Roller bearing

Abstract

The purpose of the present invention is to suppress temperature rise when used under the condition that an inner member having a raceway surface on the outer side rotates and an outer member having a raceway surface on the inner side is stationary, and to easily insert rollers between retaining sections of adjacent columns of a rolling-element-guided cage. In a virtual plane orthogonal to a central axis (O) of the roller (30), a contact angle (theta) formed by a first virtual straight line (L1) connecting a contact point (P) of the roller (30) and the column (41) to the central axis (O) and a second virtual straight line (L2) orthogonal to the radial direction and passing through the central axis (O) is 20-24 degrees, in the virtual plane orthogonal to the central axis (O) of the roller (30).

Description

Technical Field

[0001] The present invention relates to a roller bearing, and more particularly to a roller bearing having a rolling element guided cage. Background Art

[0002] Roller bearings usually have: an inner part having a raceway surface on the outer diameter, an outer part having a raceway surface on the inner diameter, a plurality of rollers between the inner part and the outer part, and a retainer that retains these plurality of rollers. The retainer has a plurality of columns arranged at equal intervals in the circumferential direction. The rollers are arranged between pairs of columns that are adjacent to each other in the circumferential direction. In order to prevent the rollers from falling off from between the paired columns, an anti-falling portion is formed on each column to prevent them from falling off. The retainer can move freely in the radial direction relative to the plurality of rollers within the range of the pocket gap. As a form of retainer that guides the oscillating rotation during the rotation of the bearing in the radial direction, a raceway ring-guided retainer that guides the retainer in the radial direction by contact between the raceway ring constituting the inner part or the outer part and the retainer, or a rolling element-guided retainer that guides the retainer in the radial direction by contact between the rollers and the columns is usually used.

[0003] In the case of high-speed rotating roller bearings such as those used to support the spindle of a machine tool, if a raceway-guided retainer is used, there is a concern that the contact between the raceway and the retainer will cause heat and deteriorate the lubricant discharge performance on the guide surface of the raceway and the retainer. To avoid this, a rolling element-guided retainer is used in high-speed rotating roller bearings.

[0004] In a rolling element guided retainer, the contact portion between the roller of the guide retainer and the column is located at a position closer to the inner diameter side of the retainer or the outer diameter side of the retainer than the center axis of the roller. It is known that under the use condition that the inner part of the roller bearing rotates and the outer part is stationary, if the contact portion between the roller of the guide retainer and the column is located at a position closer to the inner diameter side of the retainer than the center axis of the roller, the friction force at the contact portion between the roller and the column increases, and the heat generation increases (Patent Document 1).

[0005] In addition, it is known that the position of the contact portion between the roller and the column of the guide retainer slightly changes, and the friction force generated at the contact portion hinders the rotation of the roller, causing the roller to bite the column due to the wedge effect, thereby causing the temperature of the roller bearing to rise. As a countermeasure to prevent the occurrence of this biting phenomenon, it is proposed to set the contact angle between the roller and the column of the guide retainer to 25° or more and 35° or less (Patent Document 2).

[0006] Patent Document 1: Japanese Patent Application Publication No. 2000-274437

[0007] Patent Document 2: Japanese Patent Application Publication No. 2006-242284

[0008] However, the roller bearing disclosed in Patent Document 2 allows the rollers of the guide retainer to contact the columns at a position closer to the inner diameter side of the retainer than the center axis of the rollers. Therefore, when the inner member rotates at a high speed and the outer member is stationary, the friction force at the above-mentioned contact portion is particularly large, which is disadvantageous in that the temperature easily rises. Summary of the invention

[0009] In view of the above background, the problem to be solved by the present invention is to suppress the temperature rise when the inner part having a rolling surface on the outer side is used under the condition that the inner part having a rolling surface on the inner side is rotated and the outer part having a rolling surface on the inner side is stationary, and to facilitate the insertion of rollers between the anti-slip portions of adjacent columns of a rolling element guide type retainer.

