JP6550220B2 - Wheel bearing device - Google Patents

Description

  The present invention relates to a bearing device for a wheel that rotatably supports a wheel of an automobile or the like with respect to a suspension device, and more particularly to a bearing device for a wheel whose reliability has been improved by detecting abnormality of the bearing portion in advance. It is.

  2. Description of the Related Art Conventionally, a wheel bearing device for supporting a wheel of an automobile or the like rotatably supports a hub wheel for mounting the wheel via a double-row rolling bearing, and is available for driving wheels and driven wheels. For structural reasons, the inner ring rotation method is generally adopted for drive wheels, and the inner ring rotation and outer ring rotation methods are generally adopted for driven wheels. In addition, the wheel bearing device has a structure called first generation in which a wheel bearing consisting of double-row angular contact ball bearings and the like is fitted between a knuckle constituting a suspension system and a hub wheel. A second generation structure in which a vehicle mounting flange or a wheel mounting flange is directly formed on the outer periphery of a member, or a third generation structure in which one inner raceway is directly formed on the outer periphery of a hub wheel It is roughly divided into the fourth generation structure in which the inner raceway is directly formed on the outer periphery of the outer joint member of the fast joint.

  In these bearings, even if an abnormality such as separation of the rolling surface occurs, if the driver continues driving without being aware of the abnormality, there is a risk of causing a serious accident such as a wheel lock. A wheel bearing device having a structure as shown in FIG. 8 is known as a wheel bearing device in which the occurrence of such a bearing abnormality is sensed in advance to improve the reliability.

  A seal 52 is mounted at the opening of the annular space formed between the outer member 50 and the inner ring 51, and leakage of the lubricating grease sealed inside the bearing to the outside, rain water and dust from the outside, etc. To prevent intrusion. The seal 52 is constituted by a so-called pack seal consisting of a slinger 53 and an annular seal plate 54 disposed to face each other.

  The slinger 53 is formed by pressing a steel plate into a substantially L-shaped cross section, and includes a cylindrical portion 53a press-fitted to the outer diameter of the inner ring 51, and a standing plate portion 53b extending radially outward from the cylindrical portion 53a. Have. And the magnetic encoder 57 is integrally joined to the side surface of this standing board part 53b by vulcanization adhesion.

  On the other hand, the seal plate 54 is composed of a core metal 55 mounted on the outer member 50 and a seal member 56 integrally joined to the core metal 55 by vulcanization adhesion, and the core metal 55 is pressed from steel plate A cylindrical fitting portion 55a formed into a substantially L-shaped cross section and press-fitted into the inner periphery of the end portion of the outer member 50, and an inner diameter portion 55b extending radially inward from the fitting portion 55a There is. The seal member 56 is made of synthetic rubber, and has a side lip 56a extending radially outward and inclined, and a grease lip 56b and a dust lip 56c formed in a forked shape. The side lip 56a of the seal member 56 is disposed opposite to the upright plate portion 53b of the slinger 53 with a predetermined axial clearance, and the grease lip 56b and the dust lip 56c are disposed in a predetermined radial direction on the cylindrical portion 53a of the slinger 53. It is in sliding contact via shimeshiro. The seal plate 54 and the slinger 53 or the magnetic encoder 57 face each other via a slight radial clearance e to constitute a labyrinth seal.

  Here, the annular convex portion 58 is integrally formed on the outer diameter of the inner ring 51 on the rotating side, and a cylindrical detection surface 59 is formed on the inner periphery of the end portion of the outer member 50 on the stationary side. The surface 59 and the annular convex portion 58 of the inner ring 51 are opposed to each other via a minute radial clearance ε, and the abnormality detection unit 60 is configured. Thereby, when exfoliation and wear are promoted on the outer raceway surface 50a of the outer member 50 and the inner raceway surface 51a of the inner ring 51, the annular convex portion 58 and the detection surface 59 contact to generate noise and vibration. It is possible to notify the driver of the abnormality, detect the abnormality of the bearing in advance, avoid the occurrence of the lock or the like of the inner ring 51 on the rotating side, and provide the bearing apparatus for a wheel with improved reliability. (See, for example, Patent Document 1).

JP 2012-97823 A

  However, in such a conventional abnormality detection unit 60, since the outer member 50 and the inner ring 51 do not contact unless peeling and wear of the rolling surfaces 50a and 51a considerably progress, the abnormality detection is delayed, Serious accidents such as burn-in may occur.

  The present invention has been made in view of such circumstances, and when the temperature rises due to an abnormality occurring in the bearing portion, the bearing device for a wheel in which the driver promptly detects it and improves the reliability Intended to be provided.

  In order to achieve the above object, the invention according to claim 1 of the present invention is an outer member in which a plurality of rows of outer raceways are integrally formed on the inner periphery, and an outer raceway of the plurality of rows in the outer periphery. An inner member formed with a plurality of rows of inner rolling surfaces facing each other, and a plurality of rows of rolling elements rollably accommodated between the respective rolling surfaces of the inner member and the outer member; And a seal for sealing the opening of the annular space formed between the outer member and the inner member, in the wheel bearing device, the parts to be attached to the outer member or the inner member are shaped A memory alloy, which deforms in the direction of the inner or outer member or other parts attached to the inner or outer member when the shape recovery temperature is exceeded, based on the deformation An anomaly is recognized.

