JP2018048682A - Bearing device for wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device for a wheel which can eliminate an anxiety that the sealing performance of a seal member is lowered, can suppress the deterioration of the roundness of an outside rolling face, and also can prevent the lowering of a bearing life by preventing the damage of rolling bodies and the outside rolling face.SOLUTION: In a bearing device 1 for a wheel, a substantially-disc circular drain conduit 2g with a rotating axis of an inner member 3 as a center is formed at an external periphery of an outer side of an outer member 2, a substantially-disc circular heavy thickness part 2h with a rotating axis L of the inner member 3 as a center is formed at an external periphery of an outer side rather than the drain conduit 2g of the outer member 2, the heavy thickness part 2h has a region being an oblique side 2j at a cross section in an axial direction, and the oblique side 2j is inclined so as to descend to an inner side from the outer side.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a wheel bearing device.

  2. Description of the Related Art Conventionally, a wheel bearing device that rotatably supports a wheel in a suspension device such as an automobile is known. In the wheel bearing device, an outer member is fixed to a knuckle constituting the suspension device. In the wheel bearing device, an inner member is disposed inside the outer member, and a rolling element is interposed between the outer member and the inner member. In this way, the wheel bearing device constitutes a rolling bearing structure, and the wheel attached to the inner member is rotatable.

  By the way, in such a wheel bearing device, when muddy water or the like enters the annular space formed between the outer member and the inner member, the rolling element and its rolling surface are damaged, and the bearing life is shortened. Further, even if the grease sealed in the annular space leaks, the rolling elements and their rolling surfaces are damaged, and the bearing life is shortened. For this reason, the wheel bearing device includes a seal member that seals the annular space in order to prevent intrusion of muddy water and the like and to prevent leakage of grease. For example, it is as described in Patent Document 1 and Patent Document 2.

  The wheel bearing device described in Patent Document 1 includes an outer member, an inner member, a rolling element interposed between the outer member and the inner member, and between the outer member and the inner member. And a sealing member that seals the formed annular space. However, in such a wheel bearing device, when the muddy water reaches the seal member through the outer member (see arrow F shown in FIG. 11A), the seal member is damaged by biting in the foreign matter contained in the muddy water. There was a concern of wear and tear. That is, there is a problem that the sealing performance of the sealing member is lowered.

  Therefore, the wheel bearing device described in Patent Document 2 includes a weir member that is fitted on the outer member so as to prevent muddy water from reaching the seal member along the outer member. However, in such a wheel bearing device, there is a case where the muddy water gets over the weir member and reaches the seal member (see arrow F shown in FIG. 11B), and the seal member may be damaged or worn. was there. That is, there is a problem that the sealing performance of the sealing member is lowered.

  In addition, when the vehicle body is turning, a large load is applied to the wheels of the vehicle body on the outer side in the turning direction (the left wheel for a right turn and the right wheel for a left turn). Then, a large load is also applied to the wheel bearing device that supports the wheel on the outer side in the turning direction. Further, the outer member constituting the wheel bearing device must be thin on the outer side due to the shape of the forging die (draft angle), and further, a diameter-enlarged portion is formed at the outer side end. . For this reason, the rigidity of the outer member is lower on the outer side than on the inner side. Therefore, when a large load is applied to the wheel bearing device, the outer opening end of the outer member is deformed into a substantially elliptical shape, and the roundness of the rolling surface (outer rolling surface) is deteriorated. there were.

JP 2014-219100 A JP 2011-7272 A

  An object of this invention is to provide the wheel bearing apparatus which can prevent the problem that the sealing performance of a sealing member falls and can suppress deterioration of the roundness of an outer rolling surface. Eventually, an object of the present invention is to provide a wheel bearing device capable of preventing the rolling element and its rolling contact surface (outer rolling contact surface) from being damaged and preventing the bearing life from being reduced.

The first invention is
An outer member having a double row outer raceway formed on the inner periphery;
A hub wheel formed with a small-diameter step portion extending in the axial direction, and at least one inner ring press-fitted into the small-diameter step portion of the hub wheel, and a double-row An inner member formed with an inner rolling surface;
In a wheel bearing device comprising: a double row rolling element interposed between the rolling surfaces of the outer member and the inner member so as to freely roll.
While providing a substantially annular drainage groove around the rotation axis of the inner member on the outer periphery of the outer side of the outer member,
A substantially annular thick portion centering on the rotation axis of the inner member is provided on the outer periphery of the outer member on the outer side of the drainage groove,
The thick portion has a portion that becomes a hypotenuse in an axial section thereof, and the hypotenuse is inclined so as to descend from the outer side to the inner side.

2nd invention is the wheel bearing apparatus which concerns on 1st invention,
The thick part has an inclination of the hypotenuse with respect to the rotation axis of the inner member of 5 ° or more.

