JP2013164072A - Large engine including cylinder lubricating device or method for lubricating cylinder of large engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for detecting leakage of a lubricant of a lubricant supply system, by lubricating an operation surface of a cylinder of a large engine, and a device for avoiding leakage of a cooling system of piston rod joining-connection of a crosshead engine.SOLUTION: A large engine includes a cylinder liner, a piston movably arranged in the cylinder liner, a driving shaft and connection elements 13 and 14 for connecting the driving shaft to the piston, includes a device for lubricating or cooling the cylinder and/or the piston and/or the connection elements by using a fluid medium, and includes a first connection line for carrying the fluid medium to a use place from a storage tank. The first connection line at least partially runs through the connection elements, and the fluid medium in the first connection line is pressurized by pressure P1. A second connection line 12 is provided, and fluid medium pressurized by pressure P2 is stored in the second connection line. The pressure P2 is higher than the maximum pressure P1 in an ordinary operation mode.

Description

  The present invention relates to a large engine including a cylinder lubrication device and a method of lubricating an operating surface of a cylinder wall of a cylinder of the large engine. The large engine is, for example, a reciprocating piston internal combustion engine that is used as a low-speed large diesel engine during the construction of a ship. Large engines are frequently used as marine drive assembly, or in stationary operation, for example, to drive large generators for generating electrical energy. In this connection, the engine typically operates for a considerable period of time in continuous operation mode, which presents high demands on efforts and costs related to driving safety and availability. To this end, specifically, lubricants, particularly long intervals between maintenance, low wear, and economical handling of fuel and operating materials are central to the machine operation for the operator. Standard. Among other things, the piston operating behavior of such large bore low speed large engines is a decisive factor for availability during the interval between maintenance, directly due to operating costs through lubricant consumption. Therefore, it is also a decisive factor for economic efficiency. Thus, the ever-increasing importance is associated with the complex problem of large engine lubrication.

  For large engines, piston lubrication is performed via a lubrication device located in the reciprocating piston or in the cylinder wall, and the friction between the piston and the working surface, and therefore the working surface and the piston ring. In order to minimize wear, lubricating oil is applied over the operating surface of the cylinder wall through a lubricating device. For example, for modern engines such as Wartsila's RTA motors, the wear on the working surface is today less than 0.05 mm over a period of 1000 hours of operation. Lubricant feed rates for such engines are at or below approximately 1.0 g / kWh and must be further reduced if possible, at least for cost, wear and Leakage must also be minimized at the same time.

  With regard to both the special design of the lubrication device itself and the lubrication method, many different solutions are known as lubrication systems for lubricating the working surface. For example, a device is known in which lubricating oil is applied on a piston that operates over a plurality of lubricating openings, the lubricating device being disposed circumferentially in the cylinder wall via the lubricating openings, Is distributed both in the peripheral direction and in the axial direction via the piston ring. According to this method, the lubricant is not applied on the working surface of the cylinder wall in a large area, but more or less on the side of the piston between the piston rings.

  Other methods are also known in this regard. For example, a lubrication system has been proposed in WO 00/28194, where the lubricating oil is at high pressure using a vaporizing nozzle located in the cylinder wall and into the scavenging air that exists in the combustion space. Sprayed substantially tangentially to the cylinder wall, the lubricant is vaporized into small particles. Thereby, the vaporized lubricating oil is finely dispersed in the scavenging and thrown to the working surface of the cylinder wall due to the centrifugal force due to torsion, which supports the scavenging and therefore finely dispersed in the scavenging Also supports lubricating oil particles.

  In one different method, it is preferred that a plurality of lubricating nozzles be placed in the moving piston, where the term is simple so that the lubricant can be applied at any point over substantially the entire height of the working surface. A device having a simple outlet opening and / or a check valve.

  The type and method of how the lubricant is applied over the working surface of the cylinder wall, and the dosage and time point at which the lubricant is introduced into the cylinder of the large engine are significant to the quality of the lubrication. Have a significant impact.

  The amount of lubricant to be applied on the working surface per unit time as well as per unit area can depend on many different parameters during operation of the large engine. Thus, for example, the chemical composition of the fuel used, in particular its sulfur content, plays an important role. In addition to cylinder lubrication, this means a reduction in the friction between the piston and the cylinder working surface, more specifically between the piston ring and the cylinder working surface, and the lubricant is notably aggressive. It also serves to neutralize the acid, specifically the sulfur-containing acid that occurs during the combustion process within the combustion space of the engine. For this, depending on the fuel used, different types of lubricants can be used, which differ, inter alia, in their ability to neutralize, due to their ability to use the so-called lubricants. The BN value is a measured value. Thus, it may be advantageous to use a lubricant having a higher BN value because of the high sulfur content in the fuel than to a fuel having a low sulfur content. This is because lubricants with higher BN values have a higher neutralizing effect with respect to acid.

  However, it is often possible to use the same type of lubricant for different quality fuels. In such cases, higher or lower acid content may be compensated in the combustion product, for example through an increase or decrease corresponding to the amount of lubricant used.

  A further problem regarding the dosage of the amount of lubricant to be applied is that of the lubricant film condition, in particular the time deviation of the lubricant film thickness during the operation of the reciprocating piston internal combustion engine. time) and / or spatial deviation.

