Design and Stress Analysis of Screw Shaft for Peanut Oil Screw Press Expeller

The screw press oil expellers are reported to be more efficient than all other methods of oil extraction. The oil seeds fed through the hopper are crushed and transported by a rotating screw in a press barrel. Continuous transport of material by the screw shaft causes the pressure to increase to a level needed, which increases the friction inside the screw press and generates heat which lowers viscosity of the oil in the crushed seeds thereby increasing the oil flow rate. The oil and cake are usually collected at the oil outlet and press cake exit. Screw shaft is the main component of the oil extraction machine. Existing screw press oil expeller is the JY 200 machine with 220W motor power and 1500rpm. The von-Mises stress of existing screw design is 94.11 MPa and the modified screw design is 89.876 MPa for theoretical. In this research, the modified screw design is considered in order to improve the oil capacity, the efficiency and number of cycles to failure and then to reduce the von-Mises stress, deformation and fatigue stress of automatic oil press machine by changing the pitch of screw shaft for peanut oil screw press expeller. Peanut oil screw press expeller is easy to repair and easy to maintenance. This machine is very suitable for local production and operation.