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: An automobile air conditioner has a refrigeration cycle composed of a compressor, condenser, liquid tank, orifice means and an evaporator, as well as mechanical parts such as a radiator and radiator fan associated with the condenser and a blower combined with the evaporator. The compressor is operatively connected to the automobile engine through a connecting means so as to be driven by the engine selectively in accordance with the temperature in the passenger's compartment. According to the invention, the compressor is driven when the automobile is being braked, even if the temperature in the compartment is lower than a set temperature, to make an efficient use of the kinetic energy possessed by the mass of the automobile. The cold energy generated during braking is suitably stored and is released into the passenger's compartment as desired.

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.