JP2003194065A - Crown-shaped retainer for ball bearing and ball bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball bearing of a higher performance in which a retainer 8a made of a synthetic resin is installed. <P>SOLUTION: The retainer 8a of this ball bearing is furnished with pockets 10a ia such an arrangement that the radius R<SB>1</SB>of curvature of the section shape of each pocket 10a about the virtual plane β including the center axis α of the pocket 10a is greater than the radius R<SB>2</SB>of the maximum inscribing circle of the section shape of each pocket 10a about the virtual plane γ perpendicularly intersecting the center axis α of the pocket 10a. The radius R<SB>2</SB>of the maximum inscribing circle is made slightly larger than 1/2 of the outside diameter Da of the rolling surface of each ball 6. Thereby the edge of the pocket 10a is unlikely to contact with the rolling surface of the ball 6 even if a volume contraction is generated when the retainer 8a is molded. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The crown type retainer for ball bearings and ball bearings of the present invention are motors required to have low vibration, low noise and low torque, such as fan motors for vacuum cleaners or air conditioners. The present invention relates to an improvement of a ball bearing for supporting a rotating part of the ball bearing, and a cage incorporated in the ball bearing to guide a plurality of balls in a rollable manner.

[0002]

2. Description of the Related Art A ball bearing 1 as shown in FIG. 9 is widely used to support various rotating parts. In this ball bearing 1, an inner ring 3 having an inner ring raceway 2 formed on the outer peripheral surface thereof and an outer ring 5 having an outer ring raceway 4 formed on the inner peripheral surface thereof are concentrically arranged, and between the inner ring raceway 2 and the outer ring raceway 4 are arranged. A plurality of balls 6, 6 are provided so as to be rollable. The plurality of balls 6, 6 are rotatably held by a cage 8. Also, the outer ring 5
A ring-shaped shield plate 7,
The outer peripheral edge of 7 is locked, and the grease existing in the part where the balls 6, 6 are installed leaks to the outside by these shield plates 7, 7, or dust that floats outside is installed in this installation part. Prevents entry. As a sealing device, a contact type seal plate may be used instead of the non-contact type shield plates 7 and 7.

The cage 8 is a so-called crown type cage, and is constructed as shown in FIGS. The retainer 8 includes a ring-shaped main portion 9 and a plurality of pockets 10 and 10 provided on one axial surface of the main portion 9 at equal intervals. Each of these pockets 10 and 10 has a pair of elastic pieces 11 and 11 arranged on one axial surface of the main portion 9 and spaced apart from each other, and one pair of elastic pieces 11 on one surface of the main portion 9. , 11 and a concave surface portion 12 provided in a portion between the two. The balls 6, 6 are held in the pockets 10, 10 one by one so that they can be rolled. The inner surfaces of the pockets 10 and 10 thus configured are
The whole is a spherical concave surface having a single radius of curvature. The radius of curvature of the spherical concave surface is slightly larger than the radius of curvature of the rolling surface of each ball 6, 6. Such a retainer 8 is integrally formed by injection molding a synthetic resin.

When assembling the ball bearing 1, each of the balls 6,
6 elastically pushes the gap between the pair of elastic pieces 11 and 11 while elastically widening the gap between the distal end portions of the pair of elastic pieces 11 and 11 forming the pockets 10 and 10. Then, in the pushed-in state, the balls 6, 6 are rollably held in the pockets 10, 10. In this state, the rolling surfaces of the balls 6 and 6 and the pockets 1 are
There is a minute gap between the inner surface of 0 and 10. Therefore, in a state in which the balls 6 and 6 are held in the pockets 10 and 10, the cage 8 holds the balls 6 and 6 at equal intervals in the circumferential direction and is rollable. The diametrical position of the cage 8 is regulated by these balls 6, 6.

