AU2005205732A1 - Thermo-magnetic engine - Google Patents

Description

PATENTS ACT 1990 ORIGINAL COHPLE TE SPECIFICATION STANDARD PATENT Invention title THJERMO-MAGNETIC ENGINE The following statement is a full description of this invention, including the best method of performing known to me.

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This invention relates to mechanical powerplants. More specifically, although not exclusively it discloses a novel thermo-magnetic engine adapted to operate from a temperature differential between fluid sources.

There are a variety of well known heat engines which work on various cycles such as the otto cycle, diesel cycle and steam cycle etc. These typically require either the internal or external combustion of fuel to obtain high temperatures and pressures for generation of mechanical energy. Because of these high temperatures and pressures there are issues such as sealing, lubrication, wear and metal fatigue which have to be addessed in the engine design. Even with current technology the manufacture and maintenance costs of combustion engines are normally higher than those for non-combustion powerplants electric motors) and their service life is usually shorter.

It is therefore an object of this invention to ameliorate the aforementioned disadvantages and accordingly a thermo-magnetic engine is disclosed for operation between respective fluid sources at different temperatures, said engine including at least one pair of first and second magnetically interacting components arranged for relative reciprocating motion between closely adjacent and spaced apart positions, said first component having temperature dependent ferromagnetic properties and said second component including a permanent magnet and a fluid heat exchange means associated with said first component for coordinated heating and cooling thereof from said respective fluid sources to produce cycles of varying magnetic attraction between said components whereby at least part of said reciprocating motion generates usable mechanical energy.

Preferably said first component is cooled during movement of said components toward said closely adjacent positions and is heated during movement of said components away from said closely adjacent positions and toward said spaced apart positions.

It is further preferred that said first component includes gadolinium metal or a nickel iron alloy which has temperature dependent properties whereby said metal is paramagnetic at room temperature but becomes strongly ferromagnetic when cooled and said second component comprises a least one neodium permanent magnet.

It is further preferred that said gadolinium metal is in the form of a disc or fin configuration to maximise heat transfer.

It is further preferred that said gadolinium metal is heated and cooled within a range between about 10 degrees centigrade and about 50 degrees centigrade.

Currently preferred embodiments of the invention will now be z -3described with reference to the attached representations in which:figures 1 to 3 show side, end and plan views respectively of a first embodiment of an engine according to this concept, figures 4 to 6 shows side, end and plan views respectively of a second embodiment of the invention, figures 7 is a schematic side elevation of a third embodiment of an engine according to the invention, figure 7A is a schematic cross-sectional view along the lines A-A of figure 7, figure 8 is a schematic end elevation of the engine of figure 7, and figure 9 is a schematic cross-sectional view along lines B-B of figure 8.

Referring first to figures 1 to 3 there is an engine having a fixed gadolinium attractor and a second movable set of neodium permanent magnets 3. In this case the attractor is in the form of a metal disc 1 mounted horizontally on a support frame 2 and the magnets 3 are fixed to the upper end of a connecting rod 4 which extends down through a linear bearing sleeve 5 mounted to said support frame. The other lower end of the rod connects with a pivot arm 6 and crank 7. Rotation of the crank moves the magnets between a top dead-centre -4position closely adjacent the gadolinium attractor disc 1 and a bottom dead-centre position spaced from said disc. As best shown in figure 1 the crank 7 is fitted to a shaft 8 which extends through bearing support plates 9 and mounts a drive gear 10 and small activating magnet 11 for an electrical switch 12. A second intermediate shaft 13 is located above the crankshaft. This has a partially toothed gear wheel 14 at one end which engages the drive gear 10 and a larger gear toward the other end which meshes with a pinion gear 16 on a shaft 17 with flywheel 17A. As best shown in figure 3 a heat exchange water jacket 18 is mounted directly on top of the gadolinium attraction disc 1. This has inlet and outlet fittings 18A, 19 for connection to supply conduits from hot and cold water reservoirs (not shown). With this embodiment the water flow is preferably controlled by any suitable system of pumps and valves (not shown) which are controlled electrically from the aforementioned switch 12.

