RADIAL / -AXIALLAGER

Abstract

A radial / thrust bearing comprises radial rolling elements, a radial cage, thrust rolling elements, a thrust cage, an outer ring, and an inner ring. The outer ring has a through hole that reaches a raceway region of the radial rolling elements from the outside. The radial cage includes a pair of annular portions arranged at a distance in the axial direction, and column portions connected to the pair of annular portions and arranged at a distance in the circumferential direction to form pockets that receive the radial rolling elements. The radial outer surfaces of the column portions have grooves, each extending in the axial direction and recessed radially inward. Each of the grooves has an opening at at least one axial end of a corresponding column portion.

Description

Technical area

[0001] The present disclosure relates to a radial / thrust bearing. This application claims priority to Japanese Patent Application No. 2022-181893, filed on November 14, 2022, which is incorporated herein by reference in its entirety. State of the art

[0002] A thrust needle roller bearing with a cage for accommodating needle rollers is already known (see, for example, Patent Document 1). The cage in the thrust needle roller bearing disclosed in Patent Document 1 has a protrusion or recess that prevents the flow of lubricating oil on an axial side surface of a column portion located between the pockets. A cage for use in a double-row roller bearing is also known (see, for example, Patent Document 2). The cage disclosed in Patent Document 2 includes a single annular portion, a plurality of column portions extending from one side surface of the annular portion to one side in the axial direction, and a plurality of column portions extending from the other side surface of the annular portion to the other side in the axial direction. Reference listPatent specifications Patent Document 1: Japanese Patent Application Publication No. 2016-1026 Patent Document 2: Japanese Patent Application Publication No. 2019-65919 Explanation of the inventionTechnical problem

[0003] In recent years, in situations where a load in the radial direction and a load in the thrust direction must be supported, a radial / thrust bearing that can support both loads is used. Such a radial / thrust bearing is suitable because the bearing can be easily miniaturized compared to, for example, a radial roller bearing and a thrust roller bearing. In a situation where a heat source such as a motor is located near the bearing, or the bearing is rotated at high speed, so that the bearing is thereby heated to a high temperature, a radial / thrust bearing is used in some cases. In such cases, it is necessary to rotate the rolling elements smoothly while efficiently cooling the radial / thrust bearing.

[0004] The present disclosure is therefore based on the object of providing a radial / axial bearing which enables efficient cooling and smooth rolling of rolling elements. Solution to the task

[0005] A radial / thrust bearing according to the present disclosure supports a load in a radial direction and a load in an axial thrust direction. A radial / thrust bearing includes: a plurality of radial rolling elements subjected to the load in the radial direction; a radial cage retaining the plurality of radial rolling elements; a plurality of thrust rolling elements subjected to the load in the axial thrust direction; a thrust cage retaining the plurality of thrust rolling elements; an outer ring having a first outer ring raceway surface in contact with the raceway surfaces of the radial rolling elements; and an inner ring having a first inner ring raceway surface in contact with the raceway surfaces of the radial rolling elements. The outer ring includes a second outer ring raceway surface in contact with the raceway surfaces of the thrust rolling elements. The inner ring has a second inner ring raceway surface in contact with the raceway surfaces of the thrust rolling elements.The outer ring has a through hole that reaches a raceway area of the radial rolling elements from the outside. The radial cage includes a pair of annular portions spaced apart in the axial direction, and column portions connected to the pair of annular portions and spaced apart in the circumferential direction to form pockets that receive the radial rolling elements. The radial outer surfaces of the column portions include grooves extending in the axial direction and recessed radially inward. Each of the grooves has an opening at at least one axial end of a corresponding column portion. Solution to the task

