JP5334820B2 - Wheel bearing device with rotation speed detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing system for a wheel, equipped with a rotational-speed detection device which improves sealing performance. <P>SOLUTION: A sensor cap 16 comprises: a cap body 17 provided with a fitting section 17a made of a synthetic resin and internally suitable for the end of an outer member 2 and bottom section 17c that extends radially inward from this via a stepped section 17b closely contacting the end surface of the outer member 2; and a core metal 18 molded to this opening. A cap 14 is attached to the outer member 2. The cap includes a fitting section 14a, which is formed from a non-magnetic steel plate by press working and press-fitted into the inner circumference of the end of the outer member 2, and a disk section 14c, which extends radially inward from the fitting section via a reduced-diameter section 14b and faces a pulser ring 11 via a slight gap in the axial direction. An elastic member 15 having an annular projection 15a joined to the reduced-diameter section 14b by vulcanization adhesion. A rotational-speed sensor 19 is arranged to face the pulser ring 11 via the disk section 14c where the sensor contacts or approaches. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a wheel bearing device for rotatably supporting a wheel of an automobile or the like with respect to a suspension device, in particular, a rotation speed detection device for detecting the rotation speed of the wheel, and a rotation speed for improving the sealing performance. The present invention relates to a wheel bearing device with a detection device.

  A wheel bearing with a rotation speed detecting device that rotatably supports a vehicle wheel with respect to a suspension device and controls an anti-lock brake system (ABS) to detect the rotation speed of the wheel. Devices are generally 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 with a rotational speed detection device. This wheel bearing device with a rotational speed detection device is supported and fixed to a knuckle (not shown), and is inserted into the outer member 51 serving as a fixing member and the outer member 51 via double rows of balls 53 and 53. And an inner member 52. The inner member 52 includes a hub ring 55 and an inner ring 56 that is externally fitted to the hub ring 55.

  The outer member 51 integrally has a vehicle body mounting flange 51b on the outer periphery, and double row outer rolling surfaces 51a and 51a are formed on the inner periphery. On the other hand, the inner member 52 is formed with double-row inner rolling surfaces 55a and 56a facing the outer rolling surfaces 51a and 51a of the outer member 51 described above. Of the double row inner rolling surfaces 55 a and 56 a, one inner rolling surface 55 a is integrally formed on the outer periphery of the hub wheel 55, and the other inner rolling surface 56 a is formed on the outer periphery of the inner ring 56. The inner ring 56 is press-fitted into a shaft-shaped small-diameter step portion 55 b that extends in the axial direction from the inner rolling surface 55 a of the hub wheel 55. The double-row balls 53 and 53 are respectively accommodated between the rolling surfaces and are held by the cages 57 and 57 so as to be freely rollable.

  The hub wheel 55 integrally has a wheel mounting flange 54 for mounting a wheel (not shown) on the outer periphery, and a crimped portion 58 is formed by plastically deforming the end portion of the small diameter step portion 55b radially outward. The inner ring 56 is fixed in the axial direction by the caulking portion 58. A seal 59 and a sensor cap 63 are attached to the end of the outer member 51 to prevent leakage of the lubricating grease sealed inside the bearing and intrusion of rainwater, dust, etc. into the bearing from the outside. Yes.

  A magnetic encoder 60 is press-fitted into the outer periphery of the inner ring 56. The magnetic encoder 60 is composed of a support ring 61 formed in an annular shape having a substantially L-shaped cross section by a magnetic metal plate, and an encoder body 62 attached to a side surface of the support ring 61. The encoder body 62 is made of a permanent magnet such as rubber mixed with ferrite powder, and S poles and N poles are alternately magnetized at equal intervals in the circumferential direction.

  The cover 63 is formed of a synthetic resin in a covered cylindrical shape, and its cylindrical portion 63a is press-fitted into the inner periphery of the outer side of the outer member 51, and the opening of the outer member 51 is closed by the lid 63b. Yes. A flange 64 that abuts the end surface of the outer member 51 is formed in the cylindrical portion 63 a, whereby the entire cover 63 is accurately positioned in the axial direction with respect to the outer member 51, and a sensor attached to the cover 63. 69 position management can be easily performed.

  Further, as shown in FIG. 9, a cylindrical sensor mounting portion 65 is formed on the lid portion 63b of the cover 63, and the insertion portion 69a of the sensor 69 is inserted into a sensor mounting hole 66 formed on the inner peripheral side thereof. ing. On the other hand, the cover 63 is integrally molded with a cored bar 67 formed in a covered cylindrical shape from the inner peripheral surface of the cylindrical portion 63a to the inner surface of the lid portion 63b. The metal core 67 includes a cylindrical portion 67a molded on the cylindrical portion 63a of the cover 63, and a lid portion 67b that forms the bottom of the cylindrical portion 67a, and is provided on the side facing the encoder main body 62 of the sensor mounting hole 66. The opening is closed.

