Roller with cage

Abstract

To provide a roller with a cage which can improve durability by preventing the application of an excessively-large external force to the cage caused by a centrifugal force or the like.SOLUTION: A roller with a cage comprises: a cage 4 having a pair of circular ring parts 2 and a plurality of column parts 3; and a plurality of rollers 5, wherein each of the column parts 3 has: a pair of outside-diameter side column parts 6 connected to the circular ring parts 2 and extending toward the inside in an axial direction; a pair of inclined column parts 7 connected to inside end parts of the outside-diameter side column parts 6 and extending toward the inside in the axial direction while being inclined toward the inside in a radial direction; and an inside-diameter side column part 8 for connecting inside end parts of the pair of inclined column parts 7. Circumferential widths of the inclined column parts 7 are narrower than circumferential widths of the outside-diameter side column parts 6 and the inside-diameter side column part 8, and in a state that the cage 4 and the plurality of rollers 5 are rotated, the rollers 5 contact with both the outside-diameter side column parts 6 and the inside-diameter side column part 8 when outside diameters of the rollers 5 become flush with outside diameters of the circular ring parts 2, and the rollers 5 contact with only the outside-diameter side column parts 6 when the outside diameters of the rollers 5 protrude from the outside diameters of the circular ring parts 2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a roller and cage assembly. [Background technology]

[0002] Bearings that are subject to high acceleration due to revolving while rotating, such as planetary gears in automatic transmissions in automobiles and connecting rods in internal combustion engines, are subject to large centrifugal forces acting on their cages, which requires particularly high strength and lubrication.

[0003] For example, in the following Patent Document 1, a so-called M-type retainer is described in which the column sections connected to a pair of annular sections arranged side by side in the axial direction are composed of an outer diameter side column section, an inclined column section, and an inner diameter side column section. A recess is formed near the outer diameter corresponding to the roller pitch circle of the inner diameter side column section to prevent contact between the rollers and the inner diameter side column section, thereby preventing excessive external forces from acting on the retainer from the rollers (see paragraphs 0030-0034 and figures 1-5 of Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4581542 Summary of the Invention [Problem to be solved by the invention]

[0005] In the configuration disclosed in Patent Document 1, the rollers and the inner diameter side column are structured not to come into contact with each other on the roller pitch circle, but in reality, there are gaps between the cage and the outer ring (gear inner diameter) and the shaft, and the cage can move by the amount of this gap. For this reason, even if the rollers and the inner diameter side column are structured not to come into contact with each other only on the roller pitch circle, the strength is insufficient.

[0006] For example, in a structure such as a planetary reducer where there is a large runout caused by the rotation of the bearing and the revolution of the planetary mechanism, the load area and the direction of the centrifugal force change over time, so the relationship between the rollers and the cage does not always remain on the pitch circle. Also, the centrifugal force is at its maximum in the part perpendicular to the direction in which the centrifugal force is generated, and when the cage moves in the direction in which this centrifugal force acts and comes into contact with the inner diameter of the gear, causing the cage to deform elliptically, the inner diameter side column moves radially outward from the roller pitch circle, and there is a risk of the inner claw rollers formed on the inner diameter side column coming into contact.

[0007] In addition, in the configuration of Patent Document 1, the rollers are guided by the outer diameter side column portion and the inclined column portion, but with this shape, contact between the rollers and the inclined column portion can block the oil passage, which may deteriorate lubrication.

[0008] In addition, the cage according to Patent Document 1 is formed with a recess so that the rollers do not come into contact with the inner diameter side column portion, but this recess is formed by a fracture surface caused by punching from the inner diameter side. This forming method has high productivity, but it is difficult to control the shape of the fracture surface, and there is a risk that the desired recess amount cannot be secured. In particular, there may be a difference in the recess shape after forming between a new die and the die before replacement.

