Gear Making Machines Designed for Robotics Industry

Mitsubishi Heavy Industries Machine Tool, a part of Mitsubishi Heavy Industries (MHI) Group, has developed new models of hobbing and gear shaping machines to respond to need for precise, efficient manufacturing of strain wave gears and other precision reduction gears for robots.

The line includes a hobbing machine that is designed to create external gears and a shaping machine to make the internal gear. In contrast with conventional mass-production gears typically used in the automotive industry, which have modules (gear tooth sizes) of 1 to 4 and accuracy requirements of ISO class 8 or 9, gears for robots require greater precision, with modules of 1 or below and an ISO class of 3 to 6. The FR series was specifically designed to meet these demands.

These machines use direct-drive motors for both the main spindle to which the cutting tool (hob) is attached and the worktable spindle holding the workpiece, along with advanced control technology. By limiting the machine tool error to the greatest extent possible, this system is said to achieve a pitch error of 1 micrometer. Fast cutting speeds with rpm ranging to 8,000 is said to shorten processing time by as much as a third, contributing to greater productivity.