Friction and wear device and load measurement method of friction and wear device

Abstract

The present application provides a friction and wear device and a load measurement method for the friction and wear device. The friction and wear device includes: a pressure vessel, which includes an end cover, a cavity and a main shaft; a lower sample fixing device, which includes a fixer and a fixing member, and the fixing member can fix the lower sample to the fixer; an upper sample fixing device, which includes a guide plate and a positioning shaft, the guide plate is installed on the main shaft, the positioning shaft passes through the guide plate, and the positioning shaft is used to fix the upper sample; a loading device, which includes a spring, the spring abuts against the guide plate and the positioning shaft, and the spring is used to press the upper sample toward the lower sample. The load measurement method includes: installing the positioning shaft on the guide plate, so that in the absence of external force, the positioning shaft is fixed relative to the guide plate, and under the action of external force, the positioning shaft can move axially relative to the guide plate; the main shaft is extended axially toward the inside of the cavity until the end cover is installed in the cavity; and the distance X between the lowest point of the guide plate and the positioning shaft is measured.

Description

Technical Field

[0001] The present application relates to the field of material friction and wear, and in particular to a friction and wear device and a load measurement method for the friction and wear device. Background Art

[0002] With the development of society and technology, the application fields of mechanical equipment are constantly expanding. Mechanical equipment in some special working environments are subject to high or low temperatures, pressure, corrosive media and atmosphere, etc. Compared with general environments, the friction and wear properties of materials in these environments usually show different laws, so it is necessary to conduct experimental research on the friction and wear properties of materials in these environments.

[0003] Friction and wear studies at high or low temperatures, under pressure, in corrosive media and in atmospheres are usually carried out in corrosion-resistant pressure vessels.

[0004] The Chinese patent application with application number CN201910198034.9 and publication number CN109883870A proposes a friction and wear tester in seawater environment, which can carry out friction and wear experiments in pressure and medium environment. Its pressure vessel has two end covers and a through cavity in the middle. The shaft of one end cover is used as the moving end. The outside world inputs the rotational motion through magnetic transmission. The shaft and one of the friction pairs are fixedly connected; the other end cover is used as the stationary end to fix the other friction pair and adopt magnetic loading. The device can simulate the seawater environment of a certain pressure and carry out pin-disc friction and wear experiments. However, there are certain problems with the magnetic loading method it adopts. The loading force is transmitted to the sample through internal and external magnets, shafts, etc. The transmission path is too long, the friction loss of the load is large, and the external loading force is difficult to represent the real load. This scheme requires two shafts responsible for loading and transmission, and requires a pressure vessel with a more complex structure. Processing and sealing are more difficult, and the product cost is increased. The advantage is not as good as using a commonly used uniaxial pressure vessel.

[0005] Reference 1 proposes a friction and wear device that simulates a seawater environment. It adopts a one-end loading and one-end transmission method. The pressure vessel requires end covers on both sides and adopts an external contact loading method. The load loss is large and there is a leakage problem.

[0006] Reference 2 proposes a friction and wear device that simulates a seawater environment. It uses heavy objects for loading, has a limited load range and is difficult to adjust conveniently, and uses a double pin-disc friction pair, which is prone to friction surface deflection.

[0007] Reference 3 proposes a friction and wear device for simulating a high-pressure environment, which uses heavy objects for loading. The load range is limited and difficult to adjust conveniently, and it cannot be applied to medium environments such as seawater.

[0008] References:

[0009] Reference 1: Chen Song. Research on tribological properties of materials in water environment[D]. China Academy of Mechanical Science, 2014.

[0010] Reference 2: VERICHEV SN, MISHAKIN VV, NUZHDIN DA, et al. Experimental study of abrasive wear of structural materials under the high hydrostatic pressure [J]. Ocean Engineering, 2015, 99: 9-13.

[0011] Reference 3: RATIA VL, ZHANG D, CARRINGTON MJ, et al. The effect of temperature on sliding wear of self-mated HIPed Stellite 6in a simulated PWRwater environment[J].Wear,2019,420-421:215-225.

