This invention relates generally to rotary machines, and more specifically to rotary internal combustion engines, compressors, pumps, and turbines, for expandable gases or compressible liquids.
Rotary internal combustion engines are known, examples of which include the Wankel rotary engine and the Sarich orbital engine. These engines suffer from the disadvantage that they require complicated components and seals, exhibit lower compression ratios than some engines and an orbital rotary motion of the rotor which moves the centre of mass, increasing vibration, making balancing difficult.
The present invention seeks to provide a rotary machine which alleviates one or more of the aforementioned disadvantages.
According to one aspect of the present invention there is provided a rotary internal combustion engine or pump which includes: at least one main body having a void therein, the void having a peripheral wall; a major rotor member disposed within the void for rotation about a first axis of rotation, the major rotor member including at least one outer peripheral wall portion radially spaced from the rotation axis, the peripheral wall portion including at least one generally arcuate wall section defining at least one bight within the major rotor, the or each bight having a central axis; one or more satellite rotor members, the or each satellite rotor member disposed within the or each bight for rotation about a second axis of rotation which is generally coaxial with the central axis of the or each arcuate bight; one or more control chambers being defined generally at any time during a work cycle by any combination of two or more of a wall of the or each satellite rotor member, the peripheral wall of the void and the peripheral wall of the major rotor member; the engine further including a plurality of ports associated with the or each main body for permitting the flow of a fluid to or from the control chamber.
According to another aspect of the present invention there is provided a rotary engine or pump which includes: at least one main body having a void therein, the void having a peripheral wall and at least one generally arcuate wall defining at least one bight having a central axis; a major rotor member disposed within the void for rotation about a first axis of rotation, the major rotor member including a peripheral wall spaced from the rotation axis; one or more satellite rotor members, the or each satellite rotor member disposed within the or each bight for rotation about a second axis of rotation; one or more control chambers being defined generally at any time during a work cycle by any combination of two or more of a wall of the or each satellite rotor member, the peripheral wall of the void and the peripheral wall of the major rotor member; the engine further including a plurality of ports associated with the or each main body or rotor for permitting the flow of a fluid to or from the control chamber.
Preferably, the or each major rotor member is operatively connected to an output shaft via a transmission means.
In one preferred embodiment, the peripheral wall of the void is a generally trochoid, epitrochoid or cycloid shape, by which is defined one upper lobe and one lower lobe, meeting at a midpoint defining a waist. Other preferred embodiments include up to twelve lobes in the void.
In one form, at least part of the peripheral wall portion of the major rotor member is a circular shape (or part thereof) and is sized so that its peripheral wall forms a seal which at many points in the work cycle, defines a division between control chambers assisted by the or each waist.
In another form, the major rotor member is generally elliptical in shape. In this embodiment, the lobes are circular in shape so that the control chambers can vary in size to affect the fluid therein.
Preferably the major rotor member and satellite rotor member are operatively connected to each other via a gear system, and in one form the gears provide anti-clockwise rotation of the satellite rotor member preferably at one-third the rotation speed of the major rotor member when the major rotor member rotates clockwise. The relative speed of rotation of the major and satellite rotor members generally depends on the number of satellite rotor members associated with a major rotor member, whether the satellite rotor member is generally disposed within and rotating with the major rotor member or disposed generally outside the major rotor member, and/or the number of lobes associated with the void, the shape of the or each satellite rotor. In another preferred form the satellite rotor rotates at 1.25 times the angular speed of the major rotor member.
Preferably, the satellite rotor member is generally triangular in shape, wherein each side is generally concave. The degree of concavity may vary, and with greater concavities the or each satellite rotor may take on a spoked appearance. The-satellite rotor member may also include one or more seals generally at its vertices, so that the escape of working fluids from one control chamber to another is minimised.
A preferred embodiment of the rotary machine is suitable for use as an internal combustion engine, and in that embodiment, compression ignition fuels may be used, or spark ignition fuels may be used. One or more spark plugs may be used, for example trailing and leading, as is known in rotary engines (cf Wankel). In one form, three spark plugs may be used. Fuel injection systems may be utilised with the engine, wherein fuels may be injected in the phase just before ignition for maximum efficiency.
Preferably, the or each main body includes opposed spaced apart end walls to enclose the control chambers. In one preferred embodiment the end walls carry shafts about which the satellite rotors rotate. In this form the end walls rotate at the same rate as the major rotor and are affixed to the shaft thereof, but allow the satellites to rotate about the shaft to which they are affixed.
