JP5866821B2 - Roller bearing cage - Google Patents

Description

  The present invention relates to a rolling bearing retainer that holds a plurality of rolling elements disposed between an inner ring raceway and an outer ring raceway of a rolling bearing so as to be freely rollable.

  Rolling bearings are widely used in bearings that support rotating shafts and the like in various rotating machine devices such as automobiles and various industrial machines. FIG. 5 shows a schematic configuration of a conventional example of this rolling bearing. The rolling bearing shown in FIG. 5 is a radial ball bearing 10, and the radial ball bearing 10 has an inner ring 2 in which an inner ring raceway 1 is formed on an outer peripheral surface and an outer ring 4 in which an outer ring raceway 3 is formed on an inner peripheral surface. A plurality of balls 5 are provided between the inner ring raceway 1 and the outer ring raceway 3 so as to freely roll. The plurality of balls 5 are held by a cage 6 so as to be freely rollable. FIG. 6 is a perspective view of the cage 6 of FIG.

  The cage 6 shown in FIG. 6 is a crown type cage and is formed by injection molding a synthetic resin. The cage 6 includes a pocket 18 that rotatably holds the balls 5 (FIG. 5) at a plurality of locations in the circumferential direction of the annular main portion 17, and a pair of elastically deformable provided on both sides of the pocket 18. A plurality of elastic pieces 16a and 16b are provided. In each pocket 18, a concave surface portion 19 formed from the space between the pair of elastic pieces 16 a and 16 b disposed at a distance from each other in the main portion 17 toward the bottom portion is substantially spherical. An opening T is formed between the pair of elastic pieces 16a and 16b in the upper portion of each pocket 18 in the figure.

  When assembling a radial ball bearing as shown in FIG. 5 using the crown type cage 6 shown in FIG. 6, the ball 5 is elastically expanded with the interval between the tip edges of the pair of elastic pieces 16a and 16b of the pocket 18 being extended. It inserts so that it may push from the opening part T between elastic pieces 16a and 16b. In this way, the crown-shaped cage 6 holds the balls 5 in the pockets 18 so that the balls 5 can roll between the inner ring raceway 1 and the outer ring raceway 3.

  FIG. 7 is a view of the main part of the cage 6 of FIG. 6 as viewed from the outside in the radial direction. When the cage 6 is used in the radial ball bearing 10 of FIG. 5 with the ball 5 indicated by a two-dot chain line held in the pocket 18, the ball 5 is placed in the pocket 18 of the cage 6 as the bearing rotates. Rolling (spinning) is performed about the rolling center axis v. At this time, a lubricant such as grease filled in the bearing is scraped by contact between the balls 5 and the end portion 19a of the concave surface portion 19 of the pocket 18. Due to the fact that it is taken out, it becomes difficult for the lubricant to accumulate in the pocket 18.

  For this reason, for example, if the film of the lubricant G is only partially formed between the ball 5 and the concave surface portion 19 of the pocket 18 as shown by the broken line in FIG. The friction between them increases, and problems such as wear of the pocket 18, seizure of the balls 5 and generation of noise may occur. Further, in order to sufficiently supply the lubricant between the balls 5 and the concave surface portion 19, it is conceivable to increase the filling amount of the lubricant into the bearing. However, if this is done, the stirring resistance of the lubricant inside the bearing is reduced. It will increase, leading to an increase in rotational torque.

  As a countermeasure against such a problem, a radial ball bearing retainer shown in FIGS. 8, 9, and 10 has been proposed (see Patent Document 1). The cage includes a plurality of pockets 18 formed at equal intervals in the circumferential direction of the annular main portion. The pocket 18 has a spherical concave surface portion 19 in which the ball 5 is located. Cavities 21, 22, and 23 are formed inside the column portion 29 between the adjacent pocket 18 and communication portions 21 a and 21 b that communicate the concave portion 19 and the cavities 21, 22, and 23. , 22b, and 23a are provided. Lubricants G such as grease are prefilled and stored in the cavities 21, 22, and 23. When the radial ball bearing rotates, the lubricant enters the communication portions 21a, 21b, 22b, and 23a, and an appropriate amount of the lubricant can ooze out into the concave surface portion 19 of each pocket 18.

  Further, in the cage shown in FIG. 10, the cavities 21, 22, and 23 are closed by the lid members 31, 32, and 33, so that when the radial ball bearing rotates, The filled lubricant such as grease can be prevented from leaking out of the cage.

JP 2008-261478 A

  However, in FIG. 9 when FIG. 8 is viewed from the axial direction of the arrow II, the cavities 21, 22, and 23 open to the openings 21 c, 22 c, and 23 c of the back surface 26. There is a risk of leakage outside the cage. In FIG. 10, the opening is closed by lid members 31, 32, and 33. Therefore, although there is a low possibility that the lubricant leaks to the outside of the cage, since the lid member is provided for each hollow portion, it takes time to attach the lid member, and the manufacturing cost of the cage increases.

