Rolling bearing cage based on a tensile negative thermal expansion structure

Abstract

This invention belongs to the field of rolling bearing technology and relates to a rolling bearing cage based on a tensile negative thermal expansion structure, including a cage body, a negative thermal expansion drive structure, and a traction structure. This invention enables the negative thermal expansion drive structure, with its large coefficient of thermal expansion, to expand significantly when the temperature rises. The traction structure transforms this expansion deformation into a radially inward stretching effect on the inner and outer rings of the cage. This causes the inner diameter guide surface of the inner ring and the outer diameter guide surface of the outer ring to exhibit radial contraction with increasing temperature, resulting in a negative thermal expansion characteristic. This automatically increases the guide clearance under high-temperature conditions, effectively maintaining a reasonable fit clearance between the cage and the rolling elements and raceway flanges, suppressing excessive contact and friction between components, reducing vibration and noise during bearing operation, improving the bearing's operational stability in high-temperature environments, and extending the bearing's service life.

Description

Technical Field

[0001] This invention belongs to the field of rolling bearing technology and relates to a rolling bearing cage based on a tensile negative thermal expansion structure. Background Technology

[0002] Rolling bearings, as core components for rotational support and power transmission in modern mechanical equipment, are widely used in various types of machinery. They mainly consist of an inner cage ring, an outer cage ring, rolling elements, and a cage. The cage plays a crucial role in evenly separating the rolling elements, guiding their stable operation, and optimizing load distribution within the bearing. Its structure and thermal properties directly determine the bearing's operational stability under complex working conditions and are important factors affecting the overall reliability and service life of the bearing.

[0003] Currently, most rolling bearing cages are made of metal or conventional polymer materials with a positive coefficient of thermal expansion. As the bearing operating temperature rises, the cage body and its guiding surfaces undergo radial expansion. This positive thermal expansion characteristic causes the cage's overall dimensions to expand at high temperatures, consistent with the thermal expansion behavior of the inner and outer rings and rolling elements. This maintains the relative positional relationship between the cage and rolling elements, and between the cage and the raceway flanges. During the design phase, a certain initial guide clearance is typically reserved based on the bearing's expected operating temperature range. This ensures that, under normal temperature rise conditions, the positive expansion of the cage matches the expansion of other bearing components, guaranteeing that the bearing maintains normal clearance and guiding function even at high temperatures.

[0004] However, because the existing cage is in a state of positive thermal expansion at high temperatures, it is easy to cause the fit clearance between the cage guide surface and the rolling elements and the raceway flange to continuously decrease, resulting in interference, friction and jamming between components, which aggravates abnormal wear of the cage and bearing temperature rise, increases operating vibration and noise, and reduces the operating stability and service life of the bearing under high temperature and high speed conditions. Summary of the Invention

[0005] The purpose of this invention is to provide a rolling bearing cage based on a tensile negative thermal expansion structure, which can reduce the risk of interference and jamming between the cage and the rolling elements and raceway flanges under high-temperature conditions, reduce abnormal bearing wear and temperature rise, and improve the bearing's operational stability and service life in high-temperature environments.

[0006] To achieve the above objectives, the technical solution provided by the present invention is as follows: A rolling bearing cage based on a tensile negative thermal expansion structure, comprising: The cage body includes an inner cage ring and an outer cage ring arranged coaxially, and a plurality of pockets penetrating the inner cage ring and the outer cage ring. The plurality of pockets are evenly arranged along the inner cage ring and the outer cage ring, and each pocket is used to accommodate rolling elements. The negative thermal expansion drive structure is an annular wave structure extending circumferentially along the cage body, with multiple alternating peaks and troughs. The negative thermal expansion drive structure is located between the inner and outer rings of the cage and avoids each pocket in the radial direction. The thermal expansion coefficient of the negative thermal expansion drive structure is greater than that of the cage body. The traction structure includes multiple first traction plates and multiple second traction plates. The multiple first traction plates correspond one-to-one with multiple troughs. The two ends of each first traction plate are connected to the outer ring of the cage and the corresponding trough, respectively. The multiple second traction plates correspond one-to-one with multiple peaks. The two ends of each second traction plate are connected to the inner ring of the cage and the corresponding peak, respectively.

