KR20000006156A - Lageranordnung - Google Patents

Abstract

PURPOSE: A bearing structure is provided to include the load periodically changed according to the thickness and the direction and generated from outside. CONSTITUTION: A bearing comprises:a bearing shell(3) to hold a bearing journal(4); a gap(5) becoming narrower in the wedge form with the driving face of the bearing journal; lubricant inlets(11,12,13) installed on the wall of the bearing shell and to supply the lubricant; and a rotation member holding the load generated from outside.

Description

Bearing structure {LAGERANORDNUNG}

FIELD OF THE INVENTION The present invention relates to a bearing structure for a rotating part which is present in a crank shaft bearing for a large diesel motor and which includes a load that occurs periodically and changes periodically in thickness and direction. a bearing shell for accommodating a journal, the running surface of the bearing shell being bounded by a gap which narrows in a wedge shape to the carrying area together with the running surface of the bearing journal, the position of the gap being It is periodically changed by the load, where the angular velocity of the gap corresponds to some extent to the angular velocity of the external load, and lubricating oil can be supplied to the lubricating oil inlet on the side of the bearing shell.

In arrangements with fixed gaps in a fixed direction of the load vector, much lubricant is carried into the gap from the rotating bearing journals such that a load-capable lubricant film is maintained. However, in crankshaft bearings, a state in which the speed of the lubricating oil passing through the gap typically decreases to zero " 0 " in a defined peripheral region occurs. Thus, the angular velocity of the bearing journal is about twice as high as the angular velocity of the external load. In this case, no new lubricant is replenished. As a result, the bearing journal approaches the bearing shell, at which time the remaining lubricant is squeezed out laterally. The reason for this is that it is important here that it is not a new lubricant but still a residual lubricant, and it is also desirable that the above-mentioned lubricant is heated to such a low viscosity that it is squeezed to the side. This allows the bearing metal to be locally heated, resulting in rapid wear.

In order to prevent such wear from occurring, a lubricating oil groove is formed in the dangerous surrounding area through the entire bearing width in the axial direction and connected to the lubricating oil supply. Although the lubricating oil groove is used for the supply of fresh lubricating oil, the running surface of the bearing shell is blocked at full width, resulting in huge losses on the bearing surface. This results in a relatively large bearing width in order to generate an acceptable compression, i.e. an acceptable hydrodynamic pressure of the lubricant membrane. However, it becomes a relatively bulky structure. In many cases, however, a compact structure is required. Therefore it can be used especially for the latest large diesel motors.

The object of the present invention is to improve the bearing structure by a simple and inexpensive method according to the first mentioned method, which makes the structure of the bearing not only a compact structure but also a structure having a long service life.

The solution of the present invention is as follows. The angular velocity of the gap in the zone of the danger zone corresponds to about half of the angular velocity of the bearing journal, at least one lubricant inlet is formed, the cross section of the opening not formed as a groove is smaller than the cross section of the groove, the width of the groove This corresponds to the inner width of the boundary cross section.

This solution solves the problems mentioned previously. A new lubricant can be sufficiently supplied to the above zone via a lubricant inlet arranged in the danger zone. With a moving bearing journal separated from the previously mentioned lubricating oil inlet, the hot lubricant is squeezed reliably so that enough new lubricant is supplied to realize a load-bearing lubricant film. Each lubricant inlet formed in the zone of the danger zone affects the hydrostatic pressure that occurs when the bearing journal approaches. When the boundary cross section of the lubricating oil inlet is relatively small, and the running surface is not completely blocked, the injection amount is relatively small. Thus, the hydrodynamic pressure generated by itself remains in an acceptable frame. The solution according to the invention makes it possible to compromise between hydraulic pressure and oiling.

More important methods are preferably formed and improved for the purposes described in the claims of the present invention. In addition, for each purpose, each lubricant inlet formed in the zone of the danger zone can be simply formed as a bore with a relatively small diameter. This not only makes it simple to manufacture, but also makes the loss of the running surface particularly small.