A third invention is the wheel bearing device according to the first or second invention,
The thick part has a height from the lowest part of the drainage groove to the upper side of 3 mm or more.

The fourth invention is the wheel bearing device according to any one of the first to third inventions,
The thick portion has a thickness from the outer rolling surface formed on the outer side of the outer member to the outer periphery of 6.5 mm or more.

A fifth invention is the wheel bearing device according to any one of the first to fourth inventions,
A substantially annular thin portion centering on the rotation axis of the inner member is provided on the outer periphery on the inner side of the drainage groove of the outer member,
The thin portion has a depth of 1 mm or more from the outer periphery of the outer rolling surface formed on the outer side of the outer member.

A sixth invention is the wheel bearing device according to any one of the first to fifth inventions,
The thick portion is provided in such a manner that the upper side extends in the axial direction beyond the deepest groove bottom portion of the outer rolling surface formed on the outer side from the outer side end of the outer member. .

  As effects of the present invention, the following effects can be obtained.

  The wheel bearing device according to the present invention is provided with a substantially annular drainage groove centered on the rotation shaft of the inner member on the outer periphery of the outer member on the outer side, and on the outer side of the drainage groove of the outer member. A substantially annular thick portion centering on the rotation axis of the inner member is provided on the outer periphery of the inner member. And the thick part has the site | part used as a hypotenuse in the axial direction cross section, and it inclines so that a hypotenuse may fall from an outer side to an inner side. According to such a wheel bearing device, since the thick portion blocks the muddy water and guides it to the drainage groove, the muddy water is prevented from reaching the seal member through the outer member, and the sealing performance of the seal member is lowered. This can eliminate the concern. Further, since the thick part is provided on the outer periphery of the outer member, the amount of deformation of the outer opening end of the outer member is reduced, and the roundness of the outer rolling surface is prevented from deteriorating. it can. As a result, it is possible to prevent the rolling element and its outer rolling surface from being damaged and prevent the bearing life from decreasing.

  In the wheel bearing device according to the present invention, the thick portion has an inclination of the hypotenuse with respect to the rotation axis of the inner member of 5 ° or more. According to such a wheel bearing device, it is difficult for the muddy water to get over the thick portion, so that muddy water can be prevented from reaching the seal member through the outer member, and the concern that the sealing performance of the seal member is reduced can be eliminated. .

  In the wheel bearing device according to the present invention, the thickness of the thick part from the lowest part of the drainage groove to the upper side is 3 mm or more. According to such a wheel bearing device, it is difficult for the muddy water to get over the thick portion, so that muddy water can be prevented from reaching the seal member through the outer member, and the concern that the sealing performance of the seal member is reduced can be eliminated. .

  In the wheel bearing device according to the present invention, the thick portion has an outer rolling surface formed on the outer side of the outer member and a thickness up to the outer periphery of 6.5 mm or more. According to such a wheel bearing device, since the rigidity of the outer rolling surface formed on the outer side of the outer member is improved, it is possible to prevent the roundness of the outer rolling surface from deteriorating.

  In the wheel bearing device according to the present invention, the thin portion has a depth of 1 mm or more from the outer periphery of the outer rolling surface formed on the outer side of the outer member. According to such a wheel bearing device, it is possible to minimize the increase in weight due to the provision of the thick portion while ensuring the rigidity of the outer member.

  In the wheel bearing device according to the present invention, the thick portion is provided in a range in which the upper side exceeds the groove bottom deepest portion of the outer rolling surface formed on the outer side from the outer side end portion of the outer member in the axial direction. ing. According to such a wheel bearing device, the rigidity from the outer side end portion of the outer member to the outer rolling surface formed on the outer side is improved, so that the roundness of the outer rolling surface is prevented from deteriorating. be able to.

The perspective view which shows the whole structure of the wheel bearing apparatus. Sectional drawing which shows the whole structure of the wheel bearing apparatus. The expanded sectional view which shows the partial structure of the wheel bearing apparatus. The expanded sectional view which shows the partial structure of the wheel bearing apparatus. The expanded sectional view which shows the principal part structure of the wheel bearing apparatus which is 1st embodiment. The figure which shows the replacement | exchange operation | work of a hub bolt. The figure which shows the influence which an inclination angle exerts on muddy water resistance. The figure which shows the influence which a height dimension has on muddy water performance. The expanded sectional view which shows the principal part structure of the bearing apparatus for wheels which is 2nd embodiment. The expanded sectional view which shows the principal part structure of the bearing apparatus for wheels which is 3rd embodiment. The expanded sectional view which shows the partial structure of the conventional wheel bearing apparatus.

  Below, the wheel bearing apparatus 1 which concerns on this invention is demonstrated using FIGS. 1-4. 2 is a cross-sectional view taken along the line AA in FIG. 3 and 4 are enlarged views of a partial region in FIG.

