JP2012112494A - Sealing device of wheel bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable sealing device of a wheel bearing, protecting an inner part of the bearing by increasing airtightness of a fit portion and preventing damages during press-fitting.SOLUTION: The sealing device comprises an annular sealing plate 14 and a slinger 15 which have a substantially L-shaped cross-section and face each other. The sealing plate 14 comprises a core bar 16 and a sealing member 17 that is integrally joined to a fit portion 16a of the core bar 16 by vulcanization bonding. On the sealing member 17, an annular projection 20 is formed with a level difference of 0.25 to 0.30 mm, which is slightly larger than an outer diameter of the fit portion 16a. The annular projection 20 is formed into a tapered face having a diameter gradually increasing toward an end face 10c of an outer member 10 and having an inclination angle of 5 to 15 degrees, and is press-fitted to an inner peripheral face at an end of the outer member 10 with a fitting width of 0.43 to 2.50 mm.

Description

  The present invention relates to a sealing device in a wheel bearing that rotatably supports a wheel of an automobile or the like with respect to a suspension device.

  2. Description of the Related Art Conventionally, a wheel bearing device for supporting a wheel of an automobile or the like supports a hub wheel for mounting a wheel rotatably via a double row rolling bearing, and includes a drive wheel and a driven wheel. For structural reasons, an inner ring rotation method is generally used for driving wheels, and an inner ring rotation method and an outer ring rotation method are generally used for driven wheels. Further, the wheel bearing device has a structure called a first generation in which a wheel bearing composed of a double row angular ball bearing or the like is fitted between a knuckle and a hub wheel constituting a suspension device. Second generation structure in which body mounting flange or wheel mounting flange is formed directly on the outer periphery of the member, third generation structure in which one inner rolling surface is directly formed on the outer periphery of the hub wheel, or hub wheel, etc. It is roughly classified into a fourth generation structure in which the inner rolling surface is directly formed on the outer periphery of the outer joint member of the speed universal joint.

  These bearing portions are equipped with a sealing device for preventing leakage of grease sealed in the bearings and preventing intrusion of rainwater, dust and the like from the outside. In recent years, the maintenance of automobiles has become more maintenance-free, and even longer bearing life has been demanded for wheel bearing devices. However, there are many cases in which rainwater, dust, or the like enters the bearing and damages the bearing due to a sealing failure or a decrease in sealing performance. Therefore, the bearing life can be improved by improving the sealing performance of the sealing device.

  Conventionally, various sealing devices with improved sealing performance have been proposed. An example of such a sealing device is shown in FIG. This sealing device 51 includes a metal core 52, a slinger 53, and a seal material 54. The cored bar 52 is integrally formed by punching and plastic processing such as press working on a metal plate such as low carbon steel, and is fitted into an inner peripheral surface of an end portion of an outer ring (not shown). The outer diameter side cylindrical portion 52a has an inner ring portion 52b that is bent radially inward from the inner end edge in the axial direction (left end in the figure), and has an annular shape with a substantially L-shaped cross section.

  The slinger 53 is formed integrally with a corrosion-resistant metal plate such as a stainless steel plate by stamping or plastic processing and plastic working, and is provided with an inner diameter side cylindrical portion 53a that is fitted on the outer peripheral surface of the outer end portion of an inner ring (not shown). The outer circular ring portion 53b that is bent radially outward from the axially outer end edge (right end in the drawing) of the inner diameter side cylindrical portion 53a has a substantially L-shaped cross section and an annular shape.

  The seal member 54 is formed of an elastic material such as rubber or elastomer, and includes three seal lips 54 a, 54 b, 54 c on the outer side, the middle side, and the inner side, and the base end portion is coupled to the cored bar 52. . Then, the tip edge of the outermost outer seal lip 54a located on the outermost side is brought into sliding contact with the inner surface of the outer ring portion 53b of the slinger 53, and the tip edges of the remaining two intermediate seal lips 54b and the inner seal lip 54c are connected to the inner diameter side. The cylindrical portion 53a is in sliding contact with the outer peripheral surface.

  Further, the base end portion 55 of the sealing material 54 covers the inner peripheral surface and the outer peripheral surface of the front half portion (right half portion in the figure) of the outer diameter side cylindrical portion 52a of the core metal 52. Here, the outer diameter side cylindrical portion 52a and the outer ring of the cored bar 52 are metal-fitted with a predetermined shimoshiro, but in order to improve the airtightness of the fitting portion, the base end portion of the sealing material 54 55 is formed in a substantially trapezoidal cross section, and protrudes radially outward from the outer diameter of the outer diameter side cylindrical portion 52a to serve as a rubber packing, and has a so-called half metal structure.

  All the three seal lips 54a, 54b, 54c are inclined in the direction toward the outer space of the bearing as they approach the respective leading edges. The inner seal lip 54c is not elastically deformed at all in a state where the tip end edge of the innermost seal lip 54c located on the innermost side is in contact with the outer peripheral surface of the inner diameter side cylindrical portion 53a of the slinger 53. Shimeshiro is in a state of almost zero, which is a state where only a slight elastic deformation occurs. For this reason, the inner diameter of the inner seal lip 54c in the free state is made substantially the same as the outer diameter of the inner diameter side cylindrical portion 53a.

