KR100969335B1 - A lubrication system for a reciprocating internal combustion engine and a method for lubricating a reciprocating internal combustion engine - Google Patents

Abstract

The present invention provides a lubrication system for lubricating the sliding surface (2) of the cylinder wall (3) of a reciprocating internal combustion engine, in particular a longitudinally scavenging two-stroke large diesel engine cylinder (4), wherein a piston is provided in the cylinder (4). (5) is arranged to be movable back and forth along the slide surface (2). In this regard, the cylinder 4 has at least one lubricant nozzle 7 arranged in the recess 6 of the cylinder wall 3 to apply the lubricant 8 on the sliding surface 2. The lubricant nozzle 7 is arranged and designed such that the lubricant 8 can be applied to the sliding surface 2 of the cylinder wall 3 with at least one compressed lubricant jet, so that the lubricant jet passing through the lubricant nozzle 7 ( Dispersion of 9) can be prevented very largely. Also provided is a method for lubricating the cylinder wall 3 of a reciprocating internal combustion engine cylinder 4 with a lubrication system according to the invention.

Reciprocating internal combustion engines, cylinder walls, sliding surfaces, lubrication systems, pistons, lubricants, lubricant nozzles

Description

Lubrication system for reciprocating internal combustion engine and lubrication method for reciprocating internal combustion engine {A LUBRICATION SYSTEM FOR A RECIPROCATING INTERNAL COMBUSTION ENGINE AND A METHOD FOR LUBRICATING A RECIPROCATING INTERNAL COMBUSTION ENGINE}

1 shows an embodiment of a lubrication system according to the invention arranged in a large diesel engine.

FIG. 2 is a view of a cylinder with a lubrication system, a lubricant nozzle, a metering device, and a control device, taken along line A-A of FIG. 1.

3 a view of the lubrication system according to FIG. 2 with a lubricant nozzle and a lubricant jet.

The present invention relates to a lubricating system for lubrication of reciprocating internal combustion engines, in particular longitudinally scavenging two-stroke large diesel engines, and to a method for lubricating a reciprocating internal combustion engine with the lubrication system according to the preamble of each dependent claim.

Longitudinal scavenging two-stroke large diesel engines are often used as drive devices for ships or to drive large generators for stationary operation, for example to produce electrical energy. In this regard, engines are generally operated over time for substantial periods of permanent operation, so the demand for reliability and utility of operation is very high. Thus, especially long service intervals, low wear, and economical use of fuels and operating materials are important criteria for the driver to select a machine. The piston operability of such large, low-speed running diesel engines is a determining factor, in particular, over the length of service intervals, availability and lubricating oil consumption or for direct operating costs. Thus, the complex problems associated with lubrication of two-stroke large diesel engines are becoming increasingly important.

In a longitudinal scavenging two-stroke large diesel engine, lubricating oil is applied to the sliding surface of the cylinder via a lubrication device on the cylinder wall to perform piston lubrication by minimizing friction between the piston and the sliding surface, i.e. wear of the sliding surface. For example, in a modern engine, that is, a low RTA engine, the wear of the sliding surface is 0.05 mm or less at the present 1000 hours of operation time. The lubricating oil flow rate of the motor is approximately 1.3 g / kWh or less, especially due to the cost and should be reduced further as possible.

For both the specific design of the lubrication device and the lubrication method, very different solutions are known as lubrication systems for lubricating the sliding surface. For example, lubricating oil is radially applied to a piston running through the lubricating oil aperture through a plurality of lubricating oil apertures received in the circumferential direction on the cylinder wall, the lubricating oil being circumferentially or axially by the piston ring. Lubrication devices to be dispensed are known. In this method, since lubricant is not applied over a large area on the sliding surface of the cylinder wall, but on the side of the piston in a roughly spot way between the piston rings, the lubricant is not sufficiently distributed on the sliding surface, resulting in excessive friction, Ultimately, excessive friction in the welding of the contact area between the piston and the sliding surface results in material failure, ie the piston stops.

