Shell-type roller bearing, and rotating machine and electric axle unit that comprise the same

Abstract

To reduce the bearing width of a shell-type roller bearing that comprises a shell outer ring, a radial bearing portion, and a thrust bearing portion, suitable for use in supporting an end portion of a shaft.SOLUTION: A shell outer ring 4 includes one inner flange portion 4b protruding from one axial end of a cylindrical portion 4a, and another inner flange portion 4c protruding comparatively from the other axial end of the cylindrical portion 4a. A radial bearing portion includes a first raceway surface 4e of the cylindrical portion 4a, a plurality of first needle rollers 5, and a first retainer 6. A thrust bearing portion includes a second raceway surface 4f of the other inner flange portion 4c, a plurality of second needle rollers 8, and a second retainer 9. The first retainer 6 has one end ring portion 6a and another end ring portion 6b. The other inner flange portion 4c includes a central cylindrical portion 4d that supports the second retainer 9 radially from the radially inner side. The thrust bearing portion is arranged radially inwardly apart from the cylindrical portion 4a, and the other end ring portion 6b projects between the cylindrical portion 4a and the thrust bearing portion so as to be positioned radially outwardly of the thrust bearing portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a drawn cup roller bearing that includes a shell outer ring, a radial bearing portion, and a thrust bearing portion and is used to support the end of a shaft, as well as to a rotating machine and an electric axle unit that include the same. [Background technology]

[0002] For example, in an electric axle unit (so-called e-Axle) that integrates an electric motor for vehicle drive, a parallel shaft gear reducer, and an inverter, helical gears are used as gears mounted on the second and subsequent shafts of the parallel shaft gear reducer. Both radial and axial loads are generated at the meshing portions of the helical gears. Both of these loads are applied to the rolling bearings that support the shaft rotatably relative to the housing. As in this example, a drawn cup roller bearing equipped with a radial bearing portion and a thrust bearing portion is available as a compact rolling bearing for carrying radial and axial loads between the end of the shaft and the housing (Patent Document 1).

[0003] The drawn cup roller bearing disclosed in Patent Document 1 includes a shell outer ring having inner ribs on both sides of a circular cylindrical portion, the inner rib on one end of which is radially higher than the inner rib on the other end of the shell outer ring. A radial bearing section and a thrust bearing section are assembled inside the shell outer ring. The radial bearing section includes a raceway formed on the cylindrical portion of the shell outer ring, multiple needle rollers that roll on this raceway, and a cage that holds the needle rollers. The thrust bearing section includes a washer supported axially on the end face of the shaft, a raceway formed on the inner rib on the other end of the shell outer ring, multiple needle rollers arranged between this raceway and the washer, and a cage that holds the needle rollers. The cage of the thrust bearing section is guided radially by the cylindrical portion of the shell outer ring or by a central cylindrical portion formed on the inner rib on the other end of the shell outer ring. The washer, cage, and needle rollers of the thrust bearing part are arranged to protrude radially outward so as to axially face the cage and needle rollers of the radial bearing part. This arrangement of the washer, cage, and needle rollers of the thrust bearing part enables the radial bearing part to restrict the non-fixed elements of the thrust bearing part (the washer, cage, and needle rollers) from falling out of the shell outer ring in the axial direction, even when the drawn cup roller bearing is in a standalone state. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-206546 (Figs. 14 and 16) Summary of the Invention [Problem to be solved by the invention]

[0005] However, the shell roller bearing disclosed in Patent Document 1 requires an axial gap between the needle rollers of the radial bearing section and the thrust bearing section to accommodate the annular portion at the other end of the retainer of the radial bearing section, which requires a wider shell roller bearing, leaving room for improvement.

[0006] In view of the above background, the problem to be solved by the present invention is to reduce the bearing width of a shell roller bearing that is adapted to support the end of a shaft and that is equipped with a shell outer ring, a radial bearing portion, and a thrust bearing portion. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a shell outer ring having a cylindrical portion extending in the axial and circumferential directions, a one-end side inner rib portion protruding radially inward from one axial end side of the cylindrical portion, and an other-end side inner rib portion protruding radially inward from another axial end side of the cylindrical portion opposite the one axial end side, beyond the one-end side inner rib portion; a radial bearing portion having a first raceway surface formed on the cylindrical portion, a plurality of first rollers rolling on the first raceway surface, and a first cage holding these first rollers; and a thrust bearing portion having a second raceway surface formed on the other-end side inner rib, a plurality of second rollers rolling on the second raceway surface, and a second cage holding these second rollers, The shell-type roller bearing has a first cage having a one-end annular portion extending circumferentially at one axial end side relative to the plurality of first rollers, and an other-end annular portion extending circumferentially at the other axial end side relative to the first rollers, wherein the other-end inner rib portion is located radially inward relative to the second cage and has a central cylindrical portion that supports the second cage radially, the thrust bearing portion is arranged radially inward and spaced apart from the cylindrical portion, and the other-end annular portion is arranged protruding between the cylindrical portion and the thrust bearing portion so as to be located radially outward relative to the thrust bearing portion.

[0008] As in configuration 1 above, by providing a central cylindrical portion that radially supports the second cage in the other-end inner rib portion of the shell outer ring, it becomes unnecessary to radially support the second cage by the cylindrical portion, and it becomes possible to separate the thrust bearing portion and the cylindrical portion of the shell outer ring radially inward, thereby ensuring space for the other-end annular portion of the first cage to protrude to a position radially outward from the thrust bearing portion. It becomes possible to position the protruding portion of the other-end annular portion, the first cage, and all of the plurality of first rollers close to the other-end inner rib portion, which narrows the axial distance between the first rollers and the thrust bearing portion and reduces the bearing width of the shell roller bearing.

[0009] In the above configuration 1, a configuration 2 can be adopted in which the other end side ring portion is wider than the one end side ring portion.

[0010] According to the above configuration 2, the width of the annular portion on one end of the first retainer is made relatively short, thereby making the first rollers longer, and the width of the annular portion on the other end is made relatively long, thereby ensuring the annular rigidity of the first retainer.

[0011] In the above-mentioned configuration 2, a configuration 3 can be adopted in which the one-end side ring portion has a joint portion welded at a portion that is butted together in the circumferential direction, and the other-end side ring portion has a joint portion welded at a portion that is butted together in the circumferential direction at a position axially opposite to the joint portion of the one-end side ring portion, and a notch cut out before welding so as to reduce the difference in axial length between the joint portion of the one-end side ring portion and the joint portion of the other-end side ring portion.

[0012] According to the above configuration 3, it is possible to provide a first cage in which the difference in thermal influence caused by welding between the joint portion of the other end side annular portion and the joint portion of the one end side annular portion is suppressed.

[0013] In any one of the above configurations 1 to 3, a configuration 4 can be adopted in which the other end side annular portion is arranged so as to be able to abut against the other end side inner flange portion in the axial direction.

[0014] According to the above-mentioned configuration 4, it is possible to utilize almost the entire axial cross-sectional height of the thrust bearing portion for arranging the other-end side annular portion, which in turn makes it possible to set an especially narrow axial distance between the first roller and the thrust bearing portion, and also, when the first roller skews, even if the thrust bearing portion does not support the first roller or the other-end side annular portion, the other-end side inner flange, which is axially supported by the housing, can support the other-end side annular portion and suppress the skew behavior.

[0015] In any one of the above configurations 1 to 4, configuration 5 can be adopted in which the second rollers are arranged so as not to be able to face the first rollers in the axial direction.

[0016] According to the above configuration 5, it is possible to arrange all of the second rollers of the thrust bearing portion between the end face of the shaft and the housing, so that the second rollers can be used without waste to support the axial load.

[0017] In any one of the above configurations 1 to 5, a configuration 6 can be adopted in which the outer diameter of the thrust bearing portion is set smaller than the pitch circle diameter of the plurality of first needle rollers.

[0018] According to the above-mentioned configuration 6, interference between the other end side annular portion and the thrust bearing portion can be avoided.

[0019] In any one of the above configurations 1 to 6, a configuration 7 can be adopted in which the thrust bearing portion includes a washer that faces the other-end side inner rib portion in the axial direction, and the washer has an outer circumferential portion located radially outward from the second cage, and a separation stop portion that keeps the outer circumferential portion in a position facing the second cage in the radial direction.

[0020] According to the above-mentioned configuration 7, when assembling the shell roller bearing, the outer periphery of the washer and the separation stopper hold the radial and axial positions of the washer relative to the second cage in a predetermined position, preventing separation, and these can be supported together radially by the central cylindrical portion, making it easy to assemble the shell roller bearing.

[0021] In the above configuration 7, configuration 8 can be adopted in which the outer diameter of the bearing washer is set to be larger than the diameter of an imaginary inscribed circle for the plurality of first rollers.

