JP6239842B2 - Wheel bearing device - Google Patents

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, and more particularly to a wheel bearing device to which a rotation speed sensor for detecting the rotation speed of a wheel is attached.

  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 make it more compact, a wheel bearing device to which a rotational speed sensor is also attached has recently been proposed. .

  As an example of such a wheel bearing device, a structure as shown in FIG. 9 is known. The wheel bearing device includes an inner member 51, an outer member 52, and a plurality of rows of balls 53a and 53b accommodated between the members 51 and 52 so as to roll freely. The inner member 51 includes a hub ring 54 and an inner ring 55 that is press-fitted into the hub ring 54 through a predetermined shimiro.

  The hub wheel 54 integrally has a wheel mounting flange 56 at one end, and has a small diameter step portion through one inner rolling surface 54a on the outer periphery and a shaft-like portion 54d extending in the axial direction from the inner rolling surface 54a. 54b is formed.

  The inner ring 55 is formed with the other inner rolling surface 55a on the outer periphery, press-fitted into the small-diameter step portion 54b of the hub ring 54, and a caulking portion 54c formed by plastically deforming the end portion of the small-diameter step portion 54b. It is fixed in the axial direction.

  The outer member 52 integrally has a vehicle body mounting flange 52c on the outer periphery, and is opposed to the outer rolling surface 52a facing the inner rolling surface 54a of the hub wheel 54 and the inner rolling surface 55a of the inner ring 55 on the inner periphery. The outer rolling surface 52b is integrally formed. A seal 57 and a sensor cap 58 are attached to the opening of the annular space formed between the outer member 52 and the inner member 51, and leakage of grease sealed inside the bearing to the outside and from the outside Rain water and dust are prevented from entering the bearing.

  The pitch circle diameter PCDo of the ball 3a row on the wheel mounting flange 56 side is set larger than the pitch circle diameter PCDi of the ball 3b row on the anti-wheel mounting flange 56 side, and the ball diameter do of the ball 3a row is set to the ball 3b. The diameter is set smaller than the ball diameter di of the row (do <di). Further, due to the difference between the pitch circle diameters PCDo and PCDi and the rolling element diameters do and di, the number of balls Zo in the row of balls 3a is set larger than the number of balls Zi in the row of balls 3b (Zo> Zi). Thereby, the bearing rigidity of the wheel mounting flange 56 side portion can be increased compared to the anti-wheel mounting flange 56 side, and the life of the bearing can be extended.

  As shown in FIG. 10, a pulsar ring 59 is press-fitted to the outer periphery of the inner ring 55. The pulsar ring 59 includes a support ring 60 formed in an annular shape, and a magnetic encoder 61 integrally joined to the side surface of the support ring 60 by vulcanization adhesion or the like.

  The sensor cap 58 is fitted and fixed to the inner end of the outer member 52 to close the opening of the outer member 52. The sensor cap 58 is formed into a cup shape by press-molding an austenitic stainless steel plate, and has a cylindrical fitting portion 58a that is press-fitted into the inner periphery of the end of the outer member 52, and a diameter reduced from the fitting portion 58a. A bottom 58c that extends radially inward via the portion 58b and covers the end of the inner member 51 is provided.

  Here, an elastic member 62 made of synthetic rubber such as NBR (acrylonitrile-butadiene rubber) is integrally joined to the outer periphery of the reduced diameter portion 58b by vulcanization adhesion. The elastic member 62 protrudes inward from the side surface of the bottom portion 58c of the sensor cap 58 and is joined so as not to interfere with the rotational speed sensor 63, and is an annular protrusion that protrudes radially outward from the outer diameter of the fitting portion 58a. 62a is provided. The annular protrusion 62a is elastically deformed and pressure-bonded to the inner periphery of the end of the outer member 52 when the sensor cap 58 is fitted, thereby improving the airtightness of the fitting part 58a.

  In addition, a circular recess 64 is formed at a substantially central portion in the radial direction of the bottom portion 58c of the sensor cap 58, and a nut 65 is press-fitted and fixed to the circular recess 64. Then, the rotation speed sensor 63 is fixed to the sensor cap 58 by fastening the fixing bolt to the female screw 65a of the nut 65 via a mounting flange (not shown). As a result, when the fixing bolt is fastened, torque that is offset from the sensor cap 58 is not generated, and the rotational speed sensor 63 can be smoothly fixed.