[0005]

Since the cage 8 is manufactured by injection molding a synthetic resin, the volume shrinkage of the synthetic resin occurs after the injection molding, and the dimensions of each part of the cage 8 have desired values. May be smaller than. Further, each of these dimensions tends to be smaller in the radial direction than in the circumferential direction of the main portion 9. On the other hand, in the case of the conventional cage 8 described above, a plurality of pockets 10, 10 are designed at the time of designing.
It was designed on the premise that the inner surface of the above is a spherical concave surface having a single radius of curvature, which is slightly larger than the radius of curvature of the rolling surface of each ball 6 held in each of these pockets 10, 10. Therefore, when the above-mentioned volume contraction occurs during the injection molding of the cage 8, the inner surface shape of each of the pockets 10 and 10 is larger than the dimension of the main portion 9 in the circumferential direction,
The radial dimension of the main portion 9 tends to be small.

Then, as shown in FIG. 12, the radius of curvature R of the inner surface of each pocket 10 in the radial direction of the main portion 9 is increased.
_{When 1} becomes smaller, this radius of curvature R ₁ becomes smaller than 1/2 of the outer diameter D _a of each ball 6, which is the radius of curvature of the rolling surface of the ball 6 held in each pocket 10 (R ₁ <D _a /
2) There is a possibility. In this case, each of the pockets 10
A pair of edge portions 13, 13 located on both sides in the diametrical direction (left and right direction in FIG. 12) of the cage 8 contact the rolling surface of each ball 6. Then, the holding performance of the cage 8 with respect to the balls 6 may be deteriorated, and the cage 8 may vibrate during the operation of the ball bearing 1, resulting in a loud cage noise.

Lubricant such as grease adhered to the rolling surfaces of the balls 6 is scraped off by the edge portions 13 and 13, and the rolling surfaces of the balls 6 and the inner surfaces of the pockets 10 are removed. It becomes difficult for lubricant to be taken into the gap existing between and. If a sufficient amount of lubricant does not exist at the sliding contact portion between the inner surface of each pocket 10 and the rolling surface of each ball 6, the frictional force acting on this sliding contact portion becomes large. Further, during operation of the ball bearing, the balls 6 held in the pockets 10 are
Based on the revolving movement, the edge of each pocket 10 is pressed against a pair of edge portions 13, 13 located on one side in the circumferential direction (front and back direction in FIG. 12) of the cage 8. Therefore, the frictional force acting on the sliding contact portion between the inner surface of each pocket 10 and the rolling surface of each ball 6 becomes larger.
When the frictional force increases in this way, the rotational resistance (dynamic torque) of the ball bearing increases, making it difficult to reduce energy consumption (electric power) of various mechanical devices incorporating the ball bearing. In view of such circumstances, the crown type cage for ball bearings and the ball bearing of the present invention have improved performance of a ball bearing incorporating a crown type cage made of a synthetic resin that may cause volume shrinkage during molding. It was invented to achieve

[0008]

Among the crown type cages for ball bearings and ball bearings of the present invention, the crown type cage for ball bearings described in claim 1 is the conventional type shown in FIGS. Similar to the cage 8 of No. 3, the cage 8 is integrally made of synthetic resin and has an annular main portion and a plurality of pockets provided on one axial surface of the main portion. Each of these pockets is provided between a pair of elastic pieces which are arranged on the one axial surface of the main portion with a space therebetween. In particular, in the crown bearing for ball bearings of the present invention, the radius of curvature R ₁ of the cross-sectional shape of each pocket with respect to an imaginary plane including the central axis of each pocket, which coincides with the radial direction of the main portion,
It is larger than the radius R ₂ of the inscribed circle of the cross-sectional shape of each pocket with respect to the virtual plane orthogonal to the central axis of each pocket at the portion where the inner diameter of each pocket is largest with respect to the central axis of each pocket.

