Maintenance crews acknowledge that frequent lubrications with small amounts of grease extend the working life of bearings and seals. But long hours of hub crawling is physically and mentally demanding work. A useful idea is a centralized and automated lubrication system for wind turbines. One version for lubrication tasks in a nacelle can also handle main-shaft bearings. The equipment also reduces lubricant consumption. Most equipment of this sort makes refilling the grease pump simple and quick. Centralized lubrication systems are said to reduce turbine operating costs, increase operational reliability, and extend service intervals.
Another lubricator, a 24-Vdc electric-powered device, greases heavy-duty equipment without tapping into hydraulic or pneumatic lines. It is said to set up easily and fit directly onto a 5-gallon grease pail. It works with a hose reel and hand grease gun, and can be used stand-alone or with a centralized lubrication system. It weighs about 24 lbs. A metal follower plate has a wiping seal on its circumference. The follower plate works in straight or tapered pails, and ensures the complete removal of grease from a container. The pump can refill automated lubrication systems inside wind turbines or act as the driving pump behind the system. Its maximum discharge pressure of more than 4,000 psi is one of the industry’s highest. Discharge volume is 80 to 120 grams/min in continuous operation and 70 to 80 grams/min in 30-min periods. Operating temperatures range from 14 to 104°F.
Trends: Hydraulic-component companies are designing more complete lubrication-oil systems for wind-turbine gearboxes. These systems would come with filters, pumps, valves, coolers, and heaters as well as manifolds and piping to connect components. The advantage here is that the assemblies are probably more thoroughly tested and proven and carry the assurance of reliability from a qualified supplier.
Tools: The equipment used to maintain the machinery in a nacelle are much like those used by other technicians except they are fitted with tethers to prevent them from falling many feet to the ground. See the safety and bolting sections for additional discussions.
Cold weather filters: A recent element intended for wind turbines is said to ensure sufficient and effective filtration levels and prevent the filter from going into bypass mode, an event common to cold starts. Also, offline filters can remove water from oil. Existing systems on turbines can be upgraded with these capabilities.
Filed Under: Lubricants, O&M