Abstract: A foam pump including a diaphragm made of a flexible material defining a mixing chamber and having an inlet and an outlet. An inlet passageway, having a one-way valve therein, is in fluid communication with a reservoir containing a foamable liquid and the inlet. The inlet passageway includes an air inlet and associated one-way valve. The pump includes an outlet passageway, having a one-way valve therein, in fluid communication with the outlet. The foam pump includes an electric motor. that drives a motor driven element to collapse and expand the diaphragm. Expansion of the diaphragm creates a vacuum causing foamable liquid and air to flow into the mixing chamber. Collapsing of the diaphragm causes the liquid and air mixture to be forced out as foam.

Abstract: A hermetic compressor includes a hermetic container, a motor element, and a compression element. A shaft of the compression element includes a main shaft, a flange projecting from the main shaft, and an eccentric shaft connected to the flange. A main bearing has a thrust surface contacting and sliding on the flange of the shaft. The thrust surface consists of a first portion and a second portion. The first portion is farther from the compression chamber than the center axis is. The second portion is closer to the compression chamber than the center axis is. The area of the first portion is larger than the area of the second portion. This hermetic compressor has a high efficiency and a high reliability.

Abstract: A hermetic compressor includes a hermetic container arranged to store lubricating oil, a motor element accommodated in the hermetic container, an oil-feeding mechanism arranged to carry the lubricating oil, and a centrifugal pump arranged to carry the lubricating oil to the oil-feeding mechanism. The centrifugal pump includes a cylindrical portion having a hollow opening at the opening, and an aperture plate having a suction aperture formed therein. The aperture plate has an inner edge facing the suction aperture, and an outer edge of the aperture plate contacting an inner surface of the cylindrical portion. A portion of the aperture plate between the inner edge and the outer edge of the aperture plate is positioned more outward from the cylindrical portion than the inner edge and the outer edge are. This hermetic compressor does not produce fine metal powder during manufactured, having high reliability.

Abstract: An apparatus and method for pumping fluids, such as water and/or hydrocarbons, from a subterranean formation or reservoir, include a linear rod pump having a mechanical rack and pinion drive arrangement, adapted for attachment to a pumping mechanism, such as the polished rod at the top of a rod string in a hydrocarbon well. The rack gear, of the rack and pinion drive arrangement, is adapted for connection to, and movement with, the polished rod. The pinion gear does not translate with the rack gear, and is driven by a reversible motor for affecting up and down reciprocating motion of the rack gear and pumping mechanism. Some forms of the invention include a compressible gas counter-balance arrangement. Some forms of the invention include an electronic drive configured for dealing with electric power generated by the motor during a portion of the pumping cycle.

Abstract: A pump assembly as a feedback pump of a hydraulic, slip-controlled vehicle brake system having a piston pump and an electric motor for driving it is disclosed. The electric motor is embodied as an external rotor and the stator is mounted on a printed circuit board which has an electronic system for commutating the electric motor and/or for performing slip control of the vehicle brake system.

Abstract: A modular fluid end for a multiplex plunger pump, each module machined from a single-piece steel forging with a plunger bore intersected by a linear suction/discharge bore and pumped fluid is discharged straight out through a top of the module into a discharge manifold made up using 1502 frac iron components. A compression clamp applies a crush load to opposed sides of the modules to extend service life.

Abstract: A high pressure pump for use in the injection of liquid chemicals into subsea oil or gas wells, and intended to be positioned in the subsea environment adjacent to the wellhead, comprises a piezoelectric actuator (19) for reciprocating a plunger (22) which acts to compress and expand the effective volume of a pumping chamber (29) having a valved inlet (15) connected to a source of the liquid and a valved outlet (16) to lead the liquid to the well. The device has a minimum of moving parts and in particular avoids the need for any rotating parts and attendant high performance bearings and seals.

Abstract: A dual rocking piston pump which includes a first piston with a first connecting rod eccentrically mounted to a rotor shaft and a second piston with a second connecting rod eccentrically mounted to the rotor shaft. The rotor shaft passes through a first bearing and a second bearing before being connected to a rotor body. The rotor body is disposed within a stator. The first and second bearings and stator are supported by a bracket. The bracket includes a hub which, in turn includes a first end connected to a wall at an opening in the wall. The hub also includes a second end. The first end of the hub supports the first bearing at the wall and the second end of the hub supports the second bearing. Both the first and second bearings are disposed in front of the motor or in front of both the rotor and stator.

