ADVERTISEMENT FEATURE COVER STORY
CNC SOLUTION BOOSTS automated threaded wheel grinding
Automated threaded wheel grinding on a gear production machine has been boosted by a new CNC solution from NUM which speeds threading-in times by an order of magnitude and increases accuracy to DIN class 3
N
UM has announced a high performance CNC solution for gear
production machines that fully automates threaded wheel grinding. Incorporating high speed gear alignment technology that is believed to be an order of magnitude faster than comparable control schemes, the 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 grinders. Based on NUM’s new-generation
Flexium+ CNC platform, the threaded wheel grinding solution joins the 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 manufacturers of gear production machines. 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, 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
8 MARCH 2014 | DESIGN SOLUTIONS
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. As an example, aligning the grinding wheel with a 180mm 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 development, NUM found that the diamond plated dressing wheel did not come up to specification. To overcome this without incurring major tooling costs, NUM decided to help to modify the technology programs. The positive results exceeded expectations, and NUM’s solution can help a machine 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. “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 competitive advantage.” NUM is one of the longest
NUMgear now includes a high performance CNC solution for gear production machines that use threaded wheel grinding
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.”
The accuracy of NUM’s Fast Gear Alignment function eliminates the need to acquire acoustic signatures during dressing or grinding
NUM (UK) Ltd
www.num.com Enter 203
/ DESIGNSOLUTIONS T: 02476 301259
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52