[0009] Therefore, an object of the present invention is to provide a roller and cage that can prevent excessive external forces from acting on the cage when the relative position of the cage and roller changes due to centrifugal force or the like, thereby improving its durability. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention provides: a cage including a pair of annular portions arranged side by side in an axial direction and a plurality of pillar portions connecting the pair of annular portions to each other in an axial direction; a plurality of rollers held between adjacent column portions in the circumferential direction; the column portion has a pair of outer diameter side column portions connected to the annular portion and extending axially inward, a pair of inclined column portions connected to inner ends of the outer diameter side column portions and extending axially inward while inclining radially inward, and an inner diameter side column portion connecting the inner ends of the pair of inclined column portions, the circumferential width of the inclined column portions being narrower than the circumferential widths of the outer diameter side column portions and the inner diameter side column portions, and in a state in which the cage and the plurality of rollers are rotating, when the outer diameter of the rollers is flush with the outer diameter of the annular portion, the rollers contact both the outer diameter side column portions and the inner diameter side column portions, while when the outer diameter of the rollers protrudes from the outer diameter of the annular portion, the rollers contact only the outer diameter side column portions.

[0011] In this way, when the outer diameter of the roller is flush with the outer diameter of the annular portion, the roller is supported by both the outer diameter side column portion and the inner diameter side column portion, so that even if a large load is applied, the load is distributed to both columns, improving the durability of the cage. Also, when the outer diameter of the roller protrudes from the outer diameter of the annular portion, the contact portion with the roller comes into contact only with the outer diameter side column portion close to the annular portion, and the moment load between the annular portion and the contact portion can be reduced, so that the durability of the cage can be improved in the same manner as above.

[0012] In the above configuration, it is preferable that an inclined surface is formed on the outer diameter side of the inner diameter side column part, the inclined surface having a radial width of 1% to 50% of the radial width of the inner diameter side column part, and the circumferential width of the inner diameter side column part is reduced from the inner diameter side to the outer diameter side. In this way, the inner claws and rollers formed on the inner diameter side column part are less likely to come into contact with each other compared to a case where the inclined surface is not formed, and the need to displace the inner diameter side column part to the inner diameter side to prevent this contact is reduced. If the radial width is narrower than 1%, the effect of the inclined surface cannot be obtained, and if it is wider than 50%, there is a possibility that a contact state between the inner diameter side column part and the rollers will be impaired when the outer diameter of the annular part and the outer diameter of the rollers become flush with each other, so it is preferable to keep the radial width within the above range.

[0013] In all of the above configurations, a recess may be formed in the axial center of the inner diameter side column portion, the recess having a smaller circumferential width than both sides thereof. In this way, the contact position between the inner diameter side column portion and the rollers is displaced from the entire axial direction of the inner diameter side column portion to both axial sides closer to the annular portion, thereby alleviating the moment load when the rollers come into contact with the inner diameter side column portion, and improving the durability of the cage in the same manner as above.

[0014] In all of the above configurations, the inclination angle of the inclined column portion relative to the axial direction as viewed from the circumferential direction may be within a range of 45 degrees or more and 70 degrees or less. In this way, the contact portion between the inner diameter side column portion and the rollers is located closer to the axial outer side of the inner diameter side column portion, and the moment load between the annular portion and the contact portion can be reduced, thereby improving the durability of the cage as described above. If the inclination angle is less than 45 degrees, the axial distance between the annular portion and the contact portion becomes large, which tends to increase the moment load, and if it exceeds 70 degrees, there is a possibility that the support of the rollers becomes unstable, so it is preferable to keep it within the above range. Effect of the Invention

[0015] In this invention, the column portions of the retainer are composed of an outer diameter side column portion, an inclined column portion, and an inner diameter side column portion, and when the outer diameter of the roller is flush with the outer diameter of the annular portion, the roller comes into contact with both the outer diameter side column portion and the inner diameter side column portion, distributing the load to both columns, while when the outer diameter of the roller protrudes from the outer diameter of the annular portion, the roller comes into contact only with the outer diameter side column portion, thereby reducing the moment load between the contact portion of the annular portion and the roller. As a result, it is possible to provide a roller with a retainer with improved durability of the retainer. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a cross-sectional view showing a main portion of one embodiment of a roller and cage assembly according to the present invention; [Diagram 2] Cross-sectional view taken along line II-II in Figure 1. [Diagram 3] Cross-sectional view taken along line III-III in Figure 1. [Figure 4]2 is a cross-sectional view of the main part of the roller and cage assembly shown in FIG. 1, in which (a) shows a state in which the outer diameter of the annular portion and the outer diameter of the rollers are flush with each other, and (b) shows a state in which the outer diameter of the rollers protrudes from the outer diameter of the annular portion. [Diagram 5] 2A and 2B are cross-sectional views of the main part of the first modified example of the roller and cage assembly shown in FIG. 1, in which (a) shows a state in which the outer diameter of the annular portion and the outer diameter of the rollers are flush with each other, and (b) shows a state in which the outer diameter of the rollers protrudes from the outer diameter of the annular portion. [Figure 6] FIG. 2 is a view showing a main part of a second modified example of the roller and cage assembly shown in FIG. 1 as seen from the radially outer side. [Figure 7] Cross-sectional view taken along line VII-VII in Figure 6. [Figure 8] FIG. 7 is a cross-sectional view showing a variation of the second modified example shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] One embodiment of a roller and cage assembly 1 according to the present invention will be described with reference to Figures 1 to 4(a) and (b). In the following description, the direction along the rotation axis of the roller and cage assembly 1 will be referred to as the axial direction, the direction perpendicular to the rotation axis will be referred to as the radial direction, and the direction along a circular arc centered on the rotation axis will be referred to as the circumferential direction.

