Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
  • F02F1/00—Cylinders; Cylinder heads 
  • F02F1/18—Other cylinders
  • F02F1/20—Other cylinders characterised by constructional features providing for lubrication
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16J—PISTONS; CYLINDERS; SEALINGS
  • F16J10/00—Engine or like cylinders; Features of hollow, e.g. cylindrical, bodies in general
  • F16J10/02—Cylinders designed to receive moving pistons or plungers
  • F16J10/04—Running faces; Liners
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
  • F02F7/00—Casings, e.g. crankcases or frames
  • F02F2007/0097—Casings, e.g. crankcases or frames for large diesel engines

Definitions

• the invention relates to a reciprocating piston machine, in particular a large two-stroke diesel engine, with at least one cylinder, the cylinder liner of which is provided with at least one groove in the region of its running surface facing the associated piston to form an oil pocket.
• a reciprocating internal combustion engine of this type is known from GB 1773058.
• the cross section of the oil pocket or oil pockets corresponds to the cross section of the respectively assigned groove cut into the cylinder liner.
• the depth of the grooves decreases with increasing wear on the cylinder liner.
• the depth of the oil pockets formed by the grooves themselves decreases in the known arrangement. Conditions therefore deteriorate with increasing service life.
• Another, very particular disadvantage of the known arrangement is, however, that material particles that have broken out of the cylinder liner due to possible heat corrosion etc. cannot be fixed in the grooves of the known arrangement.
• This object is achieved according to the invention in that a filling is associated with the groove, the depth of which corresponds at least to the maximum wear thickness of the cylinder liner, and in that the material forming the filling of the groove has a lower wear resistance than the base material of the cylinder liner.
• the groove When new, the groove can be completely closed due to the assigned filling. The result is a smooth, non-profiled surface that can be easily processed.
• the desired oil pocket is formed, the depth of which, however, is smaller than the depth of the groove and progresses to an extent dependent on the wear of the cylinder liner.
• the depth of the oil pocket or pockets that form correlates with the degree of wear.
• the measures according to the invention thus also effectively prevent damage and malfunctions which can be caused by material particles broken out of the cylinder liner, for example material welding or caking, which would lead to an acceleration of heat corrosion and seizure.
• the measures according to the invention therefore advantageously ensure a long service life.
• the material forming the filling of the groove can expediently have greater thermal expansion than that Have the basic material of the cylinder liner.
• the result of this is that the filling expands faster than the base material in the event of overheating, as a result of which the piston is stabilized and so-called seizure can be prevented.
• This advantage is further increased if the filling material also advantageously has dry lubrication properties.
• the filling of the groove can at least partially consist of aluminum and / or aluminum bronze and / or graphite, wherein preferably an aluminum bronze with 9-11% Al, 0.5-2% Fe and the rest Cu can be used.
• a material of this type has the desired properties mentioned above to an excellent degree. But it would also be conceivable, e.g. to use a graphite alloy with preferably 15-25% graphite and 75-85% aluminum bronze. This material also has the desired properties to a high degree.
• At least one helical groove can advantageously be provided. This results in a particularly good distribution and a particularly good transport of the oil over a larger area of the cylinder liner and thus particularly high reliability.
• the filling can be designed as a welding or spraying application, depending on the suitability of the materials used. This easily ensures a non-porous filling with reliable adhesion to the base material.
• FIG. 2 shows an enlarged representation of a region of the running surface of the cylinder liner provided with a groove according to the invention
• Figure 3 shows a variant with respect to the groove cross section
• Figure 4 shows another variant with respect to the groove cross section.
• the present invention is used in reciprocating engines, in particular reciprocating internal combustion engines, preferably in the form of slow-running two-stroke large diesel engines.
• reciprocating engines in particular reciprocating internal combustion engines, preferably in the form of slow-running two-stroke large diesel engines.
• the structure and mode of operation of such arrangements are known per se and therefore require no further explanation in the present context.
• the cylinder of a large two-stroke diesel engine shown in FIG. 1 contains a cylinder liner 2 provided with inlet slots 1, one of which is not shown here Exhaust arrangement containing cylinder head 3 is placed.
• the inside of the cylinder liner 2 is designed as a running surface 4 with which a piston 6 provided with circumferential piston rings 5 cooperates.
• the tread 4 is supplied with lubricating oil via lubricating oil supply lines 7.
• At least one incised groove 9 is provided in the area of the tread 4, in which an associated oil pocket 8 is formed.
• the groove 9 contains a filling 10, which consists of a material whose wear resistance is less than the wear resistance of the base material on which Z3dinderbucb.se is based.
• the cylinder liner is usually made of cast steel.
• An aluminum bronze can advantageously be used to form the filling 10. As experiments have shown, this should contain at least 2-20%, preferably 9-11% Al, 0.5-8%, preferably 0.5-2% Fe and a Cu residue.
