JP2001336535A - Cage for rolling bearing - Google Patents

Abstract

(57) [Summary] [Problem] To reduce the clearance between the pocket surface and the rolling surface of the rolling element, and to make the retainer radial direction relative to the ball without using the inner ring guide or the outer ring guide. The amount of movement of the cage is regulated to suppress the cage sound. When a ball (B) is rollably held by disposing a cage (20) between an inner ring (10) and an outer ring, a first inclined surface (22a) is formed.
Are inclined toward the groove bottom of the inner raceway 12, and the second inclined surface 2
2b is inclined toward the groove bottom of the inner raceway 12, and the ball B is in a state where the convex portion 22 enters the groove space of the inner raceway 12.
Is held rotatably. Here, the retainer inner diameter dc, the maximum outer diameter Dout of the inner ring, and the inner ring raceway diameter Din of the inner ring 10
Is set to Din <dc ≦ Dout. By doing so, the amount of movement of the retainer 20 in the radial direction is significantly reduced, and the retainer sound can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a cage which constitutes a rolling bearing used for supporting a rotating member incorporated in various types of rotary mechanical devices. The present invention relates to a cage for a rolling bearing that reduces cage noise during operation of a bearing.

[0002]

2. Description of the Related Art Ball bearings are widely used as rolling bearings incorporated in various types of rotating machinery and used to support rotating members. In this ball bearing, an inner race having an inner raceway on an outer peripheral surface and an outer race having an outer raceway on an inner peripheral surface are arranged concentrically with each other, and a plurality of balls are provided between the inner race and the outer race so as to roll freely. Bearings. And the above-mentioned ball is rollably held in a pocket of a cage arranged between the inner ring and the outer ring. FIG. 7 shows a cage 1 called a crown-shaped cage. The cage 1 can freely roll balls at a plurality of circumferential positions of an annular main portion 2 formed of synthetic resin or the like. Are provided.

Each of the pockets 4 has one side surface of a pair of elastic pieces 6 arranged at an interval from the upper portion of the main part 2 and a spherical pocket provided at a portion between the pair of elastic pieces 6. Surface 8. The radius of curvature of the pocket surface 8 is
The radius of curvature is set slightly larger than the radius of curvature of the ball rolling surface described above. FIG. 8 shows a state in which the ball B is held by the pocket 4 of the cage 1 disposed between the inner ring 10 and the outer ring, but the cage facing the groove-shaped inner raceway 12 of the inner ring 10. 1 is formed in a cylindrical surface shape (hereinafter, referred to as a straight surface shape) in which the center of curvature coincides with the rotation axis Pa, and the inner diameter dc ₀ of the retainer 1 is set to the inner ring 1.
0 larger than the maximum outer diameter Dout (dc ₀ > Dou).
t).

[0004] The ball bearing provided with the retainer 1 having the above-described structure allows the inner ring 10 and the outer ring to rotate relative to each other as the plurality of balls B roll. At this time, each ball B revolves around the inner ring 10 while rotating. The cage 1 rotates around the inner ring 10 at the same speed as the revolution speed of the ball B. By the way, the space between the inner raceway 12 of the inner race 10 and the outer raceway of the outer race is filled with grease or other lubricant so that the relative rotation can be performed smoothly. In addition to preventing occurrence, seizure and the like are prevented.

[0005]

By the way, when a ball bearing incorporating the retainer 1 shown in FIG. 7 is used at a high speed, vibration is induced in the retainer even if a required amount of lubricant is filled. Therefore, noise or vibration called retainer sound may be generated. Noise and vibration caused by such a cage 1
Due to the large amount of movement of the cage 1 in the radial direction (radial direction) with respect to the ball B, the frictional force is generated based on the sliding friction between the ball B and the cage 1.

