JP2013221549A - Wheel bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel bearing device in which sealing performance of a fitting part between a sensor cap and an external member is improved at low cost without reducing productivity.SOLUTION: In a wheel bearing device, a sensor cap 10 is comprised of a bottomed and cylindrical cap body 14 made of a synthetic resin and a core metal 15 integrally molded in an opening part of the cap body. In a radially outer portion of the cap body 14, a mounting part 16 is formed while protruding axially. An insertion hole 16a extending axially is formed in the mounting part 16, and a sensor unit 20 is mounted into the insertion hole 16a. An end face of the mounting part 16 of the cap body 14 is abutted to an end face 4c of an external member 4, an annular lock recessed groove 18 is formed on the end face of the mounting part 16, an O-ring 23 is mounted into the lock recessed groove 18, and a protrusion 24 is formed in an opening part of the lock recessed groove 18, and thereby preventing the O-ring 23 from being dropped off.

Description

  The present invention relates to a wheel bearing device that rotatably supports a wheel of an automobile or the like with respect to a suspension device, and more particularly, to a wheel that is equipped with a rotation speed detection device that detects the rotation speed of the wheel to improve the sealing performance. The present invention relates to a bearing device.

  In general, a wheel bearing device in which a wheel of an automobile is rotatably supported with respect to a suspension device and an anti-lock brake system (ABS) is controlled to detect a rotation speed of the wheel is incorporated. Are known. Conventionally, in such a wheel bearing device, a sealing device is provided between an inner member and an outer member that are in rolling contact with a rolling element, and a magnetic encoder in which magnetic poles are alternately arranged in a circumferential direction is provided as the sealing device. In addition, the rotational speed detecting device is constituted by a magnetic encoder and a rotational speed sensor that is arranged facing the magnetic encoder and detects a magnetic pole change of the magnetic encoder accompanying the rotation of the wheel.

  In general, the rotational speed sensor is attached to the knuckle after the wheel bearing device is attached to the knuckle constituting the suspension device. However, in order to eliminate the complexity of adjusting the air gap between the rotational speed sensor and the magnetic encoder and to achieve a more compact design, recently, a bearing for a wheel with a rotational speed detection device that also incorporates the rotational speed sensor in the bearing. A device has been proposed.

  A structure as shown in FIG. 8 is known as an example of such a wheel bearing device. In the wheel bearing device, a cover (sensor cap) 52 made of synthetic resin is attached to the inner end opening of the outer member 51 and closes the inner end opening of the outer member 51. A sensor 53 is embedded on the outer surface side of the cover 52. An outer half portion of the sensor 53 formed in an annular shape protrudes outward from the outer surface of the cover 52. A connector 54 for taking out a detection signal of the sensor 53 is formed integrally with the cover 52 on the inner side surface of the cover 52. On the outer surface of the cover 52, a convex portion 55 protruding outward is formed over the entire circumference at a portion slightly inward in the diameter direction from the outer peripheral edge. The inner end portion of the sensor 53 is embedded in the central portion of the convex portion 55 in the diameter direction.

  A sleeve (core metal) 56 is attached along the outer peripheral surface of the convex portion 55. The sleeve 56 is a metal plate such as a stainless steel plate, which is formed in an annular shape with an L-shaped cross section and is bent outward in the diameter direction from the inner end edge of the cylindrical portion 56a and the cylindrical portion 56a. It has the collar part 56b. Of these, the cylindrical portion 56 a is disposed along the outer peripheral surface of the convex portion 55, and further protrudes outward from the tip edge (outer end edge) of the convex portion 55. Therefore, the inner and outer peripheral surfaces of the tip of the cylindrical portion 56 a are not covered with the synthetic resin that constitutes the cover 52. On the other hand, the flange portion 56 b is embedded in the central portion in the thickness direction of the outer peripheral edge portion of the cover 52 that is present on the outer side in the diameter direction than the convex portion 55. Note that the outer peripheral edge of the flange portion 56 b does not reach the outer peripheral edge of the cover 52, but is embedded in the cover 52.

