To achieve maximum life for a spiral bevel gear than two tooth pairs are simultaneously in contact
set, low vibration levels and appropriate bearing and an iterative numerical solution must be used.
pattern location and dimensions must be present. The This paper presents a general approach to calculate
kinematical behaviour of a gear pair (bearing how load is shared between meshing teeth in spiral
pattern, line of action and motion error) is bevel gear pairs, taking into account tooth composite
therefore an important consideration at the design deflection (bending, shearing), tooth contact
stage. The size of the bearing pattern and the deformation and initial profile separation due to
location of the line of action (LOA) both influence profile modification.
the contact deformation and bending displacement of
a gear tooth while kinematical motion error
determines whether unloaded motion will transfer 2.
One of the recent advances in gear train design is _-1, _0, _+1 torque vectors
the increase in the number of simultaneous tooth _p total applied torque vector
pairs in contact: if two to three tooth pairs, as in _-11, _00, =K+ll stiffness vectors at contact
high .contact ratio gears (HCR), are in simultaneous points
contact instead of one to two pairs, as in low K-11 x,y,z stiffness vector x, y and z
contact ratio gears (LCR), the overall mesh stiffness components at contact points
can be increased and the load share carried by each _-ii, _00, _+11 compliance vectors
tooth pair can be significantly reduced. Although _pij, _sij primary and secondary displacement
actual load share values can differ substantially, it vectors
is possible under certain conditions to increase the Coo, Cl0, C01, C11 weighting coefficients
load carrying capacity of a gearset without _c, _c, _c contact point reference frame
increasing its weight [13]. HCR gears can be _#3 motion error without load
obtained in several ways: I) by decreasing the _3L motion error under load
pressure angle, 2) by increasing the addendum, 3) by m_ speed ratio
using teeth of finer pitch and 4) by increasing bias
on the LOA of spiral bevel gears.