CN214174114U

CN214174114U - Friction experiment device suitable for low-temperature vacuum condition

Info

Publication number: CN214174114U
Application number: CN202023314686.1U
Authority: CN
Inventors: 李蒙正; 叶必卿; 张利
Original assignee: Zhejiang University of Technology ZJUT
Current assignee: Zhejiang University of Technology ZJUT
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2021-09-10
Anticipated expiration: 2030-12-30

Abstract

The utility model discloses a friction experiment device suitable for low temperature vacuum condition, including drive arrangement, loading device, transmission, second thermal-insulated shaft coupling, controllable temperature vacuum chamber, normal atmospheric temperature case and test piece, normal atmospheric temperature case sets up in controllable temperature vacuum chamber, and test piece and transmission set up in controllable temperature vacuum chamber, and loading device passes through the load input end of transmission connection test piece, and drive arrangement passes through the drive end of second thermal-insulated shaft coupling connection test piece; the utility model discloses can arrange servo motor in and pass through the fixed normal atmospheric temperature case that forms of screw and normal atmospheric temperature case end cover by the normal atmospheric temperature case, under the condition that both can satisfy the high rotational speed test requirement of big moment of torsion, need not vacuum tank external drive and loading for need not customized special vacuum tank when accomplishing the test and only need can put down the shortening transmission chain length that mounting platform can just very big degree, easily guarantee the axiality.

Description

Friction experiment device suitable for low-temperature vacuum condition

Technical Field

The utility model relates to a friction test field of skidding under the low temperature vacuum condition, more specifically the utility model relates to a friction experiment device suitable for under the low temperature vacuum condition that says so especially.

Background

There is a brake suitable for the aerospace field, the purpose of which is to slow down the rotating shaft until it stops rotating. The main working environment of the brake is a low-temperature vacuum environment, and the main principle of the brake is as follows: the friction pair in the brake is used for generating and stopping torque for rotating the rotating shaft, so that the target shaft is decelerated until the target shaft stops rotating. Corresponding simulation tests are required to be carried out on the ground in order to research the performance, service life and other characteristics of the brake under different working conditions, different environments and different steering.

In order to complete the ground simulation test of the brake, a driving loading platform under the low-temperature vacuum condition needs to be designed, and the tests to be completed by the driving loading platform under the low-temperature vacuum condition include: 1. the method comprises the following steps of (1) performing brake slip test at different rotating speeds, wherein the rotating speed required to be achieved in the test is extremely high and the torque is large; 2. skid tests under different steering; 3. and (4) loading test at different temperatures.

Currently, ground vacuum driven loading devices typically use a vacuum motor to provide rotational speed and torque, but the vacuum motor may provide limited rotational speed and may operate in a vacuum environment but with a limited temperature range. When the experiment needs high rotating speed and high torque, the vacuum motor is difficult to meet the experiment requirement, a test piece needs to be placed in a vacuum box, magnetic fluid sealing shafts are arranged on two sides of the vacuum box, and a servo motor with high rotating speed and high torque is connected with a magnetic fluid on one side outside the vacuum box so as to drive the test piece; and the magnetic fluid sealing shaft on the other side is connected with a magnetic hysteresis brake and the like, so that a test piece is loaded. The method inevitably leads to a long transmission chain, the coaxiality of the transmission chain is difficult to ensure, and the required field is large; and a special vacuum box needs to be customized to be matched with a proper magnetic fluid sealing shaft, so that the economic benefit is low.

At present, when a loading and slipping experiment is carried out, a hysteresis brake is mostly adopted for providing loading, but the loading and the unloading of the hysteresis brake are delayed due to the principle of the hysteresis brake, and the instantaneous loading and unloading cannot be finished, so that the accuracy of the experiment can be influenced.

At present, no design for arranging a normal temperature box in a low-temperature vacuum environment exists. In a low-temperature vacuum environment, the temperature of the constant temperature box is mainly considered to influence the test environment temperature of the test piece, so that the accuracy of the experiment is influenced. Thermal convection cannot be generated in a vacuum environment, main heat transfer modes are heat conduction and heat radiation, and only the two heat transfer modes need to be inhibited, so that the experimental accuracy can be greatly improved.

