Abstract: A reciprocating pump having a power end, a fluid end, and a spacer section interposing the power and fluid ends. The power end includes a structural support frame having structural members that are each a discrete, unitary member. Each structural member forms a portion of a crankcase frame, a portion of a crosshead support frame, and a portion of a support base. The support base portion extends beneath the crosshead support frame and the spacer section.

Abstract: A mechanism for transforming rotating into reciprocating motion, or vice versa, comprising first and second annular components (1, 3) located coaxially along a longitudinal axis (?A). The first and second annular components are both able to rotate around and reciprocate along the longitudinal axis. A side (A) of the first annular component (1) is in continuous contact, in at least one point, with a neighboring side (??) of the second annular component (3) so that the second annular component (3) is able to rotate relative to and in continuous contact with at least one point with the adjacent side (A). The contacting sides are undulated surfaces (A, ??) such that if the first and second annular components are forced into rotational motion, they remain in continuous contact so that every point of the undulated surfaces will trace, relative to the other, an undulated trajectory and also execute reciprocating motion.

Abstract: The invention relates to a hydraulic brake system for a vehicle, comprising a cylinder (3) and a piston (4) movably arranged inside the cylinder (3), wherein the piston (4) has a closed end, an open end (6) and a piston wall surrounding a cavity (8) of the piston (4) between the closed end and the open end (5), the piston (4) being movable along a longitudinal axis (5) of the cylinder (3) by hydraulic pressure within the cavity (8) for pressing at least one brake pad (9) against a brake disc (2). An outer diameter of the piston (4) is smaller in a central section (13) between the open end (6) and the closed end than at the open end (6) and at the closed end so that, in the central section (13), a space (14) remains between the piston wall and an inner wall of the cylinder (3).

Abstract: A vibration damper, which can be utilized in a chassis of a vehicle, may comprise a damper tube and a working piston that is guided in a longitudinal axis over an inner side of the damper tube. The vibration damper may also include a reinforcing sleeve that is positioned on an outer side of the damper tube. A receptive fork for attachment to the chassis can be arranged on the reinforcing sleeve. The reinforcing sleeve may be delimited in a direction of the longitudinal axis by a peripheral edge. In a region of the peripheral edge, a sealing element enclosing the outer side of the damper tube may be accommodated in the reinforcing sleeve. The peripheral edge may have a plastically deformed reshaping section that engages around the sealing element.

Abstract: An aluminum piston including a cooling gallery with titled inner and outer side walls is provided. The piston comprises a ring belt with a ring grooves, and an iron insert is disposed in a top one of the ring grooves. To reduce stress and mass of the piston, material located under the iron insert is removed, so that the outer side wall of the cooling gallery is tilted toward the center axis. The inner side wall of the cooling gallery is tilted away from the center axis.

Abstract: A steel piston (10) for an internal combustion engine comprises a ring zone (12), a shaft (14), openings (16) between the ring zone (12) and shaft (14) which extend from the piston outer side to the piston inner side, and, between two openings (16), a rib (18) which is substantially central with respect to a length of a piston pin to be received, wherein, when viewed in the circumferential direction, the rib (16) has a decreasing thickness from the middle thereof, as measured in the radial direction.

Abstract: Hydraulic bi-directional flow switches are disclosed. A disclosed example apparatus includes a piston disposed in a fluid channel between a first fluid connection and a second fluid connection, where the first and second fluid connections define a fluid pathway for hydraulic steering fluid. The example apparatus also includes a detector to detect a movement of the piston away from a default position of the piston, where the piston is to displace from the default position when the hydraulic steering fluid flows along the fluid pathway.

Abstract: A coating composition for a lubricating coating film includes: (A) a phenolic resin; (B) an epoxy resin having an epoxy equivalent weight of 600 to 4000; and (C) at least one type of solid lubricant. The epoxy equivalent weight is generally defined by the number average molecular weight per the number of epoxy groups in a single molecule. The coating composition has a weight ratio of component (A) to the total weight of component (A) and component (B) of at least 50 weight %. A lubricating coating film, formed from the coating composition, has a high level of flexibility on surfaces of various base materials.

Abstract: An end part of a piston on a front edge side is formed so as to have a crowning of a 1.2-order to 2.5-order curve where a length is 10% or more and 80% or less of a length of a cylindrical part and a height is 10% or more and 160% or less of a clearance. An end part of a cylinder block on a front edge side is formed so as to have a crowning of a 1.2-order to 2.5-order curve where a length is 8% or more and 60% or less of the length of a cylindrical part and a height is 12% or more and 125% or less of the clearance.

