Abstract: A small size gear pump having a disc-shaped case, inside which a flat cylindrical motor rotor chamber, a bearing chamber and a flat cylindrical gear chamber are arranged eccentrically from the bearing chamber and the rotor chamber, which are piled sequentially along an axial direction and are communicating to each other.

Abstract: 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.

Abstract: A pump apparatus of simple construction has a bearing structure for which a lubricant is unnecessary. A flow passage for a refrigerant (liquid ammonia) is formed in a housing to provide communication between a suction port and a discharge port, and slide bearing members formed of amorphous carbon are provided in the housing to be fitted into the flow passage to support a rotating shaft. A drive for rotating the rotating shaft is constituted by a rotor, which is fitted into the flow passage and provided with the rotating shaft, and a stator, which is provided outside the housing to surround the rotor, and a pump body is provided midway the flow passage and connected to the rotating shaft to pump a fluid.

Abstract: It is an object of the invention to provide a pump apparatus of simple construction with a bearing structure, for which a lubricant is unnecessary. A flow passage for a refrigerant (liquid ammonia) is formed in a housing to provide communication between a suction port and a discharge port, and slide bearing members formed of amorphous carbon are provided in the housing to be fitted into the flow passage to support a rotating shaft. Drive means for rotating the rotating shaft is constituted by a rotor, which is fitted into the flow passage and provided with the rotating shaft, and a stator, which is provided outside the housing to surround the rotor, and a pump body is provided midway the flow passage and connected to the rotating shaft to pump a fluid.

Abstract: A magnetic head apparatus has a piezoelectric element comprising a pair of piezoelectric members. A magnetic head is mounted on the piezoelectric element and records/reproduces desired data. A non-magnetic metal member having a predetermined coefficient of thermal expansion is formed between the piezoelectric members. A driving circuit is connected to the piezoelectric element and the non-magnetic metal member, and drives the magnetic head in a direction substantially perpendicular to the head trace direction, by applying a predetermined voltage.