  When the cover 52 closes the inner end opening of the outer member 51, the sleeve 56 is fitted into the inner end of the outer member 51, and the outer peripheral surface portion of the cover 52 is brought into contact with the inner end. In this state, the flange portion 56b of the sleeve 56 is embedded in a portion near the outer peripheral surface of the cover 52 so as to be flush with the outer surface. In addition, a locking groove 57 is formed over the entire circumference in a portion closer to the outer peripheral surface of the cover 52 and closer to the outer peripheral edge than the flange portion 56b. The O-ring 58 locked in the locking groove 57 is brought into elastic contact with the inner end surface of the outer member 51. As described above, since the O-ring 58 is provided in an elastically compressed state, muddy water or the like can be reliably prevented from leaking into the cover 52 and the outer member 51.

  In addition, while increasing the relative speed between the facing surfaces of the sensor 53 and the tone wheel 59 and simultaneously changing the magnetic resistance between the two members 53 and 59 at two locations, the output change of the sensor 53 can be changed. It is getting bigger. The sensor 53 includes an annular permanent magnet 60 magnetized in the axial direction. The base end portion of the first stator 61 is brought into contact with the axially outer end surface of the permanent magnet 60, and the outer peripheral surface of the distal end portion of the first stator 61 is intermediate between the large diameter portion 59 a constituting the tone wheel 59. It is made to oppose the inner peripheral surface of the part through a minute gap. Further, the base end portion of the second stator 62 is brought into contact with the inner end surface of the permanent magnet 60 in the axial direction, and the outer peripheral surface of the distal end portion of the second stator 62 is connected to the inner peripheral surface of the large diameter portion 59a in the axial direction. Furthermore, they are opposed to each other through a minute gap.

  By forming notches 63 in the inner half of the large-diameter portion 59a, and forming notches 64 and 64 in the tip portions of the first stator 61 and the second stator 62, respectively, Is formed in a comb-teeth shape. Of course, the pitches of the notches 63 and 64 are equal to each other, and the phases of the notches 64 and 64 formed in the first and second stators 61 and 62 are equal to each other. For this reason, the through holes 65 and 65 formed in the first and second stators 61 and 62 are engaged with the convex portions 68 and 68 formed on the bobbin 67 for winding the conducting wire constituting the coil 66. ing. A coil 66 is provided in a portion surrounded by the permanent magnet 60, the first stator 61, and the second stator 62. A voltage changing at a frequency proportional to the rotational speed of the tone wheel 59 is caused by a change in density of the magnetic flux flowing through these members 67, 61, 62.

  Due to the above-described configuration, the resistance to the flow of magnetic flux with the rotation of the tone wheel 59 is not limited to the facing portion between the tip portion of the first stator 61 and the large diameter portion 59a, but also the second stator 62. It also changes at the same time at the opposing portion of the leading end portion and the large diameter portion 59a. Therefore, the change in the magnetic flux density accompanying the rotation of the tone wheel 59 is increased, and the output of the sensor 53 can be increased. Further, the sensor 53 is disposed on the inner diameter side of the large diameter portion 59a constituting the tone wheel 59, and the inner peripheral surface of the large diameter portion 59a and the outer peripheral surface of the sensor 53 are opposed to each other. The relative speed between each other becomes faster. As described above, the output of the sensor 53 is also increased by increasing the relative speed between the two peripheral surfaces (see, for example, Patent Document 1).

Japanese Patent No. 3633048

  In such a conventional wheel bearing device, as shown in FIG. 9, the O-ring 58 is mounted in the locking groove 57 of the cover 52 and elastically contacts the inner end surface of the outer member 51. 52 and the outer member 51 can be prevented from leaking muddy water or the like. However, as shown in FIG. 10, when the cover 52 is assembled or transported, that is, in the state of the cover 52 alone, there is a possibility that the O-ring 58 may come off from the locking groove 57 of the cover 52. As a result, the sealing performance of the fitting portion between the cover 52 and the outer member 51 is lowered, and there is a possibility that foreign matters such as rainwater and dust may enter the bearing from the outside.

