GB2059172A

GB2059172A - Electric generators for waterborne craft

Info

Publication number: GB2059172A
Application number: GB7931844A
Authority: GB
Original assignee: Evans S R
Current assignee: Evans S R
Priority date: 1979-09-13
Filing date: 1979-09-13
Publication date: 1981-04-15
Also published as: GB2059172B

Abstract

An electric generator for use on waterborne craft, comprises a stator (10) preferably constituting the magnet and a rotor (11) preferably constituting the coils, a sleeve member (13) carrying aerofoil blades (15) and detachably keyed to the rotor, and a nose member (16) permitting attachment at eye (17) of a torque line for driving the rotor without requiring detachment of the bladed member (12). The rotor (11) can therefore be driven by either, or both, of the blades (15) and the torque line. The torque line is connected either to the craft's propeller, Figure 4 (not shown), or to a screw that is trailed behind the craft, Figures 2, 3 (not shown). <IMAGE>

Description

SPECIFICATION Electric generators for waterborne craft Background of the invention This invention relates to an electric generator for waterborne craft, more especially for providing electric power, for example to charge the battery, on small boats such as yachts and sailing dinghys.

Various types of generator for small boats are already known, including generators adapted to be driven by wind power and generators adapted to be driven by a turbine means trailed behind the boat.

Some of these generators include accessory kits enabling the two sources of power to be used alternatively. In general however, conversion of known generators from one source of power to the other is not simple, and the simultaneous use of both sources of power is not possible.

It is an object of the present invention to provide an improved generator for waterborne craft substantially overcoming or minimising the above-stated disadvantages of the known generators.

The invention According to the invention, there is provided an electric generator for use on waterborne craft, comprising a stator, a rotor at least partly exposed externally of the stator, means for mounting the generator to the craft, a set of aerofoil blades and means for detachably keying said set of blades to the rotor, and means carried by the rotor permitting the drivable connection of a torque line to the rotor without necessitating detachment of the set of blades.

The generator itself may be in the form of an alternator or a dynamo, but in both cases it is preferred if the stator includes a magnet and the rotor includes coils for rotation in the field of said magnet.

In a preferred arrangement, the set of blades is fixedly carried by a sleeve member adapted to surround the rotor and to be rotationally keyed thereof. Said sleeve member is preferably also adapted to surround the stator with clearance permitting its rotation relative thereto. Said means permitting connection of a torque line may conveniently comprise a nose detachably mounted to the rotor at an end face thereof beyond one end of the sleeve member. An eye in said nose may be provided to facilitate attachment of the torque line.

In the preferred arrangement, the stator mounting means comprises a shaft fixedly carrying the stator and rotatably supporting the rotor, said shaft being carried at the upper end of an arm adapted to be mounted at its bottom end of the craft. Said arm is adapted to be mounted on the craft to turn about a vertical axis, and the arm detachably carries a wind vane for turning said arm in use to maximisethe drive applied to the aerofoil blades by the wind.

The invention also extends to the generator in combination with a torque line drivably connected to the rotor, and the further combination of a spinner attached to the end of said torque line remote from the rotor. Such an arrangement is suitable for driving the generator in open water. Alternatively, however, in crowded water conditions, the end of the torque line remote from the rotor may be attached to the propeller drive of an underwater motor on the craft.

In the accompanying drawings: Figure 1 is a view in axial section of a preferred construction of generator; Figure 2 is a diagrammatic view of an arrange mentwherein the generator is driven through a torque line by a spinner trailed in the water; Figure 3 shows a preferred construction of spinner; and Figure 4 is a diagrammatic view of an arrange mentwherein the generator is coupled to an underwater propeller drive.

Description ofembodiment The construction of electric generator shown in Figure 1 comprises an alternator having a stator 10 comprising a magnet and a rotor 11 comprising coils disposed in the field of the magnet. The rotor 11 is coaxial with the stator 10 and is exposed externally thereof. Thus, the stator 10 is fixedly keyed on a shaft 12 at an intermediate position therealong, and the rotor 11 is rotatably supported by the shaft immediately forward of said stator. The rear end of the shaft 12 is adapted to be mounted to a waterborne craft, as later described.

A stepped sleeve member 13 surrounds the coaxial stator 10 and rotor 11. This sleeve member 13 is adapted to be keyed for rotation with the rotor 11 (the line 14 indicates the position of a keying screw or peg), and carries a set of aerofoil blades 15. At the front end of the rotor 11, a nose boss 16 having an eye 17 is detachably mop table to the rotor for rotation therewith. When the nose boss 16 is detached, removal of the keying screw permits the bladed sleeve member 13 to be withdrawn forwardly for detachment from the rotor. The nose boss 16 may then be resecu red to the front end of the rotor 11.