Abstract: An actuator assembly for generating a fluid pressure and applying the fluid pressure to a first device. The actuator assembly comprises a first fluid chamber and a first piston disposed adjacent to the first fluid chamber, a second fluid chamber and a second piston slidably received in the second fluid chamber, a fluid passage connecting the first fluid chamber with the second fluid chamber, and an actuator motor for selectively reciprocating the first piston so that axial movement of the first piston generates a fluid pressure within the first fluid chamber. The first piston is disposed within the actuator motor. As the first chamber is fluidly communicating with the second fluid chamber, the linear motion of the first piston causes corresponding linear motion of the second piston for applying the fluid pressure to the first device.

Abstract: Provided is a simplified design for spring retainers in a hermetically enclosed refrigerant compressor. A hermetically enclosed refrigerant compressor includes a hermetically tight enclosure, and an electrical motor unit and a compressor supported relative to the enclosure by springs. The electrical motor unit and compressor include a first spring retainer and the enclosure includes a second spring retainer. The first and second spring retainers hold springs such that the electrical motor and compressor are supported relative to the enclosure. The first spring retainer is integrated with the electrical motor unit and the compressor.

Abstract: A dosing pump for a liquid additive in fuel of a heavy fuel engine includes a piston, a cylinder, and a high resolution linear actuator, including a motor driven by a controller, for moving the piston axially in the cylinder. The pump includes a manifold, and a low friction dish-shaped seal having a peripheral portion forming a seal between the cylinder and the manifold in a fully extended position of the piston. The dish-shaped seal includes a top portion attached to the piston that moves with the piston such that the top portion of the seal is compressed against the manifold in the fully extended position. The shape of the seal minimizes non-linearity of the volume dosed as a function of movement of the piston, and the controller drives the motor so as to remove a remaining non-linearity of the volume dosed as a function of movement of the piston.

Abstract: The present invention discloses a mounting structure of a linear compressor, comprising: a shell which is a hermetic space, a connection terminal for supplying power being fixed to one side of the shell; a main body frame installed in the shell, one end of a cylinder forming a compression space for compressing a refrigerant with a piston being fixed to the main body frame; and a motor cover, a linear motor comprised of an inner stator, an outer stator and a mover, for reciprocating the piston by a mutual electromagnetic force being fixed to the outer circumference of the cylinder, the outer stator being bolt-fastened between the main body frame and the motor cover. Here, the main body frame is left-right symmetric.

Abstract: According to the present invention, a recess (25) which is induction means is provided in a top end surface (24) of a piston (16), the recess (25) guides working fluid (3) staying near an inner peripheral surface of a compression chamber (13) from an outer peripheral edge of the top end surface (24) toward an opposite position of the top end surface (24) facing a discharge hole (19), and the recess (25) smoothens discharging motion of working fluid (3) from the discharge hole (19).

Abstract: A hand-held vacuum device includes a housing to hold an electrical motor operable to drive a piston pump that is configured to draw a substantially continuous vacuum for each complete cycle of the piston pump. The hand-held vacuum device also includes an expansion chamber releasably connected to and in fluid communication with the housing and a vacuum interface that has a vacuum connector in fluid communication with the expansion chamber and is configured to releasably couple to a valve disposed on a container. The expansion chamber separates air and liquid from a fluid drawn into the expansion chamber.

Abstract: An embodiment discloses a fluid pump for use in a fluid separation system for separating compounds of a fluidic sample in a mobile phase, the fluid pump comprising a reciprocatable piston configured for moving the mobile phase, a pump drive configured for driving the reciprocatable piston, and a control unit configured for controlling the pump drive so that pressure ripples in a pressure profile of the fluid pump are at least partially compensated to thereby bring the pressure profile in accordance with a predefined target characteristic. Another embodiment discloses a fluid pump for use in a fluid separation system for separating compounds of a fluidic sample in a mobile phase, the fluid pump comprising a reciprocatable piston configured for moving the mobile phase, and a pump drive configured for driving the reciprocatable piston using a piezomechanism.

Abstract: The present invention refers to a system for actuation in an ad mission valve (5) of a gas compressor (1) comprising at least: one set formed by a cylinder (2) and a piston (3); one electric motor (4), operatively associated with said set, capable of providing an axial movement of the piston (3) to compress the gas inside the cylinder (2), the admission valve (5) being configured to allow the input of gas inside the cylinder (2) upon the axial movement of the piston (3) in a first axial direction; and a discharge valve (6) configured to allow the output of gas from inside the cylinder (2) upon the axial movement of the piston (3) in a second axial direction opposite to the first axial direction. The system comprises at least one actuator element (7), operatively associated with the admission valve (5), capable of keeping the admission valve (5) open when the electric motor (4) stops and starts-up.