[0006] The radial / axial bearing ensures effective cooling and smooth rolling of the rolling elements. Short description of the drawings [ Fig. 1] Fig. 1 is a schematic perspective view illustrating the appearance of a radial / thrust bearing according to a first embodiment of the present disclosure. [ Fig. 2] Fig. 2 is a schematic plan view of the Fig. 1 shown radial / axial bearing, viewed in the axial direction. [ Fig. 3] Fig. 3 is a schematic side view of the Fig. 1 shown radial / axial bearing, viewed from a radial outer side. [ Fig. 4] Fig. 4 is a schematic cross-sectional view showing the Fig. 1 partially illustrated radial / axial bearings. [ Fig. 5] Fig. 5 is a disassembled view of the Fig. 1 shown radial / axial bearing. [ Fig. 6] Fig. 6 is an enlarged view showing the Fig. 1 partially illustrated radial / axial bearings. [ Fig. 7] Fig. Fig. 7 is a view illustrating a state in which an outer ring described below is inserted into the Fig. 6 shown radial / axial bearing has been removed. [ Fig. 8] Fig. 8 is an external perspective view of a radial cage. [ Fig. 9] Fig. Figure 9 is an enlarged view of a portion labeled IX of the Fig. 8 shown radial cage. [ Fig. 10] Fig. 10 is an enlarged view of a portion of the radial / thrust bearing from which the outer ring has been removed, viewed in the radial direction. [ Fig. 11] Fig. 11 is an enlarged cross-sectional view partially illustrating the radial cage. [ Fig. 12] Fig. 12 is a view of a portion of the radial cage viewed from a radially outer side. Description of the embodiments[Detailed description of the embodiments]

[0007] A radial / thrust bearing according to the present disclosure supports a load in a radial direction and a load in an axial thrust direction. The radial / thrust bearing includes: a plurality of radial rolling elements subjected to the load in the radial direction; a radial cage retaining the plurality of radial rolling elements; a plurality of thrust rolling elements subjected to the load in the axial thrust direction; a thrust cage retaining the plurality of thrust rolling elements; an outer ring having a first outer ring raceway surface in contact with the raceway surfaces of the radial rolling elements; and an inner ring having a first inner ring raceway surface in contact with the raceway surfaces of the radial rolling elements. The outer ring includes a second outer ring raceway surface in contact with the raceway surfaces of the thrust rolling elements. The inner ring has a second inner ring raceway surface in contact with the raceway surfaces of the thrust rolling elements.The outer ring has a through hole that reaches a raceway area of the radial rolling elements from the outside. The radial cage includes a pair of annular portions spaced apart in the axial direction, and column portions connected to the pair of annular portions and spaced apart in the circumferential direction to form pockets that receive the radial rolling elements. The radial outer surfaces of the column portions include grooves extending in the axial direction and recessed radially inward. Each of the grooves has an opening at at least one axial end of a corresponding column portion.

[0008] Since the radial / thrust bearing according to the present disclosure includes a plurality of radial rolling elements subjected to the load in the radial direction and a plurality of thrust rolling elements subjected to the load in the thrust direction, the radial load and the thrust load can be properly accommodated by one bearing. As a result, the bearing can be miniaturized. Furthermore, since the bearing includes the radial cage that accommodates the radial rolling elements and the thrust cage that accommodates the thrust rolling elements, the positions of these rolling elements can be stabilized.

[0009] In a case where the radial / thrust bearing is used near a heat source or rotated at high speed, the radial / thrust bearing itself may be heated to a high temperature. In such cases, the bearing must be cooled to allow the radial rolling elements and the thrust rolling elements to roll stably. The outer ring included in the radial / thrust bearing of the present disclosure has a through-hole that reaches the raceway area of the plurality of radial rolling elements from the outside, and thus, a flowable lubricant, such as oil air or oil mist, can be introduced into the interior of the bearing through the through-hole. Accordingly, the inside of the bearing can be cooled, and an improvement in lubrication performance can be achieved. Here, the radial outer surfaces of the column portions of the radial cage have grooves, each of which has an opening at at least one axial end of a corresponding column portion.Each groove extends in the axial direction and is recessed radially inward. Accordingly, the lubricant that has penetrated the through hole onto the radial outer surface of the radial cage can be supplied axially toward the opening via the grooves. The radial bearing configured in this way can efficiently cool the interior of the bearing by supplying the lubricant via the grooves, thereby improving the lubrication performance of the supplied lubricant on the radial rolling elements and the thrust rolling elements. In this manner, the radial / thrust bearing ensures effective cooling and smooth rolling of the rolling elements.

[0010] In the thrust bearing, a wall surface forming each of the grooves may have an arcuate curve when viewed in the axial direction. With this configuration, the lubricant supplied through the through hole is evenly discharged from the grooves in the axial direction, reducing the possibility of lubricant remaining in the grooves. As a result, more efficient cooling and smoother rolling of the rolling elements can be achieved.