  In essence, the required amount of lubricant is different, such as, for example, speed, combustion temperature, engine temperature, cooling performance available to cool the engine, load, and many other operating parameters. It also depends on the operating parameters. Thus, it may be possible to apply different amounts of lubricant on the working surface of the cylinder for a given speed and load higher than the same speed and less load.

  Furthermore, the state of the internal combustion engine itself can also have an influence on the amount of lubricant. Thus, for example, the amount of lubricant to be used can vary depending strongly on the wear conditions of the cylinder operating surface, piston ring, piston, etc. Thus, for a new non-running cylinder operating surface and / or for a new piston ring during the running-in phase, the opposing partners, i.e. the piston ring, for example, It is desirable to increase the friction to some extent so that the piston ring groove and the working surface can be ground in and ideally installed together. This can be achieved, inter alia, so that it generally works with different amounts of lubricant during the break-in phase of the cylinder rather than for a cylinder that has been operated for a significant number of operating hours. To this end, in particular, for each cylinder, the amount of lubricant can often be set separately from each other for a cylinder having a plurality of cylinders.

  Also, the cylinder operating surface generally wears differently in both the peripheral and longitudinal directions depending on the number of operating hours provided. This applies, for example, to the piston ring and the piston itself as well.

  Therefore, not only the amount of lubricant has to be set depending on the number of operating hours provided to the reciprocating piston internal combustion engine, but also the amount of lubricant depends on the type of application depending on time as well as on position. Depending, it must be variably administrable in one and the same cylinder at different points on the working surface of the cylinder wall.

  For this reason, it has long been known to provide lubrication nozzles in different areas of the working surface of the cylinder or in the moving piston, and these nozzles are lubricated depending on the application in both time and position. It is preferred that they can all be controlled independently so that the amount of the agent can be flexibly changed.

  Many different methods are known for determining the amount of lubricant to be introduced by a particular lubrication nozzle at a particular time. In the simple case, taking into account the possible quality of the fuel used and the lubricant itself, if possible, the amount of lubricant depends on the operating state of the reciprocating piston internal combustion engine, for example as a function of load or speed. Depending on the operating time already provided, it is possible to take into account the wear state between the two facing each other.

  Thus, those skilled in the art distinguish so-called hydrodynamic lubrication from deficient lubrication and / or mixed lubrication. When the lubricating film having such a thickness is formed between the opposite sides, that is, for example, between the working surface of the cylinder wall and the piston ring of the piston, the state of dynamic pressure lubrication is spoken. Since the working surfaces are separated sufficiently by the lubricant film, they do not contact each other. Different boundary cases are presented by so-called mixed friction or mixed lubrication conditions. In the case of mixed friction, since the lubricating film between the oppositely acting sides is at least partially thin, the oppositely facing sides are in contact with each other. In this case there is also a risk of scuffing and, ultimately, the formation of piston sticking. So-called deficient lubrication is found between these two boundary cases. In the deficient lubrication state, the lubricant film is exactly thick, so the opposing counterparts no longer contact each other, but the amount of lubricant is insufficient, so dynamic pressure lubrication is between the opposing counterparts. Can be formed. Previously, both mixed lubrication and chipped lubrication conditions were prevented as much as possible. This means that the thickness of the lubricant film has been suitably selected so that the dynamic pressure lubrication state is set between the oppositely operating parties.

  Operation in the state of dynamic lubrication inherently results in a correspondingly high consumption of lubrication. On the other hand, this is not only considerably uneconomical, but it also surprisingly shows that not only lack of lubrication but also excess lubrication can cause damage to the opposing counterparts in the cylinder.

  This problem has been successfully solved for the first time by using a sensor to determine the characteristic parameters for the lubricating film in operating conditions, and then evaluating the sensor signal with the aid of a regulating device. The lubricating film condition parameters, in particular the thickness of the lubricating film, are preferably optimized locally by supplying a corresponding dose of lubricant. Corresponding devices and related methods have already been discussed in detail by the applicant in the patent document 2 (EP 1 270 270 A1).

  The problem of determining the amount of lubricant required to be supplied at a specific position on the cylinder operating surface is ideally solved by this innovative method, and the difficulty has hitherto been injected into the cylinder. There was a point to determine the ideal time to do.

  In this connection, the ideal time point can depend on many parameters, in particular the different operating conditions in which the internal combustion engine is operated. Many of the parameters that can play a role in this relationship are the same, they relate to the correct lubricant thickness and have already been listed at the beginning. Specifically, the correct time point depends primarily on the different lubrication methods described above. Thus, the correct point in time for the injection of lubricant depends essentially on it, and should the lubricant be introduced, for example, in the scavenging or, for example, on the piston moving part Regardless of whether it must be injected directly into the piston ring package of the piston, for example.

  The lubricant line for the supply of lubricant to the piston of the internal combustion engine can in particular run inside the piston rod. Lubricants can also be used for the lubrication of piston rod bearings, which are shown in US Pat. This lubricant is supplied to the bearing via a storage tank or via a feedback line from the cylinder internal space. The piston rod is guided in a filling box (stuffing box). Since the filling box housing is maintained at overpressure, air is injected into the filling box via a piston pump driven by a piston. Since the filling box housing is maintained at an overpressure, the appearance of lubricant is prevented, which means that leakage is avoided.