The ground simulation test of the brake is required to be realized, the experiment under the conditions of large torque and high rotating speed can be realized, the transmission chain is short, the higher coaxiality is easy to ensure, the loading and unloading speed is high, a vacuum box does not need to be customized, and the field required by the experiment is small. The vacuum motor of the existing ground vacuum driving loading equipment cannot meet the required rotating speed and torque, the length of a transmission chain required by driving and loading outside the vacuum box is long, the coaxiality is difficult to guarantee, the required field is large, the loading and unloading have certain delay, and the corresponding vacuum box needs to be customized. And further provides a friction experiment device which is suitable for the low-temperature vacuum condition, short in transmission chain, high in coaxiality, small in required field, good in heat insulation and high in loading speed.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the problem that there is the required rotational speed of unable satisfying experiment, moment of torsion and operating temperature in current ground vacuum drive loading equipment vacuum motor, provided that the driving chain is short, the axiality is high, required place is little, realize good thermal-insulated and the fast friction experiment device under the low temperature vacuum condition of loading.

The utility model discloses a following technical scheme realizes above-mentioned purpose: a friction experiment device suitable for a low-temperature vacuum condition comprises a driving device, a loading device, a transmission device, a second heat insulation coupling, a temperature-controllable vacuum box, a normal temperature box and a test piece, wherein the test piece is provided with a loading input end and a driving end, and the loading input end and the driving end are two ends of the same shaft on the test piece; the normal temperature box is arranged in the temperature-controllable vacuum box, a horizontally-installed heat insulation mounting plate is arranged on the bottom surface inside the normal temperature box, the driving device and the loading device are installed in the normal temperature box, the temperature sensor and the heating sheet are also arranged on the heat insulation mounting plate inside the normal temperature box, the testing piece and the transmission device are arranged in the temperature-controllable vacuum box, the loading device is connected with the loading input end of the testing piece through the transmission device, and the driving device is connected with the driving end of the testing piece through a second heat insulation coupling;

the driving device comprises a servo motor, a driving main shaft, a driving small belt wheel, a driving large belt wheel support, a driving end belt, a first coupling and a driving magnetic fluid sealing shaft, wherein the servo motor is fixed on a heat insulation mounting plate in a normal temperature box, the driving small belt wheel is fixed on an output shaft of the servo motor, the driving large belt wheel support is vertically installed on the heat insulation mounting plate, one end of the driving main shaft is horizontally installed on the driving large belt wheel support through a bearing, the driving large belt wheel is fixed on the driving main shaft, the driving large belt wheel is connected with the driving small belt wheel through the driving end belt, and the other end of the driving main shaft is sequentially connected with the first coupling and the driving magnetic fluid sealing shaft; the axes of the driving main shaft, the first coupling and the driving magnetic fluid sealing shaft are on the same straight line, and the driving magnetic fluid sealing shaft is arranged on the side wall of the normal temperature box; the output end of the driving magnetic fluid sealing shaft extends out of the normal temperature box and is connected with the driving end of the test piece through a second heat insulation coupler;

the loading device comprises a brake support, a brake, a rotating speed sensor, a brake shaft, a second coupler, a hysteresis brake, a third coupler, a second torque sensor, a fourth coupler and a magnetic fluid loading sealing shaft, wherein the brake is fixed on the heat insulation mounting plate through the brake support; the output end of the magnetic fluid loading sealing shaft extends out of the normal temperature box;

the transmission device comprises a first heat insulation coupler, a first torque sensor, a third heat insulation coupler, an intermediate shaft, a loading end small wheel support, a loading end large wheel support, a loading large belt wheel, a loading small belt wheel, a loading main shaft and a fourth heat insulation coupler, wherein the loading end small wheel support and the loading end large wheel support are fixed on a bottom plate of the controllable temperature vacuum box; the other end of the intermediate shaft is sequentially connected with a third heat insulation coupler, a first torque sensor, a first heat insulation coupler and a loading input end of a test piece; the other end of the loading main shaft is connected with one end, extending out of the normal temperature box, of the loading magnetic fluid sealing shaft through a fourth heat insulation coupler.

Furthermore, the shells of the loading magnetic fluid sealing shaft and the driving magnetic fluid sealing shaft are fixedly connected with a normal temperature box. The loading magnetic fluid sealing shaft and the driving magnetic fluid sealing shaft realize heat insulation sealing and torque transmission inside and outside the constant temperature box.

Further, the heat insulation mounting plate is made of heat insulation materials and is fixed at the bottom of the inner side of the normal temperature box through screws.