Preferably, the peripheral wall of the void is roughened slightly, as with a hone or similar tool to increase lubricant retention and to increase feedback control of the satellite rotor member when operated without gears operatively connecting the satellite and major rotor members.
Preferably, the or each main body has associated therewith two ports, one port being an inlet port and the other being an exhaust port. The inlet and exhaust ports may be disposed at one end of the cylinder in close proximity to one another. The inlet port is adapted to allow a working fluid such as air or a fuel air mixture into the control chamber at a selected part of the rotation of the rotor members. The exhaust port is adapted to allow egress of spent working fluid from the control chamber and drawn away to, for example an exhaust pipe. In one form the ports may be associated with the or each major rotor, such that each port terminates at the peripheral wall of the major rotor. In other embodiments, more ports per main body may be provided, generally in pairs of inlet and exhaust ports.
Known methods of sealing may be employed to reduce combustion or other losses, for example, gas blow-by.
Advantageously, in operation, in the case of the internal combustion engine, an explosive force provided by the igniting of the working fluid in the control chamber bears on the shaft upon which the or each satellite rotor is mounted. Generally ignition occurs once the satellite rotation axis rotates past an axis generally extending between the major rotor member's central rotation axis and the spark plug. In this case generally all torque is provided in the required direction.
According to yet another aspect of the present invention there is provided a piston element suitable for use in an internal combustion engine or pump, the piston element when in use operatively mounted disposed for rotation within a void having a cooperating interior peripheral wall, the piston element including: a plurality of working surfaces in the form of peripheral working walls; one or more peripheral link walls, each peripheral link wall connecting adjacent peripheral working walls at each end thereof; a vertex at the junction of each peripheral link wall end and peripheral working wall end; a plurality of seal elements, each seal element disposed at each vertex, so that the seal elements improve sealing with the interior peripheral wall by subtending an angle with the cooperating interior peripheral wall as close to 90° as possible.
Preferably a biasing means is provided in the form of a spring to bias the seal elements outwardly towards a cooperating wall of a chamber in which the piston element when in use is disposed. Preferably, the spring is a compression spring which provides a generally linear biasing response. In one preferred embodiment the spring is a helical compression spring.
Preferably a carriage is provided for mounting and carrying the or each seal element.
Preferably the carriage is disposed within a cooperating housing, allowing the carriage to reciprocate in a direction generally normal to the cooperating surface.
Preferably apertures are provided in the piston or rotor in order to house the seal elements. In preferred rotor embodiments the apertures are disposed at the or each vertex of the rotor, and provide a passage between the or each vertex and the cooperating housing for the carriage.
Preferably, the or each rotor member is generally triangular in shape, wherein each side is generally concave. The degree of concavity may vary, and with greater concavities the or each satellite rotor may take on a spoked appearance. In preferred embodiments of rotor, each rotor member includes two vertices at the ends of each spoke, and a seal element disposed at each vertex, to minimise the escape of working fluid past the seal elements, especially when the radius of the cooperating surface becomes small.
According to one aspect of the present invention there is provided a piston element, when in use disposed within a chamber having a side wall, the piston element including side wall sections which when in use bear against or are disposed in close proximity to the side wall of the chamber, the side walls of the piston element being biased so as to be urged towards the side walls of the chamber.
Preferably the piston element is a rotor mounted for rotation within a chamber of an internal combustion engine or pump.
Preferably a biasing means is provided in the form of a spring which provides a generally linear biasing response to the axially spaced portions. The spring may in preferred embodiments be a leaf or coil spring or one or more Belleville washers.
In preferred embodiments the adjacent, axially spaced portions are halves of the piston element, or may include a main body and one or more covers.
Preferably the side wall sections of the chamber is a side boundary of a cylinder or void in which the piston element moves.
In order to enable a clearer understanding of the invention, drawings illustrating example embodiments are attached, and in those drawings:
FIGS. 1(i)-(viii) shows front schematic elevation section views along a diametral plane of a rotary engine of the single satellite rotor type at various stages, in sequence, of its work cycles;
FIGS. 3 to 6 and 6A show differing schematic elevation views along a diametral plane of the same twin satellite rotor engine at differing stages around the work cycle;
Referring to
The rotor block is operatively connected to end plates (not shown in this embodiment but similar to 151 and 153 on a second embodiment shown in
An upper peripheral wall 32 further defines an upper lobe of the void, as well as a lower peripheral wall 34, defining a lower lobe of the void 15, and a waist 42 and 44 is disposed between the two lobes. The peripheral walls 32 and 34 define generally trochoid, epitrochoid or cycloid shapes, more particularly defined by the following mathematical equations:
Ordinate
Abscissa:
Definitions of θ, R1, R2 and R3 may be found in
θ indicates angular displacement of the rotors in a clockwise direction; starting at zero in the 12 o'clock position.
