GB2262569A

GB2262569A - Oscillatory rotating engine.

Info

Publication number: GB2262569A
Application number: GB9127580A
Authority: GB
Inventors: Bryan Nigel Victor Parsons
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-12-21
Filing date: 1991-12-21
Publication date: 1993-06-23
Anticipated expiration: 2011-12-21
Also published as: GB2262569B; GB9127580D0

Abstract

Concentric rotors 20, (21, Fig 1) are mounted for rotation within a cylindrical housing 10, each rotor 20, (21) having a pair of diametrically opposed lobes 30, 32; 31, 33 which engage the walls of the housing 10 to define four working chambers 40, 41, 42, 43. The rotors are interconnected in a manner which will impose a variation in relative angular velocity on them so that the volumes of the working chambers alternately expand and contract. An inlet port 81 and an exhaust port 80 are provided, the position of the inlet port corresponding to an expansion phase of the working chambers to draw in air or air/ fuel mixture. Means 88, 90, 91 are provided to vary the angular extent of the inlet port 81 in the plane of rotation of the rotors to vary the period for which the port 81 is open, for a given overall rotor speed. A slide valve (95, Fig 7) may be used in place of butterfly valves 90, 91. <IMAGE>

Description

OSCILLATORY ROTATING ENGIlJE The present invention relates to oscillatory rotating engines and in particular to engines of the Kauertz type.

The Kauertz engine comprises a pair of concentric rotors each rotor having a pair of diametrically opposed sectors or lobes which sealingly engage the end walls and circumferential surface of a cylindrical housing, to define four working chambers, each working chamber being defined between a sector or lobe of one rotor and a sector or lobe of the other rotor. The rotors are driven about their common axes, their relative angular velocity varying so that the volume of each working chamber is alternately expanded and then contracted. An inlet port, exhaust port and induction device are provided at appropriate points on the cylindrical housing, so that the expansion and contraction of the working chambers will provide induction, compression, expansion and exhaust strokes.

With such engines, the lobes of the rotors serve to open and close the inlet and exhaust ports, as the rotors rotate within the cylindrical casing. The power output of the engine is controlled by means of a throttle valve which varies the rate at which air or air/fuel mixture is delivered to the inlet port, the rate being reduced at low power outputs and increased at high power outputs.

However, the duration of opening of the inlet port is inversely proportional to the rotor speed and hence power output. Consequently, at low power outputs when a reduced air or air/fuel charge is required, high throttling must be used which results in high pumping losses with consequent reduction in engine efficiency.

The present invention provides means for varying the duration of opening of the inlet port independently of the rotor speed, so that the duration of opening at low speeds may be reduced, thus reducing the degree of throttling required and hence the pumping losses.

According to one aspect of the present invention an oscillatory rotating engine comprises a cylindrical housing defined by a pair of end walls and a circumferential wall; a pair of concentric rotors mounted for rotation within the cylindrical housing, each rotor having a pair of diametrically opposed lobes which sealingly engage the end walls and circumferential wall of the cylindrical housing to define four working chambers, each working chamber being defined between a lobe on one rotor and a lobe on the other rotor, the rotors being rotatably interconnected in a manner which will impose a variation in relative angular velocity on the rotors so that the volume of the working-chambers are alternately expanded and then;lcontracted;; an inlet port and an exhaust port being provided to the cylindrical housing, the inlet port being located in a position corresponding to an expansion phase of the working chambers, so that a charge of air or air/fuel mixture may be drawn into the working chambers through the inlet port; means being provided to vary the angular extent of the inlet port in the plane of rotation of the rotors, thereby varying the period for which the inlet port is open, for a given overall rotor speed.

With the above engine, the angular extent of the inlet port may be reduced at low rotor speeds, thereby reducing spillage of the air or air/fuel mixture back into the inlet manifold.

According to a preferred embodiment, a plurality of inlet passages feed the inlet port, the passages being arranged such that they will be closed sequentially by the lobes of the rotor, each passage having a throttle valve and means being provided to actuate the throttle valves sequentially in accordance with the power output required. Alternatively, the inlet port may be provided with sliding closure means which will provide a seal with the lobes of the rotor.

The extent of opening of the inlet port is preferably varied in accordance with the present invention, by advancing or retarding closing of the inlet port. The variation in duration of opening of the inlet port may however be effected by varying the opening point of the inlet port or varying the opening and closing points of the inlet port.

