RU2529422C1 - Electromagnetic gear - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: in electromagnetic gear containing a housing with mounted stator with multiphase winding coupled to the voltage source as well as the first and second rotors rigidly fixed at the input and output shafts respectively, according to the invention the stator winding is coupled to the voltage source through a regulated frequency converter and placed in grooves of the stator inner surface thus forming poles, while the first rotor is mounted coaxially with stator and fixed rigidly to the input shaft end, is designed as a squirrel cage, which rods are inserted into the rings made from non-magnet material, they have prismatic shape and form teeth of the first rotor, and the second rotor is placed inside the first one and made as a toothed magnetic core with the teeth number z₂, equal to z₂ = (z₁ - p₁), where z₁ - number of teeth of the first rotor; p₁ - number of pole pairs of the stator winding; while the stator, teeth of the first rotor and the second rotor are laminated and made from ferromagnetic thin steel plates.

EFFECT: preserving the possibility of regulation of reduction coefficient at simultaneous providing of design simplification.

1 dwg

Description

The invention relates to general mechanical engineering, to electrical engineering, to electromagnetic mechanisms, and in particular to non-contact electromagnetic gears, and can be used as a transmission device with an adjustable gear ratio in mechanical systems with a long service life in the absence of lubrication.

Known two-stage gearbox, which is a multiplier (article Dergachev P.A., Kiryukhin V.P., Kulaev Yu.V., Kurbatov P.A., Molokanov O.N. "Analysis of a two-stage magnetic multiplier", J. "Electrical Engineering", No. 5, 2012, p. 39-45), having three rotating rotors, an external stator and an internal modulating ring, an external rotor and external magnets of the intermediate rotor form the first stage of the multiplier. The second (intermediate) rotor has radially magnetized magnets on the outer and inner sides. The stator, the outer rotor and the outer magnets of the intermediate rotor form the first stage of the multiplier. The third (inner) rotor is rigidly connected to the output shaft. The internal magnets of the intermediate rotor, the second squirrel cage and the internal rotor form the second (output) stage of the multiplier. The disadvantage of this magnetic gearbox is a large number of stages. The magnetic system contains four air gaps. Modern high-energy permanent magnets made of rare-earth elements have a high cost. The harmonics of the magnetic field in the second air gap, interacting with external magnets, create variable electromagnetic moments - a source of vibration and noise. A significant drawback of the multiplier is the inability to control the speed of the output shaft in a wide range.

Closest to the claimed device is an electromagnetic gearbox (patent RU 2012980, H02K 16/00, H02K 51/00) containing a stator with two multiphase windings, a primary rotor with an excitation system, a secondary rotor with a winding, a rectifier and an inverter, and the input of the rectifier and the inverter output is connected respectively to two stator windings, the rectifier output and the inverter input are interconnected, the stator and rotors being made end-face, the stator windings are located at its two ends, opposite which the rotors are installed. One of the rotors is fixed on the input shaft of this gearbox, on which the magnetic circuit and the field winding are located; another rotor is mounted on the output shaft, having a different magnetic circuit and a short-circuited winding. Between the rotors, coaxial with each other and with each other, are stators with their own magnetic circuits and multiphase (for example, three-phase) windings. The stators are fixed in a housing with bearings using shields. Each of the shafts rotates in two bearings. The stator windings are connected by means of a semiconductor converter with a rectifier and a dependent inverter.

Changing the direction of rotation of the output shaft (reverse) is provided by changing the control algorithm of the inverter.

For the convenience of controlling the modes of the electromagnetic gearbox, a microprocessor device is used, which can provide automatic regulation according to a given law.

The disadvantage of this electromagnetic gearbox is the presence of two multiphase windings on the stator and two rotors with windings. The control is carried out through two channels: the frequency of the voltage supplied to the stator, and the current supplied to the excitation winding of the rotor. This complicates the design, complicates the regulation, leads to excessive losses. The disadvantage of the prototype is associated with its complexity and, accordingly, low reliability when used in power transmissions.

