Auxiliary spindle for challenging grinding
Published:
The machining of gears with interfering contours for the aerospace industry places the highest demands on the grinding tool and often cannot be carried out with standard grinding heads due to the small tool diameters. Liebherr has developed an auxiliary spindle for these applications which can be retrofitted. This enables the production of challenging aerospace components on existing LGG gear grinding machines.
The greatest possible flexibility, even for special applications, by means of simple conversion or retrofitting of the necessary tools: Liebherr has been successfully pursuing this approach for several years with its adaptable internal grinding arms.
With the existing range of internal grinding arms, a machine can be converted from external grinding to profile grinding of internal gears in a very short time. So why shouldn’t this proven concept also work for the external grinding of special aerospace components? Following this thought, Liebherr developed an auxiliary spindle as an optional accessory that can be offered for LGG gear and profile grinding machines and can be retrofitted to existing machines.
A further option for special applications
The newly developed auxiliary spindle was part of a machine purchase and was handed over to production at sister company, Liebherr-Aerospace Lindenberg GmbH, at the end of 2020. This sophisticated new development is designed in close cooperation with the user so that the practical needs of machine operators can be incorporated into the design at an early stage. This applies to setup procedures and service tasks, in particular. A typical aerospace application is profile grinding of what is known as a 3-stage planetary gear, which is required for the wing flap adjustment. Due to the weight-optimised, compact component geometry, only small CBN grinding wheels are technically possible for final hard gear finishing.
With the auxiliary spindle, the user can use the LGG gear grinding machine to produce aerospace components with interference contours, along with their special technical challenges, in small batch sizes without having to invest in an expensive, possibly underutilised, special machine. The geometrically demanding components can thus be manufactured with high gear quality and surface quality. This expands the range of LGG grinding applications to include an additional option for critical, very small and high-quality components.
The auxiliary spindle, just like the internal grinding arm, can be mounted on all new Liebherr grinding heads with counter bearings via a changeover interface, which ensures short setup times. The additional functions of the grinding heads, such as an inductive meshing sensor, a movable cooling lubricant nozzle and a swivelling measuring probe, can also be used in combination with the auxiliary spindle.
Liebherr-Verzahntechnik GmbH
Tel: 0049 8317860
