JP5169886B2 - Rolling bearing unit with rotational speed detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roller bearing unit with a rotation speed detection device capable of preventing a cover 18a from being pushed to an encoder 21 side based on pushing of a detection part of a sensor 22a or the like, capable of accurately regulating an axial position of the cover 18a, and capable of preventing deformation of the cover 18a resulting in lowering of detection accuracy of the sensor 22a, resulting from supporting and fixing of the cover 18a to an outer ring 4. <P>SOLUTION: The cover 18a is formed to be a bottomed cylindrical shape having a bottom plate part 19a and a cylindrical part 20a, and an outward flange-shaped abutting part 25 is provided on a part near an outer peripheral end. The cover 18a is internally fixed to an axially inner end of the outer ring 4 by interference fit in such a state that an axially outer side surface of the abutting part 25 is abutted on an axially inner end surface of the outer ring 4. A swelling part 27a swelling to an axial direction more than a plane part 26 opposed to the detection part of the sensor 22a is provided in the center of the bottom plate part 19a. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an improvement in a rolling bearing unit with a rotational speed detecting device for rotatably supporting a vehicle wheel (driven wheel) with respect to a suspension device and detecting the rotational speed of the wheel. Specifically, the cover that closes the axially inner end opening of the internal space in which the encoder is installed is prevented from being pushed into the encoder side based on the pressing of the detection part of the sensor, and the axial direction of the cover A structure that can regulate the position with high accuracy and prevent the cover from being deformed to reduce the detection accuracy of the sensor as the cover is supported and fixed to the outer ring is realized.

  2. Description of the Related Art Conventionally, various structures are known as rolling bearing units with a rotational speed detecting device for rotatably supporting a wheel on a suspension device of an automobile and detecting the rotational speed of the wheel. In any structure, the detection part of the sensor supported and fixed to the non-rotating part is opposed to the detection surface of the encoder supported and fixed to a part of the hub that rotates together with the wheel. And it is comprised so that the rotational speed of the said wheel which rotates with this encoder may be calculated | required based on the frequency or the period of the output signal of this sensor which changes with rotation of the said encoder.

  This encoder is used to prevent the encoder constituting the rolling bearing unit with such a rotational speed detection device from being damaged by adhesion of muddy water, dust, etc., or when foreign particles such as magnetic powder adhere to this encoder. In order to prevent the reliability of rotation speed detection from being impaired, a structure in which the encoder is separated from the outside by a cover made of a non-magnetic plate has been conventionally known as described in Patent Documents 1 and 2. FIG. 12 shows an example of the structure described in Patent Document 1 among them.

  This rolling bearing unit 1 with a rotational speed detection device is formed by combining a rolling bearing unit 2 and a rotational speed detection device 3. Among them, the rolling bearing unit 2 includes an outer ring 4, a hub 5, and a plurality of rolling elements 6 and 6. Outer ring 4 has double-row outer ring raceways 7 and 7 on the inner peripheral surface and stationary flange 8 on the outer peripheral surface. And the said outer ring | wheel 4 is supported by the knuckle 9 which comprises a suspension apparatus, and does not rotate in use condition. The hub 5 is formed by coupling and fixing a hub body 10 and an inner ring 11 by a caulking portion 12. The hub 5 has double-row inner ring raceways 13 and 13 on the outer peripheral surface, and is arranged on the inner diameter side of the outer ring 4. The outer ring 4 is supported concentrically. Also, the axially outer end of the hub body 10 (outside with respect to the axial direction refers to the side that is outside the width direction of the vehicle body when assembled to the suspension device. The same applies throughout the present specification and claims. )), A rotation-side flange 14 for supporting the wheel is provided at a portion protruding outward in the axial direction from the axially outer end opening of the outer ring 4. The rolling elements 6 and 6 are held by the cages 15 and 15 between the outer ring raceways 7 and 7 and the inner ring raceways 13 and 13 by a plurality for each row. It is provided so that it can roll freely. Further, both end portions in the axial direction of the internal space 16 in which the rolling elements 6 and 6 are installed are closed by a seal ring 17 and a cover 18.

  The cover 18 is made of a nonmagnetic plate such as a nonmagnetic metal plate such as an aluminum alloy plate or an austenitic stainless steel plate. Such a cover 18 includes a bottom plate portion 19 and a cylindrical portion 20 bent at a right angle from the outer peripheral edge of the bottom plate portion 19 in the axially outward direction. In the structure of FIG. 12, since the rolling bearing unit 2 for the driven wheel (rear wheel of FF vehicle, front wheel of FR vehicle, MR vehicle) is targeted, the bottom plate portion 19 is opened in the axial inner end of the outer ring 4. The inner part in the axial direction means the side closer to the center in the width direction of the vehicle body in the state assembled to the suspension device (the same applies to the entire specification and claims). . On the other hand, in the case of a rolling bearing unit for driving wheels (front wheels of FF vehicles, FR wheels, rear wheels of MR vehicles, all wheels of 4WD vehicles), like the structure described in Patent Document 2, In order to insert the drive shaft into the inner diameter side of the cover, the bottom plate portion is formed into an annular shape.

  On the other hand, the rotational speed detection device 3 includes an encoder 21 and a sensor 22. The encoder 21 includes a support ring 23 having a magnetic metal plate having an L-shaped cross section and a ring shape as a whole, and an encoder body 24 made of a permanent magnet such as a rubber magnet. The encoder main body 24 is magnetized in the axial direction, and by alternately changing the magnetization direction with respect to the circumferential direction at equal intervals, the S pole and the N pole are provided on the inner side surface in the axial direction, which is the detected surface. These are arranged alternately and at equal intervals. The detected surface of the encoder body 24 is opposed to the axially outer surface (inner surface) of the cover 18 in close proximity via a minute gap. In other words, the cover 18 is pushed into the axially inner end of the outer ring 4 until the axially outer surface of the bottom plate 19 is in close proximity to the detected surface of the encoder body 24.

