How to determine the safety factor when selecting S series reducers

When determining the safety factor (usually also known as service factor or operating condition factor) for the selection of S-series reducers, it is not enough to simply give a fixed value, but rather to comprehensively evaluate it based on specific actual operating conditions. Generally speaking, the range of safety factor values is usually between 1.2 and 2.5.

The following are several core factors that need to be considered when determining the safety factor:

1. Load type (most critical factor)

The stability of the load directly determines the magnitude of the safety factor:

Uniform load: The load is very stable and has no impact. For example, fans, water pumps, conveyor belts that run at a constant speed, etc. The safety factor is usually taken as 1.0-1.25.

Medium impact load: The load has slight fluctuations or intermittent movements. For example, mixers (uneven materials), packaging machines, some machine tools, etc. The safety factor is usually taken as 1.25-1.5.

Heavy impact load: The load fluctuates violently, with frequent start stop or strong impact. For example, crushers, stamping machines, excavators, cranes, etc. The safety factor usually needs to be taken as 1.5-2.0 or even higher.

2. Daily working hours (working system)

The longer the equipment runs every day, the higher the requirements for the heating and fatigue life of the gearbox, and the corresponding increase in safety factor should also be made:

Short term operation (such as ≤ 3 hours per day): a smaller safety factor can be selected.

Medium duration operation (such as 3-10 hours per day): The safety factor needs to be appropriately increased.

Continuous operation (such as running continuously for more than 10 hours a day or 24 hours a day): a larger safety factor must be selected, and the thermal power of the reducer must be checked with emphasis.

3. Type of prime mover

The type of power source that drives the gearbox will also affect the selection of the coefficient. Generally speaking, the smoother the output of the prime mover, the lower the coefficient can be:

Electric motor: The output is the smoothest and the required safety factor is relatively lowest.

Multi cylinder piston engines (such as 4-6 cylinders): There is a certain fluctuation in output, and the coefficient needs to be appropriately increased.

Low cylinder piston engines (such as 1-3 cylinders): The output fluctuates and impacts are significant, requiring the highest safety factor.