Piston engine without connecting rod

Abstract

A mechanism replaces the connecting rod-crankshaft assembly of a piston engine while retaining the same functions. It consists of three elements: - a carriage moving on slides to which two opposing pistons are attached. It has crosspieces, each with a cell. - a rotor attached to the engine shaft has three peripheral pinion teeth, each 120 degrees apart, which mesh successively with the cells. The carriage pushes these teeth and turns the rotor, and therefore the engine shaft. - a cam acts on the carriage to synchronize the movements, gradually slow down the movement of the pistons, and limit their stroke.

Description

Title of the invention: Connecting rodless piston engine

[0001] This invention relates to piston heat engines. Although piston heat engines have existed for a long time, they are the subject of research to bring about improvements which require innovations.

[0002] This invention provides a means for more simply replacing the connecting rod-crankshaft system which is universally used, which would bring savings in the number of parts and therefore reduce costs.

[0003] The alternating movement exerted by the pistons is always retained in a rotary movement driving the motor shaft.

[0004] On examining the attached figures we see:

[0005] Figures 1 to 3 briefly show the three fundamental elements of the invention.

[0006] -Figures 4 to 8 show a different design of the mechanism while retaining the fundamental principles.

[0007] - Figures 9 and 10 propose a conceptual use of the invention, according a profitable simplification of piston thermal engines.

[0008] [Fig. 1] [Fig. 1] represents one of the basic elements where we notice two piston heads on the right and left aligned (1) and (2) connected by two arms to a frame made up of two crosspieces (3) and (4) and two vertical uprights. This assembly is called "carriage". It is crossed in its middle by the motor shaft (5) and moves horizontally, alternately according to the movements of the pistons and held by slides (6) constituting the chassis or engine block. We also see that the crosspieces have cells (7 and 8) similar to rack slots.

[0009] This mechanism makes it possible to reduce the size of the pistons which no longer require skirts since the carriage is held and guided by slides in the chassis.

[0010] A second important part is represented by [Fig.2] [Fig.2] which is a rotor (9) fixedly attached to the motor shaft placed in the same vertical plane as the frame of the carriage. It comprises radially three arms (10, 11, 12) each spaced 120° apart. The termination of these arms is similar to pinion teeth which are provided to mesh with the cells (7) and (8).

[0011] According to the configuration shown in this [Fig.2] it is easily seen that if the carriage is intended to move from left to right, the socket (7) drives the tooth of the arm (10) which will turn clockwise as well as the motor shaft (5). In this operating phase, the carriage is almost at the end of its travel on the right. The tooth of the arm (10) acting on the right part of the socket (7) pushes the piston (1) to the limit of the top dead center. As long as the tooth in question is in contact with the socket, the carriage cannot move in the left-right direction. It is necessary to immobilize the carriage for a brief moment to allow the tooth of the arm (12) to position itself properly in the socket of the lower crosspiece. From there, the carriage can move in the opposite direction, i.e. from right to left. The piston (2) can begin its descent towards the bottom dead center. The arm (12) is pushed to the left and drives the motor shaft always in the same direction. When the right-left end of travel arrives, the piston is at top dead center, and the piston (2) at bottom dead center. The tooth of the arm (12) will separate from the socket (8) of the lower crosspiece, and it is up to the arm (11) this time to engage the socket of the upper crosspiece. The carriage will then move from left to right, and we find ourselves in the same situation as that seen above, illustrated by [Fig.2]. A complete cycle will then be carried out.

[0012] If the rotor arms push the carriage to reach the limits of the "top dead center bottom dead center" of the pistons, nothing in the current state prevents the carriage from exceeding these limits. It can go beyond. It is therefore necessary to provide a limitation. A stop alone would not be suitable because of the sudden stop that would follow. It is necessary to gradually reduce the speed of movement of the carriage before it comes to a complete stop.

