JP2018013230A - Bearing device for wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device for wheel in which, when fitting in a snap ring, a tip of a tool does not come into contact with a seal member and which does not break the seal member.SOLUTION: In a bearing device 1 for wheel, a bearing 2 is constituted by: an outer ring 3; a pair of inner rings 4; a plurality of rows of rolling elements 5 interposed between rolling surfaces of the outer ring 3 and inner rings 4 respectively in a freely rolling manner; and seal members 6, 7 arranged so as to block both side openings of an annular space formed between the outer ring 3 and the inner rings 4. The bearing device for wheel includes: a housing 8 for accommodating the bearing 2; and a snap ring 10 for sealing the bearing 2 in the housing 8. The bearing device for wheel is assembled in such a manner that, after press-fitting the bearing 2 in a hole 8a of the housing 8, the snap ring 10 is fitted in a ring groove 8d formed on an inner periphery of the hole 8a. The bearing device for wheel includes a substantially disc shaped protection tool 9 mounted on an outer side end part of the bearing 2. The protection tool 9 covers one part or the whole of the outer side seal member 7 out of the seal members 6, 7.SELECTED DRAWING: Figure 7

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. The wheel bearing device constitutes a rolling bearing in which a plurality of rolling elements arranged in a double row between an outer ring and an inner ring are interposed, and the rolling bearing is accommodated in a housing. For example, it is as described in Patent Document 1 and Patent Document 2.

  By the way, in such a wheel bearing device, when muddy water, sand dust, or differential oil enters the annular space formed between the outer ring and the inner ring, the rolling elements are damaged and the bearing life is shortened. Further, even if the grease sealed in the annular space leaks, the rolling elements are damaged and the bearing life is shortened. For this reason, the wheel bearing device includes a seal member (an inner side seal member and an outer side seal member) that seals the annular space in order to prevent intrusion of muddy water, sand dust, or differential oil and to prevent leakage of grease. Yes.

  In addition, such a wheel bearing device is assembled by fitting a snap ring into a ring groove formed on the inner periphery of the hole after press-fitting a rolling bearing (hereinafter referred to as “bearing”) into the hole of the housing. However, in the wheel bearing device completed through such steps, when the snap ring is fitted, a tool (such as a plier) for fitting the snap ring comes into contact with the seal member (outer side seal member). There was a case where it was damaged. In other words, in the process of passing the tip of the tool through the small hole in the snap ring and fitting it into the ring groove while gripping the snap ring, the tip of the tool may come into contact with the seal member (outer side seal member) and be damaged. (See FIG. 10). Therefore, it is necessary to confirm whether or not the seal member (outer side seal member) is damaged after the snap ring is fitted, which requires man-hours and costs.

JP 2009-208708 A JP 2009-190655 A

  An object of the present invention is to provide a wheel bearing device in which a tip of a tool does not contact a seal member when the snap ring is fitted, and the seal member is not damaged.

  That is, the present invention includes an outer ring having a double row outer rolling surface formed on the inner periphery, a pair of inner rings formed with an inner rolling surface facing the double row outer transfer surface on the outer periphery, and the outer ring. A double-row rolling element interposed between the respective rolling surfaces of the inner ring so as to freely roll, and a seal disposed so as to close both side openings of an annular space formed between the outer ring and the inner ring. And a housing that accommodates the bearing, and a snap ring that latches the bearing on the housing, and press-fitting the bearing into the hole of the housing, In the wheel bearing device assembled by fitting the snap ring into a ring groove formed in the periphery, the wheel bearing device includes a protector attached to an outer side end portion of the bearing, By covering the part or the whole of the outer side seal member of the seal member, to protect the outer side sealing member from the tip of the tool for fitting the snap ring it is intended.

  In the wheel bearing device according to the present invention, the inner diameter when the snap ring is fully contracted is A, the outer diameter of the protector is B, the inner diameter of the housing is C, and the diameter of the snap ring is When the width dimension is D, the relationship of A <B <C-2D is satisfied.

  The wheel bearing device according to the present invention satisfies the relationship of E> F, where E is the thickness dimension of the protector and F is the length dimension of the tip of the tool.

  The wheel bearing device according to the present invention satisfies the relationship of G <H, where G is the inner diameter dimension of the protector and H is the outer diameter dimension of the axle inserted through the bearing.

