JP2020003045A - Wheel bearing device - Google Patents

Abstract

To provide a wheel bearing device which can accurately position a shaft part in an accommodation hole even if forming the accommodation hole whose bottom part is blocked to a support member for supporting a magnetic field sensor which is formed by sealing a magnetic field detection element by the sealing member, and accommodating the shaft part of the sealing member for holding the magnetic field detection element in the accommodation hole.SOLUTION: A wheel bearing device 1 comprises: an inner member 2 attached with a wheel; an outer member 3 for supporting the inner member 2 via a plurality of rolling bodies 4; an encoder 5 fixed to the inner member 2, and having a magnetic member 52 having a plurality of magnetic poles in a peripheral direction; a magnetic field sensor 7 which is formed by sealing a magnetic field detection sensor 71 by a columnar shaft part 721; and a cover 6 having an accommodation hole 610 for accommodating the shaft part 721, and supporting the magnetic field sensor 7 to the outer member 3. The cover 6 has first to third protrusions 615 to 617 which protrude inward from an internal peripheral face 610b of the accommodation hole 610, abut on an external peripheral face 721a of the shaft part 721, and position the shaft part 721.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a wheel bearing device that supports a wheel.

  Conventionally, a wheel bearing device for supporting a wheel includes an inner member having a flange to which the wheel is mounted, and a cylindrical outer member rotatably supporting the inner member through a plurality of rolling elements. ing. Some of such wheel bearing devices have a function for detecting the rotational speed of the wheel (for example, see Patent Document 1).

  The wheel bearing device described in Patent Literature 1 detects an encoder in which a pulsar ring having a plurality of magnetic poles is attached to a cored bar and a magnetic field of a magnetic pole of the pulsar ring as a configuration for detecting a rotation speed of a wheel. And a sensor. The core metal of the encoder is externally fitted and fixed to the inner member. The sensor is embedded in the sensor holder and faces the encoder via a predetermined axial clearance. The sensor holder has a cylindrical shaft portion, and this shaft portion is inserted into a mounting hole of the cover via an O-ring. The cover is externally fitted and fixed to an end of the outer member, supports the sensor holder, and suppresses intrusion of muddy water and the like. The mounting hole penetrates the cover, and a gap between the inner peripheral surface of the mounting hole and the outer peripheral surface of the shaft portion of the sensor holder is sealed by an O-ring.

JP 2009-150421 A

  In the wheel bearing device configured as described above, since the O-ring is fitted to the shaft portion of the sensor holder, the number of parts and the number of assembling steps increase. Therefore, the present inventors formed an accommodation hole with a closed bottom in a support member that supports the magnetic field sensor with respect to the outer member, and a shaft portion of a sealing member that seals the magnetic field detection element in the accommodation hole. It is considered that the O-ring becomes unnecessary by accommodating the O-ring. However, in this case, the shaft portion rattles in the housing hole due to a gap unavoidably generated due to a difference in diameter between the inner diameter of the housing hole and the outer diameter of the shaft portion, and the position of the magnetic field detecting element reduces the strength of the magnetic field of the encoder. There is a possibility that the position is shifted from the strongest position in the radial direction of the encoder.

  Accordingly, the present invention provides a support member for supporting a magnetic field sensor in which a magnetic field detecting element is sealed by a sealing member, wherein a receiving hole having a closed bottom is formed in a supporting member, and a sealing member for holding the magnetic field detecting element in the receiving hole. It is an object of the present invention to provide a wheel bearing device that can position a shaft portion with high accuracy in a housing hole even when the shaft portion of a member is housed.

  The present invention, in order to achieve the above object, an inner member having a flange to which a wheel is mounted, a cylindrical outer member rotatably supporting the inner member via a plurality of rolling elements, An encoder having an annular magnetic member fixed to an inner member and having a plurality of magnetic poles in a circumferential direction, a magnetic field detecting element for detecting magnetic fields of the plurality of magnetic poles of the magnetic member, and sealing the magnetic field detecting element A magnetic field sensor having a sealing member having a columnar shaft formed therein, and a support member having a receiving hole for housing the shaft and supporting the magnetic field sensor with respect to the outer member; The member provides a wheel bearing device that has a positioning projection that projects inward from an inner peripheral surface of the housing hole and abuts on an outer peripheral surface of the shaft portion to position the shaft portion.