  The present invention has been made in view of such a conventional problem, and is a wheel bearing in which the sealing performance of the fitting portion between the sensor cap and the outer member is improved at a low cost without reducing the productivity. An object is to provide an apparatus.

  In order to achieve such an object, the invention according to claim 1 of the present invention includes an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and a wheel for attaching a wheel to one end. A hub ring having an integral mounting flange and formed with a small-diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter step portion of the hub ring, the outer periphery of the double row on the outer periphery An inner member in which a double row of inner rolling surfaces facing the rolling surface is formed, and a double row of rolling members accommodated between the inner member and the outer member so as to roll freely. This sensor includes a moving body, a pulsar ring that is externally fitted to the inner ring, and whose characteristics are alternately changed at equal intervals in the circumferential direction, and a sensor cap that is fixed to an inner end of the outer member. The cap has a bottomed cylindrical cap body made of synthetic resin and the cap. A metal core integrally molded in the opening of the main body, and a mounting portion is formed to protrude in the axial direction on the radially outer portion of the cap main body. The mounting portion is axially positioned at a position corresponding to the pulsar ring. In the wheel bearing device in which the sensor insertion hole extending to the end is formed, the end surface of the mounting portion of the cap body abuts on the end surface of the outer member, and an annular locking groove is formed on the end surface of the mounting portion. An O-ring is attached to the locking groove, and a retaining mechanism for preventing the O-ring from dropping off is formed integrally with the opening of the locking groove.

  As described above, the sensor cap includes a pulsar ring that is fitted onto the inner ring, and whose characteristics are alternately changed at equal intervals in the circumferential direction, and a sensor cap that is fixed to the end on the inner side of the outer member. Consists of a bottomed cylindrical cap body made of synthetic resin and a cored bar molded integrally with the opening of the cap body, and a mounting portion projects in the axial direction on the radially outer portion of the cap body. In the wheel bearing device in which the sensor insertion hole extending in the axial direction is formed at a position corresponding to the pulsar ring of the mounting portion, the end surface of the mounting portion of the cap body abuts on the end surface of the outer member, An annular locking groove is formed on the end surface, and an O-ring is attached to the locking groove, and a retaining mechanism for preventing the O-ring from dropping off is formed integrally with the opening of the locking groove. So production Without lowering the can to provide a wheel bearing apparatus with improved sealability of the fitting portion between the sensor cap and the outer member at a low cost.

  Preferably, as in the invention described in claim 2, the retaining mechanism may be constituted by a protrusion formed in the opening of the locking groove.

  Further, as in the third aspect of the invention, if the projections are formed at a plurality of locations on the circumference, the mold can be easily removed during injection molding.

  Further, as in the invention described in claim 4, the inner diameter surface and / or the outer diameter surface of the locking groove is tapered so that the opening of the locking groove is narrow. As a result, the mold can be easily removed during the injection molding, and the O-ring can be easily attached, so that the assembling workability can be improved and the cost can be reduced.

  As in the fifth aspect of the present invention, if an annular recess is formed on the inner diameter surface side of the locking groove, a retaining mechanism is provided on the inner diameter surface side of the locking groove. However, the wall thickness on the inner diameter side becomes substantially thin and is easily deformed at the time of injection molding, the mold can be more easily removed, and the size and accuracy of the locking groove can be improved.

  Further, as in the invention described in claim 6, if the locking groove is formed by shifting to the outer diameter side of the mounting portion, a retaining mechanism is provided on the outer diameter surface side of the locking groove. Even if it is provided, the wall thickness on the outer diameter surface side is substantially reduced and it becomes easier to deform during injection molding, the mold can be more easily removed, and the size and accuracy of the locking groove can be improved. .

