Mitsubishi Electric RH-FRH Series Instruction Manual page 131

5) Install surely the new belt to the timing pulley A <5> and timing pulley B <6>, and fix the J3 axis motor <3> with
J3 axis motor fixing screw <2>.
Confirms having related the timing belt <4> to the timing pulley A <5> and the timing pulley B <6> securely.
6) Lightly loosen J3 motor installation screws <2> (Be careful not to overly loosen the screws.).
7) The nut which is fixing tension adjustment screw <1> is loosened, turn tension adjustment screw <1>, and
adjust the tension of timing belt <4>.
When the screw is turned to the right, the belt will be stretched, and when turned to the left, will loosen.
Adjust the belt tension slack to within the range as shown in
Before the tension measurement, rotate the timing pulley at least three times in each direction so that the
timing belt fits in the pulley. Check the tension measurement method in
measurement".
If the belt is loosened too much when adjusting the tension causing it to come off the timing pulley A <5> and
the timing pulley B <6>, or if the belt and pulley teeth engagement is deviated, the machine system's origin will
deviate.
8) Fasten the two J3 axis motor fixing screws <2> certainly with the following torque.
Model
RH-3FRH series
RH-6FRH/12FRH/20FRH series
Moreover, also fasten the nut of tension adjustment screw <1> certainly. Improper tightening can cause the belt
to loosen with vibration.
9) Install No.2 arm cover U securely as before.
10) Reset the origin of J3 and J4 axis with referring to the
11) When the maintenance forecast function is valid, reset the accumulation data about the belt. Reset by the
dedicated screen or parameter MFBRST of RT ToolBox3. Refer to "RT ToolBox3/RT ToolBox3 mini User's
Manual" for operation of RT3 and refer to "Instruction Manual/Detailed Explanation of Functions and
Operations" for the parameter.
Replacement of the J3 axis timing belt is completed.
Page 125, "(12) Timing belt
Page 111, "(2) Timing belt tension
Screw size: tightening torque
M4: 4.51Nm
M5: 9.31Nm
Page 142, "5.6 Resetting the origin"
Maintenance and inspection procedures 5-118
5 Maintenance and Inspection
tension".