Abstract: An accumulator for use in an automobile, has an inner housing located within an outer housing. The inner housing has a channel formed therein, such that a fluid-tight flow path which goes down one side across the bottom and back up the other side to an exit orifice is defined. A cap having inlet and outlet orifices therethrough is secured to the outer housing and seals both the inner and the outer housings to prevent any leakage of any fluid.

Abstract: In a cooling device for a rotary piston compressor, in particular a screw-type compressor, which is part of a refrigerant circuit together with a condenser and an evaporator, coolant of the refrigeration system and oil serving to lubricate bearings as well as to cool and seal the screw-type compressor are injected into the screw-type compressor. In order to cool the oil serving to lubricate the compressor bearings separately and to thereby achieve a more economical functioning of the entire cooling device, it is suggested that only the part of the oil serving to lubricate the bearings of the compressor is cooled as a function of the oil temperature sensed behind the bearings and that a branched stream of coolant is used for this, the stream on its part subsequently being fed to the compressor again.

Abstract: A compressor is prevented from the problem of seizure at start-up even when return of lubricant to the compressor is delayed. In such a refrigerant cycle, a bypass passage bypasses an expansion member and an evaporator. The bypass passage opens for a predetermined time when the compressor starts. The predetermined time is dependent upon external temperature, the compressor speed, compressor capacity, etc.

Abstract: Two embodiments (FIGS. 1+ & FIGS. 5+) of a double, by-pass valve system for a closed refrigerant system allowing its safe servicing, the first being included in the original manufacturing of the compressor unit in the refrigerant exit line of the compressor (FIG. 4 ) and the second installed as a retro-fit on the compressor unit and provided "in-line" in the liquid refrigerant line. In the first a double valve body with a transverse bore through a main shut-off valve allows the flow of refrigerant to pass or be shut down to the rest of the system, while a secondary, access port with a transverse bore intersects the main flow valve on the upstream side of the seats by means of a manifold bore, providing a by-pass passageway to an access connection (minus a depressible valve core or "Schrader" valve) for a refrigerant hose to connect to the manifold charging gauges, allowing communication with the closed refrigerant system.

Abstract: In a multiroom air-conditioning apparatus, refrigerant flow between plural outdoor side units is controlled so that abnormality (lack or excess) of refrigerant amount in an outdoor side unit in operation is redressed. For example, when surplus refrigerant exists in an outdoor side unit, the refrigerant flow is so controlled that the surplus refrigerant is pushed out (flow out) into an outdoor side unit in non-operation. In addition, the output of the air-conditioning apparatus is smoothly variable (controllable) in accordance with an air-conditioning load over the whole air-conditioning load range from the minimum (zero) load to the maximum load.

Abstract: A crankcase heater control system for a refrigeration system includes a first temperature sensor for sensing the outdoor temperature, and, a second temperature sensor for sensing compressor discharge temperature. A controller is operatively connected to temperature sensors and the crankcase heater. When the ambient temperature falls below a first pre-determined temperature the controller compares the compressor discharge temperature to a second pre-determined temperature which is greater than the first pre-determined temperature and energizes the crankcase heater when the compressor discharge temperature falls below the second pre-determined temperature.

Abstract: A refrigeration system (10) having a compressor rotor (20) rotatably supported by a plurality of hydrodynamic bearings (22 and 24) lubricated by oiless pressurized liquid refrigerant supplied to a refrigerant circuit (36) coupled to the hydrodynamic bearings at least in part from the compressor rotor and pressurizing refrigerant which flows to a condenser (34) providing liquid refrigerant which flows to an evaporator (68) in fluid communication with the condenser includes a bearing pump (26), coupled to the refrigerant circuit and to the condenser, for providing pressurized refrigerant to the refrigerant circuit at a pressure higher than a pressure of the refrigerant provided by the compressor rotor when the bearing pump is operating; and a controller (28) for activating the bearing pump in accordance at least one the predetermined conditions of operation of the refrigeration system.

Abstract: The temperature is sensed at the compressor, indoor coil and outdoors. The sensed temperatures are compared and if the compressor temperature is not a specified amount higher than the lower of the other two sensed temperatures, then the crankcase heater is energized. When the compressor temperature rises to or is a specified amount above the lower of the other two temperatures, the crankcase heater is deenergized.

Abstract: A control apparatus for a multi-air-conditioner system provided with a freezing cycle wherein refrigerant is supplied from a common outdoor unit to a plurality of indoor units via respective control valves. In order for a compressor to recover refrigerant and oil contained therein remaining in an indoor unit under interception, the control valve of the indoor unit under interception is opened cyclically to a degree of opening corresponding to the rated capacity of the indoor unit for the predetermined time while circulating the refrigerant cyclically for a predetermined time to the indoor unit.

Abstract: In a variable speed air conditioning system driven by an electronically commutated DC motor, the large DC capacitor associated with the compressor motor drive discharges to the normally AC powered compressor oil sump heater upon the loss of AC power to the system.

