A new type of radial floating seal structure of a ball bearing

Abstract

This utility model relates to the technical field of heavy-duty truck transmission components, and discloses a novel radial floating seal structure for ball bearings, comprising: a drive shaft and a ball bearing sleeved on the drive shaft. The inner ring of the ball bearing is fastened to the drive shaft by a set screw. An upper dust cover is provided at the upper end of the ball bearing, and a lower dust cover is provided at the lower end of the ball bearing. A bearing sleeve is sleeved on the outside of the ball bearing, and a bearing cover is fixedly connected to the outside of the bearing sleeve. The lower dust cover is fixedly connected to the bearing sleeve at the bottom by a pressure plate. This novel radial floating seal structure for ball bearings has the following advantages: excellent sealing and protection effect; multiple small clearance fits and grease reservoir seals form multiple sealing barriers, which can effectively prevent water, mud, and dust from entering the ball bearing, solve the problem of ball bearing corrosion and jamming damage under harsh working conditions, and significantly improve the service life of the middle / lower steering drive shaft assembly.

Description

Technical Field

[0001] This utility model relates to the technical field of heavy truck transmission components, specifically a novel radial floating seal structure for ball bearings. Background Technology

[0002] The steering drive shaft assembly of a heavy-duty truck is the core transmission component of the steering system. Depending on the overall vehicle design requirements, there are single-shaft, dual-shaft, and triple-shaft connection structures. Among them, the dual-shaft and triple-shaft connection steering drive shaft assemblies will have transition support components with ball bearings on the middle / lower steering drive shaft assembly. The ball bearings realize the torque transmission and rotation guidance of the drive shaft, ensuring the stability of the steering transmission.

[0003] As a core component of the transition support, the sealing and protection effect of ball bearings directly determines the service life and operational reliability of the middle / lower steering drive shaft assembly.

[0004] Currently, the sealing and protection structure of this type of ball bearing on heavy trucks has certain defects. One type of structure uses a large clearance fit between the upper and lower dust covers of the ball bearing and the steering drive shaft. Heavy trucks often operate under harsh conditions such as ore transportation and cement mixing. External water, mud, sand and dust can easily enter the interior of the dust cover through the gap, and then invade the ball bearing, causing wear and jamming of the ball bearing raceway, and ultimately leading to steering failure of the middle / lower steering drive shaft assembly.

[0005] Another type of structure uses a small interference fit between the dust cover and the drive shaft. Although it can block impurities from entering to a certain extent, the drive shaft at the lower end of the transition support has a large radial rotation / swing. The interference fit will cause continuous friction between the drive shaft and the dust cover. After a period of use, serious friction noise will appear. Moreover, long-term friction will cause wear on the sealing surface of the dust cover, and eventually the sealing effect will be lost. The after-sales failure feedback rate is high.

[0006] Existing ball bearing sealing protection structures cannot simultaneously achieve reliable impurity sealing protection and dynamic adaptation without frictional noise, making it difficult to meet the usage requirements of heavy-duty trucks under harsh operating conditions. Utility Model Content

[0007] The purpose of this invention is to provide a novel radial floating seal structure for ball bearings to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, this utility model provides the following technical solution: a novel radial floating sealing structure for ball bearings, comprising: a drive shaft and a ball bearing sleeved on the drive shaft, wherein the inner ring of the ball bearing is fastened to the drive shaft by a set screw, an upper dust cover is provided at the upper end of the ball bearing, and a lower dust cover is provided at the lower end of the ball bearing, a bearing sleeve is sleeved on the outer side of the ball bearing, a bearing cover is fixedly connected to the outer side of the bearing sleeve, and the lower dust cover is fixedly connected to the bearing sleeve by a pressure plate at its lower end, the upper dust cover is clamped and fixed between the bearing cover and the bearing sleeve, and the lower dust cover comprises: a lower dust cover, an outer sealing ring, and an inner sealing ring, wherein the outer sealing ring is embedded in the mounting groove of the lower dust cover, and the inner sealing ring is embedded inside the outer sealing ring.

[0009] Preferably, the upper dust cover is made of EPDM rubber, the upper dust cover and the inner ring of the ball bearing are fitted with a small clearance of 0.1mm, the inner diameter of the upper dust cover is provided with double grease reservoirs, and the outer end of the upper dust cover is integrally formed with radial buffer texture.