[0022] According to the above-mentioned configuration 8, the washer and the plurality of first rollers are secured to face each other in the axial direction, and even when the shell roller bearing is in a standalone state, the plurality of first rollers can prevent the washer, which has been made non-separable from the second cage, from falling out in the axial direction, thereby preventing disassembly of the thrust bearing portion.

[0023] In the above configuration 7 or 8, a configuration 9 can be adopted in which the other end side inner flange has a retaining portion that holds the second cage in a position radially facing the central cylindrical portion.

[0024] According to the above-mentioned configuration 9, even when the shell roller bearing is in a standalone state, the second cage that is not separated from the washer can be supported radially by the central cylindrical portion and can be restricted by the retaining portion to prevent it from falling out in the axial direction, and as a result, disassembly of the thrust bearing portion can be prevented regardless of the relationship between the outer diameter of the washer and the diameter of the imaginary inscribed circle for the multiple first rollers.

[0025] In the above configuration 9, a configuration 10 can be adopted in which the outer diameter of the bearing washer is set to a size equal to or smaller than the diameter of an imaginary inscribed circle for the plurality of first rollers.

[0026] According to the above configuration 10, a wide space is provided between the other end side annular portion and the bearing washer, making it possible to facilitate the flow of lubricating oil between the thrust bearing portion and the radial bearing portion.

[0027] In any one of the above configurations 1 to 6, a configuration 11 can be adopted in which the outer diameter of the second retainer is larger than the diameter of an imaginary inscribed circle for the plurality of first rollers, and the thrust bearing portion does not include a bearing washer.

[0028] According to configuration 11, the axial cross-sectional height of the thrust bearing portion does not include the washer, so the width of the shell outer ring is reduced compared to when the washer is included, thereby reducing the bearing width of the drawn cup roller bearing. Furthermore, even when the drawn cup roller bearing is in a standalone state, the second cage can be supported radially by the central cylindrical portion and restricted by the multiple first rollers to prevent it from falling out in the axial direction, thereby preventing disassembly of the thrust bearing portion.

[0029] In any one of the above configurations 1 to 6 and 11, a configuration 12 can be adopted in which the other-end side inner flange portion has a retaining portion that keeps the second retainer in a position radially opposite the central cylindrical portion, and the thrust bearing portion does not include a bearing washer.

[0030] According to configuration 12, the axial cross-sectional height of the thrust bearing portion does not include the washer, so the width of the shell outer ring is reduced compared to when the washer is included, thereby reducing the bearing width of the drawn cup roller bearing. Also, even when the drawn cup roller bearing is in a standalone state, the second cage can be supported radially by the central cylindrical portion and restricted by the retaining portion to prevent it from falling out in the axial direction, and as a result, disassembly of the thrust bearing portion can be prevented regardless of the relationship between the outer diameter of the second cage and the diameter of the imaginary inscribed circle for the plurality of first needle rollers.

[0031] In the above configuration 12, a configuration 13 can be adopted in which the outer diameter of the second cage is set to a size equal to or smaller than the diameter of an imaginary inscribed circle for the plurality of first rollers.

[0032] According to the above configuration 13, a large space is provided between the other end side annular portion and the second cage, and it is possible to facilitate the flow of lubricating oil between the thrust bearing portion and the radial bearing portion.

[0033] In any one of the above configurations 1 to 13, a configuration 14 can be adopted in which the inner flange portion on one end side has a Vickers hardness of 250 or more.

[0034] According to the above configuration 14, it is possible to prevent deformation of the inner flange portion on one end side that is pressed in the axial direction when the shell outer ring is press-fitted into the housing.

[0035] In any one of configurations 1 to 14 above, configuration 15 can be employed, in which the shell outer ring has a tapered surface whose diameter increases from an outer peripheral end portion connecting the cylindrical portion and the other-end-side inner flange to the outer periphery of the cylindrical portion toward the one end in the axial direction.

[0036] According to configuration 15, when the inner flange portion on one end side of the shell outer ring is pressed to press the shell outer ring into the housing, the shell outer ring can be easily press-fitted at a continuous gradient from the outer peripheral end, via the tapered surface, to the outer periphery of the tubular portion.

[0037] In any one of the above configurations 1 to 15, configuration 16 can be adopted in which at least one of the first retainer and the second retainer is arranged with at least one pocket empty.

[0038] According to the above configuration 16, the lubricating oil can easily flow through the empty pockets inside the bearing while the drawn cup roller bearing is in operation, thereby promoting lubrication inside the bearing.

[0039] Configuration 17 can be adopted: a rotating machine comprising: a shell roller bearing according to any one of configurations 1 to 16 above; a housing inner periphery that supports the cylindrical portion radially; a housing end face that supports the other-end-side inner rib portion axially; and a shaft having a cylindrical surface inscribed in the plurality of first rollers, an end face that faces the plurality of second rollers in the axial direction, and a chamfer formed at a corner connecting the cylindrical surface and the end face, wherein the first roller is arranged so that it can face the chamfer of the shaft in the radial direction within a range that the first cage can move axially towards the other end.

[0040] According to the seventeenth aspect, the thrust bearing portion and the first roller are disposed close to each other to the extent of the chamfer width of the shaft, so that the bearing width of the drawn cup roller bearing can be particularly reduced.

[0041] Configuration 18 can be adopted, which includes an electric motor, a gear reduction mechanism that reduces the speed of rotation of the electric motor, and a housing that accommodates the gear reduction mechanism, wherein the gear reduction mechanism includes an input shaft that is arranged coaxially with the electric motor, a shaft that is arranged parallel to the input shaft, a helical gear provided on the shaft, and a cup roller bearing according to any one of configurations 1 to 17 that is arranged between the shaft and the housing.

[0042] According to the above configuration 18, the axial load and radial load applied to the shaft from the helical gear can be received by one drawn cup roller bearing, so that the support structure of the shaft relative to the housing can be simplified. [Effects of the Invention]

[0043] As described above, by adopting the above configuration 1, the present invention makes it possible to reduce the bearing width of a shell roller bearing that is equipped with a shell outer ring, a radial bearing portion, and a thrust bearing portion and is suitable for use in supporting the end of a shaft. [Brief explanation of the drawings]

[0044] [Figure 1] FIG. 1 is a longitudinal sectional front view showing a main portion of a drawn cup roller bearing and a rotary machine according to a first embodiment of the present invention; [Figure 2] Enlarged view of half cross section of drawn cup roller bearing in Figure 1 [Figure 3] FIG. 10 is a longitudinal sectional front view showing the main parts of a drawn cup roller bearing and a rotary machine according to a second embodiment of the present invention. [Figure 4] FIG. 10 is a longitudinal sectional front view showing the main parts of a drawn cup roller bearing and a rotary machine according to a third embodiment of the present invention. [Figure 5] FIG. 10 is a longitudinal sectional front view showing the main parts of a drawn cup roller bearing and a rotary machine according to a fourth embodiment of the present invention. [Figure 6] FIG. 10 is a longitudinal sectional front view showing the main parts of a drawn cup roller bearing and a rotary machine according to a fifth embodiment of the present invention. [Figure 7] FIG. 10 is a longitudinal sectional front view showing the main parts of a drawn cup roller bearing and a rotary machine according to a sixth embodiment of the present invention. [Figure 8] FIG. 10 is a partial vertical sectional front view showing a modified example of the shell outer ring according to the embodiment. [Figure 9] FIG. 10 is a partially exploded plan view showing a modified example of the first cage according to the embodiment; [Figure 10] FIG. 1 is a schematic diagram showing an electric axle unit including a drawn cup roller bearing according to the embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0045] A drawn cup roller bearing according to a first embodiment of the present invention and a rotating machine including the same will be described with reference to the accompanying drawings, Figures 1 and 2. Note that, although needle rollers are used as an example of the first rollers and second rollers in this embodiment, there is no need to be limited to this, and cylindrical rollers, rod-shaped rollers, etc. may also be used.

[0046] The rotating machine shown in Figures 1 and 2 comprises a drawn cup roller bearing 1, a shaft 2, and a housing 3. The drawn cup roller bearing 1 supports one end of the shaft 2 rotatably relative to the housing 3, and is designed to withstand the radial load and unidirectional axial load applied to the shaft 2.

[0047] The drawn cup roller bearing 1 comprises a shell outer ring 4, a radial bearing portion that receives only radial loads, and a thrust bearing portion that receives only axial loads.

[0048] Hereinafter, the direction along the bearing central axis of the drawn cup roller bearing 1 will be referred to as the "axial direction," the direction perpendicular to the bearing central axis will be referred to as the "radial direction," and the direction in which the circumference centered on the bearing central axis extends will be referred to as the "circumferential direction." In addition, in the radial direction, the side closer to the bearing central axis will be referred to as the "radially inner side," and conversely, the side away from the bearing central axis will be referred to as the "radially outer side." In Figures 1 and 2, the axial direction corresponds to the left-right direction, and the radial direction corresponds to the up-down direction.

