Abstract: A refrigeration system with a high percentage of fresh air. The system comprises a supply air duct; an indoor heat exchange coil operably positioned in the supply air duct; a reheat heat exchange coil operably positioned in the supply air duct; an outdoor heat exchange coil; at least one compressor; and an expansion device. The system also comprises refrigeration system tubing connected to and serially arranging the compressor, the outdoor heat exchange coil, the expansion device and the indoor coil into a refrigeration circuit; and reheat tubing connecting the reheat coil to the refrigeration tubing so as to arrange the reheat coil in a parallel circuited arrangement with the outdoor heat exchange coil and in a series circuited arrangement with the compressor, the expansion device and the indoor heat exchange coil.

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 system with a high percentage of fresh air. The system comprises a supply air duct; an indoor heat exchange coil operably positioned in the supply air duct; a reheat heat exchange coil operably positioned in the supply air duct; an outdoor heat exchange coil; at least one compressor; and an expansion device. The system also comprises refrigeration system tubing connected to and serially arranging the compressor, the outdoor heat exchange coil, the expansion device and the indoor coil into a refrigeration circuit; and reheat tubing connecting the reheat coil to the refrigeration tubing so as to arrange the reheat coil in a parallel circuited arrangement with the outdoor heat exchange coil and in a series circuited arrangement with the compressor, the expansion device and the indoor heat exchange coil.

Abstract: A refrigeration system with a high percentage of fresh air. The system comprises a supply air duct; an indoor heat exchange coil operably positioned in the supply air duct; a reheat heat exchange coil operably positioned in the supply air duct; an outdoor heat exchange coil; at least one compressor; and an expansion device. The system also comprises refrigeration system tubing connected to and serially arranging the compressor, the outdoor heat exchange coil, the expansion device and the indoor coil into a refrigeration circuit; and reheat tubing connecting the reheat coil to the refrigeration tubing so as to arrange the reheat coil in a parallel circuited arrangement with the outdoor heat exchange coil and in a series circuited arrangement with the compressor, the expansion device and the indoor heat exchange coil.

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: An expansion device in a refrigeration chiller defines at least two fixed orifices and employs at least two positionable valve members in order to minimize the overall flow area through the expansion device under a first set of chiller operating conditions, to maximize the overall flow area through the expansion device under a second set of chiller operating conditions and to define a flow area intermediate said minimum and said maximum flow areas when a third set of chiller operating conditions exist.

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: Oil management apparatus for a refrigeration chiller includes a housing mounted to the head wall of an oil supply tank. The housing defines a series of ports and internal flow passages in communication with a valve cavity. A valve spindle disposed in the cavity is configured and positionable such that a plurality of oil flow passages within the chiller are capable of being setup in order to accommodate various chiller lubrication needs including those as they relate to both chiller operation and maintenance. The combination of an integral housing and single valve eliminates a large number of individual valves and the need to connect those valves and various chiller lubrication components, such as an oil filter and oil pressure regulator, with individual sections of difficult to fabricate piping. As a result, the likelihood of error in the setup of a chiller lubrication system is significantly reduced.

Abstract: A variable flow rate expansion valve designed for in-line installation in a fluid conveying conduit such as between the high pressure condenser and lower pressure evaporator of a refrigeration system includes an integrally defined restrictor disc and a closure disc for controlling the flow of fluid through the valve. The restrictor disc has a first set of flow apertures and the closure disc a second set of flow apertures. The closure disc is rotatably coupled to the restrictor device in a plane parallel to the plane of the restrictor disc and perpendicular to refrigerant flow. A stepper motor is coupled to the closure disc through a linear actuator. Movement of the linear actuator causes the closure disc to rotate relative to the restrictor disc such that the flow apertures of the closure disc are selectively brought into and out of registry with the apertures of the restrictor disc.

Abstract: An air valve actuated by an electric motor has a cylindrical inlet section. The inlet section defines a seating surface upstream of which is a support grid. A backplate, upon which the actuating motor is mounted, is fixedly supported by a plurality of rods that extend downstream of the inlet section. A damper assembly includes a generally planar damper mounted for movement axially of the inlet section. The damper assembly includes a splined rod which extends upstream and into a cooperating spline in the support grid. A threaded spindle extends downstream of the damper plate through a cooperatively threaded motor-driven drive gear which is mounted for rotation on the backplate. Because a portion of the damper assembly is splined, the damper assembly cannot rotate and is driven axially within the valve by the rotation of the drive motor and drive gear.

Abstract: Inside the hermetic shell of a scroll compressor, a normally closed solenoid valve seats against the back side of a stationary scroll plate to close a discharge opening through the plate. A coil circuit that actuates the valve has an electrical resistance that increases with temperature. The temperature dependent resistance allows the coil circuit to also function as a discharge temperature sensor. Should the discharge gas over-heat, the compressor motor and the valve are de-energized in response to the resistance exceeding a predetermined limit. The closed valve prevents backflow from rapidly reversing the rotational direction of the compressor, which can be extremely noisy and damaging to the compressor. Both the valve and the compressor motor are energized at the same time, regardless of the compressor's direction of rotation.

Abstract: A centrifugal fan includes a fan wheel having airfoil blades mounted for pivotal movement about their center of gravity. A yoke mechanism exterior of the fan wheel, when moved axially of the fan wheel drive shaft axis, causes actuator rods to move through the sidewall of the fan wheel. The axial movement of the actuator rods is translated first into rotary movement of a quill hub relative to the fan wheel and finally to radial movement of blade pivoting levers interior of the fan wheel. The movement of the blade pivoting levers causes the pitch of the individual fan blades to be changed in accordance with the degree of movement of the yoke mechanism. The yoke mechanism, actuator rods, quill hub and blade pivoting levers operate independently of the fan wheel so that blade pitch can be varied over an operating range irrespective of whether the fan wheel is stopped or is rotating.

Abstract: Apparatus for unloading a scroll compressor to modulate its capacity by separately controlling fluid flow into first and second inlets. The first and second inlets are disposed diametrically opposite each other in a fixed scroll plate, and are enclosed by a perimeter wrap which extends from the radially outer end of the fixed spiral shaped wrap element. A compliant sealing member is provided between the inner surface of the perimeter wrap and the outer flank surface of the orbiting scroll wrap to interrupt fluid flow between the two inlets through this area. Valves connected to the first and second inlets selectively control the flow of suction fluid into fluid pockets being formed between the radially outer ends of the orbiting and fixed wrap elements to unload the compressor over an extended range of its rated output capacity.

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 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 gas compressor of the scroll type is disclosed wherein means are provided for reducing its degree of compression as it starts from a standing start in order to reduce the initial starting torque required. To this end, passage means are provided which extend through the end plate means of the compressor from a location in communication with the closed moving volumes defined between the wrap elements to a second location in communication with working gas normally at discharge pressure during operation of the compressor. Valve means are associated with the passage means for permitting flow therethrough when the pressure within the closed moving volumes exceeds the discharge pressure at said second location as the compressor starts from a standing start, and for blocking flow therethrough during operation of the compressor when discharge pressure normally exceeds the pressure in the closed moving volumes.