  In view of the above-described problems of the prior art, the present invention allows the lubricant to efficiently contribute to lubrication while suppressing an increase in the manufacturing cost of the cage, and between the rolling element and the concave surface portion of the pocket. It is an object of the present invention to provide a rolling bearing retainer that suppresses an increase in rotational torque by suppressing the increase in stirring resistance.

  In order to achieve the above object, a rolling bearing retainer according to the present invention holds a plurality of rolling elements disposed between an inner ring raceway and an outer ring raceway of a rolling bearing so that the rolling elements are positioned. In a rolling bearing retainer having a pocket having a concave surface portion, a column portion formed between the pockets, and a cavity portion formed in the column portion, the cavity portion is partitioned by a bridging portion provided in the center of the column portion. The hollow portion is characterized by opening in the concave surface portion of the pocket.

  In the rolling bearing cage of the present invention, the cage is composed of an outer member and an inner member, and screw grooves are formed on the opposing surfaces of the outer member and the inner member, respectively. It is characterized by that.

  According to the rolling bearing cage of the present invention, it is possible to improve the assembly while suppressing an increase in the manufacturing cost of the cage. In addition, it contributes to lubrication efficiently, makes it possible to supply the lubricant appropriately between the rolling elements and the concave surface of the pocket, and suppresses an increase in stirring resistance, thereby suppressing an increase in rotational torque. A bearing cage can be provided.

The perspective view of the cage for rolling bearings concerning this invention The perspective view of the outer member for cage maintenance for rolling bearings concerning the present invention The perspective view of the inner member for cage maintenance for rolling bearings concerning the present invention The partial perspective view of the cage for rolling bearings concerning this invention Perspective view of a conventional rolling bearing A perspective view of a conventional rolling bearing cage View of a conventional rolling bearing retainer viewed from the outside in the radial direction View of a conventional rolling bearing retainer viewed from the outside in the radial direction Side view of a conventional rolling bearing cage viewed from the axial direction View of a conventional rolling bearing retainer viewed from the outside in the radial direction

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a rolling bearing cage according to an embodiment of the present invention. A rolling bearing retainer 40 according to the present invention is a combination of an outer member 50 and an inner member 60, and holds a plurality of rolling elements disposed between an inner ring raceway and an outer ring raceway of the rolling bearing in a freely rollable manner. In order to achieve this, the whole is formed in an annular shape, and pockets 41 are provided at a plurality of locations in the circumferential direction. A column portion 43 is provided between the pockets 41 and 41, and a hollow portion 44 is provided in the column portion 43. The hollow portion 44 is open to the concave surface portion.

  FIG. 2 shows the outer member 50 of the rolling bearing cage 40 of FIG. FIG. 3 shows the inner member 60 of the rolling bearing retainer 40. The rolling bearing retainer 40 is configured by combining the outer member 50 and the inner member 60. The outer member 50 shown in FIG. 2 has a pocket 51 and a concave portion 52 in which a rolling element is located in the pocket 51, and a column portion 53 is provided between the pockets 51 and 51. A bridging portion 55 is provided at the center of the column portion. A hollow portion 54 is provided on both sides of the column portion 53, and the hollow portion 54 has a structure partitioned by a bridging portion 55.

  The inner member 60 shown in FIG. 3 has a pocket 61 and a concave surface portion 62 where a rolling element is located in the pocket 61, and a column portion 63 is provided between the pockets 61 and 61. A bridging portion 65 is provided at the center of the column portion. A hollow portion 64 is provided on both sides of the column portion 63, and the hollow portion 64 is partitioned by a bridging portion 65.

  A thread groove is formed on the inner surface 56 of the outer member 50. Further, a thread groove is also formed on the outer surface 66 of the inner member 60 which is a surface facing the inner surface 56 of the outer member 50. The retainer 40 is formed by integrating the outer member 50 and the inner member 60 by screwing the thread grooves formed on these opposing surfaces. In addition, as a thread part, it is more preferable on an assembly that it is a taper screw.

  The cage 40 of the present invention is formed, for example, by injection molding a resin. As the resin material, 66 nylon can be used, but 46 nylon excellent in high temperature strength and heat resistance is preferably used. Further, for example, in applications where wear resistance, oil resistance, and heat resistance are required, it is more preferable to use linear polyphenylene sulfide that is excellent in wear resistance, oil resistance, and heat resistance.

  FIG. 4 is a perspective view of a part of the rolling bearing cage 40 of FIG. Grease as a lubricant is sealed in the hollow portion 44 of the cage 40 incorporated in the rolling bearing from the direction of the arrow.