  ADVANTAGE OF THE INVENTION According to the bearing device for wheels which concerns on this invention, a shaft part can be positioned with high precision in an accommodation hole, and it becomes possible to detect the magnetic field of the magnetic pole of an encoder with a magnetic field detection element reliably.

It is a sectional view showing the bearing device for wheels concerning a 1st embodiment of the present invention. It is the elements on larger scale of FIG. (A) is a top view which shows the state which looked at the cover from the vehicle inner side. FIG. 3B is an enlarged view showing the periphery of the housing hole of the cover as viewed from the vehicle inner side. (C) is sectional drawing which shows the magnetic field sensor accommodated in the accommodation hole by the cross section of a shaft part and a magnetic field detection element. (A) is the top view which looked at some magnetic members of the encoder from the vehicle inner side. (B) is a graph showing the cross section of the magnetic member and the magnetic field strength of the N magnetic pole and the S magnetic pole. (A) is an enlarged view which expands and shows the periphery of the accommodation hole of the cover according to the second embodiment of the present invention. (B) is sectional drawing which shows the axial part and magnetic field detection element of the magnetic field sensor accommodated in the accommodation hole shown to (a). (A) is an enlarged view which expands and shows the periphery of the accommodation hole of the cover which concerns on 3rd Embodiment of this invention. (B) is sectional drawing which shows the axial part and magnetic field detection element of the magnetic field sensor accommodated in the accommodation hole shown to (a).

[First Embodiment]
A first embodiment and a modified example of the present invention will be described with reference to FIGS. It should be noted that the embodiments described below are shown as preferable specific examples for carrying out the present invention, and there are portions specifically illustrating various technical matters that are technically preferable. However, the technical scope of the present invention is not limited to this specific embodiment.

(Overall configuration of wheel bearing device)
FIG. 1 is a cross-sectional view showing the overall configuration of the wheel bearing device according to the first embodiment of the present invention. FIG. 2 is a partially enlarged view of FIG.

  This wheel bearing device 1 is used for rotatably supporting a wheel with respect to a knuckle 10 of a vehicle suspension system. The wheel bearing device 1 includes a cylindrical outer member 2 attached to a knuckle 10, an inner member 3 to which wheels are attached, and a plurality of rolling members arranged between the outer member 2 and the inner member 3. A moving body 4, an encoder 5 fixed to the inner member 3, a cover 6 fixed to an end of the outer member 2, a magnetic field sensor 7 attached to the cover 6, and a wheel side of the outer member 2. A sealing member 8 disposed between the end portion and the inner member 3. In FIG. 1, the knuckle 10 is indicated by a virtual line (two-dot chain line).

  In the following description, the side of the wheel bearing device 1 on which the wheels are mounted (the left side in FIG. 1) is referred to as the vehicle outer side, and the opposite side (the right side in FIG. 1) is referred to as the vehicle inner side. In the following description, “upper” and “lower” refer to up and down in the vertical direction in a state where the wheel bearing device 1 is assembled to a vehicle.

  The outer member 2 includes a cylindrical base 21, a plurality of vehicle body mounting flanges 22 for mounting to the knuckle 10 on the vehicle body side, and an extending portion 23 extending to the vehicle inner side of the vehicle body mounting flange 22. And the inner member 3 is rotatably supported via a plurality of rolling elements 4. FIG. 1 shows only one vehicle body mounting flange 22 of the plurality of vehicle body mounting flanges 22. Each of the plurality of vehicle body mounting flanges 22 has a bolt insertion hole 22a through which a bolt screwed to the knuckle 10 is inserted. A first outer raceway surface 2a and a second outer raceway surface 2b for rolling the rolling element 4 are formed on the inner periphery of the base 21 in parallel with each other along the circumferential direction.

