X-DM Variable Pressure & Speed Friction Testing Machine



1. General Introduction

X-DM Variable Pressure & Speed Friction Testing Machine perform the following five specifications: GB5763-2008 auto braking slice; GB/T5764-2011 auto clutch slice; GB/T 11834-2011 asbestos friction slice for industrial machine; QC/T 227.1-2009 Motorcycle & light motorcycle brake friction testing; SY/T 5023-2012Petrol-drilling machine braking block testing. Besides, it can conduct the integration experiments in which different positive pressure, different speeds, and complex temperatures and can test the internal nature of the friction materials comprehensively.


2. Composition

X-DM Variable Pressure & Speed Friction Testing Machine consists of the four parts: main unit, electrical controlling equipment, positive pressure loading system, computer control system.


3. The Working Principle

         This machine is driven by the rotation of the friction disc on the main shaft with a belt connected with the standing motor (clock-wise). The motor rotation speed is controlled by vector frequency convert, positive pressure is directly loaded by cylinder from preset pressure to sample slice, friction torque is measured by stretch transmitter, which is fixed between the door frame and force measuring pole, the surface temperature of the friction disc is transmitted by thermocouple, the turns are measured by the proximity switch installed on the side of main shaft, and then data can be acquired by computer. The acquired data can be shown on the screen as curve after proper process. At the end of experiment, the data can be stored in hard disk or printed with wanted color if necessary.

3.1 Friction coefficient:

f---friction (the average value of the stable friction of the total rear friction distance), N.

N—positive pressure (vertical force on the sample slice: sample pressure Mpa*sample area mm²)

Friction varies with temperature and the condition of friction surface during the experiment, the temperature is unstable among 0 and 2500 turns, thus, friction coefficient is calculated with the half rear average friction, that is, from 2500 to 5000 turns. Meanwhile the total average friction and wearing rate are calculated among 0 and 5000 turns.

3.2 Wearing Ratio:

R--- The distance between the sample center and the rotating shaft center (0.15m);

n--- The total turns of friction disc in testing (5000 turns);

A--- The total area of wearing sample surface, cm² (2*2.5*2.5);

D1--- The average sample thickness before testing, cm; (measured by micrometer)

D2--- The average sample thickness after testing, cm; (measured by micrometer)

fm--- The total average friction force during testing, N.

3.3 The implement of pressure control:

       The testing machine’s positive pressure loading is done through the air of preset pressure in cylinder in the vertical direction on the friction surface. The pressure in cylinder is different, so is the corresponding positive pressure. The store tank pressure keeps certain pressure and loads to the cylinder according to the preset value, and, the cylinder load the pressure to the sample surface through the loading shaft. The store tank pressure value signals to computer through the pressure sensor, according to the preset value, the computer controls the air valve to adjust the pressure in the store tank continuously to keep a constant pressure, in this way; it keeps the accuracy of the positive pressure.

3.4 The implement of speed control:

       The testing unit adopts Japanese FUJI 5000 series 15G1S vector frequency converter to carry out the speed control. The power is supplied by alternating current motor, which revolving speed 1460rpm under 50Hz and 15kw-power. The operator preset the revolving value and the computer controls the motor speed by vector frequency converter.


4.  The testing mode and function:

4.1 Different temperature testing (100℃~400℃) under the same pressure and same speed;

4.2 Different speed testing (tangent speed 5.0~31.4 m/s) under the same temperature and same pressure;

4.3 Different positive pressure testing (0.5MPa~2.0MPa) under the same temperature and same speed;

4.4 Different temperature testing (compulsory wearing testing) under the same pressure and same speed;

4.5 Simulated braking testing under the same speed and same pressure;


5. Technical parameters:

5.1 Total power: 20KW;

5.2 Power type: 3 phases 4 lines / AC380V

5.3 Testing maximum friction: 2000N;

5.4 Positive pressure: 0.5Mpa~2.0Mpa;

5.5 Friction disc rotation speed: 300~2000r/min;

5.6 Testing highest temperature: 400℃;

5.7 The distance between the sample center and the revolving shaft center (0.15m);

5.8 The material of the friction disc is gray cast iron HT250 with the specification as GB/T9493, hardness is H195 (Brinell hardness is 180~220HB), friction disc crystal structure is pearlite; its surface is processed through moderate granularity sandpaper P240. (Special demands can be made according to customer’s parameter)


6. Testing accuracy:

6.1 Repeated error: ≤1%;

6.2 Speed control error: ±10r/min;

6.3 Friction disc temperature testing error: ±1℃, control error: ±5℃;

6.4 Friction testing accuracy: ±1N, testing error: ±5N;

6.5 Positive pressure accuracy: ±2N, control error: ±10N;


7. Software introduction:

The computer’s operating system uses the Microsoft Win7 operating system, the application software uses the visual programming software, with the function of both Chinese & English shifting, with the beautiful, instructive operating human-machine interface. Each testing data can be stored or printed, when printing, the same testing data can be printed in either Chinese or English, and, the printed data can be conveyed to printer or saved as the PDF format document. The storing data format is: ACCESS database, txt text, PDF Acrobat Reader document. Each testing data can be saved automatically in the hard disk according to the date and testing serial number, the customer can read out any of the testing data for inquiry and print so as to make statistical and analyzing data.

         The data acquired uses Ethernet communication port, it transmits data with control system, the computer uses Legend type, and the computer controls automatically the temperature, pressure and speed according to the sample data.


8. Table of the vulnerable parts:








Metal Friction Disk





Electric Heating Tube

1.5 KW×3




Thermo Couple


E class



Revolving Belt

V Belt 2000




The Bearing of Main Revolving Axis





Proximity Switch





Force Transmitter





Electromagnetic Valve