JP2007101352A - Rolling bearing unit with rotation detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid adhesion of foreign matters existing in external space on an encoder 18, shorten the distance between the surface to be detected on the encoder 18 and the detection part of a sensor 19 and realize a structure of the sensor 19 hardly damaged by a flying stone and the like. <P>SOLUTION: The encoder 18 is provided on a surface facing the internal space 23 comprising a rotor 14 on a wheel part 22 of a support ring 20 fixed on the inner end of a rotating inner wheel 13a. The sensor 19 faces a surface to be detected on the encoder 18 from the inner space 23 side in a state held by a holder 24 supported with a non-rotating outer wheel 12. The tip end part of seal lips 34, 34 added on the outer edge of the wheel part 22 is slid on a part of the holder 24 over whole circumference. With this constitution, the above problem is resolved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The rolling bearing unit with a rotation detecting device according to the present invention supports a vehicle wheel rotatably with respect to a suspension device, and is used for detecting the rotation speed or rotation angle of the wheel.

  A rolling bearing unit is used to rotatably support the wheels of the automobile with respect to the suspension system. In order to control the anti-lock brake system (ABS) or 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 rotation detection device incorporating a rotation speed detection device in the rolling bearing unit supports the wheel rotatably with respect to the suspension device, and detects the rotation speed of the wheel. In recent years, it has been widely performed.

  The rolling bearing unit with rotation detector used for such a purpose is an annular encoder on the rotating side bearing ring that rotates during use among the rotating side and stationary side bearing rings constituting the wheel supporting rolling bearing unit. Are configured such that the sensors are supported on stationary stationary rings that do not rotate during use. Among these encoders, the characteristics of the detected surface provided concentrically with the rotation center of the rotating side raceway are changed alternately (generally at regular intervals) in the circumferential direction. In addition, the sensor has its detection unit in close proximity to the detected surface of the encoder, and changes its output signal in response to a change in the characteristics of the detected surface. The period of change of the output signal becomes shorter (the frequency becomes higher) as the rotation speed of the rotation side raceway becomes faster. Therefore, the rotation speed of the rotation side raceway ring is obtained by the period or frequency of the output signal. The ABS and TCS can be appropriately controlled.

  Conventionally, in order to constitute a rolling bearing unit with a rotation detection device as described above, it is considered to use a permanent magnet as an encoder and a magnetic detection element such as a Hall element or a magnetoresistive element as a sensor. And some have been implemented. If a rotation detection device is configured with such an encoder and sensor, the sensor can be downsized, and the magnitude (amplitude) of the output signal of this sensor can be made substantially constant from low speed to high speed to detect rotational speed. Can improve reliability.

  However, when configuring a rotation detection device using an encoder made of a permanent magnet as described above, it is necessary to consider in order to prevent foreign matters such as dust existing in the external space from adhering to the encoder. . The first reason for this is that when magnetic powder or the like adheres to the surface to be detected of this encoder, the state of the characteristic change of this surface to be detected changes from the intended state, and the accuracy of rotation speed detection by the above sensor This is because it gets worse. The second reason is to prevent wear of the encoder. That is, an encoder made of a permanent magnet is obtained by mixing a magnetic powder such as ferrite in a polymer material such as rubber or synthetic resin, and is soft and easy to wear as a whole. For this reason, if a hard foreign matter adheres to the detected surface and the foreign matter is caught between the detected surface and the detection portion of the sensor, the encoder may be worn. When the volume of the encoder decreases with wear, the density of magnetic flux reaching the detection portion of the sensor from the detected surface decreases, and the accuracy of rotational speed detection by the sensor deteriorates.

  In order to prevent such a problem from occurring, it is conceivable to shield the portion where the encoder and sensor are installed from an external space where foreign matters such as dust are present. Conventionally, for example, those described in Patent Documents 1 and 2 are known as rolling bearing units with a rotation detection device considered in such circumstances. First, FIG. 6 shows a first example of a conventional structure described in Patent Document 1. In the case of the first example of this conventional structure, the detection surface of the encoder 2 made of a permanent magnet fitted and fixed to the rotating inner ring 1 and the detection portion of the sensor 4 supported by the non-rotating outer ring 3 are connected to a seal ring. It is made to oppose through the metal core 6 which comprises 5. The metal core 6 is made of a nonmagnetic metal plate. FIG. 7 shows a second example of the conventional structure described in Patent Document 2. In the case of the second example of the conventional structure, a through hole 8 is formed in a part of the support ring 7 for supporting the sensor 4a on the non-rotating outer ring 3, and the detection portion of the sensor 4a supported on the support ring 7 is formed. Is arranged in the through-hole 8 portion, and the detection portion and the detected surface of the encoder 2a are directly opposed to each other.