[0010] In order to achieve the above-mentioned problem, the present invention adopts a first structure, namely: a roller bearing, which includes: an inner member having a raceway surface on the outside, an outer member having a raceway surface on the inside, a plurality of rollers interposed between the inner member and the outer member, and a rolling element guide type retainer retaining the plurality of rollers, the retainer having a plurality of columns arranged at equal intervals in the circumferential direction, the rollers being arranged between the columns adjacent to each other in the circumferential direction, the roller bearing having an anti-slip portion for preventing the rollers from escaping from between the columns toward the outer diameter side of the retainer, wherein the columns are shaped to be able to contact the rollers guiding the retainer on the anti-slip portion, and when considered in an imaginary plane orthogonal to the center axis of the roller guiding the retainer by contact with the columns, an angle formed by a first imaginary straight line connecting the contact point of the roller with the anti-slip portion of the column to the center axis of the roller and a second imaginary straight line orthogonal to a straight line passing through the radial direction of the center axis of the roller and passing through the center axis of the roller, i.e., a contact angle, is set to be not less than 20° and not more than 24°.

[0011] According to the first structure, since the column can contact the roller at the anti-slip portion located on the outer diameter side of the retainer than the center axis of the roller of the guide retainer, when the inner component having a raceway surface (raceway surface of the inner component) on the outer side is rotated and the outer component having a raceway surface (raceway surface of the outer component) on the inner side is stationary, the force acting from the roller to the column at the contact portion between the roller and the column acts in a direction that helps the rotation of the retainer. Therefore, the friction force at the contact portion between the roller and the column can be reduced to suppress the heat generation. In addition, if the contact angle at the contact portion between the roller of the guide retainer and the column is 20° or more, the seizure phenomenon can be prevented, so the temperature rise of the roller bearing can be suppressed. If the contact angle is 24° or less, the distance between the anti-slip portions of adjacent columns will not become too small compared to the diameter of the roller, and the roller can be easily inserted between the anti-slip portions of adjacent columns from the outer diameter side of the retainer.

[0012] In addition to the first structure, a second structure can be adopted, in which the distance between the inner ends of the adjacent columns located on the inner diameter side of the retainer relative to the center axis of the roller in the imaginary plane is set to be larger than the diameter of the roller. According to the second structure, compared with the case where the distance between the inner ends of the adjacent columns is smaller than the diameter of the roller, the lubricant easily passes between the roller and the adjacent columns, so that the stirring resistance can be suppressed and the temperature rise of the roller bearing can be suppressed.

[0013] In addition, based on the first structure, a third structure can be adopted, that is, the distance between the inner ends of the adjacent columns located on the inner diameter side of the retainer relative to the center axis of the roller in the imaginary plane is set to be smaller than the diameter of the roller. According to the third structure, although it is not conducive to suppressing the stirring resistance, it has the advantage of easily improving the strength of the column.

[0014] Based on any one of the first to third structures, a fourth structure can be adopted, that is, the inner member integrally includes a first flange protruding radially on one axial side relative to the raceway surface of the inner member, and a second flange protruding radially on the other axial side relative to the raceway surface of the inner member, and the retainer integrally includes a first ring continuous on one axial side of the plurality of columns, and a second ring continuous on the other axial side of the plurality of columns. According to the fourth structure, the retainer and the inner member can be respectively constituted by a single member to reduce the price, and the inner member, the retainer and the plurality of rollers can be formed as an assembly.

[0015] Based on any one of the first to fourth structures, a fifth structure can be adopted, that is, the retainer is formed by injection molding. As described above, there is an allowable angle range of 20° to 24° as a contact angle, so there is no need to perform precision management of the degree of cutting processing on the anti-detachment part of the column. Therefore, the retainer is formed as an injection molded product as in the fifth structure, so that it can be lightweight and have improved high-speed performance compared to a machined retainer, thereby suppressing the manufacturing cost of the retainer.

[0016] The present invention adopts the above-mentioned first structure, which can suppress the temperature rise when the inner member having a rolling surface on the outside rotates and the outer member having a rolling surface on the inside is stationary, and it is easy to insert the roller between the anti-separation parts of the paired columns of the rolling element guide type retainer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a cross-sectional view showing a roller bearing according to a first embodiment as an example of the present invention.

[0018] Figure 2 yes Figure 1 II sectional view.

[0019] Figure 3 It is a cross-sectional view showing a column according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0020] Based on the attached pictures Figure 1-2 A roller bearing according to a first embodiment of the present invention will be described.

