Elastomeric ring rolling contact performance evaluation fixture assembly

Abstract

The present invention relates to an elastic ring rolling contact performance evaluation fixture assembly, comprising a center fixture and an outer ring fixture, wherein the center fixture is sleeved on a rotating shaft through a rotating shaft mounting hole, an outer ring raceway is provided on the outer ring fixture, and a center raceway is provided on the center fixture, wherein the outer ring raceway is arranged on the outer side of the center raceway to form a rolling space between the two raceways so that the outer peripheral surface of the elastic ring can roll with the two raceways and revolve around the rotating shaft. Since the outer ring fixture is arranged on a frame and the center fixture is arranged on a rotating shaft, the outer ring fixture and the center fixture can rotate relative to each other. After the elastic ring is placed on the outer ring raceway and the center raceway, the elastic ring can roll relative to the outer ring fixture and the center fixture, so the present invention can perform a rolling friction contact test on an existing sliding friction tester equipped with a rotating shaft, and can also perform a rolling current-carrying friction contact test, thereby solving the problem that there is no equipment for studying the rolling contact performance of the elastic ring in the prior art.

Description

Technical Field

[0001] The invention relates to an elastic ring rolling contact performance evaluation fixture assembly. Background Art

[0002] Using current-carrying friction pairs to conduct current is one of the main ways to transmit electrical power and electrical signals between moving parts. Typical current-carrying friction pairs in high-end equipment include current receiving and return systems in rail transit equipment, solar panel collector rings in aerospace equipment, and collector rings in radars of military equipment. Current-carrying friction pairs are one of the few core components with single-point failure, and their failure may lead to the paralysis of the power supply system of the entire machine. In order to ensure the reasonable design and high-reliability operation of current-carrying friction pairs, basic research on their performance characteristics and failure mechanisms must be carried out. Sliding current-carrying friction pairs represented by bow nets and conductive slip rings meet the electrical conductivity requirements of high-speed trains, satellites and other equipment. In order to study the basic performance and failure mechanism of the above-mentioned sliding current-carrying friction pairs, researchers have developed a variety of sliding current-carrying friction testing machines, most of which are pin-disc pairs.

[0003] However, the traditional sliding power transmission device shows shortcomings such as high friction coefficient, high wear rate, high resistance fluctuation, and arc damage during use. Inspired by rolling bearings, based on the inherent advantages of low friction coefficient and low wear rate of rolling friction, rolling current-carrying friction pairs came into being. Its structure includes an inner ring, an outer ring, and an elastic ring, among which the elastic ring is the core component of rolling electrical contact, and has been successfully applied to key parts such as aircraft carrier early warning radars and missile signal transmission systems. The rolling contact performance of the elastic ring includes rolling friction contact performance (non-conductive during operation) and rolling current-carrying friction contact performance (conductive during operation), but most of the existing friction testers are pin-disc structures, which are only suitable for sliding contact research, and there is no equipment for elastic ring rolling contact research. Summary of the invention

[0004] The object of the present invention is to provide an elastic ring rolling contact performance evaluation fixture assembly to solve the problem that there is no equipment for conducting elastic ring rolling friction research in the prior art.

[0005] To achieve the above-mentioned purpose, the technical solution of the elastic ring rolling contact performance evaluation fixture assembly of the present invention is:

[0006] The elastic ring rolling contact performance evaluation fixture assembly includes a center fixture for being mounted on the rotating shaft of a friction testing machine and rotating with the rotating shaft, and also includes an outer ring fixture for being fixed on the frame of the friction testing machine. The center fixture is provided with a rotating shaft mounting hole, and the center fixture is mounted on the rotating shaft through the rotating shaft mounting hole. The outer ring fixture is provided with an outer ring raceway composed of an annular groove whose opening faces the rotating shaft when in use, and the center fixture is provided with a center raceway composed of annular groove whose opening faces away from the rotating shaft when in use. The axes of the outer ring raceway and the center raceway are both on the rotating axis of the center fixture, and the outer ring raceway is arranged on the outside of the center raceway to form a rolling space between the two raceways so that the outer circumferential surface of the elastic ring rolls with the two raceways and revolves around the rotating shaft.

