Optibelt ZRP - Standards, Pulley Tolerances

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5 Design Hints, Dimensions and Tolerances
5.4 Standards, pulley tolerances
Helix angle, standards see Table 5.6
The teeth must be parallel to the axis of the bore, with a maximum
deviation of 0.001 mm per millimetre of width.
For inch-dimensioned sections: 0.01 mm per 10 millimetres of
width.
Draft, standards see Table 5.6
Draft may be a maximum of 0.001 mm per millimetre of face width
and may not exceed the permissible outside diameter tolerance in
accordance with Table 5.7.
For inch-dimensioned sections: 0.01 mm per 10 millimetres of
face width.
Surface finish in accordance with ISO/R 468
The surface finish may not exceed the value R
a
= 3.2 µm on tooth
flanks and tops.
Section Timing belt Pulley
standard standard
MXL; XL; L; DIN ISO 5296 DIN ISO 5294
H; XH Part 1
5M works standard works standard
8M; ISO/DIS ISO/DIS
14M 13050 13050
T2.5; T5; T10; DIN 7721 Part 1 DIN 7721 Part 2
T20
AT5; AT10; based on based on
AT20 DIN 7721 Part 1 DIN 7721 Part 2
Table 5.7: Outside diameter tolerances, standards see Table 5.6
Outside diameter Tolerance
d
a
d
a
(mm) (mm)
Inch pitch Metric pitch MXL; XL; L; H; XH; T2.5; T5; T10; T20;
5M; 8M; 14M AT5; AT10; AT20
≤ 25.40 ≤ 25
+ 0.05 + 0
0 – 0.05
> 25.40 ≤ 50.80 > 25 ≤ 50
+ 0.08 + 0
0 – 0.05
> 50.80 ≤ 101.60 > 50 ≤ 100
+ 0.10 + 0
0 – 0.08
> 101.60 ≤ 177.80 > 100 ≤ 175
+ 0.13 + 0
0 – 0.08
> 177.80 ≤ 304.80 > 175 ≤ 300
+ 0.15 + 0
0 – 0.10
> 304.80 ≤ 508.00 > 300 ≤ 500
+ 0.18 + 0
0 – 0.10
> 508.00 > 500
+ 0.20 + 0
0 – 0.15
Table 5.8: Axial runout tolerance, standards see Table 5.6
Outside Total runout
diameter d
a
(mm) (mm)
Inch Metric MXL; XL; L; T2.5; T5;
pitch pitch H; XH; T10; T20;
5M; 8M; 14M AT5; AT10;
AT 20
≤ 101.60 ≤ 100 0.1 0.1
> 101.60 > 100 0.001 per 1 mm 0.01 mm per 10 mm
≤ 254.00 ≤ 250 of outside diameter of outside diameter
(not 5M, 8M, 14M) (also 5M, 8M, 14M)
> 254.00 > 250 0.25 mm and 0.25 mm and -
plus 0.0005 mm plus 0.005 mm
per 1 mm per 10 mm
of outside diameter of outside diameter
Table 5.9: Eccentricity tolerance, standards see Table 5.6
Outside diameter
d
a
(mm)
≤ 203.2
> 203.2
≤ 200
> 200 ≤ 500
> 500
≤ 200
> 200
Table 5.6: Sections and standards
MXL; XL; L;
H; XH
5M; 8M;
14M
T 2.5; T 5;
T 10; T 20;
AT 5; AT 10;
AT 20
Section
Maximum
eccentricity
(mm)
0.13
plus 0.0005 per 1 mm
of outside diameter
0.10
0.0005 per 1 mm of outside
diameter maximum 0.18
0.20
0.05
plus 0.005 per 10 mm of
outside diameter