JP2002327753A - Retainer and rolling bearing using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a retainer capable of preventing retainer noises and realizing low rotating torque by controlling movement of the retainer against a rolling body in an axial direction. SOLUTION: In the wholly ring-shaped retainer in which a pocket 32 containing and retaining a rolling body B by a pocket face is formed in a plurality of places in a circumferential direction and an opening portion 38 having an opening width smaller than the rotating diameter of the rolling body is arranged on one side of each pocket in an axial direction A, the relation of the pocket diameter D of the pocket and the rotating diameter Da of the rolling body is set and D/Da=103.5 to 105.0%, and the relation of an axial gap δbetween the rolling surface of the rolling body in an axial direction and pocket face, and the rotating diameter Da of the rolling body is set as δ/Da=0 to 2%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing retainer used for a motor or the like that requires low vibration and low noise, and a rolling bearing provided with the retainer.

[0002]

2. Description of the Related Art A deep groove ball bearing for supporting a bearing portion and a rotating portion of various rotary machine devices is an inner ring provided with a deep groove inner ring track on an outer peripheral surface and an outer ring provided with a deep groove outer ring track on an inner peripheral surface. Are arranged concentrically with each other, and a plurality of balls are arranged between the inner raceway and the outer raceway so as to roll freely. Each ball is rollably held in a pocket provided in the retainer, and is filled with a lubricant such as grease or other lubricating oil between an outer peripheral surface of the inner ring and an inner peripheral surface of the outer ring, The relative rotation of the inner ring and the outer ring accompanying the rolling of the ball is made free.

[0003] In this deep groove ball bearing, noise or self-excited vibration called cage noise is generated based on the sliding friction between the ball and the cage due to the large amount of movement of the cage relative to the ball. May be. As a method of preventing the retainer noise, a method of using a low-viscosity lubricant that reduces a coefficient of friction at a sliding contact portion between the pocket surface of the retainer and the ball has been conventionally performed.

[0004]

However, even when a low-viscosity lubricant that reduces the friction coefficient between the pocket surface and the ball is used, the amount of movement of the retainer with respect to the ball is large, so that the collision between the pocket surface and the ball occurs. The self-excited vibration of the cage caused by the above cannot be sufficiently suppressed. Here, by reducing the pocket clearance between the pocket surface and the ball, the amount of movement of the cage with respect to the ball can be reduced to suppress self-excited vibration of the cage. If too long, the pocket will restrain the ball and the torque will increase. In particular, the lubricant is easily scraped off at the pocket edge portion, and the acoustic life is likely to be shortened due to poor lubrication.

Accordingly, the present invention has been made in view of the above circumstances, and suppresses the axial movement of the cage with respect to the rolling elements, thereby preventing the generation of cage noise and realizing low rotational torque. And a rolling bearing using the same.

[0006]

In order to achieve the above-mentioned object, a cage according to the present invention is provided with a pocket for accommodating and holding a rolling element at a plurality of circumferential positions at a plurality of positions in a circumferential direction. And a cage having an opening having a smaller opening width than the rotation diameter of the rolling element on one side in the axial direction of each pocket, wherein the pocket diameter D of the pocket and the rotation diameter Da of the rolling element are The relation is D / Da = 10
3.5% to 105.0%.

By incorporating the cage of the present invention into a rolling bearing, the rolling element is restrained by a part of the pocket circumference instead of being restrained by the entire pocket surface as in the conventional cage. , The contact portion is reduced, and low rotational torque is realized. Since the contact between the rolling element and the inner and outer edges of the retainer can be avoided, the lubricant attached to the rolling element is not scraped off, and the lubrication performance is improved.

The relationship between the axial gap δ provided between the rolling surface of the rolling element and the pocket surface in the axial direction and the rotational diameter Da of the rolling element is expressed by δ /
Da = 0 to 2%. By doing so, the noise level such as the cage sound can be suppressed while realizing low rotational torque.

