Angular contact ball bearings

Abstract

To provide an angular ball bearing which can be manufactured at lower cost and prevents the separation of a bearing ring and balls from each other so as to achieve excellent handleability.SOLUTION: Bearing rings 20, 30 include extending parts 23, 33 extending from raceway surfaces 21, 31 in the axial direction toward the opposite side to a side where an action line L of a contact angle θ with respect to a center O of a ball 11 passes through the raceway surfaces 21, 31 in the axial direction. The extending parts 23, 33 have folded-in portions 24, 34 folded in the radial direction, the folded-in portions 24, 34 are provided on the whole circumference or on at least two sites in the peripheral direction, and overlapping with the ball 11 in view from the axial direction to form engaging margins δ1, δ2, respectively.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an angular contact ball bearing, and more particularly to an angular contact ball bearing in which at least one of the outer and inner raceways is formed by press working. [Background technology]

[0002] For example, angular contact ball bearings used in automobile clutch mechanisms are known that prevent the outer and inner rings from separating after assembly and allow them to be handled as a single unit. Such bearings have the advantage of being easy to transport or install in equipment.

[0003] Patent Document 1 discloses a wheel bearing device that includes an outer member, an inner member (hub ring and inner ring), and double rows of balls interposed between them, in which a raceway surface and a convex portion provided near the raceway surface are simultaneously machined by grinding on the inner member made of steel, and the balls and the convex portion interfere with each other to prevent the bearing from being separated.

[0004] Also known is an angular contact ball bearing in which each raceway ring (outer ring and inner ring) is manufactured by pressing a metal plate material. For example, Patent Document 2 discloses a wheel bearing in which a rolling surface and a counter portion provided in the vicinity of the rolling surface are simultaneously formed on a raceway ring by pressing or cold rolling a pipe material, and further, the transfer surface and counter portion are optionally ground after heat treatment, so that the raceway ring is made non-separable due to interference between the counter portion and the balls. Patent Document 3 also describes a ball bearing in which an inner and outer ring are formed by press working of steel plate, and an engaging portion is provided at a portion that extends contiguous with at least one of a bent portion of the outer ring and a radially extending portion of the inner ring, and the outer ring and inner ring are engaged by the engaging portion to prevent separation. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-193745 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-52709 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-197920 Summary of the Invention [Problem to be solved by the invention]

[0006] In the ball bearing described in Patent Document 1, the convex portions that make the bearing non-separable are formed simultaneously with the raceway surface by grinding, but grinding is expensive, which has been an obstacle to reducing the cost of the bearing. Furthermore, in the wheel bearing described in Patent Document 2, the groove shoulder is filled with material during rolling, so there is a possibility that the thickness of the portion through which the contact angle of the groove shoulder passes may become thin. Furthermore, the ball bearing described in Patent Document 3 makes the bearing inseparable by engaging the outer ring and the inner ring with an engaging portion provided on the outer ring or the inner ring, which requires a shape for forming the engaging portion on the outer ring or the inner ring, posing the problem of increasing the axial size of the bearing.

[0007] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide an angular contact ball bearing that can be manufactured at low cost, prevents the raceway from separating from the balls, and is easy to handle. [Means for solving the problem]

[0008] The above object of the present invention can be achieved by the following configuration. [1] A bearing comprising an outer ring having an outer ring raceway surface on its inner peripheral surface, an inner ring having an inner ring raceway surface on its outer peripheral surface, a plurality of balls arranged to roll freely with a contact angle between the outer ring raceway surface and the inner ring raceway surface, and a cage that holds the plurality of balls at predetermined intervals in the circumferential direction, an angular contact ball bearing in which at least one of the outer ring and the inner ring is a press-formed product of a steel plate, the bearing ring has an extension portion extending in the axial direction from the raceway surface toward a side opposite to a side where a line of action of the contact angle with respect to the center of the ball passes through the raceway surface, The extension portion has a folded portion bent in the radial direction, and the folded portion is provided at least in two places around the entire circumference or in the circumferential direction, and overlaps with the ball when viewed from the axial direction to form an overlapping margin. Angular contact ball bearing. [Effects of the Invention]

