For gear transmissions dfferent levels of requirements with regard to noise excitation have to be matched.
Industrial applications for conveyor belts or cement mills are without doubt much less sensitive with respect to noise emission than military applications, e.g. for navy ship propulsion. However, also for industrial applications the air borne and structure borne noise behavior more and more becomes an important feature.
RENKhas been developing optimum gear units for all aplications with a transmitted power level ranging up to 145 MW. This paper describes requirements and solutions with regard to noise behavior focusing on examples taken from navy applications and wind turbine gear transmissions. The individual approaches have to be a suit-able compromise to meet the challenge of noise requirement and cost optimization without any restriction on gear load carrying capacity. Therefore, there is no general but individual solution for optimum design.
The paper comprises basic considerations with regard to gear noise, noise requirements and measurements at shop and field tests in comparison to gear geometry and calculation results.
Power generation or Navy vessel propulsions are two examples for the application of advanced gear systems. Typical applications are wind turbine mul- iple stage step up gears, or CODOG and CODAG marine gears for up to 30 MW gas turbines and diesel engines up to 7 MW to controllable pitch propellers. In any case, the supplier of main reduc-tion gears has to provide the optimized technology for any kind of installation at utmost interface flexi-bility. This can only be achieved in close Co-operation with power train suppliers, or Navies and shipyards.
Furthermore, in continuous development of tech-nology enhancement, single components are sub-jected to increased refinement such as gear teeth as the heart of gear transmissions for the beneft of optimization of the load carrying capacity and low-est noise performance. To achieve optimum noise behavior, different criteria of gear design have to be observed, such as selection of bearings (damping features) and housing (mass, noise dissipation fea-tures) and gear geometry. In this respect, an ex-treme importance comes to the correct selection of macro geometry parameters as well as tooth cor-rection values, where the proper evaluation of both is supported by continuously adapted calculation methods. However, theory needs to be transferred to real operable gears with the required accuracy applied, and therefore production means such as heat treatment processing and grinding tools are simultaneously to be maintained on the latest stage of technology.
In completion of a modern main transmission gears, the environmental demands on control aspects require an ongoing adaptation. Today, integral pro- rammable logic control (PLC) systems provide an utmost flexibilty, safety and comfort for the opera-tion of reduction gears. The gear is not just a me-chanical transmission – it is developed to a system with functional sub stations interfacing with theplant’s operational environment.