Flexible Gear Cutting Solution by EMAG
HKS Dreh-Antriebe has invested in high-efficiency gear cutting solutions. The company has opted for the R 300 hobbing machine from EMAG Richardon.
Rotary actuators are a jack of all trades. Known to find use in case an object needs to be rotated or swivelled like the case with the production of utility vehicles, ships, machines, power plants, and production areas, they support a diverse range of applications. This broad spectrum of applications defines the challenging tasks that HKS Dreh-Antriebe GmbH faces. EMAG Richardon’s vertical hobbing machines create special external gearings on the centre piston of the rotary actuator. Two of these are installed at the HKS location in Hesse, in Germany, with a new R 300 unit installed at the Neukirch plant, in Saxony. Known to have a stringent set of requirements to be met coupled with its diverse applications, the hobbing machine must be retooled frequently. The flexible gear cutting solution must deliver flawless gearing quality.
Executives at HKS are claimed to have made an “all-round positive” assessment of this new investment decision.
Being able to accelerate, brake, precisely position and then hold an object in place is a common request. With such a teething requirement in a diverse range of applications, rotary actuators are found everywhere. One frequently runs into this technology on a day-to-day basis. For instance, when a garbage truck from the local disposal service lifts the container and empties it with a swivelling motion, more often than not a powerful HKS actuator is providing the lifting power. The same applies for the fire department’s rescue platforms or particularly large excavator shovels. At the other end of the spectrum, rotary actuators from HKS are used in industrial production, for example, to ensure precise tipping of collection bins, quick movement of mixing devices or easy completion of a tool changes on a machine. Rotary actuators are based on various actuator principles and feature different performance characteristics and sizes. Given all this diversity, it is said to lay the foundation for success at HKS. Explains Mario Vogt, Head of Operations at the HKS plant in Neukirch, “At the end of the day, for us, it’s always a matter of developing very precise actuators, being able to durably withstand the highest loads and work efficiently.” “We, therefore, develop highly customised solutions for many customers and operate our three production sites in Germany with high vertical integration. Our vast experience flows into each and every development. This is the basis on which we have become one of the leading manufacturers in this field worldwide,” he adds.
Focus on Quality and Flexibility
A particularly challenging type of gear production becomes obvious when one takes a look at the various operating principles of rotary actuators. Take helical rotary actuators, for instance. In this type of actuator, the linear movement of an actuated piston is converted into the required rotary motion. The piston’s high-helix thread is then combined with the internal gearing of a cylinder that surrounds it. The longer the linear movement of the piston, the greater the rotational movement will be. The principle is said to be as simple as it is effective. However, depending on the area of application, a tremendous amount of force may also be placed on these gearings. The typical areas of application for HKS torque motors are in the industry and at places where
engineering demand reliability. This is why only extremely stable and precise gearings are said to be produced. Add to it, the fault tolerance is zero.
The fact that HKS executives approached EMAG with this challenge is no coincidence. Two Richardon hobbing machines are used at the production site in Wächtersbach, Hesse. Their reliability and efficiency are expected to make an impact at the Neukirch site, considering that the existing gear-cutting machines are ageing. Mentioned Vogt, “One of our goals was to handle growing production volumes for gears at a higher machining pace since our technology is being implemented in a growing number of application areas.” “At the same time, retooling the hobbing machine must be very fast and easy, since our batch sizes can range from one to 50. Batch size changes occur almost daily. That’s why it’s important for us that the retooling process can be completed within a few minutes, depending on the component. Production starts immediately once we’ve run in the machine with a sample,” he mentions.
Performance Booster
The R 300 vertical hobbing machine from EMAG Richardon has been running at HKS since March 2019. Throughout this time, there has been a tremendous increase in performance when compared to the previously used technology: the operation time has been drastically reduced from up to three hours to about 30 minutes when machining very large gearings. At the same time, the tool life of the hob used has increased by approximately 30 per cent. This means that tool costs are decreasing at HKS. To sum it up, the vertical hobbing machine is able to machine module 3 external gearings from 90 to 350 millimetres (4 – 14 in) in width. The R 300 vertical hobbing machine from EMAG Richardon has been running at HKS since March 2019. Throughout this time, there has been a tremendous increase in performance when compared to the technology used previously. The operation time has drastically reduced from up to three hours to about 30 minutes when machining very large gearings. At the same time, the tool life of the hob used has increased by approximately 30 per cent. This means that tool costs are decreasing at HKS. To sum it up, the vertical hobbing machine is able to machine module three external gearings from 90 to 350 millimetres (four to 14 inch) in width. The pistons generally range from 200 to 500 millimetres (eight to 20 inch) in length and weigh between two to 200 kilograms (four to 441 lbs). “This broad range of components is directly linked to a particular strength of EMAG Richardon’s technology and built on exceptionally generous fundamental design principles according to Michael Ossot, Sales at EMAG. “We value the large machining area with long travel paths, as well as the wide range of speeds and performance capabilities, which allows us to machine components of all different sizes, ” he mentions. The machine also stands out because of a variety of details in its design. For instance, the base of the machine is made of high-quality cast iron, said to reduce vibrations. The machine is also very thermostable. The workpiece table with torque motor is another important aspect since its direct drive is free of wear, backlash, and maintenance, and very precise in its movements. This benefits precision during the machining process. The double V guideways on all axes are another distinctive mark of quality.
Great Experience with this Technology
In 2017, the EMAG Group acquired Richardon and gained their extensive experience in gear cutting for large components. It was important to HKS that the transition did not lead to any technological changes to the design of the machines, as confirmed by Vogt. “We have had a great experience with this technology and obviously wanted to establish the same efficiency and flexibility at our Neukirch site without any change in mechanical engineering,” he said. EMAG according to Vogt was able to guarantee this. “We’re continuing to see the benefits of our investment decision. The machine allows us to produce significantly larger unit volumes in a comparable time period,” he added. Considering that rotary actuators are continuing to be implemented in a growing number of application areas and the market for this technology is growing, this is a key enabler of our success, signed off Vogt.