Rolling bearing device having lubricating function
Patent Information
- Application Number
- PCT/JP2025/007420
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-03-08
- Filing Date
- 2025-03-03
- Publication Date
- 2025-10-02
AI Technical Summary
Existing lubrication methods for high-speed bearings, such as forced lubrication and under-race lubrication, lead to excessive oil supply, increased rotational torque, and require costly machining, making them inefficient and costly.
A rolling bearing device with an outer and inner ring spacer system that supplies lubricant through nozzles and scoops, allowing under-race lubrication without altering the bearing's housing design, reducing oil supply and torque.
The solution reduces oil consumption, heat generation, and torque while maintaining efficiency and reducing costs by optimizing lubrication without machining the bearings.
Smart Images
Figure JP2025007420_02102025_PF_FP_ABST
Abstract
Description
Lubricated rolling bearing device
[0001] The present invention relates to a rolling bearing device with lubrication function that has an outer ring spacer and an inner ring spacer and that provides an oil supply / drain function that enables under-race lubrication without processing the angular ball bearing used under high-speed rotation, thereby optimizing the amount of oil supplied and achieving low heat generation and low torque.
[0002] One method of supplying lubricating oil to bearings that rotate at high speeds is forced lubrication, in which the oil passes through the housing and is supplied directly to the inside of the bearing from the outer ring spacer. With this method, when the inner ring rotates, the oil supply speed must be fast enough to break through the air curtain (wall of air) created by the peripheral speed of the inner ring outer diameter surface, which tends to result in an excess amount of oil being supplied compared to the amount needed to control the bearing temperature. Furthermore, the difference between the revolution speed of the rolling elements and the oil supply speed increases stirring resistance. These two factors not only increase the rotational torque of the bearing, reducing equipment efficiency, but also require the use of larger ancillary equipment because more oil than necessary is supplied.
[0003] In addition, in the case of inner ring rotation, there is an under-race lubrication method in which an oil supply passage that opens to the inner ring raceway surface is provided in the inner ring of the bearing, and lubricating oil is supplied from the inner surface of the inner ring to the inside of the bearing (see, for example, Patent Documents 1 and 2).
[0004] Japanese Patent Publication No. 2017-110776 Japanese Patent Publication No. 2006-283984
[0005] However, when an under-race lubrication method such as that described in Patent Documents 1 and 2 is implemented by providing an oil supply passage in the inner ring of the bearing, it may be necessary to perform appropriate machining not only on the bearing but also on the shaft. Furthermore, it is often necessary to supply oil from the end face of the shaft, which may not be applicable due to the structure of the equipment.
[0006] The present invention has been made to solve these problems, and its purpose is to provide a rolling bearing device with a lubrication function that can be given an under-race lubrication function without processing the angular ball bearing, while maintaining the same housing design as forced lubrication, thereby reducing the amount of oil supplied, thereby reducing the heat generation and torque of the bearing, and also reducing costs.
