RU2509214C1 - Rack and tooth piston machine with switching of compression stage and disconnection of pistons - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: piston machine comprises cylinders, pistons with tooth racks, a shaft with gears, engaged by these racks, at the same time in gears the teeth are cut on the arc with length of not more than half of the circumference length. Gears on the shaft are installed freely between half-couplings of switching with fixators of their position on the shaft. Capabilities of the piston machine are expanded. Switching of the piston travel value, i.e. the compression stage, makes it possible to use various types of fuel: petrol with different octane numbers, petrol and gas, petrol and diesel fuel, etc. Disconnection of some pistons from the shaft, with simultaneous disconnection of fuel supply to cylinders of these pistons, makes it possible to operate the piston machine in cost-effective mode under different conditions of operation; motor start-up conditions in winter period are facilitated.

EFFECT: layout capabilities are expanded, a shaft without cranks is easy to manufacture, has sufficient strength and stiffness, does not require large number of supports, it may be tubular, a transmission shaft may be pulled inside, which increases transmission efficiency; a piston machine may be inline, V-shaped, W-shaped, "Ш"-shaped, opposite with oppositely turned pistons, star-like.

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Description

The proposed device relates to mechanical engineering, in particular to engine building, the production of compressors, pumps.

Piston machines are used as internal combustion engines, compressors or pumps.

A device is known - ICE (internal combustion engine), the basis of which is KShM (crank mechanism), which converts the reciprocating motion of the piston into rotational motion of the crankshaft (1. Internal combustion engines: Design and operation of piston and combined engines. / V .P. Alekseev et al .; Under the general editorship of A.S. Orlin, M.G. Kruglov. - M.: Mechanical Engineering, 1990. - 288 s).

However, the crankshaft has significant drawbacks: the force from the gas pressure on the piston is not fully used to rotate the crankshaft, reducing the efficiency of the mechanism and the engine, “shifting” of the piston occurs at dead points — a change in the direction of the lateral force, which creates dynamic loads. The crankshaft is structurally complex - the crankshaft cranks are difficult to manufacture, it has several loaded swivel joints: main and connecting rods, piston pin bearings, requiring a perfect lubrication system with the supply of engine oil under pressure. To balance the mass of the cranks, it is necessary to install balances, you need a flywheel that accumulates the energy of the stroke, providing other engine strokes, as well as the passage of the piston through the dead points / 1. p. 63-79 /.

The force from the gas pressure on the piston is decomposed into two components: one along the axis of the connecting rod, the other creates a lateral load on the piston, causing energy loss due to friction and wear. The force acting along the connecting rod axis on the crank pin also decomposes into two components: one loads the main necks, and the payload - the torque on the crankshaft creates only the second force component perpendicular to the crank / 1. p.66, fig. 21 /. With a significant lateral load on the piston, it is necessary to use a crosshead / 1. p.63, fig. 19, b /.

Known rodless internal combustion engines without crankshaft on the basis of copyright certificate No. 118471 (2. Balandin S.S. Rodless piston internal combustion engines. - M .: Mechanical Engineering, 1972. - 176 s). The rod-free mechanism makes it possible to constructively carry out a two-sided working process in cylinders with small dimensions and high speed of engines and, as a result, obtain almost twice the liter and overall power / 2 /.

However, the rodless mechanism has complex kinematics / 12. Fig. 3-10 and others. In a number of designs, the function of the connecting rods is performed by the sliders, but in any case, the crankshaft remains, which is difficult to manufacture, its main journals need lubrication under pressure, gears must be installed between the crankshaft and drive shafts / 12. Fig. 12 /, complicating the design of the engine.

Known rack gears interconnected with pistons. The world’s first steam three-wheeled wagon, Kunho, was driven to the front wheel by two pistons of steam engines with racks working alternately. One of N. Otto’s first engines had a vertical cylinder, the piston of which interacted with the rack and pinion of the power take-off shaft through an overrunning clutch.

However, these machines and mechanisms were imperfect, had a low efficiency, low rotational speed, and hence low power. Freewheels are short-lived, they do not provide a clear response at high speed.

Closest to the proposed technical solution is a piston machine with rack and pinion mechanism / 1. p.262, fig. 182, b /.

It is known that such a piston machine consists of cylinders located in them oppositely deployed pistons with a gear rack pivotally mounted on each piston engaged with a gear fixed to the shaft.

