RU2500906C1 - Free-piston engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: free-piston engine made at least from one cylinder, inside of which there are two oppositely installed pistons with a stem, comprising spark plugs, a linear generator, a stator winding arranged on the cylinder, systems of gas distribution at the ends of the cylinder, a header of fuel and air medium supply and a header of exhaust gases, in accordance with the invention, each system of gas distribution is made in the form of a hollow body installed at the end of the cylinder, inside of which there is a bushing with inlet and outlet windows of the fuel and air mixture and exhaust gases, capable of communicating accordingly with inlet and outlet headers, on the axis of the bushing there is a master wheel of flexible gear, and on the stem there is a geared rack, with which a geared wheel contacts with a master shaft, on the outer end of which there is a master wheel of flexible gear. On the master shaft there is an interrupter connected with the electric plug. The engine is equipped with a control unit, on the shaft of the master wheel there is a sensor of piston positions. The cylinder is made with two coaxial walls, forming a gap for passage of cooling liquid.

EFFECT: increased efficiency and reliability.

4 cl, 4 dwg

Description

The invention relates to power plants and can be used in the automotive industry, heavy machinery and small energy, in particular in the form of auxiliary engines of transport mechanisms in mobile or portable power plants, electric welding units, etc.

Known free-piston engine according to A.S. USSR A.S. 985365 USSR, MKI 5 F02B 71/04. publ. 12.30.82, containing a diesel internal combustion engine, a linear generator and a fuel supply system. The engine is a cylinder with end combustion chambers, in the area of which there are intake and exhaust valves. Inside the cylinder there are pistons connected by a jumper (rod).

The generator consists of a stator, an armature and excitation and load relieving systems. The stator is made in the form of stator windings and field windings. These windings are mounted on the outer surface of the cylinder. The anchor is made in the form of current collector and field windings, which are laid inside the pistons and connected to each other in series. The excitation system is made in the form of connecting excitation terminals, and the load shedding system is made in the form of load shedding terminals.

The fuel supply system is a nozzle located in the end parts of the cylinder and designed to supply fuel to the combustion chamber.

The energy conversion process is divided into two main cycles: the first cycle is the conversion of energy from the chemical energy of the fuel into the mechanical energy of the movement of the pistons, and the second - the mechanical energy of the movement of the pistons is converted into electrical energy. The first cycle is the workflow of a two-stroke diesel engine, and the second, in turn, is divided into two stages. At the first stage, by crossing the winding of the first piston of the magnetic field created by the first stator winding (field winding), a magnetic field is excited in the first piston. At the second stage, the formation and removal of electricity occurs, and the winding of the first piston plays the role of the field winding for the second piston.

Using the principle of electromagnets in both parts of the linear generator allows you to get a high power magnetic field and, as a result, minimize the size of the installation.

However, the known device has the following disadvantages. When the device is operating, the movement of one piston is used to excite a magnetic field in another. This leads to the loss of the working process of the first piston to produce energy for current collection. Incomplete use of a two-stroke diesel engine workflow to generate energy for current collection is the cause of low efficiency. In addition, from overheating of the windings to a temperature of 500-600 ° C, their magnetic properties are reduced, which also reduces the efficiency of the motor.

Known free piston engine a. St. USSR No. 1733650 USSR, MKI 5 F02B 71/04, publ. 05/15/92 g, consisting of a diesel internal combustion engine, a linear generator, a fuel supply system and a cooling system.

This engine comprises a cylinder with exhaust valves in the end parts of the engine and a purge window in the central part of the engine. Inside the sleeve is a piston with a rod.

The generator consists of a stator, an armature, an excitation system and a load lifting system. The stator is made in the form of windings mounted on the outer surface of the cylinder. An anchor is a winding laid inside a piston. The excitation system is made of brushes and excitation wires. Brushes are located inside the piston. They are the first part of the sliding contact of the excitation system with the armature winding. The second part of the sliding contact is the excitation current receiving plate located on the armature winding. The plate is connected to the terminals of the armature winding. The excitation supply wires are located in the stock.

