Abstract: A compressor (20) has an unloading slide valve (100). The valve has a valve element (102) having a range between a first condition and a second condition, the second condition being unloaded relative to the first condition. A piston (124) is in a cylinder (128) and mechanically coupled to the valve element. A control valve (40; 42) is coupled to a headspace (138) of the cylinder to selectively expose the headspace to a fluid source (144), pressure of fluid in the headspace producing a force on the piston and valve element in a direction from the second condition toward the first condition. The compressor includes means (190, 192; 210; 220) for relieving excess pressure in the headspace.

Abstract: A compressor (20) has an unloading slide valve (100). The valve has a valve element (102) having a range between a first condition and a second condition, the second condition being unloaded relative to the first condition. A piston (124) is in a cylinder (128) and mechanically coupled to the valve element. A control valve (40; 42) is coupled to a headspace (138) of the cylinder to selectively expose the headspace to a fluid source (144), pressure of fluid in the headspace producing a force on the piston and valve element in a direction from the second condition toward the first condition. The compressor includes means (190, 192; 210; 220) for relieving excess pressure in the headspace.

Abstract: An all-electric transport refrigeration system receives its compressor drive motor power and all other electrical power from at least one on-board fuel cell. The fuel cell is able to power all of the refrigeration system electrical components. In one example a single fuel cell is used. Another example includes multiple fuel cells.

Abstract: An all-electric transport refrigeration system receives its compressor drive motor power and all other electrical power from at least one on-board fuel cell. The fuel cell is able to power all of the refrigeration system electrical components. In one example a single fuel cell is used. Another example includes multiple fuel cells.

Abstract: The seat of a suction valve of a reciprocating compressor is modified to limit the radial extent and thereby the area in which an annular oil film can be established between the valve and the valve seat. The preferred radial extent of the seating surface is 0.014 to 0.018 inches and the preferred ratio of the area of the suction valve seat to the passage therethrough is in the range of 13% to 25%.

Abstract: The seat of a suction valve of a reciprocating compressor is modified to limit the area in which an annular oil film can be established between the valve and the valve seat. The seat is configured to limit the oil film from 3% to 33% of the total inlet port opening. In a modified embodiment gas at discharge pressure exerts an opening bias to the suction valve at the end of the discharge stroke.

Abstract: A spring must be engaged and deformed by the suction valve in order for the suction valve to seat. The spring provides an opening bias to the suction valve with negates most, if not all, of the effects of adhesion due to the presence of a thin oil film between the suction valve and suction valve seat when the suction valve is closed. Accordingly, the opening of the suction valve takes place sooner in the suction stroke and is essentially solely responsive to the differential pressure across the suction valve.

Abstract: At start up, at least one bank of cylinders of a compressor is allowed to compress gas and deliver the compressed gas to the system while at least the majority of the other banks are subject to hot gas bypass. The entire compressor is subject to suction modulation such that the amount of gas that can be compressed and delivered by all of the operating banks can be controlled and thereby the compressor power demand is controlled.