  In the wheel bearing device according to the present invention, an inclined surface that gradually increases in diameter as it goes from the outer end surface toward the inner side is formed on the outer periphery of the protector.

  The wheel bearing device according to the present invention is provided with a gap connecting from the outer periphery to the inner periphery of the protector.

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

  That is, the wheel bearing device according to the present invention includes a protector attached to the outer side end of the bearing. And the protector has protected the outer side sealing member from the front-end | tip of the tool for fitting a snap ring by covering a part or all of the outer side sealing member among sealing members. Thereby, when this wheel bearing apparatus fits a snap ring, the front-end | tip of a tool does not contact an outer side seal member, and an outer side seal member is not damaged. As a result, the defect rate is reduced and the reliability is improved.

  In the wheel bearing device according to the present invention, the inner diameter when the snap ring is fully contracted is A, the outer diameter of the protective device is B, the inner diameter of the housing is C, and the diameter width of the snap ring is D. In this case, the relationship of A <B <C-2D is satisfied. This makes it difficult for the wheel bearing device to guide to the ring groove while gripping the snap ring with a tool. The tip of the tool does not contact the outer seal member, and the outer seal member is not damaged. As a result, the defect rate is further reduced and the reliability is improved.

  The wheel bearing device according to the present invention satisfies the relationship of E> F, where E is the thickness dimension of the protector and F is the length dimension of the tip of the tool. This makes it more difficult for the wheel bearing device to guide to the ring groove while holding the snap ring with a tool, and to guide the ring ring by pushing with the tool after expanding the snap ring on the way. The tip of the tool does not contact the outer seal member, and the outer seal member is not damaged. As a result, the defect rate is further reduced and the reliability is improved.

  The wheel bearing device according to the present invention satisfies the relationship of G <H, where G is the inner diameter of the protector and H is the outer diameter of the axle inserted through the bearing. As a result, in this wheel bearing device, since the protective device is pushed out when the axle is inserted from the inner side, the step of removing the protective device is not required, and the productivity is improved.

  In the wheel bearing device according to the present invention, an inclined surface that gradually increases in diameter from the outer end surface toward the inner side is formed on the outer periphery of the protector. As a result, the wheel bearing device can begin to pass through the outer side of the protector in a state where the snap ring is fully contracted or close to the total contraction.

  The wheel bearing device according to the present invention is provided with a gap that leads from the outer periphery to the inner periphery of the protector. Thereby, since the elastic coefficient about the shrinkage | contraction and expansion to the radial direction of a protector becomes small, the operation | work which attaches and removes a protector becomes easy, and this wheel bearing apparatus improves productivity.

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 projection figure which shows the shape of a protector. The projection figure which shows the shape of a snap ring. Sectional drawing which shows the assembly order of the bearing apparatus for wheels. The expanded sectional view which shows the process of fitting a snap ring. Sectional drawing which shows the attachment order of the bearing apparatus for wheels. The expanded sectional view which shows the process of inserting an axle shaft in a bearing. The figure which shows the process of fitting a snap ring in the conventional wheel bearing apparatus.

  A wheel bearing device 1 according to the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 is a cross-sectional view showing the overall configuration of the wheel bearing device 1. 2 and 3 are enlarged sectional views showing a partial structure of the wheel bearing device 1. FIG. 4 is a projection view showing the shape of the protector 9, and FIG. 5 is a projection view showing the shape of the snap ring 10.

  The wheel bearing device 1 supports a wheel rotatably in a suspension device such as an automobile. The wheel bearing device 1 includes a bearing 2, a housing 8, a protector 9, and a snap ring 10.

  First, the bearing 2 will be described.

  The bearing 2 includes an outer ring 3, a pair of inner rings 4, rolling elements 5, a seal member 6 (hereinafter referred to as “inner side seal member 6”), and a seal member 7 (hereinafter referred to as “outer side seal member 7”). And). In the following, “one side” represents the vehicle body side of the wheel bearing device 1, that is, the inner side. The “other side” represents the wheel side of the wheel bearing device 1, that is, the outer side.

