Abstract: Lift valves are used for controlling the capacity of a rotary compressor and to vary the built-in volume in the rotary compressor. When controlling the capacity of the rotary compressor, the built-in volume is adjusted by controlling the opening and closing of the lift valves in relation to one another.

Abstract: In a rotary compressor of a cooling or heat pump system, the inner volume relation should be related in a predetermined way to the pressure relation of the compressor for an optimal efficiency to be achieved. The built-in volume relation must therefore be variable to be adapted, for example, to full load and partial load. In order to achieve the highest efficiency with respect to loading requirements, a valve device has been developed, in which the outlet port is formed in such a way as to substantially correspond to the theoretically correct radial outlet port and in which a valve body (13) adapted for the purpose has its line of action oriented towards the outlet plane.

Abstract: For controlling the internal volume of a rotary compressor (5), adjustable valve bodies (3) are used on the outlet side. External control means, often of an extremely complicated nature, have previously been used to control the internal volume in the rotary compressor. By allowing the different pressure levels of the rotary compressor (5) to directly influence a control section (1), the position of the valve body (3) can be controlled by an operating section (2). In the control section (1) an intermediate pressure (9) from the compressor is balanced against a pressure from the high-pressure side (19) of the compressor by a plunger (6) having different diameters. The position of the plunger (6) then determines the control of the internal volume by the position of the valve body (3) connected to the operating section (2).

Abstract: Adjustable valve bodies are used on the outlet side for controlling the internal volume of a rotary compressor. External control means, often of an extremely complicated nature, have been used to control the internal volume in the rotary compressor. By allowing the different pressure levels of the rotary compressor directly influence a control section (1), the position of the valve body (3) can be controlled by an operating section (2). In the control section a spring pressure and a medium pressure (9) from the compressor are balanced by a plunger (6) against a pressure from the high-pressure side (19) of the compressor. The position of the plunger (6) then determines control of the internal volume via the setting of the valve body (3) connected to the operating device (2).

Abstract: Ice is formed by allowing water to partially evaporate in a vacuum. The ice can then be removed and be collected for subsequent use. For the creation of the vacuum, means for reduction of the pressure are required. A vapor compressor may be used for suction and compression of the water vapor to a pressure which enables condensing on a cold surface without freezing occurring. To be able to manufacture ice in a vacuum without using an expensive water vapor compressor, a method and a device for the manufacture of an ice slurry include which several cooperating vacuum chambers (1, 2, 3) with cold surfaces (6, 7, 8) used in a plant without a water vapor compressor. In this plant fresh water is supplied to one of the vacuum chambers for defrosting thereof, the thermal energy of the fresh water being utilized for that purpose. The precooled water thus formed is supplied to the other vacuum chambers, in which they will then form ice.

Abstract: In a rotary compressor for refrigeration and heat pump systems with an integrated drive motor on the high-pressure side, the operating medium will flow over the drive motor. During operating of the rotary compressor gas pulsations/pressure pulses will occur on both low-pressure and high-pressure sides. In order to suppress these pressure pulses on the high-pressure side one or more chambers with different volumes are provided, joined by channels between the discharge opening and the drive motor.

Abstract: In coolant systems oil mixed with the coolant is often removed in a separate oil separator on the high-pressure side of the compressor. In order to obtain a compact design in a coolant system comprising a unit including an oil-injection rotary compressor, a pressure-gas cooled driven motor and an oil separator, the oil separator is applied directly to the drive motor connected to the rotary compressor.

Abstract: When regulating the capacity of a rotary screw compressor in a refrigeration and heating pump system and when varying the built-in volume therein, lift valves are used which operate instantaneously and are either open or closed. In order to ensure sufficient pressure on the lift valves to effect closing, the wall of the lift valves is shaped with two different diameters and a sharply defined step therebetween. Upon closing, the sharply defined step is influenced by a pressure which is lower than the pressure influencing the end surfaces of the lift valve.

Abstract: A rotary compressor in a cooling or a heat pump system which is provided with an oil injector and includes an oil separator on the high pressure side of the system. Oil is returned to the compressor for lubrication, cooling and sealing and is normally caused to circulate by means of the natural pressure differences in the cooling system. When the pressure level is too small to provide sufficient oil circulation, an oil pump is connected. By employing a pressure controlled regulating valve in the system, which serves both as a pressure regulating and a flow regulating valve, the oil pump may be caused to run idle when a sufficient pressure difference has been attained in the system.

Abstract: A compressor of the rotary type is driven by a motor via a gear wheel arranged on the shaft of the compressor and cooperating with a gear wheel arranged on the shaft of the motor, the gear wheels and the shafts being enclosed in a gear housing. The motor is fastened to a detachable wall part of the gear housing, and the motor shaft is journalled solely in the bearings of the motor and protrudes into the gear housing through an opening in the wall part. The opening is provided with sealing means which prevent a medium from forcing its way out of the gear housing. The gear wheels are accessible for dismantling and assembly when the wall part together with the motor is detached from the rest of the gear housing.