  The wheel bearing device 1 supports a wheel rotatably in a suspension device such as an automobile. The wheel bearing device 1 includes an outer member 2, an inner member 3 (hub wheel 4 and inner ring 5), a rolling element 6, a seal member 7 (hereinafter referred to as “inner side seal member 7”), a seal Member 10 (hereinafter referred to as “outer side sealing member 10”). Here, the inner side represents the vehicle body side of the wheel bearing device 1 when attached to the vehicle body, and the outer side represents the wheel side of the wheel bearing device 1 when attached to the vehicle body.

  The outer member 2 constitutes the outer ring portion of the rolling bearing structure. The outer member 2 is made of a medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C formed in a substantially cylindrical shape. An enlarged diameter portion 2 a is formed at the inner side end of the outer member 2. Further, an enlarged diameter portion 2 b is formed at the outer side end portion of the outer member 2. Furthermore, between the enlarged diameter portion 2a and the enlarged diameter portion 2b, an outer rolling surface 2c and an outer rolling surface 2d are formed in an annular shape so as to be parallel to each other. In addition, the outer rolling surface 2c and the outer rolling surface 2d are subjected to induction hardening and cured so that the surface hardness is in the range of 58 to 64 HRC. A knuckle mounting flange 2 e is integrally formed on the outer periphery of the outer member 2. The knuckle mounting flange 2e is provided with tapped holes 2f in a circumferentially equidistant arrangement on a concentric circle centering on the rotation axis L of the inner member 3 (hub wheel 4 and inner ring 5).

  The inner member 3 constitutes an inner ring portion of the rolling bearing structure. The inner member 3 includes a hub ring 4 and an inner ring 5.

  The hub wheel 4 is made of medium-high carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C formed in a substantially cylindrical shape. A small-diameter step portion 4 a is formed at the inner end of the hub wheel 4. The small-diameter step portion 4a is formed with a caulking portion 4b that fixes the axial position of the inner ring 5 by bending the end portion radially outward. An opening 4 c is formed at the outer end of the hub wheel 4. Furthermore, an annular inner rolling surface 4 d is formed on the outer periphery of the hub wheel 4. The inner rolling surface 4 d faces the outer rolling surface 2 d of the outer member 2. The hub wheel 4 is induction hardened from the small-diameter step portion 4a to the seal land portion (consisting of a shaft surface portion 4e, a curved surface portion 4f, and a side surface portion 4g, which will be described later) through the inner rolling surface 4d. Is cured so as to be in the range of 58 to 64 HRC. A wheel mounting flange 4 h is integrally formed on the outer periphery of the hub wheel 4. The wheel mounting flange 4h is provided with bolt holes 4i arranged in a circumferential direction on a concentric circle centering on the rotation axis L of the inner member 3 (hub wheel 4 and inner ring 5), and hub bolts 40 are provided in the respective bolt holes 4i. Is press-fitted.

  The inner ring 5 is made of a high carbon chrome bearing steel such as SUJ2 formed in a substantially cylindrical shape. On the outer periphery of the inner ring 5, an inner rolling surface 5a is formed in an annular shape. That is, the inner ring 5 is fitted to the small-diameter step portion 4a of the hub wheel 4 and constitutes the inner rolling surface 5a on the outer periphery of the small-diameter step portion 4a. The inner rolling surface 5 a faces the outer rolling surface 2 c of the outer member 2. In addition, the inner ring 5 is subjected to so-called quenching and is cured so as to be in the range of 58 to 64 HRC up to the core.

  The rolling element 6 constitutes a rolling part of the rolling bearing structure. The rolling element 6 is made of high carbon chrome bearing steel such as SUJ2. The ball row 6a is obtained by holding a plurality of rolling elements 6 in a ring shape by a cage. The ball row 6a is accommodated in a freely rollable manner between an inner rolling surface 5a formed on the inner ring 5 and an outer rolling surface 2c of the outer member 2 facing the inner rolling surface 5a. On the other hand, the ball row 6b also has a plurality of rolling elements 6 held in a ring shape by a cage. The ball row 6b is accommodated between the inner rolling surface 4d formed on the hub wheel 4 and the outer rolling surface 2d of the outer member 2 opposite to the inner rolling surface 4d. Each rolling element 6 of the ball row 6a and the ball row 6b is subjected to so-called quenching and is hardened so that the core portion is in a range of 58 to 64 HRC.

  The inner side sealing member 7 seals the inner side end portion of the annular space S formed between the outer member 2 and the inner member 3. The inner side seal member 7 includes an annular slinger 8 and an annular seal ring 9.

  The slinger 8 is fitted (externally fitted) to the outer periphery of the inner ring 5.