In operation of the engine the disc 1 is alternately cooled by water from the cold reservoir during the upward stroke of the crank to thereby increase magnetic attraction and draw the neodium toward the gadolinium and then heated by water from the hot reservoir on the downward stroke to decrease the magnetic attraction. Once the engine is started the stored rotational energy or momentum of the flywheel 17A from the upward power stroke carries the mechanism through the downward stroke and onto the next upward stroke where the gadolinium attractor disc is again cooled to repeat the cycle.

With this embodiment the pump and valve operation for the heating and cooling water is preferably coordinated with crank rotation by the aforementioned switch 12 and magnet 11 mounted on the crankshaft. Also, to provide a suitable delay in crank rotation at top and bottom dead-centre sufficient for the attractor disc 1 to heat and recool before the next stroke the gear wheel 14 is toothed through only a portion of its circumference. This operates to disconnect the flywheel shaft 17 from the crankshaft 8 at top and bottom dead-centre for delay periods, with this embodiment, of about 6 seconds.

As the flywheel continues to freewheel under its own momentum it subsequently re-engages the crankshaft drive gear 10 after each delay and the magnets are again moved through the downstroke away from the now heated attractor disc or pulled by the neodium permanent magnets up through the power stroke toward the re-cooled disc.

In experimental trials the above embodiment has maintained a continuous operating speed of about 40 RPM for periods of up to two hours.

With the second and third embodiments of the invention the main components that correspond in function to those of figures 1 to 3 are identified by the same numbers which however are primed and to distinguish them.

With the second embodiment shown in figures 4 to 6 the gadolinium attractor is a disc 1' mounted vertically and the connecting rod is replaced by a swing arm 20 which is pivotal about a bearing 21. The upper portion of this swing arm carries the neodium magnets 2' over a lateral arcuate path with respect to the disc The lower portion of the arm engages the crank 7' in a slot 22. It is considered that replacement of the linear bearing sleeve of the first embodiment with a conventional rotation bearing 21 reduces manufacturing costs and also friction losses on the rod. It is further believed that the arcuate power stroke approach path of the magnets to the disc provided by the swing arm design may increase efficiency.

With the third embodiment of the invention shown in figures 7 to 9 the permanent magnets 3" are mounted at one end of a horizontal connecting rod 4" which is slidable through a linear bearing block The other end of the rod 4" connects with a pivot arm 6" and crank Rotation of the crank moves the magnets between a "top dead-centre" or right position closely adjacent the gadolinium attractor (indicated generally as and a "bottom dead-centre" or left position spaced from said attractor 1".

With this embodiment as shown in figure 7A the attractor is formed by spaced apart vertical gadolinium metal fins 23 arranged within a heat exchange water chamber 24. Such configuration increases the metal/water contact area to facilitate rapid heat transfer.

At the position shown in figures 7 and 8 the crank 7" is at an intermediate position between "top dead centre" and "bottom dead-centre". The crank is fitted to a shaft 8" which extends through bearing support plates 9" and mounts a set of gears 10", 14" and sprocket 25. These rotate the flywheel shaft 17" and drive hot and cold water piston pumps 26. The pumps 26 are driven through a chain 27 and drive shaft 28. As best shown in figure 9 the gear set 10", 14" is adapted to engage through only a portion of the flywheel rotation so that a suitable time delay is provided at top and bottom dead centre sufficient for the fins 23 to heat up and recool in a similar manner to that described for the first embodiment.

