Abstract: A cooling system for combustion-powered fastener-driving tools comprises the use of cooling fin structures upon the external wall members of the combustion chamber and cylinder. Fluid flow paths are constructed between internal wall portions of a surrounding tool housing and the cooling fin structures mounted upon the external wall members of the combustion chamber and cylinder. In this manner, ambient cooling air is passed over and through the cooling fin structures whereby the combustion chamber and cylinder components of the fastener-driving tool are efficiently cooled such that the temperature level of the fastener-driving tool is maintained at a desirable temperature level despite the substantial amount of heat normally generated during each combustion cycle.

Abstract: Disclosed are a sintered composite machine part as a cylinder block for piston pumps or piston motors, and a manufacturing method thereof. The machine part has an air-tight main body of sintered porous iron alloy and having an iron oxide layer on the surface; and a sliding part of sintered porous copper alloy being bonded direct to the main body. The sliding part is to be slid in tight contact with a fluid supply/return device. The manufacturing is made by preparing a main body of sintered porous iron alloy and a green compact for sliding part from a raw material metal powder having a composition corresponding to the copper alloy; sintering the green compact for sliding part in contact with the main body to bond the sliding part to the main body by diffused junction; and subjecting the main body to steam treatment to provide an iron oxide layer.

Abstract: A delivery device includes a durable housing portion and a separable disposable portion that selectively engage and disengage from each other. The disposable housing portion secures to the patient-user and may be disposed of after it has been in use for a prescribed period. Components that normally come into contact with a patient-user or with an infusion medium, including a pump device, are supported by the disposable housing portion for disposal after the prescribed use, while the durable housing portion supports other components such as electronics for controlling delivery of the infusion medium from the reservoir and a drive device and drive linkage.

Abstract: A hydraulic cylinder having a gland that is rotatable relative to the cylinder tube, the pivotal connection provided by a pair of aligned annular grooves on the gland and the cylinder tube, a key slot located through the cylinder tube, and a key positionable through the key slot to be located within the annular grooves to rotatably attach the gland to the cylinder tube. The key includes one end configured to engage the gland for facilitating installation and another end configured in a wedge shape to facilitate removal of the key.

Abstract: An airless sprayer for paint or the like consists of an electric drive unit connected to a piston. Driven by the electric drive unit, the piston reciprocates within the cylinder, thus spraying the paint or the like. Because of the close tolerance between the piston and cylinder (typically about 0.0002 to about 0.0003 inches), the sprayed liquid provides a seal between the piston and cylinder. To prevent this tolerance from increasing to the point of failure, the cylinder is manufactured from nitride hardened steel. A process for manufacturing the airless sprayer is also disclosed.

Abstract: The present device relates to a housing module 1 for a brake booster. The housing module has a housing shell 3 that accommodates a movable wall 4. The movable wall subdivides an interior space of the brake booster into a low-pressure chamber 5 and a working chamber 6. Also, a control housing 11, in which a control valve 10 is arranged, controls a pressure difference acting on the movable wall 4 and is operable of an actuating rod 9. The control valve includes two sealing seats 12, 13 which are arranged concentrically to one another and of an elastically deformable valve body 14.

Abstract: A reducing agent pump has a pump inlet part and a pump outlet part closing off the pump body at its ends. One or both of the inlet and outlet parts is of two-part construction, with a closure element and another element. The two elements are prestressed relative to one another with a spring element, so that in the event of a pressure which exceeds the spring force of the spring element, a relative movement can be carried out between the two elements of the two-part member. This makes it possible to absorb an increase in the volume of the reducing agent inside the pump body caused by freezing and therefore to prevent damage to the reducing agent pump.

Abstract: A hydraulic linear drive, in particular for a hydraulic transmission actuator, has a piston/cylinder unit in which an adjusting piston is situated so that it is longitudinally displaceable in a cylinder housing and divides a cylinder space into at least two pressure spaces. The pressure spaces can be acted upon by hydraulic oil via controllable pressure supply through hydraulic lines. A sealing ring is situated on the adjusting piston or on the cylinder housing for sealing, the two pressure spaces with respect to one another. The sealing ring is accommodated in a ring groove on the cylinder housing so as to seal with its inside against the adjusting piston. A sealing pressure supply system communicates hydraulic oil to the outside of the sealing ring so as to control the sealing pressure of the sealing ring on the piston surface.

