Automotive Tribology

We are interested in:
 

• the effect of different lubricants on the frictional contact between the cam and tappet;
• the use of new materials (especially hard coatings such as diamond-like-carbon (DLC)) for reducing friction and wear.

 In order to study cam tappet friction, an innovative engine testing rig is being developed.  The rig will be used to study friction in engines, which is one of the main sources of inefficiency and energy loss. Frictional losses occur in all automotive engines, primarily in the piston system, the valve-train and the engine bearings. The focus of the research work on the rig will be on valve train friction.

The facility is being developed as part of an on-going collaboration with Jaguar Engineering Centre at Whitley Road, Coventry. The rig uses a Jaguar 4.2L V8 engine cylinder head and can be driven at a range of speeds up to 1000rpm. It tests in the range of slow or idle speeds where engines suffer most friction and wear on start-up.  Lubricants can be circulated cold or can be heated up to 150°C.

The valve-train in an engine is responsible for approximately 10% of the engine’s frictional losses at high engine speeds but is far more significant at low engine speeds This is an important area for controlling and reducing frictional losses.

The rig allows the frictional torque between a cam and tappet to be measured. It will allow engineers to investigate new materials, contact geometries or oil formulations, and is a versatile tool for looking at ways in which friction in the engine can be controlled.

The rig is shown below:
 
 

The cam-tappet testing rig	Typical output from the cam-tappet testing rig

 

Anyone interested in further details of the research in progress should contact me at:
 

Department of Engineering
University of Leicester
University Road
Leicester
LE1 7RH

Telephone: 0116 252 5692
Fax: 0116 252 2525
 
 

E mail: svh2@le.ac.uk
 
 

Author: Sarah Hainsworth, last updated 23/3/2004.