Power skiving
Power Skiving is also used at GROB AG. The purchase of the PITTLER PV315 SkiveLine will see reductions in processing times while also reaching even higher standards in the quality of gearwheel production. This is thanks to the reduction or even omission of individual processes.
For a long time, power skiving only played a minor role in manufacturing gear drives as the machines were not productive. However, thanks to technological developments the process has now become profitable.
Power skiving - also used at GROB AG
Like gear hobbing and gear shaping, power skiving is a cutting process involving a geometrically defined blade. The cutting motion is generated by the diagonal arrangement of the skiving wheel (tool) to the workpiece, which is known as the shaft angle. The cutting speed is significantly influenced by the degree of tilt and tool speed. The front side of the cutting wheel gear forms the cutting face. Thanks to the spindle speeds that can be reached in today’s machines, power skiving allows for high productivity with minimal tool run-off. The necessary kinematic motion is generated with the help of the machine axes, whereby the tool and workpiece each have their own rotary axis.
The machine
The PITTLER PV315 SkiveLine is particularly suited to machining gear parts such as ring gears. It has been specially designed for gear cutting using power skiving and, in addition to turning, drilling and milling work, can also be used for thread cutting and deburring as part of complete machining.
The PV315 SL is suitable for workpieces up to a diameter of 400 mm. It is equipped with a multifunction head, Y-axis and tool magazine and avoids the problems seen in gear hobbing and gear shaping.
The tool magazine offers space for up to 20 different machining tools in total. Here, a roughing tool is exchanged in the machine enclosure followed by a finishing tool. As a result, the service life of the more expensive finishing tool is significantly increased. The ability to exchange different tools in the machine enclosure also allows for the flexible adaptation of individual steps in the complete machining process, even after the process has started.
Advantages for GROB AG and our customers
With power skiving, GROB AG is reaching new standards in the quality of gearwheel production. The high quality combined with more efficient production also offers our customers new opportunities in their gear cutting applications.
Helical internal gears
We are now able to manufacture helical internal gears (e.g. for planetary gears). Furthermore, we can finish the gears with high precision following heat treatment using hard skiving. Thanks to position-oriented gear cutting, processing can also be tailored to a surface, bore or edge.
Shorter processing times
Processing times are significantly reduced using power skiving. In turn, the time saved then primarily has a positive effect on the unit costs for our customers, though this only becomes noticeable when manufacturing medium quantities and above. The reason for this is that an individual skiving tool has to be procured for every gear cutting application.
Integrated tool magazine as key benefit
The integrated tool magazine results in the efficient implementation of upstream and downstream processes such as turning, milling, drilling and deburring, all the way through to complete machining. Furthermore, swarf is removed in a tool-friendly manner thanks to the use of a roughing tool followed by a finishing tool.
Constant high quality
The automatic quality inspection following the production of internal and external gears is also particularly important for GROB AG. With the automatic inspection, the gears are examined for production-related faults directly after machining. The transmission of the measuring values in real time guarantees a constantly high quality. The gear qualities of the workpieces are of class IT5 and are also characterised by low surface roughness on the tooth flank (Rz value less than 2 μm). Minimal coaxial errors (radial and axial run-out) occur as the support seats are manufactured in the same setting as the gear.