High pressure pump systems with reduced pressure ripple for use with waterjet systems and other systems are described herein. A pump system configured in accordance with a particular embodiment includes four reciprocating members operably coupled to a crankshaft at 90 degree phase angles. The reciprocating members can include plungers operably disposed in corresponding cylinders and configured to compress fluid (e.g., water) in the cylinders to pressures suitable for waterjet processing, such as pressures exceeding 30,000 psi.

Provided is a reciprocating compressor having a structure in which friction losses between a shaft and a bearing can be reduced without impairing the ability of the bearing to support the shaft. A reciprocating compressor (100) includes a cylinder (5), a piston (4), a connecting rod (6), a shaft (1), and a bearing (2). The shaft (1) has a journal portion (28) as a portion covered by the bearing (2). The journal portion (28) has a first journal portion (7) located closer to the connecting rod (6) with respect to a midpoint M of the journal portion (28) in a direction parallel to a rotational axis and a second journal portion (8) located farther from the connecting rod (6) with respect to the midpoint M. The bearing (2) has a first sliding portion (10) for supporting the first journal portion (7) and a second sliding portion (11) for supporting the second journal portion (8). The first sliding portion (10) has a first recessed portion (29) in at least one range selected from a range of 0° to 180° and a range of 270° to 360° in a rotational direction of the shaft (1) from a reference position.

A vehicular crash sensing system includes a bumper cap for contacting a bumper. A chamber fits into a side rail attached to the bumper, the chamber being sealed by the bumper cap. A stop element limits movement of the chamber into the side rail. A pressure sensor detects an increased chamber air pressure during crushing of the chamber resulting from movement of the bumper with respect to the stop element.

A sensor assembly for a motor vehicle adapted for sensing impacts including pedestrian impacts. The sensor assembly includes first and second energy absorbing elements formed of differing materials which couple an applied force to the vehicle to a compressive force acting on a compressive sensor element. The first and second energy absorbers are combined in a manner to tune the response between the applied force and forces acting on the compressive sensor to provide desired response characteristics. The first and second energy absorbers can be configured to produce force flow paths which further aid in response tuning. Another embodiment utilizes an energy absorber having a shaped cross section which focuses and balances impact force is applied to the compressive sensor.

A method of making a compressible elastomeric spring including at least one compressible elastomeric pad enclosed by a pair of metal plates includes the steps of forming plates with a center aperture and a plurality of prongs positioned about a peripheral edge thereof, forming each end of the pad with an axial projection and abutting groove, aligning the plurality of prongs with each respective projection and respective groove and applying axial force to one end of the spring to frictionally interlock the plurality of prongs with such projection and groove. The method also provides for making a multi-tiered stack of pads separated by plates in the above described manner and pre-shortening the spring prior to installation into the conventional yoke. The above described method additionally improves axial straightness and lateral stability of the multi-tiered spring assembly.

A facility for grinding inorganic material include a roller press, a first static separator having an intake supplied with raw material, a dynamic separator having an intake connected to a first output of the first static separator, a ventilation circuit provided through the first static separator and the dynamic separator, and a second static separator having an intake that is connected to an output of the roller press. The first static separator includes two outputs, one for low-granulatory matter and one for larger granulatory matter, whereby the second output is connected to the roller press. The dynamic separator further includes a first output for particles having the desired granulometry and a second output for matter with larger granulometry connected to an intake of the roller press. The ventilation circuit participates in the separation, drying, and transport of low-granulometry particles.

Disclosed is a pressurized hollow fiber membrane module that exhibits improved durability without deterioration in packing density and permeation flux. The pressurized hollow fiber membrane module includes a composite hollow fiber membrane comprising a tubular braid woven by yarns and a polymer film on the outer surface of the tubular braid. At least one of the yarns comprises a small-fineness filament and a medium-fineness filament. The small-fineness filament comprises first monofilaments having a fineness of 0.01 to 0.4 denier, the medium-fineness filament comprises second monofilaments having a fineness higher than 0.4 and lower than 3, and a ratio of thickness of the tubular braid to outer diameter thereof is 15 to 35%.