[0049] The shell outer ring 4 has a cylindrical portion 4a extending in the axial and circumferential directions, a one-end inner rib portion 4b protruding radially inward from one axial end of the cylindrical portion 4a (the right side in the drawing, the same applies hereinafter), and an other-end inner rib portion 4c protruding radially inward beyond the one-end inner rib 4b from the other axial end opposite the one axial end of the cylindrical portion 4a (the left side in the drawing, the same applies hereinafter). The bearing width of the shell roller bearing 1 is the same as the width of the shell outer ring 4. Here, the "width" of an object means the overall length of the object in the axial direction.

[0050] The one-end inner flange 4b ​​extends radially. The other-end inner flange 4c has a central cylindrical portion 4d that extends radially and then bends toward one axial end. The central cylindrical portion 4d faces the cylindrical portion 4a at a distance from the radial direction and includes a cylindrical portion that extends circumferentially along the axial direction. The inner diameter surface of the central cylindrical portion 4d defines the inner diameter of the drawn cup roller bearing 1.

[0051] The shell outer ring 4 is formed from a metal plate. In this example, a steel plate is used as the metal plate. Examples of such steel plate include SCM415 and SPC materials specified in the JIS standard.

[0052] Since the shell outer ring 4 is formed by pressing from a single metal plate, the other-end inner flange 4c has the thickest wall thickness. The cylindrical portion 4a is thinner than the other-end inner flange 4c due to the ironing process performed during the press work. The one-end inner flange 4b ​​is thinner than the cylindrical portion 4a because it is bent radially inward from one axial end of the cylindrical portion 4a.

[0053] The radial bearing portion of the shell roller bearing 1 is composed of a first raceway surface 4e formed on the inner peripheral side of the cylindrical portion 4a, a plurality of first needle rollers 5 that roll on the first raceway surface 4e, and a first cage 6 that holds these first needle rollers 5.

[0054] The thrust bearing portion of the shell roller bearing 1 is composed of a raceway 7 that faces the other-end inner rib portion 4c in the axial direction, a second raceway surface 4f formed on one axial end side of the other-end inner rib portion 4c, a plurality of second needle rollers 8 that roll on the second raceway surface 4f, and a second cage 9 that holds these second needle rollers 8.

[0055] The first needle rollers 5 and second needle rollers 8 are each cylindrical rollers whose diameter does not exceed 5 mm and whose length is between three and ten times the diameter. The length of the first needle rollers 5 is greater than the length of the second needle rollers 8. The diameter of the first needle rollers 5 is greater than the diameter of the second needle rollers 8. Note that the relationship between the lengths of the first needle rollers 5 and the second needle rollers 8 and the relationship between the diameters of the first needle rollers 5 and the second needle rollers 8 may be changed as appropriate, and the total number of first needle rollers 5 and the total number of second needle rollers 8 may be determined as appropriate.

[0056] The shaft 2 has a cylindrical surface 2a inscribed in the multiple first needle rollers 5, an end surface 2b extending radially at a position closer to the other end in the axial direction than the cylindrical surface 2a, and a chamfer 2c formed seamlessly at the corner connecting the cylindrical surface 2a and the end surface 2b.

[0057] A radial gap is provided between the cylindrical surface 2a of the shaft 2 and the one-end inner flange 4b. This radial gap serves as a flow path for lubricating oil to flow in and out of the shell outer ring 4.

[0058] An end face 2b of the shaft 2 supports the back surface of the bearing washer 7 in the axial direction.

[0059] The housing 3 has a housing inner periphery 3a that radially supports the cylindrical portion 4a, a housing end surface 3b that axially supports the other end side inner flange portion 4c, and an oil passage 3c used as a passage for lubricating oil.

[0060] The housing end face 3b is aligned radially and axially opposed to the second raceway surface 4f and all of the plurality of second needle rollers 8. Because the shell outer ring 4 does not include an outer peripheral portion that protrudes toward the other axial end side relative to the other-end inner rib portion 4c, it is not necessary to provide a recessed space around the housing end face 3b in which to place the shell outer ring 4.

[0061] The housing end face 3b intersects with an oil passage 3c. The oil passage 3c is axially connected to a space surrounded by the inner periphery of the center cylinder portion 4d. Notches 4g that penetrate radially between the inner and outer peripheries of the center cylinder portion 4d are formed at one or more locations along the circumference. When lubricating oil flows from the oil passage 3c to the inside of the center cylinder portion 4d, it easily flows into the thrust bearing portion through the gap between the notches 4g and the end face 2b of the shaft 2 or between the center cylinder portion 4d and the end face 2b of the shaft 2.

[0062] The first cage 6 has a one-end side ring portion 6a extending circumferentially at a position on one axial end side of the plurality of first needle rollers 5, an other-end side ring portion 6b extending circumferentially at a position on the other axial end side of the plurality of first needle rollers 5, and first pillar portions 6c separating the one-end side ring portion 6a and the other-end side ring portion 6b at equal intervals in the circumferential direction.

[0063] The first cage 6 is formed of a metal plate such as a steel plate.

[0064] Circumferentially adjacent first column portions 6c and both annular portions 6a, 6b form pockets, which are spaces that penetrate between the inner and outer peripheries of the first cage 6. The first needle rollers 5 are housed in these pockets. The total number of pockets formed in the first cage 6 need only be equal to or greater than the total number of first needle rollers 5.

[0065] The width of the first cage 6 is set smaller than the axial distance between the one-end inner rib portion 4b and the other-end inner rib portion 4c. The one-end annular portion 6a and the other-end annular portion 6b are disposed between the inner ribs 4b, 4c. The one-end annular portion 6a and the other-end annular portion 6b are cylindrical and axially opposed to each other, and extend axially at positions axially opposed to the pitch circles of the plurality of first needle rollers 5.

[0066] Circumferentially adjacent first column portions 6c are arranged to prevent the first needle rollers 5 from falling radially inward. An axially intermediate portion of each first column portion 6c is located radially inward of the pitch circle diameter of the plurality of first needle rollers 5 and includes a stopper portion that prevents the first needle rollers 5 from falling. Furthermore, both ends of the axial length of each first column portion 6c extend axially at positions axially opposing the pitch circle, and are able to receive the rolling surfaces of the first needle rollers 5 in the circumferential direction.

[0067] Here, "the pitch circle diameter of the multiple first needle rollers 5" refers to the diameter of an imaginary circle (i.e., pitch circle) that passes through the roller central axis of each of the first needle rollers 5 arranged in a normal state. The "normal state" refers to a state in which the roller central axis of each of the first needle rollers 5 is aligned in the axial direction and the rolling surface of each of the first needle rollers 5 is in contact with the first raceway surface 4e. The pitch circle diameter of the multiple first needle rollers 5 corresponds to (the diameter dr of the imaginary inscribed circle for the multiple first needle rollers 5 + the diameter of the first raceway surface 4e) / 2. The "diameter dr of the imaginary inscribed circle" refers to the diameter of an imaginary circle that is inscribed in the rolling surfaces of the multiple first needle rollers 5 when the bearing is assembled.

[0068] The radial cross-sectional height of the first cage 6 corresponds to the radial height between the surface located radially innermost in the axial middle part of the first pillar portion 6c and the outer diameter surface of the other end side annular portion 6b extending axially from the other axial end side of the first pillar portion 6c. The one end side annular portion 6a and the other end side annular portion 6b extend axially from the first pillar portion 6c in order to reduce the radial cross-sectional height of the first cage 6, and do not include any radially bent portions.

[0069] The second retainer 9 has an inner diameter side ring portion 9a extending circumferentially at a position radially inward from the plurality of second needle rollers 8, an outer diameter side ring portion 9b extending circumferentially at a position radially outward from the plurality of second needle rollers 8, and second pillar portions 9c separating the inner diameter side ring portion 9a and the outer diameter side ring portion 9b at equal intervals in the circumferential direction.

[0070] The second cage 9 is formed of a metal plate such as a steel plate.

[0071] Circumferentially adjacent second column portions 9c and both annular portions 9a, 9b form pockets, which are spaces that penetrate between the side surface at one axial end of second cage 9 and the side surface at the other axial end. Second needle rollers 8 are housed in these pockets. The total number of pockets formed in second cage 9 need only be equal to or greater than the total number of second needle rollers 8.

[0072] The inner diameter surface of the inner diameter side annular portion 9a defines the inner diameter of the second cage 9. The central cylindrical portion 4d is located radially inward of the inner diameter side annular portion 9a. When the cup roller bearing 1 is in a standalone state, the second cage 9 is supported radially by the outer diameter surface of the central cylindrical portion 4d.

[0073] The outer diameter surface of the outer diameter side annular portion 9b defines the outer diameter of the second cage 9. The outer diameter side annular portion 9b has a double ring structure bent to form an inner ring continuous with the outer diameter side of the second pillar portion 9c, an outer flange extending radially outward from one axial end of the inner ring, and an outer ring extending from the outer flange to the other axial end. This double ring structure is adopted to increase the rigidity of the outer diameter side annular portion 9b.

