Yuken Kogyo Kabushiki Kaisha

Tsuyoshi Kitamira

Toshio Hashimoto

Kenichi Hirano

A hydraulic pump with a built-in electric motor wherein an electric motor and a pump unit are arranged in tandem fashion and accommodated within a common housing. In this pump, the housing is in the form of a metal box having a rectangular parallelepiped external shape and forms an electric motor frame fixedly accommodating a stator of the electric motor therein. A space in the metal box on the electric motor side is separated as a dry space from an internal space of said pump unit by a seal mechanism. At least one hydraulic oil receiving chamber is formed in a peripheral wall of the metal box, and the hydraulic oil receiving chamber is communicated with a passage for receiving return oil externally and another passage communicating with a suction port of the pump unit. The pump is capable of simultaneously achieving the cooling of a built-in electric motor and the prevention of contamination of hydraulic oil due to the rotation of the electric motor, without any possibility of electrical troubles with the built-in electric motor even if a water-containing hydraulic oil or aqueous hydraulic oil is fed and discharged.

Growing community of inventors

Kanagawa, Japan

Tsuyoshi Kitamira