[0021] Figure 1 , Figure 2 The roller bearing shown comprises: an inner component 10 having a raceway surface (raceway surface of the inner component) 11 on the outer side; an outer component 20 having a raceway surface (raceway surface of the outer component) 21 on the inner side; a plurality of rollers 30 disposed between the raceway surface 11 of the inner component 10 and the raceway surface 21 of the outer component 20; and a retainer 40 that retains these plurality of rollers 30.

[0022] here, Figure 1 : represents a cross section in a virtual plane perpendicular to the central axis of the retainer 40 and the roller 30. Figure 2 The central axes (not shown) of the inner member 10, the outer member 20, and the retainer 40 are arranged coaxially. Hereinafter, the direction along the coaxial central axis is referred to as the "axial direction", the direction perpendicular to the central axis is referred to as the "radial direction", and the direction along the circumference of the circle centered on the central axis is referred to as the "circumferential direction".

[0023] The inner member 10 is configured as a single raceway ring integrally provided with a first flange 12 and a second flange 13, the first flange 12 protruding radially on one axial side relative to the raceway surface 11 on the outer periphery of the inner member 10, and the second flange 13 protruding radially on the other axial side relative to the raceway surface 11. The outer member 20 is configured as a single raceway ring having a raceway surface 21 on its inner periphery. The inner and outer raceways 11, 21 are respectively formed into cylindrical surfaces extending in the circumferential direction. The outer member 20 does not have a portion protruding radially from the raceway surface 21 on its inner periphery, and the roller bearing becomes a separable roller bearing capable of axially separating the outer member 20 from the assembly of the inner member 10, the retainer 40, and the plurality of rollers 30.

[0024] The inner member 10 is mounted on the shaft S. The outer member 20 is mounted on the housing H which is stationary relative to the shaft S. The inner member 10 rotates integrally with the shaft S. The outer member 20 is supported in the radial direction by the housing H. The shaft S may be, for example, a spindle of a machine tool. As a lubrication method for such a roller bearing for high-speed rotation purposes, for example, oil-air lubrication, oil mist lubrication, or jet lubrication may be mentioned.

[0025] The roller 30 has a rolling surface 31 that rolls on the inner and outer raceway surfaces 11 and 21. The rolling surface 31 is formed in a cylindrical surface shape.

[0026] The retainer 40 is configured as a single annular body integrally including a plurality of columns 41 arranged at equal intervals in the circumferential direction, a first ring 42 continuous on one axial side of the plurality of columns 41, and a second ring 43 continuous on the other axial side of the plurality of columns 41. The retainer 40 as a whole has a shape having multiple rotational symmetry in the circumferential direction.

[0027] The rollers 30 are arranged between the circumferentially adjacent pairs of columns 41. The spaces, that is, pockets, which house the rollers 30 in the cage 40 are formed into a cage shape by the paired columns 41, the first ring 42, and the second ring 43.

[0028] The retainer 40 is seamlessly formed as a whole by injection molding. A synthetic resin is used as a material for forming the retainer 40. Here, the synthetic resin refers to a composition having a polymer such as polyamide (PA), polyetheretherketone (PEEK), polyphenylene sulfide (PPS) as a main component, and may also contain appropriate secondary components such as glass fiber, carbon fiber, and a modifier.

[0029] like Figure 2 As shown in FIG. 1 , the paired columns 41 have anti-detachment portions 44 for preventing the rollers 30 from detaching from each other between the paired columns 41 toward the outer diameter side of the cage. The anti-detachment portions 44 are located on the outer diameter side of the cage relative to the imaginary cylinder surface C including the center axis O of the plurality of rollers 30 in the columns 41. The distance Lo between the anti-detachment portions 44 of the paired columns 41 is smaller than the diameter Dw of the roller 30.

[0030] Here, the outer diameter side of the retainer refers to, in an imaginary plane orthogonal to the center axis of the retainer 40, when considering an imaginary circle (circumscribed circle) coaxial with the retainer 40 and circumscribed to the retainer 40 and an imaginary circle (inscribed circle) coaxial with the retainer 40 and inscribed in the retainer 40, the side radially closer to the circumscribed circle, and conversely, the side radially closer to the inscribed circle is called the inner diameter side of the retainer.