  In this manner, the outer member has a plurality of rows of outer raceways integrally formed on the inner periphery, and the inner side has a plurality of rows of inner raceways opposed to the outer rows of double raceways on the outer periphery. An annular space formed between the outer member and the inner member, and a double row of rolling elements housed rollably between the respective rolling surfaces of the inner member and the outer member; And a seal for sealing the opening, wherein the part mounted on the outer member or the inner member is formed of a shape memory alloy, and the inner member is formed when the shape recovery temperature is exceeded. Or, it deforms in the direction of the outer member or in the direction of the other components attached to the inner member or the outer member, and an abnormality is recognized based on this deformation, so peeling and wear are promoted on each rolling surface, and the inside of the bearing When the temperature rises, for example, the deflector fixed to the inward member deforms and the inner circumferential surface of the outward member Contact, it is possible to inform the abnormality to the driver by generating a noise and vibration. As a result, it is possible to provide a bearing device for a wheel, in which an abnormality in the bearing portion is sensed at an early stage and the reliability is improved.

  Further, as in the invention according to claim 2, when the part formed of the shape memory alloy exceeds the shape recovery temperature, it is attached to the inward member or the outward member or the inward member or the outward member. It may be configured to be deformed in the direction of another part and to be in contact with the other part.

  Further, as in the invention described in claim 3, the component may be a component of a seal.

  Further, as in the invention according to claim 4, a deflector made of the shape memory alloy is press-fitted to the outer peripheral surface of the inward member, and the deflector is formed into an L shape in cross section, and the inward member is made of A cylindrical portion pressed into the outer peripheral surface and a rising plate extending radially outward from the cylindrical portion are provided, and the tip of the rising plate is opposed to the inner peripheral surface of the outer member with a slight clearance. If arranged, peeling and wear are promoted on each rolling surface, the temperature inside the bearing rises, and when the shape recovery temperature of the deflector is exceeded, the upright plate portion of the rotating side is deformed and the fixed side By contacting the inner circumferential surface of the outer member, noise and vibration can be generated to notify the driver of the abnormality.

  Further, as in the invention according to claim 5, the component of the seal formed of the shape memory alloy is deformed when the shape recovery temperature is exceeded, and the contact state of the seal changed along with the deformation is It may be detected from the resistance value.

  Further, as in the invention according to claim 6, a cylindrical fitting portion in which the seal is press-fitted to the inner periphery of the end portion of the outer member, and radially inward from the end portion of the fitting portion A cored bar having a U-shaped cross section having an extending inner diameter portion, and a wheel mounting flange integrally formed on the cored core by vulcanization bonding and extending radially outward and having an arc shape. When the core is a component of the seal according to claim 3 or 5, peeling and wear are promoted on each rolling surface to raise the temperature inside the bearing. When the shape recovery temperature of the cored bar is exceeded, for example, the inner diameter portion of the cored bar contacts the base by causing the end of the cored bar to face the base with a minute gap, generating noise and vibration. Can inform the driver of the abnormality.

  Further, as in the invention according to claim 7, if the seal member has an intermediate lip opposed to the base with a minute gap, peeling and wear are accelerated on each rolling surface. When the temperature inside the bearing rises, the core metal deforms beyond the shape recovery temperature, whereby the intermediate lip contacts the base, and the electric resistance value of the base changes. By detecting the change in the resistance value, the driver can be notified of an abnormality.

  Further, as in the invention according to claim 8, the seal is constituted by a pack seal consisting of an annular seal plate and a slinger which are formed to be L-shaped in cross section and opposed to each other, and the slinger is A cylindrical portion pressed into the outer peripheral surface of the inward member and a rising plate portion extending radially outward from the cylindrical portion, and a cylinder in which the seal plate is pressed into the inner periphery of the end portion of the outer member A cored bar comprising an annular fitting portion and an inner diameter portion extending radially inward from an end of the fitting portion, and integrally bonded to the cored bar by vulcanization adhesion, and the diameter from the inner diameter side of the cored bar The seal member according to claim 3 or 5, further comprising: a seal member having a side lip extending obliquely to the inner side in the direction outward and in sliding contact with the side surface of the standing plate portion of the slinger. For example, peeling and wear are promoted on each rolling surface to The temperature was raised, when exceeding the shape recovery temperature of the metal core, for example, the inner diameter portion of the core metal is brought into contact with the cylindrical portion of the slinger can inform the abnormality to the driver by generating a noise and vibration.

  Further, as in the invention according to claim 9, when the shape memory alloy is formed of a Ti-Ni-based alloy, the shape memory is hard to be broken and can exhibit stable properties.

  Further, as in the invention according to claim 10, if the shape recovery temperature of the shape memory alloy is set to 120 ° C., a seal formed of a synthetic rubber such as NBR or a thermoplastic synthetic resin such as PA 66 etc. Corresponding to the heat-resistant temperature of the cage formed from the above, and the deterioration of these parts can be prevented.

