Roller with retainer

Abstract

To prevent, in a roller with a retainer including the retainer of a single split mold, peeling and wear of the roller in contact with a split part without the need for a circumferential width limitation of the split part and local thinning of a rim part in the retainer.SOLUTION: At least one of two split parts 4 and 5 opposed to each other in a circumferential direction so as to form a split 3 of a retainer 1 includes oil groove parts 4d, 4e, 5d, and 5e which extend across both ends in the circumferential direction of the split parts 4 and 5 and open toward a roller 2 in contact with the split parts 4 and 5.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a roller and cage assembly that combines a plurality of rollers with a split cage. [Background technology]

[0002] Conventionally, split cages have been used to facilitate the assembly of a roller and cage assembly inside a housing. Split cages have two split sections facing each other with a circumferential gap between them, two rim sections connecting the split sections circumferentially, and multiple bar sections separating the two rim sections at predetermined intervals in the circumferential direction. Rollers are positioned between circumferentially adjacent bar sections or between circumferentially adjacent split sections and bar sections. Each split section and bar section has claws on the inner and outer diameter sides of the cage to prevent the rollers from falling out of the cage. Split cages are guided by rolling elements. The rollers are guided radially by the rollers. Therefore, during rotation of the roller and cage assembly, the rollers that guide the cage radially are constantly in contact with the claws on the inner diameter side of the split sections (Patent Documents 1 and 2).

[0003] In this type of roller and cage assembly, the cage is forcibly reduced in diameter by utilizing the gap between the two splits and fitted inside the shell outer ring or housing raceway, and then the cage is expanded in diameter by its elastic restoring force (spring back).This spring back can increase the contact force between the claws on the inner diameter side of the split and the rollers.

[0004] Furthermore, when this type of roller and cage assembly rotates at high speed, the cage may be deformed by centrifugal force, and the contact force between the claws on the inner diameter side of the split and the rollers may increase.

[0005] When the roller and cage assembly rotates, if the oil film breaks where the claws on the inner diameter side of the split and the rollers come into contact, peeling and wear may occur on those rollers.For example, when a roller and cage assembly rotates at high speed under oil lubrication with low viscosity oil, such as in a transmission idler bearing, there is a concern that peeling and wear may occur on the rollers in contact with the split.

[0006] In the roller and cage assembly disclosed in Patent Document 1, the circumferential width of the split is limited to reduce the weight of the split in order to suppress deformation of the cage due to centrifugal force. This reduces the contact force between the split and the roller during high-speed rotation, making it less likely that oil film will run out at the contact point between the split and the roller. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2023-104661 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-89612 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in recent years, in order to reduce the cost of roller and cage assemblies, there has been a demand to reduce the total number of rollers held in the cage without changing the circumferential length of the cage or the pitch diameter of the rollers. In this case, the circumferential width of each slot of the cage must be relatively increased, and the distance between the rollers contacting one slot and the roller contacting the other slot must be increased. As a result, the larger the gap between the two slots due to centrifugal force, the stronger the claws on the inner diameter side of the slot press against the rollers, increasing the contact force. For this reason, when reducing the total number of rollers, there may be cases where it is not possible to limit the circumferential width of the slots as in Patent Document 1, or where even if it can be limited, it may not be sufficient to prevent peeling and other problems.

[0009] In particular, when the roller and cage assembly rotates at high speeds, the centrifugal force acting on the lubricating oil causes a relatively large amount of lubricating oil to remain in the space between the outer periphery of the cage and the outer raceway surface, and the lubricating oil becomes diluted in the space between the inner periphery of the cage and the inner raceway surface, making it difficult for lubricating oil to be supplied to the contact area between the claws on the inner diameter side of the split and the rollers.For this reason, if the contact force mentioned above becomes higher by reducing the total number of rollers, it becomes more likely that the occurrence of peeling and the like cannot be sufficiently prevented.

[0010] As in Patent Document 2, if the thickness of the rim portion is intentionally made thinner on the circumferentially opposite side of the crack between the two split portions, this can be one measure to reduce the rigidity of the cage, weaken the above-mentioned springback, and suppress the contact force between the split portion and the rollers. However, in order to ensure the mechanical strength of the cage, there is a limit to how locally thinning the thickness of the rim portion can be done.

[0011] In view of the above background, the problem to be solved by this invention is to prevent peeling and wear of the rollers in contact with the split portion in a roller and cage assembly having a single split cage, without requiring restriction of the circumferential width of the split portion of the cage or local thinning of the rim portion. [Means for solving the problem]

[0012] In order to solve the above problems, the present invention employs Configuration 1, in which a roller and cage assembly is provided, comprising a plurality of rollers lined up in the circumferential direction, and a cage that holds the plurality of rollers, wherein the cage has two split sections facing each other with a circumferential gap between them, two rim sections that connect the split sections together in the circumferential direction, and column sections that separate the rim sections at a predetermined interval in the circumferential direction, and the rollers are arranged between circumferentially adjacent column sections or between circumferentially adjacent split sections and column sections, and at least one of the split sections has an oil groove section that extends between both circumferential ends of the split section and is open towards the roller that contacts the split section.

[0013] According to the above-mentioned configuration 1, when the roller and cage assembly rotates, the lubricating oil is collected in the oil groove of the split as the cage rotates relative to the lubricating oil, and the lubricating oil that flows out from the oil groove is supplied to the rollers, so more lubricating oil is supplied to the contact area between the split and the roller. Furthermore, the mass of the split is reduced by the volume of the oil groove, suppressing deformation of the cage due to centrifugal force, thereby reducing the contact force between the split and the roller. These actions make it less likely that the oil film will break down at the contact area between the split and the roller, preventing peeling and wear on the rollers. The adoption of an oil groove extending between the circumferential ends of the split does not require limiting the circumferential width of the split or locally thinning the rim.

[0014] In the above configuration 1, a configuration 2 can be adopted in which the oil groove portion is provided on the inner periphery of the cage.

[0015] According to the above configuration 2, the oil groove portion on the inner circumference of the cage collects and discharges the lubricating oil, so that the lubricating oil is easily supplied to the contact portion between the claw portion on the inner diameter side of the cage of the split portion and the roller, even when the roller and cage assembly rotates at high speed.

[0016] In the above configuration 2, a configuration 3 can be adopted in which the at least one split portion has the oil groove portion on each of the inner periphery and the outer periphery of the cage.

[0017] According to the above-mentioned configuration 3, more lubricating oil can be supplied to the rollers in contact with the split portion than when the oil groove portion is provided only on the inner periphery of the cage, and the split portion can be made lighter.

[0018] In the above configuration 3, a configuration 4 can be adopted in which the at least one split portion has the oil groove portion located on the inner circumference of the retainer and the oil groove portion located on the outer circumference of the retainer at the axial center of the split portion, and has a shape having a radial width between each of the oil groove portions and the rim portion that is equivalent to that of the rim portion.

[0019] According to the above-mentioned configuration 4, it is possible to supply a large amount of lubricating oil from the oil grooves on the inner and outer peripheries of the split portion to the axial center of the roller, while ensuring a maximum difference in radial width between the part of the split portion other than the oil grooves and the rim portion.

