Definition
A gearbox uses meshing gears of different sizes to change rotational speed and torque between an input shaft (typically from a motor) and an output shaft, trading speed for torque or vice versa according to the gear ratio. It is a mechanical power-transmission component distinct from an electrical drive's frequency-based speed control.
Key facts
- Changes speed and torque via a fixed mechanical gear ratio, distinct from a VFD's electrical, continuously variable frequency control.
- Higher gear ratio typically trades output speed for increased output torque, and vice versa.
- Requires adequate lubrication to manage friction and wear between meshing gear teeth.
- Common failure symptoms include gear tooth wear, misalignment-driven vibration, and lubricant contamination.
How does Gearbox work or appear?
A gearbox works by meshing gears of different tooth counts on connected shafts, so that as the input shaft rotates at its given speed, the output shaft rotates at a different speed determined by the gear ratio, with torque changing inversely: a smaller output speed generally corresponds to greater available output torque.
What should technicians inspect for Gearbox?
A gearbox achieves a speed and torque change through fixed mechanical gear ratios, typically set at design time (though some gearboxes offer selectable ratios). This is a mechanical approach distinct from a VFD, which achieves continuously variable speed control electrically by varying the motor's supply frequency rather than mechanical gearing.
FAQ
Frequently asked questions
How does a gearbox change speed and torque?
It changes them using meshing gears of different sizes between an input and output shaft, trading speed for torque or vice versa according to the fixed gear ratio.
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