EP0060822A1 - Motor with a linear movement, and a swash plate for it - Google Patents

Abstract

The invention relates to an engine comprising at least one piston with reciprocating linear translational movement and a swash plate mounted at an angle on a shaft driven in rotation in the casing. It is characterized by the fact that each piston (21) is integral with a rod (10) whose end situated opposite the piston comprises a slide (11) guided in a slide and by the fact that each slide ( 11) traps two shells (18, 18 ') forming a housing for a ball joint (19) connected to the swash plate.

Description

The invention relates to an engine or similar device comprising at least one piston with reciprocating linear translational movement and a swash plate mounted at an angle on a shaft driven in rotation in the casing or engine block by the reciprocating movements of said plate in contact with said piston.

It has already been proposed to transform the alternative linear movements of one or more pistons by making use of a swash plate to cause the rotation of a drive shaft on which the swash plate in question is wedged. Examples of the species are described, among others, in US patents 3,611,879.3 621,761.3 807,283 and 4,108,049 as well as in German patent 1,810,808.

In general, the motors or pumps according to these patents lack robustness due, on the one hand, to the absence of means for ensuring rigorous linearity of the piston rods and, on the other hand, to a lack compactness generally causing excessive fatigue of the swash plate and rapid wear.

Any deviation in the strictly linear path of the connecting rods causes an ovalization of the cylinders, while the lack of compactness referred to above, combined with a weakness of the swash plate, does not allow the development of effective power of high level.

An essential object of the present invention is to strive for a low weight / power ratio, which can only be envisaged by an exceptionally robust construction of the swash plate without departing from the compactness criterion mentioned above.

A first object of the invention is therefore a linear motion motor comprising an oscillating plate of new and original design, capable of withstanding considerable efforts. For this purpose, the piston is integral with a rod, the end of which is opposite the piston, comprises a slide guided in a slide forming part of the engine block and the geometric axis of which coincides with that of the rod, the slide. trapping two shells constituting a housing for a ball joint connected by a neck to the aforementioned swash plate and extending laterally relative to said swash plate.

In an advantageous embodiment, the slide consists of a cylinder having a first slot parallel to the geometric axis of said cylinder, intended for the passage of the neck of the above-mentioned ball joint, trapped between the two aforementioned shells. Advantageously, the slide is constituted by a cylindrical piece having a central housing in which the two aforementioned shells are mounted to slide.

A detail of the invention resides in the fact that the slide is provided, on the side opposite to the first aforementioned slot, with a pin fitted at its end a roller: said journal passing, during the reciprocating translational movements of the piston, a second slot provided in the wall of the slide diametrically opposite with respect to the first slot and the roller being retained, outside said cylinder, between two guide profiles.

Another object of the invention is a swash plate capable of withstanding very high stresses in an engine of the type concerned by the invention. To this end, the swash plate according to the invention consists of a crown externally carrying at least one, and preferably two or four ball joints intended to each bear on a piston driven by a reciprocating linear movement and by a central sleeve having a bore whose geometric axis forms an angle with the plane of symmetry of the aforementioned crown, the aforementioned central sleeve being mounted in rotation relative to the crown either by means of two needle bearings, or by means of two rings with smooth pads hydrodynamically lubricated, said bearings or pads being arranged on either side of the crown to allow rotation of the latter relative to one _. annular element mounted on this socket.

• la figure 1 est une vue partiellement en coupe longitudinale et partiellement en élévation d'un moteur selon l'invention;
• la figure 2 est une vue explosée montrant un piston et son système de guidage dans un cylindre faisant partie du bloc moteur ainsi que la partie latérale du plateau oscillant selon l'invention;
• la figure 3 est une vue schématique illustrant la course d'un galet monté sur un tourillon posé dans l'axe géométrique reliant les deux rotules d'um même plateau;
• la figure 4 est une vue schématique en perspective d'un plateau équipé de deux rotules et d'un galet circulant entre deux profilés de guidage;
• la figure 5 est une vue analogue d'une variante dans laquelle le plateau oscillant est équipé de quatre rotules;
• la figure 6 est une coupe selon la ligne VI-VI de la figure 1;
• la figure 7 est une coupe analogue se rapportant à un plateau oscillant à deux rotules;
• la figure 8 est une coupe à une plus grande échelle d'un plateau oscillant, coupe comprenant l'axe géométrique du plateau;
• la figure 9 se rapporte à un volant à masselottes centrifuges vu en coupe radiale.

