Bearing with bearing pin for use in engines and other devices
阅读说明：本技术 用在发动机和其他装置中的具有轴承销的轴承 (Bearing with bearing pin for use in engines and other devices ) 是由 R·祖格尔 于 2019-08-21 设计创作，主要内容包括：本发明涉及用在发动机和其他装置中的具有轴承销的轴承。所述轴承包括轴承壳(2)和具有旋转轴线(X)的轴承销(1、11、12),其中,所述轴承销(1、11、12)被布置成能围绕所述旋转轴线(X)在所述轴承壳(2)中旋转。所述轴承销(1、11、12)具有相对于其旋转轴线(X)的不对称削弱部(3),从而所述轴承销(1、11、12)因在所述轴承壳(2)的方向上作用的外力(F)的作用而能变形,使得所述轴承壳(2)和所述轴承销(1、11、12)之间的有效力区域借助所述轴承销(1、11、12)的变形而增大。(The present invention relates to bearings having bearing pins for use in engines and other devices. The bearing comprises a bearing shell (2) and a bearing pin (1, 11, 12) having a rotation axis (X), wherein the bearing pin (1, 11, 12) is arranged rotatable in the bearing shell (2) around the rotation axis (X). The bearing pin (1, 11, 12) has an asymmetrical weakening (3) with respect to its axis of rotation (X), so that the bearing pin (1, 11, 12) is deformable by the action of an external force (F) acting in the direction of the bearing shell (2), such that the effective force area between the bearing shell (2) and the bearing pin (1, 11, 12) is increased by the deformation of the bearing pin (1, 11, 12).)
1. Bearing comprising a bearing shell (2) and a bearing pin (1, 11, 12) having an axis of rotation (X), wherein the bearing pin (1, 11, 12) is arranged rotatable in the bearing shell (2) around the axis of rotation (X),
it is characterized in that the preparation method is characterized in that,
the bearing pin (1, 11, 12) comprises an asymmetrical weakening (3) with respect to the axis of rotation (X), so that the bearing pin (1, 11, 12) is deformable by the action of an external force (F) acting in the direction of the bearing shell (2), so that the effective force area between the bearing shell (2) and the bearing pin (1, 11, 12) can be increased by means of the deformation of the bearing pin (1, 11, 12).
2. Bearing according to claim 1, wherein the bearing pin (1, 11, 12) is a cylindrical bearing pin (1, 11, 12).
3. Bearing according to any of the preceding claims, wherein the axis of rotation (X) of the bearing pin (1, 11, 12) is an axis of symmetry of the bearing pin (1, 11, 12), such that the bearing pin (1, 11, 12) is arranged rotationally symmetrically rotatable in the bearing shell (2) around the axis of symmetry.
4. Bearing according to any of the preceding claims, wherein the bearing pin (1, 11, 12) comprises an asymmetric weakening with symmetry with respect to a first cross-sectional axis (S) orthogonally crossing the rotation axis of the bearing pin (1, 11, 12).
5. The bearing of claim 3, wherein the bearing pin includes an asymmetric weakened portion of symmetry with respect to a second cross-sectional axis orthogonally intersecting the axis of symmetry of the bearing pin.
6. Bearing according to any of the preceding claims, wherein the bearing comprises a force element, in particular a force lever, a piston rod (21) or a push rod (22), and the force element is in particular arranged on the bearing pin (1, 11, 12) such that the force (F) can be introduced via the force element in a predetermined direction on the bearing pin (1, 11, 12).
7. Bearing according to any of the preceding claims, wherein the asymmetrically weakened portion (3) of the bearing pin (1, 11, 12) is an asymmetric recess, in particular a hole.
8. Bearing according to any of the preceding claims, wherein the bearing pin (1, 11, 12) is a crosshead pin (12) or a crankpin (11).
9. Bearing according to any of the preceding claims, wherein the asymmetric weakening (3) of the bearing pin (1, 11, 12) is configured in the form of a variation of the material type and/or the material density and/or the material structure.
