A pressure monitoring apparatus for a membrane compressor, with at least one pressure transducer for recording the pressure within a certain volume, with at least one nonreturn valve and with at least one shutoff valve, for blocking of the nonreturn valve, the shutoff valve and the nonreturn valve each being located in a flow path through which a medium can flow between the volume and the pressure transducer. A pressure monitoring unit delivers exact measured values and which can be economically implemented is achieved by there being at least two nonreturn valves which are located anti-parallel in respective flow paths, the first nonreturn valve blocking in the flow direction from the volume to the pressure transducer and the second nonreturn valve blocking in the flow direction from the pressure transducer to the volume, and by there being at least two shutoff valves for blocking a respective flow path.

In order to improve a refrigerant compressor, including a compressor unit having a compressor housing and at least one compressor element that is arranged in the compressor housing, for compressing refrigerant, and further including a drive unit having a drive housing and an electric motor that is arranged in the drive housing and connector terminals that are arranged on the drive housing, for the electric motor, and further including an electronic functional unit, such that the connection between the refrigerant compressor and the electronic functional unit is achievable as simply as possible, it is proposed that the connector terminals should be provided in a housing that is arranged on the drive housing, and that an electronic functional unit which performs at least one compressor function should be provided in the housing.

A displacement control valve includes a housing a first, a second, and a third chamber; a valve body having a first reciprocating valve part that opens or closes discharge paths in the first chamber; and a solenoid that applies electromagnetic force to the valve body in the direction that closes the first valve part. The control valve has a spool valve part formed on the external circumference of the valve body and a spool seating part formed on the internal circumference of the valve housing and that is opened while the first valve part is closed and vice versa upon reciprocation of the valve body to control the rate of flow between a control chamber and an inlet chamber.

In order to improve a refrigerant compressor, including a compressor unit having a compressor housing and at least one compressor element that is arranged in the compressor housing, for compressing refrigerant, and further including a drive unit having a drive housing and an electric motor that is arranged in the drive housing and connector terminals that are arranged on the drive housing, for the electric motor, and further including an electronic functional unit, such that the connection between the refrigerant compressor and the electronic functional unit is achievable as simply as possible, it is proposed that the connector terminals should be provided in a housing that is arranged on the drive housing, and that an electronic functional unit which performs at least one compressor function should be provided in the housing.

A displacement control valve includes a housing a first, a second, and a third chamber; a valve body having a first reciprocating valve part that opens or closes discharge paths in the first chamber; and a solenoid that applies electromagnetic force to the valve body in the direction that closes the first valve part. The control valve has a spool valve part formed on the external circumference of the valve body and a spool seating part formed on the internal circumference of the valve housing and that is opened while the first valve part is closed and vice versa upon reciprocation of the valve body to control the rate of flow between a control chamber and an inlet chamber.

In order to improve a refrigerant compressor, including a compressor unit having a compressor housing and at least one compressor element that is arranged in the compressor housing, for compressing refrigerant, and further including a drive unit having a drive housing and an electric motor that is arranged in the drive housing and connector terminals that are arranged on the drive housing, for the electric motor, and further including an electronic functional unit, such that the connection between the refrigerant compressor and the electronic functional unit is achievable as simply as possible, it is proposed that the connector terminals should be provided in a housing that is arranged on the drive housing, and that an electronic functional unit which performs at least one compressor function should be provided in the housing.

Systems and methods (e.g., a method for controlling and/or operating a compressor) are provided that includes the steps of monitoring a crankcase pressure of a first compressor; analyzing the monitored crankcase pressure that includes calculating an average of the crankcase pressure over a time period and comparing the average of the crankcase pressure over the time period to a nominal crankcase average pressure; identifying a condition of the first compressor based on the analysis of the monitored crankcase pressure; and adjusting operation of a second compressor to compensate for the first compressor in response to identifying the condition of the first compressor based on the analysis of the monitored crankcase pressure. (The method may be carried out automatically or otherwise by a controller).

A manually actuated feed pump is provided with a primer bulb to be manually actuated by an operator. The primer bulb has a pump chamber. A travel-controlled valve connects the pump chamber to a fuel line. The travel-controlled valve has a valve member that is moved by an actuation travel of the primer bulb into an open position that opens the travel-controlled valve. A first spring is operatively connected to the valve member and to the primer bulb. The primer bulb acts through the first spring on the valve member.

A pressure monitoring apparatus for a membrane compressor, with at least one pressure transducer for recording the pressure within a certain volume, with at least one nonreturn valve and with at least one shutoff valve, for blocking of the nonreturn valve, the shutoff valve and the nonreturn valve each being located in a flow path through which a medium can flow between the volume and the pressure transducer. A pressure monitoring unit delivers exact measured values and which can be economically implemented is achieved by there being at least two nonreturn valves which are located anti-parallel in respective flow paths, the first nonreturn valve blocking in the flow direction from the volume to the pressure transducer and the second nonreturn valve blocking in the flow direction from the pressure transducer to the volume, and by there being at least two shutoff valves for blocking a respective flow path.

Systems and methods (e.g., a method for controlling and/or operating a compressor) are provided that includes the steps of monitoring a crankcase pressure of a first compressor; analyzing the monitored crankcase pressure that includes calculating an average of the crankcase pressure over a time period and comparing the average of the crankcase pressure over the time period to a nominal crankcase average pressure; identifying a condition of the first compressor based on the analysis of the monitored crankcase pressure; and adjusting operation of a second compressor to compensate for the first compressor in response to identifying the condition of the first compressor based on the analysis of the monitored crankcase pressure. (The method may be carried out automatically or otherwise by a controller.)