[0031] The retaining portion 44 has a curved pocket surface 44a that can contact the roller 30 in the circumferential and radial directions, and an end surface 44b that is farther from the roller 30 in the circumferential direction than an end e on the cage outer diameter side of the pocket surface 44a.

[0032] The column 41 has a pair of anti-slip portions 44 on both sides in the circumferential direction, and the pair of anti-slip portions 44 are formed in a symmetrical arrangement in the circumferential direction with respect to a radial section passing through the circumferential center of each column 41. During the injection molding of the retainer 40, the mold for molding the surface portions of the paired columns 41 that are opposed to each other in the circumferential direction is forcibly pulled out from between the paired columns 41 toward the outer diameter side of the retainer.

[0033] The roller 30 is pressed into between the anti-separation portions 44 of the paired posts 41 from the outer diameter side of the retainer, and is forcibly passed between the anti-separation portions 44, thereby being inserted between the two flanges 12 and 13 of the inner member 10. By inserting a plurality of rollers 30 between different pairs of posts 41 as described above, the inner member 10, the retainer 40, and the plurality of rollers 30 are assembled into an assembly.

[0034] The end surface 44b of the column 41 extends from the end e of the pocket surface 44a on the outer diameter side of the cage in a flat surface shape, and further extends from the flat surface in a tapered surface shape. The tapered surface portion of the end surface 44b is used to facilitate pressing the roller 30 from the outer diameter side of the cage between the anti-slip portions 44 of the paired columns 41.

[0035] In addition, the column 41 has a groove 45 extending in the axial direction between the anti-slip portions 44 on both sides of the circumferential direction. The groove 45 is open to the outer circumference of the retainer 40, and the groove bottom is located at a position closer to the inner diameter side of the retainer than the end e on the outer diameter side of the pocket surface 44a. The groove 45 is also used to facilitate the roller 30 to be pressed between the anti-slip portions 44 of the paired column 41 from the outer diameter side of the retainer. The groove bottom of the groove 45 may also be located at a position closer to the outer diameter side of the retainer than the end e on the outer diameter side of the pocket surface 44a.

[0036] In addition, the outer end portion of the anti-slip portion 44 having the end surface 44b is formed into a protruding portion that is axially away from the first ring 42 and the second ring 43. The axial interruption between the outer end portion of the anti-slip portion 44 and the two rings 42 and 43 is also used to facilitate the press-fitting of the roller 30 between the anti-slip portions 44 of the paired posts 41 from the outer diameter side of the cage.

[0037] Pocket gaps are set between the paired posts 41, the first ring 42, the second ring 43, and the rollers 30. The cage 40 is movable in the radial direction relative to the plurality of rollers 30 within the range of the pocket gaps set between the paired posts 41 and the rollers 30.

[0038] The retainer 40 is a rolling element guided type guided in the radial direction by the rollers 30. That is, the radial clearance between the retainer 40 and the inner member 10 and the radial clearance between the retainer 40 and the outer member 20 are set to be larger than the free radial movement amount of the retainer 40 based on the above-mentioned pocket clearance. When the retainer 40 moves in the radial direction relative to the inner member 10 and the outer member 20, the retainer 40 is guided in the radial direction by the contact between the rolling surface 31 of the roller 30 and the anti-separation portion 44 of the column 41 at the stage before the retainer 40 contacts the inner member 10 or the outer member 20 in the radial direction.

[0039] here, Figure 2It shows that during the rotation of the inner component 10, the retainer 40 moves to the maximum extent in the radial direction, the central axis O of the roller 30 in the center of the figure is located at a position 180° opposite to the moving direction A of the retainer 40 in the circumferential direction, and the roller 30 that contacts the anti-slip portion 44 of the column 41 in the moving direction A guides the retainer 40.

[0040] The distance Li between the inner ends 46 of the paired columns 41, which are located on the inner diameter side of the retainer with respect to the center axis O of the roller 30 in a virtual plane orthogonal to the center axis O of the roller 30, is set to be larger than the diameter Dw of the roller 30. The gap between the roller 30 and the inner end 46 of the column 41 is larger than the pocket gap defined between the roller 30 and the pocket surface 44a. That is, the column 41 is shaped so as to be able to contact the roller 30 of the guide retainer 40 on the pocket surface 44a of the anti-detachment portion 44.

