NL2018451B1

NL2018451B1 - Engine with two annular cylinders and two crankshafts

Info

Publication number: NL2018451B1
Application number: NL2018451A
Authority: NL
Inventors: Liu Lili; Tang Xiaoyu
Original assignee: Univ Xuzhou Technology
Priority date: 2016-12-31
Filing date: 2017-03-01
Publication date: 2018-01-26
Also published as: NL2018451A; CN206346830U

Abstract

The invention discloses an engine with two annular cylinders and two crankshafts, which relates to the technical field of the engine. The present invention includes two opposite cylinders, two double-headed pistons, and two crankshafts, and gear output members. Each cylinder has an inner chamber with an annularly curved surface. A piston inlet is provided at each end of each cylinder. A central shaft is provided between the two cylinders. Each double-headed piston includes a piston arm. A piston head is fixed to each end of each piston arm. The piston arm is hinged to the central shaft. A sealed combustion chamber is formed between two opposite piston heads in one cylinder. A connecting rod is hinged between the crankshaft and the piston arm. The crankshafts, the connecting rods, the piston arms, and the central shaft form a crank-rocker mechanism enabling the two double-headed pistons to swing synchronously and enabling the reciprocating swivel of the piston heads about the central shaft between the outer dead center and the inner dead center. The present invention efficiently reduces the wear and impact between the piston and the cylinder liner, significantly improves the reliability of the ceramic material applied in the engine, and increases the actual thermal efficiency, with a simple structure and a stable output.

Description

ENGINE WITH TWO ANNULAR CYLINDERS AND TWO CRANKSHAFTS TECHNICAL FIELD

[0001] The present utility model relates to the technical field of engines, more particularly to an engine with an annular cylinder.

BACKGROUND

[0002] At present, in the technical field of engines, the gasoline engine is an internal combustion engine that approximately follows the Otto cycle and has an actual thermal efficiency of about 30%. The diesel engine is an internal combustion engine that approximately follows the Diesel cycle and has an actual thermal efficiency of about 35%. The actual thermal efficiencies of the gasoline engines and the diesel engines are much lower than their respective theoretical thermal efficiencies. One of the main reasons for this phenomenon is that the cylinder liner, piston and other components which directly contact with the high-temperature combustion gas are made of metal materials having a poor thermal insulating property. The continuous and reliable work of metal materials relies on the continuous cooling of the cooling system which absorbs heat from the closed combustion chamber. The ceramic material has a better thermal insulating property. If the cylinder liner, the piston, and other parts are made of ceramic material, the actual thermal efficiency will be improved. However, the low reliability caused by the brittleness of the ceramic material prevents this material from being applied to the engine.

SUMMARY OF INVENTION

[0003] In order to overcome above defects in the prior arts, the present utility model provides an engine with two annular cylinders and two crankshafts, which can effectively lower the wear and impact between the piston and the cylinder liner, significantly improve the reliability of the ceramic material applied to the engine, and increase the actual thermal efficiency. This engine also has a simple structure, a stable output, and a good manufacturability.

[0004] The present utility model is realized by the following technical solutions. An engine with two annular cylinders and two crankshafts includes two opposite cylinders. Each cylinder is formed to have an inner chamber with an annularly curved surface. The annularly curved surface refers to a spatially curved surface formed by rotating a circle located in a plane about an axis located in the plane. The circle in the plane is called a generatrix circle of the annularly curved surface. The axis is called a generatrix axis. The vertical distance from the center of the generatrix circle to the generatrix axis is called a generatrix radius. A piston inlet is provided at each end of the cylinder. A central shaft is provided between the two opposite cylinders. The axis of the central shaft coincides with the generatrix axis of the annularly curved surface. Two double-headed pistons fit the cylinders. Each of the two double-headed pistons includes a piston arm. A piston head is fixed to each end of each piston arm. A hinged end protrudes from the center of each piston arm and is hinged to the central shaft. An outer surface of each piston head is formed as an annularly curved surface fitting the annularly curved surface of the inner chamber of the corresponding cylinder. The generatrix axis of the annularly curved surface of each piston head coincides with the generatrix axis of the annularly curved surface of the inner chamber of each cylinder. The generatrix radius of the annularly curved surface of each piston head equals the generatrix radius of the annularly curved surface of the inner chamber of each cylinder. The piston heads are inserted into two ends of each cylinder. A sealed combustion chamber is formed between two opposite piston heads in one cylinder. A small gap is provided between the inner chamber of the cylinder and an outside surface of the piston heads and ensures movements of the pistons and sealing of the combustion chamber. An intake hole and an exhaust hole are disposed in pairs on a wall of each cylinder and located w'ithin a range between a piston head’s inner end face at an outer dead center of the piston and a piston head’s outer end face at an inner dead center of the piston. Two crankshafts are respectively disposed outside the two double-headed pistons. The crankshaft on each side has a crankpin. A connecting rod is hinged between the crankpin and the piston arm. Each piston arm has a hinge joint near either piston head. The connecting rod is hinged to the hinge joint by a pin shaft. The crankshafts, the connecting rods, the piston arms on both sides, and the central shaft form a crank-rocker mechanism by which the tw'o double-headed pistons can swing synchronously and the piston heads can swivel about the central shaft back and forth between the outer dead center and the inner dead center. Transmission gears are mounted on the crankshafts at ends on the same side. A central output gear is mounted to one end of the central shaft corresponding to the ends of crankshafts that are mounted with transmission gears. The central output gear engages with the transmission gears.

