High load capacity spherical cylindrical hybrid bearing structure

Abstract

This invention discloses a high-load-bearing ball-roller hybrid bearing structure, comprising an inner ring, an outer ring, a single row of steel balls, and a double row of cylindrical rollers. A first raceway is circumferentially formed on the outer peripheral wall of the inner ring and the inner peripheral wall of the outer ring. Two first raceways combine to form a central raceway for the movement of the single row of steel balls. Second raceways are formed at both ends of the outer peripheral wall of the inner ring and the inner peripheral wall of the outer ring. Two second raceways on the same side combine to form an outer raceway for the movement of the single row of cylindrical rollers. Two outer raceways are symmetrically positioned on either side of the central raceway. The central raceway is a four-point contact raceway. The single row of steel balls forms a four-point angular contact fit with the first raceways of the inner and outer rings, respectively. The double row of cylindrical rollers corresponds one-to-one with the two outer raceways, and each row of cylindrical rollers forms a line contact fit with its corresponding outer raceway. This invention solves the problems of existing cylindrical roller bearings being unable to withstand bidirectional axial loads and the insufficient radial load-bearing capacity of traditional four-point contact ball bearings.

Description

Technical Field

[0001] This invention relates to the field of bearing technology, specifically to a high-load-bearing ball-and-screw hybrid bearing structure. Background Technology

[0002] In the field of heavy-duty rotating bearings, cylindrical roller bearings have strong radial load capacity due to their line contact characteristics and can withstand large radial loads. However, they can only withstand radial loads and cannot provide effective bidirectional axial load and positioning capabilities, thus making it difficult to meet the requirements of equipment axial positioning and resistance to axial impact. On the other hand, traditional four-point contact ball bearings achieve four-point corner contact through a double-lobed peach-shaped groove structure and can withstand bidirectional axial loads, but their point contact form results in limited radial load capacity, making it difficult to adapt to the high radial load requirements under heavy-duty working conditions.

[0003] In conventional hybrid bearing schemes, two independent sets of cylindrical roller bearings and four-point contact ball bearings are often arranged in series. This not only requires high coaxiality and has low assembly efficiency, but also results in an overall large bearing assembly size, which cannot meet the development trend of equipment miniaturization and integration. At the same time, the load distribution between the ball and roller raceways of some integrated hybrid bearings is unreasonable. Radial loads are easily applied directly to the ball raceways, causing premature wear of the steel balls and stress concentration in the raceway contact, which reduces the overall bearing life and rigidity, and may even lead to load interference and reduced load-bearing efficiency. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a high-load-bearing ball-roller hybrid bearing structure, which solves the problems that existing cylindrical roller bearings cannot withstand bidirectional axial loads and that traditional four-point contact ball bearings have insufficient radial load-bearing capacity.

[0005] To achieve the above objectives, the present invention provides a high-load-bearing ball-and-roller hybrid bearing structure, comprising an inner ring, an outer ring, a single row of steel balls, and a double row of cylindrical rollers. A first raceway is circumferentially formed on the outer peripheral wall of the inner ring and the inner peripheral wall of the outer ring. Two first raceways combine to form a central raceway for the movement of the single row of steel balls. Second raceways are formed at both ends of the outer peripheral wall of the inner ring and the inner peripheral wall of the outer ring. Two second raceways on the same side combine to form an outer raceway for the movement of the single row of cylindrical rollers. The two outer raceways are symmetrically arranged on both sides of the central raceway. The central raceway is a four-point contact raceway. The single row of steel balls forms a four-point angular contact fit with the first raceways of the inner and outer rings respectively. The double rows of cylindrical rollers correspond one-to-one with the two outer raceways, and each row of cylindrical rollers forms a line contact fit with its corresponding outer raceway.

[0006] The advantages of adopting the above technical solution are as follows: The technology employs an integrated ball-and-roll hybrid bearing structure with an inner ring, outer ring, single-row steel balls, and double-row cylindrical rollers. This creates a layout where the central axial bearing raceway and the two radial bearing raceways work in tandem. The central raceway uses a four-point contact structure and forms a four-point angular contact with the steel balls, enabling it to stably withstand bidirectional axial loads and provide reliable axial positioning. The two outer raceways form a line contact with the cylindrical rollers, significantly improving radial load capacity and structural deformation resistance. Furthermore, the symmetrically distributed outer raceways ensure uniform radial load transfer and effective stress dispersion. With the steel balls and cylindrical rollers each performing their respective functions and their load paths not interfering with each other, the overall bearing performance, operational stability, and structural reliability are greatly improved, extending the bearing's service life under heavy load conditions.

