Combustion engine

Abstract

The invention relates to a combustion engine comprising cylinders (2) arranged in parallel in a circle around a rotary output shaft (3) and provided with fuel injectors (5), spark plugs (6), gas outlets (7) and pistons attached to longitudinally movable piston arms (8). The piston arms (8) comprise a freewheel (9) on which a gear (10) is mounted, the gear being provided with a series of free-rotation rollers (11) that make contact with helical tracks (20) of a rotor (19) that is solidly connected to the output shaft (3), rotating same. The output shaft (3) comprises a helical ramp section (21) which, during operation of the combustion engine, acts sequentially on the successive piston arms (8), moving same towards top dead centre in a compression cycle or time.

Description

[0001] DESCRIPTION

[0002] Internal combustion engine.

[0003] Technical sector.

[0004] The present invention belongs to the sector of reciprocating piston engines with a main rotating shaft other than a crankshaft and more specifically to an internal combustion engine.

[0005] Prior art

[0006] In the state of the art, internal combustion engines are widely known, which have several cylinders equipped with valves for fuel intake, respective spark plugs for igniting the air-fuel mixture, and pistons that move inside their respective cylinders, between bottom dead center and top dead center in each of the intake, compression, power, and exhaust strokes of the engine.

[0007] In this type of internal combustion engine, the use of connecting rods that convert the longitudinal movement of the pistons into a rotary movement of a crankshaft is widely known; this results in high mechanical stresses, a lot of friction between the pistons and the cylinders, and wear on both the connecting rods and the cylinders.

[0008] In invention patent ES 2 900 427, from the same applicant of the present invention, an internal combustion engine is described which is the document closest to the present invention and which partially solves the drawbacks of internal combustion engines of the type mentioned above, especially with regard to the friction of the pistons with the cylinders and the stresses to which the connecting rods are subjected during the operation of the engine, using for this purpose an output shaft that has a worm rotor provided with helical teeth and to which are connected some thrust pinions, also provided with helical teeth and mounted on bars that move longitudinally with the respective pistons.

[0009] The applicant has determined that the friction between the helical teeth of the rods and the main shaft rotor results in a significant loss of generated power. In this design, the rods attached to the pistons are arranged in opposing positions on racks connected by intermediate gears. These racks transform the movement towards bottom dead center (BDC) of the piston corresponding to one rod into a movement towards top dead center (TDC) of the piston corresponding to an adjacent rod in the engine's operating sequence.

[0010] The owner himself has confirmed that these rack and pinion mechanisms for synchronously moving the different bars and pistons during engine operation are structurally complex and costly.

[0011] Therefore, the technical problem that arises is the development of an internal combustion engine with alternative drive mechanisms to those of the aforementioned predecessor, which allow the aforementioned drawbacks to be solved, significantly simplifying the means used to convert the longitudinal movement of the pistons into a rotary movement of the output shaft, and using the movement of a piston towards the bottom dead center, caused by the explosion of the fuel, to move the piston towards the top dead center in a compression cycle.

[0012] Explanation of the invention.

[0013] The internal combustion engine of this invention is of the type described in the preamble of the main claim and comprises: cylinders arranged parallel to each other and in a circular arrangement around a rotating output shaft and provided with fuel injectors, spark plugs, exhaust gas outlets and pistons fixed to arms movable in a longitudinal direction; said rotating output shaft being mechanically driven by the reciprocating and sequential movement of the pistons between top dead center and bottom dead center.

[0014] This internal combustion engine has technical characteristics that allow it to overcome the drawbacks of the aforementioned predecessor, providing alternative means of drive that, from a constructive point of view, simplify and reduce the cost of the aforementioned predecessors.

[0015] According to the invention, the piston arms comprise in an intermediate zone a free wheel on which is mounted a crown provided with a series of free-spinning rollers oriented in a radial direction and which, during the operation of the engine, are sequentially engaged with helical tracks of a rotor that rotates in unison with the output shaft, and transform the longitudinal movement of the pistons, generated by the explosion of the fuel in the successive cylinders, into a rotational movement of the output shaft.

[0016] The freewheels mounted on the arms allow the crowns to rotate freely in one direction, without interfering with the rotational movement of the rotor, during the upward movement of the corresponding piston arm, and are prevented from rotating in the opposite direction so that, during the downward movement of the corresponding piston arm, they act by means of the free-rotating rollers against the helical tracks of the rotor, causing the rotation of said rotor and the output shaft in the direction of travel of the motor.