Furthermore, brake support, motor support, the big band pulley support of drive and temperature sensor all pass through the bolt fastening on the thermal-insulated mounting panel of the inside of constant temperature box.

Furthermore, a key groove and a threaded positioning hole are formed in an output shaft of the servo motor, and the small driving belt wheel is fixedly connected with the output shaft of the servo motor through the key groove and the threaded positioning hole. The servo motor is fixed on the motor support through a bolt.

Further, the bottom surface of the test piece is processed by a heat insulation material. The bottom surface of the test piece can also be provided with an independent heat insulation base, and the test piece is arranged on the normal temperature box through the heat insulation base.

Further, the first torque sensor and the second torque sensor are both double-output shaft type torque sensors.

Furthermore, the hysteresis brake is a double-output-shaft hysteresis brake, and the hysteresis brake is fixed on the heat insulation mounting plate through a brake support.

The beneficial effects of the utility model reside in that:

1. the utility model discloses can arrange servo motor in and pass through the fixed normal atmospheric temperature case that forms of screw and normal atmospheric temperature case end cover by the normal atmospheric temperature case, under the condition that both can satisfy the high rotational speed test requirement of big moment of torsion, need not vacuum tank external drive and loading for need not customized special vacuum tank when accomplishing the test and only need can put down the shortening transmission chain length that mounting platform can just very big degree, easily guarantee the axiality.

2. The utility model discloses a first thermal-insulated shaft coupling, the thermal-insulated shaft coupling of second, the normal atmospheric temperature case, normal atmospheric temperature case end cover and test piece, in the vacuum test environment of low temperature, pass through the screw by the normal atmospheric temperature case and can produce the temperature influence to the test piece with the fixed normal atmospheric temperature case that forms of normal atmospheric temperature case end cover, the heat transfer mode under the vacuum condition mainly is heat-conduction and heat radiation, first thermal-insulated shaft coupling and the thermal-insulated shaft coupling of second are made by thermal insulation material, and the bottom of test piece not only is made by thermal insulation material and has more processed many rectangle through-holes, be used for having restrained the heat-conduction of normal atmospheric temperature case to test piece upper portion, experimental error has been reduced. The radiation protection coating is coated inside and outside the normal temperature box end cover of the normal temperature box, so that the influence of heat radiation on a test piece is greatly reduced, and the experimental error is reduced.

3. The utility model discloses a heating plate and temperature sensor, when work was in low temperature vacuum environment, heated the normal atmospheric temperature incasement portion of fixed formation of normal atmospheric temperature case end cover through the screw by normal atmospheric temperature case through the heating plate, ensured original paper work such as servo motor at suitable temperature to accessible temperature sensor real time monitoring normal atmospheric temperature incasement portion temperature, be convenient for to opening of heating plate whether adjust in real time.

4. The utility model designs a pass through the screw by the normal atmospheric temperature case and pass through the screw and the fixed normal atmospheric temperature case that forms of normal atmospheric temperature case end cover and drive end belt and pass through tensile force and the cooperation of the little band pulley of drive, the big band pulley of drive, realize driven mechanism. When the vacuum motor can not provide the torque, the rotating speed and the precision required by the experiment, the servo motor which can not work under the vacuum condition can be arranged in the vacuum box, the torque can be increased through the belt pulley, the experiment requirement can be met, the loading driving outside the tank is not needed, and the field size required by the experiment is reduced.

5. The utility model discloses a brake, adopt the motor to drive the survey test piece in the general experiment and rotate, then the experiment of skidding is realized in the hysteresis brake loading, and the hysteresis brake loading has a period of delay, can influence the experimental data. The utility model discloses in when the motor reaches the required rotational speed of experiment, through the brake ware locking brake axle in the twinkling of an eye, make test piece one end stall through the cooperation of loading end belt, the big band pulley of loading, the little band pulley of loading, realize reaching the purpose of the experiment of skidding in the twinkling of an eye to the load in the twinkling of an eye of test piece, shortened the loading time.

Drawings

Fig. 1 is a front view of the friction experiment device suitable for the low temperature vacuum condition of the present invention.

Fig. 2 is a left side view of the friction experiment device suitable for the low temperature vacuum condition of the present invention.

Fig. 3 is a right side view of the friction experiment device suitable for the low temperature vacuum condition of the present invention.

Fig. 4 is a schematic structural view of the constant temperature box of the present invention.

