Wind turbine yaw, pitch bearing code method using JB / T 10471-2004 turntable bearing the code, but in the wind turbine yaw, pitch bearings, double row four point contact ball bearing wheel bearing This structure bearing the code is no requirement of JB / T 10471-2004, double four-point contact ball slewing bearing the code in this standard. Single-row four point contact ball slewing bearing structure of type code 01 structure type code 02 double Reducing ball slewing bearing structure, and therefore the provisions of 03 double-row four point contact ball slewing bearing structure
2 Technical Requirements
2.1 Materials
This standard specifies the yaw, pitch bearing ring material selection, 42CrMo, heat treatment the overall quenching and tempering after quenching and tempering hardness 229HB-269HB, the raceway part surface hardening, quenching hardness is 55HRC-62HRC.  Wind turbines host life requirement of 20 years, bearing the cost of installation, thus requiring the yaw, pitch bearing life to attain 20 years. So bearing rings matrix hardness 229HB-269HB, able to withstand impact without plastic deformation, the part of the surface of the roller quenching hardness of 55HRC-62HRC, increase the contact fatigue life, thus ensuring the bearing of long-life use.
2.2 low-temperatures impact energy
this standard low-temperature impact energy of the yaw, pitch turntable bearing ring requirements: -20 ℃ the AkV not less than 27J, the AKV value in the cold state can be determined in consultation with users. Wind turbines may work in very cold areas, the ambient temperature down to -40 around the bearing operating temperature of about -20 ~ C,, the bearings must be able to withstand large impact loads at low temperatures, therefore, require bearing rings the material must be done in the quenched low-temperature impact energy test, take the bearing rings made part of the sample or with the ring of the same performance and the sample under the same heat treatment conditions, -20 ~ C environment impact function test.
2.3 bearing ring gear
Transmission accuracy of wind turbine bearings and ring gear diameter, gear modulus, general requirements for gear accuracy grade 9 or 10 in the GB/T10095.2---2001. However, due to the impact of working conditions between the pinion and the bearing ring gear bearing ring gear tooth surface hardening, and the pinion tooth surface hardness generally 60HRC, taking into account the design life, the gear tooth surface quenching hardness requirements not be less than 45HRC.