JP2019074121A - Wheel bearing device - Google Patents

Abstract

To provide a wheel bearing device capable of setting a pressure in a sealed space inside of a bearing to a desired magnitude by mounting one cover among multiple kinds of covers.SOLUTION: A wheel bearing device 1 comprises: an outer ring 2 in which multiple rows of outer rolling faces 2d and 2d which are formed in an inner periphery are formed integrally with an inner-side opening 2a including a fitting part to which a cover is fitted; an inner member which includes at least one inner ring 4 that is press-fitted to a small-diameter step 3a of a hub ring 3 and with which multiple rows of inner rolling faces 4a opposite to the multiple rows of outer rolling faces are formed in an outer periphery; multiple rows of rolling bodies 5a and 5b which are accommodated between the rolling faces of the outer ring 2 and the inner member; and an outer-side seal member 8 which is fitted to an outer-side opening 2g of the outer ring 2 and seals a clearance gap between the outer ring 2 and the hub ring 3. In the wheel bearing device, one cover among multiple kinds of covers 6H and 6L which set a pressure in a sealed space inside of a bearing to different pressures is mounted to the inner-side opening 2a.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a bearing device for a wheel.

  2. Description of the Related Art Conventionally, there has been known a wheel bearing device which rotatably supports a wheel in a suspension system of a car or the like. For example, in the wheel bearing device, a hub wheel, which is an inward member connected to the wheel, is rotatably supported via rolling elements. In the wheel bearing device, the grease enclosed in the outer member and the inner member leaks out, and foreign matter such as muddy water or dust enters the inside, causing rusting or rolling elements or raceways. Will damage and shorten the bearing life. For this reason, in the bearing apparatus for a wheel, a sealing member or the like is provided in the gap between the outer member and the inner member in order to prevent the entry of foreign matter such as muddy water, sand and dust, etc. to improve sealing performance.

  In such a wheel bearing device with improved sealing performance, a pressure difference between the inside and the outside of the bearing causes a force to press the seal lip of the seal member against the sliding surface or a force to separate the sealing lip from the sliding surface. There is. Therefore, there is a wheel bearing device in which a through hole is formed in the outer member (outer ring) and the regulator is mounted in the through hole. The regulator includes a control member which is inserted into the through hole and movable in the axial direction of the through hole, and an elastic member which closes the gap between the control member and the through hole and which slidably supports the control member. There is. In the wheel bearing device, foreign matter such as muddy water and dust is prevented from entering by the seal member etc. while keeping the pressure difference between the outside and the inside of the bearing zero by moving the control member of the regulator according to the fluctuation of the external pressure. can do. For example, it is as described in Patent Document 1.

  In addition, there is a wheel bearing device in which at least one communication hole is formed in the outer ring, which communicates the inside of the bearing (the space inside the bearing) and the outside (the space outside the bearing). The wheel bearing device releases the pressure rise in the internal space due to the fitting of the seal member to the outside. The open position on the bearing external space side of the communication hole is formed in the fitting portion located on the inner side (the vehicle side when the wheel bearing device is attached to the vehicle body). The fitting portion is a portion that is fitted into and fixed to the knuckle on the vehicle body side. By configuring in this manner, the wheel bearing device is fixed to the knuckle, whereby the communication hole is sealed in the knuckle, and the inside of the bearing is sealed. For example, it is as described in Patent Document 2.

JP, 2011-190910, A JP, 2013-32832, A

  In the wheel bearing device described in Patent Document 1, a control member that moves in a through hole formed in the outward member is inserted. For this reason, when dirt etc. get into the through hole, the movement of the control member is hindered in the bearing device for a wheel, and there is a possibility that a pressure difference can occur because the pressure inside the bearing can not follow the fluctuation of the external pressure. In addition, since the wheel bearing device has a complicated configuration in which the control member moves inside the through hole, the air tightness may be reduced. In the wheel bearing device described in Patent Document 2, the pressure inside the bearing is maintained at the external pressure when it is fixed to the knuckle, so that a pressure difference may occur between the external and internal due to fluctuations in the external pressure. There was a sex.

  The present invention has been made in view of the above situation, and the pressure in the sealed space inside the bearing can be set to a desired size by mounting one cover selected from a plurality of types of covers. An object of the present invention is to provide a bearing device for a wheel.

  That is, according to the first aspect of the present invention, there is provided an outer member having a plurality of rows of outer raceways formed on the inner periphery, and a fitting portion to which the cover is fitted, and a small diameter step extending in the axial direction on the outer periphery An inner member having a formed hub ring and at least one inner ring press-fitted into the small-diameter step portion, and having a double-row inner rolling surface opposed to the double-row outer rolling surface on the outer periphery And a plurality of rows of rolling elements rollably accommodated between the rolling surface between the inner rolling surface and the outer rolling surface, and the outer side opening of the outer member being fitted. In the bearing device for a wheel including the outer side sealing member for sealing between the outer member and the inner member, the pressure of the sealed space inside the bearing is set to a different pressure in the fitting portion. One cover is configured to be attachable from a plurality of different types of covers.

