WO2014117756A1

WO2014117756A1 - Piston machine with adiabatic expansion space

Info

Publication number: WO2014117756A1
Application number: PCT/CZ2014/000013
Authority: WO
Inventors: Vavřinec KORČIŠ
Original assignee: Korčiš Vavřinec
Priority date: 2013-01-31
Filing date: 2014-01-30
Publication date: 2014-08-07
Also published as: CZ304390B6; CZ201367A3

Abstract

The piston machine with adiabatic expansion space has an expansion space (8) in which there occurs the adiabatic thermodynamic action, when there occurs thermal exchange between the operation medium and the surrounding environment only in negligible volume, which means an increase of the piston machine efficiency. The base of the machine is the set (1) of the cylinder, the complex piston (3) with gudgeon pin (4) for connection of the piston (3) with the piston rod (5) and crank shaft (6) in the case (11). The complex piston (3) consists of the carrier (7), the piston (9) and the guide ring (10). The set (1) of the cylinder consists of the bushing (12) and the cylinder (14). The bushing (12) and the guide ring (10) create the set for straight guide of the piston (9) in the cylinder (14) and for absorption of side pressures between them. The expansion space (8), consisting of the bottom (20) of the piston (9) and inner surface (19) of the cylinder (14), is separated from the bushing (12) and the guide ring (10) by thermal insulation (16). The movement of the guide ring (10) on the walls of the bushing (12) is supported by the lubricant which is not subject to degradation by influence of heat or chemical influence of the medium. When there is flexibly placed the cylinder (14) and the piston (9) and there is selected the suitable material, a freely aligned set is developed in the expansion space (8) where tightness is reached without piston rings and where no cooling or lubrication is needed due to absence of side pressures and impacts.

Description

Piston Machine with Adiabatic Expansion Space

Technical Field

The invention relates to the field of piston machines, mainly combustion engines - Diesel and spark ignition, four stroke and two stroke, steam engines, compressors, vacuum pumps, pumps, hydraulic machines and catapults.

State of the Art

In state of the art combustion piston engines, where the piston bottom and the cylinder make the combustion space, the piston and the cylinder are thermally and mechanically loaded and under that load they have to keep an oil film between themselves to reduce friction and simultaneously they have to seal the combustion and expansion space against the crank mechanism space. Also in case of steam piston machines and piston compressors, the presence of steam or pressed medium is in contradiction with the requirement of perfect lubrication between the cylinder and the piston and sealing of the expansion space. The above stated machines were brought to perfection thanks to introduction of new technologies and materials, so the faults related to lubrication and sealing were nearly eliminated, but anyway, further improvement of efficiency at piston machines is practically impossible.

Summary of the Invention

The disadvantages of the above stated categories of piston machines are eliminated to a large extent by the presented invention - the piston machine with adiabatic expansion space. The invention is based on known constructions with the base being a cylinder equipped with a device for operation medium input and output, usually the suction and exhaust channels, valve operating mechanisms, slide valves, injection mechanisms and other construction arrangements. A piston moves in the cylinder and it is equipped with a gudgeon pin, connecting the piston with the piston rod. The piston rod, together with the crank shaft, convert straight motion of the piston to rotation movement and vice versa and the invention supposes the same way of movement change.

The purpose of the invention is the use of the adiabatic expansion space for the piston machine. It is the expansion space in which the adiabatic thermodynamic action is held, when there occurs the thermal exchange between the operation medium and the surroundings only in negligible extent. The action is performed under perfect thermal insulation, so the set does not release nearly any heat to the cooling medium or to the surroundings of the machine, which means an increase of the machine efficiency. The base of the machine is the set of the cylinder, equipped with filling and exhaust device for operation medium input and output and the complex piston, push-placed in the set of the cylinder. The complex piston consists of the carrier connected with the piston and its guide ring. The set of the cylinder consists from the bushing equipped with cooling hollows and the cylinder. The complex piston is equipped with a gudgeon pin for connection of the complex piston with the piston rod. The opposite side of the piston rod is connected with the crank shaft placed in the case and they together cause the change of the straight movement to rotation movement and vice versa. The bushing and the guide ring are designed for straight lead of the piston in the cylinder and for absorption of side pressures between the piston and the cylinder. The expansion space is delimited by the piston bottom and the inner surface of the cylinder. The expansion space is separated from the bushing and the guide ring by thermal insulation. When the complex piston moves, the insulation inserts into the inter-space between the set of the cylinder and the complex piston.

