JP2006336810A - Large multi-cylinder two-cycle diesel engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a large multi-cylinder two-cycle diesel engine having the same performance as that of a conventional engine of this type as well as reduced or unchanged weight and size. <P>SOLUTION: The cross head type of large multi-cylinder two-cycle diesel engine comprises a number of crank-through two-crank shafts 1 mutually joined to main journals 5 supported by main bearings. Each crank-through has two arms 3 connected to each other via a crank pin 4. The arm 3 is joined to the relating main journal 5 with the shrink fitting of the end of the main journal to a hole portion of the arm 3. Bearing portions of the main journals 5 can be individually designed at lengths M<SB>1</SB>, M<SB>2</SB>, ..., M<SB>n+x</SB>. A cylinder pitch and a main bearing pitch are variable and individually adaptable to the crank through 2 and the main bearing 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a crosshead type large multi-cylinder two-cycle diesel engine including a crankshaft assembled with a plurality of parts.

  The low-speed crosshead large two-cycle diesel engine is a huge and highly efficient engine that generates power. The largest of these engines generates about 100,000 kW at 94 revolutions, has a total length of 33 meters and a weight of about 3,500 tons.

  This type of conventional engine is divided into a plurality of cylinder parts having equal axial lengths. This is represented as a base plate by the distance between adjacent cross beams, an A-shaped crankcase frame by the distance between adjacent horizontal stiffeners, and a cylinder frame by the cylinder pitch.

  These engines comprise a crankshaft assembled with a crank throw that is interconnected by a main journal each supported by a main bearing. Each crank throw includes two crank arms that are interconnected by a crank pin, and the arms are joined to the associated main journal by shrink fitting into the arm hole at the end of the main journal. Each throw may be manufactured as one piece or assembled with two arms and a crankpin.

  The largest engine throws about 25 tons, and the complete crankshaft weighs up to about 400 tons. This crankshaft must be able to transmit a torque of up to about 12,000kNm. The dimensions of the components of the crankshaft are determined in consideration of various structural aspects. In particular, the transmitted force and the force generated by the vibration action of the crankshaft influence the dimensional design of each part. Furthermore, the safety factors in the joint and component dimensional design are defined by the requirements of the respective classification societies.

  It is a common feature of known semi-assembled and fully assembled crankshafts that the shrinkage pressure is limited by the post-assembly condition and that yield can occur around the inner surface of the hole, i.e. near the interface. is there. If the contraction pressure becomes higher during engine operation and a greater yield occurs in the shaft material, the shaft must undergo unacceptable deformation when attempting to transmit the applied torque. The contraction pressure determines the individual shaft components that are interrelated, and thus, together with the contraction surface area, determines the amount of torque that the shaft can transmit. As mentioned above, the maximum contraction pressure is actually limited, so the shaft must be dimensionally stable during rotation. If the shaft is designed to transmit greater torque, the shrinking surface area and associated axial or radial dimensions need to be increased.

  This means that both the engine crankshaft and nearby components require more space and become heavier, making the engine more expensive and less effective.

  The main journal of a large multi-cylinder two-cycle diesel engine of the crosshead type must withstand the large force exerted by the piston on the crankshaft in addition to the force generated by the vibration mass and vibration action of the crankshaft.

  The main bearing of a large two-cycle diesel engine is a sliding bearing, which creates a pressure on the oil film between the bearing surface and the journal due to the hydrodynamic effect of the journal's rotational movement, and this pressure lifts the journal from the bearing surface. Yes. A minimum oil film thickness must be maintained to prevent bearing surface wear. The load applied to each main crankshaft bearing in a large multi-cylinder two-cycle diesel engine of a crosshead type is not uniformly distributed to each bearing, but varies depending on the bearing. These changes are caused by the dynamic mass forces that occur during rotation of the crankshaft and the resulting crankshaft vibration effects. Bending due to combustion pressure and torsion in the eccentric crank throw due to fluctuations in transmission torque also cause axial deviations and deviations between the bearings during engine operation, which also contributes to changes in the load on each bearing. .

  Larger bearing surfaces are required as the maximum load on the bearing increases, but it is likewise necessary to provide longer bearing portions for each main journal.

  This means that both the engine crankshaft and adjacent components require more space and become heavier, making the engine more expensive and less effective.

