Development Of Load Spectrum Measuring Device For Miniature Gear Mechanism And Research On Its Wear Behavior

Gear mechanism is the most common transmission mechanism in mechanical transmission system,with high transmission efficiency,compact structure,stable transmission ratio and high reliability.Among them,the gear mechanism with an index circle diameter of less than 10 mm is called a miniature gear mechanism.Miniature gear mechanism is widely used in industry,scientific research and daily life.Typical applications include robotic transmission systems,counter devices,precision scientific instruments,micro motors and pumps,smart toys,etc.Gear mechanism is a key component of load transmission and motion transmission,and gear wear seriously affects the performance of the entire transmission system.This paper proposes to develop a load spectrum measuring device for the miniature gear mechanism.Then,wear behavior of the miniature gear mechanism is studied by analyzing the load spectrum information measured by the device.The main conclusions are as follows:(1)Based on the analysis of the load spectrum,the research method of the wear behavior of the micro gear mechanism is proposed.By developing a measuring device for the load spectrum of the miniature gear mechanism,the measurement of the speed spectrum and driving torque spectrum of the gear mechanism has been realized.According to the characteristics of the driving torque spectrum,it is judged whether the gear mechanism is worn out or not,and then the material characterization method is used to characterize the key friction pair of the gear mechanism,and the wear mechanism is analyzed.(2)Developed a load spectrum measuring device for micro gear mechanism.The speed spectrum measurement module of the load spectrum measuring device of the miniature gear mechanism adopts a non-contact magnetic encoder.It realizes the measurement of the driving gear motion.Its gear shaft is only 1.2 mm in diameter,and the effective connection length of the gear shaft is only 3-4 mm.The driving torque spectrum measurement module uses a high-precision torque sensor.It can measure the torque of a few millinewton meters.The high-precision torque sensor establishes an effective and firm connection with the drive gear through the"coupling+micro chuck"connection scheme,which can realize the measurement of the drive torque of the gear mechanism under 10~5cycles.(3)The main reasons for the wear failure of the miniature gear mechanism is analyzed and revealed.After 10~5 cycles,the absolute value of the average value of the driving torque is increased by about 46%compared to the initial value,and the absolute value of the average value has exceeded 4 m N.m,which exceeds the normal value by about 13%.The miniature gear mechanism has failed.The key friction pairs all produce a large amount of wear debris,and the balance pendulum pin is particularly worn under the combined action of impact and sliding,and pits appear.Therefore,it can be concluded that the generation of a large amount of debris and severe wear of the balance pin are the main reasons for the wear failure of the micro gear mechanism.