  The inner member 3 is disposed so as to be rotatable with respect to the outer member 2 about the rotation axis O. On the outer periphery of the inner member 3, a first inner raceway surface 3a and a second inner raceway surface 3b for rolling the rolling element 4 are formed parallel to each other along the circumferential direction. The first inner raceway surface 3a faces the first outer raceway surface 2a of the outer member 2, and the second inner raceway surface 3b faces the second outer raceway surface 2b of the outer member 2. Hereinafter, a direction parallel to the rotation axis O is referred to as an axial direction.

  In the present embodiment, the inner member 3 includes a hub wheel 31 and an annular inner ring member 32. The hub wheel 31 includes a wheel mounting flange 311 to which the wheel is mounted, a body 313 disposed inside the base 21 of the outer member 2, and a connecting portion 312 connecting the wheel mounting flange 311 and the body 313. It has integrally. The wheel mounting flange 311 is formed with a plurality of bolt insertion holes 311a into which serrated bolts 33 for wheel mounting are pressed and inserted.

  The body portion 313 has a large-diameter portion 314 on the wheel mounting flange 311 side and a small-diameter portion 315 on the opposite side to the wheel mounting flange 311 side. A first inner raceway surface 3a is formed on the outer peripheral surface of the large diameter portion 314. The inner ring member 32 is fitted on the outer peripheral surface of the small diameter portion 315. The inner ring member 32 is fixed to the hub wheel 31 by a caulking portion 315a obtained by plastically deforming a part of the small diameter portion 315. On the outer peripheral surface of the inner ring member 32, a second inner raceway surface 3b is formed.

  The plurality of rolling elements 4 are held by the retainer 40 and are arranged between the first outer raceway surface 2a and the first inner raceway surface 3a and between the second outer raceway surface 2b and the second inner raceway surface 3b. Have been. In the present embodiment, the rolling element 4 is a sphere, but is not limited thereto and may be a tapered roller. Further, in the present embodiment, the inner member 3 has one inner ring member 32, but the present invention is not limited to this, and the inner member 3 has two inner ring members, and one of the inner ring members A first inner raceway surface 3a may be formed, and a second inner raceway surface 3b may be formed on the other inner race member.

  The encoder 5 has a metal core 51 and an annular magnetic member 52 attached to the metal core 51. The core metal 51 is made of, for example, a metal such as stainless steel or iron, and is fitted on the outer peripheral surface of the inner ring member 32. The magnetic member 52 is attached to the metal core 51 by, for example, a vulcanization bonding method. The magnetic member 52 is formed by mixing ferrite-based stainless steel powder into a rubber ring member, for example, and a plurality of magnetic poles (N-pole and S-pole) having different magnetism are alternately provided along the circumferential direction. I have.

  The cover 6 closes an opening on the vehicle inner side of the outer member 2 and functions as a support member that supports the magnetic field sensor 7 with respect to the outer member 2. The cover 6 is formed by integrally molding a metal core 62 and a nut 63 by insert molding on a main body 61 made of resin. The main body 61 is made of, for example, 66 nylon. The cover 6 is attached to one end of the outer member 2 in the axial direction on the vehicle inner side, and prevents entry of foreign matter from between the outer member 2 and the inner member 3 from the vehicle inner side. On the other hand, the entry of foreign matter from the vehicle inner side into the space between the outer member 2 and the inner member 3 is suppressed by the seal member 8.

  The magnetic field sensor 7 includes a magnetic field detecting element 71 such as a Hall IC, a sealing member 72 having a columnar shaft portion 721 for sealing the magnetic field detecting element 71 and a fixing portion 722 fixed to the cover 6, and a magnetic field detecting element 71. And a cable 73 that supplies an operating power to the power supply and transmits an electric signal output from the magnetic field detecting element 71. In the present embodiment, the shaft portion 721 has a columnar shape. However, the shaft portion 721 may be, for example, a prism having a polygonal cross section. The magnetic field detecting element 71 is housed at a distal end portion of the shaft portion 721 (an end portion opposite to a base end portion on the fixed portion 722 side), and detects magnetic fields of a plurality of magnetic poles of the magnetic member 52. 1 and 2, the magnetic field detecting element 71 is indicated by a broken line.