  Against this background, the present invention provides a lighter and shorter large multi-cylinder two-cycle diesel engine that has the same performance as a conventional engine of this type, or has a higher performance than a conventional engine of this type. An object of the present invention is to provide a large multi-cylinder two-cycle diesel engine having the same weight and size.

This object is in accordance with claim 1 and is a large, multi-cylinder two-stroke diesel engine of in-line, V-type or U-type crosshead type, comprising n or n * 2 cylinders and n + 1 + x A main shaft and a crankshaft with n crank throws connected to each other by a main journal supported by the main bearing, each crank throw having two arms connected to each other by a crank pin The arm is joined to the associated main journal by shrink fitting by shrink fitting into a hole in the arm at the end of the main journal, whereby the arm has a maximum thickness in the axial direction of the crankshaft ( T ₁ , T ₂ ,... T _{n * 2} ) and the axial length (L ₁ , L ₂ ,... L _{n * 2} ) of each crank throw is the arm of the crank throw the maximum thickness of _{(T 1, T 2, ...} T n * 2) to At least partially determined Te, wherein the sintering fit junction, the length _{(l 1, l 2, ...} l n * 2) have, the length _{(l 1, l 2, ...} l n _{* 2} ) is dimensioned individually based on the individual loads applied to the shrink-fit joints during engine operation, and the maximum thickness of each arm (T ₁ , T ₂ , ... T _{n * 2} ) , Individually dimensioned so that it can be realized within the length (l ₁ , l ₂ ,... L _{n * 2} ), and the distance (D ₁ , D _2, ... D _n) is a variable, the axial length of between the crank throw (L _1, L _2, ... conform to individually L _n), in-line, V-type or This is achieved by providing a U-shaped crosshead large multi-cylinder two-cycle diesel engine.

The lengths l ₁ , l ₂ ,. . . By individually dimensioning l _{n * 2} , it is possible to make many of the shrink-fit joints shorter than shrink-fit joints with a larger load. The maximum thicknesses T ₁ , T ₂ ,. . . By individually dimensioning T _{n * 2} to a minimum, the lengths l ₁ , l ₂ ,. . . l _{n * 2} is possible, and the lengths L ₁ , L ₂ ,. . . L _n can be shortened. By adapting the distance D between the side surfaces of the pair of adjacent main bearings, the distance between the adjacent main bearings is shortened. By shortening the distance between the main bearings, the overall length of the engine is shortened. Many large two-cycle diesel engines are used in the propulsion engines of ships, especially container ships, bulk carriers and oil carriers, etc. The In addition, reducing the length results in a reduction similar to the weight of the engine and is a competitive factor.

The lengths l ₁ , l ₂ ,. . . l _{n * 2} can be individually dimensioned so that the maximum strain of the shrink-fit joint during engine operation is the same for all shrink-fit joints. Thereby, the total length of the arm can be kept short.

The maximum thicknesses T ₁ , T ₂ ,. . . T _{n * 2} and the lengths l ₁ , l ₂ ,. . . l _{n * 2} can be selected to be equal to the two arms of the same crank throw.

The lengths M ₁ , M 2,... Of the bearings of the main journal between two adjacent arms. . . M _{n + 1 + x} can be individually dimensioned based on the individual loads on the main journal that are involved during engine operation, and the pitches P ₁ , P ₂ , . . . P _{(n or n * 2) -1} can be made variable, and the lengths M ₁ , M ₂ ,. . . It is possible to adapt to M _{n + 1 + x} individually. Due to the individually variable lengths of the bearing portions of the main journal, the cylinder pitch between a pair of adjacent cylinders can be increased if the main bearing in between is not as heavily loaded as the other journals of the engine. Can be shortened. By individually shortening the cylinder pitch between a pair of adjacent cylinders, the overall length and weight of the engine can be further reduced.

The pitches P ₁ , P ₂ ,. . . P _{(n or n * 2) -1} is the maximum thickness of the arms of the crankshaft T ₁ , T ₂ ,. . . T _{n * 2} can also be individually adapted.

The distance between the shaft centers of a pair of adjacent main bearings is the length of the crank throw L ₁ , L ₂ ,. . . L _n and the respective lengths M ₁ , M ₂ ,. . . Both M _{n + 1} can be individually addressed.

