EP0252108B1 - Heat engine with cooling of the pistons and jackets - Google Patents

Abstract

Barrel-type machine and especially engine of which the cooling is effected by means of turbines (5 and 6) mounted about a central shaft (4) and distributing outer air from the central part of the engine, particularly inside the pistons and the jackets. The suppression of fluids, water and oil, is thus made possible mainly if an aerosol is used as cooling agent.

Description

The present invention relates to a machine with cylinders arranged in barrels.

The problem of the cooling of the compression chamber is a problem of paramount importance for thermal engines; it is also of some interest for positive displacement compressors where the rise in temperature of the walls of the cylinders creates difficulties in certain cases.

Conventionally, this problem is solved by only cooling the external walls of the cylinders by a circulation of water or air, but nothing is provided to cool the piston except for certain very large heat engines where provision is made sometimes watering the pistons with a complicated device.

Furthermore, according to FR-A-852 974, and according to the preamble to the new claim 1, a machine is known comprising parallel cylinders arranged in barrels, pistons moving back and forth in the cylinders, movement transmission means with connecting rods interposed between the pistons and a movement transformer connected to a rotary shaft, and distribution means.

Also known from FR-A-1 073 747 is a thermal machine with cylinders arranged flat or in a star, operating according to the two-stroke cycle, and in which a turbine mounted on the output shaft drives the air either in the working chambers or against the face of the pistons facing the crankshaft and the connecting rods.

This cooling mode has the disadvantage that the cooling air, after being heated in contact with the pistons, is evacuated by the crankshaft casing and therefore comes to heat the crankshaft. In addition, the piston is only cooled intermittently, when there is coincidence between the intake duct and the piston lights.

The object of the invention is to improve the cooling of barrel motors.

According to the invention, the machine is characterized in that it comprises, between the movement transformer and the cylinders a thermal separation compartment defined between two walls traversed by the rotary shaft and by the transmission means and extending all two between the movement transformer and the cylinders, a first wall comprising at least one light communicating a movement transformation stage with the thermal separation compartment, and the second wall comprising lights communicating the thermal separation compartment with the inside the cylinders, and in that a turbine is mounted on the shaft in the thermal separation compartment, said turbine sucking from the movement transformation stage a coolant which passes through said separation compartment and is discharged into the variable volume inside the cylinders, on the side of the pistons facing the biel the respective ones.

Thus, the thermal separation compartment thermally separates the cylinders and the motion transformer. The cooling of the interior of the cylinders, instead of constituting a risk of excessive heating for the motion transformer, on the contrary contributes to minimizing the heating of the latter.

In addition, the cooling according to the invention, unlike the device according to FR-A-1 073 747, is not dependent on an intermittent coincidence between lights defining the cooling path. The arrangement of the separation compartment makes it possible to maintain a permanent cooling flow, instead of to cool the pistons by a succession of thermal shocks.

The thermal separation compartment according to the invention advantageously combines with the barrel arrangement. The turbine mounted on the central shaft makes it possible to supply all the cylinders equally. In addition, the barrel arrangement has the advantage of greatly limiting the lateral movement of the connecting rods, which is favorable to the installation of a fairly tightly closed compartment between the cylinder block and the movement transformation stage.

Preferably, a second turbine is mounted on the shaft between the cylinders so as to ensure a flow of cooling fluid along the outer wall of the cylinders.

It is advantageous that the machine comprises four geometrically clearly separated stages, but rigidly connected together, namely a movement transformation stage, the thermal separation compartment, a compression stage, defining the cylinders, and a distribution stage.

The rotary shaft may comprise a primary shaft cooperating with the motion transformer, and a secondary shaft extending the primary shaft in the direction of the cylinders along the axis of the barrel, the secondary shaft carrying the turbine or turbines and carrying, at its end opposite to the motion transformer, a rotary distribution control means.

Cooling is particularly effective if the coolant is an aerosol.

