SPONSORS OF GEARBOX V DD
CHANGING UP A GEAR DIRECT DRIVE V GEARBOX
If the wind industry achieves its forecasted growth, there will be more pressure than ever on wind turbines to last longer and operate with better productivity. A smooth operating gearbox is crucial to delivering a fully functioning, long lasting turbine.
GEARBOXES
Gear boxes are lubricated with oil, and direct drives generally use grease for lubrication. The reputation of gearbox turbines has been somewhat challenged because of reportedly high failure rates. On the other hand a major turbine manufacturer has reported that the mean age of their turbines is 23 years, with excellent gearbox reliability within that.
DIRECT DRIVE
Conversely, direct drive turbines have been criticised for costing more and weighing more than the gearbox alternatives, although lighter weight options are now being developed.
CONFLICTING VIEWS
So there are different, often conflicting views on which type of system is more
WIND TURBINE DRIVETRAINS GEARED V DIRECT DRIVE
Turbine reliability is key to maximising power generation and ultimately it is a direct influencer of cost and profitability. With wind turbine operators focused on driving down the cost of energy, David Brown has worked with numerous collaborators, from customers, industrial partners and academia, designing and developing drive train solutions to deliver these cost efficiencies. Through evaluation of numerous multi-MW wind turbine drive train concepts the company has now identified the optimum solution for offshore systems – an integrated, geared drive train.
RESEARCH AND DEVELOPMENT PROGRAMME
The company’s targeted R&D programme addressed both gearbox and generation equipment including novel axial flux generator technology, for both geared and direct drive configurations. Research showed each option has distinct characteristics that strongly influence both reliability and lifecycle costs. For example, the conceptual simplicity of a direct drive may appear to offer the most elegant
solution, however gearboxes have been proven in a broad range of assurance critical industries to be a highly efficient and reliable means of converting the low speed, high torque of a rotor shaft to a condition optimum for a cost effective, efficient generator.
RELIABILITY PARAMOUNT Ensuring reliability of the turbine driveline is paramount to availability and begins with performance specification and design. The highly variable nature of the wind power generation environment can make identification of service duty challenging, yet any inaccuracy in the specification of the load regime can significantly compromise drive train component reliability. Such risks apply to both direct drive and geared turbines, however the smaller scale of geared system driveline components simplifies the task of design for service reliability.
ACCESSIBILITY CONSTRAINTS In addition, accessibility constraints offshore lead to the necessity of modular drive
The right lubrication can help to enhance performance, lifetime and productivity, as well as reduce downtime – all of this can help to deliver commercial benefits and competitive advantage.
Daryl Luke
Castrol Industrial
www.castrol.com
train architectures that simplify the task of assembly and installation and geared drive trains intrinsically provide this. With a geared drive train all subsystems and components can be removed and replaced with no disturbance to the primary hub/blade assembly, rotor mainshaft and bearings.
CONCLUSION – INTEGRATED GEARED DRIVE TRAIN
With all this in mind it is a truly integrated geared drive train that offers the most reliable, cost effective and efficient solution to the industry’s need to drive down the cost of energy. The direct drive train has higher acquisition and installation costs due to larger, heavier components and is relatively unproven technology in the offshore wind environment.
Structural design, thermal effects, assembly and maintainability are also challenging for multi-MW scale direct drive generators. By contrast, geared or integrated medium speed generators utilise proven technologies, offering turbine operators higher reliability and the least risk.
These lower weight, compact and modular configurations facilitate manufacture, installation, maintenance and where necessary, removal. Engineered with integrity, the combination of these benefits of a geared drivetrain system provides a robust solution to the goal of minimising the cost of energy production.
David Brown
www.davidbrown.com www.windenergynetwork.co.uk 47
favourable. What is clear, however, is that improvements in both technologies will continue as the wind power industry grows. At the moment gearbox turbines provide the majority of systems.
LUBRICATION ESSENTIAL Therefore lubrication is essential to eliminate many of the problems of gearbox maintenance.
In order to determine the right lubricant it’s important to identify the differences between the direct drive systems and gearboxes that power the turbines.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108