  The core metal 67 is formed of a non-magnetic steel plate having a thickness of approximately 0.3 mm, and has a cover portion 67b, thereby increasing the strength of the cover 63 and being non-magnetic. Does not affect accuracy.

  The sensor 69 is attached to the cover 63 by inserting the insertion portion 69 a into the sensor attachment hole 66 of the cover 63. The insertion portion 69 a faces a part of the encoder main body 62 via a predetermined axial clearance across the lid portion 67 b of the core metal 67, and rotates the magnetic encoder 60 in the vicinity of the surface facing the encoder main body 62. The detector (not shown) which detects the magnetic field fluctuation | variation which generate | occur | produces by is built in. The detection unit outputs an electrical signal at one end of the output cable 68 in the sensor 69 via the cable 68.

  As described above, the opening of the sensor mounting hole 66 of the cover 63 on the side facing the encoder main body 62 is closed with the lid portion 67b of the cored bar 67 formed of a nonmagnetic steel plate in a covered cylindrical shape. Since the sensor mounting hole 66 does not penetrate the cover 63, there are few foreign substance intrusion paths into the apparatus, and the sealing performance of the entire apparatus is excellent (see, for example, Patent Document 1).

Japanese Patent No. 4286063

  In such a conventional wheel bearing device with a rotational speed detection device, the joint portion of the core metal 67 and the cover 63 made of synthetic resin, that is, the cylindrical portion 67a of the core metal 67, the cylindrical portion 63a of the cover 63, and the core metal. 67 and the lid portion 67b of the cover 63 are peeled off due to a difference in linear expansion coefficient due to a temperature change due to a thermal shock or the like, and a fine clearance is maintained, and the initial sealing performance is maintained over a long period of time. difficult.

  The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a wheel bearing device with a rotational speed detection device that improves the sealing performance.

  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 integrally having a 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. An inner member in which a double row of inner rolling surfaces facing the outer rolling surface is formed, and a double row of rolling members housed between the outer member and the inner member so as to roll freely. 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 bottomed cylindrical shape that is internally fitted and fixed to an end on the inner side of the outer member. A sensor cap, and a predetermined axial air gap at a position corresponding to the pulsar ring. In the wheel bearing device with a rotational speed detection device in which the rotational speed sensor is disposed, the sensor cap is formed by injection molding a synthetic resin, and is a cylinder that is press-fitted into the inner periphery of the inner side end of the outer member. And a cap body having a bottom portion extending radially inward from the fitting portion via a stepped portion that is in close contact with the end face on the inner side of the outer member, and an opening of the cap body And a cap-shaped cap is attached to the outer member, and the cap is formed by pressing from a non-magnetic steel plate. A cylindrical fitting portion in which an elastic member made of synthetic rubber is provided on the outer peripheral surface press-fitted into the periphery, and extends radially inward from the fitting portion, and is opposed to the pulsar ring via a slight axial clearance. Do And a plate portion, the rotational speed sensor is abutting or close to the circular plate portion, is arranged opposite to the pulser ring through the cap.

  Thus, 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 bottomed cylindrical sensor that is fitted and fixed to the inner side end of the outer member. A wheel bearing device with a rotational speed detecting device, wherein the rotational speed sensor is disposed at a position corresponding to the pulsar ring via a predetermined axial air gap. The sensor cap is formed by injection molding synthetic resin. A cylindrical fitting portion that is press-fitted into the inner periphery of the inner member end of the outer member, and a radially inward portion through a stepped portion that is in close contact with the inner member end surface of the outer member. It consists of a cap body with a bottom that extends, and a metal core molded integrally with the opening of the cap body, and a cup-shaped cap is attached to the outer member, and this cap is pressed from a non-magnetic steel plate. In A cylindrical fitting portion provided with an elastic member made of synthetic rubber on the outer peripheral surface that is press-fitted into the inner periphery of the inner side end of the outer member, and extends radially inward from the fitting portion. A disk portion facing the pulsar ring through a slight axial clearance, and a rotational speed sensor is abutted or brought close to the disk portion and is opposed to the pulsar ring via the cap. Rotation speed that improves the assembly workability by eliminating the air gap adjustment and seals the inside of the bearing with a cap provided with an elastic member made of synthetic rubber at the fitting part. A wheel bearing device with a detection device can be provided.

