Bearing device

Abstract

The present invention provides a bearing device that can suppress the generation of resistance that hinders the rotation of the rotating shaft when lubricating oil collides with the rolling elements and cage during lubrication of the rolling bearing. [Solution] The bearing device 10 has a rolling bearing 11 mounted in the housing portion 21 of the housing 20. The rolling bearing 11 of the bearing device 10 has an inner ring 15 fixed to the outer circumference of the shaft 50 which is the rotating shaft, an outer ring 12 fixed to the housing 20, rolling elements 13 that roll between the inner ring 15 and the outer ring 12, and a cage 14 that maintains the distance between the rolling elements 13. The bearing device 10 is provided with a discharge port 40A in the housing portion 21 for discharging lubricating oil. The bearing device 10 discharges lubricating oil from the discharge port 40A to the side of the inner ring 15 that is closer to the center of the inner ring 15 than to the outer circumference of the inner ring 15 in the rolling bearing 11.

Description

Technical Field

[0001] This invention relates to a bearing device.

Background Art

[0002] Patent Document 1 discloses a bearing device including an oil supply unit that discharges lubricating oil toward balls that are rolling elements of a rolling bearing.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When supplying lubricating oil to a bearing device, if the supplied lubricating oil collides with rotating rolling elements or a cage, a resistance force that hinders the rotational movement of the rolling elements or the cage is generated due to the speed of the lubricating oil. This resistance force causes a decrease in the driving force of the rotating shaft.

Means for Solving the Problems

[0005] A bearing device for solving the above problems has a rolling bearing attached to a housing accommodation portion. The rolling bearing of this bearing device has an inner ring fixed to the outer peripheral surface of a rotating shaft, an outer ring fixed to the housing, rolling elements that roll between the inner ring and the outer ring, and a cage that holds the intervals between the rolling elements. This bearing device has a discharge port for discharging lubricating oil provided in the accommodation portion. This bearing device discharges lubricating oil from the discharge port to the center side of the inner ring rather than the outer periphery of the inner ring in the rolling bearing.

Effects of the Invention

[0006] According to the bearing device described above, when lubricating a rolling bearing, it is possible to suppress the generation of resistance that hinders the rotation of the rotating shaft due to the lubricating oil colliding with the rolling elements and cage. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a cross-sectional view of a bearing device according to one embodiment. [Figure 2] Figure 2 is a front view of the housing section of the bearing device shown in Figure 1, as seen from the opening side of the housing section. [Figure 3] Figure 3 is a cross-sectional view showing a modified bearing device. [Figure 4] Figure 4 is a cross-sectional view of a bearing device in another modified example. [Modes for carrying out the invention]

[0008] The following describes a bearing device 10, which is one embodiment of the bearing device, with reference to Figures 1 and 2. In Figure 1, the central axis of the bearing device 10 is shown as the central axis C by a dashed line. The central axis C extends horizontally. Figures 1 to 4 show the central axis C. In Figures 1 to 4, the vertical direction is indicated by an arrow, and the vertically upward and vertically downward directions are shown.

[0009] <Configuration of bearing device 10> Figure 1 is a cross-sectional view of the bearing device 10, cut along a vertical plane parallel to the central axis C. The bearing device 10 is installed, for example, in a transmission having multiple rotating shafts.

[0010] As shown in Figure 1, the bearing device 10 supports the end of a shaft 50, which is one of the rotating shafts. The housing 20 of the bearing device 10 is provided with a housing section 21. A rolling bearing 11 is housed in the housing section 21. The bearing device 10 is part of the transmission. Therefore, the housing 20 of the bearing device 10 is part of the transmission case.

[0011] As shown in Figure 1, the housing section 21 is composed of a housing hole 27 and a housing groove 29 provided in the opening of the housing hole 27. The housing hole 27 is a circular hole provided in the housing 20.