  Slinger 8 is composed of a ferritic stainless steel sheet (JIS standard SUS430 series, etc.), an austenitic stainless steel sheet (JIS standard SUS304 series, etc.), or a rust-proof cold rolled steel sheet (JIS standard SPCC system, etc.). Has been. The slinger 8 is formed in a shape in which a steel plate cut into an annular shape is bent by pressing and the axial cross-section is bent at a right angle. Thereby, the slinger 8 is formed with a cylindrical fitting portion 8a and a disc-shaped side plate portion 8b extending from the end portion toward the outer member 2. The fitting portion 8 a and the side plate portion 8 b intersect each other vertically, and the fitting portion 8 a is press-fitted along the outer peripheral surface of the inner ring 5. The side plate portion 8b extends toward the outer member 2 and faces a side plate portion 91b of a cored bar 91 described later.

  The seal ring 9 is fitted (internally fitted) to the enlarged diameter portion 2 a of the outer member 2. The seal ring 9 includes a cored bar 91 and a seal rubber 92 that is an elastic member.

  The core 91 is made of a ferritic stainless steel plate (JIS standard SUS430 or the like), an austenitic stainless steel plate (JIS standard SUS304 or the like), or a rust-proof cold-rolled steel plate (JIS standard SPCC system or the like). It is configured. The cored bar 91 is formed in a shape in which a steel plate cut out in an annular shape is bent by pressing and the axial cross section is bent at a right angle. Thereby, the metal core 91 is formed with a cylindrical fitting portion 91a and a disk-shaped side plate portion 91b extending from the end portion toward the inner member 3 (inner ring 5). The fitting portion 91a and the side plate portion 91b intersect each other substantially perpendicularly, and the fitting portion 91a is press-fitted and fitted along the inner peripheral surface of the enlarged diameter portion 2a. The side plate portion 91b extends toward the inner member 3 (inner ring 5) and faces the side plate portion 8b of the slinger 8 described above. A seal rubber 92, which is an elastic member, is vulcanized and bonded to the fitting portion 91a and the side plate portion 91b.

  The seal rubber 92 is NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated acrylonitrile-butadiene rubber) excellent in heat resistance, EPDM (ethylene propylene rubber), ACM (polyacrylic rubber) excellent in heat resistance and chemical resistance, It is made of synthetic rubber such as FKM (fluoro rubber) or silicon rubber. The seal rubber 92 is formed with a radial lip 92a, an inner axial lip 92b, and an outer axial lip 92c which are seal lips. The seal rubber 92 is formed with an edge seal portion 92d so as to go around the fitting portion 91a of the cored bar 91.

  Thus, the inner side seal member 7 is disposed so that the slinger 8 and the seal ring 9 face each other. At this time, the radial lip 92a contacts the fitting portion 8a of the slinger 8 through the oil film. Further, the inner axial lip 92b contacts the side plate portion 8b of the slinger 8 through an oil film. The outer axial lip 92c also contacts the side plate portion 8b of the slinger 8 via the oil film. In this way, the inner side sealing member 7 prevents intrusion of muddy water and the like and prevents leakage of grease. The edge seal portion 92d is formed because water enters the fitting portion of the outer member 2 and the cored bar 91 (refers to the part where the outer member 2 and the cored bar 91 are in contact: the same applies hereinafter). This is to prevent corrosion.

  The outer side seal member 10 seals the outer side end portion of the annular space S formed between the outer member 2 and the inner member 3. The outer side seal member 10 is constituted by an annular seal ring 11.

  The seal ring 11 is fitted (internally fitted) to the enlarged diameter portion 2 b of the outer member 2. The seal ring 11 includes a cored bar 111 and a seal rubber 112 that is an elastic member.

  The core metal 111 is a ferritic stainless steel plate (JIS standard SUS430 series, etc.), an austenitic stainless steel plate (JIS standard SUS304 series, etc.), or a rust-proof cold rolled steel plate (JIS standard SPCC system, etc.). It is configured. The cored bar 111 is formed in a shape in which a steel plate cut out in an annular shape is bent by pressing and the axial cross section is bent in a complicated manner. Thereby, the metal core 111 is formed with a cylindrical fitting portion 111a and a disk-shaped side plate portion 111b extending from one end thereof toward the inner member 3 (hub wheel 4). The fitting portion 111a and the side plate portion 111b intersect with each other while being curved, and the fitting portion 111a is press-fitted and fitted along the inner peripheral surface of the enlarged diameter portion 2b. The side plate portion 111b extends toward the inner member 3 (hub wheel 4) and faces the curved surface portion 4f and the side surface portion 4g of the hub wheel 4. Seal rubber 112, which is an elastic member, is vulcanized and bonded to the fitting portion 111a and the side plate portion 111b.