  Preferably, as in the invention according to claim 2, a reduced diameter portion is formed between the fitting portion and the disc portion of the cap, and an elastic member made of synthetic rubber is vulcanized and bonded to the reduced diameter portion. Are joined together so that the elastic member protrudes from the side surface of the disc portion of the cap to the inner side so as not to interfere with the rotational speed sensor, and is radially outward from the outer diameter of the fitting portion. If the annular protrusion is provided on the inner member, the annular protrusion is elastically deformed and pressure-bonded to the inner periphery of the end portion of the outer member when the cap is fitted, so that the airtightness of the fitting portion can be improved.

  In addition, as in the invention described in claim 3, if the thickness of at least the disk portion of the cap is formed thinner than the thickness of other portions, the air gap can be set small. , Detection accuracy can be increased.

  Further, as in the invention described in claim 4, if the fitting surface on the inner periphery of the end portion of the outer member is restricted to a chatter height of 3 μm or less, the elastic member made of synthetic rubber has deteriorated due to corrosion or the like. Even if it will be in a state, the airtightness of the fitting part of metal surfaces can be ensured, and the airtightness of a fitting part can be improved further.

  Further, as in the invention described in claim 5, a mounting portion protruding in the axial direction is integrally provided on the radially outer portion of the bottom portion of the sensor cap, and an insertion hole is formed in the mounting surface on the road surface. On the other hand, if the rotation speed sensor is mounted in a horizontal position, the air of the rotation speed sensor and the pulsar ring can be obtained even when the outer member and the inner member are relatively inclined due to a lateral load from the wheel. Gap fluctuation can be suppressed, and stable detection accuracy can be obtained.

  Further, as in the sixth aspect of the present invention, if a drain is formed on the side close to the radially outer road surface of the bottom of the sensor cap, for example, foreign matter such as rainwater enters from the outside into the sensor cap. Even if this occurs, the foreign matter can flow and fall within the sensor cap, and the foreign matter can be effectively discharged from the bottom in the radial direction of the bottom.

  According to a seventh aspect of the present invention, a fixing nut is embedded in the mounting portion of the sensor cap by insert molding, and the rotation speed sensor is connected to the fixing nut via a mounting member. If it is fixed, the rotational speed sensor can be mounted in a state where the inside of the bearing is closed with the sensor cap, and the sealing performance can be improved.

  Preferably, as in the invention described in claim 8, if the end face on the inner side of the fixing nut is set so as to be flush with or slightly protrude from the end face of the mounting portion, the fixing bolt is fastened at the time of fastening. And the end face of the fixing nut can be brought into close contact with each other to improve the sealing performance and the fastening force.

  If the nut is made of stainless steel as in the invention described in claim 9, rusting can be prevented over a long period of time, and durability can be improved.

  If the cap is made of a non-magnetic austenitic stainless steel plate as in the invention described in claim 10, the cap has corrosion resistance over a long period of time, and the durability is improved and the rotation is improved. The desired detection accuracy can be ensured without adversely affecting the sensing performance of the speed sensor.

  Further, as in the invention described in claim 11, when the core of the sensor cap is formed by pressing from a non-magnetic steel plate, high accuracy without adversely affecting the sensing performance of the rotational speed sensor. Speed detection can be performed.

  Further, as in the invention described in claim 12, the pitch circle diameter of the outer side rolling element row of the double row rolling element rows is set larger than the pitch circle diameter of the inner side rolling element row. In addition, the rolling element diameter of the outer rolling element row is set smaller than the rolling element diameter of the inner rolling element row, and the number of rolling elements in the outer rolling element row is set to the inner rolling element row. If the number of rolling elements is set to be greater than the number of rolling elements, the bearing rigidity of the outer side portion can be increased compared to the inner side, the life of the bearing can be increased, and the outer side of the outer member can be increased. High rigidity can be achieved while suppressing the diameter.

