We are looking to find a company that can produce machined spiral crown gears from Delrin with a matching steel spiral pinion gear oriented at 90 degrees. Gears will be produced in low volumes 100-200 per year.
I would like to thank diamondjim and the others on this forum for their assistance.
In our application we have decided on spiral bevel gears. This gear type meets our requirements for higher strength with a greater number of teeth engaged at all times. Our transmission ratio is 5.0, a module of 2.5 with a shaft angle of 90 degrees, a 20 degree pressure angle and 35 degree spiral angle. The larger driven gear needs to rotate in the horizontal plane and turns anti-clockwise when viewed from above. We now need to choose the spiral direction.
My understanding is that changing the spiral direction will change the contact surface of the teeth from either concave or convex. This will in turn change the ratio of axial force to radial force.
So my question, which spiral direction should I choose and what might be the consequences of getting it backwards?
Usually the choice is to have the pinion thrust away and have a thrust bearing right behind the pinion head. The gears don't care about direction, but the bearing syatem must handle the thrust along with the radial load.