  The engine further includes a base plate having a cross beam having a bearing support of the main bearing, and a welded A-shaped crankcase frame having a horizontal stiffener supporting a guide plate for a cross head. Possible, whereby the distance between the respective cross beams individually adapts to the distance between the axial centers of the main bearings supported by the related cross beams, and the A-shaped crankcase frame It is mounted on the base plate together with the horizontal stiffener disposed substantially above the cross beam.

Maximum axial thicknesses T ₁ , T ₂ ,. . . The dimensions of the arms other than _{Tn * 2} are preferably substantially the same as all the arms of the crankshaft.

  The diameter of the main journal is preferably the same for all main journals of the crankshaft.

The above-mentioned object is a large-cylinder two-cycle diesel engine of in-line type, V type or U type cross-head type according to claim 15, wherein n or n * 2 cylinders and a main bearing are respectively provided. A crankshaft with n crank throws connected to each other by supported n + 1 + x main journals, each crank throw having two arms connected to each other by crank pins The arm is joined to the related main journal by shrink fitting by shrink fitting to the hole of the arm at the end of the main journal, and the main journal is the shaft end of the crankshaft, each of the two arms. The length of the bearing portion (M ₁ , M ₂ ,... M _n ) between the two adjacent arms at the shaft end of the crankshaft or the main journal portion of one adjacent arm. _{+ 1 + x),} the engine operation Individually is dimensioned on the basis of the individual load applied to the main journals of the relevant pitch between a pair of adjacent cylinder _{(P 1, P 2, ...} P (n _{or n * 2) -1} is variable In-line type, V type or U type crosshead type individually adapted to the length (M ₁ , M ₂ ,... M _{n + 1 + x} ) of the bearing portion of the main journal in between This is achieved by providing a large multi-cylinder two-cycle diesel engine.

The length of the bearing portion of the main journal between two adjacent arms can be individually sized based on the individual loads on the main journal involved during engine operation, Pitch P ₁ , P ₂ ,. . . P _{(n or n * 2) -1} can be made variable, and can be individually adapted to the length of the bearing portion of the main bearing in between. Due to the individually variable lengths of the bearing portions of the main journal, the cylinder pitch between a pair of adjacent cylinders can be increased if the main bearing in between is not as heavily loaded as the other journals of the engine. Can be shortened. By individually shortening the cylinder pitch between a pair of adjacent cylinders, the overall length and weight of the engine can be further reduced.

  The lengths of the main journal parts can be individually dimensioned to make the relevant main journal length as short as possible.

  The engine may further comprise a base plate including a transverse beam with a bearing support of the main bearing, and a welded A-shaped crankcase with a transverse stiffener supporting the guide plate, thereby The distance between the respective cross beams is individually adapted to the distance between the axial centers of the main bearings supported by the related cross beams, and the A-shaped crankcase frame is substantially It is mounted on the base plate by the horizontal stiffener disposed right above.

  Further objects, features, advantages and characteristics of the engine of the present invention will become apparent from the detailed description.

Detailed description

  In the following detailed part of the description, the invention will be described in more detail with reference to the exemplary embodiments shown in the drawings. In the following detailed description, a crosshead type large two-cycle diesel engine is disclosed by a preferred embodiment.

  1 and 2 show a low-speed crosshead type large in-line two-cycle diesel engine 10 having a piston diameter of 98 cm and can be used as a marine propulsion engine or a power plant prime mover. These engines typically have 6 to up to 16 cylinders in a row. In FIG. 1, 9, 10, 11, and 12 cylinder type engines are shown by auxiliary lines together with a side view of the 8-cylinder engine 10. The meter scale under engine 10 indicates the absolute size of these engines, and their length varies from approximately 18 meters for the 8-cylinder model to 28 meters for the 14-cylinder model.

  The engine is assembled from a base plate 11 having a main bearing of the crankshaft 1. The base plate 11 is divided into parts of appropriate sizes according to available manufacturing apparatuses. This base plate consists of a welded transverse girder 31 provided with a welded stringer and a bearing support 32 (FIG. 4) made of cast steel.