  However, the filling box housing is spatially fixed, so that this sealing is possible in a simple manner. For a joined connection, a housing must be provided for this purpose, which either carries out the movement of the joint connection or encapsulates the entire joint connection, which makes it very demanding of pressurized air. Invite. For this reason, the solution provided in US Pat. No. 6,057,077 does not appear to be practical for avoiding lubricant leakage associated with joint connections.

  Due to the problems associated with the supply of lubricant via the piston, several solutions have been developed, in that the lubrication location where the lubricant is introduced is provided over the cylinder liner by injection or by a nozzle. Ensures lubrication between the piston and the inner wall of the cylinder liner.

  In order to achieve efficient lubrication of the piston / cylinder unit, in addition to the amount of lubricant and its distribution, the position of the piston in the cylinder at the time of introduction is also of great importance. This position is also described by the so-called crank angle of the crankshaft of the motor. Specifically, for very small amounts of lubricant that must be reduced further for the reasons described above, it is important that the lubricant be applied at the correct piston position in the cylinder at the correct position in the piston. . Only then can it ensure the most efficient use of a small amount of lubricant.

  Due to the idea of a lubrication device with a lubricant nozzle in the moving piston, the lubricant must be transported to the lubricant nozzle via a long and complex supply, so that they relate to the use of knee levers. Associated with large tolerances. A valve for dispensing the lubricant is arranged outside the cylinder for reasons of construction space as well as due to operating conditions in the cylinder. Thus, the supply lines for large engines have a length of a few meters and furthermore have a very complex structure between the valve and the lubrication nozzle. The control of the valve is done very precisely. However, the delay between control and actual introduction of the lubricant cannot be accurately reduced, and therefore the delay cannot be accurately predicted. Moreover, it is not guaranteed that a valve controlled amount of lubricant actually reaches the lubricant nozzle and is introduced into the lubricant nozzle over this long supply line. For this reason, due to the actual introduction of the lubricant into the cylinder liner, the time point, and therefore the piston position in the cylinder, cannot be set accurately, and the amount of lubricant introduced cannot be set accurately. .

International Publication No. 00/28194 European Patent Application No. 1505270A1 JP 60-125713 A

  To this end, it is an object of the present invention to provide an improved lubrication system and to provide an improved method of lubricating the operating surface of a large engine cylinder and detecting lubricant leakage in a lubricant supply system. . It is a further object of the present invention to provide an improved cooling system for a coupling connection for a piston rod of a crosshead engine, in particular to provide an apparatus for avoiding leakage in the cooling system. It is.

  The subject matter of the present invention which satisfies the above objectives is characterized by the function of the independent term of each category from the viewpoint of the apparatus as well as from the viewpoint of the method. Each dependent claim relates to a particularly advantageous embodiment of the invention.

  A large engine according to the present invention includes a cylinder liner, a piston movably disposed within the cylinder liner, a drive shaft, and a connecting element for connecting the drive shaft to the piston. The large engine includes a device for lubricating or cooling cylinders and / or pistons and / or connecting elements using a fluid medium, and a first for transporting (transmitting) the fluid medium from a reservoir to a place of use. Includes connection lines. The first connection line runs at least partly through the connection element, and the fluid medium in the first connection line is substantially pressurized with a pressure P1. A second connection line is provided, and the second connection line contains a fluid medium pressurized at pressure P2, and in normal operating mode, pressure P2 is higher than maximum pressure P1.

  In particular, the decrease in pressure P1 due to leakage in the first connection line can be measured, which is the pressure decrease in the first connection line, and thus the pressure difference between pressure P1 and pressure P2. Increase. A leak in the second connecting line causes a decrease in the pressure P2, and thus a decrease in the pressure difference between the pressure P1 and the pressure P2.

  The connecting element includes a piston rod having a crosshead, the crosshead joining at least one connecting rod connected to the drive shaft so that rotational movement of the drive shaft can be generated by movement of the piston. )including.

  According to certain embodiments, a plurality of bores may be provided in the connection. These bores can be part of the second connecting line. A pump may be provided between the connection and the reservoir for the generation of pressure P2. Alternatively, the reservoir itself may be maintained at pressure P2 or higher to compensate for pressure loss in the line. In the normal operation mode, the pressure P2 is substantially constant. The pump can be connected to the first connecting line via a throttle element. Specifically, a pulse generator may be provided between the throttle element and the first connecting line, and the pulse generator specifically includes at least one valve or slide valve or solenoid valve. A joined arm may be provided for supplying a fluid medium to the first connection line and / or the second connection line. This connecting arm is called a knee lever. Alternatively, for example, a pressure resistance hose (pressure resistant hose) may be provided.

  In order to detect the pressure P1 in the first connection line and the pressure P2 in the second connection line, pressure sensors may be provided in the first connection line and in the second connection line. The pressure sensor sends a signal that can be introduced into the evaluation device. The measured pressure can be compared with a corresponding reference pressure in the evaluation device. If a pressure result above the operating pressure fluctuation range is obtained, an output indicating leakage is output.

  The place of use for the device according to the invention can be, for example, cylinder lubrication, including a lubrication point for the application of lubricant on the working surface of the cylinder. In essence, a plurality of lubrication points may be provided as well. Specifically, a seal may be provided between the second connecting line and the crankshaft space.

