What is meant by shock load in gears?

What are steady, light, medium and heavy shock loads?

I found this table in a design data handbook


2 Answers 2


a shock load on gearing is imposed when the gear train is forced to start or stop turning very suddenly, or when a heavy load is suddenly applied to a set of rotating gears. A good example of this is when the driver of a car with a manual transmission slams or "bangs" the gear changes without skilled use of the clutch, causing the car to suddenly lurch. This imposes high stresses on the gear teeth for over short timescales. Gears subjected to shock loads may fail due to metal fatigue of the gear teeth rather than wearout of the contact faces on the teeth themselves.


In gear design for different machinery there is a combination of loads that causes damage and excessive wear and the equation for that load:

F* = Ka Kv Km Ft

Ka is application factor inherent in connecting to moving parts.

Kv is dynamic factor caused by imbalance and deficiency in gears.

Km is load distribution factor on gear.

Ft is service design load.

The part your question refers to is application factor.

These factors combine with the other above mentioned are used to define the shock load and service need.

Applicatin load factor for machinery gears.

Source: http://www-mdp.eng.cam.ac.uk/web/library/enginfo/textbooks_dvd_only/DAN/gears/failure/failure.html


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.