  In the wheel bearing device according to the present invention, an outer member having a double row of outer rolling surfaces integrally formed on the inner periphery, and a double row of inner rolling members on the outer periphery facing the double row of outer rolling surfaces An inner member having a surface, a double row of rolling elements rollably accommodated between rolling surfaces of the inner member and the outer member, the outer member and the inner member; And a seal for sealing the opening of the annular space formed between the parts, the part mounted on the outer member or the inner member being formed of a shape memory alloy, the part being When the shape recovery temperature is exceeded, it deforms in the direction of the inward member or outward member or the other part mounted on the inward member or outward member, and an abnormality is recognized based on this deformation. For example, when the temperature inside the bearing rises due to the exfoliation and wear on the running surface, it is fixed to the inner member Were deflector is in contact with the inner peripheral surface of the outer member is deformed, it is possible to inform the abnormality to the driver by generating a noise and vibration. As a result, it is possible to provide a bearing device for a wheel, in which an abnormality in the bearing portion is sensed at an early stage and the reliability is improved.

It is a longitudinal section showing one embodiment of a bearing device for wheels concerning the present invention. (A) is a principal part enlarged view which shows one seal part of FIG. 1, (b) is a principal part enlarged view which shows the state at the time of temperature rising of (a). (A) is a principal part enlarged view which shows the modification of the other seal | sticker part of FIG. 1, (b) is a principal part enlarged view which shows the state at the time of temperature rising of (a). (A) is a principal part enlarged view which shows the modification of the seal | sticker of FIG. 2, (b) is a principal part enlarged view which shows the state at the time of temperature rising of (a). (A) is a principal part enlarged view which shows the modification of the seal | sticker of FIG. 3, (b) is a principal part enlarged view which shows the state at the time of temperature rising of (a). (A) is a principal part enlarged view which shows the other modification of the seal | sticker of FIG. 2, (b) is a principal part enlarged view which shows the state at the time of temperature rising of (a). (A) is a principal part enlarged view which shows the modification of the seal | sticker of FIG. 5, (b) is a principal part enlarged view which shows the state at the time of temperature rising of (a). It is a principal part enlarged view which shows the abnormality detection part of the conventional bearing apparatus for wheels.

  An outer member integrally provided with a vehicle body mounting flange for being attached to a vehicle body on the outer periphery, and an outer member having a double row of outer raceways integrally formed on the inner periphery, and a wheel mounting flange for attaching a wheel to one end A hub ring integrally formed, having an inner race surface facing the outer race surface on one side of the multi-row outer race surface, and a small diameter step portion axially extending from the inner race surface, and the hub wheel An inner member comprising an inner ring press-fitted into the small diameter step portion of the inner race and having an inner race surface facing the other of the double row outer race surface on the outer periphery, and the inner member and the outer member Wheel having a plurality of rows of rolling elements rollably accommodated between the rolling surfaces of the wheels, and a seal for sealing the opening of the annular space formed between the outer member and the inner member Device, in which a deflector is press-fitted to the outer peripheral surface of the inner ring, the deflector A cylindrical portion which is L-shaped in cross section from a shape memory alloy made of a Ti-Ni-based alloy, and a standing plate portion extending radially outward from the cylindrical portion. The front end portion of the standing plate portion is disposed opposite to the inner peripheral surface of the outer member with a minute gap, and the deflector is set to be deformed toward the outer member when the shape recovery temperature is exceeded. It is done.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.
1 is a longitudinal sectional view showing an embodiment of a bearing device for a wheel according to the present invention, FIG. 2 (a) is an enlarged view of an essential part showing one seal portion of FIG. 1, FIG. 3 (a) is an enlarged view of the main part showing a modification of the other seal part of FIG. 1, FIG. 3 (b) is at the time of temperature rise of FIG. 4 (a) is an enlarged view of an essential part showing a modified example of the seal of FIG. 2, and FIG. 4 (b) is an enlarged view of an essential part showing a heated state of (a). 5 (a) is a main part enlarged view showing a modified example of the seal of FIG. 3, (b) is a main part enlarged view showing a state at the time of temperature rise of (a), FIG. 6 (a) is The principal part enlarged view which shows the other modification of the seal of FIG. 2, (b) is a principal part enlarged view which shows the state at the time of temperature rising of (a), FIG. 7 (a) is a deformation | transformation of the seal of FIG. The main part enlarged view which shows an example, (b) is a main part which shows the state at the time of temperature rising of (a) It is a large figure. In the following description, the side closer to the outer side of the vehicle in a state of being assembled to the vehicle is referred to as the outer side (left side in FIG. 1) and the side closer to the center as the inner side (right side in FIG. 1).

  The wheel bearing shown in FIG. 1 is referred to as the third generation on the drive wheel side, and includes double-row rolling elements (inward members 1 and outward members 10 and rolling members housed between both members 1 and 10) Balls 6 and 6 are provided. The inward member 1 includes a hub wheel 2 and an inner ring 3 press-fitted and fixed to the hub wheel 2.

  The hub wheel 2 integrally has a wheel mounting flange 4 for attaching 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 are planted. In addition, one (outer side) inner raceway surface 2a and a cylindrical small diameter step 2b axially extending from the inner raceway surface 2a are formed on the outer periphery of the hub wheel 2, and torque transmission is performed on the inner periphery Serrations (or splines) 2c are formed. The inner race 3 has the other (inner side) inner raceway 3a formed on the outer periphery, and is press-fitted to the small diameter step 2b of the hub wheel 2 through a predetermined shim.

