GB2262570A - Cooling rotors of an oscillatory rotating engine. - Google Patents

Abstract

In an oscillatory rotating engine in which a pair of concentric rotors 20 (21, Fig 1) are mounted for rotation within a cylindrical housing 10, each rotor 20, (21) has 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 40, 41, 42, 43 alternately expand and contract. An inlet port 81 and an exhaust port 80 are provided through a wall 13 of the housing 10 and each of the lobes 30, 31, 32, 33 of the rotors 20, (21) is hollow to allow coolant gas to flow through from a coolant inlet port 112 to a coolant outlet port 113 in order to cool the rotors. <IMAGE>

Description

OSCILLATORY ROTATING ENGINE 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 alld exhaust strokes.

Passages are provided in the walls of the cylindrical housing through which a coolant may be circulated to cool the engine. However, hitherto cooling of the rotors has been a problem, it being necessary to rely on conduction across adjacent surfaces of the rotors and cylindrical housing for this purpose.

The present invention provides means for direct cooling of the rotors of an oscillatory rotating engine.

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 contracted; an inlet port and an exhaust port being provided through a wall of the housing; each of the lobes of the rotors being of hollow construction and a coolant port being provided through which a coolant gas may be passed into the hollow lobes as they pass the coolant port, in order to cool the rotor.

According to a preferred embodiment the inlet and exhaust ports are provided in the cylindrical wall of the housing. Each of the lobes of the rotors has a transverse passageway and a transverse coolant port is provided in each of the side walls of the housing, the transverse coolant ports being coaxial and aligned radially of the passageways in the lobes. Preferably t1ie passageways in the lobes are provided with vanes to increase the surface area and hence the heat transfer to the coolant gas.The coolant gas may be delivered to the coolant ports in pulses, so as to correspond to alignment of the coolant ports with the passageway in each of the lobes. However the coolant ports are preferably positioned to correspond to the exhaust stroke of the working chambers and the coolant gas is delivered continuously, so that when the coolant ports are not aligned with one of the lobes, the coolant gas will be delivered to the working chamber to scavenge combustion gases therefrom.

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 in accordance with the present invention; Figure 2 is a sectional side elevation of the engine illustrated in Figure 1; Figure 3 is a sectional view along the line II 1-111 of Figure 2; and Figures 4 to 7 illustrate various phases of the engine illustrated in Figures 1 to 3.

The oscillatory rotating engine illustrated in the accompanying drawings 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 extendiny 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 exhaust port 80 is connected via exhaust manifold 84 to an exhaust system (not shown) and 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.

Each of the lobes 30, 31, 32 and 33 has a series of transverse passageways 110 defined by a series of vanes 111. A transverse coolant inlet port 112 is provided through wall 11 of housing 10 and a transverse coolant outlet port 113 in wall 12 of housing 10. The inlet and outlet ports 112 and 113 are coaxial and aligned radially of the passageways 110 through the lobes 30, 31, 32 and 33 at a position aligned angularly with the latter portion of exhaust port 80, relative to the direction of rotation of rotors 20 and 21. The inlet port 112 is connected via duct 114 to a source, for example an engine driven compressor or fan, of air under pressure and duct 115 permits the passage of air through passages 110 and out through port 113.

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 through those illustrated in Figures 4 to 7, 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 81 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 position illustrated in Figure 7, 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.

Air is delivered continuously to inlet port 112, so that when port 112 is aligned with the passageways 110, the air will pass through the passageways 110 and out through outlet port 113 and duct 115, thereby cooling the rotors 20 and 21. When the inlet port 112 is open to the working chambers 40, 41, 42 and 43 towards the end of the exhaust stroke thereof as illustrated in Figure 6, air passing through port 112 will enter the working chamber 43 and will force combustion gases therein, out through the exhaust port 80, thereby scavenging the working chamber 43.Where a catalytic convertor is fitted to the exhaust system of the engine, the exhaust port 80 may be divided into two angularly separated passageways 116 and 117 by baffle 118, so that exhaust gases diluted by air from inlet port 112, may pass through passage 117 and bypass the catalyst, thereby avoiding undesirable cooling thereof.

Various modifications may be made without departing from the invention. For example, while in the above embodiment the ports 112 and 113 are positioned relative to exhaust port 80 so that air passing through port 112 may be used to scavenge the working chambers 40, 41, 42 and 43; the cooling air system of the present invention may be totally independent of the exhaust system, the ports 112 and 113 being located coaxially of one another and in radial alignment with the passageways 110 at any desirable angular position, air being delivered to inlet port 112 only when it is aligned with the passageways 110 through one of the lobes 30, 31, 32 and 33. Furthermore the inlet and exhaust ports may be provided through a side wall of the housing, the coolant inlet and outlet ports being provided in the cylindrical wall and apertures being provided in the faces of the lobes engaging the cylindrical wall of the housing to allow the coolant gas to pass therethrough.

Claims (9)

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 through a wall of the housing; each of the lobes of the rotors being of hollow construction and a coolant port being provided through which a coolant gas may be passed into the hollow lobes as they pass the coolant port, in order to cool the rotor.

2. An oscillatory rotating engine according to Claim 1 in which the inlet and exhaust ports are provided in the cylindrical wall of the housing, each of the lobes having a transverse passageway and a transverse coolant port being provided through each of the side walls of the housing, the transverse cooling ports being coaxial and aligned radially with the passageways in the lobes.

3. An oscillatory rotating engine according to Claim 2 in which the passageway through each of the lobes is provided with vanes to increase the surface area.

4. An oscillatory rotating engine according to Claim 3 in which the vanes define a plurality of passageways.

5. An oscillatory rotating engine according to any one of the preceding claims in which means is provided to deliver the coolant gas to the coolant port in pulses, the pulses corresponding to alignment of the coolant port with each of the lobes.

6. An oscillatory rotating engine according to any one of Claims 1 to 4 in which the coolant port is aligned angularly with the exhaust port, coolant gas being delivered continuously to the coolant port, so that when the coolant port overlaps a working chamber, coolant gas will be delivered to the chamber to scavenge combustion gases therefrom.

7. An oscillatory rotating engine according to Claim 6 in which the coolant port is aligned with the latter portion of the exhaust port relative to the direction of rotation of the rotors, so that the coolant port will overlap the working chambers toward the end of the exhaust stroke of said working chambers.

8. An oscillatory rotating engine according to Claim 6 or 7 having an exhaust system including a catalytic convertor, the exhaust port being divided into two angularly separated passageways, one of said passageways which is open when the coolant port overlaps each working chamber, bypassing the catalytic convertor.

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