  The plurality of types of covers of the bearing apparatus for a wheel according to the second aspect of the present invention are formed in different shapes on the bottom surface of the uneven portions according to the shape of the inner end of the inner member. According to the shape, the sealed space is configured to have a desired size.

  The cover of at least one of the plurality of types of the bearing device for a wheel according to the third aspect of the present invention is formed such that a bottom surface is inserted into a recess formed at the inner end of the hub wheel.

  The effects of the present invention are as follows.

  That is, in the first aspect of the invention, since the fitting portion common to a plurality of types of covers is formed in the outward member of the wheel bearing device, the cover according to the environment in which the wheel bearing device is assembled Is fitted to the fitting portion of the outer member. Thereby, the pressure of the sealed space inside a bearing can be set to a desired magnitude | size by mounting | wearing one cover selected from several types of covers.

  The second invention is an outer member in which the size of the entire wheel bearing device and the cover are fitted by fitting one cover selected from a plurality of types of covers to an outer member having a common fitting portion. The volume of the enclosed space inside the bearing is controlled without changing the shape of the bearing. Thereby, the pressure of the sealed space inside a bearing can be set to a desired magnitude | size by mounting | wearing one cover selected from several types of covers.

  In the third invention, the volume of the sealed space inside the bearing is efficiently managed by forming a plurality of types of covers in consideration of the shape of a structure such as a hub ring disposed in the internal space. Thereby, the pressure of the sealed space inside a bearing can be set to a desired magnitude | size by mounting | wearing one cover selected from several types of covers.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows the whole structure of the bearing apparatus for wheels. Sectional drawing which shows the body structure of the bearing apparatus for wheels. The partially expanded sectional view which shows the state in which the cover for normal pressure was fitted by the bearing apparatus for wheels. The partially expanded sectional view which shows the state in which the cover for high voltages was fitted by the bearing apparatus for wheels. The partially expanded sectional view which shows the state in which the cover for normal pressure was fitted by the bearing initial stage by the bearing apparatus for wheels. The partially expanded sectional view which shows the state in which the cover for high voltages was fitted by the bearing initial stage by the bearing apparatus for wheels. The schematic diagram which shows a mode that the cover corresponding to the pressure change inside a bearing is fitted by the bearing apparatus for wheels. The part expanded sectional view which shows the relationship between the pressure inside a bearing when the cover for normal pressure is fitted with the bearing apparatus for wheels, and the pressure in the outside. The part expanded sectional view which shows the relationship between the pressure inside a bearing when the cover for high voltages was fitted by the bearing apparatus for wheels, and the pressure in the outside. (A) A partial enlarged cross-sectional view showing the fitting state of the cover in the case where the pressure in the bearing is substantially normal pressure in the second embodiment of the bearing device for a wheel, (b) similarly maintaining the pressure in the bearing at a high pressure The partial expanded sectional view which shows the fitting state of the cover in case. Partially enlarged sectional view showing the engaging groove formed in the outer ring of the wheel bearing device and the engaging claw formed in the cover, (b) similarly the cover is fitted to the outer ring, and the engaging claw is engaged with the engaging groove Is a partially enlarged cross-sectional view showing a state in which is engaged.

  Below, the bearing apparatus 1 for wheels which is one Embodiment of the bearing apparatus for wheels which concerns on this invention is demonstrated using FIG. 1 and FIG.

  As shown in FIGS. 1 and 2, the wheel bearing device 1 rotatably supports wheels in a suspension system of a vehicle such as a car. The wheel bearing device 1 includes an outer ring 2 which is an outer member, a hub wheel 3 which is an inner member, an inner ring 4, two inner ball rows 5a (see FIG. 2) which are rolling rows, and an outer ball row. 5b (see FIG. 2), a cover 6, an annular inner seal member 7 (see FIG. 2) provided on the cover 6, and an outer seal member 8 (see FIG. 2). Here, the inner side represents the vehicle 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. Further, the axial direction represents a direction along the rotation axis of the wheel bearing device 1.

  As shown in FIG. 2, the outer ring 2 supports the hub wheel 3 and the inner ring 4. The outer ring 2 is formed in a substantially cylindrical shape. The outer ring 2 is made of, for example, a medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C. The inner side opening 2a of the outer ring 2 is opened so that the cover 6 can be fitted, and the inner side seal fitting portion 2b and the cover fitting portion 2c are formed. On the inner peripheral surface of the outer ring 2, an inner outer side rolling surface 2 d formed in an annular shape and an outer side outer rolling surface 2 e are formed in parallel in the circumferential direction. A hardened layer having a surface hardness in the range of 58 to 64 HRC is formed, for example, by induction hardening on the inner side outer raceway surface 2d and the outer side outer raceway surface 2e. On an outer peripheral surface of the outer ring 2, a vehicle mounting flange 2 f for mounting on a member (knuckle) on the vehicle side (not shown) is integrally formed. An outer seal member 8 is formed in the outer opening 2 g of the outer ring 2 so as to be fittable.