  The wheel bearing device with a rotational speed detection device according to the present invention is integrally formed with an outer member in which a double row outer rolling surface is integrally formed on the inner periphery and a wheel mounting flange for mounting a wheel on one end. And a hub ring 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. An inner member in which opposing double-row inner rolling surfaces are formed, a double-row rolling element housed in a freely rolling manner between the respective rolling surfaces of the outer member and the inner member, and the inner ring And a pulsar ring whose characteristics are alternately changed at equal intervals in the circumferential direction, and a bottomed cylindrical sensor cap that is internally fitted and fixed to the inner side end of the outer member. Rotate through a predetermined axial air gap to a position corresponding to the pulsar ring. In the wheel bearing device with a rotational speed detection device in which the speed sensor is arranged, the sensor cap is formed by injection molding a synthetic resin, and is fitted into a cylindrical fit that is press-fitted into the inner periphery of the outer side end of the outer member. A cap body having a bottom portion extending inward in the radial direction from the fitting portion and a stepped portion closely contacting the inner end face of the outer member from the fitting portion, and an opening of the cap body are integrally molded A cup-shaped cap is attached to the outer member, and this cap is formed by pressing from a non-magnetic steel plate and is press-fitted into the inner periphery of the inner side end of the outer member. A cylindrical fitting portion provided with an elastic member made of synthetic rubber on the outer peripheral surface thereof, and a disk portion extending radially inward from the fitting portion and facing the pulsar ring via a slight axial clearance And be prepared Since the rotational speed sensor is abutted or brought close to the disc portion and is disposed opposite to the pulsar ring via the cap, it is possible to improve the assembly workability by eliminating complicated air gap adjustment and fitting. The inside of the bearing can be sealed by the cap in which the elastic member made of synthetic rubber is arranged at the joint, and the wheel bearing device with a rotational speed detecting device can be provided with improved sealing performance.

It is a longitudinal cross-sectional view along the I-O-I line of FIG. 2 which shows one Embodiment of the wheel bearing apparatus with a rotational speed detection apparatus which concerns on this invention. It is a side view of FIG. It is a principal part enlarged view which shows the detection part of FIG. FIG. 3 is a main part enlarged view showing a drain part of FIG. 2. It is a principal part enlarged view which shows the modification of FIG. (A) is the longitudinal cross-sectional view along the VI-O-VI line of (b) which shows the sensor cap single-piece | unit which concerns on this invention, (b) is a side view of (a). It is a side view at the time of vehicle mounting of FIG. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus with a rotational speed detection apparatus. It is a principal part enlarged view 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 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 rolling of each of the outer member and the inner member. A double row rolling element accommodated between the faces in a freely rolling manner, a pulsar ring that is fitted on the inner ring and has alternating characteristics in the circumferential direction at equal intervals, and an inner side of the outer member A bottomed cylindrical sensor cap that is fitted inside and fixed to the end of the pulsar In a wheel bearing device with a rotational speed detection device in which a rotational speed sensor is disposed at a position corresponding to a predetermined axial air gap, the sensor cap is formed by injection molding synthetic resin, A cylindrical fitting portion that is press-fitted into the inner circumference of the inner side end of the member, and a bottom portion that extends radially inward from the fitting portion through a stepped portion that is in close contact with the inner side end surface of the outer member. The cap body is provided with a core metal integrally molded in the opening of the cap body, and a cup-shaped cap is mounted on the outer member, and the cap is formed from a non-magnetic steel plate by pressing. A cylindrical fitting portion provided with an elastic member made of synthetic rubber that is press-fitted into the inner periphery of the inner side end portion of the outer member, and a radially inner portion from the fitting portion via a reduced diameter portion Extending to An elastic member made of synthetic rubber is integrally joined to the reduced diameter portion by vulcanization adhesion, and the elastic member is attached to the outside of the fitting portion. An annular protrusion protruding radially outward from the diameter is provided, and the rotational speed sensor is abutted or brought close to the disk part, and is disposed opposite to the pulsar ring via the disk part.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view taken along the line I-O-I in FIG. 2 showing an embodiment of a wheel bearing device with a rotational speed detection device according to the present invention. FIG. 2 is a side view of FIG. 3 is an enlarged view of the main part showing the detection part of FIG. 1, FIG. 4 is an enlarged view of the main part showing the drain part of FIG. 2, FIG. 5 is an enlarged view of the main part showing a modification of FIG. a) is a longitudinal sectional view taken along line VI-O-VI of (b) showing the sensor cap alone according to the present invention, (b) is a side view of (a), and FIG. 7 is the vehicle of FIG. It is a side view at the time of mounting | wearing. 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 with a rotational speed detection device is called the third generation on the driven wheel side, and is a double row of rollers accommodated between the inner member 1 and the outer member 2 and between both members 1 and 2 so as to be freely rollable. Rolling elements (balls) 3a and 3b are provided. The inner member 1 includes a hub ring 4 and an inner ring 5 press-fitted into the hub ring 4 through a predetermined shimiro.

  The hub wheel 4 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at an end portion on the outer side, and has one (outer side) inner rolling surface 4a on the outer periphery and the inner rolling surface. A small-diameter step portion 4b is formed via an axial portion 4d extending in the axial direction from the surface 4a. Hub bolts 6a are planted on the wheel mounting flange 6 at equal intervals in the circumferential direction.