[0009] According to the angular contact ball bearing of the present invention, it is possible to provide an angular contact ball bearing that can be manufactured at low cost and is easy to handle by preventing separation of the raceway and the balls. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view of a main portion of an angular contact ball bearing according to a first embodiment of the present invention. [Figure 2] FIG. 2(a) is an enlarged view of a main portion showing the shape of the folded portion of the outer ring, and FIG. 2(b) is an enlarged view of a main portion showing the shape of the folded portion of the inner ring. [Figure 3] FIG. 10 is a side view showing an outer ring and a plurality of balls according to a modified example of the first embodiment. [Figure 4] 4(a) is an enlarged perspective view of the folded portion of the outer ring in FIG. 3, and FIG. 4(b) is an enlarged view of the portion surrounded by the dashed line IV in FIG. [Figure 5] FIG. 5(a) is a cross-sectional view showing the shape of the folded portion of the outer ring of another modified example of the first embodiment, and FIG. 5(b) is a cross-sectional view showing the shape of the folded portion of the outer ring of yet another modified example of the first embodiment. [Figure 6] FIG. 5 is a cross-sectional view of a main portion of an angular contact ball bearing according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a cross-sectional view of a main portion of an angular contact ball bearing according to a third embodiment of the present invention. [Figure 8] FIG. 10 is a cross-sectional view of a main portion of an angular contact ball bearing according to a fourth embodiment of the present invention. [Figure 9]9(a) is an enlarged view of a main portion of the outer ring shown in FIG. 8, and FIG. 9(b) is an enlarged view of a main portion of the inner ring shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, each embodiment of an angular contact ball bearing according to the present invention will be described in detail with reference to the drawings.

[0012] (First embodiment) As shown in Figure 1, angular contact ball bearing 10 is a clutch release bearing used, for example, in an automobile clutch mechanism, and comprises a substantially annular outer ring 20 with an outer ring raceway surface 21 formed on its inner peripheral surface, a substantially annular inner ring 30 with an inner ring raceway surface 31 formed on its outer peripheral surface, a plurality of balls 11 arranged freely to roll between outer ring raceway surface 21 and inner ring raceway surface 31 and in contact with both raceway surfaces 21, 31 at a predetermined contact angle θ, and a double-supported type cage 12 that holds the plurality of balls 11 at predetermined intervals in the circumferential direction. The cage 12 may be a cantilever type such as a crown type cage.

[0013] The outer ring 20 and the inner ring 30 are press-formed products made of steel plate. Specifically, the outer ring 20 and the inner ring 30 are formed by pressing a plate made of an alloy material containing 0.7 to 0.9 wt % carbon, 0.3 to 0.9 wt % manganese, 0.3 to 1.0 wt % chromium, and 0.01 to 0.15 wt % silicon.

[0014] As shown in Figure 2(a), the outer ring 20 has a substantially cylindrical outer ring extension portion 23 that extends axially from the curved outer ring raceway surface 21 toward one axial side (toward the right in Figures 1 and 2), and a flange portion 25 that curves axially and extends further radially inward on the other axial side (toward the left in Figure 1) of the outer ring raceway surface 21. Furthermore, a step portion 23a is formed on the inner peripheral surface of the outer ring extension portion 23 that constitutes the outer ring 20 by press working, and is deformed radially outward relative to the inner peripheral surface of the portion that forms the outer ring raceway surface 21. The step portion 23a has a thickness to that is thinner than the thickness t1 of the portion that forms the outer ring raceway surface 21. A cylindrical counter portion 23b is formed on the inner peripheral surface of the outer ring extension portion 23, between the outer ring raceway surface 21 and the step portion 23a. The inner diameter of the counter portion 23b is the same as the inner diameter of the groove bottom (maximum inner diameter portion) of the outer ring raceway surface 21.

[0015] Furthermore, outer ring extension portion 23 is bent inward by press working to form folded portion 24 around the entire circumference, with the inner diameter of the tip portion reduced. A chamfered portion 24a that is approximately parallel to axis X of angular contact ball bearing 10 is provided at the tip portion of the inner peripheral surface of folded portion 24. Step portion 23a is provided between outer ring raceway surface 21 and folded portion 24.

[0016] Similarly, as shown in Figure 2(b), the inner ring 30 has a substantially cylindrical inner ring extension portion 33 that extends axially from the curved inner ring raceway surface 31 toward the other axial side, and a flange portion 35 that is curved axially on one axial side of the inner ring raceway surface 31 and further extends radially outward. Furthermore, a step 33a is formed on the outer peripheral surface of the inner ring extension 33 that constitutes the inner ring 30 by press working, and is deformed radially inward relative to the outer peripheral surface of the portion that forms the inner ring raceway surface 31. The step 33a has a thickness ti that is thinner than the thickness t2 of the portion that forms the inner ring raceway surface 31. The inner ring extension 33 does not have a counter portion, and the radially outer end of the step 33a is aligned with the center O of the ball 11 in the axial direction.

[0017] Furthermore, the inner ring extension portion 33 is bent outward by press working to form a folded portion 34 around the entire circumference, with the outer diameter of the tip portion being enlarged. A chamfered portion 34a that is approximately parallel to the axis X of the angular ball bearing 10 is provided at the tip portion of the outer peripheral surface of the folded portion 34. The step portion 33a is provided between the inner ring raceway surface 31 and the folded portion 34.

