Special bearings for wind power generation

Descripción del producto

Clean energy is one of the solutions when consideration must be given to both industrial development and environmental protection. By physical methods transferring the endless nature energy into electricity without impacting the environment, it is the very way that most governments commit to develop. Wind power generation is an option other than solar power, geothermal power and tidal power generation in these years.
A wind power generator is composed by three major parts, Tower, Blades and Primary generator. All these major parts need various special bearings to achieve their performances. Based on our experiences of large bearings and combined R&Ds with our alliances, Sino Precision is developing and manufacturing high quality and durable special bearings for wind power generators.
Better environment is something that we concern too.
 
Kinds of special bearings for wind power generator
Usually, there are three kinds of special bearings, a yaw bearing, three pitch bearings and a set of transmission bearings (spindle and gearbox bearings) in a typical wind power generator. Sino Precision supplies yaw bearings and pitch bearings.
1.          A yaw bearing is applied at the joint between the tower and the cockpit of the generator. Four contacting points slewing bearing and cylindrical crossed rollers slewing bearing usually are the candidates of yaw bearing.
2.          A pitch bearing is applied at the joint between each blade and the hub. Single row and double rows four contacting points slewing bearing usually are the candidates of pitch bearing.
 
The concept of designing a special bearing for wind power generator
Generally, the life span of a wind power generator is not less than *0 years and its maintenance cost is not cheap. Thus, the service life of those special bearings for the generator is required for *0 years at least as well. But the working conditions of those special bearings are quite complicated when driven by wind. The bearings have to withstand both high impact and vibration very frequently. Therefore, a material with very high mechanical strength is required for these bearings, where alloy *2CrMo is adopted for the bearing ring. The hardness of the bearing ring is increased to **0 **0 HB by integrate quenching and tempering treatment and the hardness of its race way is even improved to *5 *2 HRC by particular surface quenching to ensure the impact deformation and the contacting fatigue will not occur during the required service life.
There are impacts as well in between gear and the gear of bearing ring. Thus a particular surface quenching is required on the gear of the bearing ring to ensure the low temperature impact resistance not less than *7J under —*0℃ Akv. And this property is negotiable with customers.
 
Moisture-proof treatment for the special bearings
Wind power generators may be polluted by air when they work at wildness where they usually are located. Their yaw bearing and pitch bearings are opened to the air and may be polluted as well. A high humidity environment will corrode the bearings too. Therefore, a particular anti-corrosion surface treatment is applied on the bearings. Instead of applying high environmental pollution zinc plating, we adopt thermal spraying galvanized treatment. There even is an additional special painting treatment on the bearings external layer if necessary.
The clearance of pitch bearings is set to negative slightly to reduce the fretting wear in order to withstand high impacts and high vibrations on blades cause by wind. A specialized seals for wind power generator made by Germanic Simrit (C.F.W.)^R are adopted on our bearings. These seals are low temperature resistance, corrosion resistance and wear resistance, and heavy duration.