Type, Length and Pitch.
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RollerType
The Following points are very important in the selection of a Roller Type:
Selection of Roller Length
Roller Lengths greater than 1.25 to 1.3 times the width of the product are not generally used. This is to prevent an unacceptable point load. The load capacity at the point is 60% of the values given in the diagram above. Selection of Pitch
To transport a product without any problems, there should be at least three load rollers under the load-bearing surface of the product: the maximum pitch is the product length divided by three. If the load in the box, case or crate is unevenly distributed, a smaller pitch must be chosen. The same is true if the height of the product is more than twice its length. If the contact surfaces are soft and slack and the pitch is too large, then the product will tend to droop down either side of the roller tube, which will increase the drag forces. This can largely be prevented by reducing the pitch. |
L = Length of the Product Transported
H = Height of the Product Transported S = Pitch or operation between the rollers |
Load Capacity
The maximum load capacity of a Roller is determined by:
The weight of the product to be transported must not be greater than the total load capacity of the load-bearing rollers. If the product or its packaging have hard, stiff and irregular contact surfaces, a situation may occur in which the rollers directly beneath the product are not taking the whole weight. This can mean that only two or three rollers may be carrying the total weight of the product. In practice this may lead to more rollers having to be placed than theoretically calculated, or that stronger rollers have to be used.
The maximum load capacity of a Roller is determined by:
- bearing cases (side A + B);
- the tube and spindle diameter;
- the spindle type;
- the partial length under the load;
- the load pattern (evenly distributed or point load).
The weight of the product to be transported must not be greater than the total load capacity of the load-bearing rollers. If the product or its packaging have hard, stiff and irregular contact surfaces, a situation may occur in which the rollers directly beneath the product are not taking the whole weight. This can mean that only two or three rollers may be carrying the total weight of the product. In practice this may lead to more rollers having to be placed than theoretically calculated, or that stronger rollers have to be used.