(16-2)The tangential component, F1, can be further resolved into circular subcomponent, Fu, and axial thrust subcomponent, Fa.
(16-3)Substituting and manipulating the above equations result in:
(16-4)The directions of forces acting on a helical gear mesh are shown in Figure 16-4. The axial thrust sub-component from drive gear, Fa1, equals the driven gear's, Fa2, but their directions are opposite. Again, this case is the same as tangential components Fu1, Fu2 and radial components Fr1, Fr2.
The forces acting on a straight bevel gear are shown in Figure 16-5. The force which is normal to the central part of the tooth face, Fn, can be split into tangential component, Fu, and radial component, F1, in the normal plane of the tooth.
(16-5)
Again, the radial component, Fr1, can be divided into an axial
force, Fa, and a radial force, Fr, perpendicular to
the axis.
(16-6)
And the following can be derived:
(16-7)
Let a pair of straight bevel gears with a shaft angle S
= 90º, a pressure angle an
= 20º and tangential force, Fu, to the central part of tooth
face be 100. Axial force, Fa, and radial force, Fr,
will be as presented in Table 16-2.
| Table 16-2 Values of Axial Force, Fa, and Radial Force, Fr | |||||||||||||||||||||||
| (1) Pinion | |||||||||||||||||||||||
|
|||||||||||||||||||||||
| (2) Gear | |||||||||||||||||||||||
|
|||||||||||||||||||||||
