RU2567159C2 - Two-stage expansion with new crank gear configuration in opposed ice with opposed cranks - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: claimed engine comprises two internal working pistons rigidly coupled by the rod to displace coaxially in the sleeves of the second pair of working pistons. Internal piston displaces simultaneously with the second piston and features the stroke and speed two times higher than those of the second piston. Air charge is, first, compressed in the common chamber, then in the internal piston working chamber whereto fuel is injected, to initiate combustion and expansion of working gases. First, gases are expanded in the internal piston first cylinder expansion stage then in the second expansion stage opened adjacent chamber composed of the second piston and its cylinder to allow water injection before its opening. After communication of adjacent chambers the engine vapour phase initiation with high-intensity vaporization and utilisation of working gas thermal power. Internal piston displacement is transmitted to paired con rods in length corresponding to crank radius and with one end secured at the rod bearings and with opposite end in crank bearings of the cranks running in opposition and fitted in the crankcase frame bearings and mechanically coupled by matching gear. Second pistons are coupled with opposite cranks by paired con rods to balance sign-variable loads and feature the stroke equal to diameter of said cranks.

EFFECT: higher efficiency of engine operation.

2 dwg

Description

The invention relates to mechanical engineering.

The principle of a two-stage expansion volume is to increase the expansion phase of the piston ICE and to divide it into two stages in order to fully use the expansion energy of the working gases. The boxer engine with a two-stage expansion volume can be used to organize the “vapor phase” in piston ICEs in order to use not only kinetic, but also thermal energy of the working gases. And the new type of crank mechanism developed by the author (KSHM) allows the creation of a compact, multi-rod drive mechanism for two opposed pairs of sliding pistons, which determine the creation of two adjacent chambers in the engine’s working volume. Without an additional piston, this type of crankshaft can be used in conventional piston engines with an opposed circuit to balance alternating lateral loads in conjunction with the piston and the cylinder of the engine.

No analogues were found in the reviewed databases and literature.

Reciprocating internal combustion engines with the classic KShM scheme are known and widely used. Where the translational movement of the piston is converted into rotational motion of the crankshaft using a connecting rod and parallel, unidirectionally rotating cheeks (cranks) of the crankshaft. Such a conversion scheme has a major drawback, as it is unbalanced and creates alternating lateral loads in the conjugation of the piston and the engine cylinder (in the throttle ICE), vibration, and also does not allow to obtain a sufficient piston stroke relative to the dimensions and diameter of the crankshaft.

To reduce the impact of these shortcomings, methods were used such as installing an intermediate slider that accepts these loads in crosshead ICEs and shifting the axis of the engine cylinders relative to the radial position to the crankshaft, which partially reduced wear in the throttle ICEs, but further reduced the piston stroke.

The proposed KShM design balances the alternating loads of the twin connecting rods and allows you to get twice the piston stroke compared to the classical KShM design, which is used in the proposed engine to drive a small internal piston and create a compact, multi-rod drive mechanism for four multi-moving engine pistons.

The objective of the invention is to eliminate alternating lateral loads in the pairing of the piston and the cylinder of the engine; reduce the diameter of crankshafts KShM (respectively, and the dimensions of the engine) relative to the stroke of the piston; make full use of the expansion energy of the working gases; use the temperature of the gases and the walls of the engine cylinders by implementing a “vapor phase” in the engine; reduce the effect of fuel detonation on the kinematic diagram of the engine.

This is achieved by the fact that:

- the construction uses paired, synchronous, counter-rotating bloodworms, mechanically connected to each other;

- the presence of two adjacent expansion chambers in the working volume of the engine;

- two pistons are used with different speeds and stroke lengths in adjacent chambers of the engine displacement;

- the presence of each piston in a pair of opposed pistons, two paired connecting rods, balancing alternating loads;

- the kinematic movement pattern of the connecting rods changes their direction when passing the diametrical plane of the cranks, thereby doubling the working piston stroke.