  In the inner side opening 2a of the outer ring 2, an inner side seal fitting portion 2b and a cover fitting portion 2c are formed on the same axial center. The inner seal fitting portion 2 b is a hole into which the inner seal member 7 is fitted. The cover fitting portion 2 c is a hole into which the cover 6 is fitted. The cover fitting portion 2c is formed as a hole of a predetermined axial length from the outer side end of the inner seal fitting portion 2b with a predetermined outer diameter smaller than the seal fitting diameter of the inner seal fitting portion 2b. ing. That is, on the inner periphery of the inner side opening 2a of the outer ring 2, the inner side seal fitting portion 2b on the large diameter side and the cover fitting portion 2c on the small diameter side are formed sequentially from the outer side (inner side).

  The hub wheel 3 constituting the inward member rotatably supports wheels of a vehicle (not shown). The hub wheel 3 is formed in a cylindrical shape. The hub wheel 3 is made of, for example, a medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C. At the inner side end of the hub wheel 3, a small diameter step 3a whose diameter is reduced on the outer peripheral surface is formed. At the outer end of the hub wheel 3, a wheel mounting flange 3b for mounting the wheel is integrally formed. The wheel mounting flange 3b is provided with hub bolts 3e at circumferentially equidistant positions. An outer side inner raceway surface 3 c is formed on the hub wheel 3 so as to face the outer side outer raceway surface 2 e of the outer ring 2. Further, on the hub wheel 3, a lip sliding surface 3 d of the outer side sealing member 8 is formed on the base side of the wheel mounting flange 3 b. The inner ring 4 is fixed to the small diameter step 3 a of the hub wheel 3 by caulking. At the inner side end of the hub wheel 3, a caulking portion 3f plastically deformed so as to expand radially outward and a tool insertion hole 3g which is a recess into which a caulking tool is inserted are formed.

  The inner ring 4 is a rolling train and applies a preload to the inner side ball row 5a disposed on the vehicle body side when mounted on the vehicle and the outer side ball row 5b disposed on the wheel side when mounted on the vehicle. The inner ring 4 is formed in a cylindrical shape. The inner ring 4 is made of, for example, a high carbon chromium bearing steel such as SUJ 2 and is hardened in the range of 58 to 64 HRC up to the core portion by zubb hardening. An annular inner raceway surface 4 a is formed on the outer peripheral surface of the inner ring 4 in the circumferential direction. The inner ring 4 is fixed to the small diameter step 3 a of the hub wheel 3 by press-fitting and caulking. That is, on the inner side of the hub wheel 3, the inner race 4 is configured by the inner race 4. In the hub wheel 3, the inner raceway surface 4 a of the inner ring 4 at the inner side end faces the outer raceway surface 2 d on the inner side of the outer ring 2, and the inner raceway surface 3 c on the outer side is the outer side of the outer race 2 It is arrange | positioned so as to oppose the rolling contact surface 2e.

  The inner side ball row 5a and the outer side ball row 5b, which are rolling rows, rotatably support the hub wheel 3. In the inner ball row 5a and the outer ball row 5b, a plurality of balls, which are rolling elements, are annularly held by a cage. The inner side ball row 5a and the outer side ball row 5b are made of, for example, high carbon chromium bearing steel such as SUJ 2 and are hardened in the range of 62 to 67 HRC up to the core portion by slide quenching. The inner ball row 5 a is rollably interposed between the inner raceway surface 4 a of the inner ring 4 and the outer raceway surface 2 d on the inner side of the outer ring 2. The outer ball row 5 b is rotatably held between the inner raceway surface 3 c of the hub wheel 3 and the outer raceway surface 2 e on the outer side of the outer race 2. That is, the inner ball row 5 a and the outer ball row 5 b rotatably support the hub wheel 3 and the inner ring 4 with respect to the outer ring 2.

  In the wheel bearing device 1, a double-row angular contact ball bearing is configured by the outer ring 2, the hub wheel 3, the inner ring 4, the inner ball row 5 a and the outer ball row 5 b. In addition, in this embodiment, although the double row angular contact ball bearing is comprised by the bearing apparatus 1 for wheels, you may be comprised by bearings, such as a double row conical roller bearing.

  The cover 6 closes the inner side opening 2a of the outer ring 2 to prevent foreign matter such as muddy water and dust from entering from the outside, and sets the pressure inside the bearing to a desired size according to the environment. Here, “the pressure inside the bearing according to the environment” in the wheel bearing device 1 is different from the atmospheric pressure in the region where the wheel bearing device 1 is assembled and the atmospheric pressure in the region where the wheel bearing device 1 is used. In this case, the pressure difference between the pressure inside the bearing and the pressure in the area where it is used does not lower the sealability of the outer seal member 8 or increase the rotational resistance of the hub wheel 3 (inner ring 4). Say to adjust the pressure inside. Also, even if there is no difference in the atmospheric pressure between the area where the wheel bearing device 1 is assembled and the area where it is used, the pressure inside the bearing is adjusted by the temperature difference between the temperature of the area where it is assembled and the temperature of the area used. Also includes.