[0005] Two guiding blocks are fixed to the cylinders from outside. Each guiding block has an inner arc surface fitting a circular motion curve of the double-headed piston. Each piston arm has an arc guiding block. An outside surface of the arc guiding block has an outer arc surface fitting the inner arc surface of the guiding block.

[0006] Portions of the piston heads and the cylinders that directly contact with high-temperature gas are made of ceramic material.

[0007] The piston arm has a double-layer plate structure. Each layer of the double-layer plate structure has a sector shape. A central portion of a narrow end of the sector shape is connected to the hinge end.

[0008] The two cylinders are combined by a cylinder body. A piston hinge chamber and a shaft chamber are disposed in the center of the cylinder body. The hinge end of the double-headed piston is disposed in the piston hinge chamber. The central shaft passes through both the shaft chamber and the hinge end.

[0009] The present utility model has following beneficial effects. The present utility model provides a new-style engine, which can transfer the force bearing point can from the reciprocating area of the cylinder liner and the piston that is under a high temperature, high pressure, and high speed to other areas that are under a lower temperature and easy to be lubricated such that there is no acting force between the piston and the cylinder liner except the back pressure of the piston ring. It is realized that the cylinder liners, pistons, and other parts that are made of ceramic material only undergo pressure load of high temperature combustion gas. It is realized that the reliability and life-span are increased without increasing the tenacity of the ceramic material and manufacturing cost. Comparing with the prior art, in the present utility model, the connecting rod is directly connected to the piston arm. The compression stiffness of the connecting rod is much larger than that of the bending stiffness of the piston arm. The fact that the connecting rod and the piston arm share the gas pressure effectively ensures that the deflected motion trace of the piston is less than 0.1 mm. Therefore, the present utility model can effectively lower the friction and impact between the piston and the cylinder liner. There is no acting force between the piston and the cylinder liner except the back pressure of the piston ring. Parts such as the cylinder liner and the piston that directly contact w'ith high-temperature combustion gas can be manufactured with the ceramic material, such that the reliability and lifespan can be significantly improved, and thereby the thermal efficiency is notably increased.

[0010] The rotating-type engine has a better space utilization and smaller size with respect to the lineal-reciprocating-type engine. Compared w'ith the traditional tw'o-stroke engine, the intake hole and the exhaust hole of the present utility model are located on two sides of the cylinder, respectively. The uniflow scavenging manner can maximally lower the amount of residual exhaust gas in the cylinder. One cylinder has tw'o opposite pistons, w'hich simultaneously work such that the acting forces are offset. Therefore, better stability and less vibration of the whole engine can be achieved. The present utility employs two crankshafts and gears. With respect to the engine with one crankshaft, two crankshafts and gears can output more evenly and stably. Each crankshaft only need one crankpin and one connecting rod. Therefore, a reduced structural complexity and a good manufacturability are obtained. It is convenient for manufacture and popularization.

[0011]

BRIEF DESCRIPTION OF DRAWINGS

[0012] The present utility model is further illustrated hereafter with reference to the embodiments and the draw'ings.

[0013] Figure 1 is a front view of the present utility model.

Figure 2 is a top view of Figure 1.

Figure 3 is a cross-sectional view taken along A-A in Figure 2.