[0007] The invention is further characterized by: The coefficient of thermal expansion of the main body of the cage is 20×10. -6 K -1 ~40×10 -6 K -1 .

[0008] The cage body is made of one of the following materials: polyetheretherketone, polyimide, polyamide-imide, and polyphenylene sulfide.

[0009] The coefficient of thermal expansion of the negative thermal expansion driven structure is 50×10. -6 K -1 ~80×10 -6 K -1 .

[0010] The material of the negative thermal expansion driven structure is one of nylon 12, polyhexamethylene adipamide, polyoxymethylene, or thermoplastic elastomer.

[0011] The circumferential periodic cross-sectional profile of the annular wave driven by negative thermal expansion is trapezoidal.

[0012] The negative thermal expansion drive structure has clearance holes near each pocket, through which the rolling element passes.

[0013] The cage body, negative thermal expansion drive structure, and traction structure are all integrally formed using additive manufacturing.

[0014] The rolling bearing cage based on a tensile negative thermal expansion structure of the present invention has the following advantages: This invention enables the negative thermal expansion drive structure with a large coefficient of thermal expansion to expand significantly when the temperature rises. Through a traction structure, the expansion deformation is converted into a radial inward stretching effect on the inner and outer rings of the cage. This causes the inner diameter guide surface of the inner ring and the outer diameter guide surface of the outer ring to exhibit a radial contraction negative thermal expansion characteristic as the temperature rises. As a result, the guide clearance is automatically increased under high-temperature conditions, effectively maintaining a reasonable fit clearance between the cage and the rolling elements and raceway flanges, suppressing excessive contact and friction between components, reducing vibration and noise during bearing operation, improving the running stability of the bearing in high-temperature environments, and extending the service life of the bearing. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0016] Figure 2 This is a schematic diagram of the negative thermal expansion driven structure in this invention.

[0017] Figure label: 1. Cage body; 11. Inner ring of cage; 12. Outer ring of cage; 13. Pocket; 2. Negative thermal expansion drive structure; 21. Crest; 22. Trough; 23. Clearance hole; 3. Traction structure; 31. First traction plate; 32. Second traction plate. Detailed Implementation

[0018] The technical solutions of the present invention will now be described clearly and in detail with reference to the accompanying drawings. In the description of the embodiments of the present invention, unless otherwise stated, " / " indicates "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Furthermore, in the description of the embodiments of the present invention, "multiple" refers to two or more. The terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0019] like Figure 1 , Figure 2As shown, the present invention provides a rolling bearing cage based on a tensile negative thermal expansion structure, including a cage body 1, a negative thermal expansion drive structure 2, and a traction structure 3. The cage body 1 includes a coaxially arranged inner cage ring 11 and outer cage ring 12, and a plurality of pockets 13 penetrating the inner cage ring 11 and the outer cage ring 12. The inner cage ring 11 is located inside the outer cage ring 12. The plurality of pockets 13 are evenly arranged along the inner cage ring 11 and the outer cage ring 12, and each pocket 13 is used to accommodate rolling elements. The negative thermal expansion drive structure 2 is an annular wave structure extending circumferentially along the cage body 1, having a plurality of alternately distributed wave peaks 21 and multiple... Each trough 22, the negative thermal expansion drive structure 2 is located between the inner ring 11 and the outer ring 12 of the cage and avoids each pocket 13 in the radial direction. The thermal expansion coefficient of the negative thermal expansion drive structure 2 is greater than the thermal expansion coefficient of the cage body 1. The traction structure 3 includes multiple first traction plates 31 and multiple second traction plates 32. The multiple first traction plates 31 correspond one-to-one with the multiple troughs 22. The two ends of each first traction plate 31 are connected to the outer ring 12 of the cage and the corresponding trough 22, respectively. The multiple second traction plates 32 correspond one-to-one with the multiple peaks 21. The two ends of each second traction plate 32 are connected to the inner ring 11 of the cage and the corresponding peak 21, respectively. This invention enables the negative thermal expansion drive structure 2, which has a large coefficient of thermal expansion, to expand significantly when the temperature rises. The expansion deformation is converted into a radial inward stretching effect on the inner ring 11 and outer ring 12 of the cage by the traction structure 3. This causes the inner diameter guide surface of the inner ring 11 and the outer diameter guide surface of the outer ring 12 to exhibit a radial contraction negative thermal expansion characteristic as the temperature rises. This automatically increases the guide clearance under high-temperature conditions, effectively maintains a reasonable fit clearance between the cage and the rolling elements and the raceway flanges, suppresses excessive contact and friction between components, reduces vibration and noise during bearing operation, improves the running stability of the bearing in high-temperature environments, and extends the service life of the bearing.