  Further, as in the invention described in claim 7, a sensor unit is mounted in the sensor insertion hole, and a rotation speed sensor embedded in the sensor unit is opposed to the pulsar ring via a predetermined axial air gap. May be.

  Further, as in the invention according to claim 8, the sensor unit includes a sensor holder integrally including an insertion portion in which the rotation speed sensor is embedded and a mounting flange fixed to the mounting portion of the sensor cap. If the nut is embedded in the mounting part by insert molding and the sensor holder is detachably fixed to the mounting part via a fixing bolt, the sensor unit is securely fixed without being displaced for a long period of time. can do.

  The wheel bearing device according to the present invention integrally has an outer member integrally formed with a double row outer rolling surface on the inner periphery, and a wheel mounting flange for mounting the wheel on one end, and on the outer periphery. A hub ring formed with a small-diameter step portion extending in the axial direction, and at least one inner ring press-fitted into the small-diameter step portion of the hub ring, the inner side of the double row facing the outer rolling surface of the double row on the outer periphery An inner member in which a rolling surface is formed, a double row rolling element housed in a freely rolling manner between the respective rolling surfaces of the inner member and the outer member, and an outer fit to the inner ring, A pulsar ring whose characteristics are alternately changed at equal intervals in the circumferential direction, and a sensor cap fixed to the inner side end of the outer member. The sensor cap is a bottomed cylinder made of a synthetic resin. Shaped cap body and an integral molding at the opening of the cap body The mounting portion is formed to protrude in the axial direction on the radially outer portion of the cap body, and a sensor insertion hole extending in the axial direction is formed at a position corresponding to the pulsar ring of the mounting portion. In the wheel bearing device, the end surface of the mounting portion of the cap body is in contact with the end surface of the outer member, and an annular locking groove is formed on the end surface of the mounting portion, and an O-ring is formed in the locking groove. And a retaining mechanism for preventing the O-ring from falling off is integrally formed in the opening of the locking groove, so that the sensor cap can be manufactured at a low cost without reducing productivity. It is possible to provide a wheel bearing device in which the sealing performance of the fitting portion with the outer member is improved.

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. It is a principal part enlarged view which shows the detection part of FIG. (A) is a front surface which shows the sensor cap single-piece | unit of FIG. 1, (b) is sectional drawing along the III-III line, (c) is a rear view of (b). It is the A section enlarged view of FIG. It is a principal part enlarged view which shows the modification of FIG. It is a principal part enlarged view which shows the modification of FIG. It is a principal part enlarged view which shows the other modification of FIG. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus. It is a principal part enlarged view of FIG. It is a principal part enlarged view which shows the state before the assembly to the outward member of FIG.

