JP5227144B2 - Wheel bearing - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a wheel bearing for rotatably supporting a wheel of an automobile or the like, and more particularly to a wheel bearing that prevents an inner ring from falling off by a cage and can be easily assembled without damaging rolling elements. .

  Conventionally, a wheel bearing device for supporting a wheel of an automobile or the like is such that a hub wheel for mounting a wheel is rotatably supported via a wheel bearing composed of a double row rolling bearing. In general, a double-row angular ball bearing having a desired bearing rigidity, exhibiting durability against misalignment, and above all, having a small rotational torque from the viewpoint of improving fuel efficiency is frequently used. On the other hand, double row tapered roller bearings are used in vehicles such as off-road cars and trucks that have a heavy vehicle body weight.

  Further, the wheel bearing device has a structure called a first generation in which a wheel bearing composed of a double row angular ball bearing or the like is fitted between a knuckle and a hub wheel constituting a suspension device. A second generation structure in which a vehicle body mounting flange or a wheel mounting flange is directly formed on the outer periphery of the side member, a third generation structure in which one inner rolling surface is directly formed on the outer periphery of the hub wheel, or a hub wheel It is roughly classified into a fourth generation structure in which the inner rolling surface is directly formed on the outer periphery of the outer joint member of the constant velocity universal joint.

  The wheel bearing shown in FIG. 11 is a typical example. This wheel bearing 50 is referred to as a first generation, and an outer ring 51 in which arc-shaped double-row outer rolling surfaces 51a and 51a are formed on the inner periphery, and the double-row outer rolling surfaces 51a and 51a on the outer periphery. A pair of inner rings 52, 52 formed with an arcuate inner rolling surface 52a facing each other, double-row balls 53, 53 accommodated between both rolling surfaces, and these balls 53 can roll freely. The holders 54 and 54 for holding are provided. The pair of inner rings 52, 52 are set in a state where the end surfaces on the small diameter side (front side) are butted together to form a so-called back-to-back type double row angular ball bearing.

  In this type of double-row rolling bearing 50, balls 53 are incorporated in a retainer 54 in advance, and these retainer sub-assemblies are inserted into the double-row outer rolling surfaces 51a and 51a from both sides of the outer ring 51, respectively. Thereafter, a pair of inner rings 52, 52 are fitted and inserted from both sides of the outer ring 51, and a seal (not shown) is attached to the opening of the annular space formed between the outer ring 51 and the inner ring 52 to complete the assembly. To do.

  The retainer 54 includes a base 55 having a small diameter, a column 56 extending gradually from the base 55 toward the distal end side 56a, and a pocket 57 formed between the columns 56. 56a is formed with an outer-diameter protruding portion 58 that protrudes in a cylindrical shape that is tapered in the bearing outer-diameter direction from the outer-diameter peripheral surface 56b. The outer diameter dimension of the retainer 54 has an outer diameter dimension D2 that is slightly smaller than the maximum diameter D1 of the outer rolling surface 51a when the bearing is assembled. Further, on the outer side in the axial direction of the outer raceway surface 51a of the outer ring 51 (see the left-pointing arrow in the figure), the outer diameter of the outer diameter protrusion 58 is smaller than the outer diameter D2 in the bearing inner diameter direction. A small diameter portion 59 projecting with an inner diameter dimension D3 is continuously formed in the circumferential direction. The cross-sectional shape of the small-diameter portion 59 has a shape in which both skirt portions gently bulge from the maximum diameter D1 of the outer rolling surface 51a.

  When the cage sub-assembly is inserted into the outer rolling surface 51a, the small-diameter portion 59 presses the outer-diameter protruding portion 58 of the cage 54 in the bearing axial direction (see the downward arrow in the figure). At this time, the retainer 54 is bent in the bearing axial direction (refer to the downward arrow in the drawing) together with the ball 53 accommodated in the pocket 57 due to its elasticity, and the outer diameter dimension D2 and the small diameter part 59 of the outer diameter protrusion 58 are obtained. Are equal in inner diameter dimension D3. Thereby, the ball 53 passes through the small diameter portion 59 without contacting the small diameter portion 59. Further, since the rolling surface 53a of the ball 53 does not collide with the small diameter portion 59 of the outer ring 51 when inserted into the outer rolling surface 51a, there is no friction and the rolling surface 53a is not damaged. .