[0020] The coefficient of thermal expansion of the cage body 1 is 20×10⁻⁶. -6 K -1 ~40×10 -6 K -1 This ensures that the radial dimension of the cage body 1 changes very little at high temperatures, thereby providing a stable rigid support foundation for the negative thermal expansion drive structure 2, and enabling the traction structure 3 to effectively convert the expansion deformation into radial inward contraction of the inner ring 11 and the outer ring 12 of the cage.

[0021] The cage body 1 is made of one of polyetheretherketone, polyimide, polyamide-imide and polyphenylene sulfide, which gives the cage body 1 a low coefficient of thermal expansion and good high-temperature mechanical stability, ensuring that the dimensional change of the cage body 1 is minimal under high-temperature conditions, and providing a stable and reliable rigid constraint boundary for the negative thermal expansion drive structure 2.

[0022] Among them, the coefficient of thermal expansion of the negative thermal expansion driven structure 2 is 50×10. -6 K -1 ~80×10 -6 K -1 This ensures that the negative thermal expansion drive structure 2 generates a thermal expansion deformation significantly greater than that of the cage body 1 when the temperature rises, thereby generating sufficient tensile force through the traction structure 3 to force the inner ring 11 and outer ring 12 of the cage to contract radially inward, thereby increasing the guide gap.

[0023] The negative thermal expansion driving structure 2 is made of one of the following materials: nylon 12, polyhexamethylene adipamide, polyoxymethylene, or thermoplastic elastomer. This gives the negative thermal expansion driving structure 2 a high coefficient of thermal expansion and good elastic deformation ability, ensuring that sufficient thermal expansion driving force can be generated and converted into elastic tensile force when the temperature rises.

[0024] like Figure 2 As shown, the annular wave of the negative thermal expansion drive structure 2 has a trapezoidal cross-sectional profile along the circumferential direction, which makes the negative thermal expansion drive structure 2 form a uniform and continuous wave-shaped distribution in the circumferential direction, ensuring that the thermal expansion deformation is uniformly transmitted to each traction plate along the circumferential direction, thereby driving the inner ring 11 and the outer ring 12 of the cage to produce uniform radial contraction.

[0025] like Figure 2 As shown, the negative thermal expansion drive structure 2 has a clearance hole 23 near each pocket 13. The rolling element passes through the clearance hole 23 to ensure that the negative thermal expansion drive structure 2 avoids mutual clearance with the pocket 13 in the circumferential direction, thus avoiding interference with the installation and movement of the rolling element.

[0026] Among them, the cage body 1, the negative thermal expansion drive structure 2 and the traction structure 3 are all integrally formed by additive manufacturing, realizing high-precision integrated manufacturing of complex annular wave structure and traction plate, ensuring the reliability of fixed connection between each component and the efficiency of thermal expansion deformation transmission.

[0027] Each first traction plate 31 is provided with reinforcing ribs between itself and the outer ring 12 of the cage and the trough 22, and each second traction plate is provided with reinforcing ribs between itself and the inner ring 11 of the cage and the crest 21, in order to improve the connection strength.