So as to remove vibrations and to arrange mutual alignment of mutually moving parts of the set of cylinder and the complex piston and so as to improve the thermal insulation, it is favourable for the carrier to be connected by a flexible connection with pre-set scope with the piston or if the bushing and the cylinder are inter-connected by a flexible free connection respectively if both of the possibilities are used. The flexible placement of the cylinder and the piston allows development of freely-faying set, in which high tightness is reached without piston rings and which does not need any lubrication and cooling. The guide ring movement on the walls of the bushing is not affected by lubrication layer degeneration at combustion engines or by chemical influences of the pressed substance at compressors, where - just to the contrary - the medium is not affected by the lubricant. The adiabatic expansion space according to this technical solution consists of the piston and the cylinder and it is separated from the bushing and the guide ring by thermal insulation. The thermal insulation for arrangement of adiabatic thermodynamic action is preferably inserted to the inter-space between the cylinder and the bushing. It arranges thermal separation of the expansion space consisting of the piston and cylinder from the bushing and the guide ring. The guide ring and the bushing arrange straight guide and absorption of side pressures. Between them there is a highly loaded lubricant film and any heat load is undesirable there.

A preferred alternative of thermal insulation is an increase of the volume of mass of mutually movable parts, creating the expansion space. Then, the thermal insulation is the mass of the cylinder and the mass of the piston. The mass feature is the low coefficient of heat passage and low friction coefficient. In such a case, the inter-space is fully filled with the mass. It seems advantageous for the parts to be made of ceramic or composite material. There is also favourable combination of such performed parts with the below stated alternative of insulation.

The other alternative of thermal insulation is creation of a lamella labyrinth, when the thermal insulation is created by lamellas concentrically inserted into the inter-space in the shape of a thin-walled cylinder and connected alternatively to the set of the cylinder and the complex piston.

So as to decrease the construction height of the piston machine and to reduce the torsion oscillations of the crank shaft it is preferred for the guide ring to be movable with its inner surface on the outer surface of the outer bushing and if the guide ring is equipped on its external surface with two opposite gudgeon pins in angular distance of 180° for piston rod fixation. There are two connecting rod pins on the crank shaft for every set of the cylinder. Another advantage of this layout is that the guide ring and the carrier and the bushing replace the function of the cross-head, usual at large machines.

The compact sets of the piston machine according to this technical solution can be reached in such a way that the bushing includes also an extension changing from the bushing to the tube shape and oriented to the inner space of the set of the cylinder. The extension axis is identical with the set of the cylinder axis and the composed set axis. The guide ring moves on the extension. The bigger diameter of the extension is smaller than the external diameter of the guide ring and the smaller diameter is bigger than the inner diameter of the guide ring. A guide hollow is developed in the guide ring for the movement of the guide ring on the extension. The guide hollow is unilaterally open and it has a negative shape of the extension. For the purpose of pressures balancing the hollow is ventilated by a ventilation hole as well as all the inter-spaces and hollows between the cylinder and piston, when undesirable change of pressures would occur during the machine operation.

Brief Description of the Drawings

Fig. 1 up to Fig. 4 show examples of piston machine with adiabatic expansion space. Fig. 1 shows the piston machine with the adiabatic expansion space, where the thermal insulation is the mass of the cylinder and the mass of the piston and also the mass of the thick-wall tube encircling the cylinder. Fig. 2 shows the piston machine with the adiabatic expansion space, where the thermal insulation consists of lamellas in the shape of a thin-wall cylinder, concentrically organised in the inter-space. Fig. 3. shows the piston machine with the adiabatic expansion space, where the guide ring is astride the bushing, so its inner surface is sliding on the outer surface of the bushing. The guide ring is equipped with two opposite gudgeon pins on external surface for catching the piston rods. Fig. 4 shows the piston machine with the adiabatic expansion space, where the bushing is connected with the extension passing to the shape of the tube designed for guiding the guide ring, which houses a guide hollows for the extension.

