CN106950139B - Friction and wear testing machine for joint bearing and hinge - Google Patents

Abstract

The utility model relates to a friction and wear testing machine for joint bearings and hinges. The actuating rod of the actuating cylinder passes through the installation hole of the actuating cylinder. Two supports are distributed on both sides of the actuator mounting hole. Two tapered sleeves are installed on the inner support plate of each support. The two ends of the test piece pin shaft are respectively installed in two tapered sleeves. The pin shaft of the test piece is installed in the center of the fixture, the outer ring of the fixture is installed on the upper end of the tension pressure sensor, and the tension pressure sensor is installed on the top end of the actuator rod of the cylinder. Two displacement sensors are located on both sides of the fixture. One end of the torque sensor located between the outer support plate and the inner support plate of each support is respectively connected to the pin shaft of the test piece, and the other end of each torque sensor is fixedly connected to the reducer respectively. Two servo motors are located outside each support respectively. The invention can respectively realize the rotation of the pin shaft and the shaft sleeve, and can realize the loading and real-time monitoring of the radial load, as well as the real-time monitoring of the wear amount and friction torque, and has the advantages of convenient installation and disassembly, and high measurement accuracy of wear amount and friction torque. features.

Description

A friction and wear testing machine for joint bearings and hinges

technical field

The invention relates to the field of friction and wear testing machines, in particular to a friction and wear testing machine for joint bearings and hinges capable of realizing the simultaneous rotation of pin shafts and bushings.

Background technique

Joint bearings and hinges, as important components of motion mechanisms, are widely used in industrial robots, aerospace, automobiles, construction machinery and other fields. Spherical joint bearings generally consist of an inner ring and an outer ring, which can rotate relative to each other in two directions. The hinge is generally composed of a pin shaft and a bushing, which can rotate circumferentially between the two. It can be seen that, in terms of structure and motion, joint bearings and hinges have certain similarities. For the convenience of expression, in the present invention, the pin shaft of the hinge and the inner ring of the joint bearing are collectively referred to as "pin shaft", and the shaft sleeve of the hinge and the outer ring of the joint bearing are collectively referred to as "shaft sleeve".

The main form of damage in spherical plain bearings and hinges is increased play and frictional moments due to wear. The above two forms of damage can lead to greater operating noise and vibration of the moving mechanism, reduced movement accuracy and efficiency, and even failure modes such as stagnation. Therefore, in order to study the durability and reliability of the motion mechanism, it is necessary to predict the evolution law of friction and wear performance of joint bearings and hinges. However, due to the strong system dependence and time-varying nature of wear behavior, at the current level of tribology research, it is still not possible to predict the friction and wear of spherical plain bearings and hinges only by relying on numerical simulation and friction and wear test data of material standard samples. Evolution law. In order to ensure the reliability of the movement function of the mechanism, it is necessary to conduct friction and wear tests on joint bearings and hinges on a special friction and wear testing machine, considering the real working conditions.

Jiang Qinyu's paper "Solving the Wear Probability Life of Hinge Mechanism Based on Numerical Simulation Technology" published in "Journal of Mechanical Engineering" Vol. 43 No. 1 in 2007 believes that there are three types of motion in the hinge: (1) The pin shaft rotates and the sleeve does not move; (2) The pin shaft does not move, and the shaft sleeve rotates; (3) The pin shaft and the shaft sleeve rotate simultaneously. In the same way, joint bearings also have a motion form in which the outer ring and inner ring of the bearing rotate circumferentially at the same time. Radial load is one of the main factors affecting the evolution of friction and wear of joint bearings and hinges. The testing machine should be able to apply radial load to the specimen and monitor it in real time. In addition, in order to obtain the friction and wear performance evolution curve of the test piece, it is necessary to monitor the wear amount and friction torque of the test piece in real time. In summary, based on the purpose and requirements of the test, the testing machine should be able to meet the following requirements: (1) load a certain radial load on the specimen; (2) simultaneously realize the circumferential rotation of the pin shaft and the sleeve; (3) Realize real-time monitoring of parameters such as radial load, wear amount, and friction torque.

