Sensor holder and wheel bearing device

Abstract

To provide a sensor holder or the like which can prevent that the reading performance of an encoder is affected by a sensor.SOLUTION: A sensor holder 12 comprises: a cap part 121 which is fit to an outer ring 2 so as to block an inner-side opening part 2a of the outer ring 2; a sensor support part 122 protruding to one side in an axial direction from the cap part 121 in a position opposing a magnetic encoder 11 of the cap part 121, and supporting a rotational speed sensor 13 for detecting a displacement of the magnetic encoder 11; and a nut holding part 123 protruding to one side in the axial direction from the cap part 121, and holding a nut 124 for fixing the rotational speed sensor 13 to the cap part 121. The sensor holding part 122 and the nut holding part 123 are formed in separated states, and a one-side end face 124a of the nut 124 which is held to the nut holding part 123 in the axial direction protrudes to one side in the axial direction rather than a one-side end face 122c of the sensor holding part 122 in the axial direction.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a sensor holder and a wheel bearing device. [Background technology]

[0002] Conventionally, there is known a wheel bearing device that rotatably supports the wheels in the suspension of an automobile, etc. Some wheel bearing devices are equipped with a rotation speed detection device that detects the rotation speed of the wheels in order to control an antilock brake system (ABS).

[0003] For example, the wheel bearing device disclosed in Patent Document 1 has an encoder supported at one axial end of the inner member, and a sensor holder supporting a sensor for detecting displacement of the encoder is attached to one axial end of the outer member.

[0004] The sensor holder includes a cap portion fitted to one axial end side of the outer member, a sensor support portion protruding from the cap portion to one axial side and supporting a sensor for detecting displacement of the encoder, and a nut holding portion protruding from the cap portion to one axial side and holding a nut for fixing the sensor to the cap portion. In addition, a mounting flange portion is fixed to the sensor, and the sensor is fixed to the cap portion by fastening the mounting flange portion to the nut with a bolt while the sensor is fitted to the sensor support portion.

[0005] The sensor support portion and the nut holding portion protrude to the same height in the axial direction, and when the sensor is fixed to the cap portion, the mounting flange portion is in contact with both the sensor support portion and the nut holding portion. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2016-148422 A Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, the sensor support portion and the nut holding portion protrude to the same height and both contact the mounting flange portion. Therefore, if the sensor support portion is warped or the sensor holder is deformed when attached to the outer member, the posture of the sensor in contact with the sensor support portion may be tilted, which may affect the encoder reading performance by the sensor.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and provides a sensor holder and a wheel bearing device that can prevent the encoder reading performance by the sensor from being affected by warping of the sensor support portion or deformation of the sensor holder. [Means for solving the problem]

[0009] That is, the sensor holder is located on the outer diameter side of an inner member supporting an encoder at one axial end thereof, and is attached to one axial end of an outer member which rotatably supports the inner member via a double row of rolling elements, and comprises a cap portion which is fitted onto the outer member so as to cover an opening at one axial end side of the outer member, a sensor support portion which protrudes from the cap portion to one axial side at a position opposite the encoder of the cap portion and supports a sensor which detects displacement of the encoder, and a nut holding portion which protrudes from the cap portion to one axial side and holds a nut for fixing the sensor to the cap portion, the sensor support portion and the nut holding portion being formed in a state separated from each other, and one axial end face of the nut held by the nut holding portion protrudes to one axial side beyond one axial end face of the sensor support portion. Effect of the Invention

[0010] According to the present invention, it is possible to prevent the sensor from affecting the reading performance of the encoder. [Brief description of the drawings]

[0011] [Figure 1] 1 is a side cross-sectional view showing a wheel bearing device. [Diagram 2] FIG. 2 is a perspective view showing a sensor holder. [Diagram 3] 13 is a diagram showing the sensor holder as viewed from the axial direction of the inner side. FIG. [Figure 4] FIG. 4 is a side cross-sectional view showing the sensor holder. [Diagram 5] FIG. 4 is a partially enlarged cross-sectional side view showing a sensor holder to which a rotation speed sensor is attached. [Figure 6] FIG. 4 is a partially enlarged side cross-sectional view showing the sensor holder. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0013] [Wheel bearing device] A wheel bearing device 1 shown in FIG. 1 is one embodiment of a wheel bearing device equipped with a sensor holder according to the present invention, and supports a wheel rotatably in a suspension system of a vehicle such as an automobile.

[0014] The wheel bearing device 1 has a configuration referred to as the third generation, and includes an outer ring 2 as an outer member, a hub ring 3 and an inner ring 4 as inner members, two rolling rows consisting of an inner ball row 5 and an outer ball row 6, a magnetic encoder 11, and a sensor holder 12.