[0007] The beneficial effects of the elastic ring rolling contact performance evaluation fixture assembly of the present invention are as follows: the elastic ring rolling contact performance evaluation fixture assembly of the present invention is provided with an outer ring fixture and a center fixture, the outer ring fixture is provided with an outer ring raceway, and the center fixture is provided with a center raceway. Since the outer ring fixture is arranged on a frame and the center fixture is arranged on a rotating shaft, the outer ring fixture and the center fixture can rotate relative to each other. After the elastic ring is placed on the outer ring raceway and the center raceway, the elastic ring can roll relative to the outer ring fixture and the center fixture under the drive of the rotating shaft, so the present invention can perform a rolling friction test on an existing sliding friction tester equipped with a rotating shaft, and in the case where a certain insulation treatment is performed between the outer ring fixture and the frame, a rolling current-carrying friction test can also be performed, which solves the problem that there is no equipment for conducting elastic ring rolling friction research in the prior art.

[0008] Furthermore, in order to enable the elastic ring rolling contact performance evaluation fixture assembly to perform a current-carrying friction test, the outer ring fixture and the center fixture are both conductors.

[0009] Furthermore, the outer ring fixture has a rotating shaft through hole for the rotating shaft to pass through, and the elastic ring rolling contact performance evaluation fixture assembly also includes an insulating sleeve for being sleeved on the rotating shaft to isolate the outer ring fixture from the rotating shaft, and the insulating sleeve can prevent the outer ring fixture and the rotating shaft from being penetrated.

[0010] Furthermore, in order to facilitate the positioning of the center fixture, one end of the insulating sleeve has a first stop surface for cooperating with the shoulder of the rotating shaft, and the other end has a second stop surface for cooperating with the center fixture along the extension direction of the rotation axis of the center fixture. The elastic ring rolling contact performance evaluation fixture assembly also includes a fastening bolt for threaded assembly on the rotating shaft to tighten the center fixture so that the center fixture is pressed against the second stop surface. The center fixture can adjust its position on the rotating shaft according to the length of the insulating sleeve.

[0011] Furthermore, in order to facilitate the installation of the center fixture, the rotating shaft mounting hole is a conical hole, and the elastic ring rolling contact performance evaluation fixture assembly also includes a fixed conical sleeve for inserting into the mounting hole to tighten the center fixture and a fastening nut for pushing the fixed conical sleeve to fasten the fixed conical sleeve to the center fixture. The position of the center fixture positioned by the conical surface is more precise.

[0012] Furthermore, in order to insulate the frame from the outer ring fixture, an insulating gasket is provided between the outer ring fixture and the frame, and the outer ring fixture is fixed to the frame by insulating bolts.

[0013] Furthermore, in order to make the outer ring fixture concentric with the rotating shaft, the rotating shaft through hole has an entry for the rotating shaft to enter and an exit for the rotating shaft to exit. The rotating shaft through hole of the outer ring fixture is provided with a conical surface or an inclined surface which gradually moves away from the center of the rotating shaft from the entry to the exit. The elastic ring rolling contact performance evaluation fixture assembly also includes a centering sleeve, which is provided with an inclined surface or a conical surface which cooperates with the rotating shaft through hole to make the outer ring fixture concentric with the rotating shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of a specific embodiment of the elastic ring rolling contact performance evaluation fixture assembly of the present invention;

[0015] Figure 2 It is a structural schematic diagram of an outer ring fixture of a specific embodiment of an elastic ring rolling contact performance evaluation fixture assembly of the present invention;

[0016] Figure 3 It is a structural schematic diagram of a center fixture of a specific embodiment of an elastic ring rolling contact performance evaluation fixture assembly of the present invention;

[0017] Figure 4 It is a schematic structural diagram of a tapered sleeve of a specific embodiment of the elastic ring rolling contact performance evaluation fixture assembly of the present invention.