  The fixing portion 722 of the magnetic field sensor 7 is fixed to the cover 6 by bolts 9 outside the cover 6 (on the vehicle inner side). The bolt 9 has a head portion 91 abutting on an end surface of the fixed portion 722 on the vehicle inner side, a male screw portion 92 inserted into a bolt insertion hole 722 a formed in the fixed portion 722, and screwed into the nut 63.

(Operation of wheel bearing device)
When the inner member 3 rotates, the magnetism of the magnetic pole of the magnetic member 52 whose magnetic field is detected by the magnetic field detecting element 71 changes. The magnetic field detection element 71 outputs a change in a magnetic field accompanying rotation of the inner member 3 as an electric signal, and the electric signal is transmitted to an ECU (Electronic Control Unit) of the vehicle by a cable 73. The ECU can detect the rotation speed of the wheel based on the electric signal of the magnetic field detection element 71, and adjusts the braking force applied to the wheel, for example, according to the detected rotation speed of the wheel to lock the wheel during braking. Deter.

(Detailed configuration of cover 6)
The main body 61 of the cover 6 includes a circular disk part 611, a boss part 612 protruding from the disk part 611 toward the vehicle inner side when viewed in an axial direction parallel to the rotation axis O, and an extension part 23 of the outer member 2. It has a cylindrical fitting part 613 integrally press-fitted inside. The main body 61 of the cover 6 has a receiving hole 610 for receiving the shaft 721 of the sealing member 72 of the magnetic field sensor 7. The accommodation hole 610 extends from the inner end surface 612a of the boss 612 on the vehicle inner side to the vehicle outer side in parallel with the rotation axis O. As shown in FIG. 2, an end surface 722b of the fixing portion 722 of the magnetic field sensor 7 on the vehicle outer side contacts the end surface 612a of the boss portion 612. The shaft portion 721 is erected on an end surface 722b of the fixing portion 722.

  The accommodation hole 610 is a blind hole that does not penetrate the main body 61, and the bottom (the end on the vehicle outer side) of the accommodation hole 610 is closed by the bottom wall 614. The length of the accommodation hole 610 in the depth direction is longer than the axial length of the shaft portion 721 of the magnetic field sensor 7, and a gap S is formed between the bottom surface 610 a of the accommodation hole 610 and the tip end surface 721 a of the shaft portion 721. Is done. Since the receiving hole 610 is a blind hole, entry of foreign matter such as muddy water into the cover 6 from the receiving hole 610 is suppressed. In addition, since the gap S is formed, the end face 722b of the fixing portion 722 of the magnetic field sensor 7 on the vehicle outer side adheres to the end face 612a of the boss portion 612, and the accumulation of muddy water or the like in the accommodation hole 610 is suppressed. Is done.

  Further, as shown in FIG. 2, assuming that the thickness of the bottom wall 614 is t, a preferable range of the thickness t is 0.5 mm or more and 1.0 mm or less. When the thickness t of the bottom wall 614 is less than 0.5 mm, the strength of the bottom wall 614 becomes weak. When the thickness t of the bottom wall 614 exceeds 1.0 mm, the distance between the magnetic member 52 and the magnetic field detecting element 71 is reduced. This is because the distance becomes longer and the magnetic field detected by the magnetic field detecting element 71 becomes weaker. The distance d between the bottom wall 614 and the surface 52a of the magnetic member 52 facing the bottom wall 614 is set to be at least larger than 0 mm in consideration of dimensional errors and assembly errors of each part.

  FIG. 3A is a plan view illustrating a state in which the cover 6 is viewed from the vehicle inner side. FIG. 3B is an enlarged view showing the periphery of the housing hole 610 of the cover 6 viewed from the vehicle inner side. FIG. 3C is a cross-sectional view illustrating the magnetic field sensor 7 housed in the housing hole 610 in a cross section of the shaft portion 721 and the magnetic field detecting element 71.

