Abstract: An engine component comprises one or more thermal barrier coatings applied to one or more areas of the engine component. The thermal barrier coatings reduce the temperature rate of change of the areas to which the thermal barrier coating is applied. Reducing the temperature rate of change can help reduce lattice structure damage caused by different temperatures in different areas of the engine component. The thermal barrier coating can be applied as a monolithic layer on a surface of the engine component or can be applied in different areas using patterns. The patterns allow for the tuning of the performance characteristics (temperature rate of change) of the areas of the engine component and can help reduce defect propagation, such as cracks, in the thermal barrier coating from one area of the thermal barrier coating to other areas of the thermal barrier coating.

Abstract: An actuating device for actuating a valve element of an exhaust gas turbocharger includes a pressure chamber which is delimited in part by a first housing element and in part by a diaphragm formed separately from the first housing element. A fluid is introducible into the pressure chamber. The diaphragm is reversibly deformable in order to actuate the valve element and the diaphragm is held on the first housing element by a first cooling ring in which sodium is accommodated.

Abstract: A valve train arrangement constructed in accordance to one example of the present teachings includes a rocker arm, a deactivating hydraulic lash adjuster (HLA) capsule, a lost motion spring (LMS) capsule and a lever. The rocker arm has a first end and a second end. The second end cooperates with a valve. The HLA capsule cooperates with the first end of the rocker arm. The LMS capsule has a lost motion spring. The LMS capsule is located in a position on the valve train arrangement that is offset from the HLA capsule. The lever is configured between the HLA capsule and the LMS capsule. During cylinder deactivation, load is transferred from the HLA capsule to the lever arm and ultimately to the lost motion spring in the LMS capsule.

Abstract: An engine valve includes a stem, a head comprising an outer lip surface, a seating surface extending from the outer lip surface toward the stem, and a combustion surface extending from the outer lip surface on the opposite side of the head as compared to the seating surface. The combustion surface includes a first convex arcuate surface spaced away from the outer lip surface, at least partially forming a raised ring, and a first concave arcuate surface spaced away from the outer lip surface, at least partially forming a dimple.

Abstract: To find compromises in the relationship between the component costs of intake and exhaust valves and the downsizing of an engine and the relationship between the cooling performance and the followability of the intake and exhaust valves and coordinate these conflicting relationships as much as possible. A hollow valve encapsulating coolant having a good cooling function is used as an exhaust valve, which is exposed to a higher temperature environment than an the intake valve, to eliminate a disincentive to downsizing. In contrast, a hollow valve that has no coolant, relatively low component cost, light weight, and good followability is used as the intake valve, which does not need to have a better cooling function than the exhaust valve and needs to have better followability than the exhaust valve to improve combustion efficiency.

Abstract: Embodiments of the present invention include a plasma cutting torch and plasma cutting torch components, such as electrodes, cathodes, retainer caps, etc. having a unique physical features, including threads relationships. Embodiments include torch components having modified square thread with a specialized thread configuration including a particular relationship between thread crest and root, and included angles of thread sidewalls.

Abstract: A valve arrangement for supplying air to an internal combustion engine includes a first valve and a second valve arranged within the first valve. A valve guide for use in a valve arrangement is also provided.

Abstract: A system and methods for a vehicle are provided for adjusting each of a speed of a radiator fan and a position of grille shutters of the vehicle responsive to a temperature at a wastegate exceeding a temperature threshold. In one example, a system may include a radiator fan at a front end of a vehicle, an engine coupled to an exhaust passage, a turbine in the exhaust passage having a bypass conduit, a wastegate positioned in the turbine conduit, and the wastegate receiving airflow from downstream of the radiator fan via a cooling duct.

Abstract: Systems are provided for an oil system including a filter with a large surface area. In one example, a system may include an oil filter with a prismatic shape. This shape may include a filter surface area greater than an inlet area of an oil port and the filter surface area may also be located a distance away from the oil port.

Abstract: Provided is a sliding member having a steel back metal layer and a sliding layer. The sliding layer includes a resin composition and a porous sintered layer including Fe or Fe alloy phase particles and a Ni—P alloy phase functioning as a binder. The steel back metal layer is made of a carbon steel including 0.05 to 0.3 mass % carbon and includes a ferrite phase and a pearlite phase. A central portion in a thickness direction of the steel back metal layer includes not greater than 30 volume % of the pearlite phase. The steel back metal layer includes a high pearlite phase portion in its surface facing the sliding layer. The high pearlite phase portion includes not less than 50 volume % of the pearlite phase.