  The present invention further relates to a method for lubricating or cooling a large engine, the large engine connecting a cylinder liner, a piston movably disposed in the cylinder liner, a drive shaft, and the drive shaft to the piston. And a device for lubricating or cooling the cylinder and / or the connecting element using a fluid medium. The fluid medium is transported from the reservoir to the place of use. A first connection line is provided that runs at least partially through the connection element. The fluid medium is substantially pressurized with a pressure P1 in the first connecting line. A second connecting line is provided for containing a fluid medium pressurized at pressure P2, which is higher than the maximum pressure P1 in the normal operation mode. Specifically, the pressure P1 can settle due to leakage in the first connecting line.

  The reservoir for lubricant or coolant connected to all lubricant lines or coolant lines for each cylinder may be designed as a common rail reservoir. This ensures that the same pressure is present in each of the lubricant lines and each of the coolant lines.

  Lubrication points may be located at different positions on the cylinder wall with respect to the axial direction determined by the longitudinal axis (A) of the cylinder. Lubricant is not only introduced at multiple points distributed around the cylinder periphery, but is also introduced at different axial positions, allowing the lubricant to be evenly distributed over a larger surface of the working surface. As a result, lubricant application can occur simultaneously. This means that all the locking elements are open at the same time. However, it is also possible to introduce the lubricant at different times, which means, for example, that the lubrication precedes the movement of the piston.

  A further application of the present invention is in the detection of coolant (refrigerant) leaks for large engine cylinders or pistons. In that case, the coolant forms a fluid medium that can circulate in the cylinder wall or in the piston. Like lubricants, pumps can be used to carry coolant to the corresponding point of use.

  The pump can be specifically designed as a piston pump having a plurality of feed positions. The feed piston is preferably driven by a camshaft. Specifically, the camshaft can be driven by an electric motor. For this purpose, the rotational speed of the camshaft, that is, the number of feed strokes per unit time, is arbitrarily variable within the rotational speed range determined by the electric motor. According to a further variant, the feed piston can also be connected to the working piston, which can be moved using fluid pressure means so that a feed hub can occur. The feed piston transfers lubricant or coolant into the distributor. When the rotary piston pump feed pistons carry out their feed strokes one after another, especially when the camshaft cams are arranged angularly displaced from each other, the pressure deviations in the distributor are reduced. obtain.

  The fluid pressure means may be a lubricant or coolant provided by an additional reservoir. This reservoir may specifically be at a higher pressure than the reservoir used for lubrication. This reservoir may be at a pressure above 50 bar, typically in the range from 50 bar up to 100 bar. The lubricant for the lubrication device is specifically provided by a reservoir at a pressure of up to 50 bar. Due to the impact, the lubricant or coolant pressure can reach up to 50 bar and is preferably located in the range of 40-50 bar with a base pressure in the range of 10-15 bar. This pressure corresponds to the pressure P1, which must take into account the pressure loss in the line. The use of two reservoirs at different pressures, typically the use of a lubricant reservoir or lubricant container or coolant container, allows the pump to operate with the lubricant or coolant. As a result, it is obsolete to provide a seal between the driving fluid and the operating fluid, which means a lubricant or coolant for lubrication. As a result, the provision of a sealing element in the pump can be omitted, which results in a more cost effective manufacture of the pump and simplification in operation and its maintenance.

  The pressure of the reservoir for the lubrication device is preferably smaller than the pressure of the reservoir for the operation of the working piston of the pump.

  The installation of the locking element is preferably performed depending on the load of the large engine. As a result, the lubricant supply can be exactly matched to the requirements.

  Specifically, the locking element is installed depending on the crank angle and / or rotational speed and / or torque and / or cylinder position of a large engine.

  According to a particularly simple deformation, the application of lubricant on the working surface of the cylinder wall is stopped when the pressure in the cylinder space is higher than the lubricant feed pressure. As a result, it can be ensured that the lubricant does not reach the combustion space of the cylinder when the piston is in the vicinity of the top dead center. As a result, the presence of the lubricant in the combustion space during the combustion process can thus be prevented from causing the combustion of the lubricant, which can lead to undesirable deposits or exhaust gases.

  For example, a pressure sensor may be used to measure the lubricant pressure and communicate the lubricant pressure to the evaluation device. The evaluation device checks whether the pressure is within a predetermined pressure range bounded by the upper threshold value and the lower threshold value. This check is made for both pressure P1 and pressure P2. The evaluation device calculates the differential pressure between the pressure P2 and the pressure P1. In the normal operation mode, the pressure P2 is located above the pressure P1. If the differential pressure is negative, this indicates the presence of a leak.

  An alarm may be generated due to a negative pressure difference. Dropping below that pressure, particularly over a longer period of time, may indicate a leak in the lubrication system that must be immediately confirmed to avoid damage through defective lubrication.

  The present invention will be described in detail below with reference to the accompanying drawings.

It is sectional drawing which shows the cross section through the piston cylinder structure in a large sized engine. 1 is a schematic diagram showing a cylinder of a two-cycle heavy duty diesel engine according to an embodiment for a lubrication device according to the present invention. FIG. FIG. 5 is a detailed view showing an assembly for determining different pressures between a first connection line and a second connection line. It is the schematic which shows lubricant supply. It is a pressure temperature diagram (p, t diagram) showing the process and breakdown of lubricant pressures P1 and P2 in the normal operation mode.