Other details and particularities of the invention will emerge from the description which follows, given with reference to the attached drawings in which:

• Figure 1 is a view partially in longitudinal section and partially in elevation of an engine according to the invention;
• Figure 2 is an exploded view showing a piston and its guide system in a cylinder forming part of the engine block and the side part of the swash plate according to the invention;
• Figure 3 is a schematic view illustrating the race of a roller mounted on a pin placed in the geometric axis connecting the two ball joints of the same plate;
• Figure 4 is a schematic perspective view of a plate equipped with two ball joints and a roller circulating between two guide profiles;
• Figure 5 is a similar view of a variant in which the swash plate is equipped with four ball joints;
• Figure 6 is a section along the line VI-VI of Figure 1;
• Figure 7 is a similar section relating to an oscillating plate with two ball joints;
• Figure 8 is a section on a larger scale of a swash plate, section comprising the geometric axis of the plate;
• Figure 9 relates to a flywheel with centrifugal weights seen in radial section.

The engine represented in figure 1 comprises an engine block equipped with two pairs of cylinders arranged in barrel of revolver as shown in figure 6. Each cylinder contains two opposite pistons such as 2 ', 2 "-or 3', 3" visible in Figure 1. The reference numerals 6 and 7 denote the intake ports of the two cylinders, the references 4 and 5 denote the exhaust ports. Lights 4 and 5 lead to a common collector. Lights 6 and 7 open onto a common manifold per cylinder.

The combustion of the gas mixture in each of the chambers 8 and 9 is done by known means which are not described here since the type of combustion is foreign to the object of the invention.

To obtain a rigorous linearity of the movements of the pistons, each piston is rigidly connected to a rod 10. The opposite end of this rod 10 comprises a slide 11 guided in a slide 16 which can, in practice, be part of the engine block . The assembly of the slide 11 is shown in particular in the exploded view of FIG. 2.

Referring to Figure 2 we see that the slide 11 has a central housing with two parallel walls 12 and terminated by a cover 13 fixed to the slide 11 with four screws 14 passing through four holes 15 and screwed into the plate 13 '. In the central housing of the slide 11 are disposed shells 18 and 18 'which trap a ball joint 19 of the swash plate 20. The width of the housing between the faces 12 of the slide is equal if not slightly greater than the width of the shells 18 and 18'. These adapt to one another by means of pins 21 provided on one of the shells to be housed in orifices (not visible in the drawing) provided in the other shell. The shells 18-18 'slide without play along the faces 12 of the slide housing 11.

The slide 11 is guided in a cylinder 16 which can, in practice, constitute a cylindrical cavity of the engine block. The cylinder 16 has a first slot 17 whose width is sufficient to allow the movement of the swash plate. When the latter is provided with one or two ball joints, the movement of the swash plate takes place in a single plane passing through the plane of symmetry of the housing and therefore through the geometric axis of the rod 10 (cf. FIG. 3) .

To prevent rotation of the oscillating plate 20 about its geometric axis, the plate is provided with a roller cooperating with a guide means. When the swash plate is provided with two ball joints as in the motor shown for example in FIG. 7, a pin 23 (FIG. 4) equipped with a roller 24 is mounted on a ball 19 and the roller is trapped to circulate between two sections guide 25. When the swash plate has four ball joints as shown in Figure 5, the roller can be mounted on the plate between two ball joints 18. Figure 5 shows the position of the roller 24 'shown on the pin 23'.

The rotation of a piston is prevented by the presence, on the cover 13 of the slide 11, of a pin 26 provided with a roller 27 trapped between the opposite faces of the narrow longitudinal slot 28 provided in the cylinder 16 in a position diametrically opposite to that of the wide slot 17.

Referring to FIG. 1, it can be seen that the swash plate 20 is wedged on a shaft 20 in a ball bearing or in a plain ring bearing hydrodynamically lubricated. The lower swash plate 20 'shown in section in Figure 1, is mounted on the same shaft 29 but in an arrangement which prevents its rotation relative to the shaft, but not a certain longitudinal sliding. Such an assembly, known per se, is achieved by the presence of an edge 31 provided on the shaft 29 to cooperate with a recess of the elements constituting the swash plate 20 '.