  In the case of the structure of the first example, the distance between the detection unit and the detection surface is increased by the presence of the cored bar 6 between the detection unit of the sensor 4 and the detection surface of the encoder 2. . As a result, the density of the magnetic flux that comes out of the surface to be detected and reaches the detection unit is lowered, and it becomes difficult to ensure the reliability of the rotation speed detection of the encoder 2 by the sensor 4. On the other hand, in the case of the structure of the second example, the distance between the detection portion of the sensor 4a and the detected surface of the encoder 2a is shortened, and the reliability of the rotation speed detection of the encoder 2a by the sensor 4a is reliable. Easy to secure. However, in the case of the structure of the second example, the sensor 4a is exposed to the external space as in the structure of the first example. In both of the structures of the first and second examples, the sensors 4 and 4a are embedded and held in the holders 9 and 9a, but the holders 9 and 9a are made of synthetic resin and do not necessarily have sufficient strength. There is a possibility of damage if pebbles, etc., from which the wheel bounces collide.

JP-A-10-160744 JP 2003-254985 A

The present invention has been invented to realize a structure that simultaneously satisfies the following conditions (1) to (3) in view of the circumstances as described above.
(1) Foreign matter existing in the external space does not adhere to the encoder.
(2) The distance between the detected surface of the encoder and the detection portion of the sensor is shortened to ensure the reliability of rotation detection of the inner ring equivalent member that supports the encoder.
(3) Make the sensor less susceptible to damage by stepping stones.

The rolling bearing unit with a rotation detection device of the present invention includes an outer ring, an inner ring equivalent member, a plurality of rolling elements, an encoder, and a sensor, as in the conventionally known rolling bearing unit with a rotation detection device. Prepare.
Of these, the outer ring has a mounting flange for mounting on the suspension device on the outer peripheral surface and an outer ring track on the inner peripheral surface, and does not rotate during use.
Further, the inner ring equivalent member has an inner ring raceway opposed to the outer ring raceway on the outer peripheral surface, and rotates during use.
Each rolling element is provided between the outer ring raceway and the inner ring raceway so as to roll freely.
The encoder is supported by the inner end of the inner ring equivalent member in the axial direction, and the characteristics of the detected surface that is concentric with the inner ring equivalent member are alternately changed in the circumferential direction.
Further, the sensor is supported by the inner end in the axial direction of the outer ring with the detection portion facing the detection surface, and changes the output signal in response to a change in characteristics of the detection surface. .

In particular, in the rolling bearing unit with a rotation detection device of the present invention, the encoder has an annular shape in which the characteristics of the surface facing the internal space where the rolling elements are installed are alternately changed in the circumferential direction. . Further, the inner ring corresponding to the inner space of the axially opposite side surfaces of the annular ring portion extending in the radial direction, which constitutes a support ring fixed to a portion deviated from the inner ring raceway on the outer peripheral surface of the inner end portion of the inner ring equivalent member. Attached to the surface to cover the entire circumference.
The sensor is opposed to the detection surface of the encoder from the inner space side while being held by an annular holder supported by the outer ring.
Further, the tip edge of the sealing lip made of an elastic material, the base end of which is attached to the outer peripheral portion of the annular portion in the radial direction from the encoder over the entire circumference, is part of the holder. It is slid over the circumference.

Preferably, as described in claim 2, the holder includes an outer case made of a metal plate and an inner case made of a synthetic resin.
Among these, the outer case has a cylindrical portion that is fitted and fixed to the inner end portion of the outer ring by an interference fit. The inner case holds the sensor in part. Further, the axially inner end portion of the metal plate constituting the outer case is pushed and bent radially inward to cover at least a part of the axial inner side surface of the inner case over the entire circumference. Yes. Then, the tip edge of the seal lip is brought into sliding contact with the part of the metal plate that covers the entire inner circumference in the axial direction of the inner case.
When carrying out such a structure described in claim 2, more preferably, as described in claim 3, the holder is present around the inner end in the axial direction of the inner ring equivalent member. Then, the inner end portion in the axial direction of the holder is not protruded inward in the axial direction from the inner end surface in the axial direction of the member corresponding to the inner ring.

