Wet clutch performance and durability: test bench design

Abstract: Volvo CE manufactures heavy duty machinery. In almost all of the applications
a gearbox with a wet clutch can be found. To further increase the
effectiveness of the clutches new research is necessary.
A lot of research has been done concerning different types of friction
materials, oil and temperature. But research concerning how the pressure is
applied to the clutch and how much power the clutch transfer has not been
investigated.

This thesis work aims to build test equipment that is able to control the
pressure applied to the clutch. The test equipment should be able to measure
load, pressure, temperature and wear of a clutch. Also the equipment should
be designed with several of Volvo CE original components from the gearboxes.
The rig was designed and built with the help of a designer at Volvo,
engineers at Lulea University of Technology and the in house machine shop
Centralverkstan. The design aimed to use the standard Volvo parts, have easy
access to sensors and easy assembly/disassembly of the clutch.

The test rig is operational and produces data that is comparable to the real
applications. The performance of the rig is well within the requirements of
specification. Approximately three engagements can be done in one minute. The
acceleration of the rig can be done in less than 10 s and the engagement time
is as low as 350 ms. With a hydraulic pressure of 2,4 MPa a torque of
approximately 1080 Nm is generated with the specific running conditions of
the rig.