  An outer member integrally having a vehicle body mounting flange to be attached to the vehicle body on the outer periphery, a double row outer rolling surface formed integrally on the inner periphery, and a wheel mounting flange for mounting a wheel on one end A hub wheel integrally formed and having an inner rolling surface facing one of the outer rolling surfaces of the double row on the outer periphery, and a small-diameter step portion extending in the axial direction from the inner rolling surface, and the hub wheel An inner member formed of an inner ring that is press-fitted into a small-diameter step portion and formed with an inner rolling surface facing the other of the double row outer rolling surfaces, and the inner member and the outer member. A double-row rolling element accommodated between the running surfaces so as to be freely rollable, a pulsar ring that is externally fitted to the inner ring and whose characteristics are alternately changed at equal intervals in the circumferential direction, and an inner member of the outer member The sensor cap is fixed to the end of the side. It consists of a bottomed cylindrical cap body made of fat and a cored bar integrally molded in the opening of the cap body, and a mounting portion projects in the axial direction on the radially outer portion of the cap body, In the wheel bearing device in which a sensor insertion hole extending in the axial direction is formed at a position corresponding to the pulsar ring of the mounting portion, an end surface of the mounting portion of the cap body abuts on an end surface of the outer member, and the mounting portion An annular locking groove is formed on the end surface of the ring, and an O-ring is attached to the locking groove, and a projection is formed at the opening of the locking groove.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention, FIG. 2 is an enlarged view of a main part showing a detection unit of FIG. 1, and FIG. 3 (a) is a sensor cap of FIG. (B) is a cross-sectional view taken along line III-III, (c) is a rear view of (b), FIG. 4 is an enlarged view of part A in FIG. 2, and FIG. FIG. 6 is an enlarged view of a main part showing a modification example of FIG. 5, and FIG. 7 is an enlarged view of a main part showing another modification example of FIG. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  This wheel bearing device is referred to as the third generation on the driven wheel side, and the hub wheel 1 and the double row rolling bearing 2 are configured as a unit. The double row rolling bearing 2 includes an inner member 3, an outer member 4, and double row rolling elements (balls) 5, 5 accommodated between the members 3, 4 so as to be freely rollable. The inner member 3 indicates a hub wheel 1 and an inner ring 7 that is press-fitted and fixed to the hub wheel 1.

  The hub wheel 1 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at an end portion on the outer side, and the wheel mounting flange 6 is used for fastening a wheel at a circumferentially equidistant position. Hub bolt 6a is planted. In addition, an outer side (one) inner rolling surface 1a and an axial small-diameter step portion 1b extending in the axial direction from the inner rolling surface 1a are formed on the outer periphery, and an inner ring 7 is connected to the small-diameter step portion 1b. It is press-fitted through shimeshiro. Then, the end portion of the small-diameter step portion 1b is plastically deformed radially outward to form a caulking portion 1c, and the inner ring 7 is given a predetermined bearing preload to the hub wheel 1 by the caulking portion 1c. It is fixed in the axial direction in the state. An inner side inner rolling surface 7 a is formed on the outer periphery of the inner ring 7.

  On the other hand, the outer member 4 integrally has a vehicle body mounting flange 4b fixed to a knuckle (not shown) constituting a suspension device on the outer periphery, and double row inner rolling of the inner member 3 on the inner periphery. Double row outer rolling surfaces 4a and 4a facing the surfaces 1a and 7a are integrally formed. The double row rolling bearing 2 includes double row rolling elements 5 and 5 accommodated between the rolling surfaces 4a, 1a and 4a and 7a, and the double row rolling elements 5 and 5 are equally arranged in the circumferential direction. Cages 8 and 8 are provided to hold the rolls freely.

  Seals 9 and sensor caps 10 are attached to both ends of the outer member 4 to seal the opening of the annular space formed between the outer member 4 and the inner member 3. The seal 9 and the sensor cap 10 prevent leakage of the lubricating grease sealed inside the bearing and intrusion of rainwater, dust and the like from the outside into the bearing.

  The hub wheel 1 is made of medium and high carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and includes an inner raceway surface 1a and a base portion on the inner side of the wheel mounting flange 6 that serves as a seal land portion of the seal 9. The surface hardness is hardened in the range of 58 to 64 HRC by induction hardening from 6b to the small diameter step 1b. The caulking portion 1c is an unquenched portion having a surface hardness of 30 HRC or less after forging.

  Further, the outer member 4 is formed of medium and high carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, similar to the hub wheel 1, and at least the double row outer raceway surfaces 4a and 4a are formed by induction hardening. The surface hardness is set in the range of 58 to 64 HRC. On the other hand, the inner ring 7 and the rolling element 5 are made of high carbon chrome bearing steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core part by quenching. Here, as the double row rolling bearing 2, a double row angular contact ball bearing using the rolling elements 5, 5 as a ball is illustrated, but not limited to this, a double row tapered roller bearing using a tapered roller as the rolling element. There may be. Further, although the third generation structure has been illustrated, a so-called second generation structure in which a pair of inner rings are press-fitted into the hub ring may be used.

