RU1816876C - Internal combustion engine - Google Patents

Abstract

The engine consists of an integral housing with a crank shaft located in it with a cantilever crank. The body material is a light alloy with a linear expansion coefficient greater than that of the main shaft neck, and the temperature in the area of the rolling bearings is lower due to air blowing at the inlet to the cooling system. The mounting clearance in the bearings is selected with a nut screwed onto the shaft against the inner ring of the bearing. The skewness of the crank axis and the shaft is compensated by mating the outer ring of the crank bearing and the connecting rod stem, or by introducing a layer of elastic material between the outer surface of the outer ring of the connecting rod and piston bearing and the inner surface of the seat for this ring in the connecting rod stem, or due to the compliance of the fit of the outer ring of the crank bearing, characterized by the ratio of the fit length to its diameter of not more than 0.25. The crank chamber is closed by the housing of the auxiliary drive mechanism. 5 cp f-ly. 4 ill.

Description

ate with

FIELD OF THE INVENTION The invention relates to engine building and can be used in engines of predominantly small displacement and low power intended. for mobile energy, drive of cultivators, walk-behind tractors and other means of small-scale mechanization.

The purpose of the invention is to improve the overall dimensions of an internal combustion engine.

In FIG. 1 shows a longitudinal section through the engine, FIG. 2 is a cross-sectional view of the engine; FIG. 3 and FIG. 4 - the lower head of the connecting rod.

The engine consists of a housing 1, to which a cylinder 2 with a cylinder head 3 is attached. In the housing 1, a crank shaft 4 s is placed perpendicular to the axis of the cylinder 2

cantilever crank 5. The inner rings of the bearings 6 and 7 of the crank shaft 4 are tightened to each other with a nut 8 through an folding lock washer 9 to eliminate mounting clearances. Sealing of the crank cavity and the cavity of the rear rolling support 7 is provided by cuffs 10 and 11. In the exit area of the shank of the crank shaft 4, the housing 1 is closed by a cover 12, in which a sleeve 11 is installed. Cover 12 is also a seat for the flywheel magneto base 13. A flywheel 14 with magnets 15 is mounted on the shank of the crank shaft 4. The base is connected to the switch (not shown in FIG.), And the switch is connected to the ignition coil 16 mounted on the candle 17. A groove is made on the flywheel 14, on which 00

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ABOUT

half the coupling 18 is mounted coaxially with the shaft and fixed to the flywheel wall with screws 19. On the opposite side of the flywheel 14, the fan impeller 20 is mounted and bolted to the flywheel flange. The intake part of the inlet of the cooling fan is facing the cylinder 2, and the inner walls of the inlet are the outer surface of the housing 1 in close proximity to the outer rings of the rolling bearings 6 and 7. The hole in the housing 1 through which the crank shaft is mounted has a diameter of not only providing unhindered installation of the crank shaft, but also allowing the inner cavities of the housing to be formed in a rodless manner in the manufacture of the housing by injection molding.

The auxiliary drive mechanism in the above embodiment includes a cord start mechanism and a speed controller. The cord start mechanism includes a housing 21, hermetically closing the cavity of the crank chamber from the side opposite the crank, a cover 22, a shaft 23, a leash 24 through splines and a retaining ring connected to one end of the shaft 23 and through an opening with a cantilever crank 5; at the other end of the shaft 23, weights, axles, latches, a pusher and a speed controller lever (not shown in the figures) are installed, as well as cams 25 of the free-wheeling mechanism of the starting device and the axis of these cams 26. A drum 27 is mounted on the central part of the housing 21, with its hub connected to the return spring 28, has a stream for laying the launch cord 29 and a skirt, the inner surface of which is made in the form of a ratchet interacting with the cams 25 of the freewheel, and the outer one interacts with the working edge of the seal itelnoy cuff 30, pressed into the cover 22 and the insulating lubricant cavity frequency of the rotation regulator and the freewheel together with the sealing ring 31, is performed simultaneously as one yuschim shaft bearing 23. Another bearing 32 of the shaft 23 is set to cor- pus21. The adjusting spring of the rotational speed controller is installed outside the auxiliary drive mechanism and is not shown in the figures in the same way as the levers and rods for controlling the power system are not shown.

The connecting rod of the engine consists of at least two parts: the stem 33 and the sleeve 34, articulated with the stem so that the non-parallelism of the axis of the console crank 5 relative to the axis of the crank shaft 4 can be compensated either by reducing the length of the seating surface S to 0.25 or less relative to the size of the bore diameter D, or by introducing into the gap between the bushing and the connecting rod stem a layer of elastic material 35, which will become deformed when non-parallelism occurs, and in both cases the unequal Roughness of the load on the rollers 49 along their length, which will improve their performance, ceteris paribus.

An air cleaner housing 36 is mounted above the cylinder, a carburetor 37 is located in the inner cavity of the air cleaner housing, filter elements 38 are located on its side surfaces, a portion of the side surfaces of the air cleaner housing 36 is used externally to place control system elements on them.

