RU2409885C1 - Electromagnetic step propeller - Google Patents

Abstract

FIELD: electricity. ^ SUBSTANCE: electromagnetic step propeller includes in-series connected pulse generator with adjustable frequency, D-trigger and pair of current switches the inputs of which are connected to non-inverting and inverting outputs of D-trigger respectively. Outputs of current switches are connected to windings of electromagnets of the first and the second active elements fixed on ends of balance arm with its rotation axis. The first and the second active elements of the same construction consist of non-magnetic tube inside which there located is electromagnet and solid-state and sound-conducting pin, which are rigidly attached to each other. Sound-conducting pin is rigidly fixed on one end of non-magnetic tube. On its other end there rigidly fixed is ferromagnetic plate located from magnetic poles of electromagnet with small gap comparable to elongation of solid-state sound-conducting pin under influence of magnetic force of electromagnet the winding of which is connected to the appropriate current switch through the appropriate pair of annular contacts installed on rotation axis. The first and the second active elements are attached to the balance arm so that their ferromagnetic plates are located on both sides of the balance arm. ^ EFFECT: decreasing the pitch of angular shaft turn, and enlarging functional capabilities of active element as the part of the proposed device. ^ 7 dwg

Description

The invention relates to the field of physics and electronics and can be used as a model of an electromagnetic propulsion device such as a Segner wheel, but without ejection of reactive masses.

Known stepper motors that convert electrical signals into discrete angular displacements of the shaft. Using an electronic switch, voltage pulses are generated, which are applied to the control windings located on the stator of the stepper motor. The law of rotation of the rotor is determined by the sequence, duty cycle and frequency of control pulses, as well as the type and design parameters of the stepper motor [1]. As electronic control devices in known systems with step motors with variable shaft rotation speed, a pulse generator with an adjustable frequency, a D-trigger and a pair of current switches (power amplifiers) connected to the inputs with the non-inverting and inverting outputs of the specified D-trigger are used in series, and outputs - with control windings of the stator of a stepper motor. The prototype of the proposed technical solution is the specified connection of electronic nodes.

A disadvantage of the known stepper motor is the relatively large step of the angular rotation of the shaft under the action of each pulse generated by the master pulse generator, which is associated with the number and constructive arrangement of the stator poles with their windings.

The specified disadvantage of the known solutions is eliminated in the inventive device.

The objectives of the invention are to reduce the pitch of the angular rotation of the shaft for each control pulse, as well as expanding the functionality of the active element in the composition of the claimed device.

These goals are achieved in the inventive electromagnetic stepper motor containing a series-connected pulse generator with an adjustable frequency, a D-trigger and a pair of current keys, the inputs of which are connected respectively to the non-inverting and inverting outputs of the D-trigger, characterized in that the outputs of the current keys are connected respectively to the windings electromagnets of the first and second active elements attached to the ends of the rocker with the axis of its rotation, and the first and second active elements of the same design consist of a non-magnetic tube, inside of which there is an electromagnet rigidly fixed to each other and a solid-state sound-conducting rod rigidly fixed to one end of the non-magnetic tube, the ferromagnetic plate is rigidly fixed to the other end, located from the magnetic poles of the electromagnet with a small gap commensurate with the extension of the solid-state sound-conducting rod under the influence of the magnetic force of the electromagnet, the winding of which is connected to the corresponding current switch through the corresponding pair to ring contacts mounted on the axis of rotation, and the first and second active elements are fixed to the beam so that their ferromagnetic plates are located on different sides of the beam,

The achievement of these goals is explained by the occurrence of an unbalanced force acting on the side of the electromagnet on the ferromagnetic plate when a current pulse is applied to its winding with a duration equal to the delay time of the pulsed power excitation in the solid-state sound-conducting rod, which creates a time division of the force pulse moving the active element in the direction of action magnetic force, and the impulse of the reaction force stopping the active element, provided that the delay time of the impulse power excitation in solid sonically conductive rod of predetermined length and pulse repetition rate of the pulse generator with adjustable frequency. In this case, the first and second active elements operate alternately with the duration of the current pulses in the windings of their electromagnets due to the use of a D-trigger in the electronic control device, at the outputs of which meander pulse sequences are formed.

The inventive device is clear from the drawings. Figure 1 shows a top view of the device, figure 2 is a side view with electronic controls. Figure 3 is a sectional view of the structure of the active element of the device. Figure 4a shows a graph of the frequency pulses F of the _IMP generated at the output of a variable frequency pulse generator, the repetition period of which is T. Figure 4b and 4c show graphs of currents I ₁ and I ₂ in the windings of the electromagnets of the first and second active elements. Figure 5 shows a graph of the linear velocities of the first and second active elements - different thicknesses with dashed lines, and, therefore, the joint movement of the latter around the circumference for the ends of the rocker arm - a solid line.

Figure 1 shows:

1 - the first active element,

2 - the second active element,

3 - rocker

4 - axis of rotation,

Figure 2, in addition to the above, shows the following elements and blocks:

5a and 5b - bearings of the axis of rotation 4,

6, 7 and 8 - rings of sliding electrical contacts on the axis of rotation,

9 - pulse generator with adjustable frequency,

10 - D-trigger

11 - current switch of the first active element 1,

12 - current switch of the second active element 2.