  2, the engine includes a piston 28 joined to a crosshead 24 via a piston rod 29. The cross head 24 is guided by the guide surface 23. The connecting rod 30 joins the cross head 24 and the crank pin of the crankshaft 1.

  A welded A-shaped crankcase frame 12 is placed on a base plate 11. The cylinder frame 13 is placed on the upper part of the crankcase frame 12. Reserving bolts 26 (shown in FIG. 3) join the base plate 11 to the cylinder frame 13 and maintain the structure of each other. The cylinder 14 is carried by the cylinder frame 13. The exhaust valve assembly 15 is placed on the upper part of each cylinder 14. The cylinder frame 13 also carries a fuel injection device 19, an exhaust receiver 16, a turbocharger 17, and a scavenging receiver 18.

  As shown in FIG. 3, the crankcase frame 12 is disposed between the cylinders provided with the stiffeners in a form that passes through the lateral plates 21 that interconnect the outer walls 22 of the crankcase frame 12 extending in the longitudinal direction. The A-shaped crankcase frame 12 for increasing the lateral rigidity extends from the top to the bottom.

  The vertical guide surface 23 for receiving a lateral force acting on the cross head 24 (FIG. 2) is placed on the lateral plate 21 by welding, for example. The rear surface of each guide surface 23 is supported by a vertically extending auxiliary wall 25 that joins the guide surface 23 and the lateral plate 21. The guide surface 23, the auxiliary wall 25, and the horizontal plate wall 21 form a hollow shape having high torsional rigidity with respect to the torsion received by the retaining bolt 26.

  As shown in FIG. 4, the base plate 11 includes a cross beam in a form that passes through the plate 31. The bearing support 32 is placed on the cross beam 31 by welding, for example. The lower bearing shell 33 is received by the bearing support 32. The main bearing also includes an upper bearing shell and a bearing cap (not shown), which are fastened to the bearing support 32 after the crankshaft 1 is disposed on the base plate 11.

  FIG. 5A shows a crankshaft 1 of a conventional 12-cylinder engine. FIG. 5D shows a crankshaft according to a preferred embodiment of the present invention. 5B and 5C apply to both conventional crankshafts and crankshafts according to preferred embodiments. Crank throws / cylinders are numbered 1-12, crank throw number 1 is attached to the tip of crankshaft 1, and crank throw number 12 is attached to the exit end thereof. For engines with different throw numbers, this number can be expressed as n. The number of cylinders of the in-line engine is n. The number of cylinders of a U-type or V-type engine (not shown) is n * 2.

  The crankshaft 1 is assembled from the rear portion 1b and the front portion 1a because it is extremely difficult to obtain a crane that can lift the complete crankshaft 1 having a weight of about 400 tons. Each crankshaft component 1a and 1b comprises six of the twelve crank throws 2 in total. (Other combinations are possible, for example, a 14-cylinder engine can be divided into two crankshafts with four throws and one crankshaft with six throws.) In the portion 1b and the rear portion 1a, one main journal 5 is placed on each bearing shell 33. Thereafter, the front and rear portions of the crankshaft are assembled in the longitudinal direction by the flange joint 37. The front part and the rear part of the crankshaft are connected to the flange of the flange joint 37 by bolting, and after placing the bearing cap, the crankcase frame 12 is placed on the base plate 11.

  Each crankshaft portion 1a and 1b is assembled from six (n / 2) crank throws 2 and seven (n / 2) +1 main journals 5. The crank throw 2 has a crank pin 4 formed integrally with the two arms 3 of the crank throw. The crank throw 2 is manufactured as an integral form of cast steel or forged steel. The six crank throws 2 of each crankshaft portion 1a and 1b are connected to each other by a main journal 5. The total number of complete crankshaft main bearings is therefore 14 (n + 1 + x), where x is designed so that the number of crankshaft main bearings in which the crankshaft part and fittings are assembled is variable It is variable depending on the method. In addition, some flange joints do not increase the total number of main bearings, so the total number of main bearings is determined by the number of flange joints and the type of flange joint. Therefore, as shown in the figure, the value of x is 1 on the crankshaft.

  The rear portion 1a includes a thrust bearing 39 that receives a force generated by a propeller driven via an intermediate shaft (not shown).

  FIG. 5B is an axial image of the crankshaft showing the angular distribution of each throw 2 of the front portion 1b.

