JP3586065B2 - Reciprocating piston engine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention includes a crankshaft and a bearing device attached to the crankshaft. The bearing device includes a relatively thin inner bearing shell and an outer support ring attached to the bearing shell. The invention relates to a reciprocating piston engine provided, in particular for large diesel engines.
[0002]
[Prior art]
Since a large force acts on the crankshaft during driving, this force causes bending and twisting of the crankshaft in addition to a large reaction force in the area of the bearing. It has been found empirically that this results in a high load on the edge region of the bearing shell. To cope with this, a device is provided for accommodating the bearing shell on a rocking bearing device for the main bearing of the crankshaft of a large diesel engine. This oscillating bearing device has a rotational degree of freedom about an oscillating shaft extending in a direction transverse to the bearing shaft. However, it has been found that this type of device is extremely complex and expensive to manufacture, since in addition to the original bearing surface the bearing surface of the oscillating bearing device must also be formed. Apart from this, the known device requires high maintenance costs, since it is very sensitive and relatively susceptible to relative movements in the area of the rocking bearing device.
[0003]
In other known means, the bearing shell projects beyond the support ring. However, this type of device has also proven to be very sensitive (prone to failure) and requires a relatively large installation space, which is undesirable.
Thus, the known devices have proven to be neither simple nor sufficiently reliable.
[0004]
[Problems to be solved by the invention]
The present invention therefore provides, using simple and inexpensive means, a device of the kind mentioned at the outset to overcome the above-mentioned disadvantages, thereby preventing overloading of the edge region of the thin-walled bearing shell, In addition, it aims at realizing a simple and inexpensive manufacturing and a compact and robust structure.
[0005]
[Means for Solving the Problems]
According to the invention, according to the invention, the support ring has an elastic region provided at least on one side at least in the angular range in which the bearing force reaches a maximum, corresponding to the end face side edge of the bearing shell. This is solved by arranging the elastic region radially inside at least one elasticity-imparting recess of the support ring.
[0006]
One or more elastic regions formed by one or more elasticity providing recesses allow the support ring to be easily elastically deformed in a region where a large axial force is generated, and thus are installed on the support ring device and the support ring. The bearing shell can follow the deformation of the crankshaft. As a result, the load on the bearing shell is also substantially uniform throughout. Also, local overload of the edge region is prevented. The device according to the invention thus requires no maintenance and has fewer failures, since only elastic movements occur and no relatively movable bearing surfaces are required. The degree of freedom provided by the elastic flexibility allows the bearing shell to be supported in its entirety axially in a preferred manner, thus fully utilizing the available space and maximizing the supporting bearing surface . This also allows the bearing housing to have a relatively slim and lightweight structure. Another advantage of the measures according to the invention is that the elasticity recesses, which impart the desired elasticity to one or more elastic regions, can be formed more simply and cheaper than the bearing surface. The measures according to the invention thus guarantee excellent economics.
[0007]
Preferred constructions and advantageous embodiments of the above measures are set out in the dependent claims. Advantageously, the one or more resilient recesses are eccentric with respect to the bearing axis and / or have a recess shape which is asymmetric with respect to the machine central longitudinal plane and / or with respect to the transverse plane. This makes it possible in a suitable way to better adapt the elastic properties provided by the one or more elasticity-imparting recesses to the actual load distribution which is normally not symmetrical in the longitudinal and transverse directions.
[0008]
In many cases, it has proven to be advantageous to provide a number of identical or different elasticity recesses. This makes it possible to optimally adapt the elasticity of the elastic region to a specific load distribution.
[0009]
In a preferred embodiment, at least one elasticity providing recess is formed as an elasticity providing groove. This provides good elasticity over a large surrounding area.
[0010]
In another embodiment of the above means, at least one elasticity providing recess is formed as a through hole or a bag-like hole. Thereby, higher rigidity can be obtained as compared with the case where the groove is provided. Also, the holes and the like can be formed very easily.