Abstract: The invention relates to a valve guide manufactured by a powder-metallurgical process for combustion engines, said guide comprising a central section, a cam-side end piece, and a duct-side end piece, wherein the central section consists of a first material and the duct-side end piece of a second material, with the second material having a hardness in excess of 70 HRB and the first material having a hardness that is by at least 10 HRB lower than that of the second material.

Abstract: The invention relates to a cylinder head (1) for an internal combustion engine having at least one cylinder, having at least one valve seat ring (3) for a lifting valve, wherein the valve seat ring (3) is surrounded by an annular cooling duct (4) for a coolant that is at least partly molded into the cylinder head (1), wherein the cooling duct (4) at least partly surrounds the valve seat ring and extends between an inlet (5, 15, 25) and at least one outlet (6). In order to reduce the valve wear, provision is made for a plurality of inlets (5, 15, 25) to open into the cooling duct (4), wherein the inlets (5, 15, 25) are preferably arranged asymmetrically in relation to a meridian plane (?) of the valve seat ring (3) through the outlet (6).

Abstract: A system and methods for a vehicle are provided for adjusting each of a speed of a radiator fan and a position of grille shutters of the vehicle responsive to a temperature at a wastegate exceeding a temperature threshold. In one example, a system may include a radiator fan at a front end of a vehicle, an engine coupled to an exhaust passage, a turbine in the exhaust passage having a bypass conduit, a wastegate positioned in the turbine conduit, and the wastegate receiving airflow from downstream of the radiator fan via a cooling duct.

Abstract: A poppet valve includes a head and a stem, which extends from the head. At least a part of the back of the head is covered by a cover with a heat insulating space provided in between. A support portion is provided between the cover and the head to support the cover on the head with rubber member having a lower heat conductivity than that of the head between the cover and the head.

Abstract: A valve guide insert for lining and relining a valve guide bore in an internal combustion engine includes a one-piece, thin-walled, cylindrically-shaped metallic tube made from reformable bearing material having first and second ends and an intermediate portion. An inwardly tapered portion is disposed at the first end, wherein an end diameter of the inwardly tapered portion is less than an outer diameter of a valve guide bore, and wherein the outer diameter of the intermediate section is greater than an inner diameter of a valve guide bore. A longitudinal slit is included having a stepped portion along a length of the longitudinal slit. An interference portion is disposed proximate the second end, wherein the interference portion is configured to substantially secure the valve guide insert within a valve guide bore.

Abstract: An active pressure relief valve system and method for lubricating an internal combustion engine includes a reservoir, a pump for pumping fluid from the reservoir through the internal combustion engine, and an active relief valve fluidly disposed downstream from the pump for both variably adjusting pressure of the fluid within the internal combustion engine and limiting the pressure of the fluid within the internal combustion engine to a maximum pressure threshold. The active relief valve is configured to variably and electronically adjust the pressure of the fluid within the internal combustion engine when commanded by a controller, and further configured to mechanically limit the pressure of the fluid within the internal combustion engine to a maximum pressure threshold.

Abstract: A cooling circuit for a liquid-cooled internal combustion engine for motor vehicles, includes a main cooling circuit including a feed line leading to a radiator and a return line, and a bypass line, which bypasses the radiator and can be controlled as a function of temperature and secondary cooling circuit for a retarder of a braking device of the motor vehicle, which is connected, likewise by a feed line, a return line and a control valve, to the main cooling circuit. The two cooling circuits (2, 3) can be controlled by a single rotary slide valve (10). Both cooling circuits (2, 3) are interconnected in such a way that the flow rates thereof to the radiator (6) and/or to the retarder (4) can be varied in a predetermined or defined manner, in particular between 0% and 100%.

Abstract: A valve stem seal can include an elastomeric component having a first portion for having a sealed engagement with a valve stem, and a pressure relief lip engaging a valve guide. The pressure relief lip can have a sealing configuration and a venting configuration. The venting configuration can allow excess exhaust gases to vent from a combustion chamber. After the venting of excess exhaust gases, the pressure relief lip can close to the sealing configuration to prevent oil from entering the combustion chamber. The elastomeric body or the valve guide can include a pressure relief channel. The elastomeric body can also include a bumper engaging the valve guide. The pressure relief channel can be disposed in the bumper.