To ensure good dispersion of the lubricating oil, i.e. to ensure a more uniform lubricating oil film on the sliding surface, sprayed with small particles into the air filled in the combustion chamber substantially in contact with the cylinder wall by a spray nozzle housed in the cylinder wall. A lubrication system for spraying lubricated lubricating oil at high pressure is proposed in WO 00/28194. Thus, the atomized lubricant is finely dispersed into the full air and hits the sliding surface of the cylinder wall by centrifugal force of the angular momentum supported by the full air, ie the finely dispersed lubricant particles in the air. In this method, a much more uniform lubricant film is reliably produced on the sliding surface than spraying lubricant in the radial direction, but the method is that most of the lubricant used is swept away in full air or burned during the subsequent combustion action. The major drawback is that. Therefore, lubricating oil consumption is unnecessarily high, which has a very negative effect in terms of running costs. In addition, the quality of the lubricating oil that can be used is particularly required because not all lubricating oil is properly finely atomized, thereby limiting the choice of lubricating oil that can be used for lubrication. In particular, inexpensive lubricants, ie low quality lubricants as well as high quality lubricants, are often not able to be atomized, which further reduces the efficiency of the process when using such lubricants.

 It is therefore an object of the present invention to provide an improved lubrication system for lubricating the sliding surface of a cylinder wall of a reciprocating internal combustion engine, in particular a longitudinally purged two-stroke large diesel engine cylinder, the lubricating system being lubricated on the sliding surface of the cylinder. A good dispersion of the lubrication flow rate can be ensured and the reciprocating internal combustion engine can be operated more economically compared to known lubrication systems. It is also an object of the present invention to provide a corresponding method of lubricating the sliding surface of a cylinder by means of a lubrication system according to the invention.

The subject matter of the invention, which satisfies the above object in apparatus and technical methods, is characterized by the features of the independent claims in each category. The dependent claims relate to particularly preferred embodiments of the invention.

In the present invention, there is proposed a lubrication system for lubricating the sliding surface of a cylinder wall of a reciprocating internal combustion engine, in particular a longitudinally scavenging two-stroke large diesel engine cylinder, in which a piston that can move back and forth along the sliding surface is arranged. do. The cylinder has at least one lubricant nozzle arranged in the recess of the cylinder wall for applying lubricant to the sliding surface. In this regard, lubricant nozzles are arranged and designed so that lubricant can be applied to the sliding surface of the cylinder with at least one compressed lubricant jet, whereby dispersion of the lubricant jet by the lubricant nozzle can be largely prevented.

This is ensured by the arrangement and design of the lubricant nozzles of the lubrication system according to the invention in which lubricant can be applied directly to the sliding surface of the cylinder wall of the reciprocating internal combustion engine cylinder. Thus, it has been found that equal dispersion and economical use of lubricants are secured simultaneously.

In a preferred embodiment, the lubrication system comprises a plurality of lubricant nozzles arranged along the outer circumference of the cylinder of the reciprocating internal combustion engine, since the symmetrical arrangement is preferably spaced at equidistant intervals. The area enclosed by the outer circumference is preferably perpendicular to the cylinder axis extending along the cylinder. In certain cases, the lubricant nozzles may of course be arranged in different ways on the cylinder wall, for example on a helical track extending in the cylinder axial direction, rather than on the periphery. Also, a lubrication system may be considered that includes a plurality of lubricant nozzles arranged along a plurality of parallel outer periphery lines. For example, a lubricant nozzle may be provided on one or more of said outer periphery of different levels of the cylinder, ie near and / or near the upper inversion point and / or near the lower inversion point at which the piston moves, for example in the cylinder. May be interposed between the lower inversion points. Therefore, an ideal supply of lubricating oil can be ensured anywhere on the slide surface.

In this regard, the lubricant is applied directly to the sliding surface with a substantially compressed lubricant jet. That is, the jet can be significantly prevented from dispersing into fine particles. In order to apply evenly on the sliding surface, a lubricant nozzle is arranged on the cylinder wall such that the lubricant is discharged into the lubricant jet substantially in contact with the cylinder wall. Within the structure of the present application the "tangential" direction naturally relates to the area of the cylinder wall in which the lubricant nozzle in question is accommodated.