Abstract: A yoke structure for a compressor is disclosed, which is applied to a scotch yoke type reciprocating compressor. The yoke structure comprises a crankshaft (10); a crankpin (20) connected to the crankshaft (10), to rotate along a predetermined round trajectory which has the crankshaft at its pivot, as the crankshaft rotates; a frame having a pair of slide ways (41) formed on two parallel inner faces of the frame (40) opposing each other, one or more pistons (30) to be fixed to outer faces of the frame outside the slide (41) ways; a sliding block (30) positioned between the pair of slide ways (41) and rotatably connected to the crankpin (20); and a pair of self-lubricating materials (32) attached to the sliding block (30) so as to be in contact with opposing faces of the slide ways (41).

Abstract: A pumping system including a pump is disclosed. The pump includes a replacement piston and a replacement cylinder associated with the replacement piston. The replacement piston has a cross sectional area smaller than a cross sectional area of an original piston of the pump.

Abstract: A device for detecting the position of a hydraulic piston-cylinder system, where the hydraulic piston-cylinder system is connected to a position-detecting means which comprises a magnet and a Hall sensor and the connection between the hydraulic piston-cylinder system and the position-detecting means comprises a lever.

Abstract: Disclosed herein is a linear compressor. In the present invention, the configuration that a sealing protrusion is protruded in a sealing part of a cylinder toward an exhale cover leads line contact with the exhale cover and the sealing protrusion of the sealing part. Even though small power is applied to the exhale cover, the exhale cover and the sealing protrusion are closely adhered to each other, thus effectively sealing the exhale cover and the cylinder. Furthermore, as power transmitted from the exhale cover to the cylinder becomes reduced, a transformation of the cylinder can be prevented, and a performance and reliability of the linear compressor can be enhanced.

Abstract: A method for assembling a piston on a rod, and resultant piston and rod assembly, uses one or more lock rings that are mechanically deformed radially inwardly into respective locking grooves in the rod, thereby axially locking the lock ring to the rod. The lock ring can function as an axial stop for the piston or can be formed integrally with the piston. The method of assembly minimize unwanted strains and stresses in the piston and rod, while providing a secure and durable joint between the piston and rod.

Abstract: A pressure assembly including a cylinder, an end plug and a split ring band. The cylinder has an end, an inner surface and an outer surface. The end plug is inserted into the end of the cylinder, the end plug having an outer surface that is in partial contact with the inner surface of the cylinder. The split ring band is in contact with the outer surface of the cylinder, the split ring band being secured to the cylinder and to the end plug.

Abstract: A continuously lockable adjustment device for immobilizing elements which are movable relative to each other includes a stepped cylinder having a first cylinder step and a second cylinder step, the second cylinder step having a larger cross-sectional area than the first cylinder step, a stepped piston having a first piston step guided in the first cylinder step and a second piston step guided in the second cylinder step, and a piston rod connected to the piston opposite the first piston step and extending sealed off out an end of the cylinder. The cylinder has a first working space and a second working space separated by the piston and filled with a working fluid in which the piston can be displaced axially, thereby displacing working fluid from one working space to the other working space.

Abstract: In a guide system with a pneumatic stop structure comprising a cylinder with a piston including a piston seal element movably disposed in the cylinder and a piston rod connected to the piston and extending from the cylinder wherein a displacement chamber is formed at one side of the piston, the cylinder has a cross-section which steadily increases toward the end of the displacement chamber and the piston seal element which, in the area of the smallest cylinder cross-section is in sealing engagement with the cylinder wall is out of sealing contact with the cylinder wall at the opposite end of the cylinder where the cylinder has an increased diameter.

Abstract: A lifting platform for motor vehicles has at least one extendable lifting column that is formed by a tubular jacket and a lifting cylinder unit arranged at least partially therein. The upper end of the lifting cylinder unit supports a load receptacle. The tubular jacket and the lifting cylinder unit are air-tightly connected to one another and form a compressed air storage chamber between the inner wall of the tubular jacket and the outer wall of the lifting cylinder unit. The compressed air storage chamber is provided with a compressed air supply connector and, in the upper end area, with a compressed air outlet connector. The lifting device is preferably an underfloor lifting platform with hydraulic cylinders. A check valve is arranged in the filling direction upstream of the compressed air supply connector.