On the other hand, according to the rolling bearing according to the third aspect, since the cage according to the first or second aspect is provided, the rolling bearing can suppress the noise of the cage while achieving low rotation torque.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cage according to the present invention will be described below with reference to the drawings. FIG. 1 shows a cage 30 according to one embodiment of the present invention.
The retainer 30 is a crown-shaped member formed by injection molding using a synthetic resin or the like as a material. A plurality of pockets 32 are provided on one side in the axial direction P of the retainer 30 at predetermined circumferential intervals. Are formed. Each pocket 32 is partitioned by a column 34, and a pocket entrance 38 is opened between a pair of claws 36 extending in an arc from the tip of the column 34.

FIG. 2 shows that the retainer 30 of FIG.
2 shows a state in which the ball B is stored and held in a no-load state. Here, the broken line A extending in the up-down direction in FIG. 2 is referred to as an axial direction along the axial direction P of the retainer 30. The diameter of the ball B is set to the dimension Da (ball diameter Da), and the pocket 32 whose pocket surface 40 is formed as a spherical concave surface has the diameter dimension set to D (pocket diameter D). ing. The outer peripheral surface of the ball B and the pocket surface 4 of the pocket 32 in the axial direction A
0, an axial gap δ is provided.

Next, the cage 30 of this embodiment is assembled as a bearing component, and the pocket diameter / ball diameter (D
/ Da), the axial clearance / ball diameter (δ / Da) ratio was changed, and the vibration of the cage (cage sound) and the rotational torque of the bearing generated with rotation were measured from FIG. 3. The results are shown in the graph of FIG. In the experiment, a deep groove ball bearing having an outer diameter of 26 mm, an inner diameter of 10 mm and a width of 8 mm was used.
The inner ring was rotated at 4800 rpm while an axial preload of (0.7 kgf) was applied.

The graph of FIG. 3 shows the pocket diameter / ball diameter (D /
Products A (◆), Products B (△), Products C (×), Products D (■), Products E (*), Products F (▲) with different ratios of Da)
Is a result of an experiment of rotational torque performed using the retainer of FIG. 5, the horizontal axis represents the value of D / Da, and the vertical axis represents the ratio based on the rotational torque of the current product A (marked with ◆). Indicates the rotational torque.

From the graph of FIG. 3, it can be seen that if the ball diameter Da is constant, the pocket diameter D changes and the rotational torque is divided into a high torque region and a low torque torque region. That is,
The region of the low rotation torque is D / Da = 103.5 to 105.
%, Preferably D / Da = 104.0 to
It is good to design so as to be in the range of 105%.
The graph of FIG. 4 shows the axial gap / ball diameter (δ / Da).
Are the results of an experiment of the rotational torque performed using the cages of the products A (◆) to F (▲) with different ratios, and the horizontal axis is δ /
3, and the vertical axis indicates the rotational torque in a ratio based on the rotational torque of the current product A (marked with ◆) as in FIG.

From the graph of FIG. 4, when δ / Da is in the positive region, there is no large change in rotational torque and the operation is stable. On the other hand, when δ / Da enters the negative region (eliminating the axial gap δ). , The rotational torque is rapidly increasing. This indicates that δ / Da must be in a positive region in order to set a low rotation torque. Next, FIG.
The graph of the results of the experiment of the vibration of the cage using the cages of the product A (◆ mark) to the product F (▲ mark) having different ratios of the axial gap / ball diameter (δ / Da), The horizontal axis is δ / Da
The vertical axis indicates the vibration value of the cage.

From the graph of FIG. 5, the smaller δ / Da is,
It can be seen that there is an effect in suppressing the cage sound. As a result, in order to realize low noise, δ / Da must be reduced as much as possible. However, since the rotational torque sharply increases from δ / Da = 0 to the negative region, low noise (cage sound The range for satisfying both the low rotation torque and the low rotation torque is in the range of δ / Da = 0 to 2%.
It is preferable to design so that δ / Da = 0.5 to 1.3%.

Next, FIG. 6 shows the results of the performance evaluation of the retainers A to F shown in the graphs of FIG. 3 to FIG. In this figure, the claimed range of the pocket diameter indicates a range of D / Da = 103.5 to 105%, and the claimed range of the axial gap is δ / Da = 0.
It shows a range of ２2%. From the results of the performance evaluation shown in this figure, the claims of the pocket diameter (D / Da = 103.5)
To 105%) and the axial gap (δ / Da)
= 0 to 2%) B product and C product designed in
It can be seen that both low noise (reduction of cage sound) and low rotation torque are compatible.

