JP2015137754A - Wheel bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel bearing device to which a cover for sealing the inside of a bearing is attached, which structures a labyrinth seal between a knuckle and itself, is reduced in clearance of the labyrinth seal, and improved in sealing performance as a rigid labyrinth structure.SOLUTION: In a wheel bearing device, a cover 18 comprises: a cylindrical fitting part 18a to be externally press-fitted to an inner ring 5; a circular ring part 18b extending outward in a radial direction; and a cylindrical outside-diameter part 18c extending inward in the axial direction of a bearing from the circular ring part. The outside-diameter part 18c enters an annular space which is formed by a small-diameter part 2d formed at an end part of an outer member 2 and a support hole 7a of a knuckle 7, and the outside-diameter part 18c proximally opposes the support hole 7a, thus a labyrinth seal 19 is structured, and a seal 10 integrally has a seal lip 20 which extends while being inclined outward in a radial direction from an end part, and the seal lip 20 proximally opposes a side face of the circular ring part 18b of the cover 18, thus a labyrinth seal 21 is structured.

Description

  The present invention is for a wheel in which a wheel of an automobile or the like is rotatably supported and a cover for sealing the inside of the bearing is mounted, and a labyrinth seal is formed with a knuckle constituting a suspension device to improve a sealing performance. The present invention relates to a bearing device.

  In a wheel bearing device that rotatably supports a wheel with respect to a suspension device, a knuckle support hole that constitutes the independent suspension suspension is used to rotatably support a wheel on an independent suspension suspension that is a kind of suspension device. In addition, an outer member (outer ring) of the bearing is internally fitted, and the outer member and the knuckle are coupled by a plurality of bolts.

  As an example of such a wheel bearing device, a structure as shown in FIG. 6 is known. This wheel bearing device is configured such that the inner diameter side cylindrical portion 52 of the cover 51 is fitted and fixed to the inner ring 54 that is press-fitted and fixed to the hub ring 53, and the outer diameter side annular portion of the annular portion 55 of the cover 51. A labyrinth seal 58 is provided between the 56 axially outer surface and the axially inner end surface of the outer ring 57. A labyrinth seal 61 is provided between the inner peripheral surface of the outer diameter side cylindrical portion 59 of the cover 51 and the outer peripheral surface of the outer ring small diameter portion 60 of the outer ring 57. Further, a labyrinth seal 64 is provided between the inner peripheral surface of the support hole 63 of the knuckle 62, the outer peripheral surface of the outer ring 57, and the opening portion of the outer diameter side cylindrical portion 59 of the cover 51.

  Further, the distance between the inner diameter side circular ring portion 65 of the cover 51 and the inner side surface in the axial direction of the slinger 69 constituting the seal ring 68 that closes both axial openings of the ball installation space 67 that accommodates the ball 66 is A space having a sufficient volume is provided in this portion so as to be larger than the distance between the outer side surface in the axial direction of the radial ring portion 56 and the inner end surface in the axial direction of the outer ring 57.

  A space 70 is provided by causing the tip edge of the outer diameter side cylindrical portion 59 of the cover 51 and the step surface existing at the inner end of the outer ring small diameter portion 60 to face each other, and the axial dimension of the space 70 of the portion is increased to some extent. Then, by providing the space 70 having a relatively large volume between the labyrinth seal 61 and the labyrinth seal 64, the labyrinth effect can be further enhanced. By adopting such labyrinth seals 58, 61, 64, the hub wheel 53 and the outer ring 57 are oscillated and displaced based on the moment load applied to the wheel bearing device from the road surface during traveling, so that the axial direction of the space 70 is increased. Even when the clearance fluctuates, the pumping action due to the fluctuation can be suppressed, and the decrease in the labyrinth effect can be suppressed (see, for example, Patent Document 1).

JP 2013-92213 A

  However, in such a conventional wheel bearing device, the labyrinth seals 58, 61, 64 by the cover 51, the outer ring 57, and the knuckle 62 have a structure in which foreign matters such as rain water and muddy water do not easily enter the seal ring 68. In order to avoid interference between the metal of the cover 51 and the outer ring 57, the clearances of the labyrinth seals 58, 61, 64 must be set large.

  Since such a wheel bearing device is in an environment where it is directly exposed to rainwater, muddy water, and the like, a seal ring 68 having a strong sealing property is attached so that the rainwater, muddy water, etc. do not enter the inside of the bearing. In recent years, there has been a demand for longer life in this type of wheel bearing device used in such a severe environment. Therefore, it is needless to increase the sealing performance of the seal ring 68, and it is necessary to further improve the sealing performance of the above-described cover 51 mounted on the inner side in the axial direction of the seal ring 68.

  The present invention has been made in view of such circumstances. A cover that seals the inside of the bearing is mounted, and a labyrinth seal is formed with the knuckle, and a gap between the labyrinth seal is reduced to provide a strong labyrinth. An object of the present invention is to provide a wheel bearing device that is improved in sealing performance as a structure.

