduced.

In the case of this reference example , as described above, the short cylindrical portion 41a is formed on the side opposite to the encoder 3a with respect to the bottom plate portion 38a. Therefore, the outer diameter of the encoder 3a is the first example described above. The portion where the inner edge of the outer ring 1 can be abutted can be provided on the entire circumference without interruption without being made smaller than in the above case. That is, by forming the short cylindrical portion 41a in this way, the portion where the die abuts when the insertion hole 40 is formed in the cover 18b by burring is the inner surface of the bottom plate portion 38a (FIG. 4). The right side surface is around the portion where the insertion hole 40 is to be provided. And a part of part which abuts the outer ring 1 also becomes a part of the periphery. Therefore, as compared with the case of the first example described above, the outer ring 1 does not shorten the distance between the shaft center and the center of the insertion hole 40, that is, without reducing the outer diameter of the encoder 3a. It is possible to continuously provide a portion that can be abutted against the inner end edge of the rim around the entire circumference. As a result, the sealing performance between the outer ring 1 and the cover 18b can be improved even when the detection capability of the sensor is assumed to be the same as in the first example described above.
Since other configurations and operations are the same as those in the first example described above, the same parts are denoted by the same reference numerals, and redundant description and illustration are omitted.

In the first example described above, the stepped recess 49 (FIGS. 1 and 2) provided in the projection 39 constituting the cover 18a is a simple recess similar to the case of this reference example , The head portion of the bolt 53 may be fixed, and conversely, in the present reference example , the recess 57 is a stepped recess similar to the case of the first example described above, and the nut 52 is provided in the stepped recess. It is good also as a structure which fixes. Further, the shape of the recess or stepped recess is hexagonal or the like such that the head of the bolt 53 or the nut 52 can be fitted in a non-rotatable manner, and the welded or bonded portion of the head of the bolt 53 or the nut 52 can be attached. It is also possible to prevent excessive stress from being applied.

[Third example of reference example of the present invention ]
Next, FIG. 6 shows a third example of a reference example related to the present invention . In the case of this reference example , it is provided in the sensor unit 42 in a state where the insertion portion 43 provided in the sensor unit 42 is inserted into the insertion hole 40 provided in the cover 18c at a part of the end surface of the protrusion 39a provided in the cover 18c. Similarly to the case of the second example described above, a bottomed recess 60 is provided in a portion aligned with the through hole 59. In particular, in the case of this reference example , unlike the case of the second example described above, the head of the bolt 53 and the nut 52 (see FIG. 4) are not fixed in the recess 60, but instead the recess 60 A female thread portion 74 is formed on the inner peripheral surface of the inner thread . Then, the threaded portion of the bolt 53 is inserted through the through hole 59 provided in the sensor unit 42, and then screwed into the female threaded portion 74, and further tightened to couple the sensor unit 42 to the cover 18c. It is fixed. The female screw portion 74 is formed by erecting a tap after the concave portion 60 is formed by plastic deformation.

Also in the case of the rolling bearing unit with the rotational speed detection device of this reference example configured as described above, in the same manner as in the second example described above, in order to screw the sensor to the cover 18c, it is attached to the plate portion of the cover 18c. A corresponding through hole is not provided in the corresponding protrusion 39a. For this reason, foreign matter such as muddy water does not enter from the outside into the space 30 where the rolling elements 9 and 9 exist through the screwed joint portion. As a result, a structure in which the sensor is screwed and coupled to the cover 18c is employed, and it is not necessary to provide a seal member to ensure the sealing performance of the screwed coupling portion. The cost of the entire unit can be reduced. In particular, in the case of the present reference example , unlike the case of the first and second examples described above , the internal thread portion is directly formed on the inner peripheral surface of the recess 60 provided in the cover 18c, so the nut 52 is omitted. By reducing the number of parts, the cost can be further reduced. Since other configurations and operations are the same as those in the second example described above, the same parts are denoted by the same reference numerals, and redundant description and illustration are omitted.