  The cover 6 is formed in a cylindrical shape having a bottom by pressing. The cover 6 is made of, for example, 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 anti-corrosion treatment (SPCC series etc. according to JIS standard) It consists of The cover 6 is integrally formed with a fitting portion 6a, a seal support portion 6b, and a bottom portion 6c. The seal support portion 6 b is provided with an annular inner seal member 7.

  A cylindrical fitting portion 6 a and a seal support portion 6 b are formed coaxially on the cylindrical portion of the cover 6. The fitting portion 6 a is a portion fitted to the cover fitting portion 2 c of the outer ring 2. The fitting portion 6 a is formed in a cylindrical shape at the open end of the cover 6. The fitting portion 6a is a cylinder smaller than the inner seal fitting portion 2b of the inner opening 2a and having an outer diameter and an axial length which can be press-fitted to the cover fitting portion 2c. That is, the fitting portion 6a is a cylinder having an outer diameter and an axial length which can be press-fitted to the cover fitting portion 2c without contacting the inner seal fitting portion 2b.

  The seal support portion 6 b is a portion that supports the inner seal member 7. The seal support portion 6b is formed in a cylindrical shape via a step portion extending radially inward at a position adjacent to the fitting portion 6a. That is, the seal support portion 6b is a cylinder in which the bottom portion 6c side in the axial direction from an arbitrary position on the outer peripheral surface of the cover 6 is formed to have an outer diameter smaller than that of the fitting portion 6a. Thus, the seal support portion 6b forms a space in which the inner seal member 7 can be disposed between the seal support portion 6b and the inner peripheral surface of the cover fitting portion 2c.

  The bottom 6 c which is the bottom of the cover 6 is a portion that covers the inner opening 2 a of the outer ring 2. The bottom 6 c is formed in a disk shape at a position adjacent to the seal support 6 b. That is, the bottom portion 6c constitutes a bottom surface for closing one of the cylindrically formed covers 6. The bottom portion 6c has a convex portion 6d cylindrically projected around the axial center of the cover 6 as an uneven portion for adjusting the volume inside the bearing, and an axial center of the cover 6 with an inner diameter smaller than the outer diameter of the convex portion 6d. And a concave portion 6e which is recessed in a cylindrical shape centering on the That is, in the bottom portion 6c, an annular convex portion 6d having a predetermined width and a cylindrical concave portion 6e are formed inside thereof. In the present embodiment, although one convex portion 6d and one concave portion 6e which are concave and convex portions are formed in the bottom portion 6c, at least one of the convex portion 6d and the concave portion 6e is formed as the concave and convex portions. The plurality of convex portions 6 d and the concave portions 6 e may be respectively formed.

  The annular inner seal member 7 closes the gap between the outer ring 2 and the cover 6. The inner seal member 7 is bonded by vulcanization to the outer peripheral surface of the seal support portion 6 b of the cover 6. That is, the inner side seal member 7 is provided adjacent to the fitting portion 6a. The inner side sealing member 7 is made of, for example, NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated acrylonitrile butadiene rubber) excellent in heat resistance, EPDM (ethylene propylene rubber), ACM (polyamide excellent in heat resistance and chemical resistance) It is made of synthetic rubber such as acrylic rubber), FKM (fluorinated rubber), or silicone rubber.

  In this manner, the cover 6 is fixed to the outer ring 2 by fitting the fitting portion 6a to the cover fitting portion 2c of the inner side opening 2a of the outer ring 2 and seals the inner side opening 2a. ing. Further, the inner seal member 7 provided on the cover 6 closes the gap between the outer ring 2 and the cover 6 by being in close contact with the inner seal fitting portion 2 b.

  The outer side seal member 8 mainly closes the gap between the outer ring 2 and the hub wheel 3. In the outer seal member 8, a plurality of seal lips made of synthetic rubber such as NBR (acrylonitrile-butadiene rubber) are bonded by vulcanization to a substantially cylindrical core metal. The outer seal member 8 has a cylindrical portion fitted to the outer opening 2g of the outer ring 2, and a plurality of seal lips are in contact with or close to the lip sliding surface 3d of the hub wheel 3 via the oil film. It is configured to be slidable with respect to 3. Thus, the outer seal member 8 prevents the leakage of the lubricating grease from the outer opening 2g of the outer ring 2 and the entry of foreign matter such as rain water and dust from the outside. In addition, various specifications exist in the outer side sealing member 8, and it is not limited to the specification of this embodiment. Further, the inner seal member 7 and the outer seal member 8 are bonded by vulcanizing a lip or the like to a core metal or the like, but other bonding methods may be used.

  In the wheel bearing device 1 configured as described above, the hub wheel 3 and the inner ring 4 are rotatably supported by the outer ring 2 via the inner ball row 5a and the outer ball row 5b. In the wheel bearing device 1, the gap between the inner opening 2 a of the outer ring 2 and the inner ring 4 is closed by the cover 6, and the gap between the outer opening 2 g of the outer ring 2 and the hub wheel 3 is the outer seal It is closed by a member 8. Thus, in the wheel bearing device 1, the hub wheel 3 and the inner ring 4 supported by the outer ring 2 rotate while preventing leakage of lubricating grease from the inside and intrusion of rain water and dust from the outside.

