JPH09203412A - Sliding bearing for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent breakage of a bearing metal by arranging seal devices for preventing oil leakage on the bearing width direction both ends of upper and lower bearing metals, providing with a lubricating oil oiling hole on one side of the bearing metal, providing with oil discharge holes on the other side thereof, and arranging a throttle device for regulating the flow rate of discharge lubricating oil on the drain oil hole. SOLUTION: An oiling hole 51 is arranged on the central part of an upper bearing metal 2a having small load action so as to supply lubricating oil to a bearing 50 bearing surface which consists of the upper bearing metal 2a and a lower bearing metal 2b. A semicircular upper seal device 52a and a lower seal device 52b are installed on both end parts of the bearing metals 2a, 2b. The seal devices 52a, 52b are arranged to make fiber 52-1 such as resin, carbon, and aluminum alloy tightly in a circumferential and an axial directions in the device main bodies. Oil discharge holes 53 are arranged on the both end sides of the lower bearing metal 2b to discharge old oil having a high temperature. A throttle device 54 is installed on the outlet side of the oil discharge hole 53 to prevent generation of oil shortage on the bearing surface, and a drain oil rate is regulated. It is thus possible to level high oil film pressure generated by two dimensional uneven contact of a crank shaft in a normal condition, and also it is possible to prevent breakage of the bearing metal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plain bearing for an engine for supporting an output shaft of an engine, such as a crankshaft of a large-sized marine diesel engine, in which a large load fluctuation occurs.

[0002]

2. Description of the Related Art As an example of a conventional sliding bearing for an engine of this type, a main bearing used for a crankshaft bearing of a diesel engine is shown in FIGS. FIG.
5 is a cross-sectional view of a portion where a main bearing of a diesel engine is provided, FIG. 5 is a detailed view of a portion A of FIG. 4, and FIG. 6 is a cross-sectional view taken along the line AA of FIG.

In the figure, a crankshaft 1 for outputting a driving force generated in a diesel engine to the outside is supported by a plurality of main bearings 15 provided in the longitudinal direction thereof. This main bearing 1
Reference numeral 5 denotes a bearing material 2 such as white metal or kelmet on the inner peripheral surface of the backing metal 2-1 formed of a ferrous material in a semi-cylindrical shape.
-2 lined half-cylindrical upper bearing metal 2a
And a lower bearing metal 2b having a half-cylindrical shape, the outer peripheral surface of the lower bearing metal 2b is fitted to and supported by a cylindrical inner surface provided on the saddle 3, and a bearing crown is provided on the outer peripheral surface of the upper bearing metal 2a. 4 is fitted with the cylindrical mounting surface provided on the bottom portion thereof, and the mating surfaces 2a-1 and 2b-1 provided on the upper bearing metal 2a and the lower bearing metal 2b, respectively, are arranged so as to abut each other. Then, the bearing crown 4 is formed by fastening it to the mounting surface 3-1 of the bearing saddle 3 with bolts 5.

Further, mating surfaces 2a-1 and 2a are provided on the inner peripheral surfaces of the upper bearing metal 2a and the lower bearing metal 2b, respectively.
Since the lubricating oil is supplied from both side positions where b-1 is provided, the circumferential direction oil supply groove 2 is formed at an angle of β in the circumferential direction at the same position.
a-2 and 2b-2 are provided respectively. further,
The mating surfaces 2a of the upper bearing metal 2a and the lower bearing metal 2b are arranged so that the lubricating oil does not run short in the bearing width direction.
-1, 2b-1 is provided with an axial direction oil supply groove 2-3 in the axial direction, and the cross-shaped oil supply groove shape is integrated with the circumferential direction oil supply grooves 2a-2, 2b-2 to form an upper bearing metal. 2a and the lower bearing metal 2b, and formed on both sides.

The lubricating oil that slides on the inner peripheral surfaces of the upper and lower bearing metals 2a and 2b is supplied from the oil supply hole 14 formed in the bearing crown 4 to the inner peripheral surface of the bearing crown 4 and the outer peripheral surface of the upper bearing metal 2a. Between the upper bearing metal 2a and the circumferential oil supply groove 2a-
2 is supplied to the inside of the main bearing 15 from an oil supply hole 2a-3 provided in the inside of the main bearing 15, passes through the circumferential oil supply grooves 2a-2, 2b-2, and the axial oil supply groove 2-3, and then the upper and lower bearing metals. 2a, 2
It is supplied to the inner peripheral surface of b. Although not shown in the figure, the oil supply hole 14 is connected to an oil supply pipe connected to an oil supply pump. The lubricating oil supplied to the inner peripheral surfaces of the upper and lower bearing metals 2a and 2b is subjected to an oil film pressure generated while passing through the inner surfaces of the upper and lower bearings 2a and 2b by a hydrodynamic action accompanying the rotation of the crankshaft 1. As a result, they are discharged from both ends of the main bearing 15 and fall into the oil pan 16 provided at the bottom of the diesel engine.