  FIG. 5C is an axial image of the crankshaft showing the angular distribution of each throw 2 in the rear portion 1a.

  The main journal 5 has one bearing portion and two ends that are shrink-fitted in the hole portion of the arm 3 to the crank throw 2 adjacent when the crankshaft 1 is assembled. The main journal 5 positioned at the longitudinal ends of the front portion 1b and the rear portion 1a has end portions that are shrink-fitted into the respective hole portions of the bearing portion and the arms of the respective crank throws 2.

In FIG. 6, the shrink-fit joint between the arm 3 of cylinder number 1 and each journal 5 is shown in more detail. The length of the shrink-fit joint is in the range of l _{1 in} the arm 3. (Shown cylinder number 2 of the length of the crank throw l ₃ and l _4, the length of the crank throw of cylinder number 3 as l _3). The magnitude of torque that can be transmitted by shrink-fit joints is the contact pressure of the shrink-fit joints, the diameter of the hole and its length l ₁ , l ₂ ,. . . l Determined by _{n * 2} (n = number of engine throws). That is, the greater the length and diameter, the greater the torque that can be transmitted. The shrink-fit joints are usually dimensioned with a safety factor of 2 based on the requirements of the respective classification societies.

Available axial lengths l ₁ , l ₂ ,. . . l _{n * 2} is mainly the axial width T ₁ , T ₂ ,. . . Determined by T _{n * 2} . The maximum pressure is determined by the extra diameter with respect to the diameter of the hole of the main journal 5 and the structural strength and stability of the arm 3 surrounding the hole. The structural strength of the material surrounding the hole depends on the thickness of the material layer around the hole and the properties of the material. In general, all the components of the crankshaft 1 are made of high-tensile steel. The components can be manufactured after casting or forging, followed by post-treatment and finishing, respectively, to obtain the desired material properties and surface quality.

Each shrink-fit joint l ₁ , l ₂ ,. . . l The maximum torque transmitted by _{n * 2} is not the same for all joints. Each cylinder 14 in the combustion stroke at a given time applies the maximum torque transmitted by the part of the crankshaft 1 between the cylinder concerned and the outlet end of the crankshaft. In a 12-cylinder two-cycle engine, six cylinders are in the combustion stroke at the same time at any given time. The torque transmitted by a portion of the crankshaft 1 near the output (rear) end of the crankshaft of a large two-cycle engine is therefore significantly greater than the torque to be transmitted by the tip of the crankshaft. Dynamic torsional effects and vibrations have a further effect on the distribution of the maximum torque load on each shrink-fit joint, and thus the required contraction length l ₁ , from the front end of the crankshaft 1 to the rear end, l ₂ ,. . . l It does not necessarily increase linearly at _{n * 2} . The maximum torque transmitted by each shrink-fit joint can be determined numerically, analytically, experimentally, or a combination of these methods. Accordingly, the lengths l ₁ , l ₂ ,. . . l _{n * 2} is determined and the safety factor provided in such a way is substantially the same for all shrink-fit joints of the crankshaft. Since the torque transmitted by these two shrink-fit joints is generally the same, for practical reasons, the lengths l ₁ , l ₂ ,. . . l _{n * 2} can be chosen to be identical (l ₂ = l ₃ , l ₄ = l ₅ , l ₆ = l ₇ etc.).

Lengths l ₁ , l ₂ ,. . . l _{n * 2} is usually the axial thickness T ₁ , T ₂ ,. . . This is a determinant when dimensional design of T _n . Generally, axial thicknesses T ₁ , T ₂ ,. . . T _{n * 2} is the required length l ₁ , l ₂ ,... For shrink fitting to make room for the rounded stress reduction transition 39 between the main journal 5 and the crank arm 3. . . l Slightly thicker than _{n * 2} .

In a preferred embodiment, the maximum thicknesses T ₁ , T ₂ ,. . . The dimensions of the arm 3 other than _{Tn * 2} are substantially the same for all the arms of the crankshaft.

According to another embodiment (not shown), the crank arm is connected to the maximum axial thickness T ₁ , T ₂ ,. . . It can be grouped to be the same within the group by T _{n * 2} , and the maximum axial thickness T ₁ , T ₂ ,. . . T _{n * 2} is different for each group.

