GB2433967A

GB2433967A - Electromagnetic torque converter

Info

Publication number: GB2433967A
Application number: GB0700009A
Authority: GB
Inventors: Roy Edward Flack
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-01-07
Filing date: 2007-01-02
Publication date: 2007-07-11
Also published as: GB0700009D0; GB0600266D0

Abstract

An electromagnetic torque converter comprises input rotors 1, stators 2, intermediate rotor 3, an epicyclic gearbox 4 and output rotors 5. Intermediate rotor 3 contains magnetic material. The input rotors 1, the stators 2 and the output rotors 5 contain magnetic material and electric windings. The input rotors 1 are connected to one member of the epicyclic gearbox, the intermediate rotor 3 is connected to a second member of the epicyclic gearbox and the output rotors 5 are connected to the third member of the epicyclic gearbox. As the input rotors 1 rotate, the intermediate rotor 3 and output rotors 5 rotate in the same direction as the input rotors 1 at a slower speed. The torque convener may be used in a vehicle, e.g. a bicycle, having an infinitely variable automatic transmission and a lock-up clutch. It may also used as an independent electrical motor for powering the vehicle and as an independent generator. Electrical power is extracted to act as a vehicle brake or to regenerate an energy store.

Description

94'oc-i -JJ_/_) I

ELECTROMAGNETIC TORQUE CONVERTER

The invention relates to an electromagnetic torque converter.

Torque converters for automotive use are usually hydraulic and are efficient only within a small operating range. Electrical transmissions exist in hybrid vehicles but tend to be complicated with separate generators and motors.

A first aspect of the invention provides an electromagnetic torque converter comprising of one or more input rotors containing magnetic material and electrical windings, one or more stators containing magnetic material and electrical windings, one or more intermediate rotors containing permanent magnets, one or more output rotors containing magnetic material and electrical windings and a differential gear unit with three members. The input rotor(s) are connected to one of the members of the differential gear unit and the intermediate rotor(s) to a second member of the differential gear unit. Rotation of the input rotor(s) causes a corresponding rotation of the intermediate rotor(s) and the output rotor(s).

Preferably the output rotor(s) are connected to the third member of the differential gear unit.

Alternatively the third member of the differential gear unit can be fixed.

Preferably, rotation of the intermediate rotor magnets causes a rotating magnetic field to be induced in the output rotors, the stators and the input rotors.

Preferably, a device is included on the output rotors or shaft that prohibits the output rotor from rotating n the opposite direction to the input rotors.

Preferably, all the current generated in the stator is allowed to flow in one or more self-contained circuits. Alternatively, some or all of the current may be extracted and used for other purposes such as for re-charging a battery or other energy storage device or powering electrical accessories. Similarly, electrical power can be imported into the stator to provide extra motive power to the output rotor.

Power factor correction devices may be installed in the stator electncal circuits.

The permanent magnets may also be replaced by electromagnets.

A further aspect of the invention provides an infinitely variable automatic transmission for a vehicle utilising the electromagnetic torque converter of the first aspect of the invention. Such a transmission may be used on road or off-road vehicles including such vehicles as bicycles or human/electric vehicles.

Preferably, the infinitely variable transmission is provided between a vehicle motor and one or more wheels.

Each wheel or each pair of wheels of the vehicle may be provided with its own infinitely variable transmission. Alternatively, a single infinitely variable transmission unit may be utilised for driving the front wheels, the rear wheels or all the wheels of the vehicle.

Preferably, a lock-up device is provided for use at cruising speeds.

Drive to the input rotor may be disconnected from the vehicle motor so that the transmission may be used as an independent electrical motor for powering the vehicle.

Electrical power may be extracted from the transmission system to act as a vehicle brake.

This power may be used to regenerate an energy storage device or may be dissipated as heat through a resistance.

An additional aspect of the invention provides an independent electrical generator utilizing the input rotors, the intermediate rotors, the stators and the differential gear unit. In this case the third member of the differential gear unit is fixed.

By way of example, specific embodiments of the present invention will now be described, with reference to the accompanying diagrammatic drawing, Figure 1, whiCh shows the major components of the electromagnetic torque converter.

The electromagnetic torque converter has five major components: input rotors I * stators 2, intermediate rotor 3, an epicyclic gearbox 4 and output rotors 5.

