Drive & Control Technology for Wind Turbines The Drive & Control Company 2 Technology for Wind Turbines | Product Overview Everything is Going Round: Drive & Control Technology Wind energy continues on its Broad Range of Supplies road to success by greatly No matter whether the traditional increasing its share in electri- concept comprising rotor, gear- cal power production on a box, generator or a direct-drive worldwide basis. The nominal solution is involved: Rexroth offers power of wind turbines has matching gearbox and hydraulics risen from 100 kW to 3,000 kW. solutions for any type of wind Now the first 5-MW installa- turbine. Within our mechanical tions are harvesting power. drive technology segment we Rexroth as producer of hydrau- develop and manufacture all types lic and gear technology sys- of gearboxes required for wind tems is a competent partner turbine installations: efficient and comprehensive supplier generator gearboxes, highly precise to manufacturers of wind yaw drives for permanent wind turbines. tracking purposes and compact pitch drives used for rotor blade adjustment. Being the world’s leading supplier of industrial hydraulic equipment we also offer hydraulic solutions for wind energy applications: our supply range includes highly dyna- mic hydraulic pitch adjustment systems, reliable drive train brakes as well as yaw drive brakes. Bosch Rexroth. 4 The Drive & Control Company Rotor Blade Adjustment 6 Electromechanical 7 Rotor Blade Adjustment Hydraulic 8 Rotor Blade Adjustment Generator Gearboxes 10 for Systems up to 2,000 kW Differential Gearboxes 12 for Multi-Megawatt Turbines Yaw Drives 14 Yaw and Drive Train Brakes 16 Service 18 4 Technology for Wind Turbines A Company on the Upswing: Good Reasons for Rexroth Drive systems to be incor- Experience and Know-how Competence in Marketing porated in wind turbines must For about 100 years Rexroth have and Design satisfy many specific needs: been producing drive system com- The importance of industry- Variable wind loads, higher ponents. Already in the early specific drive system solutions is outputs, less available instal- nineties we built gearboxes for 3.2- steadily growing. Rexroth has taken lation space and minimum MW turbines and thus were among these trends into account by having weights are just a few techni- those that from the beginning took established market-oriented appli- cal requirements designers part in the technical development cation centers. In the application and engineers must observe of wind turbines. Long-standing center renewable energies, product aside from climatically induced contacts with leading universities experts are at your disposal, who strains. and renowned antifriction bearing are not only specialized in drive manufacturers help us to improve technology and hydraulics, but are our products on a constant basis. also familiar with the specifics of Rexroth concentrates its know-how your application. This enables us and technical expertise in its wind to provide tailored solutions for energy product sector and thus each wind turbine project. strengthens its position as sought- after partner of wind turbine manu- Being able to offer customer-specific facturers. engineering services is thus one of our strong points. The advantages our clients can thus expect from us are the result of decades of experi- ence with planetary gears and Simulation hydraulic components as well as our innovative power. Moreover, unpleasant surprises may be avoided thanks to our know-how in engin- eering, manufacturing and testing. Before a complex component is actually manufactured, we have made sophisticated FEM calcula- tions. Rexroth gearboxes are designed for maximum safety and reliability. In their design and development activities, our experienced engin- eers are assisted by modern com- puter software for gearing design and component optimization. Measurements on built-in proto- milling and grinding operations Heat treatment types are performed based on many involved in the manufacture of years of experience. In the field gearbox components and gear teeth we carry out, for example, air- is continually being further devel- and structure-borne noise as well oped and forms the basis of the as torque and load measurements. highest possible product quality. Rexroth invests systematically in Top Performance from advanced production machinery to Start to Finish ensure maximum quality and We know that quality greatly economic efficiency. depends on selecting the right suppliers. Therefore, our suppliers On our test benches all our com- must satisfy the same high stan- ponents are checked to most dards we have adopted. Quality stringent quality criteria prior to also means doing things right from shipment. In our manufacturing the start: from machining, to heat facilities we subject our generator treatment and assembly, including gearboxes to full-load tests up to a inspection, painting and shipment. nominal power of 5 MW; special In this context, our quality man- test configurations may be set up agement system to DIN EN ISO to comply with customer specifica- Grinding 9001:2000 is the basis and guarantor tions. Advanced software packages of a consistently high quality level. enable temperature and noise Another area of major concern to characteristics to be recorded. Assembly of REDULUS GPV Rexroth is environmental protec- tion. For many years we have also been operating an environmental management system to DIN EN ISO 14001 at our locations. Modern heat treatment methods have a decisive impact on the quality of gearings and components. Our vast experience in heat treatment technology is a most significant quality factor ensuring our gear- boxes meet maximum standards in terms of strength, load-carrying capacity, compactness and service life. The know-how we have gained over several decades in the various 6 Technology for Wind Turbines | Pitch Drives MOBILEX GFB Facing the Wind Optimally: Rexroth Solutions for Rotor Blade Adjustment 100 m above ground. A strong wind is blowing at this height. The pitch drives of the wind turbines – com- pactly arranged at the root of the three rotor blades – constantly rotate with the rotor and make sure the blades are correctly po- sitioned. They must meet highest requirements with respect to de- sign and functional safety. Aside from reliability, precise position- ing is of utmost importance. By providing both hydraulic and electromechanical pitch drives, Rexroth is capable of satisfying these technical needs. Technology for Wind Turbines | Electromechanical Pitch Drives MOBILEX GFB 7 MOBILEX GFB Pitch Drives The Rexroth supply scope includes a complete range of MOBILEX GFB planetary gearboxes for all wind turbine sizes. To this end we can draw on 40 years of experience in the manufacture of swing gears for mobile equipment, such as exca- vators or cranes. The proven tech- nological solutions in that field have been advanced to electro- mechanical pitch drives. The pitch drive supply range spans from small, two-stage planetary gears with output torques of about 1 kNm and ratios of 60:1 to three-stage types featuring output torques of about 20 kNm and ratios of 200:1. These space-saving drives consist of a compact two- or three-stage planetary gear unit equipped with output pinion and electric motor. Since electromechanical pitch drives are constantly rotating together with the rotor hub they are provided with special seal sys- tems. Where confined mounting Technical Features situations are encountered, an MOBILEX GFB Pitch Drives: angle-type input gear stage is avail- • Output torques from able as necessary. 1 to 20 kNm • Ratios ranging between 60 – 200 • Compact, space-saving two or three-stage planetary gearboxes • Optional bevel gear stage • Sturdy antifriction bearing • For the attachment of electric motors • Easy to install • Convenient oil change • Low-noise running charac- teristics 8 Technology for Wind Turbines | Hydraulic Pitch Drives Hydraulic Pitch Control The hydraulic pitch drive com- bines all desirable characteristics in a single system: high positioning forces, compact size, distributed intelligence, high dynamics as well as long service life and reliability. Plug & Play After assembly all pitch drives are checked for correct functioning on the test bed. Moreover, our staff makes sure all electrical modules are attuned to each other. This enables the pitch drives to be mounted and put into operation as soon as they arrive on site. Thus complex matching of signals and other electrical characteristics can be dispensed with – plug & play. Fail-Safe Properties The Fail-Safe operation of the individual pitch drives is achieved by establishing logical connectives between the individual hydraulic components. 9 Lead-in Their functions are based on purely High-quality hydraulic compo- mechanical principles and are nents from company-own fabri- highly reliable. Nevertheless, should cation, amply sized filters for highest complications arise all the same, oil purity as well as coolers and the rotor blade, powered by hydrau- heaters ensuring optimum operat- lic accumulators, will move into ing temperature are prerequisite to the safe end position without ex- a long service life. ternal control action being neces- sary. Using hydraulically pressure- controlled variable displacement Distributed Intelligence pumps in conjunction with hy- Proportional valves with inherent draulic accumulators results in processors and storage modules high actuating forces and spare are capable of performing all neces- capacity