Background:

The TE 88ONE is a single test station version of the TE 88 Multi-Station Friction and Wear Test Machine. It includes three test assemblies for performing tests in pin on disc, reciprocating pin on plate and block on ring test configurations. It is suited to the wear testing of materials under high contact pressures. In reciprocating mode the machine can perform tests in the ASTM F 732 geometry, in Pin on Disc mode according to ASTM G 99, DIN 50 324 and ISO/DIS 7148-2 and in Block on Ring Mode according to ASTM G 77 and ISO/DIS 7148-2.

The machine incorporates an integrated SLIM 2000 Serial Link Interface Module and COMPEND 2000 software running on a host PC.

Reciprocating Test Assembly:

The flat plate specimen is mounted in a reservoir to retain lubricating fluid with a lid to avoid spillage and reduce evaporation during long term tests. It is fitted with electrical heating (for temperatures up to 400°C) and a thermocouple that is pushed into contact with the plate.

The reservoir is mounted on a plate, which is located by ball bushings on a linear bearing assembly. The plate is reciprocated by the variable throw crank, driven by the variable speed gear motor.

Pin on Disc Test Assembly:

The disc specimen is mounted on a holder on the vertical output shaft of a spiral bevel gearbox. The input shaft is driven by the variable speed geared motor.

A heated non-rotating fluid enclosure is provided, which permits tests to be performed in fluid environments with a temperature limit of 200°C. The enclosure is a simple push-fit (sealed with an O ring) over the bearing support block. A lid is provided to minimise fluid splashing. A thermocouple is fitted to the lower part of the enclosure to monitor and control the temperature.

The optional TE 88ONE/TW Thrust Washer Test Adapters may also be fitted interchangeably in place of the pin/disc specimens.

Block on Ring Test Assembly:

The ring specimen is mounted on the horizontal output shaft of a spiral bevel gearbox. The input shafts is driven by the base unit variable speed motor for continuous sliding tests and to the variable throw crank for oscillating tests.

Load Station and Friction Measurement:

The test pin or block is fixed in a retainer attached to the loading beam. Pins may have spherical tips, balls or be flat-ended and the beam MUST be levelled to ensure a flat contact is produced at the start of the test. The block may be conforming or non-conforming to the ring diameter.

The loading beam is pivoted at one end and a spring balance is used to apply a load at the other end. There is a four to one ratio between balance load and the load seen by the specimen. In traditional dead-weight loaded beam systems there can be considerable inertial loading caused by weight bounce and this has profound effects on friction levels and wear rates in the contact. The spring balance system presents a constant inertial stiffness over the whole load range and thereby reduces the inertia effects on test data.

The load beam pivot is also trunnion mounted and restrained from movement, when in the horizontal position, by pads mounted on the load application bracket. A strain gauge force transducer mounts on the load beam and fits snugly between these pads when the arm is horizontal. The transducer therefore will sense the friction forces in the contact in both directions.

The transducer output connects to a strain gauge amplifier module and the output from this may be connected direct to the interface for uni-directional friction measurements (pin on disc and block on ring tests). The output signal from the strain gauge amplifier module may also be passed through a true rms/dc converter and then connected to the interface to give averaged friction readings in reciprocating pin on plate and oscillating block on ring modes.

TE 88ONE/PHOT Heating and Temperature Sensing Package:

An optional higher temperature air heating system TE 88/PHOT is available for use with the pin on disc test assembly only. The heated fluid enclosure is replaced by a simple stainless steel enclosure with an inlet and outlet “port”. Hot air from a electrically heated blower unit is then directed into the inlet port and a chimney directs the “exhaust” upwards from the outlet port.

The temperature of the disc specimen is measured using an optical pyrometer. The pyrometer is a non-contacting device with a focal distance of 76 mm (distance between the lens and the disc edge) with a k-type thermocouple output. The pyrometer is used to monitor and control the temperature in the enclosure. A lid is provided to minimise heat. The pyrometer is powered by 12 V a.c. and the thermocouple output plugs in to the thermocouple signal conditioning module.

TE 88ONE/WEAR:

An optional wear transducer can be fitted. This consists of a LVDT mounted in an adapter so that it contacts the underside of the load beam. As the pin or block wears, the load beam gradually pivots downwards about a horizontal axis, and the vertical movement is detected by the transducer. Wear of up to 1.5 mm at the contact can be measured.

The LVDT is self-powered and plugs directly into the interface. Up to two transducers can be accommodated.

Control and Data Acquisition:

The TE 88ONE has PC based sequence control and data acquisition features. This is provided by an integrated SLIM 2000 Serial Link Interface Module and COMPEND 2000 software running on a host PC.

The COMPEND 2000 software is Windows based and Windows 95, 98, NT and Y2K compatible. The software employs Windows “look and feel” features for easy user access to all machine and test set-up parameters. On-screen tool tips are provided.

Data may be stored to hard disc and the software includes an auto-scaling trend display for monitoring test progress. At the end of a test this graph may be dumped to a Windows printer and the stored data may be manipulated for calculation or graphical presentation in standard spreadsheet software programs.

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 during the operation of the test sequence.