Abstract: A hydraulic control device for an automatic transmission, the hydraulic control device includes: a throttle valve, a primary regulator valve and a failure circuit that includes a first solenoid valve that is switched when the throttle valve is subjected to a failure in which the throttle valve is unable to output the throttle pressure, and that leads a predetermined hydraulic pressure based on switching of the first solenoid valve to the control oil chamber of the primary regulator valve.

Abstract: A hydraulic control device for an automatic transmission, the hydraulic control device includes: a throttle valve, a primary regulator valve and a failure circuit that includes a first solenoid valve that is switched when the throttle valve is subjected to a failure in which the throttle valve is unable to output the throttle pressure, and that leads a predetermined hydraulic pressure based on switching of the first solenoid valve to the control oil chamber of the primary regulator valve.

Abstract: Hydraulic passages for an oil pump for a speed reducer used in electric vehicle include a first passage for connecting an inlet port of an oil pump to an oil reservoir through a first check valve, a second passage for connecting an outlet port of the oil pump to a discharged-oil demand part through a second check valve, a third passage for connecting the outlet port to the oil reservoir through a third check valve, and a fourth passage for connecting the inlet port to the discharged-oil demand part through a fourth check valve. The check valves are disposed such that, upon normal rotation of the oil pump, the first and second check valves are opened, and upon reverse rotation thereof, the third and fourth check valves are opened.