Designing machines requires numerous considerations for selecting couplings, ball screws, chain and sprockets, as well as a gearbox, motor, and drive. Every designer needs to ensure these key components work together well. This episode of STOBER’s Power Tips will explain 3 critical areas to examine when designing a machine.
1. What factors are important for this machine? Accuracy, speed, and load are crucial when selecting your mechanisms, motor, and drive. In a gearbox, Backlash, stiffness, and ratio are the key selections that affect cost. Planetary gearboxes increase in price by 30%when ratios are over 10:1 as more stages of gearing are needed. However, STOBER helical bevel gearboxes are the same price for ratios4:1 up to 70:1. Maximizing the mechanical advantage of the gearbox ratio results in a smaller motor and drive, which brings down the cost of the total system.
2. How will you connect to the load? If you aren’t connecting to the load through a coupling, then you will need to look at the effect of belts and pulleys, rack and pinion, or cam-driven mechanisms. The external loads and friction from these mechanisms can impact the bearing life of the gearbox. Gearboxes require torque to rotate, even when there is no load. This has to be accounted for when sizing – especially with hypoid or worm gearboxes due to their inefficiencies. Shaft loads greatly impact the lifetime of gearboxes.
3. What is the desired lifetime of the machine? Ratings are typically based on 10,000 or 20,000 hours, so check the manufacturer’s catalog for the application factors that are needed to achieve the desired life and the number of cycles per hour. All STOBER product ratings are based on 20,000 hours of operation.
Other factors for considering a motor
When a servo motor is attached to a gearbox, the torque ratings are reduced. This is because oil seals and gearing efficiency cause losses that result in heat. There are many considerations when selecting a motor: Speed, torque, physical size, type of motion, and environment.
STOBER can help solve these complex issues
STOBER has the product breadth and experience needed to design the best machine possible. The entire machine is considered and studied to determine which product can best fit your needs. STOBER geared motors are sized and optimized by our engineers to maximize performance of the motor and gearbox. Plus, STOBER’s industry leading,2-year warranty guarantees life – especially for those high speed or high cycle-rate applications.