  Further, the sensor 22 is in contact with the inner side surface (outer surface) in the axial direction of the bottom plate portion 19 while being supported and fixed to the knuckle 9. In this state, the detection portion faces the detection surface of the encoder body 24 through the bottom plate portion 19. When the encoder body 24 rotates together with the hub 5 in this state, the S pole and the N pole existing on the detected surface pass alternately in the vicinity of the detection portion of the sensor 22, and the output of the sensor 22 Changes. Since the frequency of the change is proportional to the rotational speed of the hub 5 and the period of the change is inversely proportional to the rotational speed, the rotational speed of the wheel fixed to the hub 5 can be obtained based on one of them.

  In the case of the conventional structure shown in FIG. 12 as described above, the encoder body 24 made of permanent magnets and the external space are separated by the cover 18 made of a non-magnetic plate. It can prevent foreign matter such as magnetic powder from adhering. Therefore, it is possible to ensure the reliability of rotation speed detection using the encoder body 24 while keeping the detected surface in a clean state. However, there is room for improvement in the following points from the aspect of further improving the reliability of the rotational speed detection.

  First, in the case of the conventional structure, since there is no means for restricting the displacement of the cover 18 in the axial direction outside, it is difficult to accurately regulate the position of the cover 18 in the axial direction. For example, after restricting the position of the cover 18 in the axial direction to the position shown in FIG. 12, the cover 18 is moved to the position described above by strongly pressing the detection portion of the sensor 22 against the axial inner surface (outer surface) of the bottom plate portion 19. There is a possibility of pushing into the encoder 21 side (axially outer side). When the amount of pressing of the cover 18 increases, the axially outer surface (inner surface) of the bottom plate portion 19 collides with the detected surface of the encoder body 24 to damage the detected surface, or the encoder body. The detection gap (air gap) between the detected surface of 24 and the detection part of the sensor 22 may be inappropriate, resulting in a sensing error. Further, a part of the support ring 23 constituting the encoder 21 comes into contact with the rolling surfaces of the rolling elements 6 in the inner row in the axial direction and the cage 15 that holds the rolling elements 6, thereby rolling bearing units. The bearing function of 2 may be impaired.

  Second, as the cover 18 is supported and fixed to the outer ring 4, the bottom plate portion 19 constituting the cover 18 may be deformed so as to reduce the detection accuracy of the sensor 22. . That is, when the cylindrical portion 20 is fitted and fixed to the inner end in the axial direction of the outer ring 4 so as to support and fix the cover 18 to the outer ring 4, the bottom plate existing on the inner diameter side of the cylindrical portion 20 is fixed. A force directed radially inward is applied to the portion 19. Then, based on this force, there is a possibility that the bottom plate portion 19 is distorted and deformed in the thickness direction (axially inward and outward directions) so as to be curved. Since the direction and degree of the deformation cannot be predicted, the axial position of the portion of the bottom plate portion 19 between the detected surface of the encoder body 24 and the detecting portion of the sensor 22 can be accurately determined. It becomes impossible to regulate. For example, when positioning the sensor 22 by abutting the detection part of the sensor 22 against the inner side surface in the axial direction of the bottom plate part 19, the positioning becomes inaccurate if the bottom plate part 19 is distorted. As a result, the density of the magnetic flux that comes out of the surface to be detected of the encoder body 24 and reaches the detection portion of the sensor 22 varies, which is disadvantageous in terms of ensuring the reliability of rotation speed detection.

Japanese Patent No. 4206550 German Patent Application Publication No. 19644744

  In view of the circumstances as described above, the present invention prevents a cover that closes an axially inner end opening of an internal space in which an encoder is installed from being pushed into the encoder side based on pressing of a sensor detection unit or the like. The position of the cover in the axial direction can be regulated with high accuracy, and the cover can be prevented from being deformed to reduce the detection accuracy of the sensor as the cover is supported and fixed to the outer ring. Invented to realize the above.

Each of the rolling bearing units with a rotational speed detection device of the present invention is similar to the above-described conventionally known rolling bearing unit with a rotational speed detection device, and includes an outer ring, a hub, a plurality of rolling elements, an encoder, A cover and a sensor.
Of these, the outer ring has a double-row outer ring raceway on the inner peripheral surface, and is not rotated by being supported by a suspension device such as a knuckle in use.
The hub has a double-row inner ring raceway on the outer peripheral surface, and is supported concentrically with the outer ring on the inner diameter side of the outer ring, and more than the outer end in the axial direction of the outer ring on the outer peripheral surface. A rotation-side flange for supporting a wheel (driven wheel) is provided at a portion protruding outward in the axial direction.
Further, a plurality of rolling elements are provided between the outer ring raceways and the inner ring raceways so as to be freely rollable in both rows.
The encoder has an annular shape in which the magnetic characteristics of the inner surface in the axial direction are alternately changed in the circumferential direction, and is supported concentrically with the hub at the inner end in the axial direction of the hub.
The cover is made of a non-magnetic plate, and is supported and fixed to the inner end portion in the axial direction of the outer ring, thereby closing the opening portion in the axial direction of the outer ring.
Further, the sensor has its detection unit abutting on or close to the inner surface in the axial direction of the cover, and the detection unit is made to face the inner surface in the axial direction (detected surface) of the encoder through the cover. ing.