Abstract: A magnet type rodless cylinder comprised of cylinder tube of a double tube structure provided with an outside tube of an elliptical flattened outside circumferential shape and two inside tubes inserted into the outside tube. When pressurized air is supplied alternately to the inside tubes from a port provided at an end cap, two pistons move reciprocatingly inside the inside tubes. Due to this reciprocating motion, this reciprocating motion causes reciprocating motion of a slide magnetically coupled with the two pistons at the outside of the outside tube. The inside pressure caused by the pressurized air acts exclusively on the inside tubes and does not directly act on the outside tube of the flattened outside circumferential shape, so the thickness of the outside tube can be reduced and, even if the cylinder tube is made a double tube structure, the total thickness will not become greater than in the past.

Abstract: A compressor assembly including a cylinder block defining first and second cavity portions. A central axis extends through first and second cavity portions. A compressible fluid respectively enters and exits the first cavity portion through an inlet and outlet. A piston is reciprocatingly disposed along the central axis and includes first and second piston portions which are at least partially disposed within the first and second cavity portions, respectively. The first piston portion defines a compression chamber within the first cavity portion. Reciprocation of the piston compresses the fluid within compression chamber. The second piston portion has a radial outer surface at least partially engageable with a sidewall of second cavity portion whereby forces transverse to the central axis are transferable between the radial outer surface and the sidewall. A variable volume space is defined by the second piston and cavity portions. A vent passage communicates with the variable volume space.

Abstract: One advantageous embodiment of the claimed invention is an air cylinder (12) for a pneumatic fan drive system (10). The air cylinder (12) is comprised of a single-piece stamping, which is utilized for covering a piston (22) of the pneumatic fan drive system (10). This single-piece stamping has an e-coating (40) applied thereon for improving a surface finish of the single-piece stamping and inhibiting corrosion of said single-piece stamping.

Abstract: A telescopic pneumatic device comprises an outer cylinder, an inner cylinder disposed in the outer cylinder and having a cylinder wall defining an air chamber, a piston mounted in the air chamber and having a piston rod connected thereto, a flow passage provided between the cylinder wall and the outer cylinder, and a control valve operable to permit or interrupt fluid communication between the flow passage and the air chamber. The inner cylinder is made of a rigid plastic material and includes a valve mounting part for receiving the control valve, the valve mounting part being formed in one piece with the cylinder wall.

Abstract: A fluid power linear drive has a drive housing (1) in which a housing chamber (4) is located containing at least one piston (5). The drive housing possesses two housing parts (2 and 3) placed alongside each other, which at mutually facing joint faces (16 and 17) are provided with half chambers (18a and 18b) constituted by elongated, groove-like recesses, which half chambers are united in a complementary fashion to form at least one housing chamber (4).

Abstract: A pneumatic force-generating device, for example, a pneumatic cylinder for balancing the ram weight on a press, is provided with an impact or catching device having an impact plate (24) for catching the piston (18) upon discharge of the weight. The deformable impact plate (24) is securely clamped along its edge or held by a clamping device (31), that permits a controlled slipping through. The impacting piston (18) deforms the impact plate (24) to absorb the kinetic energy produced if this piston is released as a result of damage and is accelerated by the existing gas bolster and thrown against the impact plate (24).

Abstract: Smaller and lighter hydraulic pump/motors provide remarkably improved volumetric efficiency with pistons having body portions substantially as long as the axial length of the respective cylinders in which they reciprocate. A plurality of respective lubricating channels form a single, continuous lubricating passageway entirely within the cylinder block and not connected by either fluid “input” or fluid “output” passageways, being replenished solely by a minimal flow of fluid to and from the valve end of each cylinder and passing between each respective cylindrical wall of each cylinder and the axial cylindrical body of each respective piston. Several embodiments are disclosed in combination with various spring-biased hold-down assemblies. The preferred embodiment included a fixed cylinder block, a roller bearing mounting between the wobbler and rotor of a split-swash plate, with piston shoes contacting the wobbler directly without any intermediary apparatus.

Abstract: A method and an arrangement in an energy-accumulating piston-cylinder arrangement (A) has a piston/piston rod part (2), guide/end (3) and tubular casing (1). The casing (1) is provided with a fracture or sprain mark (7) in order to initiate a controlled deformation of the casing in the event of a load that produces a stress in excess of a sprain or fracture limit, or of repeated cyclical stressing that gives rise to material fatigue, so that an excess pressure in the arrangement (A) is discharged past the deformed casing.