Abstract: Disclosed is a modified valve guide for a four-stroke internal combustion engine that utilizes compressed air to accelerate outflow of exhaust gases from a combustion chamber and through the exhaust manifold. The device comprises a ported valve guide that is concentrically mounted about an exhaust valve stem. The valve guide is a hollow cylinder that surrounds the exhaust valve stem, and includes a vertically mounted port on its working end. Below the port is a circumferential ring and guide tube connection that accepts compressed air input, communicating forced air through the valve guide port on its working end into the combustion chamber and exhaust manifold. The introduction of forced air increases volumetric efficiency of the system by improving scavenging and forcibly removing exhaust gases from the cylinder during the exhaust stroke. Both the power and efficiency of the engine are improved, along with reduced emissions from the engine exhaust.

Abstract: During engine operation, valve retainers and valve springs are constantly rubbing and impacting each other resulting in heat and wear. The purpose of this invention is to provide a surface coating onto the valve retainer to reduce the friction with the valve spring and thus improve durability. Specifically, this invention teaches a method to thermally apply coatings to the surface of the valve retainer. Although typically fabricated from steel, the usage of lighter weight titanium valve retainers is increasing for high performance, or racing engines. The reduced mass allows valves to move more readily and requires less spring pressure to operate, producing more power and a faster revving engine, however titanium is typically not as wear resistant as the steel it replaces. In one embodiment, a porous molybdenum or other oleophilic metal is applied to the surface of the valve retainer. In another embodiment, hard coatings of cermets, carbides, and super alloys are applied as coatings to valve retainers.

Abstract: Movable valve apparatus having conditioned lubricating surfaces are described. An example valve includes a valve packing having a graphite packing ring disposed within a bonnet of the fluid valve and a stem or shaft has a conditioned surface to hold a lubricating material. The conditioned surface of the stem or shaft is disposed within the bonnet and moves the lubricating material relative to and in contact with the graphite packing ring during operation of the fluid valve.

Abstract: In an engine having an oil pump wherein an oil filter is incorporated into the oil pump without allowing the oil pump to become large in size. An oil pump and a hydraulic line changeover valve including a spool valve are disposed so as to have axes extending in parallel with each other. The oil pump has a plate-shaped oil filter disposed at a discharge port thereof. The plate-shaped oil filter is curved arcuately along an outer periphery of a pump rotor as viewed from a pump axial direction.

Abstract: A valve cooling device of an internal combustion engine in which engine oil is circulated in a valve that faces a combustion chamber, the valve includes a valve umbrella portion and a valve stem. An inside of the valve stem is formed with an oil introduction channel and an oil lead-out channel, a jet portion that includes a jet oil passage coaxially disposed with the oil introduction channel is provided in the extended direction of the valve stem, and the engine oil is injected from an orifice provided on a tip portion of the jet oil passage to an inner portion of the oil introduction channel.

Abstract: In an EGR valve provided in an exhaust gas recirculation passage for recirculating the exhaust gas of an engine, a filter 26b is provided on the side of an exhaust gas passage 22 of a bearing 26a supporting a valve rod 25, while a diameter-reduced section 25a is provided in an area on the valve rod 25 in proximity to the filter 26b.

Abstract: There is provided a saddle-riding type small vehicle where a power unit is mounted on a vehicle body frame. The power unit includes a valve control device that controls the operation of valve-operation mode changing mechanisms capable of changing operation modes of engine valves, and a clutch control device that controls the operation of a clutch unit provided between a crankshaft and a shift mechanism so as to shift the connection/disconnection of power transmission. In the vehicle, the valve control device and the clutch control device are disposed to balance the center of gravity, so as to make a power unit compact. A valve control device and a clutch control device are disposed on left and right sides of a center line CB of a vehicle in a width direction of the vehicle.

Abstract: Disclosed is a modified valve guide for a four-stroke internal combustion engine that utilizes compressed air to accelerate the outflow of exhaust gases from a combustion chamber and through the exhaust manifold. The device comprises a ported valve guide that is concentrically mounted about an exhaust valve stem. The valve guide is a hollow cylinder that surrounds the exhaust valve stem, and includes a vertically mounted port on its working end. Below the port is a circumferential ring and guide tube connection that accepts compressed air input, communicating forced air through the valve guide port on its working end into the combustion chamber and exhaust manifold. The introduction of forced air increases volumetric efficiency of the system by improving scavenging and forcibly removing exhaust gases from the cylinder during the exhaust stroke. Both the power and efficiency of the engine are improved, along with reduced emissions from the engine exhaust.

