Rolling bearing adaptive to intermittent oil lubrication

Abstract

The invention provides a rolling bearing (1) comprising an inner ring (2), an outer ring (3) and at least one row of rolling bodies (4) arranged between an inner ring raceway (20) and an outer ring raceway (30). And oil storage rings (6) for partially sealing the lateral opening (G) of the bearing are arranged on the two axial sides of the outer ring (3). The oil storage ring (6) extends inwards from the outer ring (3) in the radial direction, and the radial inner edge (6b) of the oil storage ring (6) is higher than blocking shoulders (32) on the two sides of an outer ring raceway (30) and used for partially keeping lubricating oil within the range of the outer ring (3) during bearing operation. On the basis of the structure, the two axial sides of the inner ring (2) are provided with oil blocking rings (7) which partially seal the lateral opening (G) of the bearing. The oil blocking ring (7) extends outwards from the inner ring (2) in the radial direction, and the radial outer edge (7b) of the oil blocking ring (7) is higher than blocking shoulders (22) on the two sides of an inner ring raceway (20) and used for partially keeping lubricating oil within the range of the inner ring (2) when the bearing runs.

Description

Technical Field

[0001] The invention relates to a rolling bearing, in particular to a rolling bearing applicable to intermittent oil lubrication. Background Art

[0002] In a powertrain consisting of a motor and a gearbox, the reliable operation of bearings and gears depends largely on the effective implementation of lubrication. Especially when space and cost are limited, most powertrains use splash lubrication. The so-called "splash lubrication" refers to an automatic lubrication method in which a rotating part (e.g., a gear) partially immersed in lubricating oil splashes lubricating oil onto itself and / or other parts (e.g., bearings) by rotating. Taking the motor bearing as an example, when the speed of the motor changes, the speed of the gear as a rotating part will also change, causing the lubricating oil to splash on the bearing sometimes and not splash on the bearing sometimes. Intermittent lubrication with too long intervals can easily cause oil-starved wear of the bearing, leading to premature failure of the bearing. Reality calls for a self-lubricating rolling bearing that can adapt to longer time intervals. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a rolling bearing, comprising an inner ring, an outer ring, and at least one row of rolling elements arranged between the inner ring raceway and the outer ring raceway. The outer ring is provided with oil storage rings on both axial sides thereof, which partially close the lateral opening of the bearing. The oil storage ring extends inward from the outer ring in the radial direction, and its radial inner edge is higher than the shoulders on both sides of the outer ring raceway, so as to keep the lubricating oil partly within the range of the outer ring when the bearing is running.

[0004] Because the oil storage ring is higher than the shoulders on both sides of the outer ring raceway in the radial direction, the lubricating oil can be gathered under the outer ring in the longitudinal direction under the action of gravity. When the bearing is running, the oil storage ring can block the lubricating oil splashed by the rolling elements to a certain extent and guide it back into the bearing. This structure can extend the self-lubricating operation time of the bearing and avoid the bearing from wearing due to lack of oil during the lubrication interval.

[0005] On the basis of the outer ring oil storage ring, the present invention can also provide oil blocking rings on both axial sides of the inner ring to partially close the lateral opening of the bearing. The oil blocking ring extends outward from the inner ring in the radial direction, and its radial outer edge is higher than the shoulders on both sides of the inner ring raceway, so as to keep the lubricating oil partly within the range of the inner ring when the bearing is running.

[0006] When the bearing is running, the oil blocking ring can block the lubricating oil stirred up by the rolling element to a certain extent and guide it back into the bearing. Together with the oil storage ring, the oil blocking ring can further extend the self-lubricating operation time of the bearing, thereby avoiding the oil starvation and wear of the bearing caused by intermittent lubrication to a greater extent.

