Also known as “in-line” gearing, helical gearing are available as small units, large units, single-stage, and multiple-stage. Helical gearing units are generally efficient, losing only about 2% of energy per stage of gearing, and are found in various applications. These units are configured in straight lines with input and output shafts either parallel or in the same plane.
A worm gear is an inclined plane wrapped around a shaft to create a helix. Using right-angle configuration, worm gearing reducers are available in a variety of sizes and ratios. It is important to note that for this particular type of gearing, ratio has a greater impact on efficiency than that of other gearing types. Single reduction, 5:1 ratio boxes can have efficiency ratings up to 98% while the same units with 60:1 ratios may only be 50% efficient. Worm gearing can also be combined into two and three-stage units with high ratios and torque ratings, but low gear reducer efficiency ratings. Worm boxes can be inexpensive to purchase but expensive to operate, as efficiency can be lower.
Also known as “miter” gearing, bevel gearing is similar in structure to worm gearing units, possessing right-angle configuration. These gearing units however, are more efficient, losing only a few percentage points per gearing stage. Additionally, bevel gearing units can be combined with helical gearing units to create high-ratio systems with high efficiency. While this type of gearing system may be more expensive to purchase, higher efficiency ratings allow operating costs to be lower than those of worm boxes.