Liebherrrsquos onetable design establishes conditions for consitent quality throughout the production sequence there is one clamping fixture one geometry Every machined part is manufactured under the same conditions for the highest reproducibility

Consistency for Large-Scale Gear Grinding

July 2, 2014
Two new single-table machines reduce grinding times for twist-free profile and generating grinding Planetary and sun gears, bore-type gears, drive and pinion shafts Head rotation speeds up to 10,000 rpm Cost-effective sub-µ range waviness

With a one-table design and a new-design grinding head, Liebherr’s new LGG 180 (to be demonstrated in September at IMTS 2014) and LGG 280 machines reduce grinding times for twist-free profile and generating grinding. Both  machines are designed to deliver consistent high large-scale production quality in automotive applications, including conical gearing.

According to a representative of the machine tool builder,  “With this series of space-saving machines, vehicle manufacturers can develop a complete production line, in which all gearing components for a passenger vehicle transmission can be ground: planetary and sun gears, bore-type gears, as well as drive and pinion shafts with lengths up to 500 mm.”

The advantage of Liebherr’s one-table design is higher quality throughout the production sequence. There is one clamping fixture, one geometry. Every machined part is manufactured under the same conditions for the highest reproducibility.

Also, the one-table approach provides the statistical capability and reliability in continuously producing controlled, µ-range finish quality for gear noise optimization.

The new grinding head allows rotation speeds up to 10,000 rpm and has spindle power of 35 kW. With this performance data, the head enables high cutting speeds and high feed rates. The new grinding machine can exploit the considerable potential of the innovative 3M abrasive Cubitron II.  Changing the grinding arbor with HSK-C 100 tool holder is a fast and simple process.

A second grinding head is available also, featuring a small worm diameter for collision-critical parts.

For the first time, this design allows undulations to be applied specifically to gear wheel flanks, for noise optimization. The ability to produce sub-µ range waviness cost-effectively gives designers a whole new range of optimization options.

The touchscreen user interface on the machine control permits easier, intuitive programming and machine operation and incorporates an integrated webcam. The control also can incorporate substantial additional documentation, such as fixture layouts and tool mounting instructions.

The LGG machines are easily coupled with Liebherr automation platforms to create a fully automated production sequence, for high-quality gears in the shortest possible cycle times.