As a method of suppressing the cage noise, a method of reducing the clearance between the pocket surface 8 and the rolling surface of the ball B (hereinafter, a first solution), and the cage 1 guided by the inner ring 10. A method (second solution) and a method (third solution) of using the cage 1 as an outer ring guide (not shown) are conceivable.
However, the first solution is that the lubricant does not easily flow into the clearance between the pocket surface 8 and the rolling surface of the ball B, so that a sufficient amount of lubricant is not taken into the clearance, and the cage 1 and the ball B
The frictional vibration at the sliding contact portion with the contact member cannot be sufficiently suppressed, and vibration and noise may be induced.

Further, according to the second solution, the cage 1
Sufficient lubricant may not be taken in between the inner peripheral surface of the inner ring 10 and the inner ring raceway 12 of the inner ring 10, and the frictional vibration of the sliding contact portion between the retainer 1 and the inner ring 10 may not be sufficiently suppressed. When the ball bearing is used at high speed rotation, heat generation increases due to sliding contact between the inner peripheral surface of the cage 1 and the inner raceway 12 of the inner race 10, and the life of the cage 1 is shortened. Further, when the ball bearing rotates at a high speed, the cage 1 may open outward due to the centrifugal expansion, so that the ball B may not be reliably guided to the inner ring 12. Furthermore, it is necessary to polish the inner raceway 12 of the inner race with high precision, which leads to an increase in the number of processing steps and an increase in cost.

Further, in the third solution, the life of the cage 1 may be shortened because the cage 1 that opens outward due to the centrifugal force contacts the outer ring. Therefore, the present invention has been made in view of the above circumstances, and does not reduce the clearance between the pocket surface and the rolling surface of the rolling element, and furthermore, retains the cage without using the inner ring guide or the outer ring guide. It is an object of the present invention to provide a rolling bearing retainer capable of restricting the amount of movement of a retainer in a radial direction with respect to a ball, thereby suppressing retainer noise.

[0009]

In order to achieve the above object, a rolling bearing retainer according to the present invention is provided with a pocket having a whole annular shape and having spherical pocket surfaces at a plurality of positions in a circumferential direction. Are formed concentrically between an inner ring provided with an inner raceway on the outer peripheral surface and an outer race provided with an outer raceway on the inner peripheral surface, and are rollable between the inner raceway and the outer raceway. In order to hold the rolling element provided on the rolling element, the pocket face is formed in a spherical shape concentric with the rolling face of the rolling element and having a slightly larger radius of curvature than the rolling face. , The retainer inner peripheral surface is formed to bulge in the direction of the rotation axis, and the relationship among the retainer inner diameter dc, the maximum outer diameter Dout of the inner race, and the inner raceway diameter Din of the inner race is set to Din <dc ≦ Dout. Set.

[0010] The retainer inner diameter dc is the maximum outer diameter Dout of the inner ring.
If the value is larger (dc> Dout), the amount of movement of the cage in the radial direction increases, and when the bearing is used at a high speed, the cage due to vibration and noise due to sliding friction between the rolling element and the cage. Sound is easy to generate. On the other hand, when Din <dc ≦ Dout is set as in the present invention, the amount of movement of the retainer in the radial direction is reduced, and even when the bearing is used at a high speed, the sliding contact between the retainer and the rolling element occurs. The frictional vibration of the portion is suppressed, and the induction of vibration and noise is prevented, and the retainer sound is reduced.

Therefore, without reducing the clearance between the pocket surface where the lubrication performance is a problem and the rolling surface of the rolling element,
By regulating the amount of radial movement of the cage with respect to the rolling elements, cage noise can be suppressed even when the bearing rotates at high speed. However, when the cage inner diameter dc becomes too small and approaches the value of the inner ring raceway diameter Din of the inner ring (dc ≒ Di
n), there is a problem in terms of assemblability of the bearing. Therefore, the ratio (Din) of the inner ring raceway diameter Din of the inner ring to the retainer inner diameter dc.
If / dc) is set to Din / dc <1, it is possible to improve the assemblability of the bearing while suppressing the retainer sound. The lower limit at this time is dc / Do, which will be described later.
It is determined from the condition of ut ≦ 1.