[0012] The depth direction of the housing hole 27 coincides with the axial direction of the central axis C. The bottom surface 28 of the housing hole 27 is perpendicular to the central axis C. As shown in Figures 1 and 2, a storage groove 29 is provided at the opening of the storage hole 27. The storage groove 29 enlarges the diameter of the opening in the storage hole 27.

[0013] Hereinafter, the portion of the housing hole 27 closer to the bottom surface 28 than the housing groove 29 will be referred to as the small diameter portion 25. The portion of the housing hole 27 closer to the housing groove 29 will be referred to as the large diameter portion 23. As shown in Figure 1, the rolling bearing 11 has an outer ring 12, a cage 14, an inner ring 15, and a plurality of rolling elements 13. The rolling bearing 11 is a ball bearing equipped with spherical rolling elements 13.

[0014] As shown in Figure 1, the inner ring 15 is fixed to the outer surface of the shaft 50. The outer ring 12 is fixed inside the housing 20 while fitted into the housing groove 29. Each rolling element 13 rolls between the inner ring 15 and the outer ring 12 while sliding against them. The cage 14 maintains the spacing between the rolling elements 13 and suppresses any unevenness in their alignment.

[0015] The central axis C shown by the dashed line in Figure 1 is the central axis of the rolling bearing 11. In other words, the central axis C is the central axis of the outer ring 12 and inner ring 15 of the rolling bearing 11. The central axis C coincides with the axis of rotation of the shaft 50. As shown in Figure 1, the axial direction of the central axis C is perpendicular to the vertical direction. In other words, the axial direction of the central axis C coincides with the horizontal direction. Thus, in the bearing device 10, the rolling bearing 11 is mounted in the housing 21 in a orientation in which the axial direction of the central axis C of the inner ring 15 coincides with the horizontal direction.

[0016] As shown in FIG. 1, the end of the shaft 50 fixed to the inner ring 15 of the rolling bearing 11 faces the bottom surface 28. As described above, the accommodating portion 21 is closed by the rolling bearing 11 fitted in the accommodating groove 29 and the end of the shaft 50.

[0017] As shown in FIGS. 1 and 2, a discharge port 40A for discharging lubricating oil is provided on the bottom surface 28 of the accommodating hole 27. The discharge port 40A is provided at a position on the extension line of the central axis C of the shaft 50 on the bottom surface 28. The discharge port 40A is connected to an oil pump via an oil supply passage provided in the housing 20. The oil supply passage leading to the discharge port 40A extends horizontally along the axial direction of the central axis C. The lubricating oil sent from the oil pump is discharged from the discharge port 40A.

[0018] As shown by the arrow 71 in FIG. 1, the discharge port 40A discharges lubricating oil toward the center of rotation of the shaft 50 at the end of the shaft 50. <Notch portion 41> As shown in FIG. 1, the accommodating portion 21 has a space with a circular cross-section formed by the small-diameter portion 25 on the side of the discharge port 40A with respect to the rolling bearing 11. The diameter of the small-diameter portion 25 is equal to the inner diameter of the outer ring 12.

[0019] As shown in FIGS. 1 and 2, the bearing device 10 includes a notch portion 41 on the lower surface of the accommodating portion 21 on the side of the discharge port 40A with respect to the rolling bearing 11. The lower surface is a surface located vertically below on the inner peripheral surface of the accommodating portion 21. The notch portion 41 is connected to the accommodating groove 29 and is adjacent to the outer ring 12. The notch portion 41 is a notch that is substantially rectangular when viewed from vertically above.

[0020] As shown in FIGS. 1 and 2, the position of the notch bottom surface 43, which is the bottom surface of the notch portion 41, is the same as the outer diameter of the outer ring 12 of the rolling bearing 11. That is, the depth of the notch portion 41 is equal to the thickness of the outer ring 12.