Solution to the purpose is as follows. A plurality of lubricating oil inlets are formed in the zone of the danger zone, and the lubricating oil can be supplied via at least one supply recess located in the rear region of the bearing shell. The plurality of lubricant inlets are divided by a preferred method such that a smooth distribution of the new lubricant oil supplied can be achieved. In order to facilitate the distribution as described above, a small distribution groove may be formed starting from the inner bore edge. In many cases, however, this measure can be omitted. Individual feed recesses may also be arranged at each lubricating oil inlet to improve the stability of the bearing shell.

In crankshaft bearings for large diesel motors, the lubricating oil inlet located in the zone of the hazardous zone is suitably 30 ° to 60 ° from the end of the lower half of the bearing shell, which is forward in the direction of rotation of the bearing journal, as desired. Placed within each range away. This ensures that the above mentioned lubricating oil inlet is present in each of these ranges, each of which is located next to the range where the pressure on the highest bearing is expected, which is in compliance with the permissible height of the hydrodynamic pressure generated by itself. It will have a desirable effect on.

It is also possible to present a preferred solution by having at least one lubricating oil tank which can be adjacent to the side of the bearing shell in the area of the danger zone. When the bearing journal is actuated, an absorbing action takes place in the open gap, and this absorbing action acts for the absorption of fresh lubricant oil from the above-mentioned lubricant tank, thereby promoting the lubricant supply in the danger zone.

Lubricating oil inlets located in front of and behind the hazard zone can be formed for the purpose, the lubricant inlet forming a larger boundary cross section than the lubricant inlet located in the region of the hazard zone. The region adjacent to the danger zone also benefits from the lubricant inlets located at the front and rear, so that the lubricant inlets arranged in the adjacent region can be limited to a relatively narrow angle range.

The more important method will be advantageously formed and improved for the purpose to be described in the appended claims and will be more clearly understood by reference to the description of the embodiments according to the accompanying drawings.

1 is a view of a crankshaft bearing of a large diesel motor.

FIG. 2 is a diagram of the load and track of the bearing journal of the crankshaft bearing according to FIG. 1. FIG.

3 is a cross-sectional view of the lower half of the bearing shell of the crankshaft bearing according to FIG. 1.

For example, the principle design and operation of large diesel motors, such as two-stroke large diesel motors used in marine motors, are well known and will not be discussed further. The crank shaft of the motor consists of a plurality of linearly aligned bearing journals mounted on the main bearing in a manner based on FIG. 1. The main bearing shown in FIG. 1 consists of a bearing housing consisting of two parts: a lower member 1 inserted into a machine frame and a detachable upper member 2. The two parts of the bearing housing have recesses that complement each other as bores, with half of the bearing shells 3 disposed in each of the two parts. The bearing shells have bearing journals 4 arranged therein. The upper member 2 is separated with the upper half of the bearing shell 3 for insertion of the bearing journal 4.

The outer diameter of the bearing journal 4 and the inner diameter of the bearing shell 3 are adjusted to each other so that the performance of the operation can be successful. This smooth operation is carried out by allowing the bearing journal 4 to move longitudinally with respect to the bearing shell 3. Under the action of the load, the bearing journal 4 can be adjacent to the support area and pushed to the extent that a gap is formed in which the end is wedge-shaped. The gap is relatively small in actual use, and is largely shown to be easily distinguishable from FIG. 1.

In the motor according to the invention, the load transmitted from the bearing journal 4 to the bearing housing is changed periodically and also according to size and direction by known methods. The curve 6 shown in FIG. 2 shows the periodic change of the load. The periodic push of the bearing journal 4, which is driven by a load that varies periodically in size and direction, is shown by the curve 7 in FIG. The movement of the last vector and the pushing movement of the bearing journal 4, represented by the arrow 8 in FIG. 1, occur with the change of position of the gap 5. It is to move at an angular velocity to some extent corresponding to the angular velocity of the load vector (8). For practical verification the values are set equal.

Lubricating oil is injected into the running surfaces of the bearing shell 3 and the bearing journal 4. To this end, the bearing housings 1, 2 and the bearing shell 3 form a channel which is connected to the supply conduit 9 shown in FIG. 1, in which the bearing shell 3 and the bearing journal 4 are connected. Lubricating oil inlet ends are placed in the interspace between the). Correspondingly, the lower half shell 3a shown in FIG. 3 forms a channel 10 formed by a rear groove and which can receive lubricant, and the longitudinally formed bores 11, 12 of the channel. Lube oil can be supplied to the space between the bearing shell 3 and the bearing journal 4 via the bores.

