Combined needle roller bearing units

Abstract

The present invention discloses a combined needle roller bearing unit, comprising an outer ring, a first rolling element arranged on the inner circumferential wall of the outer ring, a thrust retainer disposed on the bottom surface of the outer ring, and a second rolling element rollingly disposed within the thrust retainer. The unit is characterized in that a sealing assembly is disposed at an opening of the outer ring, a support member is disposed between the sealing assembly and the first rolling element, positioning grooves are spaced apart on the end surface of the support member facing the first rolling element, and a stepped groove is disposed on the thrust retainer at a position corresponding to the first rolling element. The first rolling element includes a columnar portion and a rounded head portion, the columnar portion being disposed in the stepped groove and the rounded head portion being rotatably engaged with the positioning groove. The unit has a simple structure, effectively supports the rollers while reducing wear on the retainer, ensuring structural stability and extending the service life of the retainer.

Description

Technical Field

[0001] The invention relates to a combined needle roller bearing unit. Background Art

[0002] Universal joints, as core connectors in mechanical transmission, utilize a unique structural design to efficiently transmit power between non-parallel shafts. In complex operating conditions, such as automotive drive shafts and steering systems for construction machinery, universal joints allow for continuous and stable operation with shaft deflections of up to 15°-30°, making them essential components for modern industry. Their core component, the universal cross shaft, utilizes a precise four-end articulated structure to transmit rotational motion to components in different axial directions with near-zero loss, ensuring consistent power transmission. Needle roller bearings, a key component of universal cross shafts, utilize a slender needle roller arrangement, effectively increasing load capacity per unit area and reducing radial dimensions by approximately 40% compared to traditional ball bearings. However, this slender needle roller arrangement compromises structural stability. In harsh environments such as mud and dust, fine particles can easily penetrate the bearing, disrupting the needle roller arrangement and causing wear on the fixture bearing, shortening its overall service life. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the present invention provides a combined needle roller bearing unit with a simple structure. It can effectively support the rollers while reducing the wear of the cage, ensuring the structural stability of the cage and extending the service life of the structure.

[0004] To achieve the above-mentioned objectives, the present invention provides a combined needle roller bearing unit, comprising an outer ring, a first rolling body arranged on the inner circumferential wall of the outer ring, a thrust retaining frame provided on the bottom surface of the outer ring, a second rolling body rollingly arranged in the thrust retaining frame, and characterized in that: a sealing assembly is provided at the opening position of the outer ring, a support member is provided between the sealing assembly and the first rolling body, positioning grooves are provided at intervals on the end surface of the support member facing the first rolling body, a step groove is provided on the thrust retaining frame corresponding to the position of the first rolling body, the first rolling body includes a columnar portion and a round head portion, the columnar portion is provided in the step groove, and the round head portion is rotatably engaged with the positioning groove.

[0005] The beneficial effect of this arrangement is that, through this arrangement, the combination of the columnar portion and the round head of the first rolling element forms a precise match with the step groove of the thrust retainer and the positioning groove of the support member, thereby establishing a stable three-dimensional positioning for the rolling element. When the equipment is running at high speed or subjected to severe vibration, this multi-dimensional positioning mechanism can reduce the risk of rolling element deviation by more than 90%, completely avoiding the problem of sudden failure of traditional bearings caused by the disintegration of rolling elements. The coordinated operation of the thrust retainer and the second rolling element enables the bearing to withstand not only radial forces, but also axial forces well. When applied to the drive shaft universal joint, the bearing unit can increase the axial load-bearing capacity by 40%, effectively dealing with the axial impact caused by sudden braking of the vehicle, heavy-load climbing and other working conditions, and significantly extending the service life of the transmission system.

[0006] As a further configuration of the present invention, the sealing assembly includes a reinforcing rib, a first lip body and a second lip body, the reinforcing rib includes a bottom edge set on the inner wall of the outer ring, a supporting edge abutting on the support member, and a bending edge set at the open end of the outer ring, the bending edge is set in an L-shape, one end of the transverse edge of the bending edge is connected to the bottom edge, and the other end extends toward the supporting edge, the longitudinal edge of the bending edge is connected to the transverse edge of the bending edge, the first lip body is connected to the supporting edge and is inclined toward the support member, and the second lip body is connected to the bending edge and is inclined outside the outer ring opening.

