Low-friction contact type sealing structure for turntable bearing

Abstract

The utility model belongs to the technical field of bearing sealing, and particularly relates to a low-friction contact type sealing structure for a turntable bearing, which comprises a bearing inner ring and a bearing outer ring sleeved on the outer side of the bearing inner ring, steel balls which are uniformly distributed are arranged between the bearing inner ring and the bearing outer ring; isolation blocks which are uniformly distributed are arranged among the steel balls; two annular sealing grooves are formed in the positions, close to the inner diameter, of the lower end face of the bearing outer ring. Openings of the two annular sealing grooves face downwards, and annular rubber seals with rectangular cross sections are arranged in the grooves; the left end face, the right end face and the lower end face of the annular rubber seal are all provided with evenly-distributed sealing lips. The sealing structure is simple, the annular rubber seal can prevent water vapor, corrosive gas, granular foreign matters and the like from entering a bearing raceway, meanwhile, the contact friction force between the annular rubber seal and the inner ring and the outer ring of the bearing is small, and the sealing performance is greatly improved when the annular rubber seal is combined with the labyrinth seal for use.

Description

Technical Field

[0001] The utility model belongs to the technical field of bearing seals, and particularly relates to a low-friction contact seal structure for a slewing bearing. Background Art

[0002] A slewing bearing, also known as a slewing ring, is a medium and large-sized bearing that can simultaneously bear large axial loads, radial loads, and overturning moments. It is widely used in large rotary devices such as lifting and transportation machinery, mining machines, construction engineering machinery, port machinery, wind power generation, medical equipment, radar, precision turntables, optical telescopes, and radio telescopes. The sealing requirements of slewing bearings vary according to working conditions. Currently, the commonly used sealing forms for slewing bearings are contact rubber strip seals and non-contact labyrinth seals. In the contact rubber strip seal structure, one end of the rubber strip is embedded in the seal groove on one ring, and the lip of the rubber strip rests on the end face or cylindrical surface of the other ring to form an axial or radial interference. This seal structure has the advantages of simple structure, small occupied space, and reliable sealing performance. However, the axial or radial interference formed by the seal lip and the corresponding ring will increase the rotational friction resistance of the bearing. On the other hand, it will also affect the fluctuation of the bearing rotation torque. In occasions where high requirements are placed on the bearing friction torque and the fluctuation of the friction torque, such as precision turntable measuring instruments, the interference contact seal structure cannot fully meet the requirements; the labyrinth seal structure can prevent foreign objects with larger particles from entering the bearing interior and does not affect the rotational friction torque of the bearing, but its waterproof, corrosion-resistant gas, and heat insulation effects are not good.

[0003] In the patent application No. 201120169255.2, a seal structure for a slewing bearing is disclosed. Grooves are provided on the upper end face of the outer ring and the lower end face of the inner ring. A pressing plate is installed and connected in the grooves. One end of the pressing plate has a step. Two annular seal grooves are opened on the upper end face of the inner ring and the lower end face of the outer ring; the step of the pressing plate on the upper end face of the outer ring is embedded in one annular seal groove on the upper end face of the inner ring to form a labyrinth seal structure, and an oil-impregnated asbestos rope is placed in the other annular seal groove on the upper end face of the inner ring. The oil-impregnated asbestos rope contacts the inner ring and the pressing plate to form a contact seal structure. However, in the above seal structure, the pressing plate in the slewing bearing is fixed to the ring with screws, which increases the complexity of the structure. On the other hand, when the bearing size is large, it is difficult to ensure the machining accuracy of the pressing plate as a thin-walled part. If the thickness of the pressing plate is increased for the convenience of machining, the height of the bearing will increase, the bearing cost will increase, and the bearing weight will also increase; in addition, the axial runout of the ring of the seal structure slewing bearing will also affect the contact area between the oil-impregnated asbestos rope and the inner ring and the pressing plate, thereby affecting the rotational friction torque of the bearing. Summary of the Utility Model

[0004] The purpose of the utility model is to overcome the problems existing in the existing seal structure and propose a low-friction contact seal structure for a slewing bearing.