Exemplary Embodiment of the Invention

Figure 1 shows the technical solution, the piston machine with adiabatic expansion space. For given space there was selected a diesel four stroke engine. In the head of the set 1 of the cylinder there is the filling and exhaust device 2, for operation medium input and output, which in case of the Diesel four stroke engine, represents the injection device and valve control / camshafts. The complex piston 3 in the set 1 of the cylinder creates during its movement a variable expansion space 8, delimited by the bottom 20 of the piston 9 and inner surface 19 of the cylinder 14. The complex piston 3 is equipped with a gudgeon pin 4 connecting it with the piston rod 5. Its opposite side is connected with the crank-pin bearing with the crank shaft 6, which is placed in the bearings in the case 11.. The complex piston 3 consists of the carrier 7, connected via flexible connection 17 with the piston 9 and fastened together with the guide ring 10. The cylinder set i consists of the bushing 12 and connected cylinder 14 via flexible connection 27. In the bushing 12 there are cooling cavities 13 for the cooling medium. The inter-space 15 between the cylinder 14 and the bushing 12 is ventilated by the ventilation hole 26. The thermal insulation 16 is inserted to the inter-space 15. It performs heat insulation of expansion space 8 from the bushing 12 and the guide ring 10. The thermal insulation 16 includes in this embodiment even the increased mass of the piston 9. The feature of the ceramic mass, from which is manufactured even the cylinder 14, is the low coefficient of heat passage and low friction coefficient. The bushing 12 and the guide ring 10 make a set for straight guiding of the complex piston 3 in the set of the cylinder ± and for absorption of side pressures between them. That means elimination of side pressures between the piston 9 and the cylinder 14, so in case of flexible placement of the cylinder 14 and piston 9 there is created a freely aligned set, where tightness is reached without piston rings and where no lubrication or cooling is needed. The movement of the guide ring 10 on the walls of the bushing 12 is supported by lubricant, which is not - in given embodiment - subject to degradation by influence of heat or chemical influence of fuel and combustion gases of the Diesel engine.

Figure 2 shows the piston machine with adiabatic expansion space practically identical with the previous one, but the thermal insulation 16 included also the increased mass of the cylinder 14 and as the thermal insulation 16 in the inter-space 15 there are used even fixed lamellas 18a and movable lamellas 18b, both of them in the form of a thin-walled cylinder. Two fixed lamellas 18a, concentrically placed in the inter-space 15 are connected with the bushing 12. Opposite to them, there is concentrically placed the movable lamella 18b connected with the carrier 7. The flexible connection 17 connects only the piston 9 with the carrier 7. The inter-space 15 between the inner cylinder 14 and outer cylinder 12 is ventilated by the ventilation hole 26.

Figure 3 shows the piston machine with adiabatic expansion space, the Diesel four-stroke engine, principally identical with the previous examples. The set of the cylinder consists of the bushing 12 and cylinder 14. The bushing 12 includes cooling cavities 13 for cooling medium circulation. The inter-space 15 between the cylinder 14 and the bushing 12 is ventilated by the ventilation hole 26. The head of the set 1 of the cylinder includes a device 2 for operation medium input and output, which means the spraying device and valve control. The composed piston 3 consists of the carrier 7, connected via the flexible connection 17 with the piston 9 and connected on fixed basis with the guide ring 10. The guide ring 10 is astride on the bushing 12, so its inner space 22 is sliding on the external surface 21 of the bushing 12. The guide ring 10 is equipped on its outer surface 23 with two opposite gudgeon pins 4 for fixation of two piston rods 5, connected with gudgeon pins of the crank shaft 6, placed in main bearings of the engine, in case 11.. Thermal insulation 16 in given embodiment consists of the increased mass of the piston 9 and the cylinder 14. The advantage of this embodiment is the decrease of construction height of the piston machine and decrease of torsion oscillations of the crank shaft.

The identical principle, but different performance can be seen in figure 4, showing the piston machine with adiabatic expansion space, combustion engine. The complex piston 3 consists of the carrier 7 fixed to the guide ring 10, connected via the flexible connection 17 with the piston 9. The bushing 12 is connected with the extension 24 turning into the shape of a tube, situated in the inner space of the machine. Its axis is identical with the axis of the set ± of the cylinder and complex piston 3. The bigger diameter of the extension 4 is smaller than the outer diameter of the guide ring 10 and the smaller diameter of the extension 24 is bigger than the inner diameter of the guide ring 10, where there is created a guide cavity 25 for the extension 24 and it is concentric with its surface. The cavity 25 has a negative shape of the extension 24, it is unilaterally open and its cut has the shape of an annular area. So as to balance the pressures, the guide cavity 25 is ventilated by a ventilation hole 26. The thermal insulation 16 is given embodiment includes the increased mass of the piston 9 and the cylinder 14. The feature of the ceramic mass, from which there is manufactured the piston 9 and the cylinder 14, is the low coefficient of heat passage and low friction coefficient. A compact set of the piston machine can be reached by the above described embodiment.