[0074] The second pillar portions 9c adjacent to each other in the circumferential direction are provided so as to be able to prevent the second needle rollers 8 from falling toward one end side in the axial direction.

[0075] The bearing washer 7 has a seamless annular surface 7a axially facing the second raceway surface 4f, an outer peripheral portion 7b located radially outward from the outer diameter side annular portion 9b, and a separation stopper portion 7c that keeps the outer peripheral portion 7b in a position radially facing the outer diameter side annular portion 9b.

[0076] The bearing washer 7 is formed from a metal plate such as a steel plate.

[0077] The annular surface 7a forms a raceway surface that contacts one axial end of the plurality of second needle rollers 8. The plurality of second needle rollers 8 are arranged so that they cannot face the plurality of first needle rollers 5 in the axial direction. In other words, the annular surface 7a and all of the plurality of second needle rollers 8 are arranged so that they face the end face 2b of the shaft 2 in the axial direction. Therefore, there is no concern that the washer 7 will deform into a tapered shape due to an axial load, and the annular surface 7a and all of the rolling surfaces of the second needle rollers 8 can be used without waste to support the axial load.

[0078] The outer peripheral portion 7b protrudes from the outer diameter side of the annular surface 7a toward the other axial end. The width of the outer peripheral portion 7b is set larger than the width of the second cage 9. The outer peripheral portion 7b faces the outer diameter side annular portion 9b in the radial direction. When the drawn cup roller bearing 1 is in a standalone state, the outer peripheral portion 7b restricts radial movement of the washer 7 relative to the second cage 9.

[0079] The outer diameter surface of the outer peripheral portion 7b defines the outer diameter of the bearing washer 7. The outer diameter of the bearing washer 7 is equal to the outer diameter Ds of the thrust bearing portion. The outer diameter Ds is set smaller than the inner diameter of the cylindrical portion 4a so that the thrust bearing portion can be disposed radially separated from the cylindrical portion 4a and a space can be secured for the other-end annular portion 6b to protrude radially outward relative to the thrust bearing portion without contacting the thrust bearing portion or the cylindrical portion 4a.

[0080] In addition, the outer diameter Ds is set larger than the diameter dr of the imaginary inscribed circle for the multiple first needle rollers 5 so as to ensure that the bearing washer 7 and the multiple first needle rollers 5 face each other in the axial direction.

[0081] In addition, the outer diameter Ds is set smaller than the pitch circle diameter of the plurality of first needle rollers 5 so that a radial gap can be provided between the pitch circle of the plurality of first needle rollers 5 and the other end side annular portion 6b extending in the axial direction at a position opposite to the pitch circle of the plurality of first needle rollers 5 in the axial direction.

[0082] The separation stopper portions 7c protrude radially inward from the outer peripheral portion 7b at a position on the other axial end side of the outer diameter side annular portion 9b. The separation stopper portions 7c face the outer peripheral edge of the outer diameter side annular portion 9b in the axial direction and prevent the bearing washer 7 and the second cage 9 from separating in the axial direction. The separation stopper portions 7c are arranged at multiple locations spaced apart in the circumferential direction and are provided, for example, by partially crimping the edge on the other axial end side of the outer peripheral portion 7b.

[0083] During operation of the drawn cup roller bearing 1, the second cage 9 is radially guided by the central cylindrical portion 4d, guiding the inner diameter surface of the inner diameter side annular portion 9a in the radial direction.

[0084] On the other hand, the first cage 6 is guided in the radial direction by a plurality of first needle rollers 5 .

[0085] Movement of the first cage 6 relative to the shell outer ring 4 toward the one end in the axial direction is restricted by the one end side annular portion 6a and the one end side inner flange portion 4b butting against each other in the axial direction.

[0086] The other-end annular portion 6b protrudes between the cylindrical portion 4a and the outer periphery 7b of the thrust bearing portion so as to be positioned radially outward from the thrust bearing portion, and is arranged so as to face both portions 4a, 7b in the radial direction. The other-end annular portion 6b does not have a portion that faces the outer periphery 7b of the thrust bearing portion in the axial direction, and cannot come into contact with the thrust bearing portion while the drawn cup roller bearing 1 is in operation.

[0087] The other-end annular portion 6b is wider than the one-end annular portion 6a. By shortening the width of the one-end annular portion 6a, the length of the first needle rollers 5 can be extended axially toward the one end without extending the width of the shell outer ring 4 toward the one end. Shortening the one-end annular portion 6a would be a disadvantageous change in terms of ensuring the ring rigidity of the first cage 6, but by increasing the width of the other-end annular portion 6b, the ring rigidity of the first cage 6 can be ensured. As long as the other-end annular portion 6b is wider than the one-end annular portion 6a within the range of the axial cross-sectional height of the thrust bearing portion (equivalent to the axial distance from the second raceway surface 4f to the back surface of the bearing washer 7 in the illustrated example), it is not necessary to increase the width of the shell outer ring 4, and therefore the bearing width of the drawn cup roller bearing 1 will not be increased.

[0088] Movement of the first cage 6 toward the other axial end relative to the shell outer ring 4 is restricted by the axial abutment between the other-end annular portion 6b and the other-end inner rib portion 4c. The axial distance between the washer 7 and the first needle rollers 5 is set so that the first needle rollers 5 cannot come into contact with the washer 7 in a state where the other-end annular portion 6b and the other-end inner rib portion 4c abut in the axial direction. The skew behavior of the first needle rollers 5 is indirectly suppressed by supporting the first cage 6 with the one-end inner rib portion 4b and the other-end inner rib portion 4c.

[0089] The amount of axial movement of the first needle rollers 5 toward the other end, relative to the shell outer ring 4 and the thrust bearing portion, is set so that the first needle rollers 5 can face radially against the chamfer 2c of the shaft 2. In other words, when the other-end annular portion 6b moves from the position shown in the figure until it axially abuts the other-end inner rib portion 4c during operation of the drawn cup roller bearing 1, the chamfer on the other axial end of the first needle rollers 5 is allowed to face radially against the chamfer 2c of the shaft 2. If the first needle rollers 5 are allowed to face radially against the chamfer 2c of the shaft 2, the first needle rollers 5 and the first cage 6 can be positioned as close as possible to the other-end inner rib 4c and the chamfer 2c of the shaft 2 in the axial direction, making it possible to make the axial distance between the first needle rollers 5 and the thrust bearing portion and the end face 2b of the shaft 2 as narrow as possible.

[0090] Furthermore, the amount of axial movement of first needle rollers 5 toward the other end that is permitted relative to the shell outer ring 4 and thrust bearing portion is preferably set so that the entire rolling surface of first needle rollers 5 can be maintained in a state facing radially opposite cylindrical surface 2a even when first needle rollers 5 move axially until the other-end annular portion 6b abuts against the other-end inner rib portion 4c. If the rolling surfaces of first needle rollers 5 protrude beyond the cylindrical surface 2a of shaft 2, this is detrimental to ensuring radial load capacity.

[0091] The amount of movement of first needle roller 5 toward the other end in the axial direction can be set based on the axial pocket clearance between first needle roller 5 and first cage 6, and the axial distance secured between the thrust bearing portion (end face 2b of shaft 2) and the end face of first needle roller 5. The axial distance between the end face of first needle roller 5 and the thrust bearing portion or end face 2b of shaft 2 can be set to, for example, 0.3 mm or more and 1 mm or less.

[0092] When assembling the drawn cup roller bearing 1, a shell-shaped workpiece is used that has a cylindrical portion 4a and an other-end inner rib portion 4c and in which the one-end inner rib portion 4b is not bent (the portion that will become the one-end inner rib portion 4b extends straight from the cylindrical portion 4a toward one end in the axial direction). This shell-shaped workpiece is quenched as a whole to increase the surface hardness of the cylindrical portion 4a and the other-end inner rib portion 4c, and then the portion that will become the one-end inner rib portion 4b is annealed to prevent cracks from occurring during the bending process described above. After the thrust bearing portion is incorporated into this shell-shaped workpiece, the first cage 6 is inserted axially into the inside of the cylindrical portion 4a of the shell-shaped workpiece. After the radial bearing portion is incorporated, the inner flange portion 4b on one end side is bent radially inward, thereby completing the shape of the shell outer ring 4 shown in Figure 1 and assembling the shell outer ring 4, thrust bearing portion, and radial bearing portion, thereby completing the assembly of the shell roller bearing 1.

[0093] After the thrust bearing portion is installed between the inner flange portion 4c on the other end side of the shell-shaped workpiece and the cylindrical portion 4a, during the assembly stage up until the radial bearing is installed, the separation of the washer 7 and the second retainer 9 is restricted by the separation stopper 7c, so the thrust bearing portion is not easily disassembled and the radial bearing portion can be easily installed.

