NCCER Millwright Practice Exam

A grid coupling is often referred to as a flexible coupling due to its design, which allows for some degree of misalignment and movement between the connected shafts. This adaptability is particularly beneficial in applications where shafts may not be perfectly aligned, reducing the risk of wear and damage to the equipment.

Flexible couplings, like the grid coupling, are specifically engineered to handle torque while accommodating misalignment, vibration, and thermal expansion. They achieve this through their construction, which typically includes a grid or lattice structure that can flex and compress, thus maintaining connection while providing cushioning.

In contrast, rigid couplings do not allow for any misalignment or movement, meaning they require precise alignment during installation and can transmit stress and vibrations directly between the shafts. Chain couplings and disc couplings have their specific uses and advantages, but they do not typically encompass the flexible design associated with grid couplings. This focus on flexibility and adaptability under varying conditions makes "flexible coupling" an appropriate alternative name for a grid coupling.