Skip to main navigation Skip to main content
The University of Southampton
Engineering Our research

Reciprocating (TE77) Tribometer

The TE 77 High Frequency Friction Machine is a versatile reciprocating tribometer with a maximum stroke of 25 mm and maximum load of 1,000 N. It is now a well-established research and development tool for evaluation of lubricants, materials, coatings and surface treatments. With the TE 77, sliding contact conditions can be matched to a number of machine elements. Specimens may either be of a standard format, or cut from real components, preserving surface finish and other properties.

Return to main nCATS facility page

TE 77 High Frequency Friction Machine, manufactured by Phoenix Tribology Ltd. , is supplied with its own floor standing bench and with integral control unit incorporating a SUPERSLIM Serial Link Interface Module, which is connected to a host PC with COMPEND 2000 sequence control and data acquisition software installed. The system provides sequence control of load, frequency and temperature plus data acquisition of measured parameters, at both low and high speed.

The moving specimen is mounted in a carrier. A number of different geometries can be accommodated by using a range of simple clamping fixtures.  These include point contacts, with a 6 mm ball, line contact with 6 mm diameter cylinder and area contact with a self-aligning button. The specimen is oscillated mechanically against the fixed lower specimen. The mechanical drive comprises a motor driven cam and scotch yoke assembly, providing pure sinusoidal motion.  The lower specimen is clamped in either a bath, for lubricated tests, or dry mounting plate.

TE77 reciprocating tribometer
TE77 reciprocating tribometer

The stroke length is altered manually by adjusting splined eccentric cams on a splined eccentric shaft. Two fixed cams are provided as standard allowing strokes to be set from 0.4 to 12.5 mm and 12.5 mm to 25 mm

The moving specimen is loaded against the fixed specimen through a lever mechanism actuated by a geared servomotor with in-line spring. The normal force is transmitted directly onto the moving specimen by means of the needle roller cam follower on the carrier head and the running plate on a loading stirrup. A strain gauge transducer is mounted on the lever at a point directly beneath the contact and this measures the applied load.

The piezo electric transducer used to measure the friction force and the output range is set to match expected friction levels in the contact. The maximum friction level is +/- 500 N.  A charge amplifier converts the measured force to a proportional voltage. This is followed by a low pass filter, which fixes the upper cut off frequency of the measuring system. This serves to suppress transducer resonance. Final scaling of the signal for voltage output takes place in a second stage amplifier.

The moving specimen carrier is electrically isolated from the drive shaft and therefore from the fixed specimen. This allows a millivolt potential to be applied across the contact using a Lunn-Furey Electrical Contact Resistance Circuit. The voltage signal is taken to a true rms/dc converter amplifier to give a time-smoothed average of the contact potential.  Variations in this voltage are indicative of the level of metallic contact, provided that both test specimens are conductors of electricity. This measurement may be used for observing the formation of chemical films from anti-wear and extreme pressure lubricants, the breakdown of non-conducting layers and coatings or the build-up of oxides.  The instantaneous value of contact potential is also available for data logging as high speed data.

The TE 77 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).

The reciprocating tribometer (TE77) is the busiest tribometer in the facility and has been utilised in various student and research projects, as well as numerous consultancy projects.

Projects range from testing of material combinations and coating performance evaluations to tribocorrosion experiment utilising a 3D polymer bath and ceramic balls to minimise unwanted galvanic coupling.  The rig was even been used to successful generate the unwanted lubricous organic layer associated with 'leaves on the line' in railway tribology, this required the design and manufacturer of a new rolling head.

The adjustable radius piston ring clamp was utilised during the early stages of development of this head adaptor for studying scuffing in ring-liner contacts.

Projects include:

Contact Configurations:

  • Ball on Plate (Point Contact)
  • Cylinder on Plate (Line Contact)
  • Area Contact
  • Piston-Ring and Cylinder Liner

Tribometer Specifications:

Attribute Range/Value
Load Range: 5 to 1000 N
Force Range: – 500 to 500 N
Loading Rate: 50 N/s
Temperature Range: Ambient to 600°C
Heating Power: 800 W
Frequency Range*: 2 to 50 Hz
Stroke Range: 0.4 to 25 mm
Linearity: 0.50%
Maximum velocity 1 m/s (20 Hz at 25 mm stroke)

* - there is a 20:1 reduction gearbox that allows frequencies down to 0.1 Hz

Sensors:

Measurement Sensor
Temperature k-type thermocouple
Contact Potential 50 mV dc signal
Friction Transducer Piezo-Electric Type
Stroke Transducer Magneto Inductive


Data Acquisition and software:

Attribute Value
Low Speed Interface: Serial Link Interface Module
Resolution: 12 bit
Number of Input Channels: 1 to 8
Number of Output Channels: 1 to 4
Maximum Data Rate: 10 Hz
High Speed Interface: USB
Resolution: 16 bit
Number of Input Channels: 6
Maximum Data Rate: Six channels at 50 kHz
Software: COMPEND 2000

Measured and controlled parameters

Controlled Parameters
Frequency
Load
Temperature
Test Duration
Measured Parameters – Low speed data
Load
Friction (rms)
Friction Noise (time smoothed)
Contact Potential (time smoothed)
Temperature
Frequency
Number of Cycles
Friction Coefficient (derived)
Measured Parameters – High speed data
Friction (instantaneous)
Contact Potential (instantaneous)
Stroke Position (instantaneous)

Services

Service Value
Electricity: 220/240 V, single phase, 50/60 Hz, 3.2 kW
Installation: Floor-standing machine
Footprint: 900 mm x 900 mm x 600 mm high, 250 kg

Three adaptors have been acquired for the TE77 reciprocating tribometer:

This includes a 20:1 reduction gearbox , that bolts on the motor and enable reciprocating frequency from 0.1 Hz up to 2.5 Hz.  The gearbox allows smooth motion even at these lower frequencies due to the torque made available by its incorporation. Phoenix Tribology Ltd. part no. TE 77/GB/20

The second is cooling sample holder/plate , this replaces the standard plate with the four cartridge heaters.  The replacement is a hollow, channel plate that allows a coolant flow, using a laboratory chiller, temperature below zero can be easily achieve, but icing of components and samples can become an issue, unless dry atmosphere can be employed.  Phoenix Tribology Ltd. part no. TE 77/COOLER.

Lastly the Adjustable Radius Piston Ring Clamp -

The ring clamp allows the curvature to be adjusted to allow ring samples to conform with liner samples. The standard clamp can accommodate rings of diameter 90 to 110 mm. The clamp back plate is mounted on a bush, which is mounted in turn on the machines reciprocating shaft. The bush is free to rotate allowing axial alignment between the ring and liner sample. The clamp back plate incorporates two tensioning screws, which engage with the ends of the ring sample; tightening these tensions the ring against the lower side of the bush. The ring is clamped in place by a clamp plate (red). The gap between the two halves of the clamp is adjusted by set screws.

The reciprocating shaft has a hollow bore and connection for an oil feed. The bore communicates via oil-ways in the bush and clamp components to small jets either side of the ring sample. This allows lubricant to be added in small volumes to either side of the ring sample.

A larger clamp has been designed to accommodate rings up to 200 mm diameter. Use of this sized ring requires modification of the lubricant bath to reduce the side wall height.

Below are links to download technical drawings for the TE77 samples.

Note that these are generic drawings and are dependent on the type of testing intended and the material, thus should only be used as a guidance.

Note that the small area contact was designed by Dr. Timothy Kamps

Privacy Settings