[0018] 1 and 2, this roller and cage assembly 1 comprises a cage 4 having a pair of annular portions 2 arranged side by side in the axial direction and a number of bar portions 3 axially connecting the pair of annular portions 2, and a number of rollers 5 held between circumferentially adjacent bar portions 3. Note that in each of the drawings shown below, the rollers 5 are drawn with imaginary dot-dash lines to make the shape of the cage 4 that holds the rollers 5 easier to see.

[0019] As shown in Fig. 3, the cage 4 is a so-called M-shaped cage in which the annular portion 2 and the column portion 3 form an M shape when viewed in the circumferential direction, and its outer diameter surface is guided by, for example, the inner surface of a gear (not shown) of a planetary mechanism, and a shaft (not shown) is provided on the inner diameter side of the cage 4. The column portion 3 has a pair of outer diameter side column portions 6 that are connected to the outer peripheral edges of the pair of annular portions 2 and extend axially inward, a pair of inclined column portions 7 that are connected to the inner ends of the outer diameter side column portions 6 and extend axially inward while inclining radially inward, and an inner diameter side column portion 8 that connects the inner ends of the pair of inclined column portions 7 to each other. As shown in Fig. 2 and other figures, the circumferential width of the inclined column portions 7 is narrower than the circumferential widths of the outer diameter side column portions 6 and the inner diameter side column portions 8.

[0020] An inclined surface 9 is formed on the inner diameter side end of the outer diameter side column portion 6, which reduces the circumferential width of the outer diameter side column portion 6 toward the inner diameter side, and this inclined surface 9 functions as an outer claw (hereinafter, appropriately given the same reference number as the inclined surface 9) that comes into contact with the roller 5. In addition, the outer diameter side end of the inner diameter side column portion 8 is an edge 10, and this edge 10 functions as an inner claw (hereinafter, appropriately given the same reference number as the edge 10) that can come into contact with the roller 5.

[0021] For example, when the planetary mechanism rotates, the cage 4 of the caged roller 1 provided in the planetary mechanism revolves around the sun gear while rotating around a shaft provided on the inner diameter side of the cage 4, and is deformed into an elliptical shape by the centrifugal force accompanying the revolution. At this time, the radial positional relationship between the cage 4 and the rollers 5 changes over time. For example, when the cage 4 is displaced to the outer diameter side and pressed against the inner surface of the gear of the planetary mechanism, the outer diameter of the rollers 5 becomes flush with the outer diameter of the annular portion 2, and as shown in FIG. 4(a), the rollers 5 are in contact with both the outer claws 9 of the outer diameter side column portion 6 and the inner claws 10 of the inner diameter side column portion 8 on one side in the circumferential direction. Also, when the cage 4 is displaced to the inner diameter side and separated from the inner surface of the gear of the planetary mechanism, the outer diameter of the rollers 5 protrudes from the outer diameter of the annular portion 2, and as shown in FIG. 4(b), the rollers 5 are in contact with only the outer claws 9 of the outer diameter side column portion 6 on one side in the circumferential direction.