[0041] During the rotation of the inner member 10, within the load circle of the roller bearing, the contact portion between the roller 30 of the driving retainer 40 and the anti-slip portion 44 of the column 41 is located at a position closer to the outer diameter side of the retainer than the center axis O of the roller 30. Therefore, the force acting on the retainer 40 from the driven roller 30 acts to press the roller 30 (non-driven roller 30) of the non-driven retainer 40 against the raceway surface 11, rather than pressing against the stationary raceway surface 21. The non-driven roller 30 actively starts to rotate by being pressed against the raceway surface 11. Alternatively, even if the rotation of the non-driven roller 30 is braked by being pressed against the raceway surface 11, it is intended to revolve together with the rotating raceway surface 11 (at a speed of about twice that of normal rolling). In any case, the friction force at the contact portion between the non-driven roller 30 and the anti-slip portion 44 of the column 41 acts in a direction that helps the rotation of the retainer 40.

[0042] In addition, when the rollers of the guide retainer are in contact with the column on the inner diameter side of the retainer relative to the center axis of the rollers, the force applied from the rollers of the driving retainer to the column acts to press the non-driven rollers against the raceway surface of the stationary outer member. Therefore, the rotation of the non-driven rollers is strongly braked, and the braking force in the opposite direction to the rotation of the retainer is applied from the non-driven rollers to the column, resulting in an increase in the friction force at the contact portion between the rollers and the column.

[0043] Considering an imaginary plane that is orthogonal to the center axis O of the roller 30 that guides the retainer 40 through contact with the anti-slip portion 44 of the column 41, the angle formed by the first imaginary straight line L1 connecting the contact point P between the roller 30 and the anti-slip portion 44 of the column 41 to the center axis O of the roller 30 and the second imaginary straight line L2 that is orthogonal to the radial direction and passes through the center axis O of the roller 30, that is, the contact angle θ, is set within a specified angle range.

[0044] The larger the contact angle θ is, the smaller the friction force generated at the contact point P is, and the smaller the contact angle θ is, the larger the friction force generated at the contact point P is. Therefore, the smaller the contact angle θ is set, the greater the friction force generated at the contact point P is, which hinders the rotation of the roller 30, and easily causes the roller 30 to bite the pocket surface 44a of the column 41. Therefore, the minimum value of the contact angle θ is set to 20°. As a result, the friction force generated at the contact point P will not become too large, and it is not easy to hinder the rotation of the roller 30, so the biting phenomenon can be prevented.

[0045] In addition, when the inner member 10 rotates and the roller 30 rotates and revolves between the inner and outer raceways 11 and 21, the lubrication mode at the contact portion between the roller 30 and the anti-slip portion 44 of the column 41 becomes a mixed lubrication state (friction coefficient 0.005-0.1) or a fluid lubrication state (friction coefficient 0.001-0.005). In the case of a particularly thin lubrication environment in high-speed rotation applications, there is a possibility that the oil supply to the contact portion is insufficient, and the lubrication mode becomes a boundary lubrication state (friction coefficient 0.1-0.3), so that the friction force in the contact portion in the boundary lubrication state is particularly large and it is easy to cause a biting phenomenon. Therefore, if the minimum value of the contact angle θ is pre-set in such a way that the rotation of the roller 30 will not stop due to the friction force at the contact portion when in the boundary lubrication state (friction coefficient 0.3), the biting phenomenon can be effectively prevented.

[0046] On the other hand, if the maximum value of the contact angle θ is set too large, the distance Lo between the anti-slip portions 44 of the paired posts 41 becomes too small compared to the diameter Dw of the roller 30, so that it becomes very difficult to carry out the process of forcibly inserting the roller 30 between the anti-slip portions 44 of the paired posts 41 from the outer diameter side of the retainer as described above. Therefore, the maximum value of the contact angle θ is set to 24°. As a result, the distance Lo between the anti-slip portions 44 of the paired posts 41 does not become too small, and the process of inserting the roller 30 between the anti-slip portions 44 of the paired posts 41 from the outer diameter side of the retainer can be facilitated to the extent that the process of inserting the roller 30 between the anti-slip portions 44 of the paired posts 41 from the outer diameter side of the retainer can be carried out realistically.

