24
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4.2 Calculation of the Torsion Angle
Calculation of the Torsion Angle
φ
at Torque T:
4.3 Accuracy of the Oldham Coupling
Information concerning the Oldham coupling can be found in section 5.5.
In the region of tooth engagement Harmonic Drive® gears have no backlash. If an Oldham coupling is used for the compen-
sation of eccentricity errors of the motor shaft, a small backlash in the range of a few seconds of arc can occur at the output
shaft, as listed in table 24.5.
φ
= Angle [rad]
T = Torque [Nm]
K = Stiffness [Nm/rad]
φ
=
60 Nm - 29 Nm
11
. 10
4
Nm/rad
29 Nm
6.7
. 10
4
Nm/rad
+
φ
= 7.15 . 10
-4
rad
φ
= 2.5 arc min
180 . 60
�
φ
[arc min] =
φ
[rad] .
Example: HFUC-32-100-2UH
T = 60 Nm
K
1
= 6.7 . 10
4
Nm/rad
T
1
= 29 Nm
K
2
= 1.1 . 10
5
Nm/rad
T
2
= 108 Nm
K
3
= 1.2 . 10
5
Nm/rad
T T
1
T
K
1
<–
φ
=
<
φ
=
T - T
1
K
2
T
1
K
1
+
T
1
T ≤T
2
<
T T
2
φ
=
T
2
- T
1
K
2
T
1
K
1
T - T
2
K
3
+
+
Equation 24.1
Equation 24.2
Equation 24.3
Equation 24.4
Sizes
14
17
20
25
32
40
45
50
58
Ratio
30
60
33
28
28
23
–
–
–
–
50
36
20
17
17
14
14
12
12
10
80
23
13
11
11
9
9
8
8
6
100
18
10
9
9
7
7
6
6
5
120
–
8
8
8
6
6
5
5
4
160
–
–
6
6
5
5
4
4
3
[arcsec]
Table 24.5
