Abstract: A variable-delivery compressor having plural compression chambers whose volume is changed as a rotor is rotated in a housing to compress a gas sucked through a suction port and deliver the compressed gas through a discharge port, comprising: a by-pass passage for communication between a compressing and a sucking compression chamber of the plural compression chambers; a device for changing the position of the discharge-side extremity of an opening of the by-pass passage on the side of the compressing compression chamber, in the circumferential direction of the rotor, to retard the compression start timing of the compressing compression chamber; and at least one of a variable flow restrictor device associated with a suction passage communicating with the suction port to adjust a flow of the gas which is sucked through the suction passage, and a pressure relief device including a pressure relief passage and a switching device for closing and opening the pressure relief device.

Abstract: A piston for a swash plate type compressor is disclosed in which a plurality of similar pistons are reciprocated to provide a compressing operation by means of a swash plate which is mounted on the drive shaft and rotated in the compressor cylinder. The piston comprises a piston main body or blank made of aluminium or aluminium alloy, and a coating layer applied to the overall surface of the piston blank except central portions of both outer end faces of the blank, said coating layer being of ethylene fluoride or a copolymer of ethylene fluoride and a vinyl compound, the heat conductivity of which is lower than that of the piston blank.

Abstract: A volumetric fluid compressor or a so-called scroll type compressor is provided in which a rotary shaft is placed centrally in the front side of a housing, a helical portion of a movable scroll member is contacted eccentrically with a helical portion of a fixed scroll member, the helical portion of the movable scroll member is rotated about the axis of the rotary shaft to which the movable scroll member is mounted with an offset, in such a manner that a closed space defined between the two helical portions may be contracted towards the center for compressing the refrigerant gas which may thus be discharged towards rear from the center of the fixed scroll member.

Abstract: An apparatus for controlling a driving force transmitted from a vehicle engine, via an electromagnetic clutch, to a compressor for a vehicle air conditioning equipment being provided with at least a sensor detecting the revolving rate of the compressor, and a clutch controller for providing a signal to disengage the electromagnetic clutch when the revolving rate of the compressor detected by the sensor is reduced below a prescribed reference revolving rate.

Abstract: The volumetric fluid compressor device or so-called scroll type compressor device comprises a rotary shaft mounted centrally at the front side of a housing and a movable scroll member having its scroll portion partially contacted with a scroll portion of a fixed scroll member. Sealed chambers or compression chambers delimited between the two scroll portions are contracted towards the center for compressing the refrigerant gas therein. A slider is mounted at the inner end of the rotary shaft for reciprocation radially thereof. An offset pin having an axis offset from the axis of the rotary shaft is fast with the slider and carries the movable scroll member. The slider is normally urged by a compression spring in a direction to reduce the amount of offset, that is, to reduce the radius of offset rotation of the offset pin, and may be urged by the pressure in the compression chamber in a direction to increase the radius of offset rotation of the offset pin against resiliency of the compression spring.

Abstract: An operation control apparatus is provided of a compressor having a rotary shaft which is rotated by a driving apparatus by way of a clutch. The operation control apparatus comprises a recess or projection formed in or on one end surface of the rotary shaft as a portion-to-be-sensed offset from the axis thereof, an electromagnetic sensor disposed in facing relation with a locus described by the recess or projection according to the rotation of the rotary shaft, and a pulse monitoring circuit connected to the sensor. The sensor generates a periodic pulse signal in response to rotation of the rotary shaft. The pulse monitoring circuit generates a clutch release commanding signal to the clutch when it receives no pulse signal from the sensor for a predetermined time duration to protect the driving apparatus.

Abstract: A rotation sensor for sensing a swash-plate type compressor being in rotational state. An electromagnetic sensor including a permanent magnet and a coil disposed in the neighborhood thereof is fixed on a housing of the compressor such that it may be opposed to a part of a rotational locus described by a specific portion of the external periphery of the swash-plate. The electromagnetic sensor generates a signal pulse everytime the specific portion passes nearby. When the swash-plate is made of a non-magnetic material some magnetic body is fixed on the external periphery of the swash-plate for constituting a portion-to-be-sensed. This magnetic body may be a ring or lump of ferrous material, a temperature sensitive ferrite, a permanent magnet, etc.

Abstract: A protecting device for protecting a refrigerant compressor from overheating or seizure caused by a shortage of refrigerant by any chance such as leakage thereof. The device includes a temperature sensor disposed on the outer wall of the compressor casing in the vicinity of a refrigerant intake suction suction port for sensing the temperature of the outer wall to output the sensed or measured data and a discriminator for discriminating an occurrence of refrigerant shortage by an excess of the data over a predetermined condition for comparison. The signals from the discriminator cause a warning issuance of the refrigerant shortage or an automatic stoppage of the compressor operation.