Failure Cause of Turbine Worm Wheel of Submerged Sewage Pump

Turbine oil tank contains more free water. As the worm gear drive by the meshing of the tooth surface to achieve its friction surface must establish the extreme pressure lubricating film, it is the lubricant in the extreme pressure agent and metal surface reaction generated by the lubricating film, which has high strength, can withstand The load produced by the worm gear meshing. Lubricant with water will cause extreme pressure inactivation, the meshing surface can not form a lubricating film, resulting in direct contact with the surface of the worm, causing surface wear. As the worm gear material is tin bronze (code ZQSn10-1), the allowable contact stress is 220MN / m2, while the worm is made of alloy steel (steel: 35CrMo), the allowable contact stress 850MN / m2, relative to the worm worm Soft, so the failure of the form of performance for the worm gear tooth wear.

We carried out a comprehensive analysis of the lubricating oil system, and finally confirmed: the oil system from the steam turbine seal leakage of steam condensate. As the turbine insulation is sealed very well, part of the leakage of steam will inevitably enter the oil seal through the bearing oil system.

In order to solve the problem of worm gear failure caused by oil water, we sampled and analyzed the water content of lubricating oil every month according to the random operation manual of turbine. We regularly drained water from the bottom of the tank and set up the relevant management system.

After the above improvement measures, E-GT501 turbine from October 2000 put into operation, the normal operation has reached more than 2 years, still no signs of damage, for the stable operation of the device provides a strong guarantee, the turbine can balance each year Medium-pressure steam 8,000 tons, the annual energy-saving 15Kw × 8000h = 120000 degrees, 0.6 yuan per degree basis, the annual savings of 72,000 yuan electricity, the economic benefits are obvious.

Due to the lack of the original design gear tooth contact strength, the frequent failure of the turbo-worm gear was changed. By changing the material of the worm wheel, the relevant management system was established according to the requirement and solved the problem. With the increase in the introduction of foreign equipment in China, according to the differences in conditions of the original design conditions for verification, in the process of localization of spare parts should be taken seriously. The solution process of turbine turbine failure problem of liquid sewage pump has certain reference significance