  Further, after the cage sub-assembly is inserted into the outer rolling surface 51a, the cage 54 is released by the restoring force to be restored to the neutral state. At this time, the outer diameter dimension D2 of the outer diameter protruding portion 58 of the retainer 54 is larger than the inner diameter dimension D3 of the smaller diameter portion 59 of the outer ring 51 and is caught by the smaller diameter portion 59. It will not drop out.

  Further, an inner diameter protruding portion 60 protruding in the bearing inner diameter direction is provided on the inner diameter surface 55 a of the base portion 55 of the cage 54. Further, the inner ring 52 is continuously formed with a concave groove 61 at a position where the inner ring 52 can be engaged with the inner diameter protrusion 60 of the retainer 54 after the inner ring 52 is assembled.

When the inner ring 52 is inserted, the inner diameter protruding portion 60 of the retainer 54 is pushed by the end face of the inner ring 52 and is bent by its elasticity, so that the inner ring 52 can be pushed toward a predetermined position. When the inner ring 52 is pushed into a predetermined position, the position of the inner diameter protrusion 60 of the retainer 54 and the position of the recessed groove 61 of the inner ring 52 coincide with each other. Thus, the inner diameter protruding portion 60 of the cage 54 and the concave groove 61 of the inner ring 52 are fitted. Thereby, the retainer 54 is positioned at a predetermined position.
JP 2008-144813 A

  However, in such a conventional wheel bearing 50, after the inner ring 52 is inserted, the bending force is released by the restoring force of the inner diameter protruding portion 60 of the cage 54, and the inner diameter protruding portion 60 of the cage 54 and the inner ring 52 are recessed. When the groove 61 is fitted, the inner ring 52 does not easily fall off, but sufficient consideration is not given to the insertability of the retainer 54, the proof strength, and the low torque. That is, the insertability of the inner ring 52 is greatly affected by the position of the inner diameter protrusion 60 of the cage 54 in the inner ring 52, the cage 54 is damaged, or the groove shoulders of the inner ring 52 and the outer ring 51 There was a risk that the rolling surface 53a of the ball 53 would be damaged.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a wheel bearing that can be easily assembled without damaging the rolling elements while preventing the inner ring from falling off by a cage. .

  In order to achieve the object, the invention according to claim 1 of the present invention includes an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and an outer rolling surface of the double row on the outer periphery. An inner member in which double-row inner rolling surfaces facing each other are formed, a double-row rolling element accommodated so as to be freely rollable between the two rolling surfaces, and the rolling elements at equal intervals in a pocket. A retainer made of synthetic resin to be held, and a protrusion is formed on the annular inner peripheral surface of the retainer so as to protrude radially inward, and the inner member has a separate inner ring. In the wheel bearing in which the protrusion of the cage is engaged with the annular concave groove formed on the outer periphery of the small diameter side end of the inner ring, the small diameter extends from the small diameter side end surface of the inner ring to the concave groove. A guide surface having a predetermined inclination angle with respect to the outer peripheral surface is formed, and the inner diameter of the protrusion of the cage is equal to the outer diameter of the guide surface. They are formed slightly larger diameter.

  As described above, a cage made of a synthetic resin that holds the rolling elements in the pockets at equal intervals is provided, and a projection formed to project radially inward is formed on the annular inner peripheral surface of the cage. In the wheel bearing in which the inner member has a separate inner ring and the projection of the cage is engaged with the annular groove formed on the outer periphery of the small diameter side end of the inner ring, the inner ring is separated from the small diameter side end surface of the inner ring. A guide surface having a predetermined inclination angle with respect to the outer peripheral surface on the small diameter side is formed over the concave groove, and the inner diameter of the protrusion of the cage is slightly larger than the outer diameter of the guide surface. Therefore, when the inner ring is fitted and inserted, the protrusion of the cage is pushed by the guide surface of the inner ring, and the cage is bent by its elasticity, so that the inner ring can be pushed toward a predetermined position. As a result, it is possible to provide a wheel bearing that prevents the inner ring from falling off by the cage, improves the insertability of the inner ring, and can be easily assembled without damaging the rolling elements.

