Ultrahigh-temperature-resistant full ball bearing and design method thereof

Abstract

An ultrahigh-temperature-resistant full ball bearing comprises a bearing outer ring, a bearing inner ring and a roller, the roller is spherical and is arranged in a roller path in a full complement mode, and the bearing outer ring, the bearing inner ring and the roller are all made of carbon fiber reinforced ceramic matrix composite materials. The design method comprises the following steps: S1, determining the inner diameter d, the outer diameter D and the width B of the bearing; and S2, determining an inner groove curvature radius coefficient fi and an outer groove curvature radius coefficient fe of the bearing based on a principle of reducing the working contact stress of the bearing and prolonging the fatigue relieving life of the bearing. And S3, the value ranges of the roller diameter DW, the center diameter DWP and the roller number Z of the bearing are determined. And S4, optimizing and determining the roller diameter DW, the center diameter DWP and the roller number Z of the bearing by taking the principle of obtaining the maximum radial basic rated static load. By applying the high-temperature-resistant bearing, the technical problems that an existing bearing loses efficacy quickly due to high temperature and insufficient lubrication in a high-temperature environment for a long time, and a bearing made of a ceramic material is low in fracture toughness and thermal shock resistance can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of roller bearing design, in particular to an ultra-high temperature resistant full ball bearing and a design method thereof. Background Art

[0002] With the development of technology, the performance requirements for the main engine are getting higher and higher, and the working conditions are becoming more and more harsh, especially for bearings used in special environmental conditions. For example, in industrial enterprises such as steel and glass, the transmission systems in high-temperature working environments, such as continuous casting machine rollers, steel-making machine rollers, rolling mill furnace rollers, cooling beds, etc., have long-term working temperatures of more than 500°C and the highest temperature can reach 1000°C. The working temperature of bearings used in the inner components of future hypersonic aircraft is close to 1000°C.

[0003] Therefore, facing the ultra-high temperature working environment, the traditional high temperature resistant bearing steel can no longer meet the requirements, and the ultra-high temperature environment cannot use the traditional effective and reliable grease lubrication. The ceramic materials that can withstand high temperatures have poor fracture toughness and thermal shock resistance, and are prone to breakage under the action of alternating thermal stress in a temperature change environment. Summary of the invention

[0004] The purpose of the present invention is to provide an ultra-high temperature resistant full ball bearing and a design method thereof, which can solve the technical problems that existing bearings fail rapidly due to high temperature and insufficient lubrication in a high temperature environment for a long time, and bearings made of ceramic materials have low fracture toughness and thermal shock resistance.

[0005] In order to achieve the above object, the present invention adopts the following technical solution.

[0006] A super-high temperature resistant full ball bearing comprises a bearing outer ring, a bearing inner ring and rollers. The rollers are spherical and fully arranged in a raceway. The bearing outer ring, the bearing inner ring and the rollers are all made of carbon fiber reinforced ceramic matrix composite materials.

[0007] A design method for an ultra-high temperature resistant full ball bearing comprises the following steps:

[0008] S1. Determine the structural dimension parameters of the bearing, including the bearing inner diameter d, the bearing outer diameter D and the bearing width B, and determine the contact angle α of the bearing;

[0009] S2. Based on the principle of reducing the working contact stress of the bearing and improving the fatigue life of the bearing, determine the inner groove curvature radius coefficient fi and the outer groove curvature radius coefficient fe of the bearing;

[0010] S3. Determine the roller diameter D of the bearing W , center diameter D WP , the range of values ​​of the roller number Z;

[0011] S4. Optimize and determine the roller diameter D of the bearing based on the principle of obtaining the maximum radial basic rated static load. W , center diameter D WP , roller number Z.

[0012] Furthermore, in S2, in order to improve the bearing capacity of the bearing and reduce the contact stress between the roller and the inner groove when the bearing is working, the value range of the inner groove curvature radius coefficient fi is 0.505≤fi≤0.515.

[0013] Furthermore, the outer groove curvature radius coefficient fe adopts an isostress design, and its value range is 0.510≤fe≤0.520.

[0014] Furthermore, in S3, the roller diameter D W The constraint formula is: K Wmin (Dd)≤D W ≤K Wmax (Dd), Among them, K Wmin and K Wmax are the maximum and minimum values ​​of the cross-sectional coefficient, respectively.

[0015] Furthermore, in order to improve the bearing capacity, the section coefficient takes a larger value K Wmin =0.28, K Wmax =0.34.

[0016] Furthermore, in S3, the bearing center diameter D WP =0.5(D+d).