[0018] In the figure: 1. outer ring fixture; 2. center fixture; 3. elastic ring; 4. rotating shaft; 11. outer ring raceway; 12. rotating shaft through hole; 13. insulating gasket; 14. fastening bolt; 21. center raceway; 22. insulating sleeve; 23. fixed conical sleeve; 24. fastening nut; 25. rotating shaft mounting hole; 121. through-port; 122. through-port; 221. first stop surface; 222. second stop surface; 231. conical section; 232. cylindrical section. DETAILED DESCRIPTION

[0019] The embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0020] In the specific embodiment of the elastic ring rolling contact performance evaluation fixture assembly of the present invention, the friction tester in this embodiment is a sliding current-carrying friction tester. Figures 1 to 4 As shown, the sliding current friction tester includes a main body and a frame, and the main body is provided with a rotating shaft for output and a fixture assembly for clamping an elastic ring, wherein the loading test end of the rotating shaft is stepped. The fixture assembly mainly includes an outer ring fixture 1 fixed on the frame of the sliding current friction tester and a center fixture 2 sleeved on the rotating shaft of the sliding current friction tester and rotating with the rotating shaft, and the center fixture 2 is provided with a rotating shaft mounting hole 25 for fixing the center fixture on the rotating shaft, and the outer ring fixture 1 is provided with an outer ring raceway 11 composed of a circular groove with an opening facing the center of the rotating shaft 4, and the center fixture 2 is provided with a center raceway 21 composed of a circular groove with an opening facing away from the center of the rotating shaft 4, and the elastic ring can be placed between the two raceways to achieve rolling. The outer ring raceway is arranged on the outside of the center raceway to form a rolling space between the two raceways so that the outer peripheral surface of the elastic ring can roll with the two raceways and revolve around the rotating shaft.

[0021] The outer ring fixture 1 in this embodiment includes a fixed portion perpendicular to the axis of the rotating shaft 4 and a raceway portion extending horizontally from the outer edge of the fixed portion toward the axial end of the rotating shaft 4. In order to enable the outer ring fixture 1 to be fixed on the frame without contacting the rotating shaft 4, the fixed portion is detachably connected to the frame by fastening bolts 14, and a rotating shaft through hole 12 for the rotating shaft 4 to pass through is provided in the center of the fixed portion.

[0022] Since the elastic ring is arranged between the outer ring fixture 1 and the center fixture 2, and the center fixture 2 is arranged on the rotating shaft 4, the concentricity of the outer ring fixture 1 and the rotating shaft 4 is very important. In order to align the outer ring fixture 1, the rotating shaft through hole on the outer ring fixture has a through hole 121 for the rotating shaft to pass through and a through hole 122 for the rotating shaft to pass through. The rotating shaft through hole of the outer ring fixture is provided with a conical surface gradually away from the center of the rotating shaft from the through hole to the through hole. The elastic ring rolling contact performance evaluation fixture assembly also includes a centering sleeve, and the centering sleeve is provided with an inclined surface that cooperates with the rotating shaft through hole to make the outer ring fixture concentric with the rotating shaft. By matching the outer ring fixture 1 with the centering sleeve, the outer ring fixture 1 can be concentric with the rotating shaft 4. After the outer ring fixture 1 is fixed to the frame by the fastening bolts 14, the centering sleeve can be pulled out. In other embodiments, the bolt positions can be measured and holes can be punched on the frame before installation, and then the outer ring fixture can be fixed to the frame by bolts. In this case, the outer ring fixture no longer needs a centering structure. In other embodiments, the fixing part can also be arranged outside the raceway part, and in this case, the outer ring fixture has no rotating shaft through-hole.