  Preferably, if the inclination angle of the guide surface of the inner ring is set in the range of 10 to 30 ° as in the invention described in claim 2, the allowance of the protrusion of the cage to the concave groove of the inner ring is increased. The inner ring can be inserted, and the inner ring can be smoothly inserted without hindering the elastic deformation in the radial direction of the cage.

  Further, as in a third aspect of the present invention, when a plurality of protrusions of the cage are arranged in the circumferential direction, the rigidity of the cage can be secured and the inner ring can be secured without being damaged. Insertability can be improved.

  Preferably, as in the invention described in claim 4, if the protrusions are respectively disposed at positions corresponding to the pockets of the cage, the rigidity of the cage can be ensured and the cage can be secured when the inner ring is inserted. Elastic deformation is uniformly performed, and the insertability of the inner ring can be improved without damaging the cage.

  Further, as in the invention according to claim 5, the protrusion of the cage has a locking surface that hangs at a substantially right angle from the inner peripheral surface of the cage, and is opposed to the locking surface from a predetermined inclination angle. If the guide surface is provided, the pulling strength of the inner ring can be secured, and the insertability of the inner ring can be improved without damaging the cage.

  Further, as in the invention described in claim 6, the width dimension of the protrusion of the cage is set smaller than the width dimension of the concave groove of the inner ring, and the width dimension of the protrusion and the inner diameter position of the protrusion are If the dimensional difference with the width dimension of the concave groove is set in the range of 0.5 to 1.5 mm, the protrusion of the cage interferes with the concave groove during operation and the rotational torque of the bearing increases. In addition to preventing this, it is possible to improve the reliability by preventing the wear of the protrusions.

  Further, as in the invention according to claim 7, the inscribed circle diameter of the rolling element is set larger than the outer diameter of the outer peripheral surface on the small diameter side of the inner ring, and the inner diameter of the protrusion of the cage is If the inner ring is set to have a larger diameter than the outer diameter of the concave groove, the rolling element can be prevented from coming into contact with the inner ring when the inner ring is inserted, and the cage can be moved in the radial direction by the pocket clearance. Even so, it can prevent the protrusion from interfering with the groove,

  Further, as in the invention described in claim 8, the hook allowance h1 of the protrusion of the cage with respect to the inner ring is set in a range of 0.2 to 0.3 with respect to the height H of the protrusion (h1 / H = 0.2-0.3), the pulling strength of the inner ring can be secured sufficiently, and the cage can be bent without difficulty when the inner ring is inserted, and the inner ring can be inserted without damaging the cage. Can increase the sex.

  Further, as in the ninth aspect of the present invention, if the same grease as the grease enclosed in the bearing is previously applied to the outer peripheral surface on the small diameter side and the guide surface of the inner ring, the cage is damaged when the inner ring is inserted. The insertability of the inner ring can be further enhanced without being attached.

  Further, as in the invention described in claim 10, a chamfered portion is formed at a corner portion of the guide surface of the inner ring and a small diameter side end surface, and the small diameter side outer peripheral surface of the inner ring, the guide surface and the chamfered portion are If it is formed by grinding with a general grinding wheel at the same time as the inner rolling surface, the dimensional accuracy will be improved and the coaxiality will be as high as possible, and the cage will bend flexibly when the inner ring is inserted. The insertability of the inner ring can be improved without being damaged.

  Further, as in the invention described in claim 11, a counter portion is formed in the vicinity of the outer rolling surface of the outer member, and the inner diameter of the counter portion is set larger than the outer diameter of the cage. In addition, if the height h2 of the counter portion is set in a range of h2 / Dw = 0.07 to 0.10 with respect to the outer diameter Dw of the rolling element, the cage sub-assies are rolled outward. When inserting into the surface, the rolling element can smoothly pass through the counter unit without the counter unit coming into contact with the cage, and the cage is not abraded or damaged. In addition, when the cage sub-assembly is inserted into the outer rolling surface, abnormal rolling is not caused and damaged, and the cage sub-assembly does not fall off after being inserted into the outer rolling surface.

  In addition, as in the invention described in claim 12, the corner portion of the counter portion of the outer member is formed in an arc shape, and the counter portion and the corner portion are formed on the outer rolling surface and the inner diameter of the double row. If it is formed by grinding with a grinding wheel at the same time as the surface, the dimensional accuracy and concentricity of the counter part and its corner part can be improved as much as possible, and the corner part of the counter part can be formed smoothly. When the cage sub-assembly is inserted, the insertability can be improved without damaging the rolling elements.

