Abstract: A fluid rotating apparatus includes a casing having gas inhaling inlet and a gas discharge outlet, rotors driven in the casing by a driving mechanism and having fluid-transporting grooves which engage each other in synchronous rotation, and bearing portion for supporting the rotors. A communicating path is formed at one of the rotor and the casing for communicating a gas discharge-side inner space and a space defined by an inner surface of the casing and the fluid-transporting groove of an outer surface of each rotor with each other. The gas discharge-side inner space is defined by an end surface of the rotor opposite to a gas inhaling-side surface thereof, and a sealing portion is formed between the rotor and the casing to prevent fluid from flowing into the gas discharge-side inner space.

Abstract: A fluid rotating apparatus of a positive displacement pump includes a plurality of rotors accommodated in a housing, a bearing for rotatably supporting the rotors, a suction port and a discharge port formed in the housing, a suction chamber and a discharge chamber in the housing respectively communicating with the suction port and the discharge port, a plurality of motors for individually rotating the rotors, and a detecting device for detecting rotating angles and rotating numbers of the motors. In the apparatus, a fluid is sucked and discharged due to capacity change of a space defined by the rotors and the housing through synchronous control of the rotation of the plurality of motors by a signal from the detecting device. The housing has a communicating path with a flow control device to make an upstream side communicate with a downstream side of the apparatus when the rotational numbers of the rotors are less than a predetermined value.

Abstract: A control apparatus of a magnetic bearing controls electromagnets so that both a displacement deviation of a center of gravity of a rotary shaft and an angle of twist around the center of gravity of the rotary shaft become 0, thereby supporting the rotary shaft in space by the magnetic force of the electromagnets. The apparatus includes .theta..sub.X and .theta..sub.Y control devices for controlling angles .theta..sub.X and .theta..sub.Y of twist of the two degrees of freedom of a rotational motion orthogonal to each other around the center of gravity and perpendicular to an axial direction of the rotary shaft, a cross feedback being produced so that both a feedback signal of the rotary angle .theta..sub.X and a feedback signal of the rotary angle .theta..sub.Y are respectively fed back as cross feedback signals to the .theta..sub.Y and .theta..sub.X control devices. A rotational speed detecting device for detecting a rotational number of the rotary shaft.

Abstract: A rotary apparatus includes a rotary spindle, a front end portion of which projects from a shell to an outside thereof and which is supported by magnetic force while the spindle is rotating, a working tool being mountable on the front end portion of the spindle. A first sensor is provided for detecting a position of the front end portion of the spindle in a radial direction thereof and is provided on the front end portion of the shell and in an annular space formed at a periphery of the front end portion of the spindle such that the first sensor occupies a volume of not more than 50% of the annular space. A second sensor is provided, for detecting a position of a rear end portion of the spindle in the radial direction thereof and is provided on the rear end portion of the shell.

Abstract: A rotor shaft provided with a fan is rotatably supported by pneumatic bearings for the purpose of high speed rotation with low noise. The rotor shaft provided with the fan can also be supported at one end by a resilient bearing so as to provide high speed rotation even if the concentricity of the bearings is low.

Abstract: A dynamic pressure air bearing unit comprising a rotating shaft and a bearing member fitted around the rotating shaft, wherein a first spiral groove is disposed on a part of one of two cylindrical bearing surfaces facing each other, one being of the rotating shaft and the other of the bearing member, the first spiral groove acting to impel lubrication air between the cylindrical bearing surfaces toward the innermost portion of the bearing member with the rotation of the rotating shaft, and a second spiral groove is disposed on a portion of the cylindrical bearing surface adjacent to the open end of the bearing member, the second spiral groove acting to discharge, air toward the open end of the bearing member, an air conducting passage being provided to connect the boundary portion between the first and second grooves with the outside of the bearing unit, and the air passage having a filter installed at the open end thereof, thereby providing a dynamic pressure air bearing unit capable of operating in an envir