[0012] Ordinary pressure vessels are generally composed of end covers, cavities, etc., with simple structures, low prices, and suitable for laboratory research. However, pressure vessels generally have small internal spaces and closed structures, making it difficult to accommodate and install ordinary friction and wear devices, and it is also impossible to observe and measure the relative position of the internal structure. Summary of the invention

[0013] In order to improve or solve at least one of the problems mentioned in the background technology, the present application provides a friction and wear device and a load measurement method for the friction and wear device.

[0014] The friction and wear device provided in the present application is used for friction and wear test between an upper sample and a lower sample, and the friction and wear device comprises:

[0015] A pressure vessel, the pressure vessel comprising an end cover, a cavity and a main shaft, the end cover being capable of abutting against the cavity, a portion of the main shaft extending into the cavity, and another portion of the main shaft passing through the end cover;

[0016] A lower sample fixing device, the lower sample fixing device comprising a fixer and a fixing member, the fixer is fixed to the inner wall of the cavity, and the fixing member can fix the lower sample to the fixer;

[0017] An upper sample fixing device, the upper sample fixing device comprising a guide plate and a positioning shaft, the guide plate is mounted on the main shaft, the positioning shaft passes through the guide plate, and the positioning shaft is used to fix the upper sample;

[0018] A loading device, wherein the loading device comprises a spring, wherein the spring abuts against the guide plate and the positioning shaft, and the spring is used to press the upper sample toward the lower sample.

[0019] In at least one embodiment, the guide plate has a hole for the positioning shaft to pass through, and the positioning shaft is clearance-matched with the hole of the guide plate.

[0020] In at least one embodiment, the portion of the spindle extending into the cavity has an external thread and a spindle step structure for guiding the disk to position.

[0021] The upper sample fixing device comprises a positioning nut, the positioning nut is mounted on the main shaft, and the guide plate is mounted between the positioning nut and the main shaft step structure for positioning the guide plate.

[0022] In at least one embodiment, the guide plate includes an upper guide plate and a lower guide plate, and the upper sample fixing device includes a positioning sleeve, and the positioning sleeve is disposed between the upper guide plate and the lower guide plate.

[0023] In at least one embodiment, the positioning shaft comprises a non-circular cross-section,

[0024] The upper guide plate and the lower guide plate have a hole for the positioning shaft to pass through, and the cross section of the hole of the upper guide plate and / or the hole of the lower guide plate is non-circular and matches the non-circular cross section of the positioning shaft.

[0025] In at least one embodiment, the upper sample fixing device includes an upper sample clamp having a flange portion, and the upper sample clamp is used to fix the upper sample. When the spring is squeezed, one end of the spring abuts against the flange portion of the upper sample clamp, and the other end of the spring abuts against the bottom surface of the lower guide plate.

[0026] The friction and wear device described in the load measurement method of the friction and wear device provided in the present application is the friction and wear device mentioned above,

[0027] The load measurement method of the friction and wear device comprises:

[0028] The positioning shaft is mounted on the guide disk, so that the positioning shaft is fixed relative to the guide disk in the absence of external force, and the positioning shaft can move axially relative to the guide disk under the action of external force;

[0029] Prolonging the main shaft axially toward the interior of the cavity until the end cover is installed in the cavity, during which the positioning shaft slides relative to the guide plate due to contact with the lower sample; and

[0030] Measure the distance X between the guide plate and the lowest point of the positioning shaft.

[0031] In at least one embodiment, the positioning shaft is attached to the guide plate using a magnet, and the upper sample is mounted on the positioning shaft.

[0032] The distance X is the axial distance between the portion of the guide plate that contacts the spring and the lowest point of the upper sample.

[0033] In at least one embodiment, the load measurement method of the friction and wear device further includes:

[0034] Obtaining the length S1 of the spring in a natural state;

[0035] Obtaining a distance Y from a portion of the lower sample fixture that is used to abut against the lower end of the spring to the lowest point of the upper sample; and

[0036] The compressed length S2 of the spring is obtained by using the formula S2=XY, and the compression amount of the spring is obtained by using the formula S3=S1-S2.