[0007] Various embodiments and beneficial technical effects of the present invention are described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A partial cross-sectional view showing a rolling bearing having an oil storage ring disposed on the outer ring;

[0009] Figure 2 An axial side view showing a rolling bearing with an oil storage ring disposed on the outer ring;

[0010] Figure 3 An axial side view showing a local protrusion provided on the oil storage ring;

[0011] Figure 4 A partial cross-sectional view showing a rolling bearing with an oil blocking ring disposed on the inner ring;

[0012] Figure 5 Display the three-dimensional distribution diagram of the oil blocking ring on the inner ring;

[0013] Figure 6 show Figure 4 A partial enlarged view of the oil blocking ring shown in ; and

[0014] Figure 7 A partial cross-section of a rolling bearing showing both an outer ring oil reservoir and an inner ring oil blocker. DETAILED DESCRIPTION

[0015] In the following description, the same or similar reference numerals are always used to indicate the same or similar components. In addition, the terms indicating directions, such as "axial", "radial" and "circumferential direction", refer to the axial, radial and circumferential directions of the components being described unless otherwise limited or specified.

[0016] Figure 1 A partial cross-sectional schematic diagram of a rolling bearing with an oil storage ring disposed on the outer ring is shown. As shown in the figure, the rolling bearing 1 comprises an inner ring 2, an outer ring 3, and at least one row of rolling elements 4 disposed between the inner ring raceway 20 and the outer ring raceway 30. A retaining cage 5 is disposed on the rolling element 4 for maintaining a regular circumferential spacing between the rolling elements. The inner ring 2 is formed with inner ring raceway shoulders 22 on both axial sides of its raceway 20, and the outer ring 3 is formed with outer ring raceway shoulders 32 on both axial sides of its raceway 30.

[0017] An important feature of the present invention is that the outer ring 3 is provided with oil storage rings 6 extending radially inward from the outer ring 3 on both sides of the axial direction. The oil storage ring 6 is fastened in the grooves 34 on both sides of the axial direction of the outer ring 3 through its root 6a, and the height of its radial inner edge (i.e., free end) 6b exceeds the shoulder 32 on both sides of the outer ring raceway 30. Therefore, the oil storage ring 6 can form a "dam" on both sides of the axial direction of the outer ring raceway 30 to collect the lubricating oil in the outer ring raceway 30. In addition, the oil storage ring 6 is also configured to partially close the lateral (i.e., axial) opening G of the bearing 1, so that the lubricating oil can be prevented from leaking from the opening G to a certain extent.

[0018] In most types of powertrains, the shaft system of the motor and the gear is arranged roughly parallel to the ground (hence referred to as a "horizontally arranged shaft system"). This situation will be described first below.

[0019] Since the outer ring 3 is provided with oil storage rings 6 on both sides of its axial direction, the lubricating oil splashed into the bearing 1 will be collected under the outer ring 3 in the longitudinal direction (hereinafter referred to as "below the longitudinal direction") under the action of gravity, forming an oil storage pool with a certain liquid level. It can be imagined that the liquid level of the lubricating oil in the oil storage pool is limited by the height of the radial inner edge 6b of the oil storage ring 6. Regardless of whether the inner ring 2 or the outer ring 3 rotates, when the rolling body 4 rolls over the oil storage pool located below the outer ring 3 in the longitudinal direction, it will carry the lubricating oil to the inner ring raceway 20 and the outer ring raceway 30 of the bearing 1 in the entire circumferential direction, thereby achieving the purpose of extending the self-lubricating time of the bearing. In addition, when the rolling body 4 rolls over the outer ring raceway 30, a part of the lubricating oil squeezed out and splashed will also be blocked by the oil storage ring 6 and redirected back to the inside of the bearing. It can be seen that the existence of the oil storage ring 6 can at least keep the lubricating oil inside the bearing to a certain extent, thereby improving the ability of the bearing to improve lubrication by storing the lubricating oil in the outer ring raceway. In other words, the presence of the oil reservoir ring can extend the time the bearing can withstand lubrication intervals.

