Can multiple tolerance zones exist for the same shaft diameter? \"Help question\"”
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The attached diagram shows the transmission shaft structure designed by the company earlier. As shown in the diagram, elements in contact with the shaft of diameter φ100 include bearings, sealing gaskets, and a coupling (from left to right). The tolerance zones for these components at the corresponding mating points are k6, f9, and m6 respectively. Multiple tolerance zones exist for the same shaft diameter (it is not clear from any relevant standards whether this is allowed). Installing the bearings first may be difficult due to the long shaft diameter; moreover, there is also an m6 tolerance zone. Is it possible to change the entire 100-mm shaft to have a single tolerance zone of k6? (Would changing it to k6 affect the performance of the sealing gaskets?) Even if that were done, the long shaft diameter would still make it difficult to install the bearings. In that case, would it be necessary to reduce the diameter of the rear part of the shaft, leaving only the portion where the bearings are located with a diameter of 100 mm, thereby creating a stepped shaft? This would require replacing the coupling. This equipment has already been manufactured as a complete set and has just started operation. Personally, I believe that the design in this area could be improved, and I kindly ask the members of this forum to share their ideas on how to make improvements
Do you mean that multiple tolerance zones can exist on the same shaft diameter? Are there any requirements regarding the length of the shaft end for each tolerance zone – is it sufficient for it to be slightly longer than the length of the mating portion, or are there special requirements? Additionally, if the shaft diameter is too large, it might be difficult to install the bearing; is further optimization needed?
Sure. 1 As long as it can be installed. 2 Proper coordination is important. 3 It should facilitate maintenance.
It means there’s no need for any improvements; it’s good as it is, right?
Facilitates maintenance. It’s just multiple repairs, with little actual effect.
There should be no problem with the reduced diameter on the right side, but it’s unlikely that the hole for a standard coupling has a diameter of 98. If the standard size is only 90, could there be issues with torque? Everything changes if that happens
Couplings of the same model are suitable for shaft diameters of various sizes; the most common ones are 90 and 95. The torque, speed, and other dimensional parameters remain the same in these cases. Would it be okay to reduce the diameter of the shaft at the fitting part of the coupling on the right side and create a shoulder there? However, the shaft that the coupling on the right side fits with is the shaft of the reduction motor, with a diameter of 100. In this case, the shafts at the fitting points of the coupling have different diameters. Snake spring couplings probably aren’t designed for such a setup, so it’s not advisable to make such changes
I’ve repaired so many pieces of equipment, but I really have never seen bearings and couplings with the same diameter