[0007] The present invention further specifies that the contact angle between the single row of steel balls and the first raceway is 15 degrees, 25 degrees, 30 degrees, 35 degrees, or 40 degrees.

[0008] The advantages of adopting the above technical solution are: setting the contact angle between the steel ball and the first raceway to adapt to the working conditions allows for matching the corresponding axial load capacity and overall bearing rigidity according to actual usage requirements, optimizing the contact stress distribution between the steel ball and the raceway, reducing the risk of fatigue wear in the contact area, balancing friction loss and load-bearing efficiency during bearing operation, and thus improving the adaptability and stability of the bearing under complex load conditions. This broadens the range of bearing applications, enabling the bearing to maintain a stable working state under different speeds and load ratios, reducing the probability of early failure, and improving overall reliability.

[0009] The invention further includes the following: an outer groove is provided circumferentially on the outer peripheral wall of the outer ring to prevent the central raceway from bearing the main radial load when an external load is applied to the outer ring. The outer groove is positioned corresponding to the first raceway of the outer ring, and the relative height difference between the bottom wall of the outer groove and the outer peripheral wall of the outer ring is 1 mm.

[0010] The advantages of adopting the above technical solution are as follows: The external groove provided on the outer circumferential wall of the outer ring corresponding to the center raceway position allows for controllable elastic deformation when the outer ring bears external radial loads. This guides the radial load to be preferentially transferred to the cylindrical roller raceways on both sides, preventing the center raceway and steel balls from bearing the main radial force. This avoids stress concentration, contact fatigue, and abnormal wear on the steel balls and center raceway due to radial load impacts. Therefore, it ensures that the four-point contact structure only bears axial loads, optimizes the internal load distribution mechanism of the bearing, and thus improves the overall structural stability and load-bearing safety of the bearing, extending its service life.

[0011] The present invention further comprises: an inner groove is provided circumferentially on the inner peripheral wall of the inner ring for preventing the central raceway from bearing the main radial load when an external load is applied to the inner ring; the inner groove is provided in a manner corresponding to the position of the first raceway of the inner ring; and the relative height difference between the bottom wall of the inner groove and the inner peripheral wall of the inner ring is 1 mm.

[0012] The advantages of adopting the above technical solution are as follows: The inner groove provided on the inner ring's inner circumferential wall corresponding to the center raceway position allows for controllable elastic deformation when the inner ring bears external radial loads. This enables efficient transfer of radial loads to the bearing areas of the cylindrical rollers on both sides, preventing the center raceway and steel balls from bearing excessive radial loads. This maintains the stable state of pure axial bearing of the four-point contact raceway, reduces fatigue damage and abnormal wear in the contact area between the steel balls and the raceway, thereby improving the rationality of bearing load distribution and operational stability, enhancing the overall rigidity and impact resistance of the bearing, and ensuring long-term stable operation.

[0013] The present invention further comprises: limiting flanges provided on both the inner peripheral wall of the outer ring and the outer peripheral wall of the inner ring; the two limiting flanges are respectively located on both sides of the central raceway and are arranged opposite to each other; the inner wall of the limiting flange and the outer peripheral wall are connected by a smooth arc surface and form a limiting surface for preventing the single row of steel balls from axially disengaging from the first raceway; the limiting surface is arranged facing the single row of steel balls; and the two limiting flanges are staggered.

[0014] The advantages of adopting the above technical solution are as follows: In the above technology, corresponding limiting stops are set on both sides of the central raceway to form a limiting surface facing the steel ball, which can effectively constrain the axial movement trajectory of the steel ball and prevent the steel ball from leaving the raceway under axial load, thereby improving the structural safety during bearing assembly and operation. In addition, the limiting stops are connected by a smooth arc surface, which can reduce edge stress concentration and reduce the risk of structural fatigue cracking. At the same time, the staggered arrangement of the limiting stops can avoid assembly interference and optimize the internal space layout, improving the smoothness of steel ball movement and the overall structural reliability of the bearing.

[0015] The present invention further comprises: an oil replenishment cavity is provided on both the outer ring and the inner ring, and the oil replenishment cavity is filled with lubricating grease; the oil replenishment cavity of the outer ring is connected to the limiting surface of the limiting stop edge of the outer ring to form a first oil outlet; the oil replenishment cavity of the inner ring is connected to the limiting surface of the limiting stop edge of the inner ring to form a second oil outlet; the first oil outlet and the second oil outlet are offset from each other, and the openings of the first oil outlet and the second oil outlet are both oriented towards the single row of steel balls.

