Abstract: A compressor of this invention includes a flow passage supplying lubricant to an outlet bearing and to an inlet bearing. An orifice is disposed within the flow passages for controlling lubricant flow to the bearing assemblies. A choke orifice is disposed in series with one of the orifices for either the inlet or outlet for controlling lubricant flow relative to the other orifice.

Abstract: A vaned diffuser for a centrifugal compressor has provision for selectively adjusting the pitch of the vanes in order to accommodate variable load conditions. Each of the vanes is rotatable about a pivot pin near its leading edge and is engaged with an actuation member near its trailing edge. The actuation members are attached to a common ring which can be selectively rotated to move to the vanes in unison. The ring is supported by rollers at its outer periphery and is positioned at the outer periphery of a diffuser wall such that there is no forward facing step projecting into the flow stream. A throat is defined between adjacent vanes, and the pivot pin for each vane is located downstream of the throat on the pressure side of the vane to reduce turbulence in the flow at the throat.

Abstract: A vaned diffuser for a centrifugal compressor has provision for selectively adjusting the pitch of the vanes in order to accommodate variable load conditions. Each of the vanes is rotatable about a pivot pin near its leading edge and is engaged with an actuation member near its trailing edge. The actuation members are attached to a common ring which can be selectively rotated to move to the vanes in unison. The ring is supported by rollers at its outer periphery and is positioned at the outer periphery of a diffuser wall such that there is no forward facing step projecting into the flow stream. A throat is defined between adjacent vanes, and the pivot pin for each vane is located downstream of the throat on the pressure side of the vane to reduce turbulence in the flow at the throat.

Abstract: A vaned diffuser for a centrifugal compressor has provision for selectively adjusting the pitch of the vanes in order to accommodate variable load conditions. Each of the vanes is rotatable about a pivot pin near its leading edge and is engaged with an actuation member near its trailing edge. The actuation members are attached to a common ring which can be selectively rotated to move to the vanes in unison. The ring is supported by rollers at its outer periphery and is positioned at the outer periphery of a diffuser wall such that there is no forward facing step projecting into the flow stream.

Abstract: A vaned diffuser for a centrifugal compressor has provision for selectively adjusting the pitch of the vanes in order to accommodate variable load conditions. Each of the vanes is rotatable about a pivot pin near its leading edge and is engaged with an actuation member near its trailing edge. The actuation members are attached to a common ring which can be selectively rotated to move to the vanes in unison. The ring is supported by rollers at its outer periphery and is positioned at the outer periphery of a diffuser wall such that there is no forward facing step projecting into the flow stream.

Abstract: In order to accommodate a labyrinth seal whose diameter is too large to form a gas passage using conventional techniques, the labyrinth seal is made in two parts. A first part is an inner ring whose outer diameter is sufficiently small so as to permit the forming of a passage therein with conventional techniques. The second part is an outer ring which can then be fastened to the inner ring so as to then extend, in combination, to the radial extent necessary to complete the sealing engagement with an adjacent element. The outer and inner rings are preferably interconnected by way of an interference fit.

Abstract: An axial restraint system for use in a variable pipe diffuser having an inner ring rotatably positioned within an outer ring. The axial restraint system includes a housing fixedly mounted to the outer ring and having a mounting hole disposed therein in perpendicular arrangement to the inner ring. A shaft having a first end and a second end and having a bearing pad mounted to the first end. The second end of the shaft is threadably engaged within the mounting hole and rotatably operable to effect an adjustment of the position of the bearing pad. The shaft is positioned such that the bearing pad contacts the inner ring and thereby limits the axial movement of the inner ring relative to the outer ring.

Abstract: A gear shroud is provided in close surrounding relationship to the drive gear of a centrifugal compressor such that the turbulence within the surrounding gear housing is substantially reduced and the resulting high speed flow of refrigerant is instead directed into an adjacent oil sump. In order to prevent localized churning in the sump and the resulting cavitation at the oil pump as might be caused by the high velocity flow of refrigeration gas from the gear shroud, a baffle is provided over the oil pump to divert the inflow of gas into other areas of the sump.

Abstract: In the transmission of a centrifugal compressor, where a gear is located adjacent to a lubricated bearing, a barrier is provided between the bearing and the gear to restrain the flow of oil to the gear and thereby reduce the pumping and windage losses that would otherwise occur. An oil port is made to communicate with the internal area of the barrier to thereby provide drainage of the accumulated oil to a sump.

Abstract: A shaft-mounted piston is reciprocally disposed on the axis of a valve inlet opening such that increased pressure from within the motor casing of a centrifugal compressor causes the piston to move in the direction of the refrigerant flow, against a biasing means, to increase the flow of refrigerant through the opening, and to thereby regulate the pressure drop across said valve to a predetermined level. The shaft has an extended portion projecting through the piston toward the motor casing such that when the compressor is shut down and the pressure is thus greater in the valve than in the motor casing, the piston can move out of the inlet opening to the extended portion of the shaft to thereby allow the unrestricted flow of refrigerant into the motor casing.