[0011]
In another embodiment of the above means, at least one elasticity recess is provided through the support ring. This allows in a favorable manner a good reaction of the bearing to large pressures, which is also favorable for a uniform load on the bearing shell. In this connection, it is desirable for the two elasticity-imparting recesses located opposite one another to be connected by at least one through recess, whereby particularly good results are obtained.
[0012]
Other preferred structures and advantageous embodiments of the above measures are set forth in the remaining dependent claims and will be apparent from the following description of embodiments.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, description will be made with reference to the drawings.
FIG. 1 is a side view schematically showing a first embodiment of a main bearing of a crankshaft of a large diesel engine according to the present invention.
FIG. 2 is a sectional view taken along the line II-II in FIG.
FIG. 3 is a side view showing another embodiment of the main bearing of the crankshaft according to the present invention, similarly to FIG.
FIG. 4 is a sectional view taken along the line IV-IV in FIG.
The basic structure of the two embodiments is identical. Therefore, the following description relates to the two embodiments, unless otherwise described.
[0014]
The construction and operation of large two-stroke diesel engines are known per se and will therefore not be described in further detail herein. In order to convert the reciprocating piston movement into rotary movement, a crankshaft 1 is provided in the lower engine area, which extends over the entire engine length. The crankshaft has journals 2 which are aligned with each other and are journaled by this journal on the base side.
[0015]
For this purpose, a so-called main bearing is provided, which is divided by a horizontal separating seam 3 into a lower part 4 and an upper part 5. The lower part 4 is fixed and integrated in the base structure. The upper part 5 is formed as a removable lid, and is correspondingly indicated only in broken lines in FIGS. 1 and 3. In FIGS. 2 and 4, the upper part 5 is completely omitted.
[0016]
The base is formed in the area of the main bearing as shown in FIGS. 1 and 3 so as to have a gate shape with two lateral case parts 6, through which tie rods (not shown) are passed. It is plugged in. The lateral case 6 supports the lower part 4 of the main bearing. This lower part consists of a solid support ring 7, which is connected in a T-shape as a half-ring-shaped collar to a wall 8 connecting the two case parts 6 to one another. Therefore, the wall portion 8 functions as a fin-shaped reinforcing member for the support ring 7. A thin bearing shell 9 is inserted into the bearing hole for the lower part 4 and the upper part 5, and this bearing shell is constituted by a thin bearing half shell corresponding to the lower part 4 and the upper part 5, respectively. . As shown in FIGS. 2 and 4, the lower side of the bearing shell 9 is supported over its entire axial direction by corresponding components of the support ring 7. The thin half shell of the bearing shell 9 inserted into the bearing hole of the upper part 5 can be supported in the same manner.
[0017]
The crankshaft 1 is deformed by receiving a load. The deformation and the resulting bearing load fluctuate according to the crank angle. In order to prevent overloading of the bearing shell 9, which is made of a thin and very thin and strong material due to its thinness, a variable displacement of the rotating crankshaft 1 is provided at least at the point where the maximum bearing force occurs in the bearing shell. Is provided, so that the bearing load can be equalized. For this purpose, the region connected to the bearing shell 9 of the main bearing and supporting the bearing shell is formed elastically so that it can carry out an elastic movement following the deformation of the rotating crankshaft 1. . Thereby, the bearing shell 9 can be deformed in accordance with the deformation of the rotating crankshaft 1, and the occurrence of a peak value in the load on the bearing shell 9 is prevented. It is preferable that the change in the elasticity enhanced by the elasticity applying means follows the change in the bearing force as the bearing force increases within the angle range including the maximum value of the bearing force.
[0018]
The removable upper part 5 is a relatively elastic component. Therefore, in the region of the upper portion 5, even if a large force is generated in this region, other elasticity applying means is usually not required, or only a small amount is required. In a device of the type shown, the maximum load occurs in an angular range in the lower part 4. The lower part 4 integrated into the base structure is a relatively hard area. However, by using appropriate elasticity imparting means, the desired elasticity is imparted to the region of the support ring 7 which is connected to the bearing shell 9 and supports the bearing shell.