The air cleaner housing is closed from above by a cover 39, through which the float quencher 40 is introduced outside; a layer of porous sealing material 41 is glued to the lid 39 from the inside, which helps to reduce the noise arising at the inlet. The tank 42 is located above the engine in the immediate vicinity of the air cleaner housing and through a settling tank 43 via a connecting pipe 44 is connected to the carburetor 37. All carburetor controls and pipe 44 are sealed when entering the air cleaner housing 36.

The dampers 47, which regulate the air supply to the fin area of the cylinder and the head, are located in the insert 48, which fills the technological opening in the casing 1, which is necessary to obtain the casing blank by the rodless method - die casting. The inner surface of insert 48 is part of the duct and fan coil. The adjustment of the position of the shutters can be either manual step-by-step seasonal or automatic with the drive of a cylinder temperature sensor (not shown in the figures).

The application range in terms of displacement and power of the proposed simplified engine design is limited by the bearing capacity of the crank and piston bearings, which, in turn; depends on the rigidity of the cantilever crank and the stability of the position of the axis of the crank shaft in the entire operating temperature range of the housing 1 and the crank shaft 4. To create conditions for stabilizing the axis of the crank shaft, the housing 1 is made of light alloy with a linear expansion coefficient greater than that of the crank shaft 4, and the average its temperature due to the fact that the heat flow is directed from the center of the cavity of the supports to the periphery, and the latter is blown by the air entering the fan inlet, lower than that of the crank shaft 4, For complete stabilization In order to position the axis of the crank shaft, the condition must be met:

ATi cn -L AT2-052 -L 4dg

where ATi is the increment of the shaft temperature; АТ2 - increment of body temperature;

"1 is the coefficient of linear expansion of the shaft;

O2 is the coefficient of linear expansion of the housing;

L is the distance between the bearings along the mounting surfaces of the bearings of the shaft bearings;

A g is the total radial clearance / tension g from thermal deformations in both angular contact bearings of the rolling bearings (with tension, the value of Dg is negative)

/ is the angle of inclination of the rollers in the rolling bearings.

Obviously, the ideal fulfillment of the indicated condition in all modes in real mechanisms is impossible. However, it should be borne in mind that if the left half is larger than the right, then the installation clearance (axial play of the bearing assembly) will increase, and if less, it will decrease. In practice, when finishing the engine, the temperature difference Tf and Т can be controlled, if necessary, either by applying a heat-protective layer to the surface of the body in the area of the supports, or by increasing its finning.

When the engine starts, the cord start mechanism through the shaft 23 and the leash 24 transfers the starting torque to the crank shaft 4 through the pin 5. After starting, the torque will be transmitted in the opposite direction to drive the speed controller installed on the end of the shaft 23. When the housing 1, bearings are heated b and 7 and the crank shaft 4 of the engine during operation due to the fact that the temperature of the casing blown outside by air entering the fan is lower than the temperature of the crank shaft 4, and the coefficient of linear expansion of the mater housing more than the material of the crank shaft 4. The mounting position of the bearings 6 and 7 will not undergo significant

changes in the entire range of engine operating temperatures. The parallel axis of the console crank 5 relative to the axis of the crank shaft 4 and the axis of the connecting rod sleeve

5 34, which arises and repeats during each revolution of the engine, will be compensated by the cyclic displacement of the sleeve 34 (within mating flexibility) relative to the stalk of the connecting rod 33, caused by some redistribution of the load along the length of the roller 49.

Using the proposed solution will significantly reduce the complexity of manufacturing the engine and its mass

Claims (5)

1. The internal combustion engine is predominantly two-stroke, comprising a housing, at least one cylinder mounted on it with a piston placed in it, a cantilever shaft with a cheek, connecting rod and root neck, a connecting rod with heads and a rod, a starting mechanism and a valve a cooling torch mounted on the shaft and located in the cochlea of the housing in which the air channels are made with inlet openings, characterized in that, in order to improve the overall dimensions, the housing is made integral with through coaxial apertures of different diameters, a smaller diameter hole using 5 of the rolling bearings, a root neck is installed, and in the hole of a larger diameter, an annular cover with an axial hole in which the axis is located, with a starting mechanism installed at one end of the axis and the other end connected with a connecting rod with a connecting rod. 2. The engine according to claim 1, with the fact that the inlet openings of the air channels are located on the side of the body, the root neck is made of material with a coefficient of linear expansion less than the coefficient of linear expansion of the body, and the outer the surface of the latter in the region where the radical 0 of the shaft journal is the inner wall of the air channel. 3. The engine according to paragraphs. 1 and 2, characterized in that at least one 5 head of the connecting rod is made in the form of an outer ring of the bearing ring mounted with a preload in the hole, the landing width of the hole being made not exceeding 0.25 of the diameter of the latter. 4. The engine according to paragraphs. 1 and 2, characterized in that at least one head of the connecting rod is made in the form of an outer ring of a bearing mounted in the hole of its rod, and a layer of elastic material is located between the outer surface of the ring and the inner surface of the hole. 5. An engine according to claim 4, characterized in that the interlayer is made in the form of at least one ring mounted in the bore of the hole.