[0010] Preferably, the lower dust cover is made of EPDM rubber, the inner wall of the lower dust cover is integrally formed with axial buffer texture, and an outer sealing ring mounting groove is opened at the lower end of the inner diameter of the lower dust cover, and the inner end opening diameter of the mounting groove is larger than the outer end opening diameter, and the outer sealing ring and the mounting groove of the lower dust cover are in a small interference fit.

[0011] Preferably, the outer sealing ring is made of POM plastic material, the inner end opening diameter of the outer sealing ring is larger than the outer end opening diameter, the left and right side gaps between the inner sealing ring and the outer sealing ring are 0.1mm, the upper and lower end face gaps between the inner sealing ring and the outer sealing ring are 1.5mm, and the gaps are filled with grease.

[0012] Preferably, the inner sealing ring is made of polyurethane material, and the inner diameter of the inner sealing ring is integrally formed with two inner lips. The two inner lips are fitted with the drive shaft with a small clearance of ≤0.1mm. A grease storage groove is provided between the two inner lips, and the grease storage groove is filled with grease.

[0013] Preferably, the bearing cover and the pressure plate are fixedly connected by rivets, and the pressure plate presses and fixes the lower dust cover assembly to the lower end face of the bearing sleeve, thereby achieving a sealed connection between the lower dust cover assembly and the transition support assembly.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: This novel radial floating seal structure for ball bearings has the following advantages:

[0015] It has excellent sealing and protection effect. Through multiple small clearance fits and grease seal of grease reservoir, multiple sealing barriers are formed, which can effectively prevent water, mud and dust from entering the ball bearing, solve the problem of ball bearing corrosion and jamming damage under harsh working conditions, and improve the service life of the middle / lower steering drive shaft assembly.

[0016] It can dynamically adapt to the movement of the drive shaft. The radial buffer texture of the upper dust cover and the axial buffer texture of the lower dust cover, combined with the radial floating effect of the inner / outer sealing rings, can effectively counteract the force brought by the radial swing and up-and-down movement of the drive shaft, eliminate frictional noise between the seals and the drive shaft and the inner ring of the ball bearing, and improve the overall driving comfort of the vehicle.

[0017] With strong adaptability and practicality, the materials of each component are selected as needed, and the structure of the installation slot with a large inner and small outer part takes into account both the ease of assembly and the anti-detachment effect. The overall structure is compact and can be directly adapted to the original transition support without major modifications. It is easy to disassemble and assemble, has good promotion and application value, and reduces the after-sales replacement cost for customers. Attached Figure Description

[0018] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0019] Figure 1 This is a schematic diagram of the structure of this utility model;

[0020] Figure 2 for Figure 1 Schematic diagram of the upper and middle dust covers;

[0021] Figure 3 for Figure 1 A schematic diagram of the structure of the middle and lower dust covers;

[0022] Figure 4 for Figure 1 Schematic diagram of the structure of the lower dust cover;

[0023] Figure 5 for Figure 1 Schematic diagram of the structure of the inner and outer sealing rings;

[0024] Figure 6 for Figure 1 A schematic diagram of the inner seal.

[0025] In the diagram: 1. Lower dust cover, 2. Outer sealing ring, 3. Inner sealing ring, 4. Pressure plate, 5. Bearing cover, 6. Bearing sleeve, 7. Upper dust cover, 8. Ball bearing, 9. Set screw, 10. Rivet, 11. Radial buffer groove, 12. Double grease reservoir, 13. Grease reservoir, 14. Two inner lips, 15. Drive shaft. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] Please see Figures 1-6 This utility model provides a technical solution: a novel radial floating sealing structure for ball bearings, comprising: a drive shaft 15 and a ball bearing 8 sleeved on the drive shaft 15. The inner ring of the ball bearing 8 is fastened to the drive shaft 15 by a set screw 9. An upper dust cover 7 is provided at the upper end of the ball bearing 8, and a lower dust cover is provided at the lower end of the ball bearing 8. A bearing sleeve 6 is sleeved on the outside of the ball bearing 8, and a bearing cover 5 is fixedly connected to the outside of the bearing sleeve 6. The lower dust cover is fixedly connected to the bearing sleeve 6 by a pressure plate 4 at the bottom. The upper dust cover 7 is clamped and fixed between the bearing cover 5 and the bearing sleeve 6. The lower dust cover includes: a lower dust cover 1, an outer sealing ring 2, and an inner sealing ring 3. The outer sealing ring 2 is embedded in the mounting groove of the lower dust cover 1, and the inner sealing ring 3 is embedded inside the outer sealing ring 2.