Figure 4 is a rear view of Figure 1.

Figure 5 is a left view of Figure 1.

Figure 6 is a cross-sectional view taken along B-B in Figure 1.

Figure 7 is the structural schematic diagram of the cylinder and the cylinder body of the present utility model.

Figure 8 is a left view of Figure 7.

Figure 9 is the structural schematic diagram of the double-headed piston of the present utility model.

Figure 10 is a left view of Figure 9.

[0014] In the Drawings, 1. cylinder, 2. exhaust hole, 3. double-headed piston, 4. crankshaft, 4-1. crankpin, 5. piston arm, 5-1. arc guiding block, 6. piston head, 6-1. outside surface, 6-2. outer end surface of piston head, 6-3. inner end surface of piston head, 7. hinge end, 8. central shaft, 9. intake hole, 10. combustion chamber, 11. pin shaft, 12. connecting rod, 13. transmission gear, 14. guiding block, 15. cylinder body, 15-1. piston hinge chamber, 15-2. shaft chamber, and 16. central output gear.

DETAILED DESCRIPTION OF INVENTION

[0015] Referring to Figs. 1-1.0, an engine with two annular cylinders and two crankshafts includes two opposite cylinders 1. An inner chamber of cylinder 1 is formed to have an annularly curved surface. The annularly curved surface refers to a spatially curved surface formed by rotating a circle located in a plane about an axis located in the plane. The circle in the plane is called a generatrix circle of the annularly curved surface. The axis is called a generatrix axis. The vertical distance from the center of the generatrix circle to the generatrix axis is called a generatrix radius. A piston inlet is provided at each end of cylinder 1. Central shaft 8 is provided between two cylinders 1. The axis of the central shaft coincides with the generatrix axis of the annularly curved surface. Two double-headed pistons 3 that are provided in pairs match with cylinder 1. Each of two double-headed pistons 3 has piston arm 5. Piston head 6 is fixed to each end of piston arm 5. Hinged end 7 protrudes from the center of piston arm 5 and is hinged to central shaft 8. Outer surface 6-1 of piston head 6 is formed to be an annularly curved surface fitting the annularly curved surface of the inner chamber of cylinder 1. The generatrix axis of the annularly curved surface of piston head 6 coincides with the generatrix axis of the annularly curved surface of the inner chamber of cylinder 1. The generatrix radius of the annularly curved surface of piston head 6 equals the generatrix radius of the annularly curved surface of the inner chamber of cylinder 1. Piston heads 6 are inserted into two ends of each cylinder 1. Sealed combustion chamber 10 is formed between two opposite piston heads 6 in cylinder 1. There is a small gap between the inner chamber of cylinder 1 and outside surface of piston heads 6 to ensure the movement of the piston and the sealing of combustion chamber. The fact that the connecting rod and the piston arm share the gas pressure effectively ensures that the deflected motion trace of the piston is less than 0.1 mm. Intake hole 2 and exhaust hole 9 are disposed in pairs in a cylinder wall and located within a range between piston head’s inner end face 6-3 at an outer dead center of a piston and piston head’s outer end face 6-2 at an inner dead center of the piston.

[0016] Two crankshafts 4 fit double-headed pistons 3. Two crankshafts 4 are disposed outside two double-headed pistons 3, respectively. Each crankshaft 4 has a crankpin 4-1. Connecting rod 12 is hinged between crankpin 4-1 and piston arm 5. Each piston arm 5 has a hinge joint near either piston head. Connecting rod 12 is hinged to the hinge joint by pin shaft 11. The crankshafts, the connecting rods, the piston arms on both sides, and central shaft 8 form a crank-rocker mechanism by which the two double-headed pistons can swing synchronously and the piston heads can swivel about the central shaft back and forth between the outer dead center and the inner dead center. Transmission gears 13 are mounted on crankshafts 4 at ends on the same side. Central output gear 16 is mounted to one end of central shaft 8 corresponding to the ends of crankshafts 4 that are mounted with transmission gears 13. Central output gear 16 engages with transmission gears 13.

[0017] Guiding blocks 14 are fixed to the cylinders from outside. Each guiding block has an inner arc surface fitting a circular motion curve of the double-headed piston. Each piston arm 5 has an arc guiding block 5-1. The outside surface of arc guiding block 5-1 has an outer arc surface fitting the inner arc surface of the guiding block.