  The hub wheel 2 is formed of medium-high carbon steel containing 0.40 to 0.80% by weight of carbon such as S53C, and includes the base 11 on the inner side of the wheel mounting flange 4 which is a seal land portion of the seal 8 described later The surface hardness is hardened 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 2b. As a result, not only the wear resistance of the base portion 11 of the wheel mounting flange 4 is improved, but also mechanical strength sufficient for rotational bending load applied to the wheel mounting flange 4 is obtained. Strength and durability improve. On the other hand, the inner ring 3 and the rolling elements 6 are made of high carbon chromium bearing steel such as SUJ 2 and hardened to a core of 58 to 64 HRC and rolling elements 6 to 62 to 67 HRC by core quenching.

  The outer member 10 integrally has a vehicle body mounting flange 10b on the outer periphery for attachment to a vehicle body (not shown), and a double row facing the inner raceway surfaces 2a and 3a of the inner member 1 on the inner periphery. The outer raceways 10a, 10a are integrally formed. Similar to the hub wheel 2, the outer member 10 is formed of medium-high carbon steel containing 0.40 to 0.80% by weight of carbon such as S53C, and at least the double row of outer raceway surfaces 10a and 10a are induction hardened. The surface hardness is hardened in the range of 58 to 64 HRC. Then, double rows of rolling elements 6, 6 are accommodated between the respective rolling contact surfaces 10a, 2a and 10a, 3a, and these double rows of rolling elements 6, 6 are rotatably held by the cages 7, 7 ing. Further, seals 8 and 9 are attached to the opening of the annular space formed between the outer member 10 and the inner member 1, and leakage of the lubricating grease enclosed in the bearing, rain water and dust from the outside Etc. are prevented from entering the inside of the bearing.

  The cage 7 is formed by injection molding of a thermoplastic synthetic resin such as PA (polyamide) 66 or the like and containing an appropriate amount of reinforcing material such as GF (glass fiber), and formed into a concave spherical surface. A pocket is provided, and the opening is elastically deformed so that the rolling element 6 is mounted, and it is configured as a so-called snap-on type which is held via a predetermined pocket clearance.

  In addition to PA 66 described above, thermoplastic resin or polyphenylene sulfide (so-called engineering plastic such as PPA (polyphthalamide), PBT (polybutylene terephthalate), etc. is also used as the material of the cage 7). PPS), polyetheretherketone (PEEK), polyamide imide (PAI), etc., so-called super engineering plastic called thermoplastic synthetic resin, or phenol resin (PF), epoxy resin (EP), polyimide resin (PI) And the like may be those containing a reinforcing fiber such as CF (carbon fiber) on the basis of or the like.

  In addition, although the bearing apparatus for wheels comprised with the double row angular contact ball bearing which used the ball | bowl for the rolling element 6 was illustrated here, the double row conical roller bearing which used not only this but the rolling element 6 conical roller It may be composed of Further, although the third generation structure in which the inner raceway surface 2a is directly formed on the outer periphery of the hub wheel 2 is illustrated here, 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.

  In the present embodiment, the seal 8 on the outer side is constituted by an integral sealing device comprising a core 12 and a seal member 13 integrally bonded to the core 12 by vulcanization. The core metal 12 is a ferritic stainless steel plate (SUS430 series etc. according to JIS standard) or an austenitic stainless steel plate (SUS304 series etc. according to JIS standard), or a cold-rolled steel plate subjected to rust proofing treatment (SPCC series etc. according to JIS standard) And a cylindrical fitting portion 12a having a substantially L-shaped cross section and pressed into the outer periphery of the outer member 10 through a predetermined shime, and the fitting portion 12a And an inner diameter 12b extending radially inward from the end of the Then, the seal member 13 is wound around and joined so as to cover the outer surface extending from the inner diameter portion 12b to the fitting portion 12a, forming a so-called half metal structure. Thereby, the airtightness of fitting part 12a can be improved and the inside of a bearing can be protected.

  On the other hand, the seal member 13 is made of synthetic rubber such as NBR (acrylonitrile-butadiene rubber), extends in a radially outward direction, extends in an inclined manner, and is fixed to the base 11 of the wheel mounting flange 4 formed in an arc shape. Side lip 13a and dust lip 13b which are in sliding contact with each other, and grease lip 13c which extends in an inclined manner to the inner side of the bearing and which is in sliding contact with the base 11 via a predetermined radial direction. . In addition to the exemplified NBR, the material of the sealing member 13 is, for example, HNBR (hydrogenated acrylonitrile butadiene rubber), EPDM (ethylene propylene rubber), etc., which are excellent in heat resistance, heat resistance and chemical resistance. And ACM (polyacrylic rubber), FKM (fluorinated rubber), silicone rubber, etc.

