environment to make impact function tests.

This standard yaw, pitch wheel bearing rings cryogenic impact energy requirements: -20 ℃ Akv not less than 27J, cold condition Akv value can be determined in consultation with the user. Wind turbines may operate in very cold areas, the ambient temperature as low as about -40 bar, the bearing operating temperature of about -20 ~ C, bearing in low temperature conditions must be able to withstand large impact load, therefore, requires the bearing rings The material must be done after quenching temperature impact test, take part on the Precision bearing rings made of sample or with the same performance and the same rings under the sample heat treatment conditions, at -20 ~ C environment to make impact function tests.
Bearing ring
?As the wind turbine bearing transmission accuracy is not high, but relatively large diameter ring gear, gear modulus is relatively large, therefore, the general level of accuracy required by GB/T10095.2---2001 gear in the 9 or 10. However, due to operating conditions between the pinion and ring gear bearing has an impact, therefore, the bearing ring gear tooth surface to be hardened pinion tooth surface hardness generally 60HRC, taking into account other life design, hardened gear tooth surface hardness requirements of not less than 45HRC.
Clearance
?Yaw, pitch bearings have special clearance requirements. Relative to the yaw bearing, pitch bearing the impact load is relatively large, the wind to shake the leaves are large, so they requested the pitch bearing clearance should be zero or slightly negative clearance clearance values, so that the vibration situation bearing can be reduced under fretting.
Requirements for the small yaw bearing clearance values, ie 0-501 ~ m. Further, since the wind turbine yaw and pitch rotation of the bearing by the drive motor, the bearing clearance in the negative state or a small clearance in order to drive the motor can be driven, Therefore, the bearing assembly is required after the starting frictional load measurement torque, specific torque values ??differ according to the host of the drive system are not the same.
?Preservative treatment
Work in the field of wind turbine equipment, and yaw, pitch bearing the exposed part will be subject to atmospheric pollution and high humidity environments may cause corrosion of the bearing base, so the exposed yaw and pitch bearings the site requirements for surface corrosion treatment, commonly used galvanized. If necessary, outside zinc coating paint protection treatment