Abstract: A linear abstract includes a cylinder part and a piston part. A spring connects the cylinder part and the piston part and operates in the direction of reciprocation of the piston part relative to the cylinder part. The piston part includes a radially compliant but axially stiff linkage and a piston. The cylinder part includes a cylinder and a cylinder liner therewithin. A bore runs through the cylinder liner and the piston reciprocates in the bore. Gas bearing passages are formed between the cylinder and the cylinder liner leading to openings through the wall of the cylinder liner to the bore. A gas bearing manifold receives compressed gases and supplies the compressed gases to the gas bearing passages. The gas bearing passages follow a tortuous path to the openings.

Abstract: A pair of sliding elements for machine parts exposed to high-pressure and high-temperature steam, preferably piston-cylinder arrangements for steam engines. The first sliding element is produced from a synthetic, fired but not graphitized carbon material which comprises graphitized carbon black and/or natural graphite as significant filler and whose pores are filled with metal, metal alloy, a ceramic, synthetic resin and/or pitch which has been carbonized, preferably in the form of a piston and/or piston ring. The second sliding element, preferably in the form of a cylinder liner or guide bush, comprising an iron-containing, high-temperature-resistant material which is preferably alloyed with chromium and/or nickel and is provided at least on the surface layer with a nitride layer.

Abstract: A central release device (10) is disclosed having a cylinder housing (12), with a cylindrical wall (14), and a guide sleeve (16), which is arranged concentrically therewith and on which an annular piston (18), which can be operatively connected to a clutch and can be hydraulically actuated by way of a pressure chamber (20) defined by the cylindrical wall and the guide sleeve, is displaceably guided. At its end the guide sleeve has an annular flange (22) with an end face (24) facing away from the annular piston and a radially outer circumferential surface (26), by way of which flange the guide sleeve is fixed to an end face (28) of the cylinder housing.

Abstract: The present invention is directed to a master cylinder provided with an annular seal member (S1) having an annular groove of U-shaped cross section formed on its one end face, and a substantially annular seal retainer (30) for restricting at least axial movement of the seal member, and including a substantially annular lifted wall portion (31) formed to extend axially into the U-shaped annular groove of the seal member, and a substantially annular step portion (32) formed on an inner periphery of the lifted wall portion, for contacting an open end face of the seal member. The seal retainer is reduced in diameter by radial pressing force produced when it is received in a cylinder bore (1), and restored when the pressing force is released. The seal member is placed in an annular hold groove (1d), and the seal retainer is received from an open end of the cylinder bore to be placed in an annular transfer groove (1b), with the seal retainer reduced in diameter.

Abstract: Valve guide and spring retainer assemblies are described for use in plunger pump housings that incorporate structural features for stress-relief. These pump housing structural features accommodate correspondingly-shaped valve guides and/or spring retainers that are internally fixed in place using one or more non-threaded spacers. Plunger pumps so constructed are relatively resistant to fatigue failure because of stress reductions, and they may incorporate a variety of valve styles, including top and lower stem-guided valves and crow-foot-guided valves, in easily-maintained configurations. Besides securing valve guides and/or spring retainers, non-threaded spacers may be shaped and dimensioned to aid in further reducing stress and to improve volumetric efficiency of the pumps in which they are used.

Abstract: A carbon piston whose piston crown underside forms in the region between the increased-thickness boss portions independently of the surface configuration of the top side of the piston crown a curved surface, preferably an ellipsoidal surface, which adjoins the increased-thickness boss portions. The piston skirt has an axial profile in the form of a conical surface with rectilinear generatrices, which tapers upwardly to the connection to the ring portion.

Abstract: A swash type compressor includes sleeves which are fixedly fitted in cylinder bores. The lengths of the sleeves in an axial direction are greater than the lengths of the cylinder bores in the axial direction. A sleeve end of each of the sleeves is flush with an end surface of a cylinder block defining the cylinder bores. The opposite sleeve end of the sleeve extends beyond the cylinder bore and away from the opposite end surface of the cylinder block.

Abstract: A pneumatic force-generating device, for example, a pneumatic cylinder for balancing the ram weight on a press, is provided with an impact or catching device having an impact plate (24) for catching the piston (18) upon discharge of the weight. The deformable impact plate (24) is securely clamped along its edge or held by a clamping device (31), that permits a controlled slipping through. The impacting piston (18) deforms the impact plate (24) to absorb the kinetic energy produced if this piston is released as a result of damage and is accelerated by the existing gas bolster and thrown against the impact plate (24).