Further, in the case of the ball bearing described in claim 2, as in the conventional ball bearing 1 shown in FIG. 9, the inner ring having the inner ring raceway formed on the outer peripheral surface and the outer ring raceway on the inner peripheral surface. An outer ring that forms the outer ring, a cage arranged between the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring so as to be rotatable relative to the inner ring and the outer ring, and a plurality of pockets provided in the cage, respectively. A plurality of balls arranged between the inner ring raceway and the outer ring raceway in a rollably held state. In particular, in the ball bearing of the present invention, the cage is the crown cage for a ball bearing according to claim 1, and the radius of curvature of the cross-sectional shape with respect to an imaginary plane including the central axes of the pockets. it is twice the R _1, the diameter D of each pocket about a radial of the main portion, the ratio D / D _a of the outer diameter D _a of the balls, and the 1.035 to 1.050.

[0010]

In the crown-type cage for ball bearings according to the present invention having the above-mentioned structure, the radius of curvature of each pocket in the radial direction of the main portion can be obtained even if volume shrinkage occurs during injection molding. R ₁ is less likely to be smaller than the radius of curvature of the rolling surface of the balls held in these pockets. Therefore, during operation of the ball bearing incorporating the crown type cage for the ball bearing of the present invention,
At the edge of each pocket, a pair of edge portions located on both sides in the diametrical direction of the main portion are less likely to contact the rolling surface of each ball. Therefore, the holding performance for each of the balls can be sufficiently secured, and the cage noise can be reduced. Lubricant such as grease adhered to the rolling surface of each ball is prevented from being scraped off by each edge portion, and the above-mentioned lubrication is applied to the gap between the rolling surface of each ball and the inner surface of the pocket. The agent can be taken in easily. Therefore, it is possible to prevent a large amount of lubricant from being taken into the sliding contact portion between the inner surface of each pocket and the rolling surface of each ball to increase the frictional resistance at this sliding contact portion. Further, the thickness of the gap between the inner surface of each pocket and the rolling surface of each ball can be increased, and the shear resistance acting on the lubricant present in this gap can be reduced. As a result, it is possible to reduce the rotational resistance of the ball bearings and improve the wear resistance of the cage in combination with the fact that the sliding contact portion between each ball and the inner surface of each pocket is located at one position. .

Further, in the case of the ball bearing according to the present invention as defined in claim 2, a sufficient amount of the lubricant can be introduced into the gap between the inner surface of each pocket and the rolling surface of each ball, and the lubrication once incorporated. It is possible to prevent the agent from flowing out. Therefore, the frictional resistance acting on the sliding contact portion between the inner surface of each pocket and the rolling surface of each ball can be sufficiently reduced. Further, since the thickness of the gap can be made sufficiently large, the shear resistance of the lubricant present in this gap can be made sufficiently small. Therefore, the rotational resistance of the ball bearing can be sufficiently reduced.

[0012]

1 and 2 show a first example of an embodiment of the present invention. The crown type cage for ball bearings and the ball bearing of the present invention are characterized in that the inner surface of the pocket 10a constituting the cage 8a is designed to improve the performance of the ball bearing incorporating the cage 8a made of synthetic resin. The point is that the shape of the is devised. The overall basic structure of the cage 8a and the basic structure of the ball bearing incorporating the cage 8a are substantially the same as the conventional structure shown in FIGS. Therefore,
The same parts as in this conventional structure are designated by the same reference numerals,
The illustration and description of the overlapping parts will be omitted, and the characteristic part of the present invention will be mainly described below.

In the case of this embodiment, the concave surface portion 12a provided on the inner surface of each of the pockets 10a is formed in the radial direction of the main portion 9 of the cage 8a (the front and back directions in FIG. 1A, the left and right directions in FIG. 1B). Direction} and the circumferential direction of each of the pockets 10a, they are curved with different predetermined radii of curvature.
That is, the radius of curvature of the sectional shape of each pocket 10a with respect to the virtual plane β including the central axis α of each pocket 10a that coincides with the radial direction of the main portion 9 (= the radius of curvature of the pocket 10a in the radial direction of the main portion 9). ) Is R ₁ and the inner diameter of each pocket 10a is the largest with respect to the central axis α of each pocket 10a (C- in FIG. 1B).
The central axis α of each of these pockets 10a in the C section}
Each of these pockets 10a on the virtual plane γ orthogonal to
The radius of the inscribed circle (= radius in the circumferential direction of the pocket 10a) of the cross-sectional shape is R ₂ . In the case of the present invention, the regulation is such that R ₁ > R ₂ . Therefore, in the case of this example, the inner surface of each of the pockets 10 _a has a shape that becomes a part of the inner peripheral surface when the both ends of the substantially ellipsoid in the major axis direction are cut. In this example, the center O of the radius of curvature R ₁ of each pocket 10a in the radial direction of the main portion 9 is located at the radial center of the main portion 9.