The bearing saddle 3 is integrated with the tie bolt support columns 6 on both sides and the reinforcing plate 7 on the lower side, and is a basic element for receiving the load applied to the main bearing 15. Also, both lower parts of the base plate 8 are attached to the mounting legs 8-
Both are attached to the mounting part via 1. Further, the frame 9 and the cylinder block 10 are firmly connected to the upper portion of the base plate 8 by tightening tie bolts 6-1 provided through the tie bolt support columns 6.

The crankshaft 1 thus constructed and supported by the main bearing 15 moves up and down in the cylinder 10 and the explosive force generated in the cylinder block 10.
Inertia force of the piston not shown in the figure is added. Therefore, the main bearing 15 supporting the crankshaft 1 is simultaneously subjected to the above-mentioned load and the partial contact due to the elastic deformation of the crankshaft due to the load. As a result, a high oil film pressure is locally generated on the inner surface of the bearing metal 2a or 2b of the main bearing 15.

This high oil film pressure is generated at a specific position on the bearing surface, but the load and the uneven contact change during one rotation of the crankshaft 1, so that the oil film pressure at the specific position is also during one rotation. Repeats large fluctuations. As a result, the stress variation range proportional to the oil film pressure variation is within the bearing material 2-
After the fatigue strength of No. 2 is exceeded, the bearing material 2-2 lined on the inner peripheral surface of the back metal 2-1 may show damage such as cracking or peeling after a predetermined time.

By the way, the condition for locally increasing the oil film pressure is a case where a large two-dimensional piece contact occurs. Here, the two-dimensional one-side contact is a state in which the inclination of the crankshaft 1 about the horizontal axis and the inclination of the crankshaft 1 about the vertical axis act simultaneously, and in particular, the two of the upper bearing metal 2a and the lower bearing metal 2b. When the two-dimensional one-sided contact is received in the vicinity of the mating surfaces 2a-1 and 2b-1 while the shaft center is moving (the shaft center is displaced to a position that balances the fluctuating load), the oil film pressure is set by the axial oil supply groove 2-3. The generation is blocked, the supporting force of the crankshaft 1 is reduced in the axial oil supply groove 2-3 portion, and the load applied to the peripheral portion of the axial oil supply groove 2-3 is increased accordingly.
100 near the bearing end near the mating surfaces 2a-1 and 2b-1.
A high oil film pressure exceeding MPa may occur.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the conventional sliding bearings for engines, the present invention has hitherto been provided in the vicinity of the mating surfaces of the upper bearing metal and the lower bearing metal.
By eliminating the axial lubrication groove that was provided in the axial direction, the high oil film pressure on the bearing near the axial lubrication groove, which was caused by this axial lubrication groove, was prevented from occurring, and it was dispersed to the surroundings and leveled. It is an object of the present invention to provide a sliding bearing for an engine, which can reduce the oil film pressure to prevent cracking or damage of the bearing metal and improve reliability.

[0011]

Therefore, the sliding bearing for an engine of the present invention has the following means.

(1) A semi-cylindrical upper bearing metal in which a bearing material is lined on the inner peripheral surface of a semi-cylindrical backing metal, and the semi-divided surface is used as a mating surface to form a generally cylindrical bearing. Sealing devices were provided at both ends of the lower bearing metal in the bearing width direction so as to prevent the lubricating oil from leaking in the axial direction from the inside of the bearing and to allow the lubricating oil to fill the inside of the bearing.

(2) At least one of the upper bearing metal and the lower bearing metal is provided with an oil supply hole for introducing lubricating oil into a cylindrical bearing formed by combining the upper bearing metal and the lower bearing metal. It should be noted that one or a plurality of oil supply holes may be provided, or either one or both of the upper bearing metal and the lower bearing metal may be provided. It is preferable to set the refueling position so that no extreme difference occurs.

(3) An oil drain hole is formed in at least one of the upper bearing metal and the lower bearing metal to discharge the lubricating oil introduced into the bearing and deteriorated due to high temperature to the outside of the bearing. did. One or a plurality of oil drain holes may be provided, or either one or both of the upper bearing metal and the lower bearing metal may be provided, but the position where the oil supply hole is provided It is preferable that the lubricant oil supplied from the oil supply hole is prevented from flowing out from the bearing by being provided at a position away from the oil supply hole.