Abstract: An oil pressure cylinder has an adjusting ring. The adjusting ring is prolonged and is formed by two parts which are buckled with one another. An elastic element is used to buckle the adjusting ring. A spring is embedded at a slot of the adjusting ring so as to tightly seal the adjusting ring. The sealing washer in the steel tube has a plane shape and has a convex ring. An outer side of the convex ring is enclosed by an elastic wearing compensating spring; a connecting portion of the selecting seat with the adjusting ring is formed as a plane for matching the plane sealing washer. The adjusting ring is formed integrally, the adjusting ring has an opening, the opening has two parallel long sides and two parallel short sides, four corners of the opening are cambered; in interior of the adjusting ring has a plurality of blocks.

Abstract: A submersible gas compressor is described which has a ceramic high pressure piston in contact with a ceramic sleeve, a drive piston mounted to the ceramic high pressure piston and a crank in mechanical connection with the drive piston. The submersible gas compressor can be used as a second stage compressor in a gas delivery system that includes a first stage low pressure compressor, an absorption bed containing molecular sieve material, a second stage compressor to pressurize a gas stream to a pressure between 5000 and 10,000 psig, a cascade system for storing the pressurized gas stream between 3500 and 5000 psig, a control system, and an outlet for delivering the pressurized gas stream.

Abstract: A fluid-operated piston-type actuator includes a body having first and second axial ends and an inner surface that defines a bore that opens through at least one of the first and second axial ends to define an open end of the bore. A piston is slidably positioned in the bore. An end wall is positioned in blocking relation with the open end of the bore. The end wall comprises a peripheral surface that defines a first circumferentially extending groove that is axially aligned with a second circumferentially extending groove defined in the inner surface of the body when the end wall is positioned in blocking relation with the open end of the bore. The end wall further comprises an inner face oriented toward the piston and an opposite outer face oriented away from the piston. The first groove is located axially between the inner and outer faces.

Abstract: An oil pressure cylinder has an adjusting ring. The adjusting ring is prolonged and is formed by two parts which are buckled with one another. An elastic element is used to buckle the adjusting ring. A spring is embedded at a slot of the adjusting ring so as to tightly seal the adjusting ring. The sealing washer in the steel tube has a plane shape and has a convex ring. An outer side of the convex ring is enclosed by an elastic wearing compensating spring; a connecting portion of the selecting seat with the adjusting ring is formed as a plane for matching the plane sealing washer. The adjusting ring is formed integrally, the adjusting ring has an opening, the opening has two parallel long sides and two parallel short sides, four corners of the opening are cambered; in interior of the adjusting ring has a plurality of blocks.

Abstract: The present invention relates to a method and an arrangement in an energy-accumulating piston-cylinder arrangement (A) having a piston/piston rod part (2), guide/end (3) and tubular casing (1).

Abstract: A submersible gas compressor is described which has a ceramic high pressure piston in contact with a ceramic sleeve, a drive piston mounted to the ceramic high pressure piston and a crank in mechanical connection with the drive piston. The submersible gas compressor can be used as a second stage compressor in a gas delivery system that includes a first stage low pressure compressor, an absorption bed containing molecular sieve material, a second stage compressor to pressurize a gas stream to a pressure between 5000 and 10,000 psig, a cascade system for storing the pressurized gas stream between 3500 and 5000 psig, a control system, and an outlet for delivering the pressurized gas stream.

Abstract: A piston position in a cylinder of a hydraulic assembly is measured using microwave pulses. The microwave pulses are launched along a conductor coupled to the piston or cylinder. A sliding member is slidably coupled to the conductor and moves with the piston or cylinder. Position is determined as a function of a reflection from the end of the conductor and the sliding member.

Abstract: A piston for a setting tool and including a piston head (10) having a hollow-chamber (12) adjoining opening (11) formed in the end surface of the piston head, and a stopper (20) securable in the hollow chamber (12) of the piston head (10) with a solder seam for closing the opening (11), a centering element (23) provided on an outer circumference of the outer surface (22) of the stopper (20).

Abstract: The friction clutch between the prime mover and the change-speed transmission in the power train of a motor vehicle is actuatable by a slave cylinder cooperating with a master cylinder wherein the piston is movable by a clutch pedal or by an electric actuator. The casing of the slave cylinder is made, at least in part, of a plastic material and defines a plenum chamber arranged to receive pressurized fluid from the master cylinder by way of a conduit extending through a bell which contains the clutch and the slave cylinder. The annular piston of the slave cylinder surrounds the input shaft of the transmission. The plastic material of the casing of the slave cylinder can contain one or more additives which enhance its strength and/or influence its frictional engagement with the adjacent surfaces of the piston or of a lip seal which reciprocates with the piston.

