Drive shaft, drive assembly and related method
AssigneeBaker Hughes Incorporated
InventorJohn Hyll
Life of this patent
Estimating the term…
Abstract
A drive shaft has a driving end and a driven end and is provided at the driving end with an external helical thread and a cylindrical pilot surface disposed between the thread and the driving end, the pilot surface having a diameter approximately equal to the inner diameter of the thread. During a mounting of an impeller to the drive shaft, a crest flat of an internal helical thread in the impeller rides on the pilot surface. The shaft has an additional pilot surface on the other side of the shaft thread. Upon a mounting of the impeller to the shaft, the two pilot surfaces on the shaft engage two precision impeller hub bores which straddle the threads to provide a controlled close fit of impeller and shaft to one another and to maintain the geometric axes of impeller and shaft true with one another.
Claims12
A drive assembly comprising:
- a drive shaft having a driving end and a driven end, said shaft being provided at said driving end with said thread and said driving end, said thread having a flat crest and a flat trough;
- and
- a driven member attached to said shaft at said driving end, said driven member having an internal helical thread matingly engaging said external helical thread, said driven member being provided with an internal surface at least partially surrounding and in contact with said pilot surface, said external helical thread having a flat crest and a flat trough.
A method for mounting a driven member having an internal helical thread to a drive shaft having an external helical thread, comprising the steps of:
- supporting said shaft in a horizontal orientation;
- suspending said driven member at a free end of said shaft;
- shifting said driven member towards said shaft so that said free end is inserted into an opening in said driven member;
- during said step of shifting, engaging a flat of said internal helical thread with a substantially cylindrical pilot surface at said free end of said shaft, thereby aiding alignment of said opening and said driven member with said shaft, the external thread on said shaft being disposed on a side of said pilot surface opposite said free end;
- upon contact, during said step of shifting, of said external helical thread with said internal helical thread, turning one of said driven member and said shaft relative to the other of said shaft and said driven member to screw said external helical thread and said internal helical thread to one another;
- and
- partially resting said flat on said pilot surface during said step of turning so as to partially support weight of said driven member.
Dependencies are inferred from the claim text.