The fuel supply system includes two nozzles located in the opposed parts of the cylinder. The cooling system consists of two water nozzles, also located in the opposite parts of the cylinder.

Energy conversion is carried out in the same way as in the above engine, and consists of two cycles: the first cycle is the conversion of energy from the chemical energy of the fuel into the mechanical energy of the movement of the pistons, the second - the mechanical energy of the movement of the pistons is converted into electrical energy. The first cycle is a two-stroke diesel engine workflow. The second cycle, unlike the above engine, consists of one stage and represents the working process of a linear generator with direct excitation. The exception of one stage is achieved thanks to the direct excitation system, the wires of which pass through the rod.

The principle of operation of the cooling system is that when a certain temperature of the exhaust gases is reached (600-800 ° C) through a special water nozzle, a cooling liquid is supplied to the combustion chamber, which, evaporating and mixing with the exhaust gases, forms a cooling medium that cools the combustion chamber . The cooling system reduces the temperature of the exhaust gases to 100-200 ° C. But the temperature of the cooled exhaust gases is lower than the temperature of the piston and armature winding, because first, the exhaust gases are cooled, and then they remove the excess heat from the piston and winding. Because of this, the temperature of the piston and windings decreases only to 250-300 ° C.

The advantage of this engine is an increase in efficiency due to the full use of the working process of a two-stroke engine for the production of electricity for current collection. In addition, the efficiency is increased by reducing the magnetic field loss due to a decrease in the temperature of the windings (in particular the armature windings).

However, the known device has the following disadvantages. The lack of direct contact of the cooling medium with the armature winding located inside the piston leads to insufficient cooling of the winding. The temperature of the winding is reduced only to 250-300 ° C. In this case, the loss of electromagnetic field on copper windings is 50% greater than the loss of electromagnetic field at a temperature of 20 ° C.

In addition, the supply of coolant to the combustion chamber leads to sharp changes in temperature and, as a result, to fluctuations in the magnetic field and the strength of the generated current, which also affects the reduction of efficiency.

Known free piston engine according to the patent of the Russian Federation No. 2166231, IPC F02B 71/04, publ. 02/27/2002, the prototype.

This engine contains a diesel internal combustion engine made of a cylinder with nozzles, inside which a piston with a rod is located, a linear generator made of stator windings located on the cylinder, from an armature winding located on the piston and in contact with an excitation system consisting of brushes with excitation supply wires, a load-lifting system and a cooling system, two additional shut-off rings of the cooling system fixed to the rod and cooling tubes connected to it are additionally introduced into it with an internal piston chamber, while the armature winding is located on the piston rod, each cut-off ring is installed between the winding and the end parts of the piston, and the brushes are installed in the cylinder body.

Disadvantages: low efficiency due to the lack of a system for timely opening and closing of valves and low reliability due to the use of windings and current collectors in explosive atmospheres: oil and fuel vapors. In addition, the GTE launch system has been developed.

The challenge facing the inventors was to develop a free piston engine with high efficiency and reliability.

The solution of these problems was achieved in a free-piston engine made of at least one cylinder, inside of which there are two opposed pistons with a rod, containing spark plugs, a linear generator, which, in turn, contains a stator winding located on the cylinder, gas distribution systems at the ends a cylinder and a manifold for supplying a fuel-air medium and an exhaust manifold, in that according to the invention each gas distribution system is made in the form of a hollow body, installed about at the end of the cylinder, inside of which there is a sleeve with inlet and outlet windows of the fuel-air mixture and exhaust gases that can communicate with the intake and exhaust manifolds respectively, a driven gear wheel is made on the axis of the sleeve, and a gear rack is made on the rod with which the gear contacts a wheel with a drive shaft, at the outer end of which a drive wheel of a flexible transmission is installed. A breaker connected to an electric candle can be installed on the drive shaft. The free piston engine can be equipped with a control unit, at least one piston position sensor is installed on the drive wheel shaft, which is electrically connected to the control unit. The cylinder can be made with two coaxial walls forming a gap for the passage of coolant.