In the figure, 1-a temperature-controllable vacuum box, 2-a loading end small wheel bracket, 3-a loading end belt, 4-a loading main shaft, 5-a loading end large wheel bracket, 6-a normal temperature box, 7-a first torque sensor, 8-a loading magnetic fluid sealing shaft, 9-a first heat insulation coupling, 10-a testing part, 11-a second torque sensor, 12-a second heat insulation coupling, 13-a temperature sensor, 14-a heat insulation mounting plate, 15-a heating plate, 16-a brake support, 17-a brake, 18-a rotating speed sensor, 19-a brake shaft, 20-a magnetic hysteresis brake, 21-a motor support, 22-a servo motor, 23-a driving large belt wheel bracket, 24-a driving end belt, 25-a driving main shaft, 26-a driving magnetic fluid sealing shaft, 27-vacuum box end cover, 28-electric connector flange, 29-loading large belt wheel, 30-loading small belt wheel, 31-normal temperature box end cover, 32-driving small belt wheel, 33-driving large belt wheel, 34-middle shaft, 601-first step, 602 second step

Detailed Description

The present invention will be further explained with reference to the accompanying drawings:

as shown in fig. 1 to 4, the friction experiment device suitable for the low-temperature vacuum condition comprises a driving device, a loading device, a transmission device, a second heat insulation coupler 12, a temperature-controllable vacuum box 1, a normal temperature box 6 and a test piece 10, wherein a vacuum box end cover 27 is arranged on one side of the temperature-controllable vacuum box 1. The test piece 10 is provided with a loading input end and a driving end, and the loading input end and the driving end are two ends of the same shaft on the test piece 10; the normal temperature case 6 sets up in controllable temperature vacuum chamber 1, be provided with horizontal installation's thermal-insulated mounting panel 14 on the inside bottom surface of normal temperature case 6, drive arrangement and loading device install in normal temperature case 6, still be provided with temperature sensor 13 and heating plate 15 on the thermal-insulated mounting panel 14 of normal temperature case 6 inside, test piece 10 and transmission set up in controllable temperature vacuum chamber 1, loading device passes through the loading input of transmission connection test piece 10, drive arrangement passes through the drive end of second thermal-insulated shaft coupling 12 connection test piece 10.

The driving device comprises a servo motor 22, a driving main shaft 25, a driving small belt wheel 32, a driving large belt wheel 33 support 23, a driving end belt 24, a first coupler and a driving magnetic fluid sealing shaft 26, wherein the servo motor 22 is fixed on a heat insulation mounting plate 14 in the normal temperature box 6, the driving small belt wheel 32 is fixed on an output shaft of the servo motor 22, the driving large belt wheel 33 support 23 is vertically installed on the heat insulation mounting plate 14, one end of the driving main shaft 25 is horizontally installed on the driving large belt wheel 33 support 23 through a bearing, the driving large belt wheel 33 is fixed on the driving main shaft 25, the driving large belt wheel 33 and the driving small belt wheel 32 are connected through the driving end belt 24, and the other end of the driving main shaft 25 is sequentially connected with the first coupler and the driving; the axes of the driving main shaft 25, the first coupling and the driving magnetic fluid sealing shaft 26 are on the same straight line, and the driving magnetic fluid sealing shaft 26 is arranged on the side wall of the normal temperature box 6; the output end of the driving magnetic fluid sealing shaft 26 extends out of the normal temperature box 6 and is connected with the driving end of the test piece 10 through a second heat insulation coupling 12.

The loading device comprises a brake support 16, a brake 17, a rotating speed sensor 18, a brake shaft 19, a second coupler, a hysteresis brake 20, a third coupler, a second torque sensor 11, a fourth coupler and a loading magnetic fluid sealing shaft 8, wherein the brake 17 is fixed on the heat insulation mounting plate 14 through the brake support 16, the brake shaft 19 of the brake 17 is sequentially connected with the rotating speed sensor 18, the second coupler, the hysteresis brake 20, the third coupler, the second torque sensor 11 and the loading magnetic fluid sealing shaft 8, the hysteresis brake 20 is fixed on the heat insulation mounting plate 14 through a brake support, and the axes of the brake 17, the rotating speed sensor 18, the second coupler, the hysteresis brake 20, the third coupler, the second torque sensor 11 and the loading magnetic fluid sealing shaft 8 are on the same straight line; the output end of the loading magnetic fluid sealing shaft 8 extends out of the normal temperature box 6.