Further, in the rolling bearing unit with a rotational speed detection device of the present invention, the cover is formed in a circular flat plate shape (disk shape), and the axially outer side surface near the outer peripheral edge is the axially inner end surface of the outer ring. Hit it. Then, the sensor holding plate that supports the sensor on a part of the inner ring in the axial direction of the outer ring in a state where the outer peripheral edge portion of the cover is sandwiched from both sides in the axial direction between the inner end surface in the axial direction of the outer ring. It is externally fixed to the end.

In particular, in the case of the invention described in claim 1, the outer peripheral edge of the cover is covered with a sealing material having elasticity over the entire circumference. The sealing material is sandwiched between the outer peripheral edge of the cover and the inner peripheral surface of the sensor holding plate over the entire circumference in a state of being elastically compressed in the radial direction.
On the other hand, in the case of the invention described in claim 2, the inner peripheral edge portion of the contact portion between the axial side surface near the outer peripheral edge portion of the cover and the mating surface contacting the axial side surface has elasticity. It is blocking over the entire periphery by a sealing material.

According to the rolling bearing unit with a rotational speed detection device of the present invention having the above-described configuration, the cover that closes the axial inner end opening of the internal space in which the encoder is installed is based on the pressing of the sensor detection unit or the like. The cover can be prevented from being pushed into the encoder, the axial position of the cover can be regulated with high accuracy, and the cover can be prevented from being deformed to reduce the detection accuracy of the sensor.
That is, in the case of the present invention, in a state in which the axial outer side of the outer peripheral edge portion close to a circular plate-shaped cover, abutted against the axially inner end face of the outer ring is supported and fixed with respect to the outer ring. For this reason, the cover can be prevented from being pushed into the encoder side based on the pressing of the detection portion or the like of the sensor, and the axial position of the cover can be accurately regulated. Therefore, in the case of the present invention, the axial outer surface of the cover can be prevented from colliding with the detected surface of the encoder, and the detected surface can be prevented from being damaged. It is also possible to prevent the detection gap between the sensor and the detection unit from becoming inappropriate. Furthermore, since a part of the encoder can be prevented from coming into contact with the rolling elements constituting the rolling bearing unit, the bearing performance of the rolling bearing unit can be prevented from being lowered.

Further, in the case of the present invention , the cover is formed in a circular flat plate shape, so that the sensor is held against the outer ring without the cover being fitted and fixed to the inner end in the axial direction of the outer ring. It is supported and fixed by using a plate (by clamping from both sides in the axial direction between the outer ring and the sensor holding plate). For this reason, an axial distortion deformation does not occur in the cover. Therefore, it is possible to effectively prevent the cover from being deformed so as to reduce the detection accuracy of the sensor. As a result, according to the present invention, it is possible to ensure the reliability for detecting the rotational speed.

In the case of the invention according to claim 1 , it is possible to maintain water tightness between the outer peripheral edge portion of the cover and the inner peripheral surface of the sensor holding plate.
Further, in the case of the invention according to claim 2 , the internal space or sensor in which the encoder is installed through the contact portion between the axial side surface near the outer peripheral edge of the cover and the counterpart surface contacting the axial side surface It is possible to prevent foreign matter such as rainwater from entering the space where the is installed.

The fragmentary sectional view which shows the 1st example of the reference example relevant to this invention . The figure similar to FIG. 1 which shows the 2nd example. Sectional drawing which abbreviate | omits a sensor and a sensor holding | maintenance board and shows a 3rd example. The figure similar to FIG. 3 which shows the 4th example. The figure similar to FIG. 3 which shows the said 5th example. The figure similar to FIG. 3 which shows the said 6th example. The expanded sectional view equivalent to the A section of Drawing 2 showing the 7th example. The figure similar to FIG. 7 which shows the said 8th example. The figure similar to FIG. 1 which shows the 1st example of embodiment of this invention . The expanded sectional view equivalent to the B section of Drawing 9 showing the 2nd example . The figure similar to FIG. 10 which shows the 3rd example . The half part sectional view which shows an example of the conventional structure of a rolling bearing unit with a rotational speed detection apparatus.

[First example of reference example related to the present invention ]
FIG. 1 shows a first example of a reference example related to the present invention . In addition, including this reference example , the feature of the rolling bearing unit 1a with a rotational speed detection device of the present invention is the structure of a cover 18a for closing the internal space 16 in which the encoder 21 is installed. Since the structure and operational effects of the other parts are substantially the same as the structure widely known from the past including the structure shown in FIG. 12, the same reference numerals are given to the equivalent parts. The description which overlaps is abbreviate | omitted and demonstrates below focusing on the characteristic part of this reference example , and the part which was not demonstrated previously.

The cover 18a constituting the rolling bearing unit 1a with the rotational speed detecting device of the present reference example is made of SUS304, austenitic SUS300 series stainless steel plate, nonmagnetic metal plate such as aluminum alloy, or a synthetic resin plate. It is made of a non-magnetic plate such as a product. The cover 18a has a bottomed cylindrical shape including a bottom plate portion 19a and a cylindrical portion 20a bent at a right angle inward in the axial direction from the outer peripheral edge of the bottom plate portion 19a. In particular, in the case of the present reference example , the outward flange-shaped butting portion 25 is provided in a state where the cylindrical portion 20a is bent at right angles outward in the radial direction from the inner end edge in the axial direction. The outer diameter dimension of the abutting portion 25 is the same as or slightly smaller than the outer diameter dimension of the inner end surface in the axial direction of the outer ring 4 constituting the rolling bearing unit 2.