[0021] The lubricating oil discharged from the discharge port 40A is stored in the oil reservoir 42, which is the area enclosed by the notch 41 and the outer ring 12. <Operation of this embodiment> In the bearing device 10, the cage 14 and each rolling element 13 are located between the inner ring 15 and the outer ring 12. In other words, the cage 14 and each rolling element 13 are located radially outward relative to the inner ring 15. In the bearing device 10, the discharged lubricating oil is discharged towards the center of the inner ring 15 rather than the outer circumference of the inner ring 15 of the rolling bearing 11, as shown by arrow 71 in Figure 1. Therefore, the lubricating oil discharged from the discharge port 40A does not directly collide with the cage 14 and each rolling element 13 located outside the inner ring 15. In the bearing device 10, the lubricating oil that has lost momentum after colliding with the inner ring 15 or the shaft 50 is supplied to the cage 14 and each rolling element 13.

[0022] <Effects of this embodiment> (1) The bearing device 10 makes it possible to suppress the generation of resistance that hinders the rotation of the shaft 50 when lubricating the rolling bearing 11, as the lubricating oil collides with the cage 14 and each rolling element 13.

[0023] (2) The rolling bearing 11 of the bearing device 10 is mounted in the housing 21 in a orientation such that the axial direction of the central axis C of the inner ring 15 coincides with the horizontal direction. The housing 21 has a space on the discharge port 40A side of the rolling bearing 11, which is made up of a small diameter portion 25 whose diameter is less than or equal to the inner diameter of the outer ring 12. A notch 41 is provided adjacent to the outer ring 12 on the lower surface of the housing 21, which is part of the wall surface of this space, on the discharge port 40A side of the rolling bearing 11. The bottom surface 43 of the notch is located radially outward of the outer ring 12, relative to the inner surface of the outer ring 12.

[0024] In the bearing device 10, as shown by arrow 71 in Figure 1, the lubricating oil that collides with the shaft 50 falls toward the lower surface of the housing 21, as shown by arrow 72 in Figure 1. The fallen lubricating oil is stored in the notch 41 provided on the lower surface of the housing 21. Therefore, in the bearing device 10, the fallen lubricating oil is less likely to bounce off the lower surface of the housing 21 and directly collide with the cage 14 or each rolling element 13.

[0025] As shown by arrow 73 in Figure 1, the lubricating oil stored in the oil reservoir 42 is supplied to the inside of the outer ring 12. The bearing device 10 lubricates the cage 14 and each rolling element 13 with the lubricating oil that has weakened in the notch 41.

[0026] The bearing device 10 allows for proper lubrication of the cage 14 and each rolling element 13 while suppressing the collision of high-velocity lubricating oil that bounces off the lower surface of the housing 21 with the cage 14 and each rolling element 13 when supplying lubrication to the rolling bearing 11.

[0027] (3) The rolling bearing 11 of the bearing device 10 supports the end of the shaft 50. The housing portion 21 of the bearing device 10 is closed with the rolling bearing 11 fitted into a housing groove 29 provided in the opening of a circular housing hole 27 provided in the wall surface of the housing 20, such that the end of the shaft 50 and the bottom surface 28 of the housing hole 27 face each other. The diameter of the small diameter portion 25 of the housing portion 21 of the bearing device 10, which is the part of the housing hole 27 that is on the bottom surface 28 side of the housing hole 27 than the housing groove 29, is less than or equal to the inner diameter of the outer ring 12 and greater than the outer diameter of the inner ring 15. The discharge port 40A of the bearing device 10 is provided on the bottom surface 28 of the housing hole 27 and discharges lubricating oil toward the center of rotation of the shaft 50 at the end of the shaft 50.

[0028] The resistance force acting when discharged lubricating oil collides with the inner ring 15 or shaft 50 increases as the distance of the lubricating oil collision from the center of rotation of the inner ring 15 or shaft 50 increases. The bearing device 10 discharges lubricating oil at the center of rotation at the end of the shaft 50, as shown by arrow 71 in Figure 1. Therefore, the resistance force generated by the collision of lubricating oil can be minimized.