The transmission device comprises a first heat insulation coupler 9, a first torque sensor 7, a third heat insulation coupler, an intermediate shaft 34, a loading end small wheel support 2, a loading end large wheel support 5, a loading large belt wheel 29, a loading small belt wheel 30, a loading main shaft 4 and a fourth heat insulation coupler, wherein the loading end small wheel support 2 and the loading end large wheel support 5 are both fixed on a bottom plate of the controllable temperature vacuum box 1, one end of the intermediate shaft 34 is horizontally arranged on the loading end small wheel support 2 through a bearing, one end of the loading main shaft 4 is horizontally arranged on the loading end large wheel support 5 through a bearing, the loading small belt wheel 30 is fixed on the intermediate shaft 34, the loading large belt wheel 29 is fixed on the loading main shaft 4, and the loading small belt wheel 30 and the loading large belt wheel 29 are connected through a loading end belt 3; the other end of the intermediate shaft 34 is sequentially connected with a third heat insulation coupler, a first torque sensor 7, a first heat insulation coupler 9 and a loading input end of a test piece 10; the other end of the loading main shaft 4 is connected with one end of a loading magnetic fluid sealing shaft 8 extending out of the normal temperature box 6 through a fourth heat insulation coupler.

The shells of the loading magnetic fluid sealing shaft 8 and the driving magnetic fluid sealing shaft 26 are fixedly connected with the normal temperature box 6.

The heat insulation mounting plate 14 is made of heat insulation material, and the heat insulation mounting plate 14 is fixed at the bottom of the inner side of the constant temperature box 6 through screws. The brake support 16, the motor support 21, the driving large belt wheel 33 support 23 and the temperature sensor 13 are all fixed on a heat insulation mounting plate 14 in the constant temperature box 6 through bolts.

The whole structure of the normal temperature box 6 is in a step shape, a bottom step extends from the bottom surface of the normal temperature box, the bottom step is provided with a first step 601, one side of the first step 601 is provided with a second step 602, the heights of the bottom step, the first step 601 and the second step 602 rise in sequence, and the bottom surface of the test piece 10 is formed by processing a heat insulating material. The test piece 10 is fixed on the horizontal cross plate of the second step 602, the vertical side plate of the second step 602 is provided with an electric connector flange 28 and a through hole for connecting the loading magnetic fluid sealing shaft 8, and the first step 601 is provided with a through hole for connecting the driving magnetic fluid sealing shaft 26. The side surface of the normal temperature box 6 is provided with a normal temperature box end cover 31.

A key groove and a threaded positioning hole are formed in the output shaft of the servo motor 22, and the driving small belt wheel 32 is fixedly connected with the output shaft of the servo motor 22 through the key groove and the threaded positioning hole. The servo motor 22 is fixed to the motor mount 21 by bolts.

The first torque sensor 7 and the second torque sensor 11 are both double output shaft type torque sensors.

The hysteresis brake 20 is a double-output type hysteresis brake 20, and the hysteresis brake 20 is fixed on the heat insulation mounting plate 14 through a brake support.

The utility model discloses can carry out the experiment of skidding under the different rotational speeds:

1) after the installation is finished, adjusting the temperature-controllable vacuum box 1 to enable the internal temperature to reach the temperature required by the experiment and pumping out air to realize a hot vacuum environment;

2) the heating sheet 15 is started to heat a normal temperature box formed by fixing the normal temperature box 6 and a normal temperature box end cover 31 through screws, the heating sheet 15 is closed when the normal temperature box is heated to a preset temperature, the internal temperature of the heating sheet 15 is monitored in real time through the temperature sensor 13, and the heating sheet 15 is started when the temperature is lower than a lowest threshold value in the experimental process;

3) starting the servo motor 22 to reach the minimum rotation speed required by the experiment; the motor drives the small driving belt wheel 30, the small driving belt wheel 32 drives the large driving belt wheel 33 to rotate through the driving end belt 24, the large driving belt wheel 33 drives the magnetic fluid sealing shaft 26 to rotate, and therefore the test piece 10 starts to rotate

4) Starting a brake 17, instantly locking a brake shaft 19 by the brake 17, stopping the rotation of a magnetic fluid loading sealing shaft 8 so as to load a large belt wheel 29 to stop rotating, stopping the rotation of a small belt wheel 30 by the loading end belt 3 so as to stop the rotation of one side of a test piece 10, instantly realizing the slip of the test piece 10, judging whether the rotation is stopped to realize the slip by a rotating speed sensor 18, and transmitting real-time data to a data processing system by a first torque sensor 7 and a second torque sensor 11;

5) the brake 17 is closed, and the rotating speed of the servo motor 22 is adjusted to the next required speed;

6) and repeating the fourth step and the fifth step until the experiment is completed.