Abstract: A system for refrigeration comprises: a compressor having an inlet, an oil sump, and an outlet; a condenser having an outlet, and an inlet connected to the compressor outlet; an expansion valve operable for controlling refrigerant flow in the system and having an outlet, and an inlet connected to the condenser outlet; an evaporator having an inlet connected to the expansion valve outlet and an outlet connected to the compressor inlet; and a control unit for operating the expansion valve to maintain a predetermined temperature differential between the temperature of oil in the oil sump and the saturated temperature of the refrigerant in the vicinity of the compressor inlet. The temperature differential is selected such that refrigerant in liquid phase in the compressor does not excessively dilute the compressor oil.

Abstract: Start-up problems in an intermittently operated evaporative cooling system to low temperature environments is avoided by the provision of one or more heaters 62, 64, 66 in the system. Typically the system will include an evaporator 10, a compressor 24, a condenser 42, a receiver 62 and an expansion valve 56. When low ambient temperatures reduce internal pressure within the system to a value below which it can be started through operation of the compressor 24, the heaters 62, 64, 66 may be energized to vaporize refrigerant and thus generate a pressure of sufficient magnitude so as to allow starting.

Abstract: A microprocessor controlled system for use in a refrigeration system which includes a plurality of pulse controlled solenoid flow control valves suitable for use as expansion valves is disclosed. A pulse width modulated control signal is generated for cyclically opening and closing the flow through the solenoid expansion valve. The duty cycle of the pulsed control signal determines the average flow rate through the valve. The microprocessor controls, periodically, the opening of each expansion valve to permit full flow therethrough to flush any accumulated compressor lubrication oil logged in any associated evaporator coils.

Abstract: An oil control system and regulator for controlling the oil level in the crankcase of one or more refrigeration compressors or the like are disclosed. The regulator comprises a shell and end cap closures defining a closed chamber for containing the oil. An inlet extends through one of the end cap closures and includes a float controlled valve for admitting liquid to the chamber as necessary to maintain the oil level in the chamber and compressor crankcases and also includes a piston which is movable up and down to adjust the float and the oil level in the regulator chamber. A threaded adjusting pin extends through the end cap closure and into the chamber and threads on the adjusting pin are threaded through a coupling bracket which couples the pin with the piston to move the piston, float and valve for adjusting the oil level.

Abstract: This invention provides a direct oil return system from the accumulator tank in the refrigerant circuit of a transport refrigeration system to the crankcase of the compressor for returning oil entrained in the refrigerant to the oil sump. A pressure relief valve in the lubricating oil circulating system positively opens under the influence of oil pressure from the positive displacement oil pump whenever the compressor is operating to bleed excess oil from the pump back to the sump. The oil return line from the accumulator tank of the refrigeration system is connected to the valve to enter through another inlet port which opens in response to the pressure relief valve being opened and flows therethrough to another outlet in the valve also in communication with the sump.

Abstract: A refrigerant system with a high speed centrifugal compressor has an arrangement for promoting the continuous return of oil to gear and bearing housing 12 including a coalescing type filter 62 from which separated oil is passed to a jet pump 74, a thermostatically controlled expansion valve 50 operating at a low superheat value, and inwardly pumping shaft seals 26.

Abstract: A compressor for a heat pump using a condensible gas as a working fluid has a lubricant temperature controller comprising a heater for the lubricant in the sump, the heater being controlled by differential pressure responsive means comprising the vapor pressure above the lubricant in the sump with a pressure obtained from a sensor bulb in the sump oil, the bulb containing a solution, in a lubricant of a refrigerant, the refrigerant preferably being the same as the working fluid of the heat pump.

Abstract: In a refrigerant system having a liquid trapping suction accumulator between the evaporator exit and the compressor entrance and a very short bore capillary as an expansion tube to replace the thermostatic expansion valve, a recirculating ejector is added to recirculate any liquid that may be trapped by the accumulator back into the evaporator inlet where it can be used to provide desired refrigerating effect without requiring additional work in the compressor. The expansion tube is positioned so that it functions as the primary nozzle of the ejector. Thus the high-pressure liquid refrigerant being expanded through the expansion tube becomes the prime mover that is needed to drive the liquid from the accumulator into the evaporator. Because the high-pressure liquid refrigerant must be expanded to the relatively lower evaporator pressure in any vapor cycle refrigeration system, the recirculating function is accomplished without using additional energy or penalizing system capacity.

Abstract: A positive displacement compressor, such as a helical screw rotary compressor without capacity control element, is coupled in a refrigeration loop main line between the evaporator and an oil separator and upstream of the condensor. To unload the screw compressor at low evaporator load, any refrigerant discharging from the compressor is bypassed by a line connecting the suction and discharge sides of the screw compressor, and main line connection from the evaporator to the screw compressor is shut off such that the driven, unloaded screw compressor pulls oil from the separator through a restrictor and oil injection port and some refrigerant vapor which passes to the evaporator side through the screw compressor bypass line. As the evaporator pressure increases, the evaporator is connected through a restrictor within the main line to the screw compressor suction.

Abstract: A refrigeration plant including an oil-injected compressor, an oil separator, a condenser and an evaporator. The plant comprises means to introduce liquid refrigerant to the compression phase of the cycle ahead of the oil separator. The plant further comprises means to adjust the amount of liquid refrigerant introduced in response to the temperature difference between the condenser and the oil separator, in order to keep the difference on a constant level of 5.degree. C. to 15.degree. C.