EP1350929A1 - Lubrication system for the cylinder of an internal combustion engine and method of lubricating the same - Google Patents

Abstract

The lubrication system has a lubricant nozzle (7) in the cylinder wall (3) for applying lubricant (8) to the bearing surface (2) of the cylinder wall in at least one compact jet (9) of lubricant directed onto the bearing surface. Atomization of the lubricant jet by the nozzle can be substantially prevented. The nozzle has several outlet openings for applying lubricant. Independent claims are also included for the following: a method of lubricating a bearing surface of a cylinder wall of a cylinder in an internal combustion engine and an internal combustion engine with an inventive system.

Description

The invention relates to a lubrication system for lubricating a Reciprocating piston internal combustion engine, in particular a large two-stroke diesel engine with longitudinal rinsing, and a method of lubrication a reciprocating internal combustion engine with such a lubrication system according to the preamble of the independent claim of the respective Category.

Large two-stroke diesel engines with longitudinal purge are often considered Drive units for ships or in stationary operation, e.g. to the Drive large generators for generating electrical energy. The engines usually run over considerable periods of time Continuous operation, which places high demands on operational safety and Availability. Therefore, the operators are particularly long Maintenance intervals, low wear and economical handling Fuels and operating materials are central criteria when selecting machines. Among other things, the piston behavior of such large-bore is slow running diesel engines a determining factor for the length of the Maintenance intervals, the availability and the lubricating oil consumption too directly for the operating costs. With that comes the complex problem the lubrication of large two-stroke diesel engines is becoming ever larger Meaning too.

For large two-stroke diesel engines with longitudinal purge, this is done Piston lubrication through lubrication devices in the cylinder wall through which Lubricating oil is applied to the tread of the cylinder wall Friction between the piston and the tread and thus the wear of the Minimize tread. So today lies with modern engines, e.g. the Sulzer RTA engines, the tread wear at less than 0.05 mm with an operating time of 1000 hours. The lubricating oil flow rate is in such engines at about 1.3 g / kWh and less and should last but not least Costs can be reduced even further if possible.

There are many different lubrication systems for lubricating the treads Known solutions, both what the specific execution of the Lubrication devices themselves, as well as what the procedures for lubrication As. So lubrication devices are known in which the lubricating oil through several lubricating oil openings in the circumferential direction in the Cylinder wall are housed in the radial direction on the Lubricating oil opening passing piston are applied, the Lubricating oil through the piston rings both in the circumferential direction and in axial direction is distributed. Because the lubricating oil at this Method not on the running surface of the cylinder wall, but rather more or less selectively between the piston rings on the side surfaces of the piston is applied, the distribution of the lubricating oil on the Tread often insufficiently guaranteed, leading to excessive Development of heat due to excessive friction and ultimately locally for welding the contact surfaces of the piston and the running surface with subsequent material breakout, i.e. lead to a piston seizure can.

To better distribute the lubricating oil, i.e. for a more even one To ensure lubricating oil film on the tread is described in WO 00/28194 proposed a lubrication system in which the lubricating oil under high Pressure using atomizing nozzles housed in the cylinder walls are, essentially tangential to the cylinder wall in the combustion chamber located purge air is sprayed, the lubricating oil to small particles is atomized. This makes the atomized lubricating oil in the purge air fine distributed and by the centrifugal force of the swirl that the purge air and thus also wear the finely distributed lubricating oil particles against the tread hurled the cylinder wall. With this procedure a becomes clear More even lubricating oil is produced on the tread than in the radial one Oil injection; there is a serious disadvantage of this method however, that a not inconsiderable part of the used Lubricating oil carried away with the purge air or in the following Combustion cycle is burned with. This creates an unnecessarily high one Lube oil consumption, which has a significantly negative impact on operating costs effect. In addition, there are special quality requirements of the lubricating oil that can be used, since not all lubricating oils are suitably fine atomize, making the selection of the lubrication for Available lubricating oils is limited. In particular, often cheaper lubricating oils, i.e. lubricating oils of poor quality, worse atomize as high quality lubricating oils, which means when using such Lubricating oils further reduce the effectiveness of the process.