The radius R ₂ of each of the pockets 10a in the circumferential direction is the radius of curvature of the rolling surface of the ball 6 incorporated in each of the pockets 10a.
_It is larger than 1/2 of _a (R ₂ > D _a / 2).
The radius R _{2 of} each of the pockets 10a in the circumferential direction is
Is the cage 8a after completion, the amount of movement of the stylus is measured with a circularity measuring device with respect to the inner surface of each of the pockets 10a, and the amount of movement is measured with a micrometer or dial gauge. It can be confirmed by calibrating.

Further, in the case of the ball bearing of the present invention incorporating the cage of this example, the radius of the main portion 9 is twice the radius of curvature R ₁ of the pocket 10a in the radial direction of the main portion 9. The diameter D (= 2) of each of these pockets 10a in the direction
The ratio D / D _a of R ₁ ) to the outer diameter D _a of each ball 6 incorporated in each pocket 10 _a is 1.035 to 1.05.
It is regulated to 0 (preferably 1.040 to 1.050). In order to regulate the above ratio D / D _a in this way,
The diameter D of each of the pockets 10a in the radial direction of the main portion 9 after completion and the outer diameter D _a of each ball 6 are measured, and further, the ratio D / D _a is set within _a predetermined range. To
It is necessary to properly combine the cage 8a and the plurality of balls 6. Therefore, the diameter D of each pocket 10a in the radial direction of the main portion 9 is measured by a shape measuring instrument or the like.

As described above, in the case of the crown-type cage for ball bearings of the present invention, the radius of curvature R ₁ of each pocket 10a in the radial direction of the main portion 9 is the radius R in the circumferential direction of each pocket 10a. _It is larger than ₂ (R ₁ > R ₂ ).
Therefore, even if volume shrinkage occurs during injection molding, the radius of curvature R ₁ of each of the pockets 10a in the diametrical direction of the main portion 9 is equal to the curvature of the rolling surface of each ball 6 held in each of the pockets 10a. It is less likely to be smaller than the radius (= D _a / 2). As a result, during operation of the ball bearing incorporating the retainer 8a of the present invention, a pair of edge portions 13 located on the diametrically opposite sides of the main portion 9 at the edge of each pocket 10a,
It becomes difficult for 13 to contact the rolling surface of each ball 6. Therefore, the holding performance for each of the balls 6 can be sufficiently secured,
The cage noise can be reduced. That is, during operation of the ball bearings, the balls 6 move in the circumferential direction of the pockets 10a based on their orbital movements (the revolving direction is the left-right direction in FIG. 1A, the front-back direction in FIG. 1B). } Displace to one side. And
The balls 6 contact the inner surfaces of the pockets 10a,
It makes sliding contact with this inner surface based on its rotation motion. Even in this case, the sliding contact portion between the inner surface of each pocket 10a and the rolling surface of each ball 6 is located at one position on the inner surface of each pocket 10a at the center of the cage 8a in the radial direction. The edge portions 13, 13 are less likely to come into contact with the rolling surfaces of the balls 6. Therefore, the above holding performance can be sufficiently secured,
The cage noise can be reduced based on the vibration of the cage 8a.

