The Journal Bearing Test allows to test materials and coatings for use in plain bearings on spacecrafts or for exploration (torque and life time).
Plain bearings are used for articulations or linear guidance systems dedicated to single shot or low life time requirement. These include for example solar array panel articulations, radiator panel articulations, HDRM fold back articulations, exploration rovers articulations and linear guidances, landing pointing system articulations. The plain bearing tribometer allows the measurements of friction and wear of a complete journal bearing for alternate rotations <180°C and small loads
Post-Analysis may cover measurement of wear by profilometry, SEM, investigation of surface structure or material transfer by SEM/EDX.
The device is fully PC-controlled. To the control parameters, e.g. sliding distance, motion profiles (uni, oscillating, ..), can be selected. On-line-data acquisition offers to post-process data, e.g. for automatic calculation of torque in running-in- or steady state, as well as endurance of solid lubricant coatings.
- Torque / Friction force / coefficient
- Environmental Data
Optional (e.g. residual gas, user defined)
Image of the Ultra High Vacuum Tribometer:
Internal View showing the Tribo-System with ball holder and disc
Test principle: Bush is radially loaded against shaft
Different options are available:
- Testing in controlled gas environment: eg simulating Martian atmosphere (6 mbar in CO2)
- Contamination monitoring: a mass spectrometer may by used ot detect on-line contamination (e.g. outgassing of fluid lubricants or their cracks).
|Test||online measurement of
· Torque / Friction force / coefficient
· Environmental Data
· residual gas analysis (mass spectrometer of outgassing particles)
|Temperature||from -100 up to + 300 °C, thermal cycles available
|Loads||10 <> 250 N|
|Speed / Motion||Motion selectable from unidirectional to reciprocating (angles from 5° to 360°)
0.00005 <> 0,262 m/s (0,1 to 500rpm)
|Environments||Vacuum selectable downto 10-6mbar
Air with controlled humidity
Gases with controllable pressure (e.g CO2 at 6mbar)
|Samples||Bush on shaft|
|Accuracy||Friction force ± 0.01 N
Sample temperature (pin and disc separately): ±2°C
Linear Wear: 0 <> 2mm, ± 0.002 micrometer
Further AAC-devices enabling component testing under vacuum:
SALOTTE1: gear testing
BBT: ball bearing testing