[0007] In order to solve the above problems, the present invention provides the following rolling bearing device with lubrication function: (1) A pair of angular contact ball bearings used for inner ring rotation, each bearing comprising an outer ring having an outer ring raceway groove on its inner circumferential surface, an inner ring having an inner ring raceway groove on its outer circumferential surface, and a plurality of balls rollably disposed between the outer ring raceway groove and the inner ring raceway groove, an outer ring spacer disposed adjacent to each outer ring of the pair of angular contact ball bearings, and a pair of inner ring spacers disposed adjacent each inner ring of the pair of angular contact ball bearings, wherein the outer ring spacers and each inner ring spacer cooperate to supply lubricant to each angular contact ball bearing, wherein the outer ring spacers have nozzle portions that protrude toward the inner diameter side and allow lubricant to flow therethrough, and each inner ring spacer is formed in a stepped shape, with a small diameter portion facing the inner circumferential surface of the tip of the nozzle portion and a large diameter portion facing the axial side surface of the tip of the nozzle portion, a rolling bearing device with lubrication function, wherein the large diameter portion has an annular scoop that opens on an axial side surface facing the tip end of the nozzle portion, and a discharge nozzle that communicates between the scoop and the bearing space of each of the angular contact ball bearings, and the outer ring spacer has a radial flow passage that extends radially inside the nozzle portion, and a pair of supply nozzles that open from the radial flow passage to both axial side surfaces of the tip end of the nozzle portion that face each of the scoops of the pair of inner ring spacers.(2) A rolling bearing device with lubrication function, comprising: an angular contact ball bearing used for inner ring rotation, comprising an outer ring having an outer ring raceway groove on its inner peripheral surface, an inner ring having an inner ring raceway groove on its outer peripheral surface, and a plurality of balls provided so as to be able to roll between the outer ring raceway groove and the inner ring raceway groove; an outer ring spacer arranged adjacent to the outer ring; and an inner ring spacer arranged adjacent to the inner ring, wherein the outer ring spacer and the inner ring spacer cooperate to supply lubricant to the angular contact ball bearing, wherein the outer ring spacer has a nozzle portion that protrudes toward the inner diameter side and through which lubricant can flow, and the inner ring spacer is formed in a stepped shape, having a small diameter portion facing the inner peripheral surface of the tip of the nozzle portion and a large diameter portion facing the axial side surface of the tip of the nozzle portion, a rolling bearing device with lubrication function, wherein the large diameter portion has an annular scoop that opens onto an axial side surface facing the tip end of the nozzle portion, and a discharge nozzle that communicates between the scoop and a bearing space of the angular contact ball bearing, and the outer ring spacer has a radial flow path that extends radially inside the nozzle portion, and a supply nozzle that opens from the radial flow path onto an axial side surface of the tip end of the nozzle portion that faces the scoop.
[0008] According to the present invention, it is possible to impart under-race lubrication function to angular contact ball bearings without processing them, while maintaining the same housing design as forced lubrication. This reduces the amount of oil supplied, thereby reducing the heat generation and torque of the bearing, and also reduces costs.
[0009] Fig. 1 is a cross-sectional view of a rolling bearing device with lubrication function according to one embodiment of the present invention, Fig. 2(a) is a side view of an outer ring spacer, and Fig. 2(b) is an enlarged view of a main part as seen from arrow A in Fig. 2(a).
[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rolling bearing device with lubrication function according to an embodiment of the present invention will be described in detail below with reference to the drawings.
[0011] 1, the lubricated rolling bearing device 1 of this embodiment comprises a pair of angular contact ball bearings 10A, 10B, an outer ring spacer 20 and a pair of inner ring spacers 30A, 30B arranged between the pair of angular contact ball bearings 10A, 10B. The rolling bearing device 1 has a lubrication function in which the outer ring spacer 20 and each of the inner ring spacers 30A, 30B work together to supply lubricating oil (lubricant) to each of the angular contact ball bearings 10A, 10B.
[0012] A pair of angular contact ball bearings 10A, 10B are used for inner ring rotation and include an outer ring 11 having an outer ring raceway groove 11a on its inner peripheral surface, an inner ring 12 having an inner ring raceway groove 12a on its outer peripheral surface, a plurality of balls 13 rollably disposed between the outer ring raceway groove 11a and the inner ring raceway groove 12a at a contact angle α, and a cage 14 that holds the plurality of balls 13. The contact angle α is defined as the angle between a plane P perpendicular to the bearing center axis X and a line of action connecting the contact points Pa and Pb where the balls 13 come into contact with the outer ring 11 and the inner ring 12, respectively.