The object of the invention is therefore to provide an improved lubrication system Lubricate a tread of a cylinder wall of a cylinder Reciprocating piston internal combustion engine, in particular a large two-stroke diesel engine propose with longitudinal rinse, through which Lubrication system a better distribution of a lubricant on the Tread of the cylinder wall is guaranteed and at the same time the amount of Lubricants significantly reduced compared to known lubrication systems can be and thus a more economical operation of such Reciprocating internal combustion engines is made possible. It is also a task the invention, a corresponding method for applying the Lubricant on the tread of a cylinder wall using the Propose lubrication system according to the invention.

These tasks in terms of apparatus and process engineering Solving objects of the invention are characterized by the features of marked independent claim of the respective category. The dependent claims relate to particularly advantageous Embodiments of the invention.

According to the invention, a lubrication system for lubricating a Tread of a cylinder wall of a cylinder Reciprocating piston internal combustion engine, in particular a large two-stroke diesel engine with longitudinal flushing, in which cylinder a piston runs along the tread is arranged back and forth proposed. The Cylinder has at least one in a recess in the cylinder wall arranged lubricant nozzle for applying lubricant to the Tread on. The lubricant nozzle is arranged and configured that the lubricant in at least one compact Lubricant jet can be applied to the tread of the cylinder and a Atomization of the lubricant jet through the lubricant nozzle is largely avoidable.

The arrangement and design of the lubricant nozzles Lubrication system according to the invention ensures that the Lubricant directly onto the tread of the cylinder wall of the cylinder Reciprocating internal combustion engine can be applied. It has been shown that this means an even application of lubricant and more economical Use can be guaranteed.

In a preferred embodiment, the lubrication system comprises multiple lubricant nozzles running along a circumferential line of the cylinder the reciprocating internal combustion engine, preferably in symmetry reasons equidistant distances are arranged. That from the perimeter The enclosed area is preferably perpendicular to a longitudinal of the cylinder extending cylinder axis. Of course it can be in Certain cases may well be possible that the lubricant nozzles not on such a circumference, but in a different way in the Are arranged cylinder wall, for example on one in the direction of Cylindrical axis running spiral path. It is also conceivable that the lubrication system includes multiple lubricant nozzles that run along several parallel circumferential lines are arranged. For example Lubricant nozzles on one or more such circumferential lines different heights in the cylinder, for example near the lower one Reversal point of the piston movement in the cylinder and / or in the vicinity of the upper reversal point and / or between the upper and lower Reversal point can be arranged. This can ensure that the Tread is optimally supplied with lubricating oil everywhere.

The lubricant is in an essentially compact, Lubricant jet applied directly to the tread. That is, a Spraying the jet into fine particles is largely avoidable. to The lubricant nozzles are evenly applied to the tread arranged in the cylinder wall such that the lubricant is related to the cylinder wall is substantially tangential in a lubricant jet exit. The indication of direction tangential refers to this Registration of course always on the area of the cylinder wall in the the lubricant nozzle in question is housed.

The lubricant jet can in a preferred embodiment in Reference to a cylinder axis, the direction of which in this application as usual parallel to the direction of movement of the piston Reciprocating internal combustion engine, i.e. perpendicular to the radial direction of the Cylinder, is to be assumed at a predeterminable angle in tangential Exit direction from the lubricant nozzle. Through one spiral application of the lubricant, it is possible to the tread optimally with both in the circumferential direction and in the axial direction apply a uniform film of lubricant. The Lubricant nozzles with respect to the cylinder axis also in Different directions can be aligned, creating a larger area the tread with lubricant directly through the lubricant nozzles is acted upon. For example, seen in the circumferential direction Lubricant nozzles each under the same or different Angular amount alternately in different directions in relation be aligned with the cylinder axis. Even a single can Lubricant nozzle several outlet openings for dispensing the Have lubricants which are the same as or openings allow different lubricant throughput, e.g. by the Outlet openings have the same or different opening cross-sections and configured and arranged so that the lubricant is the same or can exit in different directions. Of course The lubricant nozzles can also be arranged such that the Lubricant jet perpendicular to the cylinder axis from the lubricant nozzle can leak. In addition, of course, is any suitable combination of the previously mentioned design variants conceivable.

