Wind Turbine Gearbox Oil Maintenance with Rotary Piston Pump

Wind Turbine Technology

Wind power is one of the most common and preferred renewable energy sources, this technology consists of transforming wind power into electricity via wind turbines, the wind spins the blades causing the shaft to rotate that is connected to a gearbox, designed to increase the rotating speed so that the motor generator can produce electricity. Wind turbines typically stand anything from 75 to 180 metres tall, therefore maintaining the components can prove to be quite challenging. The gearbox is a critical component; hence its lubrication is key for correct operation and reliability, it is recommended for the gearbox oil to be analysed periodically and changed to avoid failure as this could lead to catastrophic damage and significant costs.

Enquiry from a UK Wind Turbine Maintenance Specialist

Our customer, a UK wind turbine maintenance specialist was having difficulties servicing the gearboxes installed at the top of the turbines, the problem was that their current hydraulic gear pumps could not handle the rise in viscosity they were experiencing due to temperature drop. The oil temperature can be anything between 10 to 40 °C and as a result they were struggling to service the equipment in an efficient and timely manner. This client is responsible for maintaining around 150 wind turbines and therefore cannot afford for the engineers to spend more time than necessary on each unit. The requirement was for a small/light weight electrically driven oil pump, yet reliable and capable of producing a minimum of 15 l/min while handling viscosities from 320 to 2000 cSt.

North Ridge Pumps Robust Rotary Piston Pump Solution for High Viscosity Fluids

Having taken everything on board, we selected one of our rotary piston pumps for this application as these units are ideal for high viscosity fluids as well as being extremely robust. We supplied the NR-RPPACCM01-0.75 model, a ¾” close coupled self-priming positive displacement pump with a 0.75 kW three phase motor, running at 1500 rpm, this particular configuration has a capacity of 25 litres per minute at a discharge head of 5 metres. It is extremely compact as the pump is directly coupled to the motor and the absence of a gearbox also makes it very light weight. The total weight of the oil pump is only 13.5 kg, this is incredibly important and beneficial to our customer as they have to carry the pump to the top of the wind turbine in order to empty and change the gearbox oil. We installed a built-in relief valve to protect the gear box from over-pressure, the relief-valve opens and recirculates the oil in the pump head if the pressure gets too high.

Our NR-RPP range of rotary piston pumps can handle viscosities from 10 to 20,000 cSt and temperatures up to 300 °C, our largest model from this range can deliver a maximum flow rate of 1066 l/min. These positive displacement pumps are also reversible and have great suction lift capabilities, furthermore they can maintain a fantastic volumetric efficiency even when pumping highly viscous fluids such as resins, molasses, adhesives, bitumen etc.

All our rotary piston self-priming pumps can be supplied with ATEX motors for flammable liquids or/and non-safe hazardous areas. Some models are available with heating or cooling chambers to maintain the fluid viscosity.

Specific details of the pump supplied is as follows: