Protective unit for hollow axle of mill end cap and end cap of grate type mill thereof

Abstract

A protecting part of the hollow shaft for the end cover of grinder is a cylindrical permanent-magnetic liner composed of rectangular of trapezoidal permanent-magnet lining plates and magnetically attached to the inner surface of hollow shaft. A checked end cover of grinder is composed of cover body, hollow shaft and its protecting part, and the cover's protecting part, which is a permanent-magnet liner consisting of rectangular, trapezoidal and L-shaped permanent-magnet permanent-magnetic lining plates.

Description

technical field [0001] The invention relates to a mill end cover hollow shaft protector and the mill end cover thereof. Background technique [0002] Mills are widely used in mineral processing, coal, electric power, building materials, chemical industry and other industries. There are many classification methods, some of which are divided into grid type mills and overflow type mills. For the structure of the mill, refer to pages 131-141 of the teaching book "Mining Machinery" published by Metallurgical Industry Press in April, 1992 (mining machinery part). Flanges are welded at both ends of the cylinder, and the two end covers of the mill are connected with the flanges of the cylinder. In order to protect the hollow shafts of the end covers, hollow shaft protection parts are installed inside the two hollow shafts. The existing The hollow shaft protection of the ball mill and rod mill is the bushing. Both the feed bush and the discharge bush are cylindrical steel castings,...

AI Technical Summary

Problems solved by technology

The bushing 19 and the hollow shaft 18 of the end cover have higher requirements for cooperation, which is H8 / f9. Since it is not easy to lift, it is particularly difficult to install, and it is very difficult to replace a bushing, which takes 48 hours.

2. Although the inner side of the mill bushing 19 and the hollow shaft 18 of the end cover are of matching size, after installation, there must be a certain gap 16 between the two. In order to prevent the slurry from flowing into the cavity 17 from the gap 16, in the gap 16 places generally need to add packing 6 for sealing. Since the size of the junction is large and the bushing 19 is very heavy, the packing 6 is not easy to compress and easy to fall off

But in fact, the feasibility of this filling method is small, because: (1), the gap between the dustpan plate 10 and the end cover body 13 is generally 5 to 15 mm, if the mortar is thinner, the fluidity is good, but it is easy to flow When passing through the gap 12 between the dustpan board 10 and the end cover body 13, it flows into the fan-shaped chamber in the hollow shaft bushing or the grid plate, so it is difficult to survive in the gap 12 space; if the cement mortar is thicker, its fluidity is poor, only If a small part of the space can be effectively filled with cement, the protection effect is not good; (2), because the cement mortar can only be solidified after standing for more than 24 hours, so it will affect the timely transfer after maintenance; (3), due to the vibration of the ball mill itself is particularly (4) It is difficult to fill cement in 12 gaps; (5) The sealing cover plate of the filling hole must be cut off before the cement is poured, and it must be re-welded after the filling is complete, which is a large workload. And easily mill end cover body 13 mill end cover body 13 cuts

4. The casting dustpan plate 10 and dustpan plate 11 are heavy. Taking the φ3600×4500 grid ball mill as an example, the inner ring dustpan plate weighs 270kg / piece, and the outer ring dustpan plate weighs 240kg / piece. It is necessary to replace the dustpan plate in a small space. very difficult

5. The bolt 14 that fixes the dustpan board is easy to loosen and mine leaks, which not only affects the sanitation around the equipment, but also easily enters the gear pair, causing gear wear

6. The service life of the dustpan board is short, generally it needs to be replaced after about 1.5 years, and the replacement cost is relatively high

Taking the φ3600×4500 grid-type ball mill as an example, the replacement cost of materials and spare parts is more than 90,000 yuan, and the installation cost is 30,000 yuan, which affects production for 48 hours.

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