Rolling bearing

Abstract

The utility model provides a rolling bearing which comprises an outer ring, an inner diameter surface of the outer ring is provided with an outer ring raceway groove, and two sides of the outer ring raceway groove are provided with outer ring annular grooves; an inner ring raceway groove corresponding to the outer ring raceway groove in the radial direction is formed in the outer diameter surface of the inner ring, and inner ring annular grooves are formed in the two sides of the inner ring raceway groove; the rolling body is arranged between the outer ring raceway groove and the inner ring raceway groove; the retainer is used for retaining the rolling bodies; a sealing member not in contact with the inner ring annular groove; eccentric contact is formed between the rolling body and the retainer, so that the rolling body is closer to the outer ring relative to the radial position of the retainer. According to the non-contact type sealing retainer, the rolling body generates thrust on the retainer along the radial outer side in the running process, so that grease is guided to move towards the outer ring, the grease is prevented from being accumulated at the inner ring, the problems of grease leakage and non-uniform distribution in the prior art are effectively solved, and meanwhile, due to the non-contact type sealing design, the running resistance is also reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of rolling bearings for servo motor, in particular to a kind of rolling bearings capable of effectively preventing grease leakage and small running resistance. BACKGROUND

[0002] As a common mechanical element, rolling bearings are widely used in various mechanical equipment, and its main function is to support rotating shaft or bearing seat and reduce the friction coefficient between them. As a kind of high-precision and high-response speed control motor, servo motor has particularly strict requirements on the performance of bearings, especially in terms of grease leakage and running resistance.

[0003] At present, the common sealing methods of rolling bearings mainly include contact sealing and non-contact sealing.

[0004] Contact sealing: the sealing lip made of elastic material directly contacts with the inner ring or outer ring of the bearing to form a seal. This method has good sealing effect, but the friction resistance is large, especially at high speed, which will generate a lot of heat and affect the service life of the bearing. In addition, the interference between the sealing lip and the bearing is required to be high, and the interference that is too small will lead to sealing failure, and the interference that is too large will increase the friction resistance and affect the running accuracy of the bearing.

[0005] For example, the Chinese utility model patent (publication number CN204458848U) discloses a rolling bearing which adopts a contact sealing component. The inner diameter part of the sealing component is interference-fitted with the outer diameter surface of the bearing inner ring to form elastic contact, thereby sealing the bearing. However, this design has the problem that the interference of the sealing lip is difficult to control. If the interference is insufficient, the sealing will be poor, and if the interference is too large, the bearing will not run smoothly.

[0006] Non-contact sealing: using labyrinth sealing or gap sealing and other methods, the narrow channel or gap is used to increase the resistance of grease leakage to achieve sealing. This method has small friction resistance and low heat generation, but the sealing effect is relatively poor, especially in high-speed operation or under large vibration conditions, which is prone to grease leakage. Some servo motor bearings use labyrinth sealing, but this design still cannot completely avoid grease leakage in high-speed operation or vibration environment. In addition, the distribution of oil inside the bearing will also affect its sealing performance and running resistance. If the oil is concentrated near the rotating shaft inside the bearing, it is easy to be thrown onto the sealing element under the action of centrifugal force, resulting in sealing failure. If the oil is not evenly distributed, it will lead to poor lubrication of the bearing, increase the friction resistance, and affect the running accuracy and service life.

[0007] Therefore, the rolling bearings in the prior art have the following technical problems:

[0008] The contradiction between sealing performance and running resistance is difficult to balance: the contact type sealing has good sealing effect, but has large friction resistance; the non-contact type sealing has small friction resistance, but has poor sealing effect.

[0009] The oil leakage problem is difficult to completely solve: the existing sealing mode is still difficult to completely avoid oil leakage under high-speed operation or vibration environment.

[0010] The uneven oil distribution affects the lubrication effect and running resistance: the uneven oil distribution can cause local poor lubrication, increase the friction resistance, and affect the bearing performance.

[0011] In order to solve the above technical problems, it is urgent to provide a rolling bearing which can effectively prevent oil leakage and reduce running resistance. Practical new type content

[0012] The rolling bearing provided by the utility model can effectively prevent oil leakage and has small running resistance.

[0013] The utility model discloses a technical scheme to solve the above technical problems:

[0014] A rolling bearing, comprising an outer ring, the inner diameter surface of the outer ring is provided with an outer ring raceway groove, and the both sides of the outer ring raceway groove are provided with outer ring annular grooves; an inner ring, the outer diameter surface of the inner ring is provided with an inner ring raceway groove corresponding to the outer ring raceway groove in the radial direction, and the both sides of the inner ring raceway groove are provided with inner ring annular grooves; a plurality of rolling elements are arranged between the outer ring raceway groove and the inner ring raceway groove; a retainer is used for retaining the rolling elements; a sealing component is embedded into the outer ring annular groove at one end, and the other end is adjacent to the inner ring annular groove, and the sealing component comprises a lip portion extending to the direction of the inner ring annular groove, and at least a part of the lip portion is located in the inner ring annular groove and is not in contact with the inner ring annular groove; eccentric contact is formed between the rolling elements and the retainer, so that the radial position of the rolling elements relative to the retainer is closer to the outer ring. The eccentric contact between the rolling elements and the retainer makes the rolling elements generate a radial outward thrust on the retainer during operation, so as to guide the oil to move to the direction of the outer ring, avoid the accumulation of oil at the inner ring, effectively solve the problems of oil leakage and uneven distribution in the prior art, and reduce the running resistance due to the design of the non-contact type sealing.