Abstract: An electrohydraulic aggregate for converting electric energy into mechanical energy, comprising an electric motor with a stator and with a rotor, comprising magnets or electric windings that produce electromagnetic fields, at least one connecting component for connecting the windings to at least one energy supply, with the connecting component extending through at least one through-hole, the through-hole is provided in an accommodating member accommodating electrohydraulic valves as well as at least one piston pump for the energy supply of a slip-controlled brake system, the piston pump being connected to the electric motor by a gear, and a rotor mounting support comprising at least two spaced rotor bearings, of which at least one so-called A-bearing supports a shaft in the accommodating member, and a so-called B-bearing that is supported in a pot-shaped motor housing.

Abstract: While ceramic materials possess properties that make them suitable for use in fuel system components, they tend to be susceptible to failure when exposed to tensile stresses. The retention system described herein helps to reduce the tensile stresses experienced by a retained member by providing a retained member with an engagement structure, a multi-piece retention ring that engages the engagement structure, a resilient member coupled to the retention ring, and a retainer coupled around at least a portion of the retention ring and resilient member and spaced apart from the retention ring and/or resilient member by a gap. The retained member, retention ring, resilient member, and retainer are configured so that the retention ring is moveable in an axial direction relative to the retained member and so that the movement of the retention ring acts to expand the resilient member against the bias provided by the resilient member.

Abstract: A piston is slidably provided in a cylinder and partitions a first pump chamber, and a second pump chamber connected to an object to be operated. A first on-off valve is provided between the first pump chamber and the outside. A second on-off valve is provided in a connecting flow passage that connects the first pump chamber and the second pump chamber to each other. When the piston is moved forward by an electromagnetic force of a solenoid portion, a capacity of the first pump chamber decreases, and a capacity of the second pump chamber increases. When the piston is moved backward by a biasing force of a spring, the capacity of the first pump chamber increases, and the capacity of the second pump chamber decreases. A pressure receiving area of the front face of the piston is larger than that of the back face thereof.

Abstract: The present invention relates to a discharging noise system of a hermetic compressor.

Abstract: An air pump structured to facilitate the installation of a pair of pistons includes a casing (17) having a pair of cylinder chambers (14) slidably accommodating a pair of pistons (16), respectively, and a drive chamber accommodating electromagnets between the pair of cylinder chambers. The pump casing has mutually opposing side walls and a cylindrical peripheral wall defining the drive chamber. The side walls have circular cylindrical inner peripheral surfaces (28-1) of the cylinders defined therein, respectively. A piston assembly having the pistons connected to the opposite ends of an armature (34) is inserted into the pump casing through one of the cylindrical inner peripheral surfaces and installed therein. The peripheral wall has an electromagnet-loading opening (26-2) through which electromagnet pedestal members (26-7) and the electromagnets are inserted into the casing and secured therein.

Abstract: There is provided an air pump in which vibration noise generated in a drive unit of the pump is suppressed from being transmitted to the outside through a suction passage. A casing (17) of the air pump has a suction port (26-12) extending from an outer peripheral surface to inner peripheral surface of the casing, a noise reduction wall (26-9) annularly formed on the outer peripheral surface of the casing such that the suction port opens in a region of the outer peripheral surface of the casing surrounded by the noise reduction wall, and a lid member closing the opening of the top of the noise reduction wall and cooperating with the noise reduction wall and the outer peripheral surface of the casing to define a noise reduction chamber (26-14) communicating with the suction port. The noise reduction wall has an elongated noise reduction passage (26-11) extending circumferentially in the noise reduction wall. One end of the noise reduction passage opens on the outer surface of the noise reduction wall.

Abstract: A compressor assembly includes a compressor coupled to a motor via a belt drive. The belt drive provides a speed reduction between the motor and compressor and causes the compressor shaft to rotate in the direction opposite that of the motor shaft. The relative values of the mass moments of inertia about the axes of rotation of the rotating motor and compressor shafts are engineered to be inversely proportional to the relative shaft speeds, allowing the mass moments of inertia to be balanced to at least substantially eliminate torsional vibration.