[0016] The advantages of adopting the above technical solution are as follows: In the above technology, oil replenishment chambers are set inside the inner and outer rings and filled with lubricating grease. The lubricating medium can be continuously delivered to the contact area between the steel ball and the raceway through the corresponding oil outlet, which reduces the contact friction coefficient and operating temperature rise, reduces wear and fatigue damage on the contact surface, and the oil outlet is set towards the steel ball to improve the utilization rate of lubricating grease. The staggered arrangement of the oil outlets can achieve multi-point uniform lubrication, avoid lubrication blind spots, improve the internal lubrication environment of the bearing, reduce operating noise, and improve the stability and durability of the bearing under high-speed and heavy-load conditions.

[0017] The present invention further provides that the two oil replenishment chambers are staggered.

[0018] The advantages of adopting the above technical solution are: the staggered arrangement of the inner and outer ring oil replenishment chambers can avoid structural position interference during processing and assembly, reduce manufacturing difficulty and assembly error risk, optimize the utilization rate of the bearing's internal space, and enable the lubrication system to work in coordination with the raceway, flanges and other structures without affecting each other, thereby ensuring smooth lubrication channels and stable oil supply, improving the reliability of the lubrication system, and enhancing the overall compactness of the bearing structure, facilitating miniaturization and integrated design, and improving bearing adaptability.

[0019] The present invention further comprises: the two oil replenishment chambers are respectively located close to the two outer raceways.

[0020] The advantages of adopting the above technical solution are: the oil filling chamber is arranged close to the outer raceways on both sides, which can make full use of the effective space inside the bearing, optimize the compactness of the structural layout, avoid spatial conflicts with the center raceway and the limiting flange, and at the same time ensure the structural rigidity of the outer and inner ring areas where the center raceway is located. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of the present invention; Figure 2 This is a cross-sectional view of the present invention, wherein arrow A indicates the contact angle position between the steel ball and the first raceway. Detailed Implementation

[0022] This invention provides a high-load-bearing ball-and-roller hybrid bearing structure, comprising an inner ring 1, an outer ring 2, a single row of steel balls 3, and a double row of cylindrical rollers 31. First raceways 11 are circumferentially formed on the outer peripheral wall of the inner ring 1 and the inner peripheral wall of the outer ring 2. Two first raceways 11 combine to form a central raceway 21 for the movement of the single row of steel balls 3. Second raceways 12 are formed at both ends of the outer peripheral wall of the inner ring 1 and the inner peripheral wall of the outer ring 2. Two second raceways 12 on the same side combine to form an outer raceway 22 for the movement of the single row of cylindrical rollers 31. The two outer raceways 22 are symmetrically arranged on both sides of the central raceway 21. The central raceway 21 is a four-point contact raceway. The single row of steel balls 3 respectively contact the inner ring 1 and the outer ring 2. The first raceway 11 forms a four-point angular contact fit. The two rows of cylindrical rollers 31 correspond one-to-one with the two outer raceways 22, and each row of cylindrical rollers 31 forms a line contact fit with the corresponding outer raceway 22. The contact angle between the single row of steel balls 3 and the first raceway 11 is 15 degrees, 25 degrees, 30 degrees, 35 degrees, or 40 degrees. The outer ring 2 has a circumferential groove 23 on its outer peripheral wall to prevent the central raceway 21 from bearing the main radial load when an external load is applied to the outer ring 2. The outer groove 23 is positioned corresponding to the first raceway 11 of the outer ring 2. The relative height difference between the bottom wall of the outer groove 23 and the outer peripheral wall of the outer ring 2 is 1 mm. The inner ring 1 has a circumferential groove 23 on its inner peripheral wall. An inner groove 13 is provided to prevent the central raceway 21 from bearing the main radial load when an external load is applied to the inner ring 1. The inner groove 13 is positioned corresponding to the first raceway 11 of the inner ring 1. The relative height difference between the bottom wall of the inner groove 13 and the inner circumferential wall of the inner ring 1 is 1 mm. Limiting flanges 4 are provided on both the inner circumferential wall of the outer ring 2 and the outer circumferential wall of the inner ring 1. The two limiting flanges 4 are respectively positioned on both sides of the central raceway 21 and are positioned opposite each other. The inner wall and the outer circumferential wall of the limiting flange 4 are connected by a smooth arc surface and form a limiting surface 41 for preventing the single row of steel balls 3 from axially disengaging from the first raceway 11. The limiting surface 41 faces the single row of steel balls. The ball 3 is set, and the two limiting flanges 4 are staggered. Both the outer ring 2 and the inner ring 1 are provided with oil filling chambers 42, which are filled with lubricating grease. The oil filling chamber 42 of the outer ring 2 is connected to the limiting surface 41 of the limiting flange 4 of the outer ring 2 to form a first oil outlet 43. The oil filling chamber 42 of the inner ring 1 is connected to the limiting surface 41 of the limiting flange 4 of the inner ring 1 to form a second oil outlet 44. The first oil outlet 43 and the second oil outlet 44 are staggered, and the openings of the first oil outlet 43 and the second oil outlet 44 are both facing the single row of steel balls 3. The two oil filling chambers 42 are staggered and are respectively located close to the two outer raceways 22.