[0017] Furthermore, in S3, the constraint formula for the number of rollers Z is: The bearing is a full ball bearing with Φ=360°, and the number of rollers Z is a positive integer.

[0018] Furthermore, in S3, the roller diameter D W , center diameter D WP , the number of rollers Z must satisfy the bearing circumferential clearance S C Constraints:

[0019] Furthermore, in S4, the radial basic static load rating C or The expression is: C or =f 0 ×Z×D W 2 , Among them, f 0 according to The value of is determined.

[0020] After adopting the above technical solution, the present invention has the following beneficial effects: 1. The bearing of the present invention adopts carbon fiber reinforced ultra-high temperature ceramic composite material, which greatly improves the strength and oxidation resistance and ablation resistance of the bearing in ultra-high temperature environment, as well as mechanical properties such as fracture toughness and impact resistance, and solves the problems of brittleness and poor thermal shock resistance of the bearing in ultra-high temperature environment; 2. Carbon fiber can provide effective and reliable lubrication in high temperature environment, reduce the friction and heat between the moving parts of the bearing, reduce the power consumption and wear of the bearing, and can effectively improve the service life and operation reliability of the bearing in ultra-high temperature environment; 3. The bearing in the present invention adopts a separable, full-ball structure, and reduces the curvature radius coefficient of the inner and outer ring grooves as much as possible, thereby reducing the working contact stress. On this basis, the main structural parameters are optimized with the radial basic rated static load as the objective function, thereby improving the bearing's load-bearing capacity, reducing friction and wear, extending the bearing's service life, and improving the bearing's operating reliability in high temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the cross-sectional structure of the bearing in the present invention.

[0022] Description of the drawings: 1. Bearing inner ring, 2. Bearing outer ring, 3. Roller, 4. Outer ring lock. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the characteristics and performance of the design method of the ultra-high temperature resistant full ball bearing in the present invention are further described in detail below in conjunction with the accompanying drawings and embodiments.

[0024] A super-high temperature resistant full ball bearing comprises a bearing outer ring, a bearing inner ring and rollers. The rollers are spherical and fully arranged in a raceway. The bearing outer ring, the bearing inner ring and the rollers are all made of carbon fiber reinforced ceramic matrix composite materials.

[0025] A design method for an ultra-high temperature resistant full ball bearing comprises the following steps.

[0026] S1. Determine the structural dimension parameters of the bearing, including the bearing inner diameter d, the bearing outer diameter D and the bearing width B, and determine the bearing contact angle α. The tolerance range of the bearing contact angle α is ±2°.

[0027] S2. Based on the principle of reducing the working contact stress of the bearing and improving the fatigue life of the bearing, determine the inner groove curvature radius coefficient fi and the outer groove curvature radius coefficient fe of the bearing.

[0028] For ultra-high temperature bearings, extending fatigue life is very important. In order to improve the bearing's load-bearing capacity and reduce the contact stress between the roller and the groove when the bearing is working, the inner ring groove curvature radius coefficient fi and the outer groove curvature radius coefficient fe should be minimized during design.

[0029] Therefore, the value range of the inner groove curvature radius coefficient fi is 0.505≤fi≤0.515. As a preferred embodiment, the inner groove curvature radius coefficient fi=0.51 is selected.

[0030] When adopting equal stress design, the range of the outer groove curvature radius coefficient fe is 0.510≤fe≤0.520, which is used to ensure that the contact stress between the roller and the inner and outer rings is equal. As a preferred option, the outer groove curvature radius coefficient fe=0.52

[0031] S3. Determine the roller diameter D of the bearing W , center diameter D WP , the value range of roller number Z.

[0032] Roller diameter D W The constraint formula is: K Wmin (Dd)≤D W ≤K Wmax (Dd), Among them, K Wmin and K Wmax are the maximum and minimum values ​​of the cross-sectional coefficient, respectively.

[0033] In order to improve the bearing capacity, the section coefficient takes a larger value K Wmin =0.28, K Wmax =0.34. Combined roller diameter D W The constraint formula can calculate the roller diameter D W The value range of the roller diameter D is selected according to the discrete values ​​given in the national standard GB / T 308.2. W .

[0034] Bearing center diameter D WP =0.5(D+d).

[0035] The constraint formula for the number of rollers Z is: The bearing is a full ball bearing with Φ=360°, and the number of rollers Z is a positive integer. Combined with the selected roller diameter D W and bearing center diameter D WP , calculate the range of roller number Z. If the roller diameter D W If there are multiple possible values, the corresponding range of values ​​of the number of rollers Z is calculated respectively.