  The outer ring 3 is made of a high carbon chromium bearing steel containing 0.95 to 1.10 wt% of carbon such as SUJ2 formed in a substantially cylindrical shape. A sealing surface 3a is formed at the inner side end of the outer ring 3 (see FIG. 2). Moreover, the sealing surface 3b is formed in the outer side edge part of the outer ring | wheel 3 (refer FIG. 3). Further, on the inner periphery of the outer ring 3, an outer rolling surface 3c and an outer rolling surface 3d are formed in an annular shape. In addition, the outer ring | wheel 3 is given quenching and the hardening process is carried out to the core part. The outer rolling surface 3c and the outer rolling surface 3d have a surface hardness in the range of 58 to 64 HRC.

  The pair of inner rings 4 is made of carbon steel containing 0.95 to 1.10 wt% of carbon such as SUJ2 formed in a cone shape. A sealing surface 4 a is formed on the inner side end of the inner ring 4 on the inner side. Further, a sealing surface 4 b is formed at the outer side end of the outer side inner ring 4. Furthermore, an inner rolling surface 4c and an inner rolling surface 4d are formed on the outer circumferences of the pair of inner rings 4 in an annular shape. In addition, the pair of inner rings 4 are each subjected to sub-quenching and cured to the core. The pair of inner rings 4 has a surface hardness in the range of 62 to 67 HRC.

  The rolling element 5 is interposed between the outer ring 3 and the pair of inner rings 4. The rolling element 5 includes an inner side tapered roller row 5a (hereinafter referred to as “one side tapered roller row 5a”) and an outer side tapered roller row 5b (hereinafter referred to as “other side tapered roller row 5b”). Have. The one side tapered roller row 5a and the other side tapered roller row 5b are made of high carbon chromium bearing steel such as SUJ2. It should be noted that the one side tapered roller row 5a and the other side tapered roller row 5b are subjected to so-called quenching and are cured so as to be in a range of 58 to 64 HRC up to the core. As shown in FIG. 2, the one side tapered roller row 5a has a plurality of tapered rollers held in a ring shape by a cage. The one-side tapered roller row 5a is accommodated between the outer rolling surface 3c formed on the outer ring 3 and the inner rolling surface 4c of the inner side inner ring 4 facing the outer rolling surface 3c. In the other side tapered roller row 5b, as shown in FIG. 3, a plurality of tapered rollers are held in an annular shape by a cage. The other side tapered roller row 5b is accommodated between the outer rolling surface 3d formed on the outer ring 3 and the inner rolling surface 4d of the outer side inner ring 4 facing the outer rolling surface 3d.

  The inner side sealing member 6 is disposed so as to close the inner side end portion of the annular space formed between the outer ring 3 and the inner side inner ring 4. As shown in FIG. 2, the inner side seal member 6 includes an annular slinger 61 and an annular seal ring 62.

  The slinger 61 is press-fitted and fixed to the sealing surface 4 a of the inner ring 4.

  The slinger 61 is 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. In the slinger 61, an annular steel plate is bent by press working, and the axial cross section is formed in an approximately L shape. Thereby, the slinger 61 is formed with a cylindrical fitting portion 61a and a disc-shaped side plate portion 61b extending from the end portion toward the outer ring 3. The fitting part 61 a and the side plate part 61 b are perpendicular to each other, and the fitting part 61 a is press-fitted and fixed to the sealing surface 4 a of the inner ring 4. Further, the side plate portion 61 b extends toward the outer ring 3, and its tip is close to the fitting portion 63 a of the seal ring 62.

  The seal ring 62 is press-fitted and fixed to the sealing surface 3 a of the outer ring 3. The seal ring 62 includes a metal core 63 and a seal rubber 64 that is an elastic member.

  The core metal 63 is a ferritic stainless steel plate (JIS standard SUS430 series, etc.), an austenitic stainless steel sheet (JIS standard SUS304 series, etc.), or a rust-proof cold rolled steel plate (JIS standard SPCC system, etc.). It consists of The cored bar 63 is formed by bending an annular steel plate by press working, and has an axial cross section formed in a substantially L shape. Thereby, the cored bar 63 is formed with a cylindrical fitting part 63a and a disk-like side plate part 63b extending from one end thereof toward the inner ring 4. The fitting part 63 a and the side plate part 63 b are perpendicular to each other, and the fitting part 63 a is press-fitted and fixed to the sealing surface 3 a of the outer ring 3. Further, the side plate portion 63 b extends toward the inner ring 4, and the tip thereof is close to the fitting portion 61 a of the slinger 61. A sealing rubber 64 that is an elastic member is vulcanized and bonded to the fitting portion 63a and the side plate portion 63b.