[0047] Furthermore, the position of the contact point P when the contact angle θ is 24° is preferably set at the end e on the cage outer diameter side of the pocket surface 44a of the column 41 (the inflection point that becomes the boundary between the pocket surface 44a and the end surface 44b). In this way, compared with the case where the end surface 44b of the column 41 is omitted and the pocket surface 44a is extended toward the cage outer diameter side, the distance Lo between the anti-slip portions 44 of the paired columns 41 is made relatively large and the end surface 44b is formed, which facilitates the insertion of the roller 30 between the anti-slip portions 44 of the paired columns 41.

[0048] As mentioned above, Figure 1 , Figure 2The roller bearing shown comprises: an inner component 10 having a raceway surface 11 on the outer side, an outer component 20 having a raceway surface 21 on the inner side, a plurality of rollers 30 between the inner component 10 and the outer component 20, and a rolling element guided retainer 40 for retaining the plurality of rollers 30, wherein the retainer 40 has a plurality of columns 41 arranged at equal intervals in the circumferential direction, the rollers 30 are arranged between circumferentially adjacent columns 41 (pairs of columns 41), and the retainer 40 has an anti-detachment portion 44 for preventing the rollers 30 from detaching from between the adjacent columns 41 toward the outer diameter side of the retainer.

[0049] In particular, the roller bearing is constructed so that the column 41 is shaped so as to be able to contact the roller 30 of the guide retainer 40 on the anti-slip portion 44. Therefore, when it is used under the condition that the inner component 10 rotates and the outer component 20 is stationary, the force acting from the roller 30 on the column 41 at the contact portion between the roller 30 and the column 41 acts in a direction that helps the rotation of the retainer 40. Therefore, compared with the case where the retainer is guided on the inner diameter side of the retainer relative to the center axis of the roller, the friction force at the contact portion between the roller 30 and the column 41 can be relatively small, thereby suppressing the heat generation.

[0050] In addition, the roller bearing is constructed so that, considered in an imaginary plane orthogonal to the center axis O of the roller 30 that guides the retainer 40 by contact with the column 41, the angle formed by the first imaginary straight line L1 connecting the contact point P between the roller 30 and the column 41 to the center axis O of the roller 30 and the second imaginary straight line L2 orthogonal to the radial direction and passing through the center axis O of the roller 30, that is, the contact angle θ is set to be greater than 20°, thereby preventing the roller 30 from biting the anti-slip portion 44. From this point of view, it is also possible to suppress the temperature increase of the roller bearing when it is used under the condition that the inner component 10 rotates and the outer component 20 is stationary.

[0051] In addition, the roller bearing is constructed so that the contact angle θ is set to be less than 24°, so that the distance Lo between the anti-slip portions 44 of adjacent columns 41 (paired columns 41) does not become too small compared to the diameter Dw of the roller 30, so the roller 30 can be easily inserted from the outer diameter side of the retainer between the anti-slip portions 44 of adjacent columns 41 (paired columns 41).

[0052] In this way, the roller bearing can suppress the temperature increase when it is used under the condition that the inner part 10 having the rolling surface 11 on the outside rotates and the outer part 20 having the rolling surface 21 on the inside is stationary, and it is easy to insert the roller 30 between the anti-slip portions 44 of adjacent columns 41 (paired columns 41) of the rolling element guide type retainer 40.

[0053] In addition, the roller bearing is constructed so that the distance Li between the inner end portions 46 of adjacent columns 41 (paired columns 41) located on the inner diameter side of the retainer relative to the center axis O of the roller 30 in the above-mentioned imaginary plane is set to be larger than the diameter Dw of the roller 30. As a result, compared with a case where the distance Li is smaller than the diameter Dw of the roller 30, during the rotation of the bearing, the lubricant easily passes through the rolling surface 31 of the roller 30 and the adjacent columns 41 (paired columns 41) from the inner diameter side of the retainer to the outer diameter side of the retainer, thereby suppressing the stirring resistance and suppressing the temperature rise of the roller bearing.