Abstract: A device for fixing a shaft journalled in a roller bearing, in an axial direction of the shaft, comprising a resilient element which presses the bearing against a supporting surface of a bearing housing and provides a measure of radial adjustment of the shaft in the housing. The fixing device also includes a screw-threaded member, which in its screwed-in position limits axial movement of the roller bearing.

Abstract: A device for controlling the volumetric capacity of a screw compressor having two rotors, which are in meshing engagement with each other, in a compression chamber enclosed in a housing, in which there is also arranged a bore in parallel with the rotors, the bore being connected to the compression chamber through a number of channels distributed axially in the bore, a plunger being arranged to be movably guided in the bore as volume control is effected. Depending on the position of the plunger in the bore, the number of the channels covered thereby varies. The plunger is hollow and has an opening at one end through which a rod fixed in the bore passes, the rod carrying a piston sealingly engaging the inside surface of the plunger. At its other end, the plunger is closed by an end wall. The position of the plunger in the bore is adjusted by the supply of a control medium, such as oil, which influences both sides of the end wall. Any volatile refrigerant, such as R.sub.22 or R.sub.

Abstract: In a compressor having at least two cooperating rotors of which at least one has a screw form, the medium to be compressed is supplied through a stationary inlet port located radially outside the screw-formed rotor at the meshing zone between the rotors, where new volume on rotation of the rotors is continuously formed for sucking the medium into the compressor. The inlet port extends in the axial direction of the screw-formed rotor with a substantially constant width and shows an area which is substantially in accordance with the sum of the cross-sectional areas of the grooves of the screw-formed rotor, which grooves communicate with the inlet port and in which the medium is transported further on into the compressor.

Abstract: In the operation of a refrigeration system comprising a compressor, a condensor, an expansion valve and an evaporator which form a circulation circuit containing NH.sub.3 refrigerant as a first medium, the compressor being lubricated by a second medium, oil, part of the oil quantity being continuously discharged from the compressor together with compressed NH.sub.3 -gas into the circulation circuit for recirculation of oil to the compressor, continuously or batchwise, from the low pressure region of the circulation circuit, that is, the region located between the expansion valve and the compressor, the part of the oil transferred to the low pressure region (5, 6, 8, 9, 10, 11) of the circulation circuit is contacted with a third medium, added to the circulation circuit and which is substantially insoluble in liquid NH.sub.

Abstract: A rotary compressor has an outlet port with a variable area for discharging compressed medium from a working chamber to the outlet. The degree of opening of the outlet port is controlled by a regulator which senses the energy supplied to the compressor for compressing the medium and which from time to time changes the degree of opening of the outlet port until the need of drive energy for the compressor becomes minimal.

Abstract: Flexible pipes unwound from a supply drum are placed adjacent a wall to be supported, and water is applied to the outside of the pipes while passing through them a cooling medium at a temperature below the melting point of ice, thereby freezing a first ice layer against the wall. Cooling medium at a temperature above the ice melting point is then passed through the pipes to loosen them from the ice; and at least some of the pipes are rewound on the drum to remove them from the first ice layer and are then replaced outside but adjacent thereto, after which the procedure is repeated until enough ice layers are formed to provide a block of desired thickness.

Abstract: In a rotary compressor of the sliding vane type, the vanes maintain sliding contact with the inner wall of the housing while moving periodically inward and outward in generally radial slots in the cylindrical rotor, which is provided with conduits for injecting oil or other liquid into the working chambers formed by the rotor, the vanes and the housing's inner wall. The housing has inlet ports for a gas to be compressed in the working chambers and has outlet ports for the compressed gas. Valves are provided to open and close said rotor conduits in synchronism with said periodic moving of the vanes, whereby the liquid is injected into the working chambers only during such periods when these chambers are closed to the gas inlet and outlet ports.

Abstract: A compressor, a condenser, an expansion valve and an evaporator are interconnected in a refrigeration circuit, the evaporator discharging the refrigerant toward the compressor as a two-phase flow which is a mixture of liquid particles and superheated vapor. A flow disturbing element is located in the circuit downstream from the evaporator and operates to give the two flowing phases an increased mutual relative speed.

Abstract: A slide bearing journals the rotor shaft in the compressor housing with a clearance radially of the shaft; and an anti-friction bearing mounted on the shaft journals it axially thereof, the housing having a fixed support surface against which the anti-friction bearing abuts axially in one direction and which allows radial movement thereof. Yielding means are provided to press the anti-friction bearing against the support surface with a predetermined precise force.

Abstract: A rotor is journalled in a housing having gas inlet ports and outlet ports for compressed gas, the gas being compressed in working chambers formed between the rotor, an inner surface of the housing and vanes which periodically move inward and outward in slots in the rotor during its rotation and while sliding against said inner surface of the housing. Oil or other liquid is injected into the working chambers through grooves in at least one internal wall of the housing, the grooves being positioned to communicate with the working chambers through small recesses, located in edge portions of the rotor, during at least parts of the periods starting when a vane immediately trailing one of said recesses has just passed a said inlet port, thus blocking the connection between said last inlet port and the corresponding working chamber immediately preceding said vane, and ending when the pressure in said corresponding working chamber equals the liquid injection pressure.