Maximum Torque Of Pump Shaft And Rotor Material Combination; Mass Moment Of Inertia; Axial And Radial Clearances - Johnson Pump TG GS2-25 Instruction Manual

3.10.4 Maximum torque of pump shaft and rotor material combination

The maximum allowable torque is a constant independent from speed and may not be exceeded to
avoid damaging the pump i.e. pump shaft, rotor/shaft fitting and rotor teeth.
TG GS pump size
2-25
3-32
6-40
15-50
23-65
58-80
86-100
185-125
The nominal torque (Mn) has to be checked for the normal working conditions and the installed
nominal motor torque (M n.motor) but converted to the pump shaft speed.
The starting torque (Md) may not be exceeded during start up. Use this value for the maximum torque
set of a torque limiter if installed on the pump shaft.

3.11 Mass moment of inertia

TG GS
J (10-3 x kgm2)

3.12 Axial and radial clearances

TG GS
Minimum (µm)
Maximum (µm)
20
Mn (nominal torque) in Nm
N Rotor
R Rotor
G Rotor Nitrided
Stainless
Iron nodular
steel
iron
21 – 31
21 – 31
67 67 67
255 255 255
255 255 255
390 390 390
600 600 600
1300 1300 1300
2-25 3-32 6-40 15-50
0.25 0.30 0.75 3.5
2-25 3-32 6-40 15-50
80 80 90 120
134 134 160 200
Md (starting torque in Nm
N Rotor
R Rotor
G Rotor Nitrided
Stainless
Iron nodular
steel
iron
29 – 43
29 – 43
94 94 94
360 360 360
360 360 360
550 550 550
840 840 840
1820 1820 1820
23-65 58-80 86-100 185-125
6.8 32 54
23-65 58-80 86-100 185-125
125 150 165
215 250 275
A.0500.501 – IM-TGGS/05.01 EN (03/2013)
200
190
320