10. Bearing according to any of the preceding claims, wherein the bearing pin (1, 11, 12) comprises a plurality of asymmetric weakenings (3) with respect to the rotation axis (X).
11. Bearing according to any of the preceding claims, wherein the bearing pin (1, 11, 12) is a two-piece bearing pin (1, 11, 12) comprising a bearing pin ring (102) and a bearing pin core (101), and the bearing pin core (101) is arranged in the bearing pin ring (102).
12. Bearing according to any of the preceding claims, wherein the bearing pin (1, 11, 12) is configured as a bearing pin (1, 11, 12) for a large engine (100), in particular as a bearing pin (1, 11, 12) for a large diesel engine of the crosshead type.
13. A bearing pin (1, 11, 12) according to any one of claims 1 to 12,
it is characterized in that the preparation method is characterized in that,
the bearing pin (1, 11, 12) comprises an asymmetric weakening (3) such that the bearing pin (1, 11, 12) is deformable under the action of a force (F).
14. A crosshead, in particular for a large engine, in particular for a two-stroke large diesel engine, comprising a bearing according to any one of claims 1 to 12.
15. A large engine, in particular a large diesel engine, in particular of the crosshead type, comprising a bearing according to any one of claims 1 to 12.
Technical Field
The invention relates to a bearing having a bearing shell and a bearing pin. The invention also relates to a bearing pin for a bearing, a crosshead comprising a bearing and a large engine comprising a bearing.
Background
In the prior art, many different types of bearings are known. In motors and centrifugal pumps, sliding bearings are generally used in which a moving part slides in a fixed workpiece.
The task of various bearings in internal combustion engines or other devices is to fix rotating or oscillating parts or to guide them on a given path. Bearings are used to absorb and transmit forces between components that move relative to each other. To reduce mechanical losses and ensure a long service life, bearings are required for all rotational, linear (sliding) and pivotal movements. Bearings absorb radial forces acting perpendicular to the axis of rotation and/or axial forces acting in the direction of the axis of rotation and transmit these forces to other rotating or stationary components, among other uses. In modern internal combustion engines, sliding bearings as well as rolling bearings are used, among others.
Since the predominance of plain bearings prevails, plain bearings are used almost exclusively for crank drives (until now). However, in order to reduce the friction loss, a rolling bearing is used as the load and mounting conditions permit.
In the case of sliding bearings for internal combustion engines, hydrodynamic lubrication conditions are targeted, in which the shaft and the bearing are separated from one another by a load-bearing lubrication film and metallic contact is largely avoided. Since the liquid friction is mostly free of wear, the liquid friction ensures low friction losses and a long service life. The rotational movement of the shaft in the bearing causes a flow of viscous medium, as the lubricant adheres to the surfaces of the sliding fit. If the wedge-shaped lubrication gap between the bearing surface and the eccentric pin narrows in the direction of movement, hydrodynamic pressure is generated in the lubrication film, since the toughness of the lubricant prevents lateral flow. This pressure tries to push open the surface that restricts the lubrication film and thus creates a load capacity that keeps the external bearing forces balanced (wedge pressure).
The bearing shell may be configured as a half shell or a bearing cartridge. Which type is used depends on constructional aspects. The construction aspect depends mainly on the design of the bearing block and the shaft.
In the prior art, thin-walled bearing shells are known (thin-walled bearing shells: thickness/diameter ratio >0.05) which are mounted under preload to ensure good contact of the bearing shells in the housing. This also provides good protection against twisting during operation. To ensure the necessary compression, extensions and protrusions are used.
The various possible bearing shapes depend on controlling the dynamic behavior of the forces acting on the bearing. In particular, the vibrational behavior of the sliding bearing arrangement depends essentially on the mass of the rotor, the mass distribution, the bending stiffness of the shaft and the suspension and damping properties of the bearing under given load conditions. By appropriate arrangement of the bearings, lateral vibrations (forced and self-excited) can be prevented or optimised. The choice of bearing shape and bearing configuration is an essential part of the optimization, since different bearing shapes and bearing configurations also have different properties.