  The wheel bearing according to the present invention includes an outer member in which a double-row outer rolling surface is integrally formed on an inner periphery, and a double-row inner rolling surface that faces the outer rolling surface of the double-row on an outer periphery. An inner member formed with a plurality of rolling elements that are slidably accommodated between both rolling surfaces, and a synthetic resin cage that holds the rolling elements in a pocket at equal intervals. A protrusion is formed on the annular inner peripheral surface of the retainer so as to protrude radially inward, and the inner member has a separate inner ring, and the outer periphery of the small-diameter side end of the inner ring In the wheel bearing in which the projection of the cage is engaged with the annular concave groove formed in the inner ring, a predetermined inclination angle with respect to the outer peripheral surface of the small diameter side from the small diameter side end surface of the inner ring over the concave groove A guide surface is formed, and an inner diameter of the protrusion of the cage is slightly larger than an outer diameter of the guide surface. In, when interpolating fitting the inner ring, the cage projections is pushed by the inner ring of the guide surface, by the retainer flexes by its elasticity, it is possible to push toward the inner ring in place. As a result, it is possible to provide a wheel bearing that prevents the inner ring from falling off by the cage, improves the insertability of the inner ring, and can be easily assembled without damaging the rolling elements.

  A pair of outer members formed integrally with the outer rolling surface of the arc-shaped double row on the inner periphery, and a pair of outer members formed with the arc-shaped inner rolling surface facing the outer rolling surface of the double row on the outer periphery. An inner ring, a double row of balls accommodated in a freely rolling manner between the rolling surfaces, and a synthetic resin cage that holds the balls in a pocket at equal intervals. In a wheel bearing in which a projection is formed by projecting radially inward on the inner peripheral surface, and the projection of the cage is engaged with an annular concave groove formed on the outer periphery of the small-diameter side end of the inner ring. A guide surface having an inclination angle of 10 to 30 degrees with respect to the outer peripheral surface on the small diameter side is formed from the end surface on the small diameter side of the inner ring to the concave groove, and a plurality of protrusions of the cage are arranged in the circumferential direction. The protrusions are arranged so that the inner diameter of the protrusion is slightly larger than the outer diameter of the guide surface.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing an embodiment of a wheel bearing according to the present invention, FIG. 2 is an enlarged view of a main part of FIG. 1, FIG. 3 is an enlarged view of a part A of FIG. 2, and FIG. FIG. 5 is an explanatory view showing the grinding process of the inner ring according to the present invention, FIGS. 6 and 7 are explanatory views showing the positional relationship between the cage and the inner ring, and FIG. ) Is a front view showing a single cage according to the present invention, (b) is a front view showing a modified example of (a), FIG. 9 is an enlarged view of part B of FIG. 2, and FIG. It is explanatory drawing which shows the grinding process of the outer member which concerns. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  This wheel bearing 1 is used in a wheel bearing device and is referred to as a first generation. An outer member 2 in which arc-shaped double-row outer rolling surfaces 2a and 2a are integrally formed on an inner periphery, and an outer periphery A pair of inner rings 3 and 3 formed with arc-shaped inner rolling surfaces 3a facing the double-row outer rolling surfaces 2a and 2a, and double-row rolling elements ( Balls) 4 and 4, cages 5 and 5 that hold these rolling elements 4 in a freely rollable manner, and openings in an annular space formed between the outer member 2 and the inner rings 3 and 3. The seals 6 and 7 are provided.

  The outer member 2 is made of high carbon chromium bearing steel such as SUJ2 (JIS G 4805) or carburized steel. In the case of high carbon chromium bearing steel, after quenching at 820 to 860 ° C., it is tempered at 160 to 200 ° C. and cured to the core in the range of 58 to 64 HRC. In the case of carburized steel, the surface is hardened in the range of 58 to 64 HRC. On the other hand, the inner ring 3 is also made of high carbon chrome bearing steel such as SUJ2 or carburized steel like the outer member 2, and in the case of high carbon chrome bearing steel, the core is hardened in the range of 58 to 64 HRC and carburized steel. In the case of, the surface is cured in the range of 58 to 64 HRC. Moreover, the rolling element 4 consists of high carbon chromium bearing steel, such as SUJ2, and is hardened in the range of 58-64HRC to a core part by submerged hardening.