[0015] In the following description, the axial direction refers to the direction along the rotation axis X of the wheel support bearing device 1. The inner side refers to one side in the axial direction, which is the vehicle body side of the wheel support bearing device 1 when mounted on the vehicle body, and the outer side refers to the other side in the axial direction, which is the wheel side of the wheel support bearing device 1 when mounted on the vehicle body.

[0016] An inner side opening 2a into which a sensor holder 12 can be fitted is formed at an inner side end of the outer ring 2. An outer side opening 2b into which an outer side seal member 9 can be fitted is formed at an outer side end of the outer ring 2. The sensor holder 12 is fitted into the inner side opening 2a, which is an opening on one axial end side of the annular space S formed by the outer ring 2 and the hub wheel 3, and the outer side seal member 9 is fitted into the outer side opening 2b, which is an opening on the other axial end side of the annular space S, thereby sealing the annular space S inside the bearing.

[0017] An inner-side outer raceway surface 2c and an outer-side outer raceway surface 2d are formed on the inner peripheral surface of the outer ring 2. A vehicle body mounting flange 2e for mounting the outer ring 2 to a vehicle body member is integrally formed on the outer peripheral surface of the outer ring 2. The vehicle body mounting flange 2e is provided with bolt holes 2g into which fastening members (here, bolts) for fastening the vehicle body member and the outer ring 2 are inserted. The outer ring 2 is located on the outer diameter side of the hub ring 3 and the inner ring 4.

[0018] The inner end of the hub wheel 3 has a small diameter step 3a formed on the outer circumferential surface, the diameter of which is smaller than that of the outer end. A wheel mounting flange 3b for mounting a wheel is formed integrally with the outer end of the hub wheel 3. A plurality of bolt holes 3f are formed in the wheel mounting flange 3b. Hub bolts 3e for fastening the hub wheel 3 to a wheel or a brake component are press-fitted into the bolt holes 3f.

[0019] An outer-side inner raceway surface 3c is provided on the outer peripheral surface of the hub wheel 3 so as to face the outer raceway surface 2d on the outer side of the outer ring 2. In other words, the inner raceway surface 3c is formed by the hub wheel 3 on the outer side of the inner member. A seal land portion 3d of the outer side seal member 9 is formed on the base side of the wheel mounting flange 3b of the hub wheel 3.

[0020] The outer seal member 9 has a core metal 91 that is fitted into the outer opening 2b of the outer ring 2, and a seal member 92 that is integrally joined to the core metal 91. A metal ring 35 is fitted into the seal land portion 3d of the hub wheel 3. A side lip 92a of the seal member 92 is in sliding contact with the metal ring 35. In other words, the side lip 92a of the seal member 92 is in sliding contact with the seal land portion 3d of the hub wheel 3 via the metal ring 35.

[0021] However, the wheel bearing device 1 may also be configured so that the side lip 92a of the seal member 92 directly contacts the seal land portion 3d of the hub wheel 3 without providing the metal ring 35. The grease lip 92b of the seal member 92 directly contacts the seal land portion 3d of the hub wheel 3.

[0022] An inner ring 4 is provided on the small diameter step 3a of the hub ring 3. The inner ring 4 is fixed to the small diameter step 3a of the hub ring 3 by press fitting and crimping. The inner ring 4 applies preload to the inner ball row 5 and the outer ball row 6, which are the rolling rows. The inner ring 4 has an inner end face 4b at its inner end. At the inner end of the hub ring 3, a crimped portion 3h is formed that is crimped to the inner end face 4b of the inner ring 4.

[0023] An inner-side inner raceway surface 4a is provided on the outer peripheral surface of the inner ring 4 so as to face the inner-side outer raceway surface 2c of the outer ring 2. In other words, the inner ring 4 forms the inner raceway surface 4a on the inner side of the inner member.

[0024] The inner ball row 5 and the outer ball row 6, which are rolling rows, are formed by a plurality of balls 7, which are rolling bodies, being held by a cage 8. The inner ball row 5 is rollably sandwiched between the inner raceway surface 4a of the inner ring 4 and the inner outer raceway surface 2c of the outer ring 2. The outer ball row 6 is rollably sandwiched between the inner raceway surface 3c of the hub ring 3 and the outer outer raceway surface 2d of the outer ring 2. In other words, the inner ball row 5 and the outer ball row 6 are rollably housed between the raceway surfaces of the outer member and the inner member. The outer ring 2 rotatably supports the hub ring 3 and the inner ring 4 via the inner ball row 5 and the outer ball row 6.