[0019]
At least the region of the support ring 7 that supports the edge region in the axial direction of the bearing shell 9 is formed as an elastic region having great elasticity. To achieve this, the support ring 7 is provided with an elasticity-imparting recess located radially outward with respect to the joint surface with the bearing shell 9 and located in the end face region. This recess can be formed as a groove 10, a bag-like hole 11, a through slit 12, a through hole 13, or the like. These shapes are provided in various combinations. The arrangement and shape of the elasticity imparting recesses, that is, the configuration of the recesses, are determined based on the expected deformation of the crankshaft 1 that fluctuates with the rotation of the crankshaft 1 and the resulting bearing load distribution. In an angle region where a load is high and a large amount of elasticity is required, a large amount of elasticity is provided by appropriately forming the elasticity imparting concave portion, and a small amount of elasticity is provided in a region where the load is small. Can be
[0020]
In the embodiment shown in FIGS. 1 and 2, one elasticity providing groove 10 and two elasticity providing bag-like holes 11 are formed in the end face region of the support ring 7 shown in FIG. 1. In this embodiment, the elasticity imparting recess is formed so that the shape of the recess does not have the central axis and the plane of symmetry, and is therefore eccentric with respect to the axis and asymmetric with respect to the machine central longitudinal plane and other longitudinal planes. Is formed. In this case, the elasticity imparting groove 10 is provided in the left quadrant of FIG. The elasticity-imparting bag-shaped hole 11 is provided in the right quadrant of FIG. The elasticity imparting groove portion 10 extending in a curved manner along the length direction is eccentrically arranged with respect to the bearing shaft. By using the asymmetrical and eccentric concave shape as described above, the driving characteristics when the crankshaft of a combustion machine having a reciprocating piston, such as a large diesel engine, rotates can be best secured.
[0021]
The depth and the cross-sectional shape of the elasticity providing groove 10 can be made variable along the length of the groove. At this time, it is preferable to change gradually. In the embodiment shown in FIG. 1, the resilient groove 10 is flat and narrow and closed in the lower top region of the bearing, which corresponds to a linear change along the length. Similarly, the diameter of the elasticity imparting bag-shaped hole 11, the distance from the bearing shell 9, and the depth of the elasticity imparting bag-shaped hole 11 can be made different. In the embodiment shown, the elasticity-imparting bladder hole 11 closest to the lower top region has the largest diameter, which diameter is larger than the inner width of the elasticity-imparting groove 10.
[0022]
In the end face region on the opposite side of the support ring 7, as is apparent from FIG. The shape and arrangement of the recesses are independent of the elasticity-imparting recesses provided on the opposite end face, and are determined based on the expected deformation of the crankshaft in that region. In the illustrated embodiment, the elasticity imparting groove 10 is also provided in the region of the end surface of the support ring 7 shown on the right side in FIG. However, this groove has a smaller depth and a smaller inner width than the elasticity providing groove 10 on the opposite side. The radial distance from the bearing shell 9 is greater than on the opposite side. The same applies to the elasticity-imparting bag-like holes provided in some cases. The elasticity-imparting bag-shaped hole does not need to be associated with the opposite hole. By the way, in the illustrated embodiment, the elasticity imparting bag-shaped hole 11 is provided. However, it is also conceivable to form a through hole. Similarly, elasticity providing slits are provided between the elasticity providing grooves 10 which are located in opposite directions to each other, so that the penetration from one side to the other side extends over the entire length or a part of the length of the groove 10. It is also conceivable to form
[0023]
In the embodiment shown in FIGS. 3 and 4, unlike the embodiment shown in FIGS. 1 and 2, both end faces of the support ring 7 are concentric with the bearing axis and have a machine center. Each of the elasticity providing grooves 10 symmetrical with respect to the vertical plane is formed. The resilient groove extends in this embodiment over a large angular range of about 160 °, with its end reaching the vicinity of the separating seam 3. Furthermore, in addition to the elasticity-imparting grooves 10, a through-elasticity-imparting slit 12 symmetrical to the machine center longitudinal plane, extending over an angle range of about 30 ° and connecting the elasticity-imparting grooves 10 in the two end face regions to each other An elasticity-imparting hole 13 is formed on the side of the elasticity-imparting slit and similarly penetrates. The diameter of the elasticity-imparting hole is smaller than the inner width of the elasticity-imparting slit 12.
