* solution speeds threading-in times by an order of magnitude, and increases machining accuracy to DIN class 3!
Naperville, IL, December 10, 2013 ---- Today, NUM has announced a high
threaded wheel grinding. Incorporating unique high speed gear alignment
technology that is believed to be an order of magnitude faster than
comparable control schemes, the new CNC system dramatically reduces grinding
machine threading-in times to accelerate throughput significantly. The
comprehensive new solution is ideal for machine tool manufacturers seeking
to improve the performance of their gear production machines, or to help
companies expand their gear manufacturing range with threaded wheel
Based on NUM's new-generation Flexium+ CNC platform, the threaded wheel
grinding solution joins the company's NUMgear suite of gear production
software. Originally developed for gear hobbing applications, the capability
of NUMgear has been continually extended and now includes solutions for a
broad range of gear manufacturing processes, including shaping, grinding and
honing, and is used by many of the world's foremost manufacturers of gear
NUM developed the latest addition to its NUMgear portfolio while helping an
Asian gear manufacturing machine company to improve the performance of a
prototype threaded wheel grinder. To improve grinding speed compared with
current levels, NUM decided it needed to develop custom technology software.
The principal aims were to reduce the time overhead of learning the teeth
positions of the hardened gear prior to grinding, and improve the accuracy
of the gear grinding process.
NUM's new product offers a comprehensive CNC solution for gear manufacturing
machines. At the heart of the system is a high performance electronic
gearbox that allows all master axes - such as the grinding, X, Y and Z axes
- and the spindle (C axis) to be fully synchronized. As part of the
development work on the new threaded wheel grinder, NUM has added a major
new capability to the gearbox, which is now able to predict the acceleration
of axes as well as their speed, in order to minimize synchronization time.
Together with the Fast Gear Alignment, it forms part of the new NUMgear
threaded wheel grinding application.
During gear production, 'threading-in' - the process of bringing the
grinding wheel into contact with the gear blank - involves continuously
adjusting the position of the grinding wheel relative to the work piece. A
similar process is employed when bringing the machine's dressing wheel into
contact with the grinding wheel. Using acoustic emission sensors to learn
the sound signatures of a master gear and then using them to control
positioning during production runs is a common technique for automating
processes like this. However, the speed and accuracy of NUM's
newly-developed Fast Gear Alignment Function eliminates the need for this
entirely. As an example, aligning the grinding wheel with a 180 mm diameter
gear with 71 helical teeth takes just 0.5 of a second - without any need to
acquire acoustic signatures or make manual adjustments.
A second aim of NUM's development required that the gear grinder CNC control
should generate gears as accurately as possible. The latest machine from
NUM's Asian customer produced gears with a tooth profile quality of DIN
class 7. During the development process, NUM found that the diamond plated
dressing wheel did not come up to specification. To overcome this problem
without incurring major tooling costs, NUM decided to support their customer
by helping to modify the technology programs. The positive results of this
action far exceeded expectations, and NUM's solution can help a machine to
consistently grind gear teeth profiles to within 3.5 microns, comfortably
achieving DIN class 3 - an improvement of four class levels.
The latest gear grinding development is an example of one of the major
principles underpinning NUM's business philosophy: a willingness to
customize its CNC technology for machine makers. NUM supports this with a
decentralized R&D structure which locates engineering staff around the world
to allow it to work closely with machine builders. In this case, the new
gear grinding solution was jointly developed by NUM's HQ in Switzerland and
the company's technology centre in Chanzhou, China, which is close to many
major gear manufacturing machine builders and is currently undergoing major
"NUM is committed to helping its customers develop market-leading machines
through close partnership", according to Peter von Rüti, CEO of NUM Group.
"Our local presence and willingness to work directly with customers to
resolve technical issues very quickly provides both parties with a key
NUM is one of the longest established players in the CNC market, having
brought out its first numerical controller in 1961. Expansion in Asia has
become promising for NUM as Asian manufacturers have progressively improved
the capabilities and quality of their machines. To support this development,
NUM is currently making significant investments in its Asian infrastructure,
including the recent opening of a new regional support centre in Seoul,
South Korea, and the expansion of its technology centre in Chanzhou, China,
which opened in 2010.
Peter von Rüti points out that the European market for NUM and its partners
is also promising. "NUM's ability to create individual solutions for
different machines provides medium-sized companies with a huge competitive
advantage. The open and flexible nature of our products, and our
decentralized development structure, combined with the know-how of our
customers, provides unique market opportunities. We welcome the chance to
become involved in new projects."