  In order to achieve such an object, the invention according to claim 1 of the present invention has a vehicle body mounting flange integrally attached to the knuckle constituting the suspension device on the outer periphery, and double row outer rolling on the inner periphery. A hub wheel having an integrally formed outer member, a wheel mounting flange for mounting a wheel at one end, and a small-diameter step portion extending in the axial direction on the outer periphery, and the hub wheel An inner member comprising at least one inner ring press-fitted into a small-diameter step portion, and having an outer periphery formed with a double-row inner rolling surface opposite to the double-row outer rolling surface, the inner member and the outer member A double row rolling element accommodated between the rolling surfaces of each side member so as to roll freely, and a seal attached to both side openings of an annular space formed between the outer member and the inner member And the outer member is formed in a support hole formed in the knuckle. The outer diameter part on the inner side is fitted inside, and a metal cover is press-fitted and fixed to the inner side end of the inner ring to close the opening between the outer member and the inner ring, and the cover is In a wheel bearing device in which a labyrinth seal is configured to face and oppose a support hole of a knuckle, the cover extends in a radially outward direction from the fitting portion that is press-fitted into the inner ring. The seal has an annular portion, and the seal on the inner side of the seal integrally has a seal lip extending from the end of the seal to the inner side so as to incline radially outward, and this seal lip is a circle of the cover. A seal is configured to face the side surface of the ring portion.

  As described above, a seal mounted on both side openings of the annular space formed between the outer member and the inner member is provided, and an outer diameter portion on the inner side of the outer member is provided in the support hole formed in the knuckle. And a metal cover is press-fitted and fixed to the inner ring end of the inner ring, the opening between the outer member and the inner ring is closed, and the cover is close to the support hole of the knuckle so that the labyrinth In the wheel bearing device in which the seal is configured, the cover includes a cylindrical fitting portion that is press-fitted into the inner ring, and an annular portion that extends radially outward from the fitting portion. The seal integrally has a seal lip extending from the end portion of the seal to the inner side so as to incline radially outward, and the seal lip is configured to face the side surface of the annular portion of the cover. So labyrinth seal close to the external space Coupled with, it is possible to provide a wheel bearing apparatus with improved sealability over a long period of time.

  According to a second aspect of the present invention, the cover includes a cylindrical outer diameter portion that extends from the ring portion toward the axial bearing inward side, and the outer diameter portion is formed on the outer member. If the labyrinth seal is configured by entering the annular space formed by the small-diameter portion formed at the inner side end portion and the support hole of the knuckle, and the outer-diameter portion facing the support hole of the knuckle Thus, unlike the conventional case, it is not necessary to consider the interference between the outer diameter portion of the cover and the outer member, and the clearance of the labyrinth seal close to the outer space can be set as small as possible, thereby providing a strong labyrinth structure. be able to.

  According to a third aspect of the present invention, the inner-side seal is composed of a pack seal composed of a slinger and an annular seal plate arranged to face each other, and the slinger is cross-sectioned by pressing from a steel plate. A cylindrical portion formed in an L shape and press-fitted into the outer diameter portion of the inner ring, and a standing plate portion extending radially outward from the cylindrical portion, and the seal plate is an end portion of the outer member And a seal member that is integrally joined to the core metal by vulcanization adhesion and has a side lip that is in sliding contact with the standing plate portion of the slinger, and the seal lip extends from the end of the seal member. If it extends beyond the tip of the fitting portion of the cored bar to the inner side and faces the annular portion of the cover, this rainwater can be used even in an environment where it is directly exposed to rainwater, muddy water, etc. And muddy water does not enter the bearing It is possible to provide a wheel bearing apparatus provided with a sealing performance.

  If the labyrinth seal is configured such that the seal lip is close to and opposed to the side surface of the annular portion of the cover as in the invention described in claim 4, a strong labyrinth is achieved without increasing the bearing torque. It becomes a structure and can maintain sealing performance over a long period of time.

  According to a fifth aspect of the present invention, the cover is formed from a stainless steel plate by pressing, and the seal lip is in sliding contact with the side surface of the annular portion of the cover to form a contact seal. Accordingly, the corrosion resistance and wear resistance of the cover are improved, and the sealing performance can be maintained for a long period.

  Further, as in the invention described in claim 6, a magnetic encoder having magnetic poles N and S alternately magnetized in the circumferential direction is integrally joined to the side surface on the inner side of the standing plate portion of the slinger, If the cover is formed by press working from an austenitic stainless steel plate, the rotational speed sensor is brought close to the ring portion of the cover, and the magnetic encoder and the rotational speed sensor are arranged to face each other through the cover, the magnetic encoder While it is possible to prevent foreign particles such as iron powder and other small ferromagnetic particles and powder from adhering to the surface, and the non-magnetic cover rotates with the inner ring, it is difficult for foreign objects to adhere to the surface of the cover, The detection accuracy by the rotation speed sensor is increased, and the reliability can be improved.