For the kinematic pairs of rotating pairs and joint bearings, there are currently two types of friction and wear testing machines, namely: (1) The paper "Bearing Wear Test" published by Chi Chengfang in the third issue of "Engineering and Testing" in 2008 The joint bearing friction and wear testing machine represented by the development of the machine" can only realize the rotation of the joint bearing pin; (2) the invention patent "composite swing joint bearing test machine", the patent number is 201010276423. Joint Bearing Life Tester", patent No. 201310191988.X represents the joint bearing friction and wear testing machine, which can realize the circumferential reciprocating swing of the pin shaft and the reciprocating swing of the shaft sleeve in the inclined direction at the same time, but cannot simultaneously realize the shaft Set of circumferential swing. For the hinge pair, the above two types of testing machines can only simulate the working conditions of the pin shaft rotating and the shaft sleeve not moving. For joint bearings, the existing testing machine cannot realize the simultaneous circumferential rotation of the inner ring and outer ring of the bearing. However, for the working condition of the pin shaft and the bushing rotating circumferentially at the same time, the wear law of the kinematic pair and the change law of the contact form of the contact surface caused by wear are completely different from the previous two working conditions. To sum up, the existing friction and wear testing machines cannot fully meet the friction and wear test requirements of joint bearings and hinges.

Contents of the invention

In order to overcome the deficiencies in the prior art that cannot meet the friction and wear test requirements of joint bearings and hinges, the present invention proposes a friction and wear testing machine for joint bearings and hinges.

The invention includes a bench, two servo motors, two torque sensors, two self-aligning roller bearings, two reducers, a first support, a second support, a fixture, a test piece pin, a rocker arm, a displacement sensor, Pull pressure sensor and actuator. The stand includes a base and a mounting plate.

The geometric center of the mounting plate has an actuator mounting hole. The actuator is fixed on the upper surface of the base; the actuator rod of the actuator passes through the installation hole of the actuator. The first support and the second support are installed on the upper surface of the mounting plate respectively, and are distributed on both sides of the installation hole of the actuator along the long side direction of the stand. There are through holes on the inner support plate of the first support and the inner support plate of the second support respectively, and two tapered sleeves are installed on the inner sides of the first support and the second support respectively through spherical roller bearings through holes in the support plate. The tapered surfaces at both ends of the pin shaft of the test piece are respectively loaded into the two tapered sleeves. The pin shaft of the test piece is installed in the center of the fixture, the outer ring of the fixture is installed on the upper end of the tension pressure sensor, and the tension pressure sensor is installed on the top end of the actuating rod of the actuator. The actuator is fixed on the upper surface of the bottom plate of the base. Two displacement sensors are respectively installed on the two long sides of the mounting plate and are located on both sides of the fixture.

A torque sensor is installed between the outer support plate and the inner support plate of the first support. One end of the torque sensor is connected with the test piece pin shaft located inside the first supporting inner support plate; the other end of the torque sensor is fixedly connected with a speed reducer. The reducer is fixedly connected with the servo motor.

A torque sensor is also installed between the outer support plate and the inner support plate of the second support. One end of the torque sensor is fixedly connected with the lower end of the rocker rocker of the rocker arm; the other end of the torque sensor is fixedly connected with another reducer installed on it. The reducer is fixedly connected with the servo motor. The upper end of the rocker arm is fixedly connected with one end of the rocker link; the other end of the rocker link is fixedly connected with the inner ring of the clamp.

Among the two servo motors, one servo motor is located outside the outer support plate of the first support, and the other servo motor is located outside the outer support plate of the second support.

The fixture includes the outer ring of the fixture, the inner ring of the fixture, the test piece shaft sleeve, the expansion joint sleeve and the ball bearing. Set them together, and make the test piece shaft sleeve at the innermost ring, and make the fixture outer ring at the outermost ring. After the test piece shaft sleeve, the expansion joint sleeve and the inner ring of the fixture are assembled together, the tight fit between the test piece shaft sleeve and the clamp inner ring is realized through the expansion joint sleeve. Both the outer ring of the fixture and the ball bearing, and the ball bearing and the inner ring of the fixture are interference fits.