In a further exemplary embodiment, the cylinder wall can additionally have a circumferential groove, for example in the form of a closed circular line, for storing the on the tread have applied lubricating oil. The area that the groove includes standing vertically or obliquely on the cylinder axis. The groove can also be a non-closed in the form of a spiral in the cylinder wall Form a curve. It is also conceivable that the groove one or more separate Has sections that are not in the form of a closed curve extend certain areas of the cylinder wall. It goes without saying any suitable combination of the different possible shapes of grooves possible. In operation, unnecessary lubricant can be caused, for example, by the Piston rings are stripped into the grooves so that the lubricant closes later for lubrication of the piston Available.

Each lubricant nozzle is preferably connected to a separate feed line Dosing unit connected, the lubricant nozzle the necessary amount Provides lubricating oil at a predetermined time. Is conceivable however, that either part of the lubricant nozzles or all of them Lubricant nozzles using a common supply line, e.g. in form of Common rail system, supplied with lubricant by the dosing unit become. The metering unit is preferably of a freely programmable one Control unit controlled or regulated. This makes it possible to or time of the lubricant to be supplied depending on various operating parameters, e.g. of the speed, the load, the Cylinder temperature or other operating parameters or for Example depending on the fuel quality, the lubricant quality or the quality of other operating materials in the company. It can e.g. may not be possible at every work cycle of everyone Lubricant nozzle Apply lubricant to the tread must, or is the amount of lubricant to be applied depending on Operating state and / or location in the cylinder individually adjustable. Of course, both the time of the lubricant supply and also the amount of lubricant supplied, for example in addition Depending on the piston position.

In the method according to the invention for lubricating a tread a cylinder wall of a cylinder of a reciprocating piston internal combustion engine, especially a large two-stroke diesel engine with longitudinal purge, in which cylinder a piston can reciprocate along the tread is arranged by at least one in a recess Lubricant nozzle arranged on the cylinder wall Tread applied. The lubricant is compact Lubricant jet applied to the tread of the cylinder wall and a Atomization of the lubricant jet through the lubricant nozzle largely avoided.

Each lubricant nozzle receives the lubricant from a dosing unit, preferably to each lubricant nozzle via a separate feed line, supplied, the dosing unit using a freely programmable Control unit can be controlled or regulated so that the amount and / or the time of each lubricant nozzle Lubricant depending on various operating parameters can be specified.

Fig. 1

ein Ausführungsbeispiel eines erfindungsgemässen Schmiersystems in einem Zylinder eines Grossdieselmotors;

Fig. 2

ein Zylinder mit Schmiersystem, Schmiermitteldüse, Dosiereinheit und Ansteuereinrichtung im Schnitt, gemäss Fig. 1 entlang der Schnittlinie A - A;

Fig. 3

Schmiersystem gemäss Fig. 2 mit Schmiermitteldüse und Schmiermittelstrahl

The invention is explained in more detail below with reference to the drawing. The following are shown in a schematic, not to scale:

Fig. 1

an embodiment of a lubrication system according to the invention in a cylinder of a large diesel engine;

Fig. 2

a cylinder with lubrication system, lubricant nozzle, metering unit and control device in section, according to Figure 1 along the section line A - A;

Fig. 3

Lubrication system according to FIG. 2 with lubricant nozzle and lubricant jet

The lubrication system according to the invention for a Reciprocating internal combustion engine, which is collectively referred to below as Reference numeral 1 is designated, in particular for large two-stroke diesel engines suitable with longitudinal rinsing, such as in Shipbuilding is widely used. Fig. 1 shows, partly in Longitudinal section, a section of a cylinder 4 of a two-stroke large diesel engine with longitudinal rinse with for understanding the Invention essential parts, and an embodiment of Lubrication system according to the invention 1. On the representation of further, per se known components of such cylinders 4, was for the sake of Clarity waived.