Figure 3 presents the design of the active element 1 (or 2) of the elements:

13 - solid-state sound-conducting rod,

14 - concentric cylindrical electromagnet,

15 - windings of an electromagnet,

16 - ferromagnetic plate,

17 - non-magnetic tube, for example, aluminum,

18 - insulating washers mounted in a non-magnetic tube 17,

19 - bearings for the rod 13 along its axis of symmetry.

On figa is a graph of the periodic sequence of pulses of a pulse generator with an adjustable frequency F _IMP = 1 / T.

On figb and 4c are given graphs of currents I ₁ and I ₂ in the windings 15 of the electromagnets 14, respectively, of the first and second active elements 1 and 2.

In Fig. 5, a thin dashed line 20 shows a graph of the speed of the first active element 1, a thick dashed line 21 shows a graph of the speed of the second active element 2, and a solid line shows a graph of the linear velocity of the end of the rocker 3, which is a superposition of the first two graphs of speeds 20 and 21.

Consider the action of the claimed device,

The pulse sequence (Fig. 4a) from a pulse generator with an adjustable frequency of 9 is supplied to the counting input of the D-flip-flop 10, and pulse non-inverting and inverting outputs form pulse meanders (with a duty cycle equal to two) with a half frequency F _IMP / 2, Each of of these sequences opens alternately the current switches 11 and 12 (Fig. 3) of the first and second active elements 1 and 2, which leads to the pulsed magnetization of the electromagnets 14 by the currents I ₁ and I ₂ (Figs. 4b and 4c) in their windings 15.

First, we consider the process of microdisplacement of the active elements 1 and 2 along the axes of their symmetry during pulse-magnetic excitation of electromagnets 14 by the indicated current pulses (Fig. 3). Under the action of a current pulse in the winding of the electromagnet, the latter is magnetized and creates an attractive force F _{accele of the} ferromagnetic plate 16 to the poles of the electromagnet 14 (this force is indicated by arrows in Fig. 3) for the entire duration of the pulse T. The resulting impulse of the acceleration force of the active element of mass m is equal to p _accele = F _accele · T is suppressed by the braking impulse p _brake = - p _accele in accordance with the law of conservation of momentum, equal in magnitude and opposite in the direction of action of the vector. However, the action of acceleration and deceleration pulses occurs at different time intervals T following each other, if the delay time Δt _ass in the solid-state sound-conducting rod 13 is selected by the condition Δt _ass = L / V _sv , where L is the length of the solid-state sound-conducting rod, V _sv - the propagation velocity of longitudinal vibrations (shock wave) in the material of the rod 13, so that Δt _ass = T.

If we consider the movement (in a first approximation, in the absence of friction) of only the active element 1 (or 2), then under the action of the acceleration pulse p _accele = F _accele · T due to the equality of the momentum of the force to the momentum m · V ₀ at the end of the action of the acceleration pulse we obtain the final linear velocity of the active element V ₀ = p _accele · T / m, and with uniformly accelerated movement the displacement of the active element ΔS = V ₀ T / 2 = F _accele · T ² / 2m.

The same shift will be from the action of the second active element, therefore, the end of the rocker 3 will continuously rotate with a linear speed V * = ΔS F _imp = (F _accele · T ² / 2m) F _imp = V ₀ ; if we neglect the mass of the rotating beam 3 with the axis of rotation 4. With the radius of the beam R its angular velocity ω ₀ = V * / R = F _accele · T / 2 m · R. When substituting the condition Δt _ass = T we get ω ₀ = F _accele · L / 2 m · R · V _sound . Thus, the angular velocity ω _{0 of the} axis of rotation 4 is proportional to the magnetic force F _accele and the length L of the solid-state sound-conducting rod 13 and inversely proportional to the total reduced mass 2 m of the device (with additional consideration for the different attached mass), the radius R of the rocker 3 and the speed V _{sound of a} sound wave sound-conducting material in the solid rod 13. The kinetic energy of the system W = m (V *) ² = (F _USH · L / 2 · V _ulcers) ² / m = F · T _USH ^{2 2/4} m.

It is interesting to note that the mass of the solid-state sound-conducting rod 13 grows in proportion to its length, that is, the delay Δt _ass = T, therefore, to increase the kinetic energy of the system W, it is advisable to increase the length L of the sound duct transmitting the shock wave formed by the magnetic field in the electromagnet 14.