A pressure-stable cylinder/piston unit which blocks water vapor and oxygen and is designed for a needle-free injector, with a chamber arranged in a cylinder, which blocks water vapor and oxygen, and designed for long-term and sterile storage of an injection solution, an end wall with at least one nozzle bore or one outlet element, a pressure-stable outer cylinder, and a pressure-stable piston arranged movably in the chamber and blocking water vapor and oxygen. Methods for bubble-free, automatic or manual filling of the cylinder/piston unit, also at atmospheric pressure are also disclosed.

A support bracket for a cabin air compressor (CAC) assembly includes a CAC mounting portion with a plurality of CAC mounting holes distributed in an arc configuration along a CAC mounting hole circle radius. A support portion includes a ramped face that transitions to an upper lug portion and a substantially perpendicular face relative to the CAC mounting portion. An upper lug extends from the upper lug portion. The upper lug includes a coupling hole that is offset from a first CAC mounting hole of the CAC mounting holes at a length in a first direction and a length in a second direction. A ratio of the CAC mounting hole circle radius to the length in the first direction is between 2.14 and 2.20, and a ratio of the CAC mounting hole circle radius to the length in the second direction is between 1.16 and 1.19.

Systems and methods for activating a down hole tool in a wellbore. A piston is moveable from a first position to a second position for activating the down hole tool. The piston includes a first side exposed to a first chamber, and a second side exposed to a second chamber. A rupture member has a first side exposed to the first chamber and a second side exposed to a third chamber. The rupture member is configured to rupture when a pressure differential between the first chamber and the third chamber reaches a predetermined threshold value, at which point the rupture member allows fluid communication between the first chamber and the third chamber. When the rupture member is intact, the piston is in the first position, and when the rupture member ruptures, the piston moves to the second position and activates the down hole tool.

A device for compensating deviations from a coaxial arrangement of components of a regulating organ, said regulating arrangement being comprised of a regulating organ, a crown pipe, and an immersion cup which serve for controlling the gas pressure of a coke oven chamber, with the regulating arrangement being comprised of an immersion cup with a water immersion that seals the gas space of a coke oven chamber versus the gas collecting main and/or plant units downstream, and wherein the height of the water level of the water immersion represents a regulating means to control the gas pressure, and wherein said regulating arrangement is furthermore comprised of an immersion pipe that configures a specially shaped crown pipe at its end submerging into the water of the immersion cup, and that is comprised of a regulating organ to regulate the water level.

A pressure lock system passes a wire along a wire path from a wire source at a high pressure first region to a destination at a low pressure second region. The pressure lock system includes a pressure lock chamber. A first conduit has an interior positioned to pass the wire along the path and is mounted for rotation. A second conduit has an interior positioned to pass the wire from the pressure lock chamber and is also mounted for rotation. A motor may drive rotation of the first conduit and the second conduit. Pumps may maintain a pressure of the pressure lock chamber lower than a pressure of the first region.

A compressible stop member for use on a crane includes: a housing having a first sealed end, a second end, a first cylindrical surface and a second cylindrical surface; a free piston slidably contained within the housing in a sealing engagement with the first cylindrical surface; a compressed gas chamber in the housing between the free piston and the first sealed end; and a rod comprising a cylindrical portion with a diameter less than the diameter of the second cylindrical surface and a rod support portion that separates a first liquid chamber comprising the volume inside the housing between the free piston and the rod support portion from a second liquid chamber comprising the volume between the rod support portion and the second end of the housing. Also, the rod support portion includes at least one flow channel allowing liquid to flow between the first and second liquid chambers.