  In carrying out the present invention, for example, as described in claim 4, the outer ring having a double-row outer ring raceway formed on the inner peripheral surface is used. Then, the inner ring equivalent member is a hub having a coupling flange for coupling and fixing the wheel to a portion near the outer end in the axial direction of the outer peripheral surface, and a hub having double row inner ring raceways in the middle portion to the inner end portion.

According to the rolling bearing unit with a rotation detector of the present invention configured as described above, the following conditions (1) to (3) can be satisfied simultaneously.
(1) Foreign matter existing in the external space does not adhere to the encoder.
(2) The distance between the detected surface of the encoder and the detection portion of the sensor is shortened to ensure the reliability of rotation detection of the inner ring equivalent member that supports the encoder.
(3) Make the sensor less susceptible to damage by stepping stones.

  First of all, the encoder is attached to a surface facing the inner space among the annular parts constituting the support ring fixed to the inner ring equivalent member, and the outer peripheral edge of the annular part The gap between the holder and the holder fixed to the outer ring is closed by a seal lip over the entire circumference. Accordingly, the space in which the encoder is installed is cut off from the external space, and foreign matter existing in the external space can be prevented from adhering to the encoder {satisfies the condition (1)}.

  Second, the encoder is attached to a side surface of the annular portion that faces the internal space, and the detection portion of the sensor faces the detected surface of the encoder from the side of the internal space. ing. Therefore, even if it is considered that foreign matter does not adhere to the encoder, it is not necessary to provide a shielding object between the detection portion of the sensor and the detected surface of the encoder. For this reason, the detection unit and the surface to be detected are sufficiently close to each other, the output signal of the sensor is surely changed with the rotation of the encoder, and the rotation detection of the inner ring equivalent member supporting the encoder is performed. Reliability can be ensured {satisfying condition (2) above}.

  Third, at least a portion of the holder that holds the sensor can be covered with the support ring. Therefore, the stepping stone or the like does not hit the part of the holder that holds the sensor, and the stepping stone or the like can hardly damage the sensor {the condition (3) can be satisfied}. And even when used under severe conditions over a long period of time, it is possible to ensure reliability regarding rotation detection.

Further, as described in claim 2, if the holder is composed of a metal plate outer case and a synthetic resin inner case, the entire synthetic resin inner case holding the sensor can be formed by a stepping stone or the like. It can prevent being damaged. For this reason, the reliability regarding rotation detection can be more sufficiently achieved.
Further, the sliding contact portion of the seal lip is brought into sliding contact with a portion of the metal plate constituting the outer case that covers the entire inner circumference in the axial direction of the inner case. It is possible to improve the sealing performance and durability. That is, since the wear resistance of the metal plate is superior to the wear resistance of the synthetic resin, the wear of the portion where the tip edge of the seal lip is in sliding contact is suppressed regardless of the use over a long period of time. Sufficient durability can be secured.

  According to a third aspect of the present invention, the holder is present around the axial inner end of the inner ring equivalent member, and the axial inner end of the holder is the axial inner end surface of the inner ring equivalent member. If a configuration that does not protrude further inward in the axial direction is employed, the axial dimension of the rolling bearing unit with rotation detection device can be kept short, and the rolling bearing unit with rotation detection device can be reduced in size and weight.

[First example of embodiment]
1 and 2 show a first example of an embodiment of the present invention corresponding to claims 1 to 3. In this example, when the present invention is applied to a wheel bearing rolling bearing unit for rotatably supporting a drive wheel supported by a semi-floating suspension device such as a rear wheel of a commercial vehicle such as a truck. It shows. The rolling bearing unit with rotation detection device of this example is formed by combining a rotation detecting device 11 with a double-row angular wheel supporting rolling bearing unit 10 provided with a rear combination type contact angle.

