Wide-temperature-range angular contact bearing assembly and design method thereof

Abstract

The invention discloses a wide-temperature-range angular contact bearing assembly and a design method thereof. The bearing assembly comprises a paired bearing composed of two rows of angular contact bearings, an outer space ring located between two outer rings of the paired bearing and an inner space ring located between two inner rings of the paired bearing. The outer space ring is formed by superposing a first branch outer space ring and a second branch outer space ring in the axial direction of the paired bearing; the inner space ring is formed by superposing two space rings, namely a first sub-inner space ring and a second sub-inner space ring in the axial direction of the paired bearing; according to the wide-temperature-range angular contact bearing assembly and the design method thereof, the relatively constant pre-tightening force can be kept in a wide-temperature-range application scene, the influence on the function of the bearing assembly is avoided, and the stable operation of a shaft system is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of bearings, and specifically to a wide-temperature-range angular contact bearing assembly and its design method. Background Art

[0002] The angular contact ball bearing assembly after back-to-back or face-to-face assembly can simultaneously bear radial load, axial load and tilting moment load, and has the advantages of high stiffness, strong stability, high precision, etc., and is widely used in many fields such as aerospace, precision instrument equipment, robots, etc. The preload of the conventional assembled angular contact ball bearing assembly is often applied by grinding the protruding amount of the bearing end face, or adding a spacer ring and adjusting the preload by grinding the height difference of the spacer ring.

[0003] However, in the application scenario of a wide temperature range, such as in the lunar surface environment, the conventional assembled angular contact ball bearing assembly often has the situation of too large or too small preload due to the large day-night temperature difference, which in turn affects the functional performance of the bearing assembly, interferes with the normal operation of the shafting, and even causes jamming failure. Summary of the Invention

[0004] The purpose of the present invention is to provide a wide-temperature-range angular contact bearing assembly and its design method, which can maintain a relatively constant preload in the application scenario of a wide temperature range and ensure the stable operation of the shafting.

[0005] The technical solution adopted by the present invention is: a wide-temperature-range angular contact bearing assembly, including a paired bearing composed of two rows of angular contact bearings, an outer spacer ring located between the two outer rings of the paired bearing, and an inner spacer ring located between the two inner rings of the paired bearing;

[0006] The outer spacer ring is composed of two separated rings, namely a No. 1 outer separated spacer ring and a No. 2 outer separated spacer ring, which are stacked axially on the paired bearing;

[0007] The inner spacer ring is composed of two separated rings, namely a No. 1 inner separated spacer ring and a No. 2 inner separated spacer ring, which are stacked axially on the paired bearing;

[0008] The designed height h 1 and the thermal expansion coefficient α 1 of the used material of the No. 1 outer separated spacer ring, 2 the designed height h 2 and the thermal expansion coefficient α 3 of the used material of the No. 2 outer separated spacer ring, 3 the designed height h 4 and the thermal expansion coefficient α 4 of the used material of the No. 1 inner separated spacer ring,

[0009] α 1 h1 +α 2 h 2 -α 3 h 3 -α 4 h 4 = k

[0010] Where: k is the change rate of the axial clearance of the bearing with temperature.

[0011] As a preferred solution, the No. 1 outer spacer ring and the No. 2 outer spacer ring have different thermal expansion coefficients; the No. 1 inner spacer ring and the No. 2 inner spacer ring have different thermal expansion coefficients.

[0012] As a preferred solution, the thermal expansion coefficient of the No. 1 outer spacer ring is less than that of the No. 2 outer spacer ring; the thermal expansion coefficient of the No. 1 inner spacer ring is less than that of the No. 2 inner spacer ring.