[0011] In the radial / thrust bearing, each of the grooves has an opening only at one axial end of a corresponding column section. With this configuration, in a case where a heat source is located on one side in the axial direction, the groove openings are located on the heat source side, allowing the lubricant to be positively supplied toward the heat source. As a result, more efficient cooling can be achieved.

[0012] In a radial / thrust bearing, a wall surface forming each of the grooves at a different axial end can contain a portion of a spherical surface. This configuration reduces the possibility of lubricant remaining in the grooves on the closed side. As a result, more efficient cooling and smoother rolling of the rolling elements can be achieved.

[0013] In the radial / thrust bearing, each of the column sections may have protruding portions on a radially outer side and a radially inner side of the pair of annular sections toward the pockets. With this arrangement, the protruding portions can prevent the rolling elements housed in the pockets from falling out.

[0014] In a radial / thrust bearing, the through-hole may comprise a plurality of through-holes spaced circumferentially and having openings on a radially outer surface of the outer ring. With this arrangement, lubricant is supplied from and removed from the through-holes. As a result, more efficient cooling can be achieved.

[0015] In a radial / thrust bearing, each of the wall surfaces forming the through holes can be aligned straight in the radial direction. This arrangement can reduce the resistance to lubricant supply into the bearing. Accordingly, the lubricant can be smoothly supplied from the outside into the raceway area of the radial rolling elements.

[0016] In a radial / thrust bearing, each of the wall surfaces forming the through holes can be tapered, so that the wall area gradually increases toward the radial outer surface. This arrangement allows the lubricant to be forcefully introduced into the grooves, allowing the lubricant to be supplied quickly to the bearing.

[0017] In the radial / thrust bearing, the plurality of thrust rolling elements may be arranged in double rows at both axial ends of the thrust rolling elements in the axial direction. The thrust cage may comprise a pair of thrust cages that accommodate the plurality of thrust rolling elements arranged in the double rows. With this configuration, a larger load can be absorbed by the plurality of thrust rolling elements arranged in the double rows, thereby increasing the load in the axial thrust direction. [specific embodiments]

[0018] An example of specific embodiments of a radial / thrust bearing according to the present disclosure will be described below with reference to the drawings. In the following, the same or corresponding parts are designated by the same reference numerals, and the description will not be repeated. (FIRST EMBODIMENT)

[0019] First, a first embodiment which is an embodiment of the present disclosure will be described. Fig. 1 is a schematic perspective view illustrating an appearance of a radial / thrust bearing according to a first embodiment of the present disclosure. Fig. 2 is a schematic plan view of the Fig. 1 radial / axial bearings shown, viewed in axial direction. Fig. 2 is a view from a direction corresponding to that shown in Fig. 1 is opposite to the direction of arrow Z. In Fig. In Figure 1 and the following drawings, the Z direction indicates an axial direction. This means that a shaft supported by a radial / thrust bearing extends in the Z direction, although it is not shown. An X direction and a Y direction indicate radial directions in an axial direction as viewed from the center of the radial / thrust bearing. The X direction is a direction orthogonal to the Y direction in a plane perpendicular to the axial direction. Fig. 3 is a schematic side view of the Fig. 1 shown radial / axial bearing viewed from a radial outer side. Fig. 4 is a schematic cross-sectional view showing the Fig. 1 partially illustrated radial / axial bearings. Fig. 4 is a cross-sectional view in a case where the bearing is cut along an XZ plane. Fig. 5 is a disassembled view of the Fig. 1 shown radial / axial bearing. Fig. 6 is an enlarged view showing the Fig. 1 partially illustrated radial / axial bearings. Fig. Fig. 7 illustrates a state in which an outer ring described below is in the Fig. 6 shown radial / axial bearing has been removed.

[0020] Referring to the Fig. 1 to Fig. 7, a radial / thrust bearing 11 according to a first embodiment of the present disclosure is a bearing capable of supporting a load in a radial direction and a load in a thrust direction. A radial / thrust bearing 11 includes: an outer ring 12; an inner ring 13; a plurality of radial rollers 14 as a plurality of radial rolling elements subjected to a load in a radial direction; a plurality of thrust rollers 15 as a plurality of thrust rolling elements to which a load is applied in a thrust direction; a plurality of thrust rollers 16 as a plurality of thrust rolling elements to which a load is applied in a thrust direction; a radial cage 17 holding the plurality of radial rollers 14; a thrust cage 18 holding the plurality of thrust rollers 15; and a thrust cage 19 holding the plurality of thrust rollers 16.All radial rollers 14, thrust rollers 15, and axial rollers 16 can have the same shape. That is, the rollers are classified into radial rollers 14, axial rollers 15, and axial rollers 16, depending on the positions where the rollers are arranged.