Abstract: A piston ring system, having an internal diameter >400 mm, for a piston of a two-stroke internal combustion engine, includes at least a first and a second piston ring each having a convex running surface with a crest of the convexity in contact with a cylinder wall and each being inserted into a respective first and second piston ring groove in the piston, wherein the first piston ring faces a combustion chamber and the second piston ring is disposed axially beneath the first piston ring, and wherein the crest of the convexity of the first piston ring is disposed beneath a radial plane passing through a midpoint of axial height of the first piston ring, and the crest of the second piston ring is disposed above a radial plane passing through a midpoint of axial height of the second piston ring.

Abstract: A plunger pump includes a pump fluid end having a fluid chamber and a suction bore, discharge bore, and plunger bore in communication with the fluid chamber. A plunger is arranged to reciprocate into and out of the fluid chamber through the plunger bore. The plunger has a plunger body with an inner cavity and an insert disposed in the inner cavity such that the combined stiffness of the insert and plunger body is greater than the stiffness of the plunger body. A crank mechanism is coupled to the plunger and operable to reciprocate the plunger.

Abstract: A piston arrangement comprising: a piston, a first chamber, a second chamber and a power transfer assembly; wherein the piston comprises a first head movable within the first chamber and a second head movable within the second chamber; wherein, in operation, the piston follows a linear path in reciprocating motion along a first axis; wherein the power transfer assembly comprises a shaft rotatably coupled to a shuttle bearing and arranged to convert the reciprocating motion of the piston to rotary motion of the shaft; wherein the shuttle bearing moves relative to the piston in reciprocating motion along a second axis substantially transverse to the first axis; and wherein the shuttle bearing is coupled to the piston via a non-planar bearing surface thereby allowing rotation of the shuttle bearing.

Abstract: A piston assembly (12) comprising a reciprocating sleeve (14) incorporating an integral internal piston surface (28), which sleeve is slidably mounted upon a cylinder head (18) so as to define a piston chamber (26) therewith, the piston chamber being sealed in the vicinity of the cylinder head (18) by a circumferential static seal (20) that acts to seal against the reciprocating sleeve (14). The static seal (20) may occupy a horizontal plane and may include sacrificial wear zones and be formed from a graphite-based material. The piston assembly may be an oversquare assembly for use in an oil-free environment for processing high temperature gases, for example, a hot gas engine or heat pump or heat engine such as may be used in an energy storage system.

Abstract: A method for assembling an actuating ram of air bleed valves, which ram is placed between low pressure and high pressure compressors of a turbomachine, the ram including a piston rod surrounded by a spacer extending from the piston cylinder and configured to be connected to an end of the transmission mechanism linked to the bleed valves, the method including: deploying the piston rod such that it projects from the spacer; connecting the projecting piston rod to the end of the transmission mechanism; retracting the piston rod to bring the cylinder closer to the case wall; and attaching the spacer to the case wall.

Abstract: A piston engine may include a heat pipe capable of transferring heat away from a portion of the piston engine such as a combustion section. The heat pipe may be included as part of a piston assembly, a cylinder, or both. The heat pipe may be filled with a suitable heat pipe fluid that may undergo a phase change such as, for example, water, ethanol, ammonia, sodium, other fluids or combinations thereof. Boiling and condensing of the fluid within the heat pipe may utilize the latent heat of the fluid during heat transfer. Multiple heat pipes may be used in some instances.

Abstract: A piston assembly includes a piston having a crown with an upper combustion surface with a cylindrical outer surface extending downwardly from the upper combustion surface. A pair of pin bosses depends from the crown to a pair of pin bores having generally cylindrical bearing surfaces aligned along a pin bore axis with a top wall portion extending between the pin bosses. The top wall portion has a concave bearing surface forming a continuous concave bearing surface with the pin bores. A separate skirt is fixed to the piston against relative movement. At least one rib extends upwardly from the top wall portion of the piston on opposite sides of the pin bore axis to a lower wall surface of the crown. The at least one rib joins the crown to the top wall portion to provide structural support to the top wall portion against unwanted deflection.