The invention is now described by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a sectional isometric view of a Kauertz engine; Figure 2 is a sectional side elevation of the engine illustrated in Figure 1, showing an exhaust port, ignition device and inlet port in accordance with the present invention; Figures 3 to 6 illustrate various phases of the engine illustrated in Figures 1 and 2; and Figure 7 illustrates an alternative form of variable inlet port for use in the engine illustrated in Figure 1, in accordance with the present invention.

The oscillatory rotating engine illustrated in Figures 1 and 2 comprises a cylindrical housing 10 formed by a pair of annular end walls 11 and 12 and a cylindrical wall 13 which are bolted together in-suitable manner. The walls 11, 12 and 13 are provided with passages 15 through which coolant may be circulated.

A pair of rotors 20 and 21 are mounted coaxially of one another, within the housing 10 on concentric shafts 22 and 23 respectively. Each rotor 20, 21 comprises a hollow cylindrical core 25, 26 which extends half the width of the housing 10, a seal being provided between juxtaposed ends of the cores 25 and 26 in a manner which will permit relative movement therebetween.

Each of the rotors 20, 21 has a pair of diametrically opposed radially extending sectoral lobes 30 and 32; and 31 and 33 respectively. The lobes 30, 31, 32 and 33 extend the full width of the housing 10, sealing means being provided to produce a seal between each lobe 30, 31, 32 and 33 and; the core 26, 25 of the other rotor 21, 20; the end walls 11, 12 of the housing 10; and the cylindrical wall 13 of the housing 10. The lobes 30, 31, 32 and 33 thereby divide the housing 10 into four working chambers 40, 41, 42 and 43, each working chamber 40, 41, 42 and 43 being defined between a lobe 30, 32 on one rotor 20 and a lobe 31, 33 on the other rotor 21.

Gears 50 and 51 are mounted on the shafts 22 and 23 for rotation with the rotors 20 and 21 respectively. The gears 50 and 51 mesh with internal gears 60 and 61 respectively, which are rotationally mounted in bearings 62 and 63 on the internal diameter of an annular link 64.

The annular link 64 is connected to an output shaft 100 by means of a crank 101 and has a pair of idler cranks 102 (only one shown) to constrain the annular link 64 to move in an orbital path centred on the axis of rotation of the shafts 22 and 23.

The gears 60 and 61 each have an arm 65, 66 which extends radially of the gears 60, 61. The arms 65, 66 have radially extending slots 67, 68 which are slidingly engaged by pins 69, 70. The pins 69 and 70 are located in fixed positions relative to the cylindrical housing 10, at equal distances from the axis of rotation of the shafts 22, 23 but at diametrically opposite sides thereof.

Upon rotation of the rotors 20 and 21, and gears 50 and 51 connected thereto, the internal gears 60 and 61 will be driven to perform an eccentric oscillation, rotation of the internal gears 60 and 61 being prevented by engagement of pins 69 and 70 in slots 67 and 68. The reaction between the gears 50 and 60 and 51 and 61 will cause the annular link 64 to move about its orbital path so that crank 101 will cause output shaft 100 to rotate.

The ratio of the diameter of gears 50 and 51 and the internal gears 60 and 61 is two to three, giving an overall drive ratio of one to two between the rotors 20, 21 and output shaft 100.

As a result of the rotational oscillation of internal gears 60 and 61, a substantially sinusoidal variation in angular velocity is imposed on the rotors 20 and 21. As the arms 65 and 66 are disposed in opposite directions, the variation in angular velocity of the rotors 20 and 21 will be 1800 out of phase, so that the rotors will alternately move together and then apart so that the volumes of the working chambers 40, 41, 42 and 43 defined therebetween are alternately expanded and then contracted. Because of the gearing of the drive mechanism, each working chamber 40, 41, 42 and 43 will be subjected to two compression phases and two expansion phases per revolution of the rotors 20 and 21.These compression and expansion phases of the working chambers correspond to the induction, compression, expansion and exhaust strokes of a four stroke internal combustion engine. As each of the working chambers 40, 41, 42 and 43 will undergo this cycle during each revolution of the rotors, this will provide four detonations per revolution.