  In addition, the rotational speed sensor 63 is opposed to a position corresponding to the magnetic encoder 61 in the radially outer portion of the bottom portion 58c of the sensor cap 58 until it abuts or approaches. Then, a change in the magnetic flux of the magnetic encoder 61 is detected by the rotation speed sensor 63 via the bottom 58c, and the rotation speed of the wheel is detected. As a result, a desired air gap can be obtained, and it is possible to improve the assembly workability by omitting complicated air gap adjustment, and the detection unit is closed by the sensor cap 58, which affects the sensing performance. It is possible to provide a wheel bearing device with a rotational speed detection device that ensures sealing performance without any problems (see, for example, Patent Document 1).

JP2011-196425A

  In such a conventional wheel bearing device, the elastic member 62 is integrally joined to the sensor cap 58 attached to the end portion of the outer member 52, and the elastic member 62 is more radial than the outer diameter of the fitting portion 58a. Since the annular protrusion 62a protruding outward is provided, the annular protrusion 62a is elastically deformed and pressure-bonded to the inner periphery of the end of the outer member 52 when the sensor cap 58 is fitted, thereby improving the airtightness of the fitting part 58a. It has the feature that it can be.

  However, when the sensor cap 58 is fitted, the fitting portion 58a causes a slit-like press-fitting to the fitting surface of the outer member 52, and the annular protrusion 62a is partially crushed to make the fitting portion 58a airtight. There is a risk of damage.

  The present invention prevents the occurrence of press-fitting of the outer member at the time of press-fitting the cap, prevents damage to the elastic member joined to the cap, and improves the airtightness of the fitting portion to improve the reliability. An object is to provide a wheel bearing device.

In order to achieve such an object, the invention described in claim 1 of the present invention has a vehicle body mounting flange integrally attached to the vehicle body on the outer periphery, and a double row outer rolling surface is integrated on the inner periphery. A hub wheel integrally formed with a formed outer member and 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 a small-diameter step portion of the hub ring An inner member formed of at least one inner ring that is press-fitted, and formed with a double row inner rolling surface facing the double row outer rolling surface on the outer periphery, and each of the outer member and the inner member A double row rolling element housed in a freely rolling manner between the rolling surfaces, and an opening in the outer space of the annular space formed between the outer member and the inner member. A seal and a cap attached to the opening on the inner side. Is provided with a cylindrical fitting portion that is press-fitted into the inner fitting surface of the outer member, and a bottom portion that extends radially inward from the fitting portion and covers the inner side end of the inner member. An elastic member made of synthetic rubber is integrally joined to the outer periphery of the inner side end of the fitting portion by vulcanization adhesion , and the elastic member is formed to protrude outward in the radial direction from the outer diameter of the fitting portion. In the wheel bearing device thus formed, the inner periphery of the inner side end portion of the outer member is formed on the inner side through the inner fitting surface into which the cap is press-fitted, and a step portion from the inner fitting surface, The flank has a larger diameter than the inner fitting surface, and the flank is formed in a tapered shape that gradually increases in diameter toward the opening, and the elastic member is elastically deformed to the flank. It has a tapered surface to be crimped.

As described above, the seal is mounted on the outer opening of the annular space formed between the outer member and the inner member, and the cap is mounted on the inner opening. The cap includes a cylindrical fitting portion that is press-fitted into the inner fitting surface of the outer member, and a bottom portion that extends radially inward from the fitting portion and covers the inner side end of the inner member. An elastic member made of synthetic rubber is integrally joined to the outer periphery of the inner side end of the fitting portion by vulcanization adhesion , and the elastic member is formed to protrude outward in the radial direction from the outer diameter of the fitting portion. In the wheel bearing device, the inner side end inner circumference of the outer member is formed on the inner side through the stepped portion from the inner side fitting surface into which the cap is press-fitted, and the inner side fitting surface. With a larger diameter flank and the flank gradually toward the opening Since the elastic member has a tapered surface that is elastically deformed and crimped to the flank, the fitting portion of the cap and the press-fitting surface of the elastic member are not the same diameter but have a diameter difference. Since a large-diameter relief surface is formed through this step portion, when the cap is fitted, for example, a slit-shaped press-fitting is made on the inner fitting surface of the outer member by the fitting portion of the cap. Even so, this part is not press-fitted, and the elastic member is prevented from being partially crushed and damaged, thereby improving the airtightness of the fitting part of the cap and improving the reliability. Can be provided.

  Preferably, as in the invention described in claim 2, when the inner diameter of the flank is set to be larger than the maximum tolerance of the inner diameter of the inner fitting surface, the cap is fitted. The elastic member is not press-fitted to the flank, and the elastic member can surely prevent the inner fitting surface of the outer member from being slit-fitted.

