Gear grinding is an important process in the production of gears. It is a necessary step to reduce noise, which is especially critical as electric vehicles make inroads into everyday life.
However, noise reduction is just one of several goals in manufacturing modern gears, and UNITED GRINDING has been perfecting that process with its grinding machines for almost a century.
“We’ve been a manufacturing company for a long time,” said Andrew Osborn, national sales manager in the cylindrical division of STUDER, a UNITED GRINDING company. “And STUDER has over 100 years in the industry of making grinding machines. We started in the very early 1900s making cylindrical grinding machines, and we’ve been developing new technologies ever since.”
Grinding company umbrella
STUDER is part of the UNITED GRINDING Group of grinding companies that also includes BLOHM, MÄGERLE, WALTER, EWAG and others, according to Osborn.
“Now we have tool and cutter grinders, cylindrical, surface, and profile surface grinders,” he said. “We’ve developed all of our technologies and brought them together to form one company that focuses on precision manufacturing technologies.”
What UNITED GRINDING does for gear manufacturing, oddly enough, doesn’t involve the teeth of the gear at all. The company’s grinding expertise focuses on other areas of gears where higher tolerances of grinding are required to produce highly technical parts, according to Osborn.
“(Our machines) don’t actually grind the gear teeth, but what they do is grind the journals on gears; grind the IDs of gears, the faces, and all those different features,” he said. “A lot of what we do on the cylindrical side is making sure the journals are in relation to the pitch diameter of the gears — whether it’s a helical gear or a normal straight gear or anything like that. Our machines grind the parts that are more strictly cylindrical on the gear shafts or the gear IDs themselves.”
The machines offered by UNITED GRINDING are capable of performing several operations, including multiple spindle machines that can create different features on a gear, according to Osborn.
“Whether it’s an automotive transmission gear, aerospace gear, or anything like that, we have different operations that we can do with our machines, such as grinding the ID, the face, and the OD journals, all in a single setup,” he said. “What we can do is clamp on the pitch diameter of the gears to create a relationship from these diameters that we’re grinding, and then we’re basically cleaning up. We make sure the roundness, surface finish, and all the features for where these shafts and gears are mounting to their end position are true round and are not creating noise or vibration when the gear is being utilized.”
Round journals are needed to create accurate pitch diameters, according to Osborn, and there are two ways to go about it.
“One, we clamp on the rough gear before the gear teeth are ground, and that creates a good round surface that can be put on a separate machine for creating those gear teeth,” he said. “The other option is the gear teeth are finished already, so we need to be really accurate to get the run out between the pitch diameter and the diameters that the gear is running on. On our machine, we can do it two ways: We can have this be the operation before the gear grind or the operation after the gear grind to create those features.”
Streamlining the manufacturing process
One of UNITED GRINDING’s goals is to reduce operator intervention in the manufacturing process, and in order to do that, the company has made big pushes in creating flexible and productive machines that can do the entire part in a single setup, according to Osborn.
“What we’re trying to do is reduce the need for an operator to make a lot of manual corrections that involve multiple steps or having multiple machines throughout the process,” he said. “We’ve done gears recently where, previously, it was done on three machines with multiple part flips. Now, we’re able to do those gears in a single setup on our machine by just hitting the green button once, instead of having to set it up. Every time you have to set up the part again, you’re introducing potential places for error into the process. What we’re really looking to do is reduce the operator intervention and have long productive runs without a lot of manual operations in between them.”
In order to reduce those operations during the manufacturing process or even across machines, UNITED GRINDING has been working to make its machines smarter, especially as tolerances have needed to be tighter and tighter, according to Osborn.
“We’re trying to take away some of the work that is typically needed to be done in secondary processes,” he said. “What we’ve done is develop software that can set up the feeds and speeds of the grind to the operator, so he or she doesn’t have to set up those feeds or speeds based on their history or experience in the industry. We’re allowing younger and less experienced people to get in and manufacture these really tough parts without having all that background and history in the industry for making gears.”
And with the older, more experienced machine workers aging out of the workforce, developing smarter machines is the perfect way to introduce gear manufacturing to the next generation of workers while continuing to make high-quality gears designed for the next level of technology, according to Osborn.
“We’re looking at the people who can grind these parts now that just need basic knowledge of a touch screen or an iPad or things like that,” he said. “We let our software dictate the rest of the features and the process for them. What that allows people to do is to make these parts now when it used to be a ‘feel and sound’ process. Now, it’s more of a science.”