[0018] With respect to the outer ring 20, the one axial side is the side opposite in the axial direction from the side where the line of action L of the contact angle θ relative to the center O of the ball 11 passes through the outer ring raceway surface 21, and therefore the other axial side is the side where the line of action L of the contact angle θ relative to the center O of the ball 11 passes through the outer ring raceway surface 21. With respect to the inner ring 30, the other axial side is the side opposite in the axial direction from the side where the line of action L of the contact angle θ relative to the center O of the ball 11 passes through the inner ring raceway surface 31, and the one axial side is the side where the line of action L of the contact angle θ relative to the center O of the ball 11 passes through the inner ring raceway surface 31.

[0019] Therefore, in outer ring 20, inner diameter Do of bent portion 24 (chamfered portion 24a) is smaller than inner diameter D1 of outer ring raceway surface 21, and bent portion 24 overlaps ball 11 when viewed from the axial direction, providing an overlap δ1 of (Do-D1) / 2. Note that inner diameter D1 of outer ring raceway surface 21 is approximately the same as the diameter of the circumscribing circle of multiple balls 11. As a result, even if the outer ring 20 moves relative to the balls 11 so as to move away from them in the axial direction, the folded portions 24 come into contact with the plurality of balls 11, so that the outer ring 20 and the balls 11 do not separate.

[0020] Similarly, in the inner ring 30, the outer diameter Di of the bent portion 34 (chamfered portion 34a) is larger than the outer diameter D2 of the inner ring raceway surface 31, and the bent portion 34 overlaps with the balls 11 when viewed from the axial direction, providing an overlap δ2 of (Di-D2) / 2. The outer diameter D2 of the inner ring raceway surface 31 is approximately the same as the diameter of the inscribed circle of the multiple balls 11. As a result, even if the inner ring 30 moves relative to the balls 11 so as to move away from them in the axial direction, the folded-in portions 34 come into contact with the plurality of balls 11, so that the inner ring 30 and the balls 11 do not separate.

[0021] The outer ring 20 and the inner ring 30 are each formed from a plate of alloy or steel material into the desired overall shape shown in FIG. 1 by a series of press processes, including a step of bending the folded portions 24, 34 in the radial direction. Thereafter, heat treatments including carburizing and induction hardening are performed on necessary locations including the outer ring raceway surface 21 and the inner ring raceway surface 31. Furthermore, the outer ring raceway surface 21 and the inner ring raceway surface 31 are subjected to finishing treatments such as superfinishing (SF) and barrel machining to remove burrs and scales.

[0022] To assemble the angular contact ball bearing 10, first, the balls 11 are fitted into the retainer 12, and then the balls 11 held in the retainer 12 are passed over the bent portion 24 and fitted into the outer ring 20. Furthermore, in a state in which outer ring 20 has been thermally expanded to twice the inner ring overlap allowance δ2, inner ring 30 is inserted, and multiple balls 11 are assembled into inner ring 30, passing over folded portions 34 of inner ring 30. Thereafter, outer ring 20 is cooled, and multiple balls 11 become unseparated by folded portions 24, 34.

[0023] However, the press working for bending the folded portions 24, 34 in the radial direction may be performed separately from the press working for forming shapes other than the folded portions 24, 34 after the outer ring 20 and the inner ring 30 are heat treated. In either case, the outer ring raceway surface 21 and the inner ring raceway surface 31 are not subjected to expensive grinding, which allows for reduction in manufacturing costs.

[0024] Furthermore, the thickness t0 of step portion 23a is set to be 40 to 75% of the thickness t1 of the portion where outer ring raceway surface 21 is formed. If the thickness t0 of step portion 23a is less than 40% of the thickness t1, folded portion 24 is likely to deform and it becomes difficult to hold ball 11, and if the thickness t0 exceeds 75% of the thickness t1, it becomes difficult to form folded portion 24 by press working.

[0025] Furthermore, a step portion 23a having a thickness to is formed on the inner peripheral surface of the outer ring 20, and the thickness to of the folded portion 24 is formed thin. Therefore, when the folded portion 24 is press-formed, the folded portion 24 deforms from the step portion 23a that is axially spaced apart from the outer ring raceway surface 21, and therefore the folded portion 24 can be formed without affecting the shape or precision of the outer ring raceway surface 21.

[0026] For the same reasons as for the outer ring extension portion 23, the thickness ti of the inner ring extension portion 33 is also set to 40 to 75% of the thickness t2 of the inner ring raceway surface 31. Furthermore, for the same reasons as for the stepped portion 23a of the outer ring 20, the stepped portion 33a is formed on the outer peripheral surface of the inner ring 30.