Further, as in the invention described in claim 3 , the inner ring is fitted with a pulsar ring whose characteristics are alternately changed at equal intervals in the circumferential direction, and the cap is formed of a non-magnetic steel plate. If the rotational speed sensor is abutted or brought close to the pulsar ring via the cap and is opposed to the pulsar ring through a predetermined axial air gap, the air gap is reduced without adversely affecting the sensing performance of the rotational speed sensor. It becomes possible to set, and it is possible to improve the detection accuracy and improve the sealing performance of the bearing space.

Further, as in the invention described in claim 4 , an outer fitting surface is formed on the opening side of the inner fitting portion of the outer member via the relief surface, and a sensor cap is formed on the outer fitting surface. While being press-fitted through a predetermined shimoshiro, the sensor cap is overlapped radially outward from the fitting portion with a cylindrical fitting portion to be press-fitted into the outer fitting surface of the outer member. A horizontal position corresponding to the pulsar ring at the bottom, extending and closely contacting the inner side end face of the outer member, and a bottom for closing the inner side opening of the outer member from the flange If the rotation speed sensor is attached to the insertion hole, the rigidity can be increased and the positioning accuracy of the rotation speed sensor can be improved. When the side member and the inner member are relatively inclined Oite also, it is possible to suppress the air gap variation between the rotational speed sensor and pulser ring, it is possible to obtain a stable detection accuracy.

Further, if the sensor cap is formed with a rust preventive film made of cationic electrodeposition coating as in the invention according to claim 5 , the fitting portion of the sensor cap is rusted over a long period of time. It can prevent, and favorable airtightness is acquired between the fitting parts of an outer member.

The wheel bearing device according to the present invention has an outer member integrally formed with a vehicle body mounting flange for mounting to the vehicle body on the outer periphery, and an outer member formed integrally with a double row outer rolling surface on the inner periphery, and one end portion. And a hub ring integrally having a wheel mounting flange for mounting a wheel on the outer periphery, 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 having a double row inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and freely rollable between the rolling surfaces of the outer member and the inner member. Among the accommodated double row rolling elements and the annular space formed between the outer member and the inner member, the seal is attached to the outer opening and the inner opening. And the cap is press-fitted into the inner mating surface of the outer member. A cylindrical fitting portion and a bottom portion extending radially inward from the fitting portion and covering an inner side end portion of the inner member, and is synthesized with an outer periphery of the inner side end portion of the fitting portion. In a wheel bearing device in which an elastic member made of rubber is integrally joined by vulcanization bonding, and the elastic member protrudes radially outward from the outer diameter of the fitting portion, the inner member of the outer member The inner periphery of the end portion on the side is formed on the inner fitting surface into which the cap is press-fitted, and on the inner side through a step portion from the inner fitting surface, and a clearance surface having a larger diameter than the inner fitting surface. The flank is formed in a tapered shape that gradually increases in diameter toward the opening side, and the elastic member has a tapered surface that is elastically deformed and pressure-bonded to the flank. The fitting part and the press-fit surface of the elastic member are not the same diameter but have a difference in diameter. Since a large-diameter relief surface is formed through the stepped portion, even when the cap is fitted, for example, even if a slit-like press-fitting is made on the inner fitting surface of the outer member by the fitting portion of the cap, The part is not press-fitted, and the elastic member can prevent the inner fitting surface of the outer member from being slit-fitted and can prevent the elastic member from being partially crushed and damaged. In addition, it is possible to provide a wheel bearing device in which the air tightness of the fitting portion of the cap is improved to improve the reliability.

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. It is a principal part enlarged view which shows the drain part of FIG. It is a principal part enlarged view which shows the fitting part of the cap of FIG. It is a principal part enlarged view which shows the modification of the wheel bearing apparatus of FIG. It is a principal part enlarged view which shows the modification of the cap fitting part of FIG. It is a principal part enlarged view which shows the other modification of the cap fitting part of FIG. It is a principal part enlarged view which shows the other modification of the cap fitting part of FIG. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus. It is a principal part enlarged view which shows the fitting part of the sensor cap 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 surfaces so as to be freely rollable, and a seal attached to an opening on the outer side of the opening of the annular space formed between the outer member and the inner member; A magnetic encoder fitted on the inner ring, and an inner end of the outer member. A cup-shaped cap, and a cup-shaped sensor cap that is fitted to the inner end of the cap and has a rotational speed sensor mounted on a radially outer portion thereof, wherein the rotational speed sensor is the magnetic encoder. In the wheel bearing device opposed to each other through a predetermined axial air gap, the 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. And a disc portion extending radially inward from the fitting portion and facing the magnetic encoder through a slight axial clearance, and the rotational speed sensor is opposed to the disc portion. The inner end of the outer member on the inner side is disposed on the inner fitting surface on which the cap is press-fitted, and on the inner side. An elastic member made of synthetic rubber is formed on the inner side through the stepped portion from the mating surface, and is composed of a flank with a larger diameter than the inner fitting surface. The elastic members are integrally joined by vulcanization bonding, and the elastic member is formed to protrude radially outward from the outer diameter of the fitting portion, and is elastically deformed and pressure-bonded to the flank.