Abstract: Brushless DC motor (4) is driven based on a first or second waveform signal output from switching determination unit (11), which switches outputting so that a first waveform signal by first waveform generation unit (6) is output when the speed of rotor (4a) is determined to be lower than a predetermined speed, and a second waveform signal by second waveform generation unit (10) is output when the speed of rotor (4a) is determined to be higher than the predetermined speed. Thereby, drive is stable even at high speed/under high load, and a driving range is extended.

Abstract: In one example, a handheld fluid sprayer is provided and includes a housing, an assembly having at least one of a motor and a fluid pump, and at least one assembly support feature. The assembly is mounted to the housing with the at least one assembly support feature. The at least one assembly support feature includes a first portion having first and second opposed surfaces and a second portion having first and second opposed surfaces. The second portion extends from the first portion such that at least one of the first and second surfaces of the second portion is at least substantially orthogonal to the second surface of the first portion.

Abstract: In accordance with the method, a gas bearing is energized to center the piston in the cylinder prior to rigidly attaching the planar spring or springs between the piston and the compressor frame. This automatically and very accurately centers the piston in the cylinder to provide the added stiffness of a planar spring and gas bearing in an easily manufactured configuration. Various exemplary embodiments are disclosed, including embodiments having the piston cantilevered from one end using a single or multiple springs, an embodiment having a spring on each end of the piston, a double piston embodiment and embodiments using and not using the gas bearing during operation of the compressors.

Abstract: Apparatus and Method for Handling Fluids at Nano-Scale Rates. A linear displacement pump produces non-pulsatile liquid flow rates as low as the nl/mm range. The pump includes a servo motor, a gear reduction, a lead screw, a linear stage, a barrel, and a plunger extending into the barrel and coupled to the stage. A microfluidic interconnect device can be coupled to the barrel. One or more of these pumps can be disposed in a thermally controlled pump assembly that includes a pump housing, a thermally conductive body disposed in the housing and including first and second opposing sides, and a temperature regulating element such as a thermoelectric device disposed in thermal contact with the thermally conductive body on a side thereof opposite to the barrel or barrels of the pumps.

Abstract: A cam driven piston compressor includes one or more cams powered by a motor, the cams being adapted to rotate through 360 degrees, and one or more cam followers, each of which is in contact with one of the cams. The compressor also includes one or more pistons wherein each of the pistons is attached to one of the cam followers, one or more cylinders wherein each of the cylinders encloses one of the pistons, and a compressor head in contact with the cylinders.

Abstract: A heat dissipating system for a hermetic compressor includes a thermal energy transfer duct having a heat absorbing end mounted to the cylinder block of the compressor to absorb the heat generated by the compression of the refrigerant fluid in the cylinder block and a heat releasing end positioned away from the heat absorbing end and away from the cylinder block in order to release the heat conducted from the cylinder block by the transfer duct.

Abstract: Pump device for hydraulically activating a valve in particular used for oil and gas exploration wherein such a valve may be a safety valve assigned to a riser or a tree, said pump device including a piston cylinder unit from which pressurized hydraulic fluid can be pumped in direction to the valve. To improve such a pump device so that the pressure of the hydraulic fluid is produced in particular at the corresponding site and near to the valve and is safe and constructed in a simple way an electrical drive means is movably connected to a piston of the piston cylinder unit for alternating movement in axial direction of the piston within the cylinder.

Abstract: There is provided a linear compressor (100), which has a reduced number of front main springs (820) located at the front among springs continuously transmitting a force so that a piston (300) can move in a resonance condition.

Abstract: An oscillating type piston is connected to an output shaft of an electric motor through a crankshaft. The piston is provided with a lip ring that slidingly contacts a cylinder. The motor is rotated forward and reversely by using a control circuit. Thus, different regions of the piston are subjected to a load during forward rotation of the motor and during reverse rotation thereof. Accordingly, wear of the lip ring can be distributed to different regions thereof.

Abstract: An air pump has a bracket, a motor, a transmission device and pneumatic cylinder assembly. The bracket is formed from sheet metal and has a backplate, two side plates formed on the backplate and two top plates formed respectively on the side plates. The motor is mounted on the transmission device. The transmission device is mounted on the bracket and is connected to the motor. The pneumatic cylinder assembly is mounted on the bracket and is connected to the transmission device. The bracket formed from sheet metal is light and has a low cost.

