NEIEP Mechanics Practice Exam

The use of a double-wrapped secondary sheave is specifically required for U-Groove configurations. This is because U-Grooves have a unique geometry that allows for deeper grooves, which can provide better grip and stability for the drive belts. When a system utilizes U-Grooves, the belt must wrap around the sheave in such a way that helps to accommodate the deeper profile of the groove. A double wrap is necessary to ensure the belt maintains adequate tension and alignment, reducing the risk of slippage and wear.

In contrast, the other groove configurations—A-Grooves, B-Grooves, and C-Grooves—do not possess the same depth or shape characteristics that would require a double wrap of the secondary sheave. These other configurations can effectively manage belt tension and alignment without necessitating the specialized approach needed for U-Grooves. Thus, the requirement for a double-wrapped secondary sheave highlights the specific engineering considerations that come into play with U-Groove drive systems.