RU2537971C1 - Built-in piezoelectric alternating-current source for inertial axysymmetrical bodies rotated clear - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: generator comprises a thin-walled cylindrical piezoelectric cell fixed by its outer side to the inner surface of the body rotation and several symmetrical weights fixed to it from the inner side. When a body is rotated in regard to its longitudinal axis, the weights under centrifugal forces perform circular deformation of the piezoelectric cell that generates electric voltage.

EFFECT: reducing weight and dimensions and improving reliability and capacity of the piezoelectric current source.

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Description

The invention relates to electromechanical energy converters, namely to converters operating on the basis of the use of piezoelectric materials.

The invention can be used as an AC source for internal consumers of freely rotating inertial bodies in the design of space and military equipment.

An analog of most of the currently known converters is the electromagnetic mechanism.

Due to the long history of development and operation, these mechanisms are brought to constructive perfection. At the same time, the disadvantages of electromagnetic converters are known: this is a relatively large mass, the use of expensive scarce materials, the complexity of a device containing a coil, magnet, or field winding, the dependence of the generated voltage on the rotor speed, induction on sparking and electromagnetic fields, etc.

The practice of designing transducers shows that at present many electromagnetic mechanisms can be replaced by solid-state piezoceramic devices [1]. At the same time, many qualitative indicators can be significantly improved. Thus, greater reliability, manufacturability and, on the basis of this, lower cost, high conversion efficiency are achieved.

One of these devices is a piezoceramic direct current generator, selected as a prototype [2].

This generator has a cylindrical thin-walled piezoelectric element made in the form of a flat bimorph disk fixed in the center of the disk and deformed axially by two rollers mounted on the rotor through a flexible insulating gasket.

Upon deformation by rollers of a radially polarized piezoelectric element on the electrodes, which are metallized surfaces, charges arise due to the direct piezoelectric effect, which are transmitted in the form of voltage to the consumer through collector rollers.

The disadvantages of the prototype are:

- design complexity;

- large weight and size characteristics of the device;

- low electric power of the generator;

- relatively low reliability due to the fact that a thin-layer coating (piezoelectric element electrodes) is subject to rapid wear by rolling pressure and current collection rollers.

The technical result obtained by the implementation of the invention is to eliminate the enumerated disadvantages of the prototype, that is, reducing the weight and size characteristics and simplifying the design of the device, and, as a result of this, improving the reliability and electrical power of the piezoelectric current source.

This technical result is achieved due to the fact that in a known piezoelectric current source containing a stator made in the form of a body of revolution with a piezoelectric element attached to it with collectors, and a rotor made in the form of loads deforming a piezoelectric element of loads, forming an axisymmetric stator body of rotation, and an insulating gasket located between the stator and the rotor, the piezoelectric element is made in the form of a thin-walled cylinder mounted on the inner surface of the stator, while the loads deforming the piezoelectric element are located wife inside this cylinder.

Moreover, the piezoelectric deforming loads are made in the form of prisms with external radial bases repeating the inner surface of a thin-walled cylinder.

The outer surface of the cylindrical piezoelectric element is coated with a dielectric, and the collectors are attached to the external and internal surface of the piezoelectric element and output through the dielectric coating.

The invention is illustrated by drawings. Figure 1 schematically shows an axisymmetric inertial body rotating with an angular velocity ω; figure 2 - diagram of the generator; figure 3 is a diagram of a current source according to an additional claim.

To clarify the invention, Fig. 1 schematically shows an axisymmetric inertial body rotating with an angular velocity ω. The nature of the rotational motion of the inertial body is complicated by the phenomena of precession and nutation that occur during rotation.

The generator (figure 2) consists of a cylindrical thin-walled piezoelectric element 1, mounted on the inner surface of the housing (stator) 2, made in the form of a body of revolution, and a rotor 3, made in the form of loads deforming the piezoelectric element 1 and located inside the piezoelectric element 1, forming axially symmetric stator 2 body rotation. Deforming loads (rotor) 3 are in the form of prisms with an external radial base, repeating the mating radial shape of the inner surface of the piezoelectric element. The shape of the cargo 3 allows you to achieve uniform loading of the piezoelectric element when centrifugal accelerations occur.

The loads 3 are not mechanically interconnected and can move in the radial direction relative to the longitudinal axis of the housing (stator) 2 within the linear radial deformation of the piezoelectric element 1.

Between the housing (stator) 2 and the rotor 3 is an insulating gasket (not shown).

For electrical insulation and the possibility of voltage selection on the inner and outer cylindrical surfaces of the piezoelectric element 1, electrodes 4 are mounted with attached conductors-down conductors 5 and an external dielectric 6 is installed (Fig. 3).

The generator operates as follows.

When the body of the inertial body (stator) rotates (view AA in Fig. 1) relative to the longitudinal axis with its own angular velocity ω, the centrifugal acceleration force F _C arises, with which the deforming loads (rotor) 3 act on the inner cylindrical surface of the piezoelectric element 1. on the outer cylindrical surface of the piezoelectric element 1 acts reaction force F _R housing (stator) 2. When a constant angular velocity of rotation of the housing (stator) 2 resulting from the total resultant force causes radial deformation of the piezoelectric element 1. When the radial deformation piezoelectric element at its electrodes, by direct piezoelectric effect, there are charges forming a potential difference at its inner and outer cylindrical surfaces. The potential difference is determined by the angular velocity of rotation of the housing (rotor) and, as a result, is proportional to the magnitude of the radial deformation of the piezoelectric element. Due to nutation resulting from rotation of the housing (rotor) 2, a change in the potential difference will have a variable sinusoidal character. To exclude electrical losses of the piezoelectric element and current-carrying elements in the design of the generator, the use of a dielectric insulator is provided.

This power source allows you to achieve the technical result and apply the developed source for freely rotating inertial bodies.

Information sources

1. Erofeev A.A. Piezoelectric transformers and their use in radio electronics. - M., 1988, pp. 10-12, fig. 1.1.2.zh. SU 320 839 A, 02.17.1972. JP 51-31155 A, 09/04/1976. JP 51-43756 A, 11.24.1976.

2. Samoilov Valery Mikhailovich; Chernyaev Victor Nikolaevich. Piezoelectric dc generator. - M. 1993.03.19. Patent of the Russian Federation RU 2113757 - prototype.

3. Kozlov V.I. Designs WU. TSNIINTI, 1983.

4. Goldin A.S. Vibration of rotary machines. - M.: Mechanical Engineering, 1999 .-- 344 p.

Claims (3)

1. The built-in piezoelectric AC source for freely rotating inertial axisymmetric bodies, containing a stator in the form of a body of revolution with a piezoelectric element attached to it with current leads and a rotor in the form of loads deforming a piezoelectric element of loads, forming an axisymmetric stator body of revolution, and an insulating gasket located between the stator and the rotor, characterized in that the piezoelectric element is made in the form of a thin-walled cylinder mounted on the inner surface of the stator, while the load deforming the piezoelectric element We are located inside this cylinder. 2. The built-in piezoelectric AC source for freely rotating inertial axisymmetric bodies according to claim 1, characterized in that the piezoelectric deforming loads are made in the form of prisms with external radial bases repeating the inner surface of a thin-walled cylinder. 3. The built-in piezoelectric AC source for freely rotating inertial axisymmetric bodies according to claim 1, characterized in that the outer surface of the cylindrical piezoelectric element is coated with a dielectric, and the collectors are attached to the outer and inner surface of the piezoelectric element and brought out through the dielectric coating.

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