An arrangement for testing a fire suppression sprinkler system includes a supply conduit for supplying a fire suppression fluid to a plurality of sprinklers. A sensor senses a flow of fire suppression fluid through the supply conduit. A drain conduit drains fire suppression fluid when the fire suppression system is tested. A drain valve controls the flow of the fire suppression fluid so that when the fire suppression system is tested the fire suppression fluid is controlled to enter the drain conduit. A fire suppression fluid collection tank collects the fire suppression fluid which has entered the drain conduit for reintroducing the collected fire suppression fluid to the supply conduit. A circulation valve controls the flow of the fire suppression fluid so that when the fire suppression system is tested the fire suppression fluid enters the fire suppression fluid collection tank.

In one featured embodiment, a spring assembly for a valve comprises a spring, a spring seat including a cup-shaped portion for seating one end of the spring, and a ball received within a recess formed within the cup-shaped portion of the spring seat. The ball is defined by a ball diameter. A disc prevents the ball from contacting a piston. The disc is defined by an outer diameter and includes a center opening defined by an inner diameter. A ratio of the inner diameter to the ball diameter is between 0.60 and 0.65.

A portable device to compress a bow comprising a pulley system with a block and tackle and fixed pulleys which, by wiring, are connected to a set of fastening supports with fastening ends. The fastening ends fasten and pull the ends of the arms or limbs of a bow, under traction exerted by the block and tackle. The block and tackle has a drive portion and a brake controlling the traction and release of the cables connected to the fastening supports. Upon pulling the drive portion, the block and tackle produces the approach between the first and the second pulleys. This displacement between the pulleys acts on the cables which, through the fixed pulleys, cause the approach between the fastening supports. This displacement of the fastening supports overcomes the resistance of the bow and compresses it. Once the desired compressive level is reached, the brake or blockage is actuated.

Exemplary embodiments of a gas pressure regulator comprise a regulator body, an adaptor sleeve, a retainer and an indexing ring. The regulator body includes a proximal portion, a distal portion, a ported intermediate portion therebetween, and a main bore. The adaptor sleeve axially receives the distal portion and includes an outer threading for engaging an air source adaptor of a paintball marker. The retainer threadably engages the main bore within the distal end, thereby axially securing the adaptor sleeve onto the distal end. The indexing ring receives the distal portion therethrough for resiliently biased axial movement of the indexing ring between a locking position and an unlocking position. When the indexing ring is in its unlocking position, the adaptor sleeve is rotatable with respect to the regulator body. When the indexing ring is in its locking position, the adaptor sleeve is rendered substantially non-rotatable with respect to the regulator body.

A grip guard may be used with a crossbow that has a main beam including a stock and a barrel. The grip guard may have a first wall that is positioned between the stock and the barrel and a second wall that extends outwardly from the main beam. The first wall may have dampening properties to attenuate sounds and vibrations caused by firing the crossbow and the second wall may prevent a user's fingers from inadvertently extending from the handle toward the barrel.

A line launching device is provided with a tube for receiving a projectile and including an externally threaded bottom and a cap put on the tube; a cylinder including a first externally threaded extension at one end, an internally threaded cup secured to the first externally threaded extension, a second externally threaded extension at an other end, and an internally threaded ring securing to both the second externally threaded extension and the externally threaded bottom; a hollow anchor fastened in one end of the tube; a hollow fin assembly in a bottom of the projectile and including slits on a housing, pivotal fins, and an internal biasing member biasing against the fins; and a rope having one end attached to the nose and an other end fastened in the anchor. The fins project out of the slits after the projectile being propelled out of the tube by pressurized gas.

Solid state light emitting devices include multiple LED components providing adjustable melatonin suppression effects. Multiple LED components may be operated simultaneously according to different operating modes according to which their combined output provides the same or similar chromaticity, but provides melatonin suppressing effects that differ by at least a predetermined threshold amount between the different operating modes. Switching between operating modes may be triggered by user input elements, timers/clocks, or sensors (e.g., photosensors). Chromaticity of combined output of multiple LED components may also be adjusted, together with providing adjustable melatonin suppression effects at each selected combined output chromaticity.

