Mitsubishi Electric MELSERVO-J5 User Manual page 279

■When the gear ratio of the gear connected to the servo motor is identified
Setting [Pr. PF66.0-3 Gear for backlash estimation - Numerator] and [Pr. PF66.4-7 Gear for backlash estimation -
Denominator] limits the travel distance during the backlash estimation to the minimum. The backlash estimation value of the
gear connected to the servo motor is the value in the load-side unit.
1.
Set the gear ratio of the gear connected to the servo motor in hexadecimal.
If the number of gear teeth on machine side is 25 and the number of gear teeth on servo motor side is 11, set [Pr. PF66.0-3] to
"0019" and [Pr. PF66.4-7] to "000B".
If multiple gears are connected to the servo motor, set the gear ratio up to where the load is applied.
2.
Set the backlash nominal value presented by the manufacturer of the gear connected to the servo motor.
Set the backlash nominal value in [Pr. PF67 Backlash nominal value] taking the gear ratio for backlash estimation into
account.
If the backlash nominal value is 10 [degree], the following equation is used for the calculation.
Backlash nominal value presented by the manufacturer × 100 × ([Pr. PF66.0-3] / [Pr. PF66.4-7]) = 10 × 100 × (25/11) =
2272.727...
Round up the calculated value, thereby set 2273 [0.01 degree] in [Pr. PF67].
3.
Select the unit for the travel distance which is to be automatically set in the backlash estimation function.
A time-out will occur at execution of the backlash estimation function depending on the setting values for the electronic gear
([Pr. PA06 Electronic gear numerator]/[Pr. PA07 Electronic gear denominator]). In this case, set [Pr. PF62.0 Backlash
estimation unit selection] to "1".
4.
Adjust the settings of the gear failure prediction function.
To change the backlash threshold used for the gear failure prediction function, change [Pr. PF68 Backlash threshold
multiplication]. When "0" (initial value) is set, a value twice the value of [Pr. PF67] / 100 is set as the backlash threshold.
The threshold used for gear failure prediction is calculated with the following equation.
Backlash threshold = [Pr. PF67] / 100 × [Pr. PF68] / 10
When setting the backlash threshold to 5000 [0.01 degree] while the backlash nominal value is 2273 [0.01 degree], use the
following equation for the calculation.
[Pr. PF68] = Backlash threshold [0.01 degree] / [Pr. PF67] × 10 = 5000 / 2273 × 10 = 21.99...
Therefore, set [Pr. PF68] to 22 [0.1 times].
■When the gear ratio of the gear connected to the servo motor is not identified
When either [Pr. PF66.0-3 Gear for backlash estimation - Numerator] or [Pr. PF66.4-7 Gear for backlash estimation -
Denominator] is set to "0", the travel distance during the backlash estimation is two rotations each in the forward and reverse
rotation side from the starting position of the backlash estimation. The backlash estimation value of the gear connected to the
servo motor is the value in the servo motor-side unit.
1.
Set the backlash nominal value presented by the manufacturer of the gear connected to the servo motor.
Set the backlash nominal value in [Pr. PF67 Backlash nominal value] after converting the value into the rotation angle on the
servo motor side.
If the backlash nominal value is 10 [degree], the following equation is used for the calculation.
Backlash nominal value presented by the manufacturer × 100 = 1000
Therefore, set [Pr. PF67] to 1000 [0.01 degree].
2.
Select the unit for the travel distance which is to be automatically set in the backlash estimation function.
A time-out will occur at execution of the backlash estimation function depending on the setting values for the electronic gear
([Pr. PA06 Electronic gear numerator]/[Pr. PA07 Electronic gear denominator]). In this case, set [Pr. PF62.0 Backlash
estimation unit selection] to "1".
3.
Adjust the settings of the gear failure prediction function.
To change the backlash threshold used for the gear failure prediction function, change [Pr. PF68 Backlash threshold
multiplication]. When "0" (initial value) is set, a value twice the value of [Pr. PF67] / 100 is set as the backlash threshold.
The threshold used for gear failure prediction is calculated with the following equation.
Backlash threshold = [Pr. PF67] / 100 × [Pr. PF68] / 10
When setting the backlash threshold to 2000 [0.01 degree] while the backlash nominal value is 1000 [0.01 degree], set [Pr.
PF68] to 20 [0.1 times].
4 APPLICABLE FUNCTIONS
4.5 Machine diagnosis
4
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