RU2545269C1 - Magnetic transmission - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: magnetic transmission contains drive and driven elements, magnetic cores, permanent magnets and screen. The driven elements are installed between the magnetic core and screen. The driven elements and screen are made out of non-magnetic material. The screen is installed with clearance between the drive and driven elements. In the screen the elements out of the magnetically soft material are installed, and permanent magnets are installed in the driven elements.

EFFECT: ensuring of tightness due to screen use and simplified design of the magnetic drive.

4 cl, 4 dwg

Description

The invention relates to magnetic gear transmissions and can be used in mechanical engineering, instrumentation, aviation, space and radiochemical industries.

Known magnetic coupling [RU No. 2091624, F16D 27/01. Publ. 09/27/1997] containing half-couplings with magnetic cores on which permanent magnets are placed. The coupling halves are separated by a screen that seals the internal cavity of the machine, to which the torque generated by the coupling is transmitted.

The disadvantage of this device is the inability to control the speed of the shaft only with the help of a magnetic coupling.

Known magnetic transmission [SU No. 1839927, F16D 27/01. Otub. 06/20/2006. Bull. 17], adopted as a prototype. In magnetic transmission, the input shaft is mounted on bearings in the housing. In the housing on the input shaft, a permanent magnet and a magnetic circuit are fixed. The cutting disc is made in one piece with the input shaft or mounted on it. The second magnetic circuit is made in one piece with the output shaft and is mounted on bearings in the housing. During transmission operation, the input shaft begins to rotate with the split disk, the magnetic closure zones on the magnetic circuits begin to rotate at the same angular velocity. The initial equilibrium of the tangents in the area of the disk cut-outs is violated, and the teeth of the magnetic circuit begin to shift by an angle equal to the difference between the tooth divisions of the magnetic circuits beyond the angle of rotation of the input shaft 360 ° / Z _c , where Z _c is the number of teeth of the magnetic circuit on the input shaft. The gear ratio of the transmission is determined by the expression

, $$\text{i}=\frac{{\text{Z}}_{\text{p}}}{{\text{Z}}_{\text{p}}-{\text{Z}}_{\text{c}}}$$

,

where Z _p - the number of teeth of the moving magnetic circuit on the output shaft.

This magnetic gear does not ensure the tightness of the gear and is quite difficult to manufacture.

The problem to which the invention is directed, is to develop a magnetic transmission that provides tightness, the ability to adjust the speed of rotation with the simplest design.

The problem is solved in that the magnetic transmission contains leading and driven elements, magnetic circuits, permanent magnets and a screen installed with gaps between the driven elements, and the driven elements are installed between the magnetic circuit and the screen, the elements and the screen are made of non-magnetic material, the elements of soft magnetic material, permanent magnets are installed in the driven elements, and the number of magnets in each of the driven elements and elements of soft magnetic material is different. Magnets and elements made of soft magnetic material are in the shape of a parallelepiped or cylinder. Magnets are made on the basis of neodymium-iron-boron alloy.

Figure 1 shows a disk single-row version of a magnetic transmission, figure 2 - disk multi-row version of a magnetic transmission, figure 3 is a cylindrical version of a magnetic transmission, figure 4 is a flat version of a magnetic transmission.

The magnetic transmission contains driving elements 1 and 2, on which the magnetic circuits 3 and 4 are located. On the magnetic circuits, the driven elements 5 and 6 are made of non-magnetic material, in which the permanent magnets 7 and 8 are installed. The location and number of magnets depends on the version of the magnetic transmission (see Fig. 1-4), the transmitted torque and magnetic gear ratio. Between the driven elements with minimal gaps δ is a screen 9 of non-magnetic material, in which elements 10 of soft magnetic material are installed. The number of elements 10 depends on the required gear ratio in the magnetic gear. If you use the screen as a sealing wall when transmitting torque from a neutral environment to a more aggressive or unhealthy screen can be covered with a plating layer 12.

Magnetic transmission works as follows.

In the proposed designs, the driving link during rotation (or movement) can be any of the parts pos. 1, 2 or 9 (for example, the driving element 1). In this case, another, also any of the remaining part, must be fixed (for example, screen 9), and the remaining part (for example, driving element 2) will move under the influence of a magnetic field. The number of elements 10 (active elements) in the screen 9 and the number of magnets 7 and 8 (active elements) in parts 5 and 6 should be different, because their number in each of the parts affects the gear ratio i in the magnetic gear in accordance with the formula

$$\text{i}=\frac{{\text{N}}_{\text{one}}-{\text{N}}_{\text{2}}}{{\text{<figure-callout id="3" label="N" filenames="00000004.png,00000005.png" state="{{state}}">N</figure-callout>}}_{\text{3}}},\text{(one)}$$

where N ₁ is the number of active elements of the leading part;

N ₂ - the number of active elements of a fixed part;

N ₃ - the number of active elements of the driven part.

If the gear ratio is positive, the driving and driven parts rotate in the same direction; if the gear ratio is negative, the driven part rotates (or moves) in the opposite direction relative to the driven part.

In the course of the research, an experimental single-row disk version (see Fig. 1) of magnetic transmission was made, on which the validity of formula (1) was practically confirmed.

If you need to change the gear ratio of the magnetic transmission, it is enough to replace the fixed link (in our example, screen 9) with a similar link, but with a different number of elements 10, determined by the formula (1). In this case, the magnetic drive does not change.

As permanent magnets, it is desirable to use high-energy magnets, for example, based on a neodymium-iron-boron (Nd-Fe-B) alloy. Thanks to the use of high-energy magnets, the magnetic field strength in the gap between the parts reaches 0.5-0.8 T without using any design complications, for example, the gear design of the leading parts. The magnets used have a simple cylinder or parallelepiped shape.

The application of the invention allows:

- to ensure, if necessary, the complete tightness of the magnetic transmission through the use of the screen;

- adjust the speed of rotation by changing the number of active elements or using as a slave or leading link any of the three parts;

- to simplify the design of the magnetic drive by eliminating the use of any structural complications, such as the gear version of the driven and leading parts.

Claims (4)

1. A magnetic transmission containing leading and driven elements, magnetic circuits, permanent magnets and a screen, characterized in that the driven elements are installed between the magnetic circuit and the screen, the driven elements and the screen are made of non-magnetic material, the screen is installed with a gap between the leading and driven elements, the screen has elements made of soft magnetic material, and permanent magnets are installed in the driven elements. 2. The magnetic transmission according to claim 1, characterized in that the number of magnets in each driven element and elements of soft magnetic material is different. 3. The magnetic transmission according to claim 1, characterized in that the magnets and elements of soft magnetic material are in the form of a parallelepiped or cylinder. 4. The magnetic transmission according to claim 1, characterized in that the magnets are made on the basis of a neodymium-iron-boron alloy.

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