[0024]
As described above, since the elasticity imparting concave portion is located substantially outside the joint surface with the bearing shell 9, as is clear from FIGS. 2 and 4, the thin supporting region 14 supporting the bearing shell 9 is formed. It is formed. This support region is formed as a flange for the elasticity providing groove 10. In the illustrated embodiment, the inner width of the elasticity imparting groove 10 increases outward. Accordingly, the thickness of the flange decreases outward. The amount of elastic deformation of the support region 14 thus formed increases toward the end face side of the support ring 7.
[0025]
In the region of the elasticity providing grooves 10 facing each other, a bridge 15 located between them is formed, which is off-center as shown in FIG. 2 or in the center as shown in FIG. , Is arranged. The structure of the end face of the bridge 15 corresponds to the structure of the bottom of the groove. In the embodiment shown in FIG. 4, the inside of the two elasticity providing grooves in the end face region is formed round. Accordingly, the bridge 15 has an end surface that is concave inward. In the embodiment shown in FIG. 2, one elasticity providing groove 10 has a flat groove bottom, and the opposite elasticity providing groove 10 has a curved groove bottom. Accordingly, the bridge 15 has a flat end face and an inwardly concave end face. The end face side area of the support area 14 can be elastically displaced in the radial direction by a corresponding elasticity providing recess, and accordingly, functions as an elastic area for elastically supporting the bearing shell 9. The bridge 15 is displaceable in the direction of the end face, and accordingly functions as an elastic hinge. Thereby, favorable elastic displacement can be given to the support portion of the bearing shell 9 as a whole. Therefore, the bearing shell can be supported by the support ring 7 over the entire axial direction.
[0026]
In this embodiment, the amount of displacement of the end surface side region of the support region 14 that supports the bearing shell 9 and the elasticity of the bridge 15 are formed by the penetrating elastic concave portion having the shape of the elastic slit 12 and the elastic hole 13. Is further increased and the appropriate elasticity in the radial direction occurs, so that the bearing shell 9 can be adapted to the load. Therefore, there is no need to worry about local overload of the bearing shell 9. Rather, a substantially uniform load distribution over the entire length and width direction, i.e., over the entire bearing surface, of the bearing shell 9 or the lower part of the bearing shell 9 corresponding to the lower part 4 is obtained by the above-described measures. Along with this, the entire bearing surface is optimally used, so that a bearing structure having a relatively small axial length and correspondingly slim overall can be realized.
[0027]
In the area of the upper part 5, such elasticity-imparting means as described above are not normally required. This is because, unlike the lower part 4, the upper part 5 is not solid. However, it is also conceivable to form an elastic region as described above by providing an elasticity imparting concave portion also in the region of the upper portion 5.
[0028]
In the illustrated example, the provided elasticity providing recess is empty. However, for example, the elasticity imparting concave portion having the shape of the elasticity imparting groove portion 10, the elasticity imparting bag-shaped hole portion 11, the elasticity imparting slit 12 or the elasticity imparting hole portion 13 is filled, or an elastic reinforcing member is attached to the support ring 7. It is also conceivable to insert them integrally.
[Brief description of the drawings]
FIG. 1 is a side view schematically showing a first embodiment of a main bearing of a crankshaft of a large diesel engine according to the present invention.