[0013] A design method for a wide-temperature angular contact bearing assembly includes the following steps:

[0014] Step 1: Design a pair of bearings, obtain the curve of the axial clearance of the pair of bearings changing with temperature and the change rate k of the axial clearance of the bearing with temperature of this curve;

[0015]

[0016] Where: ΔQ is the change amount of the axial clearance of the pair of bearings with temperature; T is the working condition temperature; T 0 is the initial normal temperature;

[0017] Step 2: Obtain the designed height h of the outer spacer ring according to the axial height of the installation position of the pair of bearings 1 +h 2 and the designed height h of the inner spacer ring 3 +h 4 ;

[0018] Step 3: Based on the design requirements of the spacer rings, select the materials used for the spacer rings to determine their respective thermal expansion coefficients, and then distribute the designed heights of the spacer rings according to the designed heights of the outer spacer ring and the inner spacer ring;

[0019] Machine the No. 1 outer spacer ring and the No. 2 outer spacer ring and axially stack the two between the two outer rings of the pair of bearings to form an outer spacer ring; machine the No. 1 inner spacer ring and the No. 2 inner spacer ring and axially stack the two between the two inner rings of the pair of bearings to form an inner spacer ring;

[0020] Step 4: Determine the factory preload of the bearing assembly at the initial normal temperature T 0 by trimming the initial height difference ΔH of the outer spacer ring and the inner spacer ring 0 at the time.

[0021] As a preferred solution, the coefficient of thermal expansion α 1 is not equal to the coefficient of thermal expansion α 2 ;

[0022] The coefficient of thermal expansion α 3 is not equal to the coefficient of thermal expansion α 4 .

[0023] As a preferred solution, the difference in the coefficients of thermal expansion of the materials used for the No. 1 outer spacer ring and the No. 2 outer spacer ring is as large as possible;

[0024] The difference in the coefficients of thermal expansion of the materials used for the No. 1 inner spacer ring and the No. 2 inner spacer ring is as large as possible.

[0025] As a preferred solution, when machining the outer spacer ring or the inner spacer ring in Step 4, select any one of the spacer rings and grind its end face.

[0026] As a preferred solution, the materials used for the No. 1 outer spacer ring and the No. 1 inner spacer ring are ceramics or titanium alloys.

[0027] As a preferred solution, the materials used for the No. 2 outer spacer ring and the No. 2 inner spacer ring are aluminum alloy, copper alloy, polytetrafluoroethylene or polyimide.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. By designing and adjusting the height ratio of each spacer ring, the present invention can accurately control the curve of the height difference between the inner spacer ring and the outer spacer ring changing with temperature, so as to accurately control the preload of the bearing assembly within a wide temperature range, and has extremely strong adaptability to the wide temperature environment;

[0030] 2. The present invention adopts positioning preloading. Compared with constant pressure preloading, it has high stiffness, good positioning accuracy and strong bidirectional axial load-bearing capacity;

[0031] 3. The structure is simple, easy to implement, convenient to install, and the preload is determined at the time of leaving the factory, without the need for complex grinding and matching work. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0033] Figure 1 is a three-dimensional schematic diagram of the present invention;

[0034] Figure 2Longitudinal sectional view of the present invention when assembled back-to-back;

[0035] Figure 3 Longitudinal sectional view of the present invention when assembled face-to-face;

[0036] Figure 4 Height schematic diagram of the inner and outer spacer rings of the present invention.

[0037] Reference numerals:

[0038] 1. Angular contact bearing, 101. Outer ring, 102. Inner ring;

[0039] 2. Outer spacer ring, 201. No. 1 outer sub-spacer ring, 202. No. 2 outer sub-spacer ring;

[0040] 3. Inner spacer ring, 301. No. 1 inner sub-spacer ring, 302. No. 2 inner sub-spacer ring. Detailed implementation manners

[0041] Next, the present invention will be specifically described through exemplary implementation manners. However, it should be understood that without further description, the elements, structures, and features in one implementation manner can also be beneficially combined into other implementation manners.

[0042] It should be noted that: Unless otherwise defined, the technical terms or scientific terms used herein should have the ordinary meaning understood by those of ordinary skill in the field to which the present invention belongs. The words such as "a", "an", or "the" used in the specification and claims of this patent application for the present invention do not express a limitation of quantity, but mean that there is at least one; the "first", "second", and "third" used herein should not be regarded as a limitation on the order of components, but are only used to distinguish different components; words such as "comprising" or "including" indicate that the elements or objects appearing before "comprising" or "including" cover the elements or objects listed after "comprising" or "including" and their equivalents, but do not exclude other elements or objects having the same functions.