The bottom plate portion 19a has a flat plate portion 26 and a bulging portion 27, of which the flat plate portion 26 is provided at a portion near the outer peripheral edge of the bottom plate portion 19a, with respect to the central axis of the cover 18a. It lies on a virtual plane that exists in a perpendicular direction. In the case of the present reference example , a detection portion (a tip portion 36 of the holder) of the sensor 22a, which will be described later, is abutted against a part of the inner circumferential surface of the flat plate portion 26 in the circumferential direction. On the other hand, the bulging portion 27 is provided in a central portion of the bottom plate portion 19 a and is provided in a portion that is radially inward from the flat plate portion 26, and is directed inward in the axial direction from the flat plate portion 26. Bulges. In the case of this reference example, the outer peripheral surface of the inner end portion in the axial direction of the cylindrical portion 20a is covered with a sealing material 38 having elasticity such as rubber or vinyl over the entire circumference. . The sealing material 38 can be constituted by, for example, vulcanizing a rubber material, or an O-ring can be used.

Such a cover 18a is supported and fixed to the outer ring 4 by fixing the cylindrical portion 20a to the inner end in the axial direction of the outer ring 4 by an interference fit. In particular, in the case of the present reference example , in this state, the axially outer surface of the abutting portion 25 is abutted over the entire inner circumference of the outer ring 4 and the axial direction of the flat plate portion 26 The outer side surface (inner surface) is made to face and oppose to the detection surface of the encoder main body 24 constituting the encoder 21 that is fitted and fixed to the portion near the inner end of the hub 5 through a minute gap. In addition, the sealing material 38 is elastically compressed in the radial direction over the entire circumference between the outer peripheral surface of the inner end portion in the axial direction of the cylindrical portion 20a and the inner peripheral surface of the inner end portion of the outer ring 4 in the axial direction. It is pinched with. Thus, in the case of this reference example , foreign matter such as rainwater that has entered from the contact portion between the axially outer surface of the abutting portion 25 and the axially inner end surface of the outer ring 4 is separated from the cylindrical portion 20a. Through the fitting portion with the outer ring 4, entry into the internal space 16 in which the encoder 21 is installed is prevented.

Further, in the case of the rolling bearing unit 1a with the rotational speed detection device of this reference example , a sensor holding plate 28 for supporting a sensor 22a described later is attached to the inner end of the outer ring 4 in the axial direction by an interference fit. It is fitted and fixed. The sensor holding plate 28 is made of a ferrous metal such as carbon steel or stainless steel, a non-ferrous metal such as an aluminum alloy, or a synthetic resin, and has a petri dish as a whole. That is, the sensor holding plate 28 includes a circular flat plate-shaped bottom plate portion 29 and a fitting cylinder portion 30 bent at a right angle from the outer peripheral edge of the bottom plate portion 29 outward in the axial direction. Further, a through hole 31 is formed in a portion closer to the outer diameter of the bottom plate portion 29, and a mounting hole 32 is formed in a portion closer to the center than the through hole 31. And the nut 33 is being fixed to the part which surrounds the said attachment hole 32 by a part of outer surface (axial direction inner surface) of the said baseplate part 29 by welding, adhesion | attachment, press-fit, caulking, etc. When the sensor holding plate 28 is made of a metal material such as carbon steel that easily causes rust, the surface thereof is subjected to surface treatment for rust prevention. As such a surface treatment, cationic electrodeposition coating can be preferably used from the viewpoint of preventing moisture such as rainwater from entering the fitting portion between the outer ring 4 and the axially inner end.

Such a sensor holding plate 28 is supported and fixed to the outer ring 4 by fitting the fitting cylinder 30 to the inner end in the axial direction of the outer ring 4 with an interference fit. In particular, in the case of the present reference example , in this state, the abutting portion 25 of the cover 18a is disposed between the axially outer surface of the bottom plate portion 29 near the outer peripheral edge and the axially inner end surface of the outer ring 4. Is sandwiched from both sides in the axial direction. Thus, the cover 18a is prevented from being displaced inward in the axial direction (exiting inward in the axial direction). In the case of this reference example, the sensor holding plate 28 is fitted and fixed to the inner end of the outer ring 4 in the axial direction, and the cover 18a is attached to the cover 18a via the space 34 by the sensor holding plate 28. It covers from the inside in the axial direction.

  On the other hand, the encoder 21 constituting the rotational speed detection device 3 constitutes the rolling bearing unit 2 prior to closing the axial inner end opening of the outer ring 4 with the cover 18a and the sensor holding plate 28. The hub 5 (inner ring 11) is fitted and fixed to the inner end in the axial direction by interference fitting. At this time, the axial position of the inner surface in the axial direction of the encoder body 24, which is the detected surface of the encoder 21, is regulated with reference to the inner end surface in the axial direction of the outer ring 4.

  The sensor 22a that constitutes the rotational speed detection device 3 together with the encoder 21 as described above is fixedly attached to the sensor holding plate 28 with bolts 35 and nuts 33. The sensor 22a is formed by embedding and supporting a magnetic detecting element, such as a Hall element or a magnetoresistive element, in a tip end portion 36 of a synthetic resin holder, whose characteristics change depending on the direction of magnetic flux. A distal end portion 36 embedding and supporting the detection element is projected outward in the axial direction. Further, a mounting flange 37 is provided in an intermediate portion of the holder in the axial direction, and an insertion hole for inserting the flange portion of the bolt 35 is formed at the tip of the mounting flange 37.

  In order to attach and fix the sensor 22a to the sensor holding plate 28, the front end portion 36 of the holder is inserted into the space 34 through the through hole 31 formed in the sensor holding plate 28, and the bottom plate portion 19a. And an insertion hole formed in the mounting flange 37 with the mounting flange 37 butted against the axial inner surface of the nut 33 and the sensor holding The mounting holes 32 formed in the plate 28 are aligned. Then, the bolt 35 inserted through the insertion hole from the inside in the axial direction is screwed into the nut 33 and further tightened.

