Investigation of the Portal-Type Machine Tool Gear-Belt Gearbox

Резюме

Many modern technological processes are implemented at high speeds of the machine tool operating bodies relative to the workpieces. With significant dimensions of the processed parts, rack-and-gear drives are used. The design features of the rack-and-gear drive require coordination of the servo drive with the machine operating bodies movement speeds using a gearbox. This paper considers the possibility of creating a gear-belt gearbox for drives of high-speed equipment. The applied gearbox should not cause additional errors in the movement process. The work carried out experimental investigations of a servomotor dynamic characteristics and the qualitative characteristics of measuring encoders, the gearbox influence on the displacement error, machine tool axis movement. The dynamic characteristics of a servomotor without load, assembled with a gearbox and as part of a controlled axis of a portal-type machine have been investigated. It is determined that the delay time of the movement start is no more than 0.002 s for a servomotor without load and as part of a gearbox, and the delay time of the movement start of the gearbox output shaft does not exceed 0.003 s. It has been determined that the maximum possible acceleration of the controlled bodies of the machine during using the considered drive is 8 m/s2. The dynamic error of the axis movement along a straight trajectory does not exceed 0.023 mm, and along a circular trajectory – 0.035 mm. The error of position determining for the operating body is no more than ±1 discrete. This indicates that the gearbox error is less than the error of the position measurement system used in the investigated machine.