The boxer engine with a two-stage expansion volume and oncoming bloodworms (FIG. 1) consists of an engine crankcase with paired, synchronous, counter-rotating bloodworms (1) located in it installed in frame bearings (2). On them in crank bearings (3) are installed connecting rods (4), also working in pairs. The second end of the pair connecting rods are mounted in the rod bearing of the small opposed pistons (5). Counter bloodworms are mechanically interconnected by means of a matching gear gear (8). The load can be removed from any bloodworm or matching gear, depending on the layout. Small pistons, with a rod (9) rigidly fixed on them, move coaxially in the bushings of large pistons (10) translationally, without lateral loads. Since alternating lateral loads are compensated by twin connecting rods and with the help of oncoming rotation of the cranks are converted into the translational movement of the piston rod. The connecting rods are made with a length corresponding to the radius of the pair of bloodworms, which allows you to get the dynamics of their movement with a change in its direction (transfer) during their passage through the diametrical plane of oncoming cranes. This makes it possible to double the working stroke of small pistons, in relation to large ones. Big pistons with a bushing for a small piston have a classic connecting rod drive (11) from each of the oncoming cranks, also balancing lateral loads, and have a stroke equal to the diameter of these cranks.

Duty cycles of the engine (Figure 2):

1. a small piston, moving together with a large, but twice as fast speed to TDC, compress the air charge first in the total working volume, then in the combustion chamber with a high compression ratio;

2. fuel is injected into the combustion chamber and the combustion-expansion process begins;

3. when the small piston reaches the edge of the combustion chamber, hot gases enter the second expansion chamber and use the expansion energy to the end. And when implementing the "vapor phase", water is injected and the process of vaporization is used to convert the temperature of the working gases to additional expansion of the steam, reduce the temperature of the exhaust gases and cool the walls of the working volume of the engine;

4. when the large piston, moving to the BDC, opens the exhaust and purge windows, the exhaust and air charge change in the working volume of the engine.

The small diameter and high speed of the small working piston, as well as the subsequent increase in engine displacement, where the blast wave is extinguished and scattered, allows the use of various types of fuel without fear of the detonation process.

The presence of a second expansion chamber and the use of “ready-made” hot gases for expansion made it possible to implement the “vapor phase” in the second circuit.

This method of using the internal energy of the elevated temperature of gases in ICE is practically poorly used, they try to dissipate it as quickly as possible and allocate it into the surrounding space through the cooling system.

They have been trying to use the attempt to somehow utilize the heat of combustion of fuel in the internal combustion engine, turning its temperature into additional “portions of pressure”, for more than 100 years.

Attempts were made in several directions: 1 - "Water supply with a gaseous working mixture to the engine cylinders at the" Inlet "cycle through the intake manifold." Those. water dust was present in the fresh charge of the working mixture, which had to be set on fire. When it was set on fire and the first phase of heat evolution, part of the water instantly turned into steam, the pressure in the cylinder rose, and the temperature dropped. Naturally, such a decrease in temperature, and even filling the cylinder with steam and evaporating water, interfered with the further normal process of burning the remaining part of the working mixture. As a result, by slightly increasing the thermal efficiency of the process, we obtain a significant portion of unburned fuel vapor, i.e. low fuel efficiency and dirty exhaust, with a significant content of fuel vapor.

2 - "The supply of water to the cylinder through a separate nozzle in the initial period of the cycle" combustion - expansion "." In this case, the process of organizing the vapor phase is carried out so that it interferes with the combustion process as little as possible. Water injection should be carried out after completion of the combustion of the working mixture, on average, at a value of 40 ° from TDC.

But there are serious difficulties. At this time, the pressure in the cylinder is from 90 to 60 atmospheres, and in order to inject a few drops of water through the nozzle, you need a large and complex high pressure pump and spend a lot of energy from the engine crankshaft to drive it. In addition, steam takes some time to form. During this time, the piston actively goes down and the path for triggering the additional pressure remains very small. It should be added that the expansion ratio in a traditional piston ICE is equal to the compression ratio, so even the exhaust gases from the classic ICE cycle do not have time to convert their pressure into useful work and go to the exhaust with a pressure of 6-8 atmospheres. Therefore, the additional pressure from the vapor phase will not have any “place-volume” at all in order to prove itself, this requires a considerable duration of the working stroke. What is needed here is an engine where the expansion ratio was 50-70% higher than the compression ratio (at least), which is almost impossible with the classic piston engine design.

3 - "Water supply in a separately arranged for this measure." To do this, the duty cycle is extended by 2 cycles. In this case, it looks like this: - “inlet of the working mixture” - “compression” - “combustion-expansion” - “exhaust gas discharge” - “water injection-expansion of steam” - “steam release”. In this case, the duty cycle is completed in 6 cycles (3 revolutions of the engine crankshaft). The seemingly rational way of organizing work processes has one serious drawback. At the 4th step "Exhaust", the main part of the hot gases of the working fluid is exhausted. And the vapor phase does not use this heat in any way, but turns only the temperature of heating of the engine surfaces into the work of steam pressure. Those. this method immediately intends to try to turn into operation not more than 50% of the heat loss of the piston ICE.