Abstract: A magnetic armature is attracted and driven by a magnetic force which is intermittently generated between magnetic poles, and a piston reciprocated by being pushed back by a coil spring is not rotated by the coil spring. When the magnetic armature (28) as attracted between the magnetic pole members (10,12) by the magnetic force comes to a predetermined rotational angle position about the axis, the armature receives a rotational torque that is derived from the magnetic force and acts in a direction opposite to that of the rotational torque applied by a coil spring (30), thereby preventing the armature from being rotated in the predetermined direction. More specifically, the armature (28) has a circular cross-section as a whole and has a chamfered part (28?) parallel to the axis. When the chamfered part enters between the magnetic pole members, the armature receives a rotational torque that is derived from the magnetic force.

Abstract: The invention relates to a medical pump, especially for water jet surgery, in which a pump unit is assembled as a single use article and can be reversibly connected to a pump actuating device. Within the pump, the pump actuating device is also used to open up the connection between the pump unit and the pump actuating device.

Abstract: A reciprocating liquid or gas pump is driven by bi-directional force. A prime mover causes eccentric weights to rotate, which in turn cause pistons to be driven in linear paths under bi-directional force. This bi-directional force then drives opposing sets of pistons to pump a fluid. The pressurized fluid can then be used for, e.g., driving a hydraulic motor.

Abstract: A miniature cooling device includes numerous improvements capable of increasing the reliability and useful lifetime of the device, as well as improving electrical power to cooling power conversion efficiency. The improvements include a DC motor shaft design that incorporates a flywheel mass 314 with a solid shaft cross-section 300 for increasing shaft stiffness and magnetic flux density in the DC motor. Additional improvements include a bend resistant flexible vane 1114 in the DC motor to compression piston drive coupler, and a sealed cover set configured to be removable to make a motor repair and then replaced.

Abstract: A pump primarily for liquid paint includes first and second pistons reciprocable rectilinearly in respective first and second cylinders. The first and second pistons are moved relative to their respective pistons by operation of an A. C. electric motor the rotary output shaft of which is coupled to the first and second pistons by a constant velocity cam and a cam follower mechanism converting rotary motion of the output shaft into reciprocatory motion of the first and second pistons 180° out of phase with one another.

Abstract: A highly efficient fluid pump and pumping method are disclosed. The pump includes a cylinder, a piston in the cylinder defining a first and second volume in the cylinder, and a motive actuator for driving reciprocatively a rod attached to the piston at a rate of substantially sinmx for x=0 to ?, where m is a number greater than one, during a power stroke of that piston.

Abstract: A method of simulating attenuation of an impulse signal of a reciprocating compressor includes providing a reciprocating compressor that includes a crank connected to a motor, a compression chamber, a reciprocating piston positioned in the compression chamber, and a connecting rod attached to the piston. The method also includes connecting the connecting rod to the crank with a first crank pin, mounting at least one transducer on the reciprocating compressor, running the compressor, measuring a first impulse signal with the at least one transducer, replacing the first crank pin with a second crank pin, the second crank pin having a diameter different than the diameter of the first crank pin, running the compressor, measuring a second impulse signal with the at least one transducer, and comparing the first impulse signal to the second impulse to determine an amount of attenuation between the first and second impulse signals.

Abstract: A method and apparatus for direct measurement of rider band wear in a valve assembly for a reciprocating compressor is provided. A distance transducer probe is inserted through a compressor valve assembly to measure a distance between a piston assembly and the transducer probe and the wear of a rider band is determined based on the distance.

Abstract: A piezoelectric micro-blower includes an inner case to which a peripheral portion of a vibrating plate including a piezoelectric element is fixed such that a blower chamber is defined between the inner case and the vibrating plate and an outer case arranged to cover an outer periphery of the inner case with a gap therebetween. The inner case is elastically retained in the outer case by a plurality of connecting portions. A first opening is provided in a top plate portion of the inner case that faces a central portion of the vibrating plate, and a second opening is provided in a top plate portion of the outer case that faces the first opening. A central space is provided between the top plate portions, and fluid introduced from the outside is guided to the central space through the gap between the inner and outer cases. The vibrating plate is driven in a bending mode so that air is sucked into the central space and is discharged through the second opening.

Abstract: An air compressor structure includes a main body, a fixing plate and a cap member. The main body includes a pair of cylinders each having a fixture thereon. The fixture has a pair of first threaded holes. The fixing plate has a pair of second threaded holes corresponding to the first threaded holes. The cap member has a pair of third threaded holes corresponding to the first and second threaded holes. Fasteners are inserted through the first, second and third threaded holes to secure the main body, the fixing plate and the cap member together so as to minimize vibration when the compressor is working and to prevent the compressor from leakage through an air passage and a chamber.