  A mortar-shaped recess 10 extending in the axial direction is formed at the outer end of the hub wheel 4. The recess 10 is formed up to the groove bottom of the inner side rolling surface 4a on the outer side by forging, and the thickness of the outer side of the hub wheel 4 is set to be substantially uniform.

  The inner ring 5 is formed with the other (inner side) inner rolling surface 5a on the outer periphery and is press-fitted into the small-diameter stepped portion 4b of the hub wheel 4 to form a back-to-back type double-row angular ball bearing. The inner ring 5 is fixed in the axial direction by a caulking portion 4c formed by plastically deforming the end portion of 4b. Thereby, weight reduction and size reduction can be achieved. The inner ring 5 and the rolling elements 3a and 3b are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core part by quenching.

  The hub wheel 4 is formed of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the inner raceway surface 4a and the base portion 6b on the inner side of the wheel mounting flange 6 are connected to the small diameter step portion 4b. Thus, the surface hardness is set to a range of 58 to 64 HRC by induction hardening. Note that the caulking portion 4c is left with a raw surface hardness after forging. Thereby, it has sufficient mechanical strength with respect to the rotational bending load applied to the wheel mounting flange 6, the fretting resistance of the small-diameter step portion 4b serving as the fitting portion of the inner ring 5 is improved, and the minute There is no occurrence of cracks and the like, and the plastic working of the caulking portion 4c can be performed smoothly.

  The outer member 2 integrally has a vehicle body mounting flange 2c to be attached to a knuckle (not shown) on the outer periphery, and the outer side outer rolling facing the inner rolling surface 4a of the hub wheel 4 on the inner periphery. The surface 2a and the inner side outer rolling surface 2b facing the inner rolling surface 5a of the inner ring 5 are integrally formed. Double-row rolling elements 3a and 3b are accommodated between these rolling surfaces and are held by the cages 7 and 8 so as to roll freely. A seal 9 is attached to an opening on the outer side of the annular space formed between the outer member 2 and the inner member 1, and a cap 14 described later is attached to the opening on the inner side. This prevents leakage of grease sealed inside the bearing and intrusion of rainwater and dust from the outside into the bearing.

  The outer member 2 is formed of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the double row outer rolling surfaces 2a and 2b have a surface hardness in the range of 58 to 64HRC by induction hardening. It has been cured. In addition, although the double row angular contact ball bearing which used the ball | bowl for the rolling elements 3a and 3b was illustrated here, not only this but the double row tapered roller bearing using a tapered roller may be sufficient. In addition, the second generation or the fourth generation structure is not limited to the third generation structure on the driven wheel side.

  In the present embodiment, the pitch circle diameter PCDo of the outer rolling element 3a row is set larger than the pitch circle diameter PCDi of the inner rolling member 3b row, and the outer rolling element 3a row of rolling elements. The diameter do is set to a smaller diameter (do <di) than the rolling element diameter di of the inner rolling element 3b row. Due to the difference between the pitch circle diameters PCDo and PCDi and the rolling element diameters do and di, the number of rolling elements Zo in the outer rolling element 3a row is set larger than the number of rolling elements Zi in the inner rolling element 3b row. (Zo> Zi). Thereby, the bearing rigidity of an outer side part can be increased compared with an inner side, and lifetime improvement of a bearing can be achieved. Here, the outer side rolling elements 3a and the inner side rolling elements 3b are illustrated as having different sizes. However, the present invention is not limited to this, and the same size may be used in both rows.

  In the present embodiment, the pulsar ring 11 is press-fitted into the outer periphery of the inner ring 5. As shown in an enlarged view in FIG. 3, 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. ing. 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 formed by pressing a ferromagnetic steel plate such as a ferritic stainless steel plate (JIS standard SUS430 or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC or the like). It has a cylindrical portion 12a that is formed in a substantially L-shaped cross section and is press-fitted into the inner ring 5, and a standing plate portion 12b that once extends radially outward from the cylindrical portion 12a and is folded and polymerized. The magnetic encoder 13 is joined to the side surface on the inner side of the upright plate portion 12b.

  Here, as shown in FIG. 1, a cap 14 is attached to the outer member 2 and closes the opening on the inner side of the outer member 2. This cap 14 has corrosion resistance, and a non-magnetic austenitic stainless steel plate (JIS standard SUS304, etc.) is press-molded so as not to adversely affect the sensing performance of the rotational speed sensor 18 described later. A cylindrical fitting portion 14a provided with an elastic member made of synthetic rubber and press-fitted into the inner periphery of the inner side end of the outer member 2, and a reduced diameter portion 14b from the fitting portion 14a. A disc portion 14c that faces the magnetic encoder 13 via a slight axial clearance, and a bottom portion 14e that covers the inner end of the inner member 1 from the disc portion 14c via a bent portion 14d. I have.