(4) A throttling device for adjusting the flow rate of the lubricating oil discharged from the oil discharging hole to the outside so as to keep the lubricating oil filled inside the bearing is provided in the oil discharging hole.

In the sliding bearing for the engine of the present invention, the oil supply groove conventionally provided at the mating surface position by the means of the above-mentioned (1) to (4) has a small load action including one-sided bearing. It is possible to make the oil supply hole moved on the metal, which allows the bearing lubrication surface of the same part to continue even if two-dimensional one-side contact occurs while the crankshaft axis passes near the bearing metal mating surface. Therefore, an extreme difference in oil film pressure does not occur, a local high oil film pressure is not generated, and the oil film pressure can be dispersed to the surroundings and leveled.

The lubricating oil supplied into the bearing through the oil supply hole provided in the bearing metal of at least one of the upper bearing metal and the lower bearing metal is supplied by the sealing device provided at both ends of the upper bearing metal and the lower bearing metal. As a result of preventing oil leakage in the side direction, the bearing is filled with lubricating oil, and sufficient oil required for lubrication is secured even in the bearing metal portion farthest from the oil supply hole. Therefore, even if the axial oil supply groove provided on the mating surface is moved, the bearing performance does not deteriorate due to insufficient lubricating oil.

Further, the oil drain holes provided in at least one of the upper bearing metal and the lower bearing metal can be discharged outside so that the temperature rises and deteriorated oil does not stay.
The bearing can always be filled with fresh lubricating oil, and good bearing performance is secured. Furthermore, by installing a throttle device in the oil drain hole, the amount of lubricating oil discharged from the oil drain hole to the outside does not become excessive, and the filled state of the lubricating oil in the bearing is maintained. The amount of lubricating oil in the bearing can be adjusted.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a sliding bearing for an engine of the present invention will be described below with reference to the drawings. FIG.
1 is a partial cross-sectional view showing a first embodiment of a sliding bearing for an engine of the present invention, FIG. 2 is a perspective view of a sealing device shown in FIG. 1, and FIG. 3 is a perspective view of a lower bearing metal shown in FIG. . In these drawings, the same reference numerals as those shown in FIGS. 4 to 6 are the same or similar members, and the description thereof will be omitted.

In the present embodiment, conventionally, the mating surfaces 2 of the upper bearing metal 2a and the lower bearing metal 2b have been conventionally used.
Along the a-1 and 2b-1, the axial oil supply groove 2-3 provided in the axial direction is eliminated, and an oil supply hole 51 is provided at the center position of the upper bearing metal 2a having a small load action to provide necessary lubrication. The oil is supplied to the bearing surface of the bearing 50 formed by the upper bearing metal 2a and the lower bearing metal 2b.

Further, the upper bearing metal 2a and the lower bearing metal 2
The upper sealing device 52a and the lower sealing device 52b shown in FIG. 2, which are semicircular, are attached to both ends of b using studs 52-1. Therefore, as shown in FIG. 3, bolt holes 52-2 on the bearing metal side are formed on both end surfaces of the upper bearing metal 2a and the lower bearing metal 2b, respectively, and the sealing device 5
Bolts 52-3 on the sealing device side as shown in FIG. 2 are bored in 2a and 52b.

Upper sealing device 52a and lower sealing device 5
2b is a device in which fibers 52-1 made of resin, carbon, aluminum alloy, copper alloy, or the like are densely arranged in the circumferential direction and the axial direction and attached to the main body of the device, and lubricating oil is provided through a gap between the fibers 52-1. To prevent leaks. Also,
With respect to the movement of the crankshaft 1, the tip of the fiber 52-1 and the outer peripheral surface of the crank coaxial 1 are separated from each other, and the length of the fiber 52-1 is increased so that excessive oil leakage does not occur in the axial direction. The tip of the fiber 52-1 is made to follow the movement of the outer peripheral surface of the crankshaft 1 by giving a bending amount to the expansion and contraction of the bending amount.

In this embodiment, brush seals using fibers 52-1 are used for the upper and lower sealing devices 52a and 52b, but they are flexible so that they can follow the movement of the crankshaft 1. Even if a special oil seal provided is used as a sealing device, the same effect can be obtained.

Further, in order to promote the replacement of the lubricating oil introduced into the bearing 50 through the oil supply hole 51, the lower bearing metal 2
The oil drain holes 53 are provided on both end sides of b so that the old oil that has worked at the bearing surface and has a high temperature is discharged to the outside. Further, in order to prevent the oil discharged from the discharge hole 53 from being increased due to the replacement of the lubricating oil, and the oil shortage on the bearing surface does not occur, the throttle device 54 is attached to the outlet side of the oil discharge hole 12 by screwing. , The amount of oil drain is adjusted.