[0020] In any one of the above configurations 1 to 4, a configuration 5 can be adopted in which the two divided portions each have the oil groove portion, and the first pillar portion adjacent to the first divided portion and the second pillar portion adjacent to the second divided portion different from the first divided portion each have a groove portion extending between both ends in the circumferential direction of the first pillar portion or the second pillar portion.

[0021] According to the above-mentioned configuration 5, regardless of the direction of rotation of the roller and cage assembly, the lubricating oil collected in the oil groove of the split is immediately supplied to the roller that comes into contact with the split located on the counter-rotational side of the gap, and the lubricating oil taken in the groove adjacent to that roller is immediately supplied to the roller that comes into contact with the split located on the rotational side of the gap, thereby achieving lubrication between those two splits and the rollers. In addition, the mass of the first and second pillars closest to the gap is reduced by the volume of the groove, which also helps to suppress deformation of the cage due to centrifugal force.

[0022] In the above configuration 5, a configuration 6 can be adopted in which the groove is provided on the inner periphery of the cage.

[0023] According to the above-mentioned configuration 6, the grooves on the inner circumference of the cage collect and allow the lubricating oil to flow out, so that the lubricating oil is easily supplied to the contact portion between the claw portion on the inner diameter side of the cage of the split portion and the roller, even when the roller and cage assembly rotates at high speed.

[0024] In the above configuration 6, a configuration 7 can be adopted in which the first pillar portion and the second pillar portion each have the groove portion on the inner periphery and the outer periphery of the cage, respectively.

[0025] According to the above-mentioned configuration 7, more lubricating oil can be supplied to the rollers in contact with the split portion than when grooves are provided only on the inner circumference of the cage, and the first pillar portion and the second pillar portion can be made lighter.

[0026] In any one of the above configurations 5 to 7, a configuration 8 can be adopted in which the oil groove portions and the groove portions adjacent to each other on the inner periphery or the outer periphery of the cage are arranged alternately in the axial direction.

[0027] According to the above-mentioned configuration 8, after the lubricating oil that flows out from the oil groove portion or groove portion toward the counter-rotation direction of the roller with cage is caught in the oil groove portion or the roller adjacent to the groove portion, it is less likely to be immediately taken up by the oil groove portion or the groove portion or oil groove portion adjacent to the groove portion with the roller in between, making it easier for the lubricating oil to contribute to the lubrication of the roller.

[0028] In any one of the above configurations 5 to 8, configuration 9 can be adopted, in which the other pillar portion different from the first pillar portion and the second pillar portion has a radial width equivalent to that of the rim portion over the entire axial length of the other pillar portion.

[0029] According to the above-mentioned configuration 9, the mechanical strength can be ensured by the other pillar portions where the contact force with the rollers is not relatively high.

[0030] In any one of the above configurations 1 to 9, a configuration 10 can be adopted in which the two split portions each have the oil groove portion, and the oil groove portion of a first split portion and the oil groove portion of a second split portion different from the first split portion face each other in the circumferential direction.

[0031] According to the above configuration 10, regardless of the rotation direction of the roller and cage, the lubricating oil taken into the oil groove of the split located on the rotational side of the crack can easily reach the oil groove of the split located on the counter-rotational side of the crack, thereby increasing the flow rate of lubricating oil taken into the oil groove of the split located on the counter-rotational side.

[0032] In any one of the above configurations 1 to 10, a configuration 11 can be adopted in which the oil groove portion penetrates the split portion including the oil groove portion in the circumferential direction from one end to the other in the circumferential direction.

[0033] According to the above configuration 11, the lubricating oil taken into the oil groove portion can flow more smoothly, so that the flow rate of the lubricating oil taken into the oil groove portion can be increased.

[0034] In the above configuration 11, a configuration 12 can be adopted in which the oil groove portion becomes wider in the axial direction as it approaches the cleft in the circumferential direction.

[0035] According to the above-mentioned configuration 12, the axial opening width of the oil groove portion relative to the crack can be increased, making it easier for the lubricating oil to be taken into the oil groove portion.

[0036] In any one of the above configurations 1 to 12, a configuration 13 can be adopted in which the cage is made of synthetic resin.

[0037] According to the above configuration 13, the cage can be made lighter than a metal cage, thereby reducing centrifugal force and also reducing the aggressiveness of the claws of the split portions against the rollers.

[0038] In any one of the above configurations 1 to 13, configuration 14 can be adopted in which the rollers are needle rollers. [Effects of the Invention]

[0039] As described above, by adopting the above configuration 1, the present invention makes it possible to prevent peeling and wear of the rollers in contact with the split portion in a roller and cage assembly equipped with a single split cage, without requiring any restriction on the circumferential width of the split portion of the cage or localized thinning of the rim portion. [Brief explanation of the drawings]

[0040] [Figure 1]FIG. 1 is a partial perspective view showing a roller and cage assembly according to a first embodiment of the present invention during rotation; [Figure 2] FIG. 10 is a partial perspective view showing the roller and cage assembly according to the first embodiment during reverse rotation; [Figure 3] Partial cross-sectional view showing the roller and cage assembly in Figure 1 during rotation [Figure 4] FIG. 1 is a perspective view showing a cage according to a first embodiment; [Figure 5] FIG. 10 is a perspective view showing a cage according to a second embodiment of the present invention; [Figure 6] FIG. 6 is a perspective view of the cage of FIG. 5 from a different angle. [Figure 7] FIG. 10 is a perspective view showing a cage according to a third embodiment of the present invention; [Figure 8] FIG. 10 is a partial plan view showing a modified example of the oil groove portion according to each embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0041] A roller and cage assembly according to a first embodiment of the present invention will be described with reference to the accompanying drawings, FIGS. 1 to 4. FIG.

[0042] The roller and cage assembly shown in Figs. 1 to 3 is configured as an assembly in which a plurality of rollers 2 are held in a state aligned in the circumferential direction by a cage 1.

[0043] The cage 1 is a single-split type with a circumferential gap 3. As shown in Fig. 4, the cage 1 has two split portions 4, 5 that face each other with a gap between them in the circumferential direction, two rim portions 6 that connect these split portions 4, 5 in the circumferential direction, and three or more pillar portions 7 that separate the two rim portions 6, 6 at predetermined intervals in the circumferential direction without any joints. The gap 3 is a space formed between the two split portions 4, 5, and the cage 1 is discontinued in the circumferential direction at the gap 3.

[0044] Here, "circumferential direction" refers to the direction along the circumference centered on the central axis of the cage. The central axis of the cage corresponds to the cylinder axis of an imaginary cylindrical surface that includes the central axes of all rollers held by the cage. Hereinafter, the direction along the central axis of the cage will be referred to as the "axial direction." Furthermore, the direction perpendicular to the central axis of the cage will be referred to as the "radial direction."