  This wheel bearing 1 is set in a state where the small diameter side (front side) end faces 3b and 3b of the pair of inner rings 3 and 3 are abutted, and constitutes a so-called back-to-back type double row angular ball bearing. . Further, the seals 6 and 7 prevent leakage of the lubricating grease sealed inside the bearing and intrusion of rainwater, dust, and the like from the outside into the bearing. In addition, although the 1st generation structure was illustrated here, this invention is not restricted to this, It can apply also to the 2nd generation structure which has a vehicle body attachment flange integrally in an outer member.

  The cage 5 is formed by injection molding a material containing an appropriate amount of reinforcing material such as GF (glass fiber) based on a thermoplastic synthetic resin such as PA (polyamide) 66. As shown in FIG. 8 (a), the cage 5 has an opening dimension set at one end (inner side) of the annular cage body 8 smaller than the outer diameter of the rolling element 4, and a concave spherical surface. The pocket 9 is formed. Then, the rolling element 4 is mounted by elastically deforming the opening, and is configured as a so-called snap-on type that is held through a predetermined pocket clearance. Although not shown in the figure, a pair of holding claws facing each other at a constant interval in the circumferential direction is provided at one end portion of the annular cage body, and the holding claws are bent in a direction approaching each other. A pocket provided with a concave spherical surface, having a recess in which the holding claw rises between the back surfaces of the holding claw, and imparting appropriate elasticity to the holding claw may be used.

  Here, in the present embodiment, a protrusion 10 is formed on the inner peripheral surface 8a of the annular cage body 8 so as to protrude radially inward. The protrusions 10 are arranged at three positions in the circumferential direction and are engaged with annular concave grooves 11 formed on the outer periphery on the small diameter side of the inner ring 3 as shown in FIG. The protrusion 10 of the cage 5 includes a locking surface 10a that hangs at a substantially right angle from the inner peripheral surface 8a, and a guide surface 10b that faces the locking surface 10a and has a predetermined inclination angle α. Corners of the locking surface 10a and the guide surface 10b are formed as circular arc surfaces having a predetermined radius of curvature R.

  As shown in FIG. 4, the concave groove 11 of the inner ring 3 has a smooth inclined surface 13 having an arc portion from the inner rolling surface 3 a through the counter portion 12, and is opposed to the inclined surface 13, and has a small diameter side end surface 3 b. On the side, there is provided a locking surface 14 having a predetermined inclination angle θ1 that expands radially outward with respect to the vertical surface. A guide surface 16 having a predetermined inclination angle θ <b> 2 is formed from the small diameter side end surface 3 b to the small diameter side outer peripheral surface 15. Chamfered portions 17 and 18 are formed at corners of the guide surface 16, the small diameter side end surface 3 b, and the locking surface 14.

  Here, as shown in FIG. 2, after the rolling elements 4 are incorporated in the retainer 5 in advance and these retainer sub-assemblies are inserted into the outer raceway surface 2 a of the outer member 2, the inner ring 3 is moved to the arrow in the figure. (Left direction in the figure), the inner diameter d1 of the protrusion 10 of the cage 5 is set to a smaller diameter (d1 <d0) than the outer diameter d0 of the outer diameter surface 15 on the small diameter side of the inner ring 3. Therefore, when the inner ring 3 is inserted, the protrusion 10 of the cage 5 is pushed by the guide surface 16 of the inner ring 3, and the cage 5 is bent by its elasticity, so that the inner ring 3 is pushed toward a predetermined position. It becomes possible. The inner diameter d1 of the protrusion 10 of the retainer 5 is larger than the outer diameter d3 of the recessed groove 11 of the inner ring 3 so that the protrusion 10 does not interfere with the recessed groove 11 even if the retainer 5 moves in the radial direction due to the pocket clearance. The diameter (d1> d3) is set. In addition, when the inner ring 3 is inserted, the inscribed circle diameter d4 of the rolling element 4 is set to a larger diameter (d4> d0) than the outer diameter d0 of the small-diameter outer peripheral surface 15 of the inner ring.

