Pneumatically operated compressor capacity control valve with discharge pressure sensor

摘要

A pneumatically-operated control valve (10) selectively opens and closes a passage (18) between discharge and crankcase chambers of a variable capacity refrigerant compressor for purposes of controlling the compressor capacity, and includes an integral pressure sensor (60) for measuring the compressor discharge pressure. The valve (10) includes a plunger (36) having an axis (38), a stopper (26) biased against a seat (30) in the passage (18) coupling the discharge and crankcase chambers, an annular bellows (44) and a pressure sensor (60). A portion of the plunger (36) passes through the annular bellows (44), and one end (44a) of the bellows (44) is attached to the plunger (36) for axially displacing the plunger (36) to unseat the stopper (26). The stopper (26) and plunger (36) are maintained in engagement, and have axial bores(40, 42) that are aligned to form a passage between the compressor discharge chamber and a cavity (54) in which the pressure sensor (60) is retained.