RU2739160C1 - Vibration excitation method - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to vibration equipment and can be used in vibration machines used in solid media dispersion, including during processing of wastes, as well as in construction, transport, medicine, metalworking, agriculture, machine building, food, mining and other industries, where vibration with different vibration laws is used. Method of excitation of oscillations consists in the fact that two rotary bodies are conjugated by end surfaces with calibrated pressing force and, simultaneously rotating them in different directions with different angular velocities, rolling each along its own closed trajectory, having rotary symmetry around axis of symmetry of trajectory, at the same time, but not synchronously, they are exposed to two unbalanced radial forces and continuously change their direction with rotation frequency of at least one of the rotated bodies, thus, in the system oscillations with modulated properties are mechanically generated, which form volumetric vibrational fields of complex shape.

EFFECT: broader technological capabilities of the method by generating and controlling a complex shape of a volume vibration field generated by oscillations with modulated properties.

1 cl, 6 dwg

Description

The invention relates to vibration technology and can be used in vibration machines used in the dispersion of solid media, including waste processing, as well as in construction, transport, medicine, metalworking, agriculture, machine tools, food, mining and other industries, where vibration with different vibration laws is used.

There is a known method of excitation of circular vibrations [SU 1664412 A1, "A METHOD FOR EXCITING CIRCULAR VIBRATIONS AND A DEVICE FOR ITS IMPLEMENTATION", IPC В06В 1/16, publ. 07/23/1991], in which the rotated body and counterbody are coupled with a calibrated clamping force so that the contact area has a closed shape with rotational symmetry, one of the mating bodies is rotated around the axis of rotational symmetry of the contact area, while the frequency of oscillatory movements is controlled by the ratio

and their amplitude according to the ratio

while maintaining the constancy of the ratio

where R _OS is the value of the axial calibrated pressing force of the rotating body to the counterbody;

ω _VR - rotation frequency of the rotated body;

m is the mass of the rotated body;

L is the departure of the rotating body;

j is the stiffness of the rotor;

D is the diameter of the rotated body in the zone of its conjugation with the counterbody.

The disadvantage of this method is the inability to obtain and control the parameters of volumetric vibration fields of complex shapes, due to the fact that the method is intended only for the formation of quasi-circular high-frequency oscillations in the plane of conjugation of the counterbody and the rotating body.

The known method of excitation of vibrations [RU 2533743 C1, "METHOD FOR EXCITATION OF VIBRATIONS", IPC В06В 1/16, publ. 11/20/2014], which consists in the fact that the rotated body and the counterbody are coupled with the calibrated clamping force and roll it along a closed trajectory having rotary symmetry around the axis of symmetry of the trajectory and simultaneously act on them with an unbalanced radial force, constantly changing its direction with the rotation frequency body, while the total amplitude of oscillations is controlled by the ratio

Where

Δω = ω ₁ + ω ₂ ;

F ₂ - unbalanced radial force;

ω ₁ - vibration frequency of the rotating body;

ω ₂ - rotation frequency;

r ₁ - radius of the rotated body;

M is the total mass of bodies;

t is time.

The disadvantage of this method is its limited application, which is expressed in the fact that it is intended only for the formation of quasi-circular high-frequency amplitude-modulated oscillations in the plane of conjugation of the counterbody and the rotating body, and does not allow obtaining volumetric amplitude-modulated oscillations of a complex shape.

A known method of excitation of vibrations and a device for its implementation [RU 2410166 C1, "METHOD FOR EXCITATION OF VIBRATIONS", IPC В06В 1/16, publ. 01/27/2011], taken as a prototype, according to which the rotated body is mated by the end surface with the second rotated body with a calibrated clamping force and rolled along a closed trajectory having rotary symmetry around the axis of symmetry of the trajectory, while simultaneously with the rotated body in different directions and different angular speeds rotate the second rotating body around the axis of its own symmetry.

The disadvantage of the prototype is the inability to obtain volumetric amplitude-modulated oscillations that form vibration fields of complex shapes. Such vibrations are necessary, for example, to assign complex trajectories of shaping movements in machines for dimensional dispersion of solid media in order to control the shape and size of dispersed particles [4].

The technical problem to be solved by the claimed invention is to expand the technological capabilities of vibration machines.

The technical result is the task of the working body with complex shaping movements, due to the generation and control of the complex shape of the volumetric vibration field, formed by oscillations with modulated properties.

The stated technical result is achieved by the fact that in the method of excitation of oscillations, two rotated bodies are mated by their end surfaces with a calibrated pressing force and, simultaneously rotating them in different directions with different angular velocities, each is rolled along its own closed trajectory having rotary symmetry around the axis of symmetry of the trajectory, while simultaneously, but not synchronously, they are affected by two unbalanced radial forces and constantly change their direction with the rotation frequency of at least one of the rotating bodies, thereby mechanically generating oscillations in the system with modulated properties, which form volumetric vibration fields of complex shapes.