  A cross section through a large engine is shown in FIG. A large engine 100 according to FIG. 1 has a cylinder configuration with a cylinder in the form of a cylinder liner 20 and a piston 25. The cylinder configuration has an outside air supply system 101. The cylinder configuration of FIG. 1 is typically a configuration as is known from the state of the art for a two-stroke large diesel engine that is longitudinally scavenged.

  The piston 25 is disposed in the cylinder liner 20 so as to be capable of reciprocating along the cylinder wall 22 of the cylinder liner 20. The piston 25 performs a reciprocating motion between two turning points, that is, top dead center (OT) and bottom dead center (UT). The top dead center (UT) is a bottom dead center (UT) and an outlet. It is arranged between the valve 102.

  The piston 25 includes a piston ring package. The piston ring package is schematically illustrated in FIG. 2 with only three piston rings 27, 28, 29. That is, the piston ring package is located closest to the outlet valve 102 and, therefore, with respect to the upper piston ring 28 (also referred to as the top ring) located closest to the combustion space 23 and with respect to the outlet valve 102 in FIG. It has a second piston ring 27 arranged below the first piston ring 28 and a further piston ring 29 arranged below the piston ring 27.

  By way of example, the combustion space 23 is bounded at the top by a cylinder cover 103 having an injection nozzle not illustrated in detail and by an outlet valve 102 illustrated in FIG. It can be injected into the combustion space 23.

  The piston 25 is connected to the crosshead 14 via the piston rod 13 in a manner known per se, and during the operation of the large engine, the reciprocating movement of the piston 25 is transferred from the piston rod 13 to the crankshaft of the large engine. . According to an example, the piston rod 13 is guided through the scavenging space 110 as well as through the filling box 111. The scavenging space 110 is adjacent to the outlet valve 102 at the bottom of the cylinder liner 20. The filling box 111 defines the scavenging space 110 with respect to the crankshaft space 115 located below the scavenging space 110 so that the outside air symbolized by the arrow 112 cannot reach the crankshaft space 115 from the scavenging space 110. Seal. The turbocharger 113 carries outside air to the scavenging space 110 at high pressure, for example at pressures up to 4 bar.

  The piston 25 is designed as a piston 25 that is internally cooled by a coolant (refrigerant) 70, and the coolant is supplied and removed via a supply line (not shown).

  The piston 25 is illustrated in FIG. 1 at a position between top dead center (OT) and bottom dead center (UT). The piston upper edge 71 is defined by the uppermost point of the jacket surface 72 of the piston 25 in the direction of the outlet valve 102. The piston 25 is disposed in the cylinder liner 20 so as to be capable of reciprocating in the axial direction in the direction of bottom dead center along the piston axis.

  The piston 25 is designed as a two piece. The piston 25 includes a so-called piston crown (piston circular top) 73 and a piston skirt (piston collar) 74 that is screwed to the piston crown 73 using a screw (not illustrated). The piston skirt 74 is arranged in the direction of the scavenging space 110. The piston skirt 74 has a cylindrical jacket surface, the lowermost point of which defines a piston skirt lower edge 75 in the direction of the scavenging space 110.

  The three piston rings 27, 28, and 29 illustrated in FIG. 2 are disposed on the jacket surface 72 of the piston crown 73, and the first upper piston ring 28 is disposed in the direction of the outlet valve 102 and is adjacent to the second The piston ring 29 is arranged in the direction of the piston skirt lower edge 75, and the third piston ring 27 adjacent to the second piston ring 29 is arranged in the direction of the piston lower edge 75. The piston ring 27 is disposed between the uppermost piston ring 28 and the lowermost piston ring 29.

  According to FIG. 2, the lubricant and coolant are transported to the piston 25 through the piston rod 13. According to FIG. 1, the lubricant and / or coolant is supplied to the piston rod 13 via the crosshead 14. The crosshead 14 includes passages for this purpose, and these passages are illustrated in detail in FIG. These passages are supplied via a knee lever 120. The knee lever 120 represents a connecting element between the storage tank 30 (see FIG. 2) fixed in position and the crosshead 14, and the pump 1 may be provided between the storage tank 30 and the crosshead 14. Alternatively, the reservoir 30 may be designed similar to a common rail reservoir, and the reservoir 30 may include a lubricant or coolant that has already been sufficiently pressurized. Here, a sufficiently high pressure is to be understood as a pressure that lies above the pressures P1 and / or P2 and is sufficient to offset the pressure loss of the supply of the crosshead 14.

  As illustrated in FIG. 1, the knee lever 120 itself may have one or more joined connections to offset the movement of the crosshead 14.

  A cylinder of a two-cycle large diesel engine having a lubrication device 10 is schematically illustrated in FIG. A two-cycle large diesel engine includes a plurality of cylinders 20, where only one cylinder 20 is illustratively illustrated for reasons of clarity. The cylinder 20 includes a cylinder wall 22 which bounds the inner space 23 of the cylinder 20 in a manner known per se in the peripheral direction. A piston 25 is provided in the cylinder 20, and the piston 25 is disposed so as to be capable of reciprocating along the operating surface 21 of the cylinder wall 22 with respect to the axial direction A of the cylinder 20. The working surface 21 may be provided in a surface layer that is applied over the surface of the cylinder wall 22, for example by thermal spraying. At least one lubrication point 7, 17, in particular a lubrication nozzle 26, 46, is arranged in the cylinder wall 22 so that a lubricant film can be applied on the working surface 21 of the cylinder wall 22 in the operating state. At least one lubrication point is supplied with lubricant by the pump 1 in a manner known per se.