The bearing gap, which is often supplied with a liquid or a uniform (greasy) lubricant to prevent sliding friction, is formed by appropriately dimensioning the moving and stationary functions and mutually adjusting them. Due to this bearing clearance, a load-bearing lubrication wedge can be formed by the lubricant in the available space when the bearing pin has a sufficient circumferential speed. The lubrication wedge separates the sliding portions so that the bearing operates with full lubrication. This process is typical for hydrodynamic plain bearings.
In order to supply the bearing with sufficient lubricant during operation, a lubricant supply element is usually required, which continuously supplies lubricant, such as lubricating oil, as required in order to keep the sliding layer in the bearing.
For example, in small connecting rod bores, in piston pin bores for camshafts, rocker arms, drawbar, gear and oil pump shafts and water pump shafts, thin-walled multi-material bushings (composite materials) are mainly used. Such a liner may be rolled with a butt joint or manufactured by a centrifugal casting process in a steel pipe.
A pin is an extension of a component (usually cylindrical or rectangular parallelepiped) used to connect it to another component. In radial sliding bearings, the moving part is usually a pin with an axis or shaft and the stationary part is usually a bearing shell.
On the one hand, the bearing should allow the shaft to rotate while transmitting axial forces to the surrounding construction with as little deformation as possible. In modern gearboxes, the axial load capacity and stiffness are very high, so that only high-quality and optimized bearings meet the requirements. At the same time, proper installation is critical due to the axial and preload forces of these bearings.
The simplest and most cost-effective possibility is a bearing pin which is sufficiently small compared to the nominal diameter of the bearing shell. In the best case, the surface area of the bearing shell is already sufficient to absorb the forces of the bearing with an acceptable surface load.
In mechanical engineering, the pin is a stepped end with an axis that can accommodate the bearing and serve as the center of rotational movement. Such pins are usually made by turning the original axis and their dimensions are largely standardized. On the other hand, at the end of the shaft, the pin does not accommodate a bearing, but may accommodate a shaft-hub connection such as a draw key. The grooves required for this purpose are milled in previously machined pins; the length, width and depth of the groove are standardized, as are the associated pins.
The crank pin is located off-center of the axis. It accommodates a connecting rod or transmission rod, thus ensuring a crank drive. In a locomotive, the connecting rods are also connected with two corresponding wheel sets.
In the case of engines with crossheads, the crossheads absorb forces acting vertically and laterally on the crankshaft (crankpin). It shields the piston from lateral forces. As a result, the piston can be very flat (disc piston), and the hot cylinder and piston running surfaces are subjected to little stress. In the case of a piston machine, the piston shield takes over the function of the crosshead and transmits the transverse forces to the cylinder.
The kinematics of a crank drive with a crosshead is substantially the same as the kinematics of a crank drive without a crosshead.
Crosshead is mainly used in reciprocating internal combustion engines, especially in two-stroke large diesel engines, and in reciprocating steam engines.
Large diesel engines of the crosshead type, which are preferably used in shipbuilding or stationary equipment, for example to generate electrical energy, comprise three large casing sections which form the engine frame. On the bedplate with the transverse support elements beside the bearing blocks for receiving the crankshaft with the crankshaft main bearings, so-called brackets are arranged separated by the bedplate. Depending on the number of cylinders of a large diesel engine, the bracket comprises a plurality of supporting bodies arranged opposite each other, each having a vertical sliding surface for guiding two adjacent crossheads, which are connected to the crankshaft by means of push rods. In each case, two opposing vertical sliding surfaces are additionally supported by the central wall. The individual supports are usually connected to one another by a common cover plate. Then, a cylinder section, usually called cylinder liner, adapted to accommodate a plurality of cylinder liners, is arranged on the cover plate above the support. The base plate, the carrier and the cylinder segments are connected to one another by tie rods, which normally extend into the interior of the support body in the region of the carrier by screwing them into or onto the base plate under considerable preload.
