초록 ▼

The bolt or stud shaft and nut combination includes an undercut of the first thread of the shaft adjacent the load face of the nut, the undercut having a compound fillet with the smaller radius lying between the larger radius and the first thread of the shaft. The shaft threads are buried two thread

The bolt or stud shaft and nut combination includes an undercut of the first thread of the shaft adjacent the load face of the nut, the undercut having a compound fillet with the smaller radius lying between the larger radius and the first thread of the shaft. The shaft threads are buried two threads deep into the nut so that the first two teeth of the nut do not contact the threads of the shaft and overlie the undercut. The nut threads have a taper opening the pitch diameter in a direction towards the loaded face. The combination affords resistance to high-cycle fatigue of rotating structures joined together by the bolt or stud shaft and nut combination.

대표청구항 ▼

[ What is claimed is:] [1.] Apparatus for enhanced high cycle fatigue capability, comprising:first and second structures rotatable about an axis and having openings in registration one with the other in an axial direction of the structures;an elongated shaft passing through the registering openings

[ What is claimed is:] [1.] Apparatus for enhanced high cycle fatigue capability, comprising:first and second structures rotatable about an axis and having openings in registration one with the other in an axial direction of the structures;an elongated shaft passing through the registering openings and having threads at least adjacent one end of said shaft, said shaft having an unthreaded portion adjacent said threads and located on a side of said threads remote from said one end of said shaft; anda nut having threads for threaded engagement with the threads of said shaft and a surface for bearing engagement against one of said structures, said nut having at least one thread closer to said surface than remaining threads on said nut and overlying said unthreaded portion of said shaft, said one thread of said nut being out of contact with the threads of said shaft whereby said shaft is resistant to high-cycle fatigue caused by rotation of said structures; said unthreaded portion of said shaft being undercut to a diameter reduced relative to a diameter of the shaft passing through the registering openings and including a compound fillet of different radii for transitioning between said undercut and a first thread on the shaft adjacent said undercut and engaging a first of said remaining threads of said nut.