The utility model discloses can carry out the loading experiment, specifically include following step:

firstly, after the installation is finished, adjusting the temperature-controllable vacuum box 1 to enable the internal temperature to reach the temperature required by the experiment and pumping air out to realize a hot vacuum environment;

starting the heating sheet 15 to heat a normal temperature box formed by fixing the normal temperature box 6 and a normal temperature box end cover 31 through screws, closing the heating sheet 15 when the normal temperature box is heated to a preset temperature, monitoring the internal temperature of the heating sheet in real time through the temperature sensor 13, and starting the heating sheet 15 when the temperature is lower than a minimum threshold value in the experimental process;

starting the servo motor 22 to reach the lowest rotation speed required by the experiment; the motor drives the small driving belt wheel 30, the small driving belt wheel 32 drives the large driving belt wheel 33 to rotate through the driving end belt 24, the large driving belt wheel 33 drives the magnetic fluid sealing shaft 26 to rotate, and therefore the test piece 10 starts to rotate

Starting the magnetic hysteresis brake 20, loading the magnetic fluid sealing shaft 8 by the magnetic hysteresis brake 20, loading the small loading belt wheel 30 by loading the large belt wheel 29 and the loading end belt 3, loading the intermediate shaft 34, loading one side of the test piece 10, starting a loading test, and transmitting real-time data to the data processing system by the rotating speed sensor 18, the second torque sensor 11 and the first torque sensor 7;

fifthly, adjusting the loading size of the hysteresis brake 20;

sixthly, repeating the fourth step and the fifth step until the experiment is finished.

The above-mentioned embodiment is only the preferred embodiment of the present invention, and is not to the limitation of the technical solution of the present invention, as long as the technical solution can be realized on the basis of the above-mentioned embodiment without creative work, all should be regarded as falling into the protection scope of the right of the present invention.

Claims

1. The utility model provides a friction experiment device suitable for under low temperature vacuum condition which characterized in that: the device comprises a driving device, a loading device, a transmission device, a second heat insulation coupler (12), a temperature-controllable vacuum box (1), a normal temperature box (6) and a test piece (10), wherein the test piece (10) is provided with a loading input end and a driving end, and the loading input end and the driving end are two ends of the same shaft on the test piece (10); the temperature-controllable vacuum box comprises a normal temperature box (6), a temperature-controllable vacuum box (1), a heat insulation mounting plate (14) which is horizontally mounted is arranged on the bottom surface inside the normal temperature box (6), a driving device and a loading device are mounted in the normal temperature box (6), a temperature sensor (13) and a heating plate (15) are further arranged on the heat insulation mounting plate (14) inside the normal temperature box (6), a test piece (10) and a transmission device are arranged in the temperature-controllable vacuum box (1), the loading device is connected with a loading input end of the test piece (10) through the transmission device, and the driving device is connected with a driving end of the test piece (10) through a second heat insulation coupler (12);

the driving device comprises a servo motor (22), a driving main shaft (25), a driving small belt wheel (32), a driving large belt wheel (33) bracket (23), a driving end belt (24), a first coupler and a driving magnetic fluid sealing shaft (26), wherein the servo motor (22) is fixed on a heat insulation mounting plate (14) in the normal temperature box (6), the driving small belt wheel (32) is fixed on an output shaft of the servo motor (22), the driving large belt wheel (33) support (23) is vertically arranged on the heat insulation mounting plate (14), one end of a driving main shaft (25) is horizontally arranged on the driving large belt wheel (33) support (23) through a bearing, the driving large belt wheel (33) is fixed on the driving main shaft (25), the driving large belt wheel (33) and the driving small belt wheel (32) are connected through a driving end belt (24), and the other end of the driving main shaft (25) is sequentially connected with a first coupling and a driving magnetic fluid sealing shaft (26); the axes of the driving main shaft (25), the first coupling and the driving magnetic fluid sealing shaft (26) are on the same straight line, and the driving magnetic fluid sealing shaft (26) is arranged on the side wall of the normal temperature box (6); the output end of the driving magnetic fluid sealing shaft (26) extends out of the normal temperature box (6) and is connected with the driving end of the test piece (10) through a second heat insulation coupling (12);