[ Example of Embodiment]
Next, FIGS. 7 to 8 show an example of an embodiment of the present invention . In the case of this example, unlike the first and second examples of the reference example and the third example described above, a cover that covers the inner end opening of the outer ring 1 by being attached to the inner end opening of the outer ring 1 Part of 18d is made of synthetic resin. That is, the cover 18d includes a bottomed cylindrical main body 61 formed by injection molding of a synthetic resin, and a fitting cylinder 62 coupled to the opening of the main body 61. The fitting cylinder 62 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 62 and a base of the fitting cylinder 63 are provided. And an inward flange 64 that is bent inward in the diametrical direction from the end edge (the right end edge in FIG. 7). Such a fitting cylinder 62 is joined to the opening of the main body 61 by molding the inward flange 64 on the opening end of the main body 61 when the main body 61 is injection molded. In the inward flange 64, a large number of through holes 65, 65 are intermittently formed in the circumferential direction. The synthetic resin that constitutes the main body 61 flows into the through holes 65 and 65 when the main body 61 is injection-molded to increase the bonding strength between the main body 61 and the fitting cylinder 62.

  The cover 18d configured in this manner closes the inner end opening of the outer ring 1 by fitting the fitting cylinder portion 63 of the fitting cylinder 62 to the inner end portion of the outer ring 1 with an interference fit. . In this state, the end surface of the opening of the main body 61, that is, the tip end surface of the cylindrical wall portion 66 formed on the outer peripheral edge of the main body 61 is brought into contact with the inner end surface of the outer ring 1. A locking groove 67 is formed on the entire end surface of the cylindrical wall portion 66, and an O-ring 68 is locked in the locking groove 67. In a state where the tip end surface of the cylindrical wall 66 and the inner end surface of the outer ring 1 are in contact with each other, the O-ring 68 is elastically compressed between the inner end surface and the bottom surface of the locking groove 67. The joint between the cover 18d and the outer ring 1 is sealed to prevent foreign matters such as muddy water from entering the cover 18d.

Further, a part of the inner side surface (the right side surface in FIG. 7) of the bottom plate portion 69 of the main body 61 constituting the cover 18d and a portion offset from the outer part in the diametrical direction (the upper portion in FIG. 7) are axially The protrusion 70 which protrudes in is provided. Further, in the outer surface (the left side surface in FIG. 7) of the bottom plate portion 69, the portion that faces the inner surface of the encoder 3 a fixed to the inner end of the inner ring 7 penetrates the protrusion 70 in the axial direction. The insertion hole 72 is provided, and the insertion portion 43 provided in the sensor unit 42 can be freely inserted into the insertion hole 72. Further, by continuing a part of the outer peripheral wall part of the protrusion 70 and a part of the cylindrical wall part 66 in the circumferential direction, the position of the insertion hole 72 is positioned as far as possible in the outer diameter direction. Yes. With such a configuration, the diameter of the permanent magnet 37 attached to the inner surface of the annular portion 75 of the encoder 3a is increased, and the magnetization width of each magnetic pole (N pole or S pole) of the permanent magnet 37 is increased. , Improving the detection ability of the sensor. In the case of this example, a small diameter step portion 71 is formed on the outer peripheral surface of the inner end portion of the inner ring 7. Since such a small diameter step portion 71 is formed, regardless of the diametrically outward force applied to the inner end portion of the inner ring 7 by caulking the cylindrical portion 31 of the hub 2a outwardly in the diametrical direction, It is possible to prevent the inner ring raceway 8 provided on the outer peripheral surface of the inner ring 7 from being distorted. In particular, in the case of this example, the support ring 36 constituting the encoder 3a is folded back 180 degrees on the outer peripheral side, not on the inner peripheral side as in the above-described examples. That is, the support ring 36 is annular as a whole, and is folded back 180 degrees on the annular portion 75 and the outer peripheral edge side of the annular portion 75, and further, the tip end side is axially outward with respect to the annular portion 75. It is comprised from the cylindrical part 76 bent toward the direction. Of these, the cylindrical portion 76 is externally fixed by an interference fit to the inner end of the inner ring 7 constituting the hub 2a. Then, in a state where the cylindrical portion 76 is fitted and fixed to the inner end portion of the inner ring 7, the inner diameter of the permanent magnet 37 attached to the inner side surface of the circular ring portion 75 is set to be the same between the cylindrical portion 76 and the inner ring 7. The diameter of the fitting portion with the inner end portion is smaller, and the outer diameter of the permanent magnet 37 is larger than the diameter of the fitting portion between the cylindrical portion 76 and the inner end portion of the inner ring 7. For this reason, the magnetization area of each magnetic pole of the permanent magnet 37 can be increased, and the detection capability of the sensor unit 42 having the inner side surface of the permanent magnet 37 constituting the encoder 3a as the detected portion can be improved. The support ring 36 can be externally fitted to the small-diameter step 71 if the distortion of the shape of the small-diameter step 71 is small.