[0043] For a clearer description of the wide-temperature-range angular contact bearing assembly and its design method, in combination with the attached Figures 1-4 Describe this embodiment:

[0044] A wide-temperature-range angular contact bearing assembly includes a pair of bearings composed of two rows of angular contact bearings 1, an outer spacer ring 2 located between the two outer rings 101 of the pair of bearings, and an inner spacer ring 3 located between the two inner rings 102 of the pair of bearings;

[0045] The outer spacer ring 2 is composed of two separating rings, namely the No. 1 outer sub-spacer ring 201 and the No. 2 outer sub-spacer ring 202, which are stacked axially on the pair of bearings;

[0046] The inner spacer ring 3 is composed of two spacer rings, namely the No. 1 inner spacer ring 301 and the No. 2 inner spacer ring 302, which are stacked axially on the mating bearings.

[0047] The designed height h of the No. 1 outer spacer ring 201 1 and the thermal expansion coefficient α of the material used 1 , the designed height h of the No. 2 outer spacer ring 202 2 and the thermal expansion coefficient α of the material used 2 , the designed height h of the No. 1 inner spacer ring 301 3 and the thermal expansion coefficient α of the material used 3 , the designed height h of the No. 2 inner spacer ring 302 4 and the thermal expansion coefficient α of the material used 4 meet the following design requirements for the spacer rings:

[0048] α 1 h 1 +α 2 h 2 -α 3 h 3 -α 4 h 4 =k Equation (1)

[0049] Where: k is the change rate of the axial clearance of the bearing with temperature.

[0050] In the above embodiment, the No. 1 outer spacer ring 201 and the No. 2 outer spacer ring 202 have different thermal expansion coefficients; the No. 1 inner spacer ring 301 and the No. 2 inner spacer ring 302 have different thermal expansion coefficients; specifically, the thermal expansion coefficient of the No. 1 outer spacer ring 201 is less than that of the No. 2 outer spacer ring 202, and the thermal expansion coefficient of the No. 1 inner spacer ring 301 is less than that of the No. 2 inner spacer ring 302.

[0051] Figure 2 and Figure 3 respectively give the design requirements of the outer spacer ring 2 and the inner spacer ring 3 in the two assembly methods of the angular contact bearing 1 in the back-to-back assembly and the face-to-face assembly, and the design requirements do not need to change in both cases.

[0052] A design method for a wide-temperature-range angular contact bearing assembly includes the following steps:

[0053] Step 1: Design the mating bearings, calculate the amount ΔQ of the axial clearance of the mating bearings changing with temperature according to the material and dimensions, and fit the data to obtain a curve:

[0054] ΔQ = k(T - T 0 ) Equation (2)

[0055] Transform Equation (2) to obtain the change rate k of the axial clearance of the bearing with temperature for this curve.

[0056]

[0057] Wherein: ΔQ is the change in the axial clearance of the paired bearings with temperature; T is the operating temperature; T 0 is the initial normal temperature;

[0058] The change in the height difference ΔH between the outer spacer 2 and the inner spacer 3 with temperature T can be expressed by the following formula:

[0059] ΔH = Δh 12 -Δh 34 Equation (4)

[0060] Δh 12 = α 12 ×(T - T 0 )×(h 1 + h 2 ) Equation (5)

[0061] Δh 34 = α 34 ×(T - T 0 )×(h 3 + h 4 ) Equation (6)

[0062]

[0063]

[0064] Wherein: Δh 12 is the change in the height of the outer spacer 2 with temperature, and Δh 34 is the change in the height of the inner spacer 3 with temperature; α 12 is the coefficient of thermal expansion of the outer spacer 2, and α 34 is the coefficient of thermal expansion of the inner spacer 3;

[0065] Combining Equations (4), (5), (6), (7), and (8) gives the following equation:

[0066] ΔH = [(α 1 h 1 + α 2 h 2 ) - (α 3 h 3 + α 4 h 4 )](T - T 0 ) Equation (9)

[0067] By accurately controlling the changes in the inner spacer and the outer spacer with temperature Δh 12 and Δh 34, the curve of the height difference ΔH between the outer spacer 2 and the inner spacer 3 changing with temperature can be controlled. When this curve matches the curve of the axial clearance of the bearing changing with temperature (ΔH = ΔQ), the preload of the bearing assembly can be ensured to remain stable at different ambient temperatures, achieving adaptability to a wide temperature range environment. Combining Equation (2) and Equation (9) gives the design requirements for the spacer rings in Equation (1).