[0027] As explained above, according to the angular contact ball bearing 10 of this embodiment, at least one of the outer ring 20 and the inner ring 30 is formed by pressing, and the outer ring raceway surface 21 and the inner ring raceway surface 31 are formed without expensive grinding, thereby reducing production costs. Furthermore, by forming the folded portions 24, 34 having overlapping margins δ1 and δ2 in the outer ring 20 and the inner ring 30, respectively, the folded portions 24, 34 come into contact with the balls 11, preventing separation of the balls 11 from the outer ring 20 or the inner ring 30, thereby improving the handleability of the angular contact ball bearing 10.

[0028] In the above embodiment, the folded portions 24, 34 are formed around the entire circumference of the outer ring extension portion 23 and the inner ring extension portion 33, but they may also be formed in at least two locations in the circumferential direction to prevent the outer ring 20 or the inner ring 30 from separating.

[0029] For example, as shown in FIGS. 3 and 4, the outer ring extension portion 23 has folded portions 24 formed at two locations in the circumferential direction (two locations that are 180° out of phase with each other in this example). 4(b), the circumferential length L1 of the folded portion 24 is longer than the pitch P, which is the circumferential spacing between adjacent balls 11. As a result, the folded portion 24 always abuts against one of the balls 11 and holds the ball 11, preventing the outer ring 20 and the ball 11 from separating.

[0030] 5(a), a tapered portion 24b having a taper angle α of 3 to 10° with respect to the axis X of the angular contact ball bearing 10 and gradually increasing in diameter toward one axial side may be formed by press working at the tip of the inner circumferential surface of the folded portion 24 of the outer ring 20. This makes it easier to assemble the balls 11 into the outer ring 20 and makes it more difficult for the balls 11 to come out after assembly.

[0031] 5(b), a curved chamfered portion 24c may be provided at the tip of the inner peripheral surface of the folded portion 24 of the outer ring 20. This prevents the balls 11 from being damaged when they are assembled to the outer ring 20.

[0032] Furthermore, although not shown, for reasons similar to those for folded portion 24 of outer ring 20, the tip portion of the inner circumferential surface of folded portion 34 of inner ring 30 may also be a tapered portion having a taper angle of α = 3 to 10° and gradually increasing in diameter toward one axial side, or a curved chamfered portion may be provided.

[0033] (Second embodiment) Next, an angular contact ball bearing 10A according to a second embodiment of the present invention will be described with reference to Fig. 6. The angular contact ball bearing 10A according to the second embodiment differs from the angular contact ball bearing 10 according to the first embodiment in the shapes of the outer ring extension 23 of the outer ring 20 and the inner ring extension 33 of the inner ring 30.

[0034] In this embodiment, the outer peripheral surface of the outer ring extension portion 23 is deformed by press working toward the inner diameter side relative to the outer peripheral surface of the portion that forms the outer ring raceway surface 21, thereby forming a step portion 23a on the outer peripheral surface of the outer ring 20. The thickness t0 of the step portion 23a is set to 40 to 75% of the thickness t1 of the outer ring raceway surface 21, similar to the first embodiment.

[0035] Then, outer ring extension portion 23 has bent portions 24 formed around its entire circumference or at least in two locations in the circumferential direction, with the inner diameter of the axial end portion reduced by press working. The inner diameter Do of bent portion 24 is set smaller than the inner diameter D1 of outer ring raceway surface 21. That is, bent portion 24 overlaps ball 11 when viewed from the axial direction, providing an overlapping allowance δ1 of (Do-D1) / 2.

[0036] Furthermore, by press working, the inner peripheral surface of the inner ring extension portion 33 is deformed radially outward relative to the inner peripheral surface of the portion that forms the inner ring raceway surface 31, thereby forming a step portion 33a on the inner peripheral surface of the inner ring 30. The thickness ti of the step portion 33a is formed to be 40 to 75% of the thickness t2 of the inner ring raceway surface 31.

[0037] The inner ring extension portion 33 has bent portions 34 formed by pressing the outer diameter of the axial end portion to be enlarged along its entire circumference or at least in two locations in the circumferential direction. The outer diameter Di of the bent portions 34 is set larger than the outer diameter D2 of the inner ring raceway surface 31. That is, the bent portions 34 overlap with the balls 11 when viewed from the axial direction, providing an overlapping allowance δ2 of (Di-D2) / 2.

