Plastic gears are just part of the normal makeup of the gear industry now, but for the Nichiei Co., that journey began inside a washing machine almost 50 years ago.
And, as it has grown and branched out over the years, Nichiei now designs and manufactures plastic gears for many industries in need of high-performance, tight tolerance pieces, and offers patent-pending technology to significantly lower the noise level in gear sets and improve the efficiency of these gears.
Established as a precision injection molder, Nichiei quickly used that expertise to make precision parts — including gears, according to Liz Gershon, Exclusive North American Representative for Nichiei Co. Ltd.
“That is truly the specialty of Nichiei,” she said. “We focused on mechanical components, and making plastic gears became a natural extension of that. And doing that 50 years ago was somewhat unusual in the injection molding industry.”
Focus on mechanical components
Those first gears found themselves in the timer mechanisms of washing machines, according to Gershon.
“Back in the ’70s, there were no electronic timers, everything was mechanical and everything needed gears,” she said. “That was one of our first applications, and we focused on the gear industry for quite some time.”
Nichiei continued to design and manufacture plastic gears and started to work with large Japanese office automation companies such as Canon, Epson, Coursera, Rico, and Minolta, according to Gershon.
“Our ability to achieve very tight dimensional accuracy was superior to what other molders were capable of,” she said. “Injection molded gears need to meet very tight tolerances in order to perform, so that was a perfect fit for us. We were very active in manufacturing gears for fax machines, printers, and similar equipment.”
When the IT bubble in Japan burst, production of office automation equipment shifted to China and other Asian companies, which left Nichiei in search of industries that could benefit from the company’s high precision plastic gears, according to Gershon.
Initially it targeted many other industries, but then the company found a big one — the electric vehicle industry.
Solving NVH issues in EVs
“Nichiei’s mission is to identify problems and unmet needs in the market and try to meet these needs,” she said. “We know NVH has always been a problem in the automotive industry for many reasons, and now even more so given the requirements for EVs. And metal gears contribute to this issue. Of course, metal is well established in the gear industry and offers excellent properties, but there are also limitations, including NVH problems. On the other hand, there are a lot of advantages to plastic gears — lightweight, no corrosion, greaseless, no or few secondary operations, and parts consolidation. And plastic gears are often very cost-effective compared to metal gears, as long as there’s enough volume to amortize the cost of tooling.”
Plastic gears can offer very good performance when used in the right application, and that depends on the required strength, torque, and size of the gear, according to Gershon.
“We’ve been successful because we know where plastics work, and we also know where they will not, and that’s really important,” she said. “In automotive applications, when it’s a safety application or other very demanding application or very large part, plastics can’t always meet those needs, and we know that. Where safety is not as critical, plastics often work very well for parts such as actuators, pumps, and mirror and door components.”
New technology development
With the need for low-noise gears identified, Nichiei continued to differentiate itself from other companies by moving beyond offering standard nylon or acetal gears, according to Gershon.
“We knew noise was an issue, and spent many years developing a unique, patent-pending technology involving the over-molding of high performance, high strength plastic over metal gears, essentially creating a very smooth ‘coating’ of plastic over the metal,” she said. “Through innovative design of the plastic flow path within the mold, the gear tooth face keeps its strength as well as its surface smoothness.”
According to Gershon, this maintains the benefits of metal — which are many — with the advantages of plastics — which also are many.
“We’re maintaining the strength, modulus, and other advantages of metal, but we put this thin plastic coating around the teeth,” she said. “We’re leveraging the coefficient of friction of plastic, which is much lower than metal, and therefore the gears experience very little friction and run more smoothly, reducing the noise between the two gears significantly. One program using our over-molded gears showed a reduction of 3.6 dB in noise level compared to metal gears. This significant reduction was very exciting for our customer.”
And Nichiei is working on the second generation of this technology, and preliminary testing shows even further improvements in noise management, according to Gershon. In addition to this technology being able to reduce gear noise, it also greatly increases the efficiency of the gear sets, again leveraging the low coefficient of friction, increasing the overall performance of the gears as well as extending their life.
“We’re very excited with this new technology, and the market reaction has been very positive,” she said. “Innovations like this low noise/high efficiency gear technology, as well as our problem-solving capability and the overall precision of the plastic parts we manufacture is truly what differentiates Nichiei in the marketplace.”
Picking the right plastic
Another aspect of Nichiei’s expertise is being able to pick the right plastic for the right job, according to Gershon.
“We know plastics, and we can identify the correct plastic for the application,” she said. “Plastics really vary in their performance. There are lower temperature, less stiff, less chemically resistant plastics, and then there are high-temperature, high-performance plastics that typically are more difficult to mold but provide much better performance. We also are able to injection-mold plastics that have glass fiber or carbon fiber in them to increase their modulus and strength. The modulus of plastic will never be the same as the modulus of metal, and we know that, but we can do many things to improve it.”
Nichiei has been very successful in producing high-precision plastic gears for such a long time because the company has the expertise needed to not only find the proper plastic, but to design the parts as well, according to Gershon.
“We have a full engineering staff; we do CAD design where we can help a customer design from scratch or help them problem solve an existing application; sometimes a customer may have said, ‘I need a plastic gear that’s lightweight or low cost,’ but the first design didn’t work,” she said. “Since we are a fully integrated supplier, we can help these customers — we design the gear in plastic, build our own injection molding molds, manufacture the parts, and then conduct final inspection and testing utilizing proprietary test equipment, all under one roof. Being fully integrated in this way makes Nichiei unique among injection molders and enables us to act very quickly and take full responsibility throughout the process.”
Gershon added that Nichiei has excellent relationships with the large plastics suppliers as well. “We have worked with them to not only choose the correct material for the application but sometimes these companies have developed customized products for us to meet a specific performance or design solution,” she said. “All of these things really make Nichiei different — we have all the needed capabilities in-house to deliver the program from the beginning of the process all the way to the end.”
Continually evolving
Nichiei’s newest technology of low noise/high efficiency gears is a game changer for the gear-manufacturing industry and has proved that Nichiei can continue to evolve and stay crucial to an industry that itself is constantly changing, according to Gershon.
“Metal replacement has always been a big focus for suppliers of engineering and high-performance plastics in many industries, not just gears, bearings, and components” she said. “Historically, plastics have offered a huge advantage in lightweighting, compared to metal gears, and now our low noise/high efficiency designs are another innovation for the industry.”
But for Nichiei to remain a leader in high-precision injection molding, it needs to continue to develop new and improved technologies, according to Gershon.
“Other injection molders are improving their precision molding, and our goal is to continue to stay ahead of them, so we need to keep innovating, as we are doing with the second generation of our low-noise/high-efficiency overmolding gear technology.”
To that end, Nichiei will continue to look for problems like NVH and help solve them, according to Gershon.
“From Nichiei’s perspective, we must keep innovating to continue to meet the ever-changing needs in the marketplace,” she said. “I think Nichiei is unique in what we do, and our culture is one of problem solving and innovation.”
And that talent for problem solving applies to a multitude of applications, according to Gershon.
“Our team is proudest when we can solve a difficult problem, and the customer is not only satisfied, but delighted,” she said.
And for Nichiei, solutions run the gamut from holding stringent part tolerances to recommending a different plastic to solve a problem to reducing noise levels that have plagued the industry for years, according to Gershon.
“We really can help customers with innovative solutions from the beginning to the end,” she said. “I think that makes us different, and that is what it is all about. Our company philosophy is to actively do what others would not do and what others cannot do. We’re a company that never gives up on challenging issues, even the most difficult ones. That’s what makes it all worthwhile.”
More info www.nichiei-ind.com/en
