As a renewable and clean energy source, wind power is rapidly developing all over the world. Large wind turbines are giant machinery. Nowadays, many 2MW wind power plants under construction have wind turbine blades with a length of about 40 meters, a rotating shaft with a height of 60 to 100 meters and total weight of more than 200 tons. Therefore, the bearings used in wind power must also be large, with an inner diameter ranging from 100 mm to 700 mm. Some models require bearings with an inner diameter of nearly 2 meters. Bearings for wind turbines require high reliability, because the bearings are designed to keep the windmill running for 20 years; and when the fault occurs, the parts are not easy to replace (the bearing is used at a long distance from the ground). Bearing manufacturers need to have a high degree of computer analysis technology and exquisite skills in materials and heat treatment, and need to master the testevaluation technology for large bearing.

ZYS has been engaged in the technical research and production of wind power bearings for many years. ZYS products for wind power industry include yaw bearings, pitch bearings, spindle bearings and motor bearings. The bearing products are not only sold in the Chinese market, but also exported to many countries and they are fully recognized by users in the wind turbine market.

Main features of wind turbine bearings:

1. Bad use environment.

2. High maintenance cost.

3. High requirement of service life.

Bearings for wind turbines mainly include yaw bearings, pitch bearings, spindle bearings, gearbox bearings, and generator bearings.

Generator bearing

Bearing type: deep groove ball bearings, angular contact bearings.

Working conditions: high speed (1000-1500rpm), high temperature (90-120 °C) heavy load.

Grease requirements: excellent shear stability, good oxidation stability, good wear resistance, excellent low temperature bearing start-up performance.

Spindle bearing

Bearing type: tapered roller bearing, spherical bearing.

Working conditions: low speed (<25rpm), wide temperature range, heavy load, vibration, high humidity.

Grease requirements: excellent wear resistance, good oxidation stability, excellent low temperature bearing start-up performance, good water resistance and so on.

Pitch/yaw bearing

Bearing type: four point contact ball bearing

Working conditions: wide temperature range, heavy load, vibration, high humidity.

Grease requirements: excellent corrosion resistance and wear resistance, excellent low temperature bearing start up performance, good water resistance, good oxidation

stability, etc.

Each wind turbine equipment has 1 set of yaw bearing and 3 sets of pitch bearing (not equipped for the wind turbine below MW), 3 sets of generator bearings (deep groove ball bearings, cylindrical roller bearings), 2 sets of spindle bearings (spheroidal roller bearings), totally 9 sets.

In addition, there are also gearbox bearings. The gearbox has three structural forms. The first type requires 15 sets of bearings, the second type requires 18 sets of bearings, and the third form requires 23 sets of bearings. Thus, the average number of wind turbine bearings is 27 sets.

The structural forms of bearings for wind turbines mainly include four point contact ball bearings, cross roller bearings, cylindrical roller bearings, spherical roller bearings,

and deep groove ball bearings. The yaw bearing is installed at the connection between the tower and the cockpit, and the pitch bearing is installed at the joint of the root

of each blade and the hub.

Wind power bearing production process

1. Control the forging temperature.

2. Control the modulation process to ensure the mechanical properties.

3. Control the depth of the intermediate frequency quench hardened layer on the surface.

4. Avoid micro cracks on the surface.

The cleaning process of wind power bearing

1. Inspection of forging blank

2. Rough turning

3. Finish turning

4. Molding finish turning

5. Heat treatment

6. gear-hobbing and gear-milling processing

7. During drilling, according to customer requirements, it can be treated with blue, phosphating and vulcanization.

8. Rough grinding and fine grinding

9. Demagnetization, cleaning, assembly, surface coating, grease filling, packaging