Abstract: A pressure nitrided stainless steel hybrid ball bearing having an inner ring, an outer ring, and rolling elements disposed therebetween. The pressure nitrided stainless steel hybrid bearing has one or more component(s) made from a pressure nitrided stainless steel material. The pressure nitrided stainless steel hybrid bearing used with a refrigerant lubrication for chiller applications leads to a very long useful life time.

Abstract: A refrigeration chiller employs a centrifugal compressor the impellers of which are mounted on a shaft which is itself mounted for rotation using rolling element bearings lubricated only by the refrigerant which constitutes the working fluid of the chiller system. Apparatus is taught for providing liquid refrigerant to (1.) the bearings immediately upon chiller start-up, during chiller operation and during a coastdown period subsequent to shutdown of the chiller and (2.) the drive motor of the chiller's compressor for motor cooling purposes. By use of a variable speed-driven motor to drive the compressor, optimized part load chiller performance is achieved in a chiller which does not require or employ an oil-based lubrication system.

Abstract: A pressure nitrided stainless steel hybrid ball bearing having an inner ring, an outer ring, and rolling elements disposed therebetween. The pressure nitrided stainless steel hybrid bearing has one or more component(s) made from a pressure nitrided stainless steel material. The pressure nitrided stainless steel hybrid bearing used with a refrigerant lubrication for chiller applications leads to a very long useful life time.

Abstract: A refrigeration chiller employs a centrifugal compressor the impellers of which are mounted on a shaft which is itself mounted for rotation using rolling element bearings lubricated only by the refrigerant which constitutes the working fluid of the chiller system. Apparatus is taught for providing liquid refrigerant to (1.) the bearings immediately upon chiller start-up, during chiller operation and during a coastdown period subsequent to shutdown of the chiller and (2.) the drive motor of the chiller's compressor for motor cooling purposes. By use of a variable speed-driven motor to drive the compressor, optimized part load chiller performance is achieved in a chiller which does not require or employ an oil-based lubrication system.

Abstract: A refrigeration chiller employs a centrifugal compressor the impellers of which are mounted on a shaft which is itself mounted for rotation using rolling element bearings lubricated only by the refrigerant which constitutes the working fluid of the chiller system. Apparatus is taught for providing liquid refrigerant to (1.) the bearings immediately upon chiller start-up, during chiller operation and during a coastdown period subsequent to shutdown of the chiller and (2.) the drive motor of the chiller's compressor for motor cooling purposes. By use of a variable speed-driven motor to drive the compressor, optimized part load chiller performance is achieved in a chiller which does not require or employ an oil-based lubrication system.

Abstract: A refrigeration chiller employs a centrifugal compressor the impellers of which are mounted on a shaft which is itself mounted for rotation using rolling element bearings lubricated only by the refrigerant which constitutes the working fluid of the chiller system. Apparatus is taught for providing liquid refrigerant to (1.) the bearings immediately upon chiller start-up, during chiller operation and during a coastdown period subsequent to shutdown of the chiller and (2.) the drive motor of the chiller's compressor for motor cooling purposes. By use of a variable speed-driven motor to drive the compressor, optimized part load chiller performance is achieved in a chiller which does not require or employ an oil-based lubrication system.

Abstract: A refrigeration chiller employs a centrifugal compressor the impellers of which are mounted on a shaft which is itself mounted for rotation using rolling element bearings lubricated only by the refrigerant which constitutes the working fluid of the chiller system. Apparatus is taught for providing liquid refrigerant to (1.) the bearings immediately upon chiller start-up, during chiller operation and during a coastdown period subsequent to shutdown of the chiller and (2.) the drive motor of the chiller's compressor for motor cooling purposes. By use of a variable speed-driven motor to drive the compressor, optimized part load chiller performance is achieved in a chiller which does not require or employ an oil-based lubrication system.

Abstract: A refrigeration chiller employs a centrifugal compressor the impellers of which are mounted on a shaft which is itself mounted for rotation using rolling element bearings lubricated only by the refrigerant which constitutes the working fluid of the chiller system. Apparatus is taught for providing liquid refrigerant to (1.) the bearings immediately upon chiller start-up, during chiller operation and during a coastdown period subsequent to shutdown of the chiller and (2.) the drive motor of the chiller's compressor for motor cooling purposes. By use of a variable speed-driven motor to drive the compressor, optimized part load chiller performance is achieved in a chiller which does not require or employ an oil-based lubrication system.

Abstract: The position of a slide valve in a screw compressor in a refrigeration system is controlled using a gaseous medium sourced from the higher pressure one of two or more sources of such fluid. Preferred sources are refrigerant gas in a closed compression pocket in the working chamber of the compressor and refrigerant gas in the discharge passage downstream of the compressor's discharge port. The multiple sources of such gas are connected to a solenoid valve which, when open, permits gas to act on the piston which controls the position of the slide valve. Due to a check valve arrangement, it is always the one of the sources of gas which is at higher pressure that acts on the slide valve actuating piston. The adverse affects of refrigerant gas out-gassing and gas bubble collapse associated with use of hydraulic fluid rather than a gaseous medium to modulate compressor capacity are avoided while advantageous use is made of compressor overcompression in the control of slide valve position.

Abstract: A screw compressor assembly includes a motor housing section, a compressor section and an oil separator downstream of the compressor discharge port. The motor housing section defines a flow path for suction gas traveling to the working chamber of the compressor so that the compressor drive motor is cooled by suction gas. The motor housing section also internally defines an integral heat exchange structure through which a passage for the flow of oil is defined. Discharge pressure in the oil separator drives separated oil into the passage in the motor housing heat exchange structure prior to the delivery of such oil to compressor surfaces requiring lubrication. The oil flowing through the integral heat exchange structure is cooled by the suction gas passing over the surface of the heat exchange structure interior of the motor housing.