Since the torque transmitted in an engine with a large number of cylinders is relatively small, the maximum arm thickness T ₁ , T ₂ ,. . . A relatively thin arm 3 of T _{n * 2} is provided. Since the torque transmitted by the rear end portion of the engine having a large number of cylinders is relatively large, the maximum arm thicknesses T ₁ , T ₂ ,. . . A relatively thick group of arms 3 of T _{n * 2} can be provided.

FIG. 5D shows the lengths of shrink-fit joints l ₁ , l ₂ ,. . . l _Indicates a crankshaft that is dimensionally designed for _{n * 2} . As can be seen by comparing the crankshaft of FIG. 5A (conventional crankshaft) and the crankshaft according to the preferred embodiment of the present invention of FIG. 5D, a significant reduction in the overall length of the crankshaft and thus the entire engine 10 is obtained. Yes. The essential part of the length reduction is the shrink-fit joints l ₁ , l ₂ ,. . . l _{n * 2} can be obtained by dimensional design individually.

FIG. 7 shows a part of the tip 1b in more detail. Here, the axial direction of the thickness T ₃ of the arm 3 of the crank throw 2 associated with the cylinder number 3 is thicker than the axial thickness T ₂ of the arm 3 of the crank throw 2 associated with the cylinder number 2, and also It can be seen that the axial thickness T ₁ of the arm 3 of the crank throw 2 associated with the cylinder number 2 is thicker. Since the axial load applied to the crankpin bearing is normally distributed uniformly to the crankpin 4, all the crankpins 4 have the same length in this embodiment. The axial length L ₁ , L ₂ ,. . . By dimensioning L _n individually, the distances D ₁ , D ₂ ,. . . D _n can be individually adapted to the minimum value (Figure 4).

The main journal 5 located between the two crank arms 3 has two ends for receiving holes in the crank arms 3 concerned. The main journal 5 disposed at the shaft ends of the front portion 1b and the rear portion 1a has a unique end portion that fits into the bearing portion and the hole portion of the crank arm 3. The length of the end is the shrink-fit length l ₁ , l ₂ ,. . . l _Adapted individually to match _{n * 2} . The main journal 5 has lengths M ₁ , M ₂ ,. . . A bearing with M _{n + 1 + x} (FIGS. 6 and 7) is provided. The bearing support 32 and the bearing shell 33 have matching individually adapted axial lengths (FIG. 4).

The axial load on the main bearing is not evenly distributed. This uneven distribution is caused by crankshaft radial vibration and crankshaft torsional deformation. For example, the torsional deformation at the eccentric part of the crankshaft 1 as in the crank throw 2 leads to a radial deviation that affects the axial load distribution of the main bearing. The maximum axial load that each main bearing can withstand can be determined numerically, analytically, experimentally or by a combination of these methods. Accordingly, the axial lengths M ₁ , M ₂ ,. . . The dimension of M _{n + 1 + x} and the axial length of the bearing shell 33 are designed.

Further, the material thickness G ₁ , G ₂ ,. . . G _{n + 1} can also be dimensioned individually by the load of each bearing during engine operation to further reduce the weight of the engine.

Cylinder pitches P ₁ , P ₂ ,. . . P _{(n or n * 2) -1} is the axial length M ₁ , M ₂ ,. . . M _{n + 1 + x} , and the axial thicknesses T ₁ , T ₂ ,. . . Adapt individually to T _{n * 2} .

Distances S ₁ , S ₂ ,... Between the center lines of adjacent pair of cross beams 31 (FIG. 4) carrying bearing supports 32. . . S _n-1 is the axial length of the crank throw 2 between them, and the axial lengths M ₁ , M ₂ ,. . . Correspond to M _{n + 1 + x} individually.

The transverse stiffener 21 (FIG. 3) is placed directly above the cross beam 31 for reasons of stability, and the distances S ₁ , S ₂ ,. . . S _n-1 is therefore the distances S ₁ , S ₂ ,. . . Same as S _n-1 .

