A wide temperature range angular contact bearing assembly and method of designing the same

Abstract

A wide temperature range angular contact bearing assembly and a design method thereof, wherein the bearing assembly comprises a matched bearing composed of two rows of angular contact bearings, an outer spacer ring between the two outer rings of the matched bearing, and an inner spacer ring between the two inner rings of the matched bearing; the outer spacer ring is composed of two sub-outer spacer rings, No. 1 and No. 2, stacked in the axial direction of the matched bearing; the inner spacer ring is composed of two sub-inner spacer rings, No. 1 and No. 2, stacked in the axial direction of the matched bearing; the wide temperature range angular contact bearing assembly and the design method thereof can maintain a relatively constant pre-tightening force in a wide temperature range application scenario, avoid affecting the function of the bearing assembly, and ensure stable operation of the shafting.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bearings, in particular to a wide-temperature-range angular contact bearing assembly and a design method thereof. BACKGROUND

[0002] The angular contact ball bearing assembly assembled back-to-back or face-to-face can simultaneously bear radial load, axial load and overturning moment load, has the advantages of high rigidity, strong stability and high precision, and is widely used in many fields such as aerospace, precision instruments and equipment, robots, etc. The pre-tightening force of the conventional assembled angular contact ball bearing assembly is usually applied by grinding the protrusion amount of the bearing end face, or adding a spacer ring and adjusting the size of the pre-tightening force by grinding the height difference of the spacer ring.

[0003] However, in the wide-temperature-range application scenario, such as in the lunar surface environment, the pre-tightening force of the conventional assembled angular contact ball bearing assembly is often too large or too small due to the large diurnal temperature difference, which affects the functional performance of the bearing assembly and interferes with the normal operation of the shaft system, and even causes jamming failure. SUMMARY

[0004] The purpose of the present application is to provide a wide-temperature-range angular contact bearing assembly and a design method thereof, which can maintain a relatively constant pre-tightening force in a wide-temperature-range application scenario and ensure stable operation of the shaft system.

[0005] The technical scheme adopted by the present application is: a wide-temperature-range angular contact bearing assembly, comprising a pair of angular contact bearings, an outer spacer ring between the two outer rings of the pair of angular contact bearings, and an inner spacer ring between the two inner rings of the pair of angular contact bearings;

[0006] The outer spacer ring is composed of two sub-spacer rings, a first sub-outer spacer ring and a second sub-outer spacer ring, stacked in the axial direction of the pair of angular contact bearings;

[0007] The inner spacer ring is composed of two sub-spacers, a first sub-inner spacer ring and a second sub-inner spacer ring, stacked in the axial direction of the pair of angular contact bearings;

[0008] The design height h1 of the first sub-outer spacer ring and the thermal expansion coefficient a1 of the material used, the design height h2 of the second sub-outer spacer ring and the thermal expansion coefficient a2 of the material used, the design height h3 of the first sub-inner spacer ring and the thermal expansion coefficient a3 of the material used, and the design height h4 of the second sub-inner spacer ring and the thermal expansion coefficient a4 of the material used satisfy the following sub-spacer design requirements:

[0009] a1h1+a2h2-a3h3-a4h4=k

[0010] Wherein: k is the rate of change of bearing axial play with temperature.

[0011] As a preferred solution, the 1st partial outer spacer ring and the 2nd partial outer spacer ring have different thermal expansion coefficients; the 1st partial inner spacer ring and the 2nd partial inner spacer ring have different thermal expansion coefficients.

[0012] As a preferred solution, the thermal expansion coefficient of the 1st partial outer spacer ring is less than the thermal expansion coefficient of the 2nd partial outer spacer ring; the thermal expansion coefficient of the 1st partial inner spacer ring is less than the thermal expansion coefficient of the 2nd partial inner spacer ring.