  Next, the pressure inside the bearing by fitting the cover 6 to the wheel bearing device 1 will be described using FIGS. 3 to 6. In the wheel bearing device 1, any one of the normal pressure cover 6L and the high pressure cover 6H having different shapes of the convex portion 6d and the concave portion 6e formed on the bottom portion 6c of the cover 6 is selected and the outer ring It is assumed that the inner side opening 2a of 2 is fitted. Inner side opening 2a which is a fitting part of cover 6L and cover 6H is formed as a fitting part common to cover 6L and cover 6H. The cover 6L and the cover 6H are fitted to the inner opening 2a with the same fitting length Fl. That is, the cover 6L and the cover 6H are fitted to the wheel bearing device 1 in the same positional relationship. The fitting length Fl is a final fitting position P2 at which the press-fit from the initial fitting position P1 in the initial state in which the cover 6 seals the inner opening 2a to the inner opening 2a is completed. The length up to (see Figures 3 to 6).

  As shown in FIG. 3, the cover 6 </ b> L for normal pressure is a predetermined value (hereinafter simply referred to as “normal pressure reference value”) which approximates the pressure inside the bearing of the wheel bearing device 1 which rises by fitting to the external atmospheric pressure. Note) is set as follows. The cover 6L is formed such that the convex portion 6d formed on the bottom portion 6c follows the shape of the crimped portion 3f of the hub wheel 3 in the state of being fitted in the final fitting position P2. On the other hand, in the cover 6L, the recess 6e (see FIG. 2) is not formed in the bottom 6c. That is, in the cover 6L, only the convex portion 6d which protrudes in a cylindrical shape is formed at the bottom portion 6c. In the cover 6 </ b> L, a crimped portion 3 f is disposed inside (the bearing inside) of the convex portion 6 d. A gap with a width WLf is formed between the outer side surface of the convex portion 6d and the inner side surface of the crimped portion 3f. A gap of width WLg is formed between the outer side surface of the convex portion 6d and the inner side surface of the tool insertion hole 3g.

  As shown in FIG. 4, the cover 6H for high pressure is a range of a predetermined value in which the pressure inside the bearing of the wheel bearing device 1 which rises due to fitting is higher than the external atmospheric pressure (hereinafter simply referred to as “high pressure lower limit value It is set in the range of “high pressure upper limit value”). In the cover 6H, in the state of being fitted in the final fitting position P2, the convex portion 6d and the concave portion 6e formed in the bottom portion 6c conform to the shape of the crimped portion 3f of the hub wheel 3 and the tool insertion hole 3g. It is formed as. In the cover 6H, the crimped portion 3f is disposed in the inside (bearing inner side) of the convex portion 6d. Between the outer side surface of the convex portion 6d and the inner side surface of the crimped portion 3f, a gap having a width WHf which does not contact each other (for example, about 2 mm) is formed. In addition, the cover 6H is disposed such that the recess 6e is inserted into the inside of the tool insertion hole 3g. Between the outer side surface of the recess 6e and the inner side surface of the tool insertion hole 3g, a gap having a width WHg which does not contact each other (for example, about 1 mm) is formed.

As shown in FIGS. 5 and 6, in the wheel bearing device 1, the cover 6L and the outer ring are selectively engaged with one of the cover 6L and the cover 6H at the initial fitting position P1. 2. Sealed space SL which is a space surrounded by hub wheel 3, inner ring 4 and outer side seal member 8 (see thin ink portion in FIG. 5), cover 6H, outer ring 2, hub ring 3, inner ring 4 and outer side seal The volume of the enclosed space SH (see FIG. 6 thin ink portion) which is a space surrounded by the member 8 is changed.
As shown in FIG. 6, the volume of the enclosed space SH when the cover 6H is fitted to the wheel bearing device 1 is the volume of the enclosed space SL when the cover 6L is fitted to the wheel bearing device 1. The product of the difference between the projected area of the convex portion 6d of the cover 6H in the axial direction and the gap between the convex portion 6d (width WLf-width WHf) and the projection of the concave portion 6e of the cover 6H in the axial direction It is smaller by the total value of the difference between the area and the gap of the recess 6 e (width WLg−width WHg).

  In the wheel bearing device 1, the closed space SH or the closed space SL is compressed by the same volume as the cover 6L or the cover 6H is fitted to the final fitting position P2. The pressure inside the bearing when the cover 6H or the cover 6H is fitted to the final fitting position P2 of the wheel bearing device 1 is a compressed volume of the enclosed space SH or of the enclosed space SL according to Boyle's law. The higher the percentage, the higher. That is, the pressure inside the bearing when the cover 6H is fitted to the final fitting position P2 of the wheel bearing device 1 is the same as the final fitting position P2 of the wheel bearing device 1 at the final fitting position. It is higher than the pressure inside the bearing when it is fitted. As described above, the wheel bearing device 1 changes the shapes of the convex portion 6 d and the concave portion 6 e of the cover 6 constituting the sealed space SH or the sealed space SL, so that the cover 6 H and the cover 6 L It is comprised as several types of covers which set the pressure of sealed space SH or the pressure of sealed space SL to a respectively different pressure. The wheel bearing device 1 can set the pressure inside the bearing to a desired pressure by selecting and fitting one cover from the cover 6H and the cover 6L. In the present embodiment, the plurality of types of covers are composed of the cover 6H and the cover 6L, but may be composed of three or more covers having different shapes of the convex portion 6d and the concave portion 6e.