A high-pressure discharge lamp having an arc tube with a casing made of glass. The arc tube includes a light-emitting part and sealing parts connected to the light-emitting part. A pair of electrode rods are disposed within the glass casing such that their tips face each other with a gap therebetween and project into the discharge space, and their base ends are embedded in the sealing parts and overlap surfaces of metal foils provided in the sealing parts. Each base end is coated with a coating foil made of metal and having a C-like cross section with a slit formed between edges thereof. An end of the coating foil farthest from the light-emitting part is located closer to the light-emitting part than an end of the metal foil closest to the light-emitting part.

The amusement ride 1 comprises a track 2 and a vehicle 3 being moveable along the track 2 at a velocity v. Within the vehicle 3 a video camera 4 is installed. The video camera 4 takes a video film of the face of a passenger received within the vehicle 3 during a ride. A sender 5 transmits the data 6 to a facial expression recognition system 7. The result 10 of the process carried out by facial expression recognition system 7 may be downloaded from a server 11 by a client 13.

A method for manufacturing high speed pressure compensator-type drip irrigation tubes and the tubes obtained thereby having absolute radial orientation of molecular chains, the orientation imparting strength as well as flexibility to the tube material. The said method comprises extruding a tube using a plurality of extruders; blowing up the extruded tube by introducing a pressure inside the tube relatively higher than the pressure outside the tube; drawing the blown tube simultaneously to the blowing of tube; flattening the blown tube by heat welding the collapsed halves together and forming a tape immediately, subsequent to the process of blowing and drawing the tube; extrusion of a bonding polymer on one border of the tape; printing flow channels into the hot and viscous bonding polymer; and forming a tube by lengthwise folding the tape and heat welding the overlapping borders together using the bonding polymer.

In order to improve a high-pressure cleaning apparatus comprising a pump unit adapted to be driven by motor, a first connection element for detachable connection to a liquid supply conduit, said first connection element being connected to the suction side of the pump unit, and a second connection element for detachable connection to a high-pressure conduit, said second connection element being connected to the pressure side of the pump unit, such that it can be handled in a more user-friendly manner, the invention proposes that the first connection element and/or the second connection element be oriented in a direction facing upward away from a supporting surface for the high-pressure cleaning apparatus.

A seal assembly for sealing a pressure plate against an opening in a blowout preventer body has a seal groove formed in the pressure plate and a seal in the seal groove. The seal groove has a first groove portion adjacent to a sealing face of the blowout preventer, and a second groove portion extending past the sealing face into the opening of the blowout preventer body. The seal has a first seal portion in the first groove portion and a second seal portion in the second groove portion.

Due to increasingly strict requirements and regulations, it is becoming more and more important for piston compressors to reduce the amount of leakage of operating medium through the seal of the piston rod. Conventional seals comprising packing rings and/or packing ring combinations always have a certain amount of leakage, both during operation and when at standstill, which is why they are not usable for certain applications, or the complexity involved in such a seal increases considerably. A further problem involving the seals of piston rods relates to transverse movements by piston rods during which the sealing action of the seal must be maintained. Proposed is, therefore, a sealing arrangement according to the principle of a sealing medium barrier providing that the sealing elements 8, 9 are arranged in radial direction at a distance relative to the radial end of the recess 10 that receives the sealing elements 8, 9.

A multi-layer gasket including first and second functional layers, each having an opening. Each of the functional layers includes a compression bead, and the compression beads contact and seal against one another when the gasket is compressed between a cylinder head and an engine block. At least one of the functional layers includes a stopper disposed between the compression bead and the opening. The stopper has a gear-like shape including a plurality of circumferentially spaced teeth. Each tooth extends upwardly from a plane by a distance which is less than the combined height of the compression beads. When the gasket is compressed between the cylinder head and engine block, the stopper ensures that the compression beads remain elastically biased against one another and maintain a gas-tight seal.

