Motion of the Vane in a Variable Displacement Vane Pump

2nd Report : Prevention of Vane Detachment by an Additional Chamber

Abstract

This paper demonstrates a new method to prevent vane detachment resulting from excess pre-compression in the pumping chamber entrapment. Regarding the prevention method, an additional chamber was connected to the entrapment region via a restrictor.
It was clarified by simulation analyses that the restrictor effect does not contribute to the prevention of the vane detachment. Therefore, computer calculations and experimental measurements were carried out under conditions that the restrictor effect on the pumping chamber pressure can be ignored. Theoretical and experimental results on these chamber pressures and vane tip locus were almost in complete agreement.
Consequently, it was clear that an increase in the additional chamber volume was effective in reducing vane detachment even though pressure ripples and noise occur in the case of large chambers. Furthermore, a design criterion of the volume-restrictor was established by introducing the dimensionless parameter which depends on pump operating conditions.