  Here, as shown in FIG. 3, an elastic member 15 made of synthetic rubber such as NBR (acrylonitrile-butadiene rubber) is integrally joined to the reduced diameter portion 14b of the cap 14 by vulcanization adhesion. This elastic member 15 protrudes inward from the side surface of the disk portion 14c of the cap 14 and is joined so as not to interfere with the rotational speed sensor 18, and is an annular protrusion that protrudes radially outward from the outer diameter of the fitting portion 14a. 15a. The fitting surface on the inner periphery of the end of the outer member 2 is restricted to a chatter height of 3 μm or less, and the annular protrusion 15a is elastically deformed to the inner periphery of the end of the outer member 2 when the cap 14 is fitted. The airtightness of the fitting portion 14a is enhanced by being crimped.

  In the present embodiment, a sensor cap 16 is further mounted on the inner side of the cap 14. This sensor cap 16 is fitted and fixed to the inner end of the outer member 4 to close the opening of the outer member 2. The sensor cap 16 includes a bottomed cylindrical cap body 17 formed by injection molding a synthetic resin, and a cored bar 18 integrally molded in the opening of the cap body 17. The core 18 is formed in an annular shape having an L-shaped cross section by press-forming a corrosion-resistant stainless steel plate or cold rolled steel plate (JIS standard SPCC system or the like). In particular, the core 18 is formed of a non-magnetic steel plate, such as an austenitic stainless steel plate (JIS standard SUS304, etc.) so as not to adversely affect the sensing performance of the rotational speed sensor 19 described later. It is preferable.

  The cap body 17 is formed by injection molding from a thermoplastic synthetic resin such as PA (polyamide) 66 or PA 6/12, and further added with a fibrous reinforcing material such as GF (glass fiber) in an amount of 10 to 50 wt%. Is preferred. As a result, the sensing performance of the rotation speed sensor 19 is not adversely affected, the corrosion resistance is excellent, the strength and rigidity are increased, and the durability can be improved over a long period of time. The cap body 17 can be exemplified by synthetic resins that can be injection molded such as polyphenylene sulfide (PPS), PPA (polyphthalamide), PBT (polybutylene terephthalate), etc., in addition to the materials described above. 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, the cap body 17 includes a cylindrical fitting portion 17a that is press-fitted into the inner periphery of the inner side end of the outer member 2, and an inner side end face 2d of the outer member 2 from the fitting portion 17a. And a bottom portion 17c extending inward in the radial direction via a stepped portion 17b that is in close contact with the bottom. And the fitting surface of the inner periphery of the end part of the outer member 2 is restricted to a chatter height of 3 μm or less, and the airtightness of the fitting part 17a of the cap body 17 is enhanced. Further, the stepped portion 17b that is in close contact with the end surface 2d of the outer member 2 can improve the positioning accuracy of the sensor cap 16, can simplify the air gap adjustment, and can improve the detection accuracy.

  Moreover, as shown in FIG. 6, the attaching part 20 which protrudes in an axial direction is integrally provided in the radial direction outer part of the bottom part 17c, and the fixing nut 21 is embedded by this insert part 20 by insert molding. Then, the rotation speed sensor 19 is fixed to the insertion hole 19 a of the mounting portion 20 by fastening a fixing bolt to the female screw 21 a of the fixing nut 21 via a mounting flange (not shown). An annular groove 21b is formed on the outer periphery of the fixing nut 21 to prevent the fixing nut 21 from moving in the axial direction. Here, the fixing nut 21 is formed of a steel material having an antirust property such as austenitic stainless steel (JIS standard SUS304 system) or ferritic stainless steel (JIS standard SUS430 system). Thereby, rusting can be prevented over a long period of time, and durability can be improved.

  The end face 21c on the inner side of the fixing nut 21 is set so as to be flush with or slightly protrude from the end face 20a of the mounting portion 20. Thereby, at the time of fastening, the fixing bolt and the end surface 21c of the fixing nut 21 are brought into close contact with each other, thereby improving the sealing performance and increasing the fastening force.