Further, the lubricant such as grease adhered to the rolling surface of each ball 6 is made hard to be scraped off by each of the edge portions 13, 13 so that the rolling surface of each ball 6 and the pocket 10a.
It is possible to easily take in the lubricant into the gap between the inner surface and the inner surface. Therefore, the inner surface of each pocket 10a and each ball 6 are
A sufficient amount of lubricant can be taken into the sliding contact portion with and the frictional resistance can be prevented from increasing at this sliding contact portion. Further, the thickness of the gap between the inner surface of each pocket 10a and the rolling surface of each ball 6 can be increased, and the shear resistance acting on the lubricant present in this gap can be reduced. As a result, the sliding contact between the rolling surface of each ball 6 and the inner surface of each pocket 10a is located at one position, so that the rotation resistance of the ball bearing can be reduced and the cage 8a The wear resistance can be improved.

Further, in the case of the ball bearing of the present invention, these are related to the radial direction of the main portion 9 which is twice the radius of curvature R ₁ of the sectional shape of the pockets 10a in the diametrical direction of the main portion 9. The ratio D of the diameter D of each pocket 10a and the outer diameter D _a of each ball 6 incorporated in each pocket 10a.
/ D _a in the above-mentioned predetermined range (1.035 to 1.05
It is regulated to 0). Therefore, the rotational resistance of the ball bearing can be sufficiently reduced. That is, when the ratio D / D _a is less than 1.035, which is the lower limit value of the predetermined range, the rolling surfaces of the balls 6 come into contact with the edge portions 13, 13. The thickness of the gap between the rolling surface of each ball 6 and the inner surface of each pocket 10a becomes too small, and it becomes difficult to take the lubricant into the gap. Further, in this case, the shear resistance acting on the lubricant that has entered the gap becomes large. On the other hand, when the ratio D / D _a becomes larger than 1.05 which is the upper limit value of the predetermined range, the lubricant that has once entered the gap is removed from the gap. It becomes easy to flow out. Further, since this gap is large, the noise generated during the operation of the ball bearing rapidly increases. Therefore, in the case of the present invention, the ratio D / D _a is
It is regulated to 1.035 to 1.050.

By thus controlling the ratio D / D _a within the above-mentioned predetermined range, a sufficient amount of lubricant is provided in the gap between the inner surface of each pocket 10a and the rolling surface of each ball 6. The lubricant that has been taken in can be prevented from flowing out to the outside. Therefore, the frictional resistance acting on the sliding contact portion between the inner surface of each pocket 10a and the rolling surface of each ball 6 can be sufficiently reduced. Further, since the thickness of the gap can be made sufficiently large, the shear resistance of the lubricant present in this gap can be made sufficiently small. As a result, the rotational resistance of the ball bearing can be sufficiently reduced. Also, the ratio D / D _a is in the case of 1.040 to 1.050 and more preferred range is hardly affected by variations in the dimensions caused by variations in the materials and processing conditions in injection molding, Stable performance can be secured. Moreover, the effect of incorporating the lubricant into the gap becomes remarkable, and the rotational resistance of the ball bearing can be further reduced.

Next, the experiment conducted by the inventor of the present invention to confirm the effect of the ball bearing of the present invention will be described. In the experiment, several types of ball bearings having different ratios D / D _a between the diameter D of each pocket 10a in the radial direction of the main portion 9 of the cage 8a and the outer diameter D _a of the ball 6 incorporated in each pocket 10a, At least one of each type was prepared and the rotation resistance of this ball bearing was measured. FIG. 3 shows the result of the experiment conducted in this way. In this Figure 3,
The horizontal axis represents the ratio D / D _a , and the vertical axis represents the rotation resistance,
Each represents. It should be noted that, in FIG. 3, the same symbols represent ball bearings of the same type, each of which has different dimensions after completion. As is clear from the experimental results shown in FIG. 3, in the case of the ball bearing of the present invention in which the solid arrow indicates the range and the broken arrow indicates the preferable range, the rotational resistance can be sufficiently reduced.