An annular diaphragm compression driver for electro-acoustic conversion has an annular diaphragm, which bears a moving coil, and a compression driver housing with a closed housing base. Opposite the housing base is a sound wave routing element having a sound discharge channel. The compression driver also has an annular magnet system unit, which has an annular magnet gap (M) and a compression chamber, adjoining the magnet gap (M), for the annular diaphragm. The open exit end of the sound discharge channel is in slot form and its entry start is annular. The sound path between the compression chamber and the entry start contains an annular collecting space. The collecting space and the sound discharge channel contain a central sound guidance body having a portion which merges to match the slot-like exit end. The sound discharge channel is formed between the sound guidance body and the sound wave routing element.

A sound suppressor device for an air drying unit of a compressed-air supply system having a sound suppressor housing on which is arranged an inlet opening for the supply of condensate-laden compressed air to be discharged from the air drying unit and at least one outlet opening for the discharge of the condensate-laden compressed air to the outside, wherein the inlet opening issues into at least one pre-chamber of the sound suppressor housing, which pre-chamber issues into post-chambers which are connected in parallel and which are arranged around a heating rod arranged centrally in the sound suppressor housing.

Embodiments of a firearm suppressor are disclosed herein. According to various embodiments, the firearm suppressor can include a housing. The housing can include an outer surface, an inner cavity, and an attachment mechanism that attaches the housing to a barrel of a firearm. The inner cavity can accommodate a baffle. The firearm suppressor also can include a lighting attachment. The lighting attachment can include a power source and a lighting mechanism.

An applicator for applying compression stockings and bandages to the limb of a user. The applicator includes a rigid tubular body, an open top with a rim, an open base and a passageway between the base and top. The applicator includes two or more longitudinal slots in the side wall of the tubular body for use in loading. An anterior notch allows an ergonomic application of the stocking and loading. The applicator may be formed in two parts for variation of its internal dimension. It preferably includes a foot arch. The applicator may be adapted for removal of the stocking. The invention extends to a method of donning and removing a compression stocking.

The loading device according to the invention comprises a magazine for receiving at least one printing plate and transferring it from the magazine to the plate cylinder. It also comprises at least one guide rail to guide a printing plate during transfer thereof by cooperation with a notch of a front edge of the printing plate, the notch sliding along the guide rail during the transfer.

A method for controlling register settings of a printing press, includes rotating imaging cylinders of a first print unit and a second print unit, located downstream of the first print unit in a movement direction of a print medium, at a rotational speed to print an image on the print medium. The method includes of changing a length of the print image to a pre-determined length. The method further includes changing a register setting of the imaging cylinder of the second print unit based on the predetermined change in length of the print image to avoid misalignment of the print image printed by the first and the second print units on the print medium. Changing the register setting is dependent on a length of a section of the print medium between the first and the second print units. A device for controlling register settings of a printing press is also disclosed.

A method of transferring a transfer foil having an image forming layer through a transfer gap of a printing press under a foil cycle timing control that is selectively changeable such that it can be turned on, turned off, or is adjustable in its frequency and period of operation as a function of operating parameters of the press.

A method for successive printing of a first print job and a second print job on the same web using at least one printing group of the rotary press to print the first print job and the second print job is provided. The printing group includes at least a plate cylinder, a plate, a blanket cylinder and a blanket. Between the first print job and the second print job, a plate-changing stage occurs in which the blanket is held away from the web and the plates of the plate cylinder are changed. According to one aspect of the invention, between the first print job and the second print job, the web is kept traveling through the rotary press.

The invention pertains to a method and apparatus for preparing a printing form from a precursor, particularly a method and apparatus for preparing the printing form by thermally treating a photosensitive precursor having a photopolymerizable layer. The method and apparatus includes heating the photosensitive precursor to a temperature sufficient to cause a portion of the layer to liquefy, contacting the precursor with a development medium to remove the liquefied material, and supporting a development medium with a core member adjacent an exterior surface of the photosensitive precursor, wherein a compressible collar of a closed-cell foam having a Poisson's ratio of less than 0.4 is disposed between the core member and the development medium.