According to the rolling bearing unit 1a with the rotational speed detection device of the present reference example configured as described above, the cover 18a that closes the axially inner end opening of the internal space 16 in which the encoder 21 is installed has the sensor 22a. Based on the pressing of the detector (the tip 36 of the holder) or the like, it can be prevented from being pushed into the encoder 21 side (axially outer side), and the axial position of the cover 18a can be regulated with high accuracy. Further, it is possible to prevent the cover 18a from being deformed so as to reduce the detection accuracy of the sensor 22a.

In other words, in the case of the present reference example, the cover 18a is in a state where the axially outer surface of the abutting portion 25 provided near the outer peripheral edge of the cover 18a is abutted against the axially inner end surface of the outer ring 4. The inner ring 18a is fixed to the outer ring 4. For this reason, as in this reference example , even when the front end portion 36 of the holder is pressed against the inner surface in the axial direction of the bottom plate portion 19a, the cover 18a can be prevented from being pushed into the encoder 21 side. The position of the cover 18a in the axial direction can be regulated with high accuracy. Therefore, in the case of this reference example, the outer surface of the cover 18a in the axial direction can be prevented from colliding with the detected surface of the encoder body 24, and the detected surface can be prevented from being damaged. It is possible to prevent the detection gap between the detected surface and the detection portion of the sensor 22a from becoming inappropriate. Furthermore, since the support ring 23 constituting the encoder 21 can be prevented from coming into contact with the rolling surfaces of the rolling elements 6 in the inner row in the axial direction and the cage 15 holding these rolling elements 6, the rolling It is possible to prevent the bearing performance of the bearing unit 2 from being impaired.

Further, in the case of this reference example , a structure is adopted in which the cover 18a is fitted and fixed to the inner end in the axial direction of the outer ring 4 by an interference fit. It is possible to prevent distortion deformation in the direction, or to suppress the deformation amount. That is, when the cylindrical portion 20a constituting the cover 18a to the inner fitting fixed by interference fit in the axial direction in the end portion of the outer ring 4, but opposite force is applied radially inwards to the bottom plate portion 19a, the reference In the case of the example , this force is consumed to deform the bulging portion 27. Specifically, the force is consumed by further expanding the entire bulging portion 27 in the axial direction while reducing the diameter of the portion near the base end of the bulging portion 27. As a result, the deformation amount of the flat plate portion 26 can be sufficiently suppressed, and the axial position of the flat plate portion 26 can be accurately regulated. In addition, the perpendicularity of the flat plate portion 26 can be improved. Therefore, the posture of the sensor 22a and the axial position of the detection unit, which are embedded and supported in a holder that abuts the tip 36 on the inner side surface of the flat plate portion 26, are accurately regulated as designed. it can. Thus, in the case of this reference example , it is possible to prevent the cover 18a from being deformed so as to reduce the detection accuracy of the sensor 22a, and sufficiently ensure the reliability for detecting the rotational speed. .

[Second example of reference example related to the present invention ]
FIG. 2 shows a second example of a reference example related to the present invention . In the case of this reference example , the outer peripheral edge of the bottom plate portion 19b constituting the cover 18b is folded back 180 degrees to provide the abutting portion 25a at the portion. And the cylindrical part 20b is provided in the state bent at right angles to the axial direction outward from the inner peripheral edge part of this abutting part 25a. Also in the case of this reference example, the bottom plate portion 19b is composed of the flat plate portion 26 and the bulging portion 27a. However, in the case of this reference example , the bulging portion 27a is disposed outside the axial direction. It bulges towards the direction.

In the case of this reference example , the bottom plate portion 29 and the fitting tube portion 30 constituting the sensor holding plate 28a are connected via the step portion 39, and the axially outer surface of the step portion 39 is The abutting portion 25a is sandwiched between the axially inner end surfaces of the outer ring 4 from both axial sides. Further, in the case of this reference example , a nut 33 is fixed to the inner surface (axially outer surface) side of the bottom plate portion 29.

In the case of this reference example having such a configuration, the bending rigidity in the axial direction of the abutting portion 25a can be increased as compared with the case of the first example of the reference example described above. For this reason, the cover 18b can be more effectively prevented from being pushed outward in the axial direction.
About another structure and an effect, it is substantially the same as the case of the 1st example of the reference example mentioned above.

[Third example of reference example related to the present invention ]
FIG. 3 shows a third example of the reference example related to the present invention . In the case of this reference example , the taper part 40 is provided in the outer peripheral part of the bottom plate part 19c which comprises the cover 18c, and the radial direction outer side part rather than the flat plate part 26 which comprises this bottom plate part 19c. The tapered portion 40 has a partially conical cylindrical shape, and is inclined in a direction toward the axially outward direction as it goes outward in the radial direction. In the case of this reference example , the abutting portion is bent at a right angle outwardly in the radial direction from the axial inner end edge of the cylindrical portion 20b that is fitted and fixed to the axial inner end portion of the outer ring 4 with an interference fit. 25b is provided. And the outer periphery of this abutting part 25b and the outer periphery of the said taper part 40b are made to continue smoothly (with the curved surface of a cross-section convex circular arc shape).