[0013] The pair of angular contact ball bearings 10A, 10B are arranged in a back-to-back configuration. The inner ring 12 has a counterbore 12b on its outer peripheral surface facing the inner ring spacer relative to the inner ring raceway groove 12a. The cage 14 is made of resin and includes a pair of annular portions 14a, 14b and multiple pillar portions 14c connecting the pair of annular portions 14a, 14b. The annular portion 14a is guided by a shoulder portion 11b on the outer ring spacer side relative to the outer ring raceway groove 11a, forming an outer ring guide system. The inner peripheral surface of the annular portion 14a of the cage 14 is formed on the outer diameter side of the pitch circle diameter PCD of the balls 13.
[0014] The outer ring spacer 20 is disposed adjacent to each outer ring 11 of the pair of angular contact ball bearings 10A, 10B, and has an annular outer ring spacer main body 21 and an annular nozzle portion 22 that protrudes radially inward from the outer ring spacer main body 21 and through which lubricating oil can flow. The inner circumferential surface of the outer ring spacer main body 21 is formed with a diameter slightly larger than that of the shoulder portion 11b of the adjacent outer ring 11.
[0015] The outer ring spacer 20 has radial flow passages 23 extending radially inside the nozzle portion 22, and a pair of supply nozzles 24 that open from the radial flow passages 23 to both axial side surfaces of the tip portion 22a of the nozzle portion 22 that face each scoop 34 of a pair of inner ring spacers 30A, 30B, which will be described later. The number and phase θ of the radial flow passages 23 can be designed as desired, and in this embodiment, two radial flow passages 23 are provided, as shown in Fig. 2. The pair of supply nozzles 24 are inclined so as to approach the inner diameter side as they move away from the radial flow passages 23 in the axial direction.
[0016] In addition, an annular groove (oil supply rail) 25 that is continuous with the radial flow path 23 of the nozzle portion 22 is formed on the outer peripheral surface of the outer ring spacer 20, and lubricating oil can be supplied to the radial flow path 23 without considering the phase relative to the oil supply from outside.
[0017] A plurality of slits 26 that penetrate radially are formed in the outer ring spacer 20 at positions axially spaced from the nozzle portion 22 of the outer ring spacer main body 21. The slits 26 are formed in eight locations at equal intervals on the circumference, and are formed in the shape of ovals that are long in the circumferential direction. Therefore, lubricating oil that accumulates between the pair of angular contact ball bearings 10A, 10B can be discharged from the slits 26 located below.
[0018] Next, the pair of inner ring spacers 30A, 30B are arranged adjacent to the inner rings 12 of the pair of angular contact ball bearings 10A, 10B, respectively. Each inner ring spacer 30A, 30B has the same shape and is formed in a stepped shape with a small diameter portion 31 closely facing the inner circumferential surface of the tip end of the nozzle portion 22, and a large diameter portion 32 closely facing the axial side surface of the tip end of the nozzle portion 22. The pair of inner ring spacers 30A, 30B are arranged adjacent to each other, sandwiched between the inner rings 12 of the pair of angular contact ball bearings 10A, 10B, with the small diameter portions 31 abutting each other.
[0019] The large diameter portion 32 has an annular scoop (oil reservoir) 34 that opens on the axial side opposite the tip of the nozzle portion 22, and a plurality of discharge nozzles 35 that connect the scoop 34 to the bearing spaces s of each angular ball bearing 10A, 10B and are arranged at equal intervals in the circumferential direction.
[0020] Each inner ring spacer 30A, 30B has an axially protruding portion 33 that protrudes toward the corresponding angular ball bearing further than the axial end face that abuts against the inner ring 12 of the corresponding angular ball bearing 10A, 10B, and an outlet of the discharge nozzle 35 is formed in the axially protruding portion 33. In other words, the inner peripheral surface of the axially protruding portion 33 is located on the outer diameter side of the outer peripheral surface of the counterbore 12b of the inner ring 12 of each angular ball bearing 10A, 10B. In this embodiment, the outer peripheral surfaces of the large diameter portion 32 and the axially protruding portion 33 are designed to be equal to or smaller than the pitch circle diameter PCD of the balls 13.