  According to a seventh aspect of the invention, the slinger is externally fitted to the fitting portion of the cover, the inner side seal and the cover are integrated, and the magnetic encoder is an annular ring of the cover. If it is in contact with the side surface of the part, the positioning of the seal lip facing the cover and the side lip slidably contacting the slinger can be easily managed at a single point, and each lip can be managed without strictly managing the positioning accuracy of the cover. As a result, it is possible to reduce the number of assembly steps.

  A wheel bearing device according to the present invention has a vehicle body mounting flange integrally attached to a knuckle constituting a suspension device on an outer periphery, and an outer side in which a double row outer rolling surface is integrally formed on an inner periphery. And a hub wheel integrally having a wheel mounting flange for mounting a wheel at one end thereof and having a small-diameter step portion extending in the axial direction on the outer periphery, and at least one press-fitted into the small-diameter step portion of the hub ring An inner member formed of two inner rings and formed on the outer periphery with a double row inner rolling surface facing the outer row rolling surface of the double row, and between the respective rolling surfaces of the inner member and the outer member Formed in the knuckle, and a double row rolling element housed in a freely rotatable manner, and seals mounted on both side openings of an annular space formed between the outer member and the inner member. The outer diameter portion on the inner side of the outer member is fitted into the supported support hole. In addition, a metal cover is press-fitted and fixed to the inner side end of the inner ring so that the opening between the outer member and the inner ring is closed, and the cover is close to and opposed to the support hole of the knuckle to form a labyrinth seal. In which the cover includes a cylindrical fitting portion that is press-fitted into the inner ring, and an annular portion that extends radially outward from the fitting portion. The seal on the side integrally has a seal lip extending radially inwardly from the end of the seal toward the inner side, and this seal lip is opposed to the side surface of the annular portion of the cover. Therefore, in combination with the labyrinth seal close to the outer space, it is possible to provide a wheel bearing device that improves the sealing performance over a long period of time.

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 seal part of FIG. It is a principal part enlarged view which shows the modification of the seal part of FIG. It is a principal part enlarged view which shows the modification of the seal | sticker part of FIG. It is a principal part enlarged view which shows the other modification of the seal | sticker part of FIG. It is a principal part enlarged view which shows the seal part of the conventional wheel bearing apparatus.

  An outer member that integrally has a vehicle body mounting flange to be attached to a knuckle constituting a suspension device on the outer periphery, and an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and a wheel on one end A hub wheel integrally having a wheel mounting flange and having an inner rolling surface opposed to one of the double-row outer rolling surfaces and a small-diameter step portion extending in the axial direction from the inner rolling surface. And an inner member formed of an inner ring press-fitted into a small diameter step portion of the hub wheel and formed with an inner rolling surface facing the other of the double row outer rolling surfaces, and the inner member and the outer member. A double row rolling element housed between the rolling surfaces of the member so as to be freely rollable, and a seal attached to both side openings of the annular space formed between the outer member and the inner member; And a support hole formed in the knuckle on the inner side of the outer member. And a metal cover is press-fitted and fixed to the inner side end of the inner ring to close the opening between the outer member and the inner ring, and the cover is in the support hole of the knuckle. In the wheel bearing device in which the labyrinth seal is configured so as to face each other, the cover includes a cylindrical fitting portion that is press-fitted into the inner ring, and an annular portion that extends radially outward from the fitting portion, A cylindrical outer diameter portion extending inwardly from the annular portion toward the axial bearing, and the outer diameter portion includes a small diameter portion formed at an inner end of the outer member and the knuckle. A labyrinth seal is formed by entering the annular space formed by the support hole, and the outer diameter portion is in close proximity to the support hole of the knuckle, and the inner seal of the seal is an end portion of the seal Radially outward from the inner side Has a sealing lip extending inclined integrally labyrinth seal is constructed the seal lip closely opposed to the side surface of the annular portion of the cover.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
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 seal part of FIG. 1, and FIG. 3 is a modified example of the seal part of FIG. FIG. 4 is an enlarged view of a main part showing a modification of the seal part of FIG. 3, and FIG. 5 is an enlarged view of a main part showing another modification of the seal part of FIG. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  The wheel bearing device shown in FIG. 1 is for a driven wheel referred to as a third generation, and is a double row accommodated in a freely rollable manner between an inner member 1 and an outer member 2 and both members 1 and 2. Rolling elements (balls) 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 outer member 2 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and integrally has a vehicle body mounting flange 2b for mounting to the knuckle 7 on the outer periphery, and has a double row outer side on the inner periphery. The rolling surfaces 2a and 2a are integrally formed. These double-row outer raceway surfaces 2a and 2a are formed with a hardened layer having a surface hardness of 58 to 64 HRC by induction hardening.