[0094] Even when the shell roller bearing 1 is in a standalone state, the central cylindrical portion 4d of the shell outer ring 4 supports the washer 7 radially via the second retainer 9, and the washer 7 and the multiple first needle rollers 5 are ensured to face each other in the axial direction based on the difference in diameter between the outer diameter Ds of the washer 7 and the inscribed circle diameter dr for the multiple first needle rollers 5.Therefore, even if the washer 7 moves toward one end in the axial direction, it gets caught on the multiple first needle rollers 5 and cannot fall out, and as a result, the second retainer 9 and the multiple second needle rollers 8 cannot fall out toward one end in the axial direction.

[0095] When assembling the shell roller bearing 1 between the housing 3 and the shaft 2, first, a fitting process is performed in which the cylindrical portion 4a of the shell roller bearing 1 is pressed into the inner periphery 3a of the housing 3 and the inner flange portion 4c on the other end side is abutted against the housing end face 3b.

[0096] During the fitting process, the annealed one-end inner flange 4b ​​is pressed in the axial direction to press-fit the one-end inner flange 4b. If the one-end inner flange 4b ​​is not hard enough to withstand the press-fit force, deformation of the one-end inner flange 4b ​​due to the press-fit force (plastic deformation in which the one-end inner flange 4b ​​falls in the radial direction) becomes a problem.

[0097] If the Vickers hardness of the inner flange 4b ​​on one end side is 250HV0.3 or more, deformation of the inner flange 4b ​​on one end side due to a press-fit force above a certain level can be prevented. Here, Vickers hardness refers to the hardness determined by a test in accordance with "Vickers hardness test - Part 1: Test method" specified in the Japanese Industrial Standards (JIS Z2244-1).

[0098] The Vickers hardness of the one-end inner rib portion 4b can be adjusted based on the material and heat treatment conditions of the steel plate forming the shell outer ring 4. To prevent the Vickers hardness from decreasing too much during annealing, it is preferable to use SCM415 material for the steel plate.

[0099] After the fitting step is performed, the shaft 2 is inserted so that the cylindrical surface 2a of the shaft 2 is inscribed on the first needle rollers 5. At this time, the shaft 2 comes into contact with the first needle rollers 5 from the chamfers 2c, making it easy to insert the shaft 2 and preventing the rolling surfaces of the first needle rollers 5 from being damaged by the shaft 2.

[0100] The drawn cup roller bearing 1 shown in Figures 1 and 2 is as described above, and comprises a shell outer ring 4 having a cylindrical portion 4a extending in the axial and circumferential directions, a one-end inner rib portion 4b protruding radially inward from one axial end of the cylindrical portion 4a, and an other-end inner rib portion 4c protruding radially inward from the other axial end opposite the one axial end of the cylindrical portion 4a beyond the one-end inner rib portion 4b, a radial bearing portion having a first raceway surface 4e formed on the cylindrical portion 4a, a plurality of first needle rollers 5 rolling on the first raceway surface 4e, and a first cage 6 holding these first needle rollers 5, a second raceway surface 4f formed on the other-end inner rib portion 4c, and a plurality of second needle rollers rolling on the second raceway surface 4f. and a thrust bearing portion having second needle rollers 8 and a second cage 9 that holds these second needle rollers 8, wherein the first cage 6 has a one-end annular portion 6a that extends circumferentially at one axial end side of the plurality of first needle rollers 5, and an other-end annular portion 6b that extends circumferentially at the other axial end side of the first needle rollers 5, so that the cylindrical portion 4a of the shell outer ring 4 is supported radially by the housing inner circumference 3a of the housing 3, and the other-end inner rib portion 4c is supported axially by the housing end face 3b of the housing 3, and the cylindrical surface 2a of the shaft 2 is inscribed in the plurality of first needle rollers 5, thereby making it possible to use the bearing to support the end of the shaft 2.

[0101] The shell-type roller bearing 1 has, in particular, an other-end side inner rib portion 4c located radially inward relative to the second retainer 9 and a central cylindrical portion 4d that supports the second retainer 9 radially, the thrust bearing portion being arranged radially inward away from the cylindrical portion 4a, and the other-end side annular portion 6b being arranged protruding between the cylindrical portion 4a and the thrust bearing portion so as to be located radially outward relative to the thrust bearing portion.This ensures space for the other-end side annular portion 6b to protrude to a radially outward position relative to the thrust bearing portion, and makes it possible to position the protruding portion of the other-end side annular portion 6b, the first retainer 6 and all of the multiple first needle rollers 5 close to the other-end side inner rib portion 4c, thereby narrowing the axial distance between the first needle rollers 5 and the thrust bearing portion and reducing the bearing width of the shell-type roller bearing 1.

[0102] Furthermore, in this shell-type roller bearing 1, the other-end side annular portion 6b is wider than the one-end side annular portion 6a, so that the axial length of the one-end side annular portion 6a is made relatively small, thereby making it possible to make the length of the first needle rollers 5 large, while the axial length of the other-end side annular portion 6b is made relatively large, thereby ensuring the ring rigidity of the first cage 6.

[0103] Furthermore, this shell-type roller bearing 1 has a joint 6d formed by welding the portion of the one-end side ring portion 6a that is butted together in the circumferential direction, and a joint 6d formed by welding the portion of the other-end side ring portion 6b that is butted together in the circumferential direction at a position axially opposite to the joint 6d of the one-end side ring portion 6a, and a notch 6e that is cut out before welding to reduce the difference in axial length between the joint 6d of the one-end side ring portion 6a and the joint 6d of the other-end side ring portion 6b, thereby making it possible to form a first cage 6 in which the difference in thermal effects due to welding (i.e., the difference in welding quality) between the joint 6d of the other-end side ring portion 6b and the joint 6d of the one-end side ring portion 6a is suppressed.

[0104] Furthermore, because this shell-type roller bearing 1 is arranged so that the other-end side ring portion 6b can abut against the other-end side inner rib portion 4c in the axial direction, it is possible to utilize almost the entire axial cross-sectional height of the thrust bearing portion for arranging the other-end side ring portion 6b, which in turn makes it possible to make the axial distance between the first needle roller 5 and the thrust bearing portion particularly narrow, and also makes it possible to indirectly suppress the skew behavior of the first needle roller 5 by receiving the other-end side ring portion 6b on the other-end side inner rib portion 4c, which is axially supported by the housing 3, even if the thrust bearing portion does not receive the first needle roller 5 or the other-end side ring portion 6b.

[0105] Furthermore, in this shell-type roller bearing 1, the multiple second needle rollers 8 are arranged in a state in which they cannot face the multiple first needle rollers 5 in the axial direction, which makes it possible to arrange all of the multiple second needle rollers 8 between the end face 2b of the shaft 2 and the housing end face 3b of the housing 3, thereby allowing the axial load to be appropriately applied to the thrust bearing portion.

[0106] If, as in Patent Document 1, the multiple second needle rollers protrude radially outward to a position where they face the multiple first needle rollers in the axial direction, and the washer is arranged in a state where it protrudes radially outward beyond the end face of the shaft to correspond to this protruding portion, the end face of the shaft cannot support the protruding portions of the washer and second needle rollers in the axial direction. Therefore, when an axial load acts on the washer from the end face of the shaft, the radially outward protruding portion of the washer deforms in a tapered shape, and the entire length of the rolling surfaces of the second needle rollers cannot be fully utilized in terms of axial load capacity, which is not a good way to use a thrust roller bearing.

[0107] In addition, since the outer diameter Ds of the thrust bearing portion of this shell-type roller bearing 1 is set smaller than the pitch circle diameter of the multiple first needle rollers 5, interference between the other end side annular portion 6b and the thrust bearing portion can be avoided.

[0108] Furthermore, this shell roller bearing 1 includes a washer 7 whose thrust bearing portion faces the other end side inner rib portion 4c in the axial direction, and the washer 7 has an outer peripheral portion 7b located radially outward from the second retainer 9, and a separation stopper portion 7c that keeps the outer peripheral portion 7b in a position facing the second retainer 9 in the radial direction.As a result, when assembling the shell roller bearing 1, the outer peripheral portion 7b and separation stopper 7c of the washer 7 hold the radial and axial positions of the washer 7 relative to the second retainer 9 in a predetermined position and prevent separation, and these can be supported radially together by the central cylindrical portion 4d, making it easy to assemble the shell roller bearing 1.

[0109] Furthermore, in this shell roller bearing 1, the outer diameter Ds of the washer 7 is larger than the diameter dr of the imaginary inscribed circle for the multiple first needle rollers 5, thereby ensuring that the washer 7 and the multiple first needle rollers 5 are axially opposed to each other, and even when the shell roller bearing 1 is in a standalone state, the multiple first needle rollers 5 can prevent the second retainer 9 and the non-separable washer 7 from falling out in the axial direction, thereby preventing disassembly of the thrust bearing portion.