[0021] The outer peripheral surfaces of the small diameter portion 31 and the scoop 34 are formed continuously and are inclined so as to gradually increase in diameter from the small diameter portion 31 side toward the scoop 34 side, so that lubricating oil adhering to the outer peripheral surface of the small diameter portion 31 is guided into the scoop 34 by centrifugal force. The discharge nozzle 35 is formed on the bottom surface of the scoop 34 so that its inlet is continuous with the inner peripheral surface of the scoop 34, and is inclined so as to gradually increase in diameter from the inlet on the scoop 34 side toward the outlet on the axially protruding portion 33 side, so as to be directed toward the inner peripheral surface of the annular portion 14a of the cage 14 or the balls 13. In particular, by positioning the outlet of the discharge nozzle 35 within the bearing space s of each angular contact ball bearing 10A, 10B, the influence of an air curtain generated by the surrounding air rotating together with the bearing due to high-speed rotation can be suppressed, thereby improving oil supply reliability.
[0022] Furthermore, the nozzle portion 22 of the outer ring spacer 20 is formed in an annular shape and is close to the scoops 34 of the inner ring spacers 30A and 30B, so leakage from the scoops 34 can be reduced.
[0023] In the lubricated rolling bearing device 1 configured in this manner, lubricating oil pressurized by a pump (not shown) to obtain a discharge flow rate appropriate for the bearing rotation speed is filled into the annular groove 25 forming the oil supply rail from the outer diameter side of the outer ring spacer 20, and is then injected from the supply nozzle 24 through the radial flow path 23 toward the scoops 34 of the inner ring spacers 30A, 30B. The lubricating oil collected in the scoops 34 is then discharged into the bearing space s from the multiple discharge nozzles 35 of the inner ring spacers 30A, 30B by centrifugal force caused by the rotation of the inner ring spacers 30A, 30B. After lubrication, lubricating oil remaining in each angular ball bearing 10A, 10B and between the pair of angular ball bearings 10A, 10B is discharged from the counterbore 11c side of the outer ring 11 of the angular ball bearings 10A, 10B or from the slits 26 in the outer ring spacer 20.
[0024] Therefore, the rolling bearing device 1 with lubrication function of this embodiment can be given an under-race lubrication function without processing the angular ball bearings 10A, 10B, while maintaining the same housing design as forced lubrication, thereby reducing the amount of oil supplied, thereby reducing the heat generation and torque of the bearing, and also reducing costs.
[0025] It should be noted that the present invention is not limited to the above-described embodiment, and modifications and improvements are possible as appropriate. For example, in the above embodiment, the nozzle portion 22 is formed in an annular shape around the entire circumference, and the radial flow passages 23 are formed at a predetermined phase, but the present invention is not limited to this, and the nozzle portion 22 may protrude toward the inner diameter side only at the predetermined phase where the radial flow passages 23 are formed. Also, in the above embodiment, a pair of angular contact ball bearings 10A, 10B are provided on both axial sides of the outer ring spacer 20 and the inner ring spacer 30A, 30B, but the present invention may also be applied to a case where an angular contact ball bearing is provided on one axial side of the outer ring spacer and the inner ring spacer.
