Shaft (mechanical engineering)
In mechanical engineering, a shaft is a rotating machine element, usually circular in cross section, which is used to transmit power from one part to another, or from a machine which produces power to a machine which absorbs power.
Types
They are mainly classified into two types.
- Transmission shafts are used to transmit power between the source and the machine absorbing power; e.g. counter shafts and line shafts.
- Machine shafts are the integral part of the machine itself; e.g. crankshaft.
- Axle shaft.
- Spindle shaft.
Materials
The material used for ordinary shafts is mild steel. When high strength is required, an alloy steel such as nickel, nickel-chromium or chromium-vanadium steel is used. Shafts are generally formed by hot rolling and finished to size by cold drawing or turning and grinding.[citation needed]
Standard sizes
Source:[1]
Machine shafts
- Up to 25 mm steps of 0.5 mm
Transmission shafts
- 25 mm to 60 mm with 5 mm steps
- 60 mm to 110 mm with 10 mm steps
- 110 mm to 140 mm with 15 mm steps
- 140 mm to 500 mm with 20 mm steps
The standard lengths of the shafts are 5 m, 6 m and 7 m.
Usually 1m to 5m is used.
Stresses
The following stresses are induced in the shafts.
- Shear stresses due to the transmission of torque (due to torsional load).
- Bending stresses (tensile or compressive) due to the forces acting upon the machine elements like gears and pulleys as well as the self weight of the shaft.
- Stresses due to combined torsional and bending loads.
References
- ^ Mahadevan K and Reddy K.Balaveera, (2015), 'Design data hand book', CBS publishers and Distributors (P) ltd., New-Delhi, ISBN 9788123923154
External links
- Online verification of shafts according standard