Inspection: checking the center distance between two blind holes (a) is difficult. If feasible, one of the holes should be a through hole (b).
Avoiding stress concentration: In order to avoid the buildup-of stresses, move hole "h" [see (a)] away from the sudden change of shaft cross-section (at the shoulder). Relocate closer to the upper end of the shaft, as in (b).
This section contains suggestions for designing parts for ease of assembly and disassembly. Specific topics include the following: avoiding dimensional overspecification of mating parts, minimizing the need for close tolerances, allowing for thermal expansion and wear, design for ease of assembly, accessibility and ease of disassembly. As in Part A, design (a) generally represents the incorrect design, while other constructions (b, c, d etc.) represent improvements.
(a) Avoiding Overspecification Of
Dimensions Of Mating Parts
The depth of the bore for the stepped shaft, (a), should not need to match the length of the small-diameter portion of the shaft. This requires unnecessarily close tolerances, so that the shoulder seats square against the wall. In design (b) the hole is slightly elongated, thereby avoiding the need for close tolerances while insuring a square seat for the shoulder.
The axial position of the bushing relative to the housing is overdetermined in (a). A onediameter shaft, (b), eliminates this drawback.
