WO2007132071A1 - Lubrication and cooling of rotary piston engines - Google Patents

Abstract

The heat engine concerned comprises a cylinder block in which a cylindrical borehole is formed, said borehole containing two coaxially mounted rotors penetrating thereinto, one rotor (3) rotating continuously and the other intermittently. Together with the cylindrical borehole, said rotors define two working chambers in which a gaseous mixture forms according to an appropriate thermodynamic cycle. The sealing of the chambers is ensured by the segmentation created by sealing barriers mounted on the two rotors. At least the continuously moving rotor (3) comprises at least one pressurised oil circuit especially for ensuring the oiling, by means of oilers (22), of the segmentation (11, 12) associated with the continuously moving rotor (3) and the segmentation associated with the intermittently moving rotor.

Description

 LUBRICATION AND COOLING OF ROTARY PISTON MACHINES

The present invention relates to improvements relating to a rotary piston machine used in particular as a heat engine. More specifically, the present invention aims to improve the lubrication and cooling of a thermal machine of the type described in patent EP 748 415 and in US Patent 5,992,371.

This machine comprises a motor unit in which is machined a cylindrical bore in which are interposed two rotors forming with the cylindrical bore two diametrically opposed working chambers in each of which evolves a gaseous mixture according to the phases of a suitable thermodynamic cycle. One of the rotors is driven in a continuous rotational movement while the other is animated by an intermittent rotational movement at a speed double that of the rotor with continuous movement so as to achieve cyclic volumic variations of the two. working rooms. The continuously moving rotor has a central bore passing therethrough and two diametrically opposed recesses. The rotor with intermittent movement is constituted by a cylindrical shaft rotatably mounted in the central bore of the rotor with continuous movement and by two vanes integral with the shaft arranged diametrically opposite pistons, and engaged in the recesses of the rotor movement continued. Each of these pallets delimits with the corresponding recess, a working chamber in which evolves a gas mixture and a passive rear chamber.

To this continuously moving rotor is coupled a hydraulic pump hydraulically connected to a hydraulic motor coupled to the intermittently operating rotor. On the hydraulic circuit between the pump and the engine is provided a valve mechanism which ensures the opening of the circuit during the intake and expansion phases to release the rotation of the intermittent rotor and its closure during the compression phases and exhaust to rotate the intermittent rotor during these phases. The intermittent rotor is also mechanically associated with an angular stop mechanism opposing its backward rotation during the intake and expansion phases.

The object of the invention is in particular to improve the lubrication and cooling of this type of engine. For this purpose the engine of the aforementioned type is essentially characterized in that each rotor comprises at least one lubricating means capable of delivering a metered quantity of lubricating fluid on the surfaces of each working chamber in front of the sealing segments considering the direction of rotation of the rotors. According to another characteristic of the invention, each lubricating means is constituted by:

- At least one lubricator connected to a lubricant supply circuit and having a lubricating head with a lubricating orifice held in abutment against the surface to be lubricated by an elastic member, - and at least one hollow form formed in said surface, in the path of the orifice of the greaser head to fill said recessed form of lubricating fluid.

Other advantages, aims and features of the invention will appear on reading the description of a preferred embodiment given by way of non-limiting example with reference to the appended drawings in which:

FIG. 1 is a longitudinal sectional view of a machine according to the invention,

FIG. 2 is a cross-sectional view along the line AA of FIG. 1,

FIG. 3 is a perspective view of a rotor with continuous movement,

FIG. 4 is a front view of an intermittently moving rotor, FIG. 5 is a sectional view along line BB of FIG. 4,

FIG. 6 is a sectional view of a lubricator,

FIG. 7 is a partial view in longitudinal section of a rotor with continuous movement,

FIG. 8 is a view in longitudinal section of the two rotors mounted one inside the other,

- Figure 9 is a sectional view along the line CC of Figure 8, - Figure 10 is a front view of a hydraulic stop. As shown, the rotary piston machine according to the invention can be used mainly as a spark ignition engine or diesel engine comprises a motor unit 1 in which is formed a cylindrical bore 2 in which are coaxially mounted interpenetration two rotors 3, 4, one of which, the rotor 3 is in a continuous rotational movement and has an axial bore 7 and two diametrically opposite radial recesses 8, opening on the one hand in the axial bore and on the other hand in the outer cylindrical surface and whose other rotor, the rotor 4 is intermittently moving and comprises a cylindrical shaft 9 freely rotatably engaged in the axial bore 7 of the rotor with continuous movement, and two diametrically opposed radial vanes 10, forming a piston, fixed to the shaft 9 and engaged in the radial recesses 8 so as to be able to move angularly, each of said pallets forming with the évi corresponding radial direction 8 and with the bore 2 of the engine block 1 by considering the direction of rotation of the rotors, a front chamber or working chamber 5 and a rear chamber or passive chamber 6. These chambers 5, 6, by rotation of the rotors , are subject to rotate around the geometric axis of the bore 2 of the engine block. A gaseous mixture is sequentially introduced into the working chamber 5 to evolve according to the phases of a thermodynamic cycle in order to produce a mechanical work.