  Therefore, in such a sealing device 51, even if the inner seal lip 54c is externally fitted to the inner diameter side cylindrical portion 53a from the state in which the tip edge of the inner seal lip 54c is detached from the outer peripheral surface of the inner diameter side cylindrical portion 53a, it is reversed. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 10-252762

  However, in such a conventional sealing device 51, the outer ring is deformed when the bearing receives a load from the tire, and the conventional base end portion 55 has a problem of insufficient airtightness. As a solution to this problem, there is a method of increasing the width of the base end 55 or raising the outer ring, but this does not allow a compact design, but also when the sealing device 51 is press-fitted into the outer ring. Further, there is a possibility that the base end portion 55 may be damaged due to rubber breakage.

  The present invention has been made in view of such circumstances, and improves the airtightness of the fitting portion to protect the inside of the bearing, and prevents damage during press-fitting to improve reliability. The object is to provide a sealing device.

  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 attachment for attaching a wheel to one end. The hub ring has a flange integrally 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 inner rolling surface facing the running surface is formed, and a double-row rolling element that is movably accommodated between the inner and outer members. A wheel bearing sealing device for sealing an opening of an annular space formed between the outer member and the inner member, and an inner periphery of an end portion of the outer member. It has a cylindrical fitting part that is press-fitted into the surface via a predetermined scissors, and is pressed from a steel plate Therefore, a sealing member made of synthetic rubber is integrally joined to the fitting portion of the core metal by vulcanization adhesion, and the sealing member has a diameter slightly larger than the outer diameter of the fitting portion. The annular convex portion is formed to protrude with a level difference, and the annular convex portion gradually increases in diameter toward the end surface side of the outer member, and is formed into a tapered surface having a predetermined inclination angle. It is press-fitted with a predetermined fitting width to the inner peripheral surface of the end of the member.

  Thus, in the sealing device for a wheel bearing that is attached to the wheel bearing and seals the opening of the annular space formed between the outer member and the inner member, the outer peripheral member has an inner peripheral surface. It has a cylindrical fitting part that is press-fitted through a predetermined scissors, and is provided with a metal core formed by pressing from a steel plate, and a sealing member made of synthetic rubber is vulcanized and bonded to this metal core fitting part The annular convex portion is formed to protrude from the seal member with a step slightly larger than the outer diameter of the fitting portion, and the annular convex portion faces the end surface of the outer member. Since the diameter is gradually increased and formed into a tapered surface having a predetermined inclination angle and is press-fitted with a predetermined fitting width to the inner circumferential surface of the end portion of the outer member, the resistance during press-fitting is reduced, Can be raised, and the inside of the bearing is protected by increasing the air tightness of the mating part. Together, it is possible to provide a sealing device for a wheel bearing with improved reliability by preventing damage during press fitting of the sealing member.

  Preferably, as in the invention described in claim 2, if the step of the annular convex portion is set in the range of 0.25 to 0.30 mm, the resistance during press-fitting can be suppressed and the length can be increased. Over the period, the airtightness of the fitting portion between the outer member and the cored bar can be improved.

  Further, as in the invention described in claim 3, if the inclination angle of the tapered surface of the annular convex portion is set in the range of 5 to 15 °, the resistance at the time of press-fitting can be reduced and the squealing can be raised. It is possible to improve the airtightness of the fitting portion to protect the inside of the bearing, and to prevent damage at the time of press-fitting the seal member, thereby improving the reliability.

  Further, as in the invention described in claim 4, the tip position of the annular convex portion is set to be closer to the bearing inner side than the chamfered portion formed on the inner periphery of the end portion of the outer member. If the fitting width of the annular convex portion is set in the range of 0.43 to 2.50 mm, the airtightness can be improved with compactness.

  Further, as in the invention described in claim 5, the tapered surfaces of the annular convex portions may be formed on both sides, and the inclination angles thereof may be set to be substantially the same.

  Further, as in the sixth aspect of the present invention, if grease is previously applied to the fitting portion of the core metal and the annular convex portion of the seal member, damage such as rubber breakage during press fitting is prevented. be able to.

  According to a seventh aspect of the present invention, the sealing device is composed of an annular seal plate and a slinger that are substantially L-shaped in cross section and arranged to face each other, and the seal plate is the core. The slinger has a cylindrical portion that is press-fitted into the outer periphery of the inner member, and a standing plate portion that extends radially outward from the cylindrical portion, and the sealing member includes the slinger. It may be constituted by a composite type sealing device provided with a side lip that is slidably in contact with the vertical plate portion via a predetermined axial squeeze, and a radial lip that is slidably contacted with the cylindrical portion via a predetermined radial shimeoshiro.

  Further, as in the invention according to claim 8, the sealing device is constituted by an integrated sealing device composed of the cored bar and a sealing member, and the sealing member has a cross section formed in an arc shape. A side lip that slides in contact with the base portion on the inner side of the wheel mounting flange with a predetermined squeeze, a dust lip, and a grease lip formed so as to be inclined toward the inner side of the bearing may be integrally provided.

  Moreover, like invention of Claim 9, the said sealing apparatus is comprised with the protective cover formed in the cup shape which consists of the said metal core and a sealing member, and the said metal core is the said fitting part, A disc-shaped shielding portion extending radially inward from the fitting portion via a reduced diameter portion, and a bottom portion for closing the inner side end of the inner member from the shielding portion via a stepped portion. In addition, the seal member is joined to an outer peripheral portion of the reduced diameter portion, and is configured by the annular convex portion and an annular portion formed to have a slightly smaller diameter than the outer diameter of the fitting portion of the cored bar. Also good.

