Crown retainer

Abstract

This invention provides a crown-type cage that contributes to quieter bearings and longer lifespan by improving lubrication performance. [Solution] The crown-shaped holder 10 comprises an annular rim portion 11, a plurality of column portions 12 extending axially in one direction from a plurality of circumferential locations on the rim portion 11, and claw portions 13 extending axially in one direction from the axial end 12b of each column portion 12. The rim portion 11 and a pair of adjacent column portions 12 and claw portions 13 in the circumferential direction form a pocket 20. The diameter D1 of the inner diameter side wall 13a of the claw portion 13 is greater than the diameter D2 of the inner diameter side wall 12a of the column portion 12.

Description

Technical Field

[0001] The present invention relates to a crown-shaped cage.

Background Art

[0002] Generally, a ball bearing includes an inner ring having an inner raceway groove formed on its outer periphery, an outer ring having an outer raceway groove formed on its inner periphery, a plurality of balls rotatably held by a cage and interposed between the inner raceway groove and the outer raceway groove. The crown-shaped cage that rotatably holds the plurality of balls includes an annular rim portion, and a plurality of column portions and holding claws respectively extending axially on one side from a plurality of positions in the circumferential direction of the rim portion. The rim portion, column portions, and holding claws form pockets.

[0003] Patent Document 1 discloses a ball bearing that aims to improve lubrication performance, reduce the contact surface pressure between the pocket and the ball, and reduce the rotational torque by forming the holding claw by dividing it into an outer diameter side and an inner diameter side with a slit portion interposed therebetween.

[0004] Also, Patent Document 2 discloses a rolling bearing in which cylindrical portions are provided at both ends of each pocket, and the inner edge of each cylindrical portion and the both ends of the spherical concave portion formed at the center of the pocket are made continuous by chamfering with a curvature radius of 1 to 20% of the outer diameter of the ball, thereby ensuring lubrication of the sliding contact portion between the cage and the ball and reducing vibration and noise of the ball bearing.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The cage described in Patent Document 1 improves the lubrication performance of the pocket by providing a groove in the center of the retaining claw. The rolling bearing described in Patent Document 2 improves the lubrication of the sliding contact area between the rolling element and the pocket by making it easier to take in lubricant into the gap between the inner surface of the pocket and the rolling surface of the rolling element. However, neither of these describes a grease reservoir for storing grease, which raises concerns about long-term operation.

[0007] This invention has been made in view of the aforementioned problems, and its purpose is to provide a crown-type cage that contributes to quieter operation and longer lifespan of bearings by improving lubrication performance. [Means for solving the problem]

[0008] Therefore, the above objective of the present invention is achieved by the configuration of the crown-shaped retainer described below [1]. [1] Annular rim portion, Multiple columnar portions extending from multiple locations in the circumferential direction of the rim portion toward one axial direction, Each of the aforementioned column portions has a claw portion extending in the axial direction from one end on the axial side, Multiple pockets that are surrounded on three sides by the rim portion and a pair of adjacent column portions and claw portions in the circumferential direction, thereby holding the ball so that it can rotate freely, A crown-shaped retainer comprising, The diameter of the inner side wall of the claw portion is larger than the diameter of the inner side wall of the column portion. Crown type retainer. [Effects of the Invention]

[0009] The crown-type cage of the present invention provides a crown-type cage that contributes to quieter bearings and longer lifespan by improving lubrication performance. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a perspective view of a crown-shaped retainer according to the first embodiment of the present invention. [Figure 2] Figure 2 is a magnified view of a portion of the crown-shaped retainer shown in Figure 1. [Figure 3] Figure 3 is a partially enlarged perspective view of a crown retainer that holds a ball in a pocket. [Figure 4] Figure 4 is a partially enlarged side view of a crown retainer that holds a ball in a pocket. [Figure 5] Figure 5 is a partially enlarged view of a crown retainer according to the second embodiment. [Figure 6] Figure 6 is a partially enlarged side view of a crown retainer that holds a ball in a pocket. [Figure 7] Figure 7 is a partially enlarged view of a crown retainer according to the third embodiment. [Figure 8] Figure 8 is an enlarged view of Figure 7. [Figure 9] Figure 9 is a partially enlarged view of a crown retainer according to the third embodiment. [Figure 10] Figure 10 is an enlarged view of Figure 9. [Figure 11] Figure 11 is a partially enlarged view of a crown retainer according to the third embodiment. [Figure 12] Figure 12 is an enlarged view of Figure 11. [Embodiments for Carrying out the Invention]

[0011] Hereinafter, an embodiment of a crown retainer according to the present invention will be described in detail based on the drawings.