[0013] This is the role assigned to a third element of the invention. It is a cam represented by [Fig.3] [Fig.3] which has three lobes. This cam is strictly integral with the drive shaft as is the rotor. It acts on bearing surfaces 13, 14) constituting the vertical uprights of the carriage frame. When the latter, during a cycle, has traveled approximately two-thirds of its travel, the cam comes into action and intervenes on the bearing surfaces to slowly slow the carriage down to its complete stop which corresponds to the "top dead center - bottom dead center" position. The carriage is not braked because its residual force tends to push the cam which transmits the force to the drive shaft. The movement of the cam is in synchronism with that exerted by the arms such as (10) for example at the end of travel as illustrated in [Fig.2].

[0014] We have seen that when examining this figure and as mentioned previously before the arm (10) separates from the cell (7), a latency time is required for the arm (12) to position itself properly in the cell (8). Manufacturers always seeking to optimize operations, would like to limit this latency time, for example for engines intended for sports use, in this respect, another design is proposed incidentally.

[0015] Respecting the basic principle of the invention, there is therefore always the carriage

[0010] This is the role assigned to a third element of the invention. It is a cam represented by [Fig.3] [Fig.3] which has three lobes. This cam is strictly integral with the motor shaft as is the rotor. It acts on bearing surfaces 13, 14) constituting the vertical uprights of the carriage frame. When the latter during of a cycle has traveled about two-thirds of its travel, the cam comes into action and intervenes on the bearing surfaces to slowly slow the carriage until it comes to a complete stop which corresponds to the "top dead center - bottom dead center" position. The carriage is not braked because its residual force tends to push the cam which transmits the force to the drive shaft. The movement of the cam is in synchronism with that exerted by the arms such as (10) for example at the end of travel as illustrated in [Fig.2].

[0016] We have seen that when examining this figure and as mentioned previously, before the arm (10) separates from the cell (7), a latency time is required for the arm (12) to position itself properly in the cell (8). Manufacturers, always seeking to optimize operations, would like to limit this latency time, for example for engines intended for sports use; in this respect, another design is proposed incidentally.

[0017] Respecting the basic principle of the invention, there is therefore still the carriage, a rotor, and the cam. The carriage this time has the three arms, but these are not identical to those seen in [Fig.2]. They are replaced by three slides (15, 16, 17) as shown in figure 4 figure 4 of which one is shown succinctly in a top view in figure 5

[0018] Figure 5. The rotor is flush with the crosspieces.

[0019] Three slides are provided in the slides, one of which is shown in Figures 6 and 7 [Fig.6] [Fig.7]. Each slide ends at one end (always facing the motor shaft) with a cylindrical lug (18). The other end is designed to come out of the slides in order to enter the cells. If we assume, for example, that the carriage is completely at the end of its travel on the left and that it will begin to move towards the right just at this moment, a slide will come out of its slide and enter the cell (7). The carriage will therefore drive the slide, slide and the motor shaft in rotation. At the end of its travel on the right, the slide will separate from the cell and retract into its slide. At the same time, another opposite slide will be inserted into the cell (8). It should be noted that the alternating movements of the slides are rapid and optimize the actions of the pistons.

[0020] To operate the slides, it is provided that a support secured to the chassis or engine block is provided with a projecting cup (19) in which a groove (20) has been machined. This groove has convolutions. During assembly, the rotor grazes the cup so that the three lugs such as (18) penetrate into the groove. When the rotor rotates, the lugs move in the groove and follow its contour. When a lug is located in an eccentric zone (21), the end of the slide leaves the slide to penetrate the cell, but when it is located in the zone (22) it is retracted into the slide.

[0021] A mechanism with two pistons has been mentioned. Many engines have at least four cylinders. If we want to increase the number within the framework of the invention, it would therefore be necessary to have a second carriage with two other pistons. But a single device according to the invention would be sufficient, namely a rotor and a cam. Therefore, possibly two carriages would be joined together as shown succinctly in figure 8. The assembly could work well. We can measure the total simplicity of the device. There is no longer a connecting rod / crankshaft. However, as it is, this assembly could generate nuisances when we refer to the total mass that it represents; the movement itself slowed down by the cam would cause a significant force that the engine shaft would undergo. This would result in an unbalance with undesirable vibrations.