  When the inner ring 3 is pushed into a predetermined position, the position of the protrusion 10 of the cage 5 and the position of the concave groove 11 of the inner ring 3 coincide with each other, so that the cage 5 becomes the neutral position by the restoring force of the cage 5. Thus, the protrusion 10 of the cage 5 and the concave groove 11 of the inner ring 3 are fitted. As a result, the cage 5 is positioned at a predetermined position, and the locking surface 10a of the protrusion 10 and the locking surface 14 of the concave groove 11 are engaged to prevent the inner ring 3 from falling off.

  In the present embodiment, as shown in FIG. 3, the inner diameter d1 of the protrusion 10 of the cage 5 is set to be slightly larger than the rising diameter d2 of the guide surface 16 of the inner ring 3 (d1> d2). Further, the inclination angle θ2 of the guide surface 16 is set in the range of 10 to 30 °, and the inclination angle θ1 of the locking surface 14 of the concave groove 11 is set in the range of 5 to 15 °. As a result, the insertability of the inner ring 3 is improved and the inscribed circle diameter of the rolling element 4 is set larger than the outer diameter of the outer peripheral surface 15 on the small diameter side of the inner ring. The small diameter side outer peripheral surface 15 can be passed without contacting the small diameter side outer peripheral surface 15, no friction is generated, and the rolling element 4 is not damaged. Here, if the inclination angle θ2 of the guide surface 16 is less than 10 °, it becomes difficult to set a large allowance for the protrusion 10 of the retainer 5 with respect to the concave groove 11 of the inner ring 3, and the pulling strength of the inner ring 3 is insufficient. Further, if it exceeds 30 °, the elastic deformation in the radial direction of the cage 5 is hindered, which is not preferable.

  As shown in FIG. 5, the outer peripheral surface 15 on the small diameter side of the inner ring 3, the guide surface 16, and the chamfered portion 17 are ground by the overall grinding wheel 19 simultaneously with the inner rolling surface 3 a, the outer diameter surface 3 c, and the counter portion 12. Is formed by. As a result, the dimensional accuracy of the outer peripheral surface 15 on the small diameter side and the guide surface 16 is improved, the coaxiality becomes as high as possible, the cage 5 bends easily when the inner ring 3 is inserted, and the cage 5 is damaged. In addition, the insertability of the inner ring 3 can be improved.

  Further, in the present embodiment, the same grease as the grease enclosed in the bearing is applied in advance to the outer peripheral surface 15 on the small diameter side, the guide surface 16 and the chamfered portion 17 of the inner ring 3. Thereby, the insertion property of the inner ring 3 can be further enhanced without the cage 5 being damaged when the inner ring 3 is inserted.

  Next, the dimensional relationship between the protrusion 10 of the cage 5 and the concave groove 11 of the inner ring 3 will be described in detail. First, as shown in FIG. 6, the width dimension W1 of the protrusion 10 is set smaller than the width dimension W2 of the concave groove 11 (W1 <W2). Specifically, taking into account the pocket clearance and the processing error of the cage 5 and the concave groove 11, the dimensional difference between the width dimension W 2 of the concave groove 11 and the width dimension W 1 of the protrusion 10 at the position of the inner diameter d 1 of the protrusion 10. Is set in the range of 0.5 to 1.5 mm. Accordingly, it is possible to prevent the protrusion 10 of the cage 5 from interfering with the concave groove 11 during operation and increase the rotational torque of the bearing, and it is possible to prevent wear of the protrusion 10 and improve reliability.

  Further, as shown in FIG. 7, the hooking h1 of the protrusion 10 of the cage 5 with respect to the inner ring 3 is set in a range of 0.2 to 0.3 with respect to the height H of the protrusion 10 (h1 / H = 0.2 to 0.3) and h1 = about 0.3 mm. As a result, it is possible to sufficiently secure the pulling-out strength of the inner ring 3, and the cage 5 can be bent without difficulty when the inner ring 3 is inserted, and the insertability of the inner ring 3 can be enhanced without the cage 5 being damaged.

  Although the protrusions 10 of the cage 5 are illustrated as being arranged at three locations on the inner circumferential surface 8a of the annular cage body 8 at equal intervals in the circumferential direction, the present invention is not limited thereto, and as shown in FIG. In addition, the protrusions 10 ′ may be arranged at positions corresponding to the pockets 9 (15 in this case). As a result, the rigidity of the cage 5 'can be ensured, the elastic deformation of the cage 5' when the inner ring 3 is inserted is uniformly performed, and the insertability of the inner ring 3 can be improved without damaging the cage 5 '. it can.

