POWER STEERING APPARATUS

摘要

An apparatus for use in turning steerable vehicle wheels includes a power steering motor assembly connected with the steerable vehicle wheels. A first pump connected with the power steering motor assembly is continuously driven by an engine of the vehicle to supply fluid under pressure to the power steering motor assembly. A second pump connected with the power steering motor assembly is continuously driven by an engine of the vehicle. A valve connected with the power steering motor assembly and the second pump directs fluid flow from the second pump to at least one of the power steering motor assembly and reservoir during operation of both the first pump and the second pump. A pumping mechanism includes a first pumping area defining the first pump and a second pumping area defining the second pump. The first pumping area is smaller than the second pumping area.