Optimization on Key Friction Pair of Cam Mechanism Based on Load Spectrum

The load spectrum of a cam mechanism was measured via a bench test. Thereafter, the load distribution along the cam profile was obtained by dynamic analysis according to the load spectrum and the mechanism sizes. Aiming at the severe abrasion of the cam mechanism key friction pairs at the position near the maximum load, a specific sample experiment based on load distribution was conducted on a UMT tribo-test rig to explore the tribological behavior of the friction pair materials, and eventually, optimizing friction pair material. The results showed the tribological behaviors of these materials were related to their hardness and toughness. For those materials without great extent of toughness distinction, their abrasion resistance got stronger as their hardness increased. For the material with lower hardness and higher toughness, an adhesion layer on worn surface protected the base material from further abrasion and produced higher friction force. According to the experiment, it is predicted that an optimal combination of TC4 as the cam, 022Cr12Ni9Cu2NbTi as the roller, and 07Cr17Ni7Al as the roller shaft for slowing down the increment of the cam rotary shaft resistance torque. Finally, a verification test under the condition same with that of the real work was performed to validate the correctness of the prediction.