JPH08277842A - Cage for ball bearing - Google Patents

Abstract

PURPOSE: To prevent the galling and wear of a cage so as to improve the durability and reliability of the cage and a ball bearing formed using this cage. CONSTITUTION: A cage 6a is provided with an annular main part 8 and pockets 7 provided at a plurarity of circumferential places of the main part 8. The pocket 7 has a taper part 14 reduced in diameter as it gets closer to the inner peripheral surface of the main part 8, and the moving quantity of the cage 6a over the radial direction is regulated by these taper parts 14. A pair of protrusions 17, 17 are formed at the outer peripheral surface of the main part 8. The outer peripheral surface of the protrusions 17, 17 forms the sliding face that can come in sliding contact with the inner peripheral surface of an outer ring 4. That is, in the case of the contact part of the taper part 14 and a ball 5 being worn with use so as to cause the cage 6a to come close to the inner peripheral surface of the outer ring 4, the inner peripheral surface and the outer peripheral surface of the protrusions 17, 17 come in sliding contact. The cage 6a therefore functions as a ball guide type immediately after the start of use and functions as an outer ring guide type after the lapse of a long period of time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The cage for ball bearings according to the present invention is a cage for ball bearings, which constitutes a ball bearing used at a high speed and under severe lubrication conditions, such as a bearing for a main motor of a railway vehicle. Regarding the improvement of.

[0002]

2. Description of the Related Art Conventionally, in order to support various rotating parts,
Ball bearings as shown in FIG. 6 are widely used. This Figure 6
The ball bearing shown in Fig. 1 has an inner ring 2 having an inner ring raceway 1 on the outer peripheral surface.
An outer ring 4 having an outer ring raceway 3 on its inner peripheral surface, a plurality of balls 5, 5 rotatably provided between the inner ring raceway 1 and the outer ring raceway 3, and a plurality of these balls 5, A retainer 6 rotatably provided between the inner ring raceway 1 and the outer ring raceway 3 while holding 5 is provided. Pockets 7, 7 are provided at a plurality of positions in the circumferential direction of the cage 6, and the balls 5, 5 are rotatably held in the pockets 7, 7. In the illustrated example, both the inner ring raceway 1 and the outer ring raceway 3 are deep groove type.

Such ball bearings can be classified into three types of outer ring guide type, inner ring guide type and ball guide type depending on the guide state of the cage 6. For example, FIG. 7 shows an outer ring guide type ball bearing. In this outer ring guide type ball bearing, the outer peripheral surface of the cage 6 and the inner peripheral surface of the outer ring 4 are brought close to each other, so that the cage 6
This is intended for positioning in the radial direction. Although not shown in the drawings, the inner ring guide type ball bearing, in contrast to the outer ring guide type ball bearing, allows the inner peripheral surface of the cage and the outer peripheral surface of the inner ring to be close to each other, so that the radial direction of the cage is increased. To position. When using these outer ring guide type or inner ring guide type ball bearings,
Each cage 6 rotates while being guided by the inner peripheral surface of the outer ring 4 or the outer peripheral surface of the inner ring 2. FIG. 8 shows a ball guide type ball bearing. In the case of the ball guide type, the inner and outer peripheral surfaces of the cage 6 are not in close proximity to either the outer peripheral surface of the inner ring 2 or the inner peripheral surface of the outer ring 4, and the balls 5 are positioned in the radial direction. To be

The cage 6 shown in the figure, which is incorporated in each of the ball bearings as described above, is a so-called machined cage, and has a main portion 8 which is made of synthetic resin or metal and is formed into an annular shape as a whole. In the illustrated example, the main part 8 is
The main parts 9a and 9b of the pair are butted against each other,
2a and 9b are formed by joining and fixing a plurality of rivets 10 at the portions separated from the pockets 7 and 2
It has a piece structure. The engaging recesses 12a and the engaging projections 1 are respectively provided on the inner peripheral sides of the end portions of the main part pieces 9a and 9b.
2b is formed. In addition, recesses 11 and 11 that form the pocket 7 are formed at a plurality of circumferential edges at opposite side edges of the main portion pieces 9a and 9b, respectively. Therefore, the pair of main part pieces 9a, 9b are fixedly coupled in a state where the engagement concave portion 12a and the engagement convex portion 12b are engaged, and when fixedly coupled, the pockets 7 are formed by the respective concave portions 11, 11.
Is formed. However, in the case of the cage 6 shown in FIG. 7, the inner diameter of the pocket 7 is smaller than the diameter of the ball 5 over its entire length (vertical length in FIG. 7) due to the outer ring guide type. In contrast to the large cylindrical shape, in the case of the cage 6 shown in FIG. 8, since the cage 6 is guided by the balls 5, the inner peripheral side of the pocket 7 (the lower side of FIG. 8) has a tapered concave surface. The diameter of the inner end opening is smaller than the diameter of the ball 5. There is also a one-piece structure in which the main portion 8 is integrated.