The inner diameter of the inner ring of the clamp is the same as the outer diameter of the expansion joint sleeve, and the two are closely matched; there is a mounting hole for a rocker arm on one end surface of the inner ring of the clamp. The inner diameter of the expansion joint sleeve is the same as the outer diameter of the test piece shaft sleeve, and the two are tightly fitted. The inner diameter of the clamp outer ring is the same as the outer diameter of the ball bearing. The outer circumferential surface of the outer ring of the fixture is processed into squares, and a pair of protrusions are symmetrically distributed on the outer surface of the outer ring of the fixture. The protrusions are the measurement reference blocks of the displacement sensor, and the measurement reference blocks of the displacement sensor are respectively Corresponding to the positions of the two displacement sensors.

The first support is in a "U" shape, and the two side vertical plates of the first support respectively constitute the outer support plate and the inner support plate, and the inner support plate is adjacent to the clamp during assembly. There is a through hole for the output shaft of the reducer on the outer support plate; there is a mounting hole around the through hole. There are mounting holes for spherical roller bearings on the inner support plate. The structure of the second support is the same as that of the first support. Since a rocker arm is installed on one side of the second support, a concave surface for avoidance is processed on the upper surface of the second support base.

The inner surface of one end of the tapered sleeve is an outwardly expanded cone section, which is matched with the tapered surface on the outer peripheral surface of the pin shaft of the test piece; the other end of the tapered sleeve is an equal-diameter section. The middle part of the outer peripheral surface of the tapered sleeve has a radially protruding positioning platform; the inner surface of the tapered sleeve is the outer peripheral surface of one end of the tapered section, which is also a tapered surface, so as to facilitate the installation of the spherical roller bearing.

The middle part in the length direction of the test piece pin shaft is an equal-diameter section, which is the test area; the outer diameter of the equal-diameter section is the same as the inner diameter of the test piece shaft sleeve. Both ends of the test piece pin shaft are threaded sections for installing compression nuts. Between the equal-diameter section and the threaded section is a tapered section whose outer diameter gradually shrinks toward both ends. The tapered section cooperates with the inner tapered surface of the tapered sleeve to ensure that the pin axis of the test piece is coaxial with the tapered sleeve.

The rocker arm includes a rocker rocker and a rocker link, and the end face of one end of the rocker link is fixedly connected to the end face of the upper end of the rocker arm, and the other end of the rocker link is fixed on the inner ring of the fixture on one end face of . In order to realize the fixed connection between the rocker link and the top end surface of the rocker link, there is a threaded connection hole on the end surface of the rocker link; the other end of the rocker link has a 90 ° folding plate, the There are threaded connection holes fixedly connected with the inner ring of the fixture on the folding plate. The upper end of the rocker arm is a rectangular slat, and the top of the slat has a through hole for connecting the connecting rod; the lower end of the rocker arm is a semicircular block for balancing the rocker arm. The eccentric moment of inertia eliminates the interference of the centrifugal force of the rocker arm on the load on the test piece during the rotation process. There is a connection hole for connecting the torque sensor at the junction of the semicircular block and the slat.

The cross-section of the mounting plate is "concave" shape, and the groove bottom surface of the groove is the mounting surface of the second support and the first support, and at the geometric center of the mounting surface there is an actuator penetrating through the upper and lower surfaces of the mounting plate There are mounting holes for the displacement sensor on both sides of the mounting through hole of the actuator and near the two long sides of the mounting plate.

The installation surface of the installation plate is provided with a plurality of installation through holes for the second support and the first support, so as to meet the test requirements of test pieces of different sizes. The centers of the installation through holes are all symmetrical to the center line in the width direction of the installation surface, so as to satisfy the positioning of the second support and the first support.

The friction and wear testing machine proposed by the present invention for joint bearings and hinges widely used in motion mechanisms can respectively realize the rotation of the pin shaft and the shaft sleeve, and can realize the loading and real-time monitoring of radial loads, as well as the real-time monitoring of wear amount and friction torque. monitor. In addition, the testing machine should have the characteristics of convenient installation and disassembly of the test piece, and high measurement accuracy of wear amount and friction torque.

