Dynamic Behavior of Twin-Piece Vane Machine

This paper describes a twin-piece vane machine which has freely movable double vanes assembled in each slot machined in the rotor providing double seal lines between the vane tips and the inner surface of the cylinder. Analysis of the motion, forces, friction, wear and stresses in the vanes with a dynamic model demonstrates that the twin-piece vane machine has decreased the binding forces, friction losses and wear on the vane tip, but increased vane stresses. The results also indicate that most of the friction loss occurs at the vane tip with additional friction loss on the vane sides. The viscous loss caused by the oil film between the double vanes is so small that it can be neglected in engineering calculations. The ratio of the upper vane thickness to the lower vane thickness is one of the most important parameters for the twin-piece vane machine. Analysis of the influence of this ratio on the forces, friction, wear and strength of the vanes was used to optimize the thickness ratio for the twin-piece vane machine.