[0017] Each of the crowns has several free-spinning rollers, distributed around its periphery, so that during the rotation of the rotor, contact is maintained between at least one helical track of the rotor and one of the rollers of each crown.

[0018] The free-spinning rollers are mounted by means of bearings on radial shafts attached to the corresponding crowns, so that the friction against the helical tracks of the rotor during its operation is very low, and allows optimal use of power in the drive of the output shaft.

[0019] According to the invention, a helical ramp section is mounted on the output shaft by means of a freewheel, which during the operation of the engine acts sequentially on the successive piston arms and moves them towards top dead center, in the compression stroke.

[0020] This helical ramp section is designed to be positioned below the free end of the piston arms, so that as the helical ramp section rotates along with the output shaft, it sequentially acts on the lower end of the successive arms, causing them to move towards top dead center and compress the fuel mixture inside the corresponding cylinder. According to the invention, the piston arms include a contact that activates fuel injection and spark ignition when the piston reaches top dead center in the corresponding cylinder.

[0021] The exhaust ports are located in an area of ​​the cylinders near the bottom dead center of the respective pistons.

[0022] According to the invention, this internal combustion engine comprises an electric motor for starting the rotational movement of the rotor, which operates for a few seconds to initiate the rotational movement of the rotor and then stops; said electric motor being connected by means of a transmission element to a pinion coupled by means of a freewheel to the output shaft and an electric motor for starting the rotational movement of the helical ramp section responsible for moving the successive piston arms towards top dead center.

[0023] Brief description of the content of the drawings.

[0024] To complement the description being made and in order to facilitate the understanding of the characteristics of the invention, a set of drawings is included with this descriptive report in which, for illustrative and non-limiting purposes, the following has been represented:

[0025] Figure 1 shows a schematic perspective view of an example embodiment of an internal combustion engine, according to the invention, open at the front.

[0026] Figure 2 shows a plan view of one of the toothed rings with one of the free-spinning rollers removed.

[0027] Figure 3 shows a plan view of the internal combustion engine sectioned by a horizontal plane located at the height of the rotor and above the free-spinning roller carrier rings.

[0028] Detailed exposition of modes of implementation of the invention.

[0029] In the attached figures, the different elements have been identified with the numerical references indicated below: 1. Motor block

[0030] 2. Cylinders

[0031] 3. Output shaft

[0032] 4. Cylinder head

[0033] 5. Fuel injectors

[0034] 6. Spark plugs

[0035] 7. Gas outlets

[0036] 8. Piston arms

[0037] 9. Freewheel

[0038] 10. Crown

[0039] 11. Free-spinning rollers

[0040] 12. Radial axes

[0041] 13. Bearings

[0042] 14. Locking nut

[0043] 15. Linear bearing

[0044] 16. Anti-rotation linear guide

[0045] 17. Ball roller

[0046] 18. Contactor

[0047] 19. Rotor

[0048] 20. Helical tracks

[0049] 21. Helical ramp section

[0050] 22. Wheel

[0051] 23. Electric starter motor

[0052] 24. Transmission

[0053] 25. Electric motor

[0054] 26. Transmission element

[0055] 27. Pinion

[0056] In the embodiment shown in Figure 1, the internal combustion engine comprises an engine block (1) in which cylinders (2) are mounted parallel to each other and arranged in a circular arrangement around a rotating output shaft (3).

[0057] Said engine block (1) is provided with a cylinder head (4) in which the fuel injectors (5) and spark plugs (6) of the cylinders (2) are arranged. The cylinders (2) have inside them respective pistons (not referenced) that can be moved between a top dead center and a bottom dead center, and comprise exhaust ports (7) arranged within the stroke of the pistons and close to the bottom dead center of the stroke of said pistons.

[0058] The piston arms (8) comprise an initial section of circular cross-section mounted on a linear bearing (15) and a final section of polygonal cross-section mounted on an anti-rotation linear guide (16), so that said piston arms move in a longitudinal direction, without the possibility of rotation.

[0059] The output shaft (3) is mechanically driven by the reciprocating and sequential longitudinal movement of the piston arms (8).

[0060] The piston arms (8) comprise in an intermediate zone a free wheel (9) on which is mounted a crown (10) provided with a series of free-spinning rollers (11), oriented in a radial direction and which, during the operation of the engine, sequentially contact some helical tracks (20) of a rotor (19), sectioned in figure 2, which rotates in unison with the output shaft (3), transforming the longitudinal movement of the piston arms (8) in a downward direction, caused by the explosion of fuel in the successive cylinders (2), into a rotational movement of the output shaft (3).