Next, FIG. 4 shows a second embodiment of the present invention.
An example is shown. In the case of the retainer 8a of this example, the inner surface of each pocket 10a is formed by two types of curved surfaces in which the centers O ₁ and O _{2 of the} radius of curvature in the circumferential direction are different from each other. That is, in the case of this example, on the inner surface of each pocket 10a, a pair of first concave surface portions 14 and 14 are provided on the same side (upper side in FIG. 4) as the elastic pieces 11 and 11, respectively. , 11 on the opposite side (lower side in FIG. 4), a second concave surface portion 15 for connecting the pair of first concave surfaces 14, 14 is formed. The first concave surface portions 14 in the circumferential direction of the pockets 10a,
14 radius of curvature R ₃ of the center O _1, likewise the second concave portion 15 above the elastic pieces of the center O ₂ of the radius of curvature R ₃ of the first
It is provided on the opposite side of 1 and 11. Then, in the case of this example, the radius of curvature R ₁ of each of the pockets 10a in the diametrical direction of the main portion 9 is set at the portion where the inner diameter of each of the pockets 10a is the largest with respect to the central axis α of each of the pockets 10a. The radius R ₂ of the inscribed circle of the cross-sectional shape of each pocket 10a with respect to the virtual plane γ orthogonal to the central axis α of each pocket 10a is made larger (R ₁ > R).
₂ ).

In the case of this example configured as described above, each of the above first
The center of curvature O of the one concave surface portion 14 and the second concave surface portion 15
₁ , O₂ Only change the offset (offset amount)
The balls 6 held in the pockets 10a are
In each pocket 10a, the axial direction of the main portion 9 (up and down in FIG. 4).
Set the amount of displacement (axial gap) with respect to the direction
it can. To set such an axial gap,
One pair of elastic pieces forming each pocket 10a
Distance d between the tips of 11, 11₁₁Or each of the above pockets 1
Each of the first and second concave surface portions 14 in the circumferential direction of 0a,
Radius of curvature R of 15 ₃ Since there is no need to change the
The holder 8a can be easily designed. For other configurations and functions
Since it is the same as the case of the above-mentioned first example, duplicated
The description will be omitted.

Next, FIG. 5 shows a third embodiment of the present invention.
An example is shown. In the case of this example, the center O of the radius of curvature R ₁ of each pocket 10a in the radial direction of the main portion 9 (the front-back direction in FIG. 5A, the left-right direction in FIG. Is biased toward the inner diameter side (left side in FIG. 5B).
Also in the case of this example, as in the case of the first example shown in FIGS. 1 to 3 described above, the radius of curvature R ₁ of each pocket 10a in the radial direction of the main portion 9 is set as follows. The radius of curvature in the circumferential direction is made larger than R ₂ (R
₁ > R ₂ ). Therefore, even when the center O of the radius of curvature R ₁ of each pocket 10a in the radial direction of the main portion 9 is deviated to one side in the radial direction of the main portion 9 as in this example, the edge of each pocket 10a is Thus, the edge portions 13, 13 located on both sides of the main portion 9 in the radial direction can be made difficult to contact the rolling surfaces of the balls 6. On the other hand, when the inner surface of each pocket constituting the cage is a single spherical concave surface having a single radius of curvature, the edge portion located on the outer diameter side of the main portion has It is easy to contact the rolling surface.

That is, the radius of curvature R of each of the pockets 10a
_When the center of ₁ is offset to the inner diameter side of the main portion 9,
When the cage 8a and the balls 6 are assembled in a ball bearing and the balls 6 are displaced in the radial direction of the cage 8a, the pockets located on the outer diameter side of the cage 8a. The edge portion 13 of 10a easily contacts the rolling surface of each ball 6. In particular, when the cage 8a contracts in volume during injection molding, there is a high possibility that the rolling surface of each ball 6 will come into contact with the edge portion 13. When the edge portion 13 and the ball 6 come into contact with each other, the above-mentioned problems such as an increase in the rotational resistance of the ball bearing occur. On the other hand, in the case of the present invention, the radius of curvature R ₁ of each pocket 10a in the diametrical direction of the main portion 9 is made larger than the radius of curvature R _{2 of} each pocket 10a in the circumferential direction (R ₁ > R ₂ ) Therefore, as described above, the center O of the radius of curvature R ₁ of each pocket 10a in the radial direction of the main portion 9 is O.
Even when the above is offset toward the inner diameter side of the main portion, it is possible to make it difficult for the edge portion 13 to contact the rolling surface of each ball 6.
Other configurations and actions are the same as those in the case of the first example shown in FIGS.

