The roller sugar mill shaft is one of the most important parts of the sugar mill industry. This is because they are used for the separation of the sucrose containing juice from the sugar cane. This extraction of juice is achieved through squeezing the prepared cone through two rollers. It is due to this criticality and importance that it needs a careful manufacturing and testing so as to meet all the stringent requirements so as to be used under continuous wear and fatigue environments.

Materials used

The material of the sugar mill shaft is decided by taking into consideration its strength and rigidity. The conditions under which these shafts operate vary over a wide range. This makes it imperative that the bearing material that are used to make them should have certain desirable properties. These include factors like:

• A low melting point and Softness
• Mechanical strength
• Resistant to corrosion
• Low elasticity modulus
• A high thermal conductivity
• Other economic considerations

However, it is not possible to obtain all these factors to a certain desirable degree in a single sugar mill shaft, so a compromise needs to be made regarding some attributes. The commonly used materials are:

• White metal: This term is mainly used for lead base and tin metals making them highly competitive. They are mostly recommended for applications where loading is not severe. White metals suffer a reduction in fatigue strength as the temperature increases making this reduction to be a function of thickness. These are not commonly used for sugar mill shafts.

• Copper base alloys: These alloys include gun metal, lead bronze, and phosphor bronze. Amon these lead bronze is the cheapest making it popular for general service bearings. They have a low seizure tendency and has a greater fatigue strength for withstanding higher temperatures. They are mainly used in the form of a solid single unit. Gun metal is also a relatively cheap machine material with good bearing properties. They are capable of withstanding higher loads than the lead bronze alloys while also having a good resistance to corrosion due to sea water. Another metal that is used is phosphor bronze which is used in heavy loadings where high friction and stress are likely to occur.

• Aluminium base alloys

Lubrication

The sugar mill shafts do not have the ability to turn sufficiently fast so as to help in the formation of a hydrodynamic film of lubricant between the bearing and the journal. Thus, they require constant hydrostatic lubrication. This is done by supplying lubrication to the bearing under the required pressure. Attention should be given so as to ensure an adequate supply of lubrication under such conditions. This is especially true for the location of oil supply grooves and holes. Thus, considering the careful manufacturing standards and testing requirements, sugar mill shafts are considered to be an important part of this industry. After all, the main motive of the sugarcane industry is to extract maximum amount of juice per ton/ cane milled. This is achieved by ensuring the usage of right sugar mill shaft at the right place. 

Read this also:

Cardan Shaft Manufacturers

Rolling Mill Cardan Shafts