  The rotation speed sensor 19 is an IC in which a magnetic detecting element such as a Hall element, a magnetoresistive element (MR element) or the like that changes characteristics according to the flow direction of magnetic flux and a waveform shaping circuit that adjusts the output waveform of the magnetic detecting element are incorporated. The anti-lock brake system of the motor vehicle which consists of these etc. and detects the rotational speed of a wheel and controls the rotation speed is comprised. And this rotational speed sensor 19 is inserted until it contacts or approaches the disc part 14c of the cap 14 (refer FIG. 3). As a result, a desired air gap can be obtained, the complicated air gap adjustment can be omitted, and the assembly workability can be improved, and the inside of the bearing is sealed by the cap 14 provided with the elastic member 15 made of synthetic rubber at the fitting portion. Thus, it is possible to provide a wheel bearing device with a rotational speed detection device that can improve the sealing performance.

  Moreover, in this embodiment, a pair of drains 22 and 22 are formed in the bottom part 17c of the cap main body 17 (refer FIG. 2, FIG. 4). As shown in FIG. 7, the drain 22 is formed on the side close to the road surface radially outward of the bottom portion 17c. As a result, even if foreign matter such as rainwater enters the sensor cap 16 from the outside, the foreign matter can flow and drop in the sensor cap 16 and the foreign matter can be effectively discharged from the lower portion in the radial direction. In addition, although what consists of a pair of circular hole was illustrated as this drain 22, it is not restricted to this, For example, one circular hole may be sufficient and an eyebrows shape may be sufficient.

  FIG. 5 shows a modification of FIG. In this embodiment, basically, the cap configuration is only partially different from the one described above, and the same parts are denoted by the same reference numerals and the detailed description is omitted for the same parts or parts having the same function. To do.

  A cap 23 is attached to the outer member 2 and closes the opening on the inner side of the outer member 2. This cap 23 has corrosion resistance, and press-molds a non-magnetic austenitic stainless steel plate (JIS standard SUS304, etc.) into a cup shape so as not to adversely affect the sensing performance of the rotational speed sensor 19. A cylindrical fitting portion 23a provided with an elastic member 15 formed of synthetic rubber and press-fitted into the inner periphery of the inner side end of the outer member 2, and the fitting portion 23a through a reduced diameter portion 23b. The magnetic encoder 13 is provided with a disk part 23c that is opposed to the disk part 23c through a slight axial clearance, and the thickness H2 is larger than the thickness H1 of the other part from the fitting part 23a to the disk part 23c. Thinly formed. Specifically, the thickness H1 of the disk portion 23c is at least 0.2 to 1.0 mm with respect to the thickness H1 of other portions of 1.0 to 1.5 mm. As a result, the air gap can be set as small as possible, and the detection accuracy can be increased. If the thickness H2 is less than 0.2 mm, it becomes difficult to accurately shape the shape of the disk portion 23c. If the thickness H2 exceeds 1.0 mm, the air gap becomes large and desired magnetic characteristics can be obtained. This is not preferable because the detection accuracy is lowered.

  Further, as shown in FIG. 7, the rotation speed sensor 19 is disposed so as to be in a horizontal position with respect to the road surface in a vehicle-mounted state. Thereby, even in a state where the outer member 2 and the inner member 1 are relatively inclined due to the lateral load from the wheels, the air gap fluctuation between the rotational speed sensor 19 and the magnetic encoder 13 can be suppressed and stabilized. Detection accuracy can be obtained.

  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 with a rotation speed detection device according to the present invention can be applied to a wheel bearing device of an inner ring rotation type having any structure such as a drive wheel, a driven wheel, or a rolling element such as a ball or a tapered roller. .

DESCRIPTION OF SYMBOLS 1 Inner member 2 Outer member 2a, 2b Outer rolling surface 2c Car body mounting flange 2d End side 3a of outer member Outer side rolling element 3b Inner side rolling element 4 Hub wheel 4a, 5a Inner rolling surface 4b Small diameter step portion 4c Caulking portion 4d Shaft-shaped portion 5 Inner ring 6 Wheel mounting flange 6a Hub bolt 6b Base portion 7 and 8 on the inner side of the wheel mounting flange Cage 9 Seal 10 Recess 11 Pulsar ring 12 Support ring 12a Cylindrical portion 12b Standing plate Part 13 Magnetic encoder 14, 23 Cap 14a, 17a, 23a Fitting part 14b, 23b Reduced diameter part 14c, 23c Disk part 14d Bent part 14e, 17c Bottom part 15 Elastic member 15a Annular protrusion 16 Sensor cap 17 Cap body 17b Stepped Part 18 Core 19 Rotational speed sensor 19a Insertion hole 20 Mounting part 21 Fixing nut 21a Female thread 21b Annular 21c End surface 22 of the fixing nut Drain 51 Outer member 51a Outer rolling surface 51b Car body mounting flange 52 Inner member 53 Ball 54 Wheel mounting flange 55 Hub wheel 55a, 56a Inner rolling surface 55b Small diameter step portion 56 Inner ring 57 Cage 58 Caulking portion 59 Seal 60 Magnetic encoder 61 Support ring 62 Encoder body 63 Cover 63a Tube portion 63b, 67b Cover portion 64 Flange 65 Sensor attachment portion 66 Sensor attachment hole 67 Core metal 67a Tube portion 68 Cable 69 Sensor 69a Insertion portion di Inner Rolling body diameter do of outer side rolling element row do Rolling body diameter of outer side rolling element row H1 Thickness of cap H2 Thickness of disk part of cap PCDi Pitch circle diameter of inner side rolling element row PCDo Outer side rolling element Pitch circle diameter Zi of moving body row Zo Number of rolling bodies of inner side rolling element row Zo Outer side The number of rolling elements of the element row