[0013] A design method of a wide-temperature-range angular contact bearing assembly, comprising the following steps:

[0014] Step one: design a matched bearing, obtain the curve of the axial clearance of the matched bearing with temperature change and the rate k of the bearing axial clearance with temperature change of the curve;

[0015]

[0016] Wherein: ΔQ is the change amount of the axial clearance of the matched bearing with temperature; T is the working temperature; T0 is the initial normal temperature;

[0017] Step two: obtain the design height h1+h2 of the outer spacer ring and the design height h3+h4 of the inner spacer ring according to the axial height of the installation position of the matched bearing;

[0018] Step three: based on the design requirements of the partial spacer ring, select the materials of the partial spacer ring to determine the respective thermal expansion coefficients, and then distribute the respective design heights of the partial spacer ring according to the design heights of the outer spacer ring and the inner spacer ring;

[0019] Machining the 1st partial outer spacer ring and the 2nd partial outer spacer ring and axially stacking them between the two outer rings of the matched bearing to form an outer spacer ring; machining the 1st partial inner spacer ring and the 2nd partial inner spacer ring and axially stacking them between the two inner rings of the matched bearing to form an inner spacer ring;

[0020] Step four: determine the factory pre-tightening force of the bearing assembly at the initial normal temperature T0 by adjusting the initial height difference ΔH0 of the outer spacer ring and the inner spacer ring.

[0021] As a preferred solution, the thermal expansion coefficient α1 is not equal to the thermal expansion coefficient α2;

[0022] The thermal expansion coefficient α3 is not equal to the thermal expansion coefficient α4.

[0023] As a preferred solution, the difference between the thermal expansion coefficients of the materials of the 1st partial outer spacer ring and the 2nd partial outer spacer ring is as large as possible;

[0024] The difference between the thermal expansion coefficients of the materials of the 1st partial inner spacer ring and the 2nd partial inner spacer ring is as large as possible.

[0025] As a preferred solution, the outer spacer ring or the inner spacer ring is selected and reworked on the end face in step four.

[0026] As a preferred solution, the material of the first outer spacer ring and the first inner spacer ring is ceramic or titanium alloy.

[0027] As a preferred solution, the material of the second outer spacer ring and the second inner spacer ring is aluminum alloy, copper alloy, polytetrafluoroethylene or polyimide.

[0028] Compared with the prior art, the present application has the following beneficial effects:

[0029] 1. The height ratio of each spacer ring is designed and adjusted to accurately control the height difference of the inner spacer ring and the outer spacer ring with temperature change, thereby realizing accurate control of the pre-tightening force of the bearing assembly in a wide temperature range and having strong adaptability to a wide temperature range environment.

[0030] 2. The present application uses positioning pre-tightening, which has high stiffness, good positioning accuracy and strong bidirectional axial load capacity compared with constant pressure pre-tightening.

[0031] 3. The structure is simple, easy to implement and convenient to install, and the pre-tightening force is determined at the time of delivery, without the need for complex reworking and matching work. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0033] Figure 1 is a three-dimensional schematic view of the present application;

[0034] Figure 2 is a longitudinal sectional view of the present application when back-to-back assembled;

[0035] Figure 3 is a longitudinal sectional view of the present application when face-to-face assembled;

[0036] Figure 4 is a height schematic view of the inner and outer spacer rings of the present application.

[0037] LIST OF REFERENCE NUMBERS

[0038] 1. Angular contact bearing, 101, outer ring, 102, inner ring;

[0039] 2. Outer spacer ring, 201, first outer spacer ring, 202, second outer spacer ring;

[0040] 3. Inner spacer ring, 301, first part inner spacer ring, 302, second part inner spacer ring. DETAILED DESCRIPTION

[0041] The application will now be described in detail by way of example with reference to the accompanying drawings. It should be noted, however, that the elements, structures and features in one embodiment can be beneficially combined with those in another embodiment without further description.

[0042] It should be noted that, unless otherwise defined, technical terms or scientific terms used herein should be understood as having the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terms "one", "an" or "the" appearing in the application patent specification and claims are not to be construed as excluding that there are more than one of the elements or the object. The terms "first", "second" and "third" are not to be construed as limiting the order of the components, but are merely used to distinguish different components. The terms "include", "comprise" or "contain" or similar terms mean that the elements or objects before the "include", "comprise" or "contain" are encompassed by the elements or objects after the "include", "comprise" or "contain" and equivalents thereof, but do not exclude other elements or objects with the same function.

