TORSIONAL INSTABILITIES IN A SYSTEM INCORPORATING A HOOKES JOINT

Dynamic stability analysis of a driveline which incorporates a Hooke's joint is presented in this paper. In particular torsional instabiliti es due to fluctuating angular velocity ratio across the joint are exam ined. The method of averaging is used to establish the critical speed ranges by considering the linearized equations which govern the torsio nal motion of the system. Within these ranges, parametric instability characterized by exponential build up of response amplitudes of the to rsional modes occur. Closed from conditions for onset of sub-harmonic as well as sum-type combination resonance have been established. The s ignificance of the sum-type combination resonance in a typical diesel hydraulic locomotive driveline has been demonstrated. Difference-type combination resonance has been shown to be absent. The instability con ditions indicate the range of driveshaft speeds to be avoided during t he design of a driveline which employs a Hooke's joint.