  The cover 6 has a positioning protrusion for positioning the shaft 721 of the magnetic field sensor 7. In the present embodiment, first to third positioning projections 615 to 617 are formed on main body 61. The first to third positioning protrusions 615 to 617 protrude inward from the inner peripheral surface 610b of the accommodation hole 610 and are in contact with the outer peripheral surface 721b of the shaft portion 721.

  The shaft portion 721 has a cylindrical shape that is housed in the housing hole 610 in parallel to the rotation axis O, and has a cross section orthogonal to the central axis C (shown in FIG. 3B) of the housing hole 610. The shape is circular. The magnetic field sensor 7 is positioned with respect to the cover 6 by the first to third positioning protrusions 615 to 617 so that the center of the shaft 721 coincides with the center axis C, and is fixed by the bolt 9.

  The inner peripheral surface 610b of the accommodation hole 610 has a circular shape centered on the central axis C, and its diameter (inner diameter of the accommodation hole 610) is larger than the diameter (outer diameter) of the shaft portion 721. Due to this diameter difference, a gap is formed between the inner peripheral surface 610b of the housing hole 610 and the outer peripheral surface 721b of the shaft portion 721 of the shaft portion 721, and the inner peripheral surface 610b of the housing hole 610 and the shaft portion of the shaft portion 721 are formed. 721 is not in contact with the outer peripheral surface 721b. That is, the shaft portion 721 is positioned such that its outer peripheral surface 721b contacts only the tip portions 615a, 616a, 617a of the first to third positioning protrusions 615 to 617 in the accommodation hole 610.

As shown in FIG. 3B, in a natural state before the shaft portion 721 is housed in the housing hole 610, the first to third positioning protrusions 615 to 617 are inscribed in the respective distal end portions 615a, 616a, 617a. When a virtual circle and Vc, the diameter _{D 1} of the virtual circle Vc is smaller than the diameter _{D 2} of the shaft portion 721 shown in Figure 3 (c). Thus, when the shaft portion 721 is housed in the housing hole 610, the first to third positioning protrusions 615 to 617 are elastically deformed, and the respective distal end portions 615a, 616a, 617a are resilient on the outer peripheral surface 721b of the shaft portion 721. Touch The center of the shaft portion 721 coincides with the center axis C of the accommodation hole 610.

  In the illustrated example of FIGS. 3A to 3C, the first to third positioning protrusions 615 to 617 are arranged at equal intervals along the circumferential direction of the inner peripheral surface 610b of the accommodation hole 610. Although the shape formed by connecting 615a, 616a, and 617a with a straight line forms an equilateral triangle, the arrangement of the first to third positioning projections 615 to 617 is not limited to this. However, the fact that the center of the shaft portion 721 is included in the triangle formed by connecting the distal end portions 615a, 616a, 617a of the first to third positioning protrusions 615 to 617 with a straight line is important in positioning the shaft portion 721 with high accuracy. Is desirable.

  In addition, the first to third positioning protrusions 615 to 617 abut on the outer peripheral surface 721b of the shaft portion 721 at a position closer to the encoder 5 (toward the bottom wall 614) than the central portion of the housing hole 610 in the axial direction. In other words, the first to third positioning protrusions 615 to 617 are not formed on the opening side (end surface 612a side) of the axial center portion of the accommodation hole 610, and the shaft portion 721 is not Not supported. Note that FIG. 2 shows only the third positioning protrusion 617 among the first to third positioning protrusions 615 to 617, but the first and second positioning protrusions 615 and 616 also have the third positioning protrusion 615 in the axial direction. Are provided at the same positions as the positioning projections 617. Further, in FIG. 2, the central portion in the axial direction of the accommodation hole 610 is indicated by a broken line D.

  In the present embodiment, the first to third positioning protrusions 615 to 617 are formed in a range including a position corresponding to the outer peripheral side of the magnetic field detecting element 71 in the radial direction of the shaft portion 721. Thereby, the magnetic field detecting element 71 is positioned with high accuracy in the accommodation hole 610.

