A：

Before you choose the gearbox, you should consider those conditions

1.Machine Performance requirements

For example:

Torque – refers to the torque load requirement for your application.

Speed – the turning speed of the output shaft as required by your application.

Life – how many continuous hours are needed to match the desired life?

Duty cycle – how long is the gearbox capable of operating before turning off?

Efficiency

2.Environment Factors

For Example:

Space – do you need the gearbox to fit in a confined area?
Operating temperature – determine whether the temperature at which the gearbox will be operatedwill remain the same or have huge variations.

Weight – should the weight of the gearbox fall within a certain amount?

3.Cost

The cost of the gearbox is certainly one major factor that influences your purchase decision. You should realize your how much budget you have before you make a decision.

In order to make sure that the gear you choose is of the best quality and delivers optimal performance, it is important that you choose a reputed supplier or dealer.

A：According to our statistics ,helix angle in 13 degree and 18 degree’s torque, they just increase 6.37% and 2.72% than spur gear. The result of helix angle is limited.The axial force of helical gear is bigger than spur gear ,which caused lower efficiency. As a whole, spur gear and helical gear have not much difference between precision and backlash.