  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 hub bolts 6a are implanted at circumferentially equidistant positions of the wheel mounting flange 6. Yes. Moreover, the inner side rolling surface 4a which opposes one (outer side) of the said double row outer side rolling surface 2a, 2a and the small diameter step part 4b extended in an axial direction from this inner side rolling surface 4a are formed in outer periphery. Yes.

  On the other hand, the inner ring 5 is formed on the outer periphery with an inner rolling surface 5a facing the other (inner side) of the double row outer rolling surfaces 2a, 2a, and a small-diameter step portion 4b of the hub wheel 4 via a predetermined shimoshiro. And is fixed in the axial direction to the hub wheel 4 in a state where a predetermined bearing preload is applied by a crimping portion 4c formed by plastically deforming the end portion of the small-diameter stepped portion 4b radially outward. Yes.

  Between the double row outer rolling surfaces 2a, 2a of the outer member 2 and the double row inner rolling surfaces 4a, 5a facing these, the double row rolling elements 3, 3 are respectively accommodated, and the cage 8 , 8 are held so as to roll freely. Further, seals 9 and 10 are attached to the opening of the annular space formed between the outer member 2 and the inner member 1, and leakage of the lubricating grease sealed inside the bearing and the inside of the bearing from the outside. Prevents intrusion of rainwater and dust.

  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 extends from the inner raceway surface 4a to the small diameter step portion 4b from the base portion 6b on the inner side of the wheel mounting flange 6. Thus, the surface hardness is set to a range of 58 to 64 HRC by induction hardening. As a result, not only the wear resistance of the base portion 6b that becomes the seal land portion of the seal 9 is improved, but also the hub wheel 4 has sufficient mechanical strength against the rotational bending load applied to the wheel mounting flange 6. Improves durability. The inner ring 5 is made of high carbon chrome bearing steel such as SUJ2, and is hardened in the range of 58 to 64 HRC to the core portion by quenching. Moreover, the rolling element 3 consists of high carbon chromium bearing steel, such as SUJ2, and is hardened in the range of 62-67HRC to a core part by submerged hardening.

  The seal 9 on the outer side of the seals 9 and 10 is joined to a core metal 11 that is press-fitted into the inner periphery of the outer side end portion of the outer member 2 through a predetermined scissors, and is bonded to the core metal 11 by vulcanization adhesion. It is comprised by the integral type seal | sticker which consists of the sealed member 12 made. The core metal 11 is formed by press-working a cold-rolled steel plate (JIS standard SPCC system or the like).

  On the other hand, the seal member 12 is made of a synthetic rubber such as NBR (acrylonitrile-butadiene rubber), and extends inclining radially outward, and is in slidable contact with the side surface on the inner side of the wheel mounting flange 6 via a predetermined shimiro. 12a, a dust strip 12b extending in a radially outward direction on the inner diameter side, and in sliding contact with a base portion 6b having an arc-shaped cross section through a predetermined axial direction shim, and an inward bearing side And has a grease lip 12c slidably in contact with the base portion 6b via a predetermined radial shimiro. In addition to the exemplified NBR, the material of the seal member 12 includes, for example, HNBR (hydrogenated acrylonitrile butadiene rubber), EPDM (ethylene propylene rubber), etc., which have excellent heat resistance, and heat resistance and chemical resistance. Examples thereof include ACM (polyacrylic rubber), FKM (fluororubber), and silicon rubber, which are excellent in the above.

  Further, as shown in an enlarged view in FIG. 2, the inner side seal 10 is constituted by a so-called pack seal composed of a slinger 13 and an annular seal plate 14 arranged to face each other. The slinger 13 is formed from a steel plate, for example, a ferritic stainless steel plate (JIS standard SUS430 series, etc.), or a cold-rolled steel plate that has been rust-proofed, by press working, so that the inner ring 5 The cylindrical portion 13a is press-fitted into the large-diameter portion 5b, and the upright plate portion 13b extends radially outward from the cylindrical portion 13a.

  On the other hand, the seal plate 14 includes a cored bar 16 fitted into the end of the outer member 2 and a seal member 17 integrally joined to the cored bar 16 by vulcanization adhesion. The core metal 16 is formed into a thin wall by forming a substantially L-shaped cross section by pressing from a rust-proof cold-rolled steel plate, press-fitting into the outer member 2, and slightly reducing the diameter of the end. And a cylindrical fitting portion 16a and an inner diameter portion 16b extending radially inward from the fitting portion 16a. And the sealing member 17 wraps around and joins so that the front-end | tip part of the fitting part 16a may be covered, and this part has comprised the half metal structure which elastically fits to the outer member 2. FIG. Thereby, while being able to ensure an appropriate fitting force, it can prevent that muddy water etc. permeate from a fitting surface by crimping of the sealing member 17, and can improve airtightness.

