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The TE 79 Multi-Axis Tribometer is for friction and wear testing of materials under low loads in pin or ball on disc or reciprocating plate configurations. In pin on disc mode the machine can perform tests according to ASTM G 99 and DIN 50 324 and provides a Class 1 contact configuration (pin or ball loaded vertically downwards onto a horizontally rotating disc). The Tribometer is modular, with three possible configurations, each used in conjunction with the TE 79 Base Unit.
This comprises the loading and friction force measurement system mounted on a base plate, control hardware with PLINT SLIM 2000 serial interface unit and control software. The machine is bench-top mounted and includes a transparent enclosure and ambient humidity and temperature sensor. The enclosure is also used as a safety cover for the machine and incorporates a magnetic proximity switch. The machine will not run if the enclosure is removed.
The fixed pin or ball sample is carried on a trunnion and gimble mounted loading beam. This is counterbalanced both to give a neutral balance and to bring the centre of gravity onto the contact plane. Load is applied by dead weights in a range from 0.1 N to 20 N.
The loading beam is restrained by a strain gauge force transducer in a sliding link. This link ensures that only the tangential component of force in the contact (the friction force) is measured even with the large deflections associated with elastomeric test pieces. As the lower specimen surface moves the friction force on the ball or pin sample is measured.
The load beam lift/lower is servo controlled so that the load can be applied at a specific point in the test. The program can also introduce a dwell between load application and movement. This dwell period is an important parameter in determining the start-up friction in elastomeric contacts.
This Module comprises a rotating disc assembly complete with main drive motor and secondary indexing servomotor to provide the indexing, and hence spiral track, functionality. The module locates on the base plate of the TE 79 Base Unit and is fixed in place with locating screws.
The disc specimen is mounted in a reservoir to retain lubricating fluid. The reservoir is mounted on a vertical drive shaft assembly. This is mounted on a traversing slide, which permits the radius to be changed during a test. The control software may be set to run with a constant rpm or constant velocity during a traverse.
The Module locates on the base plate of the TE 79 Base Unit and is fixed in place with locating screws. It provides X/Y axis movement with linear positional feedback. Tangential (friction) force measurement is in the X direction. The axes are formed by cross-axis linear slides with 1 mm pitch lead screws and are driven by geared d.c. motors. The X-AXIS drive has interchangeable belt reductions to give an overall speed turn-down ratio of 1000:1. The Y-AXIS is direct coupled to a small servomotor giving a maximum index speed of 10 mm/min.
By combining the X-AXIS movement with the Y-AXIS indexing function a number of motion types can be configured. These are defined as follows:
INDEX = 0 The outward and return strokes are at the same Y position. This provides simple reciprocation along one track.
INDEX > 0 The Y AXIS is indexed between each stroke, thus each outward and return stroke is separated on the surface. The wear track resembles a square wave.
LOOP In this case a closed loop is defined giving a rectangular specimen path.
In this way a test may be performed both on continuously fresh surface or on the same track approached from either direction. This latter feature is important for elastomers and other materials that show direction dependence of wear.
Since both samples are simple and the fixing arrangements are flexible a variety of shapes and counter-surface materials may be accommodated. The plate sample size is typically 25 mm square. The fixture for the lower (moving) specimen includes an electrical resistance heater and two thermocouples for temperature measurement and control above ambient conditions.
The TE 79 Base Unit is provided with a plastic safety cover, which also acts as a chamber for the user to run under controlled humidity conditions. An ambient temperature and humidity sensor is mounted on the machine base inside the chamber.
This test assembly replaces the standard fixed specimen heater block on the TE 79/R Indexing Reciprocating Module with a Peltier cooler pad. With water-cooling of the hot side of the Peltier devices temperatures from -15°C to ambient may be achieved. Used in conjunction with the RE 79/R/C Laboratory Chiller unit with water/glycol mixture as the coolant, temperatures from -35°C to ambient may be achieved. To avoid ice formation, this adapter is best used in conjunction with a simple desiccant dehumidifier system used in conjunction with a controlled air supply.
The TE 79 has PC based sequence programmable control and data acquisition. This is provided by an integrated Serial Link Interface Module and COMPEND 2000 software running on a host PC, operating under Windows. Data is stored to hard disc in standard spread sheet compatible file formats (.csv or .tsv).
Tests are defined by a sequence of steps, each step containing set-point, data recording rates and alarm level information. Set-points may be adjusted by step change or ramp. The test sequence is followed unless interrupted by the operator or an alarm. Set-points may also be adjusted manually using on screen toggles.
| Normal Load: | 0.1 to 50 N |
| Friction Force Range: | 0 to 50 N |
| Humidity Sensor: | 10 to 90% RH |
| Interface: | SLIM 2000 Serial Link Interface Module |
| Software | COMPEND 2000 Windows based control and data acquisition software |
| X Position (TE 79/R) | |
| RPM (TE 79/P) | |
| X Axis Speed (TE 79/R) | |
| Y Position (TE 79/P and TE 79/R) | |
| Y Axis Speed (TE 79/P and TE 79/R) | |
| Temperature (TE 79/R) | |
| Dwell Period | |
| Test Duration |
| X Position (TE 79/R) | |
| Y Position (TE 79/P and TE 79/R) | |
| Humidity | |
| Ambient Temperature | |
| Temperature (TE 79/R) | |
| Friction | |
| Friction Coefficient |
| Contact Configurations: | Ball on Disc |
| Pin on Disc | |
| Disc Diameter: | 100 mm |
| Track Radius: | 0 to 40 mm |
| Y Traverse Speed: | 10 mm/min |
| Rotation Speed: | 30 to 400 rpm |
| Sliding Speed: | up to 1.6 m/s |
| Motor: | 150 W dc |
| Contact Configurations: | Ball on Plate |
| Plate on Plate | |
| Plate on Hemisphere | |
| X Axis Speed Ranges: | 0.9 mm/s to 10 mm/s |
| 0.05 to 0.9 mm/s | |
| 0.01 to 0.09 mm/s | |
| X Stroke: | 1 to 50 mm |
| Y Index Speed: | 20 mm/min |
| Y Index: | +/- 9 mm in steps of 0.5 mm |
| Temperature Range: | ambient to 100°C |
| Dwell (time delay): | User selected in seconds up to 8 hours |
| Temperature Sensor: | J-type thermocouple |
| Heating Power: | 150 W |
| Motor: | 125 W dc |
| Minimum Temperature: | -15°C (ambient water cooled) |
| Minimum Temperature: | -35°C (chiller water/glycol cooled) |
| Working Fluid: | 50:50 Water/Glycol |
| Minimum Fluid Temperature: | -30°C |
| Electricity: | 220/240 V, single phase, 50 Hz, 720 W |
| 110/120 V, single phase, 60 Hz, 720 W | |
| PC and Printer: | Minimum Specification |
| Bench-mounting machine: | 570 mm x 600 mm x 600 mm high, 40 kg |
| Bench-mounting controller: | 530 mm x 530 mm x 240 mm high, 20 kg |
| Packing Specifications: | 0.59 m3, GW 120 kg, NW 70 kg |
Copyright © 2002 Phoenix Tribology Ltd.