By the way, as an example of a specific shape in which the inner peripheral surface of the retainer of the present invention bulges in the direction of the rotation axis, the retainer extends from one end on the inner peripheral side in the direction of the rotation axis. A first inclined surface, a second inclined surface extending from the other end side in the direction of the rotation axis, and a ridge line portion provided at a position where the first and second inclined surfaces intersect. And a convex portion having the following.

[0013] When the projection enters the groove space of the inner raceway of the inner race, the guide area of the pocket surface of the cage for holding the rolling element in a freely rolling manner increases. In addition, by providing the above-described convex portion, when the rolling element rotates on its own, the area where the edge of the pocket surface opposes the rolling surface of the rolling element gradually increases, and the opposing area gradually increases. A narrow portion occurs. Thereby, circulation of the lubricant accumulated between the pocket surface and the rolling surface of the rolling element is promoted.

If the amount of deviation of the ridge of the projection from the groove width of the inner raceway of the inner race is set within ± 5% of the groove width, the amount of radial movement of the retainer relative to the rolling element is further increased. Thus, the cage sound can be further reduced. When the inclination angle θ of the first and second inclined surfaces of the projection with respect to the rotation axis is set in a range of 5 ° to 30 °,
It is possible to simultaneously suppress the amount of movement of the retainer in the radial direction with respect to the rolling element and improve the assemblability.

Further, as an example of a specific shape of the inner circumferential surface of the retainer of the present invention which bulges in the direction of the rotational axis, one example of the inner peripheral side of the retainer bulges in the direction of the rotational axis. A first curved surface, a second curved surface bulging from the other end side in the direction of the rotation axis, and a ridge provided at a position where the first and second curved surfaces intersect. Department is conceivable.
This convex part can also obtain the same operation as the convex part having the first and second inclined surfaces described above.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a rolling bearing retainer according to the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view showing the entire retainer 20 of the first embodiment, and FIG. 2 is an enlarged perspective view showing a main part of the retainer 20. The same components as those shown in FIGS. 7 and 8 are denoted by the same reference numerals, and description thereof will be omitted.

The retainer 20 of this embodiment is made of a synthetic resin such as linear polyphenylene sulfide, nylon 66, nylon 46, or branched polyphenylene sulfide. In order to increase the mechanical strength, a fibrous filler, a particulate filler, and the like as a filler are mixed in the synthetic resin. As the fibrous filler, there are glass fiber, carbon fiber and the like, and as the particulate filler, particles such as silica and alumina are known.

The feature of this embodiment is that the cage 20
Is provided on the inner peripheral side of the convex portion 22 swelling toward the rotation axis Pa. As shown in FIG. 2, the convex portion 22 has a rotation axis P that extends from the tip of the elastic piece 6 toward the main portion 2.
a first inclined surface 22a that is gradually inclined toward a;
A position where the second inclined surface 22b which is gradually inclined toward the rotation axis Pa from the end of the main portion 2 toward the elastic piece 6, intersects the first and second inclined surfaces 22a, 22b. And a ridge line portion 22c formed at the bottom. Also,
A chamfered portion 22d is formed on the inner peripheral side of the retainer 20 by shaving off a corner formed by the bottom surface of the main portion 2 and the second inclined surface 22b.

Then, as shown in FIG. 3, when the retainer 20 is disposed between the inner ring 10 and the outer ring and the ball B is held so as to roll freely, the first inclined surface 22 a is located on the groove bottom of the inner ring raceway 12. With the second inclined surface 22b inclined toward the groove bottom of the inner ring raceway 12, the ball B is rotatably held in a state where the convex portion 22 enters the groove space of the inner ring raceway 12. Here, the ridge line portion 22c is positioned on a line in the radial direction passing through the center C _B of the pocket 4, is set a groove bottom of the inner ring raceway 12 (widthwise center) concentric position.

Here, the amount of movement (ΔR / 2) of the cage 20 in the radial direction is obtained by the following equation (1). ΔR = DW · cos α− (Da ² − (DW · sin α) ² ) ^1/2 (1) Note that, as is clear from FIG.
W: diameter of the pocket surface 8, Da: diameter of the ball B, dm: pitch diameter of the ball B, dc: inner diameter of the retainer 20.