[0023] The raceway portion of the outer ring fixture 1 is annular, the raceway portion is concentrically arranged with the rotating shaft 4, an outer ring raceway 11 is arranged on the inner circumference of the raceway portion, the intersection of the outer ring raceway 11 and the plane passing through the axis of the rotating shaft 4 is a semicircular arc, and the center of the semicircular arc is on the inner circumference of the raceway portion, the radius of the arc is denoted as r, and the radius of the inner circumference of the outer ring fixture 1 is denoted as R1. In other embodiments, the desired raceway shape can also be freely designed according to needs.

[0024] The center fixture 2 is annular and corresponds to the outer ring raceway 11. The center raceway 21 is arranged on the outer peripheral surface of the center fixture 2. The center raceway 21 and the plane passing through the axis of the rotating shaft 4 are also semicircular with a radius r. The outer peripheral surface radius of the center raceway 21 is R2.

[0025] In order to facilitate the removal and firm fixation of the center fixture 2, the elastic ring rolling contact performance evaluation fixture assembly in this embodiment also includes a fixed tapered sleeve 23 for inserting into the rotating shaft mounting hole 25 to fasten the center fixture 2, a fastening nut 24 for pushing the fixed tapered sleeve 23 to fasten the fixed tapered sleeve 23 and the center fixture 2, and an insulating sleeve 22 sleeved on the rotating shaft 4 to isolate the outer ring fixture from the rotating shaft. One end of the insulating sleeve 22 has a first stop surface 221 for stopping with the rotating shaft shoulder, and the other end has a second stop surface 222 for stopping with the center fixture along the extension direction of the rotating axis of the center fixture. The fixed conical sleeve 23 is provided with a conical section 231 and a cylindrical section 232, and the diameter of the conical section 231 gradually decreases from the connection between the conical section and the cylindrical section to the end of the conical section. The conical section 231 of the fixed conical sleeve 23 is inserted into the rotating shaft mounting hole 25 of the center fixture so that the center fixture 2 is firmly fixed under the pressure of the insulating sleeve 22 and the fixed conical sleeve 23, and the fastening nut 24 pushes the fixed conical sleeve 23 to press the center fixture 2. In other embodiments, the center fixture can also be directly sleeved on the rotating shaft and fixed by the fastening nut.

[0026] In order to enable the elastic ring rolling contact performance evaluation fixture assembly of the present invention to test the current-carrying friction performance, a certain insulation treatment is performed between the outer ring fixture and the frame of the friction tester. On the outer ring fixture, the fastening bolts 14 used to fix the outer ring fixture 1 are nylon bolts, and an insulating gasket 13 is provided between the outer ring fixture 1 and the frame. The nylon bolts pass through the frame, the insulating gasket 13 and the outer ring fixture 1 in turn and fasten the three. The insulating sleeve 22 is made of insulating material to prevent the outer ring fixture and the rotating shaft from being broken through.

[0027] During assembly, first pass the outer ring fixture 1 through the rotating shaft through hole 12 on the rotating shaft 4, then align the outer ring fixture 1 through the centering sleeve and the wall of the rotating shaft through hole 12 of the outer ring fixture 1, and set an insulating gasket 13 between the outer ring fixture 1 and the frame when fixing, and use nylon bolts to tighten, and pull out the centering sleeve after the outer ring fixture 1 is firmly fixed. Then install the center fixture. When installing the center fixture, first set the insulating sleeve 22 on the rotating shaft 4, then put the center fixture 2 and the fixed conical sleeve 23 in turn, and use the fastening nut 24 to squeeze and limit the fixed conical sleeve 23. Finally, put the elastic ring into the outer ring fixture 1 and the center fixture 2 for testing. During the test, the rotating shaft 4, the fixed conical sleeve 23, the center fixture 2, the elastic ring to be tested, and the outer ring fixture 1 form a conductive channel, which is connected in series to the original current-carrying circuit. Turning on the test machine can realize the real-time synchronization data of the current-carrying friction performance such as the friction coefficient and contact resistance of the elastic ring.