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 part of FIG. 1, and FIG. 3 is a main part showing a drain part of FIG. FIG. 4 is an enlarged view of a main part showing a fitting part of the cap of FIG. 1, FIG. 5 is an enlarged view of a main part showing a modification of the wheel bearing device of FIG. 1, and FIG. FIG. 7 is an enlarged view of a main part showing another modification of the cap fitting part of FIG. 1, and FIG. 8 is an enlarged view of the cap fitting part of FIG. It is a principal part enlarged view which shows another modification. 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 called the third generation on the driven wheel side, and is a double row rolling element (ball) accommodated between the inner member 1 and the outer member 2 and between the members 1 and 2 so as to roll freely. 3 and 3. 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 4b extending in the axial direction from the surface 4a is formed. Hub bolts 6a are planted on the wheel mounting flange 6 at equal intervals in the circumferential direction.

  The inner ring 5 is formed with the other (inner side) inner raceway 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 contact 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 3 and 3 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 made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and includes an inner rolling surface 4a and an inner side of a wheel mounting flange 6 serving as a seal land portion of a seal 8 described later. The surface hardness is hardened to a range of 58 to 64 HRC by induction hardening from the base 6b to the small diameter step 4b. 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 2b to be attached to the knuckle 9 on the outer periphery, and a cylindrical pilot portion fitted into a knuckle (not shown) on the inner side of the vehicle body mounting flange 2b. 2c is formed, and double row outer rolling surfaces 2a, 2a facing the inner rolling surfaces 4a, 5a of the inner member 1 are integrally formed on the inner periphery. Double-row rolling elements 3 and 3 are accommodated between these rolling surfaces and are held by the cages 7 and 7 so as to be freely rollable. A seal 8 is attached to the outer opening 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 inner opening. 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 at least the double row outer rolling surfaces 2a and 2a have a surface hardness of 58 to 64 HRC by induction hardening. Has been cured.

  The seal 8 is constituted by an integral seal comprising a cored bar 9 press-fitted into the inner periphery of the outer side end of the outer member 2 and a seal member 10 integrally joined to the cored bar 9 by vulcanization adhesion. ing. The metal core 9 has a substantially L-shaped cross section formed by press working from an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a cold rolled steel plate (JIS standard SPCC type or the like).

  On the other hand, the seal member 10 is made of a synthetic rubber such as NBR, and extends sideways in the radial direction. The side lip is slidably contacted with the outer peripheral surface of the base portion 6b having a circular cross section through a predetermined axial nip. 10a, a dust lip 10b, and a grease lip 10c extending obliquely inward in the radial direction and in sliding contact with the outer peripheral surface of the base portion 6b via a predetermined radial nip. And the sealing member 10 wraps around and joins so that the outer surface of the metal core 9 may be covered, and what is called a half metal structure is comprised. Thereby, airtightness can be improved and the inside of a bearing can be protected.

  As the material of the seal member 10, in addition to the exemplified NBR, for example, HNBR (hydrogenated acrylonitrile butadiene rubber), EPDM (ethylene propylene rubber), etc. having excellent heat resistance, heat resistance, chemical resistance, etc. Examples thereof include ACM (polyacrylic rubber), FKM (fluororubber), and silicon rubber, which are excellent in the above.

  In addition, although the wheel bearing apparatus comprised by the double row angular contact ball bearing which used the ball for the rolling elements 3 and 3 was illustrated here, it is not restricted to this but is comprised by the double row tapered roller bearing using a tapered roller It may be what was done.

  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. 2, 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 from a ferromagnetic steel plate, for example, a ferritic stainless steel plate (JIS standard SUS430 series or the like) or a rust-proof cold-rolled steel plate into a substantially L-shaped cross section by press working. And a standing plate portion 12b extending radially outward 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.

