Engineering drawing data for Involute Splines:

 

When defining engineering design data on an engineering drawing for involute splines, uniform and consistant  specifications should be shown as well as complete engineering to manufacturing information. Design engineering drawing miscommunication should be avoided. The illustration given within Table A is the suggested drawing format to ensure that all detail involute spline specifications are properly defined.

 

The number of dimensional decimal places (x's) illustrated within Table B is that which is typically used within the end-item involute spline. When using tabulated type of spline engineering drawing specifications, many designers may choose to not show a drafted illustration of the spline teeth as given within Table A.

 

Table A Spline Terms, Symbols, and Drawing Data, 30-Degree Pressure Angle, Flat Root Side Fit ANSI B92.1-1970, R1993

Where:

cF	Form Clearance
D	Pitch Diameter
DFe	Form Diameter, External Spline
DFi	Form Diameter, Internal Spline
Di	Minor Diameter, Internal Spline
Do	Major Diameter, External
Dre	Minor Diameter, External Diameter
Dri	Major Diameter, Internal Spline
s	Actiual Circular Space Width
Sv	Effective Circular Space Width
t	Actual Circular Tooth Thickness
tv	Effective Circular Tooth Thickness

 

 

Table B

 

Engineering Design Exceptions:

 

a) The external major diameter, unless chamfered or reduced, may interfere with the internal form diameter on flat root side fit splines. Internal splines made to the 1957 and 1960 standards had the same dimensions as shown for the major diameter fit splines in this standard.
b) For 15 teeth or less, the minor diameter of the internal spline, unless chamfered, will interfere with the form diameter of the external spline.
c) For 9 teeth or less, the minor diameter of the internal spline, unless chamfered, will interfere with form diameter of the external spline.
d) The internal minor diameter, unless chamfered, will interfere with the external form diameter.
e) The internal minor diameter, unless chamfered, will interfere with the external form diameter.
f) For 10 teeth or less, the minimum chamfer on the major diameter of the external spline may not clear the internal form diameter.
g) Depending upon the pitch of the spline, the minimum chamfer on the major diameter may not clear the internal form diameter.

 

Spline Data and Reference Dimensions.

 

Reference data on spline data ;should not used for engineering and manufacturing purposes. Pitch and pressure angle data will then not be subject to individual dimensional inspection. As suggested within this document, reference data is an included notation or modifier to a dimension, specification, or note when that dimension, specification, or note is:

 

1) Repeated for drawing clarification.
2) Needed to define a nonfeature datum or basis from which a form or feature is generated.
3) Needed to define a nonfeature dimension from which other specifications or dimensions are developed.
4) Needed to define a nonfeature dimension at which toleranced sizes of a feature are specified.
5) Needed to define a nonfeature dimension from which control tolerances or sizes are developed or added as useful information.
6) Any dimension, specification, or note that is noted "REF" or (REF) should not be used as a criterion for part acceptance or rejection.