shift factor in involute spline 3

[cni76]

can any one tell me what is shift factor and how to
calculate a shift shift factor and put it in my
data sheet it will be very helpful for me!is shift
factor a necessary one!!!!

 

[lathanag]

hi,
To my knowledge shift factor, is a correction factor given to involute gearing for modification of tooth profile. Such gears are called corrected gears. Gears may have to be corrected for avoiding interference in cases where the minimum no. of teeth do not comply with the required one. Some times gears are corrected to impart certain properties to them such as higher load carrying capacity or greater contact ratio. The correction factor is a non dimensionless number which when multiplied by the module gives the amount of profile shift. If you require additional details please feel free to ask
Latha

 

For the majority of splines, the dimensions are taken straight from the standards e.g SAE, ISO etc. However involute splines can be modified like an involute gear.
See

http://uk.geocities.com/mikebull2001/green.html

to calculate the geometry.

 

[diamondjim]

As stated before a correction factor may
be stated as a nominal dimension or a ratio.
If it is a ratio then it would be multiplied
times the module or if in the DP system, you
would divide the ratio by the DP. Commonly a
pinion is modified to make it a long addendum
design so as to eliminate undercutting in the
root of the pinion. Typically 50 percent long
would be suggested. Machineries Handbook has
some suggested values.
you add the .50 to the addendum ratio
and subtract the .50 from dedendum ratio
and then divide these value by the DP
or times the module in the metric system.

The tooth thickness changes accordingly
to the (TT plus ((2X .50/DP) SinPressure Angle)
where TT is the normal circular tooth thickness.
For the module system the formula is
(TT plus ((2x .5o x Module) Sin Pressure Angle)

For an internal gear or spline the change
would be TT minus rather than plus.

 

[diamondjim]

Opps
The formula should be Tan of the pressure angle
instead of the Sin in the formula submitted
earlier.

 

[cni76]

thanks ,
for the info ,im just now started to work on the info
i will let u know immediately with the results.
thanks again to everybody for giving valuable
techniques

 

2 Questions: 1) What is an involute spline? 2) My company is financing the purchase of a brand new Rollex Involute Spline Rolling Machine, apprx. $302,000 U.S. Are these machine custom made for the customer and do they have a value in the used market after 7-8 years?

 

[diamondjim]

an involute spline is just a double stubbed involute
gear. The female or internal involute spline mates with
an external spline of the same pitch diameter. The
tooth thickness has minimal backlash so the parts can
slide together, but now have much slop in them. The
dedendums of both parts are slightly greater than the
addendums to provide clearance in the root of both parts.

I do not know that much about a rolling machine, but it
must have value or function beyond rolling only splines.

 

[cni76]

i hope i could throw some light on involute profiles.
the teeth profiles of 2 mating gears should satisfy law of gearing- to maintain a constant velocity ratio between 2 pairs.
curves are designed such that common normal to the tooth
profiles at the point of contact will always pass thru' the
pitch point.
one such curve is involute curve and the other is cycloidal
curve.usually gears have involute profile for no of reasons.

a simple rolling machine, I THINK, can used for rolling splines ,threads,knurling operations by changing the rolling
cutters.