shaft diameter
shaft diameter
(OP)
How can I get de diameter of the shaft that you need in this aplication:
Speed 1100 rpm.
Prssure 7 bar
Flow 927 l/min
Speed 1100 rpm.
Prssure 7 bar
Flow 927 l/min
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RE: shaft diameter
Identify the material and it's maximum shear stress.
Identify what FOS you want
Then calculate the area of the shaft that can withstand the torque induced shear stress, with the necessary FOS.
The point being, you have to do some of the work yourself. You need to learn how to do it for yourself.
Regards
HPost CEng MIMechE
RE: shaft diameter
Pump power @ 85% overall efficiency = 12.7 kW
Torque @ 1100 RPM = 110.5 Nm
RE: shaft diameter
I've calculate the torqued:
M=225000/pi *N/n ( kg.m)
Where:
M= Torque kg*m
N= Power Cv = 25 ( taking account the viscoity value )
n = rpm = 1100
So the Torqued value is:
1627.71 kg*m
Then chosen material is Steel 1140
Where:
d= cubit rt [16*M/maximum shear stress *( pi)2*N/n]
But I'm not sure where I can get thes maximu shear stress value for steel f-1140
RE: shaft diameter
d= cubic rt(16*M)/PI* maximu shera strees
If if use this value, maximum shear strees , I work out the diameter of my shaft which is able to endure this torqued. Is it right??
RE: shaft diameter
(Pressure x Flow)/510 = Power Required @ 85% OA Efficiency
@ 1100 RPM Torque = Power / Speed
You also need shear modulus of the material which is 77.8 GPa for your material
RE: shaft diameter
It would matter to me if you are trying to design a 1 piece application or production type relibilty factor you want. If weight or cost is an issue? If those are not factors then you can oversize. if weight is an issue then a hollow drive shaft would serve the purpose better.
RE: shaft diameter
So once I have the torque I'm going to this formula in order to get the shaft diameter.
d= cubic rd [ (16*TORQUE)/(PI * MAXIMUM ALLOWED SHEAR STRESS OF F- 1140)]
Is it ok???
maximum shear strees is 77.8 GPA??
RE: shaft diameter
77.8 GPa is the the shear modulus, not shear stress. You only need it if you are going to work out the angle of twist.
Shear stress of shaft is (Torque/Polar moment of area) x shaft radius
Polar Moment of Area = (Shaft Diameter^4 x PI)/32
As a guide, use 85% of tensile stress for shear stress.
RE: shaft diameter
RE: shaft diameter
First I need to calculate the Torque:
In order to get it I use the following formula.
Shear stress = 16 *T/pi d^3
Where T = Torque kg*m= (225000/pi)*(Power( cv)/rpm)=
rpm 1100
Power 12.7kw *1.36 = 17.272cv
I get a Torque of 1124,55 kg*m
Shear stress: 85% de tensile stress of F-1140 = 450 MPA
450 MPA= 4588.5591 KG/CM2
I get D diameter of my shaft. 49.97 MM
is it right??
Thanking you in advance
RE: shaft diameter