[0018] Piston arm 5 has a double-layer plate structure. Each layer has a sector shape. The naiTOW end of the sector is connected to hinge end 7 in the center. Piston arm 5 also can have other shapes, preferably, in a symmetric form, as long as it is convenient for the connection of the hinge joint and the connecting rod without affecting the movement of piston movement.

[0019] Two cylinders 1 are combined by cylinder body 15. Piston hinge chamber 15-1 and shaft chamber 15-2 are disposed in the center of cylinder body 15. Hinge end 7 of the doubleheaded piston is disposed in piston hinge chamber 15-1. Central shaft 8 passes through both shaft chamber 15-2 and hinge end 7.

[0020] Portions of piston heads 6 and cylinders 1 that directly contact with high-temperature gas are made of ceramic material.

[0021] The operation principle of the present utility model can be explained as follows. In the crankshaft mechanism of the present utility model, the gas in the combustion chamber expands after ignition, and two piston heads in the same cylinder move reversely to drive the crankshafts on two sides to rotate and output power through the gear set. The crankshafts rotate once (360 °) to complete one cycle set and accomplish the compression and expansion of the gas. The intake hole and the exhaust hole are disposed on the sides of the cylinder, respectively, i.e., both sides and/or outer circumferential side. The uniflow scavenging manner can maximally lower the amount of residual exhaust gas in the cylinder. When one outer piston is located at the outer dead center, the intake hole and the exhaust hole of the corresponding cylinder opens and finishes the gas exchanging instantaneously. For the present utility model, the power of the two-stroke engine can be 1.75-1.95 times that the four-stroke engine with the same displacement. In practice, the present utility model can efficiently reduce the wear and impact between the piston and the cylinder liner. There is no acting force between the piston and the cylinder liner except the back pressure of the piston ring. The portions of the piston and the cylinder liners that directly contact with a high-temperature gas can be made of ceramic material such that the thermal efficiency is significantly improved.

