Abstract: In order to improve an expansion installation for obtaining electrical energy from heat by means of a thermodynamic circulation procedure, comprising an expansion device, which is operated by an expanding working medium of the thermodynamic circulation procedure, and a generator driven by the expansion device, it is proposed that the expansion installation should be provided with a rotational speed sensor, which is coupled to a shaft of the expansion installation that rotates proportionally to a rotor of the generator, and which takes the form of an electrical sensor generator that generates an electrical sensor signal.

Abstract: In order to make a refrigerant compressor unit as light and compact as possible so that it can be used as a transcritical CO2 compressor, it is proposed that the cylinder head is manufactured from a cast material comprising iron and that the housing sleeve, the compressor housing portion and a cylinder housing block, which accommodates the cylinders, as well as the motor housing portion form a single-piece part, in particular made of lightweight material.

Abstract: In order to improve a method for selecting a frequency converter for a refrigerant compressor unit comprising a refrigerant compressor and an electric drive motor in such a way that the frequency converter is optimised for the application in question, it is proposed that a working state suitable for the operation of the refrigerant compressor unit is selected in an application field of an application diagram of the refrigerant compressor, that an operating frequency is selected for this selected working state, and that, on the basis of drive data, a working state operating current value corresponding to the selected working state and the selected operating frequency is ascertained for the operation of the refrigerant compressor unit.

Abstract: In order to improve a method for operating a compressor/expander machine in a circuit for a working medium, wherein the compressor/expander machine has a machine housing with a screw rotor housing, in which at least one screw rotor arranged between a low-pressure side and a high-pressure side is arranged for compressing/expanding the working medium and is coupled to a motor/generator unit, in such a way that damage is avoided in the region of the screw rotors, it is proposed that an operation control unit is provided for operating the compressor/expander machine and, in the event of termination of operation of the compressor/expander machine, operates the motor/generator unit in accordance with a predetermined speed curve until a lowest speed range of the at least one screw rotor is reached, which prevents damage in the region of the screw rotor.

Abstract: In a refrigerant compressor comprising an overall housing with a motor housing portion, in which there is arranged a motor chamber having, provided therein, an electric motor comprising a stator and a rotor, and with a compressor housing portion which has a compressor unit, in order to be able to mount the stator as easily as possible it is proposed that the stator is mounted in the motor housing portion by means of supporting elements inserted into the motor housing portion, which supporting elements on the one hand abut against a stator-receiving surface of the motor housing portion and on the other hand surround the stator inserted into the supporting elements on its outer side and support it spring-elastically relative to the stator-receiving surface.

Abstract: A scroll compressor is provided, the scroll compressor comprises two scroll bodies, one of the two scroll bodies is a stationary scroll body with a scroll wrap and the other scroll body of the two scroll bodies is a moveable scroll body with a scroll wrap, the scroll wraps of the two scroll bodies engage each other forming at least one compression chamber, and the stationary scroll body comprises a base plate and the stationary scroll body has two opposing sides with respect to the base plate and on a first side of the two opposing sides the scroll wrap of the stationary scroll body is arranged and on a second side of the two opposing sides at least one pressure pocket is formed and at least one vent passage is provided through the base plate from the first side to the second side, the vent passage opens at the second side into the at least one pressure pocket and the vent passage has an opening at the first side which is arranged such that the vent passage is fluidly connected to the at least one compression

Abstract: In a refrigerant compressor comprising an overall housing with a motor housing portion, in which there is arranged a motor chamber having, provided therein, an electric motor comprising a stator and a rotor, and with a compressor housing portion which has a compressor unit, in order to be able to mount the stator as easily as possible it is proposed that the stator is mounted in the motor housing portion by means of supporting elements inserted into the motor housing portion, which supporting elements on the one hand abut against a stator-receiving surface of the motor housing portion and on the other hand surround the stator inserted into the supporting elements on its outer side and support it spring-elastically relative to the stator-receiving surface.

Abstract: A scroll machine with an injection for a medium has a machine housing with a longitudinal axis. A first scroll unit with scroll channel is formed by a scroll rib. A second scroll unit has a first side and a second side opposite the first side. A scroll channel formed by a second scroll rib is provided on the first side, and a high-pressure chamber is arranged on the second side of the second scroll unit and connected with the scroll channel via a passage. These are arranged in the machine housing along the longitudinal axis. The first scroll unit and the second scroll unit engage with each other to form pressure chambers. The first scroll unit can be moved relative to the second scroll unit along an orbital path. An intermediate base is provided along the longitudinal axis between the second scroll unit and the high-pressure chamber.

Abstract: In order to adapt to different operating conditions a screw expander, comprising an expander housing with a screw rotor chamber arranged therein, two screw rotors arranged in the screw rotor chamber and mounted rotatably in the expander housing, which screw rotors intermesh with their screw contours in order to receive working medium supplied by means of a high-pressure chamber arranged in the expander housing and in order to discharge said medium in the region of a low-pressure chamber arranged in the expander housing, and a generator driven by the screw rotors, it is proposed that the screw expander has at least one control slide, which is arranged in a slide channel of the expander housing and is adjacent to both screw rotors with slide wall surfaces, which control slide is movable in a displacement direction parallel to the screw rotor axes and is thereby configured to influence the final volume and/or the initial volume, and that a slide drive is provided for moving the control slide into different slide

Abstract: A refrigerant compressor for refrigeration plants having a compressor unit driven by a drive unit. At least one of the compressor and drive units has a control unit which is controllable by delivery rate control system to control the refrigerant compressor at different delivery rates. An external delivery rate setpoint value is communicated to the delivery rate control system to prevent critical operating states. The delivery rate control system is configured to acquire, via a sensor, a compressor unit reference temperature. The delivery rate control system is configured to ascertain an operating state value group to acquire an operating state of the refrigerant compressor, and specify a delivery rate for operation of the refrigerant compressor outside of the critical operating states, if the value of the ascertained operating state value group based upon the compressor reference temperature permits a critical operating state of the refrigerant compressor.