In the case of this reference example having such a configuration, as in the case of the structure of the second example of the reference example described above, a butting portion 25a (see FIG. 2) is obtained by folding a nonmagnetic plate such as a stainless steel plate 180 degrees. Compared with the case of forming, the force (pressing force) required for processing the cover 18c can be reduced, and the processing cost of the cover 18c can be reduced. In the case of carrying out the present reference example , a convex arcuate cylindrical portion having a large curvature radius may be provided instead of the tapered portion 40.
For the other configurations and operational effects are substantially the same as those in the second example of the first example in the case and the above-mentioned Reference Example Reference example described above.

[Fourth Reference Example Related to the Present Invention ]
FIG. 4 shows a fourth example of the reference example related to the present invention . In the case of this reference example, the portion closer to the outer diameter of the bottom plate portion 19d constituting the cover 18d functions as the abutting portion 25c. Further, a cylindrical portion 20c is provided in a state of being bent at a right angle outward from the outer peripheral edge of the bottom plate portion 19d (the abutting portion 25c), and the cylindrical portion 20c is fastened to the inner end of the outer ring 4 in the axial direction. It is fixed by external fitting.

In the case of this reference example having such a configuration, the shape of the cover 18d can be simplified, and the processing cost of the cover 18d can be reduced. Further, since the cover 18d is fitted and fixed to the inner end of the outer ring 4 in the axial direction, the cover 18d is supported and fixed to the outer ring 4 to the bottom plate 19d constituting the cover 18d. A force directed radially inward is not applied. For this reason, in the case of this reference example , the bulging part 27a provided in this bottom-plate part 19d can also be abbreviate | omitted. However, by providing the bulging portion 27a, the nut 33 (see FIGS. 1 and 2) used for mounting and fixing the sensor 22a (see FIGS. 1 and 2) is attached to the inner surface of the sensor holding plate 28 (see FIG. 1). It becomes easy to fix to the (axial direction outer side surface), and it becomes easy to aim at shortening of the axial direction dimension of the rolling bearing unit 1a with a rotational speed detection apparatus.
About another structure and an effect, it is the same as that of the case of the 1st example and 2nd example of a reference example mentioned above.

[Fifth example of reference example related to the present invention ]
FIG. 5 shows a fifth example of the reference example related to the present invention . In the case of this reference example , the taper part 40a is provided in the part near the outer periphery of the baseplate part 19e which comprises the cover 18e. The tapered portion 40a has a partially conical cylindrical shape and is inclined in a direction toward the axially outward direction as it goes outward in the radial direction. The taper portion 40a is a cylinder in which the inner peripheral edge thereof is continued to the outer peripheral edge of the flat plate portion 26 constituting the bottom plate portion 19e, and the outer peripheral edge thereof is fitted and fixed to the inner end portion in the axial direction of the outer ring 4. It is made to continue to the axial direction outer end edge of the part 20a.

Also in the case of the present reference example having such a configuration, the cover 18e is fixed to the inner end of the outer ring 4 in the axial direction by an interference fit so that the bottom plate 19e is directed radially inward. In the case of this reference example , this force can be consumed by deforming the tapered portion 40a together with the bulging portion 27a. For this reason, the flat plate portion 26 does not undergo distortion in the axial direction, or the amount of deformation can be sufficiently suppressed. Therefore, in the case of this reference example , it becomes more advantageous in ensuring the detection accuracy of the sensor 22a (see FIGS. 1 and 2).
About another structure and an effect, it is the same as that of the case of the 1st example of the reference example mentioned above.

[Sixth Reference Example Related to the Present Invention ]
FIG. 6 shows a sixth example of the reference example related to the present invention . In the case of this reference example , the outer peripheral edge of the bottom plate portion 19 (the flat plate portion 26) constituting the cover 18f is bent at a right angle outward in the axial direction, and then folded 180 degrees to form the cylindrical portion 20d. Yes.
In the case of this reference example having such a configuration, the bending rigidity in the radial direction of the cylindrical portion 20d can be increased. For this reason, the fitting strength of the cover 18f with respect to the outer ring 4 can be improved.
About another structure and an effect, it is the same as that of the case of the 1st example of the reference example mentioned above.

[Seventh example of a reference example related to the present invention ]
FIG. 7 shows a seventh example of the reference example related to the present invention . The feature of this reference example is that the mounting structure of the sensor holding plate 28a is devised with respect to the structure of the second example of the reference example described above. That is, in the case of the present reference example , the caulking portion 41 is formed by plastically deforming the axially outer end portion (tip portion) of the fitting tube portion 30a of the sensor holding plate 28a radially inward. . Further, a concave groove 42 is formed over the entire circumference on the outer peripheral surface of the outer ring 4 near the inner end in the axial direction. The caulking portion 41 is engaged with the concave groove 42. In the case of this reference example, the caulking portion 41 is covered with the sealing material 38a over the entire circumference.

In the case of this reference example having such a configuration, it is possible to effectively prevent the sensor holding plate 28a from slipping inward in the axial direction with respect to the outer ring 4. For this reason, the displacement of the cover 18b inward in the axial direction can be more effectively achieved as compared with the structure of the second example of the reference example . Further, in the case of the present reference example , since the caulking portion 41 is covered with the sealing material 38a, foreign matter such as rainwater may enter the fitting portion between the fitting cylinder portion 30a and the outer ring 4. Can be effectively prevented.
About another structure and an effect, it is substantially the same as the case of the 1st example of the reference example mentioned above, and the 2nd example.

