GB2075122A - Rotary positive-displacement fluid-machines - Google Patents

Abstract

A machine of the reciprocating- rotary piston type, which may be a compressor, an I.C. engine or a pump, has double-acting pistons 02 with undulating surfaces and sealing strips 13 that co-operate with corresponding undulatory surfaces on fixed abutments, or "platens", 01A, 01B. The motion of the pistons is controlled, and power is transmitted to a power-output shaft- coupling 19, by mechanism comprising a crankshaft 16 and gears 05, 06. Inlet and outlet ports 09, 010 communicating with working chambers 14 may be controlled by valves 12. The platens may have cooling fins 15. Alternatively, the machine has a reciprocating single- acting piston(s) and a rotating platen(s). <IMAGE>

Description

SPECIFICATION Reciprocating rotary mechanism This device relates to the mechanisms applicable in prime movers such as heat engines, pumps compressors etc.

The object of this device is to introduce a mechanism that can extend the physical and mechanical limitations.

The said device basically consists of two plugs of equal radii to function as pistons.

They are closely fitted along their main axis inside a casing having cylindrical bore. The adjacent surfaces of pistons are fashioned in a specified bevel shape.

The void space between the two pistons forms the working chambers. When either of the pistons are moving one relative to the other, it performs a motion that cou!d be resolved mechanically in to a rotary motion and a reciprocating motion, and the working space expand and contract sequentially. Ports are provided on the casing, fluids to flow through the working space. A closed loop of mechanical assembly is set to govern the said performance.

The behaviour of such a system can be employed to perForm mechanical work, as a heat engine, using the pressure caused due to thermal expansion of a gas, vapour or steam.

To describe the mechanism more fully the piston performing motion consistin y the axial motion is termed as the "DISK" and the other piston is termed as the "PLATEN". Accordingly the platen remain stationary in some modes of operation.

A sleeve can be interposed between the pistons and the cylinder barrel. The sinner surface of the sleeve then forms the inner cylinder barrel in which pistons move. The sleeve is fitted permanently either to the disk or platen.

Ports are cut in the sleeve and through the main cylinder casting. When the sleeve is in continuous motion with the system fluid admit and exhaust due to the ports coincidence.

The principle of this mechanism is based on the behaviour of two geometrically represented wave patterns of equal wave lengths and amplitudes. When either of these wave patterns moving along the path of the other wave pattern the gap widths in between them expand and contract in a sequence.

A typical example for such set of wave patterns are cited by the functions f(x) = a.Sin x (x) f(x)= 12a. Sin- (See Fiy. 1) 2 The curve f(x) should be concaved towards the curve f(x). The extreme points of f(x) should theoritically always be in contact with the curve f(x).

The mechanism can be modified to obtain double action (i.e. working strokes are obtained in both surfaces of the "DISK".) for better dynamic balance, by arranging the same set of curves on the other side, but with a phase difference of 180 degrees. (See Fig.

2 and Fig. 3). In such a system when gaps on one side are expanding, gaps on the other side are contracting.

The shape of the surface for the "Disk" and "Platens" obtained by using the said wave patterns can be visualized from Fig. 4.

This is done by, either of the said wave patterns tracing around the circumferencial surface of the piston in the form of a continuous cyclic path, and then each point on this path is projected on to the axis of the piston.

The surface generated by the projected lines is the bevel fashioned surface of the piston.

In Fig. 4 surfaces of pistons have been obtained by straight projection lines, although the surface can be obtained by any form of projection lines. Therefore, any arbitrary concentric ring on this surface describes the same wave function with same number of cycles and same amplitude, but with varying wavel ength.

To avoid the impracticable shape near the axis a spindle or an axel should pass through the system.

Fig. 4 is an exploded view of this device constructed for double acting type. Components labelled in Fig. 4: û 1 - Upper platen (stationa') 0 1 - Lowor platen (stationary) 02 Disk Ci3 - Shaft (functioning as the spindle also).

04 - Casing 05 - Vane 06 - Non-return valve 07 - Inlet port 08 - Exhaust port 09 - Provision for spark plug.

When the system describes motion, a longi tudinal motion and a rotation results. The rotary motion can be transmitted directly to the driven shaft, and the longitudinal motion can be converted in to rotary motion as this motion is a simple harmonic one.

These resulting two rotary motions are in different geometries. However, they can be brought to a single power take off shaft, through a bevel gear mechanism, in order to inter link the relative positions of the disk and the platen simultaneously, and to act as a feed back loop.

Strokes in this mechanism are very much similar to those of ordinary piston and cylinder engines. But, once the air fuel mixture (or oil in oil engine) is compressed to maximum it sends in to the igniting chamber through a salve or nozzle.

If the required compression ratio can not be achieve for a particular case compressed air should be supplied. This can be accomplished by providing an additional cylinder barrel close to the combustion barrel with a tunnel between them. Therefore one cylinder is functioning as suction and compression barrel and the other is functioning as working and exhaust barrel. If the expansive force remain further, more units of the same device would connect in parallel Another way of doing this is providing additional concentric layer of chambers in the same cylinder, fashioned in the same way.

These layers may be separated by cylindrical spacers.

There is no hard and fast rule for other features of the combustion process in this mechanism such as for carburation, lubrication, engine cooling, exhaust, power transmitting system etc.

Furthermore the exhaust gas can be used for jet propuision if it leaves from the exhaust port with a high velocity.

When this mechanism is applied as a pump or as a compressor, disk and platten need not to be in contact essentially.

Successive positions during different phases are illustrated in Figs. 5, 6, 7, and 8. These figures should be assumed as the developments at any arbitrary circumference. In this process the upper and lower platens remain stationary while the disk (06) is sliding in between them.