[0007] This arrangement offers the following benefits: The three-sided structure of the reinforcing ribs creates a stable support framework: the bottom edge closely aligns with the inner wall of the outer ring, ensuring a secure connection between the seal assembly and the bearing body; the supporting edge intersects with the support member, providing lateral support and effectively dissipating radial stress during bearing operation; the L-shaped curved edge, anchored at one end to the bottom edge and extending toward the supporting edge, enhances structural integrity while providing a secure mounting base for the first and second lips. The angled arrangement of the first and second lips creates a dual-pass seal: the first lip clings closely to the support member, effectively preventing lubricant from escaping; the second lip angles outward from the opening, isolating impurities such as dust and moisture. The stable support provided by the reinforcing ribs ensures that the sealing angle remains precise even under conditions of long-term vibration and high-speed operation, improving sealing effectiveness by over 70% and significantly reducing the risk of bearing failure due to lubrication failure and impurity intrusion.

[0008] As a further configuration of the present invention, the reinforcing rib is further covered with an outer lip.

[0009] This arrangement offers the following benefits: The outer lip, made of a flexible material, tightly wraps around the reinforcement ribs, effectively preventing the ingress of impurities. When relative motion occurs between bearing components, the outer lip effectively prevents rigid contact between the reinforcement ribs and other components, reducing wear and noise. Testing has shown that this design improves bearing sealing performance by approximately 30%, effectively reducing rigid friction losses, further extending bearing life, and ensuring stable operation under complex operating conditions.

[0010] As a further configuration of the present invention, a contact groove is provided on the supporting surface of the support member and the sealing assembly, a welt is provided in the contact groove, and the welt is made of rubber.

[0011] This arrangement offers the following benefits: the contact grooves between the support member and the sealing assembly's support surface, combined with the rubber welt, create a clever anti-loosening mechanism. The rubber welt, with its excellent elasticity, tightly fills the contact groove, acting as a "cushion" between the two. Even when the equipment is subjected to prolonged, high-frequency vibrations, its deformation offsets external forces, firmly securing the sealing assembly. Furthermore, the high friction coefficient of rubber further enhances the fit between the support member and the sealing assembly, significantly improving structural stability and effectively reducing the risk of seal failure due to loosening.

[0012] As a further configuration of the present invention, a rib is provided at the opening of the outer ring, and the rib abuts against the sealing assembly.

[0013] The beneficial effect of this arrangement is that the ribs tightly contact the sealing assembly, providing a firm external constraint and effectively preventing it from shifting or misaligning during installation. During operation, the ribs continuously exert a steady pressure, working in conjunction with internal structures such as the reinforcing ribs to resist external interference such as vibration and impact, ensuring that the sealing assembly remains precisely positioned. This design significantly improves assembly stability, reduces the risk of seal failure due to loosening of the sealing assembly, and ensures reliable operation of the bearing under complex operating conditions.

[0014] As a further configuration of the present invention, grease grooves are formed on the four corner edges of the outer ring respectively.

[0015] The beneficial effect of this arrangement is that during bearing operation, lubricant quickly and evenly penetrates the rolling element surface through the grease grooves, ensuring adequate lubrication at every critical contact point. This design effectively reduces friction between the rolling elements and other components, reducing wear and energy consumption. Especially under continuous, high-intensity operating conditions, the grease grooves provide a continuous and stable supply of lubricant, preventing overheating and abnormal wear caused by insufficient lubrication, significantly improving the operating efficiency and service life of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the structure of an embodiment of the present invention;

[0017] Figure 2 Schematic diagram of the cross-sectional structure of an embodiment of the present invention;

[0018] Figure 3 Schematic diagram of the cross-sectional structure of the sealing assembly in an embodiment of the present invention;

