Research on Two-stroke Cycle Single Cylinder Vibrationless Reciprocating Engine Chain Saw Utilizing an Internal Gearing System : 1st Report, Analysis of This Engine and Numerical Computation

Abstract

Forestry workers who use the chain saw, daily in their works are susceptible to vascular disease disorders of the fingers and hands, due to exposure to the severe vibration. This paper presents the structure, design, dynamics of machinery and numerical computation of the equivalent moment of inertia and loads acting on each portion of a new vibrationless chain saw. The perfect balance for this chain saw engine utilizing internal gearing system are theoretically analysed. The dynamic analyses of moving parts in this chain saw engine are explained. The output torque consists of gas pressure torque, minues the friction loss torque and inertia torque resulting from unevenness of rotation. The equation for output torque is the same as that or a conventional chain saw. However, the equivalent moment of inertia acting on the crankshaft is constant, regardless of crack angle, and is about 10 percent larger than that for a convential chain saw. The values of the moment of inertia, load conditions on each portion and the tooth force are obtained by numerical computations.