To increase the magnetic accelerating force F _accele should increase the current pulse in its winding and reduce the gap h (figure 3) between the poles of the electromagnet 14 and the ferromagnetic plate 16, made, for example, of soft magnetic iron with a low constant magnetic viscosity. The gap h should be slightly larger than the elongation of the solid sound-conducting rod 13 with diameter d and length L. According to Hooke’s law, the elongation of a round rod under the action of the force F _accele electromagnet is calculated by the formula ΔL = F _accele L / E · S, where E is the shear modulus [N / m ^2], S = πd ^2/4 - cross section of the round rod. So, for a brass rod we have E = 1,03 · 10 ¹¹ N / m ² and the speed of the sound wave V _sv = 3,48 · 10 ³ m / s at a temperature of 20 ° C. With the diameter of the rod d = 5 mm and its length L = 150 mm, its elongation ΔL under the action of the force F _accele = 100 n will be ΔL = 4 · 100 · 0.15 / 1.03 _· 10 ¹¹ · 3.14 · 25 · 10 ^-6 = 0.742 · 10 ^-5 m = 7.42 microns, therefore, the gap h between the ferromagnetic plate 16 and the poles of the electromagnet 14 must be at least 10 microns, and the corresponding surfaces must be perfectly polished and parallel to each other. Delay Δt _ass = T = L / V _sv = 0.15 / 3.48 · 10 ³ = 43.1 μs, i.e., the pulse repetition rate F _imp = 1 / T = 10 ⁶ / 43.1 = 23.2 kHz . This value of the pulse repetition rate in the pulse generator with an adjustable frequency of 9 (Fig. 2) is chosen taking into account the equality Δt _ass = T and the additional delay of the shock wave in the body of the electromagnet 14. We can assume that this frequency value will be of the order of 20 kHz (T = 5 · 10 ^-5 s). Then, when _{the Start} F = 100 N and m = 0.15 kg obtain kinetic energy in the system of _{the Start} W = F ² T ^2/4 m = 10 · 25 ⁴ x 10 ^-10 / 0.6 = 41.7 mJ and linear velocity the end of the beam 3, equal to V * = F _accele T / 2 m = 100 · 5 · 10 ^-5 / 0,3 = 16.7 mm / s When the radius of the rocker arm is R = 0.25 m, the angular velocity of rotation of the shaft 3 will be equal to ω ₀ = V · / R = 0.067 rad / s or 0.0107 r / s (one revolution of the shaft in 93.74 s = 1 min 33.74 from). Therefore, the step of the rotation angle Δβ of the rotation axis 4, per each pulse of the pulse generator with an adjustable frequency of 9, is only Δβ = ω ₀ T = 0.067 · 5 · 10 ^-5 = 3.35 mrad = 192 microdegree. This is many orders of magnitude less than the step of all known stepper motors. In this case, the full circle is divided into 2 π / Δβ = 1.875 · 10 ⁶ parts, and with such accuracy you can set the axis of rotation 4, acting on the device with a given number of pulses from the generator 9,

The active elements 1 and 2 can be mounted on a light moving platform parallel to each other with the same ends in one direction. Moreover, such a platform will be able to move progressively along the symmetry axes of the active elements. For the above example, the speed of such a platform will be about 15 mm / s, taking into account the additional mass of the platform. This indicates the expansion of the functionality of the claimed device. Accordingly, changing the parameters of the device, you can significantly affect the speed of the platform. The rotation during the movement of the platform is carried out by turning the active elements parallel to it and correspondingly controlling the angular position of the platform wheels.

The ability to carry out the movement of the active element (Fig. 3) is associated with the separation in time of the action of the acceleration and deceleration pulses of the mass of the active element, that is, at the non-simultaneous action of these pulses applied to opposite ends of the body of the active element (ferromagnetic plate 16 and the bottom of the non-magnetic tube 17, with which the solid-state sound-conducting rod 13) is rigidly fixed. During operation of the device, the laws of conservation of momentum and energy are observed, that is, the fundamental laws of physics are not violated.

Note that, by virtue of Newton’s third law, the forces of action and reaction, equal in magnitude and opposite in direction (which is consistent with the law of conservation of momentum), are considered in a mechanical system with ideal bonds, that is, without delay of one impulse relative to another. In the system under consideration there is a delayed feedback: the acceleration pulses of the active element and its braking pulses act at different time intervals, which causes the movement of the active element.

Literature

Handbook of Automation, ed. V.E.Nize and I.V. Antika. M .: Energoatomizdat, p. 360-361, Fig. 10.39.

Claims (1)

An electromagnetic stepper motor containing a pulse generator with a variable frequency connected in series, a D-trigger and a pair of current keys, the inputs of which are connected respectively to the non-inverting and inverting outputs of the D-trigger, characterized in that the outputs of the current keys are connected respectively to the windings of the electromagnets of the first and second active elements fixed at the ends of the beam with the axis of its rotation, and the first and second active elements of the same design consist of a non-magnetic tube, inside The electromagnet and a solid-state sound-conducting rod rigidly fixed at one end of a non-magnetic tube, at the other end of which a ferromagnetic plate rigidly fixed to the magnetic poles of an electromagnet with a small gap, commensurate with the elongation of a solid-state sound-conducting rod under the influence of the magnetic force of the electromagnet, are located the winding of which is connected to the corresponding current switch through the corresponding pair of ring contacts mounted on the axis rotation, and the first and second active elements are fixed to the beam so that their ferromagnetic plates are located on opposite sides of the beam.

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