[0045] The first split portion 4 constitutes one circumferential end of the cage 1 over the entire axial length of the cage 1. The second split portion 5, which is different from the first split portion 4, constitutes the other end of the cage 1 opposite the one circumferential end over the entire axial length of the cage 1. The gap 3 is a space formed between the first split portion 4 and the second split portion 5, which face each other with a circumferential gap. When no external force is applied to the cage 1, each rim portion 6 forms an arc shape extending in the circumferential direction. The rim portions 6 are substantially identical in shape, and the two rim portions 6, 6 face each other at a constant distance in the axial direction. Each pillar portion 7 connects the two rim portions 6, 6 in the axial direction so as to space the two rim portions 6, 6 and the two split portions 4, 5 equally apart in the circumferential direction.

[0046] The entire cage 1 is made up of split sections 4, 5, rim sections 6, and column sections 7. The entire cage 1 is formed by injection molding of synthetic resin. The synthetic resin may be a known thermoplastic resin, a thermosetting resin, or a known fiber-reinforced resin in which carbon fiber, glass fiber, or the like is mixed into a matrix. Note that while it is possible to change the cage 1 to be made from metal, taking into account the mass of the cage 1 and the aggressiveness of the cage 1 against the rollers 2, it is preferable to use a synthetic resin.

[0047] The outer diameter surface of the rim portion 6 is a portion that defines the outer diameter of the cage 1. The inner diameter surface of the rim portion 6 is a portion that defines the inner diameter of the cage 1.

[0048] Hereinafter, the side closer to the central axis of the retainer 1, as defined by the imaginary cylindrical surface that divides the radial width of the retainer 1 in half radially, will be referred to simply as the "inner diameter side," and the opposite side, the side farther from the central axis of the retainer 1, will be referred to simply as the "outer diameter side."

[0049] 1 to 3, one roller 2 is disposed in each of the spaces between the first pillar portions 7 (hereinafter simply referred to as "first pillar portions 7") circumferentially adjacent to the first split portion 4, the space between the second pillar portions 7 (hereinafter simply referred to as "second pillar portions 7") circumferentially adjacent to the second split portion 5, and the spaces between the pillar portions 7, 7 adjacent to each other in the circumferential direction. Note that the total number of these spaces does not need to be the same as the total number of rollers 2, and these spaces do not need to be formed at equal intervals in the circumferential direction.

[0050] Rollers 2 are needle rollers. Here, a needle roller is a cylindrical roller whose length is longer than its diameter, and generally has a roller diameter of less than 5 mm and whose length is 3 to 10 times the roller diameter Dr. Note that rollers 2 do not have to be needle rollers, and can be changed, for example, to cylindrical rollers whose dimensions do not qualify as needle rollers.

[0051] As shown in Figure 3, this roller and cage assembly is disposed between an inner raceway surface 11 and an outer raceway surface 12. Figure 3 shows a state in which the inner raceway surface 11 rotates in the direction of arrow A relative to the stationary outer raceway surface 12, and the roller and cage assembly rotates in the direction of arrow A. In this state, each roller 2 rotates in the direction of arrow B while revolving in the direction of arrow A, and the cage 1 also rotates in the direction of arrow A in conjunction with the revolution of each roller 2. In Figure 3, an imaginary circle passing through the center of each roller 2 and the central axis of the cage 1 are concentric. This roller and cage assembly is used with oil lubrication. The lubricating oil may be supplied in the form of a liquid, droplets, or mist.

[0052] The two split portions 4, 5, the first pillar portion 7 and the second pillar portion 7 are flush with the outer diameter surface of the adjacent rim portion 6 at both ends of their axial lengths, and are also flush with the inner diameter surface of the adjacent rim portion 6.

[0053] 3 and 4, the first split portion 4 has claw portions 4a, 4b that restrict the escape of the rollers 2 that come into contact with the first split portion 4. The second split portion 5 has claw portions 5a, 5b that restrict the escape of the rollers 2 that come into contact with the second split portion 5. Each bar portion 7 has claw portions 7a, 7b that restrict the escape of the rollers 2 that come into contact with one circumferential end of the bar portion 7, and claw portions 7a, 7b that restrict the escape of the rollers 2 that come into contact with the side of the bar portion 7 opposite to the one circumferential end.

[0054] Each of the claws 4a, 5a, 7a located on the inner diameter side restricts the movement of the roller 2 in contact with that claw 4a, 5a, 7a so that the roller 2 cannot fall off in a direction approaching the central axis of the cage 1. Each of the claws 4b, 5b, 7b located on the outer diameter side restricts the movement of the roller 2 in contact with that claw 4b, 5b, 7b so that the roller 2 cannot fall off in a direction away from the central axis of the cage 1.

[0055] The cage 1 is guided radially by a plurality of rollers 2. When the caged roller and retainer arranged between the inner raceway surface 11 and the outer raceway surface 12 rotates at high speed, even if the cage 1 is deformed by centrifugal force, the claws 4a, 5a on the inner diameter side of the two splits 4, 5 press against the rollers 2 they come into contact with. This limits the approach of the two splits 4, 5 to the outer raceway surface 12, so the cage 1 and the outer raceway surface 12 do not come into contact.

[0056] The first split portion 4 has a protrusion 4c at its axial center that protrudes circumferentially beyond both axial ends. The second split portion 5 has a recess 5c that faces the protrusion 4c in the circumferential direction. The protrusion 4c and the recess 5c are shaped to fit together. When the cage 1 is subjected to radial contraction deformation to bring the first split portion 4 and the second split portion 5 closer together using the gap 3, the protrusion 4c is forced into the recess 5c. Because the engaged protrusion 4c and the recess 5c can engage with each other in the axial direction, it is possible to prevent axial displacement of the second split portion 5 relative to the first split portion 4. Furthermore, when the engaged protrusion 4c and the recess 5c butt against each other in the circumferential direction, further radial contraction deformation of the cage 1 is prevented, thereby preventing excessive deformation of the cage 1. When the cage 1 is springbacked, the protrusion 4c comes out of the recess 5c. When this roller and cage assembly is not in use, the convex portion 4c does not fit into the concave portion 5c in the model shown in Figures 1 to 3, but when it is in use and arranged between the shaft and the housing, some or all of the convex portion 4c fits into the concave portion 5c.

[0057] The contact force between the claws 4a, 5a on the inner diameter side and the rollers 2 is always high due to the effects of springback of the cage 1 and centrifugal force. Actively supplying lubricating oil to the rollers 2 in contact with the first split portion 4 and the rollers 2 in contact with the second split portion 5 is effective in preventing peeling and wear of these rollers 2. In particular, when using protrusions 4c and recesses 5c, the circumferential width of the first split portion 4 is increased by the length of the protrusions 4c, and the circumferential width of the second split portion is increased by the length of the recesses 5c. This increases the mass of each split portion 4, 5, strengthens the effect of centrifugal force, and further increases the aforementioned contact force, so it is important to prevent peeling and other problems between these rollers 2.