Comparison of the claimed method of excitation with the known ones allows us to conclude that a new effect has been achieved, expressed in the possibility of generating and controlling a complex shape of a volumetric vibrational field formed by oscillations with modulated properties.

The essence of the invention is illustrated by drawings, where

in fig. 1 shows a diagram of the excitation of oscillations under the forced action of two radial unbalanced forces on two coaxially located rotating bodies;

in fig. 2 shows a diagram of the formation of a trajectory of vibration displacements of two types of vibrations with different amplitudes and frequencies .;

in fig. 3 shows the projection of the change in the position of the radius vector of the total modulated oscillations of the first rotating body when it is exposed to an unbalanced radial force in the XOY coordinate system per unit of time (the lower part of the vibration drive);

in fig. 4 shows the projection of the change in the position of the radius vector of the total modulated oscillations of the second rotating body when it is exposed to an unbalanced radial force in the XOY coordinate system per unit time (the upper part of the vibration drive);

in fig. 5 shows a diagram of the formation of modulated oscillations of the first and second rotated bodies when they are exposed to two unbalanced radial forces in a three-dimensional coordinate system in time t;

in fig. 6 shows a 3D model of a vibration drive - an example of the implementation of a method for exciting spatial vibrations of complex shapes with modulated properties.

The method of excitation of vibrations (Fig. 1) consists in the fact that the first rotatable body 1 installed in the ball assembly 2, moving in the axial direction by means of the nut 3 and the end of the plate, is mated with the required calibrated pressing force P _OC with the end of the plate of the second rotatable body 4 , rigidly fixed by means of a shaft 5 having rigidity j, in a glass 6, placed in a housing 7 on rolling bearings 8 and 9, and located with the first body of rotation 1 on the same axis. Then, these rotated bodies 1 and 4 by means of rotation drives D1 and D2 through drive shafts 10, 11 rotate with rotation frequencies ω _BPP and ω _VRK, respectively, in opposite directions. In this case, the rotation of each plate of the rotating bodies 1 and 4 is accompanied by its own relative translational quasi-circular movements along the surfaces of the mating rotating bodies, and the centers of gravity of each rotating body perform their own quasi-circular high-frequency oscillations. At the same time, the first rotating body 1 is additionally forced by the unbalanced radial force F ₁ , created, for example, by the inertial mass 12, and the second rotating body with the plate 4 is forced, but not synchronously, by the radial force F ₂ , created, for example, by the inertial mass 13 and constantly change their direction with the rotation frequency ω _BPP . Thus, against the background of high-frequency oscillations generated by rotating bodies 1 and 4, low-frequency oscillations are additionally forcibly excited, which, being synchronized with high-frequency oscillations, impart modulating properties to the system.

To clarify the essence of the method, using a vector oscillation diagram as an example, we will consider the principle of formation of total (modulated) high-frequency oscillations generated by a rotating body 1, and low-frequency oscillations created by force F ₁ by means of inertial mass 12. The principle of formation of the trajectory of two oscillations with different amplitudes and frequencies can be presented in the form of movement of the radius vector (Fig. 2) of the total amplitude A _{1 of} oscillations with the angle of rotation α.

Where

And _1v.ch - radius vector of the amplitude of oscillations of the rotating body;

And _1n.h - radius vector of the amplitude of oscillations of the unbalanced radial force F ₁ .

System of equations of projections of system oscillations

Where

and

where ω ₁ is the vibration frequency of the rotating body

А _1в.чХ , А _1в.чY - projections of the radius vector of the amplitude of oscillations of the rotated body, respectively, on the axis ОХ and OY;

ω ₂ - rotation frequency;

A _1n.chX , A _1n.chY - projections of the radius vector of the amplitude of oscillations of the unbalanced radial force F ₁ , respectively, on the OX and OY axes;

A ₁ X, A ₁ Y - projections of the radius vector of the total oscillations, respectively, on the OX and OY axes.

In this case, the angle of rotation α of the radius vector of oscillations A ₁ is equal to

Where

ψ is the phase shift of the angle of rotation of the oscillation radius vector A ₁ .

And the equation of the amplitude of the resulting radius-vector of oscillations A ₁ can be as follows:

Where

Δωt - phase difference of oscillations

From the above equation (4) it can be seen that the equation of motion of the radius vector of oscillations A ₁ ultimately depends on the frequencies ω ₁ and ω ₂ and the amplitudes A _1w.ch and A _1n.h vibrations of the rotated body and the unbalanced radial force F ₁ , and the trajectory of vibration displacements can vary from quasi-circular to linear, and under certain conditions even have the shape of a polygon or Lissajous figures.

