Primary contents from here.
Load holding mechanism without chain or rollers
The BISOMAC200/300 series traction hoist uses NIHON BISOH's original traction mechanism which is completely different way from a conventional mechanism. A conventional load holding mechanism is constructed with chain or rollers which press a wire rope against the groove of a sheave and generate frictional forces to hold and transfer. In contrast, the BISOMAC200/300 series traction hoist does not use any chains or rollers; a wire rope is squeezed between the groove walls of the special sheave to hold the load. Thanks to this mechanism, stable load holding capacity is possible and the BISOMAC series traction hoist achieves high reliability.
(with chain or roller)
Major improvements in maintainability
Thanks to this new sheave, we have achieved major improvements in maintainability.
- Wire rope durability is four times longer than conventional rope
- Sheave life cycle is semi-permanent
- Number of components is reduced
In the conventional BISOMAC100 series, as shown in the following figure, rollers that hold the wire rope around the sheave were necessary, but in the new BISOMAC200/300 series traction hoist, it is not necessary to have any holding rollers at all.
We reduced the number of components around the sheave and maintainability has been greatly improved.