GB2402454A - Magnetic transmission - Google Patents

Abstract

A transmission system that transmits rotary motion without contact between the rotating bodies A & B by using permanent and/or electromagnets C. Transmission of rotary motion may be prevented by reducing the current through the electromagnets. Additional magnets may be used to provide supplemental or exclusive braking in the system. Furthermore the electromagnets in the system my be used in conjunction with other magnets to act as a starter motor or supplement the power supplied to the transmission system. Additionally as the electromagnets can be activated when required a wide range of gear ratios are available.

Description

Description

Electromagnetic transmission The invention is a transmission system for use in vehicles, machinery or other applications that require a range of output torques. It is based on the use of electromagnets and/or solid magnets.

Transmission systems used with motors are generally of the form of a gearbox that involves an array of different sizes of cogs. While such technology is well developed, it offers a small, discrete number of gears; it also suffers from frictional losses. A clutch is also necessary, so that the motor input can be disconnected when it is not required, for example when a motorist wants their car to remain stationary.

An electromagnetic transmission, as detailed below, provides a much wider range of gears than the conventional system, reduces mechanical conta* (thus reducing frictional losses), and eliminates the need for a clutch. This invention outlines how a system of electromagnets and/or solid, permanent magnets can replace a conventional gearbox and clutch in any motor system. The invention can also be used to aid braking, or can act as a starter motor.

To illustrate the use of electromagnets in a transmission system, an example of such is detailed below.

The invenffon's essential features are: À A set of wheels that are fitted with an array of small electromagnetic elements and/or permanent solid magnets around their circumferences, which act in a similar fashion to the teeth in a conventional gearbox; À An incorporated set of electromagnets that are involved when the system is used as a starter motor or to aid with braking.

When in use, the magnets and electromagnetic elements on a pair of adjacent wheels attract each other as Hey approach each other- this is analogous to the teeth on a cog meshing with the teeth of an adjacent cog, allowing torque to be transferred from one cog to the other.

Indeed, the electromagnetic wheels are arranged very similarly to a set of cogs, and only the manner in which one wheel interacts with its neighbour is different. As one wheel is turned, the electromagnetic elements on its circumference also route, dragging with them (by magnetic attraction) the magnets on an adjacent wheel. Thus, the first wheel's rotation is transferred to me second wheel.

At least one wheel has a number of small electromagnetic elements around its circumference. By activating (passing a current through) certain elements while deactivating others, the spacing between active elements can be altered. As these elements attract elements on an adjacent wheel, altering the spacing between active elements changes the gearing ratio.

Figure 1 shows a basic 2-wheel electromagnetic transmission.

figure 2 describes the positions at which electromagnetic elements should be activated.

Figure 3 shows a wheel with two strong electromagnets positioned next to it.

As shown in figure 1, a simple system of two wheels A (4 elements) and B (8 elements) acting to give a gearing ratio of 1:2, i.e. B having twice the torque and half the rotational frequency of A. If the elements on B are electromagnets, every other element can be deactivated to give a gearing ratio of 1:1. Similarly, a number of other gearing ratios are possible.

It is worth noting that the electromagnetic elements need not be active for all of the time: in figure 2, the electromagnetic element on wheel D is only active from E to F- F being the place where the two wheels are closest. By deactivating the electromagnetic element at F. any resistance to motion caused by attraction to magnetic element G as the two move apart is eliminated. The electromagnetic element is activated at E, as soon as E and G are close enough to attract each other.

This allows a greater range of torques: back in figure 1, for example, having elements in B equally spaced and constantly active allows four torques ('h, ]/2, 1 and 2 times the torque supplied by wheel A, from activating one element, two elements, four elements and eight elements respectively): if every 3, 5, Am.. etc. element is activated as it approaches point of contact C, new gearing ratios and torques are possible.

A large array of wheels compounds this, affecting a continuous transmission system (actually still a discrete system, but with sufficient discrete gears to make it seem continuous). If n gearing ratios are feasible when using two similar wheels, n2 can be obtained with three similar wheels and n3 with four, using the principles described above.

The actual number of available gears may well be less than this for a number of reasons: perhaps by design, in order to limit the maximum frequency of rotation and thus limit friction.

If no output is required, simply deactivating all of me electromagnetic elements on one wheel prevents any transmission of power between wheels. This has the effect of a clutch in a road vehicle or piece of machinery, eliminating the need for a standard clutch.

Figure 3 shows two strong electromagnets H and I on opposite sides of a wheel 3, which is fitted with electromagnetic elements. By a*ivaffng an electromagnetic element when it is closest to either H or e I, at point K (when the two are about to move apart), an appreciable braking force can be affected. Unlike drum, disc, calliper (et cetera) brakes, these do not depend on friction, and do not wear down.

Conversely, activating electromagnetic elements before they reach a 3 strong electromagnet (a*ivaffng them at M) and deactivating it before: they begin to move apart (at point K), a motor force can be created.

This can be used as a starter motor, or to supplement the engine's power under extraordinary circumstances.

Also of note is the fa* that the wheels need not touch each other.

The attraction of the magnets does not depend on their touching each other, merely their being close to each other. As such, a proportion of the friction inherent in the system can be avoided by arranging adjacent wheels very dose to each other but not touching. Indeed, if the wheels did touch, a great deal of friction would be created: as adjacent wheels normally rotate at different speeds, the touching surfaces would also be moving at different speeds. This would produce unnecessary friction; so adjacent wheels should not be allowed to touch. D

Claims (6)

1. Claims Electromagnetic transmission 1. A transmission system that operates

   using the magnetic attraction between solid, permanent magnets and/or small electromagnetic elements.
2. 2. A transmission system as in claim where magnetic elements are arranged around the circumference of a number of wheels, with each wheel operating in a similar way to the cogs in a conventional gearbox.
3. 3. A transmission system as in any preceding claim where power from the system's input is prevented from reaching the system's output by not running a current, or running a smaller than usual current, through the electromagnetic elements in the system.
4. 4. A transmission system as in any preceding claim where the electromagnetic elements in the system are used in conjunction with other magnets or electromagnets to provide exclusive or supplemental or exclusive braking in the system.
5. 5. A transmission system as in any preceding claim where the electromagnetic elements in the system are used in conjunction with other magnets or electromagnets to act as a starter motor and/or as a motor whose power supplements the power supplied to the transmission system.
6. 6. A transmission system substantially as herein described above and illustrated in the accompanying drawings.