In the present invention, the specimen clamping module adopts the structural form supported by double lugs. It consists of a connecting sleeve and a compression nut. Wherein, an inner support plate is provided on the inner side of the first support and the second support, respectively, for providing support for the pin shaft. In order to ensure the centering of the pin shaft installation, a self-aligning roller bearing is respectively installed on the inner support plates of the first support and the second support.

In the present invention, the middle part of the pin shaft is a protruding step, which is a test area, and the axle sleeve is installed here. The two sides of the step are tapered surfaces, which are used to cooperate with the tapered sleeve; the outer sides of the two tapered surfaces are respectively threaded, which are used to install the compression nut; the outer side of the thread, facing the pin drive module, is matched with the torque sensor end of the. The standard sample shape of the shaft sleeve is a round pie shape, with a pin hole in the middle, which is the test area. In order to facilitate the installation and disassembly of the pin shaft, tapered sleeves are respectively installed in the self-aligning roller bearing, and the taper is the same as the tapered surfaces at both ends of the pin shaft. After the pin shaft is installed in the inner tapered hole of the tapered sleeve, the tapered surfaces at both ends of the pin shaft are tightly fitted with the tapered surfaces inside the two tapered sleeves respectively by using compression nuts.

In the present invention, the rotation of the shaft sleeve is driven by a servo motor. The shaft sleeve drive module is composed of a servo motor, a reducer, a coupling, a drive shaft, a torque sensor, and a rocker arm. Among them, the servo motor and the reducer are connected together by bolts to form a set of drive unit. The speed reducer is installed on the outside of the second support, and its inner output end is equipped with a shaft coupling, a transmission shaft, a torque sensor and a rocker arm in sequence, and the inner side of the rocker arm is fixedly connected with the inner ring of the fixture. The friction torque of the ball bearing is calibrated before the test. During the test, the reading of the torque sensor minus the friction torque of the ball bearing is the friction torque of the test piece.

In the present invention, measuring reference blocks for displacement sensors are arranged on both sides of the outer ring of the fixture. A displacement sensor is respectively fixedly connected to the positions corresponding to the two measuring reference blocks on the mounting plate. During the test, the wear amount of the test piece is measured in a dual-channel way, that is, the wear amount of the test piece is measured by two displacement sensors respectively, and the actual wear amount of the test piece is represented by the average value of the two measured values, which can eliminate the problem caused by the outer ring of the fixture. The measurement error caused by the slight rotation of the servo motor under the torque.

Compared with the prior art, the pin shaft of the test piece in the present invention is respectively connected with the first support and the second support through two self-aligning roller bearings, the test piece shaft sleeve is connected with the outer ring of the fixture through a ball bearing, and the test piece Both the pin shaft and the specimen bushing can rotate independently under the drive of the servo motor. The load of the actuator is transmitted to the shaft sleeve of the test piece through the outer ring of the fixture, the ball bearing and other parts to realize the loading of the radial load of the test piece. Therefore, the present invention can simultaneously simulate the circumferential rotation of the pin shaft and the shaft sleeve, and can simultaneously load radial loads, and the simulated working conditions are more realistic. Using double-channel independent measurement and averaging to monitor the amount of wear can eliminate the error caused by the slight deflection of the outer ring of the fixture under the action of the motor torque; The tapered sleeve can realize the convenient installation and disassembly of the test piece; the pin shaft adopts the structure supported by double lugs, and has higher strength and rigidity than the invention patent 201010276423.8 under the same pin diameter of the test piece; The support at both ends of the shaft adopts self-aligning roller bearings, which have low requirements for the installation accuracy of the test piece.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the front view of Fig. 1;

Fig. 3 is a schematic diagram of the assembly of the specimen clamping module;

Fig. 4 is the sectional view of Fig. 3;

5 is a three-dimensional exploded schematic view of the clamp;

Fig. 6 is a schematic diagram of the connection between the bushing fixture and the rocker arm;

Fig. 7 is a schematic diagram of the connection between the clamp and the torque sensor;