Abstract: A piston for cold chamber die-casting machines includes a piston body terminating at the front with a frontal surface pushing molten metal and at least one ring seat made around the body suitable to house a respective sealing ring. An annular distribution channel is made in an intermediate annular portion of the bottom surface of the ring seat, which communicates with the frontal surface of the piston through at least two communication holes made in the piston body for flow of molten metal into the distribution channel, under the ring. The communication holes are inclined in relation to the piston axis and have a through section which increases towards the distribution channel.

Abstract: The present invention provides a variable displacement swash plate type compressor that reduces wear of cylinder bores and the amount of blow-by gas. Each piston of the compressor has a piston main body, which has a distal portion located at an end corresponding to the compression chamber. A tapering portion and an arcuate portion are formed in the distal portion. The arcuate portion is continuous with an end of the tapering portion that is closer to the compression chamber. The tapering portion and the arcuate portion each have a diameter that increases toward the skirt. The tapering portion has a tapering angle that is in a range from 0.45 degrees to 1.5 degrees. The distance between the distal end of the piston main body and a starting point of the tapering portion on an end closer to the skirt is set in a range from 1.5 mm to 5.0 mm.

Abstract: A hydraulic cylinder assembly for a fluid pump including a cylinder, a bearing attached to an approximate first end of the cylinder, a rod slideably mounted within the bearing, and a piston located about an end of the rod in the cylinder opposite the bearing. A central axis of the rod is offset from, and parallel to, a centerline of the cylinder to impede a rotation of the piston about the rod. The hydraulic cylinder assembly further including a hydraulic pump fluidly connected to the cylinder, the pump configured to provide a hydraulic pressure to the cylinder during an up-stroke of the piston and rod and the pump further configured to generate electricity on the down-stroke of the piston and rod.

Abstract: A liquid cooled piston of an internal combustion engine includes a piston lower part and piston upper part which has a combustion chamber recess. These piston components are supported via joining lands which are spaced apart radially and together form a dividing plane, and are joined together with a material-to-material fit. In order to receive piston rings, the piston upper part has a ring area and includes an annular cooling channel which extends into the piston lower part and is connected to an inner cooling space via connecting channels. The cooling channel is adjoined by recesses which are oriented in the direction of a piston head, are configured as a blind hole and widen conically starting from the cooling channel as far as a recess bottom. The recess bottom can be of a pronounced undulating enlarged surface or a finely undulating configuration.

Abstract: The present invention refers to a connecting rod/piston arrangement for alternative compressor, comprising using at least an intermediate element capable of associating said connecting rod with the piston, wherein both do not radially contact with one another. A process for assembling said connecting rod/piston arrangement for alternative compressor is also disclosed. The connecting rod/piston arrangement for alternative compressor comprises at least a piston (1), at least an intermediate element (2) and at least a connecting rod (3), wherein said piston (1) comprises at least a non-through axial channel (11); said intermediate element (2) comprises at least a through axial channel (21); and said connecting rod (3) comprises at least a connection end (31). In this regard, the intermediate element (2) is securely housed inside the non-through axial channel (11) of piston (1); and said connection end (31) of connecting rod (3) is securely housed inside the through axial channel (21) of intermediate element (2).

Abstract: A linear actuator is used with a vacuum chamber in which plasma is generated. The linear actuator comprises a moving member extending between the exterior and the interior of the vacuum chamber through an opening provided in the vacuum chamber so as to be rectilinearly reciprocated, a drive section configured to reciprocate the moving member, a cover that covers the moving member, and a slide seal section that provides a seal between the interior and the exterior of the vacuum chamber while allowing the cover to slide thereon. The cover covers a range of the moving member which is moved into both of the interior and the exterior of the vacuum chamber while the moving member is reciprocated by the drive section, and an outer surface of the cover is smaller in the amount of gas adsorption per unit area than an outer surface of the moving member.

Abstract: A piston plate assembly for a torque converter comprising: an aperture including a chamfer portion; and, a bushing installed in the aperture and including a radius portion proximate the chamfer portion, wherein the bushing is arranged to seal the piston directly to a transmission input shaft and the radius portion is arranged to ease assembly of the bushing onto the input shaft.