The intermediate rotor 3 contains permanent magnets. The input rotors 1, the stators 2 and the output rotors 5 are made of laminated soft magnetic material and electric windings The input rotors 1 are connected to the outer gear of the epicyclic gearbox.

The intermediate rotor 3 is connected to the planet carner of the epicyclic gearbox.

The output rotors 5 are connected to the sun gear of the epicyclic gearbox.

In the example shown the epicyclic gearbox has a basic ratio of minus 3.45.

As the input rotors are rotated, and with the output rotors initially stationary, the intermediate rotor will rotate in the same direction as the input rotors but at a slightly slower speed. The magnets on the intermediate rotor will induce a rotating magnetic field in the output rotors and the stators. This rotating magnetic field will be at the same speed as the intermediate rotor.

With the gearing shown, the input rotor will be rotating 29% faster than the rotating magnetic field in the stator and will therefore act as an induction generator at or close to the peak torque or pushover torque of this generator.

If an internal combustion engine is connected to the input rotors and, provided that the electromagnetic torque converter is sufficiently large, the speed of the engine will be limited to less than or equal to the engine peak torque speed at a zero road speed.

The rotating magnetic field in the stators will act as an induction motor on the output rotors. At start up the frequency and voltage are low due to the limiting of the engine speed and therefore the intermediate rotor speed. As the output speed increases the gearing ratio between the input and intermediate rotors decreases allowing the induction generator to operate at a lower torque on the torque/slip curve. This allows the engine, if operating at full throttle, to operate at a faster speed increasing both the frequency and the voltage. This provides the induction motor section with an input similar to that provided by variable frequency ac drives.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of the features and/or steps are mutually exclusive. In particular, the input and intermediate rotors may be interchanged in construction and function, such that the permanent magnets (or electromagnets) are driven at input speed and the induction rotors at a greater speed.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be reptaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMS

1. An electromagnetic torque converter comprising of one or more input rotors containing magnetic material and electrical windings, one or more stators containing magnetic material and electrical windings, one or more intermediate rotors containing permanent magnets, one or more output rotors containing magnetic material and electrical windings and a differential gear unit with three members. The input rotor(s) are connected to one of the members of the differential gear unit, the intermediate rotor(s) to a second member of the differential gear unit and the output rotors to the third member of the differential gear unit Rotation of the input rotor(s) causes a corresponding rotation of the intermediate rotor(s) and the output rotor(s).

2. A system according to claim 1, wherein the third member of the differential gear unit is fixed and is not connected to the output rotor(s).

3. A system according to claim 1, wherein rotation of the intermediate rotor magnets causes a rotating magnetic field to be induced in the output rotors, the stators and the input rotors.

5. A system according to claims I or 3, wherein a device is included on the output rotors or shaft that prohibits the output rotor from rotating in the opposite direction to the input rotors.

6. A system according to claims 1, 3 or 5, wherein some or all of the electrical power generated in the stator is extracted.

7. A system according to claims 1, 3 or 5, wherein electrical power is imported into the stator to provide extra motive power to the output rotor.

8. A system according to claims 1, 3 or 5, wherein power factor correction devices are installed in the stator electrical circuits.

9. A system according to claims 1, 3 or 5, wherein the permanent magnets are replaced by electromagnets.

10. A system substantially as described herein, with reference to the embodiments of Figure 1.

11. An infinitely variable automatic transmission according to any of the preceding claims.

12. A vehicle incorporating an infinitely variable automatic transmission according to claim 11.

13. A vehicle according to claim 12, wherein the input rotor is connected to a vehicle motor and the output rotor is connected to one or more dnving wheels of the vehicle.

14. A vehicle according to claims 12 or 13, wherein a lock-up device is provided for use at cruising speeds.

15. A vehicle according to claims 12 or 13, wherein drive to the input rotor is disconnected from the vehicle motor so that the system may be used as an independent electrical motor for powering the vehicle.

16. A vehicle according to claims 12 or 13, wherein electrical power is extracted from the system to act as a vehicle brake.

17. A vehicle according to claims 12 or 13, wherein electrical power is extracted from the system to regenerate an energy storage.

18. A system according to claim 2 that provides an independent electrical generator utiIing the input rotors, the intermediate rotors, the stators and the differential gear unit.