| This paper constructs lubrication test equipment transporting granular flow to the tribo-pairs of a ring-block. The device enables particles and air flow to mix uniformly; the sealed enclosures can be effective in preventing particulate matter from polluting environment; meanwhile, the concentration of particles, injected into tribo-pairs, can be adjusted by changing the pressure of injecting, fluidizing and stirring. Through conducting friction and wear on Timken testing machine, the device can provide a stable and continuous particles flow. Under the lubrication of graphite particles, graphite particles, transported to the tribo-pairs of a ring-block, can convert the friction of surfaces between ring and block to the friction between graphite particles, and play a good role on lubrication, and not sensitive to temperature.Due to the complexity of granular flow, theoretical study face great difficulties. In this paper, explicit finite element method is used to analyze the shear behavior of particles flow in wedge shear cell. Under the same conditions of speed, the stress, friction and model energy of steel particles flow are greater than the ones of graphite particles. With the friction coefficient improving, the friction of upper and lower boundary of the model increases gradually. In the same contact attributes, the friction of lower boundary is greater than the one of upper boundary. The steel particles will receive a larger plastic deformation when they bear extrusion and friction from submits of lower boundary. The upper boundary will bear great uplift force when steel particles flow passing through the wedge tribo-pairs. The internal energy and friction dissipation energy of the model increase with friction coefficient increasing. |