[0028] The elastic ring rolling contact performance evaluation fixture assembly of the present invention:

[0029]

[0030] F=δ×k

[0031] Among them, δ is the compression amount of the elastic ring during the test, R0 is the outer radius of the elastic ring to be tested, R1 is the inner radius of the outer ring fixture 1, R2 is the outer radius of the center fixture 2, r is the radius of the arc of the axial section of the two raceways, D is the width of the elastic ring to be tested, F is the preload force on the elastic ring during the test, and k is the elastic coefficient of the elastic ring itself. Therefore, by changing the parameters R1, R2, and r, test conditions such as different outer radius R0, different width D, different preload force F, and different elastic coefficient k can be met.

Claims

1. Elastic ring rolling contact performance evaluation fixture assembly, characterized by: It includes a center fixture for being mounted on the rotating shaft of a friction testing machine and rotating with the rotating shaft, and an outer ring fixture for being fixed on the frame of the friction testing machine. Both the outer ring fixture and the center fixture are conductors. The center fixture is provided with a rotating shaft mounting hole. The center fixture is mounted on the rotating shaft through the rotating shaft mounting hole. The outer ring fixture is provided with an outer ring raceway composed of an annular groove whose opening faces the rotating shaft when in use. The center fixture is provided with a center raceway composed of an annular groove whose opening faces away from the rotating shaft when in use. The axes of the outer ring raceway and the center raceway are both on the rotating axis of the center fixture. The outer ring raceway is arranged on the outside of the center raceway to form a rolling space between the two raceways so that the outer circumferential surface of the elastic ring rolls with the two raceways and revolves around the rotating shaft.

2. The elastic ring rolling contact performance evaluation fixture assembly according to claim 1, characterized in that: The elastic ring rolling contact performance evaluation fixture assembly is a fixture assembly for current-carrying friction test.

3. The elastic ring rolling contact performance evaluation fixture assembly according to claim 2, characterized in that: The outer ring fixture has a rotating shaft through hole for the rotating shaft to pass through, and the elastic ring rolling contact performance evaluation fixture assembly also includes an insulating sleeve used for being sleeved on the rotating shaft to isolate the outer ring fixture from the rotating shaft.

4. The elastic ring rolling contact performance evaluation fixture assembly according to claim 3, characterized in that: One end of the insulating sleeve has a first stop surface for cooperating with the shoulder of the rotating shaft, and the other end has a second stop surface for cooperating with the center fixture along the extension direction of the rotation axis of the center fixture. The elastic ring rolling contact performance evaluation fixture assembly also includes a fastening bolt for threaded assembly on the rotating shaft to tighten the center fixture so that the center fixture is pressed against the second stop surface.

5. The elastic ring rolling contact performance evaluation fixture assembly according to any one of claims 1 to 3, characterized in that: The rotating shaft mounting hole is a tapered hole, and the elastic ring rolling contact performance evaluation fixture assembly also includes a fixed tapered sleeve for inserting into the rotating shaft mounting hole to tighten the center fixture and a fastening nut for pushing the fixed tapered sleeve to tighten the fixed tapered sleeve to the center fixture.

6. The elastic ring rolling contact performance evaluation fixture assembly according to any one of claims 1 to 3, characterized in that: An insulating gasket is arranged between the outer ring fixture and the frame, and the outer ring fixture is fixed on the frame by insulating bolts.

7. The elastic ring rolling contact performance evaluation fixture assembly according to claim 3, characterized in that: The rotating shaft through hole has an inlet for the rotating shaft to pass through and an outlet for the rotating shaft to pass through. The rotating shaft through hole of the outer ring fixture is provided with a conical surface or an inclined surface that gradually moves away from the center of the rotating shaft from the inlet to the outlet. The elastic ring rolling contact performance evaluation fixture assembly also includes a centering sleeve, and the centering sleeve is provided with an inclined surface or a conical surface that cooperates with the rotating shaft through hole to make the outer ring fixture concentric with the rotating shaft.

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