Abstract: A scroll-type variable-capacity compressor is disclosed in which a single spool is moved to open or close bypass ports and thereby change the capacity of compression chambers. Especially, the capacity can be controlled in satisfactory manner by opening the bypass ports to a specific position. Specifically, a first bypass port is arranged in the neighborhood of the contact point between the inner surface of the spiral wall of a fixed scroll and the outer surface of the spiral wall of a movable scroll making up one of the compression chambers with the capacity thereof reduced to a predetermined level. A second bypass port is arranged at a position on the side beyond a discharge port from the first bypass port but where the discharge port is not located on the line connecting the particular position and the first bypass port.

Abstract: In a swash plate type compressor, a rotational shaft makes a piston reciprocate through a swash plate. A suction valve plate is connected to an eccentric portion of the shaft and caused to orbit around an axis of the shaft by rotation of the shaft. Friction between the suction valve plate and a contacting end wall in which a suction port is formed naturally suppresses the rotational motion of the valve plate. Therefore, the valve plate substantially orbits about the shaft axis without rotating and opens and closes the suction port. A relative velocity between the valve plate and the end wall when the valve plate orbits without rotating is smaller than when the valve plate only rotates.

Abstract: A variable discharge-amount compressor includes a compression unit for compressing refrigerant, and a discharge-amount varying unit for varying a discharge amount of refrigerant discharged from the compression unit. The discharge-amount varying unit has a first control room communicating with inlet and outlet of the compression unit, a second control room communicating with the inlet, and a third control room communicating with the second control room through a orifice. The first control room communicates with the inlet through a control passage opened and closed by a control valve. Further, a bypass passage communicating with the inlet is opened when the control passage is opened. Therefore, when an engine for driving the compressor is rotated to be accelerated, a pressure difference is generated between a pressure inside the second control room and a pressure inside the third control room, thereby opening the control passage and the bypass passage.

Abstract: A movable scroll element for a scroll type compressor is produced by a combination of a mold casting process and a machining process. The mold casting process produces a cast product having an end-plate forming portion, a spiral-member-forming portion and a projecting portion for forming a drive power receiving portion. The cast product has an entire outer faces covered with black scale, and the machining process machines the end-plate-forming portion, a spiral member forming portion, the projecting portion by cutting. Nevertheless, at least an outer circumference of the drive power receiving portion, i.e., a boss portion of the movable scroll element is covered with an outermost layer consisting of black scale. Thus, a sufficient mechanical strength of the movable scroll element is obtained even if the wall thickness of the drive power receiving portion, i.e., the boss portion of the movable scroll element, is reduced.

Abstract: A scroll type compressor including mutually mating stationary and movable scrolls for producing compression. A circumferentially outer part of the movable scroll portion has a flat end surface and a chamferred surface. The chamferred surface tapers outwardly at an angle relative to the flat end surface greater than an allowable tilt angle of the movable scroll. A circumferentially inner part of the scroll portion includes a flat end surface only which has a groove to receive a tip seal, the tip seal having a height greater than a depth of the groove. The circumferentially outer part has an identical outer diameter to that of the base plate portion, and the base plate portion and the scroll portion are simultaneously machined.

Abstract: A scroll type compressor having a housing unit in which a movable scroll element and a stationary scroll element are received in such a relationship that the movable scroll element orbits about the center of the stationary scroll element. The scroll type compressor further having a mechanical reinforced rotation preventing unit for preventing rotation of the movable scroll element about its own axis, and the rotation preventing unit having first stationary pin fixed to an inner end face of the housing unit and second movable pin fixed to an end face of a base plate of the movable scroll element, and a ring engaged with the first and second rings. A thickness T1 between the outer circumference of the first pin and the inner edge of the inner end face of the housing unit is set to be equal to or larger than 2.4 mm. A thickness T2 between the outer circumference of the second pin and the outer circumference of the base plate of the movable scroll element is set to be equal to or larger than 2.7 mm.

Abstract: A movable scroll element for a scroll type compressor is produced by a combination of a mold casting process and a machining process. The mold casting process produces a cast product having an end-plate forming portion, a spiral-member-forming portion and a projecting portion for forming a drive power receiving portion. The cast product has an entire outer faces covered with black scale, and the machining process machines the end-plate-forming portion, a spiral member forming portion, the projecting portion by cutting. Nevertheless, at least an outer circumference of the drive power receiving portion, i.e., a boss portion of the movable scroll element is covered with an outermost layer consisting of black scale. Thus, a sufficient mechanical strength of the movable scroll element is obtained even if the wall thickness of the drive power receiving portion, i.e., the boss portion of the movable scroll element, is reduced.

Abstract: A scroll type compressor using a crank mechanism having enough freedom so that an amount of eccentricity of the movable scroll member becomes variable. An elastic body is inserted between the facing surfaces striking each other in the inside of the crank mechanism so as to prevent generation of a noise due to the collision of the parts when starting up or shutting down the compressor.

Abstract: A method for shaping a scroll member for a scroll compressor, capable of increasing a service life of a cutter tool, while reducing the cost. At the corner between the base plate 2 and a scroll wall, a roundness 3a of a small radius R1 of curvature is first machined along an entire length of the scroll wall in its spiral direction. Then, a roundness 3b of a large radius R2 of curvature is machined only at a spirally inner end of the scroll wall.

Abstract: A scroll type compressor has a fixed scroll in a housing and a movable scroll opposed to the fixed scroll to define a compression chamber with the fixed scroll. Gas introduced into a suction chamber via an inlet is compressed in the compression chamber and then is discharged to a discharge chamber via a discharge port to exhaust the compressed gas from an outlet to the outside of the compressor in accordance with the circular movement of the movable scroll. A part of the discharge chamber is defined in the fixed scroll. An outlet flange protrudes from the fixed scroll. The outlet flange includes the outlet which communicates with the discharge chamber.

