Abstract: Various embodiments of the invention provide a screw compressor for compressing a refrigerant in a refrigeration system. The screw compressor includes a rotor case, which accommodates a primary helical rotor that is intermeshed with at least one secondary helical rotor, to compress the refrigerant in the rotor case. The rotor case also includes a slide valve supporting member that is fixed on an inner wall of the rotor case. Moreover, a slide valve, located in the rotor case, slides axially on the slide valve supporting member. The slide valve controls the volume of refrigerant during compression. The slide valve is fitted with at least one internal pressure relief valve, to relieve internal pressure in the screw compressor.

Abstract: A compressor, as well as a lightweight and strong casting for a compressor, are disclosed. The compressor, which may be a reciprocating compressor for use in compressing high-pressure refrigerants such as CO2, includes substantially reduced wall thicknesses (t) compared to prior art castings. The side walls of the compressor can be manufactured to such reduced thicknesses (t) through the use of a bridge spanning across the crankcase. This not only allows the opposing side walls to be manufactured of a thinner material, but the bottom cover removably mounted to the crankcase can be manufactured from a thinner and lighter material as well. Through the use of such a bridge, the resulting compressor is not only able to satisfy current strength requirements, but at significant weight, size and cost savings as well.

Abstract: A compressor, as well as a lightweight and strong casting for a compressor, are disclosed. The compressor, which may be a reciprocating compressor for use in compressing high-pressure refrigerants such as CO2, includes substantially reduced wall thicknesses (t) compared to prior art castings. The side walls of the compressor can be manufactured to such reduced thicknesses (t) through the use of a bridge spanning across the crankcase. This not only allows the opposing side walls to be manufactured of a thinner material, but the bottom cover removably mounted to the crankcase can be manufactured from a thinner and lighter material as well. Through the use of such a bridge, the resulting compressor is not only able to satisfy current strength requirements, but at significant weight, size and cost savings as well.

Abstract: A compressor (20) has a case (22) and a crankshaft (38). The case has a number of cylinders (30 32). For each of the cylinders, the compressor includes a piston (34) mounted for reciprocal movement at least partially within the cylinder. A connecting rod (36) couples each piston to the crankshaft. A pin (44) couples each connecting rod to the associated piston. Each pin has first (52) and second (53) end portions mounted to first (56) and second (57) receiving portions of the associated piston and a central portion (48) engaging the associated connecting rod. Each of the pistons is formed of a first cast iron. At each of the cylinders, the case is formed of second cast iron. One of the first cast iron and the second cast iron is a Meehanite type cast iron and the other of the first cast iron and the second cast iron is a gray cast iron.

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 first surface (200) of the valve element (102) is in sliding engagement with a second surface (202) of the housing (22) during movement between the first and second conditions. The valve element is coupled to an actuating piston (124). The compressor includes a linear bearing (132) guiding a piston shaft (122).

Abstract: A multi-stage reciprocating compressor includes a cylinder block and a cylinder head. The cylinder block defines a low stage cylinder and a high stage cylinder. The cylinder head is secured to the cylinder block overlying the low and high stage cylinders. The cylinder head defines a mid-stage plenum which is in fluid communication with the low stage cylinder and the high stage cylinder for communicating a working fluid discharged from the low stage cylinder to the high stage cylinder.

Abstract: A reciprocating piston compressor for use in a refrigerant compression circuit comprises first and second intake manifolds, first and second reciprocating piston compression units, an outlet manifold and a first pulsing valve. The intake manifolds segregate inlet flow into the compressor. The first and second reciprocating piston compression units receive flow from the first and second intake manifolds, respectively. The outlet manifold collects and distributes compressed refrigerant from the compression units. The first pulsing valve is mounted externally of the first intake manifold to regulate refrigerant flow into the first intake manifold. In another embodiment, a second valve is mounted externally of the second intake manifold to regulate flow into the second intake manifold, and the first and second valves are operated by a controller. The controller activates the first valve with variable width pulses having intervals less than an operating inertia of the refrigerant compression circuit.

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: Various embodiments of the invention provide a screw compressor for compressing a refrigerant in a refrigeration system. The screw compressor includes a rotor case, which accommodates a primary helical rotor that is intermeshed with at least one secondary helical rotor, to compress the refrigerant in the rotor case. The rotor case also includes a slide valve supporting member that is fixed on an inner wall of the rotor case. Moreover, a slide valve, located in the rotor case, slides axially on the slide valve supporting member. The slide valve controls the volume of refrigerant during compression. The slide valve is fitted with at least one internal pressure relief valve, to relieve internal pressure in the screw compressor.

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 first surface (200) of the valve element (102) is in sliding engagement with a second surface (202) of the housing (22) during movement between the first and second conditions. The valve element is coupled to an actuating piston (124). The compressor includes a linear bearing (132) guiding a piston shaft (122).

Abstract: An apparatus for separating an oil from a refrigerant has a housing, an inlet conduit for receiving a refrigerant/oil mixture, a separator medium, a refrigerant outlet conduit, and an oil outlet conduit. The inlet conduit has an inlet external to the housing and an outlet within the housing and provides means for limiting external sounds transmitted by the housing.

Abstract: In open drive refrigerant compressors, the location where the shaft extends through the casing provides a potential location for leakage of refrigerant. Where a shaft seal is used which requires an oil seal, the draining of oil from the shaft seal cavity, upon stopping the compressor, is prevented by placing a check valve downstream of the shaft seal cavity which forms a part of the oil distribution system. An optional check valve may be located upstream of the shaft seal cavity.

Abstract: A muffler including fiberglass packing is assembled and suitable for use in a closed refrigeration system by avoiding the generation of fiberglass debris and preventing its entry into the fluid path. A perforate tube is serially overlain by a heat resistant fabric covering, a fiberglass packing and a circumferentially adjustable and collapsible sleeve which are inserted as a subassembly into the shell of a pressure vessel.

Abstract: A muffler including fiberglass packing is assembled and suitable for use in a closed refrigeration system by avoiding the generation of fiberglass debris and preventing its entry into the fluid path. A perforate tube is serially overlain by a heat resistant fabric covering, a fiberglass packing and a circumferentially adjustable and collapsible sleeve which are inserted as a subassembly into the shell of a pressure vessel.

Abstract: The guide portion of the cylinder of a Stirling cycle device is located at least partially within and is axially coextensive with the bellows thereby providing a reduction in the height/length of the piston, cylinder and bellows assemblies. The reduction is the distance between the guide surface and the top of the piston reduces the moment arm for canting.

Abstract: A terminal plate assembly has a one piece inner terminal block for three pins or bolts and a separate outer terminal block for each pin or bolt. Sealing between the terminal plate and each pin is accomplished by two O-ring seals which are squeezed between the inner and outer terminal blocks. Additionally, one of the O-rings also serves to hold the assembled terminal blocks in place with respect to the terminal plate.