  Seal rubber 64 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 64 is formed with one radial lip 64a and two axial lips 64b and 64c as seal lips. The radial lip 64a contacts the fitting portion 61a of the slinger 61 through the oil film. Further, the axial lips 64b and 64c are in contact with the side plate portion 61b of the slinger 61 through the oil film. In this way, the inner side seal member 6 constitutes a so-called pack seal, which prevents intrusion of muddy water, sand dust, or differential oil and prevents leakage of grease.

  The outer side seal member 7 is disposed so as to block the outer side end portion of the annular space formed between the outer ring 3 and the outer side inner ring 4. As shown in FIG. 3, the outer side seal member 7 is configured by an annular seal ring 71.

  The seal ring 71 is press-fitted and fixed to the sealing surface 3 b of the outer ring 3. The seal ring 71 includes a metal core 72 and a seal rubber 73 that is an elastic member.

  The core metal 72 is a ferritic stainless steel plate (JIS standard SUS430 series, etc.), an austenitic stainless steel sheet (JIS standard SUS304 series, etc.), or a rust-proof cold rolled steel plate (JIS standard SPCC system, etc.). It consists of The cored bar 72 is formed in a substantially L shape in an axial cross-sectional view by bending an annular steel plate by press working. As a result, the cored bar 72 is formed with a cylindrical fitting part 72 a and a disk-shaped side plate part 72 b extending from one end toward the inner ring 4. The fitting portion 72 a and the side plate portion 72 b are perpendicular to each other, and the fitting portion 72 a is press-fitted and fixed to the sealing surface 3 b of the outer ring 3. The side plate portion 72 b extends toward the inner ring 4, and the tip thereof is close to the sealing surface 4 b of the inner ring 4. A seal rubber 73, which is an elastic member, is vulcanized and bonded to the fitting portion 72a and the side plate portion 72b.

  Seal rubber 73 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 73 is formed with two radial lips 73a and 73b as seal lips. The radial lip 73a contacts the sealing surface 4b of the inner ring 4 through an oil film. The radial lip 73a is fitted with a garter spring 74 to improve the sealing performance between the radial lip 73a and the sealing surface 4b of the inner ring 4. Further, the radial lip 73b also contacts the sealing surface 4b of the inner ring 4 through the oil film. In this way, the outer side seal member 7 prevents intrusion of muddy water, sand dust, or differential oil and prevents leakage of grease.

  Next, the housing 8, the protector 9, and the snap ring 10 included as components will be described.

  The housing 8 is made of spheroidal graphite cast iron such as FCD formed in a substantially cylindrical shape. The housing 8 is provided with a large-diameter hole 8a from the outer side end face toward the inner side, and a small-diameter hole 8b is provided at the inner side end. That is, the housing 8 is provided with a hole 8a and a hole 8b having different inner diameters in the axial direction, thereby forming a stepped portion 8c (see FIG. 2). In addition, the housing 8 has a ring groove 8d (see FIG. 3) formed in the inner periphery of the hole 8a. The ring groove 8d is formed at a position away from the stepped portion 8c by a predetermined dimension. The inner peripheral surfaces of the holes 8a and 8b are subjected to induction hardening, and are hardened so that the surface hardness is in the range of 13 to 30 HRC.

  The protector 9 is made of a synthetic resin such as ABS formed in a substantially disc shape. As shown in FIG. 4, the protector 9 is provided with a large-diameter lid portion 9a from the outer side end surface toward the inner side, and a small-diameter shaft portion 9b is provided at the inner side end portion. Yes. That is, the protector 9 is provided with a lid portion 9a and a shaft portion 9b having different outer diameters in the axial direction, thereby forming a step portion 9c. In addition, a through hole 9d is formed in the protector 9 from the outer side end surface to the inner side end surface, and a gap 9e is formed from the outer periphery to the inner periphery. An inclined surface 9f that gradually increases in diameter from the outer end surface toward the inner side is formed on the outer periphery of the lid portion 9a.

