A system for cryocooling an optical sensor on a satellite to a temperature below 200K with minimal vibration comprising a miniature conical rotary screw compressor comprising an inner element configured to only rotate around a first stationary axis and an outer element configured to only rotate around a second stationary axis so that both elements revolve with minimal vibration; with at least one of a) a length of at least one of the inner element and the outer element is between 10 mm and 100 mm; b) a diameter of at least one of the inner element and the outer element is between 2 mm and 45 mm; c) a compression ratio of the rotary screw compressor is between 1:2 and 1:20; and d) a shaft speed of the conical rotary screw compressor is between 1001 and 20000 revolutions per minute.

A system for cryocooling an optical sensor on a satellite to a temperature below 200K with minimal vibration comprising a miniature conical rotary screw compressor comprising an inner element configured to only rotate around a first stationary axis and an outer element configured to only rotate around a second stationary axis so that both elements revolve with minimal vibration; with at least one of a) a length of at least one of the inner element and the outer element is between 10 mm and 100 mm; b) a diameter of at least one of the inner element and the outer element is between 2 mm and 45 mm; c) a compression ratio of the rotary screw compressor is between 1:2 and 1:20; and d) a shaft speed of the conical rotary screw compressor is between 1001 and 20000 revolutions per minute.

A cylindrical rotor inside of the cylindrical stator, wherein the cylindrical rotor has a screw thread with an opposite direction relating to the stator screw thread, wherein the rotor has a curvilinear external surface shape and a stator having an internal semicircular surface shape wherein rotor external surface shape and the stator has an internal surface shape having rounded shapes without rectangular edges to obtain high speed performance with reduced vortices, wherein a gap between the internal surface of the stator and the external surface of the rotor is 0.1-0.2 millimeters and an unloading thrust bearing attached to the rotor shaft positioned between intake thrust bearing and the intake end of the rotor and a cavity in the unloading thrust bearing configured to receive production fluid from the discharge end of the rotor.

A cylindrical rotor inside of the cylindrical stator, wherein the cylindrical rotor has a screw thread with an opposite direction relating to the stator screw thread, wherein the rotor has a curvilinear external surface shape and a stator having an internal semicircular surface shape wherein rotor external surface shape and the stator has an internal surface shape having rounded shapes without rectangular edges to obtain high speed performance with reduced vortices, wherein a gap between the internal surface of the stator and the external surface of the rotor is 0.1-0.2 millimeters and an unloading thrust bearing attached to the rotor shaft positioned between intake thrust bearing and the intake end of the rotor and a cavity in the unloading thrust bearing configured to receive production fluid from the discharge end of the rotor.

A stator assembly for a progressing cavity pump is provided. The stator assembly includes a number of stator laminates having a planar body defining a primary, inner passage and a number of outer passages, the outer passages disposed effectively adjacent the inner passage whereby the inner passage is at least partially defined by a band, wherein the band is outwardly flexible. The stator laminates are coupled to each other in a stack wherein the stator laminate body inner passages define a helical passage. The helical passage is a flexible helical passage.

A compressor may include a shell, a compression mechanism, first and second temperature sensors, and a control module. The shell may define a lubricant sump. The compression mechanism may be disposed within the shell and may be operable to compress a working fluid. The first temperature sensor may be at least partially disposed within the shell at a first position. The second temperature sensor may be at least partially disposed within the shell at a second position that is vertically higher than the first position. The control module may be in communication with the first and second temperature sensors and the pressure sensor and may determine whether a liquid level in the lubricant sump is below a predetermined level based on data received from the first and second temperature sensors.

A compressor may include a shell, a compression mechanism, first and second temperature sensors, and a control module. The shell may define a lubricant sump. The compression mechanism may be disposed within the shell and may be operable to compress a working fluid. The first temperature sensor may be at least partially disposed within the shell at a first position. The second temperature sensor may be at least partially disposed within the shell at a second position that is vertically higher than the first position. The control module may be in communication with the first and second temperature sensors and the pressure sensor and may determine whether a liquid level in the lubricant sump is below a predetermined level based on data received from the first and second temperature sensors.

A hydraulic tool includes a stator and a rotor rotatably disposed within the stator. At least one of at least an inner portion of the stator and at least an outer portion of the rotor includes an insert comprising a hard material. A method of forming a hydraulic tool includes attaching at least one insert comprising a hard material to a surface of a stator or a surface of a rotor. A downhole motor or pump includes a stator and a rotor. The stator includes at least one insert comprising a hard material disposed over at least a portion of an interior surface thereof and a matrix material at least partially surrounding the at least one insert. The rotor includes at least one insert disposed over at least a portion of an exterior surface thereof and a matrix material at least partially surrounding the at least one insert.

A conical screw compressor or pump comprises an inner element configured to rotate around a first axis and an outer element configured to rotate around a second axis. An outer surface of the inner element and an inner surface of the outer element comprise cooperating grooves and teeth that intermesh on rotation. The first axis and the second axis are each stationary and the first axis is inclined relative to the second axis. The inner element and the outer element are configured to be, in operation, synchronously rotated, thereby to reduce or eliminate force exerted by the inner element on the outer element or vice versa.

A conical screw compressor or pump comprises an inner element configured to rotate around a first axis and an outer element configured to rotate around a second axis. An outer surface of the inner element and an inner surface of the outer element comprise cooperating grooves and teeth that intermesh on rotation. The first axis and the second axis are each stationary and the first axis is inclined relative to the second axis. The inner element and the outer element are configured to be, in operation, synchronously rotated, thereby to reduce or eliminate force exerted by the inner element on the outer element or vice versa.