  FIG. 4A is a plan view of a part of the magnetic member 52 of the encoder 5 as viewed from the vehicle inner side. The magnetic member 52 is provided with N magnetic poles 521 and S magnetic poles 522 alternately along the circumferential direction. FIG. 4B is a graph showing the cross section of the magnetic member 52 and the magnetic field strength of the N magnetic pole 521 and the S magnetic pole 522. In FIG. 4B, the vertical direction in the drawing corresponds to the radial direction of the magnetic member 52. The strength of the magnetic field of the N magnetic pole 521 and the S magnetic pole 522 is highest at the radial center of the magnetic member 52, and decreases as it approaches the inner and outer ends. The magnetic field sensor 7 is positioned on the cover 6 such that the magnetic field detecting element 71 detects these magnetic fields at positions where the magnetic field strengths of the N magnetic pole 521 and the S magnetic pole 522 are the highest.

(Operation and Effect of First Embodiment)
According to the first embodiment described above, the shaft portion 721 of the sealing member 72 in which the magnetic field detecting element 71 is housed in the magnetic field sensor 7 can be positioned with high accuracy in the housing hole 610 of the cover 6. The magnetic field detecting element 71 can reliably detect the magnetic field of the N magnetic pole 521 and the S magnetic pole 522 of the encoder 5. Further, even if an annular elastic body such as an O-ring is not attached to the shaft portion 721, it is possible to prevent foreign matter such as muddy water from entering the inside of the cover 6 from the housing hole 610, and the annular elastic body The number of components and the number of assembling steps can be reduced as compared with the case of mounting on the outer periphery.

  The number of positioning projections is not limited to three as exemplified above, and may be four or more. If the cover 6 has at least three positioning projections, the outer peripheral surface 721b of the shaft portion 721 and the inner peripheral surface 610b of the housing hole 610 are not in contact with each other, and the shaft portion 721 is positioned by the at least three positioning projections. be able to.

  However, the shaft portion 721 may be positioned by bringing the outer peripheral surface 721b of the shaft portion 721 into contact with the inner peripheral surface 610b of the accommodation hole 610 at one location in the circumferential direction. As examples in this case, the second and third embodiments will be described below.

[Second embodiment]
FIG. 5A is an enlarged view showing the periphery of the accommodation hole 610 of the cover 6 according to the second embodiment of the present invention in an enlarged manner. FIG. 5B is a cross-sectional view showing the shaft 721 and the magnetic field detecting element 71 of the magnetic field sensor 7 housed in the housing hole 610 shown in FIG.

In the present embodiment, the first and second positioning projections 615 and 616 are formed so as to protrude inward from the inner peripheral surface 610b of the accommodation hole 610, and the first and second positioning projections 615 and 616 form the shaft. One portion of the outer peripheral surface 721b of the portion 721 in the circumferential direction is pressed so as to abut on the inner peripheral surface 610b of the accommodation hole 610. The outer peripheral surface 721b of the shaft 721, the first positioning projection 615 of the tip portion 615a and the second positioning projection 616 of the tip perpendicular bisector _{L 2} is receiving hole 610 of the line segment _{L 1} of connecting the 616a At the intersection P intersecting with the inner peripheral surface 610b of.

  According to the second embodiment, the same operation and effect as those of the first embodiment can be obtained. In the second embodiment, since the center of the housing hole 610 and the center of the shaft portion 721 are shifted, the housing hole 610 is formed in consideration of the shift.

[Third Embodiment]
FIG. 6A is an enlarged view showing the periphery of the housing hole 610 of the cover 6 according to the third embodiment of the present invention in an enlarged manner. FIG. 6B is a cross-sectional view illustrating the shaft 721 and the magnetic field detecting element 71 of the magnetic field sensor 7 housed in the housing hole 610 illustrated in FIG.