  Further, as shown on an enlarged scale in FIG. 2A, the inner side seal 9 is a pack seal comprising an annular seal plate 14 having a substantially L-shaped cross section and disposed opposite to each other and a slinger 15 as shown in FIG. It consists of

  The annular seal plate 14 is composed of a cored bar 16 pressed into the inner periphery of the inner side end portion of the outer member 10 and a seal member 17 integrally vulcanized and bonded to the cored bar 16. The metal core 16 is formed of a ferritic stainless steel plate, an austenitic stainless steel plate, or a cold-rolled cold-rolled steel plate subjected to rust proofing to have a substantially L-shaped cross section by press processing. It has a cylindrical fitting portion 16a press-fit through a predetermined space, and an inner diameter portion 16b extending radially inward from the end of the fitting portion 16a. The end of the fitting portion 16a of the cored bar 16 is formed thin, and the seal member 17 wraps around and is joined so as to cover the end, forming a half metal structure.

  On the other hand, the slinger 15 is formed of a ferritic stainless steel plate or a cold-rolled cold-rolled steel plate subjected to rust proofing to form a substantially L-shaped cross section by press working, and a cylindrical portion 15a press-fit onto the outer peripheral surface of the inner ring 3 An 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 faces the sealing member 17 with a slight radial clearance, thereby constituting a labyrinth seal 18. And the magnetic encoder 19 is integrally joined by vulcanization adhesion etc. to the side of the inner side of this standing board part 15b. In the magnetic encoder 19, magnetic powder such as ferrite is mixed in an elastomer such as rubber, and the magnetic poles N and S are alternately magnetized in the circumferential direction to constitute a rotary encoder for detecting the rotational speed of the wheel.

  The seal member 17 is made of synthetic rubber such as NBR, and extends from the end of the inner diameter portion 16b of the core metal 16 to the radially outer inner side at an angle, and is predetermined on the side of the outer side of the upright plate 15b of the slinger 15. In the cylindrical portion 15a of the slinger 15, the pair of side lips 17a and 17b in sliding contact with each other through the axial direction of the shaft and the radially inward outer side of the pair of side lips 17a and 17b are inclined. It has a grease lip 17c which is in sliding contact via a predetermined radial direction. In addition to the illustrated NBR, examples of the material of the sealing member 15 include HNBR, EPDM, ACM, FKM, silicone rubber, and the like.

  Here, the deflector 20 on the outer peripheral surface of the inner ring 3 is press-fitted. The deflector 20 is disposed in the vicinity of the bearing inner side of the seal 9 on the inner side described above, and is formed into a substantially L-shaped cross section by pressing from a shape memory alloy such as a Ti-Ni alloy and It consists of a cylindrical part 20a press-fit to the outer peripheral surface of 3 and a standing plate part 20b extending radially outward from the cylindrical part 20a. The tip of the upright plate portion 20b is opposed to the inner circumferential surface 10c of the outer member 10 with a small axial clearance δ.

  This Ti-Ni-based shape memory alloy is an intermetallic compound exhibiting crystals arranged regularly while the atoms of titanium and nickel have a ratio of about 1: 1, and the thermoelasticity that brings about the shape memory effect The key to whether a martensitic transformation occurs is responsible for this regular structure. Among the intermetallic compounds which are often brittle and difficult to handle, this Ti--Ni-based shape memory alloy is characterized by being hard to break and exhibiting a stable property. In addition to the above, for example, a Ti-Ni-Co alloy, a Ti-Ni-Cu alloy, a Cu-Zn-Al alloy, and an Fe-Mn-Si alloy may be exemplified as the shape memory alloy. it can.

  In the present embodiment, as shown in FIG. 2B when peeling and wear are promoted on each rolling surface and the temperature inside the bearing rises and the shape recovery temperature of the deflector 20 (here, 120 ° C.) is exceeded. The upright plate portion 20b of the deflector 20 on the rotating side recovers (deforms) to the outer side (inside of the bearing) and contacts the inner circumferential surface 10c of the outer member 10 on the stationary side to generate noise and vibration. Can inform the driver of the abnormality. As a result, it is possible to detect the abnormality of the bearing in advance and at an early stage, for example, to avoid the occurrence of the lock or the like of the inner ring 3 on the rotating side, and to provide the wheel bearing device with improved reliability.

  Here, the deflector 20 made of a shape memory alloy is mounted on the inner ring 3 serving as the rotation side member, and the deflector 20 recovers its shape by raising the temperature of the bearing and contacts the outer member 10 serving as the stationary side member. Although such a configuration is illustrated, the configuration is not limited to this, and for example, a deflector may be mounted on the inner peripheral surface of the outer member and brought into contact with the outer peripheral surface of the inner ring, although not shown.

  Here, the reason for setting the shape recovery temperature of the deflector 20 to 120 ° C. is due to the deterioration of the seal 9 and the cage 7. That is, since the seal 9 is formed of synthetic rubber such as NBR, the heat resistant temperature is around 120 ° C. Therefore, if the heat resistance temperature is exceeded, the sealability may be reduced due to the deformation, deterioration, etc. of the rubber. On the other hand, since the cage 7 is formed of a thermoplastic synthetic resin such as PA 66, the heat resistant temperature is around 120 ° C. Therefore, if the heat-resistant temperature is exceeded, the holding property of the rolling element 6 may be reduced due to the deformation, deterioration, etc. of the cage 7.