Industrial Applicability

The invention can be used in the field of piston machines, mainly combustion engines, Diesel and spark ignition, four stroke and two stroke, steam engines, compressors, vacuum pumps, pumps, hydraulic machines and catapults. List of Items

1. Set of the cylinder

2. Filling and exhaust device

3. Complex piston

4. Gudgeon pin

5. Piston rod

6. Crank shaft

7. Carrier

8. Expansion space

9. Piston

10. Guide ring

1 1. Case

12. Bushing

13. Cooling hollows

14. Cylinder

15. Inter-space

16. Thermal insulation

17. Flexible connection

18. Lamellas

19. Inner surface of the cylinder

20. Piston bottom

21. Externa I surface

22. Internal surface

23. External surface

24. Extension

25. Guide cavity

26. Ventilation hole

27. Flexible connection

28. Thick-wall tube

Claims

1. Piston machine with adiabatic expansion space, with is base including the set

(I) of the cylinder, equipped with filling and exhaust device (2), for operation medium inlet and outlet and complex piston (3), push-placed in the set (1) of the cylinder, while the complex piston (3) is equipped with the gudgeon pin (4) for connection of the complex piston (3) with the piston rod (5), with its opposite side being connected - for the purpose of change of straight movement to rotation movement - connected with the crank shaft (6), placed in the case

(II) , characterised by the fact that the composed piston (3) consists of the carrier (7) connected with the piston (9) and with the guide ring (10), while the set (1) of the cylinder consists of the bushing (12), equipped with cooling cavities (13) and the cylinder (14), while the bushing (12) and the guide ring (10) are designed for straight guiding of the piston (9) in the cylinder (14) and for absorption of side pressures between the piston (9) and the cylinder (14), while the expansion space (8) delimited by the bottom (20) of the piston (9) and inner space (19) of the cylinder (14), is separated from the bushing (12) and from the guide ring (10) by thermal insulation (16),for which there is delimited an inter-space (15) between the set (1) of the cylinder and the complex piston (3).

2. Piston machine with adiabatic expansion space according to claim 1 , characterised by the fact that the carrier (7) is connected by a flexible connection (17) with the piston (9) and fixed to the guide ring (10).

3. Piston machine with adiabatic expansion space according to claims 1 and 2, characterised by the fact that the bushing (12) and the cylinder (14) are interconnected by a flexible connection (27).

4. Piston machine with adiabatic expansion space according to claims 1 up to 3, characterised by the fact that the inter-space (15) between the cylinder (14) and the bushing (12) contains thermal insulation (16) in the form of inserted thick-wall tube (28) put astride the cylinder (14).

5. Piston machine with adiabatic expansion space according to claims 1 up to 4, characterised by the fact that the thermal insulation (16) includes fixed lamellas (18a) and movable lamellas (18b), both of them in the shape of a thin- wall cylinder, concentrically placed in the inter-space (15), while fixed lamellas (18a) are connected with the set (1) of the cylinder and movable lamellas (18b) are connected with the complex piston (3).

6. Piston machine with adiabatic expansion space according to claims 1 up to 5, characterised by the fact that the thermal insulation (16) includes material of the cylinder (14) and material of the piston (9).

7. Piston machine with adiabatic expansion space according to claims 1 up to 6, characterised by the fact that the guide ring (10) is sliding with its inner surface (22) on the external surface (21) of the bushing (12).

8. Piston machine with adiabatic expansion space according to claim 7, characterised by the fact that the guide ring (10) is equipped on its outer surface (23) with two opposite gudgeon pins (4) for fixation of two piston rods (5), while it is sliding with its inner surface (22) on the external surface (21) of the bushing (12).

9. Piston machine with adiabatic expansion space according to claims 1 , 3 up to 6, characterised by the fact that the bushing (12) includes an extension (24) passing to the shape of a tube and orientated to the inner space of the set (1) of the cylinder, its axis is identical with the axis of the set (1) of the cylinder and complex piston (3), while the bigger diameter of the extension (24) is smaller than the external diameter of the guide ring (10) and the smaller diameter of the extension (24) is bigger than the inner diameter of the guide ring (10), while a guide cavity (25) is developed in the guide ring (10) for the movement of the guide ring (10) on the extension (24), the guide hollow (10) has a negative shape of the extension (24) and it is unilaterally open and for the purpose of pressures balancing it is ventilated by a ventilation hole (26).