A pump includes: a stator (4), a rotor (6) slidably and rotatably mounted at least partially in the stator, the rotor comprising a first axial extension (24) having a first diameter (D1) and a second axial extension (26) having a second diameter (D2) greater than the first diameter, a first valve (V1) formed by a first valve seal (18) mounted on the stator around the first axial extension, in conjunction with a first channel (42) in the rotor that is configured to allow liquid communication across the first valve seal when the first valve is in an open position, a second valve (V2) formed by a second valve seal (20) mounted on the stator around the second axial extension, in conjunction with a second channel (44) in the rotor that is configured to allow liquid communication across the second valve seal when the second valve is in an open position; a pump chamber (8) formed between the rotor (6) and stator (4) and between the first valve seal (18) and second valve seal (20); and a pump chamber seal (22) circumscribing the rotor second axial extension and separating the pump chamber (8) from an external environment. The stator (4) further comprises a dead-zone seal section (40) surrounding a dead-zone volume (39) formed between the rotor second axial extension (26) and the stator (4), wherein the dead-zone seal section (40) comprises axially extending portions (58) connected to upper and lower radial portions (60,60′) to form a closed sealing circuit.

In order to enable a continuous adjustment of the variable clearance space (1) of a reciprocating compressor (15), a threaded spindle drive with a threaded spindle nut (10) and a threaded spindle (9) is provided as an adjusting device (7), wherein the threaded spindle nut (10) is embodied as a plastic nut (20) with internal thread (24), the plastic nut (20) is arranged with an external thread (23) on an internal thread (22) of a nut carrier (21) of the threaded spindle nut (10), and the thread height (y) of the internal thread (22) of the nut carrier (21) and the thread height (x) of the external thread (25) of the threaded spindle (9) is respectively embodied with 50 to 80% of the radial thickness (d) of the plastic nut (20) and the plastic thickness is at least 15% of the thread pitch (z1) of the internal thread (24) at least in the region of the thread flanks (26) of the internal thread (24) of the plastic nut (20).

In order to enable a continuous adjustment of the variable clearance space (1) of a reciprocating compressor (15), a threaded spindle drive with a threaded spindle nut (10) and a threaded spindle (9) is provided as an adjusting device (7), wherein the threaded spindle nut (10) is embodied as a plastic nut (20) with internal thread (24), the plastic nut (20) is arranged with an external thread (23) on an internal thread (22) of a nut carrier (21) of the threaded spindle nut (10), and the thread height (y) of the internal thread (22) of the nut carrier (21) and the thread height (x) of the external thread (25) of the threaded spindle (9) is respectively embodied with 50 to 80% of the radial thickness (d) of the plastic nut (20) and the plastic thickness is at least 15% of the thread pitch (z1) of the internal thread (24) at least in the region of the thread flanks (26) of the internal thread (24) of the plastic nut (20).

The performance of a solenoid drive liquid pump can be very dependent on the magnitude and stability of an input voltage, with non-ideal input power resulting in loss of efficiency and potential damage to the pump. Pulse width of drive signals provided to the pump, which cause solenoids to alternately energize to move liquid through the pump, may be adjusted in duration in order to compensate for non-ideal input voltage. A drive control module of the pump gathers voltage information, determines an improved pulse width based upon that voltage information, and then provides drive signals based upon the improved pulse width. Operating in this manner, a pump can operate at or near peak efficiency despite both significant variances in input voltage and non-sinusoidal input voltage, and without customized components or adapters.

The performance of a solenoid drive liquid pump can be very dependent on the magnitude and stability of an input voltage, with non-ideal input power resulting in loss of efficiency and potential damage to the pump. Pulse width of drive signals provided to the pump, which cause solenoids to alternately energize to move liquid through the pump, may be adjusted in duration in order to compensate for non-ideal input voltage. A drive control module of the pump gathers voltage information, determines an improved pulse width based upon that voltage information, and then provides drive signals based upon the improved pulse width. Operating in this manner, a pump can operate at or near peak efficiency despite both significant variances in input voltage and non-sinusoidal input voltage, and without customized components or adapters.

The invention is based on an oscillating armature pump, in particular for a beverage machine, for conveying a liquid, having a pressure cylinder, a working cylinder, a working piston that has a piston part that is configured to be guided in the pressure cylinder and to delimit a pressure chamber together with the pressure cylinder, and that has a magnet element that is configured to be guided in the working cylinder, the working piston being configured to be set in stroke motion, in particular oscillating stroke motion, along a working axis in order to enlarge and/or reduce a volume of the pressure chamber.

It is proposed that the working piston has at least one first connection point that is configured to connect the piston part and the magnet element to one another, in particular directly, and to transmit forces having any direction from the magnet element to the piston part along the working axis.

The invention is based on an oscillating armature pump, in particular for a beverage machine, for conveying a liquid, having a pressure cylinder, a working cylinder, a working piston that has a piston part that is configured to be guided in the pressure cylinder and to delimit a pressure chamber together with the pressure cylinder, and that has a magnet element that is configured to be guided in the working cylinder, the working piston being configured to be set in stroke motion, in particular oscillating stroke motion, along a working axis in order to enlarge and/or reduce a volume of the pressure chamber.

It is proposed that the working piston has at least one first connection point that is configured to connect the piston part and the magnet element to one another, in particular directly, and to transmit forces having any direction from the magnet element to the piston part along the working axis.

A pump includes: a stator (4), a rotor (6) slidably and rotatably mounted at least partially in the stator, the rotor comprising a first axial extension (24) having a first diameter (D1) and a second axial extension (26) having a second diameter (D2) greater than the first diameter, a first valve (V1) formed by a first valve seal (18) mounted on the stator around the first axial extension, in conjunction with a first channel (42) in the rotor that is configured to allow liquid communication across the first valve seal when the first valve is in an open position, a second valve (V2) formed by a second valve seal (20) mounted on the stator around the second axial extension, in conjunction with a second channel (44) in the rotor that is configured to allow liquid communication across the second valve seal when the second valve is in an open position; a pump chamber (8) formed between the rotor (6) and stator (4) and between the first valve seal (18) and second valve seal (20); and a pump chamber seal (22) circumscribing the rotor second axial extension and separating the pump chamber (8) from an external environment. The stator (4) further comprises a dead-zone seal section (40) surrounding a dead-zone volume (39) formed between the rotor second axial extension (26) and the stator (4), wherein the dead-zone seal section (40) comprises axially extending portions (58) connected to upper and lower radial portions (60,60) to form a closed sealing circuit.

A method for operating a linear compressor includes establishing a set of predictors, and establishing a model for an estimated head clearance of the linear compressor with the set of predictors. Coefficients of the model for the estimated head clearance of the linear compressor may also be established. The model for the estimated head clearance of the linear compressor may be used to calculate an estimated head clearance during operation of the linear compressor.

A method for operating a linear compressor includes establishing a set of predictors, and establishing a model for an estimated head clearance of the linear compressor with the set of predictors. Coefficients of the model for the estimated head clearance of the linear compressor may also be established. The model for the estimated head clearance of the linear compressor may be used to calculate an estimated head clearance during operation of the linear compressor.