[0023] The foregoing has shown and described the basic principles and main features of the present invention, as well as its advantages. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope. All such changes and modifications fall within the scope of the present invention as claimed, which is defined by the appended claims and their equivalents.

Claims

1. A high-load-bearing ball-roller hybrid bearing structure, comprising an inner ring, an outer ring, a single row of steel balls, and a double row of cylindrical rollers, characterized in that: The inner ring outer circumferential wall and the outer ring inner circumferential wall are both provided with first raceways. Two first raceways are combined to form a central raceway for a single row of steel balls to move. Second raceways are provided at both ends of the inner ring outer circumferential wall and the outer ring inner circumferential wall. Two second raceways on the same side are combined to form an outer raceway for a single row of cylindrical rollers to move. The two outer raceways are symmetrically arranged on both sides of the central raceway. The central raceway is a four-point contact raceway. The single row of steel balls forms a four-point angular contact fit with the first raceways of the inner ring and the outer ring respectively. The two rows of cylindrical rollers correspond one-to-one with the two outer raceways, and each row of cylindrical rollers forms a line contact fit with the corresponding outer raceway.

2. The high load-bearing ball-and-screw hybrid bearing structure according to claim 1, characterized in that: The contact angle between the single row of steel balls and the first raceway is 15 degrees, 25 degrees, 30 degrees, 35 degrees, or 40 degrees.

3. The high load-bearing ball-and-screw hybrid bearing structure according to claim 1, characterized in that: The outer ring has a circumferential groove on its outer peripheral wall to prevent the central raceway from bearing the main radial load when an external load is applied to the outer ring. The outer groove is positioned corresponding to the first raceway of the outer ring, and the relative height difference between the bottom wall of the outer groove and the outer peripheral wall of the outer ring is 1 mm.

4. The high load-bearing ball-and-screw hybrid bearing structure according to claim 1, characterized in that: The inner ring has a circumferential groove on its inner peripheral wall to prevent the central raceway from bearing the main radial load when an external load is applied to the inner ring. The inner groove is positioned corresponding to the first raceway of the inner ring, and the relative height difference between the bottom wall of the inner groove and the inner peripheral wall of the inner ring is 1 mm.

5. The high load-bearing ball-and-screw hybrid bearing structure according to claim 1, characterized in that: Both the inner circumferential wall of the outer ring and the outer circumferential wall of the inner ring are provided with limiting edges. The two limiting edges are respectively located on both sides of the central raceway and are arranged opposite to each other. The inner wall of the limiting edge and the outer circumferential wall are connected by a smooth arc surface and form a limiting surface for preventing the single row of steel balls from axially disengaging from the first raceway. The limiting surface is set towards the single row of steel balls, and the two limiting edges are staggered.

6. The high load-bearing ball-and-screw hybrid bearing structure according to claim 5, characterized in that: Both the outer and inner rings are provided with oil filling cavities filled with lubricating grease. The oil filling cavity of the outer ring is connected to the limiting surface of the limiting stop edge of the outer ring to form a first oil outlet. The oil filling cavity of the inner ring is connected to the limiting surface of the limiting stop edge of the inner ring to form a second oil outlet. The first oil outlet and the second oil outlet are offset and the openings of the first oil outlet and the second oil outlet are both oriented towards the single row of steel balls.

7. The high load-bearing ball-and-screw hybrid bearing structure according to claim 5, characterized in that: The two oil replenishment chambers are misaligned.

8. The high load-bearing ball-and-screw hybrid bearing structure according to claim 7, characterized in that: The two oil replenishment chambers are respectively located near the two outer raceways.

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