  Next, using FIG. 7 to FIG. 9, for example, the case where the wheel bearing device 1 is assembled in the area of altitude (for example, altitude less than 100 m) where atmospheric pressure is approximately 1 atm, The setting of the pressure inside the bearing by the cover 6H or the cover 6L in a case where the wheel bearing device 1 is assembled in a low altitude area (for example, 3000 m altitude) will be specifically described. In the present embodiment, the wheel bearing device 1 is used, for example, in an area at an altitude (e.g., less than 100 m) where the atmospheric pressure is approximately 1 atm. That is, the wheel bearing device 1 holds the seal lip of the outer side seal member 8 against the sliding surface at the time of use by assembling so that the pressure inside the bearing is approximately 1 atmospheric pressure the same as the atmospheric pressure in the area used. It is possible to suppress the generation of a force or a force to separate from the sliding surface.

  As shown in FIG. 7, when the wheel bearing device 1 is assembled in an area of high altitude where the atmospheric pressure is approximately 1 atm (low altitude), the cover 6 L for low ground is used, and the atmospheric pressure is lower than 1 atm. The high altitude cover 6H is used when assembling in the area of high altitude (high altitude). In addition, when the wheel bearing device 1 is assembled in a region of lower temperature than the temperature of the region of use, the cover 6L for low temperature is used, and is assembled in the region of temperature higher than the temperature of the region of use. In the case, a cover 6H for high temperature is used. Furthermore, the wheel bearing device 1 uses the cover 6L for low temperature when the temperature at the time of assembly is lower than the average temperature (for example, in winter) in the same regional environment as the region where it is used The cover 6H for high temperature is used when the assembly temperature is higher than the average temperature (for example, in summer).

  As shown in FIG. 8, when the wheel bearing device 1 is assembled in an area at an altitude where the atmospheric pressure is approximately 1 atm (see black arrows), the area where the wheel bearing device 1 is assembled and the area used Because the atmospheric pressure is substantially the same, the wheel bearing device 1 needs to be assembled so that the pressure inside the bearing does not increase significantly due to the fitting of the cover 6. Therefore, the cover 6L in which the pressure rise inside the bearing due to the fitting becomes equal to or less than the normal pressure reference value is selected for the wheel bearing device 1 assembled in the area of altitude where the atmospheric pressure is approximately 1 atm.

  Furthermore, when the wheel bearing device 1 is assembled in an area lower than the temperature of the area used, the air density in the area in which the wheel bearing device 1 is assembled is higher than the air density in the area used. Or, if the temperature at the time of assembly is lower than the average temperature in the same regional environment as the region where it is used and the region where it is assembled, the air density when the wheel bearing device 1 is assembled is the air density at other times Higher than. It is necessary to assemble the wheel bearing device 1 so that the pressure inside the bearing does not increase significantly due to the fitting of the cover 6. Therefore, for the wheel bearing device 1 assembled in a region of lower temperature or at a lower temperature than the temperature of the region used, the cover 6L in which the pressure rise inside the bearing due to the fitting becomes lower than the normal pressure reference value is selected Be done.

  The wheel bearing device 1 is axially moved toward the cover fitting portion 2c of the outer ring 2 without the fitting portion 6a of the cover 6L coming into contact with the inner peripheral surface of the inner seal fitting portion 2b (white See painted arrows). When the end of the fitting portion 6a reaches the inner end of the cover fitting portion 2c of the outer ring 2, the cover 6L is fitted to the inner end of the cover fitting portion 2c at the initial fitting position P1 The space SL is configured (see FIG. 5). Further, the cover 6L is inserted toward the axial outer side by the fitting length Fl, and reaches the final fitting position P2. In the wheel bearing device 1, the pressure inside the bearing (refer to the thin black portion) is increased by the cover 6L being fitted to the final fitting position P2, but the pressure inside the bearing is normal pressure based on the shape of the convex portion 6d. It is set to a value or less (see dark thin black arrows).

  As shown in FIG. 9, when the wheel bearing device 1 is assembled in the area where the atmospheric pressure is lower than 1 atm (see solid arrows) (e.g., 3000 m), the area in which the wheel bearing device 1 is assembled Since the atmospheric pressure is lower than the atmospheric pressure in the area where it is used, the wheel bearing device 1 needs to be assembled so that the pressure inside the bearing is increased to a predetermined range by the engagement of the cover 6. Therefore, for the wheel bearing device 1 assembled in an area where the atmospheric pressure is lower than 1 atmospheric pressure, the cover 6H in which the pressure rise inside the bearing due to the fitting is higher than the high pressure lower limit and lower than the high pressure upper limit is selected. .

