Ball Mill And Ball Mill Hollow Shaft

Hollow shaft is the important part of the rotary cement ball mill, it has supported the running of whole grinding body, in continuous operation under the action of alternating stress, is the weakest link in the ball mill components, also the components that is the most difficult to control manufacturing quality.

They are usually made by the material of GB/T699-1999(ASTM1035/DINC35) and require a high technology to produce. No blowhole and the sand hole are allowed appears around the spherical bush and the neck of the mill shell.

To guarantee the accuracy and the smooth finish of the casting parts, the part that next to the spherical bush is needed to be polished many times. They are Cement, Metallurgy, Construction Materials, usually used in Ball Mill, Cement Making Machinery.


Hollow shaft fracture analysis of the causes

  • Hollow shaft is the key part of ball mill and required a high technology to produce. Due to the structure shape is special, and R area, No blowhole, the sand hole, slag inclusion, and crack are allowed appears. Once appear these defects, will greatly increase the likelihood of hollow shaft fracture. As a result, the casting defects are the main reasons for the hollow shaft fracture.
  • Usually, hollow shaft is large casting steel product, ranged from several tons to more than 10 tons in weight. In the castings will always exist within the stress concentration. If can’t deal with stress concentration timely, could also lead to crack and break.
  • Due to the limitation of conditions, some manufacturers often used block casting instead of whole casting, and then weld together. If can’t guarantee the quality of welding and quality of heat treatment after welding, it is easy to produce quenched structure, stress concentration and micro crack, as a result these above could also lead to crack and break.
  • During the replacing of ball mill parts, if the improper operation will cause the hollow shaft local heating temperature is too high, may cause internal stress changes, leading to fracture.

The point of Maintenance

Hollow shaft fracture is very serious equipment failure, must stop and maintenance the equipment, lest cause serious equipment accident. It is bigger difficulty to deal with hollow shaft fracture, maintenance cycle is long as well as the big intensity of labor, if do something wrong, also affect the safe operation of the ball mill, the serious influence production.

Making welding repair plan

Because of the heavy load for hollow shaft, Only use special welding method of welding cracks, can satisfy the requirement of equipment, and cannot make its heat, can only use cold welding, in order to reduce welding deformation, multiple segments inside and outside welding at the same time. Before welding, open groove with the Angle grinder, with manual arc cold welding groove. Welding requirement is to meet equipment technical requirements, ensure the normal running of the ball mill. So the key to the weld repairs: prevent deformation caused by the crack; ensure the inner quality of weld.

Our Production Capacity

We have a large foundry, with 30 ton electric arc furnace and 40 ton refining furnace; 8 m x 14 m and 4 m x 6 m heat treatment furnace; 100 tons, 70 tons, 50 tons travelling crane and other large equipment, etc. and also has a complete quality detection means. We can produce the products with carbon steel, alloy steel and other kinds of material, maximum weight of 80 tons. Sincerely welcome you to visit our factory.


Pre-sale Design

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  • According to customer requirements or drawing size provide advice on casting steel production
  • According to customer’s special requirements, design and manufacture of casting steel
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  • Free appoint special after-sale service staff, arrived at the scene to assist customer installation and debugging
  • On-site training operations staff, provide technical support for the normal operation of equipment in the future
  • Equipment warranty for one year, one year free maintenance
  • During use, if you have any problem can contact us at any time, if cannot solve in the phone, we will let professional and technical personnel door-to-door service.
  • We provide accessories production and processing services for long time

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