Hollow shaft
AssigneeROLLS-ROYCE plc
InventorPhilip T. HOWELLS
Life of this patent
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Abstract
A hollow shaft 102 for transmitting torsion or bending forces is disclosed. The hollow shaft 102 comprises a first portion 108 having a first wall thickness t1, a second portion 110 having a second wall thickness t2 which is greater than the first wall thickness t1, and a transition region 112 between the first and second portions 108, 110. The transition region comprises inner 106 and outer annular 104 shoulder fillets, the inner shoulder fillet 106 being axially offset from the outer shoulder fillet 104 towards the first portion 108. In this manner, the local stress concentrations caused by the inner and outer fillets are axially staggered along the transition region.
Claims7
A hollow shaft for transmitting torsion or bending forces, comprising:
- a first portion having a first wall thickness;
- a second portion having a second wall thickness which is greater than the first wall thickness;
- and
- a transition region between the first and second portions comprising inner and outer annular shoulder fillets;
- wherein the inner shoulder fillet is axially offset from the outer shoulder fillet towards the first portion;
- and
- in a direction towards the second portion along the inner shoulder fillet, the wall thickness is increased;
- and
- in the same direction along the outer shoulder fillet, the wall thickness is further increased.
A method of forming a transition region between first and second portions of a hollow shaft, the wall thickness of the second portion being greater than the wall thickness of the first portion, the method comprising:
- forming an outer annular shoulder fillet;
- and
- forming an inner annular shoulder fillet that is axially offset from the outer shoulder fillet towards the first portion such that
- in a direction towards the second portion along the inner shoulder fillet, the wall thickness is increased;
- and
- in the same direction along the outer shoulder fillet, the wall thickness is further increased.
Dependencies are inferred from the claim text.