[0061] As shown in Figure 2, the crowns (10) comprise radial shafts (12) on which the free-spinning rollers (11) are mounted by means of bearings (13) and locking nuts (14) that retain the free-spinning rollers in the mounting position on the respective radial shafts.

[0062] On the output shaft (3) is mounted a section of helical ramp (21), by means of a wheel (22) connected to an electric starter motor (23); during the operation of the internal combustion engine, this section of helical ramp (21) acts sequentially on the successive arms of the pistons (8), moving them towards top dead center during a compression stroke or cycle.

[0063] In order to minimize friction with the helical ramp section (21), the arms have a rolling ball (17) at their free end, forming a support element on the helical ramp section (21). The piston arms (8) comprise a contactor (18) that causes fuel injection and subsequently the spark for ignition as the piston arms (8) are displaced by the helical ramp section (21) and the respective pistons reach top dead center.

[0064] In the example shown in Figure 1, the wheel (22) carrying the helical ramp section (21) is connected by means of a transmission (24) to the electric starter motor (23); the internal combustion engine further comprising an electric starter motor (25) for the rotational movement of the rotor (19) connected by means of a transmission element (26) to a pinion (27) coupled by means of a freewheel to the output shaft (3).

[0065] To start the internal combustion engine, the electric starter motor (25) is initially started, causing the rotor (19) to rotate. A few seconds later, the electric starter motor (23) is started, which causes the helical ramp section (21) to rotate. This section sequentially moves the piston arms (8) until the pistons reach compression. When the helical ramp section (21) rotates, the contactor (18) triggers fuel injection, followed by the spark for ignition.

[0066] With the explosion of the fuel the piston descends and the free-spinning rollers (11) mounted on the crown (10) of the corresponding piston arm cause the rotation of the rotor (19) and the output shaft (3) fixed to it.

[0067] Once the nature of the invention has been sufficiently described, as well as an example of a preferred embodiment, it is noted for the appropriate purposes that the materials, shape, size and arrangement of the elements described may be modified, provided that this does not imply an alteration of the essential characteristics of the invention claimed below.

Claims

CLAIMS 1. Internal combustion engine, comprising: an engine block (1), cylinders (2) arranged parallel to and in a circular arrangement around a rotating output shaft (3) and provided with fuel injectors (5), spark plugs (6), exhaust outlets (7), and pistons fixed to piston arms (8) movable in a longitudinal direction, without the possibility of rotation; said output shaft (3) being mechanically driven by the reciprocating and sequential movement of the piston arms (8) between top dead center and bottom dead center; characterized in that the piston arms (8) comprise in an intermediate zone a freewheel (9) on which is mounted a crown (10) provided with a series of freely rotating rollers (11) oriented in a radial direction and which, during the operation of the engine, sequentially contact helical tracks (20) of a rotor (19) that rotates together with the output shaft (3),and transform the longitudinal movement of the piston arms (8) during the power stroke in successive cylinders (2) into a rotary movement of the output shaft (3), and on said output shaft (3) is mounted a section of helical ramp (21), by means of a wheel (22) connected to an electric starter motor (23), and during the operation of the internal combustion engine said section of helical ramp acts sequentially on the successive piston arms (8), moving them towards top dead center in a fuel compression stroke.

2. Engine, according to claim 1, wherein the piston arms (8) comprise a contactor (18) that causes fuel injection and subsequently the spark for ignition, as the piston arms (8) are displaced by the helical ramp section (21) and the respective pistons reach top dead center.

3. Motor, according to any previous claim, wherein the arms have at their free end a rolling ball (17) forming a support element on the helical ramp section (21).

4. Motor, according to any preceding claim, wherein the crowns (10) comprise radial shafts (12) on which the free-spinning rollers (11) are mounted by means of bearings (13), and locking nuts (14) that retain the free-spinning rollers in the mounting position.

5. Engine, according to any preceding claim, wherein the exhaust outlets (7) They are defined in an area of ​​the cylinders (2) close to the bottom dead center of the respective pistons.

6. Motor, according to any preceding claim, wherein the piston arms (8) comprise an initial section of circular cross-section mounted on a linear bearing (15) and a final section of polygonal cross-section mounted on an anti-rotation linear guide (16).

7. Motor, according to any of the preceding claims, wherein the wheel (22) carrying the helical ramp section (21) is connected by means of a transmission (24) to the electric starter motor (23).

8. Motor, according to any preceding claim, comprising an electric motor (25) for starting the rotational movement of the rotor (19) connected by means of a transmission element (26) to a pinion (27) coupled by means of a freewheel to the output shaft (3).

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