Further, the insertion portion 43 provided in the sensor unit 42 is inserted into the insertion hole 72 provided in the cover 18d, and the protrusion 70 of the cover 18d is aligned with the through hole 59 provided in the sensor unit 42. A bottomed recess 60a is provided on a part of the end surface. And the internal thread part 74 is formed in the internal peripheral surface of this recessed part 60a. A steel liner 73 called a helisert whose inner and outer peripheral surfaces are threaded is engaged with the female thread portion 74. Such a steel liner 73 is intended to reinforce the female screw portion 74 formed on the synthetic resin cover 18d. That is, with this liner 73, excessive stress is applied to a part of the female screw portion 74 as the steel bolt 53 is directly screwed and tightened to the female screw portion 74 formed in the synthetic resin portion. To prevent.

In the case of the rolling bearing unit with the rotational speed detection device of this example configured as described above, the threaded portion of the bolt 53 inserted into the through hole 59 provided in the sensor unit 42, and the liner 73 inserted into the female threaded portion 74, The sensor unit 42 is coupled and fixed to the cover 18d by further tightening. If the strength of the female screw portion 74 formed on the synthetic resin cover 18d can be secured, the female screw portion 74 and the bolt 53 may be directly screwed and tightened without using the liner 73. .
In the case of this example, the weight of the entire rolling bearing unit with a rotational speed detecting device can be reduced by making the main body 61 constituting the cover 18d made of synthetic resin.
Since other configurations and operations are the same as those of the third example of the reference example described above, the same parts are denoted by the same reference numerals, and redundant description is omitted.

As a modification of the structure of the third example of the reference example and the example of the embodiment, an insertion hole 40 provided in the cover 18d is provided with an insertion portion 43 provided in the sensor unit 42 in a part of the cover 18c (or 18d). (Or 72) In place of the bottomed concave portion 60a (FIGS. 6 and 7), a convex portion that protrudes in the axial direction is provided in a portion that is aligned with the through-hole 59 provided in the sensor unit 42 in the inserted state. An external thread part can also be formed in the outer peripheral surface of a convex part. In this case, with the insertion part 43 of the sensor unit 42 inserted into the insertion hole 40 (or 72), the male thread part of the convex part inserted through the through hole 59 and the nut are screwed together, By further tightening, the sensor unit 42 is coupled and fixed to the cover 18c (or 18d).

In each reference example described above and one example of the above-described embodiment, 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, but an eddy current type. A sensor using a photoelectric sensor can also be employed .

In addition, each of the reference examples described above and one example of the embodiment described above is the present invention or the present invention in a rolling bearing unit for supporting non-driving wheels (rear wheel of FF vehicle, front wheel of FR vehicle). an example is shown in which the structure is applied to the reference example concerning, reference examples of the present invention or the present invention is not limited to the structure for supporting such a non-driven wheels, the front wheels of the driving wheels (FF vehicle, after FR vehicle The present invention can also be applied to a structure that supports wheels, all wheels of a 4WD vehicle). However, when the present invention or the reference example related to the present invention is applied to the structure for supporting the drive wheel, the sensor unit is inserted into the cover in the diameter direction, and the nut equivalent member or the bolt equivalent member is connected to the cover. It is provided on the outer peripheral surface. In that case, a detection portion that is close to and faces the encoder is provided on the side surface of the distal end portion of the insertion portion constituting the sensor unit.