Claims

1. Motor met twee ringvormige cilinders en twee krukassen, omvattende: twee tegenover elkaar liggende cilinders (1), waarbij elke cilinder (1) is gevormd met een binnenkamer bestaande uit een ringvormig gekromd oppervlak; aan elk uiteinde van de cilinder (1) is een opening voorzien ten behoeve van een zuiger; een centrale as (8) is voorzien tussen de twee tegenovergestelde cilinders; een aslijn van de desbetreffende centrale as valt samen met een beschrijvende generatrice aslijn van het ringvormig gekromde oppervlak; twee dubbelkoppige zuigers (3) overeenkomend met de cilinders, waarbij elke cilinder een zuigerarm (5) omvat; een aan elk uiteinde van elke zuigerarm gefixeerde zuigerkop (6); een vanuit het midden van elke zuigerarm uitstekend scharnierend uiteinde (7), welke scharnierend is bevestigd aan de centrale as (8); een buitenoppervlak (6-1) van elke zuigerkop (6) is gevormd ais een ringvormig gekromd oppervlak, dat past op het ringvormig gekromde oppervlak van de binnenkamer van elke cilinder (1); een beschrijvende generatrice aslijn van het ringvormig gekromde oppervlak van elke zuigerkop (6) valt samen met de beschrijvende generatrice aslijn van het ringvormig gekromde oppervlak van elke cilinder (1); een beschrijvende generatrice aslijn van het ringvormig gekromde oppervlak van elke zuigerkop (6) is gelijk aan de beschrijvende generatrice aslijn van het ringvormig gekromde oppervlak van elke cilinder (1); de zuigerkoppen (6) worden geplaatst in twee uiteinden van elke cilinder; een afgesloten verbrandingskamer (10) is gevormd tussen twee tegenover elkaar liggende zuigerkoppen in een cilinder; een gat voor de inlaat (2) en een gat voor de uitlaat (9) zijn in paren aangebracht in de wand van elke cilinder en zich bevinden binnen een bereik tussen het binnenvlak van een zuigerkop (6-3) in het buitenste dode punt van een cilinder en het buitenvlak van een zuigerkop (6-2) in het binnenste dode punt van een cilinder; en twee krukassen (4) die zijn aangebracht aan de buitenkant van de twee dubbelkoppige zuigers (3), waarbij elke krukas een krukaspen (4-1) omvat; een tussen de krukaspen (4-1) en zuigerarm (5) scharnierend bevestigde krukstang (12); waarbij elke zuigerarm (5) een scharnierende verbinding nabij een van de zuigerkoppen omvat; de krukstang (12) is scharnierend verbonden aan de scharnierende verbinding door middel van een scharnierpen (11); de krukassen, de krukstangen, de zuigerarmen aan beide kanten, en de centrale as (8) vormen tezamen een krukas-tuimelaarmechanisme dat de twee dubbelkoppige zuigers in staat stelt om gesynchroniseerd te slingeren en om de zuigerkoppen om de centrale as te draaien tussen het buitenste dode punt en het binnenste dode punt; overbrengingstandwielen (13) zijn aan dezelfde zijde aan de uiteinden van de krukassen (4) gemonteerd; een centraal uitvoertandwiel (16) is gemonteerd aan een zijde van de centrale as (8), die correspondeert met de uiteinden van de krukassen (4); en het centraal uitvoertandwiel (16) grijpt aan op de overbrengingstandwielen (13).A motor with two annular cylinders and two crankshafts, comprising: two opposed cylinders (1), each cylinder (1) being formed with an inner chamber consisting of an annular curved surface; at each end of the cylinder (1) an opening is provided for a piston; a central axis (8) is provided between the two opposite cylinders; an axis line of the relevant central axis coincides with a descriptive generative axis line of the annular curved surface; two double-headed pistons (3) corresponding to the cylinders, each cylinder comprising a piston arm (5); a piston head (6) fixed at each end of each piston arm; a hinged end (7) protruding from the center of each piston arm, which hinge is attached to the central shaft (8); an outer surface (6-1) of each piston head (6) is formed as an annular curved surface that fits on the annular curved surface of the inner chamber of each cylinder (1); a descriptive generator axis of the annular curved surface of each piston head (6) coincides with the descriptive generator axis of the annular curved surface of each cylinder (1); a descriptive generator axis of the annular curved surface of each piston head (6) is equal to the descriptive generator axis of the annular curved surface of each cylinder (1); the piston heads (6) are placed in two ends of each cylinder; a sealed combustion chamber (10) is formed between two opposite piston heads in a cylinder; a hole for the inlet (2) and a hole for the outlet (9) are arranged in pairs in the wall of each cylinder and are located within a range between the inner surface of a piston head (6-3) in the outer dead center of a cylinder and the outer surface of a piston head (6-2) in the inner dead center of a cylinder; and two crankshafts (4) arranged on the outside of the two double-headed pistons (3), each crankshaft comprising a crankshaft pin (4-1); a crank rod (12) pivotally mounted between the crankshaft pin (4-1) and piston arm (5); wherein each piston arm (5) comprises a hinged connection near one of the piston heads; the crank rod (12) is hingedly connected to the hinged connection by means of a hinge pin (11); the crankshafts, the crank rods, the piston arms on both sides, and the central axis (8) together form a crankshaft-rocker mechanism that enables the two double-headed pistons to swing synchronously and to rotate the piston heads about the central axis between the outermost dead center and the inner dead center; transmission gear wheels (13) are mounted on the same side at the ends of the crankshafts (4); a central output gear (16) is mounted on one side of the central shaft (8), which corresponds to the ends of the crankshafts (4); and the central output gear (16) engages the transmission gear wheels (13).

2. Motor volgens conclusie 1, met twee ringvormige cilinders en twee krukassen, voorts omvattende twee geleideblokken (14) welke zijn bevestigd aan de buitenzijde van de cilinders; elk blok omvattende een boogvormig binnenoppervlak passende een ringvormige beweging van de dubbelkoppige zuiger; elke zuigerarm (5) omvattende een boogvormig geleideblok (5-1).An engine according to claim 1, with two annular cylinders and two crankshafts, further comprising two guide blocks (14) mounted on the outside of the cylinders; each block comprising an arcuate inner surface fitting an annular movement of the double-headed piston; each piston arm (5) comprising an arcuate guide block (5-1).

3. Motor volgens conclusie 1, met twee ringvormige cilinders en twee krukassen, waarbij delen van de zuigerkoppen (6) en de cilinders (1), die in direct contact staan met gassen, die een hoge temperatuur hebben, van keramisch materiaal zijn gemaakt.Engine according to claim 1, with two annular cylinders and two crankshafts, parts of the piston heads (6) and the cylinders (1) in direct contact with high temperature gases being made of ceramic material.