[0021] The plurality of thrust rollers 15 are arranged in double rows with a pitch in the axial direction, and the plurality of thrust rollers 16 are arranged in double rows with a pitch in the axial direction. In this embodiment, the plurality of thrust rollers 15 in double rows and the plurality of thrust rollers 16 in double rows are arranged in the axial direction at both axial ends of the radial rollers 14. The thrust cage 18 and the thrust cage 19 are provided as a pair to respectively hold the thrust rollers 15 arranged in the double rows and the thrust rollers 16 arranged in the double rows. The radial / thrust bearing 11 thus configured can bear a larger load with the plurality of thrust rollers 15 in the double rows and the plurality of thrust rollers 16 in the double rows. This achieves a higher withstand load in the axial thrust direction. The radial / thrust bearing 11 is suitable for use as a slewing bearing.

[0022] The outer ring 12 is in the shape of a disc, which has a bore penetrating the outer ring 12 in the axial direction at its center in the radial direction. A radially inner surface of the outer ring 12 serves as the first outer ring raceway surface 31, which is in contact with the raceways 21 of the radial rollers 14. That is, the outer ring 12 includes the first outer ring raceway surface 31, which is in contact with the raceways 21 of the radial rollers 14. The outer ring 12 has a plurality of fastening holes 32 that penetrate the outer ring 12 in the axial direction and are arranged at intervals in the circumferential direction. That is, the fastening holes 32 each extend from one axial end surface 33 of the outer ring 12 to the other axial end surface 24 of the outer ring 12. These fastening holes 32 are round holes and are used, for example, to fasten the outer ring 12 to other elements.

[0023] The outer ring 12 has through holes 35 that reach a raceway area of the plurality of radial rollers 14 from the outside. The through holes 35 are arranged at intervals in the circumferential direction. The through holes 35 are also referred to as lubricant supply holes and are open on a radial outer surface 36 of the outer ring 12. The through holes 35 penetrate the outer ring 12 in the radial direction. The wall surfaces forming the through holes 35 are straight in the radial direction. The plurality of through holes 35 are offset in the circumferential direction from the mounting holes 32. That is, viewed in the axial direction, the positions of the mounting holes 32 are offset from the positions of the through holes 35 in the circumferential direction. The through holes 35 are also round holes. The diameter of each through hole 35 is smaller than the diameter of each mounting hole 32.These through holes 35 serve to introduce a lubricant such as oil air or oil mist into the bearing or to the outside of the bearing to cool the radial / thrust bearing 11 and provide lubrication. Among the plurality of through holes 35, the ratio between the through holes 35 used for supplying oil air and the through holes 35 used for discharging oil air can be arbitrarily adjusted depending on the cooling performance, the lubrication performance, the amount of heat generated by the heat source, and other factors.

[0024] The outer ring 12 has a second outer ring raceway surface 37, which is in contact with the raceways 22 of the axial rollers 15. The outer ring 12 has a second outer ring raceway surface 38, which is in contact with the raceways 23 of the axial rollers 16. The second outer ring raceway surface 37 and the second outer ring raceway surface 38 are spaced apart in the axial direction.

[0025] The inner ring 13 consists of a combination of two raceways 41 and 42. Both the first raceway 41 and the second raceway 42 are disc-shaped, each having a bore 48 and 49 that penetrates the first raceway 41 and the second raceway 42 axially at the center in the radial direction. The first raceway 41 and the second raceway 42 are combined such that the first raceway 41 and the second raceway 42 are in axial contact with each other. The radial / thrust bearing 11 supports a shaft (not shown) disposed in the bore 48 and the bore 49 radially inward of the inner ring 13. A portion of the radial outer surface of the first raceway 41 serves as the first inner ring raceway surface 43, which is in contact with the raceways 21 of the radial rollers 14. That is, the inner ring 13 contains the first inner ring raceway surface 43, which is in contact with the raceways 21 of the radial rollers 14.A space between the first outer ring raceway surface 31 and the first inner ring raceway surface 43 in the radial direction is a raceway region in which the plurality of radial rollers 14 roll.