This plate, which consists of the same elements as the swash plate 20, will be described in detail below and constitutes an essential element of the invention.

The motor shaft 29 is, opposite the fixed bearing 30 mounted by means of a sliding bearing 32 in the opposite face of the engine block 1. This end of the shaft 29 is equipped with a bearing flywheel the general reference 33, consisting of two coaxial elements 34 and 35. The element 34 fixed to the shaft 29 has a circular groove 36 for the circular edge 37 of the element 35 of the steering wheel 33.

In opposition to the element 34 of the steering wheel, the element 35 can, thanks to a mounting known per se, slide slightly along the shaft 29 but cannot be rotated relative to this shaft. The rotation of the shaft 29 is integral with that of the element 35 of the flywheel 33 ..

Between the elements 34 and 35 of the flywheel 33 there remains a space 38 for a hydraulic fluid whose pressure can be increased or reduced at will. By increasing the pressure of the hydraulic fluid in the space 38, the swash plate 20 ′ acts via the cylindrical body 39. In fact, it can be seen that the swash plate 20 ′ abuts, in its central part, on the transverse face of the cylindrical body 39 which is integral with the steering wheel element 35.

It will easily be understood that by varying the volume of the space 38, one acts on the inclined plate 20 'in the direction of the arrows 46' or 46 "to vary the compression between the pistons 2, 2 'and 3, 3' To achieve this objective, it suffices to provide a seal impervious to hydraulic pressure between the circular flange 37 and one or more faces of the circular groove 36 of the flywheel element 34.

Another construction thanks to which it is possible to automatically adjust the ratio between the compression ratio and the number of revolutions of the motor shaft is shown in Figure 9.

The steering wheel, designated by the general reference 33, also consists of two elements, the element of which is fixed relative to the shaft 29 is designated by the reference 40. This steering wheel element 40 is equipped with a series of weights 41 arranged in a circle inside the rim 42 of the element 40. Each counterweight is subjected to the action of a spring 43 wound on a rod 44 which also serves as a guide for the corresponding counterweight.

The weights 41 have the form of wedges, the large base of which is directed towards the periphery of the steering wheel 40, that is to say in the direction of the rim 42 of the steering wheel element 40.

The steering wheel element 45 which is rotated by the shaft 29 can execute a certain longitudinal movement relative to this shaft, thanks to a construction which is moreover known per se.

Thanks to the centrifugal force the weights are pushed outwards against the springs 43 and there follows a displacement, according to arrow 46 (Figure 9). As a result, when the number of revolutions of the shaft 29 increases, there is a reduction in the compression ratio between the pistons working in opposition and vice versa. Indeed, cold starting is facilitated by the fact that the volumetric ratio is improved. In higher speed, more overeating is made possible.

From the description which has just been given it will be noted that the means for guiding the pistons 2 ', 2 "and 3, 3" ensure rigorous linearity in the movement alternating slides 11 moving inside the slides formed by the cylinders 16 or similar cylindrical cavities forming part of the engine block. This rigorous linearity is ensured thanks in particular to the design of the mounting, between shells, of the ball joints 19 of the oscillating plates 20 or 20 '. When a swash plate is equipped with only two ball joints, the oscillating movement of the ball joints is carried out strictly in a single plane comprising the geometric axis of the shaft 20 and the geometric axis of the piston rods 10. By cons , when a swash plate is equipped with four ball joints, each of these follows a non-planar trajectory. When use is made of an oscillating plate with four ball joints, no play is observed inside the housing 12 between the base of this housing, forming the base of the slide, and the underside of the cover 13 (FIG. 2). On the other hand, there is a play between the parallel faces 12 of the housing as well as a back-and-forth or translation movement inside this housing as is easily conceivable, due to the upward and downward movements of each. ball joints 19 inside each of the corresponding housings of the slides 11.

The design of the swash plates 20-21 is such that they can, without danger of fatigue which would cause premature wear of their constituent elements, be subjected to extremely high stresses.

These stresses come from the forces exerted on the ball joints 19 by means of the slides 11, the rods 10 and the various pistons 2'-2 "and 3'-3".

