Direction of the components:

The direction of these components might be calculated as follows:

 (1) The direction of the radial component or  is always towards the gear centre.

 (2) The direction of the tangential component is tangent to the pitch circle and it is opposite to the sense of rotation for driving gear & in the sense of rotation of the driven gear.

 (3) The direction of the axial component of the normal tooth load is in the direction of advancement of the screw with the similar hand like the helix while it is rotated in the direction of rotation of the driving gear. The thrust on the driven gear is equivalent and opposite of acing on the driver. It has been apparently shown in Figures 4(i), (ii), (iii) and (iv).

(i)                                              (ii)                                  (iii)                             (iv)

         Figure 4: Direction of Axial Thrust