[0026] The first raceway 41 has a second inner ring raceway surface 44 that is in contact with the raceways 22 of the thrust rollers 15. The second raceway 42 has a second inner ring raceway surface 45 that is in contact with the raceways 23 of the thrust rollers 16. The second inner ring raceway surface 44 and the second inner ring raceway surface 45 face each other in the axial direction. A space between the second outer ring raceway surface 37 and the second inner ring raceway surface 44 in the axial direction is a raceway region in which the plurality of thrust rollers 15 roll. A space between the second outer ring raceway surface 38 and the second inner ring raceway surface 45 in the axial direction is a raceway region in which the plurality of thrust rollers 16 roll.

[0027] The first race 41 has coupling bores 46 that penetrate the first race 41 in the axial direction. The coupling bores 46 are arranged at intervals in the circumferential direction. The coupling bores 46 are arranged radially inward from the second inner ring raceway surface 44. The second race 42 has coupling bores 47 that penetrate the second race 42 in the axial direction. The coupling bores 47 are arranged at intervals in the circumferential direction. The coupling bores 47 are arranged radially inward from the second inner ring raceway surface 45. The distance of the coupling bores 47 in the circumferential direction is equal to the distance of the coupling bores 46 in the circumferential direction. By using coupling bores 46 and 47, the first race 41 and the second race 42 are connected with bolts.

[0028] The thrust cage 18, which holds the plurality of thrust rollers 15, is disposed between the second outer ring raceway surface 37 and the second inner ring raceway surface 44. The thrust cage 18 is disc-shaped, and the pockets that hold the plurality of thrust rollers 15 are arranged at intervals in the circumferential direction. The thrust cage 19, which holds the plurality of thrust rollers 16, is disposed between the second outer ring raceway surface 38 and the second inner ring raceway surface 45. The thrust cage 19 is disc-shaped, and the pockets that hold the plurality of thrust rollers 16 are arranged at intervals in the circumferential direction.

[0029] Next, a structure of the radial cage 17 is described. Fig. 8 is a perspective external view of the radial cage 17. Fig. 8 also illustrates the radial rollers 14. Fig. Figure 9 is an enlarged view of an area labeled IX in the Fig. 8 shown radial cage 17. Fig. 10 is an enlarged view of a portion of the radial / thrust bearing 11 from which the outer ring has been removed, viewed in the radial direction. Fig. 11 is an enlarged cross-sectional view partially illustrating the radial cage 17. Fig. 11 is a schematic cross-sectional view taken in an XY plane. Fig. 12 is a view of a portion of the radial cage 17 viewed from a radially outer side.

[0030] Referring to the Fig. 8 to Fig. 12, the radial cage 17 holds the plurality of radial rollers 14. The radial cage 17 includes an annular portion 51 and an annular portion 52, which are arranged spaced apart in the axial direction, and a plurality of column portions 53. The annular portion 51 and the annular portion 52 are provided as a pair. Each of the plurality of column portions 53 has a shape that extends in the axial direction and is connected to the pair of the annular portion 51 and the annular portion 52. The plurality of column portions 53 are arranged at intervals in the circumferential direction to form pockets 54 in which the radial rollers 14 are housed. Each of the pockets 54 accommodates a corresponding radial roller 14.The column sections 53 include a protruding portion 55 and a protruding portion 56, which protrude toward the pockets 54 on the radially outer side and the radially inner side of the pair of the annular portion 51 and the annular portion 52. The protruding portion 55 and the protruding portion 56 can prevent the radial rollers 14 housed in the pockets 54 from falling off. The accommodation of the radial rollers 14 in the pockets 54 is achieved by elastically deforming the protruding portion 55 and the protruding portion 56 and by pushing the protruding portion 55 and the protruding portion 56 into the pockets 54 in the radial direction.

[0031] The radial outer surfaces 57 of the column sections 53 have axially extending, radially inwardly offset grooves 61. The grooves 61 are individually formed on the column sections 53. Each of the grooves 61 has an opening 62 at at least one axial end of a corresponding column section 53. In this embodiment, each of the grooves 61 has the opening 62 only at one axial end of a corresponding column section 53. A wall surface 63 forming each groove 61 has an arcuate curve when viewed in the axial direction. In this embodiment, the wall surface 63 forming each groove 61 has a semicircular curve when viewed in the axial direction. A wall surface 64 forming each groove 61 at the other axial end comprises a portion of a spherical surface. In this embodiment, the wall surface 64 forming the groove 61 at the other axial end is a portion of a spherical surface.The width of the grooves 61 in the circumferential direction, the depth of the grooves 61 in the radial direction, the positions of the closed grooves 61 and others can be freely selected.