  The minute axial clearance δ between the upright plate portion 20 b of the deflector 20 and the inner circumferential surface 10 c of the outer member 10 is set larger than the sum of axial deflection of the outer member 10 and the inner ring 3. Specifically, it is set in the range of 0.02 to 1.0 mm. If this axial clearance δ is less than 0.02 mm, the inner circumferential surface 10c of the deflector 20 outward member 10 may come into contact with the vehicle even if the bearing portion is normal, and 1.0 mm If the value is set larger than the above, it is not preferable because there is a risk that the inner circumferential surface 10c of the outer member 10 will not contact even if it recovers beyond the shape recovery temperature of the deflector 20.

  FIG. 3A shows a modification of the seal 8 on the outer side described above. Note that this embodiment is basically the same as the above-described embodiment (FIG. 1) except for the configuration of the core metal 12 and basically the same parts as the above-described embodiment or parts or parts having similar functions. Are given the same reference numerals and the detailed description is omitted.

  The seal 21 is constituted by an integral sealing device including a core metal 22 and a seal member 13 integrally bonded to the core metal 22 by vulcanization. The cored bar 22 is formed of a shape memory alloy such as a Ti-Ni-based alloy by press working, and is a cylindrical fitting portion which is press-fitted into the outer periphery of the outer member 10 through the predetermined inner circumference. 22a and an inner diameter portion 22b extending radially inward from an end of the fitting portion 22a. Then, the seal member 13 is wound around and joined so as to cover the outer surface extending from the inner diameter portion 22b to the fitting portion 22a, and forms a half metal structure.

  In the present embodiment, the tip of the inner diameter portion 22b of the core metal 22 is opposed to the base 11 with a slight radial clearance, and peeling and wear are promoted on each rolling surface, and the temperature inside the bearing is raised. When the shape recovery temperature of the core metal 22 is exceeded, as shown in FIG. 3 (b), the inner diameter portion 22b of the core metal 22 of the seal 21 on the fixed side is radially inwardly contracted and the hub on the rotation side By touching the base 11 of the wheel 2, abnormal noise or vibration can be generated to notify the driver of an abnormality. As a result, it is possible to detect an abnormality in the bearing in advance and at an early stage, for example, to avoid the occurrence of a lock or the like of the rotating hub wheel 2 and to improve the reliability.

  FIG. 4A shows a modification of the inner seal 9 described above. Note that this embodiment is basically the same as the above-described embodiment (FIG. 2) except for the configuration of the core metal 16 of the seal 9, and the same components as the above-described embodiment and parts having the same parts or similar functions. The same reference numerals are given to the parts and parts and the detailed description is omitted.

  The seal 23 is a pack seal comprising an annular seal plate 24 and a slinger 15 which are formed in a substantially L-shaped cross section and are disposed to face each other. The annular seal plate 24 is composed of a core metal 25 pressed into the inner periphery of the inner side end portion of the outer member 10 and a seal member 17 integrally vulcanized and bonded to the core metal 25. The metal core 25 is formed into a substantially L shape by press working from a shape memory alloy such as a Ti-Ni-based alloy, and is cylindrically fitted into the end inner periphery of the outer member 10 through a predetermined mesh. It has an engaging portion 25a and an inner diameter portion 25b extending radially inward from the end of the fitting portion 25a. Then, a tip portion 25c which is inclined on the outer side (inside of the bearing) is formed in the inner diameter portion 25b, and is disposed opposite to the cylindrical portion 15a of the slinger 15 with a minute gap.

  In this embodiment, peeling and wear are promoted on each rolling surface to raise the temperature inside the bearing, and when the shape recovery temperature of the core metal 25 is exceeded, it becomes the fixed side as shown in FIG. The inclination of the tip 25c of the core metal 25 of the seal plate 24 becomes gentle and contacts the cylindrical portion 15a of the slinger 15 on the rotating side, generating noise and vibration to notify the driver of an abnormality. As a result, it is possible to detect an abnormality in the bearing in advance and at an early stage, for example, to avoid the occurrence of a lock or the like of the inner ring 3 on the rotating side, and to improve the reliability.

  FIG. 5A shows a modification of the seal 21 on the outer side described above. This embodiment is basically the same as the above-described embodiment (FIG. 3) except for the configuration of the cored bar 22, and the same components as the above-described embodiment or parts or components having similar functions. Are given the same reference numerals and the detailed description is omitted.

  The seal 26 is constituted by an integral sealing device comprising a core metal 27 and a seal member 13 integrally bonded to the core metal 27 by vulcanization. The metal core 27 is formed of a shape memory alloy such as a Ti-Ni alloy by press working to have a substantially U-shaped cross section, and is press-fitted into the outer periphery of the outer member 10 through a predetermined space. A cylindrical fitting portion 27a and an inner diameter portion 27b extending radially inward from an end of the fitting portion 27a.

  In the present embodiment, when a minute current is supplied to the base 11 of the hub wheel 2 in advance, peeling and wear are promoted on each rolling surface, the temperature inside the bearing rises, and the shape recovery temperature of the core 27 is exceeded. As shown in FIG. 5 (b), the inner diameter 27b of the core metal 27 of the seal 26 on the stationary side is reduced radially inward, and the contact surface pressure of each lip of the seal member 13 is increased. The electrical resistance value of the sliding portion, here, the base 11 on the inner side of the wheel mounting flange 4 which is the seal land portion of the seal 26 changes, and the driver is notified of the abnormality by detecting the change in the resistance value. Can. As a result, it is possible to detect an abnormality in the bearing in advance and at an early stage, for example, to avoid the occurrence of a lock or the like of the rotating hub wheel 2 and to improve the reliability.

