5-74
Maintenance and inspection procedures
5Maintenance and Inspection
(6) Timing belt tension
Fig.5-8 ： Belt tension
The timing belt can satisfactorily convey the drive and keep a durable force only when it has an adequate tension.
The belt tension should not be too tight or too lose. Instead, it should be adjusted to a degree that elasticity is felt
when the belt is pressed with the thumb. If the belt tension is too weak, the belt loosening side will vibrate. On the
other hand, if the belt tension is too strong, a sharp sound will be heard and the belt tension side will vibrate.
The detailed adjustment (tension) is shown in
Check and adjust with the belt pressing force f and the slack amount d between span s.
F
Pressing force
The preset value and adjustment value in the sound wave type belt tension gauge
Axis
Belt type
Sepang ： s mm
Slack ： d mm
Pressing force ： f (N)
J1
340-5GT-20
84
1.3
10
J2
363-3GT-12
103
1.6
4
J3
297-3GT-9
77
1.2
3
J4 (Motor side)
345-3GT-6
69
1.1
2
J4 (Shaft side)
312-3GT-12
82
1.3
4
Axis
Belt type
Preset value
Standard tension
T(N)
M （g/m)
W （mm/R)
S(mm)
J1
340-5GT-20
4.0
20
84
123 ～ 151
J2
363-3GT-12
2.5
12
103
53 ～ 65
J3
297-3GT-9
2.5
9.0
77
40 ～ 48
J4 (Motor side)
345-3GT-6
2.5
6.0
69
26 ～ 32
J4 (Shaft side)
312-3GT-12
2.5
12
82
53 ～ 65
ｆ ： Pressing force
ｓ ： Span
ｄ ： Slack
T ： Tension