Variable cylinder pitch P ₁ , P ₂ ,. . . Distances S ₁ , S ₂ ,... Between P _{(n or n * 2) -1} and the variable lateral stiffener 21. . . S _n-1 is continuous in the cylinder frame 13 (FIGS. 1 and 2). The complete engine 1 is thus configured in the axial part with the lengths individually dimensioned in this way. As a result, the total engine length can be reduced by 3-7% compared to the conventional engine. The reduction in length further leads to a considerable weight reduction of the engine 10.

  Thus, while preferred embodiments of the apparatus and method are disclosed with respect to the environment in which they were developed, they are merely illustrative of the principles of the present invention. Other embodiments and configurations can be devised within the scope of the appended claims.

It is a side view of the conventional large-sized 8-cylinder 2-cycle diesel engine which displayed the length of the 9-12 cylinder engine. It is a front view of the engine of FIG. It is sectional drawing of a crankcase frame. It is sectional drawing of a base plate. FIG. 5A is a side view of a conventional crankshaft of a 12-cylinder engine. FIG. 5B is an axial image of the forward portion of the crankshaft of both FIGS. 5A and 5D. FIG. 5C is an axial image of the rear portion of the crankshaft of both FIGS. 5A and 5D. FIG. 5D is a side view of the crankshaft of a 12 cylinder engine according to one embodiment of the present invention. 5D is a detailed cross-sectional view of the main journal and crank throw of the crankshaft of FIG. 5D. 5D is a detailed view of a portion of the crankshaft of FIG. 5D. FIG.

Claims (17)