  FIG. 6A shows a modification of the seal 23 on the inner side described above. Note that this embodiment is basically the same as the above-described embodiment (FIG. 4) except for the configuration of the core metal 25 and basically the same components as the above-described embodiment or parts or components having similar functions. Are given the same reference numerals and the detailed description is omitted.

  The seal 28 is a pack seal formed of an annular seal plate 29 and a slinger 15 which are formed in a substantially L-shaped cross section and are disposed to face each other. The annular seal plate 29 is composed of a core 30 pressed into the inner periphery of the end portion of the outer member 10 on the inner side and a seal member 17 integrally bonded to the core 30 by vulcanization. The metal core 30 is formed into a substantially L shape by press working from a shape memory alloy such as a Ti-Ni-based alloy, and is cylindrically fitted into the end inner periphery of the outer member 10 through a predetermined mesh. It has an engaging portion 30a and an inner diameter portion 30b extending radially inward from the end of the fitting portion 30a.

  In this embodiment, when a minute current is supplied to the slinger 15 in advance, peeling and wear are promoted on each of the rolling contact surfaces to raise the temperature inside the bearing and the shape recovery temperature of the core 30 is exceeded. As shown in b), the tip end of the core 30 of the seal plate 29 on the fixed side is inclined to the inner side, and the contact surface pressure of the pair of side lips 17a and 17b of the seal member 17 is increased. In this case, the electrical resistance value of the slinger 15 changes, and the driver can be notified of an abnormality by detecting the change in the resistance value. As a result, it is possible to detect an abnormality in the bearing in advance and at an early stage, for example, to avoid the occurrence of a lock or the like of the inner ring 3 on the rotating side, and to improve the reliability.

  FIG. 7A shows a modification of the seal 26 on the outer side described above. This embodiment is basically the same as the above-described embodiment (FIG. 5) except for the configuration of the seal member 13, and the same parts as the above-described embodiment or parts or parts having similar functions. Are given the same reference numerals and the detailed description is omitted.

  The seal 31 is constituted by an integral sealing device including a core metal 27 and a seal member 32 integrally bonded to the core metal 27 by vulcanization. The seal member 32 is made of a synthetic rubber such as NBR, and is inclined radially outward, and is in sliding contact with the base 11 of the wheel mounting flange 4 formed in an arc shape through a predetermined axial direction. The lip 13a and the dust lip 13b and the grease lip 13c that extends inclining toward the bearing inward and is in sliding contact with the base 11 via a predetermined radial direction are integrally provided, and the dust lip 13b and the grease lip 13c An intermediate lip 32a is formed between the two. The intermediate lip 32a is opposed to the base 11 with a minute gap. In addition to the illustrated NBR, examples of the material of the sealing member 32 include HNBR and EPDM having excellent heat resistance, and ACM, FKM, silicone rubber and the like having excellent heat resistance and chemical resistance. can do.

  In the present embodiment, when a minute current is supplied to the base 11 of the hub wheel 2 in advance, peeling and wear are promoted on each rolling surface, the temperature inside the bearing rises, and the shape recovery temperature of the core 27 is exceeded. As shown in FIG. 7 (b), the inner diameter 27b of the core metal 27 of the seal 31 on the fixed side is reduced radially inward to form the side lip 13a, the dust lip 13b and the grease lip 13c of the seal member 32. The intermediate lip 32 a contacts the base 11 as the contact pressure of the As a result, the electrical resistance value of the base 11 which is the seal land portion of the seal 31 changes, and the driver can be notified of an abnormality by detecting the change in the resistance value. Thereby, the abnormality of the bearing portion can be sensed in advance and at an early stage.

  Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments in any way, and is merely an example, and various modifications can be made without departing from the scope of the present invention. The scope of the present invention is, of course, indicated by the description of the claims, and the meaning of equivalents described in the claims, and all modifications within the scope. Including.

  The bearing apparatus for a wheel according to the present invention can be applied to a bearing apparatus for a wheel of a sealed first to fourth generation structure in which a seal is attached at both ends.

DESCRIPTION OF SYMBOLS 1 Inner member 2 Hub ring 2a, 3a Inner raceway surface 2b Small diameter step 2c Serration 3 Inner ring 4 Wheel mounting flange 5 Hub bolt 6 Rolling element 7 Retainer 8, 21, 26, 31 Outer side seal 9, 23, 28 Inner side seal 10 Outer member 10a Outer raceway surface 10b Body mounting flange 10c Inner peripheral surface 11 of outer member 11 Base of inner side of wheel mounting flange 12, 16, 22, 25, 27, 30 Core metal 12a, 16a , 22a, 25a, 27a, 30a fitting portions 12b, 16b, 22b, 25b, 27b, 30b inner diameter portions 13, 17, 32 sealing members 13a, 17a, 17b side lip 13b dust lip 13c, 17c grease lip 14, 24; 29 seal plate 15 slinger 15a, 20a cylindrical portion 15b, 20b vertical plate portion 18 labyrinth seal 19 Air encoder 20 Deflector 25c Tip portion 32a Intermediate lip 50 Outer member 50a Outer raceway surface 51 Inner ring 51a Inner raceway surface 52 Seal 53 Slinger 53a Cylindrical portion 53b Standing plate portion 54 Seal plate 55 Core metal 55a Fitting portion 55b Inner diameter portion 56 seal member 56a side lip 56c dust lip 56b grease lip 57 magnetic encoder 58 annular convex portion 59 detection surface 60 abnormality detection portion δ axial clearance e radial clearance of labyrinth seal ε radial clearance of abnormality detection portion

