Pad Mounted Motors; Balancing; Couplings; Direct Coupling - WEG W22 Premium E3 Manual De Instalación, Operación Y Mantenimiento

6.2.3. Pad mounted motors

Typically, this method of mounting is used in axial fans. The motor is fixed by tapped holes in the frame. The
dimensions of these tapped holes can be checked in the respective product catalogue. The selection of the
motor mounting rods/bolts must consider the dimensions of the fan case, the installation base and the thread
depth in the motor frame.
The mounting rods and the fan case wall must be sufficiently stiff to prevent the transmission of excessive
vibration to the machine set (motor & fan). Figure 6.8 shows the pad mounting system.

6.3. BALANCING

Unbalanced machines generate vibration which can result in damage to the motor. WEG motors are
dynamically balanced with "half key" and without load (uncoupled). Special balancing quality level must be
stated in the Purchase Order.
The transmission elements, such as pulleys, couplings, etc., must balanced with "half key" before they
are mounted on the motor shaft.
The balance quality grade meets the applicable standards for each product line.
The maximum balancing deviation must be recorded in the installation report

6.4. COUPLINGS

Couplings are used to transmit the torque from the motor shaft to the shaft of the driven machine. The
following aspects must be considered when couplings are installed:
Use proper tools for coupling assembly & disassembly to avoid damages to the motor and bearings.
g
Whenever possible, use flexible couplings, since they can absorb eventual residual misalignments during the
g
machine operation.
The maximum loads and speed limits informed in the coupling and motor manufacturer catalogues cannot
g
be exceeded.
Level and align the motor as specified in sections 6.5 and 6.6, respectively.
g
Remove or fix the shaft key firmly when the motor is operated without coupling in order to prevent
accidents.

6.4.1. Direct coupling

Direct coupling is characterized when the Motor shaft is directly coupled to the shaft of the driven machine
without transmission elements. Whenever possible, use direct coupling due to lower cost, less space required
for installation and more safety against accidents.
Do not use roller bearings for direct coupling unless sufficient radial load is expected.

6.4.2. Gearbox coupling

Gearbox coupling is typically used where speed reduction is required.
Make sure that shafts are perfectly aligned and strictly parallel (in case of straight spur gears) and in the right
meshing angle (in case of bevel and helical gears).
Figure 6.8 – Mounting of the motor inside the cooling duct
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Manual of Electric Motors 93