LT6254B - Rotational movement piezoelectric actuator - Google Patents

Abstract

The invention relates to devices for high-resolution angular positioning and measurement system, including positioning devices of optical elements. Rotating movement piezoelectric actuator comprises a frame (1), equipped with a ring-shaped piezoelectric element (3) with electrodes on which upper flat surface mounted three abrasion-resistant supports (4) cooperating with the disc-shaped rotor (5), in mentioned actuator is a newly installed a disc spring (2) which outer portion of the perimeter attached to the ring-shaped piezoelectric element and its central part is rigidly fixed in the body.

Description

1

The invention relates to a range of devices, in particular high-resolution angular positioning and measuring systems, including positioning devices for optical elements.

There is a known positioning device in which a rotary motion is formed by a piezo-ceramic ring with electrodes attached to the housing and by means of a contact ring, abrasion-resistant supports, a low-abrasion support (with spring), and magnetic supports on the outer ring surface in contact with the drive chain of the analogous form. Electrodes connected to high frequency power supply (see LT patent application 2013 058).

The excited running wave oscillations used in the specified device are transmitted from the piezoelectric element to the rotor at two locations (abrasion resistant supports) arranged asymmetrically on the rotor axis of rotor, so that the motion of the drive chain is not uniform and the positioning accuracy is not assured.

There is known a rotary motion actuator consisting of a housing incorporating a ring-shaped piezoceramic element with electrodes on which an abrasion-resistant support is mounted on the upper flat surface and a rotor which is coupled to the shaft support via a ring-shaped elastic member. Piezoceramic element electrodes are connected to a high frequency power supply (see U.S. Patent No. 6,665,335 B2, H01L41 / 08; 2004-07-20).

In the prototype indicated, the rotary shaft movement is performed by the formation of stationary wave oscillations, electrically excited by a ring-shaped piezoceramic element, with all points of the upper flat surface moving by elliptical trajectories. By using the intermediate elements, the microveses are transmitted to a rotor and shaft of said form. The ring-shaped elastic member, with which the rotor is connected to the shaft, causes the angular displacement errors to occur between the rotor and the shaft, which reduces positioning accuracy, and complicated intermediate elements of the construction complicate the manufacturing technology. The object of the invention is to increase positioning accuracy and simplify construction. The object of the invention is achieved by means of a rotary motion piezoelectric actuator comprising a housing and a ring-shaped piezoceramic element with electrodes connected to a high frequency power supply;

EN 6254 B is firmly attached to the casing disk-shaped spring, the central part of which is fixedly fixed in the housing, and the outer part is attached to the lower surface of the ring-shaped piezo-ceramic element on the perimeter. The top surface of the piezoceramic element contacts the rotor with three abrasion-resistant supports (in the same plane in the direction of rotation) (Z) on one plane in the same plane. The cylindrical rotor axis with a thread at the lower end is rigidly secured in two precision bearing supports separated by a bush which center the rotor with respect to its axis of rotation and a plane perpendicular to that axis. The uniform force of the ring-shaped piezoceramic compression of the rotor is created by an elastic disc-shaped spring which protects the entire system from possible twisting motion during angular displacement of the rotor. (the resistance is adjusted by a washer with a nut at the bottom end of the rotor axis. The above springs are adjustable (the combination of resistance allows for optimal balancing of both radial and axial loads, which ensures rotor positioning with respect to its rotational axis. The actuator does not use excited oscillating wave oscillations; The invention is illustrated by a drawing depicting a basic drive diagram (section AA, section BB), comprising a housing 1 with an elastic disc-shaped spring 2 on which the ring is rigidly attached to the upper surface. shape piezoceramic element 3 with three friction-resistant abutments 4 arranged in one plane contacting the rotor 5. The supports 4 on the ring-shaped piezoceramic element 3 with respect to the central axis The rotor axis 5 with the thread at the lower end 6 is rigidly secured in the bearing supports 7 separated by the bush 8. The lower part of the bearing support 7, with the washer 9, contacts the nut 10.

Positioning is done as follows. By supplying the high frequency electrical signal to the electrodes of the ring-shaped piezo-element 3 in the casing 1, the oscillations of the wave-shaped piezoceramic element 3 in the three planes at an equal angle to the axis of rotation (Z) of the drive are transmitted to the rotor. 5. Rotor 5 rotary motion 3

The LT 6254 B is formed by a frictional force acting between the abrasion-resistant supports 4, the elliptical trajectories and the rotor 5. All points of the surfaces of the upper plates of the abrasion-resistant supports 4 are moved by elliptical trajectories caused by a standing wave effect. The flexible disc-shaped spring 2, which equally presses the entire bottom flat surface of the ring-shaped piezoceramic element 3, creates a gap between the ring-shaped piezo-element 3 and the rotor 5 having a cylindrical shaft with a thread at the lower end 6 rigidly secured in the two precision bearing supports 7 separated by a bush 8. The latter center the rotor 5 with respect to its axis of rotation and the plane perpendicular to it. The washer 9 and the nut 10 at the lower end of the rotor axis 6 regulate the force of pressing of the piezoceramic element 3 on the rotor 5. Such a drive design makes it possible to increase its rigidity, evenly distribute radial and axial loads relative to the rotary axis of the rotor and increase positioning accuracy. All this determines the position of the positioning object (not shown in the drawing) moving with the rotor. When supplying a high frequency voltage to two electrodes of piezoceramic element 3, the rotor 5 is pivotally rotated in the plane XY. In order to change the direction of rotation of the rotor 5, the electrical signals supplied to the respective two electrodes of the piezoceramic element 3 are interchangeable.

Compared to the prototype, a new set of structural elements due to the elastic disc-shaped spring 2 equally presses the ring-shaped piezoceramic element 3 to the rotor 5, thereby creating a roll that reduces the rotor angular displacement, which increases positioning accuracy and significantly simplifies the overall system design .

Claims (1)

4 LT 6254 B Definition of the invention Rotary-motion piezoelectric actuator consisting of a housing (1) having a ring-shaped piezoceramic element (3) with electrodes on which three friction-resistant supports (4) interacting with the disc-shaped rotor are mounted on the upper flat surface (4). 5), characterized in that the actuator has a newly mounted disc-shaped spring (2), the outer part of which is attached to the ring-shaped piezoceramic element (3) and its central part is fixedly fixed in the housing (1).