  Examples of the rust prevention treatment of the cored bar 16 include metal plating such as cationic electrodeposition coating and hard chrome plating. Here, since the sealing member 17 covers the exposed outer surface of the cored bar 16, rusting can be prevented even if the material of the cored bar 16 is not necessarily formed of an expensive stainless steel plate. A good cold-rolled steel sheet can be used, and cost reduction can be achieved.

  The seal member 17 is made of a synthetic rubber such as NBR, and includes a side lip 17a extending obliquely outward in the radial direction, and a grease lip 17b and a dust lip 17c formed in a bifurcated shape on the inner diameter side. The side lip 17a is in sliding contact with the outer side surface of the standing plate portion 13b of the slinger 13 via a predetermined axial shimiro, and the grease lip 17b and the dust lip 17c are in contact with the cylindrical portion 13a via a predetermined radial shimiro. Are in sliding contact.

  Further, the outer edge of the standing plate portion 13b of the slinger 13 and the seal plate 14 are opposed to each other through a slight radial clearance, whereby a labyrinth seal 15 is configured. In addition to the exemplified NBR, examples of the material of the seal member 17 include ACM, FKM, or silicon rubber having excellent heat resistance and chemical resistance, such as HNBR and EPDM having excellent heat resistance. can do.

  In addition, although the wheel bearing apparatus comprised by the double row angular contact ball bearing which used the ball for the rolling element 3 was illustrated here, it is not restricted to this, The double row tapered roller bearing which used the tapered roller for the rolling element 3 It may consist of. Here, the third generation structure in which the inner raceway surface 4a is directly formed on the outer periphery of the hub wheel 4 is illustrated, but although not illustrated, the first generation or the 2.5th generation structure may be used. .

  In the present embodiment, in order to rotatably support the wheel on an independent suspension that is a kind of suspension device, an outer member is formed in the support hole 7a formed in the knuckle 7 that constitutes a part of the independent suspension. 2 is fitted inside, and the outer member 2 and the knuckle 7 are fastened by a plurality of fixing bolts (not shown).

  Here, a small-diameter portion 5d is formed from the large-diameter portion 5b of the inner ring 5 via the step portion 5c, and a cover 18 is press-fitted into the small-diameter portion 5d, and an opening between the outer member 2 and the inner ring 5 is formed. Is blocked. The cover 18 is formed by press working from a rust-proof cold-rolled steel plate and is press-fitted into the small-diameter portion 5d of the inner ring 5, and radially outward from the fitting portion 18a. And a cylindrical outer diameter portion 18c extending from the annular portion 18b to the axially outer side (bearing inner side). The outer diameter portion 18 c enters the annular space formed by the small diameter portion 2 d formed at the inner end of the outer member 2 and the support hole 7 a of the knuckle 7, and the inner end of the outer member 2. The opening between the outer member 2 and the inner ring 5 is closed. The outer diameter portion 18c is close to and opposed to the support hole 7a of the knuckle 7 via a slight radial clearance (labyrinth clearance) 2δ, and the labyrinth seal 19 is configured.

  Here, the radial clearance 2δ is set in a range of 0.2 to 1.5 mm. The outer diameter portion 18c of the cover 18 can be manufactured with a tolerance range of ± 0.3 for a normal press and ± 0.1 for a precision press. Even if the outer diameter portion 18c is processed with a precision press and the dimensional variation in manufacturing is taken into consideration, the labyrinth clearance is set so as to prevent the interference with the knuckle 7 even if the tolerance is the worst. On the other hand, if it exceeds 1.5 mm, the labyrinth clearance becomes large, and the labyrinth effect may be remarkably lowered, which is not preferable.

  In addition, a seal lip 20 is formed integrally with the end of the fitting portion 16a of the core metal 16 so as to extend radially inward from the end of the seal member 17 toward the inner side. The seal lip 20 is opposed to the outer side surface of the annular portion 18 b of the cover 18 via a slight axial clearance (labyrinth clearance) Sa to constitute a labyrinth seal 21.

  Here, the axial clearance Sa is set in the range of 0.2 to 1.0 mm. When the cover 18 is press-fitted, the fitting portion 18a is press-fitted into the small-diameter portion 5d of the inner ring 5 by pressing the annular portion 18b with a press-fitting jig (not shown). Even if the manufacturing thickness variation is taken into account, the labyrinth clearance between the seal lip 20 and the annular portion 18b of the cover 18 remains even if the tolerance of positioning accuracy is poor, It is set so that it touches slightly. On the other hand, if the thickness exceeds 1.0 mm, the labyrinth clearance is increased, and the labyrinth effect is remarkably lowered.

