A circular disc shape case 11 includes a motor rotor chamber 12, a bearing chamber 13 and a gear chamber 14 piled sequentially and being communicated with each other. A suction port 15 is connected to the motor rotor chamber 12, and a discharge port 16 is connected to the gear chamber 14, which communicate with outside respectively. A rotating shaft 18 having an end positioned in the motor rotor chamber 13 and the other end extending to the gear chamber 14. A rotor 22 is fixed around the rotation shaft 18 in the motor rotor chamber 13. A first bearing 19 is provided for supporting the end of the rotating shaft 18 in radial and thrust directions. A second bearing 20 is provided in the bearing chamber 13 for supporting an intermediate portion of the rotating shaft 18 in radial direction. A trochoid gear 25 is provided in the gear chamber 14, having an outer rotor 26 and an inner rotor 27, which functions as a pump, taking in a fluid through the suction port pipe 15, and discharging the fluid from the discharge port 16.