  Further, as in the invention described in claim 10, a magnetic encoder is fitted on the inner ring, and the cored bar is formed from a non-magnetic steel plate by pressing, and a rotational speed sensor is provided on a side surface of the shielding portion. The magnetic encoder and the rotational speed sensor may be opposed to each other via a predetermined axial clearance via the shielding portion.

  Further, as in the invention described in claim 11, the seal member does not protrude to the inner side from the outer surface of the shielding portion in at least a single state before the core metal is fitted to the outer member. If it is set in this way, it is not necessary to move the rotation speed sensor away from the magnetic encoder more than necessary in order to avoid interference with the seal member, the air gap can be set to the minimum, and detection accuracy is further improved. Can do.

  Further, as in the twelfth aspect of the invention, if the end surface on the inner side of the outer member is formed so as to slightly protrude toward the inner side from the large end surface of the inner ring, the cored bar contacts the inner ring. Can be prevented.

  Preferably, as in a thirteenth aspect of the invention, the detection surface of the magnetic encoder and the large end surface of the inner ring are set to be substantially flush with each other or slightly protrude toward the inner side from the large end surface. Thus, the air gap can be easily adjusted, and the air gap can be aimed at smaller.

  The sealing device for a wheel bearing according to the present invention integrally includes 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 the wheel to one end. A double row comprising a hub wheel 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 wheel, and facing the outer rolling surface of the double row on the outer periphery. An inner member in which an inner rolling surface of the inner member is formed, and a double row rolling element that is rotatably accommodated between the inner member and the outer member. In a wheel bearing sealing device that seals an opening of an annular space formed between the outer member and the inner member, a predetermined shimiro is provided on the inner peripheral surface of the end of the outer member. A core formed by pressing from a steel plate with a cylindrical fitting part A sealing member made of synthetic rubber is integrally joined to the fitting portion of the core metal by vulcanization adhesion, and the annular protrusion has a step that is slightly larger in diameter than the outer diameter of the fitting portion. And the annular convex portion gradually increases in diameter toward the end surface side of the outer member, and is formed into a tapered surface having a predetermined inclination angle. The inner peripheral surface of the end portion of the outer member Since it is press-fitted with a predetermined fitting width, the resistance at the time of press-fitting can be reduced to raise the shimoshiro, and the inside of the bearing is enhanced to protect the inside of the bearing, and when the seal member is press-fitted It is possible to provide a sealing device for a wheel bearing in which the damage is improved and the reliability is improved.

It is a longitudinal section showing a 1st embodiment of a wheel bearing provided with a sealing device concerning the present invention. It is a principal part enlarged view which shows the sealing device of FIG. It is the III section enlarged view of FIG. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the wheel bearing provided with the sealing device which concerns on this invention. (A) is the principal part enlarged view which shows one sealing device of FIG. 4, (b) is the V section enlarged view of (a), (c) is the elements on larger scale which show the modification of (b). is there. (A) is the principal part enlarged view which shows the other sealing device of FIG. 4, (b) is the VI section enlarged view of (a). It is a longitudinal cross-sectional view which shows the sealing device of the conventional wheel bearing.

  A vehicle body mounting flange to be attached to the knuckle on the outer periphery, an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and a wheel mounting flange to mount a wheel on one end A hub wheel integrally formed and having one inner rolling surface opposed to the double-row outer rolling surface on the outer periphery, and a small-diameter step portion extending in the axial direction from the inner rolling surface, and the hub wheel An inner member formed of an inner ring that is press-fitted into the small-diameter step portion and formed with the other inner rolling surface opposite to the double row outer rolling surface, and the inner member and the outer member. Mounted on a wheel bearing having a double row rolling element accommodated between the running surfaces so as to roll freely, and seals the opening of the annular space formed between the outer member and the inner member. In a sealing device for a wheel bearing, a sealing member made of synthetic rubber in the fitting portion of the core metal The sealing device is integrally formed by vulcanization bonding, and the sealing device is configured by an annular seal plate and a slinger having a substantially L-shaped cross section and arranged to face each other, and the seal plate is formed of the outer member. It has a cylindrical fitting part that is press-fitted into the inner peripheral surface of the end part through a predetermined shimiro, and the cored bar formed by pressing from a steel plate is integrated with the cored bar fitting part by vulcanization adhesion. A sealing member made of synthetic rubber joined, and the slinger has a cylindrical portion press-fitted into the outer periphery of the inner ring, and a standing plate portion extending radially outward from the cylindrical portion, and the sealing member Includes a side lip that is slidably in contact with the standing plate portion of the slinger via a predetermined axial shimillo, and a radial lip that is slidably in contact with the cylindrical portion via a predetermined radial shimillo, and the fitting member is provided with the fitting portion. Slightly less than the outer diameter of An annular convex portion is formed to protrude with a step of 0.25 to 0.30 mm having a large diameter, and the annular convex portion gradually increases in diameter toward the end face side of the outer member, from an inclination angle of 5 to 15 °. And is press-fitted with a fitting width of 0.43 to 2.50 mm on the inner peripheral surface of the end portion of the outer member.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing a first embodiment of a wheel bearing provided with a sealing device according to the present invention, FIG. 2 is an enlarged view of a main part showing the sealing device of FIG. 1, and FIG. FIG. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  This wheel bearing is called the third generation on the drive wheel side, and the inner member 1 and the outer member 10, and the double row rolling elements (balls) 6 accommodated between the members 1 and 10 so as to roll freely. , 6. The inner member 1 includes a hub ring 2 and an inner ring 3 press-fitted into the hub ring 2.