[0026] As described above, this specification discloses the following: (1) A rolling bearing device with lubrication function, comprising: a pair of angular contact ball bearings used for inner ring rotation, each of which includes an outer ring having an outer ring raceway groove on its inner peripheral surface, an inner ring having an inner ring raceway groove on its outer peripheral surface, and a plurality of balls rollably disposed between the outer ring raceway groove and the inner ring raceway groove, an outer ring spacer disposed adjacent to each outer ring of the pair of angular contact ball bearings, and a pair of inner ring spacers disposed adjacent to each inner ring of the pair of angular contact ball bearings, wherein the outer ring spacers and each inner ring spacer cooperate to supply lubricant to each of the angular contact ball bearings, the outer ring spacers having nozzle portions that protrude toward the inner diameter side and allow lubricant to flow therethrough, and each of the inner ring spacers having a stepped shape with a small diameter portion facing the inner peripheral surface of the tip of the nozzle portion and a large diameter portion facing the axial side surface of the tip of the nozzle portion, a rolling bearing device with lubrication function, wherein the large diameter portion has an annular scoop opening on an axial side surface facing the tip of the nozzle portion, and a discharge nozzle connecting the scoop to the bearing space of each of the angular contact ball bearings, and the outer ring spacer has a radial flow passage extending radially inside the nozzle portion, and a pair of supply nozzles opening from the radial flow passage to both axial side surfaces of the tip of the nozzle portion of the pair of inner ring spacers facing each of the scoops. With this configuration, it is possible to impart under-race lubrication function to the angular contact ball bearing without machining it, while maintaining a housing design similar to that of forced lubrication, and this makes it possible to reduce the amount of oil supplied, thereby reducing the heat generation and torque of the bearing, and also reducing costs.
[0027] (2) The rolling bearing device with lubrication function according to (1), wherein the inner ring of each angular contact ball bearing has a counterbore on its outer peripheral surface on the inner ring spacer side relative to the inner ring raceway groove, and each inner ring spacer has an axial protruding portion that protrudes toward each angular contact ball bearing beyond the axial end face that abuts against the inner ring of each angular contact ball bearing, and where the outlet of the discharge nozzle is formed. With this configuration, the outlet of the discharge nozzle is located within the bearing space, thereby improving the reliability of oil supply to each angular contact ball bearing.
[0028] (3) The rolling bearing device with lubrication function according to (1) or (2), wherein an annular groove that is continuous with the radial flow passage of the nozzle portion is formed on the outer peripheral surface of the outer ring spacer. With this configuration, lubricating oil can be supplied to the radial flow passage without considering the phase relative to oil supply from outside.
[0029] (4) The rolling bearing device with lubrication function according to any one of (1) to (3), wherein the outer ring spacer has a slit formed therethrough in the radial direction at a position axially spaced from the nozzle portion. With this configuration, lubricating oil remaining between the pair of angular contact ball bearings can be discharged through the slit.
[0030] (5) A rolling bearing device with lubrication function, comprising: an angular contact ball bearing used for inner ring rotation, comprising an outer ring having an outer ring raceway groove on its inner peripheral surface, an inner ring having an inner ring raceway groove on its outer peripheral surface, and a plurality of balls provided so as to be able to roll between the outer ring raceway groove and the inner ring raceway groove; an outer ring spacer arranged adjacent to the outer ring; and an inner ring spacer arranged adjacent to the inner ring, wherein the outer ring spacer and the inner ring spacer cooperate to supply lubricant to the angular contact ball bearing, wherein the outer ring spacer has a nozzle portion that protrudes toward the inner diameter side and allows lubricant to flow therethrough, and the inner ring spacer is formed in a stepped shape, having a small diameter portion facing the inner peripheral surface of the tip of the nozzle portion and a large diameter portion facing the axial side surface of the tip of the nozzle portion, a bearing spacer having a radial flow passage extending radially inside the nozzle portion and a supply nozzle opening from the radial flow passage to the axial side surface of the tip of the nozzle portion facing the scoop, and a bearing spacer having a lubrication function. This configuration makes it possible to provide under-race lubrication without machining the angular contact ball bearing, while maintaining a housing design similar to that of forced lubrication, thereby reducing the amount of oil supplied and reducing the heat generation and torque of the bearing, and also reducing costs.
[0031] This application is based on a Japanese patent application (Patent Application No. 2024-36003) filed on March 8, 2024, the contents of which are incorporated herein by reference.
