Technologies are generally described for clearance adjustments in twin-screw pump assemblies. A twin-screw pump assembly may include a conically shaped portion of a drive shaft enveloped by a bushing. For clearance adjustment, both clamping nuts of the drive shaft, which provide pretention to the bushing and secure an axial position of a threaded screw to the drive shaft, may be removed on the flow side of the pump assembly and the bushing loosened to adjust the angularity between bushing and drive shaft. The bushing may then be pushed over the conically shaped portion and both clamping nuts re-assembled. In some examples, a clamping nut of the driven shaft may be designed and used as removal/loosening tool for the drive shaft bushing.

A compressor provided with a compressor element with a driven shaft, a motor with a drive shaft to drive the compressor element, and a transmission between the drive shaft and the driven shaft. The transmission includes a housing and at least a driven gearwheel that is mounted on the driven shaft and a drive gearwheel that is mounted on a drive shaft. The housing includes two separated chambers, a first chamber that is connected to the driven shaft and a second chamber which is separate from the first chamber. The first chamber is connected via a channel with the second chamber, whereby around the drive gearwheel or driven gearwheel, the second chamber is formed. The form of the second chamber is such that when the gearwheel in question rotates, a gas flow is created around this gearwheel which causes a negative pressure in the channel by the venturi effect.

An optimized mechanical expander or fluid expansion device with a delayed opening timing is disclosed. In the optimized design, rotors in the expander alternatingly rotate sequentially through an intake position in which the transport volume is open to the housing inlet, a closed position in which the transport volume is closed to the housing outlet, and a discharge position in which the transport volume is open to the housing outlet. During rotation, a first opening forms between the housing and each rotor. After further rotation, a second opening is formed that is located between the first opening and a back end of the rotor. In one aspect, the mechanical expander has an opening profile including an initial opening phase in which the opening between the rotor and outlet forms at a lesser rate than during a subsequent secondary opening phase.

An optimized mechanical expander or fluid expansion device with a delayed opening timing is disclosed. In the optimized design, rotors in the expander alternatingly rotate sequentially through an intake position in which the transport volume is open to the housing inlet, a closed position in which the transport volume is closed to the housing outlet, and a discharge position in which the transport volume is open to the housing outlet. During rotation, a first opening forms between the housing and each rotor. After further rotation, a second opening is formed that is located between the first opening and a back end of the rotor. In one aspect, the mechanical expander has an opening profile including an initial opening phase in which the opening between the rotor and outlet forms at a lesser rate than during a subsequent secondary opening phase.

A screw spindle pump having a spindle housing, in which a drive spindle and at least one running spindle which meshes therewith are received in spindle bores, and which has an axial fluid inlet and an axial fluid outlet, and also an outer housing enclosing the spindle housing, wherein either a support device which axially supports the at least one running spindle and includes an axially projecting support pin is provided on the spindle housing, which is plastic, in the region of the fluid outlet, or a support device which axially supports the at least one running spindle and includes an axially projecting support pin is provided on a housing plate which is fitted on the outer housing, axially closes the outer housing, and is plastic.

A method of operating a thermal exchange engine having a thermal energy conduction surface and rotating elements in the vessel which form a plurality of closed working chambers which increase or decrease in volume as the rotating elements move. The method involves placing a phase change fluid in each of the working chambers and operating the vessel as on a closed cycle without addition of phase change fluid into the vessel or removal of phase change fluid from the vessel. The method involves applying thermal energy to the thermal energy conduction surface, thereby thermally increasing or decreasing a pressure inside at least one working chamber positioned adjacent to the thermal energy conduction surface, such that the change in pressure inside the at least one working chamber causes the rotating elements to move the at least one working chamber away from the thermal energy conduction surface.

A method of operating a thermal exchange engine having a thermal energy conduction surface and rotating elements in the vessel which form a plurality of closed working chambers which increase or decrease in volume as the rotating elements move. The method involves placing a phase change fluid in each of the working chambers and operating the vessel as on a closed cycle without addition of phase change fluid into the vessel or removal of phase change fluid from the vessel. The method involves applying thermal energy to the thermal energy conduction surface, thereby thermally increasing or decreasing a pressure inside at least one working chamber positioned adjacent to the thermal energy conduction surface, such that the change in pressure inside the at least one working chamber causes the rotating elements to move the at least one working chamber away from the thermal energy conduction surface.

A thermal energy recovery device includes: a circulation line having an evaporator, an expander, a condenser, and a pump; a power recovery machine; a first on-off valve; a thermal energy introduction line configured to introduce a gas phase working medium into a post-expansion space; a second on-off valve; and a control unit. Until an evaporation condition that a liquid phase working medium accumulated in the post-expansion space has reached an amount equal to or smaller than a reference amount is met, the control unit closes the first on-off valve and opens the second on-off valve, and drives the pump in a state where the expander is stopped, and when the evaporation condition is met, the control unit opens the first on-off valve and closes the second on-off valve, and drives the expander.

A gear pump for power generation comprises a first rotor and a second rotor in a case. The first rotor comprises a first plurality of radially spaced teeth, wherein the first plurality of radially spaced teeth wrap around the first rotor helically in a clockwise direction, and wherein at a first position the first plurality of radially spaced teeth have a helix angle different than the helix angle of the first plurality of radially spaced teeth at a second position. The second rotor comprises a second plurality of radially spaced teeth, wherein the second plurality of radially spaced teeth wrap around the second rotor helically in a counter-clockwise direction, and wherein at a first position the second plurality of radially spaced teeth have a helix angle different than the helix angle of the second plurality of radially spaced teeth at a second position.

A gear pump for power generation comprises a first rotor and a second rotor in a case. The first rotor comprises a first plurality of radially spaced teeth, wherein the first plurality of radially spaced teeth wrap around the first rotor helically in a clockwise direction, and wherein at a first position the first plurality of radially spaced teeth have a helix angle different than the helix angle of the first plurality of radially spaced teeth at a second position. The second rotor comprises a second plurality of radially spaced teeth, wherein the second plurality of radially spaced teeth wrap around the second rotor helically in a counter-clockwise direction, and wherein at a first position the second plurality of radially spaced teeth have a helix angle different than the helix angle of the second plurality of radially spaced teeth at a second position.