Redundancy is not equal to availability
Redundancy is nowadays the keyword when it comes to drive systems for large vertical roller mills. Different gear manufacturers have developed new drive systems. This development is clearly driven by the high power demand of large and very large vertical mills and by the torque limitation of the bevel stage in conventional gearboxes as described in many other articles.
The newly developed drive systems can be split into two different groups:
Multiple drive solution: This group supplies the required drive power by a multiple of drive systems. This makes it possible to reduce the dimension of each drive train and with it to bypass the challenges presented by the manufacturing of large bevel wheels.
Integrated motor solution: This design is based on the idea of substituting the bevel stage, which is the power-limiting element, and reducing the complexity of the entire drive system.
Manufacturer of drive systems belonging to the first group claim that...