Abstract: A piston mechanism assembly includes a piston group that includes two annulus-shaped undulant-surface pistons that axially mate each other and movable relative to each other. Each undulant-surface piston includes an axial through hole and has an end forming a continuous undulant surface. Each undulant surface includes at least two crest portions and two trough portions to mate another undulant surface. Two outer rings surround an outer circumference of the piston group and are respectively movable in synchronization with each piston and have outer ring gates corresponding to the undulant surfaces. Two inner rings are respectively received in the axial through holes of each undulant-surface piston to be movable therewith and have inner ring gates corresponding to the continuous undulant surfaces. While the two pistons rotate relative to each other, an axial reciprocal motion is induced by the undulant surfaces on the pistons to cause volume variation of chambers therebetween.

Abstract: A device includes an actuation system with a dose chamber including an inlet for high pressure fluid. A working chamber extends away from the dose chamber. An annular wall separates a portion of the working chamber from the dose chamber such that the dose chamber encompasses the portion of the working chamber. In use an item to be driven along the working chamber is at least partially within the surrounded portion of the working chamber with the item at one end of its travel in the working chamber. A valve mechanism selectively allows high pressure fluid from the dose chamber to flow into the piston chamber.

Abstract: A piston and carrier assembly for an engine is provided. The assembly includes a thrust washer positioned at an interface of the carrier and the piston. The assembly also includes a retention means provided in cooperation with the thrust washer and a top surface of the carrier. The retention means is configured to restrict movement of the thrust washer relative to the carrier.

Abstract: The present invention provides a steel piston having cooling channel without flash, including an upper piston part having a circle shape outer wall and an inner wall formed inward from the outer wall with a desired distance, and a lower piston part having a circle shape outer wall and an inner wall formed inward from the outer wall with a desired distance on the place corresponding each other when they are coupled, in which one or more concave grooves are formed on the outer wall of the upper piston part, and two concave grooves are formed on the inner wall of the upper piston part, and the inner circumference surface of the upper end of the outer wall of the lower piston part is carved as much as a desired depth, and therefore, a stepped portion is formed between the inner and the outer circumference surfaces, and the inner and outer circumference surfaces of the upper end of the inner wall of the lower piston part are carved as much as a desired depth, and a protrusion is formed at the middle of the upper e

Abstract: An output rod (27) is inserted in a housing (4) so as to be movable vertically. A first piston (41) inserted in a lower part of the housing (4) is fixed to the output rod (27). A second piston (42) inserted on an upper side of the first piston (41) is fitted on the output rod (27) so as to be movable vertically. A lock chamber (44) is provided between the first piston (41) and the second piston (42). A first release chamber (51) is provided below the first piston (41). A second release chamber (52) is provided above the second piston (42). During force multiplication driving of the output rod (27), a pressurized fluid in the lock chamber (44) carries out the force multiplication driving with respect to the output rod (27) downward via the second piston (42) and engaging balls (69). A retaining spring (60) which biases the second piston (42) upward is provided in the lock chamber (44) between the first piston (41) and the second piston (42).

Abstract: A frictional vibration damper for washing machines is disclosed. The damper comprises a piston body and a piston rod which adapted to move along the primary axis of said piston body. A friction element is located in between the piston rod and the piston body. The piston rod and piston body is equipped with joint at one of their ends for connection to the frame and the drum of the washing machine. The piston rod comprises a tubular body which is made of sheet material and which is fixedly rolled around a carrier piece. The frictional damper according to the present invention preferentially comprises, on one or both sides of the tubular body, with connection elements in the longitudinal direction for engaging to corresponding connection elements located on the carrier piece.

Abstract: An air spring (10) comprises a hollow elastic sleeve (12), an upper component (22) for securing the air spring to a first frame, a hollow piston (14) for securing the air spring (10) to a second frame that is movable relative to the first frame, and a cylinder (16) surrounding the hollow elastic sleeve to constrain the diameter of the hollow sleeve (12) and reduce the effective area of the air spring to reduce the natural frequency of the air spring (10).

Abstract: A linear actuator has a housing with a bore therethrough, thus defining an axis. A shaft is in sliding engagement with a portion of the bore and a piston is coupled to the shaft. An anti-rotation apparatus has an elongate slot defined in the housing which extends parallel to the axis. The elongate slot has opposing sidewalls that are non-parallel to one another and offset from a plane perpendicular to the axis by a respective predetermined angle ranging between zero and fifteen degrees. A bearing block has opposing sides and a hole therethrough, wherein an attachment member extends through the hole, coupling the bearing block to the shaft. The opposing sides of the bearing block are parallel to the respective opposing sidewalls of the elongate slot. The attachment member provides a selective engagement force between the opposing sides of the bearing block and the opposing sidewalls of the elongate slot.