  The hub wheel 2 integrally has a wheel mounting flange 4 for mounting a wheel (not shown) at an end on the outer side, and a hub bolt for fixing the wheel at a circumferentially equidistant position of the wheel mounting flange 4. 5 is planted. Further, one (outer side) inner rolling surface 2a and a cylindrical small-diameter step portion 2b extending in the axial direction from the inner rolling surface 2a are formed on the outer periphery of the hub wheel 2, and serrations ( Or a spline) 2c is formed. The inner ring 3 is formed with the other (inner side) inner raceway surface 3a on the outer periphery, and is press-fitted into the small-diameter step portion 2b of the hub ring 2 through a predetermined squeeze.

  The hub wheel 2 is formed of medium and high carbon steel containing 0.40 to 0.80% by weight of carbon such as S53C, and includes a base portion 11 on the inner side of the wheel mounting flange 4 serving as a seal land portion of the seal 8 described later, The surface hardness is set to a range of 58 to 64 HRC by induction hardening from the inner side rolling surface 2a on the outer side to the small diameter step portion 2b. As a result, not only the wear resistance of the base 11 of the wheel mounting flange 4 is improved, but also sufficient mechanical strength against the rotational bending load applied to the wheel mounting flange 4 is obtained. Strength and durability are improved. On the other hand, the inner ring 3 and the rolling element 6 are made of high carbon chrome bearing steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core by quenching.

  The outer member 10 integrally has a vehicle body mounting flange 10b for mounting to a vehicle body (not shown) on the outer periphery, and a double row facing the inner rolling surfaces 2a, 3a of the inner member 1 on the inner periphery. The outer rolling surfaces 10a and 10a are integrally formed. The outer member 10 is formed of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, like the hub wheel 2, and at least the double row outer raceway surfaces 10 a and 10 a are formed by induction hardening. The surface hardness is set in the range of 58 to 64 HRC. And the double row rolling elements 6 and 6 are accommodated between each rolling surface 10a, 2a and 10a, 3a, and these double row rolling elements 6 and 6 are rollably hold | maintained by the holder | retainers 7 and 7. ing. In addition, sealing devices 8 and 9 are attached to the opening portion of the annular space formed between the outer member 10 and the inner member 1, and leakage of lubricating grease sealed inside the bearing, rainwater and Dust and the like are prevented from entering the bearing.

  In this embodiment, the sealing device 8 on the outer side includes a cored bar 12 and a seal member 13 that is integrally vulcanized and bonded to the cored bar 12, and this seal member 13 is made of NBR (acrylonitrile-butadiene rubber). The side lip 13a and the dust lip 13b that are slidably contacted with the base 11 of the wheel mounting flange 4 formed in a circular arc shape and the inner side of the bearing are inclined. An extending grease lip 13c is integrally provided. As the material of the seal member 13, 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.

  On the other hand, as shown in an enlarged view in FIG. 2, the inner-side sealing device 9 is a so-called pack seal comprising an annular seal plate 14 and a slinger 15 which are formed in a substantially L-shaped cross section and are arranged to face each other. This constitutes a composite type sealing device called "."

  The annular seal plate 14 includes a cored bar 16 that is press-fitted into the inner periphery of the end of the outer member 10, and a seal member 17 that is integrally vulcanized and bonded to the cored bar 16. The core 16 is made of a ferritic stainless steel plate (JIS standard SUS430 or the like), an austenitic stainless steel plate (JIS standard SUS304 or the like), or a rust-proof cold rolled steel plate (JIS standard SPCC system or the like). A cylindrical fitting portion 16a having a substantially L-shaped cross section by press working and press-fitted into the inner peripheral surface of the end portion of the outer member 10 through a predetermined shimiro, and an end of the fitting portion 16a And an inner diameter portion 16b extending radially inward from the portion. The seal member 17 is made of synthetic rubber such as NBR, and has a side lip 17a that is in sliding contact with the slinger 15 and a radial lip formed in a bifurcated shape on the inner diameter side of the side lip 17a, specifically, a grease lip 17b. It has a strip 17c.

  On the other hand, the slinger 15 is formed into a substantially L-shaped cross section by pressing from a ferromagnetic steel plate, for example, a ferritic stainless steel plate, an austenitic stainless steel plate, or a cold-rolled steel plate treated with rust prevention, The cylindrical portion 15a is press-fitted into the outer peripheral surface of the inner ring 3 and the upright plate portion 15b extends radially outward from the cylindrical portion 15a. The outer edge of the standing plate portion 15b of the slinger 15 is opposed to the seal member 17 through a slight radial clearance to form a labyrinth seal 18.

  A magnetic encoder (rubber magnet) 19 in which a magnetic substance powder such as ferrite is mixed in an elastomer such as rubber is integrally joined to the inner side surface of the standing plate portion 15b of the slinger 15 by vulcanization adhesion. The magnetic encoder 19 is magnetized with magnetic poles N and S alternately in the circumferential direction, and constitutes a rotary encoder for detecting the rotational speed of the wheel.