In a preferred embodiment, the lubricant jet is tangential to the cylinder axis, in which the direction is assumed in this application to be generally parallel to the direction in which the piston of the reciprocating smoke pipe travels, ie perpendicular to the radial direction of the cylinder. Can be ejected from the lubricant nozzle at a predetermined set angle. By applying a lubricating agent spirally as mentioned above, a uniform lubricant film can be added to a sliding surface in both a circumferential direction and an axial direction in both directions. In this regard, the lubricant nozzle can also be well aligned in different directions with respect to the cylinder axis, so that the lubricant can be applied directly through the lubricant nozzle to a wider area of the sliding surface. For example, taking into account the circumferential direction, the lubricant nozzles can be aligned alternately at the same angle or at different angles in different directions with respect to the cylinder axis, respectively. One lubricant nozzle may also have a plurality of outlets capable of ejecting the lubricant in the same or different amounts, for example, the outlet outlets have the same or different opening cross sections and the jet of ejection from the lubricant nozzles perpendicular to the cylinder axis. Are designed and arranged to be. In addition, all examples in which the above-described modifications are appropriately combined may also be considered.

In another example, the cylinder wall may further have grooves extending in the circumferential direction, for example in the form of closed circuit lines, for storing lubricating oil applied to the slide surface. In this regard, the sliding surface surrounding the groove can be perpendicular or inclined to the cylinder axis. In addition, the grooves can form spirally closed curves in the cylinder wall. It is also conceivable for the groove to have one or more different sections which do not extend in the form of a closed curve over a certain area of the cylinder wall. It is of course also possible to suitably combine all the different possible groove shapes. In operation, excess lubricant can be wiped into the groove by, for example, a piston ring, so that the lubricant can later be used to lubricate the piston.

All lubricant nozzles are preferably connected via different feeders to a metering device which allows the desired amount of lubricant to be used at any given time. However, it is also conceivable to supply lubricant to some of the lubricant nozzles or to all of the lubricant nozzles, for example by means of a common supply device in the form of a common rail system. The metering device is preferably controlled or regulated from a freely programmable control device. Thus, in operation, the amount and / or timing of the lubricant to be supplied is dependent on different operating parameters such as speed, load, cylinder temperature or other operating parameters, or the amount of fuel, lubricant amount or other operating material, for example. It can be made constant according to. Thus, it is possible to prevent lubricant from being applied to the slide surface from every nozzle every working cycle, or the amount of lubricant to be applied can be individually adjusted according to the operating state and / or the position in the cylinder. Both the lubricant supply timing and the lubricant supply amount can of course be further adjusted according to the piston position, for example.

In a method according to the invention for lubricating the sliding surface of a cylinder wall of a reciprocating internal combustion engine, in particular a longitudinally respiratory two-stroke large diesel engine cylinder, in which a piston is arranged which is movable back and forth along the sliding surface in the cylinder, the lubricant The sliding surface is applied through at least one lubricant nozzle arranged in the recess of the cylinder wall. In this regard, lubricant is applied to the sliding surface of the cylinder with a compressed lubricant jet, which greatly prevents the dispersion of the lubricant jet by the lubricant nozzle.

The lubricant is supplied to each lubricant nozzle by a metering device, preferably through each different supply line to each lubricant nozzle, and the metering device is supplied with an amount and / or timing of lubricant supplied to each lubricant nozzle. It can be controlled or adjusted by a freely programmable control device so that it can be predetermined according to these different operating parameters.

Next, the present invention will be described in detail with reference to the accompanying drawings.

The lubrication system 1 for a reciprocating internal combustion engine according to the invention is particularly suitable for longitudinal scavenging two-stroke large diesel engines as is widely used in shipbuilding. 1 is a view of a longitudinal portion of a section of a cylinder 4 of a longitudinally scavenging two-stroke large diesel engine having an important part in understanding the invention and taking the lubrication system 1 according to the invention as an example. Other known components of the cylinder are not illustrated for clarity.

