Is Your Gearbox Robbing You Blind?

Worm gear drives are found in a variety of industrial applications, and have a torque density (a measure of speed reduction divided by volume) that almost no other solution can match. Reduction ratios of up to 100:1 for a single-stage worm unit are not uncommon, and when worm drives are staged, extremely high reduction ratios can be obtained within a very small footprint. Imagine two 60:1 worm drives staged sequentially - the total net reduction would be 3,600:1, all enclosed within a space not much larger than a standard 50:1 helical. Perhaps the most attractive feature of worm gear reducers, however, is their price: generally speaking, worm drives will be the most cost-effective solution.

Or are they?

A worm reducer will most likely have the lowest upfront cost of any reducer type, but are you really getting what you paid for? Worm gear reducers are typically very inefficient, and this inefficiency only increases with reduction ratio - for larger (150:1+) reduction ratios, worm reducer efficiencies can hover around 50%. This not only requires that motors be upsized for the application, but also forces the motor to draw more current in order to perform the assigned task. This is one of the reasons why worm gear reducers are sometimes called "amp chewers."

These problems are solved by the Hub City HERA (High Efficiency Right Angle) reducer. These reducers are dimensional drop-ins for conventional worm gear reducers but feature migh higher efficiencies, and are typically 90% efficient across the entire range of reductions. HERA reducers also feature up to twice the torque density of worm gear reducers. With their high efficiency, HERA reducers even allow for drive motors to be downsized, thus giving the user a further cost incentive.

HERA reducers can also accommodate a variety of standard worm gear sizes through the use of mounting plates, further increasing their flexibility. A HERA45 reducer, for example, is the same size as a 2.38" worm, but has the torque capacity of a 3.25" worm.

How much can a HERA reducer save? A typical 60:1 HERA, when compared to a generic worm drive, can save its user up to 5,500 kilowatt-hours annually (about $700 per year in electricity cost per unit), and up to $2,232 per unit over the unit's standard 25,000-hour life. When combined with energy efficient motors, the savings only increase.

The end result is a reduced operating cost, short payback periods, higher product versatility, reduced gearbox footprint, fewer SKUs, increased life, and decreased maintenance.

HERA reducers can also cut a plant's CO₂ output by up to 3.9 tons per year per unit - no small amount, considering the global trend towards carbon taxes - which makes these gearboxes a choice that's as environmentally conscious as economically sound.

http://www.hubcityinc.com/documents/HERAflier.pdf

http://www.epa.gov