SU1214938A1 - Internal combustion engine - Google Patents

Description

12

The invention relates to mechanical engineering, in particular to engine building, and can be used in internal combustion engines for lubricating the engine crankshaft and crank bearings.

The aim of the invention is to increase reliability by improving lubrication.

FIG. 1 shows a part of an engine with a lubrication system and crankshaft bearings; in fig. 2 shows a typical wear pattern for the upper and lower liners of the main bearings of automotive engines; in fig. 3 - view of the inner surface of the upper bearing shell; in fig ;. 4 is a section A-A in FIG. 3; in fig. 5 is a view of the lower bearing insert; on 1FIG. 6 is a section BB in FIG. five; 7 is a schematic arrangement of a crankshaft rotating in a bearing; in fig. 8 shows the dynamics of wear and the appearance of protrusions on the shaft journal for unworn mating; Fig. 9 is the same for worn mating for bearings with a bottom liner without grooves; in fig. 10 - the same, for the bearing with the lower liner having grooves; in fig. 11 shows the dependence of the change in oil consumption Q l / min through the mating of the engine main bearing on the frequency of rotation of the shaft at different pressures of the oil supplied to the bearing.

The crankshaft 1 is mounted so that the connecting rod neck 2 is a pair of friction with the connecting rod bearing 3. The lubricant for this interface and other friction units in the engine is supplied from the lubrication system along the main oil line 4, which is made in the engine housing 5, 6 of each main bearing with an oil-distribution groove 7 made therein and a channel 8 passing in the main journal 9 of the crankshaft and communicating with other channels of the engine lubrication system.

Each main bearing also has a lower liner 10, on the inner surface of which at the ends one additional groove 1 1 is made.

FIG. 2 in microns are given the average values of wear of the upper and lower liners of the main bearings.

149382

The greatest wear is of the lower liner in section B, and the upper liner in section B even has an increment (indicated by +) thickness 5 relative to the nominal amount of solid particles from the oil are embedded in the anti-friction layer. FIG. 2 that the upper liner is practically unworn.

10 In the upper liner 6 there is an opening 12 (Fig. 3 and 4) for connection with the oil line for supplying oil to the oil distribution groove 7. Additional grooves 11 are spaced K from the ends of the lower liner 10 of the root bearing (Fig. 5 ) and have a width B and a depth h (Fig. 6), the grooves lie in the planes of rotation of the shaft.

20 A crankshaft 1 rotating at angular velocity uJ (Fig. 7) is shown under the action of a force P and an oil wedge in a bearing displaced from the center O of the bearing to the position 0.

25

35

40

45

50

55

 and, respectively, the minimum and maximum clearances in the coupling. The protrusions 12, which are formed as the mating on the main journal 9 of the crankshaft 1 is worn, are shown in FIG. eight.

FIG. Figure 11 shows the oil flow Q as a function of the frequency of rotation p for worn mating with the annular protrusions formed on the shaft neck, and the dotted one for the same mating but with protrusions with different projections at different oil pressures.

For automotive engines, the width of the groove must be taken

L 0,003-0,007 nominal bearing diameter. The depth should be h 0.001-0.003 of the nominal diameter of the subgap.

With such ratios, the kynavka has the least effect on the outflow of oil from the mate during the initial state of the shaft and liners and on the increase in the average specific pressure. At the same time, the selected groove width is larger than the axial shaft displacement allowed during assembly, and placing the grooves at a distance K from the corresponding end of 0.02-0.04 of the length of the main bearing shell makes it possible

minimum and maximum clearances in conjugation. The protrusions 12 that are formed as the mating on the main journal 9 of the crankshaft 1 is worn are shown in FIG. eight.

FIG. Figure 11 shows the oil flow Q as a function of the frequency of rotation p for worn mating with the annular protrusions formed on the shaft neck, and the dotted one for the same mating but with protrusions with different projections at different oil pressures.

For automotive engines, the width of the groove must be taken

L 0,003-0,007 nominal bearing diameter. The depth should be h 0.001-0.003 of the nominal diameter of the subgap.

With such ratios, the kynavka has the least effect on the outflow of oil from the mate during the initial state of the shaft and liners and on the increase in the average specific pressure. At the same time, the selected groove width is larger than the axial displacement of the shaft allowed for assembly and the placement of the grooves at a distance K from the corresponding end of 0.02-0.04 of the length of the main bearing shell makes it possible

nosti optimum use of the working length of the bearing and ensure the formation of an annular ledge on the shaft journal by the amount maximum allowed in the operation of the shaft wear.

The engine works as follows.

When the crankshaft 1 rotates in the friction units, in particular in a pair of connecting rod and neck 2 - connecting rod bearing 3, oil is consumed, coming to this mating and other units (camshaft bearings, valve bodies, etc. are not shown) from the engine lubrication system along the main oil line 4 in the housing 5 through the upper liner 6 of each main bearing. Through the oil-distribution groove 7, the oil enters the bearing clearance and through channel 8 in the main journal 9 to other friction units. Under the action of rotation with angular velocity i) and load P, as well as the shaft formed between shaft 9 and detachable inserts 6 and 10 of the oil wedge, the center of shaft 1 is displaced relative to the center O of the bearing to position 0. At the same time in the zone of the lower contribution 10 the minimum gap SfJ (Fig. 7), equal to the thickness of the oil film, and in the zone of the upper liner 6 is formed

14938

maximum gap Snasi-P gap is oil outflow from the mating. As the parts of the interface wear out (liner 10 and neck, 9 shaft -1) 5, the gap increases (FIG. 8M),

The oil consumption increases and, when significant wear levels are reached, the drop in oil pressure in the engine lubrication system reaches the limit values, after which the engine goes to overhaul.

When the engine is operating with an unworn bearing with grooves 11 on the bottom insert, 10 clearances and conditions

5, the lubricants are the same as in the known engines (FIG. 8B b).

As the engine is operating in the main bearing, the sections of the shaft neck 9 and the lower liner are worn.

20 10 between the grooves 11, but the portions of the neck 9, which lie in the planes of the grooves 11 on the lower insert, do not wear out. Due to this, annular protrusions 13 are formed on the shaft neck 9.

25 (FIG. 10).

These protrusions prevent the oil from flowing out of the mating, maintaining the oil pressure in the system for longer than 2Q of the engine than in the known engines. It also improves the performance of other lubricated under pressure joints, which also contributes to an increase in engine life.

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Editor M. Gorvat

Compiled by V. Lobanov

Tehred M.NadKorrektorMoDemchik

Order 896/48 Circulation 501 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, 1-35, Raushsk nab. e D / 5

Phi PPal Patent, Uzhgorod, st. Project, 4

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Claims (1)

INTERNAL COMBUSTION ENGINE, comprising a crankshaft with oil supply channels made therein, split main and connecting rod bearings with upper and lower liners, and a main oil line communicated through an oil distribution groove made in the upper main bearing liner, and oil supply channels to the crankshaft characterized in that, in order to increase reliability by improving lubrication, the lower main bearing shell is provided with at least two concentric and channels made in accordance with the ratios K = (0.02-0.04)? ; B = (0.003-0.007) ^ B = (o, 001-0.003) 4, where K is the distance from the edge of the groove to the nearest end of the liner; t is the length of the main bearing; B is the width of the groove; nominal diameter of the main bearing; And - the depth of the groove. h- ft Fie. 1 SU „„ 1214938 t