The symbol α in the equation (1) is the pocket surface 8
Is an angle between a straight line connecting the inner peripheral side edge and the center of the ball B and a straight line connecting the center of the ball B and the rotation axis Pa of the retainer 20, and the angle α is shown below (2) It is obtained by the formula. α = cos ⁻¹ {(DW ² + dm ² −dc ² ) / (2 · DW · dm)} (2) Further, the symbol Dout in FIG. 4 indicates the maximum outer diameter of the inner ring 10 and 3), and the symbol Δr / 2 indicates the amount of movement in the radial direction of the conventional cage having an inner peripheral surface formed in a straight surface shape and an inner diameter of dc ₀ .

As is apparent from the expressions (1) and (2), the cage 20 of the present embodiment can be used without changing the diameter DW of the pocket surface 8 and the diameter Da of the ball B. By providing the convex portion 22 on the inner peripheral side, that is, by reducing the inner diameter dc of the retainer 20, the radial movement amount ΔR / 2 of the retainer 20 can be regulated. Here, FIG. 5 shows a relationship between a change in the amount of movement of the retainer in the radial direction corresponding to a change in the inner diameter of the retainer. The bearing has an outer diameter of 47 mm, an inner diameter of 17 mm, and a width of 14 mm.
mm bearings were used. The horizontal axis in this figure indicates the change in the inner diameter of the cage by the ratio of the inner diameter of the cage to the maximum outer diameter Dout of the inner ring 10 (inner diameter of the cage / maximum outer diameter Dout of the inner ring 10). In addition, the vertical axis of this figure indicates that the amount of movement of the cage in the radial direction when the inner diameter of the cage matches the maximum outer diameter Dout of the inner ring 10 is 1 (dc / Dout =
1) shows a relative motion amount with respect to this value.

As is apparent from this figure, as the inner diameter of the cage is reduced, the amount of movement ΔR of the cage in the radial direction is reduced.
/ 2 decreases. That is, when the inner diameter ratio of the retainer is 1 (a state in which the inner diameter dc of the retainer 20 matches the maximum outer diameter Dout of the inner ring 10: dc / Dout = 1 by dc = Dout), the radial direction of the retainer 20 The movement amount of the conventional cage (dc ₀ /Dout≒1.075) in which the inner circumferential surface of the cage is a straight surface has a large value of approximately 1.4 times that of the movement amount of 1. .

When the inner diameter dc of the retainer 20 is made equal to the track diameter Din of the inner race 10 (dc = Din), the inner diameter ratio of the retainer becomes approximately 0.875, and the retainer 20
In the radial direction is reduced to approximately one half of the amount of movement of the conventional cage. Therefore, the cage inner diameter dc
If the relationship between the maximum outer diameter Dout of the inner race and the inner raceway diameter Din of the inner race 10 is Din <dc ≦ Dout (3), the radial movement amount ΔR / 2 of the retainer 20
Can be greatly reduced, and cage sound can be suppressed.

Here, if the inner diameter dc of the cage is set too small, there is a problem in terms of assemblability of the bearing. Therefore, when the inner diameter ratio (dc / Dout) of the cage is set to 0.9 ≦ dc / Dout ≦ 1 (4), the protrusion 22 is formed in the groove space of the inner raceway 12 while suppressing the cage sound. , So that the bearing can be easily assembled.

Further, as described above, ridge line portion 22c constituting the projection 22 is located on a line in the radial direction passing through the center C _B of the pocket 4, the inner ring raceway in principle 1
2, the groove width of the inner raceway 12 is L, as shown in FIG. 3, and the ridge 22c is shifted in the axial direction from the position where the ridge 22c coincides with the groove bottom of the inner raceway 12. Assuming that the amount is ΔL, | ΔL / L | ≦ 0.05 (5) That is, if the ridge 22c is designed to be within ± 5% of the center of the groove width, the retainer 20 in the radial direction The movement amount ΔR / 2 can be sufficiently reduced.