[0110] Furthermore, since the Vickers hardness of the one end side inner rib portion 4b of this shell roller bearing 1 is 250 or more, deformation of the one end side inner rib portion 4b can be prevented when the shell outer ring 4 is press-fitted into the housing 3.

[0111] Furthermore, this shell-type roller bearing 1 is formed with a notch 4g that penetrates radially between the inner and outer periphery of the central cylindrical portion 4d, which makes it easier for lubricating oil supplied from the outside when the shell-type roller bearing 1 is in use to flow between the thrust bearing portion and the outside through the notch 4g of the central cylindrical portion 4d, thereby promoting lubrication of the thrust bearing portion in particular.

[0112] Furthermore, the rotating machine according to the first embodiment comprises a shell roller bearing 1, a housing 3 that supports the cylindrical portion 4a radially and the other end side inner flange portion 4c axially, and a shaft 2 having a cylindrical surface 2a inscribed in a plurality of first needle rollers 5, an end face 2b that faces a plurality of second needle rollers 8 in the axial direction, and a chamfer 2c formed at the corner connecting the cylindrical surface 2a and the end face 2b, and the first needle roller 5 is arranged so that it can face the chamfer 2c of the shaft 2 radially within the range in which the first retainer 6 can move axially toward the other end side, so that the thrust bearing portion and the first needle roller 5 are positioned as close as approximately the width of the chamfer 2c of the shaft 2, thereby making it possible to particularly reduce the bearing width of the shell roller bearing 1.

[0113] A drawn cup roller bearing according to a second embodiment of the present invention and a rotary machine including the same are shown in Fig. 3. In the following, only differences from the first embodiment will be described, and the same reference numerals will continue to be used for components corresponding to those in the first embodiment.

[0114] In the drawn cup roller bearing 1 according to the second embodiment, the outer circumferential portion 7b of the washer 7 is larger in diameter than in the first embodiment. The radial back surface of the washer 7 axially faces the end face of the other axial end of the first needle roller 5. The axial distance between the illustrated first needle roller 5 and washer 7 is smaller than the axial distance between the other-end annular portion 6b and the other-end inner rib portion 4c, allowing contact between the first needle roller 5 and washer 7. In the second embodiment, the skew behavior of the first needle roller 5 is absorbed by the washer 7, but this can be absorbed by a high-rigidity portion near the outer circumferential portion 7b, which is radially spaced from the second needle roller 8. In the drawn cup roller bearing 1 according to the second embodiment, the outer diameter of the washer 7 is larger than in the first embodiment, but contact between the first needle roller 5 and washer 7 is allowed, allowing the first needle roller 5 to be positioned closer to the thrust bearing portion than in the first embodiment.

[0115] A drawn cup roller bearing according to a third embodiment of the present invention and a rotary machine including the same are shown in FIG.

[0116] The thrust bearing portion of the drawn cup roller bearing 1 according to the third embodiment does not include a washer, but is made up of a plurality of second needle rollers 8 and a second cage 9. The end face 2b of the shaft 2 of the rotating machine according to the third embodiment also serves as a raceway surface that contacts one axial end of the plurality of second needle rollers 8. By making the end face 2b of the shaft 2 a raceway surface, the axial distance between the first needle rollers 5 and the thrust bearing portion can be narrowed, and the width of the shell outer ring 4 can be reduced.

[0117] The outer diameter of the thrust bearing portion matches the outer diameter of the outer diameter side annular portion 9 b of the second cage 9 , and is set to a size equal to or smaller than the diameter of an imaginary inscribed circle for the plurality of first needle rollers 5 .

[0118] The other-end inner flange 4c has a retaining portion 4h that holds the second cage 9 in a position radially facing the central cylindrical portion 4d. The retaining portion 4h protrudes radially outward from the central cylindrical portion 4d at a position on one axial end side of the inner diameter side annular portion 9a of the second cage 9. The retaining portion 4h faces the inner peripheral edge of the inner diameter side annular portion 9a in the axial direction and prevents the shell outer ring 4 and the second cage 9 from separating in the axial direction. The retaining portions 4h are arranged at multiple locations spaced apart in the circumferential direction and are provided, for example, by partially crimping the edge on one axial end side of the central cylindrical portion 4d.

[0119] After the thrust bearing portion is installed between the inner rib portion 4c on the other end side of the shell-type workpiece and the cylindrical portion 4a, during the assembly stage until the radial bearing is installed, or when the shell-type roller bearing 1 is in a standalone state, the central cylindrical portion 4d supports the second cage 9 in the radial direction, and the retaining portion 4h restricts movement of the second cage 9 toward the one end in the axial direction, so the second cage 9 cannot fall out toward the one end in the axial direction. Therefore, the thrust bearing portion cannot be easily disassembled.

[0120] In this way, the drawn cup roller bearing 1 according to the third embodiment does not include the washer in the axial cross-sectional height of the thrust bearing portion, and so the width of the shell outer ring 4 is reduced compared to when the washer is included, thereby reducing the bearing width of the drawn cup roller bearing 1. Furthermore, even when used alone, the drawn cup roller bearing 1 according to the third embodiment can support the second cage 9 in the radial direction by the central cylindrical portion 4d and prevent it from falling out in the axial direction by the retaining portion 4h, and therefore can prevent disassembly of the thrust bearing portion regardless of the relative sizes of the outer diameter of the second cage 9 and the diameter of the imaginary inscribed circle for the plurality of first needle rollers 5.

[0121] Furthermore, in the shell roller bearing 1 according to the third embodiment, the outer diameter of the second retainer 9 is set to a size equal to or smaller than the diameter of the imaginary inscribed circle for the plurality of first needle rollers 5, so that the space between the other end side annular portion 6b and the second retainer 9 is made wider than in the first embodiment, making it easier for lubricating oil to flow between the thrust bearing portion and the radial bearing portion.

[0122] A rotary machine according to a fourth embodiment of the present invention is shown in FIG.

[0123] In the rotary machine according to the fourth embodiment, the oil passage is omitted from the housing 3, and an oil passage 2d is provided in the shaft 2. The oil passage 2d intersects with the end face 2b of the shaft 2. The lubricating oil that flows from the oil passage 2d to the inside of the central cylinder portion 4d passes through the notch 4g and easily flows into the thrust bearing portion. Note that although FIG. 5 shows the drawn cup roller bearing 1 of the first embodiment as an example, it is also possible to adopt those of other embodiments.

[0124] A drawn cup roller bearing according to a fifth embodiment of the present invention and a rotary machine including the same are shown in FIG.

[0125] The fifth embodiment is similar to the third embodiment in that the thrust bearing portion of the drawn cup roller bearing 1 does not include a washer, and the end face 2b of the shaft 2 of the rotary machine according to the fifth embodiment also serves as a raceway surface.

[0126] The outer diameter of the thrust bearing portion is equal to the outer diameter of the outer diameter side annular portion 9 b of the second cage 9 , and is set larger than the diameter of an imaginary inscribed circle for the plurality of first needle rollers 5 .

[0127] When the drawn cup roller bearing 1 is in a standalone state, the central cylindrical portion 4d of the shell outer ring 4 supports the second cage 9 in the radial direction, and because the outer diameter of the second cage 9 is larger than the diameter dr of the inscribed circle for the multiple first needle rollers 5, even if the second cage 9 moves toward one axial end, it gets caught on the multiple first needle rollers 5 and cannot fall out, and as a result the multiple second needle rollers 8 cannot fall out toward one axial end either. Therefore, the thrust bearing portion cannot be easily disassembled.

[0128] In this way, the drawn cup roller bearing 1 according to the fifth embodiment does not include the washer in the axial cross-sectional height of the thrust bearing portion, and so the width of the shell outer ring 4 is reduced compared to when the washer is included, thereby reducing the bearing width of the drawn cup roller bearing 1. Furthermore, even when used alone, the drawn cup roller bearing 1 according to the fifth embodiment supports the second cage 9 in the radial direction by the central cylindrical portion 4d and can be restricted by the multiple first needle rollers 5 to prevent it from falling out in the axial direction, thereby preventing disassembly of the thrust bearing portion.

[0129] If it is desired to prevent the second cage from falling off even during the assembly stage and improve the assembly ease of the drawn cup roller bearing 1, a retaining portion as in the third embodiment may be added to the central cylindrical portion 4d.

[0130] A drawn cup roller bearing according to a sixth embodiment of the present invention and a rotary machine including the same are shown in FIG.

[0131] In the shell roller bearing 1 of the sixth embodiment, the outer diameter side ring portion 9b of the second retainer 9 is changed to a folded double ring structure to reduce the outer diameter of the second retainer 9, and the outer diameter of the raceway 7 is also reduced accordingly, so that the outer diameter of the thrust bearing portion is set to a size equal to or smaller than the diameter of the imaginary inscribed circle for the multiple first needle rollers 5, and a slip-out prevention portion 4h as in the third embodiment is added to the central tube portion 4d.