1 is a view of a section of the cylinder 4 of a two-stroke large diesel engine in the region in which the lubrication system 1 is accommodated. The cylinder 4 is arranged to be movable in the front-rear direction along the cylinder wall 3 bounded by the sliding surface 2 inside the cylinder 4 and the sliding surface 2 inside the cylinder 4. Substantially including the piston (5). The piston has a known manner, namely a piston rod 51 which is connected with a crankshaft (not shown) to drive the piston 5, and a piston face 52 facing the combustion space 15. One or more piston rings 54 are received in a known manner and function on the side surface 53 of the piston 5 facing the sliding surface 2. The combustion space 15 is thus bounded in a known manner by a piston face 52, a cylinder wall 3 and a cylinder cover (not shown) opposite the piston face 52.

The cylinder wall 3 comprises at least one recess 6 in which each lubricant nozzle 7 is preferably accommodated to apply the lubricant 8 on the sliding surface 2. In a preferred embodiment, the lubricant nozzles 7 are arranged along the outer circumference line of the cylinder 4, preferably (but not necessarily), at equidistant intervals, and the area enclosed by the outer circumference line along the cylinder 4. It is perpendicular to the extending cylinder axis 10. Thus, the lubrication system 1 may comprise a plurality of lubricant nozzles 7 arranged along one or more peripheral lines in parallel. The lubricant nozzle 7 is received in a conical manner in the recess 6 of the cylinder wall 3 so that it can pass through the recess 6 without obstruction when the piston moves. In the example shown in FIG. 1, the cylinder wall 3 has at least one groove 11 extending in the circumferential direction to store the lubricant 8 applied to the sliding surface 2, and the plurality of grooves 11 are provided. It is very desirable to have. The groove 11 can thus extend, for example, in a closed line in the form of a circular line around the entire circumference of the cylinder wall 3. However, the groove 11 may have one or more different sections which do not extend in the form of a closed curve over the entire outer circumference of the cylinder wall 3.

Lubricant 8, which can be applied to sliding surface 2 via lubricant nozzle 7, can be supplied to each lubricant nozzle 7 by different supply lines 12.                     

In operation of the reciprocating internal combustion engine, the piston 5 has a surface 52 of the piston 5 with at least one recess 6 and / or at least one groove 11 of the cylinder wall 4 with a piston 5. At least one recess 6 and / or at least one groove 11 of the cylinder wall 3 when moving between the lower inversion point and the upper inversion point so that it is sometimes completely covered by the side 53 of It moves in a known manner between the inversion point OT at the top of the figure and the inversion point UT at the bottom of the figure to pass through. The positions of all recesses 6 and / or all grooves 11 in the cylinder wall 3 are all recesses 6 and / or all in the cylinder wall 3 when the piston is located at the lower inversion point UT. The groove 11 is connected to the combustion space 15, and when the piston is located at the upper inversion point OT all recesses 6 and / or all grooves 11 in the cylinder wall 3 are lower than the piston 5. Connected to the inner space of the cylinder (4).

FIG. 2 is a view taken along the line AA of FIG. 1, wherein the cylinder 4 has an example of a lubrication system 1 according to the invention with a lubricant nozzle 7, a metering device 13 and a control device 14. It includes. The lubricant 8 is supplied from the metering device 13 to the lubricant nozzle 7 by the supply device 12, and the lubricant is supplied to the center via the supply line 131. Different lines extend from the metering device 13 to each lubricant nozzle 7 and are supplied to each lubricant nozzle according to different operating parameters or different operating parameters of the reciprocating internal combustion engine such as speed, load, cylinder temperature. The lubricant 8 can be set individually. Regardless of the operating parameters of the reciprocating internal combustion engine, the lubricant 8 can of course be supplied to the lubricant nozzle 7 according to a pre-settable scheme. In order to supply the lubricant 8, it is also conceivable to connect one or more lubricant nozzles 7 to the metering device 13 via a common supply line 12, for example in the form of a common rail system. Lubricant 8 is supplied to lubricant nozzle 7 via supply line 12 at a predetermined working pressure. The lubricant nozzle 7 preferably has a valve 72, for example a spring load valve 72 in a known manner. Thus, the valve 72 opens spontaneously under the influence of the working pressure of the lubricant 8 waiting in the supply line 12 such that the lubricant 8 flows from the supply line 12 into the lubricant nozzle 7 and in a pulsed manner. It can be set to be supplied to the slide surface through the spout. The supply line 12 can also be protected against overpressure on the cylinder side by a check valve 73 in the lubricant nozzle 7. The valve 72 is preferably designed to simultaneously meet the same function as the check valve 73.