As shown in FIG. 3, the first and second inclined surfaces 22a with respect to the rotation axis Pa (axial direction),
22b is 5 ° ≦ θ ≦ 30 ° from the balance between the amount of movement of the retainer 20 in the radial direction and the ease of assembly.
Angles in the range are desirable. Further, the shape of the ridge portion 22c may be an acute angle shape or a rounded shape.

Next, the advantages of the rotation accuracy and lubrication performance of the bearing by providing the convex portion 22 on the inner peripheral side of the cage 20 of the present embodiment will be described below. In this embodiment,
By providing the retainer 20 with the protruding portion 22 that enters the groove space of the inner raceway 12 of the inner race 10, the guide area of the pocket 4 of the retainer 20, which holds the ball B in a freely rolling manner, is increased. From this, the relationship between the rotation of the ball B and the rotation of the retainer 20 approaches theoretically and stabilizes, so that the rotational accuracy of the bearing can be improved.

Further, as shown in FIG.
Since the convex portion 22 is provided by 2a and the second inclined surface 22b, the rotation direction of the ball B is in the direction of the arrow R (the rotation axis Pb).
, The edge 8 of the pocket surface 8 with respect to the rolling surface of the ball B
The facing area of a, 8b gradually widens, and the lubricant is sucked between the pocket surface 8 and the rolling surface. Also, the edge portions 8c and 8d of the other pocket surfaces gradually decrease in area facing the rolling surface of the ball B, so that the lubricant accumulated between the pocket surface 8 and the rolling surface comes out. come. Thus, the provision of the convex portion 22 promotes the circulation of the lubricant accumulated between the pocket surface 8 and the rolling surface, improves the lubrication performance, and prevents the deterioration of the lubricant. it can. At the same time, by improving the lubrication performance, the induction of vibration and noise due to sliding friction between the cage 20 and the ball B is prevented, and the cage noise can be reduced.

FIG. 6 shows a retainer 30 according to the second embodiment. Also in the present embodiment, the same components as those shown in FIGS. 7 and 8 are denoted by the same reference numerals, and the description thereof will be omitted. Cage 30 of the present embodiment
Is provided with a convex part 32 having a curved surface bulging toward the inner raceway 12 on the inner peripheral side.

The convex portion 32 has a first curved surface 32 a which bulges toward the inner raceway 12 from the tip of the elastic piece 6 toward the main portion 2, and goes from the end of the main portion 2 to the elastic piece 6. Curved surface 3 bulging toward the inner raceway 12 according to
2b, and a ridge 32c formed at a position where the first and second curved surfaces 32a and 32b intersect. On the inner peripheral side of the retainer 30, a corner formed by the bottom surface of the main portion 2 and the second curved surface 32b is cut off to form a chamfered portion 32.
d is formed.

[0032] Then, the edge line portion 32c is positioned on a line in the radial direction passing through the center C _B of the pocket 4, is set a groove bottom of the inner ring raceway 12 (widthwise center) concentric position. Also in the present embodiment, assuming that the relationship among the retainer inner diameter dc, the maximum outer diameter Dout of the inner ring, and the inner ring raceway diameter Din of the inner ring 10 is Din <dc ≦ Dout, as in the first embodiment, the retainer 30 The amount of movement ΔR / 2 in the radial direction is greatly reduced, and the retainer sound can be suppressed.

Further, the inner diameter ratio (dc / Dou) of the cage 30 is
If t) is set to 0.9 ≦ dc / Dout ≦ 1, the curved convex portion 3 is formed while suppressing the retainer sound.
2 can be prevented from entering the groove space of the inner raceway 12 so much that the assemblability of the bearing can be improved.