[0012] [First Embodiment] Figure 1 is a perspective view of a crown retainer which is an embodiment of the present invention. Figure 2 is a partially enlarged view of the crown retainer shown in Figure 1. Figure 3 is a partially enlarged perspective view of a crown retainer that holds a ball in a pocket. Figure 4 is a partially enlarged side view of a crown retainer that holds a ball in a pocket.

[0013] As shown in FIGS. 1 to 4, the crown retainer 10 includes an annular rim portion 11, a plurality of column portions 12, 12 respectively extending axially on one side (upward in FIG. 1) from a plurality of locations in the circumferential direction of the rim portion 11, and a pair of claw portions 13, 13 extending axially on one side from the axially one-side end portions 12b of the respective column portions 12.

[0014] The claw portion 13 is provided at a radially outer portion of the axially one-side end portion 12b of the column portion 12. That is, referring also to FIG. 4, the diameter D1 of the inner diameter side wall 13a of the claw portion 13 is larger than the diameter D2 of the inner diameter side wall 12a of the column portion 12 (D1 > D2). Since the column portion 12 and the claw portion 13 are formed by being divided in the circumferential direction and are not circular, more precisely, it can be said that the diameter D1 of the inscribed circle of the claw portion that is inscribed in the inner diameter side wall 13a of the claw portion 13 is larger than the diameter D2 of the inscribed circle of the column portion that is inscribed in the inner diameter side wall 12a of the column portion 12. The shapes of the inner diameter side wall 12a of the column portion 12 and the inner diameter side wall 13a of the claw portion 13 are not limited to arcs and may be any shape such as a plane.

[0015] And, the portion of the axially one-side end portion 12b of the column portion 12 excluding the claw portion 13, that is, the radially inner portion of the axially one-side end portion 12b and the portion between the pair of claw portions 13 are flat. By securing a relatively wide plane in the axially one-side end portion 12b of the column portion 12 in this way, grease can be stored in the plane (12b), and good lubrication can be maintained over a long period.

[0016] The crown retainer 10 has a pocket surface 21 surrounded by three sides by the circumferentially concave curved surfaces 14, 14 of a pair of adjacent column portions 12, 12 and a pair of claw portions 13, 13 in the circumferential direction and the bottom concave curved surface 15 of the rim portion 11, and a plurality of pockets 20 are formed. A ball 30 is disposed in the pocket 20 so as to be rollable (see FIG. 3). That is, the claw portion 13 holds the ball 30 so as to be rollable by the circumferentially concave curved surface 14 formed in the radially outer portion.

[0017] At the corner where the inner diameter side wall 13a of the claw portion 13 intersects with the pocket surface 21 (circumferential concave curved surface 14), a curved R-chamfer portion 13b is formed, smoothly connecting the inner diameter side wall 13a and the pocket surface 21.

[0018] Since the inner diameter side wall 13a of the claw portion 13 is continuous with the pocket surface 21, the grease stored at one axial end (flat surface) 12b of the column portion 12 and the ball 30 are in direct contact, making it easy for the base oil in the grease to be drawn into the pocket 20. Furthermore, since the inner diameter side wall 13a and the pocket surface 21 are smoothly continuous by the R-chamfered portion 13b, the flow of base oil in the grease is improved, making it even easier to draw it into the pocket 20.

[0019] Referring to Figure 4, if the radial width of the claw portion 13 increases, the axial end (flat surface) 12b of the column portion 12 narrows, reducing the flow of base oil in the grease. Conversely, if the radial width of the claw portion 13 decreases, the rigidity of the claw portion 13 decreases, raising concerns about whitening of the claw portion 13 when assembled into the bearing. Therefore, in this embodiment, in order to ensure the rigidity of the claw portion 13, the radial length L of the R-chamfered portion 13b is set to 15% or less of the diameter Da of the ball 30. It is preferable that the radial length L of the R-chamfered portion 13b be 2% or more of the diameter Da of the ball 30. If it is less than 2%, there is a concern that the flow of base oil in the grease will decrease.

[0020] As shown in Figure 4, when the pitch circle diameter PCD of the ball 30 is the same as the pitch circle diameter PCD of the pocket 20 of the crown-shaped retainer 10, that is, when the center of the ball 30 is located at the center of the pocket 20, the contact force (the ball 30 pushing against the crown-shaped retainer 10) is strongest near the pitch circle diameter PCD of the ball 30.

[0021] Therefore, in order to enhance the draw-in property of the grease into the pocket 20, it is desirable to bring the inner diameter side wall 13a of the claw portion 13 closer to the pitch circle diameter PCD of the ball 30. From this, the diameter D1 of the inner diameter side wall 13a of the claw portion 13 is larger than [(pitch circle diameter of the ball) × 0.9] and smaller than [(pitch circle diameter of the said ball) × 1.1]. That is, 0.9×PCD < D1 < 1.1×PCD. Thereby, the draw-in property of the base oil in the grease into the pocket 20 is improved, and the crowned retainer 10 and the ball 30 can slide smoothly.

