Integrated Drives Revolutionize Vertical Lathe Versatility

Versatility is the key issue for manufacturers of multi-axis milling machines and vertical turning lathes. The same machine tool must be able to perform various milling and lathing operations so that machining operations can be carried out with the highest accuracy (without part disassembly) and the highest productivity. These heavy constraints once meant that manufacturers had to use drives that were generally complex and did not necessarily meet every technical requirement. But now two complementary Redex integrated drives from Andantex USA Inc. (Wanamassa, NJ) for tables used on milling machines and vertical lathes are extremely easy to use and allow designers to choose the right drive for each application and based on their priorities of speed, power, accuracy and rigidity.

A global leader in high performance drives for machine tools, Redex offers new high speed versions of its DRP, KRP and KRPX drives for rotary tables of multi-axis milling machines that complement the features of its MSR drives. Compared with more conventional solutions, such as combining indexing tables with direct-drive tables, both of these one-of-a-kind solutions provide real added value to machine tool manufacturers by dramatically simplifying the design of the mechanical transmission systems of both large rotary tables used on vertical lathes (over 2,000 m) and smaller tables used on milling machines. They also improve machine accuracy and allow for smaller machine footprints.

These two complementary drives provide machine tool manufacturers with cutting-edge turnkey drives that are innovative, more user friendly and easier to maintain. The high speed versions of the DRP, KRP and KRPX drives use the heart of Redex high-performance planetary reducers. Widely recognized by the most demanding manufacturers, they have extensively proven their worth among other drives for large capacity machine tools. When meshed with a drive gear, the two reducers on the TwinDrive and DualDrive cancel 100 percent of backlash to guarantee the exceptional accuracy and momentum of these drives, which have extensively proven their worth on linear rack-and-pinion systems for many years.

These high speed reducers have been hardened using specific technology in spindle gearboxes to allow continuous operating cycles and meet the specific requirements of rotary tables. As a result, the high speed TwinDrive and DualDrive units can achieve rotational speeds of up to 28 rpm^-1. Although the MSR drive offers higher rotational speeds, the high speed versions of its DRP, KRP and KRPX drives offer far greater accuracy, rigidity and momentum. They are the standard drives with the highest positioning accuracy by a few arc-minutes.

The complementarity of both drives allows manufacturers to design the right rotary-table drives for specific applications, with priorities on speed, power, accuracy and rigidity. Redex is the only manufacturer of one-of-a-kind integrated drive systems for rotary tables on vertical turning lathes. Before this, rotary tables were designed to use two different types of drives when a C-axis was required:

• A main drive for turning operations, driven by a large spindle motor.
• A feed-preloaded gearbox to cancel the backlash during C-axis mode and which needed to be clutched and unclutched to the crown in order to shift to milling. In addition, the main drive would have to be shifted to neutral ratio.

Thanks to the exclusive features offered by the quality of the high performance reducers and the association of these reducers in TwinDrive or DualDrive mode, these new drives offer the highest positioning accuracy and also make it possible to execute additional functions on the C-axis without any additional mechanical devices or the use of position locking. This maximum accuracy is maintained during milling and/or positioning operations particularly by the electrical or mechanical preload system, which continuously manages the counter-torque between the pinions.

Drives that use two reducers, and thus two motors, are more cost effective and easier to manage in most cases. Compared to heavy duty rotary tables used in conventional configurations that require a 160 kW motor, the TwinDrive uses two 80 kW motors that are more standard and often less expensive, even when accounting for the cost of both units. Maintenance and spare parts management is also greatly simplified by the use of the smaller, standard motors. All of this dramatically simplifies rotary table design because it eliminates the need for machine tool manufacturers to design and build their own gearboxes with all the necessary components.

These high speed DRP, KRP and KRPX drives dramatically extend the Redex range of drives, particularly for high speed milling tables. Redex, a specialist in precision mechatronics for machine tools and for the steel industry, owns three industrial plants in France and Germany with a consolidated turnover of almost 50 million euros (90 percent is exported from France), and employs more than 320 people throughout the world. This is supported by a wide network of subsidiaries and agents, including three high skilled service centers located in North America, Asia and Europe.

Andantex USA Inc., 1705 Valley Road, Wanamassa, NJ 07712, 800-713-6170, Fax: 732-493-2949, info@andantex.com, www.andantex.com.

Redex SA, ZI – BP 79 F-45210, Ferrières, France, +33 2 3894 4262, Fax: +33 2 3894 4299, cfourtune@redex.fr, www.redex.fr.