[0058] 2 to 4, each of the two split portions 4 and 5 has a plurality of oil grooves 4d, 4e, 5d, and 5e. Each of the oil grooves 4d, 4e, 5d, and 5e extends between both circumferential ends of the first split portion 4 or the second split portion 5. One end of each of the oil grooves 4d, 4e, 5d, and 5e opens toward the roller 2 that contacts the first split portion 4 or the second split portion 5, and the opposite end opens toward the gap 3.

[0059] The first pillar portion 7 and the second pillar portion 7 each have a plurality of grooves 7c, 7d. Each groove 7c, 7d extends between both circumferential ends of the first pillar portion 7 or the second pillar portion 7, and serves as an oil passage that opens at both ends toward the rollers 2 located adjacent to the corresponding first pillar portion 7 or second pillar portion 7.

[0060] The two split portions 4, 5 each have an oil groove 4d, 5d on the outer diameter side, with a space continuing in the circumferential direction from the oil groove 4d on the outer diameter side to the oil groove 5d.

[0061] Each of the two split portions 4 and 5 has an oil groove 4e or 5e on the inner diameter side thereof, and a space is continuous in the circumferential direction from the oil groove 4e on the inner diameter side to the oil groove 5e.

[0062] The two split portions 4, 5 each have an oil groove 4d, 4e, 5d, 5e at the center of the axial length of the first split portion 4 or the second split portion 5. If only one oil groove 4d, 4e, 5d, 5e is formed at the axial center of the split portions 4, 5 on each of the inner and outer circumferences of the cage 1, it is possible to make each oil groove 4d, 4e, 5d, 5e wider, and therefore when this roller and cage assembly rotates, a large amount of lubricating oil can be taken in by each oil groove 4d, 4e, 5d, 5e and the lubricating oil can be supplied intensively towards the axial center of the rollers 2.

[0063] The first and second divided portions 4 and 5 have the outer oil grooves 4d and 5d and the inner oil grooves 4e and 5e in the same axial width and in the same axial region, and extend axially with a radial width between the axial region and the rim portion 6 that is equal to the radial width of the rim portion 6. The two divided portions 4 and 5 are preferably shaped so that the radial width between the oil grooves 4d and 4e or between the oil grooves 5d and 5e and the rim portion 6 is equal to the radial width of the rim portion 6. This maximizes the difference between the radial width of the axial region and the radial width of the rim portion 6, resulting in an advantageous guide shape that facilitates ensuring the amount of oil inflow. "Equal" here means that the radial width of the divided portions 4 and 5 is between 0.95 and 1.05 times the radial width of the rim portion 6.

[0064] 1 and 4, the first pillar portion 7 and the second pillar portion 7 each have two grooves 7c on the outer diameter side. The grooves 7c of the first pillar portion 7 and the oil grooves 4d of the first split portion 4 are arranged alternately in the axial direction. The grooves 7c of the second pillar portion 7 and the oil grooves 5d of the second split portion 5 are arranged alternately in the axial direction.

[0065] 2, the first pillar portion 7 and the second pillar portion 7 each have two grooves 7d on the inner diameter side. The grooves 7d of the first pillar portion 7 and the oil grooves 4e of the first split portion 4 are arranged alternately in the axial direction. The grooves 7d of the second pillar portion 7 and the oil grooves 5e of the second split portion 5 are arranged alternately in the axial direction.

[0066] The first pillar portion 7 and the second pillar portion 7 have an outer diameter side groove portion 7c and an inner diameter side groove portion 7d on both axial sides of each pillar portion 7, with the same axial width in the same axial region, and extend axially between the axial region and the rim portion 6 with a radial width equivalent to the radial width of the rim portion 6. "Equal" here means that the radial width of the pillar portion 7 is 0.95 to 1.05 times the radial width of the rim portion 6.

[0067] 1, 2, and 4, the axial center of the first pillar portion 7 faces the oil groove 4d of the first divided portion 4 in the circumferential direction on the outer diameter side, and faces the oil groove 4e of the first divided portion 4 in the circumferential direction on the inner diameter side. The axial center of the second pillar portion 7 faces the oil groove 5d of the second divided portion 5 in the circumferential direction on the outer diameter side, and faces the oil groove 5e of the second divided portion 5 in the circumferential direction on the inner diameter side.

[0068] The cross section shown in Figure 3 is a combination of a cross section on an imaginary plane that passes through the axial center of oil groove portions 4d, 4e, 5d, and 5e shown in Figures 2 and 4 and extends along the radial direction, and a cross section on an imaginary plane that passes through the axial center of groove portions 7c and 7d shown in Figures 2 and 4 and extends along the radial direction.

[0069] As shown in FIGS. 1, 3 and 4, the oil grooves 4d, 5d and grooves 7c located on the outer periphery of the cage 1 each have a groove depth in the radial direction relative to the outer diameter of the rim 6.

[0070] As shown in FIGS. 2 and 3, the oil grooves 4e, 5e and 7d located on the inner periphery of the cage 1 each have a groove depth in the radial direction relative to the inner diameter of the rim 6.

[0071] As shown in FIGS. 1 to 3, the claws 4a, 4b of the first split portion 4 are located at different axial positions from the oil grooves 4d, 4e. By adopting this positional relationship, the oil grooves 4d, 4e can be provided at a greater radial depth without being limited by the radial arrangement of the claws 4a, 4b relative to the roller 2. For example, the open end of the oil groove 4e on the inner diameter side is provided at a depth that intersects with the axial end face of the claw 4a on the inner diameter side. Similarly, the open end of the oil groove 4d on the outer diameter side is provided at a depth that intersects with the axial end face of the claw 4b on the outer diameter side. These axial positional and intersecting relationships also apply between the claws 5a, 5b and the oil grooves 5d, 5e of the second split portion 5, between the claws 7a, 7b and the grooves 7c, 7d of the first pillar portion 7, and between the claws 7a, 7b and the grooves 7c, 7d of the second pillar portion 7.

[0072] Each oil groove 4d, 4e, 5d, 5e and each groove 7c, 7d extends circumferentially between both circumferential ends of the corresponding first split portion 4, second split portion 5, first columnar portion 7, or second columnar portion 7 to ensure smooth flow of lubricating oil. Each oil groove 4d, 4e, 5d, 5e and each groove 7c, 7d is formed by a retainer surface extending in the circumferential direction. Each oil groove 4d, 4e, 5d, 5e and each groove 7c, 7d has a constant axial width over its entire circumferential length.

[0073] 1 to 3, arrows without reference numerals schematically show the flow of lubricating oil when the roller and cage assembly rotates. Note that in Figures 1 and 3, the rotation direction of the roller and cage assembly indicated by arrow A is from the convex portion 4c toward the concave portion 5c, while in Figure 2, the rotation direction of the roller and cage assembly indicated by arrow A is the opposite direction to that in Figures 1 and 3, that is, from the concave portion 5c toward the convex portion 4c.

[0074] When this roller and cage assembly rotates in the direction of arrow A, the lubricating oil flows generally in the direction opposite to arrow A relative to the cage 1 between the generally inner raceway surface 11 and the outer raceway surface 12. In this flow, the lubricating oil is entrained by the rollers 2 in the direction of arrow B, passing between the inner and outer raceway surfaces 11, 12 and the rollers 2, or peeling off from the rollers 2. In particular, because the circumferential distance between the rollers 2 in contact with the first split portion 4 and the rollers 2 in contact with the second split portion 5 is wide, the lubricating oil tends to flow circumferentially near the gaps 3.