  Here, the cap 14 is attached to the outer member 2 to close the opening on the inner side of the outer member 2. The cap 14 has corrosion resistance and is formed into a cup shape by pressing from a non-magnetic austenitic stainless steel plate so as not to adversely affect the sensing performance of the rotational speed sensor 22 described later. A cylindrical fitting portion 14a that is press-fitted into the inner periphery of the inner end, and a disc portion 14c that faces the magnetic encoder 13 from the fitting portion 14a via the reduced diameter portion 14b via a slight axial clearance. And a bottom portion 14e that covers an inner side end portion of an inner member (not shown) via a bent portion 14d that bulges outward from the disc portion 14c.

  In the cap 14, an elastic member 15 made of synthetic rubber such as NBR is integrally joined to the outer peripheral surface of the reduced diameter portion 14b by vulcanization adhesion. The elastic member 15 projects from the side surface of the disk portion 14c of the cap 14 to the inner side so as not to interfere with the rotational speed sensor 22, and is an annular protrusion that projects radially outward from the outer diameter of the fitting portion 14a. 15a.

  As shown in an enlarged view in FIG. 4, an inner fitting surface 16 into which the fitting portion 14 a of the cap 14 is press-fitted and a taper from the inner fitting surface 16 to the inner side are provided on the inner periphery of the end portion of the outer member 2. A flank 18 having a diameter larger than that of the inner fitting surface 16 is formed via the stepped portion 17. The inner fitting surface 16 of the outer member 2 is restricted to a chatter height of 3 μm or less, and the annular protrusion 15a of the elastic member 15 is elastically deformed to the flank 18 of the outer member 2 when the cap 14 is fitted. Thus, the airtightness of the fitting portion 14a is enhanced.

  In the present embodiment, the inner periphery of the end portion of the outer member 2 is composed of an inner fitting surface 16 and a flank 18 formed on the inner side from the inner fitting surface 16 via a stepped portion 17. Since the fitting portion 14a of the cap 14 is press-fitted into the fitting surface 16 and the elastic member 15 is press-fitted into the flank 18 having a larger diameter than the inner fitting surface 16, for example, when the cap 14 is fitted, 14, even if the inner fitting surface 16 of the outer member 2 is slit-fitted into the inner fitting surface 16 by the fitting portion 14 a, this portion is not press-fitted and the inner fitting surface of the outer member 2 is formed by the annular protrusion 15 a. 16 can prevent the slit-like press-fitting from being damaged, and can prevent the annular protrusion 15a from being partially crushed and damaged, thereby improving the airtightness of the fitting portion 14a of the cap 14 and improving reliability. To provide an improved wheel bearing device It can be.

  The aforementioned inner diameter Dr of the flank 18 is formed larger than the inner diameter Ds of the inner fitting surface 16. Specifically, the inner diameter Dr of the flank 18 is the maximum tolerance of the inner diameter Ds of the inner fitting surface 16. The diameter is set to be larger than the value. As a result, the fitting portion 14a of the cap 14 and the press-fitting surface of the elastic member 15 are not the same diameter, but a diameter difference is provided. Therefore, when the cap 14 is fitted, the inner fitting surface 16 of the outer member 2 is formed by the annular protrusion 15a. It is possible to reliably prevent the slit-like press-fitting from being attached to the surface.

  In the present embodiment, as shown in FIG. 2, a sensor cap 19 is further attached to the inner side of the cap 14. Specifically, an outer fitting surface 20 is formed on the opening side (inner side) of the flank 18 of the outer member 2 through a predetermined step, and the sensor cap 19 is formed on the outer fitting surface 20 with a predetermined amount. It is press-fitted through shimeshiro. The outer fitting surface 20 is simultaneously ground by the double row outer rolling surfaces 2a, 2a, the inner fitting surface 16 into which the cap 14 is press-fitted, and a general-purpose grindstone. This improves the assembly workability by minimizing the press-fitting stroke of the cap 14 and improves the accuracy of the roundness and the coaxiality of the respective fitting surfaces 16 and 20, thereby improving the airtightness of each fitting portion. Becomes higher. Further, the number of processing steps can be reduced by simultaneous grinding, and the cost can be reduced.

  The sensor cap 19 is formed into a cup shape by press working from a rust-proof cold-rolled steel plate, and is fitted into a cylindrical fitting portion 19a that is press-fitted into the inner periphery of the inner side end of the outer member 2. A flange portion 19b that overlaps and extends radially outward from the joint portion 19a and closely contacts the inner side end surface 2d of the outer member 2, and an inner side opening portion of the outer member 2 is closed from the flange portion 19b. And a bottom portion 19c. An insertion hole 21 is formed in the bottom portion 19 c of the sensor cap 19 at a horizontal position corresponding to the magnetic encoder 13, and the rotational speed sensor 22 is inserted into the insertion hole 21.