  Thus, in this embodiment, the labyrinth seal 19 is formed between the support hole 7a of the knuckle 7 and the outer diameter portion 18c of the cover 18, and the seal lip 20 is formed integrally with the seal 10. Since the labyrinth seal 21 is further formed between the annular portion 18b of the cover 20 and the cover 18, there is no need to consider the interference between the outer diameter portion 18c of the cover 18 and the outer member 2 as in the prior art. Since the clearance of the labyrinth seal 19 close to the outer space can be set as small as possible, the wheel bearing device has a strong labyrinth structure without increasing the bearing torque and maintains the sealing performance over a long period of time. Can be provided.

  FIG. 3 is a modification of the above-described seal 10. The seal 22 basically differs from the above-described seal 10 only in the shape and dimensions of the seal lip 20, and other parts and portions having the same or similar functions are denoted by the same reference numerals and details thereof. The detailed explanation is omitted.

  The seal 22 is constituted by a pack seal composed of a slinger 13 and an annular seal plate 23 arranged to face each other. The seal plate 23 includes a cored bar 16 fitted into the end of the outer member 2 and a seal member 24 integrally joined to the cored bar 16 by vulcanization adhesion. The seal member 24 is made of a synthetic rubber such as NBR, and has a side lip 17a extending obliquely outward in the radial direction, a grease lip 17b and a dust lip 17c formed in a forked shape on the inner diameter side, and a core metal 16 A seal lip 25 that extends from the end of the seal member 24 to the inner side and inclines radially outward from the end of the fitting portion 16a is integrally provided.

  On the other hand, the cover 26 is formed by press working from a stainless steel plate such as an austenitic stainless steel plate or a ferritic stainless steel plate, and is fitted with a cylindrical fitting portion 18a press-fitted into the small diameter portion 5d of the inner ring 5. An annular portion 18b extending radially outward from the portion 18a and a cylindrical outer diameter portion 18c extending axially outward from the annular portion 18b are provided. The seal lip 25 is in sliding contact with the outer side surface of the annular portion 18b of the cover 26 via a predetermined axial squeeze.

  As described above, in this embodiment, the labyrinth seal 19 is formed between the support hole 7 a of the knuckle 7 and the outer diameter portion 18 c of the cover 18, and the seal lip 25 is formed integrally with the seal member 24 of the seal 22. Since the seal lip 25 is in sliding contact with the annular portion 18b of the cover 26, the clearance of the labyrinth seal 19 close to the outer space can be set as small as possible, and further contact seals can be used for a long period of time. The sealing property can be improved.

  The seal shown in FIG. 4 is a modification of the above-described seal 22 (FIG. 3). The seal 27 basically differs from the above-described seal 22 only in a part of the configuration of the slinger 13, and other parts and portions having the same or similar functions are denoted by the same reference numerals and details thereof. The detailed explanation is omitted.

  The seal 27 is composed of a pack seal composed of a slinger 28 and an annular seal plate 23 arranged to face each other. The seal plate 23 includes a cored bar 16 fitted into the end of the outer member 2 and a seal member 24 integrally joined to the cored bar 16 by vulcanization adhesion. On the other hand, the slinger 28 is formed into a substantially L-shaped section by pressing from a ferromagnetic ferritic stainless steel plate or a cold-rolled steel plate that has been rust-proofed, and is formed on the large-diameter portion 5 b of the inner ring 5. It consists of a cylindrical portion 13a to be press-fitted and a standing plate portion 13b extending radially outward from the cylindrical portion 13a. The magnetic encoder 28a is integrally joined by vulcanization bonding or the like from the inner side surface of the upright plate portion 13b to the outer peripheral surface of the outer edge. The magnetic encoder 28a constitutes a rotary encoder for detecting the rotational speed of the wheel by mixing magnetic powder such as ferrite in an elastomer such as rubber and magnetizing the magnetic poles N and S alternately in the circumferential direction.

  Here, the cover 26 is formed by press working from a non-magnetic steel plate having corrosion resistance, for example, an austenitic stainless steel plate, so as not to adversely affect the sensing performance of the rotational speed sensor 29 described later, and the small diameter of the inner ring 5. A cylindrical fitting portion 18a that is press-fitted into the portion 5d, a circular ring portion 18b that extends radially outward from the fitting portion 18a, and a cylindrical outer diameter that extends from the circular ring portion 18b to the axially outer side. Part 18c. The seal lip 25 is in sliding contact with the outer side surface of the annular portion 18b of the cover 26 via a predetermined axial squeeze.

  In the present embodiment, the rotational speed sensor 29 is brought close to the annular portion 18b of the cover 26, and the rotational speed sensor 29 and the magnetic encoder 28a are arranged to face each other with a predetermined air gap (axial clearance) through the cover 26. Has been. Since the cover 26 is a non-magnetic material, it does not affect the flow path of the magnetic flux, has excellent corrosion resistance, and can improve durability over a long period of time.