[0043] In order to more clearly describe the wide temperature range angular contact bearing assembly and the design method thereof, the accompanying drawings are referred to, in which Figures 1-4 The present embodiment is described as follows:

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

[0045] The outer spacer ring 2 is composed of a first part outer spacer ring 201 and a second part outer spacer ring 202 stacked in the axial direction of the matched bearing;

[0046] The inner spacer ring 3 is composed of a first part inner spacer ring 301 and a second part inner spacer ring 302 stacked in the axial direction of the matched bearing;

[0047] The design height h1 of the first part outer spacer ring 201, the thermal expansion coefficient a1 of the material used, the design height h2 of the second part outer spacer ring 202, the thermal expansion coefficient a2 of the material used, the design height h3 of the first part inner spacer ring 301, the thermal expansion coefficient a3 of the material used, the design height h4 of the second part inner spacer ring 302, and the thermal expansion coefficient a4 of the material used satisfy the following design requirements of the spacer rings:

[0048] a1h1 + a2h2 - a3h3 - a4h4 = k Equation (1)

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

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

[0051] Figure 2 and Figure 3 Two assembly methods for angular contact bearing 1 are given: back-to-back assembly and face-to-face assembly. In both cases, the design requirements for outer spacer 2 and inner spacer 3 do not need to be changed.

[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 change in axial clearance ΔQ of the mating bearings with temperature based on the materials and dimensions, and obtain the curve by fitting the data.

[0054] ΔQ=k(T-T0) Equation (2)

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

[0056]

[0057] Where: ΔQ is the change in axial clearance of the paired bearing with temperature; T is the operating temperature; T0 is the initial ambient 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-T0)×(h1+h2) Equation (5)

[0061] Δh 34 =α 34 ×(T-T0)×(h3+h4) Equation (6)

[0062]

[0063]

[0064] Where: Δh12 Δh represents the change in height of outer spacer 2 with temperature. 34 α represents the change in height of inner spacer 3 with temperature; 12 The coefficient of thermal expansion of outer spacer 2, α 34 The coefficient of thermal expansion of the inner spacer 3;

[0065] Combining equations (4)(5)(6)(7)(8), we obtain the following equation:

[0066] ΔH=[(α1h1+α2h2)-(α3h3+α4h4)](T-T0) Formula (9)

[0067] By accurately controlling the temperature variation Δh of the inner and outer spacers... 12 and Δh 34 The curve of the height difference ΔH between the outer spacer 2 and the inner spacer 3 as a function of temperature can be controlled. When this curve matches the curve of the bearing axial clearance as a function of temperature (ΔH=ΔQ), the preload of the bearing assembly can be kept stable under different ambient temperatures, thus achieving adaptability to a wide temperature range environment. Combining equations (2) and (9), the design requirements for the spacer rings in equation (1) can be obtained.

[0068] By adjusting the ratio between the height h1 of outer spacer 1 201 and the height h2 of outer spacer 202 202, the coefficient of thermal expansion α of the outer spacer 2 can be precisely controlled within a certain range. 12 This allows us to realize the change in height Δh of the outer spacer 2 with temperature. 12 Accurate control is achieved by adjusting the ratio between the height h3 of inner spacer 1 (301) and the height h4 of inner spacer 2 (302). This allows for precise control of the thermal expansion coefficient α of the inner spacer 3 within a certain range. 34 This allows us to realize the change in height Δh of the inner spacer 3 with temperature. 34 Accurate control.

[0069] Step 2: Obtain the design height h1+h2 of the outer spacer 2 and the design height h3+h4 of the inner spacer 3 based on the axial height of the mating bearing installation position;

[0070] Step 3: Based on the design requirements of the partition rings, select the materials used for the partition rings (201, 202, 301, 302) to determine their respective coefficients of thermal expansion, and then allocate the design height of the partition rings according to the design height of the outer partition ring 2 and the inner partition ring 3.

[0071] Machine out outer spacer 201 and outer spacer 202, and axially superimpose them between the two outer rings of the mating bearing to form outer spacer 2; machine out inner spacer 301 and inner spacer 302, and axially superimpose them between the two inner rings of the mating bearing to form inner spacer 3;

[0072] Step 4: Determine the factory preload of the bearing assembly at the initial ambient temperature T0 by adjusting the initial height difference ΔH0 between the outer spacer 2 and the inner spacer 3;

[0073] During the repair process, select any one of the separator rings according to actual needs and perform repair and grinding on its end face.

