1 ) TECHNICAL FIELD

This invention is related to an electromagnet with a movable ant rotating iron core, according to International Patent Classification (IPC) classified as H 01 F - electromagnets

2) TECHNICAL PROBLEM

For years, classical electromagnets with a coil wound on an immovable iron core were used, which as such have a problem with powering of machines and parts which are rotating or moving in a linear manner.

3) BACKGROUND ART

There are many ways to solve the problem of powering the coil of the electromagnet. In the case of synchronous machines, powering the excitation coils on the rotor is done by slip rings on a shaft and brushes which slide over them, being attached to the case of the stator. That is a weak spot and cause of synchronous machine failure because of sparking at the contact place, especially in humid areas. The electromagnetic coil of a loudspeaker is soldered to a braided line on the membrane, moving both of them together, and the other end is soldered to the loudspeaker case. 4) DISCLOSURE OF THE INVENTION

The primary goal of the invention was to construct an electromagnet with a movable and rotating magnetic field, achieving a low maintenance technology.

The secondary goal of the invention was the improvement of electromagnets by using parts not prone to defects.

One further goal of the invention was to make possible improvements within electromagnets without additional parts.

Additional goals and gains through this invention will be shown in the following description, and partly they will be recognized by applying the invention in final products.

According to this invention, an electromagnet consists of a coil made of lacquered copper wire and an iron core in cylindrical form with poles. The diameter of the core is smaller than the inner diameter of the coil, so the core can be moved to both sides and rotates around its axis without touching the wire coil, which is pulled over the core. Only the core with its poles rotates, while the coil with the wire windings is attached to a case and is therefore immovable. The electromagnetic field which forms around the electromagnet poles doesn ^' t change its characteristics even when the iron core with its poles rotates in the magnetic field of the magnetic coil. In that way a rotating magnetic field is creating, which is the same as if we would rotate the core of the electromagnet together with the coil, powered by electricity supplied using slip rings and brushes.

Electromagnets with a rotating core and immovable coils create great possibilities to create simpler engines with static coils, in which only the iron cores rotate or move linearly.

5) SHORT DRAWINGS DESCRIPTION

Fig. 1 : scheme of an electromagnet according to the described invention

Fig. 2: similar scheme of an electromagnet with the core moved to the right side

Fig. 3: similar scheme of an electromagnet with the core moved to the left side

Fig. 4: scheme of electromagnet activity while rotating the core within an immovable coil.

6) DETAILED DESCRIPTIOPN OF AT LEAST ONE OF THE WAYS TO REALIZE THE INVENTION

Referring to figures 1 -3, one can see that the electromagnet consists of a soft iron core (position 10), round coil (pos. 14) and lacquered copper wire windings (pos. 13). It is important to stress that the iron core is of cylindrical form, with protruding magnetic poles N (north) and S (south). The coil for the copper windings (pos. 14) is made of a tubular shaped insulating material, with disk shaped rims for attaching the coil to the case. Inner diameter of the coil is larger than the outer diameter of the cylindrical part of the iron core (pos. 10), and they do not touch each other. Over the coil carrier it is attached to a base, so it is immovable.

Figure 1 shows a core (pos. 10) who's central part is positioned in the middle of the immovable coil (pos. 14) which bears copper wire windings (pos. 13). When DC current is applied to these windings, as shown in fig. 1, the iron core with protruding poles becomes an electromagnet with N poles on the left side and S poles on the right side.

Figure 2 shows the case where the iron core is moved to the right side, which results in the electromagnetic field of the wire coil creating magnetic poles within the core so that the S pole of the magnet is longer than its N pole.

Figure 3 shows the case where the iron core is moved to the left side, which results in the electromagnetic field of the wire coil creating magnetic poles within the core so that the N pole of the magnet is longer than its S pole.

Figure 4 shows the case where the iron core rotates around its longitudinal axis. According to this invention, electromagnetic field formed in the iron core by the immovable coil with wire windings, doesn't change its magnetic properties when the iron core moves to the left or to the right within the coil, or rotates around its longitudinal axis inside the electromagnetic field of the coil. The iron core behaves identically to a permanent magnet or an electromagnet of the same size and shape when moving right/left or rotating around its longitudinal axis. Figure 4 shows a method of generating alternate current in the wire windings (pos. 16) which are wound on a core made of transformer sheets (pos. 15), which itself is also immovable and attached to a base, close to the trajectory of the couples of magnetic poles of the rotating electromagnet (pos. 10). When magnetic poles N and S of the rotating iron core (pos. 10) during the rotation start to align with the ends of the magnetic core (pos. 15), it starts getting magnetized and a magnetic flux through it is established. This flux is strong at the beginning, gets weaker through magnetic saturation of the core, and stops at the moment of total alignment of the poles. When these poles begin removing themselves from each other, the iron core gets gradually demagnetized and a magnetic flux of opposite direction is established. This flux is strong at the beginning, gets weaker as the iron gets demagnetized, and disappears totally when the iron is totally demagnetized. The change of intensity of magnetic flux through the iron core (pos. 15), being a consequence of change of magnetic field coming from protruding poles of the rotating iron core (pos. 10), induces alternate voltage in windings of copper wire (pos. 16) wound on the iron core (pos. 15). Induced alternate voltage which has a sine shape (one sinusoid) is obtained by concurrent passing of only one pair of magnetic poles by the poles of the stator core. From the instance of beginning of aligning of one pair of protruding poles of the rotor core with the core of the stator coil to the moment of their total alignment, a positive half- period of the sine wave is created. If we stop the rotor at the moment of total alignment of the poles, no voltage will be created. When the poles start moving away from each other, the iron core (Pos. 15) gets demagnetized, which results in creation of the negative half-period. This proves that in order to induce alternating voltage after magnetizing the stator core by magnetic poles of one polarity it is not needed to magnetize it again by poles of the opposite polarity. Magnetizing the stator core creates one half-period; its demagnetizing creates the other half-period of alternating voltage. When the next couple of magnetic poles of the rotating electromagnetic core (Pos. 10) pass by the core (Pos. 15), the whole cycle repeats.

The induced alternating voltage in the coil (Pos. 16) depends on the rotation speed of the core (Pos. 10), strength of the attached DC voltage on the coil (Pos. 13), cross-cut area of the core, number of windings on the rotor and the stator, i.e. Uind = - Ν-Δ(Β S) / At. The frequency of the induced alternating current depends on the number of couples of protruding poles of the rotating iron core (Pos. 10), as well as on the rotating speed of its shaft, i.e. f = n p / 60.

7) WAYS OF APPLYING THE INVENTION

This invention gives us a practical, lasting and usable basis for simplification of construction of many kinds of electrical machines and devices, which includes essential improvement and simplification in comparison to known electrical machines and devices with rotating electromagnets, electromagnetic converters, instruments, relays and others. An iron core with rotating protruding poles is simple and easy to balance, because the excitation coils are not mounted on it. In theis invention all coils are static, immovable, so no copper conductors move. This enables us to create powerful machines with multiple magnetic poles for high frequencies in spite of low shaft rotational speed, which can even be immersed in a liquid, since there are no open electrical contacts. Coil cooling can be realized like with classical transformers. To experts it will be obvious that on electromagnets with rotating movable core with immovable coils according to this invention, many details can be changed and adapted without changing the essence and scope of the invention.