Centa’s Quality Assurance Excels

CENTA is the first company worldwide to which Germanischer Lloyd (GL) has conferred the responsibility for alternative product certification of type-approved couplings. In the future, CENTA will have the authority to carry out acceptance testing and final stamping of those couplings that have previously been classified as approved types. These tests must be performed in accordance with the “Alternative Product Certification,” a modular certification system developed by Germanischer Lloyd (GL). The approval becomes valid by their joint signatures on the appropriate product certificate.

CENTA is one of the leading manufacturers of flexible drive components worldwide and has been supplying couplings for marine applications for more than 20 years. In 1990, the company’s quality management system was first approved by DIN ISO 9001. All subsequent audits were passed successfully, and recently the classification society Det Norske Veritas (DNV) attested that the coupling manufacturer supports a higher-than-average quality management system.

Several international classification societies, such as the Det Norske Veritas (DNV), Nippon Kaiji Kyokai (NKK), and the Maritime Register of Shipping (MRS), have granted CENTA the authority to use their approval stamp on its series couplings. CENTA has a stock of approximately 65 approved types. In 2007, roughly 2,000 certifications by several classification societies were carried out on CENTA’s premises. In the future, CENTA will be the first manufacturer worldwide to be granted approval by Germanischer Lloyd (GL) to perform acceptance tests on its own flexible couplings up to 100 Nm.

Germanischer Lloyd (GL), one of 10 internationally recognized classification societies, has developed technology and quality standards for more than 140 years–standards that ensure the safety of more than 6,500 ships all over the world. “We have maintained close cooperation with several classification societies for more than 20 years”, says Gerhard Kirschey, founder of CENTA Antriebe Kirschey GmbH. “We continually strive to improve the quality of our products and processes. Approval by Germanischer Lloyd for carrying out acceptance testing of our couplings on our own, in-house, indicates that our quality management system is on the right track”, Kirschey explains. “We are very proud of this sign of confidence and confirmation of our efforts, which are supported by our employees’ high commitment level.”

Slip Systems for Wind Turbine Generator Protection

CENTA produces an enhanced version of its Torque Hub, the slip clutch which offers a simple and low-cost design for torque overload generator protection.

In wind power plants, electrical circuit problems are known to cause short-term torque peaks. In this event, slip clutches protect the costly gearbox against overload by slipping at a defined maximum torque in order to temporarily interrupt the drive.

The slip process takes place not on the generator shaft surface, but inside the CENTA Torque Hub, which is mounted on the generator shaft in the coupling’s clamping set.  CENTA’s latest development in slip systems-”CENTA Torque Set”-now positions the slip unit to the middle section of the shaft. By relocating the slip function, manufacturing tolerances at the generator shaft no longer cause variations in the slip torque, resulting in improved accuracy of the slip function.

Another advantage of the new design is that the slip system is made to be pre-mounted as a complete unit. The maximum torque is set on a certified test bench according to the manufacturer’s requirements and documented in a test report, eliminating the need for on-site adjustments.  The low-maintenance slip system is also designed to allow for multiple slip processes (> 200) without having a major impact on the slip torque setting. Depending on the size, a torque range of up to 120 kNm is covered. The new slip system can also be provided as a low-cost system component which does not include the coupling unit.