C4 Maintenance 7. Joint #3
94 C Series Maintenance Manual Rev.2
7.2 Joint #3 - Replacing the Reduction Gear Unit
A reduction gear unit consists of the following three parts. Also, two additional parts are included as
accessories. When replacing the reduction gear unit, be sure to replace these parts all together as a set.
Reduction gear unit: Wave generator, Flexspline (CRB combined), Circular spline
Accessory: O-ring × 2
For details, refer to C4 Maintenance: 17. C4 Maintenance Parts List.
It is recommended replacing the O-rings (for Joint #3) when replacing the reduction gear unit.
Removal: Joint #3 Reduction gear unit
1. Remove the following parts.
Arm #2 side cover
Arm #3 head cover
Arm #4 side cover
User plate
When removing the user plate, remove the following parts from the plate.
D-sub 9-pin connector
4 air tubes
For details, refer to C4 Maintenance: 3. Covers.
2. Remove the Joint #3 timing belt.
For details, refer to C4 Maintenance: 7.3 Joint #3 –
Replacing the Motor, Removal steps (1) through (3).
3. Remove the cable unit.
For details, refer to C4 Maintenance: 4.1 Replacing the Cable Unit, steps (9) through (21).
Maintenance
Joint #3 reduction gear unit
Tools
Hexagonal
wrench
For M4 hexagon socket set screws
width across flats: 2.5 mm
For M3 hexagon socket head cap bolts
For M4 hexagon socket head cap bolts
For belt tension adjustment