the loading device comprises a brake support (16), a brake (17), a rotating speed sensor (18), a brake shaft (19), a second coupler, a magnetic hysteresis brake (20), a third coupler, a second torque sensor (11), a fourth coupler and a loading magnetic fluid sealing shaft (8), wherein the brake (17) is fixed on a heat insulation mounting plate (14) through the brake support (16), the brake shaft (19) of the brake (17) is sequentially connected with the rotating speed sensor (18), the second coupler, the magnetic hysteresis brake (20), the third coupler, the second torque sensor (11) and the loading magnetic fluid sealing shaft (8), the magnetic hysteresis brake (20) is fixed on the heat insulation mounting plate (14) through a brake support, and the axes of the brake (17), the rotating speed sensor (18), the second coupler, the magnetic hysteresis brake (20), the third coupler, the second torque sensor (11) and the loading magnetic fluid sealing shaft (8) are on the same straight line; the output end of the loading magnetic fluid sealing shaft (8) extends out of the normal temperature box (6);

the transmission device comprises a first heat insulation coupler (9), a first torque sensor (7), a third heat insulation coupler, an intermediate shaft (34), a loading end small wheel support (2), a loading end large wheel support (5), a loading large belt wheel (29), a loading small belt wheel (30), a loading main shaft (4) and a fourth heat insulation coupler, the loading end small wheel bracket (2) and the loading end large wheel bracket (5) are both fixed on the bottom plate of the temperature-controllable vacuum box (1), one end of the intermediate shaft (34) is horizontally arranged on the loading end small wheel bracket (2) through a bearing, one end of the loading main shaft (4) is horizontally arranged on the loading end large wheel bracket (5) through a bearing, the loading small belt wheel (30) is fixed on the intermediate shaft (34), the loading large belt wheel (29) is fixed on the loading main shaft (4), and the loading small belt wheel (30) is connected with the loading large belt wheel (29) through a loading end belt (3); the other end of the intermediate shaft (34) is sequentially connected with a third heat insulation coupler, a first torque sensor (7), a first heat insulation coupler (9) and a loading input end of a test piece (10); the other end of the loading main shaft (4) is connected with one end of a loading magnetic fluid sealing shaft (8) extending out of the normal temperature box (6) through a fourth heat insulation coupler.

2. The friction experiment device suitable for the low-temperature vacuum condition as claimed in claim 1, wherein: the shells of the loading magnetic fluid sealing shaft (8) and the driving magnetic fluid sealing shaft (26) are fixedly connected with the normal temperature box (6).

3. The friction experiment device suitable for the low-temperature vacuum condition as claimed in claim 1, wherein: the heat insulation mounting plate (14) is made of heat insulation materials, and the heat insulation mounting plate (14) is fixed at the bottom of the inner side of the normal temperature box (6) through screws.

4. The friction experiment device suitable for the low-temperature vacuum condition as claimed in claim 1, wherein: the brake support (16), the motor support (21), the drive large belt wheel (33) support (23) and the temperature sensor (13) are fixed on a heat insulation mounting plate (14) in the normal temperature box (6) through bolts.

5. The friction experiment device suitable for the low-temperature vacuum condition as claimed in claim 1, wherein: a key groove and a threaded positioning hole are formed in an output shaft of the servo motor (22), and the small driving belt wheel (32) is fixedly connected with the output shaft of the servo motor (22) through the key groove and the threaded positioning hole; the servo motor (22) is fixed on the motor support (21) through a bolt.

6. The friction experiment device suitable for the low-temperature vacuum condition as claimed in claim 1, wherein: the bottom surface of the test piece (10) is processed by a heat insulation material.

7. The friction experiment device suitable for the low-temperature vacuum condition as claimed in claim 1, wherein: the first torque sensor (7) and the second torque sensor (11) are both double-output-shaft type torque sensors.

8. The friction experiment device suitable for the low-temperature vacuum condition as claimed in claim 1, wherein: the hysteresis brake (20) is a double-output-shaft hysteresis brake (20), and the hysteresis brake (20) is fixed on the heat insulation mounting plate (14) through a brake support.