Next, FIG. 6 shows a fourth embodiment of the present invention.
An example is shown. In the case of this example, it has a structure that is a combination of the structure of the second example shown in FIG. 4 and the structure of the third example shown in FIG. That is, in the case of this example, by the first concave surface portions 14 and 14 and the second concave surface portion 15 in which the centers O ₁ and O _{2 of the} radii of curvature in the circumferential direction of the respective pockets 10a are present at different positions, It constitutes the inner surface of each of the pockets 10a. Further, the center O of the radius of curvature R ₁ of each of the first and second concave surface portions in the radial direction of the main portion 9 (the front and back directions in FIG. 6A, the left and right direction in FIG. 6B).
Is biased toward the inner diameter side of the main portion 9 (left side in FIG. 6B). Other configurations and operations are similar to those of the above-described second example shown in FIG. 4 or the above-described third example shown in FIG. 5, and thus duplicated description will be omitted. In the case of the above-mentioned third example and this example, the center O of the radius of curvature R ₁ of the inner surface of each pocket 10a in the radial direction of the main portion 9 is
Outer diameter side of the main portion 9 {FIG. 5 (B), right side of FIG. 6 (B)}
It can also be biased.

Next, FIG. 7 shows a fifth embodiment of the present invention.
An example is shown. In the case of this example, the inner surface of each pocket 10a is composed of a plurality of small-diameter concave surface portions 16 and 16 and large-diameter concave surface portions 17 and 17 having different radiuses of curvature R ₄ and R ₅ in the circumferential direction. is doing. The small-diameter concave surface portions 16 and 16 and the large-diameter concave surface portions 17 and 17 are provided alternately in the circumferential direction of each pocket 10a. Further, in the case of this example, the inner surface of each pocket 10a located on one surface of each elastic piece 11, 11 and each pair of elastic pieces 11 constituting each pocket 10a on the inner surface of each pocket 10a. , 11 at the central portion of the portion between the upper and lower portions, and a total of three positions are provided for each of the pockets 10a. And
In the case of the present example, the small-diameter concave surface portions 16 and 16 and the large-diameter concave surface portions 17 and 17 in the radial direction of the main portion 9 (the front-back direction in FIG. 7A, the left-right direction in FIG. 7B). Radius of curvature R ₁
Is an inscribed cross-sectional shape of each pocket 10a with respect to a virtual plane γ orthogonal to the central axis α of each pocket 10a at a portion where the inner diameter of each pocket 10a is largest with respect to the central axis α of each pocket 10a. The radius of the circle is larger than R ₂ (= R ₄ ) (R ₁ > R
₂ ). In the case of this example, this inscribed circle is the above-mentioned small-diameter concave surface portion 1
It is in contact with the inner surfaces of 6 and 16.

In the case of this example configured as described above, the rolling surfaces of the balls 6 held in the pockets 10a come into contact with the inner surfaces of the small-diameter concave surface portions 16, 16. Therefore, relatively large spaces 18, 18 can be formed between the rolling surface of each ball 6 and the inner surface of each large-diameter concave surface portion 17, 17.
Therefore, a lubricant such as grease can be sufficiently taken into the spaces 18, 18, and the lubricity of the sliding portion between the rolling surface of each ball 6 and the inner surface of each pocket 10a can be improved. . Regarding other configurations and operations, the above-mentioned FIG.
Since it is similar to the case of the first example shown in FIG. 3, duplicate description will be omitted.

