EP1082520A1

EP1082520A1 - Rotary machines

Info

Publication number: EP1082520A1
Application number: EP99922267A
Authority: EP
Inventors: Ronald William Driver; Ann Margaret Driver
Original assignee: Driver Technology Ltd
Current assignee: Driver Technology Ltd
Priority date: 1998-05-23
Filing date: 1999-05-20
Publication date: 2001-03-14
Also published as: KR20010043770A; GB9811112D0; JP2002516940A; CA2332872A1; AU3937999A; WO1999061750A1; CN1307664A; MXPA00011553A

Abstract

A rotary machine having a rotatable outer drum (10) within which rotates on a different axis a rotor (13). The space between the outer drum and the inner rotor is divided into discrete arcuate compartments by vanes (15) extending across the space between the two rotating parts such that the volume of the compartments (16) varies cyclically during rotation. The vanes are rigidly attached to one of the rotating parts and extend across the space into contact with the other of the rotating parts during at least a part of the rotation of the machine. The vanes may co-operate with sliding shoes (17) or fixed grooves (20) which latter may be cylindrically formed as at (24). Such a machine may be used as an enhancement of the efficiency and economic operation of an internal combustion engine which in certain cases can overcome the problems of throttle loss at low engine speeds, or it may operate as a heat pump.

Description

ROTARY MACHINES

THIS INVENTION concerns a rotary machine in which a pair of simultaneously rotatable drums are provided, one inside the other, and rotatable on different axes.

In such a machine a space between the two drums is divided into discrete arcuate compartments by vanes extending across the space between the two rotating parts, such that the volume of the compartments varies cyclically during rotation.

The machine operates such that gaseous fluid introduced into the compartments between the vanes is alternately compressed and expanded in different zones of the rotation. Valves or ports in the wall of the casing or at the end of the machine are provided for the supply or recovery of air or gases within the compartments whereby the machine may be used either as a compressor or a turbine, or both.

The machine has many uses such as enhancement of the efficiency and economic operation of an internal combustion engine which in certain cases can overcome the problems of throttle loss at low engine speeds, or it may operate as a heat pump.

Thus , accord i ng to the present inventi on , there is provided a rotary machine comprising a pair of driven parts including a rotary drum and a rotor located for rotation within the drum, the drum and rotor being adapted for rotation simultaneously on different axes; characterised by a plurality of circumferentially spaced vanes on one of said parts extending generally radially towards the other of said parts, whereby, due to the mutually offset axes of the parts, the vanes def ine arcuate spaces of cyclically varying volume during operation; further characterised in that each vane is rigidly fixed to or formed integrally with one of said parts and in that a free end of each vane co-operates with the opposed surface of the other part to determine the ins ta ntaneous vo lumes o f adj acent arcuate compartments during operation.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:-

Fig. 1 schematically illustrates in transverse cross-section a rotary machine incorporating the invention;

Fig. 2 similarly illustrates a modified and simplified form of such machine;

and Fig. 3 s imi l arly i l lustrates a further modi f ied and simplified form of such machine.

Referring now to the drawings, in Fig. 1 there is shown an outer drum 10 which is mounted for rotation about an axis 1 1 and has an inner hub 12. Within the outer drum 10 is an inner drum 13 which is simultaneously rotatable in the same direction about an axis 14 offset from the axis 1 1. Thus, as the outer and inner drums 10 and 13 rotate simultaneously the annular space between them varies in radial extent at any circumferential position.

A plurality of rigid vanes 1 5 of equal radial length, extend inwardly from the internal wall of the drum 10 thus to bear upon the outer circumferential surface of the inner drum 13. The vanes 15 thus divide the space between the two drums into a plurality of arcuate compartments one of which is illustrated at 16.

In this embodiment, in each region of the inner drum 13 located opposite to one of the vanes 15, there is provided a sliding shoe 17 which is constrained to reside at a fixed radial position between the vane 15 and the inner hub 12.

In view o f the cycl ical ly varying depth of the space between the inner and outer drums, there is relative movement between each shoe 17 and the drum 13 as can be seen from Fig. 1. Furthermore, during rotation, the tip of each vane 1 5 is caused to move across the radial ly outer face of its associated shoe 17. The compartments 16 may be ported in an end wall of the machine to communicate with a supply of air or other gaseous fluid and also with exhaust ports whereby the cycl ical ly v arying volume o f each compartment 16 acts progressively to compress fluid therein and then to permit it to expand as the machine rotates. Lubrication of the interface between the inner face of each shoe 17 and the outer surface of the hub 12 may be provided by means of an enclosure 18 which, with the hub 12 form a closed region. The interface between the shoes 17 and the adjacent surfaces of the drum 13 may be air lubricated by porting through the shoes 17 or drum 13 to enable air in the compartments 16 to pass between the two faces. These ports are illustrated schematically at 19.