[0037] In at least one embodiment, the load measurement method of the friction and wear device further includes:

[0038] The load applied by the spring to the lower sample is obtained by the compression amount S3 of the spring and the elastic system of the spring.

[0039] The friction and wear device provided by the present application has a simple structure, uses a spring as a loading device, has a large load range, a short load transfer path, and the load range is easy to adjust and can be loaded accurately. The load measurement method proposed in the present application limits the relative movement of the positioning shaft and the guide disk before and after loading, so that in the absence of external force, the positioning shaft is fixed relative to the guide disk, and under the action of external force, the positioning shaft can move axially relative to the guide disk, which is equivalent to simulating the compression state of the spring. And by measuring the distance X between the lowest point of the guide disk and the positioning shaft after loading, the compression amount of the spring can be further obtained, and then the applied load amount can be obtained. The measurement steps are simple and the results are accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic structural diagram of a friction and wear device according to an embodiment of the present application is shown.

[0041] Figure 2 Shows Figure 1 A partial enlarged view of .

[0042] Figure 3 A top view of a retainer of a friction and wear device according to an embodiment of the present application is shown.

[0043] Figure 4 A partial schematic diagram of a friction and wear device for measuring load according to an embodiment of the present application is shown.

[0044] Figure 5a , 5b , 5c, and 5d are schematic diagrams showing load measurement steps of a friction and wear device according to an embodiment of the present application.

[0045] Description of Reference Numerals

[0046] 1 end cover; 2 cavity; 3 spindle; 4 upper guide plate; 5 positioning shaft; 6 positioning sleeve; 7 lower guide plate; 8 spring; 9 first fixture for upper sample; 10 second fixture for upper sample; 11 upper sample; 12 lower sample; 13 positioning nut; 14 spindle step structure for end cover abutment; 15 spindle step structure for guide plate positioning; 16 fixture; 17 pressure plate; 18 magnet; 19 steel ball; 20 large diameter part. DETAILED DESCRIPTION

[0047] The exemplary embodiments of the present application are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, and are not intended to exhaust all possible methods of the present application, nor to limit the scope of the present application.

[0048] The present application provides a friction and wear device and a load measurement method for the friction and wear device. Figure 1 , 2 As shown, the present application is mainly used for friction and wear test between the upper sample 11 and the lower sample 12.

[0049] The friction and wear device may include a pressure vessel, an upper sample fixing device, a lower sample fixing device, and a loading mechanism.

[0050] Pressure Vessels

[0051] The pressure vessel may include an end cover 1 , a cavity 2 and a main shaft 3 .

[0052] The cavity 2 may have a cylindrical cavity inside, and the end cover 1 may abut against the cavity 2 to play a sealing role. The abutment between the end cover 1 and the cavity 2 includes a conical surface, which can further limit the end cover 1 from continuing to move axially toward the cavity 2.

[0053] A portion of the spindle 3 can extend into the cavity 2, and another portion of the spindle 3 can pass through the end cover 1 and be exposed to the top surface of the end cover 1. Further, the spindle 3 can have a spindle step structure 14 for end cover abutment and a spindle step structure 15 for guide plate positioning. The spindle step structure 14 for end cover abutment can abut against the end cover 1, so that when an external device or an operator lifts the spindle 3, the end cover 1 can be lifted at the same time. The portion of the spindle 3 extending into the cavity 2 can have an external thread, and the position of the upper sample fixing device is fixed by a positioning nut 13 (described later).

[0054] Upper sample fixture

[0055] The upper sample fixing device may include an upper guide plate 4 , a positioning shaft 5 , a positioning sleeve 6 , a lower guide plate 7 , an upper sample fixture (eg, an upper sample first fixture 9 , an upper sample second fixture 10 ), and a positioning nut 13 .