Next, FIG. 8 shows a sixth embodiment of the present invention.
An example is shown. In the case of this example, each elastic piece 11, 11
The inner surface of each pocket 10a located on one side of the pocket 10a and the central portion of the inner surface of each pocket 10a between each pair of elastic pieces 11, 11 constituting each pocket 10a. The large-diameter concave surface portions 17, 17 are provided at a total of three positions for each. Then, on the inner surface of each of the pockets 10a, the large-diameter concave surface portions 17, 17 in the circumferential direction of each of the pockets 10a.
Small-diameter concave surface portions 16 and 16 are provided at two positions adjacent to each other. Regarding other configurations and operations, FIG.
Since it is the same as the case of the fifth example shown in FIG.

[0029]

As described above, the crown type cage and the ball bearing for ball bearings according to the present invention are constructed and operate as described above. Therefore, the performance of the ball bearing incorporating the crown type cage made of synthetic resin can be improved. hand,
The performance of various devices incorporating this ball bearing can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a first example of an embodiment of the present invention, with (A) being a C-C cross section of (B) and (B) being in a state corresponding to FIG. 12;

FIG. 2 is an enlarged cross-sectional view of section D in FIG.

FIG. 3 is a diagram showing a result of an experiment conducted to confirm the effect of the present invention.

FIG. 4 shows a second example of the embodiment of the present invention, and FIG.
The figure respectively corresponded to (A) and (B).

5A and 5B are views corresponding to FIGS. 1A and 1B, showing the third example.

FIGS. 6A and 6B are views corresponding to FIGS. 1A and 1B showing the fourth example.

7A and 7B are views corresponding to FIGS. 1A and 1B, showing the fifth example.

FIG. 8 is a view showing the sixth example and corresponding to FIGS. 1 (A) and 1 (B).

FIG. 9 is a cross-sectional view showing an example of a ball bearing incorporating a cage.

FIG. 10 is a perspective view showing an example of a conventional structure of a cage.

11 is a diagram showing a cross section taken along the line EE of FIG. 10 except for a cut portion.

12 is a view corresponding to an enlarged cross section of an F portion of FIG. 11, which is shown in a state where the radius of curvature of the pocket in the radial direction of the main portion is small.

[Explanation of symbols]

1 ball bearing 2 Inner ring track 3 inner ring 4 Outer ring track 5 outer ring 6 balls 7 Shield plate 8, 8a cage 9 Main part 10, 10a pocket 11 elastic pieces 12, 12a concave part 13 Edge part 14 First concave part 15 Second concave surface 16 Small diameter concave part 17 Large diameter concave surface 18 spaces

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3J101 AA02 AA32 AA42 AA52 AA62                       BA25 BA50 EA31 FA32 FA41                       GA24

Claims (2)

[Claims] 1. An annular main part integrally formed of a synthetic resin, and a plurality of pockets provided on one surface in the axial direction of the main part, each of which has a concave inner peripheral surface. In the crown-type cage for ball bearings, each pocket is provided between a pair of elastic pieces arranged at a distance from each other on one axial surface of the main portion. Radius of curvature R of the cross-sectional shape of each pocket with respect to an imaginary plane including the central axis of each pocket, which coincides with the radial direction of
₁ is the radius R ₂ of the inscribed circle of the cross-sectional shape of each pocket with respect to the virtual plane orthogonal to the central axis of each pocket at the portion where the inner diameter of each pocket is largest with respect to the central axis of each pocket. Crown type cage for ball bearings, which is characterized by its large size. 2. An inner ring having an inner ring raceway formed on an outer peripheral surface, an outer ring having an outer ring raceway formed on an inner peripheral surface, and a relative surface between the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring relative to the inner ring and the outer ring. A retainer rotatably arranged, and a plurality of balls arranged between the inner ring raceway and the outer ring raceway in a state of being rotatably held in a plurality of pockets provided in the retainer. In the ball bearing provided with, the retainer is the crown retainer for a ball bearing according to claim 1, and the radius of curvature R ₁ of the cross-sectional shape with respect to an imaginary plane including the central axes of the pockets. The ratio D / D _a of the diameter D of each of the pockets in the radial direction of the main portion and the outer diameter D _{a of the} balls is 1.035 to 1.050. Ball bearings.