The crosshead is a machine element for crank drive. It connects a translationally oscillating piston rod with translationally and rotationally moving connecting rods and is found primarily in large piston machines. The axis of the piston rod and the axis of the link pin intersect on the same plane. The crosshead has separate slide bearings and is rigidly connected to the piston rod and the piston. The connecting rod oscillates about the crosshead and is connected to the crankshaft.
The connecting rod forms a connection between the piston and the crankshaft, thus creating a force closure. It converts the linear up and down movement of the piston into a circular movement of the crankshaft and is therefore subject to tension, compression, bending and buckling.
The connecting rod is usually supported on the crank pin of the crankshaft by means of a plain bearing. The connecting rod bearing cap is fastened to the connecting rod foot with an expansion screw. In most cases, the connecting rod is cored or otherwise designed with an internal cast oil passage to provide lubrication for the piston pin.
In order to ensure that the connecting rod has both low weight and high strength, it is generally made of: micro-alloyed steels, sintered metals, premium aluminum, CFRP, and titanium (for high performance engines). Large series connecting rods are forged, cast or sintered. The strength to weight ratio of the forged connecting rod is superior to that of the sintered connecting rod, and the cost is lower. However, the mold is relatively expensive to manufacture.
Typically, the bearing pins of the crankshaft are disposed on the cylinder side portion of the crankcase, on a bearing half shell formed on a bearing web. Subsequently, a bearing cap or the like, preferably formed on an intermediate cap (so-called bottom plate), is screwed onto the bearing half-shell. A second part of the crankcase or crankcase cover is placed on the cylinder side part and screwed onto it, attached to it or the like, whereby the bearing shell is fixed.
It should be mentioned that a two-piece bearing shell is also possible. In the case of a two-part bearing shell, the half is positioned and fixed in the crankcase before the crankshaft is mounted, and the second part is fitted with the bearing cap after the crankshaft has been inserted.
A connecting rod connected to the crankshaft via a connecting rod bearing is typically hinged to the piston. The crankshaft may also have two crankshaft bearing pins (crankpins) and a connecting rod bearing pin, which is formed at a radial distance from its axis of rotation, on which the connecting rod is arranged. Normally, the connecting rod bearing pin is arranged between two crankshaft cheeks, which are connected to the crankshaft bearing pin and each have a flywheel mass.
A disadvantage of the bearings known from the prior art is the problem of friction, among other problems. In the case of bearings, the aim is generally to achieve hydrodynamic lubrication conditions, in which the components are separated by a load-bearing lubrication film and metal contact is largely avoided, but if an external force acting in the direction of the bearing shell acts on the bearing, an effective force area is generated between the components of the bearing (i.e. between the bearing shell and the bearing pin). This effective force area can be very small (due to the geometry of the bearing shell and the bearing pin), which results in very high pressures, so that there is a large friction effect on this small effective force area or contact area. In addition, the limited load carrying capacity of the bearings known in the prior art is a significant disadvantage. As long as the (hydrodynamic) bearing is loaded correctly, the bearing shell is protected by an oil/lubrication film, which does not cause mixed friction. In this regard, the bearing material (e.g., white alloy) may safely absorb the pressure transmitted through the oil/lubricant. However, as the load increases, the oil pressure/lubricant pressure generally increases and the bearing material eventually reaches its strength limit. At the same time (or earlier or later) there will be mixed friction (friction occurring between the two sliding surfaces when there is not enough lubrication) which can lead to further significant damage.
The friction effect causes severe wear and can lead to defects (among other things) in the entire device (e.g., motor, etc.), whereby expensive repairs must be made to replace the bearings. This not only results in unnecessary costs but of course also places a heavy burden on the environment.
