Manufacturing gears with the eyes of the designer

By Anna Bonanomi - Organi di Trasmissione
Gear production using 5-axis machine tools shows its full potential in the context of the increasingly small lots required, on the condition that the synergy achieved also includes a software environment and mechanical systems/hardware capable of optimal interpretation of the required specifications.

Manufacturing high quality gears with 5-axis machine tools calls for an essential and winning combination capable of balancing mechanical systems, software and process in order to meet designers' real needs. This is confirmed by Claudio Saurin, engineer and product development manager with Breton, a company based in Castello di Godego (Treviso - Italy) that has spent several years producing tailored machining centers featuring high technical specifications and evolved technology capable of delivering a highly competitive system in a market that is often faced with the need to produce increasingly small lots of parts. The reason lies in the fact that in this type of production (typical of medium/large size gears from 500mm to 3500mm) the tools required are frequently extremely expensive, hard to procure rapidly, etc.

Claudio Saurin continues «The ability for tooling machines capable of meeting the most stringent requirements in terms of accuracy and competitiveness expressed by gear designers and manufacturers calls for a high level of specialization. And it's essential to be able to offer the designer (especially the designer of bevel gear sets in the 400 to 1600mm range, which are perhaps still excessively reliant on tradition, ed.) a technically competent and convincing approach».

A conscious reflection, based on the experience that Claudio Saurin has accumulated during his work as a gear designer and that has been transformed into tangible innovation in the development of new solutions that touch on mechanical aspects and electronics, and that are especially focused on the process software. Just a few years ago an agreement was sealed between Breton and Kiss-Soft, a company with consolidated experience in the creation of specific software for gears and transmissions of all types, that has led to the implementation of programs, supplied on an exclusive basis (by Breton) and that allow the execution of machining processes that are impossible using conventional methods.

«Software – continues Claudio Saurin – that makes it possible, in bevel helical teeth for example, to machine the relief groove at the tooth root in the same way as it is created using hobbing cutters with protuberance on cylindrical teeth. Or to achieve refinements in the management of surface curvature in order to shift contact points by controlling the distortion of the surface in question rather than the settings on the machine. This involves making highly complex topological modifications».

At this point the transition to bring the surfaces generated by the afore-mentioned Kiss-soft software to the machine is managed by the Gear CAD and Gear CAM applications (developed by Breton using the Rhinoceros CAD engine and the RhinoNC CAM engine), which allow complete management of the process to create surfaces including chamfers, and of the associated machining operations.

Integrated process platform

«The technological synergy we have created – explains Claudio Saurin – allows the designer to develop the best material removal strategies and perform adequate simulations, allowing also the choice of the most suitable tool to create the tooth base until completing the workpiece after hardening. For example, to design a double helical gear the conventional approach is to design the left or right face and then make a specular design CAD, filleting and chamfering wherever necessary. In other words, our modus operandi is to fine tune the geometry as though we were the gear designer».

The greatest effort was therefore, on the one hand, that of creating an adequate design environment, and on the other hand to use machines that are able to optimize efficiency with high performance cutting processes.

«Not only – continues Claudio Saurin – but with the added value of a user-friendly and intuitive CAM system on board the machine. A process guided by a wizard that aids the operator in defining geometries and optimal tool paths. The decision is based on the fact that companies that manufacture exclusively gears and not the associated housings are generally unlikely to possess this kind of software».

In other words, the proposed solution is based on an integrated platform that includes a gear calculation code, a CAD application for generation of surfaces and a CAM application for the machining stage.

5 axes of quality for gears of various types

It is precisely to meet specific gear machining requirements that Breton has developed specific machining cycles to apply to its 5-axis machines, notably the Ultrix series model 1000 RT HD vertical machining center, which is particularly indicated for high speed machining of gears of diameters up to 1000mm.

«This is a high-speed machine featuring a high degree of automation – explains Claudio Saurin – designed and developed for milling, turning and grinding of workpieces of up to 1,200mm in diameter».

Equipped, in this version, with a powerful 75kW spindle with 300Nm of torque at 14,000 rpm and software for the production of helical bevel gears, this machining center can machine steel, aluminum, superalloys and composites. The machine features a monobloc structurewith gantry type travelling beam, with a 5-axis movement achieved by combining 3 linear axes with a rotary-tilting table. 

Gears can also be machined using various Breton machine models in the Maxima and Titan series (with large size gantry solutions and turning diameter). Systems that support an integrated process of turning, milling and hobbing pre- and post-heat treatment of medium and large size gears (up to 2,500mm for single piece parts).

«The know-how and experience acquired  – adds Claudio Saurin in conclusion – allow us to offer the designer a comprehensive set of tools construed in the broadest sense, including both software and process components. This makes it possible to use conventional 5-axis NC machines to design and produce a very large range of mechanical components rapidly and with superb quality results capable of guaranteeing a high level of competitiveness».

In other words, a new way of approaching the culture of gear manufacture. Not merely spur tooth and helical tooth gears, but also double helical cylindrical gears, spur tooth and spiral tooth bevel gear sets in accordance with the most common geometries, and also face gears for drive transmission between right-angle or non-parallel shafts.

To learn more, follow the considerations of Alessandro Verduci on market trends and future prospects:

For info and request about Breton machining centres and gear production using 5-axis machine tools write to mail@breton.it.
We’ll get back to you promptly.
Thanks again to Organi di Trasmissione.
Well, that’s all for today, thanks for your attention.
Bye-bye
Sergio Prior

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5-axis machine tools, 5-axis machines, Breton machining centres, Gear production, Maxima, titan, ultrix

Breton at GEAR FORUM & MECSPE - Parma

Good morning,
I wish to thank all those who attended GEAR FORUM and visited Breton stand at MECSPE in Parma.