[0005] The object of the present utility model can be achieved by the following technical solutions: A low-friction contact seal structure for a slewing bearing, comprising an inner bearing ring and an outer bearing ring sleeved on the outside thereof; evenly distributed steel balls are arranged between the inner bearing ring and the outer bearing ring; evenly distributed spacer blocks are arranged between the steel balls; two annular seal grooves are provided at positions close to the inner diameter on the lower end surface of the outer bearing ring; the openings of the two annular seal grooves face downward, and an annular rubber seal with a rectangular cross-section is arranged in the grooves; evenly distributed seal lips are arranged on the left, right and lower end surfaces of the annular rubber seal; the seal lips on the left and right sides of the annular rubber seal are in contact with the annular seal groove of the outer bearing ring to form a contact seal; the seal lip on the lower end surface of the annular rubber seal is in contact with the corresponding step surface of the inner bearing ring to form a contact seal.

[0006] Labyrinth seals with openings facing downward are provided on the right side of the upper end seal and the left side of the lower end seal between the outer bearing ring and the inner bearing ring.

[0007] The seal lip is set to be a seal with a triangular cross-section.

[0008] The frictional force generated by the contact between the seal lips on the left and right sides of the annular rubber seal and the annular seal groove of the outer bearing ring is less than the gravity of the annular rubber seal, and the seal lip on the lower end surface thereof is in contact with the corresponding step surface of the inner bearing ring.

[0009] The annular seal groove of the outer bearing ring and the outer bearing ring are integrally designed.

[0010] The surface roughness of the annular seal groove of the outer bearing ring and the surfaces of the inner bearing ring in contact with the annular rubber seal is low.

[0011] The beneficial effects of the present utility model are: The seal structure has a simple structure. The annular rubber seal can prevent water vapor, corrosive gases, particulate foreign matters, etc. from entering the bearing raceway. At the same time, the contact frictional force between the annular rubber seal and the inner and outer bearing rings is small. Since the contact frictional force between the annular rubber seal and the inner bearing ring is generated by the gravity of the seal, the axial and radial runouts of the raceway during bearing rotation do not affect the contact frictional force of the annular rubber seal. Combined with the labyrinth seal, the sealing performance is greatly improved, enabling the slewing bearing to work safely in environments such as water vapor, corrosive gases, particulate foreign matters, etc., and at the same time maintaining a small rotational frictional torque and frictional torque fluctuation. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic structural view of the present utility model;

[0013] Figure 2 is a schematic structural view of the seal lip in the present utility model;

[0014] Figure 3 is Figure 1 The enlarged schematic diagram at position Ⅰ in

[0015] Figure 4 is Figure 1 The enlarged schematic diagram at position Ⅱ in

[0016] Markings in the figure: 1. Inner ring of bearing; 2. Outer ring of bearing; 3. Steel ball; 4. Spacer block; 5. Annular seal groove; 6. Annular rubber seal; 7. Sealing lip. Specific embodiments

[0017] The following further elaborates on the specific embodiments of the present utility model in conjunction with the accompanying drawings.

[0018] As Figure 1 , Figure 2 shown, a low-friction contact seal structure for a slewing bearing includes an inner ring 1 of the bearing and an outer ring 2 of the bearing sleeved on the outside thereof; a plurality of evenly distributed steel balls 3 are arranged between the inner ring 1 of the bearing and the outer ring 2 of the bearing; a plurality of evenly distributed spacer blocks 4 are arranged between the steel balls 3; two annular seal grooves 5 are provided at the lower end surface of the outer ring 2 of the bearing near the inner diameter; the openings of the two annular seal grooves 5 face downward, and an annular rubber seal 6 with a rectangular cross-section is arranged in the grooves; sealing lips 7 are evenly arranged on the left, right and lower end surfaces of the annular rubber seal 6; the sealing lips 7 on the left and right sides of the annular rubber seal 6 are in contact with the annular seal groove 5 of the outer ring 2 of the bearing to form a contact seal; the sealing lips 7 on the lower end surface of the annular rubber seal 6 are in contact with the corresponding step surface of the inner ring 1 of the bearing to form a contact seal.

[0019] Labyrinth seals with downward openings are provided on the right side of the upper seal between the outer ring 2 of the bearing and the inner ring 1 of the bearing and on the left side of the lower seal; the labyrinth seals provided here can prevent foreign objects with larger particles from entering the bearing, and the downward openings of the labyrinth seals can prevent foreign objects with smaller particles from entering the bearing due to the action of gravity, playing a protective role for the contact seal; the sealing lips 7 are designed with a triangular cross-section, and can also be designed into other shapes with reduced friction; the frictional force generated by the contact between the sealing lips 7 on the left and right sides of the annular rubber seal 6 and the annular seal groove 5 of the outer ring 2 of the bearing is less than the gravity of the annular rubber seal 6, which can ensure that the annular rubber seal 6 freely falls under the action of gravity, and the sealing lips 7 on its lower end surface are in contact with the corresponding step surface of the inner ring 1 of the bearing; the annular seal groove 5 of the outer ring 2 of the bearing and the outer ring 2 of the bearing are integrally designed; this integral design facilitates precision machining, and the step surface structure of the inner ring 1 of the bearing in contact with the sealing lips 7 on the lower end surface of the annular rubber seal 6 is simple (non-concave bottom contact surface design), facilitating precision machining such as grinding; the surface roughness of the annular seal groove 5 of the outer ring 2 of the bearing and the surfaces of the inner ring 1 of the bearing in contact with the annular rubber seal 6 is low; the designed roughness value here is small to reduce the contact frictional force.