[0068] By adjusting the height h of the No. 1 outer sub-spacer ring 201 1 and the height h of the No. 2 outer sub-spacer ring 202 2 The coefficient of thermal expansion α of the composed outer spacer 2 can be precisely controlled within a certain range 12 , so as to realize the accurate control of the change amount Δh of the height of the outer spacer 2 with temperature 12 ; By adjusting the height h of the No. 1 inner sub-spacer ring 301 3 and the height h of the No. 2 inner sub-spacer ring 302 4 The coefficient of thermal expansion α of the composed inner spacer 3 can be precisely controlled within a certain range 34 , so as to realize the accurate control of the change amount Δh of the height of the inner spacer 3 with temperature 34 .

[0069] Step two: Obtain the designed height h of the outer spacer 2 1 +h 2 and the designed height h of the inner spacer 3 3 +h 4 ;

[0070] Step three: Based on the design requirements of the spacer rings, select the materials of the spacer rings (201, 202, 301, 302) to determine their respective coefficients of thermal expansion, and then allocate the respective designed heights of the spacer rings according to the designed heights of the outer spacer 2 and the inner spacer 3;

[0071] Machine the No. 1 outer sub-spacer ring 201 and the No. 2 outer sub-spacer ring 202 and axially stack them between the two outer rings of the mating bearings to form the outer spacer 2; machine the No. 1 inner sub-spacer ring 301 and the No. 2 inner sub-spacer ring 302 and axially stack them between the two inner rings of the mating bearings to form the inner spacer 3;

[0072] Step four: By trimming the initial height difference ΔH between the outer spacer 2 and the inner spacer 3 0 Determine the factory preload of the bearing assembly at the initial normal temperature T 0 ;

[0073] During trimming, select any one of the spacer rings according to actual needs and grind its end face.

[0074] In the above embodiment, the coefficient of thermal expansion α 1Not equal to the coefficient of thermal expansion α 2 ; the coefficient of thermal expansion α 3 Not equal to the coefficient of thermal expansion α 4 ; By designing and adjusting the ratio between the height of the first outer spacer ring and the height of the second outer spacer ring, the axial coefficient of thermal expansion of the outer spacer ring formed by them is controlled; By designing and adjusting the ratio between the height of the first inner spacer ring and the height of the second inner spacer ring, the axial coefficient of thermal expansion of the inner spacer ring formed by them is controlled;

[0075] In the above embodiments, in order to increase the adjustable range of the coefficients of thermal expansion of the outer spacer ring 2 and the inner spacer ring 3, the difference in the coefficients of thermal expansion of the materials used for the first outer spacer ring 201 and the second outer spacer ring 202 is as large as possible; the difference in the coefficients of thermal expansion of the materials used for the first inner spacer ring 301 and the second inner spacer ring 302 is as large as possible. The materials used for the first outer spacer ring 201 and the first inner spacer ring 301 are materials such as ceramics, titanium alloys, and low-thermal-expansion alloys, and the materials used for the second outer spacer ring 202 and the second inner spacer ring 302 are organic polymer materials such as aluminum alloys, copper alloys, polytetrafluoroethylene, and polyimide.

[0076] The parts not detailed in the above embodiments are prior art.

[0077] It should be noted that although the present invention has been described through the above embodiments, the present invention can also have many other embodiments. Without departing from the spirit and scope of the present invention, those skilled in the art can obviously make various corresponding changes and deformations to the present invention, but these changes and deformations should all fall within the scope protected by the appended claims of the present invention and their equivalents.