Abstract: A cylindrical standpipe extends upwardly from the bottom of a liquid refrigerant sump, and vertical slots are formed in the sides thereof near the bottom end. On the inner sides of the standpipe, a sleeve is slideably disposed to uncover the slots as the sleeve is vertically raised. On the outer side of the standpipe a toroidal shaped float device, which is secured to the sleeve by a tube extending through upper side slots in the standpipe, is vertically moveable in response to the level of liquid refrigerant in the sump to thereby regulate the sleeve vertical position and therefore the flow of refrigerant from the sump.

Abstract: A centrifugal compressor is provided with a collector for receiving refrigerant from the diffuser, and sound absorbent segments are placed within the collector and retained in place against one wall thereof. One method of retention is by way of a ring and a plurality of spring clip members. The silencer segments and the retaining ring and spring clip members are placed into the collector prior to installation of the diffuser. As the diffuser is attached to the collector, one edge engages a side of the ring so as to axially move it into its final fixed position, while at the same time causing the attached spring clip members to be placed in tension against the silencer segments to secure them in place.

Abstract: A simple flow control device is provided in a condensate drain pipe to prevent the flow of refrigerant vapor therethrough and to regulate the flow of liquid refrigerant as a function of the level of accumulated liquid refrigerant in the drain pipe. The only moving part is a float device that rides up on a cylindrical valve body in response to the level of liquid refrigerant to thereby expose slots in the valve body which allow for the flow of liquid refrigerant to the refrigerant return line to the cooler.

Abstract: A labyrinth seal is provided to isolate the transmission from a balance piston of a centrifugal compressor, the labyrinth seal being pressurized with refrigerant vapor from the motor chamber, which vapor is at a pressure slightly above that in the transmission, to thereby minimize the efficiency losses that would otherwise occur from leakage of the vapor into the transmission and to the compressor suction.

Abstract: In a centrifugal compressor having an ejector for reclaiming the oil which tends to accumulate in a lower portion of the suction housing, the ejector high pressure line is provided with its inlet at the bottom of the collector such that, in addition to providing the high pressure power to the ejector, it also functions to pump out any oil that has accumulated at the bottom of the collector and to discharge it into the oil sump.

Abstract: A rotary vane pump has restricted fluid communication between the inlet and the trapped volume for about 4.degree. of rotation beyond when the vane starts past the inlet. Similarly there is restricted communication between the trapped volume and the outlet for about 4.degree. of rotation prior to the vane reaching the outlet. Additionally, in the preferred embodiment, the trapped volume is in restricted communication with the outlet prior to its isolation from the inlet.

Abstract: An apparatus and method is provided for initializing and calibrating a microprocessor controlled refrigeration system including a centrifugal compressor having a variable width diffuser section.

Abstract: A microcomputer system and method for controlling the capacity of a refrigeration system are disclosed. The microcomputer system receives electrical input signals indicative of operator selected settings and refrigeration system operating parameters. The microcomputer system processes these input signals to generate a control signal which is a step function of the temperature difference between a desired set point temperature and the sensed temperature of a heat transfer fluid cooled by operation of the refrigeration system. The width of each step of the step function is directly proportional to a selected capacity control response factor. By selecting different capacity control response factors, capacity control of the refrigeration system is tailored to meet specific job requirements of a particular job application for the refrigeration system.

Abstract: A protective capacity control system and method for controlling the capacity of a refrigeration system are disclosed. The protective capacity control system receives electrical input signals indicative of operator selected settings and refrigeration system operating parameters. These input signals are processed to generate a control signal which is a step function, preferably having two steps, of the temperature difference between a desired set point temperature and the sensed temperature of a heat transfer fluid cooled by operation of the refrigeration system. The capacity of the refrigeration system is reduced at a first effective overall rate to provide capacity control which will reduce hunting by the capacity control system when the sensed temperature of the heat transfer fluid cooled by operation of the refrigeration system is less than a lower limit of a selected temperature deadband relative to the desired set point temperature.

Abstract: A refrigeration system is disclosed having a purge system with means for monitoring operation of the purge system and for taking corrective action in response to excessive purge system operation. Preferably, the monitoring means is a microcomputer control system for monitoring purge pump operation to determine if the purge pump has operated continuously for a period of time greater than a predetermined amount of time. If the purge pump has operated continuously for a period of time greater than the predetermined amount of time, then the microcomputer control system overrides normal purge pump operation and maintains the purge pump inoperative for a selected time period before attempting to resume normal operation. The microcomputer control system counts the number of consecutive times that normal purge pump operation is overridden and totally disables the purge system if the number of consecutive overrides exceeds a preselected number.