[0075] When the rotation direction of this roller and cage assembly is the direction of arrow A shown in Figures 1 and 3, the first split 4, which is located opposite the direction of arrow A (counter-rotational direction) from the gap 3, is downstream of the gap 3 in the general flow of lubricating oil described above. Therefore, the upstream open end of each oil groove 4d, 4e captures the lubricating oil flowing downstream from the gap 3 and collects it in the oil groove 4d, 4e. Each oil groove 4d, 4e, which has a radial groove depth, suppresses the diffusion of the captured lubricating oil and guides most of the captured lubricating oil to the downstream open end of the oil groove 4d, 4e, from which it flows toward the roller 2 in contact with the first split 4. The lubricating oil flowing out from the downstream open end of each oil groove 4d, 4e immediately reaches the roller 2. In this way, the lubricating oil captured in each oil groove 4d, 4e is supplied to the roller 2.

[0076] Here, the lubricating oil taken into each oil groove portion 4d, 4e flows through the oil groove portion 4d, 4e that penetrates the first split portion 4 in the circumferential direction, so it is less likely to escape from the oil groove portion 4d, 4e and reaches the downstream open end smoothly and quickly in the circumferential direction.

[0077] Furthermore, the lubricating oil that flows out from the downstream open ends of the inner and outer peripheral oil grooves 4d, 4e located in the axial center of the first split portion 4 hits the axial center of roller 2 that contacts first split portion 4, spreads to some extent to both axial sides of roller 2, and is drawn into roller 2 by the rotation of roller 2 in the direction of arrow B. This ensures that there is an abundance of lubricating oil at the contact points between roller 2 and each of the claw portions 4a, 4b of first split portion 4, making it less likely that the oil film will run out at those contact points.

[0078] When the lubricating oil caught in the roller 2 separates from the roller 2, it heads toward the first pillar portion 7 adjacent to the roller 2 on the downstream side. Here, because oil groove 4e located on the inner periphery of cage 1 and groove 7d of the first pillar portion 7, and oil groove 4d located on the outer periphery of cage 1 and groove 7c of the first pillar portion 7 are all staggered in the axial direction, the lubricating oil caught in the axial center portion of roller 2 is unlikely to head immediately toward grooves 7c, 7d, but is likely to hit the claw portions 7a, 7b of the first pillar portion 7 and spread out to both sides in the axial direction. For this reason, the lubricating oil caught in the axial center portion of roller 2 is more likely to contribute to the lubrication of roller 2.

[0079] The upstream open ends of grooves 7c, 7d of first pillar portion 7 take in lubricating oil that has peeled off from both axial ends of roller 2 and lubricating oil that has spread to both axial sides after hitting claw portions 7a, 7b of first pillar portion 7, and collect it in grooves 7c, 7d. Grooves 7c, 7d, which have a groove depth in the radial direction, suppress the diffusion of the taken-in lubricating oil, and guide most of the taken-in lubricating oil to the downstream open ends of grooves 7c, 7d, from which it flows out toward roller 2 adjacent to the downstream side of first pillar portion 7.

[0080] 1 and 3, in the general flow of lubricating oil, each oil groove 5d, 5e of the second split portion 5 located on the side of the gap 3 in the direction of arrow A (rotational direction) is upstream of the rollers 2 in contact with the gap 3 and the first split portion 4, and downstream of the rollers 2 in contact with the second split portion 5. Therefore, the upstream open end of each oil groove 5d, 5e captures the lubricating oil that separates from the axial center of the roller 2 in contact with the second split portion 5 and flows downstream, and collects it in the oil groove 5d, 5e. The oil grooves 5d, 5e, which have a radial depth, suppress the diffusion of the captured lubricating oil, and guide most of the captured lubricating oil to the downstream open end of the oil groove 5d, 5e, from which it flows downstream. Therefore, more lubricating oil is taken into the oil grooves 4d, 4e of the first split portion 4 located downstream of the oil grooves 5d, 5e.

[0081] Here, the lubricating oil flowing out from the downstream open ends of oil grooves 5d, 5e can easily reach the upstream open ends of oil grooves 4d, 4e smoothly because oil groove 4d of first split portion 4 and oil groove 5d of second split portion 5 face each other in the circumferential direction, and similarly oil groove 4e and oil groove 5e face each other in the circumferential direction.

[0082] As described above, when the rotation direction of this roller and cage assembly is the direction of arrow A shown in Figures 1 and 3, oil grooves 4d, 4e, 5d, and 5e cannot supply lubricating oil directly to rollers 2 that contact the upstream side of second split portion 5. Nevertheless, oil grooves 4d, 4e, 5d, and 5e of rotating cage 1 repeatedly collect lubricating oil on the inner and outer circumferences of cage 1, so that the amount of lubricating oil present in the orbital space of rollers 2 between raceway surfaces 11 and 12 and cage 1 increases all around. As a result, more lubricating oil is supplied to rollers 2 that contact second split portion 5, making it less likely that oil film breakdown will occur at the contact points between rollers 2 and claw portions 5a of second split portion 5, etc.

[0083] Furthermore, lubricating oil is supplied from the grooves 7c and 7d of the second pillar portion 7 located upstream of the roller 2 in contact with the second divided portion 5, which also reduces the likelihood of oil film breakdown at the contact area between the roller 2 and the divided portion 5. Specifically, the upstream open ends of the grooves 7c and 7d of the second pillar portion 7 capture lubricating oil that has separated from the roller 2 adjacent to the upstream side of the second pillar portion 7 and collect it in the grooves 7c and 7d. The grooves 7c and 7d, which have a radial depth, suppress the diffusion of the captured lubricating oil and guide most of the captured lubricating oil to the downstream open ends of the grooves 7c and 7d, from which it flows out toward the roller 2 adjacent to the downstream side of the second pillar portion 7 (i.e., the roller 2 in contact with the second divided portion 5). Therefore, the lubricating oil that flows out from the downstream open ends of the grooves 7c and 7d immediately reaches the roller 2 in contact with the second divided portion 5. In this way, the lubricating oil taken into the grooves 7c, 7d of the second pillar portion 7 is supplied to the rollers 2 in contact with the second split portion 5.

[0084] Here, the oil groove 5e located on the inner periphery of the cage 1 and the groove 7d of the second pillar portion 7, and the oil groove 5d located on the outer periphery of the cage 1 and the groove 7c of the second pillar portion 7 are staggered in the axial direction, and the groove 7d on the inner diameter side and the claw portion 5a face each other in the circumferential direction, and the groove 7c on the outer diameter side and the claw portion 5b face each other in the circumferential direction. Therefore, the lubricating oil flowing out from each groove 7c, 7d is caught up in both axial ends of the roller 2 and easily reaches the contact portion between the roller 2 and the claw portions 5a, 5b that contact the second split portion 5. Furthermore, the lubricating oil caught up in both axial ends of the roller 2 is unlikely to immediately flow toward the oil grooves 5d, 5e and is likely to hit the claw portions 5a, 5b. Therefore, the lubricating oil caught up in both axial ends of the roller 2 easily contributes to lubrication of the roller 2.

