GP12 inspection, grease exchange and battery replacement
GP12 maintenance follows the same structure as the GP25: the speed reducers of the basic axes (S-, L- and U-axes) get a grease exchange, and the wrist side (R-, B-axis speed reducer and R-, T-axis gear) a small grease replenishment. The grease amounts and plugs are specific to the GP12. Inspection intervals are counted in hours with the servo power ON.
Turn the power off and tag it out before maintenance. If you disconnect the connector between a motor and the multi-port connector, the encoder absolute data (ABSO data) is lost.
Inspection items
| Schedule | Items and what to do |
|---|---|
| Daily | Alignment mark; working area and manipulator (seeped oil, cracks, dirt); wire harness in manipulator for the SLU-axes (damage, dirt) |
| 1000 h cycle | Baseplate mounting bolts; connector for manipulator cable; protective tubing (for arc welding use only; replace at 24000 h) |
| 12000 h cycle | Timing belts for B- and T-axes; flexible hose of the SLU-axes wire harness; fixed part of the BT-axis wire harness; grease leakage at the S, L, U, R-axis motors; replace grease in the S, L, U-axis speed reducers; supply grease to the R, B-axis speed reducer and R, T-axis gear (hand pump or injection syringe) |
| 24000 h | Replace the wire harnesses in the manipulator (SLU- and BT-axes); replace the battery pack in the manipulator (also when the battery alarm occurs) |
| 36000 h | Overhaul (YASKAWA service company) |
Grease used (standard specification)
| Inspected parts | Grease used |
|---|---|
| S-, L- and U-axes speed reducers | Molywhite RE No.00 |
| R- and B-axes speed reducers, R, T-axes gear | Harmonic Grease SK-1A |
Grease exchange for the S-, L- and U-axes speed reducers
Always remove the plug from the grease exhaust port before injecting. Inject with a grease pump at 7 g/s or less, with the air supply pressure of the grease pump at approximately 0.3 MPa or less. When extruding or suctioning grease out, keep the pressure at 0.025 MPa or less.
| Axis to exchange grease | Amount of grease (approx.) | Amount of exhausted grease |
|---|---|---|
| S-axis | 700 g | 25 ± 5 g (30 ± 5 cc) |
| L-axis | 450 g | 50 ± 5 g (60 ± 10 cc) |
| U-axis | 350 g | 40 ± 5 g (45 ± 10 cc) |
- When replacing the speed reducer, operate the axis about 5 times at ±45° in the teach mode, then inject again.
- The maintenance manual gives no separate amount for the first supply only.
| Axis | Grease inlet | Grease exhaust port |
|---|---|---|
| S-axis | Hexagon socket head plug PT3/8 | Hexagon socket head plug NPTF3/8 |
| L-axis, U-axis | Hexagon socket head plug NPTF3/8 | Hexagon socket head plug NPTF3/8 |
The tightening torque of the plugs is 16.5 N·m, with seal tape TB4501. When ceiling-mounted, the grease inlet and exhaust port are swapped.
Grease replenishment for the R-, B-axis speed reducer and R-, T-axis gear
Use a hand pump or injection syringe to inject a small amount of Harmonic Grease SK-1A. Grease is not exhausted from the air exhaust port, so do not inject too much.
| Part | Amount of grease | Grease inlet / air exhaust port | Tightening |
|---|---|---|---|
| R-axis speed reducer | 7 g | Hexagon socket head plug PT1/8 | 4.9 N·m (0.49 kgf·m) |
| B-axis speed reducer | 7 g | Hexagon socket head cap screw M6 | 6 N·m (0.6 kgf·m), apply Three Bond 1206C |
| R-axis gear | 3 g (55 g when the speed reducer is replaced) | Hexagon socket head plug PT1/8 | 4.9 N·m |
| T-axis gear | 2 g each into grease inlet 1 and grease inlet 2 | Hexagon socket head cap screw M6 | 6 N·m |
Drip-proof and food grade grease specifications
The food grade grease specification (-F00) replaces the grease of the drip-proof specification (-C00) as follows. It is for handling applications only.
| Part | Drip-proof (-C00) | Food grade grease (-F00) |
|---|---|---|
| S-, L- and U-axes speed reducers | RV grease LB No.00 | CASSIDA grease EPS00 |
| R- and B-axes speed reducers, R, T-axes gear | Harmonic Grease SK-1A | Harmonic Grease HFL-1 |
With the food grade grease specification, a drain plug check (1000 h cycle) is added to the inspection schedule and the overhaul is at 18000 h. The recommended spare parts list CASSIDA grease EPS00 (19 kg), Harmonic Grease HFL-1 (2.5 kg) and CASSIDA grease EPS02 (19 kg).
Replacing the battery packs in the manipulator
There are three battery packs (HW1483880-A). The procedure is the same as for the GP25.
- When the power can be turned on: turn ON the controller power, turn OFF the servo power, and replace with the emergency stop button pressed.
- When the power cannot be turned on: first connect the lead wires for battery replacement (HW1471281-A) and the battery pack for backup to the "IN" port of the multi-port connector, then replace the pack. Otherwise the encoder absolute data is lost.
Related articles
- GP12 specifications
- GP25 inspection, grease exchange and battery replacement
- Encoder battery replacement
- Alarm 4312 ENCODER BATTERY ERROR
Source: based on YASKAWA manuals HW1484059 (GP12/AR1440 instructions rev 6, Japanese), HW1484061 (GP12/AR1440 maintenance manual rev 2, Japanese) and HW1485681 (GP12 supplemental instructions, food grade grease rev 0, Japanese). English terms follow HW1484060 (MOTOMAN-GP12/AR1440 INSTRUCTIONS rev 4; older than the Japanese rev 6), HW1484062 (MOTOMAN-GP12/AR1440 MAINTENANCE MANUAL rev 1) and HW1485682 (rev 0).