Study Of The 6-UPU PMT With Side-setup Drive Motors

Parallel machine tools, which came forth in the middle of 1990s, are also called virtual axis machine tools. PMT is an application of spatial multi-loop parallel mechanism in the field of NC machine tool, and is a combination outcome of mechanism theory, robotic technology and numerical control technology. The prototype of PMTS is parallel'robotic manipulators. PMTs enjoy following advantages over traditional five-coordinates NC machine tools:large stiffness weight ratio, high feed speed, high machining precision, high additional technology value, etc. PMT has the characteristic of simple hardware and complex software, an electro mechanic product with high additional technology value, and has very vast application vistas in industry.Combined with the new 6-UPU PMT researching and developing project, designed and made PMT's mechanical part. Introduced the basic types and selection of motion pair, the construction of expansion links, moved platform, hinges, machine tool body and their action principle; Introduced basic principle of the Screw Theory and the method of calculating the freedom of parallel mechanism and solved a problem:The movement of the moved platform is uncertain when the distribution of expansion links is absolutely symmetrical; Studied the software development environment, hardware platform, three modules and main arithmetic, including the interpolation arithmetic, the calculation of bar's length, the pulse number of every interpolation step and impulsion of a parallel kinematic machine's NC System Program; Introduced the principle and connection of the Motor Control Card, and the function and connection of Stepper Motor Drivers, the design and function of the strong current control circuit and made an electric control box protect the control circuit.Finally, the 6-UPU PMT can complete six-degree-of-freedom motion and perform a variety of workpiece's milling.