Further, since the convex portion 32 is provided on the retainer 30 so as to enter the groove space of the inner raceway 12 of the inner race 10,
The guide area of the pocket 4 of the cage 30 that holds the ball B so as to be able to roll freely increases, and the relationship between the rotation of the ball B and the rotation of the cage 30 approaches theoretically and stabilizes. Can be improved. Furthermore, the convex part 3 of the curved surface shape
With the provision of 2, in the direction in which the ball B rotates, a portion where the facing area of the edge of the pocket surface with respect to the rolling surface of the ball B gradually increases, and the facing area gradually decreases. Is provided. This facilitates circulation of the lubricant accumulated between the pocket surface and the rolling surface of the ball B, thereby improving lubrication performance and preventing deterioration of the lubricant. Induction of vibration and noise due to sliding friction with B can be prevented, and an effect of reducing cage noise can be achieved.

[0035]

As described above, according to the cage for a rolling bearing of the present invention, the relationship between the cage inner diameter dc, the maximum outer diameter Dout of the inner ring, and the inner ring raceway diameter Din of the inner ring is expressed by:
When Din <dc ≦ Dout is set, the amount of radial movement of the cage is reduced, and even when the bearing is used at high speed, the frictional vibration of the sliding contact portion between the cage and the rolling element is suppressed, and vibration and vibration are reduced. The induction of noise is prevented, and the cage sound is reduced. Therefore, without reducing the clearance between the pocket surface where the lubrication performance is a problem and the rolling surface of the rolling element, the bearing rotates at a high speed by regulating the amount of radial movement of the cage with respect to the ball. Even in this case, the cage sound can be suppressed.

[Brief description of the drawings]

FIG. 1 shows a first bearing used in a rolling bearing according to the present invention.
It is a perspective view showing a cage of an embodiment.

FIG. 2 is an enlarged perspective view of the vicinity of a pocket of the retainer according to the first embodiment.

FIG. 3 is a cross-sectional view showing a retainer according to the first embodiment, which is disposed between an inner ring and an outer ring and holds a ball.

FIG. 4 is an enlarged view of a main part of the retainer according to the first embodiment viewed from a rotation axis direction.

FIG. 5 is a diagram showing the relationship between the inner diameter of the cage and the amount of movement of the cage in the radial direction.

FIG. 6 is a cross-sectional view showing a retainer according to a second embodiment, which is disposed between an inner ring and an outer ring and holds a ball.

FIG. 7 is a perspective view showing a conventional cage.

FIG. 8 is a cross-sectional view showing a state where a conventional cage is disposed between an inner ring and an outer ring.

[Explanation of symbols]

 2 Main part 4 Pocket 6 Elastic piece 8 Pocket surface 8a, 8b, 8c, 8d Edge of pocket surface 10 Inner ring 12 Inner ring raceway 22, 32 Convex portion 22a First inclined surface 22b Second inclined surface 22c Ridge portion 22d Beveling Part 32a First curved surface 32b Second curved surface 32c Ridge part 32d Chamfered part B Ball (rolling element) dc Retainer inner diameter Dout Maximum outer diameter of inner ring Din Inner ring raceway diameter of inner ring Pa Rotating axis Pb Rotation axis ΔR / 2 holder Radial movement of

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Koichi Goto 1-50 50 Kugenuma Shinmei, Fujisawa-shi, Kanagawa F-term in NSK Ltd. (reference) 3J101 AA02 AA32 AA42 BA25 BA44 BA50 CA13 EA31 EA36 EA76 FA01 FA32

Claims (1)

[Claims] 1. An inner ring having an annular shape as a whole, having spherical pocket surfaces at a plurality of positions in a circumferential direction, an inner ring having an inner raceway on an outer peripheral surface, and an outer raceway being provided on an inner peripheral surface. The pocket surface is concentrically disposed between the inner raceway and the outer raceway so as to hold a rolling body rotatably provided between the inner raceway and the outer raceway on the pocket surface. In a spherical roller bearing retainer concentric with the moving surface and having a slightly larger radius of curvature than the rolling surface, the retainer inner peripheral surface is formed to bulge in the direction of the rotation axis,
A retainer for a rolling bearing, wherein a relationship among a retainer inner diameter dc, a maximum outer diameter Dout of the inner race, and an inner raceway diameter Din of the inner race is set as Din <dc ≦ Dout.