38
1021387 12/2018
V02
Remarks on Efficiency
The SHG-2UH Series Units are equipped with two rotary shaft seals at the hollow shaft as standard. The friction of the rotary
shaft has a considerable influence on the efficiency of these units because the seals are mounted on the fast running input
side and seal on the relatively large diameter of the hollow shaft.
If there is insufficient heat dissipation during operation (e. g. the unit is not connected to the machine housing and the load)
the unit may reach a high temperature within a few minutes. This may result in overpressure which may have a negative
impact on the pre-load of the rotary shaft seal. In this case the efficiency of the unit may be lower than the value given in the
catalogue.
Cleaning the area of the seals with compressed air may also result in an unacceptable overpressure within the unit.
When the unit is equipped with standard seals, the over-pressure on the seals can be released by lifting up one of the sealing
lips with a soft tool (e. g. by means of a toothpick on the outside of the sealing lip near the shaft. Be careful not to damage
the sealing lip!). If special seals are used, we ask you to contact Harmonic Drive AG.
4.5 No Load Torque values SHG-2UH
No Load Running Torque
The no load running torque is the torque required to maintain rotation of the input element (high speed side) at a defined input
speed with no load applied to the output.
No Load Starting Torque
The no load starting torque is the quasistatic torque required to commence rotation of the input element (high speed side)
with no load applied to the output element (low speed side).
No Load Back Driving Torque
The no load back driving torque is the torque required to commence rotation of the output element (low speed side) with
no load applied to the input element (high speed side). The approximate range for no load back driving torque, based on
tests of actual production gears, is shown in the matching table. In no case should the values given be regarded as a margin
in a system that must hold an external load. Where back driving is not permissible a brake must be fitted. The diagrams are
valid for: Harmonic Drive® Grease, standard grease amount according to this engineering data and ratio i = 100.
For other ratios the compensation values have to be applied. When oil lubrication is used please contact Harmonic Drive AG.
SHG-2UH
Illustration 38.4
4.4.4 Efficiency Tables
The following illustrations show the efficiency of the SHG-2UH Series Unit at rated torque and lubrication with Harmonic Drive®
Grease.
10
20
30
40
50
60
70
80
90
100
-10
0
10
20
30
40
Umgebungstemp. / Ambient Temp.[°C]
Wirkungsgrad /
Efficiency
[%]
500 rpm
1000 rpm
2000 rpm
3500 rpm
Untersetzung / Ratio = 50, 80, 100, 120
Temperature
[°C]
-10 0 10 20 30 40
Temperature
[°C]
Ratio
= 160
100
90
80
70
60
50
40
30
20
10
Wirkungsgr
ad
[%]
10
20
30
40
50
60
70
80
90
100
-10
0
10
20
30
40
Umgebungstemp. / Ambient Temp.[°C]
Wirkungsgrad /
Efficiency
[%]
500 rpm
1000 rpm
2000 rpm
3500 rpm
Untersetzung / Ratio = 160
-10 0 10 20 30 40
Ratio
= 50, 80, 100, 120
100
90
80
70
60
50
40
30
20
10
Wirkungsgr
ad
[%]
500 rpm
1000 rpm
2000 rpm
3500 rpm
500 rpm
1000 rpm
2000 rpm
3500 rpm