Lubricants
What is it?
The clutch rig is a Croda in-house test rig used to evaluate friction and friction durability of lubricants, in applications that require a lubricated clutch, such as, dual clutch transmissions, continuously variable transmissions and certain types of motorcycle. The rig is designed in such a way that the test oil can be aged in-situ whilst its friction characteristics are continuously monitored.
Why do we use it?
This machine allows screening of additives such as friction modifiers and base oils to evaluate their performance in a given formulation. The clutch material can be tailored to the application to ensure a higher degree of accuracy. The machine also has the ability to ramp speed up and down which can give an indication of SAE#2 or GKN performance, and is therefore an effective pre-screening tool.
How does it work?
A steel disc coated in clutch material is screwed in place inside a small pot. The disc is then submerged in lubricant. A steel top disc is mounted in a chuck, and rotated against the submerged clutch disc whilst ramping up speed to simulate clutch engagement.
Typical Test Conditions
- Speed : 0 - 0.5 m/s
- Temperature : Ambient to 200°C
- Load : Typical ~ 1.8 N/mm2
- Standard Specimens : AISI 52100 steel disc | 6100 disc
- Test Profile 1 : Static and Dynamic friction
- Test Profile 2 : Fluid lifetime
Clutch Rig showing a steel top disc & load sensor:
Using Croda friction modifiers and esters, clutch friction can be controlled and fluid lifetimes (drain intervals) can be increased.