[0085] Furthermore, the grooves 7c, 7d of the first pillar portion 7 and the second pillar portion 7 also collect lubricating oil on the inner and outer circumferences of the cage 1, which also increases the amount of lubricating oil supplied to the rollers 2 in contact with the first split portion 4 and the rollers 2 in contact with the second split portion 5.

[0086] When this roller and cage assembly rotates in the direction of arrow A shown in Figure 2, the first split portion 4 and first post portion 7 are located on the side of the gap 3 in the direction of arrow A (direction of rotation), and the second split portion 5 and second post portion 7 are located on the side opposite to the direction of arrow A (opposite direction of rotation), and the flow of lubricating oil is simply reversed from that in Figures 1 and 3, so a detailed explanation of the roles played by oil grooves 4d, 4e, 5d, 5e and grooves 7c, 7d in this case will be omitted. In this case, lubricating oil collected in oil grooves 5d, 5e is supplied directly to roller 2 in contact with second split portion 5, and lubricating oil collected in grooves 7c, 7d of first post portion 7 is supplied directly to roller 2 in contact with first split portion 4.

[0087] 1 to 3, when the roller and cage assembly shown in Figures 1 to 3 rotates at high speed, the amount of lubricating oil present between the inner raceway surface 11 and the inner circumference of the cage 1 is less than the amount of lubricating oil present between the outer raceway surface 12 and the outer circumference of the cage 1 due to the influence of centrifugal force acting on the lubricating oil. The inner diameter side oil grooves 4e, 5e and grooves 7d located on the inner circumference of the cage 1 are not open to the outer diameter side along their entire circumferential length, so there is no concern that the lubricating oil flowing in the inner diameter side oil groove 4e, etc. will diffuse to the outer diameter side due to centrifugal force. For this reason, it is particularly preferable to employ the inner diameter side oil grooves 4e, 5e and grooves 7d to promote lubrication of the contact areas between the inner diameter side claws 4a, 5a and the corresponding rollers 2.

[0088] Furthermore, by employing oil grooves 4d, 5d on the outer diameter side in addition to oil grooves 4e, 5e on the inner diameter side, the mass of splits 4, 5 is further reduced, and deformation of retainer 1 due to centrifugal force is further suppressed, thereby further reducing the contact force between splits 4, 5 and the corresponding rollers 2.

[0089] As shown in Figure 4, each of the other pillar portions 7 (hereinafter simply referred to as "other pillar portions 7") different from the first pillar portion 7 and the second pillar portion 7 does not have a groove. Each of the other pillar portions 7 has the same radial width as the rim portion 6 and extends over its entire axial length. Each of the other pillar portions 7 is flush with the outer diameter surface of the rim portion 6 over its entire axial length, and is flush with the inner diameter surface of the rim portion 6 over its entire axial length.

[0090] The contact force between the other bar portions 7 and rollers 2 is high in the loaded zone where a load is applied to rollers 2 between the inner raceway surface 11 (see Figure 3) and the outer raceway surface 12, but is not so high in the non-loaded zone. Furthermore, when a half-circumferential region of the cage 1 near the cleft 3 (an angular region of ±90° around the central axis of the cage 1, with the 0° position being the position that bisects the circumferential distance between the first rim portion 6 and the second rim portion 6) is deformed by centrifugal force in the direction that widens the cleft 3, the radial displacement of the other bar portions 7 is smaller than the radial displacement of the slits 4 and 5. For these reasons, the contact force between the other bar portions 7 and rollers 2 is usually not higher than the contact force between the claw portions 4a and 5a and rollers 2. In other words, there is little possibility that peeling or wear will occur due to oil film deficiency at the rollers 2 that come into contact with the other bar portions 7. The end of the life of this roller and cage assembly due to peeling or wear of the rollers 2 is believed to occur when peeling or wear occurs on the rollers 2 in contact with the first or second split portions 4 or 5. Therefore, it is preferable to provide grooves 7c and 7d in the first and second split portions 7, respectively, to increase the amount of lubricant between the first and second split portions 4 and 7, and between the second and second split portions 5 and 7. However, providing grooves in many of the split portions 7 may adversely affect the mechanical strength of the cage 1. Furthermore, reducing the weight of the split portions 7 in the half-circumferential region opposite the half-circumferential region near the gap 3 of the cage 1 is not effective in preventing deformation of the half-circumferential region near the gap 3 of the cage 1 due to centrifugal force. While reducing the weight of many of the split portions 7 in the half-circumferential region near the gap 3 of the cage 1 would be effective in preventing this, doing so would require reducing the weight of many of the split portions 7 in the opposite half-circumferential region as well to prevent imbalance of the cage 1. Taking these factors into consideration, it is preferable that, of all the pillar portions 7 of the retainer 1, each of the other pillar portions 7 except the first pillar portion 7 and the second pillar portion 7 has a radial width equal to the radial width of the rim portion 6 over the entire axial length of the other pillar portion 7.

[0091] The roller and cage assembly shown in Figures 1 to 4 is as described above, and comprises a plurality of rollers 2 lined up in the circumferential direction and a cage 1 that holds the plurality of rollers 2, the cage 1 having two split sections 4, 5 facing each other with a circumferential gap between them, two rim sections 6, 6 that connect the split sections 4, 5 in the circumferential direction, and a pillar section 7 that separates the rim sections 6, 6 at a predetermined distance in the circumferential direction, and the rollers 2 are arranged between the pillar sections 7, 7 that are adjacent in the circumferential direction, or between the split sections 4, 5 and the pillar section 7 that are adjacent in the circumferential direction.

[0092] 1 to 3, at least one of the splits 4, 5 has an oil groove 4d, 4e, 5d, 5e that extends between both circumferential ends of the split 4, 5 and is open toward the roller 2 that contacts the split 4, 5. As a result, when the roller and cage assembly rotates, the lubricating oil is collected in the oil grooves 4d, 4e, 5d, 5e as the cage 1 rotates relative to the lubricating oil, and the lubricating oil that flows out from the oil grooves 4d, 4e, 5d, 5e is supplied to the roller 2 that contacts the split 4, 5, increasing the amount of lubricating oil supplied to the contact area between the split 4, 5 and the roller 2. Furthermore, the mass of the split 4, 5 is reduced by the volume of the oil grooves 4d, 4e, 5d, 5e, and deformation of the cage 1 due to centrifugal force is suppressed, thereby suppressing the contact force between the split 4, 5 and the roller 2. These actions make it less likely that oil film breakdown will occur at the contact points between the splits 4, 5 and the rollers 2, thereby preventing peeling and wear on the rollers 2. The adoption of oil grooves 4d, 4e, 5d, 5e extending between both circumferential ends of the splits 4, 5 makes it unnecessary to limit the circumferential width of the splits 4, 5, and also makes it unnecessary to limit the radial width of the rim portion 6. In this way, this roller and cage assembly, which has a single-split cage 1, can prevent peeling and wear on the rollers 2 that come into contact with the splits 4, 5, without requiring any restriction on the circumferential width of the splits 4, 5 of the cage 1 or any localized thinning of the rim portion 6.

