Abstract: A variable displacement compressor comprises a housing forming a crank chamber, a shaft, expansible chambers including pistons, a swash plate connected to the shaft so as to be smoothly changeable in inclination against the shaft and driven to rotate, a wobble plate rotatable on the swash plate, a rotation preventing mechanism including a shoe member slidable in an axial direction, and a pressure control valve which is provided in a refrigerant passage from a suction port of the compressor to the expansible chamber to control the pressure of refrigerant to be sucked responsive to the suction pressure and both to the suction pressure and to the discharge pressure when the discharge pressure is high. The refrigerant passage has a sharply bent portion for separating lubrication oil from a refrigerant flowing therein and communicates with the crank chamber to discharge blow-by gas therefrom.

Abstract: A refrigerant flow rate measuring apparatus has a means for detecting the opening degree A of an expansion valve of a refrigeration cycle, a pressure detecting means for detecting the refrigerant pressure Pi at upstream side of the expansion valve, a pressure detecting means for detecting the refrigerant pressure Po at downstream side of the expansion valve, a refrigerant density detecting means for detecting the density .gamma.i of the refrigerant at the inlet side of the expansion valve, a converting means for directly or indirectly converting the values detected by the detecting means into electric signals, and a calculating means for calculating the flow rate of the refrigerant in accordance with the following formula, from the electric signals.

Abstract: A refrigerant flow rate control device for the refrigeration cycle of an air conditioning system of an automotive vehicle which is driven by a vacuum actuator includes a communication passageway for equalizing pressures applied to opposite ends of a valve body. The valve body has an intermediate portion maintained in communication with the atmosphere and connected to the vacuum actuator.

Abstract: In a refrigeration cycle in which the opening of the expansion valve is controlled by the super-heat degree of the refrigerant periodically detected at the outlet of the evaporator, a negative control signal is produced to rapidly change the opening of the expansion valve when the detected super-heat degree has reached zero. As a result, occurrence of the liquid back is prevented.

Abstract: An electromagnetic clutch includes a pair of rotatable driving and driven members adapted to be electromagnetically coupled together and uncoupled from each other. At least one of the driving and driven members comprises a pair of concentric annular members both made of magnetizable material and having opposed and radially spaced peripheral surfaces in which annular grooves are formed, respectively. An annular bond member of a non-magnetizable material is swaged into the annular space between the annular magnetizable members and thus into the annular grooves to mechanically connect the magnetizable members as well as to magnetically disconnect them from each other.

Abstract: An electromagnetic clutch includes a pair of rotatable driving and driven members adapted to be electromagnetically coupled together and uncoupled from each other. At least one of the driving and driven members comprises a pair of concentric annular members both made of a magnetizable material and having opposed and radially spaced peripheral surfaces in which annular grooves are formed, respectively. An annular bond member of a non-magnetizable material is swaged into the annular space between the annular magnetizable members and thus into the annular grooves to mechanically connect the magnetizable members as well as to magnetically disconnect them from each other.

Abstract: An electromagnetic clutch having an energizing device including a cylindrical yoke assembly composed of a yoke member and a yoke holder, and a winding housed in the yoke assembly. The yoke member has an outer cylindrical wall and an inner cylindrical wall constituting a double wall cylindrical structure, and a doughnut-shaped bottom wall connecting the outer and inner cylindrical walls together. The outer cylindrical wall is tapering in going from the bottom wall toward the upper end, and the inner cylindrical wall has a constant thickness lower portion of a predetermined height contiguous with the bottom wall and a tapering portion contiguous with the constant thickness lower portion and having its thickness successively reduced in going toward the upper end. The inner cylindrical wall has an annular groove formed on its inner circumferential surface in its constant thickness lower portion.

Abstract: A V-grooved pulley assembly having thick wall portion and thin wall portion therein designed for use with electromagnetic type clutches for driving air conditioning compressors on automobiles and the like wherein the component parts thereof are fabricated by cold workings so as to result in a reduction of the cost of materials and labor.

Abstract: An electromagnetic clutch comprises a pulley rotatable about a shaft, an armature which is axially movably connected to the shaft and faces a portion of the pulley so as to contact with electromagnetic force thereby coupling the pulley and the shaft, an electromagnet with a winding and a core which has cylindrical face coaxial of the shaft, a part of which core faces to a part of the pulley with small air gap so as to make magnetic circuit, a supporting member which has a cylindrical portion surrounding the shaft with a gap and rotatably supporting the pulley through a bearing, and a flange portion spreading out from the one end of the cylindrical portion. The supporting member is secured to the core of the electromagnet with the flange portion tightly inserted in the cylindrical face of the core, thereby defining an electromagnetic assembly in which a recess for engagement with a machine is formed.

Abstract: An exciting device for use in an electromagnetic clutch and a method for manufacturing same, in which a member having a cylindrical portion is secured to the end surface of a yoke of a doughnut or annular form to thereby provide a coil supporting portion which is open in the radial direction and has a U-shaped cross section, and then a cnductor is directly wound through the medium of an insulating material around the aforesaid cylindrical portion, after which the exposing portions of the coil formed of the conductor are insulated according to a resin-impregnating treatment or varnish immersion treatment, thereby providing an exciting device for an electromagnetic clutch.