[0056] The upper guide plate 4, the positioning sleeve 6, the lower guide plate 7, and the positioning nut 13 can be sequentially installed on the spindle 3 from top to bottom, and the upper guide plate 4 abuts against the spindle step structure 15 for guide plate positioning, the positioning sleeve 6 abuts against the upper guide plate 4, the lower guide plate 7 abuts against the positioning sleeve 6, and the positioning nut 13 abuts against the lower guide plate 7. By tightening the positioning nut 13, the upper sample fixture can be fixed on the spindle 3.

[0057] In one embodiment of the present application, the main shaft 3 passes through the center holes of the upper guide plate 4 and the lower guide plate 7, and the positioning shaft 5 passes through the eccentric holes of the upper guide plate 4 and the lower guide plate 7. It can be understood that the present application does not limit the specific positions where the main shaft 3 and the positioning shaft 5 pass through the upper guide plate 4 and the lower guide plate 7.

[0058] The cross section of at least a part of the positioning shaft 5 may be non-circular, such as rectangular. The cross section of the hole of the upper guide plate 4 and / or the lower guide plate 7 through which the positioning shaft 5 passes may be non-circular, such as rectangular. By matching the positioning shaft 5 with the hole with a non-circular cross section of the upper guide plate 4 and / or the lower guide plate 7, the positioning shaft 5 can be prevented from rotating around its own axis, and the positioning shaft 5 can be made to move with a single degree of freedom (axial movement) relative to the main shaft 3. This makes the experimental results more stable.

[0059] The lower end of the positioning shaft 5 can be fixedly connected to the upper sample first clamp 9 and the upper sample second clamp 10, and the upper sample 11 is fixed to the positioning shaft 5 through the upper sample first clamp 9 and the upper sample second clamp 10. It can be understood that the positioning shaft 5 and the upper guide plate 4 and the lower guide plate 7 can be clearance-fitted.

[0060] Lower specimen fixture

[0061] The lower sample fixture may include a fixture 16 and a fixing member.

[0062] The fixture 16 can be fixed on the inner wall of the cavity 2, the lower sample 12 can be placed on the top surface of the fixture 16, and the lower sample 12 can be fixed on the fixture 16 by a fixing member (such as a pressure plate 17 fixed to the fixture 16). Further, the fixture 16 can include upper and lower clamping plates and a cone ring, and the upper and lower clamping plates are used to radially squeeze the cone ring to form an interference fit between the fixture 16 and the inner wall of the cavity 2. The specific type of the fixing member is not limited, for example, it can be adhesive, buckle, bolt, etc.

[0063] Loading mechanism

[0064] The loading mechanism includes a spring 8. The spring 8 is arranged on the outside of the positioning shaft 5. When the spring 8 is squeezed, one end of the spring 8 can abut against the bottom surface of the lower guide plate 7, and the other end of the spring 8 can abut against the radial protrusion (i.e., flange portion) of the upper sample first clamp 9. The lower guide plate 7 and the main shaft 3 are relatively stationary, and the positioning shaft 5, the upper sample first clamp 9, and the upper sample 11 are relatively stationary. By moving the main shaft 3 downward, the lower guide plate 7 can be driven to press the spring 8 downward, and the spring 8 presses the upper sample 11 downward through the upper sample first clamp 9 and the upper sample second clamp 10, so as to apply load to the upper sample 11 and the lower sample 12. The dynamic friction between the upper sample 11 and the lower sample 12 can be achieved by rotating the main shaft 3.

[0065] Further, by changing the axial dimension of the positioning sleeve 6, the compression amount of the spring 8 can be changed, thereby changing the load amount applied by the friction and wear device through the spring 8. Further, by changing the elastic coefficient of the spring 8, the load amount applied by the friction and wear device through the spring 8 can be changed. It can be understood that the load amount applied by the friction and wear device is the product of the compression amount of the spring 8 and the elastic coefficient of the spring 8.

[0066] like Figure 4 As shown, when the compression amount of the spring 8 needs to be measured, the friction and wear device may include a magnet 18 and a steel ball 19, and the positioning shaft 5 has a large diameter portion 20. There may be multiple magnets 18, and the magnets 18 may be adsorbed on both axial sides of the disk surface of the lower guide disk 7 close to the positioning shaft 5, and the magnets 18 may also be adsorbed on the circumferential surface of the positioning shaft 5, and the magnets 18 on the circumferential surface of the positioning shaft 5 and the magnets 18 on the lower guide disk 7 are adsorbed together by the steel ball 19.