• Le schéma 1 est une coupe schématique du moteur lorsqu'un piston est en bas de sa course; pour la clarté du dessin aucun autre piston n'a été représenté, mais il a été indiqué l'axe; de même la retenue de couple n'a pas été représentée.
  Sur ce schéma, on voit que
  • le premier élément situé entre deux surfaces de révolution planes ou courbes a pour fonction de servir de carter au transformateur de mouvement en barillet qui peut être du type à rotule centrale (ce qui est représenté) ou du type arbre en "Z"; dans cet élément la surface inférieure (I) est traversée par l'arbre de sortie (1) (ou d'entrée) du mouvement, la surface supérieure (II) possède des ouvertures (2) permettant le passage des bielles allant aux rotules des pistons à tige et celui d'un palier (3) permettant la rotation de l'arbre médian (4) destiné à l'entraînement des auxiliaires tels que turbines (5 et 6) et distribution.
  • le deuxième élément situé entre deux surfaces de révolution planes ou courbes (II) et (III) a pour fonction d'assurer une évacuation correcte des calories dues au dégagement de chaleur qui a lieu dans les cylindres lors de la combustion (ou de la compression); pour cela un premier étage de pales (7) placées autour de l'arbre médian (4) refoule grâce à un cloisonnement approprié (8) un fluide (gaz ou liquide ou aérosol) sur le volume variable constitué par le fond du piston et la chemise tandis qu'un deuxième étage de pales, étage qui peut être situé au niveau du troisième élément, refroidit l'extérieur des chemises si le besoin s'en fait sentir; des moyens d'étanchéité sont prévus pour empêcher, si il le faut, l'arrivée du fluide dans le premier élément; l'utilisation d'un aérosol tel que air chargé de très fines gouttellettes d'eau peut être très intéressante et par l'amélioration du refroidissement et par le rôle de catalyseur produit par ces très fines gouttellettes et par l'espèce de lubrification qu'apportent ces gouttellettes;
  • le troisième élément situé entre la surface plane ou courbe (III) et obligatoirement une surface plane (IV) remplit la fonction dévolue au bloc moteur (ou bloc de compression) dans la disposition classique, c'est à dire assure la transformation de l'énergie chimique en énergie cinétique dans un moteur ou exécute une partie de la compression dans un compreseur; la surface (IV) possède un palier (9) destiné au passage de l'arbre médian (4) et assurant une étanchéité suffisante pour que la quasi totalité du fluide reste dans le troisième élément, elle est de plus convenablement cloisonnée pour que les filets de fluide assurent l'évacuation maxima des calories;
  • le quatrième élément situé au dessus de la surface plane (IV) est constitué par la distribution qui est réalisée à partir de l'arbre médian par des moyens appropriés basés sur l'utilisation de cames ou l'emploi de boisseaux tournants dont la commande est assurée par l'engrenage (10) et dont le principe est préférablement conforme au FR-A-2 608 211.
• Le schéma 2 est une coupe schématique suivant AA; il est destiné à montrer les ouvertures (11) permettant la montée dans le deuxième élément du fluide aspiré à la hauteur du premier élément.
  Les ouvertures en question peuvent être reliées à des tuyaux rigides pour que l'aspiration se produise dans une région donnée, ou des tuyaux souples dont un mouvement commandé règlera le débit d'air.
• Le schéma 3 est une coupe schématique suivant BB; il est évident que les dimensions et les formes des ouvertures (12) sont liées au débit et à la pression de la turbine (6); cette turbine peut aussi être alimentée par de l'air extérieur amené par des conduits.

The invention will now be described by way of an example, with reference to the accompanying drawings.

• Diagram 1 is a diagrammatic section of the engine when a piston is at the bottom of its stroke; for clarity of the drawing, no other piston has been shown, but the axis has been indicated; similarly the torque restraint has not been shown.
  On this diagram, we see that
  • the first element located between two planar or curved surfaces of revolution has the function of serving as a casing for the barrel motion transformer which can be of the central ball type (which is shown) or of the "Z" shaft type; in this element the lower surface (I) is crossed by the output shaft (1) (or input) of the movement, the upper surface (II) has openings (2) allowing the passage of the connecting rods going to the ball joints of the piston rods and that of a bearing (3) allowing the rotation of the median shaft (4) intended for driving the auxiliaries such as turbines (5 and 6) and distribution.
  • the second element located between two planar or curved surfaces of revolution (II) and (III) has the function of ensuring a correct evacuation of calories due to the release of heat which takes place in the cylinders during combustion (or compression ); for this a first stage of blades (7) placed around the median shaft (4) pushes back thanks to an appropriate partitioning (8) a fluid (gas or liquid or aerosol) on the variable volume constituted by the bottom of the piston and the jacket while a second stage of blades, a stage which may be located at the level of the third element, cools the outside of the sleeves if the need arises; sealing means are provided to prevent, if necessary, the arrival of the fluid in the first element; the use of an aerosol such as air charged with very fine droplets of water can be very advantageous both by improving the cooling and by the role of catalyst produced by these very fine droplets and by the type of lubrication that bring these droplets;
  • the third element located between the flat or curved surface (III) and necessarily a flat surface (IV) fulfills the function assigned to the engine block (or compression block) in the conventional arrangement, that is to say ensures the transformation of chemical energy into kinetic energy in an engine or performs part of the compression in a compressor; the surface (IV) has a bearing (9) intended for the passage of the median shaft (4) and ensuring a sufficient seal so that almost all of the fluid remains in the third element, it is moreover appropriately partitioned so that the threads of fluid ensure the maximum evacuation of calories;
  • the fourth element located above the flat surface (IV) is constituted by the distribution which is carried out from the median shaft by appropriate means based on the use of cams or the use of rotary plugs the control of which is provided by the gear (10) and the principle of which is preferably in accordance with FR-A-2 608 211.
• Figure 2 is a schematic section along AA; it is intended to show the openings (11) allowing the rise in the second element of the fluid sucked at the height of the first element.
  The openings in question can be connected to rigid pipes so that suction takes place in a given region, or flexible pipes whose controlled movement will regulate the air flow.
• Diagram 3 is a diagrammatic section along BB; it is obvious that the dimensions and the shapes of the openings (12) are related to the flow rate and to the pressure of the turbine (6); this turbine can also be supplied by outside air supplied by conduits.