Referring now to Fig. 2 in this embodiment the shoes 17 are omitted and replaced by valleys 20 within a one-part inner drum 20. The outer drum 10 and vanes 1 5 may be the same as in the embodiment illustrated in Fig. 1 , and as the machine rotates, the tips of the vanes 15 co-operate with the valleys 20 as can be seen in Fig. 2 to divide the space between the inner and outer drums into compartments 21 of cycl ically varying volume. The compartments may be further divided by flexible vanes 22 extending between the outer drum 10 and the inner drum 13.

In the two embodiments illustrated the vanes 15 are four in number but may be provided in greater numbers thus to increase the number of discrete compartments, each vane 15 co-operating with either a shoe 17 or a valley 20.

In a read i ly a l ternative f orm of the embodiments illustrated in Figs. 1 and 2, the fixed vanes may be mounted on the inner drum and co-operating with appropriate means associated with the outer drum, or in a further alternative arrangement some of the vanes may extend inwardly from the outer drum with others extending outwardly from the inner drum. I n operati on , over 1 80 ° o f drum rotation in the embodiment of Fig. 2, the inner tips of the vanes 15 describe a line on the surface on the inner drum whilst over the remaining 180° of rotation the tips describe a line in space. When the vanes are in close proximity to the inner drum, 90° of rotation can be used for compression with 90° for expansion. Further expansion beyond the 90° can only be achieved if a coil spring or a spring finger is attached to one part thus to act upon the other.

The further modified device shown in Fig. 3 comprises an outer rotary drum 10 and an inner rotor 1 3, but the simple radial vanes 1 5 of Fig. 2 are replaced by rigid protuberances 23 having contact with individual cylindrical faces 24 in place of valleys 20 on the inner rotor 13. Thus close contact between the two rotating parts 10, 13 is established for over 270° of rotation.

A drive mechanism to retai n the two drums in synchronism is by conventional dog and slot. An alternative is to provide a pair of toothed drive belts.

Claims

1. A rotary machine comprising a pair of driven parts including a rotary drum and a rotor located for rotation in the drum, the drum and rotor being adapted for rotation simultaneously on different axes; characterised by a plurality of circumferentially spaced vanes on one of said parts extending generally radially towards the other of said parts, whereby, due to the mutually offset axes of the parts, the vanes define arcuate spaces of cyclically varying volume during operation; further characterised in that each vane is rigidly fixed to or formed integrally with one of said parts and in that a free end of each vane co-operates with the opposed surface of the other part to determine the instantaneous volumes of adjacent arcuate compartments during operation.

2. A rotary machine according to Claim 1 , wherein the vanes are rigid and of equal radial length extending inwardly from the internal wall of the drum to bear upon the outer circumferential surface of the rotor.

3. A rotary machine according to Claim 1 or Claim 2, including, in each region of the rotor located opposite one of the vanes, there is provided a sliding shoe which is constrained to reside at a fixed radial position between the associated vane 15 and an inner hub.

4. A rotary machine according to any preceding claim, wherein the arcuate compartments are ported in an end wall of the machine to communicate with a supply of air or other gaseous fluid and also with exhaust ports whereby the cyclically varying volume of each compartment acts progressively to compress fluid therein and then to permit it to expand as the machine rotates.

5. A rotary machine according to Claim 3, including means to provide lubrication of the interface between an inner face of each sliding shoe and the outer surface of the inner hub.

6. A rotary machine according to Claim 3 or Claim 5, wherein the interface between each sliding shoe and at least one adjacent surface of the rotor is air lubricated by porting through the shoes and/or the rotor.

7. A rotary machine according to Claim 1 or Claim 2, wherein each vane co-operates at its free end within a recess in the outer circumferential surface of the rotor retaining contact with the outer surface of the associated recess during a part of the rotational cycle of the machine.

8. A rotary machine according to Claim 1 or Claim 2, wherein each vane includes at its inner free end a protuberance having contact with individual part-cylindrical faces on the outer circumferential surface of the rotor such that the two rotating parts are in contact for in excess of 270┬░ of rotation.

9. A rotary machine according to Claim 1 , wherein at least some of said vanes are attached to and extend outwardly from the rotor and have a free end co-operating with the inner circumferential surface of the rotary drum.

10. A rotary machine including drive means to retain the two drums in synchronism during rotation.