DE102020001845A1 - Method for improving and optimizing power transmission with a magnetic gear - Google Patents

Abstract

Process for the improvement and optimization of transmitted power with a magnetic gear for use in air, water and ground-based drives.

Description

State of the art

It is known that magnetic gears can be used to advantage in order to transmit power without direct mechanical contact.

In the DE 00000 3814455 A1 it is proposed to transmit power via magnetic gears, whereby the mechanical losses and also the use of lubricants are reduced.

In the DE 000029620114 U1 a possible speed ratio is used to achieve the higher rotational speed for material processing.

In the DE 102028205404 A1 a multi-stage gearbox for use in wind turbines is proposed and the mechanical decoupling and gradual increase in speed are used.

In these applications, the special properties of contactless magnetic field coupling are used to transmit power and increase the speed of rotation.

Physical background

Mechanical gears consist of two rotating wheels that exchange power in direct contact. Here, the power is exchanged at the point of contact and it is always the same on the drive side and the output side, reduced by the losses via bearings and contact friction. Magnetic gears have the special properties that they transmit power without contact and there are no friction losses.

However, properties can still be derived from the precise analysis of the movement process. Every rotating body stores a certain rotational energy. This is proportional to the moment of inertia and the square of the rotation speed. If, for example, the rotational speed is doubled due to the different number of magnets on the drive rotation body and the output rotation body, then the primary energy used would have to be four times as much. This has to be confirmed.

To do this, we first consider the motion processes involved in magnetic attraction and repulsion. Poles with the same name repel each other and those with different names attract each other. This is described mathematically with Coulomb's law of distance, which was derived for electrostatics on the basis of spherical potentials. According to this, the force between two potentials is proportional to the product of the potentials and inversely to the square of the distance. For magnets, this relationship only applies to an interaction along the ideal functional connection line. This is always the case for attraction, because magnets always attract each other along this connecting line. With the repulsion one observes two movement processes, a rotation by 180 ° and immediately afterwards the attraction of both. The two movement processes do not seem to be separable from each other. This means that the movement is always ended, analogous to the attraction, with the absolute energetic minimum.

However, if you move a guide magnet at an angle> 10 ° to a test magnet, you will notice a spontaneous rotation of 180 ° at a greater distance, which does not stop immediately with the attraction. This flip rotation happens spontaneously, it is a rotation around the center of gravity. In the classic sense, no work is done because the center of gravity is not moved.

If you translate this spontaneous flip effect into a gear arrangement with two rotating bodies, you notice that the output initially follows the drive with a delay, at a certain point there is a kind of equilibrium of forces and, starting from this point, the system spontaneously rotates by approx. 180 ° brings it back into a stable position.

The relationships between physical processes of motion are most clearly expressed with the Noether theorem, according to which
"Every continuous symmetry of a physical system has a conserved quantity"

The law of conservation of energy follows from the homogeneity of time. This means that every movement can be started and stopped at will. Every mechanical transmission shows these properties. A magnetic gearbox does not show this property under certain conditions!

The conservation of angular momentum follows from the homogeneity of space. If one derives this theorem from the time derivative of the torque, because of the vectorial magnitude of the angular momentum and the application of the product rule, there is an additional vectorial term that is always zero in the case of central forces. Central forces always act in a mechanical transmission. In the case of a magnetic gear, this is not generally the case, since the center of force between the two rotating bodies is at a greater distance from one another and it thus moves out of the ideal line.

The separate magnets constantly exchange their energy with the surrounding space. That System start start in the state of minimal magnetic space energy. Opposite poles form a closed magnetic field as far as possible. When the drive is turned, the center of force changes and the field lines begin to separate. The magnetic space energy increases. At the beginning of the flip effect, the stored magnetic space energy is at its maximum. Both systems form independent closed magnetic lines, which are then reunited to a largely unified system through the spontaneous flip effect. If at the beginning of the flip effect magnets of opposite polarity are facing each other, an additional torque will push the currently active output magnet into a new stable position. This additional torque can be used to advantage.

Embodiment

For the experimental proof of the use of the flip effect, a buoyant body was equipped with a small BLDC motor, which sets a water screw in rotation via a drive shaft. The speed of the vehicle on a circuit and the voltage and current were measured. Then a small magnetic gear with a gear ratio of 1: 2 was mounted between the motor and the drive shaft, the rotating bodies having the same diameter. In the classic approach, a ratio of 1: 2, i.e. a doubling of the rotational speed, would have to result in a four-fold increase in the rotational energy, and the primary power would also have to be quadrupled.

The experimental result is in shown. After that, an increase in speed can be observed, likewise an increase in input power, but not by a factor of four. A direct performance comparison is only possible at the points of the same speed of the vehicle. It can be seen that the primary power requirement is approx. 30% lower at the same speed.

By changing the test parameters, gear ratios from 1: 3 to 1: 4 and more can be achieved.

Drawings will be submitted later.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 000003814455 A1 [0002]
• DE 000029620114 U1 [0003]
• DE 102028205404 A1 [0004]

Claims (7)

Method for improving and optimizing the power transmission with a magnetic gear, such that the primary rotational energy of a first rotating body equipped with magnets is transmitted by magnetic fields to a second rotating body equipped with magnets, such that the first rotating body is preferably equipped with more magnets , as the second rotating body, in such a way that the equipping number of both rotating bodies is an even number and both rotating bodies rotate synchronously in relation to the magnet occupancy, so that the rotational energy of the second rotating body is higher than that of the first, so that the electrical primary power increases less proportionally than the rotational energy of the second body. Method for improving and optimizing the power transmission by means of a magnetic gear, in such a way that the radius of the drive wheel is smaller or larger than the radius of the driven wheel with different magnet occupancies. Magnetic gear according to Claim 1 , 2, in such a way that the primary electrical energy is transmitted to the magnets of the second rotating body by at least two V-shaped, electrically controllable magnets instead of rotating magnets, in such a way that the frequency of the controlling field determines the rotational speed of the output. Magnetic gear according to Claim 1 , 2, 3, in such a way that the rotational energy of the second rotating body is transmitted directly or via mechanical gears to a rotating air propeller. Magnetic gear according to Claim 1 , 2, 3, in such a way that the rotational energy of the second rotating body is transmitted directly or via mechanical gears to a rotating water screw. Magnetic gear according to Claim 1 , 2, 3, in such a way that the rotational energy of the second rotating body is transmitted directly or via mechanical gears to a rotating earth-bound drive wheel. Magnetic gear according to Claim 1 , 2,3, in such a way that the output train is coupled to a generator in such a way that the generator voltage is greater than the primary voltage.

Images