  A pulsar ring 11 is press-fitted into the outer periphery of the inner ring 7. The pulsar ring 11 includes a support ring 12 formed in an annular shape, and a magnetic encoder 13 integrally joined to the side surface of the support ring 12 by vulcanization adhesion or the like. This magnetic encoder 13 constitutes a rotary encoder for detecting the rotational speed of a wheel by mixing magnetic powder such as ferrite in an elastomer such as rubber and alternately magnetizing magnetic poles N and S in the circumferential direction.

  The support ring 12 is made of a ferromagnetic steel plate, for example, a ferritic stainless steel plate (JIS standard SUS430 system or the like) or a rust-proof cold rolled steel sheet (JIS standard SPCC system or the like) by press working. It has a cylindrical portion 12a that is formed in a letter shape and is press-fitted into the inner ring 7, and a standing plate portion 12b that extends radially inward from the cylindrical portion 12a. The magnetic encoder 13 is joined to the side surface on the inner side of the upright plate portion 12b.

  The sensor cap 10 is fitted and fixed to the inner end of the outer member 4 and closes the opening of the outer member 4. The sensor cap 10 is a bottomed cylindrical cap body formed by injection molding a thermoplastic synthetic resin such as PA (polyamide) 66 filled with a predetermined amount of a fibrous reinforcing material such as GF (glass fiber). 14 and a metal core 15 integrally molded in the opening of the cap main body 14. The core 15 is formed in an annular shape having an L-shaped cross section by press forming a stainless steel plate having corrosion resistance. In particular, the metal core 15 is formed of a non-magnetic steel plate, for example, an austenitic stainless steel plate (JIS standard SUS304 or the like) so as not to adversely affect the sensing performance of a rotational speed sensor 19 described later. .

  Here, PA66 is exemplified as the material of the cap body 14, but is not limited thereto, and a thermoplastic synthetic resin called so-called engineering plastic such as PPA (polyphthalamide), PBT (polybutylene terephthalate), Alternatively, thermoplastic synthetic resins called super engineering plastics such as polyphenylene sulfide (PPS), polyether ether ketone (PEEK), and polyamideimide (PAI), phenol resin (PF), and epoxy resin (EP) Thermosetting synthetic resin such as polyimide resin (PI) may be used. Moreover, as a fibrous reinforcement, not only GF but CF (carbon fiber), an aramid fiber, a boron fiber, etc. can be illustrated other than this.

  In this embodiment, as shown in enlarged views in FIGS. 2, 3, and 4, a mounting portion 16 that protrudes in the axial direction is integrally provided on the radially outer portion of the cap body 14. An insertion hole 16a penetrating in the axial direction is formed at a position corresponding to the magnetic encoder 13. The sensor unit 17 is inserted into the insertion hole 16a.

  The sensor unit 17 includes a rotation speed sensor 19 composed of a magnetic detection element that changes its characteristics in accordance with the flow direction of magnetic flux, such as a Hall element, a magnetoresistive element (MR element), and a waveform shaping circuit that adjusts the output waveform of the magnetic detection element. It is composed of an IC or the like in which an automobile is incorporated, and constitutes an anti-lock brake system for an automobile that detects the rotational speed of the wheel and controls its rotational speed.

  The rotation speed sensor 19 is embedded in a sensor holder 20 made of synthetic resin. The sensor holder 20 is integrally formed with an insertion portion 20a and a mounting flange 20b. Further, a nut 21 having an internal thread 21a formed on the inner periphery is embedded in the mounting portion 16 of the cap body 14 by insert molding. The sensor unit 17 is fixed to the mounting portion 16 by fastening the fixing bolt 22 via the mounting flange 20b. An annular groove 21b is formed on the outer periphery of the nut 21 to prevent the nut 21 from moving in the axial direction.

