13 - 2
13. OPTIONS AND AUXILIARY EQUIPMENT
(2) Selection of the regenerative option
(a) Simple selection method
In horizontal motion applications, select the regenerative option as described below.
When the servo motor is run without load in the regenerative mode from the running speed to a
stop, the permissible duty is as indicated in section 5.1 of the separately available Servo Motor
Instruction Manual.
For the servo motor with a load, the permissible duty changes according to the inerti a moment of
the load and can be calculated by the fol lowing formula.
Permissible
duty
Permissible duty for servo motor with no load (value indication Section 5.1 in Servo Motor Instruction Manual)
(m 1)
ratedspeed
running speed [times/min]
2
where m load inertia moment/servo motor inertia moment
From the permissible duty, find whether the regenerative option is required or not.
Permissible duty number of positioning times [times/min]
Select the regenerative option ou t of the combinations in (1) in this section.
(b) To make selection according to regenerative energy
Use the following method when regeneration occurs continuously in vertical motion applications or
when it is desired to make an in-depth selection of the regenerative option.
a. Regenerative energy calculation
Use the following table to calculate the regenerative energy.
M
Friction
torque
Unbalance torque
TF
TU
Servo motor speed
Generated torque
Time
Up
No
tf(1 cycle)
Down
( )
( )
(Driving)
(Regenerative)
Tpsd2
t2 t3 t4t1
Tpsa2
Tpsd1Tpsa1
1)
2)
3)
4) 5)
6)
7)
8)
Formulas for calculating torque and energy in operation
Regenerative power Torque applied to servo motor [N m] Energy [J]
1) T1(JL JM)
9.55 104
N01
Tpsa1 TUTFE12
0.1047 N0T1Tpsa1
2) T2 TU TFE2 0.1047 N0T2t1
3) T3(JL JM)
9.55 104
N01
Tpsd1 TUTFE32
0.1047 N0T3Tpsd1
4), 8) T4 TUE40 (No regeneration)
5) T5(JL JM)
9.55 104
N01
Tpsa2 TUTFE52
0.1047 N0T5Tpsa2
6) T6 TU TFE6 0.1047 N0T6t3
7) (JL JM)
9.55 104
N0
T71
Tpsd2 TUTFE72
0.1047 N0T7Tpsd2
From the calculation results in 1) to 8), find the absolute value (Es) of the sum total of negative
energies.