  Of these, the wheel support rolling bearing unit 10 includes one outer ring 12, a pair of inner rings 13 a and 13 b, and a plurality of rolling elements 14 and 14. Of these, the outer ring 12 has an attachment flange 15 for attachment to the suspension device on the outer peripheral surface, and double-row outer ring raceways 16 and 16 on the inner peripheral surface. Such an outer ring 12 is coupled and fixed to the suspension device by the mounting flange 15 during use and does not rotate. The inner rings 13a and 13b have inner ring raceways 17 and 17 facing the outer ring raceways 16 and 16 on their outer peripheral surfaces. The rolling elements 14 and 14 are provided between the outer ring raceways 16 and 16 and the inner ring raceways 17 and 17 so as to freely roll, and the inner races 13a on the inner diameter side of the outer race 12 are provided. , 13b can be freely rotated. During use, the inner rings 13a and 13b are externally fixed to an axle shaft (not shown). Accordingly, these inner rings 13a and 13b rotate during use.

  The rotation detection device 11 includes an encoder 18 and a sensor 19. Of these inner rings 13a and 13b, the encoder 18 has an inner end in the axial direction of the inner ring 13a on the inner side in the axial direction. (On the other hand, the left side of each figure outside the width direction of the vehicle is called the outside in the axial direction. The same applies in the present specification and claims.) Further, it is supported via a support ring 20. The support ring 20 is made of a magnetic metal plate such as a mild steel plate or a martensitic stainless steel plate and is formed into an annular shape as a whole with an L-shaped cross section. And an annular portion 22 that is bent at a right angle from the end toward the outside in the radial direction. Such a support ring 20 is supported and fixed to the inner ring 13a concentrically with the inner ring 13a by fitting the cylindrical part 21 to the inner end in the axial direction of the inner ring 13a with an interference fit. In this state, the inner side surface in the axial direction of the annular ring portion 22 is located on the same plane as the inner end surface in the axial direction of the inner ring 13a, or is located on the outer side in the axial direction from the inner end surface in the axial direction (in the axial direction). It does not protrude beyond the end face).

The encoder 18 has a surface (an axially outer surface) facing the internal space 23 in which the rolling elements 14 and 14 are installed, of both side surfaces in the axial direction of the annular portion 22 of the support ring 20 as described above. It is attached concentrically with the support ring 20. The encoder 18 is a permanent magnet (rubber magnet or plastic magnet) in which a ferromagnetic powder such as ferrite is mixed in a polymer material such as rubber or synthetic resin, and is in the axial direction (left-right direction in FIGS. 1 and 2). Is magnetized. The magnetization direction is changed alternately and at equal intervals over the circumferential direction. Therefore, the south pole and the north pole are alternately arranged at equal intervals on the outer surface in the axial direction, which is the detected surface of the encoder 18. Incidentally, the axial dimension L ₂₁ of the cylindrical portion 21 and, the thickness T ₁₈ of the encoder 18, regulates the proper value. Further, the base end portion of the seal lips 34, 34 is supported on the outer peripheral edge portion of the circular ring portion 22 over the entire circumference.

  On the other hand, the sensor 19 is supported on the outer ring 12 via an annular holder 24. The holder 24 includes an outer case 25 and an inner case 26. Of these, the outer case 25 is made by bending a metal plate having sufficient corrosion resistance, such as a stainless steel plate or a plated steel plate, or by subjecting the steel plate to a bending process such as cationic coating. As a result, the whole is formed in an annular shape with a substantially L-shaped cross section. A cylindrical portion 27 is provided on the outer peripheral edge portion of such an outer case 25. An inner diameter of the cylindrical portion 27 in a free state is slightly smaller than an outer diameter of the inner end portion in the axial direction of the outer ring 12, and the cylindrical portion 27 is tightly fitted to the inner end portion in the axial direction of the outer ring 12. The outer fitting is fixed. Further, the inner end portion in the axial direction of the cylindrical portion 27 is bent at a right angle inward in the diametrical direction to form an outer diameter side annular portion 28. Further, the inner peripheral edge of the outer diameter side circular ring portion 28 is bent at right angles toward the outer side in the axial direction to form an inner diameter side cylindrical portion 29, and the outer end in the axial direction of the inner diameter side cylindrical portion 29 is set in the radially inner direction. The inner ring portion 30 is bent at a right angle toward the inner side. A through hole 32 for taking out the harness 31 described below is formed in a part of the outer diameter side annular portion 28 in the circumferential direction. However, other portions (a cylindrical portion 27, an inner diameter side cylindrical portion 29) are formed. The inner diameter side annular portion 30) is continuous over the entire circumference.