  Here, the core metal 15 extends in a radially outward direction from a cylindrical fitting portion 15a that is press-fitted into the inner periphery of the end portion of the outer member 4 via a predetermined shimiro, and an end portion of the fitting portion 15a. An attachment portion 16 of the cap body 14 is formed so as to have a flange portion 15b and to embed the flange portion 15b. An annular locking groove 18 is formed on the outer end surface of the mounting portion 16 that contacts the inner side end surface 4 c of the outer member 4, and an O-ring 23 is attached to the locking groove 18. .

  In addition, a protrusion 24 serving as a so-called retaining mechanism that prevents the O-ring 23 from falling off is formed integrally with the opening of the locking groove 18. Thereby, the wheel bearing apparatus which improved the sealing performance of the fitting part of the sensor cap 10 and the outer member 4 at low cost without reducing productivity can be provided. Here, the protrusions 24 are formed over the entire circumference of the inner diameter surface 18a of the locking recess groove 18, but at a plurality of locations (at least on the circumference) so that the mold can be easily removed during injection molding. You may form in 3 places. Moreover, you may form in the outer diameter surface 18b of the latching ditch | groove 18, and you may form in both surfaces of the inner diameter surface 18a and the outer diameter surface 18b.

  FIG. 5 shows a modification of FIG. This embodiment is basically different from that described above only in the configuration of the locking groove 18, and the same parts and parts having the same functions or parts having the same functions are denoted by the same reference numerals. Is omitted.

  The locking groove 25 is formed as an annular groove on the outer end surface of the mounting portion 16 as in the above-described embodiment, and the inner diameter surface 25a of the locking groove 25 is narrow so that the opening is narrow. Is formed in a tapered shape. As a result, the mold can be easily removed at the time of injection molding, and the O-ring 23 can be easily attached, so that the assembling workability can be improved and the cost can be reduced. The outer diameter surface 25b of the locking groove 25 may be formed in a tapered shape, or both the inner diameter surface 25a and the outer diameter surface 25b may be formed in a tapered shape.

  FIG. 6 shows a modification of FIG. This embodiment basically differs from the above-described embodiment only in a part of the configuration around the locking groove 25, and other parts having the same parts or the same functions as those of the above-described embodiment. The same reference numerals are assigned and detailed description thereof is omitted.

  The locking groove 25 is formed as an annular groove on the outer end surface of the mounting portion 16 as in the above-described embodiment, and the inner diameter surface 25a of the locking groove 25 is narrow so that the opening is narrow. Is formed in a tapered shape. An annular recess 26 is formed on the inner diameter surface 25a side. As a result, even if the inner diameter surface 25a is formed in a tapered shape, the wall thickness t1 on the inner diameter surface 25a side is substantially reduced, making it easier to be deformed during injection molding, making it easier for the mold to come out, The size and accuracy of the groove 25 can be improved.

  FIG. 7 shows another modification of FIG. Note that this embodiment is basically different from the above-described embodiment only in the shape of the locking groove 25, and other parts having the same parts or the same functions as those of the above-described embodiments are denoted by the same reference numerals. Detailed description thereof will be omitted.

  The locking groove 27 is formed as an annular groove on the outer end surface of the mounting portion 16 as in the above-described embodiment, and the outer diameter surface of the locking groove 27 is narrow so that the opening is narrow. 27a is formed in a tapered shape. The locking groove 27 is formed by shifting to the outer diameter side of the mounting portion 16. As a result, even if the outer diameter surface 27a is formed in a tapered shape, the thickness t2 on the outer diameter surface 27a side is substantially reduced, and the outer diameter surface 27a is easily deformed at the time of injection molding. The size and accuracy of the concave groove 27 can be improved.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The wheel bearing device according to the present invention can be applied to a wheel bearing device in which a cap body made of synthetic resin is fitted to an outer member.