[0132] After the thrust bearing portion has been installed between the inner rib portion 4c and cylindrical portion 4a on the other end of the shell-shaped workpiece, during the assembly stage until the radial bearing is installed, or when the shell-shaped roller bearing 1 is in a standalone state, separation of the washer 7 and second cage 9 is restricted as in the first embodiment, and movement of the second cage 9 towards one end in the axial direction is restricted as in the third embodiment, so the washer 7 and second cage 9 cannot fall out towards the one end in the axial direction, and as a result the multiple second needle rollers 8 cannot fall out towards the one end in the axial direction either. Therefore, the thrust bearing portion cannot be easily disassembled.

[0133] In this way, even when the shell-type roller bearing 1 according to the sixth embodiment is in a stand-alone state, the washer 7 and the non-separable second retainer 9 are supported radially by the central cylindrical portion 4d and can be restricted by the anti-slip portion 4h to prevent them from falling out in the axial direction, and as a result, disassembly of the thrust bearing portion can be prevented regardless of the relationship between the outer diameter of the washer 7 and the diameter of the imaginary inscribed circle for the multiple first needle rollers 5.

[0134] Furthermore, in the shell roller bearing 1 according to the sixth embodiment, the outer diameter of the washer 7 is set to a size equal to or smaller than the diameter of the imaginary inscribed circle for the plurality of first needle rollers 5, so that a wide space is provided between the other end side annular portion 6b and the washer 7, making it easier for lubricating oil to flow between the thrust bearing portion and the radial bearing portion.

[0135] In the drawn cup roller bearing 1 and rotating machine according to each of the above-described embodiments, the shell outer ring 4 is press-fitted into the housing inner periphery 3a of the housing 3, but to facilitate this press-fitting, the outer periphery of the shell outer ring 4 may be sloped. An example of this modification is shown in Fig. 8.

[0136] The shell outer ring shown in FIG. 8 has an outer peripheral end 4i connecting the other-end inner rib 4c and the tubular portion 4a, and a tapered surface 4j whose diameter increases from the outer peripheral end 4i to the outer periphery of the tubular portion 4a toward the one axial end. The outer peripheral end 4i is a portion of the outer periphery of the shell outer ring 4 that faces the other-end inner rib 4c in the radial direction. The outer peripheral end 4i is formed into a curved surface by pressing the tubular portion 4a toward the one axial end relative to the other-end inner rib 4c. The tapered surface 4j extends from the outer diameter side of the outer peripheral end 4i to the outer peripheral portion that defines the outer diameter of the tubular portion 4a. The tapered surface 4j may be press-formed by ironing or other methods, or may be machined to improve dimensional accuracy. The outer diameter side of the outer peripheral end 4i and the tapered surface 4j form a radial interference with the housing inner periphery 3a of the housing 3 shown in FIG. 1, etc.

[0137] When the drawn cup roller bearing 1 is press-fitted into the housing inner periphery 3a, the outer diameter side portion of the outer peripheral end 4i (shown in Fig. 8) of the shell outer ring 4 is first pressed against the opening edge of the housing inner periphery 3a, and then the tapered surface 4j is pressed against the opening edge of the housing inner periphery 3a (shown in Fig. 1, etc.) as it is fitted all the way to the outer periphery of the tubular portion 4a. Therefore, the force required for press-fitting gradually increases, and the radial component of that force makes it easier for the tubular portion 4a to contract in diameter, making press-fitting easier. As a result, the maximum value of the press-fitting force acting on the one-end inner rib portion 4b is suppressed, and the duration for which that maximum force is exerted is shortened, which is advantageous for preventing deformation of the one-end inner rib portion 4b.

[0138] In this way, by employing a shell outer ring 4 shown in Figure 1 etc. that has a tapered surface 4j that increases in diameter from the outer peripheral end 4i connecting the tubular portion 4a and the other-end inner rib 4c toward one end in the axial direction to the outer periphery of the tubular portion 4a, as shown in Figure 8, when the one-end inner rib 4b of the shell outer ring 4 shown in Figure 1 etc. is pressed to press the shell outer ring 4 into the housing 3, it becomes easier to press the shell outer ring 4 at a continuous gradient from the outer peripheral end 4i via the tapered surface 4j to the outer periphery of the tubular portion 4a.

[0139] In the above-described embodiments, the first cage 6 shown in FIG. 1 and other figures is formed seamlessly by pressing (a so-called pressed cage), but the manufacturing method and material of the first cage 6 are not particularly limited. For example, the first cage 6 can also be formed as a welded cage in which a strip-shaped plate material is rolled into an annular shape, both ends of which are butted together in the circumferential direction, and the butted portions are welded together. Such welded cages are suitable for large-scale demand of hundreds of thousands of units per year.

[0140] Generally, in the case of a welded cage having annular portions on both sides, a strip-shaped plate material having pockets punched out therefrom is rolled into a cylindrical shape, and the abutting portion of the strip portion that will become the one-end annular portion and the abutting portion of the strip portion that will become the other-end annular portion are arranged axially opposite each other, and the abutting portions on both sides are welded together with a single resistance welding process, thereby simultaneously joining the one-end joint portion and the other-end joint portion, improving the manufacturing efficiency of the welded cage. In the case of a first cage 6 configured as such a welded cage, the one-end annular portion 6a and the other-end annular portion 6b each have a joint formed by welding the abutting portions in the circumferential direction, and these two joints are located in positions that face each other in the axial direction.

[0141] When resistance welding the two joints, if there is a large difference between the axial length of the joint at one end annular portion 6a and the axial length of the joint at the other end annular portion 6b, the difference in electrical resistance between the joint at one end annular portion 6a and the joint at the other end annular portion 6b will be large, resulting in a large difference in thermal influence between these two joints and making it difficult to achieve sufficient welding quality at both joints through welding control. Therefore, it is preferable to carry out the welding process with measures taken to suppress the difference in thermal influence described above.

[0142] Specifically, if the difference between the axial length of the butt joint portion that will be the joint of the other end side ring portion 6b and the axial length of the butt joint portion that will be the joint of the one end side ring portion 6a is actively reduced before welding is performed, it is possible to reduce the difference in electrical resistance mentioned above and suppress the difference in thermal effects.

[0143] That is, as shown in FIG. 9, the one-end side ring portion 6a has a joint formed by welding the portions that are butted together in the circumferential direction, and the other-end side ring portion 6b has a joint 6d formed by welding the portions that are butted together in the circumferential direction at a position axially opposite to the joint 6d of the one-end side ring portion 6a, and a notch 6e that is cut out before welding to reduce the difference in axial length between the joint 6d of the one-end side ring portion 6a and the joint 6d of the other-end side ring portion 6b, thereby making it possible to produce a first cage 6 in which the difference in thermal effects due to welding between the joint 6d of the other-end side ring portion 6b and the joint 6d of the one-end side ring portion 6a is reduced.

[0144] The notch 6e is a portion formed by cutting out the edge of the band at the end in the band length direction of the other-end annular portion 6b. Note that the example in Figure 9 shows the most preferable embodiment in which the formation of the notch 6e makes the axial length of the joining portion 6d of the other-end annular portion 6b equal to the axial length of the joining portion 6d of the one-end annular portion 6a.

[0145] If a notch is formed on the edge on one axial end side of the other-end side annular portion 6b that receives the end face on the other axial end side of first needle roller 5, there is a concern that the edge of the notch may damage first needle roller 5. To avoid this, it is preferable to form notch 6e on the edge on the other axial end side of the other-end side annular portion 6b.

[0146] In each of the above-described embodiments, an example has been shown in which, with emphasis placed on radial load capacity and axial load capacity, first needle rollers 5 are accommodated in all pockets of the first cage 6 shown in Figure 1 etc., and second needle rollers 8 are accommodated in all pockets of the second cage 9, but if there is a margin of error in either load capacity, the number of first needle rollers 5 or second needle rollers 8 held in the first cage 6 or second cage 9 in the radial bearing section or thrust bearing section with that margin may be reduced, and empty pockets may be left in the first cage 6 or second cage 9.

[0147] For example, if there is a margin in the radial load capacity due to the provision of long first needle rollers 5, it is possible to arrange the first cage 6 with one or more pockets 6f of the first cage 6 left empty, as shown in Figure 9. Of course, if there is a margin in the axial load capacity of the thrust bearing portion shown in Figure 1 etc., the second cage 9 may be arranged with at least one pocket left empty.

[0148] It is preferable that the empty pockets of the first retainer 6 or the second retainer 9 are arranged in two or more positions around the circumference of the corresponding first retainer 6 or second retainer 9 and are rotationally symmetrical so that the corresponding radial bearing portion or thrust bearing portion rotates smoothly.