The invention is aimed at solving the technical problem of creating a simple and inexpensive design of an electromagnetic gearbox, which can be used as a multiplier, with an adjustable reduction ratio.

The technical result of the claimed device is to simplify the design while maintaining the ability to control the reduction coefficient.

This technical result is achieved in that in an electromagnetic gearbox comprising a housing with a stator installed therein with a multiphase winding connected to a voltage source, as well as first and second rotors rigidly mounted on the input and output shafts, respectively, the stator winding is connected to a voltage source through an adjustable frequency converter and placed in the grooves of the inner surface of the stator with the formation of poles, while the first rotor located coaxially with the stator and rigidly connected end of the input shaft is formed as a squirrel cage, rods which are inserted into the ring of non-magnetic material, have a prismatic shape and form of the tine rotor, and the second rotor is disposed within the first, is designed as a toothed magnetic circuit with the number of teeth z _2, equal to

z ₂ = (z ₁ -p ₁ ),

where z ₁ is the number of teeth of the first rotor; p ₁ - the number of pairs of poles of the stator winding; moreover, the stator, the teeth of the first rotor and the second rotor are made of charge of ferromagnetic sheet steel.

The use of a multiphase winding on the stator allows you to create a continuously variable transmission device with an adjustable reduction ratio. The stator magnetic field with the number of pole pairs p ₁ arriving on one side of a ferromagnetic “squirrel” cell having z ₁ ferromagnetic rods forms the main harmonic at the output on the other side of the cell with a small number of pole pairs equal to the difference (z ₁ -p ₁ ) . This low-pole magnetic field interacts with the teeth of the inner rotor, the number of which is equal to (z ₁ -p ₁ ).

Figure 1 shows a schematic structural diagram of the inventive electromagnetic gear.

In the electromagnetic gearbox, the input shaft 1 is mounted to rotate in the shield 9 of the housing 8. The stator 3, which is fixedly mounted in the housing 8, is made of laminated sheets of electrotechnical cold-rolled steel with grooves on its inner surface. In the grooves of the stator 3 is a multiphase winding 4, forming a pair of stator poles, the number of which is p ₁ . The winding 4 is connected to an adjustable frequency converter 5. Coaxially, the stator is mounted rigidly connected to the end of the input shaft with the possibility of rotation with the bearings in the bearings of the first rotor 2. Rotor 2 is made in the form of a squirrel cage, the rods of which are made of thin laminated ferromagnetic rectangular plates of electrical steel and have the shape of a rectangular prism, and the rods are fixed in rings 11, 12 of non-magnetic material. These rods form the teeth of the rotor 2, the number of which is equal to z ₁ . The non-winding gear internal, with respect to the rotor 2, the second rotor 6 with the number of teeth z ₂ = (z ₁ -p ₁ ) is made of lined electrical steel, is rigidly mounted on the output shaft 7, rotating in the bearings of the shields of the housing 9 and 10.

An electromagnetic gearbox operates as follows. The voltage from an adjustable frequency converter 5 is applied to the conclusions of the stator winding 4. The magnetic field of the stator formed in this case interacts with the outer side of the rotor 2 with z ₁ ferromagnetic rods, forming a magnetic field on the inside of the rotor 2 with the number of pole pairs equal to the difference (z ₁ -p ₁ ). This low-pole magnetic field interacts with the teeth of the second rotor 6, the number of which is z ₂ = (z ₁ -p ₁ ). There is a synchronous rotation of the rotor 6 with a magnetic field.

