Linear ultrasonic motor for absolute gravimeter.

Area of Science:

• Mechanical Engineering
• Precision Measurement
• Robotics and Automation

Background:

• Linear ultrasonic motors (LUMs) offer advantages like compactness and vacuum compatibility for absolute gravimeters.
• Existing LUMs face limitations due to relatively low power output, hindering their adoption.
• Classical electromagnetic motors are currently the standard driving elements in absolute gravimeters.

Purpose of the Study:

• To propose a V-type linear ultrasonic motor with a new clamping method to overcome power output limitations and enhance stability for gravimeter applications.
• To investigate the influence of clamping component rigidity on the motor's mechanical output.
• To demonstrate the feasibility and performance of the proposed LUM design.

Main Methods:

• Development of a mechanical model for stators with flexible clamping components based on design criteria for LUM clamps.
• Analysis of the effect of tangential and normal rigidity of clamping components on the motor's mechanical output.
• Fabrication of a prototype V-type LUM incorporating the novel clamping method and subsequent performance testing.

Main Results:

• The proposed clamping method provides sufficient tangential rigidity and facilitates pre-load, crucial for stable operation.
• Performance tests demonstrated structural stability and high dynamic performance.
• Achieved no-load speed of 1.4 m/s and a maximal thrust of 43 N, meeting gravimeter requirements.

Conclusions:

• The V-type linear ultrasonic motor with the novel clamping method successfully addresses the limitations of existing LUMs for absolute gravimeters.
• The motor exhibits excellent structural stability and high dynamic performance, suitable for precision measurement applications.
• This advanced LUM design represents a viable and improved alternative to electromagnetic motors in absolute gravimeters.