Thermal Expansion Upwards; Thermal Axial Growth; Final Alignment; General - ABB AMA Manual

Manual for High Voltage Process Performance Motors

3.6.4.2 Thermal expansion upwards

3.6.4.3 Thermal axial growth

3.6.5 Final alignment

3.6.5.1 General

26 - Installation and Alignment
The thermal expansion of the distance between the feet and the shaft center of the electrical
machine can be approximately calculated according to the formula:
∆H = α × ∆T × Hwhere
∆H=thermal expansion[mm]
α=10 × 10 -6 -1
K
∆T=40 K
H=shaft height [mm]
NOTE: Consider the thermal expansion of the driven machine in respect to the electrical
machine in order to define the total thermal expansion.
The thermal axial expansion needs to be taken into consideration if the axial movement of the
non-drive end bearing is locked. See the dimension drawing in order to determine which end is
locked.
The expected axial thermal expansion of the rotor is proportional to the length of the stator
frame, and can be approximately calculated according to the formula:
∆L = α × ∆T × Lwhere
∆L=thermal expansion[mm]
α=10 × 10 -6 -1
K
∆T=50 K (for AMA, AMB, AMK, AMI), 80 K (for AMH, HXR, M3BM, M3GM)
L=frame length [mm]
NOTE: Make sure that a continuous free axial movement is possible between the coupling
halves (excluding rigid couplings) in order to permit axial thermal expansion of the
machine shaft as not to damage the bearings.
In the following, the final alignment is made with dial gauges, although there is other and more
exact measuring equipment on the market. The reason for using dial gauges in this text is to
provide some alignment theory.
NOTE: Measurements should be made only after proper shimming and with fixing bolts
properly tightened.
NOTE: The final alignment measurements should always be recorded for future reference.
3BFP 000 063 R0101 REV D