A method and apparatus of image coding including adaptive entropy coding are disclosed. According to this method, input pixels associated with a group of symbols generated from image or video data are received. Maximum bit-depth of the group of symbols is then determined. If the maximum bit-depth of the group of symbols is smaller than a first bit-depth threshold, the group of symbols is encoded or decoded using Golomb-Rice coding. If the maximum bit-depth of the group of symbols is greater than or equal to the first bit-depth threshold, the group of symbols is encoded or decoded using second entropy coding, where the second entropy coding is different from the Golomb-Rice coding. Outputs corresponding to encoded or decoded output associated with the group of symbols are provided. The maximum bit-depth of the group of symbols is signaled at the encoder or recovered at the decoder by parsing the bitstream.

A method and apparatus of adaptive image and video coding including an alternative transform other than the discrete cosine transform (DCT) and discrete sine transform (DST) type VII (DST-VII) are disclosed. For at least one block size belonging to the size group, a transform from multiple transforms comprising an alternative transform in addition to DCT and DST-VII is selected and applied to a current block. The alternative transform may correspond to DCT type IV (DCT-IV) or DST type IV (DST-IV).

Disclosed herein is an electric compressor including: a main housing (4) having therein a suction chamber into which low-temperature refrigerant is drawn; an inverter housing (1) including an internal seating surface (1a) formed adjacent to the suction chamber, with at least one inverter element (2) fixed at a surface thereof to the internal seating surface (1a) while making contact with the internal seating surface (1a), the at least one inverter element (2) conducting heat to the main housing (4); and at least one heat dissipation cover (6) disposed toward the main housing (4) while facing another surface of the inverter element (2) and enclosing the inverter element (2), the at least one heat dissipation cover (6) having therein a receiving space (64) in which the inverter element (2) is received.

Systems and methods are used to control operation of a rotary compressor of a refrigeration system to limit or prevent movement of rotors due to axial thrust loading resulting from rapid changes in speed of the rotors of the compressor. The operational profile of the motor is controlled to maintain acceleration torque and deceleration torque within predefined limits. The acceleration torque and deceleration torque are maintained within the predefined limits by controlling the speed of the motor, or by controlling the torque applied by the motor to the rotors during acceleration or deceleration.

According to one embodiment of this disclosure an integrated fuel cell and environmental control system includes a turbo-compressor. The turbo-compressor includes a rotatable shaft, a compressor rotatable with the shaft to generate a flow of compressed air, a motor connected to the shaft, and a turbine connected to the shaft. The system further includes a fuel cell connected to the compressor by a first compressed air supply line that supplies a first portion of the flow of compressed air to the fuel cell. The fuel cell is connected to the turbine by a fuel cell exhaust line that supplies a flow of fuel cell exhaust to the turbine and causes the turbine to rotate. The system further includes an environmental control system connected to the compressor by a second compressed air supply line that supplies a second portion of the flow of compressed air to the environmental control system.

Provided is a variable-capacity compressor control valve that can suppress a decrease in the efficiency by reducing the amount of leakage in the valve without requiring severe accuracy of the components, avoid possible operation failures, and suppress the influence on the sliding resistance as well as the influence on the control characteristics. A main valve element of a valve element or a valve body is provided with a flexible or elastic sealing member. The sealing member is adapted to, when the valve orifice is closed by the main valve element, abut an end portion on the higher pressure side in a gap between sliding surfaces that is formed between the main valve element and a guide hole into which the main valve element is adapted to be slidably fitted and inserted, and thus seal the gap between the sliding surfaces.

Provided is a variable-capacity compressor control valve where a valve body can be easily machined and the machining time and machining cost can be reduced without a decrease in the valve closing property or a decrease in the slidability of the valve element due to shaft misalignment. The valve body includes a support member having formed therein a valve orifice and a guide hole into which the valve element is adapted to be slidably fitted and inserted; and a body member having formed therein a Ps inlet/outlet port, a Pd introduction port, and a Pc inlet/outlet port. The support member is fixedly inserted into a recess hole provided in the body member. In addition, a chip sealing portion (pocket portion) for sealing chips of the body member and/or the support member is provided between the body member and the support member.

