Grinding process of aramid fiber reinforced rubber (4th report) - Form grinding mechanism and frictional characteristics of V-ribbed belt

Aramid fiber reinforced rubber (AFRR) is one of advanced composite materials, which have some excellent characteristics transmission belt. V-ribbed belt is formed by grinding to generate not only the required shape but the suitable frictional characteristics on contacting rubber surface with a pulley. The frictional characteristics of AFRR V-ribbed belt is sensitively affected by projecting condition of aramid fiber whose coefficient of friction is much lower than that of matrix rubber. In this paper, form grinding mechanism of AFRR V-ribbed belt with diamond wheel is experimentally investigated by analyzing form accuracy of V-groove and projecting length of aramid fiber. Furthermore, an estimating method for the coefficient of friction of AFRR V-ribbed belt is proposed by clearing up effects of each factor on the coefficient of friction of V-ribbed belt. Main conclusions obtained in this paper are as follows: (1) Coefficient of friction of AFRR V-ribbed belt is decided by V-groove angle and projecting fiber length on the surface generated in form grinding, and it decreases with increases of V-groove angle or projecting fiber length. (2) Coefficient of friction of V-ribbed belt can be estimated by subtracting the decrease from coefficient of friction caused by projecting aramid fiber from the coefficient of friction decided by V-groove angle of matrix rubber belt without projecting fiber. (3) Both V-groove angle and projecting fiber length increase with an increase of curvature of V-ribbed belt in form grinding process.