Abstract: In order to improve a machine for depressurizing or compressing substantially gaseous media, comprising a machine casing and at least one screw rotor, which is arranged in a screw rotor bore in the machine casing, extends between a low-pressure side and a high-pressure side of the screw rotor bore, cooperates with the substantially gaseous medium and is mounted on both sides in the machine casing by means of a respective bearing set, and a motor/generator unit that is coupled or couplable to the at least one screw rotor, it is proposed that the at least one screw rotor should be provided with at least one axial support bearing that axially supports the at least one screw rotor such that a high-pressure end face of the at least one screw rotor is guided, without making contact, to an end wall, which faces this end face, of the machine casing that receives the at least one screw rotor.

Abstract: A scroll compressor includes two scroll bodies each having a scroll rib. The scroll ribs engage each other to form at least one compression chamber. The scroll compressor further comprises a drive shaft for driving a moveable scroll body of the two scroll bodies. The moveable scroll body includes a base plate which has two opposing sides. On a first side of the two opposing sides, the scroll rib is arranged, and on a second side of the two opposing sides a hub is arranged. The hub has a receiving portion for a drive section of the drive shaft. The moveable scroll body has at least one passage from an interior of the receiving portion to a hub environment located around the hub at the second side of the two opposing sides.

Abstract: In order to improve a refrigerant compressor of the type mentioned in the introduction such that it is ensured that, even in the event of a tilt along a longitudinal direction of the refrigerant compressor unit relative to a horizontal course of the longitudinal direction, lubricant can reliably be drawn off by suction out of the lubricant sump, in order to prevent excessive accumulation of lubricant in the lubricant sump, it is proposed that there should be provided on the bottom side of the motor compartment a receiving point that takes a form such that the receiving point supplies lubricant from the lubricant sump to the suction-removal unit.

Abstract: In order to improve a method for selecting a frequency converter for a refrigerant compressor unit comprising a refrigerant compressor and an electric drive motor in such a way that the frequency converter is optimised for the application in question, it is proposed that a working state suitable for the operation of the refrigerant compressor unit is selected in an application field of an application diagram of the refrigerant compressor, that an operating frequency is selected for this selected working state, and that, on the basis of drive data, a working state operating current value corresponding to the selected working state and the selected operating frequency is ascertained for the operation of the refrigerant compressor unit.

Abstract: In order to increase the efficiency, in respect of the quantity of refrigerant to be compressed, of a reciprocating piston compressor for refrigerant, comprising a compressor housing having at least one compressor stage that has at least one cylinder unit, wherein a piston is movably arranged in the cylinder unit, a cylinder drive that is arranged in the compressor housing, for the at least one piston, a valve plate that closes off a cylinder chamber and is provided with at least one suction valve which, for its part, has a suction opening, arranged in the valve plate and closable by a suction vane, and has at least one outlet valve with an outlet opening, wherein the at least one suction valve and the at least one outlet valve are associated with the respective cylinder chamber, and a cylinder head that is arranged on an opposite side of the valve plate to the cylinder chamber, it is proposed that the valve plate should have, on its side facing the cylinder chamber, a recess, which is arranged inside an exte

Abstract: A refrigeration system, in particular a transport refrigeration system, comprising: a refrigerant circuit, which in particular works using CO2 as the refrigerant and in which there is guided a total mass flow of the refrigerant; a high-pressure-side heat exchanger arranged in the refrigerant circuit and cooling refrigerant compressed to a high pressure; at least one cooling stage which expands the principal mass flow from the intermediate-pressure collector to a low pressure in at least one cooling expansion member and in so doing makes refrigeration capacity available at a low-pressure-side heat exchanger; and a refrigerant compressor unit which compresses the principal mass flow from a low pressure to a high pressure, wherein the refrigerant compressor unit has a first compressor stage for compressing, to a medium pressure, the refrigerant of the principal mass flow supplied at low pressure, and a second compressor stage for compressing, to a high pressure, the refrigerant of the principal mass flow that ha

Abstract: In order to improve a method for selecting a frequency converter for a refrigerant compressor unit comprising a refrigerant compressor and an electric drive motor in such a way that the frequency converter is optimised for the application in question, it is proposed that a working state suitable for the operation of the refrigerant compressor unit is selected in an application field of an application diagram of the refrigerant compressor, that an operating frequency is selected for this selected working state, and that, on the basis of drive data, a working state operating current value corresponding to the selected working state and the selected operating frequency is ascertained for the operation of the refrigerant compressor unit.

Abstract: In order to improve a method for operating status determination of a refrigerant compressor/expander comprising a compressor unit and a drive unit such that information on the operating status of a refrigerant compressor/expander which is as reliable as possible can be obtained, it is proposed that, for at least one bearing of the refrigerant compressor/expander, a load value resulting from an operation of said refrigerant compressor/expander and a speed value are determined and in that, on the basis of the speed value and the load value and also at least one operating parameter, there is determined for the at least one bearing an operating prediction value for a future maintenance-free operation of the refrigerant compressor/expander.