[0038] According to the outer ring 20 and inner ring 30 of this embodiment, there are no steps on the inner surfaces of the outer ring extension portion 23 and folded portion 24 formed continuously with the outer ring raceway surface 21, and on the outer surfaces of the inner ring extension portion 33 and folded portion 34 formed continuously with the inner ring raceway surface 31, so that the balls 11 are less likely to be scratched when assembled to the outer ring 20 and inner ring 30. Other configurations and operations are the same as those of the angular ball bearing 10 of the first embodiment.

[0039] (Third embodiment) Next, an angular contact ball bearing 10B according to a third embodiment will be described with reference to Fig. 7. In the angular contact ball bearing 10B of this embodiment, the shapes of the outer ring extension 23 of the outer ring 20 and the inner ring extension 33 of the inner ring 30 also differ from those of the angular contact ball bearing 10 of the first embodiment.

[0040] In the third embodiment, there are no steps between the outer ring raceway surface 21 and the folded-in portion 24 of the outer ring 20, and between the inner ring raceway surface 31 and the folded-in portion 34 of the inner ring 30, and the portion where the outer ring raceway surface 21 is formed and the outer ring extension portion 23 have the same plate thickness, and the portion where the inner ring raceway surface 31 is formed and the inner ring extension portion 33 have the same plate thickness.

[0041] The outer ring extension portion 23 of the outer ring 20 tapers down in diameter from near the maximum diameter of the outer ring raceway surface 21 to form a folded portion 24. The inner ring extension portion 33 of the inner ring 30 tapers up in diameter from near the minimum diameter of the inner ring raceway surface 31 to form a folded portion 34. As a result, folded portion 24 has an overlapping allowance δ1 with the balls 11, and folded portion 34 has an overlapping allowance δ2 with the balls 11.

[0042] Furthermore, the angular contact ball bearing 10B of this embodiment may be formed by the same method as in the first embodiment, but it can also be formed by other methods.

[0043] For example, the outer ring 20 and the inner ring 30 are formed by pressing an alloy or steel plate material, and excluding the radial bending of the outer ring extension 23 and the inner ring extension 33, the remaining portions are formed into the desired shape. Thereafter, heat treatments such as carburizing and induction hardening are performed on the necessary areas including the outer ring raceway surface 21 and the inner ring raceway surface 31, excluding the outer ring extension 23 and the inner ring extension 33. Furthermore, the outer ring raceway surface 21 and the inner ring raceway surface 31 are subjected to finishing treatments such as superfinishing (SF) and barrel machining to remove burrs and scales. After the outer ring extension 23 and the inner ring extension 33 are subjected to the above heat treatments, they may be softened.

[0044] Then, after assembling multiple balls 11 into the outer ring 20 and the inner ring 30, a press process may be performed to bend the outer ring extension portion 23 and the inner ring extension portion 33 radially, thereby forming folded portions 24, 34 in the outer ring 20 and the inner ring 30.

[0045] In this case, the hardness of the outer ring extension portion 23 and the inner ring extension portion 33, including the folded portions 24, 34, is 15 to 30% of the hardness of the outer ring raceway surface 21 and the inner ring raceway surface 31, and even if the plate thickness of the portion where the outer ring raceway surface 21 is formed and the outer ring extension portion 23 are the same, and even if the plate thickness of the portion where the inner ring raceway surface 31 is formed and the inner ring extension portion 33 are the same, the folded portions 24, 34 can be easily formed without affecting the shape or accuracy of the outer ring raceway surface 21 and the inner ring raceway surface 31. The other configurations and operations are the same as those of the first embodiment.

[0046] (Fourth embodiment) Next, an angular contact ball bearing 10C according to a fourth embodiment of the present invention will be described with reference to Figures 8 and 9. In the angular contact ball bearing 10C according to the fourth embodiment, the folded portion 24 of the second embodiment is applied to the outer ring extension portion 23, and the folded portion 34 of the first embodiment is applied to the inner ring extension portion 33.

[0047] Specifically, outer ring 20 is provided with outer ring extension 23 extending axially from outer ring raceway surface 21 to one side, and step 23a is formed on the outer peripheral surface of outer ring extension 23. Outer ring extension 23 is formed with folded-in portions 24, which have an engagement allowance δ1 with balls 11, at two locations that are 180° out of phase with each other.

[0048] The outer ring 20 also includes a cylindrical outer ring small diameter portion 26 extending from the outer ring raceway surface 21 to the other axial side, a radial wall portion 27 extending from the axial end of the outer ring small diameter portion 26 to the inner diameter side, and a folded portion 28 extending from the radial inner end of the radial wall portion 27 to one axial side.