  In addition, although the wheel bearing apparatus comprised by the double row angular contact ball bearing which used the ball for the rolling element 6 was illustrated here, it is not restricted to this, The double row tapered roller bearing which used the tapered roller for the rolling element 6 It may consist of. In addition, here, a third generation structure in which the inner raceway surface 2a is formed directly on the outer periphery of the hub wheel 2 is illustrated, but although not shown, a pair of inner rings are press-fitted and fixed to the small-diameter step portion of the hub wheel. It may be a first generation or second generation structure.

  Here, the distal end portion of the fitting portion 16a of the core metal 16 is formed thin, and the annular protrusion 20 is formed by the seal member 17 wrapping around and joined so as to cover the distal end portion. As shown in an enlarged view in FIG. 3, the annular convex portion 20 gradually increases in diameter toward the inner side end face 10 c of the outer member 10, and is formed in a tapered surface having a predetermined inclination angle α. The core 16 is formed in a step δ having a diameter slightly larger than the outer diameter of the fitting portion 16a of the metal core 16, and is press-fitted into the end inner peripheral surface 10d of the outer member 10 through a predetermined squeeze. In addition, by applying grease in advance to the fitting portion 16a of the metal core 16 and the annular convex portion 20 of the seal member 17 before press-fitting, damage such as rubber breakage during press-fitting can be prevented.

  The inclination angle α of the annular convex portion 20 is set in the range of 5 to 15 °. As a result, the resistance at the time of press-fitting can be reduced and the squeezing can be raised, the airtightness of the fitting portion is increased to protect the inside of the bearing, and the damage at the time of press-fitting of the seal member 17 is prevented to improve the reliability. It is possible to provide a sealing device for a wheel bearing. If the inclination angle α exceeds 15 °, the resistance at the time of press-fitting increases and the risk of damage increases, and if it is less than 5 °, the effect is halved.

  Further, in the case of a wheel bearing for supporting this type of automobile wheel, the outer diameter of the fitting portion 16a of the cored bar 16 is about 45 to 160 mm. 10 is set in a range of 0.05 to 0.25 mm, and a step δ of the annular convex portion 20 with respect to the fitting portion 16 a is set in a range of 0.25 to 0.30 mm. . Thereby, the airtightness of the fitting part of the outward member 10 and the metal core 16 can be improved over a long period of time. If the step δ exceeds 0.30 mm, the resistance at the time of press-fitting increases, and there is a possibility that the rubber of the seal member may be cut. If it is less than 0.25 mm, the airtight effect is reduced, which is not preferable.

  Furthermore, in the present embodiment, the tip position of the annular convex portion 20 after press-fitting is located on the bearing inner side with respect to the chamfered portion 10e formed on the inner periphery of the end portion of the outer member 10, that is, the outer member 10. The fitting width L of the annular convex portion 20 is set to 0.43 mm or more, and preferably in the range of 0.43 to 2.50 mm.

  Next, Table 1 shows the results of the airtightness test conducted by the present applicant. Here, the air leakage of the fitting portion due to the difference between the roundness of the inner peripheral surface of the end portion of the outer member that affects the airtightness and the width of the annular convex portion was determined. In order to evaluate the airtightness of the outer member, the outer member other than the inner peripheral surface of the outer member is sealed with a sealant, and the roundness of the inner peripheral surface of the outer member is assumed to be when it is attached to the actual machine. The roundness is deteriorated by distorting the direction member. Moreover, the thing with the inclination angle (alpha) of a cyclic | annular convex part of the range of 5-6 degrees was used as a test article.

  In this test result, in the comparative example, air leakage occurred at a low pressure of 0.14 MPa, whereas in the example, air leakage occurred when the fitting width of the annular convex portion was 0.39 MPa under the worst condition. . That is, regardless of whether the roundness of the end inner peripheral surface 10d of the outer member 10 is good or not, the fitting width L of the annular convex portion is 0.43 mm or more, preferably 0.43 to 2.50 mm. It has been confirmed that this is compact and effective in air leakage.

  FIG. 4 is a longitudinal sectional view showing a second embodiment of the wheel bearing provided with the sealing device according to the present invention, FIG. 5A is an enlarged view of the main part showing the outer side sealing device of FIG. (B) is the V section enlarged view of (a), (c) is an enlarged view which shows the modification of (b). Note that the same parts and parts as those in the above-described embodiment or parts and parts having the same functions are denoted by the same reference numerals, and detailed description thereof is omitted.

  This wheel bearing device is for a driven wheel referred to as a third generation, and includes an inner member 21, an outer member 22, and a double row rolling element accommodated between both members 21 and 22 so as to roll freely. 6 and 6. The inner member 21 includes a hub ring 23 and an inner ring 3 that is press-fitted into the hub ring 23 through a predetermined shimoshiro.

  The outer member 22 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, has a vehicle body mounting flange 10b integrally on the outer periphery, and double rows of outer rolling surfaces 10a and 10a on the inner periphery. Are integrally formed.