Disclosure of Invention
It is therefore an object of the present invention to avoid the disadvantageous effects known from the prior art. In particular, it is an object of the invention to provide a low cost bearing which is simple in design and enables better and more wear resistant bearing operation. Thus, a bearing is provided which additionally exhibits an extended lifetime with respect to bearings known in the prior art.
According to the invention, a bearing is proposed, which comprises a bearing shell and a bearing pin having a rotation axis, wherein the bearing pin is arranged rotatable in the bearing shell about the rotation axis. The bearing pin of the bearing according to the invention comprises an asymmetrical weakening with respect to the axis of rotation, so that the bearing pin is deformable by the action of an external force acting in the direction of the bearing shell, so that the effective force area between the bearing shell and the bearing pin is increased by the deformation of the bearing pin. By increasing the effective force area, the oil/lubricant pressure in the bearing, in particular the maximum oil/lubricant pressure in the bearing, can be reduced, since the contact surface (in particular the effective force surface) between the bearing shell and the bearing pin is increased and thus the forces acting between the bearing shell and the bearing pin are better distributed.
Within the framework of the invention, the effective force area between the bearing shell and the bearing pin means the area: in this region, the external forces on the bearing act on the force or force transmitted from the bearing pin to the region of the bearing shell. The pressure, in particular the optimum lubricant pressure between the bearing pin and the bearing shell with respect to the specific application and/or the applied force, can be reduced in the following manner: there are no longer optimum lubrication conditions (with respect to the particular application and/or forces) at the specific part between the bearing and the bearing shell. In particular, the optimum lubricant pressure may also be a hydrodynamic lubricant pressure, whereby hydrodynamic lubrication conditions no longer exist due to the reduced pressure between the bearing pin and the bearing shell. The particular part at which the optimum lubrication conditions between the bearing and the bearing shell with respect to application and force no longer exist is the effective force area at which a large part of the external forces acting in the direction of the bearing shell are transmitted between the bearing pin and the bearing shell. In bearings according to the prior art, the lubricant layer is reduced (or completely disappears) so that no optimal, i.e. too thin (or no) lubricant film remains on the active force surfaces and between the bearing and the bearing shell, which results in a strong friction effect and corresponding wear. Thus, at the effective force area where especially hydrodynamic lubrication conditions are no longer present, only a minimal lubricant layer is present. The effective force area may also correspond to the area of direct contact between the bearing pin and the bearing shell, however, this typically only occurs in standard bearing operation under special load conditions. As already mentioned above, the bearing pin is deformed by the action of an external force acting in the direction of the bearing shell. Here, the bearing pin is deformed by the pressure on the effective force area between the bearing pin and the bearing shell, so that the effective force area between the bearing pin and the bearing shell is increased by the deformation process of the bearing pin. The increase in the effective force area caused by such a deformation according to the invention between the bearing pin and the bearing shell enables a greater (compared according to the invention without deformation) and thus an optimum lubricant thickness, in particular a minimum necessary lubricant thickness (in particular without hydrodynamic lubrication) with respect to the application and the force, so that the friction between the bearing pin and the bearing shell is reduced by the action of external forces acting in the direction of the bearing shell. However, in the prior art, the effective force area is very small, and therefore the corresponding friction due to insufficient lubricant layer thickness is also very high, which leads to severe wear to be avoided.
If an external force acting in the direction of the bearing shell acts on the bearing pin in the bearing according to the invention, an effective force area is created between the bearing pin and the bearing shell, as is the case with bearings known from the prior art. This may mean that the surface of the bearing shell and the surface of the bearing pin touch each other without a (sufficient) lubricating film, thereby separating the bearing shell and the bearing pin.