  Next, the dimensional relationship between the outer member 2 and the rolling element 4 will be described in detail. As shown in FIG. 9, here, the corner portion 20a of the counter portion 20 of the outer member 2 is formed in an arc shape, and the height h2 of the counter portion 20, that is, the groove bottom diameter of the outer rolling surface 2a. The protrusion amount (one side) with respect to d5 is set in the range of h2 / Dw = 0.07 to 0.10 with respect to the outer diameter Dw of the rolling element 4, and the inner diameter d6 of the counter portion 20 is set to the cage 5. The outer diameter is set to be larger than the outer diameter. Thereby, when inserting the cage sub-assembly into the outer rolling surface 2a, the rolling element 4 can smoothly pass through the counter unit 20 without the counter unit 20 contacting the outer diameter of the cage 5. Abnormal wear does not occur in the rolling element 4 and it is not damaged.

  Here, if the height h2 of the counter portion 20 is less than 0.07 of the outer diameter Dw of the rolling element 4, there is a possibility that the retainer sub-assembly may fall off after being inserted into the outer rolling surface 2a, and 0.10 is set. If it exceeds this, when the cage sub-assembly is inserted into the outer rolling surface 2a, the rolling element 4 may be abnormally worn and damaged.

  As shown in FIG. 10, the counter portion 20 and the corner portion 20a of the outer member 2 are formed of a double-row outer rolling surface 2a, 2a, an inner diameter surface 2b, and seal fitting surfaces 2c at both ends simultaneously with an overall grinding wheel. 21 is formed by grinding. As a result, the dimensional accuracy and the coaxiality of the counter unit 20 and its corner 20a can be improved as much as possible, and the corner 20a of the counter 20 can be formed smoothly and can be rotated when the cage sub-assembly is inserted. Insertability can be improved without the moving body 4 being damaged.

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

  The wheel bearing according to the present invention is used, for example, in a wheel bearing device having a first or second generation structure for rotatably supporting a wheel. Rollers are incorporated in a cage in advance, and these cage sub-assemblies are externally mounted. The present invention can be applied to a wheel bearing in which the inner ring is inserted and inserted from both sides of the side member into the double row outer rolling surfaces and the inner ring is inserted from the side of the outer member.

It is a longitudinal section showing one embodiment of a wheel bearing concerning the present invention. It is a principal part enlarged view of FIG. It is the A section enlarged view of FIG. FIG. 3 is an enlarged view of a main part of the inner ring shown in FIG. 2. It is explanatory drawing which shows the grinding process of the inner ring | wheel concerning this invention. It is explanatory drawing which shows the positional relationship of a holder | retainer and an inner ring | wheel. It is explanatory drawing which shows the positional relationship of a holder | retainer and an inner ring | wheel same as the above. (A) is a front view which shows the holder | retainer single-piece | unit which concerns on this invention. (B) is a front view which shows the modification of (a). It is the B section enlarged view of FIG. It is explanatory drawing which shows the grinding process of the outer member which concerns on this invention. It is a principal part enlarged view which shows the conventional wheel bearing.

Explanation of symbols

1... Wheel bearing 2... Outer member 2 a .. Outer rolling surface 2 b.・ ・ ・ ・ ・ ・ Inner diameter surface 2c ・ ・ ・ ・ ・ ・ ・ ・ Seal fitting surface 3 ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 3a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inward rolling Surface 3b ... Small diameter side end face 3c ... Outer diameter surface 4 ... Rolling elements 5, 5 '... ... Retainer 6, 7, ... Seal 8 ... Retainer body 8a ... Inner peripheral surface 9 ···················································································································· ························································································· ····· Small diameter side outer peripheral surface 17, 18 ····· Chamfered portion 19 and 21 ··················································・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Bearing bearing 51 ・ ・ ・ ・ ・ ・ ・ ・ Outer ring 51a ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer rolling surface 52 ・ ・ ・ ・ ・ ・ ・ ・Inner ring 52a ... Inner rolling surface 53 ... Ball 53a ... Rolling surface 54 ... · Cage 55 ····························· 55 Front end side 56b ··········· Outer diameter peripheral surface 57 ········································・ ・ ・ ・ Small diameter part 60 ・ ・ ・ ・ ・ ・ Inner diameter protrusion 61 ・ ・ ・ ・········································································· .... Rising diameter d3 of the guide surface of the inner ring ......... Outer diameter d4 of the inner groove of the inner ring ......... Inscribed circle diameter d5 of the rolling element ... ..... Groove bottom diameter d6 of outer rolling surface ..... Inner diameter D1 of counter section ..... Maximum diameter D2 of outer rolling surface ································································· Outer diameter of the rolling element h1 ·········································································································· ..... Projection width dimension W2 ....... Groove width dimension α ... .... Inclination angle θ1 of the guide surface of the protrusion ... ... Inclination angle θ2 of the locking surface of the groove ... Angle of inclination