  On the other hand, the inner case 26 is formed as a whole in an annular shape by injection molding synthetic resin such as polyamide resin, and holds the sensor 19 in part. When the inner case 26 is injection-molded, the sensor 19 is embedded and supported in the synthetic resin constituting the inner case 26 with its detection portion directed inward in the axial direction. In order to take out the output signal of the sensor 19 from the holder 24, a convex portion 33 is provided on a part of the inner end surface in the axial direction of the inner case 26, and the convex portion 33 is inserted into the through hole 32. ing. The proximal end portion of the harness 31 for taking out the output signal of the sensor 19 is connected to the sensor 19 through the convex portion 33. It should be noted that the method for joining the inner case 26 and the outer case 25 is not particularly limited. The separately formed inner case 26 and outer case 25 may be combined later by bonding or fitting, or in a state where the outer case 25 is set in the cavity of the inner case 26 working mold. The inner case 26 may be injection molded.

  In any case, as shown in FIGS. 1 and 2, the holder 24 formed by combining the outer case 25 and the inner case 26 is prior to externally fixing the support ring 20 to the inner end of the inner ring 13a. Then, the outer ring 12 is fitted and fixed to the inner end in the axial direction. At this time, the cylindrical portion 27 is pushed into the axial inner end portion of the outer ring 12 until the axial outer end surface of the inner case 26 contacts the axial inner end surface of the outer ring 12. Then, the inner case 26 is sandwiched between the axially inner end face of the outer ring 12 and both the outer diameter side and inner diameter side annular portions 28, 30 of the outer case 25 from both sides in the axial direction, and at the time of traveling The inner case 26 is not displaced regardless of vibration. The axial dimensions of the inner case 26 and the outer ring 12 are restricted to appropriate values in advance, and the mounting position of the sensor 19 with respect to the inner case 26 is also restricted appropriately, so that the inner case 26 holds the inner case 26. The axial position of the sensor 19 is restricted to a preset appropriate position. Further, since the outer end portion in the axial direction of the cylindrical portion 27 is fitted to the inner end portion in the axial direction of the outer ring 12 by an interference fit, the inner peripheral surface of the outer end portion in the axial direction of the cylindrical portion 27 and the axial direction of the outer ring 12 are provided. The inner end portion is in contact with the outer peripheral surface without any gap over the entire periphery. Therefore, the sealing performance of the mounting portion (fitting portion) of the holder 24 with respect to the outer ring 12 is sufficiently ensured.

If the holder 24 is attached to the outer ring 12 as described above, the support ring 20 is then fitted and fixed to the inner end of the inner ring 13a by an interference fit. At this time, the cylindrical portion 21 is moved until the leading edge (axial outer end edge) of the cylindrical portion 21 constituting the support ring 20 abuts on a step surface 35 formed on the outer peripheral surface of the intermediate portion of the inner ring 13a. The inner ring 13a is pushed into the inner end in the axial direction. The axial position of the step surface 35 is properly regulated, and the axial length L _{21 of the} cylindrical portion ₂₁ and the thickness T ₁₈ of the encoder 18 are properly regulated as described above. With the leading edge of the cylindrical portion 21 abutted against the stepped surface 35, the axial position of the detected surface (axially outer surface) of the encoder 18 is an appropriate position. Specifically, the detection surface and the detection unit of the sensor 19 face each other with a minute gap (for example, a thickness of about 0.5 to 2 mm) appropriate for detecting the rotational speed. Further, as described above, with the holder 24 attached to the outer ring 12, and with the support ring 20 fitted and fixed to the inner end of the inner ring 13a, the leading edges of the seal lips 34, 34 are Of the outer case 25, the inner peripheral surface of the inner diameter side cylindrical portion 29 and the inner surface in the axial direction of the inner diameter side annular ring portion 30 are respectively slidably covered over the entire circumference.

  When the encoder 18 rotates together with the inner ring 13a when the rolling bearing unit with the rotation detection device of this example configured as described above is used, the S pole and the N pole existing on the detection surface of the encoder 18 are The portion immediately before the detection portion of the sensor 19 passes alternately. As a result, the output signal of the sensor 19 changes in a cycle (proportional frequency) that is inversely proportional to the rotational speeds of the inner ring 13a and the encoder 18. Therefore, the output signal is sent to the ABS or TCS controller by the harness 31 and used for controlling the ABS or TCS.