DESCRIPTION OF SYMBOLS 1 Hub wheel 1a, 7a Inner rolling surface 1b Small diameter step part 1c Clamping part 2 Double row rolling bearing 3 Inner member 4 Outer member 4a Outer rolling surface 4b Car body mounting flange 4c End side of outer member on inner side 5 Rolling element 6 Wheel mounting flange 6a Hub bolt 6b Inner base 7 of wheel mounting flange Inner ring 8 Cage 9 Seal 10 Sensor cap 11 Pulsar ring 12 Support ring 12a Cylindrical part 12b Standing plate part 13 Magnetic encoder 14 Cap body 15 Core 15a Fitting portion 15b Fitting portion 16 Mounting portion 16a Insertion hole 17 Sensor unit 18, 25, 27 Locking groove 18a, 25a Locking groove inner diameter surface 18b, 25b, 27a Locking groove outer diameter surface 19 Rotation speed Sensor 20 Sensor holder 20a Insert portion 20b Mounting flange 21 Nut 21a Female thread 21b Annular groove 22 Fixing bolt 24 Projection 2 Recess 51 Outer member 52 Cover 53 Sensor 54 Connector 55, 68 Protruding part 56 Sleeve 56a Cylindrical part 56b Gutter part 57 Locking groove 58 O-ring 59 Tone wheel 59a Large diameter part 60 Permanent magnet 61 First stator 62 First Second stator 63, 64 Notch 65 Through hole 66 Coil 67 Bobbins t1, t2 Thickness

Claims (8)

An outer member in which a double row outer rolling surface is integrally formed on the inner periphery;
From a hub wheel integrally having a wheel mounting flange for mounting a wheel at one end and having a small-diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter step portion of the hub ring An inner member in which a double row inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery,
A double row rolling element housed movably between the rolling surfaces of the inner member and the outer member;
Pulsar ring that is externally fitted to the inner ring, and the characteristics are changed alternately and at equal intervals in the circumferential direction;
A sensor cap fixed to the inner side end of the outer member;
This sensor cap is composed of a bottomed cylindrical cap body made of synthetic resin, and a core metal integrally molded in the opening of the cap body,
In the wheel bearing device in which a mounting portion is formed so as to protrude in the axial direction on the radially outer portion of the cap body, and a sensor insertion hole extending in the axial direction is formed at a position corresponding to the pulsar ring of the mounting portion.
An end surface of the cap body mounting portion abuts on an end surface of the outer member, an annular locking groove is formed on the end surface of the mounting portion, an O-ring is mounted on the locking groove, and A wheel bearing device, wherein a retaining mechanism for preventing the O-ring from falling off is integrally formed in an opening of the locking groove.   The wheel bearing device according to claim 1, wherein the retaining mechanism is constituted by a protrusion formed at an opening of the locking groove.   The wheel bearing device according to claim 2, wherein the protrusions are formed at a plurality of locations on the circumference.   The wheel bearing device according to claim 1, wherein an inner diameter surface and / or an outer diameter surface of the locking groove is formed in a tapered shape so that the opening of the locking groove is narrow.   The wheel bearing device according to any one of claims 1 to 4, wherein an annular recess is formed on an inner diameter side of the locking groove.   The wheel bearing device according to any one of claims 1 to 4, wherein the locking groove is formed to be shifted to the outer diameter side of the mounting portion.   The wheel bearing device according to claim 1, wherein a sensor unit is mounted in the sensor insertion hole, and a rotational speed sensor embedded in the sensor unit is opposed to the pulsar ring via a predetermined axial air gap. .   The sensor unit includes a sensor holder integrally including an insertion portion in which the rotational speed sensor is embedded and a mounting flange fixed to the mounting portion of the sensor cap, and a nut is embedded in the mounting portion by insert molding. The wheel bearing device according to claim 7, wherein the sensor holder is detachably fixed to the attachment portion via a fixing bolt.

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