Abstract: The present invention generally relates to a new valve guide for use in an exhaust valve system. Specifically, the invention is related to a valve guide that prevents acidic corrosion between the valve and the valve guide. The valve guide includes a number of contact portions, which engage the channel that is formed in the cylinder head near the exhaust port. The valve guide also includes a recess portion, situated in relation to a water jacket and between the contact portions. The recess portion and contact portions are sized and shaped to maintain the surface temperature of the valve guide to prevent condensation of acidic gases between the valve stem and the valve guide.

Abstract: A method for preventing or inhibiting exhaust valve seat recession in a natural gas fueled internal combustion engine is disclosed. The method involves lubricating the engine with a lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity, and (b) a minor amount of a natural gas engine oil additive package, wherein the lubricating oil composition is substantially free of each of any zinc compounds and alkaline earth metal salts of a condensation product of an alkylene polyamine, an aldehyde and a substituted phenol.

Abstract: The present invention includes an engine valve including a stem portion and a head portion disposed at one end of the stem portion. A heat insulation layer is formed on a surface of the head portion. A heat conductive layer is formed on a surface of the stem portion.

Abstract: The present invention generally relates to a new valve guide for use in an exhaust valve system. Specifically, the invention is related to a valve guide that prevents acidic corrosion between the valve and the valve guide. The valve guide includes a number of contact portions, which engage the channel that is formed in the cylinder head near the exhaust port. The valve guide also includes a recess portion, situated in relation to a water jacket and between the contact portions. The recess portion and contact portions are sized and shaped to maintain the surface temperature of the valve guide to prevent condensation of acidic gases between the valve stem and the valve guide.

Abstract: A gasket for a valve in an internal combustion engine is provided with a support element having a tubular configuration according to an axis and coaxially mounted on the valve. An elastically deformable element is interposed between the support element and the valve. The support element includes a first portion elongated according to the above mentioned axis, and a second portion extending from the first portion in a direction transversal to the axis, at least partially housed in an annular seat of the elastically deformable element and having its radially outermost end connected to the first portion itself. The support element comprises a third portion extending from the radially innermost end of the second portion and folded on the second portion itself so as to generate, in the folding area, a rounded edge cooperating with the annular seat of the elastically deformable element.

Abstract: An internal combustion engine according to the invention comprises at least one cylinder and at least one valve provided for a gas exchange and having a first end comprising a valve head, and a second end, characterized in that a valve bearing has a length of a guidance area arranged for the guidance of a valve stem of at most 25%, preferably between 10 and 20%, and particularly preferably of less than 10% of a valve length.

Abstract: There is provided a saddle-riding type small vehicle where a power unit is mounted on a vehicle body frame. The power unit includes a valve control device that controls the operation of valve-operation mode changing mechanisms capable of changing operation modes of engine valves, and a clutch control device that controls the operation of a clutch unit provided between a crankshaft and a shift mechanism so as to shift the connection/disconnection of power transmission. In the vehicle, the valve control device and the clutch control device are disposed to balance the center of gravity, so as to make a power unit compact. A valve control device and a clutch control device are disposed on left and right sides of a center line CB of a vehicle in a width direction of the vehicle.

Abstract: An intake valve for a combustion engine includes a valve guide having a bore and a lower end surface surrounding the bore, and a valve stem having an upper valve stem portion moving up and down within the bore of the valve guide and a valve at the lower end of the stem. A valve guide shield is carried by the valve stem below the upper valve stem portion that moves up and down within the bore to shield the upper valve stem portion from high boiling fraction material from the fuel to lessen the accumulation of high boiling fraction between the valve stem and the valve guide.

Abstract: The present invention relates to a valve guide for an internal combustion engine, and more particularly, to a swirling valve guide having a fuel mixing means installed on an outer peripheral surface of the valve guide, which protrudes into an intake port of an internal combustion engine, to promote mixing of fuel and air. According to the present invention, there is provided a swirling valve guide including a guide portion installed to protrude into an intake port of a cylinder head of an internal combustion engine for guiding reciprocation of an intake valve of the internal combustion engine, comprising a fuel mixing mean having a member installed on an outer peripheral surface of the guide portion to mix fuel and air passing the intake port and to produce a swirl in a mixture of the fuel and air at a downstream side of the flow of the mixture.