[0025] In the wheel bearing device 1, a double-row angular ball bearing is formed by the outer ring 2, hub ring 3, inner ring 4, inner ball row 5, and outer ball row 6. Note that the wheel bearing device 1 may be formed as a double-row tapered roller bearing instead of the double-row angular ball bearing.

[0026] A support ring 10 is fitted to the inner end, which is one axial end of the inner ring 4. The support ring 10 has a cylindrical portion 10a that is press-fitted onto the outer diameter of the inner ring 4, and a standing portion 10b that extends from the inner end of the cylindrical portion 10a to the outer diameter side and the inner diameter side, and a magnetic encoder 11 is integrally joined to the inner side surface of the standing portion 10b by vulcanization adhesion. The magnetic encoder 11 is made of synthetic rubber mixed with magnetic powder such as ferrite, and is magnetized with N magnetic poles and S magnetic poles alternately at equal pitch in the circumferential direction. The magnetic encoder 11 is an example of an encoder.

[0027] A sensor holder 12 is attached to an inner side opening 2a, which is an opening on one axial end side of the outer ring 2, so as to cover the inner side opening 2a. A rotation speed sensor 13 is attached to the sensor holder 12 at a position facing the magnetic encoder 11. The rotation speed sensor 13 and the magnetic encoder 11 are disposed facing each other in the axial direction with a predetermined air gap (axial clearance) between them via the sensor holder 12. The rotation speed sensor 13 detects the displacement of the magnetic encoder 11, making it possible to detect the rotation speed of the inner ring 4. The rotation speed sensor 13 is an example of a sensor that detects the displacement of an encoder.

[0028] [Sensor holder] The sensor holder 12 is formed of, for example, a resin material. When the sensor holder 12 is formed of a resin material, the sensor holder 12 may be an injection molded product or a machined product.

[0029] As shown in FIGS. 2 to 4, the sensor holder 12 includes a cap portion 121, a sensor support portion 122, a nut holding portion 123, and a nut . The cap portion 121 has a cylindrical fitting portion 121a that is pressed into the inner side opening 2a of the outer ring 2, and a bottom portion 121b that extends radially inward from the fitting portion 121a to close the inner side opening 2a, and is fitted onto the outer ring 2 so as to close the inner side opening 2a.

[0030] The sensor support portion 122 protrudes from the bottom surface portion 121b of the cap portion 121 to one side in the axial direction, and supports the rotation speed sensor 13. The sensor support portion 122 is disposed at a position on the bottom surface portion 121b facing the magnetic encoder 11. In this embodiment, the sensor support portion 122 of the sensor holder 12 attached to the wheel bearing device 1 is located at the upper end portion of the bottom surface portion 121b.

[0031] The sensor support portion 122 has a first portion 122a and a second portion 122b formed in an arc shape when viewed in the axial direction. The first portion 122a and the second portion 122b are disposed opposite each other with a gap therebetween, and the sensor support portion 122 is formed in a generally cylindrical shape with a gap G (see FIG. 3) between the upper end and the lower end as a whole.

[0032] The rotation speed sensor 13 is inserted from one axial end side into the sensor support portion 122. Even if rainwater enters the inside of the sensor support portion 122 while the rotation speed sensor 13 is inserted into the sensor support portion 122, it can be discharged to the outside through the gap G.

[0033] A reinforcing portion 125 is formed at a base end portion, which is the end portion of the second portion 122b on the bottom surface portion 121b side. The reinforcing portion 125 is formed integrally with the second portion 122b and the bottom surface portion 121b. By forming the reinforcing portion 125, the rigidity of the sensor support portion 122 is improved.

[0034] A bottom surface 122d is formed at the end of the sensor support portion 122 on the bottom surface portion 121b side, and the sensor support portion 122 is not penetrated in the axial direction. Therefore, the rotation speed sensor 13 inserted into the sensor support portion 122 faces the magnetic encoder 11 via the bottom surface 122d. The bottom surface 122d is formed to be thinner than the other bottom surface portion 121b.

[0035] However, the sensor support portion 122 may be formed as a through-type in which the bottom surface 122d is not formed and the rotation speed sensor 13 inserted into the sensor support portion 122 directly faces the magnetic encoder 11.

[0036] The nut holding portion 123 protrudes from the bottom surface portion 121b of the cap portion 121 to one side in the axial direction. The nut holding portion 123 is discontinuously formed and separated from the sensor support portion 122, and is located on the inner diameter side of the sensor support portion 122 on the bottom surface portion 121b. In other words, the nut holding portion 123 is located closer to the rotation axis X than the sensor support portion 122.