FIG. 2 is a sectional view taken along the line II-II in FIG.
FIG. 3 is a side view showing another embodiment of the main bearing of the crankshaft according to the present invention, similarly to FIG.
FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Crankshaft 7 Support ring 9 Bearing shell 10, 11, 12, 13 Elasticity imparting concave part 14 Elastic area 15 Bridge

Claims (16)

The bearing device includes a crankshaft (1) and a bearing device attached to the crankshaft. The bearing device has a relatively thin inner bearing shell (9) and an outer support attached to the bearing shell. In a reciprocating piston engine, especially for large diesel engines, provided with a ring (7)
The support ring (7) has an elastic region (14) provided at least on one side, corresponding to the edge on the end face side of the bearing shell (9), at least in the angular region where the bearing force reaches a maximum. A reciprocating piston engine, characterized in that said resilient region is arranged radially inward of at least one resilience imparting recess (10, 11, 12, 13) of said support ring (7). 2. The reciprocating piston engine according to claim 1, wherein the elastic region is provided in end regions on both sides of the support ring. 3. 3. The reciprocating piston engine according to claim 1, wherein the elasticity providing recesses (10, 11) are provided in end face regions on both sides of the support ring (7). 4. 4. The reciprocating piston engine according to claim 1, wherein at least one elasticity-imparting recess (12, 13) penetrating the support ring (7) is provided. The reciprocating piston engine according to any one of claims 1 to 4, wherein a plurality of the same or different elasticity providing recesses (10, 11, 12, 13) are provided. One or more of the elasticity-imparting recesses (10, 11, 12, 13) may have a recess shape that is eccentric with respect to the bearing shaft and / or asymmetric with respect to the machine center longitudinal plane and / or the transverse plane. The reciprocating piston engine according to any one of claims 1 to 5, further comprising: The reciprocating piston engine according to any one of claims 1 to 6, wherein at least one of the elasticity providing recesses (10) is formed as an elasticity providing groove. The reciprocating piston engine according to claim 7, wherein a depth and / or a cross-sectional shape of the groove-shaped elasticity providing recess (10) changes linearly. 9. The reciprocating piston engine according to claim 1, wherein at least one of the elasticity providing recesses (11) is formed as an elasticity providing hole. The two elasticity recesses (10) located on opposite sides are connected by at least one elasticity recess (12, 13) penetrating a bridge (15) provided between the elasticity recesses. The reciprocating piston engine according to any one of claims 1 to 9, wherein: 11. The reciprocating piston engine according to claim 10, wherein at least one of the elasticity-imparting recesses (12) is formed as a through slit. 11. At least one elasticity-imparting hole (13), preferably a plurality of elasticity-imparting holes, arranged beside the through slit, penetrating the bridge (15). A reciprocating piston engine according to claim 11. The reciprocating piston engine according to any one of claims 1 to 12, wherein the elasticity providing recesses (10, 11, 12, 13) are at least partially filled with an elastic material. . 14. The split bearing according to claim 1, wherein at least one elastic region (14) is provided at least in the region of the bearing lower part (4). Reciprocating piston engine. The elasticity of the elastic region (14) formed by the one or more elasticity providing recesses (10, 11, 12, 13) has a change that is compatible with the change of the bearing force in a predetermined angular range of the elastic region. The reciprocating piston engine according to any one of claims 1 to 14, wherein the elasticity imparting concave portion is formed and / or arranged. The support ring (7) of the bearing device attached to the crankshaft (1) is provided with a means for reducing rigidity which is at least one elasticity imparting recess (10, 11, 12, 13). ,
The resilient recess is eccentric so that the resulting change in stiffness reduction within a predetermined angular range has a change adapted to the change in bearing load caused by the rotating crankshaft (1). 16. The reciprocating piston engine according to claim 1, wherein the reciprocating piston engine is arranged and formed asymmetrically.

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