Spur Gears

For spur gears…

• Teeth are parallel to axis
• Inexpensive
• Noisy
• High efficiency
• Easy to disengage
• Backlashes
• For transmitting tangential forces
  

Spur gears have a $W_n=\sqrt{W_t^2+W_r^2}$, $W_t$, and $W_r=W_t\tan (\varphi )$ where these forces act as follows…

We can represent the spur gear forces with just $W_t$ and $W_r$ though. Some other properties:

• Input power: $P_{in}={\omega }_{in}{T}_{in}=(2\pi n_{pinion})(\frac{D_p}{2}{W}_{tp})$
  • Where here, the far right term is just also the radial speed and torque of the pinion