[0093] Furthermore, since the oil grooves 4e, 5e are provided on the inner circumference of the cage 1, the oil grooves 4e, 5e collect and discharge lubricating oil on the inner circumference of the cage 1, making it easier for lubricating oil to be supplied to the contact areas between the claws 4a, 5a on the inner diameter side close to the inner circumference of the cage 1 and the rollers 2, even when the roller and cage are rotating at high speeds.

[0094] Furthermore, in this roller and cage assembly, at least one split portion 4, 5 has oil groove portions 4e, 4d, 5e, 5d on both the inner and outer periphery of the cage 1, so that more lubricating oil can be supplied to the rollers 2 that come into contact with the split portions 4, 5 than in the case where oil groove portions 4e, 5e are provided only on the inner periphery of the cage 1, and the split portions 4, 5 can be made lighter.

[0095] Furthermore, in this roller and cage assembly, at least one split portion 4, 5 has an oil groove portion 4e, 5e located on the inner circumference of the cage 1 and an oil groove portion 4d, 5d located on the outer circumference of the cage 1, in the axial center of the split portion 4, 5, and the space between each oil groove portion 4e, 4d, 5e, 5d and the rim portion 6 has a radial width equivalent to that of the rim portion 6, so that a large amount of lubricating oil can be supplied to the axial center of the roller 2 from the oil grooves 4e, 4d, 5e, 5d on the inner and outer circumferences of the split portions 4, 5, while ensuring a maximum difference in the radial width of the axial region of the split portions 4, 5 and the radial width of the rim portion 6.

[0096] Furthermore, in this roller and cage assembly, the two split portions 4, 5 have oil grooves 4d, 4e, 5d, 5e, respectively, and the first pillar portion 7 adjacent to the first split portion 4 and the second pillar portion 7 adjacent to the second split portion 5 different from the first split portion 4 have grooves 7c, 7d extending between both ends of the first pillar portion 7 or the second pillar portion 7 in the circumferential direction. Therefore, regardless of the direction of rotation of this roller and cage assembly (the direction of arrow A), the oil grooves 7c, 7d extend between the first split portion 4 (in the cases of Figures 1 and 3) or the second split portion 5 (in the case of Figure 2) located on the side opposite to the rotation direction (opposite the direction of arrow A) of the gap 3. The lubricating oil collected in the oil grooves 4d, 4e (in the cases of Figures 1 and 3) of the first split portion 4 or the oil grooves 5d, 5e (in the case of Figure 2) of the second split portion 5 is immediately supplied to the rollers 2 in contact with the second split portion 5 (in the cases of Figures 1 and 3) or first split portion 4 (in the case of Figure 2) located on the rotational direction (direction of arrow A) side of the gap 3, and the lubricating oil collected in the grooves 7c, 7d of the second post portion 7 (in the cases of Figures 1 and 3) or first post portion 7 (in the case of Figure 2) adjacent to the rollers 2 is immediately supplied, thereby achieving lubrication between the splits 4, 5 and the rollers 2. Furthermore, the mass of the first post portion 7 and the second post portion 7 closest to the gap 3 is reduced by the volume of the grooves 7c, 7d, which also suppresses deformation of the cage 1 due to centrifugal force.

[0097] Furthermore, since this roller and cage assembly has grooves 7d formed on the inner circumference of the cage 1, the grooves 7d collect lubricating oil on the inner circumference of the cage 1 and allow it to flow out, making it easier for lubricating oil to be supplied to the contact areas between the claws 4a, 5a on the inner diameter side close to the inner circumference of the cage 1 and the roller 2, even when the roller and cage assembly is rotating at high speed.

[0098] Furthermore, in this roller and cage assembly, the first pillar portion 7 and the second pillar portion 7 each have grooves 7d, 7c on the inner and outer periphery of the cage 1, respectively, which allows more lubricating oil to be supplied to the rollers 2 that contact the split portions 4, 5 than in the case where grooves 7d are provided only on the inner periphery of the cage 1, and also makes it possible to make the first pillar portion 7 and the second pillar portion 7 lighter.

[0099] Furthermore, in this roller and cage assembly, adjacent oil groove portions 4e, 4d, 5e, 5d and groove portions 7d, 7c are arranged alternately in the axial direction on the inner or outer circumference of the cage 1, so that the lubricating oil that flows out from oil groove portion 4e, 4d, 5e, 5d or groove portion 7d, 7c toward the counter-rotation direction (opposite the direction of arrow A) of the roller and cage assembly is caught up in the roller 2 adjacent to oil groove portion 4e, 4d, 5e, 5d or groove portion 7d, 7c, and then is less likely to be immediately taken up by the groove portion 7d, 7c or oil groove portion 5e, 5d, 4e, 4d adjacent to oil groove portion 4e, 4d, 5e, 5d or groove portion 7d, 7c with the roller 2 in between, making it easier for the lubricating oil to contribute to the lubrication of the roller 2. 1 and 3, the lubricating oil that flows out from the oil grooves 4e, 4d in the direction opposite to the arrow A is caught by roller 2 in contact with the first split portion 4, and is then difficult to be immediately taken up by the grooves 7d, 7e of the first post portion 7, and the lubricating oil that flows out from the grooves 7d, 7c of the second post portion 7 in the direction opposite to the arrow A is caught by roller 2 in contact with the second split portion 5, and is then difficult to be immediately taken up by the oil grooves 5e, 5d. Also, in the case of FIG. 2, the lubricating oil that flows out from the oil grooves 5e, 5d in the direction opposite to the arrow A is caught by roller 2 in contact with the second split portion 5, and is then difficult to be immediately taken up by the grooves 7d, 7e of the second post portion 7, and the lubricating oil that flows out from the grooves 7d, 7c of the first post portion 7 in the direction opposite to the arrow A is caught by roller 2 in contact with the first split portion 4, and is then difficult to be immediately taken up by the oil grooves 4e, 4d.

[0100] Furthermore, in this roller with cage, the other column portions 7 different from the first column portion 7 and the second column portion 7 have a radial width equivalent to that of the rim portion 6 over the entire axial length of the other column portions 7, so that the mechanical strength can be ensured in the other column portions 7 where the contact force with the rollers 2 is not relatively high.

