WO1996012872A1

WO1996012872A1 - Water turbine

Info

Publication number: WO1996012872A1
Application number: PCT/AU1995/000700
Authority: WO
Inventors: Charles Ward
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-10-24
Filing date: 1995-10-23
Publication date: 1996-05-02
Anticipated expiration: 1997-04-24
Also published as: AUPM896094A0

Abstract

A fluid turbine (10) having a casing (12), an axial inlet (14) and an outlet (16). A rotor (18) is mounted on an output shaft (24), the rotor (18) being constructed as a disc with an enclosed passage (20) extending from a central inlet (32) to a circumferential outlet. The passage (20) is curved so that the outlet is tangential to the circumference of the rotor disc, whereby the rotor (18) can operate under fluid back pressure with minimum resistance to rotation.

Description

TITLE

WATER TURBINE

TECHNICAL FIELD

This invention relates to a water turbine, more particularly to a water turbine of the reaction type which can easily be adapted to a multistage arrangement.

BACKGROUND ART

Water turbines are used in many different applications, ranging from small water driven units to provide a source of rotary power, to very large installations in hydro-electric schemes where the turbines are many metres in diameter.

Many turbines, particularly of the reaction type require the water to exit freely from the rotor or moving blade so that the rotor or blade does not have to move against the resistance of the water which has previously issued from the trailing portion of the rotor or blade. Thus the discharge water usually falls freely away the turbine through a discharge or exhaust pipe.

It is an object of the invention to provide a turbine which can operate effectively in a situation where the rotor is subject to back pressure.

A further object of the invention is to provide a multistage turbine with each stage able to operate under back pressure.

A still further object of the invention is to provide a turbine in which the rotor is shaped to provide minimum resistance to its passage through water, and in which the water flow reacting passage or passages is or are enclosed within the rotor.

Another object of the invention is to provide a multistage reaction turbine wherein the fluid flows from one stage to the next without the requirement for stator or guide blades between each stage. DISCLOSURE OF THE INVENTION

Thus there is provided according to the invention a turbine comprising a casing having a fluid inlet and a fluid outlet, a fluid supply connected to a sai fluid inlet in the said casing, a rotor operating in the casing, the rotor being operatively connected to a drive shaft, said rotor comprising one or more enclosed channels extending from the centre of the rotor to the circumferenc thereof, the passages having a region of curvature located between the cent of the rotor and the circumference of the rotor, said fluid supply being in fluid communication with the centre of the rotor, whereby fluid entering the turbine through the inlet travels through the centre of the rotor into the channels and exits the channels at the circumference of the rotor thereby causing rotation the drive shaft.

In a further aspect of the invention there is provided a turbine comprising a casing having an axial fluid inlet and a fluid outlet, a fluid supply connected t the said fluid inlet in the casing, a disc shaped rotor operating within the casing and being operatively connected to a drive shaft, said rotor having a central inlet and enclosing one or more enclosed channels extending to exit at the circumference of the rotor, said enclosed channels being curved so th the exit is tangential to the circumference of the rotor thereby causing rotation of the rotor and drive shaft.

Preferably the channels are radial from the centre of the rotor and then are curved to be tangential to the circumference of the rotor.

In another form of the invention the turbine comprises a plurality of rotors connected to the drive shaft, the rotors after the first rotor having an annular inlet about the drive shaft to receive fluid exiting from the previous rotor.

Preferably the rotor or rotors are constructed as a smooth disc, so that the turbine can operate under back pressure when the outlet of the turbine is connected to a source of use of the fluid, the rotors will be operating in conta with the fluid being passed through the turbine with little fluid resistance to th rotation of the rotors.

Preferably the curvature of the channels is such that the fluid changes direction through 90° when passing through the rotor. Preferably also where each rotor includes a plurality of passages, the passages are spaced equidistantly around the rotor.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more fully describe the invention reference will now be made to the accompanying drawings in which:

FIG 1 is a sectional view of a water turbine in accordance with one aspect of the invention,

FIG 2 is a plan view of one portion of the rotor,

FIG 3 is a view of the two portions of the rotor taken along the lines 3-3 of FIG 2,

FIG 4 is a cross sectional view of a multistage form of the invention,

FIG 5 is a plan view of one of the second later stage rotors,

FIG 6 is a cross sectional view of the rotor of FIG 5, and

FIG 7 is cross sectional view of the separated portions of the rotor of FIG 5.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring firstly to FIG 1 there is shown in cross section one form of water turbine 10 having a casing 12 including a water inlet 14 and a radially directed outlet 16 on one side thereof.

Water passing through the inlet 14 is directed axially to the rotor 18 arranged within the casing 12. The rotor 18 is shown more clearly in FIGS 2 and 3 and includes a series of spaced passages 20 extending radially from the centre of the rotor 18 to the circumference thereof. The channels 20 are disposed so as to include therein a region of curvature 22. As can be seen the opposing channels have their regions of curvature 22 directed so as to ensure that the rotor rotates in the one direction, the water exiting the passages 20 generally tangentially of the circumference of the rotor 18. The rotor 18 is mounted on the turbine shaft 24 mounted in bushes 26 in the casing 12, the drive shaft as illustrated, having a seal 28 at its driving end. Th inlet end of the drive shaft has an axial aperture 30 communicating with the inl 14, the lower end of the aperture 30 being provided with holes 32 opening to passages 20 in the rotor 18.