I visited MECSPE last Thursday (March 21st) and I must admit that I didn’t expect to see so many people. Both the Pavilions 5 and 6 were crowded.

The vertical machining centre XCEEDER 900RT was exhibited at Breton stand while machining a bevel gear with helical teeth.

 GEAR FORUM took place on Wednesday and Thursday (March 20th and 21st) and was also visited by many people interested in the production of gears.
Mr. Corletto briefly introduced Breton, while Ms. Dotto explained the new Breton method for producing large-sized gears using CNC machines with 5 interpolated axes holding simple cutters available on the market.

Here you can find the complete presentation of  Breton GEARI I hope I gave you some useful information concerning our activity in the gear sector.
By-by
Sergio Prior

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bevel gears, breton machining centre, breton vertical machining centre, cylindrical gears, face gears, herringbone gears, Maxima, skew-axis gears, titan, ultrix

Breton ULTRIX grinding gear wheel

For more info click HERE

Happy holidays to all 
by-by

Sergio Prior

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bevel gears, breton vertical machining centre, cylindrical gears, face gears, Gleason bevel gears, herringbone gears, skew-axis gears, ultrix

Thinking differently the gears manufacturing

Being able to cut high-precision tooth profiles is of primary importance in gear cutting. Traditional processes (using "gear hobbers") involve some fundamental limits, both in the design and prototype phase, as well as when cutting the gear.

These systems are competitive only for large production runs, but are unsuitable for the production of prototypes or for small scale production (often the case with big gears) as the tools are very expensive, with long supply lead times, and the geometric refinement of the toothing (done by applying geometric micro-deviations to the theoretical tooth profile) is usually an extremely time-consuming process.

5-axis machining centre aren't affected by these limits as they use standard (cylindrical, toric or spherical) tools, and the development/prototyping processing is done using very precise software of the latest generation.

Breton's experience with 5-axis machine tools, precision mechanics and in the aerospace industry, has helped the company make a name for itself in the gear-cutting sector as a reliable and decisive partner, offering professional and innovative services.

In partnership with KISSSOFT - a leader in mechanical engineering software - we've developed the Breton Gear Design, a third generation geometry tool, guaranteeing the greatest accuracy and reliability.

Breton also developed the Breton Gear Cam, a CAM tool, so you can use just the right tool and strategy for every machining process.

This has been the approach with the Ultrix (tilting turning bench), Maxima and Titan (gantry and large-size turning bench) numeric controls, for an integrated turning, milling and tooth-cutting process, with pre and post heat treatment of medium-large gears (up to 2500 mm for one-piece gears).

The solution developed by Breton makes it possible for gear designers to design and produce gears quickly, using traditional 5-axis numeric controls, with excellent results:
- cylindrical gears with straight-cut or helical-cut teeth
- herringbone gears
- bevel gears with straight-cut and spiral-cut teeth in the most common geometries
- face gears for orthogonal drive trains
- skew-axis gears

As in the past, Breton puts its know-how and experience at the customer's service, developing innovative solutions destined to leave their mark in time.

For more INFO write at mail@breton.it. 

We’ll get back to you promptly.
Thank you for the attention and best regards.

By-by

Sergio Prior

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bevel gears, breton machining centre, breton vertical machining centre, cylindrical gears, face gears, herringbone gears, Maxima, skew-axis gears, titan, ultrix

Breton Open House 2012

We perfectly know how important it is nowadays to be competitive, to make the most of the challenges the ever-demanding market throws down each day.

To do so, it's essential to use modern high-tech production systems, and keep constantly up-to-date with the latest technological developments.
It will therefore be an honour for me to welcome you on the 5th, 6th and 7th of July to show you some of the latest, interesting innovations in our works, with machining cells running specific applications for the aerospace, energy, automotive and transmission sectors. 16 installations, each with a high level of customization and the most innovative, efficient accessories.
For me, and the rest of the Breton staff, it will be a pleasure to welcome you.
Best regards
Luca Toncelli
President of Breton Spa

Don't miss:
Special materials such as carbon, resins, and fibres require specifically configured machines like the EAGLE range of machining centres, examples of which will be on show with fully-functional machines and detailed structural views.  

The XCEEDER 900RT 5-axis trochoidal machines also offer a solution for increasing productivity and reducing consumption.  

The reduction in setup times makes all the difference. You won’t believe how fast it is to change pallets on the FLYMILL gantries, the compact XCEEDER 900 RT, or how efficient it is to change the tool automatically on the ULTRIX 800 RT lathe-milling machine.

Not only is there a reduction in setup times, but also an exceptional increase in part accuracy and flexibility as on the MAXIMA 2000 K60, the big 5-axis turn-mill gantry.   

There have been new breakthroughs in the machining of gears and transmissions, thanks to the new Breton technological packages, which you'll be able to see at work on 2 ULTRIX 1000 RT machines.  

What's more, we'll be presenting the new version of our best seller, the MATRIX machine, a true evolution in design and performance.



Sergio Prior

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aerospace machining, automotive machining centre, breton vertical machining centre, change pallet, CNC turning and milling center, eagle, flymill, high speed cnc, matrix, Maxima, open house, ultrix, xceeder