However, the bearing pin according to the invention comprises an asymmetrical weakening with respect to the axis of rotation. The asymmetrical weakening of the bearing pin is therefore not arranged symmetrically about the axis of rotation. If the example of a cylindrical bearing pin is used to explain the asymmetric weakened portion, the asymmetric weakened portion may have a circular cross-sectional area, whereby the center of the circular cross-sectional area of the asymmetric weakened portion does not lie on the rotation axis. However, in the case of a symmetrical weakened portion, the center of the circular cross-sectional area of the symmetrical weakened portion is located on the rotation axis.
Due to the asymmetrical weakening, the bearing pin can be deformed by the action of an external force acting in the direction of the bearing shell. Thus, the effective force area between the bearing shell and the bearing pin is increased, because the bearing pin is deformed in the direction of the bearing shell due to the pressure generated between the bearing shell and the bearing pin when a force is applied to the bearing pin. In particular, the bearing pin is asymmetrically deformed, because the weakened portion of the bearing pin is preferably concentrated on the side of the bearing pin where the pressure force acts directly on the surface of the pin due to the external force acting in the direction of the bearing shell. The specific load is reduced by increasing the contact surface between the bearing pin and the bearing shell, because the contact surface of the bearing pin is increased.
Therefore, the bearing pin is deformed according to the design of the asymmetric weakened portion. The asymmetrical weakening of the bearing pin is adapted accordingly to the direction and point of occurrence of the external force acting in the direction of the bearing shell. The type, size and form of the asymmetric weakening is thus dependent on the application and the forces acting thereon.
The advantage of the device according to the invention is, among other things, that by means of the increased force area, the pressure and thus also the friction is reduced. This reduces the wear on the bearing, which is why the bearing according to the invention is significantly more efficient and cost-effective than bearing arrangements and devices with bearings known from the prior art. By increasing the effective force area, the surface pressure is better distributed and, therefore, the same force is distributed over a larger area. This also ensures better lubrication, i.e. according to the invention, better optimal lubrication of the bearing, which extends the service life of the bearing. If the bearing is contaminated with contamination particles, damage may occur, particularly in the case where the lubrication film thickness is small, in the case where the contamination particles are larger than the lubrication film thickness. However, due to the better distribution of the surface pressure, a greater lubrication film thickness is made possible, thus also preventing possible damage to the bearing by dirt particles.
As mentioned above, the bearing pin according to the invention can be designed as a cylindrical bearing pin. In the case of a cylindrical bearing pin, the axis of rotation will preferably correspond to the axis of symmetry of the n-rotational symmetry of the cylindrical bearing pin (i.e. the cylinder is rotationally symmetric about the axis of rotation, regardless of the angle of rotation), wherein the asymmetric weakening will be asymmetric with respect to the axis of symmetry of the n-rotational symmetry of the cylindrical bearing pin. Thus, the cylindrical bearing pin may be configured as a hollow cylinder comprising a cavity that is not centrally disposed (relative to the circular base or cross-sectional area) in the center of the cylindrical bearing pin.
As mentioned above, depending on the design of the bearing, the axis of rotation of the bearing pin may correspond to the axis of symmetry of the bearing pin, such that the bearing pin is arranged to be rotatable in the bearing shell about the axis of symmetry with rotational symmetry.
However, the bearing pin need not be a symmetrical body. The bearing pin may be designed as an n-body with rounded corners and edges, among other possibilities. It is also possible that the bearing pin is configured as a sphere or an ellipse. The advantage of an oval shape is that the oval shape has been deformed under a slightly loaded condition, so that the effective force area between the bearing pin and the bearing shell is increased, among other advantages. The bearing pin may have been designed in advance in an oval shape in order to avoid the necessity of an excessively strong (excessively pronounced) asymmetrical weakening and to achieve a similar increasing effect of the effective force area between the bearing pin and the bearing shell, without the bearing pin being weakened in such a way that it is damaged by an excessively large force (for example it breaks). In this case, however, the bearing shell should preferably have a curvature adapted to an elliptical shape.