  In the structure of this example as described above, the encoder 18 is isolated from the external space by the support ring 20 and the seal lips 34 and 34. Accordingly, it is possible to prevent foreign matters existing in the external space from adhering to the encoder 18. The detecting portion of the sensor 19 directly faces the detected surface of the encoder 18. For this reason, the detection unit and the surface to be detected are sufficiently close to each other, and the output signal of the sensor 19 is reliably changed in accordance with the rotation of the encoder 18, thereby ensuring the reliability of the rotation detection of the inner ring 13a. . Furthermore, since the entire synthetic resin inner case 26 constituting the holder 24 is covered with the outer case 25 and the support ring 20 each made of metal, a stepping stone or the like may hit the inner case 26. The sensor held in the inner case 26 is less likely to be damaged by stepping stones. And even when used under severe conditions over a long period of time, it is possible to ensure reliability regarding rotation detection.

The tip edges of the seal lips 34, 34 are made of an inner peripheral surface of the inner diameter side cylindrical portion 29 and an inner surface in the axial direction of the inner diameter side annular portion 30 among the metal plates constituting the outer case 25. Therefore, the sealing performance and durability of the sliding contact portion can be improved.
Furthermore, in the case of this example, the holder 24 is present around the inner end portion in the axial direction of the inner ring 13a, and the inner end portion in the axial direction of the holder 24 is moved from the inner end surface in the axial direction of the inner ring 13a. Is not projected inward in the axial direction. For this reason, the axial dimension of the rolling bearing unit with rotation detecting device can be kept short, and the rolling bearing unit with rotation detecting device can be made smaller and lighter.

[Second Example of Embodiment]
3-4 show a second example of an embodiment of the invention corresponding to all claims. In this example, the drive wheels supported by the independent suspension system such as front wheels (FF vehicles, 4WD vehicles) or rear wheels (FR vehicles, MR vehicles, 4WD vehicles) of passenger cars can be rotated. A case where the present invention is applied to a rolling bearing unit for supporting a wheel for supporting is shown. Also in this example, double-row outer ring raceways 16 and 16 are formed on the inner peripheral surface of the outer ring 12a. Particularly in the case of this example, the inner ring equivalent member is a hub 38 formed by combining the hub main body 36 and the inner ring 37. Of these, a flange flange 39 for coupling and fixing a wheel is provided near the outer peripheral surface of the hub body 36 in the axial direction, an inner ring raceway 40a is provided at the intermediate portion, and a small-diameter step portion 41 is provided at the inner end portion. Are formed respectively. And the said inner ring | wheel 37 which formed the inner ring | wheel track | orbit 40b in the outer peripheral surface at this small diameter step part 41 is externally fitted by interference fitting. The inner end portion of the inner ring 37 in the axial direction protrudes slightly inward in the axial direction from the inner end surface of the hub body 36 in the axial direction. The inner end surface in the axial direction of the inner ring 37 is restrained by the outer end surface in the axial direction of the housing constituting the constant velocity joint in the assembled state to the vehicle, so that the hub main body 36 is prevented from coming off. Since the configuration and operation of the other parts are the same as in the case of the first example described above, the same parts are denoted by the same reference numerals, and redundant description is omitted.

[Third example of embodiment]
FIG. 5 also shows a third example of an embodiment of the invention corresponding to all claims. In this example, a gap between the outer peripheral surface of the convex portion 33 of the inner case 26 and the inner peripheral surface of the small-diameter cylindrical portion 42 of the outer case 25 is closed by a seal ring 43 such as an O-ring or packing. And even when both the cases 25 and 26 are made separately and combined later, foreign matter such as muddy water existing in the external space is caused by the outer peripheral surface of the convex portion 33 and the inner peripheral surface of the small-diameter cylindrical portion 42. Through the gap between them, the rolling bearing unit is prevented from entering inside. Since the configuration and operation of the other parts are the same as those of the first example described above or the second example described above, illustration and description regarding the equivalent parts are omitted.

  The illustrated embodiment shows the case where the present invention is applied to a wheel bearing rolling bearing unit for driving wheels. However, the present invention shows that the outer ring is a stationary bearing ring and the inner ring equivalent member is a rotating bearing ring. If so, the present invention can be applied to a wheel bearing rolling bearing unit for driven wheels (FR wheel, front wheel of MR vehicle, rear wheel of FF vehicle). Further, when the rotation side raceway is a hub, the structure for coupling and fixing the hub main body and the inner ring is not particularly limited regardless of whether the rotation side raceway is for a driving wheel or a driven wheel. For example, a structure that holds the inner ring against the hub body with a nut screwed to the hub body, or a structure that holds the inner ring against the hub body with a caulking portion formed by plastic deformation of a part of the hub body radially outward. Can be adopted. Further, the rolling elements are not limited to balls as shown in the figure, but may be tapered rollers.