Claims (12)

An outer member in which a double row outer rolling surface is integrally formed on the inner periphery;
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 accommodated in a freely rolling manner between the rolling surfaces of the outer member and the inner 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 bottomed cylindrical sensor cap fitted and fixed to the inner side end of the outer member;
In the wheel bearing device with a rotational speed detection device in which a rotational speed sensor is disposed through a predetermined axial air gap at a position corresponding to the pulsar ring,
The sensor cap is formed by injection-molding synthetic resin, and is fitted into a cylindrical fitting portion that is press-fitted into the inner periphery of the inner side end of the outer member, and from the fitting portion to the inner side of the outer member. A cap body having a bottom portion extending radially inward via a stepped portion that is in close contact with the end surface, and a core bar integrally molded in the opening of the cap body,
A cup-shaped cap is attached to the outer member, and this cap is formed by pressing from a non-magnetic steel plate, and an elastic member made of synthetic rubber is press-fitted into the inner periphery of the inner side end of the outer member. A cylindrical fitting portion provided, and a disk portion extending radially inward from the fitting portion and facing the pulsar ring via a slight axial clearance, and the rotation to the disk portion A wheel bearing device with a rotational speed detecting device, wherein a speed sensor is abutted or brought close to the pulsar ring via the cap.   A reduced diameter portion is formed between the fitting portion of the cap and the disc portion, and an elastic member made of synthetic rubber is integrally joined to the reduced diameter portion by vulcanization adhesion. 2. An annular projection that protrudes inward from the side surface of the disc portion and is joined so as not to interfere with the rotational speed sensor, and includes an annular protrusion that protrudes radially outward from the outer diameter of the fitting portion. Wheel bearing device with a rotation speed detection device.   The wheel bearing device with a rotation speed detecting device according to claim 1 or 2, wherein at least a disk portion of the cap is formed to have a wall thickness thinner than that of other portions.   The wheel bearing device with a rotational speed detecting device according to claim 1, wherein a fitting surface on an inner periphery of an end portion of the outer member is restricted to a chatter height of 3 µm or less.   A mounting portion protruding in the axial direction is integrally provided on the radially outer portion of the bottom portion of the sensor cap, and an insertion hole is formed in the mounting portion at a horizontal position with respect to the road surface. The wheel bearing device with a rotational speed detection device according to claim 1, which is mounted.   The wheel bearing device with a rotational speed detection device according to claim 5, wherein a drain is formed on a side of the bottom portion of the sensor cap close to a radially outer road surface.   The rotation according to claim 5 or 6, wherein a fixing nut is embedded in an attachment portion of the sensor cap by insert molding, and the rotation speed sensor is fixed to the fixing nut by fastening an attachment bolt via an attachment member. Wheel bearing device with speed detector.   The wheel bearing device with a rotation speed detecting device according to claim 7, wherein an end surface on an inner side of the fixing nut is set so as to be flush with or slightly protrude from an end surface of the mounting portion.   The wheel bearing device with a rotation speed detection device according to claim 7 or 8, wherein the fixing nut is made of stainless steel.   The wheel bearing device with a rotational speed detection device according to any one of claims 1 to 3, wherein the cap is formed of a non-magnetic austenitic stainless steel plate.   The wheel bearing device with a rotation speed detecting device according to any one of claims 5 to 7, wherein the core of the sensor cap is formed from a non-magnetic steel plate by pressing.   The pitch circle diameter of the outer rolling element row of the double row rolling element rows is set larger than the pitch circle diameter of the inner rolling element row, and the rolling element diameter of the outer rolling element row is set. Is set to be smaller than the rolling element diameter of the inner side rolling element row, and the number of rolling elements of the outer side rolling element row is set to be larger than the number of rolling elements of the inner side rolling element row. A wheel bearing device with a rotational speed detection device according to claim 1.

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