Innovative software solutions
UNITED GRINDING is constantly developing and updating its machine software, according to Osborn. Every time the company has an application needed for a new material or a different grinding wheel, that information is added to the software.
“We develop that knowledge and that database,” he said. “What we say now is we have about 100 years of grinding experience that is embedded in the software to be able to utilize and develop these parts.”
Keeping machine software current means UNITED GRINDING must be vigilant to address any challenges brought by customers, which often means being able to customize machines for individual companies, according to Osborn.
“Every customer has a different challenge, of course,” he said. “We have a great team and a great process here. We have technical people who review every application, and then we have a dedicated person that’s usually specialized for different parts and processes. We have people who are, let’s say, more dedicated toward bearings or automotive production or gears. We have people who have worked on a lot of those applications. When we get a project that comes in — specific to a gear, for example — we have certain people that we’ll go to and say, ‘Hey, this is a new gear application. You’ve worked on gears for a long time.’ We can have them give their expertise on how we should set up the machine, position, the work holding, and all that to fit into the application.”
A lot of that work is done on existing machines that are customized, according to Osborn.
“Most of our machines have something custom about them; even if the base is a basic configuration, usually there’s some application, tooling, spindle, or something special to make it custom for that specific application,” he said. “For gears, usually it’s the work holding. That’s the most complicated part on the cylindrical side. Just using those helical pitch diameter chucks or clamping on pitch diameters or being able to locate those on the machine is pretty integral. We’ve used probes that can find that. We’ve used chucks that can locate on those diameters, and different chuck jaws position the part off the face so we can locate and grind the back of the part and the front of the part in a single setup.”
Durable, quality machines
During STUDER’s 100-year history, the company has been a part of large automotive projects that were extremely successful, according to Osborn, which is a tribute to the longevity and repeatability of the machines.
“We have people who really look at the machines and plan on rebuilding after a certain period of time, and for the STUDER machines, after 24/7 production over a long number of years, there’s often nothing that needs to be rebuilt or redone,” he said. “These machines last a long time. They hold the tolerances that they held from Day 1, and they’re really reliable. And I think, for UNITED GRINDING one of the things we’ve done over the years as we’ve grown our machine base — a hundred years of machines that are out there — not all of them are running, of course. But we’ve grown our service team at the same pace as we’ve grown our machine base, and that’s really allowed us to keep our machines up and running and keep our customers happy. That’s a pretty big accomplishment for a manufacturing company.”
Measurement, Industry 4.0, and more
As UNITED GRINDING looks to the future, it’s not content to keep things status quo. Osborn said the next innovative process on the company’s horizon will involve parts measurement.
“We’re always looking at new ways to measure parts in our machines, and the next step is being able to measure parts on the machine instead of post inspection — especially on gear types of parts where you have more complicated geometries,” he said. “We recently developed a laser-measuring system on the machine that’s able to measure interrupted cuts, like gears. Now, we can measure diameters on the machine while the part is spinning. This is going to give us more opportunity to measure the parts on the machine without taking them off for potential second operations.”
Another part of that innovation, especially to the company’s machine software, is to move its machines into the Industry 4.0 evolution where more connectivity between machine and user will be key, according to Osborn.
“We just came out with a new panel on our machines — we call it the C.O.R.E. panel,” he said. “It’s opened up a wealth of opportunities for us to get into Industry 4.0 and have more of a smart machine and more collaboration with our customers. C.O.R.E. allows the operator to have customizable software so, when he puts his key in, it’s going to display the software how he wants it to look.”
UNITED GRINDING’s Digital Solutions platform offers a software solution to machine connectivity, according to Osborn. This connectivity offers software options that monitor spindle up time, vibration, temperatures, and machine run time — all outside the factory via smartphones or other mobile devices. The next step in this connectivity will lead to predictive maintenance opportunities designed to keep a shop floor at maximum production potential.
Recent innovations aside, the core function of UNITED GRINDING is the actual function of grinding. After all, it’s in the company’s name. And grinding is expected to be even more essential as the technological landscape continues to shift, according to Osborn.
“What we’re seeing in the industry with the electrical vehicle changes and things like that is tolerances are getting tighter, and also the surface finish requirements on parts that used to be able to be turned or machined in different methods are changing,” he said. “So, grinding is actually taking over some of these industries where it really wasn’t in the past. You have to make sure the parts are silent when they run so you don’t have engine noise that’s overshadowing the electric vehicles. I think the future of the industry for us is looking pretty bright just because of the requirements for surface finish as well as the tolerances that are coming out on these types of parts.”
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