Fig. 8 is a schematic diagram of the connection between the clamp and the torque sensor;

Fig. 9 is a top view of the mounting plate. In the picture:

1. Base; 2. Column; 3. Mounting plate; 4. Servo motor; 5. Reducer; 6. First support; 7. Coupling; 8. Torque sensor; 9. Fixture outer ring; 10. Ball bearing ;11. Fixture inner ring; 12. Expansion connection sleeve; 13. Test piece shaft sleeve; 14. Test piece pin; 15. Compression nut; 16. Taper sleeve; 17. Spherical roller bearing; 18. Rocker arm; 19. Transmission shaft; 20. Second support; 21. Displacement sensor; 22. Actuator cylinder; 23. Pull pressure sensor.

Detailed ways

This embodiment is a friction and wear testing machine for joint bearings and hinges, including a bench, two servo motors 4, two torque sensors 8, two spherical roller bearings 17, two reducers 5, a first support 6. The second support 20, fixture, test piece pin shaft 14, rocker arm 18, transmission shaft 19, displacement sensor 21, tension pressure sensor 23 and actuator cylinder 22.

The geometric center of the mounting plate 3 of the cuboid stand has an actuator mounting hole. The actuating cylinder 22 is fixed on the upper surface of the base 1 of the stand; the actuating rod of the actuating cylinder 22 passes through the mounting hole of the actuating cylinder. The first support 6 and the second support 20 are respectively installed on the upper surface of the mounting plate 3 as the upper surface of the platform, and are distributed on both sides of the installation hole of the actuator along the long side direction of the platform. There are respectively through holes on the inner support plate of the first support 6 and the inner support plate of the second support 20, and two tapered sleeves 16 are mounted on the first support 6 and the second support 20 respectively through spherical roller bearings 17. In the through hole on the inner support plate of the second support 20. The tapered surfaces at both ends of the test piece pin shaft 14 are respectively loaded into the two tapered sleeves, and are tightened by a compression nut 15 . The test piece pin shaft 14 is installed in the center of the clamp, and the clamp outer ring 9 of the clamp is installed on the upper end of the tension pressure sensor 23 through threads, and the tension pressure sensor 23 is installed on the top end of the actuating rod of the actuator cylinder 22 through threads, as shown in the figure 7. The actuator 22 is fixed on the upper surface of the bottom plate of the base 1 . Two displacement sensors 21 are respectively installed on the two long sides of the mounting plate, and are located on both sides of the fixture.

A torque sensor 8 is installed between the outer support plate and the inner support plate of the first support 6 . One end of the torque sensor 8 is connected to the test piece pin 14 positioned at the inner side of the first supporting inner support plate, as shown in Figure 4; A speed reducer 5 is affixed to the outer surface of the outer support plate. The speed reducer is fixedly connected with the servo motor 4 .

A torque sensor 8 is also installed between the outer support plate and the inner support plate of the second support 20 . One end of the torque sensor 8 is fixedly connected with the semicircular block at the lower end of the rocker rocker in the rocker arm 18 on the inside of the second support inner support plate in a shaft-hole fit mode; the other end of the torque sensor 8 is connected through a shaft coupling The gear 7 is fixedly connected with another reducer 5 installed on the outer surface of the outer support plate of the second support 20 . The speed reducer is fixedly connected with the servo motor 4 . The upper end of the rocker arm is fixedly connected with one end of the rocker link; the other end of the rocker link is fixedly connected with the clamp inner ring 11 by bolts.

One of the two servo motors 4 is located outside the outer support plate of the first support, and the other servo motor is located outside the outer support plate of the second support.

As shown in Figure 5. The clamp includes a clamp outer ring 9, a clamp inner ring 11, a test piece shaft sleeve 13, an expansion joint sleeve 12 and a ball bearing 10, according to the test piece sleeve 13, the expansion joint sleeve 12, the clamp inner ring 11, the The order of the bearing 10 and the outer ring of the fixture 9 is fitted together from inside to outside, and the test piece bushing 13 is located in the innermost ring, and the outer ring of the fixture 9 is located in the outermost ring. After the test piece shaft sleeve, the expansion joint sleeve and the inner ring of the fixture are assembled together, the tight fit between the test piece shaft sleeve and the clamp inner ring is realized through the expansion joint sleeve. Both the outer ring of the fixture and the ball bearing, and the ball bearing and the inner ring of the fixture are interference fits.