1 shows a section of a cylinder 4 of a two-stroke large diesel engine in the area in which the lubrication system 1 is housed. The cylinder 4 essentially comprises a cylinder wall 3, which is limited inside the cylinder 4 by a tread 2 and a piston 5 in the direction of a cylinder axis 10 along the tread 2 is arranged to be reciprocable inside the cylinder 4. The piston has in a known manner a piston rod 51 which is used to drive the Piston 5 is connected to a crankshaft, not shown, and a piston surface 52 facing the combustion chamber 15 Tread 2 facing side surface 53 of the piston 5 are in themselves known manner and function one or more piston rings 54th accommodated. The combustion chamber 15 is in a known manner by the Piston surface 52, the cylinder wall 3 and one of the piston surface 52 opposite, not shown cylinder cover limited.

The cylinder wall 3 comprises one or more recesses 6, in which Recesses 6 preferably each have a lubricant nozzle 7 for application of lubricant 8 is housed on the tread 2. In one preferred embodiment are the lubricant nozzles 7 along a Circumferential line of the cylinder 4, preferably (but not necessary) in equidistant distances, the being from the circumference enclosed area perpendicular to the along the cylinder 4th extending cylinder axis 10 is. The lubrication system 1 comprise a plurality of lubricant nozzles 7 running along one or more parallel circumferential lines are arranged. The lubricant nozzle 7 is so in the cylinder wall 3 sunk in the recess 6 that the Pistons pass through the recess 6 during its movement without disability can. In the embodiment shown in Fig. 1, the cylinder wall 3 at least one groove 11 running in the circumferential direction for storage of the lubricant 8 applied to the tread 2, although definitely several grooves 11 can be advantageous. The groove 11 in a closed line, for example in the form of a circular line around the extend the entire circumference of the cylinder wall 3. But it is also conceivable that the groove 11 has one or more separate sections that are not in Form a closed curve over the entire circumference of the Extend cylinder wall 3.

The lubricant 8, which through the lubricant nozzles 7 on the tread 2 can be applied, each lubricant nozzle 7 through a separate feed line 12 fed.

When the reciprocating piston internal combustion engine is operating, the piston 5 moves known way between an upper representation Reversal point OT and a lower reversal point UT in terms of illustration, that the surface 52 of the piston 5 as it moves between the lower and upper reversal point, at least one recess 6 each Cylinder wall 3 and / or at least one groove 11 happens so that at least one recess 6 of the cylinder wall 4 and / or at least one groove 11 through the side surface 53 of the piston 5 temporarily is completely covered. The position of all recesses 6 can preferably be in the cylinder wall 3 and / or all the grooves 11 are selected such that if the piston is at the lower turning point UT, all Recesses 6 in the cylinder wall 3 and / or all grooves 11 in Connected to the combustion chamber 15, and when the piston is in the Position of the upper reversal point OT, all recesses 6 in the Cylinder wall 3 and / or all grooves 11 with the interior of cylinder 4 communicate below the piston 5.

FIG. 2 shows a section along the line A - A according to FIG. 1 Cylinder 4, comprising an embodiment of an inventive Lubrication system 1 with lubricant nozzle 7, metering unit 13 and Control device 14. The lubricant 8 can the lubricant nozzle 7 can be supplied by a metering unit 13 by means of a feed line 12 in turn centrally via a supply line 131 with lubricant 8 is supplied. Preferably leads from the dosing unit 13 to everyone Lubricant nozzle 7 a separate line, so that the supply of Lubricant 8 to each lubricant nozzle 7 depending on various operating parameters of the reciprocating internal combustion engine, such as e.g. the speed, the load, the cylinder temperature or other Operating parameters can be set individually. Of course, the feed can from lubricant 8 to the lubricant nozzles 7 also independently of the Operating parameters of the reciprocating internal combustion engine after a predefinable scheme. In particular, it is also conceivable that a or more of the lubricant nozzles 7 via a common feed line 12, e.g. in the form of a common rail system for supplying the lubricant 8 are connected to the metering unit 13. The lubricant 8 is the Lubricant nozzle 7 via the feed line 12 under a predetermined Working pressure supplied. The lubricant nozzle 7 preferably has a valve 72, for example a valve 72 spring-loaded in a known manner. there the valve 72 is adjustable so that it is under the influence of the working pressure of the lubricant 8 present in the supply line 12 opens spontaneously, so that the lubricant 8 from the feed line 12 into the lubricant nozzle 7 flow in and through the outlet opening impulsively of the tread is feedable. The feed line 12 can also on or in the Lubricant nozzle 7 through a check valve 73 against the cylinder side Protect overpressure. Preferably, the valve 72 is designed so that it also fulfills its function as a check valve 73.

