To shorten an oil passage and reduce cost by rationally arranging check valves for preventing cavitation, at a vane pump in a hydraulic coupling device of a power transmission for a four-wheel drive vehicle.
Intake ports 43L, 43R, discharge ports 44L, 44R and the check valves 53L, 53R for preventing cavitation are collectively provided at both side faces of a side plate 32 at the center held by left and right cam rings 31L, 31R, to shorten an oil passage for connecting them and to reduce a machining cost Since check valves are eliminated from left and right side plates 30L, 30R, the side plates 30L, 30R can be disused. In this case, the axial outer side faces of left and right rotors 35L, 35R are directly supported to the inner surfaces of left and right casings 21, 22.
MIYATA KAZUNORI
KUROKAWA TAKUYA
MOCHIZUKI TAKESHI
Next Patent: TRAVEL ROUTE ESTIMATING DEVICE, PRECEDING VEHICLE RECOGNIZING DEVICE AND RECORDING MEDIUM