Therefore, as is clear from the graphs of FIGS. 3 to 5 and the results of the performance evaluation of FIG. 6, D / Da ==
103.5 to 105%, δ / Da = 0 to 2%
By limiting the amount of movement of the retainer 30 with respect to the ball B in the axial direction as the range of the above, it is possible to provide a bearing that suppresses retainer noise as compared with a conventional bearing and realizes low rotational torque.

That is, the cage 30 of the present embodiment has a larger pocket diameter in the axial direction than the conventional cage, so that the contact portion between the ball B and the pocket surface 40 is reduced. In other words, the ball is not constrained on the entire pocket surface as in the conventional cage, but is constrained on a part of the pocket circumference, so that the number of contact portions with the ball B is reduced and low rotational torque can be achieved. Further, since the pocket diameter in the axial direction is large, there is a gap between the ball B and the pocket surface 40, so that the lubricant can be appropriately retained and inflow, and the ball B and the pocket 32 can be retained.
Sliding friction is reduced, and low rotational torque can be realized. Further, since the contact between the inner and outer edges of the retainer 30 can be avoided, the lubricant attached to the ball B is not scraped off, the lubricating performance is improved, and the vibration of the retainer 30 is suppressed. can do.

Next, FIG. 7 shows another embodiment different from the shape of the pocket of the retainer 30 shown in FIG. The same components as those shown in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. This FIG.
This also shows a state in which the ball B is stored and held in the pocket 50 with no load. Here, the broken line C extending in the left-right direction in FIG. 7 is referred to as a circumferential direction. The opening width of the pocket entrance 38 provided between the pair of claws 36 has a dimension kD.
a is set. Here, the constant k for determining the opening width of the pocket entrance 38 is a known value, for example, k = 0.85
The opening width of the pocket entrance 38 is set to be smaller than the diameter Da of the ball B by using a constant k of a predetermined value.

The pocket 32 containing the ball B is
The first pocket surface 44 includes a first pocket surface 44 on the inner wall of the pair of claws 36 and a second pocket surface 46 located between the first pocket surfaces 44. The second pocket surface 46 is formed as a spherical concave surface having a radius of curvature R represented by the following equation (1) with the center of curvature being the rotation center O ₀ of the ball B in the unloaded state.

[0022]

(Equation 1)

The pocket diameter D of the present embodiment is represented by the following equation (2).

[0024]

(Equation 2)

The center of curvature O ₁ of the first pocket surface 44 has a dimension h _{1 in} the axial direction A away from the center of curvature O _{0 of} the second pocket surface 44 on the opposite side to the pocket entrance 38. (hereinafter, referred to as axial uneven distribution quantity h ₁₎
Radius of curvature Ra larger than the radius of curvature R of the second pocket surface 46 from the center of curvature O ₁ .
It is formed as a spherical concave surface having (Ra> R).
Equations (3) and (4) show the axial uneven distribution amount h ₁ and the radius of curvature Ra of the first pocket surface 44 described above.

[0026]

(Equation 3)

[0027]

(Equation 4)

The cage 30 in FIG. 7 also has D / Da == 1.
By limiting the amount of movement of the cage with respect to the ball B in the axial direction by setting the range of 33.5 to 105% and the range of δ / Da = 0 to 2%, the cage sound is suppressed and the low rotational torque is obtained. However, since the axial gap δ between the second pocket surface 46 and the ball B can be freely controlled by changing the axial uneven distribution amount h ₁ , the pocket diameter D is increased. Accordingly, the ratio δ / Da between the axial gap δ and the diameter D of the ball B, which becomes a large value, can be easily set in the range of 0 to 2%.

For example, when D / Da = 104%,
to take into δ / Da = 0~2% range may be set Axial uneven distribution amount h ₁ in the range of 3.88 to 6.40%. Note that, even if a structure in which the opening width of the pocket entrance 38 between the pair of claws 36 in FIG. Can be easily put in.