Abstract: A variable diameter cylinder made from a sheet having first and second edges that are opposite to each other and that slideably connect with each other to form a helical joint of a cylinder such that sliding the edges of the sheet along the joint varies a diameter and length of the cylinder. When marked with a scale, the cylinder acts as a measuring device that is both highly accurate and easy to use. A helical-based scale can be used alone, or a linear scale can be used in combination with a Vernier scale.

Abstract: The subject invention provides a master cylinder having a compact profile. In particular, the master cylinder comprises a hollow body having a continuous outer wall with a continuous thickness. An end wall is integrally formed with the outer wall at a first end to close an end of an integrally formed bore. A number of apertures are formed within the outer wall to provide fluid communication between the outer wall and the bore. A flange is also integrally formed with the outer wall at a second end to define a fully integrated master cylinder. The outer wall further includes thickened sections extending between an inner surface of the bore and a mounting surface with the thickened sections being at least 30 percent smaller than the inner diameter of the bore for providing the compact profile of the integrated master cylinder.

Abstract: A linear drive comprising a housing having a tube body (3) and a terminally mounted housing cover (4). In the wall of the tube body (3) a cavity is located, into which a sensor (14) extends. The rear end section (21) of the sensor (14) is in a socket (18), arranged as an extension of the cavity, of the housing cover (4). This socket (18) is formed by a recess (22) and its opening (26) extends from the end face (23) facing the tube body (3), of the housing cover (4) as far as the adjacent lateral outer face (24) of the housing cover (4). The electrical lead means for the sensor (14) are associated with the lateral section of the recess's opening (26).

Abstract: A swash plate compressor includes a cylinder block, a shaft rotatably supported in a central portion of the cylinder block a swash plate which rotates along with rotation of the shaft a crankcase for retaining the swash plate, and pistons each connected to the swash plate and sliding in a corresponding one of the cylinder bores as the swash plate rotates. Each of the pistons includes a hollow cylindrical portion for sliding within the cylinder bore and a bridge for rollably supporting the pair of shoes. The bridge projects radially outward with respect to the hollow cylindrical portion. The cylinder block is formed with a projecting portion projecting from a central portion of a front end face thereof toward the crankcase, within a range limited such that the projecting portion does not interfere with the connecting portion.

Abstract: Belt guide members guide an upper belt and a lower belt for closing a slit of a cylinder tube. Belt holder sections for the upper belt and belt separators for separating the upper belt and the lower belt from each other are integrally formed in the belt guide members. Bearings for positioning a slider are disposed to engage with the belt guide members.

Abstract: A method for manufacturing a master cylinder for a brake system, comprising a cylindrical main body, at least one flange integrally connected therewith, and a bore, extending in the cylindrical main body and through said at least one flange, wherein the master cylinder is manufactured by cold forging. Preferably the flange is cold forged by upsetting. Subsequently the cylindrical main body is provided with a bore. Said bore is realized in a series of forging steps, wherein at least the portion where the bore pierces the flange is executed in a separate step.

Abstract: There is disclosed a high-pressure compressor comprising a compression mechanism for reciprocating/driving a piston with respect to a conventional cylinder by rotation of a motor and compressing an operating fluid sucked by this driving to generate the high-pressure operating fluid according to improvements in a piston shape, positions of a cylinder operation surface and the piston, specifics shapes of the cylinder and piston, and connecting constitution of the piston to a connecting rod, which solves problems such as occurrence of wear on a cylinder inner surface by displacement of the piston, size enlargement by an increase of a removal capacity, difficulty in processing the piston and connecting rod, and a large top clearance.

Abstract: Disclosed herein is a fuel pump for an inter-cylinder direct fuel injection apparatus, in which occurrence of corrosion and attrition caused by cavitation or erosion can be suppressed, their resistance against the environment can be improved, and an excellent lifetime can be achieved in the case of the use of an aluminum material even if the temperature reaches as high as 100° C. or higher and the pressure reaches as high as 7 to 12 MPa. In the fuel pump for an inter-cylinder direct fuel injection apparatus, made of aluminum or an aluminum alloy, a coating film plated with Ni—P or a Ni—P based material is formed by electroless plating.