[0020] As a preferred implementation, the inner diameter d of the oil storage ring 6 satisfies the relationship: d = 0.5 × (D O +D I )+f d ×D W , where D O D is the groove bottom diameter of the outer ring raceway. I D is the groove bottom diameter of the inner ring raceway. W is the diameter of the rolling element, f dThe range of is between 0.35 and 0.55. The above relationship limits the inner edge height of the oil storage ring to an appropriate range. When the inner edge height is too low, the capacity of the oil storage ring to store lubricating oil and the ability to prevent the lubricating oil from flowing out will decrease. On the contrary, when the inner edge height is too high, the side effect of the oil storage ring preventing the lubricating oil from entering the bearing will increase, which is not conducive to the bearing receiving splashing lubricating oil. In a further preferred case, f d The range can be between 0.40 and 0.50.

[0021] In addition, the oil storage ring 6 may also have a radial protrusion 6c at least partially formed on its radial inner edge 6b. When the inner ring rotates and the outer ring is stationary, the protrusion 6c may be arranged to be located at a longitudinally lower position of the bearing outer ring 3, such as Figure 3 As shown. Since the protrusion 6c is higher than the inner edge 6b of the rest of the oil storage ring 6, it can collect more lubricating oil when it is located at the longitudinal lower position of the outer ring, thereby forming an oil storage pool with a higher liquid level. Obviously, a larger capacity oil storage pool is conducive to further improving the self-lubricating ability of the bearing and the duration of the lubrication interval. However, the increase in the lubricating oil level means an increase in oil stirring loss, which may lead to a decrease in transmission efficiency and heating of the bearing. Therefore, the height of the protrusion 6c should have an appropriate range. Experiments have shown that the minimum spacing H between the protrusion 6c and the center axis O of the bearing 1 is C It is best to satisfy the relationship: H C =0.5×(R O +R I )+f C ×R W , where R O R is the groove bottom radius of the outer ring raceway, I R is the groove bottom radius of the inner ring raceway, W is the radius of the rolling element, f C The range is between -0.1 and 0.1.

[0022] It is necessary to point out that the oil storage rings 6 located on both sides of the outer ring 3 in the axial direction can have different heights, that is, different inner edge diameters d. Figure 1 As shown in the figure, the oil storage ring on the left side of the figure can be set to have a larger inner edge diameter, while the oil storage ring on the right side of the figure can be set to have a smaller inner edge diameter. The above asymmetric design is conducive to the splashing lubricating oil entering the bearing from one side, so that the oil storage ring on the other side has better sealing performance, thereby preventing the lubricating oil from flowing out directly from the opposite side after entering the bearing to a certain extent.

[0023] Figure 4A radial cross-sectional view showing a rolling bearing with an oil blocking ring disposed on the inner ring. As shown in the figure, the inner ring 2 is provided with oil blocking rings 7 on both axial sides thereof, which partially close the lateral opening G of the bearing 1. The oil blocking ring 7 extends outward from the inner ring 2 of the bearing in the radial direction, and its root 7a is assembled on the shoulders 22 on both axial sides of the inner ring raceway 20 through a tight fit. Since the radial outer edge 7b of the oil blocking ring 7 is higher than the shoulders 22 of the inner ring raceway in the radial direction, it can block the lubricating oil squeezed out and splashed when the rolling element 4 rolls over the inner ring raceway 20, and guide (reflect) the lubricating oil back to the inner ring raceway 20 to a certain extent.

[0024] In addition, the oil blocking ring 7 may further form a bending portion at its radial outer edge 7b that is axially bent toward the inside of the bearing, such as Figure 4 and 6 As shown. The bending angle α of the bending portion 7b is preferably between 15 and 25°. The existence of the bending portion 7b is conducive to the splashing lubricating oil entering the interior of the bearing on the one hand, and is also conducive to blocking and guiding the lubricating oil stirred up by the rolling body to return to the interior of the bearing on the other hand. In particular, when the inner ring 2 rotates, the oil blocking ring 7 can splash the lubricating oil to the surroundings under the action of centrifugal force. In this case, the bending portion 7b bent inward in the axial direction is conducive to guiding the lubricating oil splashed by the oil blocking ring 7 back to the space defined by the oil storage rings 6 on both sides of the bearing outer ring 3 in the axial direction.