The rear end of the shaft 12 is carried at the upper end of an upright arm 18 adapted to be mounted to the craft at its lower end. As indicated in Figures 2 and 4, the lower end of the arm 18 is mounted through a joint having a vertical pivot axis to a base 19 adapted to be fixed to the superstructure of the craft 20 at the stern thereof. The arm 18 detachably carries a wind vane 21, whereby the generator is enabled to turn according to the prevailing wind conditions to maximisethe action of the wind on the aerofoil blades 15. Use of the wind vane is optional.

In operation, the rotor 11 is turned by the action of the wind, and produces an electric output through the conductor 22 indicated in Figure 1. An output of 1 Amp. hour has been achieved using a 45 cm die blade assembly of fifteen blades, during a 48 hour test with winds gusting to 3 on the Belfort scale.

Additionally, as shown in Figure 2, a torque line 23 may be attached to the eye 17 of the nose boss 16, said torque line carrying a spinner 24 at its remote end. In use, the spinner 24 is dragged through the water on a line (for example of 1 cm Nylon (Trade Mark)) which may be from 20 metres long for a maximum speed of the craft up to 5 knots to 40 metres long for a maximum speed up to 15 knots. As the spinner 24 turns with movement through the water behind the craft, the torque line 23 is wound to impart a rotational drive to the rotor 11. When the rotor 11 is simultaneously turned from both sources of power, an output in excess of 1 Amp. hour is usually obtainable.

A preferred construction of spinner 24 is shown in Figure 3. This comprises a central rod 25 around which extends a convolute blade 26. The rod 25 has an eye 27 at its front end for attachment of the trailing end ofthetorque line.

Alternatively, as indicated in Figure 4, the torque line may take the form of a flexible cable drive 28 which establishes a driving connection to the rotor 11 from the propeller drive 29 of an underwater motor, which may be an outboard auxiliary motor, at the stern of the craft 20.

It is particularly to be noted that either the spinner drive or the cable drive from a motor can be used additionally to the wind drive, since the bladed sleeve member 13 does not have to be detached to enable the torque line to be attached to the rotor through the nose boss 16. However, if desired, the bladed sleeve member 13 can be detached, by the simple expedient of removing the nose boss 16, withdrawing the bladed sleeve member, and replacing the nose boss, if it is desired to use the torque line drive alternatively to the wind drive.

In general, the generator is especially suitable for yachts and similar sailing craft wherein the provision of an on-board electrical supply is more difficult than in motor powered craft wherein a generator can be driven by a petrol or diesel engine. However, even in the latter case, the above-described generator can be useful as an auxiliary or emergency source of electric power. Both the wind drive and either one of the torque line drives can be used when the craft is moving, the spinner drive being intended for open water conditions and the motor drive for crowded or congested water conditions, while either or both of the wind drive and the spinner drive may be employed when the craft is moored, depending on wind and water current conditions at the berth.

Various modifications of the above-described arrangement are possible within the scope of the invention. It is an essential requirement, however, that the rotor should be at least partially exposed externally of the statorfor attachment of the bladed sleeve member and torque line attachment nose. It is also much preferred, contrary to the usual alternator, for the stator to comprise the magnet and the rotor to comprise the coils, since this arrangement enables the rotor to be of lighter construction facilitating high speed rotation thereof by the available drives.

Claims

1. An electric generator for use on waterborne craft, comprising a stator, a rotor at least partly exposed externally of the stator, means for mounting the generator to the craft, a set of aerofoil blades and means for detachably keying said set of blades to the rotor, and means carried by the rotor permitting the drivable connection of a torque line to the rotor without necessitating detachment of the set of blades.

2. A generator according to claim 1, in which the stator includes a magnet and the rotor includes coils for rotation in the field of said magnet.

3. A generator according to claim 1 or claim 2, in which the set of blades is fixedly carried by a sleeve member adapted to surround the rotor and to be rotationally keyed thereto.

4. A generator according to claim 3, in which said sleeve member is also adapted to surround the statorwith clearance permitting its rotation relative thereto.

5. A generator according to claim 3 or claim 4, in which said means permitting connection of a torque line comprises a nose detachably mounted to the rotor at an end face thereof beyond one end of the sleeve member.

6. A generator according to any of claims 1 to 5, in which the stator mounting means comprises a shaft fixedly carrying the stator and rotatably supporting the rotor, said shaft being carried at the upper end of an arm adapted to be mounted at its bottom end on the craft.

7. A generator according to claim 6, in which said arm is adapted to be mounted to the craft to turn about a vertical axis, and the arm detachably carries a wind vane for turning said arm in use to maximise the drive applied to the aerofoil blades by the wind.

8. A generator according to any of claims 1 to 7, in combination with a torque line drivably connected to the rotor.

9. A generator according to claim 7, in combination with a spinner attached to the end of said torque line remote from the rotor.

10. A generator according to claim 7, wherein the end of the torque line remote from the rotor is attached to the propeller drive of an underwater motor on the craft.

11. An electric generator substantially as hereinbefore described with reference to the accompanying drawings.

12. A waterborne craft equipped with an electric generator according to any of claims 1 to 11.