Turnkey Gear Skiving Systems and Modular Automated Pallet Handling

In Booth N-236914, Liebherr Gear Technology, Inc. (Saline, MI) will demonstrate the gear skiving process on their LK series machines that are based on the tried-and-tested components of corresponding large hobbing machines but equipped with greater rigidity and more powerful spindles. A gear skiving machine requires a table with a direct drive owing to the high workpiece speeds required. This drive works with an automatic control that constantly has the optimal parameters. The complex clamping fixture, which links the workpiece and the machine, is designed by Liebherr.

Because skiving is a highly dynamic process, the machine is supplied on a turnkey basis with individual clamping fixtures for each workpiece, precise rigidity and contour accuracy. “This overall view is an important part for the production success,” explains Siegfried Schmidt, the team leader in the development and design of skiving. “A complex process such as skiving has many specific obstacles, which we overcome with very specific mathematical solutions.” With their skiving3 program, Liebherr not only provides the LK 300 or 500 skiving machine, but a whole process that includes machine, tools and technology for gear production. This integrated approach has already been tried and tested in practice. For many customers, the process of skiving is new, and therefore the operators of the machines need comprehensive training and assistance. On top of that, the tool design is a very complex issue.

Skiving3 is popular, especially for internal gearing with medium size and quantity, because it is much faster than shaping and more economical than broaching. In situations where gear skiving is not possible or appropriate, owing to interfering contours or quantities that are too low, technological alternatives are available with gear shaping and gear hobbing. The newly developed LHGe@rTec control system also contains the mathematical formulas for pressure angle corrections. This way, quality improvements can be easily achieved via the kinematics of the machine. The optional tool changer, which can be used to change between roughing and finishing tools, for example, is new. A ringloader is available as a standard option for the workpiece changing device, while other automation solutions, such as belts and robots, can also be realized upon request. Overview of LK 300/500 series machines includes:

• Maximum module: 5
• Maximum gearing diameter: 300 / 500 mm
• Maximum workpiece outside diameter: 500 / 600
• Maximum table speed: 3000 / 1500 1 / min
• Maximum tool diameter: 250 mm
• Maximum tool speed: 2700 rpm
• Maximum spindle output: 32 kW

Also on display will be the new PHS Allround pallet handling system that is designed to enable a broad range of shops to engage in flexible production in combination with 4-axis and 5-axis machining centers. This new modular concept, available in three capacities, can handle loads up to three tons, is extremely flexible, and can be individually configured and expanded. This corresponds to pallet sizes of 500 mm x 500 mm to 1,000 mm x 1,000 mm. Users can introduce flexible production systems with manageable investment and expand them when necessary. Shops can combine pre-configured modules as needed to match production handling needs: the storage locations can be arranged in a circular pattern, with one or more machines, or in a line. This extremely space-efficient system fits in almost every production floor. The user can easily expand a production system with the Allround, spreading investment over different expansion stages. It is no problem to start with one or two machines and increase this number to five, for example, as production changes.

For all Liebherr pallet handling systems (RLS, PHS Pro and PHS Allround), a new cell control  is offered with simple operation as its priority. The new graphically-guided interface concentrates functions on the main computer in a user-friendly manner and, if required, also allows full production control that includes resource planning, cutting tools and NC data management, plus interfaces to ERP systems.

Liebherr Gear Technology, Inc., 1465 Woodland Drive East, Saline, MI 48176, 734-429-7225, www.liebherr.com.