Instead of the activating magnet 11 and switch 12 shown in figure 1 for electronically controlling pump operation there is with this third embodiment a partially toothed gear 29 fitted to the output end of the shaft 28 which meshes with the pump drive gear 30. This provides appropriate delays to coordinate the operation of the pumps 26 with crank rotation when the heat exchange chamber 24 is filling with hot or cold water through conduits 31, 32 and inlets 33, 34. Preferably the discharge stroke of the pump pistons (only one piston being shown as 35) which occurs during disengagement of the gears 29, 30 is powered by the use of magnets or spring loading of said pistons. An outlet water flap valve 36, valve actuator 37 and outlet water diverter trough 38 are also provided at the bottom of the chamber and are synchonised via shaft 28 with the pump operation and crank rotation. The diverter trough 38 tilts to one side or the other to return the hot/cold outlet water back to separate source reservoirs (not shown). This enables re-use of the hot/cold water and increases efficiency.

This third embodiment has been found to maintain speeds of up to 150 RPM over extended periods.

It will thus be appreciated that this invention at least in the form of the embodiments disclosed provides a novel and improved form of heat engine which can operate without the high pressures and temperatures required of conventional combusion engines. Clearly however the examples described are only the currently preferred experimental forms of the engine and a wide variety of modifications may be made within the scope of the invention. For example the shape of the gadolinium attraction disc, the number and configuration of the magnets, the mechanical drive mechanism of the engine and the design of the heat exchanger and fluid supply may all be changed following further development work by the inventor.

In particular it is envisaged that:a mechanical or electrical clutch may be substituted for the gear delay mechanism, the fluid pump and outlet valve may be cam operated as opposed to the electrical switch and gear arrangements described, the surface of the gadolinium attractor may be concaved for increased strength to allow a closer approach of the neodium magnets during the power stroke, and multiple pairs of magnets and gadolinium attractors may be combined in the one engine for increased power output and efficiency.

the engine may be adapted to operate using fluids other than water such as for example oils, other chemical liquids or gases, and the engine may be adapted to operate using temperature dependent ferromagnetic materials other than gadolinium metal such as (but not limited to) nickel iron alloys.

Claims (9)

1. A thermo-magnetic engine for operation between fluid sources at different temperatures, said engine including at least one pair of first and second magnetically interacting components arranged for relative reciprocating motion between closely adjacent and spaced apart positions, said first component having temperature dependent ferromagnetic propertires and said second component including a permanent magnet and a fluid heat exchanger means associated with said first component for coordinated heating and cooling thereof from said fluid sources to produce cycles of varying magnetic attraction between said components whereby at least part of said reciprocating motion generates usable mechanical energy.

2. The thermo-magnetic engine as claimed in claim 1 wherein said first component is cooled down during movement of the components toward said closely adjacent positions and is heated during movement of said components away from said closely adjacent positions.

3. The thermo-magnetic engine as claimed in claim 2 wherein the first component is in the form of a fixed plate or disc and the second component is mounted for reciprocating movement on a connecting rod linked to a crank shaft.

4. The thermo-magnetic engine as claimed in claim 3 wherein the first component is heated and cooled by fluids from said -11- sources alternately filling a heat exchange chamber associated with said first component.

The thermo-magnetic engine as claimed in claim 4 wherein there is a delay in crank shaft rotation at said closely adjacent and spaced apart positions to enable the first component to be heated and cooled by said fluids.

6. The thermo-magnetic engine as claimed in claim 5 wherein said delay is provided by a set of flywheel drive gears which mesh through a portion only of their circumferences.

7. The thermo-magnetic engine as claimed in claim 6 wherein said fluids after discharge from the heat exchanger are returned to their respective sources to enable reuse thereof.

8. The thermo-magnetic engine as claimed in any one of claims 4 to 7 wherein said fluids are hot and cold water having a temperature difference sufficient to heat and cool said first component through a range of about 10 0 C and about 50 0 C.

9. The thermo-magnetic engine as claimed in any one of the preceding claims wherein said first component is formed from gadolinium metal and said second component is formed from a neodium permanent magnet. A thermo-magnetic engine for operation between respective fluid sources at different temperatures, said engine being -12- substantially as described herein with reference to figures 1 to 3, 4 to 6 or 7 to 9. Dated this 30th day of August, 2005 Terry William Robinson By His Patent Attorney, MICHAEL ANDERSON-TAYLOR -13-