[0149] In this way, at least one of the first retainer 6 and the second retainer 9 is arranged with at least one pocket (pocket 6f in the example of Figure 9) empty, which makes it easier for lubricating oil to flow through the empty pocket inside the bearing while the shell roller bearing 1 is in operation, thereby promoting lubrication inside the bearing.

[0150] FIG. 10 shows an example of an electric axle unit incorporating a drawn cup roller bearing 1 according to any one of the above embodiments.

[0151] The electric axle unit (so-called e-Axle) shown in Fig. 10 includes an electric motor 10, a gear reduction mechanism that reduces the rotation speed of the electric motor 10, and a housing 3 that accommodates the gear reduction mechanism. The gear reduction mechanism is a parallel-shaft gear reducer that includes an input shaft 12 arranged coaxially with a rotor shaft 11 of the electric motor 10, a shaft 2 arranged parallel to the input shaft 12, a helical gear 13 provided on the input shaft 12, a helical gear 14 and a gear 15 provided on the shaft 2, a drawn cup roller bearing 1 on one axial end side that is arranged between one axial end side of the shaft 2 and the housing 3, a drawn cup roller bearing 1 on the other axial end side that is arranged between the other axial end side of the shaft 2 and the housing 3, and a final-stage gear 16.

[0152] The drawn cup roller bearing 1, the shaft 2, and the housing 3 of the gear reduction mechanism constitute a rotary machine according to any one of the above-described embodiments.

[0153] Helical gear 13 and helical gear 14 mesh together to decelerate the rotation of rotor shaft 11. Gear 15 and gear 16 mesh together to decelerate the rotation of shaft 2, which is then output from the shaft of gear 16, the final stage.

[0154] At the meshing portion of helical gears 13, 14, both a radial load and an axial load are generated and act on shaft 2. Both of these loads are applied to a single drawn cup roller bearing 1 that supports the end of shaft 2 rotatably relative to housing 3.

[0155] The electric axle unit shown in FIG. 10 is capable of supporting both of the loads described above with a single drawn cup roller bearing 1, and therefore the support structure for the shaft 2 relative to the housing 3 can be simplified.

[0156] The radial load generated as a component force at the meshing portion of helical gears 13, 14 is greater than the axial load. Therefore, what is required of drawn cup roller bearing 1 is that its radial load capacity is greater than its axial load capacity. Therefore, for radial bearing portions where a relatively large radial load capacity is required, it is preferable to increase the number of first needle rollers 5 shown in FIG. 1 etc. as much as possible, so first needle rollers 5 are housed in all of the pockets of first cage 6. On the other hand, for thrust bearing portions where a relatively small axial load capacity is required, there is a surplus in axial load capacity, so second cage 9 is arranged with two or more rotationally symmetric pockets left empty.

[0157] The axial load generated as a component force at the meshing portion of the helical gears 13, 14 is unidirectional. The axial load applied to the shaft 2 is limited to one direction. For this reason, it is possible to use a ball bearing instead of the drawn cup roller bearing 1 on the opposite side of the drawn cup roller bearing 1 that receives the axial load. Because a single drawn cup roller bearing 1 can support the axial load applied to the shaft 2, there is no need to fix the outer ring of the ball bearing to the housing 3 so that it does not move axially. Due to the structure of the electric axle unit equipped with a parallel-shaft gear reducer, it can sometimes be difficult to fix the outer ring of the ball bearing near the end of the shaft 2 so that it does not move axially during assembly. Even in such cases, if there is no need to fix the outer ring of the ball bearing on the opposite side as described above, it becomes easier to arrange the ball bearing, which makes assembly of the electric axle unit easier.

[0158] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0159] 1 Drawn cup roller bearing 2-axis 2a Cylindrical surface 2b End face 2c Chamfer 2d oil road 3. Housing 3a Housing inner circumference 3b Housing end face 3c oil passage 4 Shell outer ring 4a Cylindrical part 4b Inner flange on one end 4c Inner flange on the other end 4d center cylinder part 4e First orbital plane 4f Second orbital plane 4g notch 4h Retaining part 4i Outer edge 4j Tapered surface 5 First needle roller 6 First Cage 6a One end side ring part 6b Other end side ring part 6c First pillar 6d joint 6e notch 6F Pocket 7 Raceway 7a Torus 7b Outer periphery 7c Separation stop part 8 Second needle roller 9 Second Cage 9a Inner ring 9b Outer ring part 10 Electric motor 14 Helical gear

Claims

1. a shell outer ring having a cylindrical portion extending in the axial and circumferential directions, a one-end side inner rib portion protruding radially inward from one axial end side of the cylindrical portion, and an other-end side inner rib portion protruding radially inward from another axial end side opposite the one axial end side of the cylindrical portion beyond the one-end side inner rib portion; a radial bearing portion including a first raceway surface formed on the cylindrical portion, a plurality of first rollers rolling on the first raceway surface, and a first cage that holds the first rollers; a thrust bearing portion including a second raceway surface formed on the other end side inner flange portion, a plurality of second rollers rolling on the second raceway surface, and a second cage that holds the second rollers, In the shell-type roller bearing, the first cage has a one-end annular portion extending circumferentially at one axial end side with respect to the plurality of first rollers, and an other-end annular portion extending circumferentially at the other axial end side with respect to the first rollers, the other end side inner flange portion has a central tubular portion located radially inward with respect to the second cage and supporting the second cage in the radial direction, A shell roller bearing, characterized in that the other end side annular portion is disposed between the cylindrical portion and the thrust bearing portion so as to be positioned radially outward from the thrust bearing portion.

2. 2. The cup roller bearing according to claim 1, wherein the other end side annular portion is wider than the one end side annular portion.

3. the one-end annular portion has a joint portion formed by welding portions butted together in the circumferential direction, 3. A shell-type roller bearing according to claim 2, wherein the other-end side annular portion has a joint portion formed by welding a portion that is circumferentially butted together at a position axially opposite to the joint portion of the one-end side annular portion, and a notch that is cut out before welding.

4. 4. A cup roller bearing according to claim 1, wherein the other end side annular portion is arranged so as to be able to abut against the other end side inner rib portion in the axial direction.

5. 4. A drawn cup roller bearing according to claim 1, wherein the second rollers are arranged so as not to be opposed to the first rollers in the axial direction.

6. 4. The drawn cup roller bearing according to claim 1, wherein the outer diameter of said thrust bearing portion is set smaller than the pitch circle diameter of said plurality of first needle rollers.

7. the thrust bearing portion includes a washer that faces the other end side inner flange portion in the axial direction, 4. A shell roller bearing according to claim 1, wherein the bearing washer has an outer circumferential portion located radially outward from the second cage, and a separation stop portion that maintains the outer circumferential portion in a position radially opposite the second cage.

8. 8. A drawn cup roller bearing according to claim 7, wherein the outer diameter of said washer is set to be larger than the diameter of an imaginary inscribed circle for said plurality of first needle rollers.

9. 8. The drawn cup roller bearing according to claim 7, wherein the other end side inner rib portion has a retaining portion that holds the second cage in a position radially opposite to the central cylindrical portion.

10. an outer diameter of the second cage is set to be larger than a diameter of an imaginary inscribed circle for the plurality of first needle rollers, 4. A drawn cup roller bearing according to claim 1, wherein the thrust bearing portion does not include a bearing washer.

11. the other end side inner flange portion has a retaining portion that keeps the second cage in a position facing the central cylindrical portion in the radial direction, 4. A drawn cup roller bearing according to claim 1, wherein the thrust bearing portion does not include a bearing washer.

12. 4. A shell roller bearing according to claim 1, wherein the shell outer ring has a tapered surface whose diameter increases from an outer peripheral end portion connecting the cylindrical portion and the inner rib on the other end side to the outer periphery of the cylindrical portion toward the one end side in the axial direction.

13. 4. A cup roller bearing according to claim 1, wherein at least one of the first cage and the second cage is arranged with at least one pocket left empty.

14. A drawn cup roller bearing according to any one of claims 1 to 3; an inner periphery of a housing that supports the cylindrical portion in a radial direction; a housing end surface that supports the other end side inner flange portion in the axial direction; a shaft having a cylindrical surface inscribed within the plurality of first rollers, an end surface axially facing the plurality of second rollers, and a chamfer formed at a corner connecting the cylindrical surface and the end surface, a rotary machine in which the first rollers are arranged to be radially opposed to the chamfer of the shaft within a range in which the first cage can move toward the other end in the axial direction.

15. an electric motor; a gear reduction mechanism that reduces the speed of rotation of the electric motor; and a housing that accommodates the gear reduction mechanism; 4. An electric axle unit, wherein the gear reduction mechanism comprises: an input shaft arranged coaxially with the electric motor; a shaft arranged parallel to the input shaft; a helical gear provided on the shaft; and the cup roller bearing according to any one of claims 1 to 3, arranged between the shaft and the housing.

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