[0049] Therefore, the portion axially opposite to outer ring extension portion 23 is formed with a generally U-shaped cross section. Also, a portion of folded-back portion 28 overlaps radially with the inner diameter side of folded-in portion 34 of inner ring 30, which will be described later, with a radial gap therebetween.

[0050] The inner ring 30 is provided with an inner ring extension 33 extending from the inner ring raceway surface 31 to the other side in the axial direction, and a step 33a is formed on the outer peripheral surface of the inner ring extension 33. The inner ring extension 33 is bent radially around its entire circumference by press working, forming a folded-in portion 34 having an overlap δ2 between it and the balls 11.

[0051] The inner ring 30 also includes an inner ring large diameter portion 36 extending from the inner ring raceway surface 31 to one side in the axial direction, and a radial wall portion 37 extending to the outer diameter side from the axial end of the inner ring large diameter portion 36. The radial wall portion 37 axially overlaps with one axial end face of the folded portion 24 of the outer ring 20, and an outer diameter side outlet clearance C3, which is an axial clearance, is formed between the radial wall portion 37 and the axial end face of the folded portion 24.

[0052] The radial clearance formed by the overlap of the folded portion 28 of the outer ring 20 and the folded portion 34 of the inner ring 30 includes an inner diameter side entrance clearance C1 and an inner diameter side exit clearance C2. The inner diameter side entrance clearance C1 is formed between the outer diameter surface of the end portion on one axial side of the folded portion 28 and the inner diameter surface of the folded portion 34, and the inner diameter side exit clearance C2 is formed between the outer diameter surface of the folded portion 28 and the inner diameter surface of the end portion on the other axial side of the folded portion 34. The outer diameter surface of the folded portion 28 is formed in a cylindrical shape with a constant outer diameter, and the inner diameter surface of the folded portion 34 is formed in a tapered shape that gradually increases in diameter toward the other axial side, so that the inner diameter side exit clearance C2 is larger than the inner diameter side entrance clearance C1 (C1 <C2)。

[0053] Furthermore, the outer diameter side outlet clearance C3, which is the axial clearance between the radial wall portion 37 and the folded portion 24 of the outer ring 20, is set larger than the inner diameter side inlet clearance C1 and the inner diameter side outlet clearance C2. That is, the size of each clearance increases in the order of the inner diameter side inlet clearance C1, the inner diameter side outlet clearance C2, and the outer diameter side outlet clearance C3 (C1 <C2<C3)。

[0054] Because the inner diameter side inlet clearance C1 is smaller than the inner diameter side outlet clearance C2, the amount of lubricating oil supplied from the inner diameter side inlet clearance C1 to the internal space of the angular contact ball bearing 10C can be controlled to an appropriate amount, and the lubricating oil can flow smoothly into the interior of the angular contact ball bearing 10C from the inner diameter side outlet clearance C2. Furthermore, because the outer diameter surface of the folded-in portion 34 is formed in a tapered shape that gradually increases in diameter toward the other axial side, the centrifugal force acting on the inner ring 30, which is the rotating ring, can cause the lubricating oil to be thrown off from the end of the folded-in portion 34 on the other axial side toward the outer ring 20.

[0055] Furthermore, because the outer diameter side outlet clearance C3 is larger than the inner diameter side outlet clearance C2, the lubricating oil inside the angular contact ball bearing 10C is smoothly discharged to the outside of the angular contact ball bearing 10C without accumulating inside, reducing the agitation resistance of the lubricating oil. In this way, by controlling the amount and flow of the lubricating oil, the agitation resistance of the lubricating oil can be reduced, resulting in lower torque. In particular, because folded-in portions 24 of outer ring 20 are formed in two or more locations in the circumferential direction, lubricating oil adhering to the inner surface of outer ring 20 can be sent to the outer diameter side outlet gap C3 side through outer ring extension portion 23 extending along the axial direction.

[0056] Therefore, according to this embodiment, it is possible to construct an angular ball bearing 10C that can be manufactured at low cost, prevents separation of the outer and inner rings from the balls, makes it easy to handle, and is capable of controlling the amount and flow of lubricating oil, thereby reducing the stirring resistance of the lubricating oil and achieving low torque. The other configurations and operations are the same as those of the first embodiment.

[0057] The present invention is not limited to the above-described embodiments and modifications, but can be modified, improved, etc. as appropriate. In the above embodiment, both the outer ring 20 and the inner ring 30 are formed by press working, but in the present invention, it is sufficient that at least one of the outer ring 20 and the inner ring 30 is formed by press working in the above embodiment.