The bore 2 of the engine block 1 comprises two hydrodynamic bearings 20 spaced apart from each other for supporting the rotor 3 with continuous movement. This rotor constitutes the power output shaft of the engine.

Each recess 8 that comprises the rotor with continuous movement 3, in a section perpendicular to the axis of said rotor conforms to the contour of a circular crown sector. According to a section containing the longitudinal axis of the rotor, the recess 8 has a cross section of rectangular or square shape. As can be seen in the accompanying figures, the recess 8 opens into the bore 7. Through its shaft 9, the rotor 4 with intermittent movement is supported by two hydrodynamic bearings 21 mounted at a distance from each other each in a housing coaxial with the bore 7 of the rotor 3.

The shaft 9 of the rotor 4 is provided with a longitudinal through bore 4a. During each of the four phases of the thermodynamic cycle, namely, admission, compression, ignition-expansion or combustion-expansion, exhaust, the rotor 3 with continuous movement accomplishes about a quarter turn. The rotor 4 with intermittent movement during the phases of admission of the gaseous mixture into each working and expansion chamber of the gases is secured by a non-return mechanism to remain angularly fixed relative to the engine block at least in the backward direction, while during each of the compression phases of the gaseous mixture and the exhaust of the flue gases it is subjected by a motion transmission means to perform approximately one half-turn relative to the engine block 1. During these two phases, the rotor with movement intermittent 4 performed relative to the rotor with continuous movement 3 about a quarter turn.

Around each radial recess 8 of the rotor with continuous movement 3, on the outer cylindrical surface of this rotor 3, and on the cylindrical surface of the axial bore 7 that comprises the latter, are formed respectively an external sealing barrier 11 and a barrier internal sealing 12.

In addition, each pallet of the intermittent rotor comprises at least one sealing barrier 13, the latter being formed continuously on the radial lateral banks 10a of the pallet 10 and on the front edge 10b of the latter.

The outer 11 and inner 12 sealing gates each comprise two arcuate circumferential side portions disposed respectively on either side of the radial recesses and at least one rectilinear part extending from one to the other part. lateral. The external sealing barrier 11 of the continuous-motion rotor 3 is supported on the cylindrical surface of the bore 2 of the engine block 1, and the internal sealing barrier 12 that comprises the continuously-moving rotor 3 is supported on the cylindrical surface of the shaft 9 of the intermittently moving rotor 3.

Each sealing barrier 13 formed on each pallet 10 of the rotor with intermittent movement bears on the lateral faces of the corresponding recess 8 and on the cylindrical face of the bore 2 of the engine block.

According to the invention, each rotor 3, 4 comprises at least one lubricating means capable of delivering a metered quantity of lubricating fluid. on the surfaces of each working chamber in front of the sealing segments by considering the direction of rotation of the rotors, said lubricating means being fed by an oil circuit comprising an external oil pump. Preferably each greasing means is constituted by at least one grease fitting 22 mounted in a bore made in the rotor 3, 4 corresponding. This lubricator is connected to a delivery circuit of a lubricating fluid and comprises a lubricating head 23 with a lubricating orifice 24 held in abutment against the corresponding surface of the working chamber by an elastic member 25. The lubricating means is also formed by recessed shapes formed in the surfaces of the working chamber, on the path of the orifice of the head of the nipples to receive lubricating fluid.

Preferably these recessed shapes are micro-cavities capable of retaining the lubricating fluid, formed by surface treatment such as honing.

In the preferred embodiment, each grease nipple 22 has a cylindrical tubular body comprising, perpendicular to its longitudinal axis, a convex end face in a truncated cone forming the head 23, said body being pierced axially from one side of a delivery channel. of oil at the orifice 24 of the truncated cone head.

The elastic member 25 keeps the head 23 of the grease nipple 22 applied against the corresponding surface of the working chamber 5. The lubrication orifice 24 is normally closed off by this surface and the oil can not escape. However, as soon as it is facing a cavity of this surface, the oil can then escape and fill the cavity. The oil present in this cavity will then be swept by the associated segment to be spread over the entire corresponding surface of the working chamber 5.

Still according to the preferred embodiment, the tubular body of the grease nipple 22 has a counterbore for receiving the associated elastic member, said elastic member 25 being constituted by a spring with non-contiguous turns. As can be seen, the oil supply channel opens into this counterbore.