Although not shown in the drawings, the technology of the rolling element guiding cage described in Japanese Patent Application Laid-Open No. 58-19511 previously proposed by the present applicant also has a pocket structure shown in FIG. By increasing the diameter D, the ratio δ / Da between the axial gap δ and the diameter D of the ball B, which becomes a large value, can be easily set in the range of 0 to 2%. That is, JP-A-58-19511
In the rolling element guide retainer, at least a part of the inner surface of the pocket for holding and guiding the rolling element forms a curved surface having substantially the same shape as the curvature of the rolling element, and the center of curvature of the curved surface is the rolling element. Is a technique in which a desired deviation amount ε is unevenly distributed with respect to the pitch circle of this technology. However, in this technology, the pocket pitch circle is radially unevenly distributed by the deviation amount ε with respect to the bearing pitch circle. Then, the ratio δ / Da between the axial gap δ and the diameter D of the ball B can be set in the range of 0 to 2%.

The present embodiment is an example of the present invention, and the present invention is not limited to the present embodiment. For example, if the axial curvature of the pocket is D
/Da=103.5 to 105%, and the cage in which the circumferential curvature δ / Da = 0 to 2% is also used.
Similar effects can be obtained.

[0032]

As described above, according to the first aspect of the present invention,
According to the cage described, by incorporating into the rolling bearing,
The rolling element is not constrained by the entire pocket surface as in the conventional cage, but is constrained by a part of the pocket circumference. Therefore, the number of contact portions with the rolling element is reduced, and low rotational torque can be realized. . In addition, since the contact between the rolling element and the inner and outer edges of the cage can be avoided, the lubricant attached to the rolling element is not scraped off, and the lubricating performance can be improved.

According to the retainer of the second aspect, it is possible to suppress the noise level such as the retainer sound while realizing a low rotational torque. Further, according to the rolling bearing of the third aspect, by providing the cage of the first or second aspect, it is possible to provide a rolling bearing that achieves low rotational torque and suppresses the sound of the cage.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a cage used for a rolling bearing according to the present invention.

FIG. 2 is a view showing a shape of a pocket according to an embodiment of the present invention.

FIG. 3 shows the relationship between the pocket diameter / ball diameter (D) of the bearing incorporating the cage according to the present invention and the bearing incorporating the conventional cage.
6 is a graph showing a change in rotational torque when the ratio of / Da) changes.

FIG. 4 is a graph showing a change in rotational torque when the ratio of axial gap / ball diameter (δ / Da) changes between a bearing incorporating a cage according to the present invention and a bearing incorporating a conventional cage. .

FIG. 5 is a graph showing a change in vibration of the cage when the ratio of axial gap / ball diameter (δ / Da) changes between the bearing incorporating the cage according to the present invention and a bearing incorporating the conventional cage. It is.

FIG. 6 is a diagram showing the results of performance evaluation of a bearing incorporating a cage according to the present invention and a bearing incorporating a conventional cage.

FIG. 7 is a view showing an embodiment different from the shape of the pocket shown in FIG. 2;

[Explanation of symbols]

30 Cage 32, 50 Pocket 36 Claw 38 Pocket entrance (opening) 40 Pocket surface 44 First pocket surface 46 Second pocket surface A Axial direction B Ball (rolling element) C Circumferential direction D Pocket diameter Da Ball Diameter (rotational diameter of rolling element) h ₁ Axial uneven distribution amount O ₀ Center of rotation of rolling element (center of radius of curvature of second pocket surface) R Radius of curvature of second pocket surface Ra Radius of curvature of first pocket surface δ axial gap

Claims (3)

[Claims] 1. A pocket for accommodating and holding a rolling element on a pocket surface at a plurality of locations in the circumferential direction, and a rotation of the rolling element on one axial side of each pocket. In a cage provided with an opening portion having an opening width smaller than the diameter, the relationship between the pocket diameter D of the pocket and the rotation diameter Da of the rolling element is D / Da = 103.5% or more.
A retainer characterized by being 105.0%. 2. The relationship between an axial gap δ provided between a rolling surface of the rolling element and the pocket surface in the axial direction and a rotation diameter Da of the rolling element is δ / Da.
The retainer according to claim 1, wherein = 0 to 2%. 3. A rolling bearing using the cage according to claim 1.