Sealing in rotary positive displacement machines based on trochoidal geometry that comprise a helical rotor that undergoes planetary motion within a helical stator is described. Seals can be mounted on the rotor, the stator, or both. The rotor can have a hypotrochoidal cross-section, with the corresponding stator cavity profile being the outer envelope of the rotor as it undergoes planetary motion, or the stator cavity can have an epitrochoidal cross-section with the corresponding rotor profile being the inner envelope of the trochoid as it undergoes planetary motion. In some embodiments, the geometry is offset in a manner that provides advantages with respect to sealing in the rotary machine. In multi-stage embodiments, the rotor-stator geometry remains substantially constant or varies along the axis of the rotary machine.

Sealing in rotary positive displacement machines based on trochoidal geometry that comprise a helical rotor that undergoes planetary motion within a helical stator is described. Seals can be mounted on the rotor, the stator, or both. The rotor can have a hypotrochoidal cross-section, with the corresponding stator cavity profile being the outer envelope of the rotor as it undergoes planetary motion, or the stator cavity can have an epitrochoidal cross-section with the corresponding rotor profile being the inner envelope of the trochoid as it undergoes planetary motion. In some embodiments, the geometry is offset in a manner that provides advantages with respect to sealing in the rotary machine. In multi-stage embodiments, the rotor-stator geometry remains substantially constant or varies along the axis of the rotary machine.

An oil-injected multi-stage compressor system that comprises at least a low-pressure stage compressor element (2) with an inlet (4a) and an outlet (5a) and a high-pressure stage compressor element (3) with an inlet (4b) and an outlet (5b), whereby the outlet (5a) of the low-pressure stage compressor element (2) is connected to the inlet (4b) of the high-pressure stage compressor element (3) through a pipeline (6), characterized in that the compressor elements (2, 3) are provided with their own drive in the form of an electric motor (2a, 3a), whereby the compressor elements (2, 3) are connected to the electric motor (2a, 3a) either directly or through a gearbox and that an intercooler (9) is provided in the aforementioned pipeline (6) between the low-pressure stage compressor element (2) and the high-pressure stage compressor element (3).

An oil-injected multi-stage compressor system that comprises at least a low-pressure stage compressor element (2) with an inlet (4a) and an outlet (5a) and a high-pressure stage compressor element (3) with an inlet (4b) and an outlet (5b), whereby the outlet (5a) of the low-pressure stage compressor element (2) is connected to the inlet (4b) of the high-pressure stage compressor element (3) through a pipeline (6), characterized in that the compressor elements (2, 3) are provided with their own drive in the form of an electric motor (2a, 3a), whereby the compressor elements (2, 3) are connected to the electric motor (2a, 3a) either directly or through a gearbox and that an intercooler (9) is provided in the aforementioned pipeline (6) between the low-pressure stage compressor element (2) and the high-pressure stage compressor element (3).

Sealing in rotary positive displacement machines based on trochoidal geometry that comprise a helical rotor that undergoes planetary motion within a helical stator is described. Seals can be mounted on the rotor, the stator, or both. The rotor can have a hypotrochoidal cross-section, with the corresponding stator cavity profile being the outer envelope of the rotor as it undergoes planetary motion, or the stator cavity can have an epitrochoidal cross-section with the corresponding rotor profile being the inner envelope of the trochoid as it undergoes planetary motion. In some embodiments, the geometry is offset in a manner that provides advantages with respect to sealing in the rotary machine. In multi-stage embodiments, the rotor-stator geometry remains substantially constant or varies along the axis of the rotary machine.

Sealing in rotary positive displacement machines based on trochoidal geometry that comprise a helical rotor that undergoes planetary motion within a helical stator is described. Seals can be mounted on the rotor, the stator, or both. The rotor can have a hypotrochoidal cross-section, with the corresponding stator cavity profile being the outer envelope of the rotor as it undergoes planetary motion, or the stator cavity can have an epitrochoidal cross-section with the corresponding rotor profile being the inner envelope of the trochoid as it undergoes planetary motion. In some embodiments, the geometry is offset in a manner that provides advantages with respect to sealing in the rotary machine. In multi-stage embodiments, the rotor-stator geometry remains substantially constant or varies along the axis of the rotary machine.

A drilling assembly includes a particle adjusting mechanism upstream of a positive displacement motor. The motor includes a metal stator, a metal rotor at least partially disposed within the metal stator, and a motor gap defined between the sealing line of the metal rotor and the lobes of the metal stator. The particle adjusting mechanism adjusts a solid particle condition of a media flowing therethrough into a treated condition in which any remaining solid particles will travel through the motor gap without widening the motor gap to a failure gap size that causes the metal rotor to lock up or to rotate inefficiently slow. The particle adjusting mechanism adjusts the solid particle condition by removing, reducing a size, reducing a dimension, deforming, modifying a shape, dissolving, or chemically reacting at least a portion of any solid particles contained in the media. The drilling assembly is suited for high temperature wellbores.

A drilling assembly includes a particle adjusting mechanism upstream of a positive displacement motor. The motor includes a metal stator, a metal rotor at least partially disposed within the metal stator, and a motor gap defined between the sealing line of the metal rotor and the lobes of the metal stator. The particle adjusting mechanism adjusts a solid particle condition of a media flowing therethrough into a treated condition in which any remaining solid particles will travel through the motor gap without widening the motor gap to a failure gap size that causes the metal rotor to lock up or to rotate inefficiently slow. The particle adjusting mechanism adjusts the solid particle condition by removing, reducing a size, reducing a dimension, deforming, modifying a shape, dissolving, or chemically reacting at least a portion of any solid particles contained in the media. The drilling assembly is suited for high temperature wellbores.

A water-cooling system for an injection-molding apparatus is configured to cool a molding mold by circulating cooling water. The water-cooling system includes a cooling channel, a coolant supply pipe, a coolant recovery pipe, and a baffle module. The cooling channel defines a straight flow path inside the molding mold and has a first end that is a channel inlet opened toward an exterior of the molding mold and a second end that defines a transition section and is a closed end of the straight flow path, where the straight flow path extends through at least a part of an interior of the molding mold toward an injection-molded product. The coolant supply pipe supplies the cooling water to the cooling channel. The coolant recovery pipe recovers the cooling water from the cooling channel.

A water-cooling system for an injection-molding apparatus is configured to cool a molding mold by circulating cooling water. The water-cooling system includes a cooling channel, a coolant supply pipe, a coolant recovery pipe, and a baffle module. The cooling channel defines a straight flow path inside the molding mold and has a first end that is a channel inlet opened toward an exterior of the molding mold and a second end that defines a transition section and is a closed end of the straight flow path, where the straight flow path extends through at least a part of an interior of the molding mold toward an injection-molded product. The coolant supply pipe supplies the cooling water to the cooling channel. The coolant recovery pipe recovers the cooling water from the cooling channel.