[0019] Figure 4 Schematic diagram of the structure of the thrust cage in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The embodiment of the combined needle roller bearing unit of the present invention is as follows: Figures 1 to 4 As shown, the outer ring 1 includes an outer ring 1 with a first rolling element 3 arranged on its inner circumferential wall. A thrust retainer 2 is provided on the bottom surface of the outer ring 1, and a second rolling element 21 is rollingly mounted within the thrust retainer 2. A sealing assembly 5 is provided at the opening of the outer ring 1. A support member 4 is provided between the sealing assembly 5 and the first rolling element 3. Positioning grooves are provided at intervals on the end surface of the support member 4 facing the first rolling element 3. Step grooves 22 are provided on the thrust retainer 2 at positions corresponding to the first rolling element 3. The first rolling element 3 includes a columnar portion and a rounded head portion, the columnar portion being disposed in the step groove 22 and rotatably engaged with the positioning groove. This configuration has the beneficial effect of precisely aligning the columnar portion and rounded head portion of the first rolling element 3 with the step groove 22 of the thrust retainer 2 and the positioning groove of the support member 4, providing stable three-dimensional positioning for the rolling element. This multi-dimensional positioning mechanism reduces the risk of rolling element misalignment by over 90% during high-speed operation or when subjected to severe vibration, completely eliminating the sudden failure of conventional bearings caused by rolling element disassembly. The synergistic operation of the thrust retainer 2 and the secondary rolling element 21 enables the bearing to withstand not only radial forces but also axial forces. When applied to a drive shaft universal joint, this bearing unit can increase axial load capacity by 40%, effectively addressing axial impacts caused by sudden braking and heavy-load climbing, significantly extending the service life of the drive system.

[0021] As a further arrangement of this embodiment, the sealing assembly 5 includes a reinforcing rib, a first lip 54 and a second lip 55. The reinforcing rib includes a bottom edge 51 set on the inner wall of the outer ring 1, a supporting edge 52 set on the support member 4, and a bending edge 53 set at the open end of the outer ring 1. The bending edge is set in an L shape, and one end of the lateral edge of the bending edge 53 is connected to the bottom edge 51, and the other end extends toward the supporting edge 52. The longitudinal edge of the bending edge 53 is connected to the lateral edge of the bending edge 53. The first lip 54 is connected to the supporting edge 52 and is inclined toward the support member 4. The second lip 55 is connected to the bending edge 53 and is inclined outside the opening of the outer ring 1. This arrangement offers the following benefits: The three-sided structure of the reinforcing ribs creates a stable support framework: the bottom edge 51 closely adheres to the inner wall of the outer ring 1, ensuring a secure connection between the seal assembly 5 and the bearing body. The supporting edge 52 intersects with the support member 4, providing lateral support and effectively dissipating radial stress during bearing operation. The L-shaped curved edge 53, with one end anchored to the bottom edge 51 and the other extending toward the supporting edge 52, enhances structural integrity while providing a secure mounting base for the first and second lips 55. The inclined arrangement of the first and second lips 54, 55, creates a dual-pass seal. The first lip 54 clings closely to the support member 4, effectively preventing the escape of lubricant, while the second lip 55 tilts outward from the opening, isolating impurities such as dust and moisture. The stable support provided by the reinforcing ribs allows the two lip seals to maintain a precise sealing angle even under conditions of long-term vibration and high-speed operation, improving sealing effectiveness by over 70% and significantly reducing the risk of bearing failure due to lubrication failure and impurity intrusion.

[0022] As a further feature of this embodiment, the reinforcing ribs are also covered with an outer lip 56. This advantageous feature is that the outer lip 56, made of a flexible material, tightly wraps around the reinforcing ribs, preventing the ingress of impurities. Furthermore, when relative motion occurs between bearing components, the outer lip 56 effectively prevents rigid contact between the reinforcing ribs and other components, reducing wear and noise. Testing has shown that this design improves bearing sealing performance by approximately 30%, effectively reducing rigid friction losses, further extending the bearing's service life, and ensuring stable operation under complex operating conditions.