Abstract: Disclosed is piston pump (10) and piston assembly (30) for such a pump. The piston pump includes a cylinder (20) having an inner wall surface (22) formed around an axis A of the cylinder, and a piston assembly (30) for sliding along said cylinder axis, said piston assembly includes a slideable flexible seal (34) in generally sealing contact with said inner wall surface, and a seal mounting (44), said seal mounting having a plurality of circumferentially arranged members (37) moveable radially of said axis to increase or decrease the size of the seal.

Abstract: A piston for a pump includes a hub portion defining opposing outer surfaces and concave lateral portions between the opposing outer surfaces. The piston also includes inserts configured to provide a replaceable surface, the inserts being coupled to each of the opposing outer surfaces. A pump includes a housing having an inlet and an outlet, and at least two pistons having a hub portion and inserts. The pump may be a positive-displacement, rotary pump, and the pistons may be circumferential pistons.

Abstract: In a spring piston airgun, a compression piston is provided for longitudinal translation within a compression tube in response to a motive force. The compression piston includes a main piston body and a piston head, wherein the piston body and piston head are coupled for partial independent translation along a longitudinal axis. A resilient compressible bushing is longitudinally intermediate a portion of the piston body and the piston head, such that upon a deceleration of the piston head, the piston body is not immediately acted upon by the deceleration, rather the bushing absorbs a portion of the deceleration and radially expands to contact the compression tube.

Abstract: In a piston-ported engine, a sealing ring may be placed in a groove in the cylinder. As the groove is of greater diameter than the cylinder, the sealing ring overlaps into a helix allowing it to be enter the cylinder. However, such a helix does not fit into a groove without when in the helix. Alternatively, a shorter sealing ring is placed into the groove. However, the gap is too large. According to one embodiment, a groove of double the width of the ring is provided and the helical ring is installed and caused to unwind in the groove so that the ring sits in a plane. A spacer ring is placed in the groove to fill the extra space in the groove. An elastomeric material or a tension spring in an outer groove in the sealing ring can be used to cause the ring to press against the piston.

Abstract: A piston for a brake caliper of a disc brake constructed as a pot which is open at one end, having a longitudinal axis, a wall, and a piston head. The piston is supported in a cylinder of the brake caliper such that it can be moved along the longitudinal direction, and it can be placed against a brake pad in the region of the piston head by an axial contact surface. When the piston is subjected to pressure by a hydraulic fluid, the piston moves in the cylinder and presses the brake pad against a brake disc. A projection having a conical surface is provided on an inner surface of the piston head. A recess is provided, which is substantially at the same distance from the longitudinal axis as the projection on the inner surface of the piston head, on an outer surface of the piston head.

Abstract: A hydraulic actuator with a minimal closed height includes a housing (11), a chamber (12), and a fluid inlet (13) formed within the housing and arranged for communicating high pressure fluid to the chamber (12), the chamber (12) being partially divided into an inner portion (P1) and a radially outer portion (P2) by a longitudinally extending sleeve (123) having an open end (1231) proximal to a base (121) of the chamber (12) and spaced apart therefrom, the outer portion (P2) being arranged to communicate high pressure fluid from the fluid inlet(13) to the inner portion (P1) through a space (S) defined between the end (1231) of the sleeve (123) and the base (121), and the inner portion (P1) being adapted to receive a piston (100) such that the piston (100) is slidably actuable in dependence on the high pressure fluid received from the outer portion (P2).

Abstract: A reservoir includes first and second chambers, and a piston having first and second ends disposed in the first and second chambers, respectively. The first and second ends isolate a first area from a second area within the first and second chambers. The first area of the first chamber is in fluid communication with a high pressure fluid source and the second area of the first chamber is in fluid communication with a low pressure fluid source. An orifice is formed in the first end and is configured to allow fluid communication between the upper and lower areas of the first chamber. A pumping system and an aircraft are also disclosed.

Abstract: A piston assembly having a piston member with a removable wear sleeve and a method for removing and replacing the same having a center pin extending at least partially through the sleeve, a housing engaging the sleeve, and a mandrel engaging the center pin and the sleeve that may be removed to allow for the replacement of the sleeve while the piston member is in service.