The invention is illustrated in figure 1 ... 4, where:

- figure 1 shows the carburetor version of the engine,

- figure 2 shows a diagram of a free piston engine with a control unit,

- figure 3 shows a view A,

- figure 4 shows a diagram of an engine with several (two) cylinders.

Free piston engine (figure 1 ... 4) contains at least one cylinder 1, inside of which two pistons 2 are installed on the opposite. Pistons 2 have compression and oil scraper rings 3 and 4, respectively. Pistons 2 are opposite mounted on the rod 5. Between the ends 6 the cylinder 1 and the pistons 2 are formed of the combustion chamber 7, and between the pistons 2 - the intra-piston chamber 8. The intra-piston cavity is partially filled with lubricating fluid.

The free piston engine comprises a fuel-air mixture supply pipe 9 and an exhaust pipe 10 and a gas distribution system 11.

The gas distribution system 11 (each), in turn, contains a hollow body 12, inside of which a sleeve 13 is installed, having a radial baffle 14, which forms two cavities 15 and 16. On the hollow body 12, manifolds for supplying air-fuel mixture 17 and an exhaust exhaust manifold are respectively made of gases 18. At the ends 6 of the cylinder 1, on the side surfaces of the hollow body 12 and the sleeve 13, respectively, the first or fourth inlet openings of the air-fuel mixture 19 ... 22 and the first or fourth exhaust outlet are made the basics 23 ... 26 for communicating the internal cavity of the cylinder 1 (more precisely, the combustion chamber 7 with the air-fuel mixture collector 17 and the exhaust manifold 18).

The gas distribution system 11, in addition to the hollow housing 12 and the sleeve 13 with holes 19 ... 26, contains a driven shaft 27, one end of which is connected to the sleeve 13, and the driven wheel 28 is in contact with a flexible coupling (belt or chain). In addition, the gas distribution system includes a drive wheel 30 in contact with a flexible coupling, which is mounted on the drive shaft 31, at the other end of which a gear wheel 32 is installed, which is in contact with a gear rack 33 made on the rod 5.

The linear electric power generator 34 consists of a stator winding 35 mounted externally in the central part of the cylinder 1 and permanent magnets 36 mounted on an intermediate piston 37 mounted in the middle of the rod 5 with a relatively large gap. The load removal system is made in the form of wires 38 with connecting terminals 39. The cylinder 1 is equipped with two spark plugs 40 and a chopper 41 mounted on the drive shaft 31. The spark plugs 40 and the chopper 41 are connected by electrical connections 42.

The control system (FIG. 2) may include a control unit 43 and at least one piston 2 position sensor 44 connected by electrical connection 42 to the control unit 43. The sensor 44 may be of any type, for example, to measure the angle of rotation of the drive shaft 31. To do this, it must be installed on the drive shaft 31.

The cooling system consists of two walls of cylinder 1: external 45 and internal 46 with a gap 47 between them, and supply and exhaust pipes of the cooler 48 and 49.

The electric circuit contains electric wires 38 connecting the stator winding 35 through terminals 39 and the switch 50 to the electric motor 51. A battery 52 is connected to the switch 50.

The control unit 43 is an electronic unit comprising a processor and a memory unit. (In Fig.1 ... 4 the electronic circuit of the control unit is not shown in detail). The control unit 43 must ensure timely timely supply of voltage to the electric spark plugs 40 and control of the operating mode of the free piston engine, for example, the frequency of movement of the pistons 2.

It is possible to use several cylinders. Figure 4 shows a diagram of a free piston engine with two cylinders 1. In this case, the stator windings 35 are connected to the switch 50.

Free piston engine operates as follows (figure 1 ... 4).

