Wind Turbine Lubrication
The main, pitch and yaw bearings inside a wind turbine's nacelle and hub sit a long climb above anyone who could grease them by hand, on a machine that has to keep turning through the climb. We supply the automatic lubrication systems that feed those bearings on a schedule: grease pumps that run off the turbine's own 12 V or 24 V supply, progressive distributors that feed every point in a fixed sequence and report a fault back down the tower, factory-fit to nacelle and hub equipment builders in India and as retrofit kits for wind farm operators.
The lubrication points
What a turbine lubrication system feeds
The bearings that turn: the yaw bearing under the nacelle, the main bearing behind the hub, and the pitch bearing at the root of every blade. The gearbox oil circuit and the generator windings are separate systems and are not fed from this one.
Point 1
Yaw bearing & gear
The bearing and open gear teeth the whole nacelle turns on to keep the rotor facing into the wind. It moves slowly and only when the wind shifts, but it carries the full weight of the nacelle, hub and blades on every turn.
Point 2
Main bearing
The bearing that carries the rotor shaft into the nacelle, taking the full weight and thrust of the hub and blades at a slow, continuous rotation speed. Slow rotation is exactly the condition that starves a bearing of a self-generated oil film, which is why it depends on a fed one.
Point 3
Pitch bearing
The bearing at the root of each blade that lets the blade rotate on its own axis to adjust pitch. It is mounted in the hub, rotates continuously with the rotor, and is fed by its own pump and distributor riding along with it rather than by the nacelle's system.
Not this system
Gearbox & generator
The gearbox runs its own circulating oil system with its own pump, filter and heat exchanger, and generator bearings need an electrically insulating grease to avoid current-induced pitting. Neither is fed from the yaw, main or pitch bearing system, and neither should be.
The architecture
Why a turbine runs two lubrication systems, not one
The pitch bearing is the reason a turbine cannot be fed from a single pump. It sits in the hub, which rotates continuously with the rotor, while the yaw and main bearings sit in the nacelle, which does not. Piping grease across that rotating joint would need a rotary union at the hub centre, so instead the turbine carries two self-contained systems: a nacelle-mounted pump and distributor feeding the yaw and main bearings, and a second, hub-mounted pump and distributor feeding the pitch bearings at each blade root, rotating with the assembly it serves. Both use the same progressive distributor architecture for the same reason it suits any machine nobody is standing next to: each piston completes its stroke before the next moves, so a blocked line stalls the whole block visibly instead of starving one bearing quietly, and a block fitted with an indicator pin can be checked without a climb. See how the three architectures meter a dose and choosing the right distributor.
The nacelle unit is built the same way as a construction plant system: a ZJ high pressure pump feeding an SD2 block, rated to 30 MPa against the distributor's 25 MPa, so the circuit is built to the distributor's figure. The hub unit works under tighter space and weight limits, riding on the rotor itself, which usually favours the smaller ZD medium pressure pump at 18 MPa over the larger ZJ, paired with its own SD2 block sized to the blade count.
| Point | Location | Lubricant | Herg components |
|---|---|---|---|
| Yaw bearing & gear | Nacelle (stationary) | Grease | ZJ high pressure pump + SD2 distributor |
| Main bearing | Nacelle (stationary) | Grease | ZJ high pressure pump + SD2 distributor |
| Pitch bearing (per blade) | Hub (rotating) | Grease | ZD medium pressure pump + SD2 distributor |
| Service & commissioning top-up | Either unit | Grease | NKGH manual grease pump, 10 MPa |
| Line branching | Either unit | N/A | TH joint fitting, 2 to 10 outlets |
| Monitoring | Either unit | N/A | Pressure switch, gauge, filter, level indicator |
Built for the nacelle
Running unattended, a long climb up
The ZJ high pressure pump runs electrically at DC 12 V or 24 V off the turbine's own supply, rated at 30 MPa through one or two outlets, each with its own piston mechanism. The housing is IP55 and a paddle vents air out of the grease as the pump works, which matters on a unit that is topped up on a scheduled visit rather than watched day to day. Where hub space and weight are the constraint, the ZD pump, rated IP65, gives a step up in sealing in a smaller, lighter package.