However, a piston machine with such a mechanism has limited capabilities and the rack and pinion mechanism is used only as a synchronizing mechanism on high-speed gas generators. Such a piston machine has a fixed piston stroke and compression ratio, which limits its operational capabilities.

The problem to which the claimed technical solution is directed is to expand the capabilities of a piston machine with a rack and pinion mechanism.

The essence of the proposed device lies in the fact that the piston machine contains cylinders, pistons with oppositely arranged gear racks, a shaft, two gears with switching half-couplings freely mounted on the shaft between the switching half-couplings with clamps of their position on the shaft, the gear teeth are cut on an arc not long more than half the circumference, they are alternately engaged with gear racks.

The proposed technical solution significantly expands the capabilities of the piston machine, it is reversible - it allows you to use it as a high-speed high-speed internal combustion engine, as well as a compressor or pump, either single-cylinder or multi-cylinder. Switching the magnitude of the piston stroke, and hence the compression ratio, allows the use of various types of fuel: gasoline with different octane numbers, gasoline and gas, gasoline and diesel fuel, etc. Disconnecting a part of the pistons from the shaft, while shutting off the fuel supply to the cylinders of these pistons, allows the piston machine to be operated in an economical mode under various operating conditions; the conditions for starting the engine in winter are facilitated - one or two cylinders are started by a starter, and then all the others from working cylinders. The layout capabilities are expanding: a shaft without cranks is simple to manufacture, has sufficient strength and rigidity, does not require a large number of bearings (modern crankshafts, as a rule, full-support - the number of main journals is one more than that of a connecting rod), it can be tubular, inside you can hold the transmission shaft, which increases its efficiency; a piston machine can be not only in-line, but also V-shaped, W-shaped, W-shaped, opposed with opposed pistons, star-shaped, etc.

Figure 1, a shows a simplified diagram of a piston machine in a state when the pistons are in the extreme left position: the left piston at TDC (top dead center), the right piston at BDC (bottom dead center). The gas distribution mechanism, cooling systems, lubrication systems, and others are not shown in the diagram. Between the points О-О 'is the magnitude of the piston stroke between the dead points. In Fig. 1, b, the piston machine is shown in a state when the pistons are in the extreme right position: the right piston at the upper dead center and the left piston at the lower dead center. Figure 1, in - top view and side view of the opposed multi-cylinder piston machine.

Figure 2a shows a view of a shaft with switching half-couplings: on the left side is a cut, in the center is a view of a switching half-coupling, on the right is a shaft without a cut, cylinders are visible behind the shaft. In Fig.2, b is given a view of the cam coupling half with an enlarged cam, fixing the position relative to the shaft. Figure 2, in a view of the shaft with a flywheel and clutch, the driven disk of which is mounted on a shaft with a cam half coupling disconnecting pistons. Figure 2, g shows a top view of a dense, "flat", opposed layout of a multi-cylinder piston machine, and figure 2, g is a side view.

Figure 3, a shows a section of the V-shaped arrangement of the piston machine: on the left - the piston in the upper dead center, on the right - in the BDC. Points O indicate the extreme positions of the gear racks. The transmission shaft is shown inside the tubular shaft with gear. If you remove one of the cylinders with a piston, we get a single-cylinder piston machine, if you place the cylinders one after another - a row layout of a multi-cylinder piston machine. Gears, gear racks, pistons and cylinders can be assembled on one shaft in various versions: both separately and in pairs (see Fig. 1), while obtaining a W-shaped, cross-shaped, star-shaped, X-shaped, perpendicular, etc. layout (see Fig.3,6).

Figure 4 shows some layout options for a multi-cylinder piston machine with several shafts. Figure 4, a shows a side view of two rows of staggered cylinders with gear racks and gears on two shafts, which are connected by gears to the output shaft of the flywheel drive, figure 4, b is a top view. Figure 4, c shows the W-shaped layout "whatnot." Three shafts (racks and gears not shown) by gears are combined with the output shaft of the flywheel drive (combined with the middle shaft). A layout of a larger number of shafts is allowed.