[0037] 3, in this embodiment, the center Q of the nut holding part 123 is located on a straight line L that extends from the rotation axis X toward the outer diameter side and connects the rotation axis X and the center P of the sensor support part 122. In other words, the rotation axis X, the center Q, and the center P are aligned on the same straight line L. However, the center Q of the nut holding part 123 may be located at a position deviated from the straight line L.

[0038] The nut holding portion 123 is formed in a cylindrical shape, and the nut 124 is held inside the nut holding portion 123. The nut 124 can be molded integrally with the sensor holder 12 by insert molding or the like when the sensor holder 12 is molded. The nut 124 can also be fitted into the nut holding portion 123 by press-fitting after the sensor holder 12 is molded. Furthermore, the nut 124 can be fixed to the nut holding portion 123 by gluing after fitting into the nut holding portion 123.

[0039] 5, a mounting flange portion 14 is fixed to the rotation speed sensor 13. The mounting flange portion 14 extends radially from the rotation speed sensor 13 toward the nut holding portion 123, and has a fixing hole 14a that penetrates in the axial direction at a position opposite to the nut 124 held by the nut holding portion 123.

[0040] With the rotation speed sensor 13 fitted into the sensor support portion 122, a bolt 15 is inserted into the fixing hole 14a of the mounting flange portion 14, and the mounting flange portion 14 is fastened to a nut 124 by the bolt 15, whereby the rotation speed sensor 13 is fixed to the sensor holder 12.

[0041] One axial end face 124a of nut 124 is formed to protrude toward one axial side from one axial end face 123a of nut holding part 123, or to be at the same position in the axial direction (see FIG. 6). One axial end face 123a of nut holding part 123 is located around one axial end face 124a of nut 124.

[0042] Therefore, when the mounting flange portion 14 is fastened to the nut 124 by the bolt 15, the mounting flange portion 14 does not come into contact with the one side end surface 123a of the nut holding portion 123 before the one side end surface 124a of the nut 124, and the mounting flange portion 14 can be closely attached to the one side end surface 124a of the nut 124. This makes it possible to fix the rotation speed sensor 13 to the sensor holder 12 with high positional accuracy.

[0043] 6, one side end face 124a of nut 124 protrudes to one side in the axial direction by dimension D1 beyond one side end face 122c in the axial direction of sensor support portion 122. In other words, a step of dimension D1 is formed between one side end face 124a of nut 124 and one side end face 122c of sensor support portion 122 in the axial direction.

[0044] Therefore, as shown in FIG. 5, when the mounting flange portion 14 is fastened to the nut 124 with the bolt 15 to fix the rotational speed sensor 13 to the sensor holder 12, a gap of dimension D1 is created between one side end face 122c of the sensor support portion 122 and the mounting flange portion 14 in the axial direction, and the mounting flange portion 14 and the sensor support portion 122 do not come into contact with each other.

[0045] In this way, by forming the sensor support part 122 and the nut holding part 123 in a separated state and with a step formed therein, even if the sensor support part 122 is warped or the sensor holder 12 is deformed, it is possible to prevent the attitude of the rotation speed sensor 13 from being tilted by the deformed sensor support part 122. This makes it possible to prevent the reading performance of the magnetic encoder 11 by the rotation speed sensor 13 from being affected.

[0046] It is preferable that dimension D1 of the step between one end surface 124a of the nut 124 and one end surface 122c of the sensor support portion 122 is 0.2 mm or more from the viewpoint of preventing tilting of the attitude of the rotation speed sensor 13. However, if the dimension D1 of the step is made too large, the depth dimension D2, which is the axial length of the sensor support portion 122, becomes small, and there is a risk that the positioning accuracy when supporting the rotation speed sensor 13 will decrease. Therefore, it is preferable that dimension D1 of the step is set to a value that ensures the depth dimension D2 to be 5 mm or more.

[0047] Furthermore, by forming the sensor support part 122 and the nut holding part 123 in a separate state, there is no need to provide a portion where the thickness of the resin member for connecting the sensor support part 122 and the nut holding part 123 is increased. This makes it easy to form the sensor support part 122 and the nut holding part 123 so that the cylindrical wall thickness is uniform in the circumferential direction.

[0048] Also, by forming sensor support portion 122 and nut holding portion 123 so that there are no thickened portions, it is possible to suppress deformation due to sink marks or warping during resin molding of sensor holder 12. Furthermore, since there is no need to perform weight reduction at the thickened portion between sensor support portion 122 and nut holding portion 123, the shape of the mold for molding sensor holder 12 can be simplified.

