Design and Development of a Clutch Test Adaptor for a Rotary Tribometer

The Technology Division within Volvo CE is responsible, among other things, for the design and specifications of components for the transmissions and axles that form the basis of the construction machinery including wheel-loaders and articulated haulers. Within the transmissions, the clutch systems and transmission fluids are extremely vital components and especially wet clutches have very high demands placed on them in comparison to similar equipment in trucks, busses and passenger cars. To assess the viability of wet clutches, there are a number of factors to be investigated such as torque transfer capacity, friction levels in conjunction with specific lubricants and limits for wear of the material after a given number of engagement cycles. However current tests are both time-consuming and require relatively large amounts of fluid and material. In this thesis, the aim was to design and manufacture a test-rig adapter in such a way so as to allow easy, quick and online measurements of friction values throughout a test run including break-away friction values if possible. The information from the tests is also useful when writing control algorithms for the clutch control software. The rig adapter was designed by considering the industrial application. The standard operating conditions such as pressure, outer to inner diameter ratio of the friction material, power and energy values that are commonly used in automotive industry are taken into account. The trial test results have shown that the frictional results obtained from the test rig are realistic although it is unstable. It was also observed that due to the torque limit of the test-rig, the maximum load that can be applied is 2 kN. In conclusion, a test assembly has been developed for quick and cost efficient tests of wet clutches and lubricants. Further testing and development is, however, required to optimise the performance of the test rig.Validerat; 20110429 (anonymous