[0028] In the specific implementation process, it is worth noting that the overall structure is adapted to the transition support of the middle / lower steering drive shaft assembly of heavy trucks. The ball bearing 8 is the core rotating component of the transition support. Through the tight connection between the inner ring and the drive shaft 15, the torque of the drive shaft is stably transmitted. The bearing cover 5 and the bearing sleeve 6 form the outer protection and mounting base of the ball bearing 8. The upper dust cover 7 and the lower dust cover form a full-seal protection for the upper and lower end faces of the ball bearing 8, respectively. The pressure plate 4 and the rivet 10 cooperate to achieve the fastening of the lower sealing structure. The overall assembly structure is compact and highly adaptable to the transition support assembly, without the need for major modifications to the original structure.

[0029] Furthermore, the upper dust cover 7 is made of EPDM rubber. The upper dust cover 7 and the inner ring of the ball bearing 8 are fitted with a small clearance of 0.1mm. The inner diameter of the upper dust cover 7 is provided with double grease reservoirs 12. The outer end of the upper dust cover 7 is integrally formed with radial buffer grooves 11.

[0030] In the specific implementation process, it is worth noting that EPDM rubber has excellent oil resistance, ozone resistance and aging resistance, which can adapt to the harsh working environment of heavy trucks and extend the service life of the upper dust cover 7. The small clearance of 0.1mm ensures that the drive shaft 15 drives the inner ring of the ball bearing 8 to rotate normally, while effectively blocking the entry of external dust and mud. The grease filled in the double grease reservoir 12 can eliminate frictional noise between the inner ring of the ball bearing 8 and the upper dust cover 7, and further improve the sealing effect. The radial buffer groove 11 can reduce the radial force on the inner ring of the ball bearing 8 when the radial swing of the drive shaft 15 is large, reduce the friction between the mating surfaces and avoid the generation of abnormal noise.

[0031] Furthermore, the lower dust cover 1 is made of EPDM rubber. The inner wall of the lower dust cover 1 is integrally formed with axial buffer texture. The lower end of the inner diameter of the lower dust cover 1 is provided with an outer sealing ring mounting groove, and the inner end opening diameter of the mounting groove is larger than the outer end opening diameter. The outer sealing ring 2 and the mounting groove of the lower dust cover 1 are in a small interference fit.

[0032] In the specific implementation process, it is worth noting that the EPDM rubber material selected for the lower dust cover 1 is the same as that for the upper dust cover 7, which can ensure the weather resistance and compatibility of the overall sealing components. The axial buffer groove can reduce the frictional force between the inner sealing ring 3 and the drive shaft 15 when the drive shaft 15 moves up and down, avoiding abnormal noise caused by axial displacement. The hole structure with a larger inner diameter and a smaller outer diameter in the mounting groove not only facilitates the assembly and molding of the outer sealing ring 2, but also effectively prevents the outer sealing ring 2 from radially dislodging after assembly, improving assembly stability. The small interference fit can achieve a firm connection between the lower dust cover 1 and the outer sealing ring 2, ensuring the integrity of the lower sealing structure.

[0033] Furthermore, the outer sealing ring 2 is made of POM plastic material. The inner end opening diameter of the outer sealing ring 2 is larger than the outer end opening diameter. The left and right side gaps between the inner sealing ring 3 and the outer sealing ring 2 are 0.1mm, and the upper and lower end face gaps between the inner sealing ring 3 and the outer sealing ring 2 are 1.5mm. The gaps are filled with grease.

[0034] In the specific implementation process, it is worth noting that POM plastic has good rigidity and moldability, which can provide stable installation support for the inner sealing ring 3. At the same time, it has certain wear resistance and is suitable for long-term assembly and use. The inner diameter structure of the outer sealing ring 2, which is larger inside and smaller outside, is adapted to the mounting groove of the lower dust cover 1, which facilitates the assembly of the inner sealing ring 3 and prevents the inner sealing ring 3 from radially dislodging. The gap between the inner and outer sealing rings is adapted to a certain amount of swing at the lower end of the drive shaft 15, so that the inner sealing ring 3 can achieve radial floating inside the outer sealing ring 2. The grease filled in the gap can eliminate the friction between the two and avoid the outer sealing ring 2 generating radial force on the inner sealing ring 3, which would increase friction and prevent abnormal noise.