  The lubrication points 7 and 17 are connected to the pump 1 via the lubricant wires 8 and 18. Each of the lubricant wires 8 and 18 has a locking element 5 and 15. The lubricant wire is part of the distributor 3 which can also be designed as a common rail storage tank. The pump 1 carries the lubricant from the storage tank 30 to the lubrication points 7 and 17 through the distributor 3. This configuration may be used when coolant is used instead of lubricant to cool the piston or cylinder.

  The pump 1 can be operated with a lubricant, with servo oil or with a coolant. This means that the reservoir 30 provides lubricant or coolant at a pressure of about 20 bar. The working pump 33 of the pump 1 is operated with a lubricant or coolant supplied by a storage tank 31 pressurized to a higher pressure than the storage tank 30. In general, the pressure in the reservoir 31 is situated between 50 and 100 bar, specifically about 50 bar plus the pressure loss of the connecting line. The reservoir 31 can also be used to supply lubricant or coolant to the crosshead 14 via the second connection line. If possible, a throttle element is provided between the reservoir and the second connecting line in order to convert the pressure to a lower pressure P1 reaching up to 40-50 bar for impact.

  The lubricant introduced into the working piston space 34 of the pump 1 reaches the feed space 36 through the respective openings 39. As long as the working piston exists in the working piston space 35, the opening 39 is connected to the working piston space 34. This means that the stroke (stroke) of the pump 1 has not yet started. As soon as the lubricant is applied on the working piston present in the working piston space 34, the lubricant starts to move against the resistance of the holding means 37. Each of the openings 39 is closed by the feed piston 38 and the lubricant present in the feed space 36 is compressed. Since the feed space 36 is in fluid communication with the distributor 3, the lubricant present in the distributor 3 and / or the lubricant lines 8, 18 is also compressed.

  When the feed stroke is complete, the lubricant obtains the desired pressure in the lubricant lines 8,18. Whether or not the pressure is within a predetermined band required to ensure lubrication can be monitored using a pressure sensor in the distributor 3. This zone is generally located in the range of 10-50 bar, specifically this range is between 10-15 bar base pressure and between 40-50 bar. Pressure for impact.

  Thus, lubricant is provided in the lubricant lines 8 and 18 to be applied to the working surface 21 of the cylinder 20 at a desired time. The desired point in time is determined by the main device 50 which transmits a signal to the corresponding opening of the locking means 5, 15 via the signal transmission lines 42, 43. Thus, the point in time of the lubricant can be determined completely freely by the main unit.

  In essence, the point of closure of the locking means 5, 15 can be arbitrarily determined by the main device 50 as well. As a result, the required amount of lubricant can be precisely set for a specific circulation cycle.

  A measurement device 40 is exemplarily shown in FIG. Using the measuring device 40, a nominal value for the operating state of the two-cycle large diesel engine is detected. The measuring device 40 generates an electrical signal that is characteristic of the nominal value and transmits this signal to the main device 50 in a single transmission line 41. The main device 50 serves to control the lubricant system. The signal is evaluated in the main device 50. If the evaluation result requires a lubricant, a signal is transmitted from the main device to the locking elements 5, 15 via a single transmission line 42, 43 so that the locking means 5, 15 are activated. . This means that the locking means is opened or closed for the flow of the lubricant. The signal can also be used for the control of the pump 1. The signal can be used for a rotary pump, such as a pump that can change the feed current, for example, a circular pump, an impeller pump. For example, the number of revolutions of a motor that drives the pump may be changed so that the volume flow rate conveyed through the pump per unit time can be changed. This possibility also exists for rotary piston pumps. Such rotary piston pumps typically include a plurality of pistons that are moved through a camshaft driven by an electric motor. In order to increase the number of rotations of the camshaft, the number of piston strokes per unit time is increased, thus changing the volumetric flow delivered through the pump. In essence, a piston with a single feed piston can also be used. In that case, the feed piston can be moved hydraulically, or the feed piston can be moved by a camshaft.

  In this case, the switching frequency of the switching valve 32 can be changed. In this case, a certain signal is transmitted from the main device 50 to the switching valve 32 via the signal transmission line 44. The switching valve 32 is specifically designed as an electromagnetic valve. The switching valve 32 can take two positions. In the first position, the connection between the working piston 33 and the storage tank 30 is opened so that the lubricant from the working piston space 34 in which the working piston 33 is present can be sent back to the storage tank 30. The connection line between the storage tank 30 and the feed space 36 is opened so that the lubricant can flow into the feed space 36.

  The working piston 33 is guided to its upper end position by the holding means 37 (spring in this embodiment), and the working piston 33 is now ready to perform a feed stroke. When the switching valve 32 obtains a signal for performing a feed stroke from the main device 50, the switching valve 32 switches so that the connection to the storage tank 30 is released. Lubricant is introduced from the reservoir 31 into the working piston space 35 at high pressure, and the working piston 33 performs a feed stroke. This means that the lubricant is pumped from the feed space into the distributor 3 using the feed piston 38. Furthermore, the working piston need not be sealingly separated from the feed space. Therefore, it is not necessary to seal the driving piston space 35 on the driving side with respect to the working piston space 34 on the feed piston side.

