Enhanced turning-milling table drive

The latest MSR drive designs have been refined using the newest generation of drive and control systems (i.e. from Siemens CNC or Fanuc). The MSR drive is composed of two identical gearboxes (TwinDrive system), sharing the driving torque (50 per cent:50 per cent) during turning operations. With the help of the CNC system, which manages the motor preload torque, the system is able to cancel 100 per cent of backlash. In addition, MSR features enable a very accurate positioning level. Thus, it allows the execution of additional functions on the C axis, without any additional mechanical devices. For instance, top accuracy is kept during milling operations with one motor driving and the other motor braking.

Before MSR, turning table manufacturers used two different types of drives when a C axis was needed: a main drive for turning operations driven by a big spindle motor, and a feed-preloaded gearbox to cancel the backlash during C axis mode that needed to be clutched and unclutched to the crown. In addition, the main drive had to be shifted to neutral ratio.

The MSR drive simplifies the design of turning table mechanical transmission systems. It eliminates the need for a complex and expensive gearbox for the C axis, including a complicated system of clutching/unclutching. An approach with two motors is less expensive and easier to manage. In comparison to high-duty turning tables used in conventional configurations that require a 160kW motor, the MSR uses two 80kW motors, which are more standard and less expensive (despite the fact that there are two of them).

When the diameter of the chuck or part to machine is large, conventional home-made kinematics consisted of using a different stage ratio of 1/1, which resulted in high costs and loss of efficiency. MSR kinematics allow the drive to be placed right under the chuck directly meshing with the crown. Spare parts management is simplified with the use of a smaller motor. Furthermore, there is no need to manage the C-axis gearbox manufacturing with all its components.

For this new MSR drive, developed as a turnkey system by REDEX, a MSD two-speed gearbox is combined with the improved version of cubic R Series right angle bevel gearbox. The design upgrade includes a new and more compact and reliable speed changer as well as a new lubrication arrangement. The external appearance has also been improved, as required for high-tech machine-tool component design. Supplied as a self contained sub-assembly, this integrated and compact system comes ready to be implemented. Depending on machine arrangement, OEM can use the bevel box as an option.

This new range improves features of the four sizes, MSR330- MSR640- MSR650- MSR660, with torque capacity at pinion from 2000/4000Nm (2 × 40kW motors) up to 9000/18000Nm (2 × 100kW motors) with three possible ratio combinations of 7.66&2, 9.88&2, 11.49&3. This, combined with pinion/ring ratio of about 10 to 15, offers turntable torques from 20,0000Nm up to 270,000Nm and global ratios (gearbox + ring gear) of 77/20 and 172/45.

To find out more about the MSR TwinDrive please go to www.andantex.co.uk.