In the preferred embodiment, the nipples 22 associated with the intermittent rotor 4 are mounted in bores made in each pallet 10 and opening into the side faces 10a thereof. Still according to this arrangement, said bores are in communication with channels made in the rotor 4 with intermittent movement and opening into the axial bore 4a of the shaft of said rotor to the right, each, of an oil distribution groove performed in an oil distribution ring 28 mounted in the bore 4a. As is understood, two oil distribution rings 28 are provided respectively associated with the lubricators 22 that comprise the two radial banks 10a of the pallet 10. This shaft is also equipped with radial channels 29 opening on the one hand into the bore 4a, the right of the oil distribution groove of the oil distribution ring 28, and secondly in its outer cylindrical face, to the right of an oil supply chamber 30 formed in a ring rotated in the rotor with continuous movement, this ring advantageously constituting the body of the hydrodynamic bearing 21. The bearing body 21 comprises an oil chamber supplied with oil by the oil circuit. As is understood, two hydrodynamic bearings 21 are provided. Each bearing ensures the rotational guidance of the intermittently moving rotor 4 in the rotor with continuous movement 3.

Still according to the preferred embodiment, the grease nipples 22 of the rotor with continuous movement 3 are mounted in cylindrical bores made in the body of said rotor 3 and opening for some on the outer cylindrical face of said rotor and for the others on the inner cylindrical face. of this rotor. These bores are in communication with oil supply channels 32 formed in the rotor with continuous movement, parallel to its longitudinal axis, said channels 32 for supplying oil also supplying oil to the hydrodynamic bearings 21 supporting the rotor with intermittent movement in the rotor with continuous movement and the hydrodynamic bearings 20 supporting the rotor with continuous movement 3 in the engine block 1, said longitudinal channels being supplied with oil by an external pump via one or several rotary joints. Advantageously, the oil circuit also ensures the cooling of the engine. For this purpose the oil circuit comprises one or more longitudinal return channels formed in the rotor with continuous movement 3 and each longitudinal feed and / or return channel is equipped with a means adapted to create a turbulent flow regime of oil to increase the degree of heat transfer between the rotor 3 and this oil. This means capable of creating the turbulent regime present in the corresponding channel, in the flow path of the oil a series of reliefs. According to a preferred embodiment, the means capable of creating a turbulent regime forces the oil to follow a helical path in the corresponding channel. This increases the length of the path of the oil flow and its speed in the corresponding channel and consequently its effectiveness.

In practice, the means capable of creating a turbulent regime and forcing the oil to follow a helical path may be constituted by an axial pin 33 occupying a central position in the channel and by a helical structure 34 wound around the central pin 33 and extending longitudinally along the entire length of the pin and extending radially from said pin 33 to the cylindrical inner face of said channel. Still according to the preferred embodiment, the rotor with continuous movement 3 is associated with a hydrodynamic axial stop 35 fed by the oil circuit, interposed between the engine block 1 and the rotor 3 with continuous movement. This hydrodynamic axial stop 35 is intended to contain the axial movements of the rotor with continuous movement 3. This axial abutment 35 has two opposed active bearing faces 351 provided with several cavities 352 for the formation of oil wedges .

The oil circuit provides, as is understood, several functions, namely a lubrication function, a cooling function for the rotors and a feed function for the hydrodynamic bearings 20, 21. It goes without saying that the present invention can receive all the arrangements and variants of the field of technical equivalents without departing from the scope of this patent.