  The snap ring 10 is made of a tool steel such as SK7 formed in a substantially ring shape. As shown in FIG. 5, the snap ring 10 is formed with a joint gap 10 a that extends from the outer periphery to the inner periphery. And small hole 10b * 10b is provided in the both ends which oppose on both sides of the abutment gap 10a. Therefore, the snap ring 10 contracts in the radial direction by bringing the tips 11a of the tools 11 passed through the small holes 10b and 10b close to each other. The snap ring 10 has elasticity so that it always returns to its original shape.

  Next, the assembly sequence and the mounting sequence of the wheel bearing device 1 will be described in detail with reference to FIGS. FIG. 6 is a cross-sectional view showing the assembly sequence of the wheel bearing device 1, and FIG. 7 is an enlarged cross-sectional view showing a process of fitting the snap ring 10. FIG. 8 is a cross-sectional view showing the mounting order of the wheel bearing device 1, and FIG. 9 is an enlarged cross-sectional view showing a process of inserting the axle 12 through the bearing 2.

  First, the assembly sequence of the wheel bearing device 1 will be described.

  FIG. 6A is a process of attaching the protector 9 to the outer side end of the bearing 2. That is, it is a step of attaching the protector 9 to the outer side end portion of the bearing 2 by inserting the shaft portion 9 b of the protector 9 into the hole 2 a of the bearing 2. The protector 9 is inserted until the stepped portion 9c comes into contact with the outer side end surface of the inner ring 4 on the outer side.

  FIG. 6B is a process of press-fitting the bearing 2 into the hole 8 a of the housing 8. The bearing 2 is press-fitted until its inner side end face comes into contact with the stepped portion 8c. At this time, the protector 9 remains attached to the outer side end of the bearing 2. However, the bearing 2 may be press-fitted into the hole 8a of the housing 8, and then the protective device 9 may be attached.

  FIG. 6C is a process of fitting the snap ring 10 into the ring groove 8 d of the housing 8. That is, it is a step of passing the outer side of the protector 9 while appropriately shrinking the snap ring 10, expanding the snap ring 10 in the middle, and pressing it with the tool 11 to fit in the ring groove 8 d. The snap ring 10 is guided along the outer peripheral surface of the protector 9 without being eccentric or inclined with respect to the rotation axis L.

  Here, the process of fitting the snap ring 10 will be described in detail.

  First, as shown in FIG. 7A, the snap ring 10 is applied to the outer periphery of the protector 9 while being appropriately contracted. At this time, the tip 11a of the tool 11 protruding from the small hole 10d of the snap ring 10 comes into contact with an inclined surface 9f of the protector 9 described later.

  Next, as shown in FIG. 7B, the tip 11 a of the tool 11 is pulled out from the small hole 10 d of the snap ring 10. Then, the snap ring 10 expands by its own tension, and comes into contact with the inner peripheral surface of the hole 8 a of the housing 8.

  Next, as shown in FIG. 7C, the snap ring 10 is pushed by the tip 11a of the tool 11, and the snap ring 10 is fitted into the ring groove 8d. It is preferable to use a dedicated tool for pushing the snap ring 10 instead of pushing the snap ring 10 with the tip 11a of the tool 11.

  By the way, the protector 9 has a role of protecting the outer seal member 7. Specifically, as shown in FIG. 7, the protector 9 prevents the tip 11 a of the tool 11 for fitting the snap ring 10 from coming into contact with the outer seal member 7 in the step of fitting the snap ring 10. The outer side sealing member 7 has a role of protecting the outer side sealing member 7 from damage. For this reason, the protective device 9 has a shape in which the lid portion 9a projects outward in the radial direction from the sealing surface 4b of the inner ring 4 (see the * mark portion in FIG. 7) and covers a part of the outer side seal member 7. It is. However, instead of covering only the radial lips 73a and 73b, which are part of the outer seal member 7, as in the wheel bearing device 1, the outer lip B of the lid portion 9a is made larger to increase the radial lip 73a. -It may be the shape which covers the whole belt including 73b.

  As described above, the wheel bearing device 1 according to the present invention includes the protector 9 attached to the outer side end of the bearing 2. And the protector 9 protects the outer side sealing member 7 from the front-end | tip 11a of the tool 11 for fitting the snap ring 10 by covering a part or all of the outer side sealing member 7 among the sealing members 6 and 7. ing. Thereby, when this wheel bearing apparatus 1 fits the snap ring 10, the front-end | tip 11a of the tool 11 does not contact the outer side seal member 7, and the outer side seal member 7 is not damaged. As a result, the defect rate is reduced and the reliability is improved.