[0028] Working principle: When the bearing operating temperature rises, the negative thermal expansion drive structure 2 exhibits a greater expansion tendency than the cage body 1 (especially its inner cage ring 11 and outer cage ring 12) because its coefficient of thermal expansion is significantly greater than that of the cage body 1. However, since its troughs 22 are fixedly connected to the outer cage ring 12 via the first traction plate 31 and its crests 21 are fixedly connected to the inner cage ring 11 via the second traction plate 32, this mismatched expansion is converted into elastic deformation of the negative thermal expansion drive structure 2. This elastic deformation acts on the inner cage ring 11 and outer cage ring 12 of the cage body 1 through the multiple first traction plates 31 and multiple second traction plates 32 of the traction structure 3, generating a force that causes the inner cage ring 11 to contract radially outward and the outer cage ring 12 to contract radially inward, i.e., a tendency for the radial dimension of the cage body 1 to decrease. Macroscopically, this manifests as follows: the inner diameter guide surface of the inner ring 11 and / or the outer diameter guide surface of the outer ring 12 of the cage decreases with increasing temperature, thus achieving a "negative thermal expansion" effect. Consequently, the guide clearance between the cage and the rolling elements or ring flanges is increased, effectively preventing interference and jamming at high temperatures.

[0029] It is understood that this invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this invention are within the protection scope of this invention.

Claims

1. A rolling bearing cage based on a tensile negative thermal expansion structure, characterized in that, include: The cage body includes an inner cage ring and an outer cage ring arranged coaxially, and a plurality of pockets penetrating the inner cage ring and the outer cage ring. The plurality of pockets are evenly arranged along the inner cage ring and the outer cage ring, and each pocket is used to accommodate a rolling element. The negative thermal expansion drive structure is an annular wave structure extending circumferentially along the cage body, with multiple alternating peaks and troughs. The negative thermal expansion drive structure is located between the inner ring and the outer ring of the cage and avoids each pocket in the radial direction. The thermal expansion coefficient of the negative thermal expansion drive structure is greater than the thermal expansion coefficient of the cage body. The traction structure includes multiple first traction plates and multiple second traction plates. The multiple first traction plates correspond one-to-one with multiple troughs. The two ends of each first traction plate are connected to the outer ring of the cage and the corresponding trough, respectively. The multiple second traction plates correspond one-to-one with multiple peaks. The two ends of each second traction plate are connected to the inner ring of the cage and the corresponding peak, respectively.

2. A rolling bearing cage based on a tensile negative thermal expansion structure according to claim 1, characterized in that, The coefficient of thermal expansion of the cage body is 20 x 10 -6 K -1 ~40 x 10 -6 K -1 .

3. A rolling bearing cage based on a tensile negative thermal expansion structure according to claim 1, characterized in that, The material of the cage body is one of polyetheretherketone, polyimide, polyamide-imide and polyphenylene sulfide.

4. A rolling bearing cage based on a tensile negative thermal expansion structure according to claim 1, characterized in that, The coefficient of thermal expansion of the negative thermal expansion driving structure is 50 × 10⁻⁶. -6 K -1 ~80×10 -6 K -1 .

5. A rolling bearing cage based on a tensile negative thermal expansion structure according to claim 1, characterized in that, The material of the negative thermal expansion driving structure is one of nylon 12, polyhexamethylene adipamide, polyoxymethylene, or thermoplastic elastomer.

6. A rolling bearing cage based on a tensile negative thermal expansion structure according to claim 1, characterized in that, The circumferential periodic cross-sectional profile of the annular wave of the negative thermal expansion driven structure is trapezoidal.

7. A rolling bearing cage based on a tensile negative thermal expansion structure according to claim 1, characterized in that, The negative thermal expansion drive structure has clearance holes near each pocket, through which the rolling element passes.

8. A rolling bearing cage based on a tensile negative thermal expansion structure according to claim 1, characterized in that, The cage body, negative thermal expansion drive structure, and traction structure are all integrally formed using additive manufacturing.

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