Claims

1. A wide temperature range angular contact bearing assembly, characterized in that: It comprises a paired bearing composed of two rows of angular contact bearings (1), an outer spacer (2) located between the two outer rings of the paired bearing, and an inner spacer (3) located between the two inner rings of the paired bearing; The outer spacer (2) is composed of two spacer rings, a No. 1 outer spacer (201) and a No. 2 outer spacer (202), which are stacked in the axial direction of the paired bearing; The inner spacer (3) is composed of two spacer rings, a No. 1 inner spacer (301) and a No. 2 inner spacer (302), which are stacked in the axial direction of the paired bearing; The design height h1 of the No. 1 outer spacer (201) and the thermal expansion coefficient α1 of the material used, the design height h2 of the No. 2 outer spacer (202) and the thermal expansion coefficient α2 of the material used, the design height h3 of the No. 1 inner spacer (301) and the thermal expansion coefficient α3 of the material used, and the design height h4 of the No. 2 inner spacer (302) and the thermal expansion coefficient α4 of the material used meet the following spacer design requirements: α1h1+α2h2-α3h3-α4h4=k Where: k is the rate of change of bearing axial clearance with temperature.

2. The wide temperature range angular contact bearing assembly according to claim 1, characterized in that: The No. 1 outer spacer (201) and the No. 2 outer spacer (202) have different thermal expansion coefficients; the No. 1 inner spacer (301) and the No. 2 inner spacer (302) have different thermal expansion coefficients.

3. The wide temperature range angular contact bearing assembly according to claim 2, characterized in that: The thermal expansion coefficient of the No. 1 outer spacer (201) is smaller than the thermal expansion coefficient of the No. 2 outer spacer (202); the thermal expansion coefficient of the No. 1 inner spacer (301) is smaller than the thermal expansion coefficient of the No. 2 inner spacer (302).

4. The design method of a wide temperature range angular contact bearing assembly according to claim 1, characterized in that: The following steps are involved: Step 1: Design a paired bearing, obtain a curve of the axial clearance of the paired bearing changing with temperature and a rate of change k of the axial clearance of the bearing changing with temperature of the curve; Where: ΔQ is the change of the axial clearance of the paired bearings with temperature; T is the operating temperature; T0 is the initial normal temperature; Step 2: Obtain the design height h1+h2 of the outer spacer (2) and the design height h3+h4 of the inner spacer (3) according to the axial height of the paired bearing installation position; Step 3: Based on the design requirements of the spacer ring, the materials used for the spacer ring are selected to determine their respective thermal expansion coefficients, and then the design heights of the spacer rings are allocated according to the design heights of the outer spacer ring (2) and the inner spacer ring (3); Processing the No. 1 outer spacer (201) and the No. 2 outer spacer (202) and axially superimposing the two between the two outer rings of the paired bearing to form an outer spacer (2); processing the No. 1 inner spacer (301) and the No. 2 inner spacer (302) and axially superimposing the two between the two inner rings of the paired bearing to form an inner spacer (3); Step 4: Determine the factory preload force of the bearing assembly at the initial normal temperature T0 by adjusting the initial height difference ΔH0 between the outer spacer (2) and the inner spacer (3).

5. The design method of a wide temperature range angular contact bearing assembly according to claim 4, characterized in that: The thermal expansion coefficient α1 is not equal to the thermal expansion coefficient α2; The thermal expansion coefficient α3 is not equal to the thermal expansion coefficient α4.

6. The design method of a wide temperature range angular contact bearing assembly according to claim 5, characterized in that: The difference in thermal expansion coefficient of the materials used for the No. 1 outer spacer (201) and the No. 2 outer spacer (202) is as large as possible; The difference in thermal expansion coefficient of the materials used for the No. 1 inner spacer (301) and the No. 2 inner spacer (302) is as large as possible.

7. The design method of a wide temperature range angular contact bearing assembly according to claim 4, characterized in that: When repairing the outer spacer (2) or the inner spacer (3) in step 4, any one of the spacers is selected and the end surface thereof is ground.

8. The design method of a wide temperature range angular contact bearing assembly according to claim 4, characterized in that: The materials used for the No. 1 outer spacer (201) and the No. 1 inner spacer (301) are ceramics or titanium alloy.

9. The design method of a wide temperature range angular contact bearing assembly according to claim 4, characterized in that: The materials used for the No. 2 outer spacer (202) and the No. 2 inner spacer (302) are aluminum alloy, copper alloy, polytetrafluoroethylene or polyimide.

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