[0049] Furthermore, when the sensor holder 12 is press-fitted into the outer ring 2, warping and deformation of the sensor holder 12 tends to occur more significantly on the outer diameter side than on the inner diameter side. In contrast, in the sensor holder 12, the nut holding portion 123 that fixes the rotation speed sensor 13 with the bolt 15 is located on the inner diameter side closer to the rotation axis X than the sensor support portion 122. This makes it possible to reduce the effect of deformation of the sensor holder 12 on the attitude of the rotation speed sensor 13, and to prevent the attitude of the rotation speed sensor 13 from tilting from the axial direction.

[0050] As shown in FIG. 2 and FIG. 3, the sensor holder 12 has a gate portion 126. The gate portion 126 is an entrance for filling a resin into a mold when the sensor holder 12 is molded using the mold. The gate portion 126 is located between the sensor support portion 122 and the nut holding portion 123 in the radial direction. In this embodiment, the gate portion 126 is located at an intermediate position between the center P of the sensor support portion 122 and the center Q of the nut holding portion 123 in the radial direction. The gate portion 126 is formed integrally with the first portion 122a and the bottom surface portion 121b. By forming the gate portion 126, the rigidity of the sensor support portion 122 is improved.

[0051] In this way, by positioning the gate portion 126 between the sensor support portion 122 and the nut holding portion 123, the fluidity of the resin filled into the mold is improved, making it possible to efficiently fill both the sensor support portion 122 and the nut holding portion 123 with resin, as well as to efficiently fill the bottom surface 122d, which is a thin-walled portion.

[0052] Furthermore, the gate portion 126 is located close to the sensor support portion 122 and the nut holding portion 123 in the circumferential direction, which allows the sensor support portion 122 and the nut holding portion 123 to be filled with resin well.

[0053] In addition, the wheel bearing device 1 in this embodiment is configured as a wheel bearing device 1 of a third generation structure in which the inner raceway surface 3c is formed directly on the outer periphery of the hub wheel 3, but this is not limited to this and may be a second generation structure in which a pair of inner rings 4 are press-fitted into the hub wheel 3.

[0054] Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, which are merely illustrative, and it goes without saying that the present invention can be embodied in various other forms without departing from the gist of the present invention. The scope of the present invention is indicated by the claims, and further includes the equivalent meanings set forth in the claims, and all modifications within the scope of the claims. [Explanation of symbols]

[0055] 1 Wheel bearing device 2 Outer ring 2a Inner side opening 2c (inner side) outer raceway 2d (Outer side) outer raceway 3 Hub wheel 3a Small diameter stepped section 3c (hub ring) inner raceway 4. Inner Circle 4a (inner ring) inner raceway 5 Inner ball row 6 Outer ball row 13 Rotational speed sensor 11 Magnetic Encoder 12 Sensor holder 121 Cap part 122 Sensor support 122c (Sensor support part) one end face 123 Nut holder 124 Nut 124a (Nut) One side end face X Rotation axis

Claims

1. A sensor holder is attached to one axial end of an outer member which is located on an outer diameter side of an inner member and which supports an encoder at one axial end of the inner member and which rotatably supports the inner member via a double row of rolling elements, a cap portion fitted to the outer member so as to close an opening on one axial end side of the outer member; a sensor support portion that protrudes from the cap portion toward one axial direction at a position facing the encoder of the cap portion and supports a sensor that detects a displacement of the encoder; a nut holder that protrudes from the cap portion toward one side in an axial direction and holds a nut for fixing the sensor to the cap portion; Equipped with The sensor support portion and the nut holding portion are formed separately from each other, A sensor holder in which one axial end face of the nut held in the nut holding portion protrudes to one side in the axial direction further than one axial end face of the nut holding portion, and also protrudes to one side in the axial direction further than one axial end face of the sensor support portion.

2. The sensor holder according to claim 1 , wherein the nut holding portion is located radially inward relative to the sensor support portion.

3. an outer member having a double row outer raceway surface on an inner periphery thereof; an inner member including a hub ring having an axially extending small diameter step on an outer periphery thereof and at least one inner ring press-fitted into the small diameter step of the hub ring, the inner member having a double row inner raceway surface facing the double row outer raceway surfaces; a double row of rolling elements rollably accommodated between the raceway surfaces of the outer member and the inner member; an encoder supported on one axial end of the inner member; the sensor holder according to claim 1 or 2, which is attached to one axial end of the outer member; A wheel bearing device comprising:

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