Let us consider the principle of obtaining in space a complex trajectory of high-frequency vibrational displacements generated by a rotating body 1, and low-frequency ones generated by force F ₁ by means of inertial mass 12 (Fig. 3). As an assumption, let us assume that the form of low-frequency vibrations excited by the inertial mass 12 can be conventionally represented in the form of a circle, and their frequency is much less than the frequency of high-frequency vibrations excited by the rotating body 1, and therefore the change in the position of the center of mass of the unbalanced radial force F ₁ , for the considered period of time, can be neglected. At the initial moment of time, the resulting vector of modulated oscillations A ₁ can be represented as the sum of the vector of high-frequency oscillations A _1v.ch , with the projection of A _1v.ch.X on the X axis and the projection of A _1v.ch.Y on the Y axis, and the vector of low frequency fluctuations And _1n.h. , with projections A _1n.ch.X on the X axis and projection A _1n.ch.Y on the Y axis. When the center of gravity of the rotating body 1 moves along a quasi-circular trajectory, the phase of the oscillations changes, which entails a change in the resulting amplitude of the modulated oscillations. As a result, a complex closed trajectory is formed.

The principle of the formation of the trajectory of the total modulated oscillations of the rotated body 4 and the inertial mass 13 by the example of the vector oscillation diagram (Fig. 4) is similar. Just as in the case of modulated vibrations of a rotated body 1 and inertial mass 12, we assume as an assumption that the shape of the trajectory of low-frequency vibrations excited by inertial mass 13 can be conventionally represented in the form of a circle, and their frequency is much less than the frequency of high-frequency vibrations excited by a rotating body with a plate 4, in connection with which the change in the position of the center of mass of the unbalanced radial force during the considered time interval can also be neglected. At the initial moment of time, the resulting radius vector of the modulated oscillations p ₁ can be represented as the sum of the vector of high-frequency oscillations p _1v.ch. , with a projection of p _1v.ch.X on the X axis and a projection of P _1v.ch.Y on the Y axis, and a vector of low-frequency oscillations p _1n.ch. , with the projections p _1n.ch.X on the X axis and the projection p _1n.ch.Y on the Y axis. When the center of gravity of the rotating body 4 moves along a quasi-circular trajectory, the oscillation phase changes, which entails a change in the resulting amplitude of the modulated oscillations. As a result, a closed trajectory is formed, which in turn can change from quasi-circular to linear, and under certain conditions even have the shape of a polygon or Lissajous figures. Thus, complex amplitude-modulated oscillations are formed in the upper and lower parts of the system, and the shape of the trajectories of oscillatory movements can be controlled by changing the frequency and amplitude of oscillations of both rotating bodies 1 and 4, and rotating unbalanced radial forces F ₁ and F ₂ .

When considering the entire oscillatory system in a three-dimensional rectangular coordinate system XYZ (Fig. 5), it can be seen that due to the presence of complex modulated oscillations generated by a rotated body 1 with an inertial mass 12, and modulated oscillations generated by a rotated body 4 with an inertial mass 13, the vibration shape the field of the entire oscillatory system is volumetric, for example, the spatial form of the vibrational field resembles the shape of an hourglass. Moreover, it is possible to control the spatial form of the oscillation field both separately for the upper and lower parts of the system, which implies wider possibilities for regulating not only the intensity, but even the direction of the oscillations of the system, without using complex design solutions.

A tangible technical effect is expected from the introduction and use of the proposed method due to the possibility of generating controlled complex volumetric modulated oscillations of the required shape by one vibration exciter.

The proposed method can be found in various industrial sectors, for example, in vibratory drives of grinders for processing waste elastic-viscous materials into high-quality secondary raw materials in the form of crushed particles with the required shape and size. Thus, based on the results obtained, we can conclude that the technical problem posed has been solved.

The proposed method for exciting bulk modulated oscillations can be implemented by a device (Fig. 6) that allows for "fine" adjustment of the parameters of the oscillatory process.

Information sources

1. SU 1664412 A1, "Method for exciting circular vibrations and a device for its implementation", IPC V06V 1/16, publ. 07/23/1991.

2. RU 2533743 C1, "Method of excitation of oscillations", IPC В06В 1/16, publ. 20.11.2014.

3. RU 2410166 C1, "Method of excitation of oscillations", IPC В06В 1/16, publ. 27.01.2011.

4. Sergeev, S.V. Improvement of the process of grinding waste metals and plastics during their processing: monograph / S.V. Sergeev, E.N. Gordeev. - Chelyabinsk: SUSU Publishing Center, 2010 .-- 110 p.

Claims (1)

The method of excitation of vibrations, which consists in the fact that two rotated bodies are mated by their end surfaces with a calibrated pressing force and, simultaneously rotating them in different directions with different angular velocities, each roll along its own closed trajectory having rotary symmetry around the axis of symmetry of the trajectory, characterized in that simultaneously, but not synchronously, they are affected by two unbalanced radial forces and constantly change their direction with the rotation frequency of at least one of the rotating bodies, thereby mechanically generating oscillations with modulated properties in the system, which form volumetric vibrational fields of complex shapes.

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