[0022] The contact state between the rollers 5 and the inner claws 10 of the inner diameter side column portion 8 is related to the radial position of the inner diameter side column portion 8, and by displacing the inner diameter side column portion 8 toward the inner diameter side within a range that does not affect the guidance method of the retainer 4 (in this embodiment, the outer diameter surface of the retainer 4 is guided by the inner surface of the gear, etc.), the contact state between the rollers 5 and the inner claws 10 can be adjusted to be less susceptible to contact.

[0023] 3, the inclination angle α of the inclined column portion 7 with respect to the axial direction as viewed from the circumferential direction is approximately 60 degrees. This inclination angle α can be determined appropriately, but is preferably within the range of 45 degrees or more and 70 degrees or less.

[0024] The cage 4 can be manufactured inexpensively by punching pockets for accommodating the rollers 5 into cold-rolled steel plate such as JIS-SPC, JIS-S15C, JIS-SCM415, or JIS-SCM420, cutting it to a predetermined length, and welding the ends while bending it into an annular shape. Alternatively, the cold-rolled steel plate can be subjected to press drawing to form an annular ring, and then the pockets can be punched. Furthermore, an annular ring can be formed by turning, and then the pockets can be punched.

[0025] In the above-mentioned roller and cage assembly 1, when the outer diameter of the roller 5 and the outer diameter of the annular portion 2 are flush with each other, the roller 5 is in contact with both the outer claw 9 of the outer diameter side column portion 6 and the inner claw 10 of the inner diameter side column portion 8, so that the roller 5 is supported by both the outer diameter side column portion 6 and the inner diameter side column portion 8. Therefore, even if a large load is applied, the load is dispersed to both column portions 6, 8. In addition, when the outer diameter of the roller 5 protrudes from the outer diameter of the annular portion 2, the roller 5 is in contact only with the outer claw 9 of the outer diameter side column portion 6, so that the contact portion with the roller 5 is in contact only with the outer diameter side column portion 6 close to the annular portion 2, and the moment load between the annular portion 2 and the contact portion can be reduced. Therefore, the durability of the cage 4 can be improved in all cases.

[0026] Furthermore, in the roller and cage assembly 1 described above, the circumferential width of the inclined column portions 7 is made narrower than the circumferential width of the outer diameter side column portions 6 and the inner diameter side column portions 8, so a gap is reliably secured between the rollers 5, which contact the outer diameter side column portions 6 and the inner diameter side column portions 8, and the inclined column portions 7. This makes it possible to ensure good lubrication inside the cage 4 and prevent wear of the inclined column portions 7.

[0027] Furthermore, in the roller and cage assembly 1 described above, the inclination angle α of the inclined column portion 7 with respect to the axial direction as viewed from the circumferential direction is set to approximately 60 degrees, which is within the range of 45 degrees or more and 70 degrees or less, so that the contact portion between the inner diameter side column portion 8 and the rollers 5 is closer to the axial outer side of the inner diameter side column portion 8, and the moment load between the annular portion 2 and the contact portion is reduced. This makes it possible to improve the durability of the cage 4.

[0028] A first modified example of the roller and cage assembly 1 described above is shown in Figures 5(a) and (b). The cage 4 according to the first modified example has a basic configuration in common with the configuration shown in Figures 4(a) and (b), but differs in that an inclined surface 11 is formed on the inner diameter side column portion 8, which reduces the circumferential width of the inner diameter side column portion 8 from the inner diameter side toward the outer diameter side, and this inclined surface 11 functions as the inner claw 10 described above. In this first modified example, the inclined surface 11 has a radial width t that is approximately 40% of the radial width T of the inner diameter side column portion 8. This radial width t can be determined as appropriate, but is preferably within a range of 1% to 50% of the radial width T of the inner diameter side column portion 8.

[0029] It is preferable to form this inclined surface 11 by surface pressing using a die. By using a die, the shape of the inclined surface 11 can be formed with high precision. When the angle β of the inclined surface 11 with respect to the radial direction is set to 30 degrees, this is favorable in terms of manufacturing such as processability, and in terms of functionality such as the contact state between the roller 5 and the inclined surface 11.

[0030] Furthermore, since the roller and cage assembly 1 of the first modified example has an inclined surface 11 formed on the inner diameter side column portion 8, it is possible to reduce contact between the roller 5 and the inner diameter side column portion 8 without lowering the inner diameter side column portion 8 toward the inner diameter side.