• the special composition depends on the circumstances of the individual case. The higher the proportion of Fe, the greater the hardness of the material. In the case of a cylinder liner of a two-stroke large diesel engine, good results were achieved with an aluminum bronze with the following components: 2-20%, preferably 9-11% AI, 0.5 - 8%, preferably 0.5 - 2% Fe,
• a graphite alloy such as nickel graphite or silicon graphite or aluminum graphite or aluminum bronze graphite, each with 5-60%, preferably 15-25% graphite and a proportion of 40-95%, preferably 75 - Use 85% of the other component.
• a graphite alloy such as nickel graphite or silicon graphite or aluminum graphite or aluminum bronze graphite, each with 5-60%, preferably 15-25% graphite and a proportion of 40-95%, preferably 75 - Use 85% of the other component.
• an aluminum bronze graphite alloy particularly good properties against corrosion and seizure can be achieved.
• the composition of the aluminum bronze can correspond to the composition mentioned above.
• the filling 10 can advantageously be introduced into the previously produced groove 9 as a spray application applied by laser spraying or arc spraying, such as plasma spraying.
• the filling 10 of the groove 9 can also be produced as a welding job.
• An aluminum bronze with 9 - 11% Al, 1 - 3% Fe, 4 - 6% Ni, 1 - 2% Mu and the rest Cu is particularly suitable for this.
• the filling of the groove 9 is advantageously carried out to the level of the tread 4. Then the tread 4 can be continuously machined, for example honed. Due to the lower wear resistance of the material forming the filling 10 compared to the base material of the cylinder liner 2, the wear of the filling 10 is already higher during the running-in phase than the wear of the cylinder liner 2. The removed material is washed away by the lubricating oil. This results in the desired oil pocket 8, which is retained throughout the life of the cylinder liner 2.
• the depth of the groove 9 indicated at d in FIG. 2 therefore corresponds at least to the wear thickness of the cylinder liner 2 and is preferably somewhat larger.
• this deep groove 9 is provided with the filling 10, which also wears as a function of the wear of the cylinder liner 2, with only a somewhat faster wear taking place, the cross section of the groove 9 is largely balanced over the entire service life of the cylinder liner 2 even different cross-sectional configurations of the oil pocket 8.
• a material can advantageously be used which has the property that when heated it expands more than the base material on which the cylinder liner is based.
• the material proposed above has this property. In the event of local overheating, the filling 10 therefore expands more than the base material on which the cylinder liner 2 is based, as a result of which the piston 6 can be stabilized, as indicated in FIG. 2 by an elongation line 11 shown in broken lines.
• the material proposed above for the filling 10 also has good dry lubrication properties, which is particularly advantageous in the event of overheating. However, it would also be conceivable to integrate or embed an additional material with good dry lubrication properties in the filling material.
• One or more grooves 9 can be provided.
• the grooves 9 on which the oil pockets 8 are based can be designed as circumferential radial grooves. Additionally or alternatively, one or more helically extending grooves 9 with an associated oil pocket 8 can also be provided. These can extend over an area or over the entire length of the tread 4.
• the figure 2 is based on a helical groove 9.
• the pitch of this groove 9 indicated at P can be 1.5% to 20% of the diameter D of the tread 4.
• the pitch P can be constant over the entire length of the groove.
• a variable slope would also be conceivable in order to obtain a greater oil pocket density in particularly endangered areas than in less endangered areas.
• the above-mentioned depth d of the groove 9 is expediently in the range between 0.1% - 0.4% of the diameter D.
• the starting width w is expediently 1% - 2% of the diameter D.
• the groove 9 has a cross section narrowing inwards from the starting width w. This takes into account the fact that the wear rate increases with increasing service life.
• the groove 9 has an approximately U-shaped cross section with flanks inclined with respect to the groove bottom.
• the angle of inclination of the flanks indicated at ⁇ can be in the range between 30 ° - 60 °.
• the transitions between the groove bottom and the groove flanks are appropriately rounded, as indicated by a radius arrow.
• FIG. 3 shows a V-shaped groove 9 with an associated filling 10 containing the oil pocket 8.
• the groove 9 on which FIG. 4 is based has a cross-section in the form of a segment of a circle. This also results in an inwardly narrowing cross section and accordingly an inwardly decreasing width of the filling 10 and the oil pocket 8 formed therein.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Pistons, Piston Rings, And Cylinders (AREA)
• Cylinder Crankcases Of Internal Combustion Engines (AREA)
• Coating By Spraying Or Casting (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=7893737

Family Applications (1)

Country Status (9)

Cited By (6)

Families Citing this family (7)

Citations (4)

Family Cites Families (2)

• 1999
  • 1999-01-08 DE DE19900386A patent/DE19900386C1/de not_active Expired - Fee Related
  • 1999-12-22 JP JP2000592533A patent/JP3636664B2/ja not_active Expired - Lifetime
  • 1999-12-22 WO PCT/EP1999/010267 patent/WO2000040850A1/de not_active Application Discontinuation
  • 1999-12-22 AU AU21008/00A patent/AU2100800A/en not_active Abandoned
  • 1999-12-22 KR KR10-2001-7008539A patent/KR100411867B1/ko active IP Right Grant
  • 1999-12-22 GB GB0115516A patent/GB2361982B/en not_active Expired - Fee Related
  • 1999-12-22 PL PL99349134A patent/PL349134A1/xx unknown
  • 1999-12-22 CN CN99815460A patent/CN1116510C/zh not_active Expired - Lifetime
• 2001
  • 2001-06-22 NO NO20013177A patent/NO20013177L/no not_active Application Discontinuation

Patent Citations (4)

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