  The hub wheel 23 integrally has a wheel mounting flange 4 at an end portion on the outer side, and hub bolts 5 are implanted at circumferentially equidistant positions of the wheel mounting flange 4. Further, an inner rolling surface 23a facing one (outer side) of the double row outer rolling surfaces 10a and 10a and a small-diameter step portion 23b extending in the axial direction from the inner rolling surface 23a are formed on the outer periphery. Yes. On the other hand, the inner ring 3 is formed on the outer periphery with an inner rolling surface 3a facing the other (inner side) of the double row outer rolling surfaces 10a, 10a, and a small diameter step portion 23b of the hub wheel 23 via a predetermined squeeze. It is press-fitted. And the inner ring | wheel 3 is being fixed to the axial direction in the state to which the predetermined bearing preload was provided by the crimping part 24 formed by carrying out the plastic deformation of the end part of the small diameter step part 23b of the hub ring | wheel 23 radially outward. .

  Double row rolling elements 6, 6 are accommodated between the double row outer rolling surfaces 10a, 10a of the outer member 22 and the double row inner rolling surfaces 23a, 3a opposite to the outer rolling surfaces 10a, 10a, respectively. , 7 are held in a rollable manner. In addition, a sealing device 25 is attached to the outer opening of the annular space formed between the outer member 22 and the inner member 21, and the magnetic encoder 26 is attached to the inner opening. A protective cover 27 is mounted to prevent leakage of the lubricating grease sealed inside the bearing and intrusion of rainwater, dust, etc. into the bearing from the outside.

  The hub wheel 23 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C and extends from the inner rolling surface 23a to the base 11 on the inner side of the wheel mounting flange 4 to the small diameter step portion 23b. The surface is hardened by induction hardening in the range of 58 to 64 HRC. The caulking portion 24 is kept with the surface hardness after forging. This facilitates the caulking process, prevents the occurrence of microcracks during the process, improves the wear resistance of the base 11 serving as the seal land part of the sealing device 25, and loads the wheel mounting flange 4. It has sufficient mechanical strength against the rotating bending load to be applied, and the durability of the hub wheel 23 is improved.

  As shown in FIG. 5A, the outer side sealing device 25 includes a cored bar 12 press-fitted into the inner periphery of the outer side end portion of the outer member 22 through a predetermined shimiro, and this core. It is composed of an integrated sealing device including a sealing member 28 joined to the gold 12.

  The seal member 28 is made of synthetic rubber such as NBR and is integrally joined to the cored bar 12 by vulcanization adhesion. The seal member 28 is formed so as to be inclined outward in the radial direction and has a side lip 28a and a dust lip 28b that are slidably contacted with a base 11 of the wheel mounting flange 4 having a circular arc shape in cross section, and a bearing inside And a grease lip 28c formed so as to be inclined toward the side.

  Here, the core metal 12 includes a cylindrical fitting portion 12a that is press-fitted into the outer peripheral end surface 22a on the outer side of the outer member 22, and an inner diameter portion 12b that extends radially inward from the fitting portion 12a. Have. And the sealing member 28 turns around and is joined so that the outer surface which extends over the fitting part 12a from the internal diameter part 12b may be formed, and the annular convex part 29 is formed. As shown in an enlarged view (b), the annular convex portion 29 gradually increases in diameter toward the outer end surface 22b side of the outer member 22, and is formed in a tapered surface having a predetermined inclination angle α. At the same time, it is formed in a step δ that is slightly larger in diameter than the outer diameter of the fitting portion 12a of the cored bar 12, and is press-fitted into the end inner peripheral surface 22a of the outer member 22 through a predetermined squeeze. As in the above-described embodiment, grease is applied in advance to the fitting portion 12a of the metal core 12 and the annular convex portion 29 of the seal member 28 before press-fitting.

  The inclination angle α of the annular convex portion 29 is set in a range of 5 to 15 °, the step δ is set in a range of 0.25 to 0.30 mm, and the tip position of the annular convex portion 29 after press-fitting is It is set so as to be closer to the bearing inner side than the chamfered portion 22c formed on the inner periphery 22a of the end of the outer member 22, and the fitting width L of the annular convex portion 29 is 0.43 mm or more, preferably 0.43. It is set in a range of ˜2.50 mm. As a result, the resistance at the time of press-fitting can be reduced and the squeeze can be raised, the airtightness of the fitting portion is increased to protect the inside of the bearing, and the damage at the time of press-fitting of the seal member 28 is prevented to improve the reliability. Can be made. FIG. 5C shows a modified example of FIG. 5B, but the tapered surfaces of the annular protrusion 29 'may be formed on both sides.

  FIG. 6A shows the inner side sealing device of FIG. Here, a support ring 30 having a substantially L-shaped cross section is fitted on the inner ring 3. The support ring 30 includes a cylindrical portion 30a that is press-fitted into the outer diameter of the inner ring 3, and a standing plate portion 30b that extends radially outward from the cylindrical portion 30a. The magnetic encoder 26 is integrally joined by vulcanization adhesion. The magnetic encoder 26 is made of a rubber magnet in which magnetic powder such as ferrite is mixed in synthetic rubber, and magnetic poles N and S are magnetized alternately at equal pitches in the circumferential direction.

  The support ring 30 is formed by pressing from a ferromagnetic steel plate, for example, a ferritic stainless steel plate or a rust-proof cold-rolled steel plate. As a result, it is possible to prevent the support ring 30 from rusting and to increase the magnetic output of the magnetic encoder 26 to ensure stable detection accuracy.