  The locking elements 5, 15 are opened for a certain period of time so that the lubricant is applied on the working surface 21 based on the measurement value of the measuring device 40. The time period during which each of the locking elements 5, 15 is kept open can be individually matched depending on the measured value detected by the measuring device 40.

  In essence, multiple measuring devices can be provided that determine different parameters of a large engine.

  Similarly, the pressure of the lubricant can be set to be between the maximum pressure existing in the combustion space and the minimum pressure existing in the combustion space. The pressure in the combustion space is above the lubricant pressure, at least during the final stage of the combustion stroke, and at the time of ignition of the fuel-air mixture and the start of the expansion phase, so that the lubricant does not enter the combustion space. . When the pressure in the combustion space is below the pressure of the lubricant, it is possible to introduce the lubricant onto the working surface of the cylinder only during the outside air supply or during the first phase of the compression stroke. . As an alternative to this, it is possible to introduce a lubricant when the piston passes the point of lubrication in the compression stroke. This means that the lubrication point opens into a cylinder space filled with scavenging that is pressurized with the corresponding scavenging pressure. In this connection, the scavenging pressure is generally located slightly above the ambient pressure, which is typically about 3 bar. Thus, a connection exists between the location of the lubrication point and the piston. If the piston, i.e. the piston ring package, is located above the point of lubrication, the scavenging pressure is substantially present in the locking element, whereas in the combustion space, i.e. the piston ring package and the outlet valve. The pressure present in the cylinder space between is significantly higher.

  Therefore, when the lubrication point is in the region covered by the piston ring package during the combustion stroke, the lubricant reaches the cylinder space when the piston is in the vicinity of the top dead center. Can occur during the feeding of lubricant to This is because the pressure on the scavenging side is substantially smaller than the pressure at the combustion space side pressure in the cylinder space.

  FIG. 2 additionally shows that a lubricant or coolant is supplied to the piston 25. The device 10 according to the invention serves to lubricate or cool the cylinder liner 20 and / or the piston 25 and / or the connecting elements 13, 14, 19, 120 using a fluid medium. The fluid medium is specifically a coolant or a lubricant. A first connecting line is provided for supplying fluid from the reservoir 30 to the use locations 20, 25, 13, 14, 19. The first connection line 11 extends at least partially through the connection elements 13, 14, 19. FIG. 1 shows only the course through the piston rod 13. However, connection lines can likewise be provided in the crosshead, in the knee lever, in the piston, in particular in the piston skirt. The fluid medium is present in the first connecting line substantially at the pressure P1. A second connection line is provided for containing a fluid medium at a pressure of P2. During normal operation, the pressure P2 is higher than the maximum pressure P1.

  FIG. 3 shows details for cooling and / or lubricating between the first connecting line 11 and the second connecting line 12. A cross section of the crosshead 14 and a part of the piston rod 13 are shown. According to FIG. 3, the sleeve element 117 is also present between the piston rod 13 and the crosshead 14. Since the piston rod 13 is rotatable with respect to the crosshead 14, a seal (sealing) 118 is provided to seal the first and second connecting wires 11, 12 with respect to the crankshaft space 115.

  A fluid medium, such as a coolant or a lubricant, is present in the first connection line 11. The fluid medium present in the first connecting line has a pressure P1. The first connecting line runs through the piston rod 13, through the sleeve element 117, and also through the crosshead 14. For this purpose, an open passage is present on the outer jacket surface of the crosshead, which represents a connection at connection line 11 to a supply line running through knee lever 120. The supply lines and the connection of the supply lines to the crosshead are not illustrated in the drawings.

  The fluid medium likewise circulates in the second connection line 12 that is pressurized with the pressure P2. Specifically, the pressure P2 can be constant for the normal operation mode. Since the pressure of the fluid medium in the second connection line 12 is larger than the pressure P1 of the fluid medium in the first connection line 11, the fluid medium in the first connection line 11 cannot go outside. Is mainly guaranteed. In the case of a leak in the first connection line 11, the appearance of the fluid medium is prevented by the pressure P <b> 2 higher than in the second connection line 12. For this reason, in the case of a leak in the first connection line 11, the fluid medium can flow into the first connection line 11 at the pressure P <b> 2. As a result, the pressure in the first connection line 11 increases and at the same time the pressure in the second connection line 12 sinks, so that a pressure balance occurs. The pressure decrease due to the pressure balance is measured and transmitted to the evaluation device. The evaluation device continuously compares the measured pressure with a reference pressure. Due to the pressure balance, the pressure difference is reduced and for this purpose the evaluation device sends a signal, for example an alarm. This alarm indicates a leak in the first connecting line.

  When there is a leak in the second connecting line 12, the pressure P2 decreases. The decrease in the pressure P2 with respect to the reference pressure is measured by the evaluation device. In this case, the evaluation device also generates an output signal, for example an alarm. This alarm may be different from an alarm indicating a leak in the first connecting line.

  FIG. 4 illustrates one embodiment illustrating different ways in which different pressures P1 and P2 in the first connection line 11 and the second connection line 12 can be generated. The fluid medium carried from the storage tank 30 by using the pump 1 is divided into the first connection line 11 and the second connection line 12 by using a distributor element not illustrated in detail. As a result, the pressure in the pressure line downstream of the pump corresponds to a higher pressure P2. A throttle element 125 is provided in the connection line 11 to reduce the pressure. A pulse transmitter 126 may also be provided at the connection at the throttle element 125. The pulse transmitter serves to distribute the pulse current. Specifically, when the fluid medium is a lubricant, it may be advantageous to output the lubricant at a predetermined time. The pulse transmitter can be designed, for example, as a locking element, in particular as a valve.