  Thus, since the sensor cap 19 includes the flange portion 19b that is in close contact with the end surface 2d of the outer member 2, the rigidity can be increased and the positioning accuracy of the rotation speed sensor can be improved, and the insertion hole 21 can be provided. If it is formed in a horizontal position and the rotational speed sensor 22 is mounted in this insertion hole 21, even if the outer member 2 and the inner member 1 are relatively inclined due to a lateral load from the wheel, the rotation is possible. Air gap fluctuation between the speed sensor 22 and the magnetic encoder 13 can be suppressed, and stable detection accuracy can be obtained.

  In addition, a fixing nut 24 is fixed by caulking processing to the inner side (outer side) of the bearing of the bottom portion 19c in the perforation 23 formed in the center portion of the outer cap 19. In addition to this, the fixing nut 24 may be fixed by, for example, welding, adhesion, press-fitting, or the like. The rotation speed sensor 22 inserted into the insertion hole 21 of the sensor cap 19 is fixed by fastening the mounting bolt 26 to the fixing nut 24 via the mounting member 25. In this way, the fixing nut 24 is pulled into the inner surface of the bottom portion 19c by fastening the mounting bolt 26, so that the falling can be prevented only by tightening the fixing nut 24.

  The rotation speed sensor 22 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. The rotational speed sensor 22 is inserted until it contacts or approaches the disc portion 14 c of the cap 14. As a result, a desired air gap can be obtained, and it is possible to improve the assembly workability by omitting complicated air gap adjustment, and the inside of the bearing is sealed by the cap 14 in which the elastic member 15 made of synthetic rubber is provided in the reduced diameter portion 14b. It is possible to provide a wheel bearing device that can be sealed and has improved sealing performance.

  A rust preventive film is formed on the sensor cap 19 by cationic electrodeposition coating. The cationic electrodeposition coating is an anionic electrodeposition coating in which the product side is energized with the product side as the negative electrode while the positive electrode is energized with the product side as the positive electrode. Also good. This anion-type electrodeposition coating has the characteristics that the coating color stability and baking temperature can be set low, but this type of sensor cap 19 is a powerful coating with excellent rust prevention and adhesion. Cationic electrodeposition coating made of an epoxy resin system or the like that can form a film is preferred.

  Thus, in this embodiment, since the rust prevention film which consists of cationic electrodeposition coating is formed in the sensor cap 19, it prevents that the fitting part 19a of the sensor cap 19 rusts over a long period of time. Therefore, good airtightness can be obtained between the outer fitting surface 20 and the end surface 2d of the outer member 2.

  Even in the above-described seal 8, although not shown, even in a half metal structure in which the seal member 10 wraps around the fitting portion of the core metal 9, a fitting surface is provided on the inner periphery of the outer side end portion of the outer member 2. A relief surface having a diameter larger than that of the fitting surface may be provided from the fitting surface via a step portion, and a part of the seal member 10 may be crimped to the relief surface.

  In the present embodiment, as shown in FIG. 3, a drain 27 is formed on the radially outer side of the bottom 19 c of the sensor cap 19. This drain 27 is formed in the bulging part 28 of the side close | similar to the road surface of the fitting part 19a and the bottom part 19c. The bulging portion 28 is formed so as to protrude from the bottom portion 19b to the inner side by a predetermined dimension L. This bulging portion 28 is effective when a knuckle (not shown) is not flush with the end surface 2d of the outer member 2 but protrudes toward the inner side. That is, by forming the drain 27 through the bulging portion 28 of the sensor cap 19 in the radial direction, even if foreign matter such as rainwater enters the sensor cap 19 from the outside, it flows into the bulging portion 28 portion. The foreign matter can easily and effectively be discharged outside without being disturbed by the knuckle.

  In the above-described embodiment, the so-called double cap structure in which the sensor cap 19 is mounted on the inner side of the cap 14 is illustrated, but not limited to this, a single cap is mounted on the inner periphery of the end of the outer member. Structure may be sufficient. That is, as shown in FIG. 5, a fitting surface 16 ′ into which the fitting portion 14a of the cap 14 is press-fitted on the inner periphery of the end portion of the outer member 2 ′, and a taper shape from the fitting surface 16 ′ to the inner side. A flank 18 'having a diameter larger than that of the fitting surface 16' is formed through the step 17 '. The annular protrusion 15a of the elastic member 15 is elastically deformed and pressure-bonded to the flank 18 'of the outer member 2' when the cap 14 is fitted, thereby improving the airtightness of the fitting portion 14a.

