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 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. When the bearing runs, the oil blocking ring can block lubricating oil raised by the rolling body to a certain extent and guide part of the lubricating oil back into the bearing, so that the self-lubricating running time of the bearing is prolonged to a certain extent, and lean oil and abrasion of the bearing caused by long-time intermittent lubrication are avoided.

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 inner ring is provided with oil blocking rings on both axial sides thereof, which 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.

[0004] When the bearing is running, the oil blocking ring can block the lubricating oil stirred up by the rolling elements to a certain extent, and guide part of the lubricating oil back to the inside of the bearing, thereby extending the self-lubricating operation time of the bearing to a certain extent and avoiding oil starvation and wear of the bearing caused by long-term intermittent lubrication.

[0005] 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

[0006] Figure 1 A partial cross-sectional view showing a rolling bearing with an oil blocking ring disposed on the inner ring;

[0007] Figure 2 show Figure 1 A partial enlarged view of the oil blocking ring on the left side of the middle; and

[0008] Figure 3 A three-dimensional diagram showing the oil blocking ring distribution on the inner ring. DETAILED DESCRIPTION

[0009] 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.

[0010] 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"). The following first discusses this situation.

[0011] Figure 1 A partial cross-sectional schematic diagram of a rolling bearing with an oil blocking ring disposed on the inner 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 frame 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.

[0012] An important feature of the present invention is that the inner ring 2 is provided with oil blocking rings 7 on both sides of the axial direction to partially close the lateral opening G of the bearing 1. The oil blocking ring 7 is assembled on the shoulders 22 on both sides of the axial direction of the inner ring raceway 20 in a tight fit through its root 7a, and extends outward from the inner ring 2 of the bearing in a substantially radial direction. The oil blocking ring 7 forms a "dam" on the shoulders 22 on both sides of the axial direction of the inner ring raceway 20, which can block the lubricating oil squeezed out and splashed when the rolling element 4 rolls over the inner ring raceway 20, thereby collecting the lubricating oil inside the bearing 1 to a certain extent. In addition, the oil blocking ring 7 is also configured to partially close the lateral (i.e. axial) opening G of the bearing 1, thereby allowing the splashed lubricating oil to enter the bearing from the opening G.

[0013] As a preferred embodiment, the oil blocking ring 7 may be formed with a bent portion at its radial outer edge 7b which is axially bent toward the inside of the bearing, such as Figure 1 The bending angle α of the bending portion 7b is preferably between 15 and 25°. The existence of the bending portion 7b is beneficial for splashing lubricating oil to enter the bearing, and is also beneficial for blocking and guiding the lubricating oil stirred up by the rolling element to return to the bearing.

[0014] 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 optimal range. Experiments have shown that the outer 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 OD 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 of f is between -0.2 and 0.5. The oil blocking ring in the above size range can achieve a better balance between not hindering the lubricating oil from entering the bearing and preventing the lubricating oil from flowing out of the bearing. In a further preferred case, f D The range of can be set between 0 and 0.4.

[0015] exist Figure 1 In the specific embodiment shown, the outer ring raceway shoulder 32 is formed with an axially extending shoulder surface, and forms a lateral opening G of the bearing 1 with the outer edge 7b of the oil blocking ring 7 in the radial direction. Since the bearing 1 is not a sealed bearing, the outer ring 3 is not provided with a groove (not shown) for assembling a seal in a conventional manner. In this case, the axially extending shoulder surface 32 facilitates the lubricating oil to enter the bearing interior. Alternatively, the outer ring raceway shoulder can also be provided with an inclined shoulder surface 32', as shown by the dotted line in the figure, so as to facilitate the lubricating oil to gather into the outer ring raceway 30 under the action of gravity.

[0016] It is necessary to point out that the oil blocking rings 7 located on both sides of the inner ring 2 in the axial direction can have different heights, that is, different outer edge diameters D. Figure 1 As shown, the oil blocking ring on the left side of the figure can be set to have a smaller inner edge diameter, while the oil blocking ring on the right side of the figure can be set to have a larger inner edge diameter. The above asymmetric design is conducive to the splashing lubricating oil entering the bearing from one side, so that the oil blocking 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.

[0017] Another important feature of the present invention is that the oil blocking ring 7 can be made of porous oleophilic materials such as phenolic bakelite and porous polyimide. The porous oleophilic material can absorb and retain lubricating oil during the period of sufficient 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. In particular, when the inner ring 2 rotates, the oil blocking ring 7 can splash out the retained lubricating oil under the action of centrifugal force, thereby replenishing the lubricating oil inside the bearing during the lubrication interval.

[0018] In addition, the oil blocking ring 7 may also be formed with an oil storage groove 7c at least in a partial circumference thereof to store lubricating oil to the greatest extent. Figure 3To prevent the lubricating oil from being collected in the longitudinal direction below the inner ring 2 under the action of gravity, the oil storage tank 7c can be formed into a segmented structure. The segmented oil storage tanks 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, causing local oil deficiency in the bearing.

[0019] It is not difficult to understand that the lubricating oil stored in the oil storage tank 7c and the lubricating oil contained 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 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.

[0020] The above describes various 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 blocking ring can still prevent (at least delay) the loss of lubricating oil from the inside of the bearing. For example, Figure 1 The bearing shown can be arranged with the left opening G facing upwards to receive lubricating oil, and the right opening G facing downwards to delay the outflow of lubricating oil. It can be seen that the oil blocking ring enables 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 is different from that in the horizontally arranged shaft system due to the influence of gravity, the function of the oil blocking ring to prevent (at least delay) the loss of lubricating oil from the bearing has not disappeared.

[0021] The various specific embodiments of the present invention are described above by taking ball bearings as an example. 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.

[0022] 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 inner ring (2) is provided with oil blocking rings (7) on both axial sides thereof for partially closing the lateral opening (G) of the bearing, the oil blocking ring (7) extending radially outward from the inner ring (2), and having a radial outer edge (7b) higher than the shoulders (22) on both sides of the inner ring raceway (20), for keeping the lubricating oil partially within the range of the inner ring (2) when the bearing is running.

2. The rolling bearing (1) according to claim 1, 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 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 value range is between -0.2 and 0.

5.

3. The rolling bearing (1) according to claim 2, characterized in that: The f D The numerical range of is further between 0 and 0.

4.

4. The rolling bearing (1) according to claim 1, characterized in that: The outer ring raceway (30) has axially extending horizontal shoulder surfaces (32) or inclined shoulder surfaces (32') formed on shoulders on both axial sides thereof, which are conducive to the lubricating oil to gather into the outer ring raceway (30) under the action of gravity.

5. The rolling bearing (1) according to claim 1, characterized in that: The oil blocking rings (7) arranged on both axial sides of the inner ring (2) have different heights.

6. The rolling bearing (1) according to claim 1, characterized in that: The oil blocking ring (7) is formed with a bending portion at its radial outer edge (7b) 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 any one of claims 1 to 7, characterized in that: The oil blocking ring (7) is made of an oleophilic material with a porous structure.

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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