It is advantageous, in order to avoid the birth of vibrations, that the elements composing the different parts of the machine are linked together in the most rigid manner so that the bores of the openings intended for the passage of the median shaft are aligned with as perfect as possible

The use of new materials in the fields of friction and thermal insulation makes this solution even more attractive; the swinging movement of the ball joints makes lubrication sufficient with a grease which will be useless to renew, the perfectly linear displacement of the piston and the reduction in friction due to the temperature of the latter makes it possible, especially if the formula is used aerosol indicated above, with a material such as Revetox, to suppress the oil circuit.

In other words, in an engine oil and water no longer play any role.

• diminution très importante du nombre de pièces, d'où
• diminution du poids,
• suppression des poids parasites: huile, eau avec leurs corollaires: radiateur, filtre, canalisations, etc...,
• diminution des frottements, d'où
• amélioration du rendement,
• prix de revient abaissé.

The advantages of such a construction are obvious:

• very significant decrease in the number of parts, hence
• weight reduction,
• elimination of parasitic weights: oil, water with their corollaries: radiator, filter, pipes, etc ...,
• reduced friction, hence
• yield improvement,
• cost price lowered.

Claims (6)

1. A machine comprising parralel cylinders in a barrel-type arrangement, pistons reciprocable in the cylinders, movement transmission means having connecting rods interposed between the pistons and a movement converter connected to a rotatable shaft (1, 4), and distribution means, characterized in that the machine comprises, between the movement converter and the cylinders, a thermal separation compartment defined between two walls (II, III) having the rotatable shaft (1, 4) and the transmission means extending therethrough, both walls extending between the movement converter and the cylinders, a first wall (II) comprising at least one aperture (11) providing communication between a movement conversion stage and the thermal separation compartment, and the second wall (III) comprising apertures providing communication between the thermal separation compartment and the inside of the cylinders, and in that a turbine (5) is mounted onto the shaft (4) in the thermal separation compartment, said turbine taking in to the movement conversion stage a coolant-fluid which passes in said separation compartment and is delivered into the variable volume inside the cylinders, adjacent that side of the pistons which faces the respective connecting rods.

2. A machine according to claim 1, characterized by a second turbine (6) mounted onto the shaft between the cylinders so as to provide a flow of coolant-fluid along the external wall of the cylinders.

3. A machine according to one of claims 1 or 2,characterized in that it comprises four stages which are geometrically clearly separated, i.e. a movement-conversion stage, the thermal separation stage, a compression stage defining the cylinders, and a distribution stage (IV).

4. A machine according to claim 3, characterized in that the four stages are rigidly connected together.

5. A machine according to one of claims 1 to 4, characterized in that the rotatable shaft comprises a primary shaft (1) cooperating with the movement-converter, and a secondary shaft (4) prolongating the primary shaft (1) towards the cylinders along the axis of the barrel arrangement, the secondary shaft (4) carrying the turbine(s) (5, 6) and carrying, at its end remote from the movement-converter, a rotatable means (10) for controlling distribution.

6. A machine according to one of claims 1 to 5, characterized in that the coolant-fluid is an aerosol

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