Shaft-mounted right angle gear motors are the new normal for conveyors. When faced with the decision of whether to use a bevel or worm gear motor, you may be tempted to choose the latter, because it is seemingly less expensive and gives you the output speed and torque that you require. What you may not have realized is that worm gears are the least efficient type of right angle gearing, and the associated long-term energy costs far outweigh the initial investment. The example below illustrates why a worm gear motor may not be the best choice.
This conveyor application requires 1.4 HP at the load with an output speed of 53 rpm.
Initial cost for end user
Required output power
Required motor power
Energy cost per year
Assumptions: Both gear motors use the same NEMA Energy Efficient motor, energy cost is $0.07 per kWh, run-time of 4,000 hrs/yr. Maintenance costs are not included.
Now let’s extrapolate these results to resemble a more typical scenario in an industrial setting. The figure below shows the total cost of 200 units over 5 years. By using helical bevel gearing instead of helical worm gearing, you would save over $52,000 with a return on investment of less than 1 year.