Claims

Claims. 1 / Rotary piston heat engine usable in particular as a heat engine comprising an engine block (1) in which is formed a cylindrical bore (2) in which are coaxially mounted interpenetration two rotors of which one (3) is moving continuous rotation and has an axial bore (7) and at least one radial recess (8) opening on the one hand in the axial bore (7) and on the other hand in the outer cylindrical surface and the other rotor (4 ) is intermittent and comprises on the one hand a cylindrical shaft (9) freely rotatably engaged in the bore (7) of the continuously moving rotor, and on the other hand at least one radial vane (10) forming a piston fixed to the shaft (9) and engaged in the radial recess (8) so as to be able to move angularly, said shaft (9) being traversed right through a cylindrical bore (4a) axial and said pallet (10) or piston forming with the radial recess ( 8) of the rotor with continuous movement (3) and with the bore (2) of the engine block (1) by considering the direction of rotation of the rotors (3, 4) a rear chamber (6) or passive chamber and a front chamber (5) or working chamber (5, 6), which chambers, by rotation of the rotors are subject to rotate about the geometric axis of the bore (2) of the engine block, a gas mixture being sequentially introduced into the chamber working to evolve according to the phases of a thermodynamic cycle to produce a mechanical work and sealing barriers (11, 12, 13) being formed around the radial recess (8) of the rotor (3) with movement continuously on the outer cylindrical rotor surface to form an outer sealing barrier (11) and on the cylindrical surface of the axial bore of the rotor to form an inner sealing barrier (12), as well as on the radial banks (10a). ) and the front edge of the moving rotor pallet intermittent, said sealing barriers (11, 12, 13) being constituted by abutting segments one another and mounted in grooves formed in the rotor with continuous movement and in the radial and frontal banks of the rotor blade with motion intermittent, characterized in that at least the continuous-motion rotor (3) comprises at least one pressurized oil circuit, in particular to ensure in particular the lubrication of the segmentation (11, 12, 13) associated with the rotor with continuous movement ( 3) and the intermittent rotor (4). 2 / Machine according to claim 1, characterized in that each rotor comprises at least one greasing means adapted to deliver a metered quantity of lubricating fluid on the surfaces of each working chamber in front of the sealing segments in consideration of the direction rotation of the rotors, the lubricating means being fed by the pressurized oil circuit. 3 / Machine according to the preceding claim, characterized in that each greasing means is constituted by: at least one lubricator (22) connected to a lubricating fluid supplying circuit and comprising a lubricating head (23) with a lubricating orifice (24) held in abutment against the surface to be lubricated, by an organ elastic (25), and at least one recessed shape formed in said surface, on the path of the orifice (24) of the head (23) of the grease nipple (22) to fill said hollow form with lubricating fluid. 4 / Machine according to claim 3, characterized in that the surfaces of the working chamber (5), are treated so as to have micro-cavities adapted to retain the lubricating oil. 5 / Machine according to claim 3 or claim 4, characterized in that each grease (22) has a cylindrical tubular body comprising perpendicularly to its longitudinal axis a convex end face truncated cone, said body being pierced axially from one side to the other an oil feed channel to the convex head. 6 / Machine according to claim 5, characterized in that the tubular body of the grease nipple, has a recess formed in the oil supply channel, adapted to receive the associated elastic member (25), said elastic member being constituted by a spring with non-contiguous turns. 7 / Machine according to any one of claims 3 to 6, characterized in that the grease nipples (22) associated with the rotor with intermittent movement are mounted in bores made in each pallet (10) and opening into the side faces of the latter said bores are in communication with channels in the intermittently-moving rotor (4) and opening into the axial bore (4a) of the shaft (9) of said rotor (4) to the right, each, of a groove for dispensing oil practiced in a oil distribution ring (28) mounted in the bore (4a) of the shaft (9) of the intermittently moving rotor (4), said shaft (9) being furthermore equipped with radial channels (29) opening a part in the internal bore (4a), in line with the oil distribution groove of the oil distribution ring (28) and secondly in its external cylindrical face with the right of a chamber ( 30) of oil supply formed in a ring set in rotation in the rotor with continuous movement, this ring constituting the body of a hydrodynamic bearing (21), said bearing body being equipped with an oil chamber supplied with oil by the oil circuit. 8 / Machine according to any one of claims 3 to 7, characterized in that the grease nipples (22) of the rotor with continuous movement (3) are mounted in cylindrical bores made in the body of said rotor and opening for some on the face cylindrical external of said rotor and for the others on the inner cylindrical face, said bores being in communication with channels (32) for supplying oil in said rotor (3), parallel to its longitudinal axis, said channels of supplying oil (32) supplying oil to hydrodynamic bearings (21) supporting the rotor with intermittent motion in the rotor with continuous movement and hydrodynamic bearings (20) supporting the rotor with continuous movement (3) in the motor block (1), said longitudinal channels (32) being supplied with oil by an external pump via a rotary joint. 9 / Machine according to any one of the preceding claims, characterized in that the oil circuit also ensures the cooling of the engine. 10 / Machine according to claim 9, characterized in that the pressurized oil circuit comprises one or more longitudinal return channels formed in the rotor with continuous movement. 11 / Machine according to the preceding claim, characterized in that each longitudinal supply and / or return channel is equipped with means capable of creating a turbulent flow of oil flow in order to increase the degree of heat transfer between the rotor (3) and the cooling oil, said means adapted to create the turbulent regime having in the corresponding channel a series of reliefs. 12 / Machine according to 11, characterized in that the means adapted to create the turbulent regime forces the oil to follow a helical path in the corresponding channel. 13 / Machine according to the preceding claim, characterized in that the means adapted to create a turbulent regime and to force the oil to follow a helical path is constituted by an axial pin (33) occupying a central position in the channel and by a helical structure (34) wound around the central spindle and extending longitudinally along the entire length of the spindle and extending radially from said spindle to the cylindrical inner face of said channel. 14 / Machine according to any one of the preceding claims, characterized in that the continuous rotor is associated with a axial stop (35) hydrodynamic powered by the oil circuit, interposed between the engine block (1) and the rotor continuous motion device (3) for containing the axial movements of the continuously moving rotor (3). 15 / Machine according to claim 14, characterized in that the axial abutment (35) has two opposed active bearing faces (351) provided with several cavities (352) for the formation of oil wedges.