[0058] As described above, the present specification discloses the following: (1) A bearing comprising an outer ring having an outer ring raceway surface on its inner peripheral surface, an inner ring having an inner ring raceway surface on its outer peripheral surface, a plurality of balls arranged to roll freely with a contact angle between the outer ring raceway surface and the inner ring raceway surface, and a cage that holds the plurality of balls at predetermined intervals in the circumferential direction, an angular contact ball bearing in which at least one of the outer ring and the inner ring is a press-formed product of a steel plate, the bearing ring has an extension portion extending in the axial direction from the raceway surface toward a side opposite to a side where a line of action of the contact angle with respect to the center of the ball passes through the raceway surface, The extension portion has a folded portion bent in the radial direction, and the folded portion is provided at least in two places around the entire circumference or in the circumferential direction, and overlaps with the ball when viewed from the axial direction to form an overlapping margin. Angular contact ball bearing. With this configuration, the folded portion overlaps with the ball when viewed from the axial direction to form an overlapping area, and the raceway ring, including the folded portion, is formed by press processing, making it possible to manufacture at low cost and preventing separation of the raceway ring and ball, thereby improving the handleability of the angular ball bearing.

[0059] (2) The circumferential length of the folded portion is longer than the circumferential pitch of the balls. The angular contact ball bearing according to (1). With this configuration, the bent portion always engages with one of the balls, preventing separation of the race and the ball.

[0060] (3) The tip of the peripheral surface of the folded portion on the side forming the overlapping portion is formed in a tapered shape having a taper angle of 3 to 10°. The angular contact ball bearing according to (1) or (2). According to this configuration, by forming the tip of the bent portion into a tapered shape, it becomes easier to assemble the balls into the raceway and makes it difficult for them to separate.

[0061] (4) The tip of the peripheral surface of the folded portion on the side forming the overlapping portion is chamfered into a curved surface. The angular contact ball bearing according to (1) or (2). This configuration prevents the balls from being damaged when they are assembled into the raceway.

[0062] (5) The extension portion has a step portion between the raceway surface and the folded portion, and the step portion is formed on a peripheral surface of the extension portion on a side that forms the engagement allowance. The angular contact ball bearing according to (3) or (4). According to this configuration, the folded portion can be formed by bending at the step portion, and the influence on the raceway surface can be suppressed.

[0063] (6) The extension portion has a step portion between the raceway surface and the folded portion, and the step portion is formed on a peripheral surface of the extension portion on a side opposite to a side where the engagement allowance is formed. The angular contact ball bearing according to (3) or (4). According to this configuration, the folded portion can be formed by bending at the step portion, and the influence on the raceway surface can be suppressed.

[0064] (7) The step portion has a thickness of 40 to 75% of the thickness of the raceway surface. The angular contact ball bearing according to (5) or (6). According to this configuration, the bent portion can be easily formed by press working without affecting the raceway surface.

[0065] (8) The thickness of the portion where the raceway surface is formed is the same as the thickness of the extension portion, and the hardness of the extension portion is 15 to 30% of the hardness of the portion where the raceway surface is formed. The angular contact ball bearing according to any one of (1) to (4). According to this configuration, by softening the hardness of the extension portion to 15 to 30% of the hardness of the raceway surface, the bent portion can be easily formed even if the thickness of the raceway surface and the thickness of the extension portion are the same.

[0066] (9) The outer ring further comprises an outer ring extension portion extending in the axial direction from the outer ring raceway surface toward one axial side that is opposite to the side where the line of action of the contact angle with respect to the center of the ball passes through the outer ring raceway surface, an outer ring small diameter portion extending toward the other axial side relative to the outer ring raceway surface, a radial wall portion extending from the axial end of the outer ring small diameter portion toward the inner diameter side, and a folded portion extending toward one axial side from the radial inner end of the radial wall portion, the outer ring extension portion has folded portions bent in the radial direction at at least two locations in the circumferential direction, the inner ring includes an inner ring extension portion extending in the axial direction from the inner ring raceway surface toward a side opposite to a side where a line of action of the contact angle with respect to the center of the ball passes through the inner ring raceway surface, the inner ring extension portion has a folded portion bent in the radial direction over the entire circumference, the folded-back portion overlaps the inner ring extension portion in the radial direction with a radial gap between the folded-back portion and an inner peripheral surface of the inner ring extension portion, the radial gap at an inner diameter side inlet formed between the axial end of the turned-back portion and the inner circumferential surface of the inner ring extension portion is smaller than the radial gap at an inner diameter side outlet formed between the axial end of the inner ring extension portion and the outer circumferential surface of the turned-back portion; The angular contact ball bearing according to any one of (1) to (7). With this configuration, the raceway and balls can be made non-separable, the amount and flow of lubricating oil can be controlled, and the stirring resistance of the lubricating oil can be reduced, resulting in low torque. [Explanation of symbols]