In an embodiment of the invention, the bearing pin may comprise an asymmetric weakened portion of symmetry with respect to a first cross-sectional axis orthogonally intersecting the axis of rotation of the bearing pin. If, for example, a cross-sectional area of the bearing pin (orthogonal to the axis of rotation) is considered, the first cross-sectional axis may extend over (or parallel to) this cross-sectional area of the bearing pin. Thus, an asymmetrically weakened portion is symmetrical if it is mirror point symmetrical with respect to the first cross-sectional axis. Depending on the applied force, the weakening can of course also be asymmetric with respect to the first cross-sectional axis, so that for example there are two different degrees of weakening on each side of the first cross-sectional axis.
The symmetrical asymmetric weakening is thus a weakening which is symmetrical with respect to the first section axis and asymmetrical with respect to the axis of rotation of the bearing pin.
In practice, the bearing pin of the bearing according to the invention may comprise a symmetrical weakening which is symmetrical with respect to a second section axis orthogonally crossing the symmetry axis of the bearing pin.
The bearing according to the invention may comprise a force element: in practice, the force element may be arranged on the bearing pin, so that a force can be applied to the bearing pin via the force element in a direction that can be predetermined. In this case, the force element can be designed as a force rod, a piston rod or a push rod. If the bearing according to the invention is mounted on an engine, such as a large diesel engine, for example, the force element may be a connecting rod of the engine (among other possibilities), whereby the bearing may then be arranged at the crosshead or crankshaft.
The asymmetrically weakened portion of the bearing pin can be designed as an asymmetrical depression, in particular a bore. In the case of an asymmetrical weakening, the bearing pin can thus be a hollow body (weakened along the axis of rotation over the entire length of the bearing pin body) or can comprise a weakening in the form of a cavity.
The bearing pin may be a cross pin or a crankpin depending on the bearing application.
In an embodiment of the invention, the asymmetrical weakening of the bearing pin can be designed in such a way that the material type and/or the material density and/or the material structure varies. Thus, at the point where there is an asymmetric weakened portion of the bearing pin, there will be a modifying material. To this end, the material may be softer at this point, or have a lower density, or the material may differ from the surrounding material in some other way. This is particularly recommended if the bearing pin is designed as a composite material or alloy. At the asymmetrical weakening, the bearing pin will accordingly have a different material composition. If the bearing pin is made of steel, the point of the asymmetric weakened portion of the bearing pin may thus comprise less carbon, nickel or similar additive or more another additive weakening the material at the corresponding point.
In practice, the bearing pin may also include a plurality of asymmetric weakenings relative to the axis of rotation, so that the bearing pin is sufficiently deformable even under complex forces. For example, there may be two (or more) equal degrees of asymmetric weakening, and the asymmetric weakening may also have different degrees or have different geometries. One or more of the asymmetric weakenings may extend along the entire length of the body along the rotation axis or as cavities along only a section of the length of the bearing pin body along the rotation axis.
In general, forces, in particular bearing forces up to approximately 10,000kN, may act in the bearing of a large diesel engine according to the invention. In this case, the optimum lubricant pressure, in particular the hydrodynamic pressure, may be up to 600 bar. In this case, the minimum optimum lubricating film thickness is 5 to 30 micrometers, in particular 5 to 25 micrometers, especially 15 to 25 micrometers.
Of course, the force and oil film pressure depend on each other, whereby the oil film thickness also depends on the size of the components and the relative speed of the moving components.
Depending on the complexity of the forces, it may be necessary to form complex weakening structures in the bearing pin according to the invention. For this purpose, the bearing pin can be designed in two parts, wherein the bearing pin comprises a bearing pin ring and a bearing pin core. In this regard, the bearing pin ring may be a hollow body and the bearing pin core may be disposed in the bearing pin ring with a bonded (e.g., milled) structure. This brings the major advantage that complex structures can be easily incorporated into the bearing pin core, whereby the bearing pin core can then simply be inserted, pressed or the like into the bearing pin ring.