The bores 11 are respectively formed in the end regions which are the surfaces of the partial joints on both sides of the half shell 3a. These bores 11 adjacent to the junction are arranged and drilled inward into groove-shaped pockets 13 which enclose an inwardly opened periphery, which form a lubricant inlet having a relatively large boundary cross section. The pocket 13, whose depth continues to decrease so that a wedge-shaped cross section is created by the distance from the joint, continues in the groove form to the upper member of the bearing shell 3, which is not shown in FIG. 3.

The lubricating oil supplied to the pocket 13 passes through the rotating bearing journal 4 and is supplied to the gap 5. Assuming that the angular velocities of the gap 5 and the load are the same as mentioned above, the following equation holds for the perfusion rate U through the gap.

U = (ω _b + ω _j ) / 2-ω _l

Where ω _b is the angular velocity of the bearing shell (3).

ω _j is the angular velocity of the bearing journal (4).

ω _l is the angular velocity of the load vector (8).

When viewed from the outside, that is, ω _b = 0 in the coordinate system to which the bearing shell 3 which does not change is applied. U = O where the angular velocity of the bearing journal 4 is twice as high as the angular velocity of the load, and the angular velocity of the load corresponds to the angular velocity of the gap 5 mentioned previously.

In the coordinate system to which the gap 5 is applied, the same applies to the gap 5 as described above. At this time, ω _l = 0 and ω _b = -ω _j , whereby the angular velocity U is likewise zero.

Conditions in this manner exist in the hazard band, indicated by Z in FIG. 2. As shown in FIG. 2 without particular improvement, the running surfaces of the bearing journal 4 and the bearing shell 3 are clearly approached. The reason is that the old lubricant is not squeezed out to the side because no new lubricant is supplied, and the old lubricant is heated, thereby making the viscosity relatively low and the thickness of the lubricant film very thin.

In order to avoid such high temperatures and wear in the zone Z, fresh lubricating oil must be supplied to the zone Z. The above-mentioned bore 12 is provided in the upper region to form a corresponding lubricant inlet. The lubricating oil inlet is formed in an angular range between 30 ° and 60 ° with respect to the tip of the half shell 3a shown in the forward direction of the bearing journal and on the left side in FIG. 3. Each of these ranges belongs to the danger zone Z for the crankshaft bearings of the methods mentioned herein, and appears after the region where the highest bearing pressure occurs. The function of the bore 12 is described in detail below.

If the bearing journal 4 is placed away from the area of the bearing shell 3 comprising the bore 12, too much fresh lubricant is used and supplied to the extent that the heated lubricant is removed and the bearing journal 4 is Proximally, the bore 12 is brought into contact with the section of the curve 7 arranged in the zone Z and not in the zone Z of the movement cycle of the bearing journal 4. A lubricant film with sufficient load capacity can be formed.

Through the bore 12 the surface under load of the half shell 3a is reduced to some extent, thereby inevitably increasing the hydrostatic pressure. However, the diameter of the bore 12 and its boundary cross section are relatively small so that the loss in the surface under load is less than the width of the bearing, and in each case is equal in axial direction in the grooves that entirely pass through the bearing width. It is smaller than the width. Therefore, the hydrostatic pressure generated by itself remains in the acceptable range. In this connection the region comprising the bore 12 preferably appears after the region in which high load is expected.

In the embodiment of the present invention the two bores 12 are within the aforementioned 30 ° to 60 ° angle ranges. In addition, few or multiple bores 12 may be formed. In the present invention, two bores 12 are arranged obliquely to one another in the circumferential direction and the axial direction in order to distribute the lubricant as appropriate as possible in the entire bearing area. In order to better distribute this lubricating oil, additionally a small distributing groove starting from the inner edge of the bore 12 can be formed. However, in most cases the dispensing groove is not necessary and does not appear in this embodiment.