The metering device 13, in which a check valve (not shown) can likewise be fitted with respect to the supply line 12, shows that the amount and / or timing of the lubricant 8 supplied to all the lubricant nozzles 7 may vary in speed, load, It may be desirable to be controlled and regulated by a freely programmable control device 14 so that it can be set according to different operating parameters such as cylinder temperature or other operating parameters. The quality of the lubricant 8 and / or the quality of the fuel or other working material may together determine the timing and amount of the lubricant 8 supplied, for example. The operating parameters are read by a sensor (not shown) and can be supplied to the freely programmable control device 14 via the data line 141 so that the control device controls or regulates the metering device via the communication line. do.                     

3 schematically shows how the lubricant jet 9 is applied to the sliding surface 2 in a preferred manner. The lubricant nozzle 7 has an ejection port 71 designed such that the ejection of the lubricant jet 9 into the compressed lubricant jet 9, ie the dispersion of the lubricant jet 9 through the lubricant nozzle 7 is significantly prevented. Dispersion into the flushing air and / or gas disposed in the cylinder is greatly prevented. Lubricant 8 is applied directly to the slide surface with a rather compressed pulsed jet. The recess 6 is provided with a lubricant jet 9 ejected from the jet port 71 so that the lubricant 8 is applied directly to the region 91 of the slide surface 2 in the direction of the lubricant jet 9. It is preferably designed as an inclined groove so that it is preferable to be ejected into the combustion space 15 in a direction substantially tangential to (2). The region 91 is, for example, circumferentially from the jet port 71 so that the lubricant 8 can be applied in the circumferential direction to the region where the sliding surface 2 can be determined by the shape of the lubricant lubricant 9. Extends to or near the other recess closest to it. Thus, each lubricant nozzle 7 is adapted to allow the lubricant jet 9 to be ejected from the lubricant nozzle 7 at a substantially preset angle relative to the cylinder axis 10 while the lubricant jet 9 is in a substantially tangential manner. It may be arranged in the set 6. Thus, the lubricant jet 9 can be applied on the sliding surface 2 helically in one of two directions of the cylinder axis 10 in the circumferential direction of the cylinder 4. The lubricant jet 9 can of course also be ejected in a substantially tangential direction, at right angles to the cylinder axis 10, so that the lubricant 8 can be applied to most of one side of the slide surface 2 in the circumferential direction.

Thus, the lubricant jet 9 is applied to the sliding surface 2 in a pulsed manner through the lubricant nozzle 7 before and / or during and / or after the piston passes through the recess 6, and the piston 5 or evenly distributed on the sliding surface 2 of the cylinder wall 3 in both the circumferential direction and the axial direction by the movement of the piston ring 54. The amount and timing of lubricant dispersed in each lubricant agent 7 can be optimized with the metering device 13 by corresponding control and adjustment by the control device 14. In order to minimize the amount of lubricant 8 used, the consumption of lubricant 8 used, for example, by stopping the supply of lubricant 8 on the slide surface 2 every one or more working cycles of the reciprocating internal combustion engine. Can be further reduced. The cylinder wall 3 may have one or more grooves 11 extending in the circumferential direction and in which a portion of the applied lubricant agent 8 may be stored. For example, some of the lubricant 8 dispersed on the slide surface 2 is wiped into the groove 11 by the piston ring 54 and temporarily stored, and the lubricant 8 is later stored in the groove 11. Can be returned to the sliding surface 2 and used again for lubrication, which substantially saves the lubricant 8.

The direct application of lubricant to the sliding surface of the cylinder wall of the reciprocating internal combustion engine cylinder is ensured in particular by the arrangement and design of the lubricant nozzles of the lubrication system according to the invention. The lubrication system according to the invention thus features a particularly simple design lubricant nozzle which, due to its simple design, may not require costly additional plant parts such as leaking oil lines or the like. Thus, the lubricant is applied much more evenly than in the prior art, ie the lubricant can be ideally dispersed on the sliding surface of the cylinder in both the axial and circumferential directions, so that the wear of the sliding surface of the cylinder or piston can be significantly reduced. It turned out to be. The lubricant can be used particularly economically and effectively because the lubricant jet is applied directly to the sliding surface without going through an intermediate step such as spraying into the flushing air.

