PNEUMATIC CLUTCH FOR COMPRESSOR

摘要

PROBLEM TO BE SOLVED: To provide at low cost a clutch for compressor using air pressure as substitute for an electromagnetic clutch. SOLUTION: In a cylinder 8b consolidated with a pulley 7, a piston 10 is inserted to form a pressure chamber 15. A friction ring 5 having friction surfaces 5c and 5d confronting the friction surfaces 8e and 10b of the cylinder and piston is coupled with the drive shaft 2 of compressor 1 in such a way as movable in the axial direction. The pressure chamber 15 is switched by a negative pressure changeover valve 18 to generate connection with either a negative pressure source 20 or the atmosphere. A bearing 9 is fitted with a seal and holds the pressure chamber 15 in air-tight condition. Because a negative pressure is supplied to the chamber 15 when a clutch is in engagement, the piston 10 is pressed by the atmospheric pressure to move in the axial direction, and pinches by pressure the friction surfaces 5c and 5d of the friction ring 5. The friction surfaces not only interlock mechanically by contact but generate air-tight seal surfaces, so that the chamber 15 is sealed perfectly and it is possible to hold a low pressure.