Abstract: A four-cycle internal combustion engine with a valve system having improved durability in the case of high revolution speed. The engine includes a cylinder head having a port, and a valve having a stem part continuous with a fillet part for opening or closing the port. A valve spring including inner and outer springs urges the valve in a direction to close the port. A valve guide holds the stem part slidably. A tubular spring guide supports an outer periphery part of an outer spring to prevent lateral deformation of the spring. A top end of the spring guide is positioned above a top end of a valve guide.

Abstract: A valve characteristic changing mechanism is supplied with oil discharged from an electric oil pump in addition to oil discharged from a mechanical oil pump that is driven by an operation of an internal combustion engine. Driving of the electric oil pump is controlled such that a work rate of the electric oil pump increases as a temperature of the oil supplied to the valve characteristic changing mechanism increases, or as a viscosity of the oil is reduced.

Abstract: A valve stem seal having an annular valve body with an upper surface, a lower surface, and defining an aperture is disclosed. The valve body is positioned for selective sealing engagement with a valve stem. At least one orifice is disposed on an inner surface of the annular valve body between the annular valve body and the valve stem. The orifice controls the rate of oil flow between the annular valve body and the valve stem.

Abstract: An engine valve, formed of a titanium alloy, enables improvement of reliability and productivity while improving creep resistance and fatigue strength at a high temperature. The engine valve, including a stem section and a bevel section provided at one end of the stem section, is integrally formed of the titanium alloy. A portion of the valve, extending from the bevel section to a medial portion of the valve stem, is formed mainly of a needle-like crystallographic texture. Another portion of the valve, extending from the medial section to the other end of the stem section, is formed of a material having a substantially equiaxed crystallographic texture. A boundary between the needle-like texture and the equiaxed texture is provided in a range of sliding movement of the valve relative to a valve guide that slidably guides the stem section within the cylinder head.

Abstract: A valve guide structure is provided which can suppress deterioration of a valve guide even if radial stress is applied on an upper portion of a stem of a valve. The valve guide structure is such that the stem 2 of the valve 1 is supported by an inner peripheral surface of the valve guide 16 to restrict moving directions of the valve 1. A recess 18 is formed on an inner peripheral surface of the valve guide 16 and extends downwardly from an upper end of the valve guide 16 along the stem 2 of the valve 1 so as to provide a clearance between the valve guide 16 and the stem 2 of the valve 1.

Abstract: An intake valve for a combustion engine having an intake port is disclosed. The intake includes a valve guide having an end proximate the intake port, a valve shield extending from the end of the valve guide and into the intake port, and a valve stem arranged proximate the valve guide and valve shield. The valve guide and valve stem define a first clearance dimension therebetween, and the valve shield and value stem define a second clearance dimension therebetween, wherein the second clearance dimension is equal to or greater than the first clearance dimension.

Abstract: A cooled valve seat ring for a cylinder head of an internal combustion engine, having a valve seat part, wherein the cooled valve seat ring comprises a sheet-metal cooling channel consisting of a thin sheet of steel and which is connected with a coolant circuit via bores which serve as inflow and outflow for a coolant, wherein the cooled valve seat ring is connected with the cylinder head material by casting technology. In one embodiment, there can be a cooled valve seat ring that is connected with a cylinder head material via a laminate casting process. There can also be a cooled valve seat ring that has an alfin layer for a connection with the cylinder head material. In addition, the cooling channel can be welded onto or soldered onto the valve seat part. Furthermore, the sheet-metal cooling channel can be connected with the valve seat part so as to form a gas-tight seal.

Abstract: A valve lift sensor detects the position of an engine valve. The valve lift sensor includes a movable target carried on an engine valve and a stationary coil carried within an engine valve assembly. A signal generator energizes the coil with an oscillating voltage to create an oscillating magnetic field, which is concentric to the coil for inductive transfer with the target. A comparator compares the voltage from the signal generator with the voltage at the resistor to determine the phase lag of resistor voltage relative to signal generator voltage and indicate the engine valve position. Using the phase lag, the comparator provides a pulse-width-modulated signal with a duty cycle proportional to the valve lift to an engine valve control operable to control the operation of the engine valve.