  The protective cover 27 attached to the inner side end of the outer member 22 is formed in an annular shape by press working from a nonmagnetic austenitic stainless steel plate. The protective cover 27 includes a cylindrical fitting portion 27a that is press-fitted into the end inner peripheral surface 22d of the outer member 22, and a disk that extends radially inward from the fitting portion 27a via a reduced diameter portion 27b. And a bottom portion 27e that closes the inner side end of the inner member 21 from the shielding portion 27c through the cylindrical portion 27d. The detection unit of the sensor (not shown) is brought close to or in contact with the shielding unit 27c of the protective cover 27, and the detection unit and the magnetic encoder 26 are arranged to face each other with a predetermined air gap (axial clearance) through the protective cover 27. Has been. Such a stepped shape increases the rigidity of the protective cover 27 and can suppress deformation due to flying stones, etc., and since the protective cover 27 is non-magnetic, it does not affect the flow path of the magnetic flux, and has excellent corrosion resistance and is long. The durability can be improved over a period of time.

  In the present embodiment, the reduced diameter portion 27b of the protective cover 27 has a stepped shape, and the seal member 31 is fixed to the outer peripheral portion thereof. The seal member 31 is made of synthetic rubber such as NBR, and is integrally joined to the protective cover 27 by vulcanization adhesion, and includes an annular convex portion 31a and an annular portion 31b as shown in an enlarged view in FIG. The annular portion 31b is formed to be slightly smaller in diameter than the outer diameter of the fitting portion 27a, and the annular convex portion 31a is formed to be slightly larger in diameter than the outer diameter of the fitting portion 27a. The inner peripheral surface 22d is press-fitted through a predetermined scissors. Thereby, the airtightness of the fitting surface of the outer member 22 and the protective cover 27 can be improved over a long period of time.

  Here, the annular convex portion 31a of the seal member 31 gradually increases in diameter toward the inner end face 22e side of the outer member 22, and is formed into a tapered surface having a predetermined inclination angle α. The inclination angle α of the portion 31 is set in the range of 5 to 15 °, and the step δ is set in the range of 0.25 to 0.30 mm. Further, the tip position of the annular convex portion 31 after press-fitting is set so as to be closer to the bearing inner side than the chamfered portion 22 c formed on the inner peripheral edge 22 d of the outer member 22, and the fitting of the annular convex portion 31 is performed. The width L is set to 0.43 mm or more, preferably in the range of 0.43 to 2.50 mm. As a result, the resistance at the time of press-fitting can be reduced and the squeeze can be raised, the airtightness of the fitting portion is increased to protect the inside of the bearing, and the damage at the time of press-fitting of the seal member 31 is prevented to improve the reliability. Can be made.

  Further, in the present embodiment, the inner end face 22e of the outer member 22 is formed so as to protrude from the large end face 3b of the inner ring 3 toward the inner side by a step L1, and the shielding portion 27c of the protective cover 27 and the outer member are formed. The end surface 22e of 22 and the detection surface of the magnetic encoder 26 and the large end surface 3b of the inner ring 3 are set to be substantially flush with each other. As a result, the protective cover 27 can be prevented from coming into contact with the inner ring 3. Further, if the detection surface of the magnetic encoder 26 and the large end surface 3b of the inner ring 3 are set to be substantially flush with each other or slightly protrude toward the inner side from the large end surface 3b, the protective cover 27 is attached to the outer member 22. The support ring 30 can be accurately positioned and fixed with reference to the end face 22e and the large end face 3b of the inner ring 3 as a reference, air gap adjustment can be facilitated, and detection accuracy can be increased.

  Here, the reduced diameter portion 27b of the protective cover 27 to which the seal member 31 is joined is illustrated as having a stepped shape, but the present invention is not limited thereto, and the reduced diameter portion 27b is formed in a tapered shape. May be. In addition, depending on the position of the rotational speed sensor (not shown), there is a possibility that the seal member 31 may interfere with the seal member 31 before being brought close to the shielding portion 27c of the protective cover 27. Is set so as not to protrude to the inner side from the outer surface of the shielding part 27c in a single state before being fitted to the outer member 22. Thereby, in order to avoid interference with the seal member 31, it is not necessary to move the rotation speed sensor away from the magnetic encoder 26 more than necessary, the air gap can be set to the minimum, and the detection accuracy can be further improved.

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

  The wheel bearing sealing device according to the present invention can be applied to a sealing device mounted on an inner ring rotating type wheel bearing of first to third generation structure.

1, 21 Inner member 2, 23 Hub wheel 2a, 3a, 23a Inner rolling surface 2b, 23b Small diameter step 2c Serration 3 Inner ring 4 Wheel mounting flange 5 Hub bolt 6 Rolling element 7 Cage 8, 25 Outer side sealing device 9 Inner side sealing device 10, 22 Outer member 10a Outer rolling surface 10b Car body mounting flange 10c End side inner surface 10d, 22a, 22d of outer member End inner peripheral surface 10e, 22c of outer member Chamfered portion 11 Base portion 12 on inner side of wheel mounting flange, 16 Core metal 12a, 16a Fitting portion 12b, 16b Inner diameter portion 13, 17, 28, 28 ', 31 Seal member 13a, 17a, 28a Side lip 13b, 17c, 28b Dustrip 13c, 17b, 28c Grease lip 14 Seal plate 15 Slinger 15a, 27d, 30a Cylindrical portion 1 b, 30b Standing plate portion 18 Labyrinth seals 19, 26 Magnetic encoder 20, 29, 29 ', 31a Annular convex portion 22b End face 24 on outer side of outer member Clamping portion 27 Protective cover 27a Fitting portion 27b Reduced diameter portion 27c Shielding portion 27e Bottom portion 30 Support ring 31b Annular portion 51 Sealing device 52 Core metal 52a Outer diameter side cylindrical portion 52b Inner ring portion 53 Slinger 53a Inner diameter side cylindrical portion 53b Outer ring portion 54 Sealing material 54a Outer seal lip 54b Intermediate seal lip 54c Inner seal lip 55 Base end L Annular convex fitting width L1 A step between the inner side end face of the outer member and the large end face of the inner ring α An inclination angle δ of the annular convex part An annular convex step

