Mitsubishi Electric MELFA RH-3FHR3515 Instruction Manual page 91

■ Inspecting the J4 axis timing belt
1) Confirm that the robot controller power is OFF.
2) Refer to Page 73, "5.3.2 Installing/removing the
cover J4.
3) Visually confirm that the symptoms indicated in
the timing belt <2>.
4) Check the belt tension as shown in
confirm that the value of belt slack is in following.
Motor side: Force to press the belt: apprpx.2N ･ m, Flexure: approx.1.1mm
Shaft side: Force to press the belt: apprpx.4N ･ m, Flexure: approx.1.3mm
■ Adjusting the J4 axis timing belt
1) Carry out steps "1)" and "2)" indicated in
2) Lightly loosen the two idler installation bolts <1>. (Do not loosen too much.)
3) The nut which is fixing tension adjustment screw <3> is loosened, turn tension adjustment screw <3>, and
adjust the tension of timing belt <2>. When the screw is turned to the right, the belt will be stretched, and
when turned to the left, will loosen.
Lightly press the center of the belt <A>, and confirm that the value of belt slack is in following.
Motor side: Force to press the belt: apprpx.2N ･ m, Flexure: approx.1.1mm
Shaft side: Force to press the belt: apprpx.4N ･ m, Flexure: approx.1.3mm
If the belt is loosened too much when adjusting the tension causing it to come off the timing pulleys <4> and
<5>, or if the belt and pulley teeth engagement is deviated, the machine system's origin will deviate
4) After adjustment fastens the fixing nut of tension adjustment screw <3>, and certainly fixes tension
adjustment screw <3>. Moreover, also fasten idler fixing screw <1> certainly. (two pc.) Improper tightening can
cause the belt to loosen with vibration.
cover", and remove the No.2 arm cover and the belt pulley
"(1)Timing belt replacement period"
"Fig.5-8 ： Belt tension"
" ■ Inspecting the J4 axis timing belt"
5 Maintenance and Inspection
. Lightly press the center of the belt <A>, and
above.
Maintenance and inspection procedures
have not occurred with
5-80