Special Double Row Yaw Bearing with Ring Gear

Special Double Row Yaw Bearing with ring gear

Yaw bearing is the main component of wind power equipment. Its performance and working conditions directly affect the performance of the rotating shaft connected to it, the yaw system device installed on the rotating shaft and even the entire wind power equipment. According to statistics, about 20% of faults in wind power equipment are caused by yaw bearing. It has practical significance to improve the reliability of yaw bearing, improve the service life of wind power equipment, improve economic efficiency, and ensure the long-term safe and stable operation of wind power equipment.

There is a pinion under the yaw motor and a huge gear mesh! This big gear is called yaw bearing.

Some small yaw bearings are external teeth, while the yaw bearings of large fans are generally internal teeth! The same is that they all rely on the drive of yaw motor.

With the rapid development of the mechanical industry, the slewing bearing is more and more widely used. Yaw bearing is a new type of slewing bearing developed by our company. It requires the finished product to have zero clearance or negative clearance, has strict regulations on the rotational damping torque of the bearing, and the precision of the finished product is very high; According to the use requirements of the host machine, the bearing surface must be subject to anti-corrosion treatment. How to solve these problems is the main topic of the study.

1. Anti-corrosion treatment of external surface

For the anti-corrosion requirements of yaw bearing, we adopt the arc spraying long-term anti-corrosion process. It uses special arc spraying equipment to melt, atomize and spray the corrosion resistant metal (pure aluminum or zinc) to the surface of the workpiece to form a metal arc spraying layer, and then seal it with a corrosion resistant coating with strong permeability to form an arc spraying long-term anti-corrosion composite coating. Its technical features are: ① long anticorrosion life, up to more than 20 years; ② High adhesion of coating; ③ The coating quality is good. The process route: preparation of semi-finished products of bearing inner and outer rings → pre-cleaning → pre-protection of workpiece → sand blasting → arc spraying → sealing treatment, which are described as follows. 

1) Preparation of semi-finished products of bearing inner and outer rings

In order to ensure that the yaw bearing has a high appearance quality, the anti-corrosion coating process is arranged after all mechanical processing, and the sprayed bearing parts are directly stored after assembly to ensure that the anti-corrosion coating will not be scratched. 

2) Pre-cleaning

Use organic solvent for degreasing treatment. There may be oil stains on the surface of bearing semi-finished products after machining. In order to ensure the spraying quality, a cleaning procedure must be arranged before spraying.

3) Workpiece pre-protection

Before sandblasting and spraying, the special surface pre-protection tooling is used to protect the arc raceway, threaded hole and the surface without spraying.

4) Sandblasting

The surface of the inner and outer rings of the bearing is roughened to increase the contact surface between the coating and the workpiece, make the workpiece surface more active, and improve the bonding strength of the coating. 5) Arc spraying

Arc spraying (pure aluminum or zinc) equipment mainly includes DC power supply, spraying gun, air compressor, air filter, etc., which mainly controls parameters such as arc voltage, current, wire feeding speed, compressed air pressure, spraying distance, etc.

6) Closed treatment

Since there are pores in the sprayed coating, sealing treatment must be carried out to increase the corrosion resistance. 

The main exposed machining surfaces of yaw bearing after painting and assembly include gear surface, installation thread surface and arc raceway surface. The first two are coated with anti-rust oil after assembly, and the latter is coated with lubricating grease during assembly. The inner packaging of the finished product is wrapped with plastic film, and the outer layer is wrapped with plastic braided tape for protection, which can meet the anti-rust requirements.