[0015] Preferably, the eccentric contact between the rolling elements and the retainer makes the rolling elements generate a radial outward thrust on the retainer during operation. The rolling elements exert a radial outward thrust on the retainer, guiding the oil to move from the center area of the bearing to the direction of the outer ring.

[0016] Preferably, the contact point between the rolling body and the retainer is located between the circle connecting the centers of the rolling bodies and the circle connecting the centers of the rolling body accommodating holes on the retainer, and is closer to the circle connecting the centers of the rolling bodies. The position of the eccentric contact is defined more precisely, so that the oil guiding effect is better.

[0017] Preferably, the lip portion includes a main lip and a sub-lip, the main lip extends further in the direction of the rolling body, and the front end of the main lip is not in contact with the annular groove of the inner ring, and the sub-lip extends in the direction of the bottom of the annular groove of the inner ring. The cooperation of the main lip and the sub-lip forms a more effective sealing structure to prevent oil leakage.

[0018] Preferably, the sealing member is attached to a sealing core plate, and the end of the sealing core plate is immersed in the sealing member near the end of the annular groove of the inner ring. The structural strength and stability of the sealing member are enhanced, and the service life is prolonged.

[0019] Preferably, the end of the sealing core plate is formed with a bending shape towards the inside. The support of the sealing core plate to the sealing member is further enhanced, and the sealing reliability is improved.

[0020] In summary, the present application effectively solves the contradiction between the sealing performance and the running resistance of the rolling bearing in the prior art through the non-contact sealing design and the eccentric contact design between the rolling body and the retainer. The non-contact sealing design avoids the high friction resistance caused by the traditional contact sealing, and the eccentric contact design effectively solves the problems of oil leakage and uneven distribution by guiding the flow of oil, thereby achieving the purpose of effectively preventing oil leakage and reducing the running resistance. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a structure schematic view of a unilateral rolling bearing of an embodiment of the present application.

[0022] Figure 2 is a structure schematic view of a lip portion of an embodiment of the present application.

[0023] Figure 3 is a structure schematic view of a rolling body and a retainer of an embodiment of the present application. DETAILED DESCRIPTION

[0024] The present application will be described more clearly and completely below by way of examples, and in conjunction with the drawings.

[0025] Figure 1 is a structure schematic view of a unilateral rolling bearing of an embodiment of the present application. As shown in the figure, Figure 1 the rolling bearing of the present embodiment mainly includes an outer ring 2, an inner ring 1, a plurality of rolling bodies 3 (such as steel balls shown in the figure), Figure 1 a retainer 4 and a sealing member 5.

[0026] The inner diameter surface of the outer ring 2 is provided with an outer ring raceway groove 7 for cooperating with the outer surface of the rolling element 3 to guide the movement of the rolling element 3. The two sides of the outer ring raceway groove 7 are provided with an outer ring annular groove 21 for accommodating one end of the sealing member 5.

[0027] The outer diameter surface of the inner ring 1 is provided with an inner ring raceway groove 6 corresponding to the outer ring raceway groove 7 in the radial direction, for cooperating with the inner surface of the rolling element 3 to guide the movement of the rolling element 3. The two sides of the inner ring raceway groove 6 are provided with an inner ring annular groove 11 adjacent to the other end of the sealing member 5.

[0028] A plurality of rolling elements 3 are arranged between the outer ring raceway groove 7 and the inner ring raceway groove 6 to support the rotation of the inner ring 1 relative to the outer ring 2. The retainer 4 is used to fix the plurality of rolling elements 3 at intervals to prevent them from contacting each other, maintain a reasonable distance between the rolling elements 3, and ensure smooth operation of the rolling bearing.

[0029] One end of the sealing member 5 is fitted into the outer ring annular groove 21, and the other end is adjacent to the inner ring annular groove 11 and includes a lip 51 extending towards the inner ring annular groove 11. At least a portion of the lip 51 is located in the inner ring annular groove 11 and does not contact the inner ring annular groove 11, forming a non-contact sealing structure that can effectively prevent grease leakage and reduce operating resistance.

[0030] The key feature of the rolling bearing of the present embodiment is that the eccentric contact is formed between the rolling element 3 and the retainer 4, so that the radial position of the rolling element 3 relative to the retainer 4 is closer to the outer ring 2. In another way of expression, the PCD design value of the rolling bearing is greater than that of the retainer 4. Here, PCD refers to "Pitch Circle Diameter", i.e. the pitch circle diameter. The PCD of the bearing refers to the diameter of the circle formed by the connecting line of the centers of all rolling elements in the bearing, and the PCD of the retainer refers to the diameter of the circle formed by the connecting line of the centers of the holes in the retainer for accommodating the rolling elements. The eccentric contact between the rolling element and the retainer means that the PCD design value of the bearing is greater than the PCD value of the retainer. This eccentric contact design causes the rolling element 3 to generate a radial outward thrust on the retainer 4 during operation, guiding the grease to move from the center area of the bearing to the outer ring direction, avoiding the accumulation of grease at the inner ring, thereby effectively solving the problems of grease leakage and uneven distribution in the prior art.