  In the present embodiment, only one positioning projection 618 is formed to protrude inward from the inner peripheral surface 610b of the accommodation hole 610. The shaft portion 721 is pressed by the positioning protrusion 618 so that the outer peripheral surface 721b at one location in the circumferential direction opposite to the positioning protrusion 618 across the center of the shaft portion 721 contacts the inner peripheral surface 610b of the accommodation hole 610. ing. The distal end portion 618a of the positioning projection 618 in contact with the outer peripheral surface 721b of the shaft portion 721 has a predetermined length in the circumferential direction of the inner peripheral surface 610b, so that the shaft portion 721 can move the inner peripheral surface 610b of the accommodation hole 610. Swinging about the contact position with the center is suppressed.

  According to the third embodiment, the same operation and effect as those of the first embodiment can be obtained. It is desirable that the positioning protrusion 618 be in contact with the outer peripheral surface 721b of the shaft portion 721 at a position closer to the encoder 5 than the center portion in the axial direction of the housing hole 610, as described above. It is more desirable that the outer peripheral surface 721b of the shaft 721 be in contact with the outer peripheral surface 721b of the magnetic field detecting element 71 in a range including a position on the outer peripheral side.

(Note)
As described above, the present invention has been described based on the embodiments, but these embodiments do not limit the invention according to the claims. Also, it should be noted that not all combinations of the features described in the embodiments are necessarily essential for solving the problem of the invention.

  In addition, the present invention can be appropriately modified and implemented without departing from the spirit thereof. For example, in the above embodiment, the case where the magnetic field sensor 7 is fixed to the cover 6 by the bolt 9 has been described. However, the present invention is not limited to this. It may be. Further, the cover 6 does not necessarily have to have the core metal 62.

DESCRIPTION OF SYMBOLS 1 ... Wheel bearing device 2 ... Outer member 3 ... Inner member 311 ... Wheel mounting flange 4 ... Rolling element 5 ... Encoder 52 ... Magnetic member 521 ... N magnetic pole 522 ... S magnetic pole 6 ... Cover (support member)
610: accommodation hole 610b: inner peripheral surface 615: first positioning protrusion 616 ... second positioning protrusion 617 ... third positioning protrusion 618 ... positioning protrusions 615a, 616a, 617a: tip 7: magnetic field sensor 71: magnetic field detection Element 72 Sealing member 721 Shaft portion 721b Outer peripheral surface Vc Virtual circle

Claims (5)

An inner member having a flange to which wheels are attached;
A cylindrical outer member rotatably supporting the inner member via a plurality of rolling elements,
An encoder having an annular magnetic member fixed to the inner member and having a plurality of magnetic poles in a circumferential direction,
A magnetic field detection element that detects the magnetic field of the plurality of magnetic poles of the magnetic member, and a magnetic field sensor having a sealing member formed with a columnar shaft that seals the magnetic field detection element;
A support member that has an accommodation hole that accommodates the shaft portion and that supports the magnetic field sensor with respect to the outer member,
The support member has a positioning protrusion that projects inward from an inner peripheral surface of the accommodation hole and contacts an outer peripheral surface of the shaft portion to position the shaft portion.
Bearing device for wheels. The positioning projection abuts on the outer peripheral surface of the shaft at a position closer to the encoder than the center of the housing hole in the axial direction,
The wheel bearing device according to claim 1. The support member has at least three of the positioning protrusions,
The shaft portion is positioned such that its outer peripheral surface contacts only the tip portions of the at least three positioning protrusions in the accommodation hole,
The wheel bearing device according to claim 1 or 2. The shaft portion of the magnetic field sensor has a cylindrical shape that is housed in the housing hole in parallel to a rotation axis of the inner member,
In the support member, in a natural state before accommodating the shaft portion in the accommodation hole, a diameter of an imaginary circle inscribed at a tip of each of the at least three positioning protrusions is smaller than a diameter of the shaft portion.
The wheel bearing device according to claim 3. The shaft portion of the magnetic field sensor is pressed by the positioning protrusion so that one circumferential position of the outer peripheral surface thereof is in contact with the inner peripheral surface of the accommodation hole.
The wheel bearing device according to claim 1 or 2.

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