The clamp inner ring 11 is a hollow rotating body. The inner diameter of the inner ring of the clamp is the same as the outer diameter of the expansion joint sleeve 12, and the two are tightly fitted; there is a mounting hole for the rocker arm 18 on an end face of the inner ring of the clamp. The inner diameter of the expansion joint sleeve 12 is the same as the outer diameter of the test piece shaft sleeve 13, and the two are tightly fitted.

The inner diameter of the clamp outer ring 9 is the same as the outer diameter of the ball bearing 10 . The outer circumferential surface of the clamp outer ring 9 is processed into squares, and a pair of protrusions are symmetrically distributed on the outer surface of the clamp outer ring 9. The protrusions are the measurement reference block of the displacement sensor, and the measurement reference of the displacement sensor The blocks correspond to the positions of the two displacement sensors 21, respectively.

The first support 6 is "U"-shaped, and the two side vertical plates of the first support respectively constitute the outer support plate and the inner support plate, and the inner support plate is adjacent to the clamp during assembly. There is a through hole for the output shaft of the reducer 5 on the outer support plate; there is a mounting hole around the through hole. There are mounting holes for spherical roller bearings on the inner support plate.

The structure of the second support 20 is the same as that of the first support 6 . Because rocking arm 18 is installed on this second supporting side, so the concave surface of avoidance is processed on the upper surface of this second supporting base plate.

There are two tapered sleeves 16 . The inner surface of one end of the tapered sleeve is an outwardly expanded cone section, which is matched with the tapered surface of the outer peripheral surface of the pin shaft of the test piece; the other end of the tapered sleeve is an equal-diameter section. The middle part of the outer peripheral surface of the tapered sleeve 16 has a radially protruding positioning platform;

The middle part of the test piece pin shaft 14 in the length direction is an equal-diameter section, which is the test area; the outer diameter of the equal-diameter section is the same as the inner diameter of the test piece shaft sleeve. Both ends of the test piece pin shaft are threaded sections for installing compression nuts. Between the equal-diameter section and the threaded section is a tapered section whose outer diameter gradually shrinks toward both ends. The tapered section cooperates with the inner tapered surface of the tapered sleeve to ensure that the pin axis of the test piece is coaxial with the tapered sleeve.

Described rocker arm 18 comprises rocker arm rocker and rocker arm link, and the end face of one end of rocker arm link is fixedly connected with the end face of described rocker arm rocker upper end, and the other end of rocker arm link is fixed in the fixture One end face of ring 11. In order to realize the fixed connection between the rocker link and the top end surface of the rocker link, there is a threaded connection hole on the end surface of the rocker link; the other end of the rocker link has a 90 ° folding plate, the There is a threaded connection hole fixedly connected with the clamp inner ring 11 on the folding plate. The upper end of the rocker arm is a rectangular slat, and the top of the slat has a through hole for connecting the connecting rod; the lower end of the rocker arm is a semicircular block for balancing the rocker arm. The eccentric moment of inertia eliminates the interference of the centrifugal force of the rocker arm on the load on the test piece during the rotation process. There is a connection hole for connecting the torque sensor at the junction of the semicircular block and the slat.

The stand is welded by a base 1, four columns 2, and a mounting plate 3, and the four columns 2 are respectively fixed on the four corners of the upper surface of the base 1; the mounting plate 3 is fixed on each of the The upper end of the column. The cross-section of the mounting plate is "concave" shape, and the groove bottom surface of the groove is the mounting surface of the second support 20 and the first support 6, and there is a work piece running through the upper and lower surfaces of the mounting plate at the geometric center of the mounting surface. The moving cylinder 22 is installed through holes, and there are mounting holes for displacement sensors 21 on both sides of the moving cylinder installing through holes, near the two long sides of the mounting plate 3 .