  In addition, as shown in FIG. 6C, the wheel bearing device 1 according to the present invention has an inner diameter when the snap ring 10 is fully contracted (here, an inner diameter when the snap ring 10 is contracted most in the radial direction). Is A, and B is the outer diameter of the protector 9 (here, the outer diameter of the lid portion 9a), the relationship of A <B is satisfied. By doing so, it is difficult to guide the snap ring 10 to the ring groove 8d while appropriately contracting and gripping the snap ring 10. The inner diameter dimension of the housing 8 (referred to here refers to the inner diameter dimension of the hole 8a) is C, and the radial width dimension of the snap ring 10 (here, refers to the diameter width dimension of the largest portion in the radial direction) is referred to as D. In this case, it is necessary to satisfy the relationship B <C-2D. In this way, the snap ring 10 is passed inside the hole 8a (see FIG. 6B).

  Thus, in the wheel bearing device 1 according to the present invention, the inner diameter when the snap ring 10 is fully contracted is A, the outer diameter of the protector 9 is B, the inner diameter of the housing 8 is C, When the diameter width dimension of the snap ring 10 is D, the relationship of A <B <C-2D is satisfied. This makes it difficult for the wheel bearing device 1 to guide the ring ring 8d while holding the snap ring 10 with the tool 11, and expands the snap ring 10 on the way and pushes it with the tool 11 to the ring groove 8d. Since it will guide, the front-end | tip 11a of the tool 11 does not contact the outer side seal member 7, and the outer side seal member 7 is not damaged. As a result, the defect rate is further reduced and the reliability is improved.

  In addition, in the wheel bearing device 1 according to the present invention, the thickness dimension of the protector 9 (in this case, the thickness dimension of the lid portion 9a) is E (see FIG. 4), and the tip 11a of the tool 11 is When the length dimension is F (see FIG. 5), the relationship E> F is satisfied. By doing so, it becomes more difficult to guide the snap ring 10 to the ring groove 8d while appropriately contracting and holding the snap ring 10.

  Thus, the wheel bearing device 1 according to the present invention satisfies the relationship of E> F, where E is the thickness dimension of the protector 9 and F is the length dimension of the tip 11a of the tool 11. . This makes it more difficult for the wheel bearing device 1 to guide the ring ring 8d while holding the snap ring 10 with the tool 11, and expands the snap ring 10 in the middle and then pushes the ring ring 8d with the tool 11. Therefore, the tip 11a of the tool 11 does not contact the outer seal member 7, and the outer seal member 7 is not damaged. As a result, the defect rate is further reduced and the reliability is improved.

  Next, the mounting order of the wheel bearing device 1 will be described.

  FIG. 8A shows a process of inserting the axle 12 through the hole (inner ring inner diameter) 2 a of the bearing 2. The axle 12 is inserted until the stepped portion 12 a abuts against the inner side end surface of the bearing 2. At this time, the protector 9 is pushed out by the axle 12. Therefore, this process is also a process of removing the protector 9 from the outer side end portion of the bearing 2 (see (A ′) in FIG. 8).

  FIG. 8B is a process in which the washer 13 is fitted to the tip screw portion 12 b of the axle 12 and the nut 14 is tightened. The nut 14 is tightened with a predetermined torque with the washer 13 sandwiched therebetween.

  Here, in the wheel bearing device 1 according to the present invention, the inner diameter dimension of the protector 9 (here, the inner diameter dimension of the through hole 9d) is G, and the tip screw portion 12b of the axle 12 inserted through the bearing 2 is used. When the outer diameter dimension (here, indicating the outer diameter dimension of the portion inserted through the bearing 2) is H, the relationship G <H is satisfied. In this way, when the axle 12 is inserted from the inner side, the protector 9 is pushed by the tip surface of the axle 12 (see arrow P in FIG. 9). 9 can be removed. This is true even if the protective device 9 is not provided with the through hole 9d and G = 0.

  Thus, in the wheel bearing device 1 according to the present invention, when the inner diameter dimension of the protector 9 is G and the outer diameter dimension of the tip screw portion 12b of the axle 12 inserted through the bearing 2 is H, G < The relationship of H is satisfied. As a result, in the wheel bearing device 1, since the protector 9 is pushed out when the axle 12 is inserted from the inner side, the step of removing the protector 9 is not required, and the productivity is improved.

