Gear transmission permitted strain

helical planetary gearbox permitted stress

Permitted stress according to the state of stress in the work living anticipation of the components and the reliableness decisiveness.

Work gear tooth by σH and σF are circular alter, ought the fatigue force of the material decide the bounded lifetime of the tiredness bound. Acknowledged by the content:

Method:

σr – the eventual strain matches to while N0

Cycloid speed reducer N – efficient bicycles

N0 – circulation base,

m – related the strain state index

Permitted strain divided up by the factor of safety for fatigue boundary:

Formula:

S – safety factor, the adjoin forcefulness: S = l, bending forcefulness: SF = 1.25 ~ 1.five

σlim – gear materials boundary fatigue (exam way to decide)

Bending fatigue the strength boundary σFlim evaluate, chequebook Figure

The adjoin Fatigue the strength boundary σHlim evaluate, chequebook Figure

KN – living element (with the amount of strain cycles N efficient living to find out the book Figure)

Description:

① Universal aim to accept the esteem of the lower side of figure

② figure every the data matching to a evaluate while the pulsating cyclic strain; such as symmetric circulation, the drawing evaluate is multiplied by 0.7 as a boundary.

③ split transmitting gear, the bend fatigue strength permitted strain ought be cut down twenty to forty%.