  Furthermore, when the wheel bearing device 1 is assembled in an area higher than the temperature of the area used, the air density in the area where the wheel bearing device 1 is assembled is lower than the air density in the area used. Alternatively, if the temperature at the time of assembly is higher than the average temperature in an area environment where the area to be used and the area to be assembled are the same, the air density at the time the wheel bearing device 1 is assembled is the air density at other times Lower than. The wheel bearing device 1 needs to be assembled such that the pressure inside the bearing is increased to a predetermined range by fitting the cover 6. Therefore, in the wheel bearing device 1 assembled in a region of higher temperature or a region of higher temperature than the temperature of the region used, the pressure rise inside the bearing due to the fitting becomes higher than the high pressure lower limit and lower than the high pressure upper limit The cover 6H is selected.

  The wheel bearing device 1 is axially moved toward the cover fitting portion 2c of the outer ring 2 without the fitting portion 6a of the cover 6H coming into contact with the inner peripheral surface of the inner seal fitting portion 2b (white See painted arrows). When the end of the fitting portion 6a reaches the inner end of the cover fitting portion 2c of the outer ring 2, the cover 6H is fitted to the inner end of the cover fitting portion 2c at the initial fitting position P1 The space SH is configured (see FIG. 6). Further, the cover 6L is inserted toward the axial outer side by the fitting length Fl, and reaches the final fitting position P2. In the wheel bearing device 1, the pressure inside the bearing (refer to the thin black portion) is increased by the cover 6H being fitted to the final fitting position P2, but the pressure inside the bearing is the high pressure lower limit value due to the shape of the convex portion 6d. As mentioned above, it is set below the high pressure upper limit (refer dark thin black arrow). As a result, the wheel bearing device 1 is selectively fitted with the cover 6L or the cover 6H according to the atmospheric pressure in the area of use, so that the pressure difference between the pressure inside the bearing and the atmospheric pressure in the area of use It is within the allowable value, and the wear of the seal lip and the increase of the rotational torque due to the force for pressing the seal lip of the seal member against the slide surface and the force for separating the seal lip from the slide surface are suppressed.

  By configuring in this manner, the wheel bearing device 1 selects the cover 6L or the cover 6H formed in a predetermined shape according to the environment in which assembly is performed, and engages the outer ring 2 with the initial fit. The volume of the sealed space SL · SH inside the bearing at the mating position P1 and the volume inside the bearing at the final mating position P2 are managed. That is, the volume of sealed space SL * SH inside a bearing is managed, without changing the whole size of the bearing apparatus 1 for wheels, and the shape of the outer ring 2 with which the cover 6 is fitted. Since the cover 6L or the cover 6H is formed in consideration of the shape of the structure such as the hub wheel 3 disposed in the internal space of the wheel bearing device 1, it is possible to efficiently form the sealed space SL · SH inside the bearing. Volume is managed. Thus, the pressure inside the bearing can be set to a desired level with a simple structure.

  In the wheel bearing device 1, the cover 6 is formed along the shape of the hub wheel 3 or the like, but the hub wheel 3 may be formed along the shapes of the covers 6L and 6H. That is, the wheel bearing device 1 adjusts the volume inside the bearing by changing the shape of the inner side of the hub wheel 3 with the shapes of the covers 6L and 6H and the final fitting positions P2 of the covers 6L and 6H fixed. The pressure inside the bearing may be set to a desired pressure.

  Next, a wheel bearing device 9 which is a second embodiment of the wheel bearing device according to the present invention will be described using FIGS. 10 and 11. The wheel bearing device 9 according to each of the following embodiments is the name used in the description as the wheel bearing device 1 is applied instead of the wheel bearing device 1 in the wheel bearing device 1 shown in FIGS. 1 to 9. The same reference numerals will be used to indicate the same parts, and in the following embodiments, the same points as those in the embodiments already described will be omitted from the specific description, and different parts will be mainly described. .

  The pressure inside the bearing by fitting the cover 6 to the wheel bearing device 9 will be described with reference to FIG. In the wheel bearing device 9, the cover 6 is fitted to one of the final fitting position P3 and the final fitting position P4 defined in the inner side opening 2a of the outer ring 2. That is, the cover 6 is fitted at the final fitting position where the inside of the bearing of the wheel bearing device 9 has a desired pressure. The fitting length F3 is a length from an initial fitting position P1 which is an initial state in which the cover 6 seals the inner side opening 2a to a final fitting position P3 (see FIG. 10A). The fitting length F4 is a length from the initial fitting position P1 to the final fitting position P4 (see FIG. 10 (b)).

  As shown in FIG. 10 (a), the final fitting position P3 of the wheel bearing device 9 sets the pressure inside the bearing of the wheel bearing device 9 that rises by the fitting of the cover 6 below the normal pressure reference value. It is a position. When the wheel bearing device 9 is assembled in an area at an altitude where the atmospheric pressure is approximately 1 atm (see solid arrows), the atmospheric pressure in the area where the wheel bearing device 9 is assembled and the area in which it is used is substantially the same. Because the wheel bearing device 9 is provided, the cover 6 is fitted at the final fitting position P3 at which the pressure rise inside the bearing due to the fitting becomes equal to or less than the normal pressure reference value. When the end of the fitting portion 6a reaches the inner end of the cover fitting portion 2c of the outer ring 2, the cover 6 is fitted to the inner end of the cover fitting portion 2c which is the initial fitting position P1. Further, the cover 6L is inserted toward the outer side in the axial direction by the fitting length F3, and is fitted at the final fitting position P3 in which the pressure inside the bearing is maintained at the normal pressure reference value or less.