[0020] As Figure 3 , Figure 4 shown, when the utility model is specifically used, the sealing lips a and b with a triangular cross-section designed on the left side of the annular rubber seal 6 are in contact with the working surface P of the annular sealing groove 5 designed on the outer ring 2 of the bearing to form a contact seal, preventing water vapor, corrosive gases, particulate foreign matters, etc. from entering the bearing; the sealing lips e and f with a triangular cross-section designed on the right side of the annular rubber seal 6 are in contact with the working surface N of the annular sealing groove 5 designed on the outer ring 2 of the bearing to form a contact seal, preventing the leakage of the grease inside the bearing; under the action of gravity, the sealing lips c and d on the lower end surface of the annular rubber seal 6 are in contact with the corresponding step surface Q of the inner ring 1 of the bearing to form a contact seal, and the sealing lip c with a triangular cross-section designed on the lower end surface of the annular rubber seal 6 is in contact with the corresponding step surface Q of the inner ring of the bearing to form a contact seal, preventing water vapor, corrosive gases, particulate foreign matters, etc. from entering the bearing, and the sealing lip d with a triangular cross-section designed on the lower end surface of the annular rubber seal 6 is in contact with the corresponding step surface Q of the inner ring 1 of the bearing to form a contact seal, preventing the leakage of the grease inside the bearing, which can not only form a sealing effect but also ensure a small friction force of the bearing.

[0021] The above is only the preferred specific embodiment of the utility model, but the protection scope of the utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the utility model, according to the technical solution and the inventive concept of the utility model, makes equivalent substitutions or changes, and all should be covered within the protection scope of the utility model.

Claims

1. A low-friction contact seal structure for a turntable bearing, comprising a bearing inner ring (1) and a bearing outer ring (2) sleeved on the outer side of the bearing inner ring; wherein: Uniformly distributed steel balls (3) are arranged between the bearing inner ring (1) and the bearing outer ring (2); uniformly distributed isolation blocks (4) are arranged between the steel balls (3); two annular sealing grooves (5) are arranged on the lower end surface of the bearing outer ring (2) near the inner diameter; the two annular sealing grooves (5) are opened downward, and an annular rubber seal (6) with a rectangular cross section is arranged in the groove; uniformly distributed sealing lips (7) are arranged on the left, right and lower end surfaces of the annular rubber seal (6); the sealing lips (7) on the left and right sides of the annular rubber seal (6) contact the annular sealing groove of the bearing outer ring (2) to form a contact seal; the sealing lip (7) on the lower end surface of the annular rubber seal (6) contacts the corresponding step surface of the bearing inner ring (1) to form a contact seal.

2. The low-friction contact seal structure for a turntable bearing according to claim 1 is characterized in that: The right side of the upper seal of the bearing outer ring (2) and the bearing inner ring (1) and the left side of the lower seal are both provided with a labyrinth seal opening downward.

3. The low friction contact seal structure for a turntable bearing according to claim 1 is characterized in that: The sealing lip (7) is configured to have a triangular seal cross section.

4. The low friction contact seal structure for a turntable bearing according to claim 1 is characterized in that: The friction force generated by the sealing lips (7) on the left and right sides of the annular rubber seal (6) contacting the annular sealing groove (5) of the bearing outer ring (2) is smaller than the weight of the annular rubber seal (6), and the sealing lips (7) on the lower end surface thereof are in contact with the corresponding step surface of the bearing inner ring (1).

5. The low friction contact seal structure for a turntable bearing according to claim 1, characterized in that: The annular sealing groove (5) of the bearing outer ring (2) is designed as an integral unit with the bearing outer ring (2).

6. The low friction contact seal structure for a turntable bearing according to claim 1 is characterized in that: The annular sealing groove (5) of the bearing outer ring (2) and the contact surfaces of the bearing inner ring (1) and the annular rubber seal (6) have low surface roughness.

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