  Seal rubber 112 is NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated acrylonitrile-butadiene rubber) excellent in heat resistance, EPDM (ethylene propylene rubber), ACM (polyacrylic rubber) excellent in heat resistance and chemical resistance, It is made of synthetic rubber such as FKM (fluoro rubber) or silicon rubber. The seal rubber 112 is formed with a radial lip 112a, an inner axial lip 112b, and an outer axial lip 112c which are seal lips. Further, an edge seal portion 112d is formed on the seal rubber 112 so as to contact the inner periphery of the enlarged diameter portion 2b.

  Thus, the outer side seal member 10 is arrange | positioned so that the seal ring 11 and the hub ring 4 may oppose. At this time, the radial lip 112a contacts the shaft surface portion 4e of the hub wheel 4 through the oil film. Further, the axial lip 112b contacts the curved surface portion 4f of the hub wheel 4 through an oil film. The outer axial lip 112c also contacts the side surface portion 4g of the hub wheel 4 through the oil film. Thus, the outer side seal member 10 prevents intrusion of muddy water and the like and prevents leakage of grease. The edge seal portion 112d is formed because water does not invade the fitting portion of the outer member 2 and the core metal 111 (refers to the portion where the outer member 2 and the core metal 111 are in contact). It is taken into consideration.

  Next, the principal part structure of the wheel bearing apparatus 1 which is 1st embodiment is demonstrated using FIG. 5 and FIG. FIG. 5 is an enlarged view of the region R in FIG. FIG. 6 shows the replacement work of the hub bolt 40.

  In the wheel bearing device 1 according to the first embodiment, the outer member 2 has a substantially cylindrical shape centered on the rotation axis L of the inner member 3 (hub wheel 4 and inner ring 5). On the outer periphery of the outer member 2 on the outer side, a substantially annular drainage groove 2g centering on the rotation axis L of the inner member 3 is provided. In addition, a substantially annular thick portion 2 h centering on the rotation axis L of the inner member 3 is provided on the outer periphery of the outer member 2 on the outer side of the drainage groove 2 g. That is, the drainage groove 2g is formed on the entire outer periphery of the outer member 2 on the outer side, and the thick portion 2h is formed on the entire outer periphery of the drainage groove 2g. However, the drainage groove 2g and the thick part 2h do not have to be a complete annular shape, and may lack a part in the circumferential direction. For example, the outer member 2 may be missing on the lower half side.

  Here, the drain groove 2g has a substantially rectangular or arcuate cross section in the axial direction. The thick portion 2h has a substantially trapezoidal cross section in the axial direction, and is inclined so that the hypotenuse 2j of the substantially trapezoidal upper side 2i and hypotenuse 2j falls from the outer side to the inner side. . Therefore, the muddy water flows down to the drainage groove 2g without being transmitted to the thick part 2h (see arrow Fa shown in FIG. 5), and also flows down to the drainage groove 2g through the inclined surface 2j of the thick part 2h (see FIG. 5). (See arrow Fb shown in FIG. 5). Further, the axial cross section may be a substantially triangular shape other than a substantially trapezoidal shape.

  By the way, in the thick part 2h, the inclination of the hypotenuse 2j with respect to the rotation axis L of the inner member 3 is 5 ° or more. This is a result found by experiment using the inclination angle θ of the hypotenuse 2j with respect to the rotation axis L of the inner member 3 as a parameter. Specifically, it is a result found by an experiment that uses the outer member 2 having different inclination angles θ and measures whether or not a certain amount of muddy water gets over the thick portion 2h and the amount of muddy water that gets over. . As shown in FIG. 7, the horizontal axis is the tilt angle θ, and the vertical axis is the muddy water resistance ratio (“1” indicates the same performance as the conventional one. If the value is larger than “1”, the conventional If the inclination angle θ is 5 ° or more, it can be seen that the performance is remarkably improved. The inclination angle θ being 5 ° or more is also a result found by analysis for measuring the deformation amount of the outer opening end of the outer member 2.

  Further, the thick portion 2h has a height of 3 mm or more from the bottom of the drain groove 2g to the upper side 2i. This is a result found by experiment using the height dimension H from the bottom of the drainage groove 2g to the upper side 2i as a parameter. More specifically, using the outer member 2 having a different height dimension H, whether or not a certain amount of muddy water gets over the thick portion 2h, and the results found by an experiment to measure the amount of muddy water overtaken. is there. As shown in FIG. 8, the horizontal axis is the height dimension H, and the vertical axis is the muddy water resistance ratio (“1” indicates the same performance as the conventional one, and if the value is larger than “1”) It is understood that when the height dimension H is 3 mm or more, the performance is remarkably improved. The height dimension H being 3 mm or more is also a result found by analysis for measuring the deformation amount of the outer opening end of the outer member 2.