[0025] In terms of the functions of guiding the lubricating oil into the bearing and preventing the lubricating oil from flowing out of the bearing, the radial height of the oil blocking ring 7 should have an appropriate range. Experiments have shown that the outer edge diameter D of the oil blocking ring 7 preferably satisfies the relationship D = 0.5 × (D O +D I )+f D ×D W Among them, D O D is the groove bottom diameter of the outer ring raceway. I D is the groove bottom diameter of the inner ring raceway. W is the diameter of the rolling element, f D The range is between -0.2 and 0.1. The oil blocking ring in the above size range can achieve the best balance between the two functions of not hindering the lubricating oil from entering the bearing and preventing the lubricating oil from flowing out of the bearing.

[0026] In addition, the oil blocking ring 7 can also be made of porous oleophilic materials such as phenolic bakelite and porous polyimide. The porous oleophilic material can absorb and retain more lubricating oil during the period of abundant oil, and release the stored lubricating oil during the period of insufficient oil, thereby providing additional and long-lasting lubricating oil replenishment for the bearing. Taking the rotation of the inner ring as an example, the oil blocking ring 7 can splash out the retained lubricating oil under the action of centrifugal force, which is used to replenish the lubricating oil inside the bearing during the lubrication interval.

[0027] As a preferred embodiment, the oil blocking ring 7 is formed with an oil storage groove 7c in at least a partial circumference thereof to store lubricating oil to the greatest extent. Figure 6 To prevent the lubricating oil from being collected at the lower position of the bearing inner ring 2 in the longitudinal direction under the action of gravity, the oil storage tank 7c can be formed into a segmented structure, such as Figure 5 The segmented oil storage grooves 7c can be evenly distributed in the circumferential direction, and the number is not less than the number of rolling elements, so as to avoid uneven distribution of the thrown lubricating oil on the circumference and cause local oil deficiency in the bearing.

[0028] It is not difficult to understand that the lubricating oil in the oil storage tank 7c and the lubricating oil in the oil blocking ring 7 material should be released under different speed conditions. For example, the lubricating oil in the oil storage tank 7c is generally released first when the inner ring speed is low, while the lubricating oil contained in the oil blocking ring 7 material is usually gradually released after the inner ring speed increases. Obviously, this mechanism in which the lubricating oil is gradually released with the change of speed is conducive to enhancing the self-lubricating ability of the bearing and extending the self-lubricating time of the bearing.

[0029] As a combination of the above features, the inner ring oil blocking ring 7 can also form a "window" W for the lubricating oil to enter and exit the bearing 1 together with the outer ring oil storage ring 6, such as Figure 7 As shown in the figure, the window W is only a part of the side opening G of the bearing in terms of size, which will not prevent the lubricating oil from entering the bearing, and will also help to keep the lubricating oil inside the bearing to a certain extent. It is not difficult to understand that the window W with appropriate structure and size can extend the self-lubricating time of the bearing by adjusting the difficulty of the lubricating oil entering and exiting the bearing.

[0030] Similar to the bent portion 7b of the oil blocking ring 7, the oil storage ring 6 may also form a bent portion (not shown in the figure) bent toward the inside of the bearing in the axial direction at its radial inner edge 6b. Thus, the bent portion 6b of the oil storage ring 6 and the bent portion 7b of the oil blocking ring 7 together form a funnel-shaped window W (not shown in the figure) that is recessed toward the inside of the bearing in the axial direction, thereby facilitating the lubricating oil to enter the bearing, but preventing the lubricating oil from flowing out of the bearing.

[0031] The above describes different embodiments of the rolling bearing of the present invention by taking a horizontally arranged shaft system as an example. In a longitudinally arranged shaft system (perpendicular to the ground), the lubricating oil in the bearing is easily lost under the action of gravity, which can easily cause premature failure of the bearing. However, in a longitudinally arranged shaft system, the oil storage ring and oil blocking ring used in the present invention can still prevent (at least delay) the loss of lubricating oil from the inside of the bearing. For example, Figure 7The bearing shown can be arranged with the left window facing upwards for receiving lubricating oil, and the right window facing downwards for delaying the outflow of lubricating oil. It can be seen that the oil storage ring and / or oil blocking ring enable the rolling bearing to achieve the purpose of extending the self-lubricating time of the bearing in the longitudinally arranged shaft system. Although the flow mechanism of lubricating oil in the longitudinally arranged shaft system under the action of gravity is different from that in the horizontally arranged shaft system, the function of the oil storage ring and / or oil blocking ring to prevent (at least delay) the loss of lubricating oil from the bearing has not disappeared.