[Eighth example of reference example related to the present invention ]
FIG. 8 shows an eighth example of the reference example related to the present invention . In the case of the present reference example, the configuration relating to the sensor holding plate 28a shown in the seventh example of the reference example described above is partially changed and applied to the structure of the fourth example of the reference example described above. That is, in the case of the present reference example , instead of omitting the sealing material 38a (see FIG. 7) covering the caulking portion 41, rubber or vinyl is formed on the inner peripheral surface in the axial direction inner end portion of the cylindrical portion 20c constituting the cover 18d. The sealing material 38b having elasticity such as the above is covered all around. The sealing material 38b is elastically compressed in the radial direction over the entire circumference between the inner peripheral surface of the inner end portion in the axial direction of the cylindrical portion 20c and the outer peripheral surface of the inner end portion in the axial direction of the outer ring 4. It is pinched.
In the case of this reference example having such a configuration, since the sealing material 38b is not directly exposed to the outside, the durability of the sealing material 38b can be ensured.
Other configurations and operational effects are substantially the same as those of the first example, the fourth example, and the seventh example of the reference example described above.

[ First example of embodiment]
FIG. 9 shows a first example of an embodiment of the present invention corresponding to claim 1 . In the case of this example, a circular flat plate is used as the cover 18g, and the axially outer surface near the outer peripheral edge of the cover 18g is abutted against the axially inner end surface of the outer ring 4. In other words, the portion near the outer peripheral edge of the cover 18g functions as the abutting portion 25d. In the case of this example, the outer peripheral edge of the cover 18g is covered with a sealing material 38c having elasticity such as rubber or vinyl over the entire circumference.

In the case of this example, the cover 18g is covered from the inner side in the axial direction by using the sensor holding plate 28b having the same configuration as that of the second example of the reference example described above. That is, the sensor holding plate 28 b includes a bottom plate portion 29 and a fitting cylinder portion 30, and a step portion 39 a that continues the bottom plate portion 29 and the fitting cylinder portion 30. Such a sensor holding plate 28b is supported and fixed to the outer ring 4 by fixing the fitting cylinder part 30 to the inner end in the axial direction of the outer ring 4 by an interference fit.

  In particular, in the case of this example, with the sensor holding plate 28b fitted and fixed to the outer ring 4 as described above, the axially outer surface of the stepped portion 39a and the axially inner end surface of the outer ring 4 are The portion near the outer peripheral edge of the cover 18g is sandwiched from both sides in the axial direction. As a result, the cover 18g is supported and fixed to the outer ring 4 with the axially outer surface of the portion near the outer peripheral edge abutted against the axially inner end surface of the outer ring 4. In this state, the sealing material 38c is compressed in the radial direction over the entire circumference between the outer peripheral edge portion of the cover 18g and the inner peripheral surface of the axially inner end portion of the fitting cylinder portion 30. It is pinched.

In the case of this example having such a configuration, with the cover 18g supported and fixed to the outer ring 4, the axially outer side surface of the cover 18g near the outer peripheral edge (the abutting portion 25d) Since it abuts against the inner end surface in the axial direction, it is possible to prevent the cover 18g from being pushed into the encoder 21 side based on the pressing of the tip 36 of the holder in which the sensor 22a is embedded and held. In the case of this example, the cover 18g is supported and fixed to the outer ring 4 using the sensor holding plate 28b without being fitted and fixed to the inner end of the outer ring 4 in the axial direction. Therefore, the cover 18g is not deformed in the axial direction as in the case of the conventional structure described above. Therefore, the detection accuracy of the sensor 22a does not decrease due to deformation accompanying support and fixing of the cover 18g. Further, in the case of this example, since the sealing material 38c is provided between the outer peripheral edge portion of the cover 18g and the inner peripheral surface of the fitting cylinder portion 30 in the axial direction, Foreign matter such as rainwater entering from the fitting portion with the fitting cylinder portion 30 is prevented from entering the inner space 16 where the encoder 21 is installed and the space 34 where the tip 36 of the holder is inserted. it can.
About another structure and an effect, it is substantially the same as the case of the 1st example of the reference example mentioned above.

[ Second Example of Embodiment]
FIG. 10 shows a second example of an embodiment of the present invention corresponding to claim 2 . In the case of this example, with respect to the structure of the first example of the above-described embodiment, instead of omitting the sealing material 38c (see FIG. 9), both side surfaces in the axial direction near the outer peripheral edge of the cover 18g and the outer ring 4 A pair of annular seal members 43a and 43b are provided in a state in which the inner peripheral edge portion of the abutting portion between the axial inner end surface and the stepped portion 39a constituting the sensor holding plate 28b is closed. Both the annular seal members 43a and 43b are made of an elastic material such as rubber or an elastomer such as vinyl, and are formed in an annular shape as a whole. Before the cover 18g is supported and fixed to the outer ring 4, The cover 18g is bonded to the portion near the outer diameter on both sides in the axial direction by vulcanization adhesion or the like.
Also in the case of this example having such a configuration, rainwater or the like that has entered from a gap between the outer peripheral surface of the inner end portion in the axial direction of the outer ring 4 and the inner peripheral surface of the fitting cylindrical portion 30 is caused by the encoder 21. It is possible to effectively prevent the intrusion into the internal space 16 in which is installed and the space 34 in which the tip 36 of the holder is inserted.
About another structure and an effect, it is the same as that of the case of the 1st example of the said embodiment .