Inlet port (01), exhaust port (02), and spark plug (03) are mounted on the casing at indicated locations. Non-return valves (04) and (05) are communicating between two chambers.

Always the apexes of concentrically moving disk is in firm contact with the surface of the platen and the casing. These volume changes accomplish the four essential phases of the internal combustion cycle.

A complete cycle consists of the following strokes, suction stroke: The leading face of the disk sweeps past and mixture of gas and air is drawn in to the chamber from the carburetor by the suddenly expanding space.

Compression stroke: As the disk continues to turn the spaces between the disk and the platen reaches its minimum, mean while the trailing apex of disk compresses and sending the compressed air fuel mixture to the igniting chamber through the non-return valve.

Working stroke: At maximum compression the air fuel mixture lies over the suction chamber and igniting chamber. The mixture is ignited and the chamber expands due to rapid rise of temperature and pressure. Meanwhile the remaining air fuel mixture in the suction chamber, passes to the igniting chamber.

Exhaust stroke: As the disk face yields to the force of the power phase, the leading apex sweeps out burnt gas to discharge through exhaust port.

Fig. 9 is an embodiment of this device constructed to obtain double action.

The casing (04) is half removed. The disk (02) and the two platens (01 and 01A) are sectioned at upper quarter portion.

Cooling ribs (15) are mounted on platens to radiate the excess heat. The disk (02) is rigidly fixed to the main shaft (03). This shaft can reciprocate while it is rotating on bearings (20). Two cam plates (08) are fitted through bearings (20) and they are independent of axial motion. The connecting rods are to communicate cam action to valves (12) through rocker arms (11). (09) and (10) are inlet and exhaust ports. The gear wheel (05) is fixed to the main shaft (03) so that it moves to and fro on another gear wheel (05A) and it receives rotary motion alone. Then the rotary motion is transmitted to the take off shaft (07) from the gear wheel 05A.

Power take off shaft is accompanied by the bevel gear mechanism (06). The main shaft (03) is fitted to a crank mechanism through a ball joint (17). The crank shaft and bevel gear inter links the rotary motion and reciprocating motion. Other labelled components are: 13 - Vane 16 - Crank shaft 18 - Bracket for train of gear wheels 19 Coupling to the driven shaft 21 - Fly wheel.

Basic theory in this mechanism can extend to obtain one revolution of rotary motion for one cycle of reciprocating motion. This is done by selecting the set of functions in the range of one cycle. Fig. 10 and Fig. 11 illustrate the shape of the disk and platen modified to give such result. Fig. 10 and Fig.

11 are the exploded elevations at different angles.

01 - Platen 02 - Disk 03A - Shaft connected to the Disk 03B -- Spindle 04 - Vane 05 - Rings for sealing Fig. 1 2 illustrates a mode designed to perform rotary motion and axial motion independently from platen and disk. A non-return valve operating at every second rotation should be provided in the casing.Components labelled in the Figure are: 01 -- Platen 02 - Disk 03 - Main shaft to deliver rotation 04 - Casing with cooling ribs 05 - Gear to transmit rotation 06 - Crank mechanism 07 - Coupling shaft 08 - Cam shaft 09 - Inlet ports 10 - Power take off shaft 11 - Exhaust port.

Fig. 13 is another embodiment which can eliminate the proportion of idle-strokes. It is accomplished by providing an additional barrel in parallel. In this device one cylinder is functioning for ignition and exhaust, while the other cylinder is functioning for suction and compression. Components labelled in the figure are: 1. Platen in combustion chamber 2. Disk in combustion chamber 3. Spindle in combustion chamber 4. Platen in suction chamber 5. Spindle in suction chamber 6. Disk in suction chamber 7, 8: Connecting rods 9. Crank shaft 10. Intake port 11. Exhaust Port 1 2. Rocker Arm 13. Camshaft 1 4. Non-return valve 1 5. Spur gear wheels 1 6. Chain drive 1 7. Drive shaft 18. Bevel gear 19. Casing 20. Cooling ribs 21. Valve 22. Coupling end 23. Rings 24. Oil Injector.

Fig. 14 shows a more improved version.

This version is very much similar to that of shown in Fig. 13. Instead of using valves in this version a sleeve is interposed between cylinder barrel and plugs in each end. Ports are cut in the sleeve and formed on the main cylinder casting. When the sleeve (4) is in continuous motion with the system gases admit and exhaust due to the ports coincidence.

Four rods (15) are guiding the motion of each disk.

1 Platen 2-Disk 3-Spindle 81- Sleeve 5---Cylinder casting 6 Crank rod 7-Bevel gear mechanism chain drive 9--Coupling end 10-Intake 'port 11-Exhaust port 1 2-Nozzle between two chambers 1 3-Oil injector 14-Disk guiding rods 1 5rank shaft.

Claims (2)

1. A reciprocating rotary mechanism applicable in prime movers comprising in combination of two closely fitted plugs of equal radii with their adjacent surfaces fashioned in a bevelled manner and fitted along the same main axis, movable inside a cylindrcial casing on which ports are provided for a flow of fluids to create gaps in a sequence in between the relative positions of the said components so that the system to perform a motion that could be resolved in to a rotary motion and a reciprocating motion accompanied by a closed loop of mechanical assembly to govern the said performance.

2. A reciprocating rotary mechanism as claimed in claim 1, in which the adjacent surfaces of pistons defines a set of wave forms of equal wave lengths and amplitudes, cited by the equations f(x) = a sin x x +(x) = 12a sin -] 2 at circumference about the main axis of the cylinder.