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About Company name: Centa Antriebe Kirschey GmbH Headquarters: Haan, Germany Established: 1970 Employees: 450 Products: Flexible couplings and drive shafts for industry, marine and rail applications as well as for power generation 03 The LORC tailored solution is 3.2 metres long, has an outer diameter of about 3 metres and weighs 56 tons electric drive of the LORC nacelle testing facility is capable of generating the full operating torque within milliseconds, adapting it to the given load profile, thereby providing an optimum simulation of real-world wind conditions. Extremely reliable misalignment couplings with an integrated overload unit are required for connecting the drive train and test nacelle. In addition, logistics and on time delivery, especially with a sight on the details of technical design, procurement and manufacturing, transportation and mounting the coupling within only seven months – were also a real challenge. As a solution, a Centawave coupling with a modular design, overload unit protecting all the components against overloads by instantaneous load separation having a length of approx. 3.2 m, outer diameter of about 3 m and weighing 56 tons was developed. Therefore, one of Centa’s big challenges MULTIMEDIA CONTENT This video outlines the benefits of the LORC test center facility in Denmark. http://bit.ly/LORCCenta was adhering to the time schedule by coordinating the material delivery by the suppliers as well as the components and the machining of such big parts. An experienced and effective project management was the key to success. “Various ‘Centanians’ and subsidiaries were involved right from the beginning, starting with the first approach to the customer over design, development, production and material sourcing”, says Lars Haarup, Managing Director of Centa Transmissioner A/S, Denmark. Powerful and capable of compensating misalignments The torsionally stiff coupling Centawave is the newest member in the portfolio of the transmission specialist and is impressive due to its extreme flexibility and power density. The coupling concept of the torsionally stiff Centawave series allows for angular misalignments of up to 12 degrees while compensating for very high axial movements at the same time, and designed for torques between 3 to 20,000 kNm and more. Even a considerable radial movement is reliably compensated in the double- cardanic system version. “Our intention was to develop a coupling that is able to compensate for extreme misalignments, but which is also compact and high-performing with regard to torque-strength, describes Jochen Exner, head of Centa R&D, he continues, “We do have solutions for a misalignment coupling in our portfolio, which are well established on the market, such as the Centalink. The power density of the Centawave, is significantly more pronounced. At the same time, it requires less space, which makes it interesting for wind turbine generators on their slower side, behind the rotor.” The name for this link coupling is derived from its functional principle: angular movement compensated by a wave-like harmonic movement of its links, which allow for uneven angular deflection at the same time. The patented design provides the coupling with kinematics unique to the market. The torque is transmitted homokinetically and entirely free of stimulation and noise. No reaction forces are exerted on the connecting components. In addition, the coupling works backlashfree and without “stick-slip-effect” when compensating misalignments; a significant selection criterion for the decision makers at LORC. Meanwhile, the coupling was delivered on time at the end of June, 2014, and mounted on site at the test dock. Vestas is the first customer renting the test center for 2.5 years. Photographs: teaser LORC Lindoe Offshore Renewables Center, 01 & 02 Centa Antriebe Kirschey www.centa.info 48 MDA Technologies 3/2015
SUCCESS STORY Altra solves vibration issues for large pumps A large raw water pumping station in Malaysia was suffering from severe vibration problems with the drivetrains on a number of large pumps which resulted in regular failures and downtime. When an update to the original parts was unsuccessful in solving the issue, the plant’s managers turned to Altra Couplings to offer a solution. The pumps, which are used to pump raw water, originally been specified with 4-section shafts forming the vertical drivetrain. However, the drivetrains always suffered from vibration issues which caused damage to the pumps’ motors and required regular maintenance, causing downtime. When some of the pumps were due for an upgrade they were fitted with 4-section U-Joint shafts in an attempt to reduce the vibration. Unfortunately the vibration on the new shafts was even worse than before, so the managers decided to look elsewhere for a solution. A spokesman comments: “After the new U-Joint shafts were installed the vibrations were more extreme than they had been before. No more than 4 or 5 of the pumps could run at a time and some of the pumps with U-Joints could never be run. The reduced pumping capacity created local drinking water shortages, hence it was crucial to find a solution to reduce the vibrations. It was clear that we needed to outsource our solution, so we approached Altra Couplings for help.” Altra Couplings is the couplings division of Altra Industrial Motion, a global supplier of power-transmission products, which includes coupling brands such as Huco, Ameridrives, TB Wood’s and Bibby. With such a wide base of product knowledge its sales engineers are able to develop solutions for applications of any size for almost any industry. After a site visit and careful analysis of the pumps and existing drivetrains, Altra Couplings was able to recommend a custom designed, 3-section, Form-Flex Composite driveshaft from TB Wood’s. The upper and lower sections of the shafts used 7” diameter tubing while the centre section used 14” tubing to span past the centre floor bearing location where the vibrations had been most severe. The three driveshaft couplings formed a four story drivetrain which connected the pump to the motor. David Proud, Global Development Director for Process Pumps, Compressors at Altra Couplings, adds: “The Form-Flex Composite driveshaft weigh up to 80% less than steel while still providing the necessary strength to transmit the torque to the pumps. The reduced weight and design, which incorporated a wider diameter at the point where the vibration was at its worst, meant that we were able to significantly reduce the problem.” Initially, a single TB Wood’s solution was installed in one of the worst affected pumps; it was readily accepted by the management, who acknowledged that it contributed significantly to the station’s improved pumping. Till date, more than half of the original installed vertical shaft systems have been replaced with the Altra Couplings. www.altramotion.com Altra Couplings was able to recommend a custom designed, 3-section, Form-Flex Composite driveshaft About Company name: Altra Industrial Motion Brands: Altra Couplings Headquarters: Braintree, Massachusetts Products: elastomeric couplings, Grid and Gear couplings, torque limiters, disc couplings, precision couplings, locking devices MDA Technologies 3/2015 49