[0067] It can be understood that the measures to keep the positioning shaft 5 and the main shaft 3 relatively still are not limited to this. The magnets 18 and steel balls 19 in the present application can be changed in number and position. For example, instead of using the steel balls 19, only the magnets 18 are used to be adsorbed on the circumferential surface of the positioning shaft 5 and the top and / or bottom surface (i.e., the axial end surface) of the lower guide disk 7. There is an adsorption effect between the magnets 18 located on the circumferential surface of the positioning shaft 5 and the axial end surface of the lower guide disk 7. When the main shaft 3 is lifted (equivalent to when the load is applied), the positioning shaft 5 and the main shaft 3 can be kept relatively still. It is also possible to use measures such as spring pressing plates and spring pins so that the positioning shaft 5 is fixed relative to the guide disk 11 in the absence of external force, and the positioning shaft 5 can move axially relative to the guide disk under the action of external force.

[0068] Figures 5a to 5d The load measurement steps of the friction and wear device are shown. It can be understood that Figures 5a to 5d The friction and wear device in the figure is a simplified schematic diagram of the friction and wear device proposed in the present application. The upper guide plate 4 and the lower guide plate 7 are both fixed on the main shaft 3. A positioning sleeve 6 may or may not be provided between the upper guide plate 4 and the lower guide plate 7. The positioning shaft 5 is loosely fitted in the upper guide plate 4 and the lower guide plate 7. Here, the upper sample first fixture 9 and the upper sample second fixture 10 are not shown in detail. The lower sample 12 is fixed to the cavity 2, and the main shaft 3 can move relative to the lower sample 12.

[0069] The steps of the load measurement method of the friction and wear device include:

[0070] like Figure 5a As shown, the magnet 18 is attracted to the positioning shaft 5 and the lower guide plate 7. The top surface of the upper guide plate 4 abuts against the large diameter portion 20 of the positioning shaft 5, which can be regarded as the initial state.

[0071] like Figure 5b , 5c As shown, after the upper sample fixture is installed into the main shaft 3, the main shaft 3 is extended into the cavity 2, and the main shaft 3 is moved downward, and the end cover 1 is installed in the cavity 2 (cannot be moved further) as the loading is completed.

[0072] like Figure 5d As shown, the spindle 3 is taken out from the cavity 2, and the distance X between the lower end surface of the lower guide plate 7 and the lowest point of the upper sample 11 (the contact point between the upper sample 11 and the lower sample 12) is measured. The distance X between the lower end surface of the lower guide plate 7 and the lowest point of the upper sample 11 can be equivalent to the sum of the length S2 of the compressed spring 8 and the distance Y between the upper surface of the flange portion of the first fixture 9 of the upper sample (the contact point with the spring 8) and the lowest point of the upper sample 11. That is, S2+Y=X, S2=XY.

[0073] The length S1 of the spring 8 in the natural state (uncompressed state, not shown in the figure) can be a known value, or can be obtained by direct measurement. The compression amount S3 of the spring = S1-S2, and the load application amount can be obtained by multiplying the spring compression amount by the elastic coefficient.

[0074] The present application concentrates loading and transmission on one main shaft, which reduces the requirements for the pressure vessel structure, simplifies its structure, and reduces costs. The present application realizes single-degree-of-freedom movement of the sample in the loading direction through the cooperation of non-circular holes. Precise loading and wide-range variable loading are achieved through springs and positioning sleeves. It is easy to adjust, not affected by the environment, small in size, simple and reliable in structure, and easy to implement. Magnets can be used to measure the load of friction and wear devices, with simple steps and accurate results.

