Abstract: An electromagnetic clutch includes a rotor, an armature plate that is disposed to face the rotor, an excitation coil that is accommodated on the inside of the rotor, and generates an attracting force attracting the armature plate onto the rotor, a temperature fuse that is disposed on the excitation coil side further than a side end surface of the rotor, and blocks the electric connection to the excitation coil when exceeding a predetermined temperature, an outer and inner magnetic blocking portion on the side end surface of the rotor, and an intermediate magnetic blocking portion in the armature plate in a position between the outer and the inner magnetic blocking portions, in which an annular groove is formed on the side end surface to include the inner magnetic blocking portion, and in which a friction member protruding from the side end surface is disposed in the annular groove.

Abstract: An electromagnetic clutch includes a rotor, an armature plate that is disposed to face the rotor, an excitation coil that is accommodated on the inside of the rotor, and generates an attracting force attracting the armature plate onto the rotor, a temperature fuse that is disposed on the excitation coil side further than a side end surface of the rotor, and blocks the electric connection to the excitation coil when exceeding a predetermined temperature, an outer and inner magnetic blocking portion on the side end surface of the rotor, and an intermediate magnetic blocking portion in the armature plate in a position between the outer and the inner magnetic blocking portions, in which an annular groove is formed on the side end surface to include the inner magnetic blocking portion, and in which a friction member protruding from the side end surface is disposed in the annular groove.

Abstract: There is provided a vane compressor which prevents leakage of refrigerant gas by decreasing the number of airtight interfaces between component parts and prevents seizure from occurring between its rotor and its side block without surface treatment of the side block. The vane compressor has a cam ring. The rotor is rotatably received in the cam ring. A first head is secured to one end face of the cam ring. A second head is secured to another end face of the cam ring in a manner such that the second head closes an opening of the another end face of the cam ring and one end face of the rotor can be brought into contact with the second head. The side block is received in the first head in a manner such that it closes an opening of the one end face of the cam ring and another end face of the rotor can be brought into contact with the side block.

Abstract: An annular piston abuts on an end face of a rotation plate on a side remote from a hollow cylinder via a thrust bearing, and delivery pressure is introduced to an end face of an annular piston on a side remote from the rotation plate via a high pressure-introducing passage. The delivery pressure acts via the thrust bearing on the rotation plate to urge the rotation plate toward the cylinder. As a result, the gap between the rotation plate and the cylinder is reduced, while a friction resistance offered to the rotation plate is reduced, thereby permitting the smooth rotation of the rotation plate.