[0031] Furthermore, the eccentric contact between the rolling element 3 and the retainer 4 can be specifically designed as follows: the contact point between the rolling element 3 and the retainer 4 is located between the circumference connecting the centers of the rolling elements 3 and the circumference connecting the centers of the rolling element accommodating holes on the retainer 4, and is closer to the circumference connecting the centers of the rolling elements 3. This design more accurately defines the position of the eccentric contact, making the grease guiding effect better.

[0032] Figure 2 , the structure schematic view of the lip part of an embodiment of the utility model. In order to further improve sealing performance, as shown in the lip part 51 can be designed to include main lip 10 and vice lip 9, main lip 10 further extends to the direction of rolling body 3, and the front end of main lip 10 is not contacted with inner ring annular groove 11, forms a barrier by the surface tension of grease, vice lip 9 extends to the direction of the bottom of inner ring annular groove 11, plays the role of auxiliary sealing, prevents grease from leaking from the bottom. The cooperation of main lip 10 and vice lip 9 forms more effective sealing structure, effectively prevents grease from leaking. Figure 2

[0033] In order to enhance the structural strength and stability of sealing component 5 and prolong its service life, sealing component 5 can be attached to a sealing core plate 8, and the end of sealing core plate 8 is immersed in sealing component 5 close to the end of inner ring annular groove 11, which provides support for sealing component 5, prevents it from deforming or shifting, thereby ensuring the durability and stability of the sealing effect. Further, the end of sealing core plate 8 can be designed to have an inwardly bent shape, further enhancing the support of sealing core plate 8 on sealing component 5 and improving sealing reliability. The inwardly bent end can better hold sealing component 5, improve its impact resistance and vibration resistance, and avoid sealing failure due to loosening.

[0034] In summary, the utility model discloses a non-contact sealing design and eccentric contact design between rolling body and retainer, effectively solves the contradiction between sealing performance and running resistance of the prior art rolling bearing. Non-contact sealing design avoids the high frictional resistance caused by traditional contact sealing, and eccentric contact design effectively solves the problems of grease leakage and uneven distribution by guiding grease flow, thereby achieving the purpose of effectively preventing grease leakage and reducing running resistance.

[0035] The above is only the preferred embodiment of the utility model, and cannot limit the scope of the utility model, that is, all equivalent changes and modifications made within the scope defined by the claims of the utility model shall still fall within the protection scope of the utility model.​

Claims

1. A rolling bearing, characterized in that, The present application relates to a seal assembly for a rolling bearing, and more particularly to a seal assembly for a rolling bearing having an outer ring, an inner ring, rolling elements, a retainer, and a seal member. The seal assembly includes: an outer ring having an inner diameter surface provided with an outer ring raceway groove, the outer ring raceway groove being provided with an outer ring annular groove on both sides thereof; an inner ring having an outer diameter surface provided with an inner ring raceway groove corresponding to the outer ring raceway groove in the radial direction, the inner ring raceway groove being provided with an inner ring annular groove on both sides thereof; a plurality of rolling elements disposed between the outer ring raceway groove and the inner ring raceway groove; a retainer for retaining the rolling elements; a seal member having one end fitted into the outer ring annular groove and the other end adjacent to the inner ring annular groove, the seal member including a lip portion extending toward the inner ring annular groove, at least a portion of the lip portion being located in the inner ring annular groove and being in non-contact with the inner ring annular groove; 2. Rolling bearing according to claim 1, characterized in that, the rolling elements and the retainer being in eccentric contact with each other such that the rolling elements are located closer to the outer ring in the radial direction with respect to the retainer.

3. Rolling bearing according to claim 2, characterized in that, The eccentric contact between the rolling elements and the retainer causes the rolling elements to generate a radial outward thrust on the retainer during operation.

4. Rolling bearing according to claim 3, characterized in that, The contact point between the rolling elements and the retainer is located between a circle connecting the centers of the rolling elements and a circle connecting the centers of the rolling element accommodating holes of the retainer, and is closer to the circle connecting the centers of the rolling elements.

5. Rolling bearing according to claim 4, characterized in that, The lip portion includes a main lip portion extending further toward the rolling elements, and a front end portion of the main lip portion being in non-contact with the inner ring annular groove, and a sub-lip portion extending toward the bottom of the inner ring annular groove.

6. Rolling bearing according to claim 5, characterized in that, The seal member is attached to a seal core plate, and an end portion of the seal core plate is immersed in the seal member near the end portion of the inner ring annular groove. An end portion of the seal core plate is formed in a bent shape toward the inner side.

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