A new tribometer for friction drives

Friction drives have great potentials in future small-sized machines for their unique features, such as no-noise operation and high position accuracy coupled with simpler design. One of the main challenges of a friction drive is to find suitable material pair for the driver and follower components such that there is no slip and/or wear at the frictional contact regions. In this paper, we present a new tribometer that can be used to study the performance of a material for friction drive applications. The design and fabrication of the apparatus are presented with initial test results conducted to investigate the power efficiency and wear performances of several polymer and metal samples. Our results show that for a fixed power transmission torque, there exists a critical pre-load between the drive components at which the wear and slip are maximum and the value of critical pre-load is independent of the material. Both wear and slip can be minimized to near-zero if an optimum pre-load, which is higher than the critical pre-load, is applied between the two components.