[0032] Since the radial / thrust bearing 11 thus constructed includes the plurality of radial rollers 14 that receive a load in the radial direction, and the plurality of thrust rollers 15 and the plurality of thrust rollers 16 that are subjected to a load in the thrust direction, the radial load and the thrust load can be appropriately accommodated by one bearing. As a result, the bearing can be miniaturized. Furthermore, the radial cage 17 that holds the radial rollers 14, the thrust cage 18 that holds the thrust rollers 15, and the thrust cage 19 that holds the thrust rollers 16 can stabilize the posture of the rollers during rolling.

[0033] In a case where the radial / thrust bearing 11 is used near a heat source or rotated at high speed, the radial / thrust bearing 11 itself may be heated to a high temperature. In such cases, the bearing must be cooled to ensure stable rolling of the radial rollers 14, the thrust rollers 15, and the thrust rollers 16. The outer ring 12 of the radial / thrust bearing 11 of the present disclosure has through holes 35 that reach the raceway area of the plurality of radial rollers 14 from the outside, so that a flowable lubricant, such as oil air or oil mist, can be introduced into the interior of the bearing through the through holes 35. Accordingly, cooling of the inside of the bearing and improvement in lubrication performance can be achieved. The radial outer surfaces 57 of the column sections 53 of the radial cage 17 have grooves 61 with openings 62 at one axial end of the column sections 53.Each of the grooves 61 extends axially and is recessed radially inward. Accordingly, the lubricant that has passed through the through-holes 35 to the radial outer surfaces 57 of the radial cage 17 can be guided axially through the grooves 61 to the openings 62. In this embodiment, which refers in particular to FIG. Fig.10, the lubricant can be forcibly supplied toward the second raceway 42, as indicated by arrow 24. On the closed side, that is, on the first raceway 41 side, the lubricant remains, as indicated by arrow 25, and is gradually supplied radially outward, as indicated by dashed arrows 26. The radial / thrust bearing 11 thus constructed can efficiently cool the interior of the bearing by supplying the lubricant via the grooves 61, thereby improving the lubricating performance of the supplied lubricant for the radial rollers 14, the thrust rollers 15, and the thrust rollers 16. In the manner described above, the radial / thrust bearing 11 can achieve efficient cooling and smooth rolling of the rollers.

[0034] In this embodiment, each of the wall surfaces 63 forming the grooves 61 has an arcuate curvature when viewed in the axial direction. Accordingly, the lubricant supplied through the through holes 35 is evenly discharged from the grooves 61 in the axial direction, thus reducing the possibility of the lubricant remaining in the grooves 61. As a result, more efficient cooling and smoother rolling of the rollers can be achieved.

[0035] In this embodiment, each of the grooves 61 has the opening 62 only at one axial end of a corresponding column portion 53. Thus, in a case where the heat source is located on one side in the axial direction, the openings 62 of the grooves 61 are arranged on the heat source side, so that the lubricant can be positively supplied to the heat source. As a result, more efficient cooling can be achieved.

[0036] In this embodiment, each of the wall surfaces 64 forming the grooves 61 at the other axial end includes a portion of a spherical surface. This can reduce the possibility of lubricant remaining in the grooves 61 on the closed side of the grooves 61. As a result, more efficient cooling and smoother rolling of the rollers can be achieved.

[0037] In this embodiment, the wall surfaces forming the through holes 35 are aligned straight in the radial direction. This can reduce the resistance during the supply of lubricant into the bearing. Accordingly, the lubricant can be smoothly supplied from the outside into the raceway area of the radial rollers 14. (OTHER EMBODIMENTS)

[0038] In the above-described embodiment, each groove can have openings at both axial ends of the corresponding column section. This allows the lubricant to be supplied to both axial ends of the column section. Accordingly, the lubricant can be easily distributed throughout the bearing, improving cooling and lubrication performance. This structure is suitable for applications where the heat source is not located only on one side in the axial direction.