[0022] On the other hand, since the claw portion 13 is provided only at the radially outer portion of the axial direction one-side end portion 12b of the column portion 12, the radial width of the claw portion 13 becomes small and the rigidity decreases, raising concerns about whitening and breakage during operation. For this reason, as shown in FIG. 4, the outer diameter Do of the crowned retainer 10 is increased so that the radial length W from the pitch circle diameter PCD of the crowned retainer 10 to the outer peripheral surface 10a of the crowned retainer 10 is 20% or more of the diameter Da of the ball 30, to ensure the rigidity of the claw portion 13. It is more preferable that the radial length W is 24% or more of the diameter Da of the ball 30.

[0023] As described above, by promoting the inflow of the base oil in the grease into the pocket 20 and reducing the contact resistance between the ball 30 and the pocket 20, the self-excited vibration of the crowned retainer 10 can be suppressed, and the sound generated from the crowned retainer 10 can be suppressed. Thereby, it can contribute to the quiet operation of the bearing. Also, since the supply property of the grease stored in the axial direction one-side end portion 12b of the column portion 12 from the pocket 20 to the raceway surface via the ball 30 is improved, it can also contribute to the long life of the bearing.

[0024] [Second Embodiment] FIG. 5 is a partially enlarged view of the crowned retainer according to the second embodiment. FIG. 6 is a partially enlarged side view of the crowned retainer that holds balls in the pockets. As shown in FIGS. 5 and 6, the diameter D3 of the outer diameter side wall 13c of the claw portion 13 is smaller than the diameter D4 of the outer diameter side wall 12c of the column portion 12 (D3 < D4). Since the column portion 12 and the claw portion 13 are formed by dividing in the circumferential direction and are not circular, more precisely, it can be said that the diameter D3 of the circumscribed circle of the claw portion that circumscribes the outer diameter side wall 13c of the claw portion 13 is smaller than the diameter D4 of the circumscribed circle of the column portion that circumscribes the outer diameter side wall 12c of the column portion 12. By adopting such a configuration, more grease can be stored in the one-side end portion (plane) 12b in the axial direction of the column portion 12. And since the stored grease is supplied from the pocket 20 to the bearing raceway surface via the ball 30, it can also contribute to extending the life of the bearing.

[0025] [Third Embodiment] FIG. 7 is a partially enlarged view of the crowned retainer according to the third embodiment. FIG. 8 is an enlarged view of FIG. 7. As shown in FIGS. 7 and 8, at the corner where the inner diameter side wall 13a of the claw portion 13 intersects with the pocket surface 21 (circumferential concave curved surface 14), a chamfered portion 13d is formed to smoothly connect the inner diameter side wall 13a and the pocket surface 21. Thus, since the inner diameter side wall 13a and the pocket surface 21 are smoothly continuous by the chamfered portion 13d, the inflow property of the base oil in the grease is improved, and the drawing into the pocket 20 becomes easier. The chamfering angle of the chamfered portion 13d is not limited.

[0026] [Fourth Embodiment] Figure 9 is a partially enlarged view of the crown-shaped retainer according to the third embodiment. Figure 10 is an enlarged view of Figure 9. As shown in Figures 9 and 10, at the corner where the inner diameter side wall 13a of the claw portion 13 and the pocket surface 21 (circumferential concave curved surface 14) intersect, a C-chamfered portion 13d is formed on the radially inward side, and an R-chamfered portion 13b is formed on the radially outward side, and these C-chamfered portions 13d and R-chamfered portions 13b smoothly connect the inner diameter side wall 13a and the pocket surface 21. In this way, the inner diameter side wall 13a and the pocket surface 21 are smoothly continuous by the R-chamfered portion 13b and C-chamfered portion 13d, which improves the flow of base oil in the grease and makes it easier to draw it into the pocket 20. Alternatively, the C-chamfered portion 13d may be placed on the radially outward side and the R-chamfered portion 13b on the radially inward side, contrary to the illustrated example.

[0027] [Fifth Embodiment] Figure 11 is a partially enlarged view of the crown-shaped retainer according to the third embodiment. Figure 12 is an enlarged view of Figure 11. As shown in Figures 11 and 12, at the corner where the inner diameter side wall 13a of the claw portion 13 and the pocket surface 21 (circumferential concave curved surface 14) intersect, an R-chamfered portion 13b is formed radially inward, a C-chamfered portion 13d is formed radially in the center, and an R-chamfered portion 13b is formed radially outward. These C-chamfered portions 13d and the pair of R-chamfered portions 13b, 13b smoothly connect the inner diameter side wall 13a and the pocket surface 21. In this way, the inner diameter side wall 13a and the pocket surface 21 are smoothly continuous due to the C-chamfered portion 13d and the pair of R-chamfered portions 13b, 13b, which improves the flow of base oil in the grease and makes it easier to draw it into the pocket 20. Alternatively, contrary to the illustrated example, a C-chamfered portion 13d may be formed on the radially inward side, an R-chamfered portion 13b may be formed in the radially central part, and a C-chamfered portion 13d may be formed on the radially outward side.