[0032] The various specific embodiments of the present invention are described above by taking ball bearings as an example. However, those skilled in the art should understand that other types of rolling bearings, such as cylindrical roller bearings, tapered roller bearings, etc., can also adopt the above technical solutions.

[0033] The rolling bearing described above is not limited by the specific implementation method, and the more general technical solution shall be subject to the definition in the attached claims. Any changes and improvements to the present invention, as long as they comply with the definition in the attached claims, shall fall within the protection scope of the present invention.

Claims

1. A rolling bearing (1), comprising an inner ring (2), an outer ring (3) and at least one row of rolling elements (4) arranged between the inner ring raceway (20) and the outer ring raceway (30), wherein the outer ring (3) is provided with oil storage rings (6) on both axial sides thereof, which partially close the lateral opening (G) of the bearing, and the oil storage ring (6) extends radially inward from the outer ring (3), and its radial inner edge (6b) is higher than the shoulders (32) on both sides of the outer ring raceway (30), so as to keep the lubricating oil partially within the range of the outer ring (3) when the bearing is running.

2. The rolling bearing (1) according to claim 1, characterized in that: The inner diameter (d) of the oil storage ring (6) satisfies the relationship d=0.5×(D O +D I )+f d ×D W , where D O D is the groove bottom diameter of the outer ring raceway. I D is the groove bottom diameter of the inner ring raceway. W is the diameter of the rolling element, f d The range is between 0.35 and 0.

55.

3. The rolling bearing (1) according to claim 2, characterized in that: The oil storage ring (6) is further provided with at least one radial protrusion (6c) on its radial inner edge (6b), and the minimum distance (H) between the radial protrusion (6c) and the central axis (O) of the bearing is C ) satisfies the relation H C =0.5×(R O +R I )+f C ×R W , where R O R is the groove bottom radius of the outer ring raceway, I R is the groove bottom radius of the inner ring raceway, W is the radius of the rolling element, f C The range is between -0.1 and 0.

1.

4. The rolling bearing (1) according to any one of claims 1 to 3, characterized in that: The inner ring (2) is provided with oil blocking rings (7) on both axial sides thereof, which partially close the lateral opening (G) of the bearing. The oil blocking rings (7) extend radially outward from the inner ring (2), and their radial outer edges (7b) extend beyond the shoulders (22) on both sides of the inner ring raceway (20), so as to keep the lubricating oil partially within the range of the inner ring (2) when the bearing is running.

5. The rolling bearing (1) according to claim 4, characterized in that: The outer diameter (D) of the oil blocking ring (7) satisfies the relationship D=0.5×(D O +D I )+f D ×D W , where f D The range is between -0.2 and 0.

1.

6. The rolling bearing (1) according to claim 5, characterized in that: The oil blocking ring (7) is formed with a bending portion at the radial outer edge (7b) thereof, which is bent toward the inside of the bearing in the axial direction.

7. The rolling bearing (1) according to claim 6, characterized in that: The bending portion has a bending angle (α) of 15 to 25°.

8. The rolling bearing (1) according to claim 4, characterized in that: The oil blocking ring (7) is made of porous oleophilic material.

9. The rolling bearing (1) according to claim 8, characterized in that: An oil storage groove (7c) capable of storing lubricating oil is formed in the oil blocking ring (7).

10. The rolling bearing (1) according to claim 9, characterized in that: The oil storage groove (7c) comprises segmented oil storage grooves spaced apart in the circumferential direction, and the number of the segmented oil storage grooves is not less than the number of rolling bodies (4).

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