Pistons 2 are installed in the cylinder 1 (see FIG. 1) (piston rings are not shown) connected by gear racks 3 and 4, which are alternately engaged with gear 5, gear teeth are cut into an arc no more than half the circumference. The arc length is less than half the circumference by two angles of engagement - the angle of engagement is mainly 20 °, i.e. arc length approximately 140 °. The compression ratio can be adjusted by moving the pistons 2 relative to the gear racks 3 and 4, for example, by installing gaskets or threaded connections (not shown in FIG. 1). The pistons 2 may have a second row of gear racks 6 and 7, which are alternately engaged with the gear 8 with the cam shift coupling (see figure 2). Toothed gears of two rows “rack-pinion” have different parameters: module, number of teeth. The shaft of gears 9 is mounted on bearings of rotation 10. The shaft of gears 9 may be continuous or tubular to accommodate the internal shaft 11, which may be transmission. The inner space of the tubular shaft of the gears 9 can be used for other purposes, for example, a gun barrel. For mounting gears 5 and 8 with cam shift half-couplings, as well as one-side shift half-couplings 12 and bilateral shift half-couplings 13, it is advisable to make the outer surface of the gear shaft 9 with splines, the number of which should be a multiple of the number of cylinders — to install the shift couplings at different angles in accordance with the order of the cylinders. On the splines of the gear shaft 9, supports of rotation T4 are installed for gears 5 and 8 with cam shift coupling halves, as well as supports 15 with external splines for one-way cam coupling halves 12. Between supports of rotation 14 are mounted supports 16 with external splines for two-way switching coupling halves 13. Half couplings switching 12, 13 have cams of increased width 17 (see Fig. 2, b), and cam half-couplings of gears 5 and 8 have recesses of the corresponding width, recesses between cams are shown by hatching. A flywheel 18 is mounted on the shaft 9 (see FIG. 2, c), on the inside of the flywheel a clutch is mounted with the pressure disk 19 and the driven disk 20 (the pressure device and the shutdown mechanism are not shown). The clutch disc 20 is mounted on the splines of the tubular shut-off shaft 21. On the splines of this shaft, next to the gear 8 with the cam shift clutch, there is a one-way shift clutch 12. The cylinders 1, pistons 2 and gear racks 3 can have a very different layout: in-line, opposed , with oppositely deployed pistons (see figure 1), a V-shaped (see figure 3) and others with the output of gear racks on one shaft of gears 9 (see figure 3,6), as well as with access to several gear shafts 9 with gears providing the connection of shafts 9 with the driving shaft and the flywheel 18. In this case, the cylinders 1 can be located in a checkerboard pattern (see figure 4, a, b), and parallel to the "whatnot" (see figure 4, c).

The gear 5 can be mounted on the shaft 9 without the use of switching coupling halves. Cylinder 1 may consist of two parts connected by a common crankcase. The gears “3.4-5 and 6.7-8” can have a different pitch and module (variable conditional gear ratio).

The proposed piston machine operates as follows.

1. ICE mode. In Fig. 1, a - on the left, the working stroke - the force from the gas pressure of the burning working mixture in the left part of the cylinder 1 acts on the left piston 2 and the upper gear rack 3, the teeth of which interact with the teeth of the gear 5, causing it and the shaft 9 to rotate clockwise arrow. The shaft 9 transfers energy to the flywheel (not shown in the diagram), which provides the drive of executive and auxiliary mechanisms, and also accumulates part of the energy for other engine strokes. The teeth of the lower rack 4 with this movement do not interact with the teeth of the gear 5 - free play. If the engine is four-stroke, then in the right cavity of cylinder 1, either an exhaust cycle can occur - exhaust gas displacement, or an air compression cycle (diesel engines or gasoline engines with direct fuel injection) or compression of the working mixture (carbureted or engines with centralized or distributed fuel injection in the intake collector).

In Fig.1, b - right working stroke. The right piston 2 through the lower gear rack 4 rotates the gear 5 and the shaft 9 also clockwise. The upper gear rack 3 makes a free run. If the right is the intake stroke of the combustible mixture or air, then the energy stored by the flywheel by the shaft 9 and gear 5 moves the lower gear rack 4 and pistons 2.

2. Compressor or pump mode. In figure 1, a shaft 9 and gear 5 rotate counterclockwise and interact with the lower gear rack 4, which moves the pistons 2 from the left to the right position. In the right half, for the compressor, the compression of air (gas) or for the pump displacing the liquid, in the left half - the inlet (intake) of air (gas) or filling with liquid. In figure 1, b, the shaft 9 and gear 5 also rotate counterclockwise and interact with the upper gear rack 3, which moves the pistons 2 from the right to the left. In the left half - air (gas) compression or liquid displacement, in the right half - air (gas) inlet (suction) or liquid filling. To change the direction of rotation of the shaft 9, it is enough to slightly shift the gear racks 3 and 4 relative to each other.