Preferably, the dosing unit 13, which also has a not shown Check valve can be equipped with the supply line 12, by means of a freely programmable control device 14 so that it can be controlled or regulated, that the quantity and / or the time of each lubricant nozzle 7 supplied lubricant 8 depending on different Operating parameters, e.g. of the speed, the load, the Cylinder temperature or other operating parameters is adjustable. Also for example the quality of lubricant 8 and / or the quality of the Fuel or other supplies can be both the timing and determine the amount of lubricant 8 supplied. The Operating parameters can be read in from sensors not shown here via data lines 141 of the freely programmable control device 14 are fed to the dosing device via a communication line 142 controls or regulates accordingly.

3 schematically shows how the lubricant jet 9 is preferably applied to the tread 2. The Lubricant nozzle 7 has an outlet opening 71, which is designed so that the lubricant 8 emerges in a compact lubricant jet 9, i.e. that atomization of the lubricant jet 9 by the Lubricant nozzle 7 is largely avoidable. In particular, a Atomize into the purge air and / or into a gas that is in the cylinder is largely avoided. Rather, the lubricant 8 becomes direct applied in pulsed form to the tread in a compact jet. The Recess 6 is preferably designed as an oblique groove so that the the outlet opening 71 emerging lubricant jet 9 with respect to the Tread 2, preferably in a substantially tangential direction, so in the combustion chamber 15 exits that in the direction of the lubricant jet 9 lying portion 91 of the tread 2 lubricant 8 immediately is applied. The partial area 91 extends for example from the Outlet opening 71 to or approximately up to one in the circumferential direction closest further recess 6, so that the tread 2 in Circumferential direction, in a by the geometry of the lubricant jet 9th definable area with which lubricant 8 can be applied. each Lubricant nozzle 7 can be in the recess 6 of the cylinder wall 3 be arranged such that the lubricant jet 9 essentially tangential, but under a predetermined in each case to the cylinder axis 10 Angle emerges from the lubricant nozzle 7. This makes it possible to Schiermittelstrahl 9 in the circumferential direction of the cylinder 4 in a spiral to apply the two directions of the cylinder axis 10 to the tread 2. Of course, the lubricant jet 9 can also be perpendicular to Exit cylinder axis 10 and essentially in the tangentilaer direction, see above that the lubricant 8 largely in one plane in the circumferential direction, that is not spiral, can be applied to the tread 2.

The lubricant jet 9 is either before and / or during and / or after the piston passes through the recess 6, on the pulse Tread 2 applied through the lubricant nozzle 7 and through the Movement of the piston 5 or the piston rings 54 both in the circumferential direction as well as in the axial direction on the tread 2 of the cylinder wall 3 additionally evenly distributed. With an appropriate control or Regulation by the control unit 14 can be done by means of the metering unit 13 both the amount and the time of each lubricant nozzle 7 dispensed lubricant can be optimized. To minimize the amount of lubricant 8 used can be the supply of lubricant 8 on the tread 2 e.g. also for one or more work cycles of the Reciprocating piston engine are omitted, which reduces the consumption of the used lubricant 8 can be further reduced. The Cylinder wall 3 can have one or more circumferential directions Have grooves 11 in which part of the applied lubricant 8 can be saved. For example, through the piston rings 54 Part of the lubricant 8, which is located on the tread 2, into the groove 11 are stripped and temporarily stored, from which groove 11 the Lubricant 8 again on the tread 2 at a later time can come back and contribute to lubrication again, a process which also contributes significantly to the saving of lubricant 8.

