Over the last 30 years, the gear industry has changed by leaps and bounds. And as it has changed, Norton | Saint-Gobain, one of the world’s largest abrasives manufacturers, has kept pace with its state-of-the-art grinding products.
Gear grinding for generating the profile of gear teeth has become an important aspect of the industry.
“In 1986, I started to get very involved in the gear market,” said Phil Plainte, senior corporate engineer with Norton | Saint-Gobain. “Gear grinding was kind of a rarity that was used to produce helicopter gears and aerospace gears, and then you’d see gear grinding sporadically used throughout the industry, but it wasn’t taken too seriously. They had what we would call very lazy grind cycles.”
But things soon changed quickly, according to Plainte.
The changing gear industry
“The machine tool business started to really step up to meet increasingly demanding gear application requirements,” he said. “The demand in the gear market quickly evolved due to changes in aerospace and automotive manufacturing. Transportation became more fuel efficient; there was a switch from rear-wheel drive to front-wheel drive, etc.; all of which contributed to new gear quality needs. Fuel-efficient vehicles went from using three-speed transmissions to eight- and nine-speed transmissions. Power density was the hot topic, more horsepower and more gears occupying less space through smaller gearboxes. Along with the concern for fuel efficiency came concern for the life of the gears themselves, which continues to drive the need for higher quality gears. The machine builders met the need with extremely sophisticated computer software and servos drives. Grinding meets the higher quality standards above all other manufacturing solutions.”
“The gear manufacturers, manufacturers of the machines, tools and abrasives they used, and automotive manufacturers, all played a role in the big changes impacting the car you drive. We supported the changes in the gear industry with our products,” Plainte said. “And we did it with the introduction of ceramics, custom engineered products, and high-speed products. These products deliver shorter grind cycles and superior quality. And we’ve been launching new products to support efficient gear manufacturing all along.”
Norton | Saint-Gobain is dedicated to innovation and continues to be a leader in abrasives technology.
“We support innovation through our research and development centers, and we also have grinding labs throughout the world to assess our products and the needs of the machine makers,” said Jim Gaffney, senior product manager for precision grinding. “We frequently partner with a machine maker or a specific end user to develop processes that are then used throughout the industry. We’re proud of the fact that we have these resources and work with companies across the globe.”
Norton | Saint-Gobain is a world leader in the abrasives industry with four global technology centers in the U.S., Germany, India, and China.
“I don’t know of any other wheel manufacturer that has four global technology centers,” Gaffney said.
Ryan Ellingworth, product manager for dressing products, said he ensures that his products keep up with development.
“We have an excellent structure in place to support customer projects in which we evolve dressing technologies to meet the demands of these new grains,” he said.
In-house grains
Part of what makes Norton | Saint-Gobain unique in how it works with its customers is the company’s ability to make all its high technology grains in-house, according to Gaffney.
“We have a full group of people developing new abrasives,” he said. “And, at the same time, we have a group that develops new grinding wheel products as well. The two technologies together can absolutely make some of the best grinding products in the world. And if you take a look at our portfolio, we have some very unique products to support the gear industry and the whole industry beyond gear.”
One of the biggest developments in the industry for conventional grinding wheels are ceramic grains, according to Gaffney.
“These grains are stronger than the older conventional grains,” said Josh Fairley, product engineer in precision grinding. “Typical grains fracture in much larger pieces during grinding, but with these micro-structured grains, they fracture much more efficiently, breaking off in smaller pieces to stay sharper much longer. This technology allows for faster grinding and significantly reduced dressing and much longer wheel life.”
“Also, we’ve developed different shaped ceramic grains,” Gaffney said. “We were the first in the industry, by 20 years, to offer shaped grains.”
The shape grains allow for better material removal rates, which in turn enables shorter cycle times, according to Gaffney.
Two divisions
This technology also lets Norton | Saint-Gobain serve what has become the two main divisions of the industry, according to Plainte.
“If you break the market up into two, you have the high-volume producers and then you have the job shops,” he said. “The big gear producers use a technology called continuous generation grinding. Using a threaded grinding wheel, the gear comes in contact with the wheel, and continuously generates the gear profile. It’s a very fast process. Machine tool builders keep increasing the speed of the wheel to increase output. So, we have to meet these demands with stronger wheels that can sustain the higher speeds, and we’ve been successful with this.”
“With high speed grinding, tighter geometry and balance tolerances are needed,” Fairley said. “We have developed a manufacturing process that results in a superior gear grinding wheel. This drastically reduces the time required for customers to true in a new wheel, and also allows for consistent performance for the duration of the wheel’s life.”