When each of the ball bearings as described above is used, the inner ring 2 and the outer ring 4 are accompanied by the rolling of the plurality of rolling elements 5.
Freely rotate relative to. For example, fixing the outer ring 4,
When the inner ring 2 is rotated, the plurality of rolling elements 5 are
It revolves around the inner ring 2 while rotating. At this time, the cage 6 rotates around the inner ring 2 at the same speed as the revolution speed of the rolling element 5.

A lubricant such as grease is filled in a portion between the outer peripheral surface of the inner ring 2 and the inner peripheral surface of the outer ring 4 so that the relative rotation can be smoothly performed. In addition, the above-mentioned FIGS.
In the case of each of the examples shown in Fig. 6, in the portion between the outer peripheral surface of the inner ring 2 and the inner peripheral surface of the outer ring 4, the axial directions of the inner and outer wheels 2 and 4 (see Figs.
8 shows a configuration in which sealing members such as a seal plate and a shield plate are not provided at both ends (in the left-right direction of 8). Such a sealing member is provided as needed.

[0007]

By the way, for example, as a bearing for a main motor of a railway vehicle, an outer ring guide type ball bearing lubricated with grease has been widely used between the housing and the shaft. When an outer ring guide type ball bearing that is lubricated with grease is used in this manner, at a portion between the outer peripheral surface of the cage 6 and the inner peripheral surface of the outer ring 4 which are in close proximity to each other and are in sliding contact during operation, at the beginning of use, There must be sufficient grease present. If the grease is insufficient, galling or wear will occur on the outer peripheral surface of the cage 6. Such galling and wear are likely to occur in the case of ball bearings under severe operating conditions, such as the above-mentioned bearings for main motors of railway vehicles, which rotate at high speed and are subjected to a large radial load. When the above-mentioned galling or abrasion occurs, not only does the abrasion powder get into the grease and contaminate the grease, but it also causes noise and vibration. In particular, in the case of the bearing for the main motor of the railway vehicle, since the bearing is operated for a long time and the period until the periodic inspection is long, it is necessary to perform the above-mentioned lubrication sufficiently.

However, in the case of the conventionally used outer ring guide type ball bearing, it is necessary to surely spread the grease between the outer peripheral surface of the cage and the inner peripheral surface of the outer ring when the lubricant is filled. It was troublesome, and it was difficult to sufficiently lubricate it at the beginning of use. For this reason, galling and wear may occur due to poor lubrication at the initial stage of use, and it is difficult to improve the durability of the cage 6, and thus the reliability and durability of the ball bearing.

If a ball guide type ball bearing is used as the ball bearing, no galling or wear due to poor lubrication at the initial stage of use as described above occurs, but it is difficult to employ it for the following reasons. That is, in the case of a ball guide type ball bearing, the mass of the cage 6 is held by a plurality of balls 5, and the sliding contact portion between the pocket 7 and the rolling surface of the ball 5 (the bearing portion of the ball 5). Wear due to slippage occurs. Further, since the sliding contact area has a smaller sliding contact area than that of the outer ring guide type and the inner ring guide type, it is relatively easily worn. Then, when such wear progresses, the amount of movement of the cage 6 in the radial direction increases, and each ball 5 moves into the cage 6.
It becomes impossible to position it in the radial direction, and the cage 6 is violently displaced in the radial direction, causing vibration.
It cannot be used as a ball bearing. Therefore, it is difficult to adopt a ball guide type ball bearing in a bearing which is particularly required to have durability such as the bearing for the main motor of the railway vehicle. The retainer for ball bearings of the present invention is designed in view of such circumstances.

[0010]

The ball bearing cage according to the present invention, like the above-mentioned conventional ball bearing cage, has an annular main portion and a plurality of circumferential portions of the main portion. A plurality of pockets, which are formed in a state of opening on both the inner and outer peripheral surfaces of the main portion, and each of which holds a ball rotatably one by one, are provided inside each of them. Then, each of these pockets has a taper that becomes smaller toward the inner peripheral surface of the main portion in order to regulate the amount of movement of the main portion with respect to the balls in the radial direction.
It has a pad part.

Particularly, in the cage for ball bearings of the present invention, a part of the tapered portion is worn by the sliding contact portion with the rolling surface of the ball during use, and the above-mentioned amount of movement causes the retainer for the ball bearings. When the gap size between the inner peripheral surface of the member corresponding to the outer ring on which the container is assembled and the outer peripheral surface of the main portion becomes approximately equal, the sliding surface that is slidably contactable with the inner peripheral surface of the outer ring equivalent member is the main portion. The outer diameter of the cage is regulated in relation to the inner diameter of the member corresponding to the outer ring so as to be provided on the outer peripheral surface.

[0012]

When the cage for ball bearings of the present invention constructed as described above holds a plurality of balls rollably between the inner ring equivalent member and the outer ring equivalent member, the action is as follows. Is. First, in the initial stage of use of a ball bearing constructed using this cage, similar to the conventional ball guide type cage described above,
The plurality of balls guide the cage to prevent the cage from being displaced in the radial direction. Therefore, the outer peripheral surface of the main part of the cage does not come into contact with the inner peripheral surface of the member corresponding to the outer ring, and no galling or wear occurs on the outer peripheral surface of the main part.

When the rolling contact surface of each ball and the taper portion are in sliding contact with the use of the ball bearing, and the contact portion of the taper portion (ball bearing portion) is worn, the cage moves in the radial direction. The amount increases from the beginning of use. Then, when this amount of movement becomes substantially equal to the gap size between the outer peripheral surface of the main portion and the inner peripheral surface of the outer ring equivalent member, the sliding surface provided on the outer peripheral surface of the main portion, It comes into sliding contact with the inner peripheral surface of the member corresponding to the outer ring. That is, the ball guide type is changed to the outer ring guide type. In this case, since the ball bearing has been used for a long period of time, sufficient lubricant is spread over the outer peripheral surface of the main portion and the inner peripheral surface of the outer ring equivalent member. Therefore, when the ball guide type is changed to the outer ring guide type, no inconvenience due to poor lubrication occurs. As a result, even if the outer ring guide type is used, it can be used for a long period of time thereafter.

[0014]

1 to 5 show an embodiment of the present invention. The cage 6a for ball bearings of the present invention has a ring-shaped main portion 8 and a plurality of circumferential portions of the main portion 8 in the same manner as the conventional ball bearing cage 6 (FIGS. 6 to 8) described above. Each of the plurality of pockets 7 is provided so as to extend through the main portion 8 in the radial direction. As shown in FIGS. 1 and 2, each of these pockets 7 opens on both the inner and outer peripheral surfaces of the main portion 8 and holds one ball 5 rotatably inside each of them.

As shown in FIGS. 1 and 2, the main portion 8 is a portion in which a pair of main portion pieces 9a and 9b are butted to each other and both main portion pieces 9a and 9b are separated from the pocket 7. It is configured by a plurality of rivets 10 which are coupled to each other in a separated manner. On the surfaces of the pair of main part pieces 9a, 9b facing each other, recesses 11, 11 forming the pockets 7 when the main part pieces 9a, 9b are assembled are formed. Further, engaging concave portions 12a and engaging convex portions 12b are formed at the ends of the facing surfaces, respectively, and the main portion piece 9
When connecting a and 9b, they are engaged with each other.

Further, each of the pockets 7 has a cylindrical portion 13 whose one end (the upper end in FIG. 1) is open to the outer peripheral surface of the main portion 8,
The cylindrical portion 13 is continuous from the other end (lower end in FIG. 1), and one end (lower end in FIG. 1) opens to the inner peripheral surface of the main portion 8 and has a smaller diameter as it approaches the inner peripheral surface of the main portion 8. And a taper portion 14 that becomes That is, each of the main part pieces 9a, 9b
Of the recesses 11 and 11 formed on one end edge side of the
Consists of a semi-cylindrical recess on the outer half side of the main part pieces 9a, 9b and a tapered recess on the inner half side of the main part pieces 9a, 9b. Then, the pocket 7 having the above-described shape is formed by abutting the pair of main part pieces 9a and 9b. When the main portion 8 is displaced in the radial direction with the ball 5 held in the pocket 7, the intermediate portion of the taper portion 14 includes the rolling surface of the ball 5 and the point P as shown in FIG. Contact at the circumference. This limits the amount of movement of the cage 6a in the radial direction. Note that FIG. 4 shows a state in which the cage 6a is displaced in the radial direction (upward in FIGS. 3 to 4) from the state of FIG.

