Abstract: To take account of the practical difficulties for an automotive hydraulic power steering greater with the high speed. Based on the study of the patent, this paper discusses the configuration and the action principle of a new variable displ- acement of double-action vane pump, which consists of a floating block. The pump belongs to an automotive hydraulic power steering system. In addition the mathematic model is presented and the simulation of flux with the pump is perf- ormed. The results show that the pump with the floating block can provide greater flow characteristic ability and prosperous utilization is expected.

Key words: Flow characteristic, Double-action vane pump, Floating block, Steering system, equal radius arc longitudinal modification, errors of alignment, profile modification, tooth contact analysis (TCA), face gear