Referring more particularly to FIG. 8, it will be noted that the swash plate consists of a ring 47 carrying at least two diametrically opposite ball joints 19 joined to the ring 47 by a collar 22. The ring 47 is mounted on a central bush 48 by through a first rollover with needles 49 and by a second needle bearing 50. The needle bearing 50 is held in position on the corresponding lateral flank of the crown 47 by a circular element 51.

The cylindrical elements which make up the needle bearing 49 are alternately composed of two and three coaxial elements. This arrangement is intended to take account of the variations in angular speed which these elements undergo when considering the rotation of the central bush 48 relative to the crown 47.

The bearing elements designated above by the reference numerals 49 and 50 may advantageously be replaced by elements with pads sliding on a film of hydrodynamic oil.

The central bush 48, the internal diameter of the central bore corresponds to the external diameter of the shaft 29, has two external flanks 52 and 53 which are mutually parallel as well as with the plane of symmetry of the crown 47 at the height of the center line 54. However, on the side where the swash plate comes into contact with the cylindrical body 39 of the flywheel, when it is the swash plate which, according to FIG. 1, cooperates with the movable flywheel element 35 , the flank 52 of the central sleeve is cut by a plane which extends at right angles to the geometric axis of the shaft 39. This plane bears the reference in FIG. 8. The part of this plane which is in permanent contact with the external face of the cylindrical body 39 is indicated in solid lines while the reference 56 indicates a parallel plane cut at an angle a with respect to the external flank 52. Note also in Figure 5 the edge 31 which drives the central bush 48 of the swash plate and allows movement axial of the assembly with respect to the shaft 29.

A third needle bearing or, in the event of lubrication under pressure, a plain bearing forming a circular crown inside the crown 47 is represented by one of these elements under the reference 56. Balancing means constituted by orifices 58, on the one hand, and bolts 59, on the other hand, are provided in the outer sides 52 and 53 of the central ring 48.

From the description which has just been given of the swash plate according to the invention, it will be realized that it has all the qualities of compactness and therefore robustness which are necessary to allow transmission from the pistons of the engine and via the ball joints 19, the extremely large forces to the central bush 48 mounted on the shaft 29 to cause the rotation thereof.

The forces to be exerted from the various pistons on the swash plate shown in FIG. 8 and supposed to be the bottom swash plate in FIG. 1, are exerted on the ball joints 19 in the direction indicated by the arrows 57.

In FIG. 8, one of the ball joints 19 has a threaded axial bore into which a trunnion 23 carrying a roller 27 can be screwed, as in FIG. 4.

It is understood that the invention is not limited to the embodiment described above and that many modifications could be made thereto without departing from the scope of the present invention.

Claims (18)