Saving Money
For small job shops, the tooling costs to cut and produce a limited number of specific gears annually is expensive. Custom hobs and milling cutters can be expensive with long lead times. Norton | Saint-Gobain shaped grain technology can be used to replace milling cutters or hobs, according to Plainte.
“We’re able to eliminate the traditional cutting process (hobbing and milling) and actually grind the gears from solid,” he said. “We’ve got a grinding wheel that produces high material removal rates similar to traditional machining processes. In our world, that’s pretty impressive. This helps job shops because they don’t have to increase their tooling inventory. They don’t have to grapple with high tooling costs and lengthy deliveries. Instead, they can take the wheel and put infinitely different profiles on it to cut all these different gears from blanks. Grinding gears from solid is a very efficient, precise process providing a job shop with flexibility and cost savings.”
The method is becoming popular, indicated by the demand of those specific grains needed for production, according to Gaffney.
“Grinding from solid has really taken off,” he said.
A rich history
Plainte said Norton | Saint-Gobain has followed the changing gear industry throughout the company’s history, which spans over a century.
“The Norton Company was founded in 1885 by seven entrepreneurs who bought a patent from Frank Norton for a grinding wheel,” said Jamie Reale, marketing and communications manager. “At about that same time, they purchased land in central Massachusetts and built the first grinding wheel plant. And that is where we sit today — on the same location where they built the original plant in 1885.”
In 1990, Saint-Gobain purchased Norton. Saint-Gobain itself is one of the world’s largest industrial companies, and has been around for more than 350 years.
“In 2001, Norton officially changed its name to Saint-Gobain Abrasives, but we retained the Norton brand because of its rich history,” Reale said.
Those historical roots have borne innovative fruit.
“With new product innovation, we identify the needs of the industry through a close relationship with customers and the gear grinding machine makers,” Gaffney said.
And as the gear industry, as well as other industries, continues to grow and change, Norton | Saint-Gobain plans to be there.
“We monitor all the industries, and the big thing we see is that the materials are changing,” Gaffney said. “The materials are getting harder and harder to machine or grind, to the point that some materials need to be ground instead of machined.”
Plainte agreed.
“That is particularly true in aerospace,” he said. “You cannot always machine exotic alloys in a traditional way.”
But Gaffney said Norton | Saint-Gobain will continue to be abreast of customers’ needs.
“I think we’ll continue to meet the processing needs of continually evolving material developments,” he said.
Latest technology
The new Norton Xtrimium™ range of gear solutions is designed for high performance gear grinding in extreme, tight tolerance environment. The newly structured portfolio of gear grinding products is specifically designed by category to provide higher profile accuracy, supreme form holding, and burn-free grinding in worm, profile, and bevel applications. Highlighting the new range is an innovative dual-worm wheel design that enables two operations in one grinding wheel, substantially saving time and cost.
Norton Xtrimium Dual-Worm Grinding Wheels feature a unique design with a high-performance vitrified bond section for grinding and a fine-grit resin section for polishing the gear teeth, enabling one wheel to perform what traditionally required two wheels. Substantial savings in wheel costs and productivity via the elimination of wheel swapping, can be achieved with the Norton design. In addition, improved surface finishes of Rz = 1.0mm and Rpk = 0.05mm, and reduced harmonics (noise) are realized. The Norton Xtrimium Dual-Worm Grinding Wheels can also be adapted to existing machines.
The Norton Xtrimium Gear Grinding Platform also covers the whole range of gear grinding processes and leverages the whole spectrum of Norton grains and bond technologies to match each customer’s requirements, whether with:
Worm Grinding Wheels, featuring micro-structured ceramic grains and providing free cutting action and wheel homogeneity, allowing constant performance throughout the wheel thickness for the life of the wheel. Superior grinding rates and increased form holding without burn are achieved with these worm grinding wheels.
Profile Grinding Wheels, which are ideal for deep profile gear grinding. The wheels feature high porosity and permeability, create exceptionally high material removal rates, and friction-free grinding.
Bevel Grinding Wheels, featuring a highly porous bevel formation for extremely fast, burn-free cutting.
IMTS 2018
At IMTS 2018, Norton | Saint-Gobain will be focusing on six or seven specific markets and showcase some of its new products, according to Reale, including for the gear industry.
“We will have our latest products showcased in Booth #237042 including our new Norton Xtrimium™ range of gear solutions designed for high performance gear grinding in extreme, tight tolerance environments,” she said.
Norton | Saint-Gobain experts will also be on hand to discuss what’s available now, as well as what to expect in the future.
“One of the things that we will discuss at IMTS is the Internet of Things and how our technology will address these needs,” Ellingworth said.
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