R1 indicates the radius (distance from centre to convex circular peripheral wall) of the major rotor member
R2 indicates the radius (distance from centre to vertex) of the or each satellite rotor member.
R3 indicates distance from major rotor centre the inside peripheral wall of the void at θ=0.
The major rotor members 14 and satellite rotor member 12 are disposed within the void 15. The major rotor member 14 is mounted on a shaft 16. A gear train (not shown in this embodiment but similar to that shown generally at 160 in another preferred embodiment shown in
The major rotor member 14 has a peripheral wall 7 which is generally circular (or circular in part) and includes a generally arcuate wall 13 which defines a bight 17 within the major rotor 14. The satellite rotor 12 is disposed for rotation at least partly within bight 17 and mounted on shaft 18.
Two ports are provided at 30 and 28 for the purpose of allowing the flow of a working fluid to 30 and from 28 the control chamber respectively. In
The satellite rotor member 12 is generally triangular in shape, each of the sides being generally concave. The satellite rotor member 12 has three vertices 4, 5,6 which are substantially always in sealing contact with either the inner peripheral wall of the void 32 or 34 or the periphery of the bight in which it rotates. Thus a number of separate control chambers are formed as appropriate by: the walls of the satellite rotor 36, 38 and 40 and the bight 17 walls; and the void periphery, 32, 34. Examples of the control chambers are shown at 70, 72, 74, 76, 78, 80, 82, 84, and 86. The satellites 12 are generally shaped to provide a balance between clearance with the contours of the void interior periphery 7 and a high compression ratio by providing a chamber as small as possible when at the commencement of the power stroke (generally TDC in Otto cycle parlance).
A spark plug is provided at 26 for ignition of the working fluid. Cooling is provided by apertures (not shown) in the walls of main body 9, for passage of coolant.
To describe the rotary machine in operation, we will follow a control chamber through a working cycle, stepping through FIGS. 1(i) to 1(viii) in sequence. The working cycle is based on the well-known Otto cycle of inlet, compression, power and exhaust stages.
In operation the major rotor 14 rotates clockwise about its shaft 16 and in
Advantageously, in operation, in the case of the internal combustion engine, an explosive force provided by the igniting of the working fluid in the control chamber bears on the shaft upon which the or each satellite rotor is mounted. Generally ignition occurs once the satellite rotation axis rotates past an axis generally extending between the major rotor member's central rotation axis and the spark plug. In this case generally all torque is provided in the required direction.
FIGS. 1(vii) and 1(viii) show the power cycle more and more advanced, until finally, we return to
Advantageously, the triangular shape of the satellite rotor allows only fresh air/charge to mix with fresh air/charge, and does not dump fuel/air charge or fresh air into the exhaust outlet. Similarly with spent charge—only spent charge within a control chamber will mix with spent charges or be dumped straight to the exhaust outlet port. This becomes particularly effective and advantageous in multi-satellite embodiments, when the interactions are complex.
Other features of the triangular satellite rotor member are that one chamber defined by walls of the satellite always undergoes a storage function. That is, only two of the chambers defined by the satellite are undergoing part of the Otto cycle. The other chamber is undergoing storage. However, as mentioned, when the storage chamber rejoins the Otto cycle, the spent and fresh charges do not mix, even to go down the exhaust, (or arguably worse, to send a spent charge back into the inlet). Similar advantages are gained by using a pentagonal-shaped satellite rotor (not shown).
More space in the engine block may be utilised than that utilised by other rotary engines. This allows higher compression ratios and greater working volumes to be used.
As will be noted by an examination of the geometry of the machine, in this first embodiment, there is provided one power cycle per rotation of the major rotor member, and thus the satellite rotor 12 rotates around the major rotor member ⅓ of a rotation per rotation of the major rotor member. However, numerals on the satellite rotor member are only valid for a single sequential reading of the cycle from 1(i) to 1(viii) thus the reader should not “loop” the cycle from 1(viii) to 1(i) because the vertices 4, 5 and 6 index around the rotor at each completion of a single major rotor member 14 rotation. It can be seen that an “empty” chamber rotates around the main body 9, doing no work on the fluid.
Referring to FIGS. 2 to 8 there is shown a rotary machine according to another embodiment of the invention, a twin satellite engine. Like features of the embodiments of those described in the first embodiment are denoted by like numerals. The embodiment in these latter Figures has two satellite rotor members, 112 and 112B, providing two power cycles per rotation of the major rotor member 114, providing greater potential for balance and efficiency. Similarly to the first embodiments, the satellite rotors 112 and 112B rotate ⅓ revolution for every single rotation of the major rotor member 114. The rotation of the satellites 112 and 112B is governed by gear trains shown at 160 in
FIGS. 10 to 14 show a 12-rotor embodiment of a machine according to the present invention, like features being are denoted by like numerals in those embodiments previously described.
The peripheral wall comprises 12 lobes 232 which are defined by the following mathematical equations on a Cartesian plane:
yα=R cos θ+R21 cos(α−3θ)
xα=R sin θ+R21 sin(α−3θ)
where: α is defined in
Whereas the previous embodiments (
Section end elevation views of the rotary engine according to the 12-rotor embodiment are shown in FIGS. 13 to 14.
A further embodiment of the rotary machine is shown at
Yet another form of the invention is shown in
where A is defined in
In this form, the peripheral wall 432 and 434 of the void 415 is generally circular, and similarly the walls of the bights 417 are circular, or part thereof. This embodiment further has two satellite rotor members 412 and 412B, associated with the main rotor 414.
In operation the major rotor 414 is, say, rotating clockwise, and the satellite rotors 412 and 412B thus rotate anticlockwise at ⅓ the rotation rate of the major rotor. Four control chambers are formed at all times in the work cycle of the engine. In the view shown in
As will be noted, this latter embodiment shown in
The embodiment shown in
Referring to
The satellite rotor element 312 rotates about its central axis 319 and each spoke on the rotor 312 generally has two vertices, and a seal element disposed within a respective aperture, each aperture itself disposed at each vertex. At least one seal element maintains sealed contact with cooperating walls (not shown in this Figure, but the walls are as above described, such as for example, void periphery 32, 34, and bight periphery 13 and like variants) to define a control chamber (also not shown in this Figure).
Two vertices per spoke are generally used in order to maintain sealed contact between rotor and cooperating wall when radii of cooperating walls becomes small. However, satellite rotors with one vertex per spoke may be utilised with this seal assembly. The two-vertex system has sealing advantages over a single-vertex seal when radii become small, because the angle between the plane of the seal and the plane of the cooperating wall may be maintained in a range above approximately 30°. When seal angles fall below approximately this figure, sealing becomes ineffective. 90° between seal and wall is the ideal angle for sealing, however, with this style of rotary engine the sealing angles vary around the work cycle.
The seal assembly 345 includes a pair of seal elements 347, 349 mounted to a carriage 359, the carriage 359 mounted within a housing 363 for reciprocation along a respective spoke. The carriage 359 is operatively connected to a biasing means 355 in the form of a helical compression spring 357. This is so that the seal elements 396, 397 are biased outwards to extend from the apertures 361 in the vertices of their respective spoke to maintain sealing contact with the corresponding wall throughout a range of seal element 396, 397 wear.
Referring to
Referring to
The side walls 651 and 653 are sealably connected to rotor block 609 by seals 635, and when in operation, rotate past rotor block 609. In this manner, the engine housing, including end walls 650 and 652 is stationary, and may be bolted to known engine mounts, while the actual work is being performed inside the motor block, with the side 651 and 653 walls rotating with the major rotor and shaft, the satellite rotors rotating about their own axis 618 as well as orbiting about the major rotor's axis 616. Gear train 660 also rotates with side walls 651 and 653.
A sump is provided at 660 and 661 to provide lubrication and cooling. Water and/or oil may be used for cooling. A pump is utilised to draw oil from the sump and spray oil from the general area of the end walls 650 and 652 onto the rotating side walls 651 and 653 and gears 660 for cooling and lubrication.
Finally, it is to be understood that various alterations, modifications and/or additions may be incorporated into the various constructions and arrangements of parts without departing from the spirit or ambit of the invention.
Number | Date | Country | Kind |
---|---|---|---|
2003900394 | Jan 2003 | AU | national |
2003902580 | May 2003 | AU | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/AU04/00112 | 1/30/2004 | WO | 1/3/2007 |