On one shaft 9 there can be several gears 5 and elements of a reciprocating machine interconnected with them - multi-cylinder reciprocating machines can be obtained. The use of multi-cylinder engines will make it possible to obtain high-power internal combustion engines, while a better balancing of engine operation will occur and a flywheel of lower relative mass will be required. Multi-cylinder multi-stage compressors with a sequential increase in gas pressure can be obtained not only due to the number of gears and the interconnected gear racks and pistons, but also by installing step pistons.

In figure 2, and the clutch is shown in a neutral state - the cam coupling halves 12 and 13 mounted on the spline bearings 14 and 15 of the gear shaft 9 do not interact with the cam coupling halves of the gears 5 and 8. When moving the cam coupling halves 12 and 13 to the right, they engage with cam half-couplings of gears 5 mounted on rotation bearings 14, interconnected with gear racks 3 and 4. The latch 17 - cam of increased width - will engage with another coupling half having a groove of the same width, only in the position corresponding to row of cylinders. The operation of the piston machine is the same as in figure 1. To increase the stroke of the pistons 2, and hence the degree of compression, we move the cam coupling halves 12 and 13 to the left, they engage with the cam coupling halves of the gears 8 mounted on the rotation bearings 14, interconnected with the gear racks 6 and 7. Switching between gears 5 and 8 with cam coupling halves is not difficult, since the difference in their angular velocities is small. To disable the cylinders 1 and pistons 2 from work, the cam half coupling or half coupling 12 and 13 are switched to the neutral state.

To activate previously disabled cylinders 1 and pistons 2, it is necessary to equalize the significant difference in angular velocities between the connected switching coupling halves 12, 13 and 5, 8. For highly skilled drivers, this inclusion is not difficult, similar to shifting gears in the gearbox with virtually no disruption in the power flow. Ordinary drivers for such an operation need a clutch that disengages, separating the clutch disc 20 with the interconnected tubular disengaging shaft 21 and the one-way cam shift clutch 12 from the driving links: the pressure plate 19 and the flywheel 18. Connecting the gear with the cam cam clutch 8 with a one-way cam shift clutch 12, engage the clutch by clamping the clutch plate 20 between the driving links: the pressure plate 19 and the flywheel 18, while the gear with the cam clutch half 8 li ne of the toothed rack 6 and 7 connects into the work previously disabled cylinders pistons 1 and 2.

To start the multi-cylinder internal combustion engine in the cold period of time (see Fig. 2, c), turn on the cam half coupling 12 only the cam half coupling of the gear 8 and when the clutch is engaged, when the pressure plate 19 presses the driven disk 20 against the flywheel 18, with a starter (not shown in the diagram) we set the pistons of the 2 extreme cylinders in motion 1. Pneumatic start is allowed when compressed air is supplied directly to the cylinders by a pneumatic distributor. When the row of cylinders 1 with pistons 2 and gear racks 6 and 7 is turned on, the clutch is turned off, the pressure disk 19 moves away from the driven disk 20, the flywheel 18 with the shaft 9 reduces the speed, the difference in rotation speeds of the adjacent switching coupling halves is also reduced and allows you to connect coupling halves. After connecting the non-started pistons to the shaft 9, we turn on the clutch and start the rest from the working extreme cylinders. With this scheme of starting the engine, a large power of the starter and its power system are not required.

In the opposite layout arrangement, the pistons 2 connected by gear racks 3 and 4 (see FIG. 1) perform the function of guide elements, perceive the forces in the gears. With other layout schemes: in-line, V-shaped and others (see FIGS. 3 and 4), the gear forces between the gear 5 and the gear racks 3 and 4 can be perceived by the walls of the cylinders 1 directly from the outer surface of the gear racks. It is necessary to take into account the fact that the maximum forces occur at TDC (see Fig. 3 on the left), when the gear racks interact with the walls of the cylinder 1 over a considerable length, with a decrease in the contact length, the force on the piston 2 decreases. For heavily loaded reciprocating machines, it is advisable to install additional guides - rolling or sliding bearings that fix gear racks 3, 4 and 6, 7 from lateral movements.

When the cylinders 1 are arranged in several rows (see Fig. 4), the torque from the shafts 9 is transmitted by gears to the output shaft and flywheel 18.

Claims (1)

A piston machine containing cylinders, pistons with opposed toothed racks, a shaft, characterized in that two gears with switching half-clutches are freely mounted on the shaft between the switching half-clutches with their position locks on the shaft, the gear teeth are cut on an arc no more than half the length circles, they are alternately engaged with gear racks.

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