[0074] In the above embodiments, the coefficient of thermal expansion α1 is not equal to the coefficient of thermal expansion α2; the coefficient of thermal expansion α3 is not equal to the coefficient of thermal expansion α4; the axial thermal expansion coefficient of the outer spacer formed by the design is controlled by adjusting the ratio between the height of the No. 1 outer spacer and the height of the No. 2 outer spacer; the axial thermal expansion coefficient of the inner spacer formed by the design is controlled by adjusting the ratio between the height of the No. 1 inner spacer and the height of the No. 2 inner spacer.

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

[0076] The parts not described in detail in the above embodiments are existing technologies.

[0077] It should be noted that although the present invention has been described through the above embodiments, the present invention may 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 modifications to the present invention, but all such changes and modifications should fall within the scope of protection of the appended claims and their equivalents.

Claims

1. A design method for a wide-temperature-range angular contact bearing assembly, characterized in that: The wide temperature range angular contact bearing assembly includes a pair of bearings consisting of two rows of angular contact bearings (1), an outer spacer (2) located between the two outer rings of the pair of bearings, and an inner spacer (3) located between the two inner rings of the pair of bearings. The outer spacer (2) is composed of two spacer rings, No. 1 outer spacer (201) and No. 2 outer spacer (202), stacked on the axial side of the paired bearing; The inner spacer (3) is composed of two spacer rings, No. 1 inner spacer (301) and No. 2 inner spacer (302), stacked axially on the paired bearing; Design height of No. 1 outer spacer ring (201) and the coefficient of thermal expansion of the materials used Design height of No. 2 outer spacer ring (202) and the coefficient of thermal expansion of the materials used Design height of No. 1 inner spacer ring (301) and the coefficient of thermal expansion of the materials used Design height of No. 2 inner spacer ring (302) and the coefficient of thermal expansion of the materials used The following design requirements for the separator ring must be met: in: This represents the rate of change of the bearing's axial clearance with temperature. The design methodology includes the following steps: Step 1: Design the mating bearings, obtain the curve of the axial clearance of the mating bearings as a function of temperature, and the rate of change of the bearing axial clearance with temperature on this curve. ; in: The axial clearance of the mating bearing changes with temperature; T is the operating temperature. Initial room temperature; Step 2: Obtain the design height of the outer spacer (2) based on the axial height of the mating bearing installation position. and the design height of the inner spacer (3) ; Step 3: Based on the design requirements of the separator ring, select the materials used for the separator ring to determine their respective coefficients of thermal expansion, and then allocate the design height of the separator ring according to the design height of the outer separator ring (2) and the inner separator ring (3); The No. 1 outer spacer (201) and the No. 2 outer spacer (202) are machined and axially superimposed between the two outer rings of the mating bearing to form an outer spacer (2); the No. 1 inner spacer (301) and the No. 2 inner spacer (302) are machined and axially superimposed between the two inner rings of the mating bearing to form an inner spacer (3). Step 4: Adjust the initial height difference between the outer spacer (2) and the inner spacer (3). Determine the bearing assembly at initial ambient temperature The factory preload at that time.

2. The design method for a 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 coefficients of thermal expansion; the No. 1 inner spacer (301) and the No. 2 inner spacer (302) have different coefficients of thermal expansion.

3. The design method for a wide-temperature-range angular contact bearing assembly according to claim 2, characterized in that: The coefficient of thermal expansion of the No. 1 outer partition ring (201) is less than that of the No. 2 outer partition ring (202); the coefficient of thermal expansion of the No. 1 inner partition ring (301) is less than that of the No. 2 inner partition ring (302).

4. The design method for a wide-temperature-range angular contact bearing assembly according to claim 1, characterized in that: When repairing the outer spacer (2) or inner spacer (3) in step four, select any one of the spacers and grind it on its end face.

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

6. The design method for a wide-temperature-range angular contact bearing assembly according to claim 1, 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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