Harmonic Drive RSF supermini Series User Manual

2-4 Duty Cycles
2-5
1
2
3
4
5
6
Selection of the RSF supermini Series
How to obtain K
La
, K
Lr
and K
Ld
and example of duty calculation 2
As a result of Calculation Example 1 shown below, the selected actuator RSF-5B-50 works fine, so
RSF-5B-50 can be used for duty factor graphs.
Operation conditions:
• The inertial load is accelecated at the maximum torque of the actuator, and decelerated at the
maximum torque after operation at a fixed speed.
• The movement angle θ of one cycle is 120°.
• The duration of one cycle is 0.4 (s).
• The other conditions are the same as Calculation Example 1.
(1) KLa and KLd: The average speed during the rotation speed change from 0 to 140r/min is 70r/min.
From the duty factor graphs, K
La=KLd≒1.5 can be obtained.
(2) K
Lr: Tr≒0 for the inertial load. Similarly, from the duty factor graphs, KLr≒0.29 can be read.
(3) The movement angle can be obtained from the area in the “Rotation speed-Time” diagram above.
In other words, the movement angle θ can be expressed as follows:
θ = (N / 60) x {tr + (ta + td) / 2} x 360
Solving the formula above for tr (operation time at a fixed speed of N), the following can be
obtained.
tr = θ/ (6 x N) – (ta + td) / 2
Substituting θ= 120° and ta= 0.03(s), td= 0.03(s), and N= 140r/min from Example 1, tr=0.113(s).
(4) Because the cycle time is 0.4(s), the %ED is obtained as follows:
%ED = (1.5x 0.03 + 0.29 x 0.113 + 1.5 x 0.03) / 0.4 x 100 = 30.7%
Because the value of %ED obtained is below 100, continuous repeated operation of this cycle can
be done.
If this value is 100 or above,
• Operation pattern
• Load reduction
must be reexamined.
0.0
0.2
0.4
0.6
0.8
1.0
0 50 100 150 200 250
回転速度[r/min]
トルク[Nm]
70
140
RSF-5B-50-E050-C
Radiation plate: 150×150×3[mm]
Acc./dec. range
KL=0.33
0.67
1
1.5
(2) KLr
Estimation line for
KL=0.29
(1) KLa, KLd
Torque [Nm]
Speed [r/min]

Harmonic Drive RSF supermini Series Specifications

General

Brand	Harmonic Drive
Model	RSF supermini Series
Category	Controller
Language	English