Abstract: A valve stem seal assembly includes a retainer and a sealing element disposed within the retainer. The retainer includes a step and one or more installation pads. The sealing element includes a first sealing lip for sealing a valve stem, and a second sealing lip for sealing a chamfer of a valve guide. The step of the retainer exerts a compression force, F, against the second sealing lip to seal the second sealing lip against the chamber of the valve guide. The one or more installation pads exerts a frictional force against the valve guide to prevent movement of said valve stem seal assembly. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Abstract: A valve stem seal assembly incorporates a cylindrical retainer having an axis and an upper end about which symmetrically and circumferentially arranged, alternating first and second sets of fingers have radially inwardly depending upper ends. The first set of fingers is generally parallel to the axis and the upper ends are generally perpendicular to the axis to engage a first exterior annular groove of an elastomeric seal body. The first set of fingers provides for axial attachment of the seal body to a top of a valve guide. The second set of fingers is generally arcuate and the upper ends extend radially inwardly to engage a second exterior annular groove of the seal body. The second set of fingers eliminates the need for a garter spring used by traditional valve stem seal assemblies by generating a force to urge the sealing lip against a reciprocating valve stem.

Abstract: A low friction sliding element for reciprocating engine parts, including a sliding contact surface that is in sliding contact with a counterpart during relative sliding motion of the sliding element and the counterpart. The sliding contact surface has microscopic recesses and plateaus interrupted by the recesses. The recesses have depths regularly varying in a sliding direction of the sliding element.

Abstract: An exhaust valve guide for engines which is not corroded with SOx contained in an exhaust gas from an engine in which EGR is carried out, or from an engine using a fuel of a high sulfur content. A tubular member of the exhaust valve guide is press-fitted in a receiving hole of a cylinder head. A valve stem of an exhaust valve is slidably inserted into a shaft hole of the tubular member. An inner side of the shaft hole of the exhaust valve guide is surface treated with a material having a corrosion resistance and an abrasion resistance. The tubular member is made of, for example, regular cast iron, and the surface treatment operations using a material having a corrosion resistance and an abrasion resistance include, for example, Cr plating, Mo flame spraying, Ni plating.

Abstract: A cylinder head for an internal combustion engine in which any of a plurality of valve guides for guiding intake and exhaust poppet valves provided with valve lifters can be press-fitted in fitting holes of the cylinder head with a substantially uniform press fit force. At least one valve guide is fitted at a different depth in the cylinder head than others of the guides valves. The intake and exhaust poppet valves have substantially uniform thicknesses in the respective longitudinal directions of the valve guides. An idle fitting hole with an inner diameter greater than an outer diameter of the valve guides is formed above one of the fitting holes which is formed deeper in the cylinder head than the other fitting holes, the idle fitting hole extending upward to a lower side of a valve spring.

Abstract: An intake and exhaust valve for an internal combustion engine is provided wherein the stem longitudinal axis is offset from the valve head center. Alternatively, the valve head may have an end having a planar surface wherein the axis and the surface are not perpendicular. Alternatively, the valve head may have an irregular perimeter having a straight edge, and another edge being rounded and generally radiused to the straight edge. Alternatively, the valve head may have a stepped, non-planar shape with respect to the plane of the face of the head. Alternatively, the valve head may have a shape that is pie-shaped. Alternatively, the stem longitudinal axis may be offset from the center point of the valve head, and the valve head may have an end having a planar surface, wherein the longitudinal axis and the planar surface are not perpendicular to one another.

Abstract: Bush 4 is fabricated by providing porous sintered metal layer 7 of copper on the surface side of back metal layer 5 of steel plate through copper plating layer 6 and coating the inside and the surface of porous sintered metal layer 7 with sliding material 8 by impregnation. Sliding material 8 comprises 1-25 vol.% of tetrafluoroethylene-perfluoroalkylvinyl ether copolymer resin, 1-25 vol.% of at least one member selected from the group consisting of oxybenzoylpolyester resin and polyimide resin and 0.1-10 vol.% of hard particles having a Mohs hardness of 4 or more and average particle sizes of 5 &mgr;m or less such as Al2O3 and SiC, the balance being polytetrafluoroethylene resin (55 vol.% or more of the total siding material) as the main component. 0.5-25 vol.% of a solid lubricant such as graphite and MoS2 can be further contained in total together with the hard particles.