Further, in the ball bearing cage 6a of the present invention, a sliding surface is provided on the outer peripheral surface of the main portion 8. As for this sliding surface, a portion of the taper portion 14 that is in sliding contact with the rolling surface of the ball 5 is worn during use, and the amount of movement of the cage 6a with respect to the ball 5 in the radial direction is as shown in FIG. As shown in Fig. 3, when the clearance dimension d (Fig. 3) between the inner peripheral surface of the outer ring 4 to which the cage 6a is assembled and the outer peripheral surface of the main portion 8 becomes substantially equal, the inner peripheral surface of the outer ring 4 is Slide in contact with. still,
FIG. 5 shows a state in which the cage 6a is displaced in the radial direction after the tapered portion 14 is worn.

The cage 6a is provided to provide the sliding surface.
The first protrusions 15 and 15 are formed on the outer peripheral surfaces of the outer end portions in the width direction (left and right direction in FIG. 1) of the pair of main portion pieces 9a and 9b. Therefore, when the main part 8 is formed by combining the pair of main part pieces 9a and 9b, the main part 8 is formed on the outer circumferential surface of both axial end parts (both lateral end parts in FIG. 1) of the main part 8. The ridges 17, 17 protruding from the outer periphery are formed. The outer peripheral surfaces of the ridges 17, 17 form the above-mentioned sliding surface, and when the cage 6a of the present invention shifts to the outer ring guide type due to use, as will be described later, the inner peripheral surface of the outer ring 4 is formed. It becomes the guided surface to be guided to. In addition, the height dimensions of the first protrusions 15 and 15 forming the protrusions 17 are equal to each other. The portion between the protrusions 17, 17 functions as a grease reservoir.
That is, when the cage 6a of the present invention is used to form a ball bearing and this ball bearing is used by being assembled between, for example, a fixed housing and a rotary shaft, grease is retained in the space between the two. In particular, since the periphery of the pocket 7 is surrounded by the ridges 17, 17 and the protrusion 18 which will be described below, the grease attached to the rolling surface of the ball 5 is splashed to the surroundings as the ball 5 rolls. However, this grease does not easily come out of the cage 6a.

Further, in the illustrated embodiment, a second protrusion is formed on the inner peripheral surface of the main portion pieces 9a, 9b at the end portions of the pair of main portion pieces 9a, 9b on the side to be brought into contact with each other. The parts 16 and 16 are provided. Therefore, when the main portion 8 is formed by combining the pair of main portion pieces 9a and 9b, the axially intermediate portion inner peripheral surface of the main portion 8 has a trapezoidal sectional shape protruding toward the inner ring 2. A protrusion 18 is formed. The protrusion 18 restricts the amount of movement of the cage 6a in the radial direction.
It is provided to increase the angle α (FIG. 3) of the contact point between the tapered portion 14 and the ball 5.

The ball bearing cage 6a of the present invention having the above-described structure is used to form a ball bearing together with the inner ring 2, the outer ring 4, and the ball 5, and this ball bearing is used, for example, in a main electric motor for railway vehicles. When assembled between the housing and the shaft, the clearance between the outer peripheral surface of the main portion 8 and the inner peripheral surface of the outer ring 4 does not make a sliding contact immediately after the start of use so that the clearance dimension between these peripheral surfaces is large. d (=
The difference between the radii of both surfaces is set. As a result, the cage 6a is of a ball guide type. For this reason, the gap dimension d and the radial movement amount a of the main portion 8 are d>
It has a relationship that satisfies a. That is, before and immediately after the start of use, da shown in FIG. 4 has a positive value (da> 0). Particularly in the case of this embodiment, d≈1.5a. When d> a is satisfied, the ball guide type is maintained.

When the taper portion 14 is worn due to the use of the ball bearing, the radial movement amount of the retainer 6a becomes a '(≈1.5a≈d) larger than the above a. The sliding contact portion between the rolling surface and the taper portion 14 is a circumferential position including a point P ′ located on the inner ring 2 side of the point P from the circumference including the point P. As a result, the cage 6a becomes movable to the outer ring 4 side as compared to the initial state, and as shown in FIG. 5, the protrusions 17, 17 are in sliding contact with the inner peripheral surface of the outer ring 4, so-called outer ring guide. It becomes a mold. That is, when a ′ ≧ d, the outer ring guide type is used. The clearance dimension d is determined in consideration of the movement amount, the outer diameter dimension of the protrusions 17, 17 forming portion of the main portion 8, and the inner diameter dimension of the outer ring 4.