As illustrated in greater detail in Figure 2, an exhaust port 80 and inlet port 81 are provided through the cylindrical wall 13 of housing 10 at positions which will open to the working chambers 40, 41, 42 and 43 at sequential compression and expansion phases thereof. An ignition device 82 is provided through the cylindrical wall 13 at a point opposite to the exhaust port 80 and inlet port 81, where the working chambers 40, 41, 42 and 43 will be at a minimum volume.

The inlet port 81 is connected by manifold 85 to means, for example an air valve or carburettor, for supplying air or an air/fuel mixture to the working chambers 40, 41, 42 and 43. The manifold 85 is divided at the end which defines inlet port 81 into two separate passages 86 and 87, by means of baffle 88. The baffle 88 extends right up to the cylindrical plane defining the inner surface of wall 13, so that that end 89 of the baffle 88 will sealingly engage the lobes 30, 31, 32 and 33 as they rotate past the inlet port 81. Each passage 86 and 87 has a butterfly valve 90, 91 respectively, which will control flow of air or air/fuel mixture through the respective passage 86, 87 to the inlet port 81.The butterfly valves 90 and 91 are connected to operating means (not shown) which will sequentially control opening thereof in accordance with the power output requirements, so that at low power output requirements, butterfly valve 90 will open while butterfly valve 91 will remain closed; while at higher power output requirements, both butterfly valves 90 and 91 will open.

Figure 2 illustrates the engine in a position at which the rotors 20 and 21 are at one extreme of their relative rotation. In this position, lobes 30 and 31 and lobes 32 and 33 respectively are at their closest, working chambers 40 and 42 being at minimum volume while chambers 41 and 43 are at maximum volume. In this position, lobe 30 closes the exhaust port 80 and lobe 31 closes the inlet port 81. Air/fuel mixture in chamber 42 will be fully compressed and ready for detonation by the ignition device 82. Detonation of the air/fuel mixture in chamber 42 will produce a force on lobes 32 and 33 urging them apart and, under control of the drive mechanism, causing the rotors 20 and 21 to rotate clockwise.

As the rotors 20, 21 move from the position illustrated in Figure 2 to that illustrated in Figure 6, lobe 31 is moving away from lobe 30 and towards lobe 32, while lobe 33 is moving away from lobe 32 and towards lobe 30. As a result of this relative movement of lobes 30, 31, 32 and 33, chambers 40 and 42 will expand in volume while chambers 41 and 43 will reduce in volume. Movement of lobe 31 will open the inlet port el permitting air or air/fuel mixture to be drawn into the chamber 40. At the same time, movement of lobe 30 will open exhaust port 80 permitting combustion gases to be expelled from the chamber 43. During this period, reduction in volume of chamber 41 will compress the air/fuel mixture in that chamber while expansion of chamber 42 will permit expansion of the combustion gases.

At the intermediate position illustrated in Figure 4, lobe 30 will engage the edge 89 of baffle 88 thus closing off passage 87.

At the position illustrated in Figure 6, the lobes 30 and 32 of rotor 20 and lobes 31 and 33 of rotor 21 have moved to the opposite extent of their relative movement, lobes 31 and 32 and lobes 33 and 30 respectively being at their closest and chambers 41 and 43 being at minimum volume while chambers 40 and 42 are at maximum volume. At this position, the air/fuel mixture in chamber 41 is detonated and lobes 33 and 30 close the exhaust port 80 and inlet port 81 respectively.

Continued rotation of the rotors 20 and 21 will then cause lobe 30 to move away from lobe 33 and towards lobe 31 and lobe 32 will move away from lobe 31 and towards lobe 33, thereby reducing the volume of chambers 40 and 42 and increasing the volume of chambers 41 and 43. This cycle is repeated until detonations have occurred in all four chambers 40, 41, 42 and 43 and the rotors 20 and 21 have completed a revolution.