  The graph shown in FIG. 5 shows the process of the pressure of the fluid medium applied on the Y axis depending on the time shown on the X axis. As a result, the solid line shows the pressure P2 and its change after the appearance of a leak in the second connection line or the first connection line. Furthermore, the broken line shows the pressure P1 and its change due to leakage in the first connecting line 11. As explained above, since the pressure P1 increases due to the presence of a leak, there is a pressure difference between the pressure P1 accumulated as the reference pressure and the pressure P1 'increased due to the leak.

  Furthermore, it shows the pressure process of the pulse when the fluid medium is to be transported in pulses. The maximum pressure of the pulse is below the minimum value for the normal operating mode of the device.

  Essentially, the device according to the invention and the method for detecting leaks are not limited to the specific embodiments illustrated in the drawings, but are the result of each fluid supply system according to the invention. .

1 pump
3. Distributor
5 locking element
7 Lubrication point
8 Lubricant line
10 devices (apparatus)
11 First connection line
12 Second connection line
13 Piston rod
14 Cross-head
15 locking element
17 Lubrication point
18 Lubricant line
19 connection element
20 Cylinder liner
21 running surface
22 cylinder wall
23 combustion space
25 piston
26 Lubrication nozzle
27 piston ring
28 piston ring
29 piston ring
30 Reservoir
31 Reservoir
32 switching valve
33 work piston
34 work piston space
35 work piston space
36 feed space
37 retaining means
38 Feed position
39 opening
40 measurement apparatus
41 signal transmitting line
42 signal transmitting line
43 signal transmitting line
44 signal transmitting line
46 Lubrication nozzle
50 central unit
70 Coolant
71 upper edge
72 jacket surface
73 piston crown
74 piston skirt
75 lower edge
100 large engine
101 fresh air supply system
102 outlet valve
103 Cylinder cover
110 Scavenging air space
111 stuffing box
112 arrow
113 Turbocharger
115 crankshaft space
117 sleeve element
118 seal
120 knee lever
125 throttle element
126 pulse transmitter

Claims (15)

A cylinder liner, a piston movably disposed in the cylinder liner, a drive shaft, and a connecting element for connecting the drive shaft to the piston, the cylinder using a fluid medium and / or the piston and And / or a device for lubrication or cooling of the connection element, and a first connection line for transporting the fluid medium from a reservoir to a place of use,
A large engine,
The first connecting line runs at least partially through the connecting element, the fluid medium in the first connecting line is substantially pressurized with a pressure P1, and a second connecting line is provided; The second connection line contains a fluid medium pressurized with pressure P2,
In the normal operation mode, the pressure P2 is higher than the maximum pressure P1,
Large engine.   The large engine according to claim 1, wherein the decrease in the pressure P <b> 1 due to leakage in the first connection line is measurable.   The large engine according to claim 1 or 2, wherein the decrease in the pressure P2 due to leakage in the second connection line is measurable.   The connecting element has a piston rod having a crosshead, the crosshead having at least one connecting rod connected to the drive shaft so that movement of the piston can generate a rotational movement of the drive shaft. The large engine according to any one of claims 1 to 3, wherein the large engine has an adjacent connecting portion.   The large engine according to claim 4, wherein a plurality of bores are provided in the connection, the bores being designed as part of the second connection line.   The large engine according to claim 4 or 5, wherein a pump is provided between the connection part and the storage tank for generating the pressure P2.   The large engine according to any one of claims 1 to 6, wherein the pressure P2 is constant.   The large engine according to any one of claims 1 to 7, wherein the pump is connected to the first connection line via a throttle element.   9. A pulse generator is provided between the throttle element and the first connecting line, and the pulse generator specifically comprises at least one valve or slide valve or solenoid valve. The large engine according to any one of the above.   The large engine according to any one of claims 1 to 9, wherein a coupling arm is provided for supplying the fluid medium to the first connection line and / or the second connection line.   In order to detect the pressure P1 in the first connection line and the pressure P2 in the second connection line, pressure sensors are located in the first connection line and in the second connection line. The large engine according to any one of claims 1 to 10, provided respectively.   The large engine according to any one of claims 1 to 11, wherein the place of use includes cylinder lubrication and a lubrication point for applying lubricant to the operating surface of the cylinder liner.   The large engine according to any one of claims 1 to 12, wherein a seal is provided between the second connecting line and the crankshaft space. A method of lubricating or cooling a large engine,
The large engine
A cylinder liner, a piston movably disposed in the cylinder liner, a drive shaft, and a connecting element for connecting the drive shaft to the piston, and the cylinder using a fluid medium and / or Or a device for lubrication or cooling of the connecting element,
The fluid medium is transported from a storage tank to a place of use within a connecting line;
A first connection line running at least partially through the connection element is provided;
The fluid medium is pressurized within the first connection line substantially at a pressure P1, and a second connection line is provided for containing a fluid medium pressurized at a pressure P2, the pressure P2 being In the normal operation mode, it is higher than the maximum pressure P1.
Method.   15. The method according to claim 14, wherein the pressure P1 sinks due to a leak in the first connection line and / or the pressure P2 decreases due to a leak in the second connection line.

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