The ball bearing cage 6a of the present invention having the above-described structure is incorporated into a ball bearing to hold each ball 5 rotatably. Bowl 6
Is the same as Particularly, in the ball bearing cage 6a of the present invention, the cage 6a is of a ball guide type in the initial stage of use. Therefore, the outer peripheral surface of the cage 6a does not come into contact with the inner peripheral surface of the outer ring 4, and galling or wear due to poor initial lubrication unlike the outer ring guide type ball bearing does not occur.

When a part of the tapered portion 14 is worn due to the sliding contact between the rolling surface of each ball 5 and the tapered portion 14 due to the use of the ball bearing, the movement amount of the cage 6a in the radial direction is It is larger than the initial value a. As a result, the cage 6
Compared to the initial stage of use, a comes into contact with the position closer to the inner diameter of the tapered portion 14, and the cage 6 can come closer to the inner peripheral surface of the outer ring 4 than in the initial stage of use.
Then, as shown in FIG. 5, when the contact point between the tapered portion 14 and the rolling surface of the ball 5 becomes the point P ′, the amount of movement increases by δ. Therefore, the amount of movement a ′ after abrasion is a ′ = a
+ Δ, and this a'is 1.5 times the initial value a (a '
.Apprxeq.1.5a) That is, this a'is equal to the gap dimension d (a'.apprxeq.d). As a result, the outer circumferential surface of the protrusions 17, 17 formed on the outer circumferential surface of the main portion 7 comes into sliding contact with the inner circumferential surface of the outer race 4 to form an outer ring guide type. In this way, when the ball guide type is changed to the outer ring guide type, the ball bearing has been used for a long time. Therefore, the outer peripheral surface of the cage 6a and the outer ring 4 are
Sufficient lubricant has spread to the area between the inner surface and the inner surface.
Therefore, when the ball guide type is changed to the outer ring guide type, the problem of poor lubrication does not occur. Therefore, even when the outer ring guide type is used, it can be used for a long period of time thereafter. For example, if a DC current flows through the ball bearing, the ball 5
Even if the constituent members including is worn out and the function as the ball guide type is impaired, it can continue to be used by functioning as the outer ring guide type.

[0024]

Since the cage for ball bearings of the present invention is constructed and operates as described above, even if the usage conditions are severe, the guided surface of the cage is unlikely to be galled or worn, and its durability is improved. To do. As a result, the durability and reliability of the ball bearing constructed using the ball bearing cage of the present invention can be improved.

[Brief description of drawings]

FIG. 1 shows a ball bearing constructed using the cage of the present invention,
Sectional drawing corresponded to the A section of FIG.

FIG. 2 is a partial perspective view of a cage according to the present invention.

FIG. 3 is a sectional view taken along line BB in FIG. 1, showing an initial stage of assembly.

FIG. 4 is a sectional view similar to FIG. 3, showing a state in which the cage is displaced in the radial direction at the same initial stage.

FIG. 5 is a cross-sectional view similar to FIG. 3, showing a state in which the cage is displaced in the radial direction after the tapered portion is worn.

FIG. 6 is a sectional view showing a conventionally known ball bearing.

7 is a cross-sectional view showing an outer ring guide type ball bearing corresponding to the portion A in FIG.

8 is a sectional view showing a ball guide type ball bearing corresponding to the portion A in FIG.

[Explanation of symbols]

 1 Inner ring raceway 2 Inner ring 3 Outer ring raceway 4 Outer ring 5 Balls 6, 6a Cage 7 Pocket 8 Main part 9a, 9b Main part piece 10 Rivet 11 Recessed part 12a Engagement recessed part 12b Engagement convex part 13 Cylindrical part 14 Tapered part 15 First Protrusion 16 Second protrusion 17 Protrusion 18 Protrusion

Claims (1)

[Claims] 1. A ring-shaped main portion and a plurality of circumferential portions of the main portion are formed so as to open on both the inner and outer peripheral surfaces of the main portion, and one ball is rolled inside each of them. In a cage for a ball bearing having a plurality of pockets for holding freely, each of the pockets has an inner portion of the main portion in order to regulate the amount of movement of the main portion with respect to the balls in the radial direction. It has a taper part that becomes smaller in diameter as it approaches the peripheral surface, and the sliding contact part of the ball with the rolling surface wears with use at a part of the taper part, and the above-mentioned amount of movement is for this ball bearing. When the clearance between the inner peripheral surface of the outer ring equivalent member to which the cage is assembled and the outer peripheral surface of the main portion becomes approximately equal, the sliding surface that is slidably contactable with the inner peripheral surface of the outer ring equivalent member is the main surface. The outer diameter of the cage was regulated in relation to the inner diameter of the outer ring equivalent member so as to be provided on the outer peripheral surface of the portion. Cage for a ball bearing according to claim.