Abstract: An oil distribution system for supplying lubricating oil to a thrust bearing, the bearing surfaces of an Oldham coupling, and a swing link bearing in a scroll compressor and allocating the oil between the bearings in proper proportion. Oil is pumped from a reservoir in the bottom of the compressor shell upward through a gallery that runs the length of a rotating drive shaft. The oil exits an opening at the top of the drive shaft and is thrown radially outward into a shallow cavity formed in a swing link that is rotatably driven by the shaft. The cavity is generally elongate in shape, so that oil collects in pools at each of its ends as a result of centrifugal force. Each of the two bearings is lubricated by oil that flows upward into the bearings either directly or through a passage from the pools of oil.

Abstract: A system for lubricating the main drive shaft bearings in a scroll compressor enclosed within a hermetic shell. The drive shaft and its main bearings are supported in a frame that defines first and second chambers adjacent each end of a main bearing. Each of the chambers includes an opening to a spatial volume contained within the compressor shell. An oil pump at the lower end of the drive shaft supplies oil through a bore in the shaft to a swing link bearing and a thrust bearing, both disposed adjacent its upper end. Oil is dispersed into the spatial volume as a mist of oil droplets by the rotating elements connected to the drive shaft. Fan means are disposed within the second chamber and are operative to develop a differential pressure between the two chambers so that oil droplets are drawn toward the first chamber, lubricating the main bearing as they pass through it.

Abstract: A tip seal back-up member is disclosed for use in fluid apparatus of the scroll type, which member comprises a strip of material extending longitudinally in generally spiroidal configuration about a reference axis and having a preformed configuration such that its radially inner and outer edge portions are disposed axially with respect to each other. The strip of material comprises an elastic material such that as one of the edge portions is displaced axially toward the other, an opposing spring force is developed. In operation, the back-up member is disposed within a groove located in a tip surface of a wrap element in fluid apparatus of the scroll type, between a bottom wall of the groove and a tip seal. Preferably, the strip of material is generally flat between its radially inner and outer edge portions and is constructed from steel.

Abstract: A wrap element and tip seal are disclosed for use in fluid apparatus of the scroll type which include a wrap element having a groove disposed within its tip surface of spiroidal configuration generally conforming to that of the wrap element. A tip seal is disposed within the groove and comprises a plurality of strips of material disposed at least partially within the groove and arranged in side-by-side relationship at least partially across the width of the groove, each said strip extending along a longitudinal axis about the spiroidal configuration of the groove. By fabricating the seal from a plurality of strips of material, the necessity for expensive machining operations is obviated while a seal is provided which is relatively flexible in a radial direction as to accommodate the precise groove shape, while remaining relatively inflexible in an axial direction so as to provide the desired sealing characteristics.

Abstract: A rolling thrust bearing for use in a scroll type positive fluid displacement apparatus is disclosed. In the invention, a plurality of ball bearings spaced apart in cavities formed in a bearing cage are operative to transmit an axial force between a supporting frame and an orbiting scroll member. The bearing cage rotates within a groove in which it is seated due to frictional forces between its flank surfaces and the sides of the groove. In a first embodiment, the diameter of the cavities is substantially larger than the diameter of the ball bearings, and the bearings are free to orbit within the cavities as the bearing cage rotates. In the second embodiment, the cavities are only slightly larger in diameter than the ball bearings, but the radial width of the bearing cage is substantially less than the width of the groove, and the bearing cage and the ball bearings together describe an epicycloidal path about the central axis of the bearing cage.

Abstract: A positive fluid displacement apparatus of the scroll type, having a swing link for translating the rotational motion of a drive shaft into the relative orbital motion of two parallel end plates. The facing surfaces of the parallel plates have involute wrap elements attached in fixed angular, intermeshed relationship with each other. Contacting surfaces of the parallel plates and wrap elements define pockets of fluid which are subjected to changes of pressure and volume as the pockets are caused to move between an inlet and an outlet by the orbital motion of the plates.A flexible member of resilient material connects a crank post on the drive shaft with the swing link and transfers the driving force of the drive shaft to the swing link. The flex member is rigid in tension, but flexible in bending. By its spring force, the flex member biases the wrap elements slightly apart when the drive shaft is not rotating, to reduce the driving torque required at start-up of the scroll apparatus.

Abstract: A compressor oil pump with integral contaminant collector and helical vane for improved pumping efficiency. A generally cone-shaped pick-up tube is adapted to be attached to the lower end of a hollow rotatably driven vertical shaft for rotation thereby about its longitudinal axis. The lower end of the pick-up tube includes an inlet opening which extends into a reservoir of oil. An annular contaminant collection groove is disposed circumferentially within the wall of the pick-up tube forming a pocket. This groove collects and retains contaminant particles contained in oil which is swept up the tapered interior surface of the tube due to the centrifugal force developed by its rotation. The helical vane is provided in the interior of the pick-up tube to increase its pumping efficiency. The vane acts to accelerate the oil to the rotational speed of the pump, thereby improving the volumetric flow output from the pump.

Abstract: An oil distribution system for lubricating bearings in a scroll compressor. The system includes an oil collector cup attached to the lower surface of a swing link. Oil pumped through an internal passage in a rotating drive shaft is retained in the collector cup when the compressor stops, so that it is immediately available to lubricate adjacent bearings upon restart of the machine. Also disclosed in two embodiments are means for distributing and properly allocating the flow of oil between a thrust bearing and a swing link bearing.

Abstract: An annular valve stop insert for a compressor body is shown which has the function of establishing the positional relationship of the valve plate, valve and compressor body.