SU1357625A1 - Controllable electrodynamic vibration isolator - Google Patents

Abstract

The invention relates to devices for damping mechanical vibrations and can be used for damping vibrations of objects located on a vibrating base. The purpose of the invention is to reduce the size by reducing the height of the gap between the working surfaces 8 and 9 of the electrodynamic vibration exciter 4. The power coils of the vibration excitation are mounted on the frame 7 associated with the vibrating object 3 and placed outside the annular gap between the working surfaces 8 and 9 magnetic system designed for installation on a vibrating base. Such an arrangement of the coils makes it possible to reduce the height of the gap of the magnetic system 10 of the vibration exciter 4. 1 sludge. e s

Description

The invention relates to a device for damping mechanical vibrations and can be applied to damping vibrations of objects located on a vibrating base.

The purpose of the invention is to reduce the size by reducing the gap between the working surfaces of the electrodynamic vibration exciter.

The drawing shows a diagram of an adjustable electrodynamic vibration isolator.

The vibration isolator contains elastic elements 1 installed between the vibrating cable; 2 and 3 isolated objects, 5 electrodynamic vibration exciter 4 with power coils 5 and 6 wound on the frame 7. Electrodynamic vibration exciter is installed

ten

lower limit of the gap. During oscillations, one of the power coils 5 or 6, through which the direct current flows, enters the gap between the working surfaces 8 and 9 by the magnitude of the oscillation amplitude. In this case, as a result of the interaction of the direct current of the coils with the magnetic field, a pushing force arises in the air gap, which is proportional to the displacement.

Through the power coils 5 and 6, electrically connected in a counter-sequential manner and connected to the source 12 of the direct current, a current I having the corresponding direction flows.

Let, under the action of some external force, the insulated object 3 will move down (up) relative to the initial position by the value x. With

parallel to the elastic elements 1 between 20 of this, the power coil 5 (6) enters the vibrating 2 and the insulated 3 objects. Power coils 5 and 6 are wound on the frame 7 so that they have a cross section along the axis in the form of rectangles and between their short sides facing one another there is a gap equal to the height of the gap between the working surfaces 8 and 9 of the magnetic system 10, the last executed as pos25

clearance by the magnitude of this displacement. As a result of the interaction of the current flowing through the coil with the magnetic field of the gap in the coil, a pushing force arises, the magnitude of which, in accordance with Ampere's law, is defined as follows:

F B1,1,

(one)

. This magnet 1 has an annular air gap of 11 and is attached to a vibrating object; 2. Power coils 5 and 6 are installed outside the pitch. the backlash on both sides, connected counter-sequentially and connected to the DC source 12. To create in coils 5 and 6 different in magnitude and direction of the currents, which makes it possible to realize a vibration isolator with an asymmetrical stiffness characteristic, these coils can be connected to separate DC sources. In this case, the electrical connection between the coils is eliminated .45 The vibration isolator operates as follows.

In the initial state, under the action of the force of gravity of the insulated object 3, the power coils 5. and 6 are arranged 50 symmetrically relative to a horizontal plane drawn through the middle of the height of the gap between the working surfaces 8 and 9 of the electrodynamic vibration exciter 4. At the same time, 55 power coils 5 and 6 turn out Eaten away from the gap and their short sides, facing one another, are located in the planes of the upper and.

where B is the magnetic induction in the gap between the working surfaces of the electrodynamic vibration exciter 4;

1) (- the length of the wire part of the coil 5 (6) located in the gap The length of the wire part of the coil 3. (6) located in the gap.

H

Nxlcp

(2)

where is 1 ...

D. N. average length of coil turn;

average coil diameter;

the number of turns corresponding to the part of the coil inserted into the gap.

N. K, S.h

(3)

where K is the fill ratio of the coil with copper; coil thickness; the height of the coil part inserted into the gap.

S / taking into account

day (2)

and (3) expression (1)

lower limit of the gap. When oscillations, one of the power coils 5 or 6, through which the direct current flows, enters the gap between the working surfaces 8 and 9 by the magnitude of the oscillation amplitude. In this case, as a result of the interaction of the direct current of the coils with the magnetic field, a pushing force arises in the air gap, proportional to the displacement.

Through the power coils 5 and 6, electrically connected anti-series and connected to the source 12 of direct current, current I flows, having the appropriate direction.

Suppose that under the influence of some external force the insulated object 3 is moved down (up) relative to the initial position by the value x. With

20 this power coil 5 (6) enters

25

clearance by the magnitude of this displacement. As a result of the interaction of the current flowing through the coil with the magnetic field of the gap in the coil, a pushing force arises, the magnitude of which, in accordance with Ampere's law, is defined as follows:

VA coil 5 (6) enters

F B1,1,

(one)

where B is the magnetic induction in the gap between the working surfaces of the electrodynamic vibration exciter 4;

1) (- the length of the wire of the coil part 5 (6) located in the gap. The length of the wire part of the coil 3. (6) located in the gap.

H

Nxlcp

(2)

de 1 ...

D. N. average length of coil turn;

average coil diameter;

the number of turns corresponding to the part of the coil inserted into the gap.

N. K, S.h

(3)

where K is the filling ratio of the carcass with copper; coil thickness; the height of the coil, into the gap.

S / taking into account

day (2)

and (3) expression

F

3 iBInx,

1357625

gle n ii D K, S K - proportionality coefficient

The + signs before the right side of (4) indicate the direction of the pushing force and are determined by the direction of the current.

Thus, as can be seen from the expression (A) J, the pushing force in an electrodynamic exciter is proportional to the displacement of an isolated object, i.e. The pushing force is equivalent to the stiffness of the elastic elements. By changing the magnitude and direction of the current in the power coils, it is possible to appropriately change the rigidity of the vibration isolator.

In a controlled electrodynamic vibration isolator, in order to maintain its operability, it is necessary that the height of each of the power coils be equal to the maximum possible oscillation amplitude. In this case, the electrodynamic vibration exciter should have a height of the gap between the pa (4) barrel surfaces equal to the height of the power coils 5 and-6, i.e. also the largest possible amplitude of oscillation.

b

F-oop mula inventions

Electrodynamic 1Q Bibroinsulator containing elastic elements designed to be installed between vibrating and isolating objects, an electrodynamic vibration exciter parallel to the elastic elements, in which the permanent magnet is fixed on the vibrating object and made with an air overlap , and its mobile system is made of electrically interconnected anti-sequentially power coils with a cross section along the axis in the form of rectangles and is intended for installation on an insulating unit, and a direct current source, characterized in that

in order to reduce overall dimensions, the power coils are installed outside the annular gap on both sides.

20

Ohr M. Blancard 5980/33

Compiled by M. Veselev Tehred M. Khodanych

Cor Pod

Circulation 804 VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, 4/5 Rastiscan nab.

Production and printing company, Uzhgorod, st. Project, 4

Corrector AO Ilyin Subscription

Claims (1)

Claim Adjustable electrodynamic A vibration isolator containing elastic elements designed to be installed between vibrating and insulating objects, mounted parallel to the elastic elements of the electrodynamics. 15 magnetic exciter, in which the permanent magnet is designed • to be mounted on the vibrating object and is made with an annular air gap, and its movable system is made of counterpropagating electrically interconnected power coils with a cross section along the axis in the form of rectangles and is intended to be mounted on insulating object, and a direct current source, characterized in that, in order to reduce the size, power coils are installed outside the annular gap on both sides.