Large, multi-cylinder 2-cycle diesel engine (10) of in-line type, V type or U type crosshead type, with n or n * 2 cylinders, n + 1 + x main bearings, and main bearings And a crankshaft (1) assembled with n crank throws (2) connected to each other by a main journal (5) supported by each, and each crank throw (2) is mutually connected by a crank pin (4) Two arms (3) to be connected are provided, and the arm (3) is joined to the related main journal (5) by shrink fitting by shrink fitting into the hole of the arm (3) at the end of the main journal. Thereby, said arm (3) has a maximum thickness (T ₁ , T ₂ ,... T _{n * 2} ) in the axial direction of said crankshaft (1), and each crank throw (2) The axial length (L ₁ , L ₂ ,... L _{n * 2} ) of the arm of the crank throw (2) (3 The maximum thickness (T _1, T ₂ of), ... T _{n * 2)} at least partially determined by the sintering fit junction length _{(l 1, l 2, ...} l n * 2 ) And this length (l ₁ , l ₂ ,... L _{n * 2} ) is individually dimensioned based on the individual loads applied to the shrink-fit joints involved during engine operation, and each arm Individually so that the maximum thickness (T ₁ , T ₂ ,... T _{n * 2} ) of (3) can be realized within the length (l ₁ , l ₂ ,... L _{n * 2} ) The dimension (D ₁ , D ₂ ,... D _n ) between the opposing side surfaces of each pair of adjacent main bearings is variable, and the axial length of the crank throw (2) between them is variable Engine (10), individually adapted to (L ₁ , L ₂ ,... L _n ).
The lengths l ₁ , l ₂ ,. . . The engine of claim 1, wherein l _{n * 2} is individually dimensioned to obtain substantially the same maximum strain during engine operation for all shrink-fit joints.
Two arms (3) on the main journal (2) having the same axial thickness (T ₁ , T ₂ ,... T _{n * 2} ) and the length of the shrink-fit joint The engine according to claim 1 or 2, which is equal to each other.
The length (M ₁ , M ₂ ,... M _{n + 1 + x} ) of the adjacent two arms or the bearing part of the adjacent arm (3) at the end of the crankshaft is related during engine operation. Are individually sized based on individual loads on the main journal (5), and the pitches P ₁ , P ₂ ,. . . P _{(n or n * 2) -1} is variable and can be individually adapted to the length (M ₁ , M ₂ ,... M _{n + 1 + x} ) of the main journal (5) in between The engine according to any one of claims 1 to 3.
The pitch between each pair of cylinders (P ₁ , P ₂ ,... P _{(n or n * 2) -1} is an arbitrary value of the crankshaft portion between the pair of cylinders (14) concerned. the maximum thickness of the arms _{(3) (T 1, T} 2, ... T n * 2) is caused to conform to the individual in an engine according to claim 4.
The distance between the shaft centers of a pair of adjacent main bearings is the length (l ₁ , l ₂ ,... _{N n} ) of the crank throw (2) between them and the associated pair of main bearings individual lengths of the bearing portions of the two main journals _{(M 1, M 2, ...} M n + 1 + x) corresponds to the individual to both engine according to claim 4 or 5 .
Welding with a base plate (11) having a cross beam (31) having a bearing support (32) of the main bearing and a horizontal stiffener (21) supporting a guide plate (23) for a cross head (24) A-shaped crankcase frame (12), whereby the distance (S ₁ , S ₂ ,... S _{n * 2} ) between the respective cross beams (31) is related to the cross beams ( 31) is individually adapted to the distance between the shaft centers of the main bearings supported, and the A-shaped crankcase frames (12) are arranged substantially directly above the respective cross beams (31). The engine according to claim 6, wherein the engine is mounted on the base plate (11) together with the horizontal stiffener (21).
The dimensions of the arms (3) other than the maximum axial thickness (T ₁ , T ₂ ,... T _{n * 2} ) are substantially equal to all the arms (3) of the crankshaft (1). The engine according to any one of claims 1 to 7, which is the same.
Engine according to any of the preceding claims, wherein the diameter of the main journal (5) is substantially the same for all main journals (5) of the crankshaft (1).
Engine according to any of the preceding claims, wherein the dimensions of each main bearing support (32) are individually sized based on individual loads on the relevant main bearing during engine operation.
11. Engine according to claim 10, wherein the main bearing supports (32) are individually dimensioned by varying their material thickness.
The crank arms (3) are grouped to be the same in the group by the maximum axial thickness (T ₁ , T ₂ ,... T _{n * 2} ) of the arms (3). 11. The engine according to any one of claims 1 to 10, wherein a maximum axial thickness (T ₁ , T ₂ ,... T _{n * 2} ) of) varies for each group.
Tip of the crankshaft is provided, the maximum arm thickness in the axial direction _{(T 1, T 2, ...} T n * 2) relatively thin Group arm (3), an engine according to claim 12 .
The rear end of the crankshaft, the maximum arm thickness in the axial direction _{(T 1, T 2, ...} T n * 2) of relatively thick group comprises an arm (3), in claim 12 or 13 The listed engine.
Large, multi-cylinder two-cycle diesel engine (10) of in-line type, V type or U type cross head type, n + 1 or n * 2 cylinders (14) and n + 1 supported respectively by the main bearing It has a crankshaft (1) with n crank throws (2) connected to each other by + x main journals (5), and each crank throw (2) is connected to each other by a crank pin (4) The arm (3) is joined to the associated main journal (5) by shrink fitting by shrink fitting into the hole of the arm (3) at the end of the main journal. The main journal (5) is joined to each of the two arms (3) at the shaft end of the crankshaft (1), and two adjacent arms (3) at the shaft end of the crankshaft (1). The length of the bearing part of the main journal part of one arm (3) between or adjacent (M ₁ , M ₂ ,... M _{n + 1 + x} ) are individually sized based on individual loads on the relevant main journal (5) during engine operation, and a pair of adjacent cylinders (14 ) Pitch (P ₁ , P ₂ ,... P _{(n or n * 2) -1} is variable, and individually the length of the bearing portion of the main journal (M ₁ , M ₂ , A large multi-cylinder two-cycle diesel engine (10) of in-line type, V type or U type crosshead type that can be adapted to M _{n + 1 + x} ).
The length of the bearing portion (M ₁ , M ₂ ,... M _{n + 1 + x} ) is the minimum length of the bearing portion (M ₁ , M ₂ ,... M _{n + 1 + x} ). The engine of claim 15, wherein the engine is individually dimensioned to provide
A base plate (11) including a cross beam (31) having a bearing support (32) of a main bearing;
A welded A-shaped crankcase frame (12) with a transverse stiffener (21) that supports a guide plate (23) for the crosshead (24);
The distance (S ₁ , S ₂ ,... S _n-1 ) between the respective cross beams (31) is individually determined by the distance between the shaft centers of the main bearings supported by the related cross beams (31). And the A-shaped crankcase frame (12) is mounted on the base plate (11) with the transverse stiffener (21) disposed substantially directly above the respective cross beam (31). The engine according to claim 15 or 16, wherein

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