Under low power demand, when a relatively low charge of air or air/fuel mixture is required to be drawn into the chambers 40, 41, 42 and 43 during the induction stroke thereof, butterfly valve 90 is opened while butterfly valve 91 remains closed. In this mode, the inlet port 81 will be effectively closed well before chambers 40, 41, 42 and 43 have fully expanded when the lobes 30, 31, 32 and 33 engage edge 89 of baffle 88, as illustrated in Figure 4. In this way, the closing point of port 81 is effectively advanced, significantly reducing the duration of opening of the port 81 for a given overall rotor speed.At high power demands, when a relatively large charge of air or air/fuel mixture is required, both butterfly valves 90 and 91 will be opened so that even after passage 86 has been closed, passage 87 will remain open so that the inlet port 81 will remain open throughout the full expansion phase of the chamber 40, 41, 42 and 43, that is to the point illustrated in Figure 6. Within the low and high power demand ranges the volume of air or air/fuel mixture entering the working chambers will be controlled by the degree of opening of butterfly valve 90 or butterfly valves 90 and 91 respectively.

In the modification illustrated in Figure 7, the multipassage inlet manifold 85 is replaced by a single passage, the angular extent of the inlet port 81 being controlled by an angularly adjustable slide valve means 95 which provides a sealing edge 96 for engagement of the lobes 30, 31, 32 or 33. The angularly adjustable valve member 95 may be controlled in suitable manner to advance or retard the closing point of the inlet port 81 in accordance with the power demand.

Various modifications may be made without departing from the present invention. For example, while in the above embodiments the inlet and exhaust ports are provided in the cylindrical wall 13 of the housing 10, one or both of these ports may alternatively be provided through the side walls 11 and/or 12. Furthermore, while in the embodiment illustrated in Figure 2 the inlet manifold is divided into two passageways, more than two passageways may be provided.

The butterfly valves 90 and 91 of the embodiment illustrated in Figure 2 or the slide valve 95 of the embodiment illustrated in Figure 7 may be controlled by a throttle control using a suitable linkage mechanism.

Alternatively, the butterfly valves 90 and 91 and slide valve 95 may be controlled by the engine management system through suitable motor means, in which case parameters other than acceleration control may be taken into account.

Claims

1. An oscillatory rotating engine comprising a cylindrical housing defined by a pair of end walls and a circumferential wall; a pair of concentric rotors mounted for rotation within the cylindrical housing, each rotor having a pair of diametrically opposed lobes which sealingly engage the end walls and circumferential wall of the cylindrical housing to define four working chambers, each working chamber being defined between a lobe on one rotor and a lobe on the other rotor; the rotors being rotatably interconnected in a manner which will impose a variation in relative angular velocity on the rotors so that the volume of the working chambers are alternately expanded and then contracted; an inlet port and an exhaust port being provided to the cylindrical housing, the inlet port being located in a position corresponding to an expansion phase of the working chambers, so that a charge of air or air/fuel fixture may be drawn into the working chambers through the inlet port; means being provided to vary the angular extent of the inlet port in the plane of rotation of the rotors, thereby varying the period for which the inlet port is open, for a given overall rotor speed.

2. An oscillatory rotating engine according to Claim 1 in which the inlet port is connected to a source of air or air/fuel mixture by an inlet manifold, the inlet manifold being divided into a plurality of passageways spaced angularly in the plane of rotation of the rotors, the passageways being separated from one another by baffles, the end of each baffle terminating in a sealing edge which will be engaged by the lobes of the rotors to provide a seal therewith, as the rotors rotate in the cylindrical housing, means being provided to separately control flow of air or air/fuel mixture through each of the passageways.

3. An oscillatory rotating engine according to Claim 2 in which each passageway is provided with a butterfly throttle valve, means being provided to control the butterfly throttle valves sequentially in accordance with the power output demand.

4. An oscillatory rotating engine according to Claim 2 or 3 in which flow of air or air/fuel mixture through the passageways is controlled such that at low power demands, the passageways at the leading edge of the inlet port relative to the direction of rotation of the rotors will be open while passageways towards the trailing edge of the inlet port will be closed.

5. An oscillatory rotating engine according to Claim 1 in which the inlet port is provided with a slide valve which is movable angularly of the plane of rotation of the rotors, the slide valve defining a sealing edge which will engage the lobes of the rotors as they rotate within the cylindrical housing, means being provided to adjust the slide valve in accordance with the power output demand of the engine.

6. An oscillatory rotating engine according to any one of the preceding claims in which the angular extent of the inlet port is varied in accordance with the throttle control mechanism of the engine.

7. An oscillatory rotating engine substantially as described herein with reference to, and as shown in, Figures 1 to 7 of the accompanying drawings.