Extremely-low-temperature low-heat-dissipation precision piezoelectric ceramic rotating table

Abstract

A low-heat-dissipation piezoelectric ceramic rotating table comprises a mechanical amplification structure, a driving device, an angle sensing system and a master control system. The mechanical amplification structure comprises two sets of identical substructures which are arranged perpendicular to each other, every two opposite substructures form a set, and the two sets of substructures rub a rotating shaft alternately through static friction force to avoid sliding friction, so that heat dissipation generated by rotation is reduced. The angle sensing system comprises a capacitance impedance sensor composed of a detection electrode, an input electrode, a grounding electrode and an output electrode, and the angle sensing system is used for measuring a rotation angle in a heat dissipation-free and high-precision mode and transmitting signals to the control system to achieve closed-loop control. The master control system comprises a measuring system used for measuring signals of the capacitive sensor, a piezoelectric ceramic control system used for controlling electric excitation of the piezoelectric ceramic stack, and a computer used as input and output of the master control system.

Description

technical field [0001] The invention relates to the technical field of precision rotation control and the technical field of extremely low temperature measurement, in particular to an extremely low temperature and low heat dissipation precision piezoelectric ceramic rotary table. Background technique [0002] Precision piezoelectric ceramic rotary stages are widely used in precision measurement systems such as electrical transport measurement systems and optical metrology systems to accurately rotate samples or experimental devices. Piezoelectric ceramic translation stages are limited by the small deformation of piezoelectric ceramics. Various translation stages with large strokes generally require a mechanical amplification structure composed of a flexible hinge and a lever amplification structure, and cooperate with the alternating actions of multiple groups of piezoelectric ceramic stacks. accomplish. The action modes of piezoelectric ceramics mainly include inertial dri...

AI Technical Summary

Problems solved by technology

[0006] In the prior art, there is disclosed a rotating structure that utilizes a friction plate to drive a translation stage fixed by a bearing, which is an inertial drive translation stage. The disadvantage of this inertial drive is that the motion accuracy is not high, and it cannot be used for sub-nanometer Precise drive control and often unavoidable heat generated by sliding friction

For extremely low temperature acquisition devices, the cooling power is usually only a few hundred microwatts at a temperature of 100mK, which is easily suppressed by the heating power generated by the aforementioned sliding friction, making the system need to wait for a long time to achieve the target work after the translation stage moves Temperature; inchworm drive can have high driving accuracy, but it cannot avoid the occurrence of sliding friction just like inertial drive; walking drive can realize friction drive without sliding, but for extremely low temperature systems, the deformation of piezoelectric ceramics itself is affected by thermal expansion and contraction The impact of the effect will be greatly reduced, and the driving efficiency only through the deformation of the piezoelectric ceramic itself is very low, and the walking drive requires high machining accuracy for the piezoelectric ceramic stack responsible for expansion and contraction, which is easily affected by temperature changes

[0007] The action efficiency of the translation stage can be improved by using the mechanical amplification structure, but the overall stiffness and displacement resolution of the structure will be reduced, and the thermal deformation of the mechanical structure itself in an extremely low temperature environment can reach the same shape as the piezoelectric ceramic stack itself. Compared with the variable phase, the normal drive at extremely low temperature needs to use a different structural size or calibration amount than that at normal temperature, which is more cumbersome to use

Low structural rigidity will reduce the resonant frequency of the translation platform, which will easily couple the translation platform with the environmental mechanical vibration and noise, which is not conducive to precision driving

[0008] The positioning sensing device of the piezoelectric displacement stage usually uses a carbon film resistor. The structure of the carbon film resistor itself will cause sliding friction. When the carbon film resistance is energized, it will also directly generate resistance heat, which will have a great negative impact on the refrigeration device.

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