1. Motor or similar device comprising at least one piston with reciprocating linear translational movement and a swash plate mounted at an angle on a shaft driven in rotation in the casing or the engine block by the reciprocating movements of said plate in contact with said piston,
characterized in that said piston (eg 21) is integral with a rod (10), the end of which is opposite the piston comprises a slide (11) guided in a slide forming part of the engine block and of which 1 'geometric axis coincides with that of the aforementioned rod, the slide (11) trapping two shells (18, 18') which constitute a housing for a ball joint (19) connected by a neck to the swash plate (20) and extending laterally with respect to said swash plate. 2. Motor or similar device according to claim 1, characterized in that the rod (10) is rigidly connected to the slide (11). 3. Motor or similar device according to claim 1, characterized in that the aforesaid slide is constituted by a cylinder (16) having a first slot (17) parallel to the geometric axis of said cylinder, intended for the passage of the neck of the ball joint (19) trapped between the two aforementioned shells. 4. Motor or similar device according to claim 1, characterized in that the aforementioned slide consists of a cylindrical piece having a central housing in which are mounted to slide, the two aforementioned shells, said housing having a width corresponding practically to the width of said first slot (17). 5. Motor or similar device according to claim 1, characterized in that the aforesaid slide is provided, on the side opposite to the first slot (17), with a pin (26) fitted at its end with a roller (27) , said journal passing through, during the reciprocating translational movements of the aforementioned piston, a second slot (28) provided in the wall of the aforementioned slideway in diametrically opposite relation to the first slot (17) and the aforementioned roller being retained at the end of said cylinder between two guide profiles. 6. Motor or similar device according to claim 1, characterized in that the aforementioned slide ends, on the side opposite to the rod (10), by a cover carrying the aforementioned pin laterally. 7. Motor or similar device according to any one of claims 1 to 6, characterized in that it comprises an engine block having a number of slides corresponding to the number of ball joints and a guide means, preferably between two cylinders, for a roller mounted at the end of a trunnion forming a part of the swash plate to oppose the rotation, about its axis, of the aforementioned swash plate. 8. Motor or similar device according to any one of claims 1 to 6, characterized in that it comprises an engine block having a number of slides corresponding to the number of ball joints and a guide means, arranged on either side of the aforementioned second slot, for a roller mounted at the end of a journal forming a body with the aforementioned plate and arranged in the extension of the geometric axis connecting two ball joints. 9. Engine according to claim 1, characterized in that the shaft on which the swash plate is fixed is housed, at least at one end of the engine block, in a bearing opposing an axial displacement of said shaft relative to the block motor, one end of said shaft being fitted with a flywheel. 10. Engine according to claim 1, characterized in that only one end of said shaft is housed in a bearing opposing an axial displacement of said shaft relative to the engine block, the other end of said shaft, housed in a sliding bearing , being fitted with a flywheel consisting of two concentric elements, the one of which located on the internal side has a central cylindrical body intended to bear on the aforementioned swash plate, means being provided for varying the spacing between the two elements concentric of said flywheel. 11. Motor according to claim 10, characterized in that the flywheel consists of two elements, one of which is fixed on said shaft and the other can slide axially thereon, defining between them a volumetrically variable cavity so that that the movable element which abuts against the aforementioned oscillating plate can move the latter to vary the volume of the combustion chamber remaining between two pistons with opposite translational movements. 12. Motor according to claim-11, characterized in that the volumetrically variable cavity constitutes a chamber subjected to variable hydraulic pressure. 13. Motor according to claim 11, characterized in that the volumetrically variable cavity is equipped with centrifugal weights having the shape of wedges whose large base is directed towards the outside while the internal surfaces of the elements of the steering wheel facing each other are inclined with respect to the motor shaft at an angle which corresponds to the taper of the weights, all things being such that the increase in the centrifugal force acting on the aforementioned weights causes the elements of the flywheel to come together and therefore an increase in the chamber between two pistons working in alignment. 14. Swing plate intended in particular for an engine comprising at least one piston with reciprocating linear translational movement and a swash plate mounted at an angle on a shaft driven in rotation in the casing or the engine block by the reciprocating movements of said plate in contact with said piston, characterized in that it is constituted by a crown externally carrying at least one, but preferably two or four ball joints intended to each take support on a piston driven by a reciprocating linear movement as well as by a central sleeve having a bore whose geometrical axis forms an angle with the plane of symmetry of the aforementioned crown, the aforesaid central sleeve being mounted in rotation relative to the aforementioned crown by means of two needle bearings arranged on either side of the aforementioned crown to allow the rolling of the latter relative, on the one hand to an annular projection of the central sleeve and, a on the other hand, to an annular element mounted on. this socket. 15. A swash plate according to claim 14, characterized in that each cylindrical element of the aforementioned needle bearing is, at least in the bearing mounted between the crown and the projection of the sleeve, consisting of at least two halves arranged ccaxially .. 16. Swing plate intended in particular for an engine comprising at least one piston with reciprocating linear translational movement and a swash plate mounted at an angle on a shaft driven in rotation in the casing or the engine block by the reciprocating movements of said plate in contact with said piston, characterized in that it is constituted by a crown externally carrying at least one, but preferably two or four ball joints intended to each take support on a piston driven by a reciprocating linear movement as well as by a central sleeve having a bore whose geometrical axis forms an angle with the plane of symmetry of the aforementioned crown, the aforementioned central sleeve being mounted in rotation relative to the aforementioned crown by means of two rings with smooth pads with hydrodynamic lubrication. 17. A swash plate according to any one of claims 14 and 16, characterized in that the internal circular face determining the central orifice of the aforementioned crown is equipped with a needle bearing. 18. A swash plate according to any one of claims 14 and 16, characterized in that the internal circular face determining the central orifice of the aforementioned crown is equipped with a smooth bearing, when lubrication under pressure is provided.

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