When a customer selects a gearreducer, one of the most important decision criteria is the relationshipbetween the cost of the gear reducer and the amount of torque generated fromthe output shaft. Worm reducers are the leaders when it comes to the cost vstorque comparison.
A principal factor driving the cost competitiveness of worm reducers relates tothe overall gear reducer ratio — the number of input shaft rotations thatresults in one rotation of the output shaft. Most worm gear reducermanufacturers offer ratios of up to 601 in a single stage of gearing, and afew offer even higher ratios.
With only one stage of gearing, the related multiple shafts, bearings, spacers,and other hardware that would be required in a multi-stage reducer are notrequired. It is typical for a 601 helical or helical-bevel reducer to have 3stages of gearing vs the one stage of gearing in a worm reducer. The gears,bearings, and shafts are the most expensive parts in a complete gear reducer.With fewer of these components, worm reducers cost less than other types ofgear reducers.
Availability and CommonalityMost domesticworm gear reducer manufacturers stock a substantial number of reducers in theirwarehouses. In addition to readily available inventory, there is alsodimensional commonality between the major domestic worm reducer manufacturerson critical mounting dimensions. Those critical dimensions include:
- the output shaft diameter and length;
- mounting hole size and location in the housing;
- output shaft height;
- overall reducer housing height.
The gearratios offered have also been standardized among manufacturers. Somemanufacturers have increased the output and input torque ratings of theirproducts through improved gear designs along with the use of high performancematerials and synthetic lubricants. Those increases in input and output torquemake it possible to easily replace an older reducer with a new reducer from adifferent manufacturer. The increased ratings provide a larger service factorand longer life than the reducer being replaced.