When starting a free piston engine, the linear generator 34 operates in a motor mode. To do this, from the battery 52 to the stator windings 35 through the switch 50, a reverse polarity starting current is supplied with respect to the current generated by the stator winding 35. Under the action of magnetic forces excited by the stator winding 35 and acting on the magnets 36, the rod 5 and pistons 2 are driven movement, making a compression stroke in one of the combustion chambers 7 of cylinder 1. Upon reaching a certain degree (at a certain position of the piston 2, detected by the sensor 44), the fuel is fed into the air-fuel mixture supply pipe 9 and simultaneously combine Then, the inlet openings 19 and 20, as well as 21 and 22, then the air-fuel mixture enters one of the combustion chambers 7. After that, a voltage is applied to the plug 40 from the interrupter 41 (Fig. 1) and the process of combustion and expansion of exhaust gases begins according to the cycle of a four-stroke engine. Simultaneously, at the opposite end of the cylinder 1, an exhaust and purge process takes place. After starting, the linear generator system 34 switches to the generator mode using the switch 50 and the electric current is supplied to the electric motor 51 and the battery 52.

A rather long operation of the electric motor (s) 51 from the accumulator 52 is possible, for example, in a garage or densely populated area. This is necessary in order to ensure the ecologists of the environment.

During the operation of the free-piston engine, each stroke of the pistons 2 is a working stroke for one of the parts of the cylinder 1, while for the opposite part this stroke is a compression process. The temperature of the piston 2 due to its contact with hot exhaust gases will be 500-600 ° C.

When the engine is operating, permanent magnets 36 reciprocate and an electromagnetic field appears in the stator winding 35 and an electric current is induced in them. The generated current is transmitted to the consumer through wires 38, terminals 39 and switch 50 to all consumers of the load-lifting system, for example, except for the electric motor (s) 51 to external lighting devices (not shown).

Simultaneously with the engine, the cooling system is operating. To do this, coolant is supplied through the pipe 48 to the gap 47, the heated fluid exits through the pipe 49 and then cooled in a heat exchanger (not specified).

When the engine stops, the linear generator switches back to engine mode and the fuel supply is turned off (not shown). Moreover, in order to counter the movement of the piston, the stop current supplied to the stator winding 35 can provide the movement of the piston 2 in the direction opposite to the actual direction of movement of the piston 2 for emergency braking.

When operating a free piston engine with several cylinders 1, one cylinder 1 is first started and, as the load increases, a second, third, etc. is started. cylinders 1 (figure 4). This will allow all the cylinders to work almost in the design mode, which will increase the efficiency of the engine. In this case, idle cylinders can be preheated. This will facilitate their launch and increase efficiency.

Because during the operation of the free piston engine, the temperature on the stator windings 35, which are located outside the cylinder 1, is approximately + 10- + 20 ° C, then the magnetic field losses in the copper windings for heating are reduced by 30-50% compared with the magnetic field losses in the prototype . Reducing losses leads to increased efficiency of the free piston engine. The absence of current collectors leads to increased fire safety, and the absence of windings in the high temperature zone increases the reliability of the engine.

The electronic control system allows you to fully automate the ignition process.

The environmental performance of the engine improves, since the vehicle in densely populated areas can move with the free-piston engine off on the battery.

Claims (4)

1. A free piston engine made of at least one cylinder, inside of which are two opposed pistons with a rod, containing spark plugs, a linear generator, which, in turn, contains a stator winding located on the cylinder, gas distribution systems at the ends of the cylinder , a manifold for supplying a fuel-air medium and an exhaust manifold, characterized in that each gas distribution system is made in the form of a hollow body mounted on the end of the cylinder, inside which There is a sleeve with inlet and outlet windows of the air-fuel mixture and exhaust gases that can communicate with the intake and exhaust manifolds and the cylinder cavity, respectively, a driven gear wheel is made on the axis of the sleeve, and a gear rack is made on the rod, with which the gear contacts the drive shaft , on the outer end of which a drive wheel of a flexible transmission is installed. 2. The free piston engine according to claim 1, characterized in that a breaker is connected to the electric spark plug on the drive shaft. 3. The free-piston engine according to claim 1 or 2, characterized in that it is equipped with a control unit, at least one piston position sensor is installed on the drive wheel shaft, which is electrically connected to the control unit. 4. Free piston engine according to claim 1 or 2, characterized in that the cylinder is made with two coaxial walls forming a gap for the passage of coolant.

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