  Thus, in this embodiment, since the magnetic encoder 28a and the rotational speed sensor 29 are disposed to face each other via the cover 26, a small piece of a ferromagnetic material such as iron powder or a foreign substance such as powder is formed on the surface of the magnetic encoder 28a. Can be prevented, and the non-magnetic cover 26 rotates together with the inner ring 5, so that it is difficult for foreign matter to adhere to the surface of the cover 26, and the detection accuracy by the rotational speed sensor 29 is increased. Can be improved.

  The embodiment shown in FIG. 5 is another modification of the above-described seal portion (FIG. 3). The seal portion basically has a different structure from the above-described seal 27 (FIG. 4) and the cover 26, the slinger 28 constituting the seal 30 is press-fitted into the cover 33, and the seal 30 and the cover 33 are integrated. Yes. Other parts and parts having the same function or the same function are denoted by the same reference numerals, and detailed description thereof is omitted.

  The seal 30 is constituted by a pack seal including a slinger 28 and an annular seal plate 31 that are arranged to face each other. The seal plate 31 includes a cored bar 16 fitted into the end of the outer member 2 and a seal member 32 integrally joined to the cored bar 16 by vulcanization adhesion. The seal member 32 is made of a synthetic rubber such as NBR, and has a side lip 17a extending obliquely outward in the radial direction, a grease lip 32a extending obliquely inward in the radial direction on the inner diameter side, and a core metal 16 A seal lip 25 is integrally formed so as to extend from the end portion of the seal member 32 to the inner side so as to incline radially outward beyond the end portion of the fitting portion 16a. The side lip 17a is slidably contacted to the outer side surface of the upright plate portion 13b of the slinger 28 via a predetermined axial nip, and the grease lip 32a is connected to the cylindrical portion 13a via a predetermined radial nip. It is in sliding contact.

  The cover 33 is formed of a nonmagnetic steel plate having corrosion resistance, for example, an austenitic stainless steel plate by press working, and is fitted into a cylindrical fitting portion 33a that is press-fitted into the large-diameter portion 5b of the inner ring 5, and the fitting portion. An annular portion 33b extending radially outward from 33a and a flange portion 33d extending radially outward from the annular portion 33b via a bent portion 33c are provided.

  In the present embodiment, the large-diameter portion 2c and the small-diameter portion 2d as described above are not formed at the inner end portion of the outer member 2 ′, and a cylindrical outer portion extending from the vehicle body mounting flange 2b to the inner side. A radial surface 2e is formed. The outer diameter surface 2e is fitted in a support hole 7a formed in the knuckle 7, and the outer member 2 'and the knuckle 7 are fastened by a plurality of fixing bolts (not shown).

  The flange 33d of the cover 33 has an outer edge facing the support hole 7a of the knuckle 7 via a slight radial clearance (labyrinth clearance) 2δ, and a labyrinth seal 34 is configured. Further, the flange portion 33d constitutes a labyrinth seal 35 with its outer side surface facing the inner side end surface 2f of the outer member 2 'via a predetermined axial clearance. The seal lip 25 of the seal 30 is in sliding contact with the side surface on the outer side of the annular portion 33b of the cover 33 via a predetermined axial squeeze.

  Here, the cylindrical portion 13a of the slinger 28 is press-fitted into the fitting portion 33a of the cover 33, and the seal 30 and the cover 33 are integrated. Specifically, the slinger 28 is press-fitted in advance until the magnetic encoder 28 a contacts the outer side surface of the annular portion 33 b of the cover 33, and the seal plate 31 is fitted and inserted into the slinger 28. The cover 33 is assembled integrally. In a state where the seal 30 and the cover 33 are integrated, they are press-fitted and fixed in an annular space between the outer member 2 ′ and the inner ring 5.

  As described above, in this embodiment, since the magnetic encoder 28a and the rotation speed sensor 29 are arranged to face each other via the cover 33, as in the above-described embodiment, a ferromagnetic material such as iron powder is provided on the surface of the magnetic encoder 28a. , And the non-magnetic cover 33 rotates together with the inner ring 5, so that it is difficult for foreign matter to adhere to the surface of the cover 33, which is detected by the rotational speed sensor 29. Accuracy can be improved and reliability can be improved.

  Further, since the seal 30 and the cover 33 are integrated, the axial squeeze of the seal lip 25 slidably contacting the cover 33 and the side lip 17a slidably contacting the slinger 28 can be easily managed at a single point. As the positioning accuracy can be managed without strictly managing the positioning accuracy, the number of assembling steps can be reduced.

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

  The wheel bearing device according to the present invention can be applied to a wheel bearing device on the driving wheel side of the 2.5th generation and first to third generation structures of the inner ring rotation type.