Abstract: The present invention relates to a linear compressor, and more particularly, to a linear compressor which supplies a necessary cooling capacity through a natural cooling capacity modulation and a forcible cooling capacity modulation, and a cooling system using the same. The linear compressor according to the present invention includes a compression space into which refrigerant is sucked, a movable member which linearly reciprocates to compress the refrigerant sucked into the compression space, one or more springs which are installed to elastically support the movable member in a motion direction of the movable member, a motor unit which includes a motor and a capacitor connected in series to the motor so as to make the movable member linearly reciprocate, and a motor control unit which performs a natural cooling capacity modulation according to a load by reciprocation of the movable member.

Abstract: The present invention discloses a reciprocating compressor which can linearly reciprocate a piston inside a cylinder as a linear motor is driven, compress a refrigerant by sucking the refrigerant into a compression space between the cylinder and the piston, and then discharge the same. In the reciprocating compressor, the piston is operated at a top dead center position and in a resonance state by symmetrically applying a voltage even if load is varied, the elastic coefficient of the mechanical spring is set in consideration of the degree of shift of the piston influenced by the gas springs varied by load, and the initial value of the piston for maintaining the stroke of the piston is set so as to correspond to a required cooling capacity condition. Accordingly, electric power consumption caused by applying an asymmetrical voltage can be reduced, a tuning operation for applying an asymmetrical voltage can be omitted, thereby decreasing inconvenience.

Abstract: A pump driver, a disposable pump cartridge for use with the pump driver and a beverage dispenser employing the pump drive are disclosed. The disposable pump cartridge comprises at least one barrel 20 having an inlet valve 24 and an outlet valve 26 associated therewith. A piston 28 movable within the barrel 20 is retained in a minimum volume position during transit by a protrusion 22 on the internal surface of the barrel 20. The piston 20 has a piston shaft 28 with a hollow end arranged, in use, to releasably engage a piston driver to drive the piston 28 from its minimum volume position to an operative position, and to reciprocate the piston 28 within the barrel 20 in its operative position to draw fluid into and pump fluid from the barrel 20 via the inlet valve 24 and outlet valve 26 respectively. Methods of engaging, disengaging and changing the disposable pump cartridge are also disclosed.

Abstract: Apparatus and method for on-board lubrication of a paint pumping piston including a reservoir for lubricant and a lubricant dispensing mechanism for delivering a predetermined repeatable amount of lubricant upon manual actuation of the lubricant dispensing mechanism. In one embodiment, a section of tubing acts as the reservoir, and in another embodiment, the reservoir is formed by a transparent or translucent chamber located adjacent an aperture in a pump housing to enable visual inspection of the level of lubricant in the reservoir. A lubricant delivery piston is actuated by an extension thereof projecting through an aperture in the housing, and a lubricant discharge nozzle is located adjacent the paint pumping piston proximate a bushing supporting the paint pumping piston. A breather valve prevents a vacuum in the reservoir as the lubricant is dispensed.

Abstract: A hermetic compressor includes a closed vessel for storing lubricating oil, an electric-driving element, and a compressing element driven by the electric-driving element. The compressing element includes a cylinder block forming a compression chamber, a piton that reciprocates inside the compression chamber, and an oiling device for supplying the lubricating oil to an outer circumference of the piston. A first oil groove is concavely formed on the outer circumference of the piston, and a second oil groove is concavely formed on a side opposite to the compression chamber relative to the first oil groove. The second oil groove has a spatial volume same or greater than that of the first oil groove. An expanded clearance portion is provided such that a clearance between the piston and the cylindrical hole portion broadens from a top dead point to a bottom dead point.

Abstract: A high pressure pump including a linear actuator comprising a servo motor adapted to axially rotate a hollow rotor shaft in alternating directions, the servo motor having a stator positioned co-axially around the hollow rotor shaft with an interior of the rotor shaft being co-axially coupled to a drive member to convert axial rotation into reciprocal displacement, the drive member being constrained against linear movement and threadingly supporting a shaft (to impart linear displacement of the shaft and an encoder monitoring movement of the drive member.

Abstract: An airless spray pump is provided with a single-acting piston pump which allows the use of a low-cost yoke drive. Motor and pump shaft are offset for most efficient force utilization.