[0022] This can be remedied by a small, simple complication. The two carriages are this time independent. Figure 9 illustrates the solution. It shows a support (23) forming part of the chassis or engine block located between the two carriages. On this support there is a vertical pivot (24), on which a hub (25) is articulated which is at the center of a connecting rod (26) whose two ends are extended by forks (27) which surround pivots (28, 29) located in supports (30, 31) of the two carriages. When one carriage moves in one direction, the movement of the connecting rod forces the other carriage to move in the other direction. This reduces the influence of inertial masses. It is possible to replace the connecting rod with a toothed wheel which is articulated on the pivot (24) and which engages two lateral racks, each one being attached to the carriage which concerns it.

[0023] When we take stock of the interest of this invention, we note that in addition to the economy in the number of parts, we can notice that at each piston stroke, the engine shaft only turns one sixth of a turn instead of half a turn with conventional engines equipped with connecting rods. Therefore, these are faster speed increases, less vibrations and less wear. In addition, we can see that, at the start of a piston descent, the carriage transmits the engine force to the rotor by acting on an arm which has an angle of thirty degrees relative to the vertical, i.e. in a better condition than that offered by the connecting rod-crankshaft system. The torque is thus favored. It is thus easily seen that the device proposed by the invention can be usefully integrated into an engine with several pistons.

[0024] It is possible if you want even more sophisticated mechanisms (racing engines) to increase the number of rotor arms, to six arms for example. You will then have to modify the cam accordingly.

Claims

Claims

1. A mechanism that can more simply replace the connecting rods and crankshafts of piston engines is composed of three complementary elements: a carriage, a rotor and a cam. The carriage is designed to be connected to two opposite pistons, it is characterized in that it consists of a frame comprising two parallel horizontal crosspieces and two vertical lateral uprights. It moves in slides attached to the engine chassis. This frame is perpendicular to the engine shaft which passes through it. It is driven by an alternating movement at the whim of the pistons. The crosspieces have two facing rack cells or notches such as (7) and (8). A second element is similar to a rotor.It is characterized in that it is integral with the motor shaft moving in the same plane as the aforementioned frame, and that it has three peripheral protuberances similar to pinion teeth, each separated by an angle of 120 degrees and which mesh in turn with the cells of the crosspieces, the latter acting there according to a back and forth movement making the rotor and therefore the motor shaft turn. A third element is a cam [Fig.3] which is characterized in that it is integral with the motor shaft and that it has three lobes which act in turn on bearing surfaces adjacent to the right and left uprights. During the rotational movement, the profiles of these lobes alternately impose on the carriage, and at the appropriate moment, a slowing down until it comes to a complete stop before it sets off again in the opposite direction.

2. According to claim 1, respecting the same provisions, there is provided another rotor integral with the motor shaft having a shape similar to that described. It is characterized in that on one of its faces there are three slides in radial position like (15) (16 (17) separated by angles of 120 degrees. These slides are flush with the periphery of the rotor and in each of them moves a slide [Fig.6] which can be either completely retracted or partly protruding. According to the back and forth movement of the carriage, when the situation is suitable, this slider enters the socket of a crosspiece so that the latter can push it to turn the rotor and therefore the motor shaft. A third element is a cam [Fig.3] which is characterized in that it is integral with the motor shaft and that it has three lobes which act in turn on bearing surfaces adjacent to the right and left uprights. During the rotational movement, the profiles of these lobes alternately impose on the carriage, and at the appropriate moment, a slowdown until it comes to a complete stop before it sets off again in the opposite direction.

3. According to claim 1, respecting the same provisions, there is provided another rotor integral with the motor shaft having a shape similar to that described. It is characterized in that on one of its faces there are three slides in radial position like (15) (16 (17) separated by angles of 120 degrees. These slides are flush with the periphery of the rotor and in each of them moves a slide [Fig.6] which can be either completely retracted or partly protruding. In the latter case, when the situation is suitable, it enters the cavity of a crosspiece so that the latter can push it to cause the rotor to rotate. A means is provided to move the slide when the time comes so that it can act with the crosspiece in question.

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