As described above, in the present embodiment,
The conventional axial oil supply groove 2-3 is removed from the mating surface position, and instead of the axial oil supply groove 2-3, an oil supply hole 51 for supplying oil to the bearing surface is provided in the center of the upper bearing metal 2a having the smallest load action. By relocating to the position, the problem of local high oil film pressure generation, which had a problem in the conventional sliding bearing for engines, was solved. Further, the problem that the lubricating oil does not reach the necessary position on the bearing surface, which may occur due to the elimination of the axial oil supply groove 2-3, is to prevent oil leakage at both ends of the upper bearing metal 2a and the lower bearing metal 2b. To prevent this, upper and lower sealing devices 52a and 52b are attached so as to be overcome by means of filling the inner surface of the bearing with lubricating oil.

By providing the upper and lower seal devices 52a and 52b, drainage holes 53 are provided on both sides of the lower bearing metal 2b so that deteriorated lubricating oil does not stay in the bearing, and the amount of drained oil is reduced. The throttling device 54 is provided with the drainage hole 52 for adjusting and adjusting the amount of lubricating oil in the bearing to an appropriate amount so that replacement with fresh oil can be performed without excess or deficiency.

[0027]

As described above, according to the sliding bearing for an engine of the present invention, the two-dimensional contact of the crankshaft causes the two-dimensional contact of the crankshaft to occur at the mating surface lubrication groove position. In addition, the high oil film pressure is dispersed and leveled to the periphery by completely removing the oil supply groove from the mating surface position, and is greatly reduced.

As a result, damage such as cracking and peeling of the bearing metal due to high oil film pressure can be prevented, the reliability of the bearing can be improved, the bearing size can be further reduced, and the entire diesel engine can be made compact. It will be possible. Also,
Oiling into the bearing is performed from the position where the load is small, but by installing seal devices to prevent oil leakage at both ends of the upper bearing metal and the lower bearing metal and filling the bearing inner surface with lubricating oil, Even if the bearing surface is farthest from the oil supply hole, it is possible to eliminate the insufficient arrival of lubricating oil. This is also effective in preventing bearing cavitation damage that may occur in a high-speed engine such as 4 cycles.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional view showing a first embodiment of an sliding bearing for an engine of the present invention,

FIG. 2 is a perspective view of the sealing device shown in FIG.

3 is a perspective view of the lower bearing metal shown in FIG. 1,

FIG. 4 is a cross-sectional view of a portion where a main bearing of a conventional diesel engine is provided,

5 is a detailed view of part A of FIG. 4, showing a cross-sectional view of an example of a conventional plain bearing for an engine;

6 is a cross-sectional view taken along the line VI-VI shown in FIG.

[Explanation of symbols]

 1 Crankshaft 2a Upper bearing metal 2a-1 Mating surface 2a-2 Circumferential oil supply groove 2a-3 Oil supply hole 2b Lower bearing metal 2b-1 Mating surface 2b-2 Circumferential oil supply groove 2-1 Back metal 2-2 Bearing material 2 -3 Axial lubrication groove 3 Bearing saddle 3-1 Mounting surface 4 Bearing crown 5 Bolt 6 Tie bolt post 6-1 Tie bolt 7 Reinforcing plate 8 Base plate 8-1 Mounting leg 9 Frame 10 Cylinder block 14 Lubrication hole 15 Main bearing 16 Oil Pan 50 Bearing 51 Oil supply hole 52a Upper sealing device 52b Lower sealing device 52-1 Fiber 52-2 Bearing metal side bolt hole 52-3 Sealing device side bolt hole 53 Oil drain hole 54 Throttling device

Claims (1)

[Claims] 1. A slide bearing for an engine, comprising a bearing made of a half-cylindrical upper bearing metal and a lower bearing metal, in which a bearing material is lined on an inner surface of a back metal, and a bearing of the upper bearing metal and the lower bearing metal. Sealing devices that are respectively provided at both ends in the width direction to prevent oil leakage from the inside of the bearing in the bearing width direction; and at least one of the upper bearing metal and the lower bearing metal, which are provided inside the bearing. An oil supply hole for supplying lubricating oil, and an oil discharge hole for discharging lubricating oil inside the bearing, which is provided in at least one of the upper bearing metal and the lower bearing metal, and attached to the oil discharge hole, A sliding bearing for an engine, which is provided with a throttle device for adjusting a flow rate of the lubricating oil discharged.