Claims (13)

An outer member in which a double row outer rolling surface is integrally formed on the inner periphery;
From a hub wheel integrally having a wheel mounting flange for mounting a wheel at one end and having a small-diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter step portion of the hub ring An inner member in which a double row inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery,
The inner member and the outer member are mounted on a wheel bearing provided with a double row rolling element that is slidably accommodated between the rolling surfaces of the outer member, and the outer member and the inner member In a sealing device for a wheel bearing for sealing an opening of an annular space formed between,
The outer member has a cylindrical fitting portion that is press-fitted into the inner peripheral surface of the end portion through a predetermined scissors, and includes a cored bar formed by pressing from a steel plate. A seal member made of synthetic rubber is integrally joined by vulcanization adhesion, and an annular convex portion is formed on the seal member with a step slightly larger than the outer diameter of the fitting portion. The convex portion gradually increases in diameter toward the end surface side of the outer member, is formed into a tapered surface having a predetermined inclination angle, and is press-fitted with a predetermined fitting width to the inner peripheral surface of the end portion of the outer member. A sealing device for a bearing for a wheel.   The sealing device for a wheel bearing according to claim 1, wherein the step of the annular convex portion is set in a range of 0.25 to 0.30 mm.   The sealing device for a wheel bearing according to claim 1 or 2, wherein an inclination angle of the tapered surface of the annular convex portion is set in a range of 5 to 15 °.   The tip position of the annular convex portion is set so as to be closer to the bearing inner side than the chamfered portion formed on the inner periphery of the end portion of the outer member, and the fitting width of the annular convex portion is 0.43 to 2. The sealing device for a wheel bearing according to any one of claims 1 to 3, wherein the sealing device is set in a range of 50 mm.   2. The wheel bearing sealing device according to claim 1, wherein tapered surfaces of the annular convex portion are formed on both sides, and the inclination angles thereof are set to be substantially the same.   The wheel bearing sealing device according to claim 1, wherein grease is preliminarily applied to the fitting portion of the core metal and the annular convex portion of the seal member.   The sealing device is configured by an annular seal plate and a slinger that are formed in a substantially L-shaped cross section and arranged to face each other, the seal plate is composed of the core metal and a seal member, and the slinger is A cylindrical portion press-fitted to the outer periphery of the inner member; and a standing plate portion extending radially outward from the cylindrical portion, and the sealing member is inserted into the standing plate portion of the slinger via a predetermined axial shimiro 2. The wheel bearing sealing device according to claim 1, wherein the wheel bearing sealing device includes a side lip that makes sliding contact and a radial sealing lip that comes into sliding contact with the cylindrical portion via a predetermined radial shimeshiro. 3.   The sealing device is constituted by an integrated sealing device including the cored bar and a sealing member, and the sealing member has a predetermined shimiro at the base portion on the inner side of the wheel mounting flange having a circular section in cross section. 2. The wheel bearing sealing device according to claim 1, wherein the side lip and the dust lip which are in sliding contact with each other and the grease lip formed so as to be inclined toward the inner side of the bearing are integrally provided.   The sealing device is configured by a protective cover formed in a cup shape including the cored bar and a sealing member, and the cored bar is radially connected to the fitting part and the fitting part through a reduced diameter part. A disc-shaped shielding portion extending inward, and a bottom portion covering the inner side end portion of the inner member from the shielding portion via a step portion, and the seal member is an outer peripheral portion of the reduced diameter portion 2. The wheel bearing sealing device according to claim 1, wherein the wheel bearing sealing device is configured by the annular convex portion and an annular portion formed to have a diameter slightly smaller than an outer diameter of the fitting portion of the cored bar.   A magnetic encoder is externally fitted to the inner ring, and the cored bar is formed by pressing from a non-magnetic steel plate, and a rotational speed sensor is brought close to or abutted on the side surface of the shielding portion, and the shielding portion is interposed therebetween. The wheel bearing sealing device according to claim 9, wherein the magnetic encoder and the rotation speed sensor face each other through a predetermined axial clearance.   The said sealing member is set so that it may not protrude to the inner side from the outer surface of the said shielding part in the single-piece | unit state before fitting the said metal core to the said outer member at least. Wheel bearing sealing device.   The wheel bearing sealing device according to any one of claims 9 to 11, wherein an end surface on an inner side of the outer member is formed to slightly protrude toward an inner side from a large end surface of the inner ring.   The wheel bearing according to any one of claims 9 to 12, wherein a detection surface of the magnetic encoder and a large end surface of the inner ring are set to be substantially flush with each other or slightly protrude toward the inner side from the large end surface. Sealing device.

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