ROTATIONAL RESPONSE AND SLIP PREDICTION OF SERPENTINE BELT DRIVE SYSTEMS

A nonlinear model is developed which describes the rotational response of automotive serpentine belt drive systems. Serpentine drives utiliz e a single (long) belt to drive all engine accessories from the cranks haft. An equilibrium analysis leads to a closed-form procedure for det ermining steady-state tensions in each belt span. The equations of mot ion are linearized about the equilibrium state and rotational mode vib ration characteristics are determined from the eigen value problem gov erning free response. Numerical solutions of the nonlinear equations o f motion indicate that, under certain engine operating conditions, the dynamic tension fluctuations may be sufficient to cause the belt to s lip on particular accessory pulleys. Experimental measurements of dyna mic response are in good agreement with theoretical results and confir m theoretical predictions of system vibration, tension fluctuations, a nd slip.