Due to the arrangement and design, especially the Lubricant nozzles of the lubrication system according to the invention ensures that the lubricant is applied directly to the tread of the Cylinder wall of the cylinder of the reciprocating internal combustion engine applied becomes. The lubrication system according to the invention is distinguished by this its particularly simple structure, especially the lubricant nozzles from which, due to their simple construction, are expensive additional parts of the system, such as on drain lines or similar, can be dispensed with. It has been shown that an im Compared to the prior art much more uniform Lubricant application is achievable, i.e. means the lubricant is both optimally on the tread in the axial direction and in the circumferential direction of the cylinder distributed, causing wear on the tread of the cylinder or the piston is significantly reduced. In that the lubricant is applied directly to the tread and not over one Intermediate step, such as by atomizing the Lubricant jet into the purge air is a particularly economical and ensures efficient use of the lubricants used.

Claims (11)

Lubrication system for lubricating a tread (2) of a cylinder wall (3) of a cylinder (4) of a reciprocating piston internal combustion engine, in particular a two-stroke large diesel engine with longitudinal flushing, in which cylinder (4) a piston (5) can be moved back and forth along the tread (2) The cylinder (4) has at least one lubricant nozzle (7) arranged in a recess (6) in the cylinder wall (3) for applying lubricant (8) to the tread (2), characterized in that the lubricant nozzle (7 ) is arranged and designed such that the lubricant (8) can be applied in at least one compact lubricant jet (9) to the running surface (2) of the cylinder wall (3) and atomization of the lubricant jet (9) through the lubricant nozzle (7) can be largely avoided , The lubrication system of claim 1, wherein the lubricant nozzle (7) several outlet openings (71) for dispensing the lubricant (8), which outlet openings (71) are the same or allow different lubricant throughput. Lubrication system according to claim 1 or 2, wherein the lubrication system comprises a plurality of lubricant nozzles (7) running along a Circumferential line of the cylinder (4), preferably at equidistant intervals, are arranged, the enclosed by the circumferential line Surface perpendicular to an extending along the cylinder (4) Cylinder axis (10) stands. Lubrication system according to one of the preceding claims, wherein the Lubrication system comprises several lubricant nozzles (7) that run along several parallel circumferential lines are arranged. Lubrication system according to one of the preceding claims, which each lubricant nozzle (7) in the recess (6) The cylinder wall (3) is arranged in such a way that the lubricant jet (9) at an angle that can be predetermined in relation to the cylinder axis (10) the lubricant nozzle (7) can escape. Lubrication system according to one of the preceding claims, which has at least one lubricant nozzle (7) in the associated one Recess (6) of the cylinder wall (3) is arranged such that the Lubricant jet (9) perpendicular to the cylinder axis (10) from the Lubricant nozzle (7) can escape. Lubrication system according to one of the preceding claims, which the cylinder wall (3) has a groove running in the circumferential direction (11) for storing the applied to the tread (2) Has lubricant (8). Lubrication system according to one of the preceding claims, which each lubricant nozzle (7) by means of the lubricant (8) a separate feed line (12) from a metering unit (13) is. Lubrication system according to one of the preceding claims, which the dosing unit (13) by means of a freely programmable Control device (14) can be controlled or regulated so that the amount and / or the time of each lubricant nozzle (7) supplied lubricant (8) depending on different Operating parameters, e.g. of the speed, the load, the Cylinder temperature or other operating parameters or also in Depending on the quality of a fuel, the lubricant (8) or other operating materials, for each lubricant nozzle (7) individually is adjustable. Method for lubricating a running surface of a cylinder wall (3) of a cylinder (4) of a reciprocating piston internal combustion engine, in particular a two-stroke large diesel engine with longitudinal flushing, in which cylinder (4) a piston (5) is arranged so that it can move back and forth along the running surface (2), wherein lubricant (8) is applied to the running surface (2) by at least one lubricant nozzle (7) arranged in a recess (6) of the cylinder wall (3), characterized in that the lubricant (8) is in at least one compact lubricant jet (9) applied to the running surface (2) of the cylinder wall (3) and atomization of the lubricant jet (9) through the lubricant nozzle (7) is largely avoided. Reciprocating piston internal combustion engine, especially a large two-stroke diesel engine with longitudinal flushing, which corresponds to a lubrication system comprises one of claims 1 to 9, or by a method operated according to claim 10.

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