GB/T 3478 consists of the following nine parts under the general title Straight cylindrical involute splines - Metric module, side fit:
——Part 1: Generalities;
——Part 2: 30° pressure angle dimensions tables;
——Part 3: 37.5° pressure angle dimensions tables;
——Part 4: 45° pressure angle dimensions tables;
——Part 5: Inspection;
——Part 6: 30° pressure angle M and W values;
——Part 7: 37.5° pressure angle M and W values;
——Part 8: 45° pressure angle M and W values;
——Part 9: Measuring pin.
This part is Part 7 of GB/T 3478.
1 Scope
This part of GB/T 3478 specifies the calculation formulae and limiting dimensions tables for M value (measurement between two pins, MRi, and measurement over two pins, MRe) and W value (average value of measurement over K teeth of external spline) of the straight cylindrical involute splines with a pressure angle of 37.5°.
This part is applicable to the involute splines with a pressure angle of 37.5° designed and manufactured in accordance with GB/T 3478.1.
2 Normative references
The following documents contain provisions which, through reference in this part of GB/T 3478, constitute provisions of this part. For dated references, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest edition of the normative document applies.
GB/T 321 Preferred numbers - Series of preferred numbers
GB/T 3478.1 Straight cylindrical involute splines - Metric module, side fit - Part 1: Generalities (GB/T 3478.1-2008, ISO 4156-1:2005, MOD)
3 Calculation formulae for measured dimensions of measuring pin
Note: Corresponding steel ball is allowed to replace measuring pin.
3.1 Calculation formulae for measured dimensions of measuring pin for internal spline
3.1.1 Determination of the diameter DRi of measuring pin (see Figure 1)