  As described above, the wheel bearing device 1 is provided with the substantially annular drainage groove 2g centering on the rotation axis L of the inner member 3 on the outer periphery of the outer member 2 on the outer side. A substantially annular thick part 2h centering on the rotation axis L of the inner member 3 is provided on the outer periphery on the outer side of the drainage groove 2g. The thick portion 2h has a substantially trapezoidal cross section in the axial direction, and the inclined side 2j of the substantially trapezoidal upper side 2i and the inclined side 2j is inclined so as to descend from the outer side to the inner side. . According to the wheel bearing device 1, the thick portion 2 h blocks the muddy water and guides it to the drain groove 2 g, so that the muddy water travels along the outer member 2 and reaches the seal member 10 (outer side seal member 10). The concern that the sealing performance of the sealing member (10) is reduced can be eliminated. Moreover, since the thick part 2h is provided in the outer periphery of the outer side of the outer member 2, the deformation amount of the outer side opening end of the outer member 2 is reduced, and the roundness of the outer rolling surface 2d is deteriorated. Can be suppressed. As a result, the rolling element 6 and its outer rolling surface 2d can be prevented from being damaged, and the bearing life can be prevented from decreasing.

  Further, in the thick part 2h, the inclination of the hypotenuse 2j with respect to the rotation axis L of the inner member 3 is 5 ° or more. According to such a wheel bearing device 1, it is difficult for the muddy water to get over the thick portion 2 h, so that the muddy water is prevented from reaching the seal member 10 (outer side seal member 10) along the outer member 3. The concern that the sealing performance of (10) is reduced can be eliminated.

  Further, the thick portion 2h has a height of 3 mm or more from the bottom of the drain groove 2g to the upper side 2i. According to such a wheel bearing device 1, it is difficult for the muddy water to get over the thick portion 2 h, so that the muddy water is prevented from reaching the seal member 10 (outer side seal member 10) along the outer member 2. The concern that the sealing performance of (10) is reduced can be eliminated.

  In addition, the thick portion 2h is formed with a guide groove 2k of the hub bolt 40 at an outer edge portion thereof. More specifically, a guide groove 2k for allowing the hub bolt 40 to pass through is formed by cutting the outer edge portion of the thick portion 2h into an arc shape.

  By adopting such a design, the wheel bearing device 1 has the outer member 2 and the inner member 3 even if the height of the thick portion 2h is increased in consideration of the difficulty of getting over muddy water. The hub bolt 40 can be replaced without disassembling.

  In addition, the wheel bearing device 1 includes five hub bolts 40 and is provided at positions where the phase angle about the rotation axis L is every 72 °. Therefore, five guide grooves 2k in the circumferential direction are formed in the outer edge portion of the thick portion 2h at positions where the phase angle about the rotation axis L is every 72 °. However, the guide grooves 2k may be provided at ten locations that are multiples. At this time, the guide groove 2k is formed at a position where the phase angle around the rotation axis L is every 36 °. The wheel bearing device 1 has five hub bolts 40. For example, the wheel bearing device 1 has four hub bolts 40, and is provided at a position where the phase angle about the rotation axis L is every 90 °. It is also good. In this case, the four guide grooves 2k are formed at positions where the phase angle about the rotation axis L is every 90 °. However, the guide grooves 2k may be provided at eight locations that are multiples.

  With this design, the wheel bearing device 1 can superimpose the positions of all the hub bolts 40 in all the guide grooves 2k, so that the hub bolt 40 can be easily replaced.

  Next, the principal part structure of the wheel bearing apparatus 1 which is 2nd embodiment is demonstrated using FIG. FIG. 9 corresponds to an enlarged view of the region R in FIG.

  Also in the wheel bearing device 1 according to the second embodiment, a substantially annular drainage groove 2g and a thick portion 2h are provided on the outer periphery of the outer member 2 on the outer side. The drainage groove 2g has a substantially rectangular or arcuate cross section in the axial direction. The thick portion 2h has a substantially trapezoidal cross section in the axial direction, and is inclined so that the hypotenuse 2j of the substantially trapezoidal upper side 2i and hypotenuse 2j falls from the outer side to the inner side. . However, in the present embodiment, the hypotenuse 2j is formed on the outer periphery at the bottom of the outer rolling surface 2d (refers to the outer periphery intersecting with a virtual line extending radially outward from the bottom of the outer rolling surface 2d). Yes.

  By the way, as for the thick part 2h, the inclination | tilt angle (theta) of the hypotenuse 2j with respect to the rotating shaft L of the inner member 3 is 5 degrees or more. This is a result found by experiment using the inclination angle θ of the hypotenuse 2j with respect to the rotation axis L of the inner member 3 as a parameter. Specifically, it is a result found by an experiment that uses the outer member 2 having different inclination angles θ and measures whether or not a certain amount of muddy water gets over the thick portion 2h and the amount of muddy water that gets over. . This is also a result found by analysis for measuring the deformation amount of the outer opening end of the outer member 2.