[0035] Furthermore, the inner sealing ring 3 is made of polyurethane material. The inner diameter of the inner sealing ring 3 is integrally formed with two inner lips 14. The two inner lips 14 are fitted with the drive shaft 15 with a small clearance of ≤0.1mm. A grease storage groove 13 is provided between the two inner lips 14, and the grease storage groove 13 is filled with grease.

[0036] In the specific implementation process, it is worth noting that the polyurethane material has excellent wear resistance and sealing performance, which can adapt to long-term dynamic cooperation with the drive shaft 15, reduce wear, and the structure of the two inner lips 14 forms a double-layer sealing barrier. The small gap of ≤0.1mm can block the intrusion of external water, mud, sand and dust to the maximum extent. At the same time, the friction of the mating surface is small, and no abnormal noise will be generated due to the rotation or up and down movement of the drive shaft 15. The grease in the grease reservoir 13 can further eliminate the friction between the two inner lips 14 and the drive shaft 15, continuously replenish lubrication, enhance the sealing effect, and protect the ball bearing 8 from the corrosion of impurities.

[0037] Furthermore, the bearing cover 5 and the pressure plate 4 are fixedly connected by rivets 10. The pressure plate 4 presses and fixes the lower dust cover assembly to the lower end face of the bearing sleeve 6, thereby achieving a sealed connection between the lower dust cover assembly and the transition support assembly.

[0038] In the specific implementation process, it is worth noting that the connection method of rivets 10 has the characteristics of firm connection and strong vibration resistance, which can adapt to the vibration conditions during the operation of heavy trucks, prevent the pressure plate 4 from loosening, and the pressure plate 4 forms a uniform clamping force on the lower dust cover assembly to ensure the sealing fit between the lower dust cover assembly and the lower end face of the bearing sleeve 6, and prevent impurities from entering the channel due to gaps. This fastening method is convenient to disassemble and assemble, which facilitates later maintenance and component replacement, and improves the practicality of the overall structure.

[0039] Working principle:

[0040] Torque transmission and basic sealing principle:

[0041] The inner ring of the ball bearing 8 is fastened to the drive shaft 15 by the set screw 9. When the drive shaft 15 rotates, it drives the inner ring of the ball bearing 8 to rotate synchronously, realizing the stable transmission of torque. The bearing sleeve 6 and the bearing cover 5 provide an outer mounting and protection base for the ball bearing 8. The upper dust cover 7 is clamped and fixed between the bearing cover 5 and the bearing sleeve 6, forming a sealed protection for the upper end face of the ball bearing 8. The lower dust cover is pressed and fixed to the lower end face of the bearing sleeve 6 by the pressure plate 4 and the rivet 10, completing the sealed encapsulation of the lower end face of the ball bearing 8. The upper and lower sealing structures work together to form a full circumferential sealed protection for the ball bearing 8, preventing external impurities from entering the interior of the ball bearing 8 from the structural basis.

[0042] Floating adaptation and noise reduction principle:

[0043] When the drive shaft 15 rotates radially, the radial buffer groove 11 at the outer end of the upper dust cover 7 can elastically deform, reducing the radial force exerted by the drive shaft 15 on the inner ring of the ball bearing 8. Combined with the small clearance of 0.1mm between the upper dust cover 7 and the inner ring of the ball bearing 8, the frictional resistance between the two is reduced. When the drive shaft 15 moves up and down, the axial buffer groove on the inner wall of the lower dust cover 1 offsets the axial force, reducing the friction between the inner sealing ring 3 and the drive shaft 15. At the same time, a 0.1mm left and right side gap and a 1.5mm upper and lower end face gap are reserved between the inner sealing ring 3 and the outer sealing ring 2 to accommodate the swing of the lower end of the drive shaft 15, so that the inner sealing ring 3 can float radially inside the outer sealing ring 2, avoiding the outer sealing ring 2 from generating radial extrusion force on the inner sealing ring 3. From the dynamic movement level, the frictional noise between each seal and the drive shaft 15 and the ball bearing 8 is eliminated.