Claims (12)

An outer member in which a double row outer rolling surface is integrally formed on the inner periphery;
An inner member in which a double row inner rolling surface facing the outer row rolling surface of the double row is formed on the outer periphery;
A double row rolling element accommodated between the rolling surfaces so as to roll freely;
A cage made of synthetic resin that holds these rolling elements in the pocket at equal intervals,
A protrusion formed to protrude inward in the radial direction is formed on the annular inner peripheral surface of the cage,
In the wheel bearing in which the inner member has a separate inner ring, and the protrusion of the cage is engaged with an annular groove formed on the outer periphery of the small diameter side end of the inner ring.
A guide surface having a predetermined inclination angle with respect to the outer peripheral surface of the small diameter side is formed from the end surface on the small diameter side of the inner ring over the concave groove, and the inner diameter of the protrusion of the cage is the outer diameter of the guide surface A wheel bearing having a slightly larger diameter than that of the wheel bearing.   The wheel bearing according to claim 1, wherein an inclination angle of the guide surface of the inner ring is set in a range of 10 to 30 °.   The wheel bearing according to claim 1, wherein a plurality of protrusions of the cage are arranged in a circumferentially equidistant manner.   The wheel bearing according to claim 3, wherein the protrusion is disposed at a position corresponding to the pocket of the cage.   5. Any one of claims 1 to 4, wherein the protrusion of the cage includes a locking surface that hangs at a substantially right angle from an inner peripheral surface of the cage, and a guide surface that faces the locking surface and has a predetermined inclination angle. A wheel bearing according to claim 1.   The width dimension of the protrusion of the cage is set to be smaller than the width dimension of the concave groove of the inner ring, and the dimensional difference between the width dimension of the protrusion and the width dimension of the concave groove at the inner diameter position of the protrusion is 0. The wheel bearing according to claim 1, wherein the wheel bearing is set in a range of 5 to 1.5 mm.   The inscribed circle diameter of the rolling element is set to be larger than the outer diameter of the outer peripheral surface on the small diameter side of the inner ring, and the inner diameter of the protrusion of the cage is larger than the outer diameter of the concave groove of the inner ring. The wheel bearing according to any one of claims 1 to 6, which is set.   The hook allowance h1 of the retainer protrusion with respect to the inner ring is set in a range of 0.2 to 0.3 with respect to the height H of the protrusion (h1 / H = 0.2 to 0.3). The wheel bearing according to any one of claims 1 to 7.   The wheel bearing according to any one of claims 1 to 8, wherein the same grease as the grease enclosed in the bearing is preliminarily applied to the outer peripheral surface on the small diameter side and the guide surface of the inner ring.   A chamfered portion is formed at the corner of the guide surface of the inner ring and the end surface on the small-diameter side, and the outer peripheral surface on the small-diameter side of the inner ring and the guide surface and the chamfered portion are ground by a grinding wheel simultaneously with the inner rolling surface. The wheel bearing according to claim 1, wherein the wheel bearing is formed.   A counter part is formed in the vicinity of the outer rolling surface of the outer member, the inner diameter of the counter part is set larger than the outer diameter of the cage, and the height h2 of the counter part is The wheel bearing according to claim 1, wherein the wheel bearing is set in a range of h2 / Dw = 0.07 to 0.10 with respect to the outer diameter Dw of the rolling element.   The corners of the counter part of the outer member are formed in an arc shape, and the counter parts and the corners are formed by grinding with a general-purpose grindstone simultaneously with the outer rolling surface and inner surface of the double row. The wheel bearing according to claim 11.

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