HORN: Gear Cutting to the Power of Three

Gear Broaching,  Gear Milling and Gear Skiving – otherwise known as the technology cycles: gearBROACHING, gearMILL and gearSKIVING. Paul Horn GmbH and DMG MORI have launched a campaign covering these three core areas in gear cutting to demonstrate the high performance of the solutions that have been jointly developed through a combination of machine, cycle and tool. A major advantage is that many existing machines can be adapted to the individual processes.

The exclusive DMG MORI technology cycles assist shop floor programming for increasing productivity and safety as well as for expanding machine capability. The advantages are clear: up to 60 percent faster programming, error minimization through conversational programming, new technologies (gear cutting) and the technology know-how stored in the application software.

As far as the tool is concerned, Horn’s standard or customer-specific special tools may be used, depending on the process and application. When skiving internal and external gears, sizes up to module 8 are possible in gear quality up to ≥ 7. Gear milling with standard tools up to module 3 achieves a gear quality of ≥ 5. Gear quality of ≥ 9 can be achieved when gear broaching internal and external gears up to module 4.

To provide practical proof of these results, there will be numerous events and trade fairs in 2022 that will focus on the joint gear cutting processes developed as part of DMQP (DMG MORI Qualified Products). The first event will be the DMG MORI Open House in Pfronten from 9th to 21st May.

For more Info: www.PHorn.de/dmqp

HORN: Gear Skiving Solutions

 

Mastering Processes: Gear Skiving

More than a century ago, Wilhelm von Pittler filed a patent for gear skiving, which in 1910 was a revolutionary idea. However, the process has only found wider application in modern manufacturing since machining centres and universal turning centres with synchronized spindles and process-optimised software have made it possible to use this highly complex technology. Horn’s product portfolio includes a wide range of tools for skiving different gear geometries. Whether external gears, internal gears, spur gears, splines or even special tooth forms, all these tooth profiles can be produced extremely economically with skiving tools.

The system includes tools for highly productive production of internal gears, splines and other internal profiles as well as external gears close to interference contours. The most important advantages of skiving in these applications are the significantly shorter processing times compared to gear shaping, its use on optimised turning/milling centres, turning and gear cutting in one clamping and elimination of undercuts at the end of the tooth. Compared to gear shaping and broaching,  gear skiving offers production efficiencies of almost four to five times shorter cycle times. There is also the possibility of hard machining of gear teeth from solid. The skiving tools are designed for producing medium to large batches. Each tool is individually adapted to the application and the material to be machined, whereby the different tool interfaces are based on the number of teeth and module size.

Especially for internal gears, Horn delivers the advantage of short processing times when skiving larger modules. Large, rigid milling/turning centres are required with the requisite synchronization between workpiece and tool spindle. The larger the module, the more critical is machine rigidity. With a cut distribution between the left and right flanks, this issue can be mitigated by the tool. After gaining experience with small, solid carbide skiving tools, Horn used the know-how to address larger modules as well. Each application is evaluated for feasibility by the company’s engineers before discussions with the user regarding the tool design and recommendations for the process parameters, followed by project implementation.

Tooling System with Solid Carbide or with a Replaceable Heads

The system includes cylindrical or conical tools for modules from 0.5 to 2. The solid carbide monobloc version is available in diameters up to 20 mm and in a slim design. They are used for producing small modules and small components, preferably when a compact shaft is required due to the risk of collision. The cutting materials and coatings matched to the application produce high surface quality on the workpiece. For tool diameters over 20 mm, skiving tools with an interchangeable head system are used. The precise interface allows the cutting head to be easily exchanged within the machine without removing the holder. The carbide holder ensures high rigidity, wear resistance and precision. For larger modules, Horn relies on the use of a tool holder with indexable inserts. Especially with the WSR tool type, Horn offers the option of placing the internal coolant supply in front of or behind the cutting edge. This means that, depending on the application, blind holes, through holes or stepped bores can be machined with the most appropriate cooling.