Abstract: A scroll type compressor comprises a fixed scroll having an end plate and a spiral element. The spiral element of the fixed scroll is integrally coupled to the inner wall of a housing. A movable scroll has an end plate and a spiral element, and faces the fixed scroll, with a plurality of fluid pockets formed between the movable scroll and the fixed scroll. When the movable scroll makes an orbital movement around the axis of the rotary shaft, refrigerant gas is led into the fluid pockets from outside the movable scroll. As the fluid pockets move toward the center of the movable scroll the fluid pockets decrease in volume, thereby compressing the refrigerant gas. A suction chamber which receives the refrigerant gas from outside the housing is formed between the movable scroll and the inner wall of the housing. A passage is formed in at least one of the inner wall of the housing, the connecting section and the end plate of the movable scroll.

Abstract: A variable capacity swash plate type compressor having compression chambers formed on one side of the plungers only, and control chambers for controlling the capacity of the compressor provided on the other side of the plungers. The capacity of the compressor is controlled by adjusting the pressure in the control chambers, whereby the inclination of the swash plate is changed because the force exerted on the plunger by the pressure in the control chamber, i.e., the force moving the swash plate, is changed. Therefore, since the volume of the compression chambers is relatively small, and a higher control pressure can be used, the response and the stability of the capacity control is improved.

Abstract: A power steering apparatus for a vehicle having a hydraulic mechanism for generating a force applied to a steering mechanism for reducing a force needed to operate a steering member (wheel). A device is provided for determining a condition wherein a yaw rate generated in the vehicle does not match a steering operation of the steering member. A hydraulic or electric torque motor is operated for generating a counter steering force applied to the steering mechanism, to cancel the yaw rate which does not match the operation of the steering member.

Abstract: A swash plate type compressor has a rotary shaft, an inclined swash plate for rotation with the shaft, and a plurality of pistons connected to the swash plate. Each piston defines at both ends thereof a pair of working chambers. The piston reciprocates while being subjected to a swing motion concomitant with the rotation of the swash plate, to suck a fluid into the working chambers for compression. The swash plate is mounted on the shaft through a support unit which serves to selectively vary the inclination of the swash plate and shift the center of rotation of the swash plate along the shaft. The fluid is introduced from a suction passage through and around the swash plate to suction chambers formed adjacent the working chambers. A bypass passage is formed to directly communicate the suction passage with the suction chamber on one side of the shaft while bypassing the swash plate.

Abstract: A variable displacement swash-plate type compressor has a swash plate rockably carried by a shaft, and a spool for changing the angle of tilt of the swash plate and also the position of the center of the swash plate, thereby to vary the displacement of the compressor. The compressor has a control valve which determines a control pressure to be supplied to a control pressure chamber behind the spool, between the level of a low-pressure introduced from a low-pressure side of the compressor and a high-pressure introduced from a high-pressure side of the compressor.

Abstract: A variable displacement swash-plate type compressor suitable for use as a refrigerant compressor of an automotive air conditioner has a cylinder block having a plurality of cylinder bores each slidably receiving a double-headed piston, a shaft driven by an automotive engine, a swash plate tiltably mounted on the shaft for rotation therewith to reciprocatorily move the pistons, and a spool for moving the swash plate axially of the shaft and changing the angle of tilt of the swash plate. The swash plate and the shaft are connected in such a manner that, when the swash plate is axially moved while changing its tilting angle, the position of stroke end of each piston is changed only in a working chamber on one end of the piston, whereas no change in the position of the stroke end occurs in the other working chamber on the other end of the piston.

Abstract: A hydraulic device having a first shaft including a first rotor, and a second shaft including a second rotor, the first and second rotors being constructed by adjacently fitting the same shape rotor elements, respectively. The rotor elements have teeth on the outer periphery thereof at a constant interval, and each tooth has a tip portion fluid-tightly engaged with an inner wall of a housing of the device. The rotor elements are adjacently fitted to the shaft in such a manner that the rotor elements are displaced in the same rotational direction along the axial direction of the shaft. The teeth tip portions of the rotor elements adjacent to each other are overlapped so that spiral paths are defined on the outer surface of the rotor.

Abstract: A multiple-turn scroll pump comprises a pumping unit on each lateral side of a base plate of an oscillatable scroll piston driven by an eccentric drive. Each pumping unit includes a spirally shaped groove in a scroll housing and a spirally shaped displacement blade forming part of the scroll piston. The groove in one of the pumping units extends from the peripheral part of the scroll housing through at least one turn of a spiral and terminates at the intermediate part of the housing. The groove in the other pumping unit also begins close to the peripheral part of the scroll housing but extends through a number of spiral turns greater than that of the groove in the first pumping unit. Passages are provided in the scroll piston to communicate grooves in both units in such a manner that the fluid drawn into the first pumping unit is compressed mainly in the second pumping unit and is discharged solely therefrom.

Abstract: A multiple-vane rotary compressor having a cylinder bore profile especially designed to reduce the fluctuation in the overall drive torque applied to the rotor shaft. The cylinder bore profile is configured and designed so that the individual drive torque applied to an individual vane during the compression and delivery strokes varies along a drive torque-vane angle curve which approximates an isosceles triangle having a lower side corresponding to a range of angle of 180.degree.. The cylinder bore profile includes, for a profile section extending through an angle of 180.degree., a first region (i) in which the amount of vane projection is held substantially constant at a maximum value (D), a second region (ii) in which the amount of vane projection decreases at a higher rate, and a third region (iii) in which the amount of vane projection decreases to zero at a lower rate, the imaginary transitional point (A.sub.3) between the second and third regions being located at an angular position of 90.degree..