[0075] The above is a preferred embodiment of the present application. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A friction and wear device, characterized in that: The friction and wear device is used for a friction and wear test between an upper sample (11) and a lower sample (12), and the friction and wear device comprises: A pressure vessel, the pressure vessel comprising an end cover (1), a cavity (2) and a main shaft (3), the end cover (1) being capable of abutting against the cavity (2), a portion of the main shaft (3) extending into the cavity (2), and another portion of the main shaft (3) passing through the end cover (1); A lower sample fixing device, the lower sample fixing device comprising a fixer (16) and a fixing member, the fixer (16) being fixed to the inner wall of the cavity (2), and the fixing member being capable of fixing the lower sample (12) to the fixer (16); An upper sample fixing device, the upper sample fixing device comprising a guide plate and a positioning shaft (5), the guide plate being mounted on the main shaft (3), the positioning shaft (5) passing through the guide plate, and the positioning shaft (5) being used to fix the upper sample (11); A loading device, the loading device comprising a spring (8), the spring (8) abutting against the guide plate and the positioning shaft (5), the spring (8) being used to apply pressure to the upper sample (11) toward the lower sample (12), The guide plate has a hole for the positioning shaft (5) to pass through, and the positioning shaft (5) is clearance-matched with the hole of the guide plate. The portion of the spindle (3) extending into the cavity (2) has an external thread and a spindle step structure (15) for positioning the guide plate. The upper sample fixing device comprises a positioning nut (13), the positioning nut (13) is mounted on the main shaft (3), the guide plate is mounted between the positioning nut (13) and the main shaft step structure (15) for positioning the guide plate, The upper sample fixing device comprises an upper sample fixture having a flange portion, the upper sample fixture is used to fix the upper sample (11), when the spring (8) is squeezed, one end of the spring (8) abuts against the flange portion of the upper sample fixture, and the other end of the spring (8) abuts against the bottom surface of the guide plate.

2. The friction and wear device according to claim 1, characterized in that: The guide plate comprises an upper guide plate (4) and a lower guide plate (7), and the upper sample fixing device comprises a positioning sleeve (6), and the positioning sleeve (6) is arranged between the upper guide plate (4) and the lower guide plate (7).

3. The friction and wear device according to claim 2, characterized in that: The positioning shaft (5) comprises a non-circular cross section, The upper guide plate (4) and the lower guide plate (7) have a hole for the positioning shaft (5) to pass through, and the cross-section of the hole of the upper guide plate (4) and / or the hole of the lower guide plate (7) is non-circular and adapted to the non-circular cross-section of the positioning shaft (5).

4. A method for measuring the load of a friction and wear device, characterized in that: The friction and wear device is the friction and wear device according to any one of claims 1 to 3, The load measurement method of the friction and wear device comprises: The positioning shaft (5) is mounted on the guide disk, so that in the absence of external force, the positioning shaft (5) is fixed relative to the guide disk, and under the action of external force, the positioning shaft (5) can move axially relative to the guide disk; The main shaft (3) is extended axially toward the interior of the cavity (2) until the end cover (1) is installed in the cavity (2), during which the positioning shaft (5) slides relative to the guide plate due to contact with the lower sample (12); and Measure the distance X between the guide plate and the lowest point of the positioning shaft (5).

5. The load measurement method of a friction and wear device according to claim 4, characterized in that: The positioning shaft (5) is attached to the guide plate using a magnet (18), and the upper sample (11) is mounted on the positioning shaft (5). The distance X is the axial distance between the portion of the guide plate that contacts the spring (8) and the lowest point of the upper sample (11).

6. The load measurement method of a friction and wear device according to claim 5, characterized in that: The load measurement method of the friction and wear device also includes: Obtaining the length S1 of the spring (8) in the natural state; Obtaining a distance Y from a portion of the lower sample fixing device that is used to abut against the lower end of the spring (8) to the lowest point of the upper sample (11); and The compressed length S2 of the spring (8) is calculated using the formula S2=XY, and the compression amount of the spring (8) is calculated using the formula S3=S1-S2.

7. The load measurement method of a friction and wear device according to claim 6, characterized in that: The load measurement method of the friction and wear device also includes: The load applied by the spring (8) to the lower test specimen (12) is obtained through the compression amount S3 of the spring (8) and the elastic system of the spring (8).

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