[0032] REFERENCE SIGNS LIST 1 Lubricated rolling bearing device 10A, 10B Angular contact ball bearing 11 Outer ring 11a Outer ring raceway groove 12 Inner ring 12a Inner ring raceway groove 13 Balls 14 Cage 20 Outer ring spacer 21 Outer ring spacer main body 22 Nozzle portion 23 Radial flow path 24 Supply nozzle 25 Annular groove 30A, 30B Inner ring spacer 31 Small diameter portion 32 Large diameter portion 33 Axial protrusion 34 Scoop 35 Discharge nozzle s Bearing space
Claims
1. A rolling bearing device with lubrication function, comprising: a pair of angular contact ball bearings used for inner ring rotation, each comprising an outer ring having an outer ring raceway groove on its inner peripheral surface, an inner ring having an inner ring raceway groove on its outer peripheral surface, and a plurality of balls rollably disposed between the outer ring raceway groove and the inner ring raceway groove; an outer ring spacer arranged adjacent to each outer ring of the pair of angular contact ball bearings; and a pair of inner ring spacers arranged adjacent to each inner ring of the pair of angular contact ball bearings, wherein the outer ring spacers and each inner ring spacer cooperate to supply lubricant to each of the angular contact ball bearings, wherein the outer ring spacer has a nozzle portion that protrudes toward the inner diameter side and allows lubricant to flow therethrough, and each of the inner ring spacers is formed in a stepped shape, with a small diameter portion facing the inner peripheral surface of the tip of the nozzle portion and a large diameter portion facing the axial side surface of the tip of the nozzle portion, a rolling bearing device with lubrication function, wherein the large diameter portion has an annular scoop that opens on an axial side surface facing the tip end of the nozzle portion, and a discharge nozzle that communicates between the scoop and the bearing space of each of the angular contact ball bearings, and the outer ring spacer has a radial flow passage that extends radially inside the nozzle portion, and a pair of supply nozzles that open from the radial flow passage to both axial side surfaces of the tip end of the nozzle portion that face each of the scoops of the pair of inner ring spacers.
2. A rolling bearing device with lubrication function as set forth in claim 1, wherein the inner ring of each of the angular ball bearings has a counterbore on its outer peripheral surface on the inner ring spacer side relative to the inner ring raceway groove, and each of the inner ring spacers has an axial protruding portion that protrudes toward each of the angular ball bearings beyond the axial end face that abuts against the inner ring of each of the angular ball bearings, and where an outlet of the discharge nozzle is formed.
3. A rolling bearing device with lubrication function according to claim 1, wherein an annular groove that is continuous with the radial flow path of the nozzle portion is formed on the outer peripheral surface of the outer ring spacer.
4. A rolling bearing device with lubrication function according to claim 1, wherein the outer ring spacer is formed with a slit penetrating in the radial direction at a position axially spaced from the nozzle portion.
5. A rolling bearing device with lubrication function, comprising: an angular contact ball bearing used for inner ring rotation, comprising an outer ring having an outer ring raceway groove on its inner peripheral surface, an inner ring having an inner ring raceway groove on its outer peripheral surface, and a plurality of balls provided so as to be able to roll between the outer ring raceway groove and the inner ring raceway groove; an outer ring spacer arranged adjacent to the outer ring; and an inner ring spacer arranged adjacent to the inner ring, wherein the outer ring spacer and the inner ring spacer cooperate to supply lubricant to the angular contact ball bearing, wherein the outer ring spacer has a nozzle portion that protrudes toward the inner diameter side and allows lubricant to flow therethrough, and the inner ring spacer is formed in a stepped shape, having a small diameter portion facing the inner peripheral surface of the tip of the nozzle portion and a large diameter portion facing the axial side surface of the tip of the nozzle portion, a rolling bearing device with lubrication function, wherein the large diameter portion has an annular scoop that opens onto an axial side surface facing the tip end of the nozzle portion, and a discharge nozzle that communicates between the scoop and a bearing space of the angular contact ball bearing, and the outer ring spacer has a radial flow path that extends radially inside the nozzle portion, and a supply nozzle that opens from the radial flow path onto an axial side surface of the tip end of the nozzle portion that faces the scoop.