Abstract: A repaired piston includes a crown composed of base and welding filler materials, and having an annular rim extending around a combustion bowl. A finite number of repaired defects are within the annular rim, and have a spatial distribution limited by a multidirectional spacing parameter, and a size distribution limited by a unidirectional sizing parameter.

Abstract: A pump element includes a body defining a chamber. A piston assembly is biased to a first position within the chamber and is configured to be driven along an axis from the first position to a second position to compress fluid. At least one flow path is defined through the piston assembly from an upstream end to a downstream end, and the at least one flow path is configured to receive flow only in the axial direction.

Abstract: Provided are, among other things, pistons and piston noses. One representative embodiment involves a brake piston that includes a piston body and a top surface, in which the top surface is wider than the piston body and has a small portion that is slightly raised, relative to the rest of the top surface, so that when in use only the small raised portion makes contact with a backing plate of a brake pad.

Abstract: A piston for an axial machine includes a piston body having a cavity that is closed in a pressure-tight way. The cavity is divided into a plurality of chambers, arranged one beside the other in cross-section.

Abstract: A method of manufacturing a coated piston ring includes applying a layer of an aluminum-based material to an outside surface of a ring body formed of an iron-based material, such as steel. The layer of an aluminum-based material is applied by thermal spraying. The method further includes an environmentally friendly heat treatment process causing the aluminum-based material to combine with the iron-based material of the ring body and form a wear resistant coating of aluminum iron (Al5Fe2). The heat treatment process can include heating to a temperature of about 550° C. for 20 minutes so that the wear resistant coating achieves a hardness of HV 1000.

Abstract: Described herein is a plunger of an injection molding machine, comprising a plunger body; a plunger tip that is a separate element from the plunger body and comprises an end surface configured to directly contact a molten material used in injection molding in the injection molding machine; wherein thermal conductance across the end surface of the plunger tip may be adjustable by moving the plunger tip relative to the plunger body such that temperature of the plunger tip may be adjusted during injection molding. When this plunger is used to injection molding of a BMG, it allows reduction of formation of crystalline phases near the plunger tip and allows replacement of the plunger tip without replacement of the plunger body.

Abstract: A piston seal includes an inner surface configured to extend proximate a perimeter of a piston. Also included is an outer surface disposed proximate a chamber wall, wherein the chamber wall defines a chamber for the piston and the piston seal to translate within. Further included is a first axial side exposed to a first pressure portion of the chamber. Yet further included is a second axial side exposed to a second pressure portion of the chamber. Also included is at least one pressure differential reducing hole extending radially through the piston seal from the inner surface to the outer surface.

Abstract: A piston assembly is disclosed which includes a crown and a skirt. The crown and skirt may cooperate to form a cooling gallery. The crown may include an axial support extending away from the combustion bowl, and radially inner and outer support surfaces that are abutted against corresponding radially inner and outer support surfaces of the skirt. The axial support may have a first diameter and a second diameter larger than the first diameter. The skirt may define an aperture receiving the first diameter of the axial support such that the second diameter of the axial support is supported in the skirt on a side of the aperture opposite the crown. The corresponding radially inner and outer support surfaces of the crown and skirt may each be abutted with a radially inner preload, and a radially outer preload, respectively.

Abstract: A piston for a pump a hub portion defining opposing outer portions, and inserts configured to provide an adjustable surface coupled to each of the opposing outer portions. The hub portion includes a first hub portion and a second hub portion configured to abut one another. Each of the inserts includes an outer shell and a base portion. The first hub portion includes a plurality of the opposing outer portions, and each of the base portions of the inserts is adjustably coupled to respective opposing outer portions of the first hub portion. A pump includes a housing having an inlet and an outlet, and at least two pistons having a hub portion and inserts. The pump may be a positive-displacement, rotary pump, and the pistons may be circumferential pistons.

Abstract: Methods, apparatuses, and systems for circumferential sealing of piston assembly in a piston actuator. A piston assembly for a piston actuator includes a piston including an extending surface, a retracting surface, and a circumferential surface that connects the extending surface and the retracting surface. The piston is adapted to engage and seal against an interior surface of a cylinder bore of an actuator. The piston assembly includes a first unidirectional passage connecting the extending surface and the circumferential surface.

Abstract: A plunger for fuel injection assembly is provided. The plunger includes a nitrided surface. The nitrided surface includes a damaged area. An electroless material is coated on the damaged area.