Claims (11)

A lubrication device for lubricating the slide surface (2) of the cylinder wall (3) of the cylinder (4) of a reciprocating internal combustion engine, wherein the cylinder (4) has a piston (5) so as to be movable forward and backward along the slide surface (2). And a recess 6 in the cylinder wall 3, the recess 6 having at least one lubricant nozzle 7 for applying a lubricant 8 to the sliding surface 2. In the provided lubrication device, Each lubricant nozzle 7 has a plurality of jets 71 for discharging the lubricant 8, the plurality of jets 71 can discharge the lubricant in the same or different amounts, The recess 6 comprises an inclined groove, The slanted grooves of the jet port 71 and the recess 6 of the lubricant nozzle 7 are provided with the sliding surface (the lubricant 8 being driven from the jet port 71 by a plurality of compressed lubricant jets 9). Characterized in that it is arranged to be discharged directly on the sliding surface 2 of the cylinder wall 3 in a direction tangential to 2) to prevent atomization of the lubricant jet 9 through the lubricant nozzle 7. Lubrication device. The method of claim 1, A plurality of the lubricant nozzles 7 are arranged along the outer circumferential line of the cylinder 4, the surface enclosed by the outer circumferential line is perpendicular to the cylinder axis 10 extending along the cylinder 4. Lubrication device made with. The method according to claim 1 or 2, Lubricating device, characterized in that the plurality of lubricant nozzles (7) are arranged along a plurality of peripheral lines parallel to each other. The method of claim 1, Each lubricant nozzle 7 is recessed 6 in the cylinder wall 3 such that the lubricant jet 9 can be ejected from the lubricant nozzle 7 at a preset angle with respect to the cylinder axis 10, respectively. Lubricating device, characterized in that arranged in). The method of claim 1, The lubricant nozzle 7 is arranged in the recess 6 of the cylinder wall 3 so that the lubricant jet 9 can be discharged from the lubricant nozzle 7 at right angles to the cylinder axis 10. Lubrication device. The method according to claim 1 or 2, Characterized in that the groove (11) is formed in the cylinder wall (3) extending along the circumferential direction of the cylinder wall (3) for storing the lubricant (8) applied to the sliding surface (2), Lubrication device. The method according to claim 1 or 2, Lubricating device, characterized in that the lubricant (8) can be supplied from the metering device (13) to each lubricant nozzle (7) by different supply lines (12). The method of claim 7, wherein The metering device 13 is characterized in that the amount or timing of the lubricant 8 supplied to each lubricant nozzle 7 depends on operating parameters including rotational speed, load, cylinder temperature, or fuel, lubricant 9 Lubrication device, characterized in that it can be controlled or adjusted by a freely programmable control device (14) so that it can be set individually for each lubricant nozzle (7) according to the quality of the working material. A method of lubricating the slide surface (2) of the cylinder wall (3) of the cylinder (4) of a reciprocating internal combustion engine, wherein the cylinder (4) is movable with the piston (5) along the slide surface (2) in a forward and backward direction. In the lubrication method, which is arranged so that the lubricant 8 is applied to the sliding surface 2 via at least one lubricant nozzle 7 arranged in the recess 6 of the cylinder wall 3. The lubricant 8 is discharged in a tangential direction with respect to the sliding surface 2 of the cylinder wall 3 through the plurality of jets 71 of the lubricant nozzle 7 and the inclined groove of the recess 6. And a plural compressed lubricant jet (9) is applied directly to the sliding surface (2) so that atomization of the lubricant jet (9) through the lubricant nozzle (7) is prevented. A reciprocating internal combustion engine, comprising a lubrication device according to any one of claims 1, 2, 4 or 5. The method of claim 10, The reciprocating internal combustion engine is a reciprocating internal combustion engine, characterized in that the two-stroke large diesel engine.

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