[0028] Furthermore, the present invention is not limited to the embodiments described above, and can be modified, improved, etc., as appropriate. For example, in the above embodiments, the pocket shape was described as a single spherical shape, but it can also be applied to other shapes such as a composite spherical shape or a cylindrical spherical shape.

[0029] As described above, the following matters are disclosed in this specification: (1) Annular rim portion, Multiple columnar portions extending from multiple locations in the circumferential direction of the rim portion toward one axial direction, Each of the aforementioned column portions has a claw portion extending in the axial direction from one end on the axial side, The rim portion and a pair of adjacent column portions and claw portions in the circumferential direction surround a plurality of pockets that hold the ball so that it can rotate, A crown-shaped retainer comprising, The diameter of the inner side wall of the claw portion is larger than the diameter of the inner side wall of the column portion. Crown type retainer. This configuration allows grease to be stored at one end of the column section in the axial direction.

[0030] (2) The corner between the inner diameter side wall of the claw portion and the pocket surface forming the pocket is provided with a chamfered portion that smoothly connects the inner diameter side wall and the pocket surface. (1) The crown-shaped retainer described above. This configuration allows grease stored at one axial end of the column to be efficiently supplied to the pocket.

[0031] (3) The radial length of the curved portion is 15% or less of the diameter of the ball. (2) The crown-shaped retainer described above. This configuration helps to suppress a decrease in the rigidity of the claw portion and whitening during assembly.

[0032] (4) The diameter of the inner side wall of the claw portion is greater than [(diameter of the pitch circle of the ball) × 0.9] and less than [(diameter of the pitch circle of the ball) × 1.1]. A crown-type retainer as described in any one of (1) to (3). With this configuration, the diameter of the inner side wall of the claw portion is close to the diameter of the ball's pitch circle, which improves the ability of grease to be drawn into the pocket.

[0033] (5) The radial length from the pitch circle diameter of the crown-shaped retainer to the outer surface of the crown-shaped retainer is 20% or more of the diameter of the ball. A crown-shaped retainer as described in any one of (1) to (4). This configuration ensures the rigidity of the claw portion. [Explanation of Symbols]

[0034] 10 Crown retainer 10a Outer surface 11 Rim section 12 Pillar section 12a Inner diameter side wall 12b One axial end 12c Outer diameter side wall 13. Nail area 13a Inner diameter side wall 13b R chamfered section (chamfered section) 13c Outer diameter side wall 13d C chamfered section (chamfered section) 20 pockets 21 Pocket side 30 balls D1 Diameter of the inner side wall of the claw portion D2 Diameter of the inner side wall of the column D3 Diameter of the outer side wall of the claw portion D4 Diameter of the outer side wall of the column section Da: Diameter of the ball L-shaped curved section radial length PCD (Pitch Circle Diameter) W is the radial length from the pitch circle diameter of the ball to the outer surface of the crown-shaped holder.

Claims

1. The annular rim portion, Multiple columnar portions extending from multiple locations in the circumferential direction of the rim portion toward one axial direction, Each of the aforementioned column portions has a claw portion extending in the axial direction from one end on the axial side, The rim portion and a pair of adjacent column portions and claw portions in the circumferential direction surround a plurality of pockets that hold the ball so that it can rotate, A crown-shaped retainer comprising, The diameter of the inner side wall of the claw portion is larger than the diameter of the inner side wall of the column portion. Crown type retainer.

2. The corner between the inner diameter side wall of the claw portion and the pocket surface forming the pocket is provided with a chamfered portion that smoothly connects the inner diameter side wall and the pocket surface. The crown-shaped retainer according to claim 1.

3. The radial length of the curved portion is 15% or less of the diameter of the ball. The crown-shaped holder according to claim 2.

4. The diameter of the inner side wall of the claw portion is greater than [(diameter of the pitch circle of the ball) × 0.9] and less than [(diameter of the pitch circle of the ball) × 1.1]. A crown-shaped retainer according to any one of claims 1 to 3.

5. The radial length from the pitch circle diameter of the crown-shaped retainer to the outer surface of the crown-shaped retainer is 20% or more of the diameter of the ball. A crown-shaped retainer according to any one of claims 1 to 3.

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