  Further, the thick portion 2h has a height of 3 mm or more from the bottom of the drain groove 2g to the upper side 2i. This is a result found by experiment using the height dimension H from the bottom of the drainage groove 2g to the upper side 2i as a parameter. More specifically, using the outer member 2 having a different height dimension H, whether or not a certain amount of muddy water gets over the thick portion 2h, and the results found by an experiment to measure the amount of muddy water overtaken. is there. This is also a result found by analysis for measuring the deformation amount of the outer opening end of the outer member 2.

  For this reason, also in the wheel bearing device 1 according to the second embodiment, the thick wall portion 2h blocks the muddy water and guides it to the drainage groove 2g, similarly to the wheel bearing device 1 according to the first embodiment. The muddy water can be prevented from reaching the seal member 10 (outer side seal member 10) along the outer member 2, and the concern that the sealing performance of the seal member (10) is reduced can be eliminated. Moreover, since the thick part 2h is provided in the outer periphery of the outer side of the outer member 2, the deformation amount of the outer side opening end of the outer member 2 is reduced, and the roundness of the outer rolling surface 2d is deteriorated. Can be suppressed. As a result, the rolling element 6 and its outer rolling surface 2d can be prevented from being damaged, and the bearing life can be prevented from decreasing.

  Furthermore, the thick portion 2h is a height from the bottom of the outer rolling surface 2d to the outer periphery of the bottom portion (refers to the outer periphery intersecting with a virtual line extending radially outward from the bottom of the outer rolling surface 2d). Is 6.5 mm or more. This is a result found by analysis using the thickness dimension T from the bottom part of the outer rolling surface 2d to the outer periphery of the bottom part as a parameter. If it demonstrates concretely, it is the result discovered by the analysis which measures the deformation | transformation amount in 2 d of outer side rolling surfaces using the outer member 2 from which the thickness dimension T differs.

  Thus, in the wheel bearing device 1, the thick part 2h has a thickness from the bottom part of the outer rolling surface 2d formed on the outer side of the outer member 2 to the outer periphery of the bottom part of 6. It is 5 mm or more. According to such a wheel bearing device 1, the rigidity of the outer rolling surface 2 d formed on the outer side of the outer member 2 is improved, so that deterioration of the roundness of the outer rolling surface 2 d can be suppressed. it can.

  Furthermore, in this embodiment, a substantially annular thin portion 2m centering on the rotation axis L of the inner member 3 is provided on the outer periphery on the inner side of the drainage groove 2g of the outer member 2. The thin portion 2m has a depth of 1 mm or more from the outer periphery at the bottom of the outer rolling surface 2d (refers to the outer periphery intersecting with a virtual line extending radially outward from the bottom of the outer rolling surface 2d). . This is a result found by analysis using the depth dimension D as a parameter from the outer periphery of the outermost rolling surface 2d. If it demonstrates concretely, it will be the result found by the analysis which measures the deformation amount in the thin part 2m using the outer member 2 from which the thickness dimension T differs.

  Thus, in the wheel bearing device 1, the thin portion 2m has a depth of 1 mm or more from the outer periphery at the bottommost portion of the outer rolling surface 2d. According to the wheel bearing device 1, an increase in weight due to the provision of the thick portion 2 h while ensuring the rigidity of the outer member 2 can be minimized.

  Next, the main structure of the wheel bearing device 1 according to the third embodiment will be described with reference to FIG. FIG. 10 corresponds to an enlarged view of the region R in FIG.

  Also in the wheel bearing device 1 according to the third embodiment, a substantially annular drainage groove 2g and a thick portion 2h are provided on the outer periphery of the outer member 2 on the outer side. The drainage groove 2g has a substantially rectangular or arcuate cross section in the axial direction. The thick portion 2h has a substantially trapezoidal cross section in the axial direction, and is inclined so that the hypotenuse 2j of the substantially trapezoidal upper side 2i and hypotenuse 2j falls from the outer side to the inner side. . However, in the present embodiment, the upper side 2i is formed on the outer periphery at the bottom portion of the outer rolling surface 2d (refers to the outer periphery intersecting with a virtual line extending radially outward from the bottom portion of the outer rolling surface 2d). Yes.

  By the way, as for the thick part 2h, the inclination | tilt angle (theta) of the hypotenuse 2j with respect to the rotating shaft L of the inner member 3 is 5 degrees or more. This is a result found by experiment using the inclination angle θ of the hypotenuse 2j with respect to the rotation axis L of the inner member 3 as a parameter. Specifically, it is a result found by an experiment that uses the outer member 2 having different inclination angles θ and measures whether or not a certain amount of muddy water gets over the thick portion 2h and the amount of muddy water that gets over. . This is also a result found by analysis for measuring the deformation amount of the outer opening end of the outer member 2.