[0054] In addition, the roller bearing is constructed such that the inner component 10 integrally has a first flange 12 that radially protrudes on one axial side relative to the raceway surface 11, and a second flange 13 that radially protrudes on the other axial side relative to the raceway surface 11, and the retainer 40 integrally has a first ring 42 that is continuous on one axial side of the plurality of columns 41, and a second ring 43 that is continuous on the other axial side of the plurality of columns 41. As a result, compared with a case where the ring and the flange are constructed as separate components in order to eliminate the press-fitting process of the rollers 30, the retainer 40 and the inner component 10 can be respectively constructed of single components, thereby reducing the price, and the inner component 10, the retainer 40 and the plurality of rollers 30 can be formed as an assembly.

[0055] In addition, the roller bearing is configured such that the cage 40 is formed by injection molding of a synthetic resin, thereby being lighter than a machined cage, improving high-speed performance, and also being able to suppress the manufacturing cost of the cage.

[0056] Figure 3 A second embodiment of the present invention is shown. In the following, only the differences from the first embodiment are described.

[0057] The column 50 of the second embodiment is extended toward the inner diameter side of the cage compared with the first embodiment, and the distance Li between the inner end portions 51 of the circumferentially adjacent columns 50 located on the inner diameter side of the cage than the center axis O in the virtual plane orthogonal to the center axis O of the roller 30 is set to be smaller than the diameter of the roller 30. The roller 30 cannot contact the inner end portion 51 of the column 50 as in the first embodiment, but the distance Li between the inner end portion 51 of the column 50 and the roller 30 is narrower than that in the first embodiment, so that during the rotation of the roller bearing, it is relatively difficult for the lubricant to pass from the inner diameter side of the cage to the outer diameter side of the cage between the roller 30 and the adjacent columns 50. Therefore, although the roller bearing of the second embodiment is not advantageous in suppressing the stirring resistance of the lubricant, it has the advantage that the cross-sectional area of ​​the column 50 is increased and the strength of the column 50 is easily improved.

[0058] The embodiments disclosed herein are illustrative in all aspects and should not be considered restrictive. Therefore, the scope of the present invention is indicated by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included.

[0059] Description of Reference Numerals

[0060] 10…inner component; 11…raceway surface (raceway surface of the inner component); 12…first flange; 13…second flange; 20…outer component; 21…raceway surface (raceway surface of the outer component); 30…roller; 40…retainer; 41, 50…columns; 42…first ring; 43…second ring; 44…anti-slip portion; 46, 51…inner end portions.

Claims

1. A roller bearing comprising: an inner member having a raceway surface on the outer side, an outer member having a raceway surface on the inner side, a plurality of rollers interposed between the inner member and the outer member, and a rolling element guide type retainer retaining the plurality of rollers, The retainer has a plurality of columns arranged at equal intervals in the circumferential direction, the rollers are arranged between the columns adjacent to each other in the circumferential direction, and the roller bearing has a disengagement prevention portion for preventing the rollers from disengaging from between the columns toward the outer diameter side of the retainer. The roller bearing is characterized in that: The column is shaped so as to be able to contact the roller guiding the retainer on the anti-detachment portion. Considered within an imaginary plane orthogonal to the center axis of the roller that guides the retainer by contacting the column, an angle formed by a first imaginary straight line connecting the contact point of the roller with the anti-slip portion of the column to the center axis of the roller and a second imaginary straight line that is orthogonal to a radial straight line passing through the center axis of the roller and passing through the center axis of the roller, i.e., a contact angle, is set to be greater than 20° and less than 24°.

2. The roller bearing according to claim 1, characterized in that: The distance between the inner end portions of the adjacent columns, which are located on the inner diameter side of the cage with respect to the central axis of the roller in the imaginary plane, is set larger than the diameter of the roller.

3. The roller bearing according to claim 1, characterized in that: The distance between the inner end portions of the adjacent columns, which are located on the inner diameter side of the cage with respect to the center axis of the roller in the imaginary plane, is set smaller than the diameter of the roller.

4. The roller bearing according to any one of claims 1 to 3, characterized in that: The inner member integrally includes a first flange protruding radially on one axial side relative to the raceway surface of the inner member, and a second flange protruding radially on the other axial side relative to the raceway surface of the inner member. The retainer integrally includes a first ring that is continuous on one side in the axial direction of the plurality of columns, and a second ring that is continuous on the other side in the axial direction of the plurality of columns.

5. The roller bearing according to any one of claims 1 to 4, characterized in that: The holder is formed by injection molding.

Images