| 摘要 |
Roller is very common part for any kind of the materials handling equipment. Some of the handling equipment, like Roller Conveyor, using the surface of the rollers to transport big lumps or boxes or other lumpy products. Other handling equipment, like Belt Conveyors, using the rollers as a supporting element for the moving belt. Most of the rollers have a shaft and a rolling shell supported by bearings. Under the load of the handled material, the roller's shaft and the shell are deflected. The effect of the deflection is a function of the load and rigidity. When the load is higher the deflection getting bigger. The shaft of the roller is much more flexible than the shell and then the deflection of the shaft (under the same load) is higher than the shell. With increasing of the load, growing the difference of the deflection between the shaft and the shell. Effect of the non-equal deflection creates few mechanical problems. One of the problems is, that the non-equal deflection (of the shaft and the shell) creates the angular misalignment of the bearings. The durability of the bearing is in inverse proportion to the angular misalignment. The bearing can function reasonably up to certain level of the angular misalignment. This limitation is accounted during the design of the roller. The second problem is, that during rotation of the shell (under the load) the unequal deflection (of the shaft and the shell) causes the pumping effect at the sealing area of the bearings. This effect is in direct proportion to the load on the roller. The pumping effect creates movement of the air through the labyrinth of the seals. Because of the existing pumping effect, all the rollers which are used in the dusty environment, required much more sophisticated seals in order to reduce the contamination of the bearing. The conventional design of the rollers, reduces but can not eliminate completely the pumping effect. The invention (Fig.5) used to overcome the above mentioned mechanical problems.
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