  Below, the other feature point and the effect in the wheel bearing apparatus 1 which concern on this invention are demonstrated.

  That is, in the wheel bearing device 1 according to the present invention, an inclined surface 9f that gradually increases in diameter from the outer end surface toward the inner side is formed on the outer periphery of the protector 9. By doing so, the snap ring 10 can begin to pass through the outer side of the protective device 9 in a fully contracted state or close to the fully contracted state, and can be guided to the inner side while being appropriately expanded along the inclined surface 9f. (See arrow T in FIG. 7C).

  Thus, in the wheel bearing device 1 according to the present invention, the inclined surface 9f that gradually increases in diameter from the outer end surface toward the inner side is formed on the outer periphery of the protector 9. As a result, the wheel bearing device 1 can begin to pass through the outer side of the protector 9 with the snap ring 10 fully contracted or close to the total contraction. Will improve.

  Furthermore, the wheel bearing device 1 according to the present invention is provided with a gap 9e (see FIG. 4) connected from the outer periphery to the inner periphery of the protector 9. By doing in this way, the elastic modulus about the shrinkage | contraction and expansion to the radial direction of the protector 9 becomes small, and the protector 9 can be attached with small force. Moreover, the protector 9 can be removed with a small force (see arrow P in FIG. 9).

  Thus, the wheel bearing device 1 according to the present invention is provided with the gap 9e connected from the outer periphery to the inner periphery of the protector 9. Thereby, since the elastic coefficient to the radial direction of the protector 9 becomes small, the operation | work which attaches and removes the protector 9 becomes easy, and this wheel bearing apparatus 1 improves productivity.

DESCRIPTION OF SYMBOLS 1 Wheel bearing apparatus 2 Bearing 3 Outer ring 3c Outer rolling surface 3d Outer rolling surface 4 Inner ring 4c Inner rolling surface 4d Inner rolling surface 5 Rolling element 6 Seal member (inner side seal member)
7 Seal member (outer side seal member)
8 Housing 8a Hole 8b Hole 8c Stepped portion 8d Ring groove 9 Protective equipment 9a Lid portion 9b Shaft portion 9c Stepped portion 9d Through hole 9e Gap 9f Inclined surface 10 Snap ring 10a Joint gap 10b Small hole 11 Tool 11a All tip A Snap ring Inner size when shrunk B Outer diameter of protector C Inner diameter of housing D Width of snap ring E Thickness of protector F Length of tip of tool G Inner diameter of protector H Outside of axle Diameter dimension

Claims (6)

An outer ring having a double row outer raceway formed on the inner circumference;
A pair of inner rings each having an inner rolling surface facing the outer transfer surface of the double row on the outer periphery;
A double-row rolling element interposed between the outer race and the inner race so as to roll freely;
A seal member arranged so as to close both side openings of the annular space formed between the outer ring and the inner ring, and a bearing,
A housing for housing the bearing;
A snap ring for latching the bearing on the housing,
In the wheel bearing device assembled after press fitting the bearing into the hole of the housing and then fitting the snap ring into a ring groove formed on the inner periphery of the hole,
It shall comprise a protector attached to the outer side end of the bearing,
The protector protects the outer seal member from a tip of a tool for fitting the snap ring by covering a part or all of the outer seal member of the seal member. Bearing device.   When the inner diameter of the snap ring is fully contracted is A, the outer diameter of the protective device is B, the inner diameter of the housing is C, and the width of the snap ring is D, A < The wheel bearing device according to claim 1, wherein a relationship of B <C-2D is satisfied.   3. The wheel according to claim 1, wherein when the thickness dimension of the protective equipment is E and the length dimension of the tip of the tool is F, a relationship of E> F is satisfied. Bearing device.   The relationship of G <H is satisfied, where G is an inner diameter dimension of the protective equipment and H is an outer diameter dimension of an axle inserted through the bearing. The wheel bearing device according to one item.   5. The inclined surface which gradually increases in diameter as it goes from the outer side end surface to the inner side is formed on the outer periphery of the protective device. Wheel bearing device.   The wheel bearing device according to any one of claims 1 to 5, wherein a gap is provided from the outer periphery to the inner periphery of the protector.

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