[ Third example of embodiment]
FIG. 11 shows a third example of an embodiment of the present invention corresponding to claims 1 and 2 . In the case of this example, the sealing material 38d made of an elastic material is provided so as to cover the portion near the outer peripheral edge of the cover 18g. The sealing material 38d is compressed in the axial direction between the axially opposite side surfaces of the portion near the outer peripheral edge of the cover 18g and the axially inner end surface of the outer ring 4 and the axially outer surface of the stepped portion 39a. And is sandwiched between the outer peripheral edge of the cover 18g and the inner peripheral surface of the fitting cylinder 30 in a radially compressed state. Also in the case of this example, the inner peripheral edge of the contact portion between the axially opposite side surfaces of the portion near the outer peripheral edge of the cover 18g and the axially inner end surface of the outer ring 4 and the axially outer surface of the stepped portion 39a. A pair of annular seal members 43a and 43b are provided in a state in which the respective parts are closed. The two annular seal members 43a and 43b and the sealing material 38d may be integrated.
In the case of this example having such a configuration, compared to the case of the first example and the second example of the above-described embodiment , foreign matter such as rainwater is caused by the internal space 16 in which the encoder 21 is installed and the tip of the holder. Intrusion into the space 34 in which the 36 is inserted can be prevented more effectively.
About another structure and an effect, it is the same as that of the case of the 1st example of the said embodiment, and a 2nd example .

In the first example and the second example of the reference examples related to the present invention, the sensor holding plate that is externally fitted and fixed to the inner end in the axial direction of the outer ring is used to show the structure for supporting the sensor. ) May be directly supported and fixed to the outer ring, or may be directly supported and fixed to a suspension device such as a knuckle. Such a sensor mounting structure is not limited to the structure of the first example and the second example of the reference example , but is similarly applied to the structures of the third to eighth examples of the reference example related to the present invention. it can.

DESCRIPTION OF SYMBOLS 1, 1a Rolling bearing unit with a rotational speed detection apparatus 2 Rolling bearing unit 3 Rotational speed detection apparatus 4 Outer ring 5 Hub 6 Rolling body 7 Outer ring raceway 8 Static side flange 9 Knuckle 10 Hub body 11 Inner ring 12 Caulking part 13 Inner ring raceway 14 Rotation side Flange 15 Cage 16 Internal space 17 Seal ring 18, 18a-18g Cover 19, 19a-19e Bottom plate part 20, 20a-20d Cylindrical part 21 Encoder 22, 22a Sensor 23 Support ring 24 Encoder body 25, 25a-25d Butting part 26 Flat plate portion 27, 27a Swelling portion 28, 28a, 28b Sensor holding plate 29 Bottom plate portion 30, 30a Fitting cylinder portion 31 Through hole 32 Mounting hole 33 Nut 34 Space 35 Bolt 36 Tip portion 37 Mounting flange 38, 38a to 38d Sealing material 39, 39a Step part 0,40a tapered portion 41 caulking portion 42 concave groove 43a, 43b annular sealing member

Claims (2)

The outer ring has a double row outer ring raceway on the inner peripheral surface, is supported by a suspension system in use, and does not rotate. The outer ring has a double row inner ring raceway, and the outer ring has an inner ring side that is concentric with the outer ring. A hub provided with a rotation-side flange for supporting a wheel at a portion of the outer peripheral surface that protrudes outward in the axial direction from the axial outer end of the outer ring, the outer ring raceways, and the inner rings. A plurality of rolling elements provided so as to be able to roll in each row between the raceway and the magnetic properties of the inner surface in the axial direction are alternately changed with respect to the circumferential direction. An annular encoder supported concentrically with the hub, and a non-magnetic plate cover supported and fixed at the axially inner end of the outer ring to block the axially inner end opening of the outer ring And the detection part is brought into contact with or in close proximity to the inner surface in the axial direction of the cover. Through it, at the detection portion in the rotation speed sensing rolling bearing unit with a sensor made to face in the axial direction in the side surface of the encoder,
The cover is in the shape of a circular flat plate, the axially outer surface of the portion near the outer peripheral edge is abutted against the axially inner end surface of the outer ring, and a sensor holding plate that supports the sensor on a part of the outer ring In a state where the portion near the outer peripheral edge of the cover is sandwiched from both sides in the axial direction between the inner end surface in the axial direction and is fitted and fixed to the inner end in the axial direction of the outer ring,
A sealing member having elasticity in the outer peripheral edge of the cover is coated over the entire circumference, the sealing material between the outer periphery and the inner peripheral surface of the sensor holding plate of the cover, Wataru all around A rolling bearing unit with a rotational speed detecting device characterized in that it is clamped in a state of being elastically compressed in the radial direction. The outer ring has a double row outer ring raceway on the inner peripheral surface, is supported by a suspension system in use, and does not rotate. The outer ring has a double row inner ring raceway, and the outer ring has an inner ring side that is concentric with the outer ring. A hub provided with a rotation-side flange for supporting a wheel at a portion of the outer peripheral surface that protrudes outward in the axial direction from the axial outer end of the outer ring, the outer ring raceways, and the inner rings. A plurality of rolling elements provided so as to be able to roll in each row between the raceway and the magnetic properties of the inner surface in the axial direction are alternately changed with respect to the circumferential direction. An annular encoder supported concentrically with the hub, and a non-magnetic plate cover supported and fixed at the axially inner end of the outer ring to block the axially inner end opening of the outer ring And the detection part is brought into contact with or in close proximity to the inner surface in the axial direction of the cover. Through it, at the detection portion in the rotation speed sensing rolling bearing unit with a sensor made to face in the axial direction in the side surface of the encoder,
The cover is in the shape of a circular flat plate, the axially outer surface of the portion near the outer peripheral edge is abutted against the axially inner end surface of the outer ring, and a sensor holding plate that supports the sensor on a part of the outer ring In a state where the portion near the outer peripheral edge of the cover is sandwiched from both sides in the axial direction between the inner end surface in the axial direction and is fitted and fixed to the inner end in the axial direction of the outer ring,
The inner peripheral edge of the contact portion between the abutting mating surfaces between the axial side surface to the axial side surface of the outer peripheral edge portion close to said cover, characterized in that are closed over the entire circumference by a sealing material having an elastic A rolling bearing unit with a rotational speed detector.

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