Patent ID: 7281372

Claim:
A hydraulic controller for a hydraulic drive unit, comprising: a housing that includes an electric motor housing configured to house an electric motor, a hydraulic pump housing configured to house a hydraulic pump, and a valve housing configured to house valves; the hydraulic pump; an operate check valve operable to control the flow of hydraulic oil in normal and reverse directions between the hydraulic pump and a hydraulic drive unit actuator; and a switching valve operable to control the flow of hydraulic oil in normal and reverse directions between the hydraulic pump and an oil tank; wherein an oil tank cover attachment portion that is configured for detachably installing an oil tank cover body is formed at a location on the housing that is opposite an electric motor arrangement surface portion that is configured to receive the electric motor; and wherein in the housing, the operate check valve, the hydraulic pump, and the switching valve are provided in that order from the side of the electric motor arrangement surface portion to the side of the oil tank cover body attachment portion.