Double-pendulum head structure driven by differential double motors

Abstract

The invention relates to a double-pendulum head structure driven by differential double motors. Both a first differential input unit and a second differential input unit are driven by double motors, so that pendulum heads have large tilt angles and torques, the driving motors and speed reducers of the two differential input units are arranged on the outer side of a U-shaped support, and moving members of the pendulum heads only include pitching pendulum shafts, rotary pendulum shafts on the pitching pendulum shafts, main shaft boxes and main shaft motors, so that the mass of the moving members of the pendulum heads is integrally reduced. The equal torques in opposite directions are loaded between a driving servo motor and a driven servo motor, so as to form certain torque difference; due to the existence of the torque difference, driving bevel gears of the differential input units are reversely engaged to a driving bevel gear of a differential output unit; under the action of reverse engagement, the transmission clearance of the differential input units is smoothly eliminated, so that non-clearance transmission of the differential input units is realized. Through the non-clearance transmission of the first differential input unit and the second differential input unit, the kinematic accuracy of the pendulum heads is guaranteed ultimately.

Description

technical field [0001] The invention relates to an A / B-axis double swing head structure in a numerical control machine tool, in particular to a double swing head structure driven by a double motor differential drive. Background technique [0002] CNC machine tools with A / B-axis double pendulum heads can meet the cutting requirements of special curved surfaces, especially five-axis linkage CNC milling machines with A / B-axis double pendulum milling heads, which have been widely used in aircraft manufacturing and other fields. [0003] At present, the existing A / B-axis double swing heads are mostly driven by worm gears, and the two sets of worm gears are coaxially arranged, and a certain preload is applied by loading a butterfly spring or an adjustment sleeve on one end of the worm, so that the transmission gear It forms a reverse mesh with the fan-shaped rack at the output end, thereby eliminating the transmission backlash and improving the transmission accuracy, but this mech...

AI Technical Summary

Problems solved by technology

[0003] At present, the existing A / B-axis double swing heads are mostly driven by worm gears, and the two sets of worm gears are coaxially arranged, and a certain preload is applied by loading a butterfly spring or an adjustment sleeve on one end of the worm, so that the transmission gear It forms a reverse mesh with the fan-shaped rack at the output end, thereby eliminating the transmission gap and improving the transmission accuracy, but this mechanical anti-backlash method will gradually reduce the reliability of the anti-backlash with the increase of time

[0004] In addition, the drive mode of the rotary servo motor accelerator and decelerator adopted by the existing A / B-axis double-swing head leads to a complex and bulky mechanical structure of the A / B-axis double-swing head, and the movement of the center of the swing head during the swing process will cause Additional torque, which often needs to be balanced by a hydraulic cylinder, therefore, the existing A / B-axis double swing head should not swing at a large angle, thus limiting the swing range of the swing head

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