[0029] (4) In the bearing device 10, the diameter of the small diameter portion 25, which is the part of the housing hole 27 on the bottom surface 28 side, is equal to the inner diameter of the outer ring 12. The bearing device 10 achieves the above effect by supplying lubricating oil overflowing from the oil reservoir 42 to the inside of the outer ring 12, as shown by arrow 73 in Figure 1.

[0030] <Example of changes> This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0031] The bearing device 10 has a discharge port 40A located on the extension of the central axis C of the shaft 50 on the bottom surface 28. The position of the discharge port on the bottom surface 28 of the bearing device 10 is not limited to the above position. For example, the discharge port may be located at a position offset on the bottom surface 28 in any direction (up, down, left, or right) from the position on the extension of the central axis C of the shaft 50 on the bottom surface 28. Alternatively, the discharge port may be located within the range of the small diameter portion 25 on the side surface of the housing hole 27.

[0032] The bearing device 10 discharges lubricating oil from the end of the shaft 50 toward the center of rotation of the shaft 50. The discharge port may discharge lubricating oil toward a direction other than the center of rotation of the shaft 50, as long as the lubricating oil is discharged toward the center of the inner ring 15, which is further toward the outer circumference of the inner ring 15 in the rolling bearing 11. For example, the discharge port may discharge lubricating oil toward a position offset in any direction from the center of rotation of the shaft 50, either up, down, left, or right.

[0033] As an example, the bearing device 10 may discharge lubricating oil toward a position offset below the center of rotation at the end of the shaft 50. In this bearing device 10, the height from which the lubricating oil falls is reduced, making it less likely for the lubricating oil that collides with the inner ring 15 or the shaft 50 and falls due to gravity to bounce back off the lower surface of the housing 21 or the surface of the lubricating oil in the notch 41. With this bearing device 10, the lubricating oil that bounces back off the lower surface of the housing 21 or the surface of the lubricating oil in the notch 41 is less likely to collide with the cage 14 or each rolling element 13.

[0034] *Referring to Figure 3, a specific example of the bearing device 10 to which the above two modification examples are applied will be described. As shown in Figure 3, in the modified bearing device 10, the discharge port 40B is located vertically above the center of the bottom surface 28. As shown in Figure 3, the discharge port 40B is positioned so as to face diagonally downward.

[0035] Lubricating oil is discharged from the discharge port 40B towards a position shifted above the center of rotation at the end of the shaft 50, as shown by arrow 81 in Figure 3. The lubricating oil that collides with the end of the shaft 50 falls toward the notch 41, as shown by arrow 82 in Figure 3. Subsequently, lubricating oil is supplied from the notch 41 to the inside of the outer ring 12, as shown by arrow 83 in Figure 3.

[0036] The discharge port may discharge lubricating oil toward the side surface of the inner ring 15 of the rolling bearing 11. The bearing device 10 has a small diameter portion 25 whose diameter is equal to the inner diameter of the outer ring 12. The diameter of the small diameter portion 25 of the bearing device 10 does not have to be equal to the inner diameter of the outer ring 12, as long as it is less than or equal to the inner diameter of the outer ring 12 and greater than the outer diameter of the inner ring 15.

[0037] The bearing device 10 has a notch bottom surface 43 at the same position as the outer ring 12 in the radial direction of the rolling bearing 11. The notch bottom surface 43 of the bearing device 10 may be located radially inward from the outer surface of the outer ring 12, as long as it is located radially outward from the inner surface of the outer ring 12. By changing the position of the notch bottom surface 43, the amount of lubricating oil that can be stored in the oil reservoir 42 can be changed.