  As described above, the inner periphery of the end portion of the outer member 2 ′ is constituted by the fitting surface 16 ′ and the flank 18 ′ formed on the inner side from the fitting surface 16 ′ via the stepped portion 17 ′. The fitting portion 14a of the cap 14 is press-fitted into the fitting surface 16 'and the elastic member 15 is press-fitted into the relief surface 18' having a larger diameter than the fitting surface 16 '. The annular protrusion 15a can prevent the fitting surface 16 'of the outer member 2' from being slit-like press-fitted, and the annular protrusion 15a can be prevented from being partially crushed and damaged. Thus, the airtightness of the fitting portion 14a can be improved and the reliability can be improved.

  FIG. 6 shows a modification of the cap fitting portion. The cap 29 has corrosion resistance and is formed into a cup shape by press working from a non-magnetic austenitic stainless steel plate so as not to adversely affect the sensing performance of the rotational speed sensor 22, and the inner side of the outer member 2. A cylindrical fitting portion 29a that is press-fitted into the inner periphery of the end portion of the head portion and a disk portion 29b that faces the magnetic encoder 13 from the fitting portion 29a through a slight axial clearance.

  In the cap 29, an elastic member 30 made of synthetic rubber such as NBR is integrally joined to the outer peripheral surface of the fitting portion 29a by vulcanization adhesion. This elastic member 30 protrudes inward from the side surface of the disk portion 29b of the cap 29 so as not to interfere with the rotational speed sensor 22, protrudes radially outward from the outer diameter of the fitting portion 29a, and has a tapered surface. An annular projection 30a having

  An inner fitting surface 16 into which the fitting portion 29a of the cap 29 is press-fitted is provided on the inner periphery of the end portion of the outer member 31, and an opening side is provided from the inner fitting surface 16 through a tapered step portion 17 to the inner side. A tapered flank 32 that gradually increases in diameter toward the surface is formed. The annular protrusion 30 a of the elastic member 30 is elastically deformed and crimped to the flank 32 of the outer member 31 when the cap 29 is fitted. In the present embodiment, since the annular protrusion 30a having a tapered surface bites into the flank 32 of the outer member 31 in a wedge shape and is crimped, the airtightness of the fitting portion 29a can be further enhanced.

  FIG. 7 shows another modification of the cap fitting portion, and the configuration of the elastic member 30 of the cap 29 described above is different. The cap 29 is a cylindrical fitting portion 29a that is press-fitted into the inner periphery of the inner side end of the outer member 2, and a circle that faces the magnetic encoder 13 from the fitting portion 29a via a slight axial clearance. A plate portion 29b is provided. And the elastic member 33 which consists of synthetic rubbers, such as NBR, is integrally joined to the outer peripheral surface of the fitting part 29a by vulcanization adhesion.

  The elastic member 33 protrudes from the side surface of the disk portion 29 b to the inner side and is joined so as not to interfere with the rotation speed sensor 22, and the elastic member 33 is elastic to the flank 18 of the outer member 2 when the cap 29 is fitted. Deformed and crimped. In the present embodiment, the annular protrusion described above is not crimped to the flank 18 of the outer member 2, but the entire outer peripheral surface of the elastic member 33 is crimped, thereby further improving the airtightness of the fitting portion 29a. Can do.

  FIG. 8 shows another modification of the cap fitting portion, and the configuration of the elastic member 30 of the cap 29 described above is different. The cap 29 is a cylindrical fitting portion 29a that is press-fitted into the inner periphery of the inner side end of the outer member 2, and a circle that faces the magnetic encoder 13 from the fitting portion 29a via a slight axial clearance. A plate portion 29b is provided. And the elastic member 34 which consists of synthetic rubbers, such as NBR, is integrally joined to the outer peripheral surface of the fitting part 29a by vulcanization adhesion.

  The elastic member 34 protrudes inward from the side surface of the disk portion 29 b so as not to interfere with the rotational speed sensor 22, and the elastic member 33 escapes from the step portion 17 of the outer member 2 when the cap 29 is fitted. The surface 18 is elastically deformed and crimped. Thereby, since the elastic member 33 fills the fitting clearance between the outer member 2 and the cap 29 and is crimped, the airtightness of the fitting portion 29a can be further enhanced.

  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 is a wheel bearing for a driven wheel, in which the rolling element is an inner ring rotating type of any structure such as a ball and a tapered roller, and a cap is mounted on the inner side end of the outer member. It can be applied to the device.