The side walls 32 of the passages 20 progressively narrow from the centre of rotor 18 to the region of the curvature 22 and then widen again towards the ex apertures 34. The rotor 18 is formed in two halves 18(a) and 18(b) with the passage 20 being formed in one of the halves 18(b), the passage 20 being closed when the rotor is assembled. The two portions 18(a) and 18(b) are formed with co-operating connecting elements such as tongue 36 and groove 38 which interengage and which additionally may be either welded, glued or otherwise connected together.

The turbine can be constructed from any suitable materials, and preferably ca be moulded from a suitable plastics material, so that rust and corrosion are prevented and preferably eliminated.

Turning now to FIGS 4 to 7, there is shown an example of a multiple stage turbine embodying the invention.

The turbine 40 has a casing 42 made up of assembled elements 42(a), 42(b), 42(c) and 42(d), the casing element 42(a) having an inlet 44 and the casing element 42(d) having an outlet 46. Inside the casing there are, in this example, three rotors 48, 50 and 52 each attached to an output shaft 54. The rotor 48, the inlet rotor, has an.inlet hollow shaft 56 which directs the fluid into the passage 20 in the rotor 48, the passage 20 being as described in the previous embodiment, the inlet shaft 56 extending into the inlet 44 of the casing 40 to receive the fluid entering the inlet 44.

Each of the elements 42(a), 42(b), 42(c) and 42(d) are shaped to have co¬ operating shaped curved portions 58 and 60 to direct the fluid exiting from one rotor into the inlet of the next rotor in the series. Thus while rotor 48 has its inlet extending into the inlet 44, the rotors 50 and 52 have annular inlets 62 and 64 respectively which are spaced around the shaft 54, the upper inner edge of each rotor 66 and 68 being spaced from the shaft 54 to thus form the annular inlets 62 and 64 for the rotors 50 and 52. The lower element 42(d) of the casing 42 is provided with the outlet 46 and also mounts the output shaft 54 by means of roller bearing 70 and seal 72.

Thus it will be seen that in operation the fluid enters the inlet 44 and passes into the inlet 56 of the inlet rotor 48, passing through the passage 20 and exiting into the curved portions 58 and 60 which redirect the fluid radially inwardly into the inlet 62 of the rotor 50 where it passes through its passage 20 thus assisting in driving the turbine. The fluid then passes through the next turbine in similar manner.

FIGS 5, 6 and 7 show an example of rotor 50. As in the previous example the rotor consists of two portions 50(a) and 50(b), the portion 50(a) being formed with the inlet lip 66 spaced from the shaft 54 to create the annular inlet 64. Also the under surface of portion 50(a) is formed with the passage 20, so that when the portions 50(a) and 50(b) are joined together the passage is enclosed. The portion 50(b) is formed with a boss 50(c) which is attached to the shaft 54. Rotor 52 and any succeeding rotors would preferably be similarly constructed.

While three stages are described it is to be realised that other numbers of stages can be provided in the turbine. The turbine is designed to operate under back pressure, such that when the outlet of the turbine is connected to a point of use of the fluid being supplied. Thus the turbine can drive an apparatus or piece of equipment which uses the fluid being supplied to the turbine, the apparatus or equipment creating a back pressure on the fluid passing through the turbine. However as above described due to the design of the turbine, the enclosed passage in the rotor or rotors of the turbine, and the disc like shape of the rotor having a smooth outer surface, the resistance to rotation of the rotor through the fluid is minimised.

Although various forms of the invention have been described in some detail it is to be realised that the invention is not to be limited thereto, but can include variations and modifications falling within the spirit and scope of the invention.

Claims

1. A turbine comprising a casing having a fluid inlet and a fluid outlet, a fluid supply connected to a said fluid inlet in the said casing, a rotor operating in the casing, the rotor being operatively connected to a drive shaft, said rotor comprising one or more enclosed channels extending from the centre of the rotor to the circumference thereof, the passages having a region of curvature located between the centre of the rotor and the circumference of the rotor, sai fluid supply being in fluid communication with the centre of the rotor, whereby fluid entering the turbine through the inlet travels through the centre of the rot into the channels and exits the channels at the circumference of the rotor thereby causing rotation of the drive shaft.

2. A turbine comprising a casing having an axial fluid inlet and a fluid outlet, a fluid supply connected to the said fluid inlet in the casing, a disc shaped rotor operating within the casing and being operatively connected to drive shaft, said rotor having a central inlet and enclosing one or more enclosed channels extending to exits at the circumference of the rotor, said enclosed channels being curved so that the exit is tangential to the circumference of the rotor thereby causing rotation of the rotor and drive shaft.

3. A turbine as defined in claim 2 wherein the channels are radial from the centre of the rotor and then are curved to be tangential to the circumference of the rotor.

4. A turbine as defined in claim 2 wherein the turbine comprises a plurality of rotors connected to the drive shaft, the rotors after the first rotor having an annular inlet about the drive shaft to receive fluid exiting from the previous rotor.

5. A turbine as defined in claim 2 wherein the rotor or rotors are constructed as a smooth disc, whereby the turbine can operate under back pressure when the outlet of the turbine is connected to a source of use of the fluid, the rotors will be operated with little fluid resistance to the rotation of the rotors.

6. A turbine as defined in claim 2 wherein the curvature of the channel or channels is such that the fluid changes direction through 90° while passing through the rotor.

7. A turbine as defined in claim 6 wherein each rotor includes a plurality of passages spaced equidistantly around the rotor.

8. A turbine as defined in claim 2 wherein the rotor has an inlet portion extending into the inlet of the casing.

9. A turbine as defined in claim 2 wherein the turbine has a plurality or rotors in multistage formation, the casing being so shaped to direct the fluid exiting from one rotor into an annular inlet of the next rotor, the annular inlet of the rotors other than the first rotor being spaced around the drive shaft.