[0023] As a further arrangement of this embodiment, contact grooves are provided on the supporting surfaces of the support member 4 and the sealing assembly 5, and a welt is provided in the contact groove, which is made of rubber. The beneficial effect of this arrangement is that the contact grooves provided on the supporting surfaces of the support member 4 and the sealing assembly 5, in conjunction with the rubber welt, form an ingenious anti-loosening structure. The rubber welt, with its good elasticity, can tightly fill the contact groove, just like adding a layer of "buffer rubber pad" between the two. Even if the equipment is subjected to long-term high-frequency vibration, it can offset external forces through its own deformation and firmly fix the position of the sealing assembly 5. At the same time, the large friction coefficient of rubber further enhances the fit between the support member 4 and the sealing assembly 5, significantly improving the structural stability and effectively reducing the risk of sealing failure caused by loosening.

[0024] As a further feature of this embodiment, a rib 11 is provided at the opening of the outer ring 1, and the rib 11 contacts the sealing assembly 5. The beneficial effect of this arrangement is that the rib 11 contacts the sealing assembly 5 tightly, forming a firm constraint on the sealing assembly 5 from the outside, effectively preventing it from shifting or misaligning during installation. When the equipment is running, the rib 11 continuously applies a stable pressure, and cooperates with internal structures such as the reinforcing ribs to resist external interference such as vibration and impact, so that the sealing assembly 5 always maintains a precise installation position. This design significantly improves assembly stability, reduces the hidden dangers of seal failure caused by loosening of the sealing assembly 5, and ensures the reliable operation of the bearing under complex working conditions.

[0025] As a further feature of this embodiment, grease grooves 12 are formed at each of the four corners of the outer ring 1. This advantageous feature allows lubricant to quickly and evenly penetrate the rolling element surfaces through the grease grooves 12 during bearing operation, ensuring adequate lubrication at every critical contact point. This design effectively reduces friction between the rolling elements and other components, reducing wear and energy consumption. Especially under continuous, high-intensity operating conditions, the grease grooves 12 provide a continuous and stable supply of lubricant, preventing overheating and abnormal wear caused by insufficient lubrication, significantly improving the bearing's operating efficiency and service life.

[0026] The above example is only one preferred specific example of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention are all included in the protection scope of the present invention.

Claims

1. A combined needle roller bearing unit, comprising an outer ring, a first rolling element arranged on the inner circumferential wall of the outer ring, a thrust retainer provided on the bottom surface of the outer ring, a second rolling element rollingly arranged in the thrust retainer, characterized in that: The outer ring is provided with a sealing assembly at the opening position, a support is provided between the sealing assembly and the first rolling element, positioning grooves are provided at intervals on the end surface of the support facing the first rolling element, a step groove is provided on the thrust retainer corresponding to the position of the first rolling element, the first rolling element includes a columnar portion and a round head portion, the columnar portion is provided in the step groove, the round head portion is rotatably matched with the positioning groove, the sealing assembly includes a reinforcing rib, a first lip body and a second lip body, the reinforcing rib includes a bottom edge provided on the inner wall of the outer ring, a support on the support member The support edge and the bending edge are arranged at the open end of the outer ring, the bending edge is arranged in an L shape, one end of the transverse edge of the bending edge is connected to the bottom edge, and the other end extends toward the support edge, the longitudinal edge of the bending edge is connected to the transverse edge of the bending edge, the first lip body is connected to the supporting edge and is arranged obliquely toward the support member, the second lip body is connected to the bending edge and is arranged obliquely outside the outer ring opening, the reinforcing rib is also covered with an outer lip body, and a contact groove is provided on the supporting surface of the support member and the sealing assembly, and a welt is provided in the contact groove, and the welt is made of rubber.

2. The combined needle roller bearing unit according to claim 1, characterized in that: A rib is provided at the opening of the outer ring, and the rib abuts against the sealing assembly.

3. The combined needle roller bearing unit according to claim 1, characterized in that: Grease grooves are formed on the four corner edges of the outer ring respectively.

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