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: A refrigerant compressor group for a refrigeration system, comprising at least two piston compressors that operate in parallel between a common low-pressure connector and a common high-pressure connector, wherein, for the purpose of adjusting it to different requirements, it is provided, in a refrigerant compressor group, for a variable overall mass flow throughput in the refrigerant compressor group to be adjustable in that, in the case of at least one of the piston compressors, its mass flow throughput is adjustable by speed selection with the aid of a frequency converter for the electric motor, and in that, in the case of at least one of the piston compressors, its mass flow throughput is adjustable by cylinder selection, and in that an operating condition controller for the refrigerant compressor group is provided which, on the basis of a performance request signal of the refrigeration system that is transmitted to the operating condition controller, controls the overall mass flow throughput by open or cl

Abstract: A refrigerant compressor for a refrigeration system comprises a common housing, a compressor unit arranged in the common housing, a mechanical compressor drive unit for the compressor unit, arranged in a drive chamber, a lubricant bath forming in the drive chamber, an intake duct that extends in a manner separated from the drive chamber and through which the compressor unit draws in by suction refrigerant that is to be compressed. The intake duct and the drive chamber are connected by a gas equaliser duct, which allows a permanent equalisation of gas, and which has on one side an opening on the drive chamber side and on the other an opening on the intake side, and of which the duct length between the openings corresponds to at least twice an equivalent duct diameter, in particular a smallest equivalent duct diameter, of the gas equaliser duct.

Abstract: Refrigerant compressor for refrigeration systems, comprising an electric motor, at least two cylinder banks and a mechanical performance control unit for activating and deactivating at least one of the cylinder banks in order to activate or deactivate its refrigerant output, wherein, for the purpose of operation in partial performance conditions, the refrigerant compressor is operable in at least two different operating modes, of which each provides an activation or deactivation of the cylinder banks that is different from the other operating modes, wherein associated with the refrigerant compressor is a frequency converter for controlling the speed of the electric motor, wherein associated with the refrigerant compressor is an operating condition controller that, in accordance with a performance request signal supplied to it for operation of the refrigerant compressor in the partial performance condition corresponding to this performance request signal, operates the refrigerant compressor in an operating mod

Abstract: In a refrigerant compressor for refrigeration plants, comprising a compressor unit driven by a drive unit, wherein at least one of these units is provided with a control unit which is controllable by means of a delivery rate control system in order to control the refrigerant compressor at different delivery rates, wherein an external delivery rate setpoint value is communicated to the delivery rate control system, in order to prevent critical operating states, it is proposed that the delivery rate control system acquires, by means of a sensor, a compressor reference temperature of the compressor unit, that the delivery rate control system ascertains an operating state value group for the acquisition of an operating state of the refrigerant compressor and, taking account of specified reference values, 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, specifies a delivery rate which has as

Abstract: In order to improve a refrigerant compressor, in particular for a refrigeration system, including a common housing, a compressor unit arranged in the common housing, a mechanical compressor drive unit for the compressor unit, arranged in a drive chamber of the common housing, a lubricant bath forming in the drive chamber, an intake duct that extends in the common housing in a manner separated from the drive chamber and through which the compressor unit draws in by suction refrigerant that is to be compressed, such that a refrigerant compressor is provided in which the spurting of lubricant is reduced to the greatest possible extent, it is proposed that that the intake duct and the drive chamber should be connected by way of a gas equaliser duct, which allows a permanent equalisation of gas between them, and which has on one side an opening on the drive chamber side and on the other an opening on the intake side, and of which the duct length between the openings corresponds to at least twice an equivalent duct

Abstract: In order to improve a semi-hermetic refrigerant compressor, comprising a reciprocating piston compressor, an electric motor, an overall housing which has a motor housing portion for the electric motor and a compressor housing portion for the reciprocating piston compressor, a suction-side refrigerant path which leads from a suction connection on the overall housing to an inlet chamber of the reciprocating piston compressor, and a pressure-side refrigerant path which leads from an outlet chamber of the reciprocating piston compressor to a pressure connection on the overall housing, such that the refrigerant compressor functions more efficiently, it is proposed that the electric motor is configured as a synchronous motor, in the rotor of which there are arranged permanent magnets for the synchronous operation of the electric motor and a squirrel cage for starting up the electric motor in asynchronous operation.