[0038] The bearing device 10 is a bearing that supports the end of the shaft 50. However, the bearing device 10 is not limited to a bearing that supports the end of the shaft 50. Figure 4 is a schematic diagram showing a modified example in which the shaft 50 is inserted through the inside of the bearing device 10. As shown in Figure 4, the housing portion 21 of the modified bearing device 10 has a small-diameter portion 30, which is a circular cross-section space, on the discharge port 40C side of the rolling bearing 11. The shaft 50 is inserted through the small-diameter portion 30. The diameter of the small-diameter portion 30 is equal to the inner diameter of the outer ring 12.

[0039] In the modified bearing device 10, the discharge port 40C is provided within the range of the small diameter portion 30 on the lower surface of the housing portion 21. The discharge port 40C is provided on the lower surface so as to face diagonally upward. The discharge port 40C discharges lubricating oil from the discharge port 40C toward the side of the inner ring 15 on the discharge port 40C side, for example, as shown by arrow 91 in Figure 4. The lubricating oil that collides with the side of the inner ring 15 falls toward the notch portion 41, as shown by arrow 92 in Figure 4. Subsequently, as shown by arrow 93 in Figure 4, lubricating oil is supplied from the notch portion 41 to the inside of the outer ring 12.

[0040] The diameter of the small-diameter portion 30 of the modified bearing device 10 does not have to be equal to the inner diameter of the outer ring 12. The diameter of the small-diameter portion 30 only needs to be less than or equal to the inner diameter of the outer ring 12. [Explanation of Symbols]

[0041] 10...Bearing device, 11...Rolling bearing, 12...Outer ring, 13...Rolling element, 14...Cage, 15...Inner ring, 20...Housing, 21...Housing section, 23...Large diameter section, 25...Small diameter section, 27...Housing hole, 28...Bottom surface, 29...Housing groove, 30...Small diameter section, 40A, 40B, 40C...Discharge port, 41...Notch section, 42...Oil reservoir section, 43...Notched bottom surface, 50...Shaft, C...Center axis

Claims

1. In the housing compartment, A bearing device is fitted with a rolling bearing having an inner ring fixed to the outer circumferential surface of a rotating shaft, an outer ring fixed to the housing, rolling elements that roll between the inner ring and the outer ring, and a cage that maintains the spacing between the rolling elements, The aforementioned storage section is provided with a discharge port for discharging lubricating oil. From the discharge port, lubricating oil is discharged to the side of the inner ring of the rolling bearing that is closer to the center of the inner ring than to the outer circumference of the inner ring. Bearing device.

2. The rolling bearing is mounted in the housing portion in a orientation such that the axial direction of the central axis of the inner ring coincides with the horizontal direction. The housing portion has a space on the discharge port side of the rolling bearing with a circular cross-section whose diameter is less than or equal to the inner diameter of the outer ring. A notch is provided adjacent to the outer ring on the lower surface of the housing, which is part of the wall surface of the aforementioned space, on the discharge side of the rolling bearing, The bottom surface of the notch is located radially outward of the outer ring than the inner surface of the outer ring. The bearing device according to claim 1.

3. The aforementioned rolling bearing supports the end of the rotating shaft, The housing section is closed in which the rolling bearing is fitted into a housing groove provided in the opening of a circular housing hole provided in the wall surface of the housing, such that the end of the rotating shaft and the bottom surface of the housing hole face each other. The diameter of the portion of the housing hole closer to the bottom surface than the housing groove is less than or equal to the inner diameter of the outer ring and greater than the outer diameter of the inner ring. The discharge port is provided on the bottom surface of the housing hole and discharges lubricating oil toward the center of rotation of the rotating shaft at the end of the rotating shaft. The bearing device according to claim 1 or claim 2.

4. The diameter of the bottom portion of the housing hole is equal to the inner diameter of the outer ring. The bearing device according to claim 3.

5. The discharge port is provided at a position on the extension of the central axis of the rotation shaft on the bottom surface of the housing hole. The bearing device according to claim 3.

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