Bellhousings (pump to motor) Information

Pump motor bellhousings are mounting devices used to connect dissimilar motor and pump bolt configurations. They are made of metals such as aluminum and machined to achieve proper alignment. Heavy-duty models are made of welded steel. Bellhousings are slotted and must provide adequate clearance for the coupling’s outer diameter (OD). Product selection requires information about the electric motor frame type, face-to-face length, and pump mounting style. Electric motor frames include both vertical and horizontal styles that meet NEMA standards. Face-to-face length is the sum of the motor shaft length, the pump shaft length, and the coupling insert thickness. Pump mounting styles cover the bolt type as well as the bolt flange dimensions. Typically, SAE 2-bolt flanges and SAE 4-bolt flanges are used.


Bellhousings include gas engine adapters and products with dampening flanges. Like the pump to motor adapters that are used to connect electric motors and pumps, gas engine bellhousings are made of strong, lightweight metals such as aluminum. To provide safe, quiet operation, gas engine adapters must enclose the shafts. Often, they use flexible couplings and do not require coupling guards, risers, or shims. Pump motor adapters for gas engines are designed to bolt to the motor’s face and accommodate a variety of power units. Openings allow operators to access the flexible coupling, which may be protected by an orange cover for visibility. High weight loading and suitability for use with multiple pumps are additional parameters to consider.


Bellhousings with dampening flanges are available. These devices may feature a vulcanized design that is locked rather than bolted into place. In addition to their sound dampening properties, pump motor adapters with dampening flanges resist the ingress of ozone and oil, both of which can reduce system life and impede performance. Adapters with an integral sealing lip do not require additional sealing and can be mounted either horizontally or vertically. For maximum noise reduction, suppliers may recommend a dampening flange with a dampening rod.  Dampening flanges with rigid connections are also available, but do not provide as much noise reduction.