[0067] 10, 10A, 10B, 10C angular contact ball bearings 11 balls 12 Cage 20 Outer ring (bearing ring) 21 Outer ring raceway 23 Extension, outer ring extension 23a, 33a Step 24,34 Folded part 24c curved chamfer 26 Small diameter outer ring 27 Radial wall 28 Folded section 30 Inner ring (raceway ring) 31 Inner ring raceway surface 33 Extension, inner ring extension C1 Inner diameter side entrance clearance (radial clearance at inner diameter side entrance) C2 Inner diameter side outlet clearance (radial clearance at inner diameter side outlet) C3 Outer diameter outlet clearance (axial clearance at outer diameter outlet) L contact angle action line P Circumferential pitch of balls t1, t2 Plate thickness (thickness of the part where the raceway surface is formed) ti, to Plate thickness (thickness of extension part) δ1, δ2 overlap allowance θ contact angle

Claims

1. an outer ring having an outer ring raceway surface on its inner peripheral surface, an inner ring having an inner ring raceway surface on its outer peripheral surface, a plurality of balls arranged to roll freely with a contact angle between the outer ring raceway surface and the inner ring raceway surface, and a cage that holds the plurality of balls at predetermined intervals in the circumferential direction, an angular contact ball bearing in which the outer ring and the inner ring are press-formed products of steel plate, the outer ring further comprises: an outer ring extension portion extending in the axial direction from the outer ring raceway surface toward one axial side that is opposite to the side where the line of action of the contact angle with respect to the center of the ball passes through the outer ring raceway surface; an outer ring small diameter portion extending toward the other axial side relative to the outer ring raceway surface; a radial wall portion extending from the axial end of the outer ring small diameter portion toward the inner diameter side; and a folded portion extending toward one axial side from the radial inner end of the radial wall portion, the outer ring extension portion has folded portions that are bent radially at at least two locations in the circumferential direction and overlap the balls when viewed from the axial direction to form an engagement allowance; the inner ring includes an inner ring extension portion extending in the axial direction from the inner ring raceway surface toward a side opposite to a side where a line of action of the contact angle with respect to the center of the ball passes through the inner ring raceway surface, the inner ring extension portion is bent radially over the entire circumference and has a folded-in portion that overlaps with the ball when viewed from the axial direction to form an engagement allowance, the folded-back portion overlaps the inner ring extension portion in the radial direction with a radial gap between the folded-back portion and an inner peripheral surface of the inner ring extension portion, the radial gap at an inner diameter side inlet formed between the axial end of the turned-back portion and the inner peripheral surface of the inner ring extension portion is smaller than the radial gap at an inner diameter side outlet formed between the axial end of the inner ring extension portion and the outer peripheral surface of the turned-back portion; Angular contact ball bearing.

2. a circumferential length of the folded portion of the outer ring extension portion is longer than a circumferential pitch of the balls; 2. The angular contact ball bearing according to claim 1.

3. In the outer ring extension portion, a tip portion of a circumferential surface of the folded-in portion on a side forming the engagement allowance is formed in a tapered shape having a taper angle of 3 to 10 degrees.

3. The angular contact ball bearing according to claim 1 or 2.

4. In the outer ring extension portion, a tip end portion of a circumferential surface of the folded-in portion on a side forming the engagement allowance is chamfered into a curved surface.

3. The angular contact ball bearing according to claim 1 or 2.

5. the outer ring extension portion has a step portion between the outer ring raceway surface and the folded-in portion of the outer ring extension portion, the step portion being formed on a circumferential surface of the outer ring extension portion on a side that forms the engagement allowance, and the inner ring extension portion has a step portion between the inner ring raceway surface and the folded-in portion of the inner ring extension portion, and the step portion is formed on a circumferential surface of the inner ring extension portion on a side that forms the engagement allowance.

5. The angular contact ball bearing according to claim 3 or 4.

6. the outer ring extension portion has a step portion between the outer ring raceway surface and the folded-in portion of the outer ring extension portion, the step portion being formed on a circumferential surface of the outer ring extension portion on a side opposite to a side on which the engagement allowance is formed, and the inner ring extension portion has a step portion between the inner ring raceway surface and the folded-in portion of the inner ring extension portion, and the step portion is formed on a circumferential surface of the inner ring extension portion on a side opposite to a side on which the engagement allowance is formed.

5. The angular contact ball bearing according to claim 3 or 4.

7. The step portion of the outer ring extension portion has a thickness that is 40 to 75% of the thickness of the outer ring raceway surface, and the step portion of the inner ring extension portion has a thickness that is 40 to 75% of the thickness of the inner ring raceway surface; 7. The angular contact ball bearing according to claim 5 or 6.

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