If the applied voltage with frequency ω = 0 (the magnetic field is constant), then when the input shaft 1 rotates at a speed of Ω _{1, the} angular velocity Ω _{2 of the} output shaft 7 will be proportional to the reduction coefficient i

$$i=\frac{z_{\mathrm{one}}}{z_{\mathrm{one}}-p_{\mathrm{one}}}$$

$${\Omega }_2=\frac{z_{\mathrm{one}}}{z_{\mathrm{one}}-p_{\mathrm{one}}}{\Omega }_{\mathrm{one}}=i\cdot {\Omega }_{\mathrm{one}}$$

(знак минус реализуется преобразователем при смене следования фаз) и взаимодействует с внешней стороной ферромагнитного ротора 2. С внутренней стороны ротора 2 образуется магнитное поле с числом пар полюсов, равным разности (z₁-p₁). Это малополюсное магнитное поле взаимодействует с зубцами z₂=(z₁-p₁) второго ротора 6, при этом угловая скорость Ω₂ If the angular velocity of the input shaft 1 is zero, Ω ₁ = 0 and the applied voltage with frequency ω> 0, the stator magnetic field rotates with the angular velocity $$\Omega =\pm \frac{\omega }{p_{\mathrm{one}}}$$

(the minus sign is realized by the converter when changing the phase sequence) and interacts with the outer side of the ferromagnetic rotor 2. On the inner side of the rotor 2 a magnetic field is formed with the number of pole pairs equal to the difference (z ₁ -p ₁ ). This low-pole magnetic field interacts with the teeth z ₂ = (z ₁ -p ₁ ) of the second rotor 6, while the angular velocity Ω ₂

. $${\Omega }_2=\frac{\omega }{z_{\mathrm{one}}-p_{\mathrm{one}}}$$

.

If the angular velocity Ω _{1 of the} input shaft 1 and the frequency of the stator supply voltage 3 ω> 0 are specified, then the angular velocity Ω _{2 of the} output shaft 5 depends on the frequency ω and the angular velocity Ω _{1 of the} input shaft 1 according to the formula

. $${\Omega }_2=\frac{z_{\mathrm{one}}}{z_{\mathrm{one}}-p_{\mathrm{one}}}{\Omega }_{\mathrm{one}}+\frac{\omega }{z_{\mathrm{one}}-p_{\mathrm{one}}}$$

.

In this case, the second rotor 6 with the output shaft 7 synchronously rotates at a speed of Ω ₂ . The rotation speed of the output shaft Ω _{2 is} directly proportional to the rotation speed of the input shaft Ω ₁ and the angular frequency ω of the voltage of the stator 3.

To change (control) the reduction coefficient smoothly or stepwise, it is necessary to smoothly or stepwise change the frequency ω of the supply voltage of the stator 3.

Such an electromagnetic gearbox has a simplified design due to the implementation of winding-free rotors and one stator with one multiphase, for example, three-phase, winding. Moreover, the inventive gearbox has a high specific moment, a smooth change in the frequency of rotation of the output shaft of the gearbox relative to the frequency of rotation of the input shaft (if you change the frequency of the stator voltage), simplicity and ease of use, the absence of permanent magnets. The reducer can find application in various transport systems, in wind energy as a multiplier. Wind wheels in operating mode have a relatively low speed of rotation. To reduce the mass of electric generators driven by wind wheels through a gearbox, a multiplier is required that will allow the use of relatively light high-speed electric generators. It is possible to create a system for automatically maintaining the output parameters of the generator by continuously regulating the reduction coefficient as a function of the input speed.

Claims (1)

An electromagnetic gearbox comprising a housing with a stator installed therein with a multiphase winding connected to a voltage source, as well as first and second rotors rigidly mounted on the input and output shafts, respectively, characterized in that the stator winding is connected to the voltage source through an adjustable frequency converter and placed in the grooves of the inner surface of the stator with the formation of poles, while the first rotor located coaxially with the stator and rigidly connected to the end of the input shaft, yen in the form of a squirrel cage, the rods of which, inserted into rings of non-magnetic material, form the teeth of this rotor, and the second rotor located inside the first is made in the form of a toothed magnetic circuit with the number of teeth z ₂ equal to
z ₂ = (z ₁ -p ₁ ),
where z ₁ is the number of teeth of the first rotor;
p ₁ - the number of pairs of poles of the stator winding;
moreover, the stator, the teeth of the first rotor and the second rotor are made of charge of ferromagnetic sheet steel.