Sectional drawing which shows the 1st example of embodiment of this invention. The A section enlarged view of FIG. Sectional drawing which shows the 2nd example of embodiment of this invention. The B section enlarged view of FIG. The fragmentary sectional view which shows the 3rd example of embodiment of this invention. The fragmentary sectional view which shows the 1st example of a conventional structure. The fragmentary sectional view which shows the 2nd example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner ring 2, 2a Encoder 3 Outer ring 4, 4a Sensor 5 Seal ring 6 Core metal 7 Support ring 8 Through hole 9, 9a Holder 10 Rolling bearing unit for wheel support 11 Rotation detector 12, 12a Outer ring 13a, 13b Inner ring 14 Rolling element DESCRIPTION OF SYMBOLS 15 Mounting flange 16 Outer ring track 17 Inner ring track 18 Encoder 19 Sensor 20 Support ring 21 Cylindrical part 22 Ring part 23 Internal space 24 Holder 25 Outer case 26 Inner case 27 Cylindrical part 28 Outer diameter side annular part 29 Inner diameter side cylindrical part 30 Inner ring portion 31 Hones 32 Through-hole 33 Convex portion 34 Seal lip 35 Step surface 36 Hub body 37 Inner ring 38 Hub 39 Connecting flange 40a, 40b Inner ring raceway 41 Small diameter step portion 42 Small diameter cylindrical portion 43 Seal ring

Claims (4)

  A mounting flange for mounting on the suspension system on the outer peripheral surface, an outer ring raceway on the inner peripheral surface, an outer ring that does not rotate during use, and an inner ring raceway that faces the outer ring raceway on the outer peripheral surface. The inner ring equivalent member is supported by a rotating inner ring equivalent member, a plurality of rolling elements provided between the outer ring raceway and the inner ring raceway, and an inner end in the axial direction of the inner ring equivalent member. And an encoder in which the characteristics of the detected surface, which are concentric with each other, are alternately changed in the circumferential direction, and the detection portion is supported on the inner end in the axial direction of the outer ring with the detected portion facing the detected surface. In a rolling bearing unit with a rotation detector provided with a sensor that changes an output signal in response to a change in characteristics of a surface to be detected, the encoder has a characteristic of a surface facing the internal space in which the rolling elements are installed. With respect to the circumferential direction An axially opposite side surfaces of the radially extending annular ring portion, each of which has a ring shape that is changed into a ring and that forms a support ring fixed to a portion outside the inner ring raceway at the outer peripheral surface of the inner end portion of the inner ring equivalent member. Among these, the sensor is attached to the entire surface of the surface facing the internal space, and the sensor is held by the annular holder supported by the outer ring. The leading edge of the sealing lip made of an elastic material facing from the inner space side and attached to the outer peripheral portion of the annular ring portion in the radial direction from the encoder over the entire circumference A rolling bearing unit with a rotation detecting device, wherein a part of the holder is slidably brought into contact with a part of the holder.   The holder is composed of an outer case made of a metal plate having a cylindrical portion that is fitted and fixed to the inner end of the outer ring by an interference fit, and an inner case made of a synthetic resin that holds a sensor in part. The portion near the inner end in the axial direction of the metal plate constituting the metal plate is pushed and bent radially inward to cover at least a part of the inner side surface in the axial direction of the inner case over the entire circumference, and the tip edge of the seal lip is The rolling bearing unit with a rotation detecting device according to claim 1, wherein a part of the metal plate is slidably in contact with a portion covering the entire inner surface of the inner case in the axial direction.   The holder is present around the axial inner end of the inner ring equivalent member, and the axial inner end of the holder does not protrude axially inward from the axial inner end surface of the inner ring equivalent member. Rolling bearing unit with rotation detector described.   A double row outer ring raceway is formed on the inner circumferential surface of the outer ring, and the inner ring equivalent member has a coupling flange for coupling and fixing the wheel to the axially outer end portion of the outer circumferential surface. The rolling bearing unit with a rotation detection device according to any one of claims 1 to 3, wherein each of the hubs has a double-row inner ring raceway in a portion.

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