[0039] In the above-described embodiment, the wall surfaces forming the through holes are aligned straight in the radial direction, but the present disclosure is not limited to this configuration. For example, each of the wall surfaces forming the through holes may be tapered so that the wall area gradually increases toward the radially outer surface. Accordingly, the lubricant can be forcefully introduced into the grooves, allowing the lubricant to be supplied quickly to the bearing.

[0040] In the above-described embodiment, the plurality of thrust rollers are arranged in double rows, but the present disclosure is not limited to this structure, and the thrust rollers may also be arranged in a single row.

[0041] In the embodiment described above, rollers are used as rolling elements, but the present disclosure is not limited to this structure, and balls may also be used as rolling elements.

[0042] It is to be understood that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims and is intended to include all changes within the scope and meaning consistent with the claims. List of reference symbols

[0043] 11 Radial / thrust bearing, 12 Outer ring, 13 Inner ring, 14 Radial roller, 15, 16 Thrust roller, 17 Radial cage, 18, 19 Thrust cage, 21, 22, 23 Raceway, 24, 25, 26 Arrow, 31 First outer ring raceway surface, 32 Fixing hole, 33, 34 End surface, 35 Through hole, 36, 57 Radial outer surface, 37, 38 Second outer ring raceway surface, 41 Raceway (first raceway), 42 Raceway (second raceway), 43 First inner ring raceway surface, 44, 45 Second inner ring raceway surface, 46, 47 Coupling bore, 48, 49 Bore, 51, 52 Annular section, 53 Pillar sections, 54 Pocket, 55, 56 protruding area, 61 groove, 62 opening, 63, 64 wall surface. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2022-181893

[0001] JP 2016-1026

[0002] JP 2019-65919

[0002]

Claims

[1] Radial / thrust bearing which supports a load in a radial direction and a load in an axial compression direction, the radial / thrust bearing comprising: a plurality of radial rolling elements subjected to the load in the radial direction; a radial cage holding the plurality of radial rolling elements; a plurality of axial rolling elements subjected to the load in the axial thrust direction; an axial cage which holds the plurality of axial rolling elements; an outer ring having a first outer ring raceway surface which is in contact with the raceways of the radial rolling elements; and an inner ring having a first inner ring raceway surface which is in contact with the raceways of the radial rolling elements, wherein the outer ring has a second outer ring raceway surface which is in contact with the raceways of the axial rolling elements, the inner ring comprises a second inner ring raceway surface which is in contact with the raceways of the axial rolling elements, the outer ring has a through hole which reaches a raceway area of the plurality of radial rolling elements from the outside, the radial cage includes a pair of annular portions spaced apart in an axial direction, and a plurality of column portions connected to the pair of annular portions and spaced apart in a circumferential direction to form pockets for receiving the radial rolling elements, the radial outer surfaces of the column sections have grooves which each extend in the axial direction and are recessed radially inwards, and each of the grooves has an opening at at least one axial end of a corresponding column section. [2] A radial / thrust bearing according to claim 1, wherein each of the grooves forming wall surfaces has an arcuate curve when viewed in the axial direction. [3] Radial / thrust bearing according to claim 1 or 2, wherein each of the grooves has an opening only at one axial end of a corresponding column portion. [4] A radial / thrust bearing according to claim 3, wherein a wall surface forming each of the grooves at a different axial end has a portion of a spherical surface. [5] A radial / thrust bearing according to claim 1 or 2, wherein each of the column portions has protruding portions on a radially outer side and a radially inner side of the pair of annular portions toward the pockets. [6] Radial / thrust bearing according to claim 1 or 2, wherein the through-hole comprises a plurality of through-holes arranged at intervals in the circumferential direction and having openings on a radially outer surface of the outer ring. [7] Radial / thrust bearing according to claim 1 or 2, wherein each wall surface forming the through holes is aligned straight in the radial direction. [8] Radial / thrust bearing according to claim 1 or 2, wherein each wall surface forming the through holes is tapered such that the wall area is gradually increased towards the radially outer surface. [9] Radial / axial bearing according to claim 1 or 2, wherein the plurality of axial rolling elements are arranged in double rows at the two axial ends of the radial rolling elements in the axial direction, and the axial cage comprises a pair of axial cages which hold the plurality of axial rolling elements arranged in the double rows.

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