Abstract
Due to the small size and harsh transmission conditions of small-module gears, it is very difficult to measure gear characteristics with a modulus smaller than 1 mm. We proposed an optical coherence tomography (OCT) method for measuring small-module gears. Testing of a 30-tooth copper gear with a small modulus of 0.5 mm was carried out for the measurement of its modulus, tooth parameter, tooth number, pressure angle, modification coefficient, and tooth thickness by using OCT. In addition, the influencing factors on the measurement were discussed. The whole teeth profile of a 0.2 mm modulus gear was imaged by processing of the data collected from different clamping angles. Compared with the visual imaging without depth information and small-scale microscopic imaging, the OCT method has shown its superiority, and it has potential in the application of the measurement of micro gears with a small modulus of less than 0.2 mm.
Highlights
Micro gears with a modulus of 0.05 mm to 0.5 mm are widely used in precision measuring tools, navigation instruments, and chronometer clocks [1]
If traditional contact measurement technology and instruments are used to measure small gears, even a thin and small measurement head is difficult to insert into the teeth, resulting in the difficulty in carrying out measurements; the contact measurement head sometimes damage the teeth
This method has high precision, high measurement efficiency, and a wide application range [6], but the tooth profile detected by this contact measurement cannot be too small, and it cannot meet the requirements of micro gear measurement
Summary
Micro gears with a modulus of 0.05 mm to 0.5 mm are widely used in precision measuring tools, navigation instruments, and chronometer clocks [1]. Contact CNC (Computer Numerical Control) micro-gear measurement based on the coordinate method [5] is one of the current methods of detections for small-module gears This method has high precision, high measurement efficiency, and a wide application range [6], but the tooth profile detected by this contact measurement cannot be too small, and it cannot meet the requirements of micro gear measurement. By controlling the rotation degree of the sample platform, optical measurements can be carried out on different parts of the tooth profile Parameters such as tooth thickness and pitch can be obtained by measuring the profile of the tooth side; the reconstruction of the entire tooth profile with a smaller modulus gear such as 0.2 mm can be realized by using data imaging algorithms. It can solve the difficulty that visual measurement and microscopic measurement are unable to obtain the contour of any position in the depth direction of the tooth width
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