Provided is a variable-capacity compressor control valve where a decrease in the sealability or the operability due to shaft misalignment can be effectively suppressed without requiring high dimensional accuracy. The dimensions and the shape of each part are designed such that when the sub valve element closes the in-valve release passage, the tapered portion (sub valve element portion) provided at the lower end portion of the sub valve element enters the release through-hole of the in-valve release passage, and the sub valve element is thus aligned with the main valve element by the tapered portion.

Provided is a variable-capacity compressor control valve where the size of a plunger can be reduced, the machining and assembly process can be simplified, weight reduction can be achieved, and cost reduction can also be achieved, for example. The plunger has a slit through which a valve element is assembled to the plunger by being inserted from a lateral side. The slit serves as a flow path for releasing the pressure Pc in the crank chamber to the suction chamber of the compressor from the Ps inlet/outlet port when the sub valve element has opened the in-valve release passage.

A valve for a reciprocating pump includes a housing, a first chamber, a second chamber, a first valve element, and a second valve element. The housing includes an inlet and an outlet. The first and second chambers are within the housing. The first chamber includes a first valve seat and is fluidly connected to the inlet. The second chamber includes a second valve seat and is fluidly connected to the outlet. The first valve element is disposed in the first chamber and includes a spring-loaded check valve element. The second valve element is disposed in the second chamber and includes a buoyant material.

A cabin air compressor assembly includes a cabin air compressor, and a cabin air compressor motor operably connected to the cabin air compressor. The cabin air compressor motor includes a rotor and a stator having a plurality of end windings. A cabin air compressor housing includes at least one cooling airflow hole formed therein. A motor cooling flow is movable across a portion of the cabin air compressor motor to cool the stator and the end windings. A duct extends from the cabin air compressor housing to an adjacent end winding such that a cooling outlet flow provided via the at least one cooling air flow hole is arranged in fluid communication with the end winding.

A control valve for an air conditioning compressor is disclosed. The control valve comprises a control piston, an electric motor, a sensor, and a control unit. The control piston connects a refrigerant flow between a high-pressure area and a crankcase pressure area of the air conditioning compressor in a first position. The control piston further connects the refrigerant flow between the crankcase pressure area and a low-pressure area of the air conditioning compressor in a second position. The electric motor moves the control piston between the first position and the second position. The sensor determines the position of the control piston. The control unit is connected to the sensor and the electric motor. The control unit controls the electric motor to move the control piston and control the refrigerant flow based on the position of the control piston determined by the sensor.

The compressor includes a bearing hub, defining a radial bearing having a first and a second end portion and supporting a crankshaft having an eccentric end portion supporting the larger eye of a connecting rod coupled to the piston, for example, by a smaller eye mounted around a piston pin. The second end portion and, optionally, the first end portion of the bearing hub and the larger and smaller eyes of the connecting rod are internally provided with bushings. End portions of the bearing hub and of the larger and smaller eyes may have their structure resistant to the pressing of a confronting compressor component supported on said end portions, or further present a terminal portion elastically deformable together with a confronting terminal portion of the associated bushing.

An aero-engine low pressure pump is provided for supplying fuel at a raised pressure to a high pressure pump. The low pressure pump has a pumping mechanism which raises the pressure of fuel flowing though the mechanism. The low pressure pump further has electrical motor which drives the pumping mechanism. The low pressure pump further has a variable frequency motor drive which supplies electrical power to the electrical motor. The variable frequency motor drive measures the electrical power supplied to the electrical motor. The low pressure pump further has a control unit which compares the measured electrical power to a reference power, and, when the measured electrical power is less than the reference power by a predetermined amount, controls the motor drive to increase the power supplied to the electrical motor thereby increasing the pressure rise produced by the pumping mechanism.