[0044] Multiple sealing and lubrication principles:

[0045] The double grease reservoir 12 in the inner diameter of the upper dust cover 7, the grease reservoir 13 between the two inner lips 14 of the inner sealing ring 3, and the gap between the inner sealing ring 3 and the outer sealing ring 2 are all filled with grease. The grease not only provides continuous lubrication for the mating surfaces of each small gap, further reducing friction loss, but also forms a grease sealing barrier. Combined with the 0.1mm small gap between the upper dust cover 7 and the inner ring of the ball bearing 8, and the ≤0.1mm small gap between the two inner lips 14 of the inner sealing ring 3 and the drive shaft 15, a multi-seal structure is constructed. The small interference fit between the lower dust cover 1 and the outer sealing ring 2, as well as the structure of the mounting groove being larger inside and smaller outside, prevents the sealing ring from radially dislodging, ensuring the integrity of the sealing structure and effectively preventing water, mud, dust and other impurities from entering the ball bearing 8, avoiding corrosion and jamming damage to the ball bearing 8.

[0046] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A novel radial floating seal structure for ball bearings, comprising: The transmission shaft (15) and the ball bearing (8) sleeved on the transmission shaft (15) are characterized in that: the inner ring of the ball bearing (8) is fastened to the transmission shaft (15) by a set screw (9), the upper end of the ball bearing (8) is provided with an upper dust cover (7), the lower end of the ball bearing (8) is provided with a lower dust cover, the outer side of the ball bearing (8) is sleeved with a bearing sleeve (6), the outer side of the bearing sleeve (6) is fixedly connected with a bearing cover (5), the lower dust cover is fixedly connected to the bearing sleeve (6) by a pressure plate (4) at the bottom, the upper dust cover (7) is clamped and fixed between the bearing cover (5) and the bearing sleeve (6), and the lower dust cover includes: a lower dust cover (1), an outer sealing ring (2) and an inner sealing ring (3), the outer sealing ring (2) is embedded in the mounting groove of the lower dust cover (1), and the inner sealing ring (3) is embedded inside the outer sealing ring (2).

2. The novel radial floating seal structure for ball bearings according to claim 1, characterized in that: The upper dust cover (7) is made of EPDM rubber. The upper dust cover (7) and the inner ring of the ball bearing (8) are fitted with a small clearance of 0.1mm. The inner diameter of the upper dust cover (7) is provided with double grease reservoirs (12). The outer end of the upper dust cover (7) is integrally formed with radial buffer textures (11).

3. The novel radial floating seal structure for ball bearings according to claim 1, characterized in that: The lower dust cover (1) is made of EPDM rubber. The inner wall of the lower dust cover (1) is integrally formed with axial buffer texture. The lower end of the inner diameter of the lower dust cover (1) is provided with an outer sealing ring mounting groove, and the inner end opening diameter of the mounting groove is larger than the outer end opening diameter. The outer sealing ring (2) and the mounting groove of the lower dust cover (1) are in a small interference fit.

4. The novel radial floating seal structure for ball bearings according to claim 1, characterized in that: The outer sealing ring (2) is made of POM plastic material. The inner end opening diameter of the outer sealing ring (2) is larger than the outer end opening diameter. The left and right side gaps between the inner sealing ring (3) and the outer sealing ring (2) are 0.1mm. The upper and lower end face gaps between the inner sealing ring (3) and the outer sealing ring (2) are 1.5mm. The gaps are filled with grease.

5. A novel radial floating seal structure for ball bearings according to claim 1, characterized in that: The inner sealing ring (3) is made of polyurethane material. The inner diameter of the inner sealing ring (3) is integrally formed with two inner lips (14). The two inner lips (14) are fitted with the drive shaft (15) with a small gap of ≤0.1mm. A grease storage groove (13) is provided between the two inner lips (14), and the grease storage groove (13) is filled with grease.

6. A novel radial floating seal structure for ball bearings according to claim 1, characterized in that: The bearing cover (5) and the pressure plate (4) are fixedly connected by rivets (10). The pressure plate (4) presses and fixes the lower dust cover assembly to the lower end face of the bearing sleeve (6), thereby achieving a sealed connection between the lower dust cover assembly and the transition support assembly.

Images