Sectional drawing which shows the 1st example of the reference example regarding this invention . The perspective view which takes out and shows only a cover. The perspective view which takes out and shows only the edge part and sensor unit of a harness. Sectional drawing which shows the 2nd example of the reference example regarding this invention . The perspective view which takes out and shows only the cover similarly used for the 2nd example. Sectional drawing which shows the 3rd example of the reference example regarding this invention . Sectional drawing which shows one example of embodiment of this invention . The perspective view which takes out and shows only the cover used for one example of embodiment similarly. FIG. 11 is a cross-sectional view taken along line A-O-B in FIG. 10 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, 18c, 18d cover 19 fitting cylinder portion 20 closing plate portion 21 bulging portion 22 through hole 24 detection portion 25 mounting flange 26 set screw 27 stud 28 bolt 29 nut 30 space 31 cylindrical portion 32 main portion 33 flange portion 34 protrusion Contact portion 35, 35a Fitting portion 36 Support ring 37 Permanent magnet 38, 38a Bottom plate portion 39, 39a Protrusion portion 40 Insertion hole 41, 41a Short cylindrical portion 42 Sensor unit 43 Insertion portion 44 Harness 45 Mounting flange portion 46 Locking groove 47 O-ring 48 Concave part 49 Stepped concave part 50 Large diameter part 51 Small diameter part 52 G 53 Bolt 54 Through-hole 55 Core metal 56 Through-hole 57 Recessed portion 58 Enlarged portion 59 Through-hole 60, 60a Recessed portion 61 Main body 62 Fitting tube 63 Fitting tube portion 64 Inward flange portion 65 Through hole 66 Cylindrical wall portion 67 Locking Groove 68 O-ring 69 Bottom plate portion 70 Projection portion 71 Small diameter step portion 72 Insertion hole 73 Liner 74 Female thread portion
75 torus
76 Cylindrical part

Claims (3)

  A stationary wheel that has a stationary side track on the stationary side circumferential surface and does not rotate during use, a rotating wheel that has a rotational side track on the rotational side circumferential surface facing the stationary side circumferential surface and rotates during use, and A plurality of rolling elements provided between a stationary side track and the rotation side track so as to be freely rotatable, and a characteristic extending in the circumferential direction fixed to a part of the rotation wheel concentrically with the rotation wheel. Encoders that are changed alternately and at equal intervals, a cover that is fixed to a part of the stationary wheel so as to face the encoder, and an insertion hole that is provided in a part of the cover that faces the encoder A rolling bearing unit with a rotational speed detection device, which is supported and fixed to a part of the cover in a state of being inserted through the insertion hole, and that changes an output as the encoder rotates. Is supported by the holder. The rudder includes an insertion portion that is inserted into the insertion hole in a state where the sensor is supported, a mounting flange portion in which the base end portion is coupled to the end portion of the insertion portion, and a through hole provided at the distal end portion of the mounting flange portion. And the cover includes a nut-corresponding portion or a bolt-corresponding portion provided in a state where the insertion portion is inserted into the insertion hole and opposed to the through-hole and not penetrating the cover. The holder is coupled and fixed to the cover on the basis of screwing between the bolt inserted through the through hole and the nut equivalent portion or the nut and bolt equivalent portion inserted through the through hole. A rolling bearing unit with a rotational speed detector.   A part of the cover is provided with a bottomed recess in a portion aligned with the through hole provided in the holder with the insertion part inserted into the insertion hole, and a nut or bolt equivalent part is provided in the recess. The rolling bearing unit with a rotational speed detection device according to claim 1, wherein the head portion of the bolt is fixed by welding or adhesion. The nut equivalent part or the bolt equivalent part is integrally provided with respect to the cover in a part aligned with the through hole provided in the holder in a state where the insertion part is inserted into the insertion hole in a part of the cover. Rolling bearing unit with a rotational speed detector described in 1.

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