[0101] Furthermore, in this roller and cage assembly, the two split portions 4, 5 each have oil groove portions 4d, 4e, 5d, 5e, and the oil groove portions 4d, 4e of the first split portion 4 and the oil groove portions 5d, 5e of the second split portion 5, which is different from the first split portion 4, are opposed to each other in the circumferential direction. As a result, regardless of the rotation direction of the roller and cage assembly, the lubricating oil taken into the oil groove portions 5d, 5e (in the cases of Figures 1 and 3) and oil groove portions 4d, 4e (in the case of Figure 2) located on the rotational direction side (direction of arrow A) of the gap 3 can easily reach the oil groove portions 4d, 4e (in the cases of Figures 1 and 3) and oil groove portions 5d, 5e (in the case of Figure 2) located on the counter-rotational direction side (opposite direction of arrow A) of the gap 3. This makes it possible to increase the flow rate of lubricating oil taken into the oil groove portions 4d, 4e (in the cases of Figures 1 and 3) and oil groove portions 5d, 5e (in the case of Figure 2) located on the counter-rotational direction side.

[0102] Furthermore, in this roller and cage assembly, the oil groove portions 4d, 4e, 5d, 5e penetrate circumferentially between both circumferential ends of the split portions 4, 5 that include the oil groove portions 4d, 4e, 5d, 5e, which makes it easier for the lubricating oil to flow smoothly through the oil groove portions 4d, 4e, 5d, 5e, and therefore the flow rate of the lubricating oil taken into the oil groove portions 4d, 4e, 5d, 5e can be increased.

[0103] Furthermore, because the cage 1 of this caged roller is formed from synthetic resin, it is lighter than a metal cage, reducing centrifugal force and also reducing the aggressiveness of the claw portions 4a, 5a against the roller 2.

[0104] A cage according to a second embodiment of the present invention is shown in Figures 5 and 6. Note that, in the following, only differences from the first embodiment will be described, and the same reference numerals will continue to be used for components corresponding to those in the first embodiment.

[0105] The first and second pillar portions 7 of the cage shown in Figures 5 and 6 do not have grooves and have the same shape as the other pillar portions 7. Since all of the pillar portions 7 of this cage have the same shape, imbalance of this cage is suppressed.

[0106] A cage according to a third embodiment of the present invention is shown in FIG.

[0107] All of the column portions 7 of the cage shown in Figure 7 have grooves 7c and 7d. Each column portion 7 has one outer diameter groove 7c and one inner diameter groove 7d at the axial center of the column portion 7. The outer diameter grooves 7c and the outer diameter oil grooves 4d and 5d are not staggered in the axial direction, but are located in the same axial region with the same axial width as the outer diameter oil grooves 4d and 5d. The inner diameter grooves 7d are also positioned in the same position as the inner diameter oil grooves 4e and 5e. Since many of the inner diameter oil grooves 4e, 5e, and grooves 7d are located on the same circumference on the inner circumference of the cage, and many of the outer diameter oil grooves 4d, 5d, and grooves 7c are located on the same circumference on the outer circumference of the cage, a particularly large amount of lubricating oil is collected in the axial center of the inner and outer circumferences of the cage. Furthermore, because all of the column portions 7 are lightweight, deformation due to centrifugal force is particularly suppressed.

[0108] In the above-described embodiments, the oil grooves are formed on the surface of the cage extending in the circumferential direction, but the shape and arrangement of the oil grooves can be modified as appropriate. An example of such a modified oil groove is shown in FIG.

[0109] The oil grooves 4d and 5d shown in Figure 8 become wider in the axial direction the closer they are to the gap 3 in the circumferential direction. Oil groove 4d is an example in which the rate of change of the axial width of oil groove 4d per unit circumferential length is set to be constant. Oil groove 5d is an example in which the rate of change of the axial width of oil groove 5d per unit circumferential length is set to gradually increase toward the circumferential direction. In either case, widening the axial opening width of oil grooves 4d and 5d relative to gap 3 makes it easier for lubricating oil to be taken into oil grooves 4d and 5d.

[0110] In addition, multiple oil grooves can be provided on either or both of the inner diameter side and the outer diameter side of the split, or the number of oil grooves can be different on the inner diameter side and the outer diameter side of the split. The open end of the oil groove on the cleft side is not limited to being located opposite the roller in the circumferential direction, and can be located, for example, opposite the rim in the circumferential direction. The depth of the oil groove is not limited to being constant, and the cross-sectional shape of the oil groove can be, for example, an arc.

[0111] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0112] 1 Cage 2. 3. Crack 4, 5 split sections 4a, 4b, 5a, 5b Claws 4d, 4e, 5d, 5e Oil groove 6 Rim 7 Pillar part 7c, 7d groove

Claims

1. a plurality of rollers arranged in a circumferential direction and a cage that holds the plurality of rollers; the cage has two split portions facing each other with a circumferential gap therebetween, two rim portions connecting the split portions in the circumferential direction, and pillar portions separating the rim portions at predetermined intervals in the circumferential direction, In a roller and cage assembly in which the rollers are arranged between the column portions adjacent to each other in the circumferential direction or between the split portions and the column portions adjacent to each other in the circumferential direction, a roller and cage assembly, wherein at least one of the split portions has an oil groove portion that extends between both circumferential ends of the split portion and is open toward the roller that contacts the split portion;

2. 2. The roller and cage assembly according to claim 1, wherein the oil groove is provided on the inner periphery of the cage.

3. 3. A roller and cage assembly according to claim 2, wherein said at least one split portion has said oil groove portion on each of the inner periphery and the outer periphery of said cage.

4. 4. The roller and cage assembly according to claim 3, wherein the at least one split portion has the oil groove portion located on the inner periphery of the cage and the oil groove portion located on the outer periphery of the cage, at the axial center of the split portion, and has a shape having a radial width between each oil groove portion and the rim portion equivalent to that of the rim portion.

5. the two split portions each have the oil groove portion, 5. The roller and cage assembly according to claim 1, wherein the first base portion adjacent to the first split portion and the second base portion adjacent to a second split portion different from the first split portion each have a groove portion extending between both ends in the circumferential direction of the first base portion or the second base portion.

6. 6. A roller and cage assembly according to claim 5, wherein said groove is provided on the inner periphery of said cage.

7. 7. A roller and cage assembly according to claim 6, wherein each of said first and second post portions has said grooves on the inner and outer peripheries of said cage.

8. 6. The roller and cage assembly according to claim 5, wherein the oil grooves and the grooves adjacent to each other on the inner or outer periphery of the cage are arranged alternately in the axial direction.

9. 6. The roller and cage assembly according to claim 5, wherein the other column portion different from the first column portion and the second column portion has a radial width equivalent to that of the rim portion over the entire axial length of the other column portion.

10. the two split portions each have the oil groove portion, 5. The roller and cage assembly according to claim 1, wherein the oil groove of a first split portion and the oil groove of a second split portion different from the first split portion face each other in the circumferential direction.

11. 5. The roller and cage assembly according to claim 1, wherein the oil groove portion penetrates the split portion in the circumferential direction from one end to the other end in the circumferential direction of the split portion including the oil groove portion.

12. 12. A roller and cage assembly according to claim 11, wherein the oil groove portion becomes wider in the axial direction as it approaches the crevice in the circumferential direction.

13. 5. The roller and cage assembly according to claim 1, wherein the cage is made of synthetic resin.

14. 5. A roller and cage assembly according to claim 1, wherein the rollers are needle rollers.

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