A turbine site is exposed, not usually arctic: onshore wind in India runs through heat and monsoon rather than the deep sub-zero cold a European or offshore site can see, so the ZJ's −35 °C to +80 °C rating and the SD2's −20 °C to +80 °C rating cover the climate the system actually has to run in. Grease grade still has to suit the site and the bearing: see choosing the right lubricant for the grade a given climate and duty calls for.
Because nobody is standing next to a bearing 80 metres up, monitoring is part of the specification, not an extra. The ZJ can report a pressure signal through a pressure switch fitted to the system and a level signal through a level switch, so a blockage or an empty reservoir raises a fault that shows up in the turbine's own monitoring rather than being found on the next scheduled climb. Every product comes with an installation and operating manual.
Who we supply
Factory-fit for nacelle builders, retrofit for wind farm operators
Nacelle & hub equipment builders
OEM production supply
We supply lubrication systems against OEM production schedules, engineered to the bearing count and point layout of the nacelle and hub assembly, with consistent specification and batch documentation for every unit. Start with the pump range and the distributor range and we will match them to the machine.
Discuss an OEM programme →Wind farm operators & O&M contractors
Retrofit & replacement
A turbine running on a manual greasing schedule can be retrofitted during a scheduled maintenance visit: a pump and distributor sized to the yaw and main bearing points in the nacelle, and a second unit sized to the pitch points in the hub. We also supply drop-in replacement pumps and distributors, with fault finding guidance online for a system already in service.
Ask about a retrofit →Common questions
Wind turbine lubrication, answered
Which points does a wind turbine lubrication system feed?
The bearings that turn: the yaw bearing and gear under the nacelle, the main bearing behind the hub, and the pitch bearing at the root of each blade. The gearbox oil circuit and the generator bearings are separate systems and are not fed from it.
Why does the pitch bearing need its own pump?
Because it moves. The pitch bearing sits in the hub and rotates continuously with the rotor, while the yaw and main bearings sit in the stationary nacelle. Rather than pipe grease across a rotating joint, the hub carries its own pump and distributor and turns with it.
Why progressive rather than another distributor?
Because it fails visibly. Each piston must complete its stroke before the next moves, so a blocked line stops the whole block instead of starving one bearing quietly, and a block with an indicator pin can be checked without a climb. On a bearing 80 metres up, that property matters more than the extra outlets a different architecture would give.
Does the pump run off the turbine's own supply?
Yes. The ZJ and ZD pumps are electrically operated at DC 12 V or 24 V and connect to the turbine's own supply. No separate mains feed is needed in the nacelle or the hub.
What pressure does the system run at?
The ZJ pump is rated at 30 MPa and the SD2 distributor at 25 MPa, so the circuit is built to the distributor's figure. In the hub, where space and weight are tighter, the ZD medium pressure pump at 18 MPa is usually the better fit.
Can the system handle an Indian wind site's climate?
Yes. The ZJ pump is specified from −35 °C to +80 °C and the SD2 distributor from −20 °C to +80 °C, which covers the heat and monsoon conditions an onshore Indian site runs through. See choosing the right lubricant for the grease grade the site and bearing duty call for.
How many points can one distributor feed?
An SD2 assembly of three to ten blocks covers 1 to 20 points per combined distributor, enough for either the nacelle unit's yaw and main bearing points or one hub unit's pitch bearing points on most turbine designs.
Will a blocked line be noticed inside the nacelle?
That is what the monitoring is for. A pressure switch fitted to the system gives a pressure signal and a level switch gives a reservoir signal, both of which the ZJ can report, so a blockage or a dry reservoir raises a fault rather than waiting for the next scheduled climb.
Can it be retrofitted to a turbine already in service?
Yes. Retrofitting is done during a scheduled maintenance visit: existing grease points are replaced with pipe connections fed from the distributor, without modifying the nacelle or hub structure. Send us an enquiry with the turbine's bearing points and access arrangement.
Running a turbine on a manual greasing schedule?
Tell us the turbine's bearing points, access arrangement and supply voltage, and we will come back with the nacelle and hub pump packages that fit, for one retrofit or a production run.