The installation surface of the installation plate is provided with a plurality of installation through holes for the second support 20 and the first support 6, so as to meet the test requirements of test pieces of different sizes. The centers of the installation through holes are all symmetrical to the center line in the width direction of the installation surface, so as to satisfy the positioning of the second support and the first support.

In Fig. 1 and Fig. 3, the lower end of the actuator is installed on the base of the stand, the upper end is equipped with a tension pressure sensor, and the upper end of the tension pressure sensor is connected with the outer ring of the fixture. The two sides of the outer ring of the fixture are provided with measuring reference blocks for the displacement sensor. A displacement sensor is respectively installed on the mounting plate corresponding to the positions of the two measuring reference blocks. Both the actuator cylinder and the expansion joint sleeve are standard parts.

During the installation of the test piece, the first support 6 and the second support 20 need to be disassembled, and the distance between the first support 6 and the second support 20 needs to be adjusted according to the size of the test piece. The first support 6 and the second support 20 are respectively installed in the grooves of the mounting plate, and can slide along the mounting plate. Through machining and other methods, it is easy to make the first support 6 and the second support 20 have a higher matching accuracy with the mounting plate, so as to ensure the two spherical roller bearings 17 on the first support 6 and the second support 20 Has high coaxiality.

During the test, the wear amount of the test piece is measured in a dual-channel way, that is, the wear amount of the test piece is measured by two displacement sensors respectively, and the actual wear amount of the test piece is represented by the average value of the two measured values, which can eliminate the problem caused by the outer ring of the fixture. Measurement error caused by slight rotation under the torque of the servo motor. In the same way, the friction torque of the specimen is also measured in a dual-channel way, that is, two torque sensors are used to measure the friction torque of the pin shaft end and the sleeve end respectively, and then the actual friction torque of the specimen is represented by the average of the two measured values .

Claims (7)

1. A friction and wear testing machine for joint bearings and hinges, characterized in that it comprises a bench, two servo motors, two torque sensors, two self-aligning roller bearings, two speed reducers, the first support, the second Two supports, fixtures, test piece pins, rocker arms, displacement sensors, tension pressure sensors and actuators; the stand includes a base and a mounting plate; the geometric center of the mounting plate has an actuator mounting hole; The cylinder is fixed on the upper surface of the base; the actuating rod of the actuator passes through the mounting hole of the actuator; the first support and the second support are respectively installed on the upper surface of the mounting plate and distributed along the long side of the stand On both sides of the installation hole of the actuator; there are through holes on the inner support plate of the first support and the inner support plate of the second support respectively, and the two tapered sleeves are respectively installed through spherical roller bearings In the through holes on the inner support plates of the first support and the second support; the tapered surfaces at both ends of the test piece pin shaft are respectively loaded into the two tapered sleeves; the test piece pin shaft is installed on The center of the fixture, the outer ring of the fixture is installed on the upper end of the tension pressure sensor, and the tension pressure sensor is installed on the top of the actuating rod of the actuator; the actuator is fixed on the upper surface of the base plate; the two displacement sensors are respectively installed on both long sides of the mounting plate and on either side of the clamp; A torque sensor is installed between the outer support plate and the inner support plate of the first support; one end of the torque sensor is connected to the test piece pin shaft located inside the first support inner support plate; the other end of the torque sensor is connected to the inner support plate. A reducer is fixedly connected; the reducer is fixedly connected with the servo motor; a torque sensor is also installed between the outer support plate and the inner support plate of the second support; one end of the torque sensor is connected to the rocker arm of the rocker arm The lower end of the rocker is fixedly connected; the other end of the torque sensor is fixedly connected with another reducer; the reducer is fixedly connected with the servo motor; the upper end of the rocker rocker is fixedly connected with one end of the rocker link; The other end of the rocker link is fixedly connected to the inner ring of the fixture; Among the two servo motors, one servo motor is located outside the outer support plate of the first support, and the other servo motor is located outside the outer support plate of the second support; The inner surface of one end of the tapered sleeve is an outwardly expanded cone section, which is matched with the tapered surface on the outer peripheral surface of the pin shaft of the test piece; the other end of the tapered sleeve is an equal-diameter section; the outer surface of the tapered sleeve There is a radially protruding positioning platform in the middle of the circumferential surface; The inner surface of the tapered sleeve is a tapered section, and the outer peripheral surface at one end is also a tapered surface, so as to facilitate the installation of spherical roller bearings; the middle part of the pin axis of the test piece is an equal diameter section, which is the test area; the outer diameter of the equal diameter section is the same as the inner diameter of the test piece shaft sleeve; The installation surface of the installation plate is provided with a plurality of installation through holes for the second support and the first support to meet the test requirements of test pieces of different sizes; the center of each installation through hole is symmetrical to the width direction of the installation surface. center line to meet the positioning of the second support and the first support. 2. the friction and wear testing machine of joint bearing and hinge as claimed in claim 1, it is characterized in that, described clamp comprises clamp outer ring, clamp inner ring, test piece axle sleeve, expansion joint sleeve and ball bearing, according to test The sleeve of the test piece, the expansion joint sleeve, the inner ring of the fixture, the ball bearing and the outer ring of the fixture are set together in sequence, and the sleeve of the test piece is located in the innermost ring, and the outer ring of the fixture is located in the outermost ring; when the After the test piece shaft sleeve, the expansion joint sleeve and the inner ring of the fixture are set together, the tight fit between the test piece shaft sleeve and the inner ring of the fixture is realized through the expansion joint sleeve. 3. The friction and wear testing machine for joint bearings and hinges as claimed in claim 2, wherein the inner diameter of the inner ring of the clamp is the same as the outer diameter of the expansion joint sleeve, and the two are tightly fitted; There is a mounting hole for the rocker arm on one end surface of the inner ring of the fixture; the inner diameter of the expansion joint sleeve is the same as the outer diameter of the test piece shaft sleeve, and the two are tightly fitted; the inner diameter of the outer ring of the fixture is in line with the ball The outer diameters of the bearings are the same; the outer circumferential surface of the outer ring of the fixture is processed into squares, and a pair of protrusions are symmetrically distributed on the outer surface of the outer ring of the fixture. The protrusions are the measurement reference blocks of the displacement sensor, and the displacement The measurement reference blocks of the sensors correspond to the positions of the two displacement sensors respectively. 4. The friction and wear testing machine for joint bearings and hinges as claimed in claim 1, wherein the first support is in the shape of a "U", and the vertical plates on both sides of the first support constitute the outer support plates respectively and the inner support plate, and make the inner support plate adjacent to the clamp during assembly; there is a through hole for the output shaft of the reducer on the outer support plate; there is a mounting hole around the through hole; There are mounting holes for spherical roller bearings on the inner support plate; the structure of the second support is the same as that of the first support. 5. the friction and wear testing machine of joint bearing and hinge as claimed in claim 1, is characterized in that, the two ends of described test piece pin shaft are threaded sections, are used to install compression nut; Between the segments is a tapered segment whose outer diameter gradually shrinks to both ends, and which is matched with the inner tapered surface of the tapered sleeve to ensure that the pin axis of the test piece and the tapered sleeve are coaxial. 6. the friction and wear testing machine of joint bearing and hinge as claimed in claim 1, is characterized in that, described rocking arm comprises rocking arm rocker and rocking arm connecting rod, and the end face of one end of rocking arm connecting rod and described The end face of the upper end of the rocker arm is fixedly connected, and the other end of the rocker link is fixed on an end face of the inner ring of the fixture; the upper end of the rocker arm is a rectangular slat, and the top of the slat is used for connecting the The through hole of the connecting rod; the lower end of the rocker arm is a semicircular block, which is used to balance the eccentric moment of inertia of the rocker arm, and eliminate the interference of the centrifugal force of the rocker arm during the rotation process on the load on the test piece; There is a connecting hole for connecting the torque sensor at the junction of the semicircular block and the lath. 7. The friction and wear testing machine for joint bearings and hinges according to claim 1, wherein the cross section of the mounting plate is in the shape of a "concave", and the bottom surface of the groove is the second support and the first support the installation surface.

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