[0036] Roller diameter D W , center diameter D WP , the number of rollers Z must also meet the constraints of the bearing circumferential clearance SC: Substitute the roller diameter D obtained from the above calculation into W , center diameter D WP , roller number Z combination, exclude the bearing circumferential clearance S that does not meet C A combination of constraints.

[0037] S4. Optimize and determine the roller diameter D of the bearing based on the principle of obtaining the maximum radial basic rated static load. W , center diameter D WP , roller number Z.

[0038] The expression of radial basic static load rating Cor is: C or =f 0 ×Z×D W 2 , Among them, f 0 according to The value of is determined.

[0039] From the radial basic static load rating C or The expression can be obtained that the radial basic static load rating C or With f 0 , roller number Z, roller diameter D W In order to obtain the maximum radial basic static load rating, the roller number Z takes the maximum value within its value range.

[0040] f 0 The value of It can be obtained by looking up the table and applying interpolation.

[0041] If there are multiple sets of roller diameters D W , center diameter D WP , roller number Z combination, calculate its radial basic static load rating C or , take the radial basic static load rating C or The largest group is the final result.

[0042] So far, the inner diameter d, outer diameter D, width B, contact angle α, inner groove curvature radius coefficient fi, outer groove curvature radius coefficient fe, roller diameter D W , center diameter D WP , the number of rollers Z have been determined.

[0043] In specific implementation, the bearing inner ring 1, the bearing outer ring 2 and the roller 3 are all made of carbon fiber reinforced ultra-high temperature ceramic matrix composite materials. The bearing adopts a separable, full ball structure, and the height of the outer ring lock 4 for ball loading is 0, which improves the bearing's load-bearing capacity.

[0044] Taking the bearing with inner diameter d = 140mm, outer diameter D = 190mm, width B = 24mm, and contact angle α = 25° as an example, the main parameters of the bearing are the inner groove curvature radius coefficient fi, the outer groove curvature radius coefficient fe, and the roller diameter D W , center diameter D WP , design steps for the number of rollers Z.

[0045] The size of the contact angle α has a great influence on the working performance of the bearing. The contact angle α is used as an optimization design variable, and the tolerance range of the contact angle α is ±2°.

[0046] In order to reduce the working contact stress of the bearing and improve the bearing's load-bearing capacity, the inner groove curvature radius coefficient fi and the outer groove curvature radius coefficient fe are minimized as much as possible during design. For this reason, the inner groove curvature radius coefficient fi is set to 0.51, and the outer groove curvature radius coefficient fe is designed with equal stress, and the outer groove curvature radius coefficient fe is set to 0.52 to ensure that the contact stress between the roller and the inner and outer rings is equal.

[0047] In order to improve the bearing capacity, the section coefficient takes a larger value K Wmin =0.28, K Wmax =0.34, K Wmin =0.28, K Wmax =0.34, inner diameter d=140mm, outer diameter D=190mm with roller diameter D W The constraint formula is: K Wmin (Dd)≤D W ≤K Wmax (Dd), Roller diameter D W The value range is 14㎜≤D W ≤17㎜, refer to the discrete value given in the national standard GB / T 308.2, D W The optional values ​​are 14㎜, 14.2875㎜, 15㎜, 15.08125㎜, 15.875㎜, 16㎜, 16.66875㎜ and 17㎜.

[0048] Center diameter of bearing D WP =0.5(D+d)=165㎜.

[0049] The above D W and D WP Substitute the value of into the constraint formula of the roller number Z: Among them, because the bearing is a full ball bearing, Φ = 360°, and the following sets of results are obtained: ①D W =14mm, D WP =165㎜, Z≤36.61, take Z=36; ②D W =14.2875 mm, D WP =165㎜, Z≤35.88, take Z=35; ③D W =15mm, D WP =165㎜, Z≤34.17, take Z=34; ④D W =15.08125㎜, D WP =165㎜, Z≤33.98, take Z=33; ⑤D W =15.875mm, D WP =165㎜, Z≤32.28, take Z=32; ⑥D W =16mm, D WP =165㎜, Z≤32.03, take Z=32; ⑦D W =16.66875 mm, D WP =165㎜, Z≤30.74, take Z=30; ⑧D W =17mm, D WP =165㎜, Z≤30.14, take Z=30.

[0050] Bring the above combination into the bearing circumferential clearance S C Constraints: Among them, groups ②, ④, and ⑦ do not meet the circumferential clearance S C The constraints of the first, third, fifth, sixth, and eighth groups satisfy the circumferential clearance S C constraints.