  According to this configuration, it can be said that the grease is surrounded by the cage, and the concave surface portion 42 that is the opening portion of the hollow portion 44 is in a state close to sealing, covered with the rolling elements. As the bearing rotates, the grease begins to flow, but its outlet is restricted to the opening. Therefore, when the grease and the base oil exuded from the grease flow to the outside, most of the grease adheres to the rolling elements and is transported to the rolling surface and contributes to lubrication. Therefore, most of the grease (including base oil) enclosed in the initial stage can be consumed efficiently without waste, and the life of the rolling bearing can be extended. Moreover, it is in a state close to sealing, and is effective in preventing grease leakage. In grease lubrication, only a small portion of the enclosed grease contributes to lubrication as a grease bulk, and most of the grease is scraped by the rolling elements and excluded from the rolling surface. The cause of leakage from the seal gap during long-time use is mainly due to the latter. In this configuration, the grease that has flowed out of the cavity 44 is removed after reaching the raceway surface, so that the entire grease is not vigorously stirred to cause leakage. Since it contributes to lubrication and there is a risk that some of the grease that has finished its role may leak, there is also an effect that the environment around the bearing can be minimized. Furthermore, since the grease is surrounded by a cage, contact with air is reduced, and wasteful oxidation on the surface can be suppressed. This is also effective for extending the life. Further, since the grease viscosity in the cavity portion decreases due to an increase in the bearing temperature accompanying the operation, an effect of efficiently promoting the seepage of the base oil can be expected.

  The amount of grease to be filled may be an amount corresponding to a volume ratio suitable for use conditions as in the conventional case, but is not limited thereto. This is because the usual method of sealing outside the cage is lubricated with a small amount of grease other than most of the grease excluded from the rolling surface. This is because the amount is considered unnecessary. That is, the small amount of grease may be enclosed in the cavity. Along with this, the volume of the cavity and the size of the cage are uniquely determined in the direction of reduction, and it is possible to reduce the weight of the cage and save grease. Furthermore, since the amount of grease is small, the stirring resistance of the lubricant is reduced, leading to a reduction in torque. The lubricant is grease, and the type of grease is not particularly limited, but since the environment where the grease is placed is difficult to be sheared, the consistency is large, the base oil viscosity is small, and the viscosity change is small with respect to temperature change. A grease exhibiting For example, the base oil can be a mineral oil or a synthetic oil such as a diester oil or a silicone oil. As the thickener, various metal soaps, inorganic thickeners such as bentonite, and heat-resistant organic thickeners such as urea and fluorine compounds can be used. Moreover, in this structure, since the cover members 31, 32, and 33 as shown in FIG. 10 are unnecessary, the cost of assembling the cover member itself or the cover member to the cage is not necessary. As described above, according to the rolling bearing cage of the present invention, the lubricant is efficiently contributed to lubrication while suppressing an increase in the manufacturing cost of the cage, and between the rolling element and the concave surface portion of the pocket. A rolling bearing retainer that suppresses an increase in rotational torque can be provided by making it possible to sufficiently supply a lubricant and suppressing an increase in stirring resistance.

  Moreover, in this structure, since it has the structure which pinches | interposes a rolling element from both sides, it can supply grease stably to the rolling element surface irrespective of the revolution direction of a rolling element.

  Moreover, since it is the structure which provided the bridge | crosslinking parts 55 and 65 in the center of the pillar part of the holder | retainer 40, although it is a structure which has the cavity part 44, the rigidity with respect to compression and centrifugal expansion of a holder | retainer can be enlarged. Furthermore, the retainer 40 can be integrated by screwing the thread groove formed on the inner surface 56 of the outer member 50 and the thread groove formed on the outer surface 66 of the inner member 60, so that the assemblability is improved. Can be improved.

DESCRIPTION OF SYMBOLS 1 Inner ring track 2 Inner ring 3 Outer ring track 4 Outer ring 5 Ball 6, 40 Cage 10 Radial ball bearing 16a, 16b Elastic piece 17 Main part 18, 41, 51, 61 Pocket 19, 42, 52, 62 Concave part 20, 30 Radial Ball bearing cage 21, 22, 23, 44 Cavity 21 a, 21 b, 22 b, 23 a Connecting portion 21 c, 22 c, 23 c Opening 26 Back surface 29, 43, 53, 63 Pillar part 31, 32, 33 Lid member 42, 52, 62 Concave portion 50 Outer member 55, 65 Bridge portion 56 Inner side surface 60 Inner member 66 Outer side surface T Opening portion

Claims (1)

A plurality of rolling elements disposed between the inner ring raceway and the outer raceway of the rolling bearing rollably held, the pocket having a concave portion in which the rolling elements are located, and the bar portion formed between said pocket in the rolling bearing cage having a cavity formed in the pillar portion, said cavity is partitioned by a cross-linking portion provided in the pillar portion center, the cavity is open to the concave surface portion ,
It consists of an outer member and an inner member,
Each of the opposing surfaces of the outer member and the inner member is provided with a thread groove,
The cage for a rolling bearing , wherein the thread groove of the outer member and the thread groove of the inner member are screwed together.

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