The use of CAE tools in the design of
rotating shafts
SEW-EURODRIVE
Rafael Rodarte / Antonio Vieira
SEW-EURODRIVE – Global Structure
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SEW-EURODRIVE - Brazil
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Joinville
1.300 Employees
Porto Alegre
Our Line of Products
Gearmotors
Industrial Gear (High Torque)
Shafts
• Steps in the development:
– Chose of material
– Geometry definition
– Determination of stresses and strains
– Determination of critical speeds
Material
The criteria for selection of a material are:
 Operating conditions: working temperature, corrosive agents (chemical
attack), wear, radiation;
 Required properties (limitations and restrictions of use);
 Availability of raw materials and technical feasibility of processing;
 Environmental impact / recyclability after use;
 Cost (processing, transformation, manufacturing, disposal, etc).
Material
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Shaft is a mechanical element rotating or stationary
(static condition) usually circular section where other
elements are mounted mechanical transmission such
as gears, pulleys, fans, wheels centered, among
others. The shafts are supported in bearings or journal
bearings, and almost always with section keyway for
mounting of components.
Material
The shafts are the efforts required
elements:
 Flexion
 Tension / compression or
 Torsion,
This effort acting individually or in
combination. For the safety of the system where
the shaft is inserted, it should be rated for static
or dynamic. To minimize the deflections, a logical
choice is steel, which has high stiffness,
represented by its modulus, which is essentially
constant for all steels.
Material
• A maioria dos eixos de máquinas são construídos de aço de baixo e
médio carbono (ANSI 1020-1050: laminados a frio ou a quente). Se uma
maior resistência é necessária, aços de baixa liga como o AISI 4140,
4340 ou 8640 podem ser selecionados.
Material
• Most shafts are constructed of steel machines of low and medium carbon
(ANSI 1020-1050: cold rolled or hot). If higher strength is required, low
alloy steels such as AISI 4140, 4340 or 8640 can be selected.
Geometry
Combined Stress
Service factors
Infinite life
Critical Speed
Ansys analisys
- Static Linear
- Buckling
- Modal
- Harmonic
Fatigue failure
Fatigue Failure
Fatigue Failure
Fractured section
Fatigue Failure
Fatigue Failure
Fatigue Failure
K(Section ) + K(Key)
Fatigue Failure
- New Material: 34CrNiMo6 +QT
(Yield strength 700MPa)
K(Section)
Distinct regions
K(KEY)
3mm Fillet on Edges
Fatigue Failure
Rev. 1
Rev. 0