Claims (8)

An outer member in which a plurality of rows of outer race surfaces are integrally formed on the inner periphery,
An inner member having a plurality of rows of inner rolling surfaces opposed to the plurality of rows of outer rolling surfaces formed on an outer periphery thereof;
Double rows of rolling elements rollably accommodated between rolling surfaces of the inward member and the outward member;
And a seal for sealing the opening of the annular space formed between the outer member and the inner member.
The part mounted on the bearing inner side of the outer member or the inner member is formed of a shape memory alloy, and when the part exceeds the shape recovery temperature, the inner member or the outer member or the inner member or the outer member A wheel bearing device characterized in that it deforms in the direction of another component mounted on a square member, and based on this deformation, abnormality is recognized by abnormal noise or vibration due to deformation of the shape memory alloy due to temperature rise. An outer member in which a plurality of rows of outer race surfaces are integrally formed on the inner periphery,
An inner member having a plurality of rows of inner rolling surfaces opposed to the plurality of rows of outer rolling surfaces formed on an outer periphery thereof;
Double rows of rolling elements rollably accommodated between rolling surfaces of the inward member and the outward member;
And a seal for sealing the opening of the annular space formed between the outer member and the inner member.
Deflector consisting of shape memory alloy on the outer peripheral surface of the inner member is press-fitted, along with the deflector is formed in an L-shaped cross-section, a cylindrical portion which is press-fitted to the outer peripheral surface of the inner member, the cylindrical portion And a distal end portion of the upright plate portion is disposed opposite to the inner peripheral surface of the outer member with a slight clearance, and the deflector exceeds the shape recovery temperature The wheel bearing device according to claim 1, wherein the wheel bearing device is deformed in a direction in which it contacts the outer member, and an abnormality is recognized based on the deformation. An outer member in which a plurality of rows of outer race surfaces are integrally formed on the inner periphery,
An inner member having a plurality of rows of inner rolling surfaces opposed to the plurality of rows of outer rolling surfaces formed on an outer periphery thereof;
Double rows of rolling elements rollably accommodated between rolling surfaces of the inward member and the outward member;
And a seal for sealing the opening of the annular space formed between the outer member and the inner member.
The seal is formed in a U-shaped cross section having a cylindrical fitting portion pressed into the end inner periphery of the outer member, and an inner diameter portion extending radially inward from the end portion of the fitting portion. The core, and a side lip integrally bonded by vulcanization to the core, extending radially outward, and slidingly contacting the base of the arc-shaped wheel mounting flange; At least the inner diameter portion of gold is formed of a shape memory alloy, and when the inner diameter portion exceeds the shape recovery temperature, it deforms in a direction to contact the base of the wheel mounting flange, and an abnormality is recognized based on this deformation. A bearing device for wheels characterized by An outer member in which a plurality of rows of outer race surfaces are integrally formed on the inner periphery,
An inner member having a plurality of rows of inner rolling surfaces opposed to the plurality of rows of outer rolling surfaces formed on an outer periphery thereof;
Double rows of rolling elements rollably accommodated between rolling surfaces of the inward member and the outward member;
And a seal for sealing the opening of the annular space formed between the outer member and the inner member.
The seal is a pack seal having an L-shaped cross section and an annular seal plate and a slinger disposed opposite to each other, and the cylindrical portion is pressed into the outer peripheral surface of the inner member by the slinger. A cylindrical fitting portion formed of a standing plate portion extending radially outward from the cylindrical portion and the seal plate being press-fitted into the end inner periphery of the outer member; and an end of the fitting portion A core metal comprising an inner diameter portion extending radially inward from the portion, and a side lip integrally joined to the core metal by vulcanization adhesion and extending from the inner diameter side of the core metal to the inner side radially outward The core metal is formed of a shape memory alloy and is deformed in a direction to contact the cylindrical portion of the slinger when the shape recovery temperature is exceeded, and an abnormality is recognized based on the deformation. Bearing device for wheels.   The wheel bearing device according to claim 3, wherein an electric current is flowing to a base on which the side lip slidably contacts, and a contact state of the seal which is changed according to a deformation of a core of the seal is detected from a resistance value of the electric current.   The side lip is in sliding contact with the standing plate portion of the slinger, and an electric current flows through the slinger, and the contact state of the seal, which changes with the deformation of the seal metal core, is detected from the resistance value of the electric current. The bearing apparatus for wheels as described in 4. The seal is a wheel bearing apparatus of claim 3 which has an intermediate lip opposed through a small clearance relative to the base.   The wheel bearing device according to any one of claims 1 to 7, wherein the shape memory alloy is formed of a Ti-Ni based alloy.

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