The bearing according to the invention can be designed as a bearing which is particularly preferred for large diesel engines, in particular as a bearing for large diesel engines of the crosshead type, whereby the bearing pin is designed accordingly.
According to the invention, a bearing pin for a bearing according to the invention is also proposed, wherein the bearing pin comprises an asymmetric weakening, such that the bearing pin can be deformed under the action of a force according to a predetermined scheme (i.e. according to the design of the asymmetric weakening and the own force), the bearing pin deforming accordingly.
According to the invention, a crosshead with a bearing according to the invention is also proposed, the bearing comprising a bearing shell and a bearing pin with a rotation axis, wherein the bearing pin is arranged rotatable in the bearing shell around the rotation axis. The bearing pin of the bearing according to the invention comprises an asymmetric weakening with respect to the axis of rotation, whereby the bearing pin is deformable by the action of an external force acting in the direction of the bearing shell, so that when a force is applied to the bearing pin, the effective force area between the bearing shell and the bearing pin is increased by the deformation of the bearing pin. The crosshead may in particular be designed for large engines, in particular for two-stroke large diesel engines.
According to the invention, a large diesel engine, in particular a crosshead large diesel engine, is also proposed, wherein the large diesel engine comprises a bearing according to the invention, which bearing comprises a bearing shell and a bearing pin having a rotation axis, wherein the bearing pin is arranged rotatable in the bearing shell about the rotation axis. The bearing pin of the bearing according to the invention comprises an asymmetric weakening with respect to the axis of rotation, whereby the bearing pin is deformable by the action of an external force acting in the direction of the bearing shell, so that when a force is applied to the bearing pin, the effective force area between the bearing shell and the bearing pin is increased by the deformation of the bearing pin.
In this context, a preferred important embodiment will be explained. In a preferred embodiment, the bearing according to the invention in a large diesel engine of the crosshead type is arranged in a crosshead, wherein the bearing pin is a cylindrical bearing pin with an asymmetric weakening with respect to the axis of rotation of the bearing pin, which asymmetric weakening, however, is symmetric with respect to the first cross-sectional axis, thereby being a symmetric asymmetric weakening.
Drawings
Hereinafter, the present invention and the related art will be described in more detail based on examples with reference to the accompanying drawings.
Figure 1 shows a schematic representation of the prior art.
Fig. 2 shows a schematic representation of a cross-section of a bearing according to the invention in a different embodiment.
Figure 3 shows a schematic representation of the crosshead.
FIG. 4 shows a schematic representation of a diesel engine in cross-section;
fig. 5 shows a schematic representation of a large diesel engine.
Detailed Description
Figure 1 shows a schematic representation of the prior art. A bearing is shown which is already known from the prior art. The bearing comprises a bearing shell 2 'and a bearing pin 1', the bearing pin 1 'being arranged rotatably in the bearing shell 2'. The intersection of the two section lines S' will be the axis of rotation of the bearing pin. In the prior art, there is a symmetrical weakened portion 3' arranged exactly in the center of the bearing pin and symmetrical about the axis of rotation. Here, the symmetrical weakened portion 3' is a recess, which is a hollow cylinder. In the prior art, a force F 'acts on the bearing pin 1', whereby this force is transmitted from the bearing pin 1 'to the bearing shell 2'. However, the effective force area between the bearing pin 1' and the bearing shell 2' is very small, because the bearing pin 1' known from the prior art is not deformed in such a way that the effective force area between the bearing pin 1' and the bearing shell 2' increases (which would reduce the pressure between the bearing pin 1' and the bearing shell 2 '). However, the recesses 3' known from the prior art are only used for reducing the mass of the pin or for returning oil.
Fig. 2 shows a schematic representation of a cross-section of a bearing according to the invention in a different embodiment. Here, all embodiments a-J comprise a bearing
Figure 3 shows a schematic representation of the crosshead. Here, the
Fig. 4 shows a schematic representation of a
Fig. 5 shows a schematic view of a
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