  As shown in FIG. 10 (b), the final fitting position P4 of the wheel bearing device 9 is such that the pressure inside the bearing of the wheel bearing device 9 is raised by the fitting of the cover 6 from the high pressure lower limit value to the high pressure upper limit value. It is set to the range. When the wheel bearing device 9 is assembled in an area where the atmospheric pressure is lower than 1 atmospheric pressure (see solid arrows), the atmospheric pressure of the area where the wheel bearing device 9 is assembled is higher than the atmospheric pressure of the area where it is used. Because the wheel bearing device 9 is low, the cover 6 is fitted in the final fitting position P4 in which the pressure increase inside the bearing due to the fitting is not less than the high pressure lower limit value and not more than the high pressure upper limit value. When the end of the fitting portion 6a reaches the inner end of the cover fitting portion 2c of the outer ring 2, the cover 6 is fitted to the inner end of the cover fitting portion 2c which is the initial fitting position P1. Further, the cover 6 is inserted toward the outer side in the axial direction by the fitting length F4, and is fitted to the final fitting position P4 in which the pressure inside the bearing is maintained at the high pressure lower limit value and the high pressure upper limit value. .

  By configuring in this manner, the wheel bearing device 9 can set the pressure inside the bearing by changing the fitting length of the cover 6. That is, the wheel bearing device 9 makes the pressure inside the bearing an environment by fitting the cover 6 to either the final fitting position P3 or the final fitting position P4 and changing the fitting length. The desired pressure can be set accordingly. In addition, the wheel bearing device 9 selectively fits the cover at a predetermined final fitting position according to the environment in which the assembly is performed, whereby the entire size of the wheel bearing device 9 and the cover 6 are fitted. The pressure inside the bearing can be set to a desired pressure according to the environment without changing the shape of the outer ring 2 to be made.

  Further, as shown in FIG. 11 (a), when the final fitting position is changed, the fitting length inside the bearing is reduced, and when the pullout resistance of the cover 6 can not be secured only by the fitting force, the wheel bearing device The cover 9 is engaged with the outer ring 2 to compensate for the fitting force. In the wheel bearing device 9, an annular engagement groove 2h is formed at the inner side opening 2a of the outer ring 2, and the engagement device is a bar that protrudes annularly outward at the fitting portion 6a of the cover 6L. Joint claws 6 f are formed. As shown in FIG. 10 (b), in the wheel bearing device 9, when the cover 6 is inserted into the inner opening 2a and reaches the final fitting position P3, the engaging claw 6f is engaged with the engaging groove 2h. Be done. The wheel bearing device 9 can prevent the detachment due to the insufficient fitting force of the cover 6.

  The wheel bearing devices 1 and 9 in the present application have an outer ring 2 which is an outer member having a mounting flange and an inner member which includes a hub wheel 3 to which one inner ring 4 is fitted as an inner member. The third generation structure of the inner ring rotation specification constituted by the fitting body of the inner ring 4 and the hub ring 3, but an outer ring 2 which is an outer member having a mounting flange and a pair of inner rings 4 which is an inner member It may be a second generation structure of the inner ring rotation specification in which the pair of inner rings 4 are fitted on the outer periphery of the hub wheel 3.

  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.

1, 9 Wheel bearing device 2 Outer ring 2a Inner side opening 2b Inner side seal fitting portion 2c Cover fitting portion 3 Hub wheel 3a Small diameter step 4 Inner ring 5a Inner side ball row 5b Outer side ball row 6 Cover 8 Outer side Seal member SL, SH Sealed space

Claims (3)

An outer member having a plurality of rows of outer raceways formed on the inner periphery and a fitting portion into which the cover is fitted;
A hub ring having a small diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fit into the small diameter step portion, and a double row inner side facing the outer row rolling surface on the outer periphery An inner member having a rolling surface formed thereon,
Double rows of rolling elements rollably accommodated between the inner rolling surface and the outer rolling surface;
In the bearing apparatus for a wheel, the outer side sealing member fitted to the outer side opening of the outer side member and sealing between the outer side member and the inner side member is provided.
A bearing apparatus for a wheel according to any of the preceding claims, wherein one of a plurality of types of covers for setting the pressure of the sealed space inside the bearing to different pressures is attachable to the fitting portion.   The plurality of types of covers are formed in different shapes on the bottom surface of the inner side end of the inner member in the shape of the uneven portion, and the shape of the uneven portion has a desired size according to the shape of the uneven portion. The wheel bearing apparatus according to claim 1, wherein the bearing apparatus is configured to:   The wheel bearing device according to claim 1 or 2, wherein at least one of the plurality of types of the cover is formed such that a bottom surface is inserted into a recess formed at an inner end portion of the hub wheel.

Images