[0051] Substitute the parameters of groups ①, ③, ⑤, ⑥, and ⑧ into the radial basic static load rating C or The expression is: C or =f 0 ×Z×D W 2 , Among them, f 0 according to The value of is determined by looking up the table and using interpolation.

[0052] We can get: In group ①, γ=0.077, and we can get f 0 =16.24, then C or =114589.44; In group ③, γ=0.082, and we can get f 0 =16.34, then C or =125001; In group ⑤, γ=0.087, and f is obtained by looking up the table. 0 =16.44, then C or =132580.38; In the ⑥th group, γ=0.088, and f 0 =16.46, then C or =134840.32; In group ⑧, γ=0.093, and we can get f 0 =16.56, then C or =143575.2.

[0053] Based on the principle of obtaining the maximum radial basic rated static load, the parameters of group ⑧ should be selected as the final result, that is: roller diameter D W =17mm, center diameter D WP =165㎜, number of rollers Z=30.

[0054] In summary, the bearing parameters designed this time are: inner diameter d = 140mm, outer diameter D = 190mm, width B = 24mm, contact angle α = 25°, inner groove curvature radius coefficient fi = 0.51, outer groove curvature radius coefficient fe = 0.52, roller diameter D W =17mm, center diameter D WP =165㎜, number of rollers Z=30.

[0055] It should be noted that the parts not described in detail in this scheme are all prior art, and the above embodiments are only used to illustrate the present invention, but the present invention is not limited to the above embodiments. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention fall within the protection scope of the present invention.

Claims

1. An ultra-high temperature resistant full ball bearing, comprising a bearing outer ring, a bearing inner ring and a roller, characterized in that: The rollers are spherical and fully arranged in the raceway. The outer ring of the bearing, the inner ring of the bearing and the rollers are all made of carbon fiber reinforced ceramic matrix composite materials.

2. The design method of a super high temperature resistant full ball bearing according to claim 1, characterized in that: The following steps are included: S1. Determine the structural dimension parameters of the bearing, including the bearing inner diameter d, the bearing outer diameter D and the bearing width B, and determine the contact angle α of the bearing; S2. Based on the principle of reducing the working contact stress of the bearing and improving the fatigue life of the bearing, determine the inner groove curvature radius coefficient fi and the outer groove curvature radius coefficient fe of the bearing; S3. Determine the roller diameter D of the bearing W , center diameter D WP , the range of values ​​of the roller number Z; S4. Optimize and determine the roller diameter D of the bearing based on the principle of obtaining the maximum radial basic rated static load. W , center diameter D WP , roller number Z.

3. A design method for a super-high temperature resistant full ball bearing according to claim 2, characterized in that: In S2, in order to improve the bearing capacity and reduce the contact stress between the roller and the inner groove when the bearing is working, the value range of the inner groove curvature radius coefficient fi is 0.505≤fi≤0.

515.

4. A design method for a super-high temperature resistant full ball bearing as claimed in claim 3, characterized in that: The outer groove curvature radius coefficient fe adopts equal stress design, and its value range is 0.510≤fe≤0.

520.

5. The design method of a super high temperature resistant full ball bearing according to claim 2, characterized in that: In S3, the roller diameter D W The constraint formula is: K Wmin (D-d)≤D W ≤K Wmax (D-d), Among them, K Wmin and K Wmax are the maximum and minimum values ​​of the cross-sectional coefficient, respectively.

6. A design method for a super-high temperature resistant full ball bearing according to claim 5, characterized in that: In order to improve the bearing capacity, the cross-sectional coefficient takes a larger value K Wmin =0.28, K Wmax =0.

34.

7. The design method of a super-high temperature resistant full ball bearing according to claim 2, characterized in that: In S3, the bearing center diameter D WP =0.5(D+d).

8. The design method of a super-high temperature resistant full ball bearing according to claim 2, characterized in that: In S3, the constraint formula for the number of rollers Z is: The bearing is a full ball bearing with Φ=360°, and the number of rollers Z is a positive integer.

9. The design method of a super high temperature resistant full ball bearing according to claim 2, characterized in that: In S3, the roller diameter D W , center diameter D WP , the number of rollers Z must satisfy the bearing circumferential clearance S C The constraints of 10. The design method of a super-high temperature resistant full ball bearing according to claim 2, characterized in that: In S4, the radial basic static load rating C or The expression of is, C or =f0×Z×D W 2 , Among them, f0 is based on The value of is determined.

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