DESCRIPTION OF SYMBOLS 1 Inner member 2, 2 ', 31 Outer member 2a Outer rolling surface 2b Car body mounting flange 2c Pilot part 2d Outer member inner side end surface 3 Rolling element 4 Hub wheel 4a, 5a Inner rolling surface 4b Small diameter step Part 4c Caulking part 5 Inner ring 6 Wheel mounting flange 6a Hub bolt 6b Base part on inner side of wheel mounting flange 7 Cage 8 Seal 9 Core 10 Seal member 10a Side lip 10b Dustrip 10c Grease lip 11 Pulsar ring 12 Support ring 12a Cylindrical part 12b Standing plate portion 13 Magnetic encoder 14, 29 Cap 14a, 19a, 29a Fitting portion 14b Reduced diameter portion 14c, 29b Disc portion 14d Bending portion 14e Bottom portion 15, 30, 33, 34 Elastic member 15a, 30a Annular protrusion 16 Inside Fitting surface 16 'Fitting surface 17, 17' Stepped portion 18, 18 ', 32 Flank 19 Sensor cap 1 b flange 19c bottom 20 outer fitting surface 21 fitting insertion hole 22 rotational speed sensor 23 perforation 24 fixing nut 25 mounting member 26 mounting bolt 27 drain 28 bulging portion 51 inner member 52 outer members 52a and 52b outer rolling surface 52c Car body mounting flange 53a, 53b Ball 54 Hub wheel 54a, 55a Inner rolling surface 54b Small diameter step 54c Clamping portion 54d Shaft portion 55 Inner ring 56 Wheel mounting flange 57 Seal 58 Sensor cap 58a Fitting portion 58b Reduced diameter portion 58c Bottom 59 Pulsar ring 60 Support ring 61 Magnetic encoder 62 Elastic member 62a Annular protrusion 63 Rotational speed sensor 64 Circular recess 65 Fixing nut 65a Female thread Ds Inner fitting surface inner diameter Dr Escape surface inner diameter L Amount of protrusion from the bottom of the bulging portion PCDi Pitch circle diameter of the row of balls on the anti-wheel mounting flange side PCDo Pitch circle diameter di of the ball row on the lunge side Ball diameter of the ball row on the anti-wheel mounting flange side ball diameter Zi of the ball row on the wheel mounting flange side Zi Number of balls in the ball row on the anti-wheel mounting flange side Zo On the wheel mounting flange side Number of balls in the ball row

Claims (5)

An outer member integrally having a vehicle body mounting flange for being attached to the vehicle body on the outer periphery, and an outer rolling surface of a double row 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;
A seal attached to an opening on the outer side of the opening of the annular space formed between the outer member and the inner member;
A cap attached to the opening on the inner side, and the cap is a cylindrical fitting portion press-fitted into the inner fitting surface of the outer member, and radially inward from the fitting portion. An elastic member made of synthetic rubber is integrally joined to the outer periphery of the inner side end of the fitting portion by vulcanization bonding , and includes a bottom portion that covers the inner side end of the inner member. In the wheel bearing device formed to protrude radially outward from the outer diameter of the fitting portion,
The inner periphery of the outer member on the inner side is formed with an inner fitting surface into which the cap is press-fitted and an inner side through a step portion from the inner fitting surface, and is larger than the inner fitting surface. It is composed of a flank with a diameter,
The wheel bearing device, wherein the flank is formed in a tapered shape that gradually increases in diameter toward the opening side, and the elastic member has a tapered surface that is elastically deformed and pressure-bonded to the flank. .   The wheel bearing device according to claim 1, wherein an inner diameter of the flank is set to be larger than a tolerance maximum value of an inner diameter of the inner fitting surface.   A pulsar ring whose characteristics are alternately changed at equal intervals in the circumferential direction is externally fitted to the inner ring, the cap is formed of a non-magnetic steel plate, and a rotational speed sensor is abutted or brought close to the cap. The wheel bearing device according to claim 1, wherein the wheel bearing device is opposed to the pulsar ring via a predetermined axial air gap.   An outer fitting surface is formed on the opening side of the inner fitting portion of the outer member via the clearance surface, and a sensor cap is press-fitted into the outer fitting surface via a predetermined shimiro, and the sensor A cap is fitted into the outer fitting surface of the outer member and a cylindrical fitting portion, and the outer portion overlaps and extends radially outward from the fitting portion, and closely contacts the inner end surface of the outer member. And a bottom portion that closes the opening on the inner side of the outer member from the flange portion, and a fitting insertion hole is formed at a horizontal position corresponding to the pulsar ring on the bottom portion. The wheel bearing device according to claim 1, wherein the rotational speed sensor is mounted. The wheel bearing device according to claim 4 , wherein a rust preventive film made of cationic electrodeposition coating is formed on the sensor cap.

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