[0031] A second modified example of the roller and cage assembly 1 described above is shown in Figs. 6 to 8. The cage 4 according to the second modified example has a basic structure in common with the structure shown in Figs. 4(a) and (b), but differs in that a recess 12 having a smaller circumferential width than those on either side is formed in the axial center of the inner diameter side column portion 8. Also, the inclination angle α1 of the cage 4 shown in Fig. 7 with respect to the axial direction of the inclined column portion 7 as viewed from the circumferential direction is approximately 60 degrees, and the inclination angle α2 of the cage 4 shown in Fig. 8 is approximately 45 degrees. When the inclination angle α1 is approximately 60 degrees, the rise of the inclined column portion 7 as viewed from the circumferential direction becomes steeper compared to when the inclination angle α2 is approximately 45 degrees, and the inter-claw distance a between the outer diameter side column portion 6 and the inner diameter side column portion 8 when the inclination angle α1 is approximately 60 degrees is shorter than the inter-claw distance b when the inclination angle α2 is approximately 45 degrees (a <b)。

[0032] In the roller and cage assembly 1 according to the second modification, a recess 12 is formed in the axial center of the inner diameter side column portion 8, so that the contact position of the inner diameter side column portion 8 and the roller 5 is displaced from the entire axial length of the inner diameter side column portion 8 to both sides in the axial direction closer to the annular portion 2. This reduces the moment load when the roller 5 contacts the inner diameter side column portion 8, and improves the durability of the cage 4. In addition, since the inclination angle α (α1, α2) of the inclined column portion 7 is set to 60 degrees or 45 degrees, the contact portion of the inner diameter side column portion 8 and the roller 5 is located closer to the axial outer side of the inner diameter side column portion 8, and the moment load between the annular portion 2 and the contact portion can be further reduced, and the effect of improving the durability of the cage 4 can be further enhanced. This inclination angle α can be appropriately changed, preferably within a range of 45 degrees to 70 degrees, taking into consideration the moment load acting on the cage 4, etc.

[0033] The roller and cage assembly 1 described above can be assembled alone into a housing, but can also be applied to various roller bearings such as drawn cup needle roller bearings.

[0034] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0035] 2 Circular ring 3 Pillar part 4 Cage 5. Around 6 Outer diameter side pillar part 7 Slanted column 8 Inner diameter side column 11 Slope 12 Recess T (radial width of inner diameter side column) t (radial width of inclined surface) α (angle of inclination of inclined column)

Claims

1. A cage (4) having a pair of annular portions (2) arranged side by side in the axial direction and a plurality of pillar portions (3) connecting the pair of annular portions (2) to each other in the axial direction; a plurality of rollers (5) held between adjacent column portions (3) in the circumferential direction; the column portion (3) has a pair of outer diameter side column portions (6) connected to the annular portion (2) and extending axially inward, a pair of inclined column portions (7) connected to inner ends of the outer diameter side column portions (6) and extending axially inward while inclining radially inward, and an inner diameter side column portion (8) connecting inner ends of the pair of inclined column portions (7) to each other, and the circumferential width of the inclined column portions (7) is the circumferential width of the outer diameter side column portions (6) and the inner diameter side column portion (8). and when the outer diameter of the roller (5) is flush with the outer diameter of the annular portion (2) while the cage (4) and the plurality of rollers (5) are rotating, the roller (5) comes into contact with both the outer diameter side column portion (6) and the inner diameter side column portion (8), while when the outer diameter of the roller (5) protrudes from the outer diameter of the annular portion (2), the roller (5) comes into contact only with the outer diameter side column portion (6).

2. 2. The roller and cage assembly according to claim 1, wherein an inclined surface (11) is formed on the outer diameter side of the inner diameter side column portion (8) having a radial width (t) of 1% to 50% of the radial width (T) of the inner diameter side column portion (8), the circumferential width of the inner diameter side column portion (8) becoming smaller as it goes from the inner diameter side to the outer diameter side.

3. 3. The roller and cage assembly according to claim 1, wherein a recess (12) having a smaller circumferential width than both sides thereof is formed in the axial center of the inner diameter side column portion (8).

4. 3. The roller and cage assembly according to claim 1, wherein an inclination angle (α) of the inclined column portion (7) relative to the axial direction as viewed in the circumferential direction is within a range of 45 degrees to 70 degrees.

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