Geared motor manufacturers have a couple of options when it comes to supplying their product, based on different demands from customers. In original equipment (OEM) applications, the preferred method is to supply gearboxes and electric motors fitted as one unit, in something called an Integrated Motor Drive (IMD). The other option is to supply the gearbox with a flange that suits externally-fitted electric motors, in either IEC or NEMA sizing. As usual, there are advantages (and drawbacks) from using either system.
Integrated Motor Drives have less parts and are usually shorter than IEC gearboxes, because the pinion gear fits directly to the motor shaft, rather than an input quill. This immediately makes them more cost-focussed, and beneficial when a lot of units are to be installed on an application.
In the case of IEC gearboxes, one of the main benefits of using a gearbox that comes with an IEC motor flange for the input is that a range of specialist motors can be fitted more easily. This primarily concerns applications in hazardous areas, where Ex’d, Ex’e, Ex’n and even DIP motors are to be used. Many of these are available only from specialist motor manufacturers.
At All Torque, we have also found that speed changes are easier to effect on IEC gearboxes. This is due both to the range of motors available with 2 pole and 6 pole speeds, and the occasional requirement to change pinions.
External power transmission options – such as in-line friction disc variators, hydraulic speed variators, electro-magnetic clutch/brakes and even ratio multipliers – all come fitted with IEC or NEMA flanges as standard.
As usual, the demands of each application are to be considered when making power transmission choices.