The bores 12 are connected to each other with the bores 11 on the face of adjacent junctions by means of a rear feed channel 10. The channel 10 therefore requires a relatively large cross section. If the stability of the half shell 3a is impaired, a small feed channel suitable for each bore 12 or bore 11 may be arranged.

The bearing journal 4 can perform a certain suction action based on its longitudinal movement. Therefore, according to the purpose, the lubricating oil tank 14 adjacent to the axial direction of the bearing shell 3 in the zone Z and shown by the dotted line in FIG. 1 is formed. If the gap 5 is open in the zone Z, i.e. when the bearing journal 4 is moved upwards to the right as in the embodiment of the present invention, additional fresh lubricant is sucked in from the lubricant tank 14 Can be done.

The lube oil inlet formed as the bore 12 and disposed at the front and rear of the lube oil inlet disposed in the zone Z, and formed in the pocket 12 respectively disposed through the bore 11 is the zone Z. Ensure a reliable supply of lubricant to the outside. According to the relative movement in the present invention, the supply of lubricating oil reliably occurs between the bearing journal 4 and the gap 5. Thereby the edge region of the zone Z is obtained so that each range can be relatively narrowed by the bore 12.

The bearing structure according to the present invention is improved by a simple and inexpensive method, resulting in not only a compact structure but also a structure having a long service life.

Claims (11)

A bearing shell (3) for receiving an installed bearing journal (4), the running surface of the bearing shell being narrowed wedge-shaped to the transport area together with the running surface of the bearing journal (4); Bounded by a gap 5, the position of the gap being periodically changed by the load, where the angular velocity of the gap 5 is somewhat similar to the angular velocity of the external load and the lubricant inlet on the side of the bearing shell ( Rotating parts comprising loads that vary periodically and vary externally in thickness and direction, especially for crank shaft bearings for large diesel motors, to which lubricant can be supplied through In the bearing structure for The angular velocity of the gap 5 in the region of the danger zone Z corresponds to half of the angular velocity of the bearing journal 4 and has at least one lubricant inlet 12 and is not formed like a groove. A boundary cross section of the lubricant inlet is smaller than a cross section of a groove, the cross section of the groove corresponding to an inner width of the boundary cross section. The bearing structure according to claim 1, wherein each of the lubricating oil inlets (12) formed in the region of the zone (Z) is formed of a hole having a relatively small diameter. 3. The bearing structure of claim 2, wherein a small distributing groove is formed starting from the edge of the inner hole. 4. The at least one feed indentation (12) according to any one of claims 1 to 3, wherein a plurality of lubricant inlets (12) are formed in the region of the danger zone and are arranged in the rear region of the bearing shell (3). Supply recess: Bearing structure for supplying lubricant through 10). 5. Bearing structure according to claim 4, having a separate feed recess at each lubricant inlet (12). 6. The lubricating oil inlet 12 according to any one of claims 1 to 5, wherein each of the lubricating oil inlets 12 disposed in the danger zone Z is located within a predetermined angle range, the angle range being the range in which the highest pressure occurs. Bearing structure located next. 7. The bearing journal according to any one of claims 1 to 6, wherein each of the lubricating oil inlets 12 disposed in the danger zone Z in the crankshaft bearing for a large diesel motor is the bearing journal of the lower bearing shell half 3a. Bearing structure located within an angular range of 30 ° to 60 ° from the front end in the rotational direction of (4). 8. Bearing structure according to any one of the preceding claims, wherein at least one lubricant tank (14) is formed in the region of the danger zone (Z) that is axially adjacent to the bearing shell (3). 9. The lubricant inlets 11, 13 according to any one of the preceding claims, wherein a lubricant inlet (11, 13) is formed which is located in front of or behind the lubricant inlet (12) located in the danger zone (Z). A bearing structure in which a boundary cross section larger than the lubricating oil inlet 12 disposed in the zone Z is formed. 10. The bearing structure according to claim 9, wherein the lubricating oil inlets (11, 13) formed outside the danger zone (Z) each have a groove-shaped pocket having a boundary cross section. The oil inlet (11, 13) formed in the crankshaft bearing for a large diesel motor, not in the danger zone (Z), is located at the end of the bearing shell lower half (3a), according to claim 9 or 10. Is a bearing structure representing an area of partially joined sides.