DESCRIPTION OF SYMBOLS 1 Inner member 2, 2 'Outer member 2a Outer rolling surface 2b Car body mounting flange 2c Large diameter part 2d of inner side of outer member Small diameter part 2e of inner side of outer member Outer diameter surface 2f of outer member End surface 3 on the inner side of the outer member Rolling element 4 Hub wheel 4a, 5a Inner rolling surface 4b Small diameter step portion 4c Clamping portion 5 Inner ring 5b Inner ring large diameter portion 5c Inner ring step 5d Inner ring small diameter portion 6 Wheel mounting flange 6a Hub bolt 6b Inner side base 7 of wheel mounting flange 7 Knuckle 7a Support hole 8 Retainer 9 Outer side seal 10, 22, 27, 30 Inner side seal 11, 16 Core metal 12, 17, 24, 32 Seal member 12a , 17a Side lip 12b, 17c Dustrip 12c, 17b, 32a Grease lip 13, 28 Slinger 13a Cylindrical portion 13b Standing plate portions 14, 23, 31 Seal plate 1 , 19, 21, 34, 35 Labyrinth seals 16a, 18a, 33a Fitting portion 16b Inner diameter portion 18, 26, 33 Cover 18b, 33b Ring portion 18c Outer diameter portion 20, 25 Seal lip 28a Magnetic encoder 29 Rotation speed detection sensor 33c Bending portion 33d Gutter portion 51 Cover 52 Inner diameter side cylindrical portion 53 Hub ring 54 Inner ring 55 Circular ring portion 56 Outer diameter side annular portion 57 Outer ring 58, 61, 64 Labyrinth seal 59 Outer diameter side cylindrical portion 60 Outer ring small diameter portion 62 Knuckle 63 Support hole 65 Inner ring portion 66 Ball 67 Ball installation space 68 Seal ring 69 Slinger 70 Space δ Radial clearance Sa Axial clearance

Claims (7)

An outer member integrally having a vehicle body mounting flange for being attached to a knuckle constituting a suspension device on the outer periphery, and an outer rolling surface of a double row integrally formed on the inner periphery;
From a hub wheel integrally having a wheel mounting flange for mounting a wheel at one end and having a small-diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter step portion of the hub ring An inner member in which a double row inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery,
A double row rolling element housed movably between the rolling surfaces of the inner member and the outer member;
A seal mounted on both side openings of the annular space formed between the outer member and the inner member;
An outer diameter portion on the inner side of the outer member is fitted in a support hole formed in the knuckle, and
A metal cover is press-fitted and fixed to an inner side end portion of the inner ring so that an opening between the outer member and the inner ring is closed, and a labyrinth seal is configured so that the cover is closely opposed to the support hole of the knuckle. In a wheel bearing device,
The cover includes a cylindrical fitting portion that is press-fitted into the inner ring, and a circular ring portion that extends radially outward from the fitting portion, and an inner seal of the seal is an end portion of the seal A seal lip integrally extending radially inwardly from the inner side to the inner side, wherein the seal lip is opposed to the side surface of the annular portion of the cover, and the seal is configured Bearing device.   The cover includes a cylindrical outer diameter portion extending inward from the annular portion toward the axial bearing, and the outer diameter portion includes a small diameter portion formed at an inner end portion of the outer member and the outer member. 2. The wheel bearing device according to claim 1, wherein a labyrinth seal is configured so as to enter an annular space formed by a support hole of the knuckle, and the outer diameter portion is in close proximity to the support hole of the knuckle.   The inner side seal is composed of a pack seal composed of a slinger and an annular seal plate arranged opposite to each other, and the slinger is formed into a L-shaped section by pressing from a steel plate, and the outer diameter portion of the inner ring A cylindrical portion that is press-fitted into the cylindrical portion, and a standing plate portion that extends radially outward from the cylindrical portion, and the seal plate is fitted into the end portion of the outer member, and the core metal A sealing member having a side lip that is integrally bonded by vulcanization and that is in sliding contact with the standing plate portion of the slinger, and the sealing lip extends from the end of the sealing member to the tip of the fitting portion of the cored bar The wheel bearing device according to claim 1, wherein the wheel bearing device extends toward the inner side and faces the annular portion of the cover.   The wheel bearing device according to any one of claims 1 to 3, wherein a labyrinth seal is configured such that the seal lip is close to and opposed to a side surface of an annular portion of the cover.   The wheel bearing according to any one of claims 1 to 3, wherein the cover is formed from a stainless steel plate by pressing, and the seal lip is slidably contacted with a side surface of an annular portion of the cover to form a contact seal. apparatus.   A magnetic encoder having magnetic poles N and S alternately magnetized in the circumferential direction is integrally joined to the side surface on the inner side of the standing plate portion of the slinger, and the cover is formed by pressing from an austenitic stainless steel plate, The wheel bearing device according to claim 3, wherein a rotation speed sensor is brought close to an annular portion of the cover, and the magnetic encoder and the rotation speed sensor are arranged to face each other through the cover.   The slinger is externally fitted to a fitting portion of the cover, the inner seal and the cover are integrated, and the magnetic encoder is in contact with a side surface of the annular portion of the cover. The wheel bearing device described.

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