  Further, the thick portion 2h has a height of 3 mm or more from the bottom of the drain groove 2g to the upper side 2i. This is a result found by experiment using the height dimension H from the bottom of the drainage groove 2g to the upper side 2i as a parameter. More specifically, using the outer member 2 having a different height dimension H, whether or not a certain amount of muddy water gets over the thick portion 2h, and the results found by an experiment to measure the amount of muddy water overtaken. is there. This is also a result found by analysis for measuring the deformation amount of the outer opening end of the outer member 2.

  For this reason, also in the wheel bearing device 1 according to the third embodiment, the thick portion 2h blocks the muddy water and guides it to the drainage groove 2g, as in the wheel bearing device 1 according to the first embodiment. The muddy water can be prevented from reaching the seal member 10 (outer side seal member 10) along the outer member 2, and the concern that the sealing performance of the seal member (10) is reduced can be eliminated. Moreover, since the thick part 2h is provided in the outer periphery of the outer side of the outer member 2, the deformation amount of the outer side opening end of the outer member 2 is reduced, and the roundness of the outer rolling surface 2d is deteriorated. Can be suppressed. As a result, the rolling element 6 and its outer rolling surface 2d can be prevented from being damaged, and the bearing life can be prevented from decreasing.

  Further, the thick portion 2h is a range in which the upper side 2i exceeds the outermost end portion of the outer rolling surface 2d from the outer end portion of the outer member 2 (the imaginary portion extending radially outward from the lowermost portion of the outer rolling surface 2d). (Range beyond the line). This is intended to improve the rigidity of the outer member 2 on the outer side.

  Thus, in the wheel bearing device 1, the thick portion 2 h is provided up to a range where the upper side 2 i exceeds the bottom portion of the outer rolling surface 2 d formed on the outer side from the outer side end of the outer member 2. It has been. According to such a wheel bearing device 1, the rigidity from the outer side end portion of the outer member 2 to the outer rolling surface 2d formed on the outer side is improved, so that the roundness of the outer rolling surface 2d is deteriorated. Can be suppressed.

DESCRIPTION OF SYMBOLS 1 Wheel bearing apparatus 2 Outer member 2c Outer rolling surface 2d Outer rolling surface 2g Drainage groove 2h Thick part 2i Upper side 2j Oblique side 2k Guide groove 2m Thin part 3 Inner member 4 Hub wheel 4a Small diameter step part 4d Inward rolling Running surface 5 Inner ring 5a Inner rolling surface 6 Rolling element 6a Ball row 6b Ball row 7 Seal member 8 Slinger 9 Seal ring 10 Seal member 11 Seal ring 40 Hub bolt L Rotating shaft of inner member

Claims (6)

An outer member having a double row outer raceway formed on the inner periphery;
A hub wheel formed with a small-diameter step portion extending in the axial direction, and at least one inner ring press-fitted into the small-diameter step portion of the hub wheel, and a double-row An inner member formed with an inner rolling surface;
In a wheel bearing device comprising: a double row rolling element interposed between the rolling surfaces of the outer member and the inner member so as to freely roll.
While providing a substantially annular drainage groove around the rotation axis of the inner member on the outer periphery of the outer side of the outer member,
A substantially annular thick portion centering on the rotation axis of the inner member is provided on the outer periphery of the outer member on the outer side of the drainage groove,
The thick wall portion has a portion which becomes a hypotenuse in an axial cross section thereof, and the oblique side is inclined so as to descend from the outer side to the inner side.   2. The wheel bearing device according to claim 1, wherein the thick portion has an inclination of the hypotenuse with respect to a rotation axis of the inner member of 5 ° or more.   The wheel bearing device according to claim 1 or 2, wherein the thick part has a height of 3 mm or more from the bottom of the drainage groove to the upper side.   The thickness of the said thick part to the said outer side rolling surface formed in the outer side of the said outer member, and outer periphery is 6.5 mm or more, Any of Claim 1 to 3 characterized by the above-mentioned. A wheel bearing device according to claim 1. A substantially annular thin portion centering on the rotation axis of the inner member is provided on the outer periphery on the inner side of the drainage groove of the outer member,
The depth of said thin part is 1 mm or more from the outer periphery in the said outer side rolling surface formed in the outer side of the said outer member, The Claim 1 characterized by the above-mentioned. The wheel bearing device described.   The thick portion is provided in such a manner that the upper side extends in the axial direction beyond the deepest groove bottom portion of the outer rolling surface formed on the outer side from the outer side end of the outer member. The wheel bearing device according to any one of claims 1 to 5.

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