Thus, the design of the piston ICE remains completely hostile to attempts to mount a “vapor phase” in its working cycle, due to the imperfect organization of their technological cycle, when the “combustion” and “expansion” processes are combined in one working cycle.

These problems are solved in an engine with a two-stage expansion volume. Since the nozzles of the water nozzles are in a lower pressure chamber, this facilitates the injection of water into the engine displacement. Hot gases of already burnt fuel are fed into the lower pressure chamber. The formation of superheated water vapor occurs at the beginning of the expansion stroke in the second circuit of the working volume. The engine design allows you to make the camera "expansion" of sufficient volume to expand the working gases and water vapor.

The proposed KShM design balances the alternating loads of the twin connecting rods and allows you to get twice the piston stroke compared to the classical KShM design, which is used in the proposed engine to drive a small internal piston and create a compact, multi-rod drive mechanism for four multi-moving engine pistons. But this KNM kinematic scheme is not a hard drive, since it has two degrees of freedom of movement of twin rods at the “transfer point” when the rods pass the diametrical plane of bloodworms. At this point, they can go to fold both up and down, depending on the direction of the force applied to the piston rod. Therefore, such a KShM scheme can only be used in an opposed push-pull ICE with two pistons on a rigid stock. Under these conditions, a force will always be applied to the stem in the required direction to pass the “transfer point”. Such a scheme will not allow starting the engine from a starter spinning the shaft. Here we apply the start with compressed air acting directly on the pistons of the engine. It is also not possible dynamic engine braking.

The significance of differences in the principle of a two-stage expansion volume with a new KShM scheme from other known kinematic schemes of piston engines is due to:

- the absence of such an expensive and difficult to manufacture parts such as a crankshaft;

- the presence of counter rotating cranks;

- the presence of each piston in a pair of opposed pistons, two paired connecting rods, balancing alternating loads;

- the movement pattern of the connecting rods changes their direction (transfer), when passing the diametrical plane of bloodworms;

- the presence of two adjacent expansion chambers in the working volume of the engine;

- the use of two pistons with different speeds and stroke lengths in adjacent chambers of the engine displacement.

Design advantages:

- Balances the alternating loads of twin connecting rods.

- Allows you to get twice the stroke of the piston, compared with the classic KShM scheme.

- Allows to reduce the diameter of crankshafts KShM (respectively, and the dimensions of the engine) relative to the stroke of the piston.

- Allows you to fully use the expansion energy of the working gases, and also use the thermal energy of the working gases.

- It makes it possible to implement the so-called "vapor phase" in a piston ICE.

- Increase engine efficiency and reduce specific fuel consumption.

- Allows you to reduce the effect of fuel detonation on the kinematic scheme of the engine.

All of the above allows the author to hope for the widespread use of the two-stage expansion volume scheme and a new type of CABG in opposed engines with long-term, stable operating modes, such as electric generator drives, marine and diesel diesel engines.

Claims (1)

A two-stage expansion method in an opposed ICE with oncoming bloodworms containing a pair of internal working pistons rigidly connected by a rod and moving coaxially in the sleeves of the second pair of working pistons, while the internal piston moves together with the second piston and has a stroke and a speed of two times greater than at the second piston, the air charge is compressed first in the total volume, then in the working volume of the cylinder of the internal piston, where fuel is injected into the combustion chamber, and then the working gas is burned and expanded s, first in the first stage of expansion of the cylinder of the internal piston, then in the opened adjacent chamber of the second stage of expansion formed by the second piston and its cylinder, where water is injected before it is opened, and after the communication of adjacent expansion chambers, the vapor phase of the engine with intensive vaporization begins and utilization of thermal energy of working gases and cylinder walls, while the movement of the internal piston is transmitted to twin rods made with a length corresponding to the radius of the cranks and one they are fixed in the rod bearings and another in the crank bearings of counter-rotating cranks installed in the crankcase frame bearings and mechanically interconnected by means of a matching gear gear, the second pistons are also connected with counter windings by twin connecting rods, balancing alternating lateral loads, and have a working a stroke equal to the diameter of these bloodworms.

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