SP225H / SP180H gas balancer pressure check
These models use a gas balancer (high-pressure nitrogen gas) to support the load on the L axis. Running the robot with the wrong gas pressure can cause failure or damage.
Inspection interval
Check the gas pressure every 6000 h.
Correct gas pressure depends on temperature
Measure the surface temperature of the gas balancer and compare the pressure with this table.
| Surface temperature °C | −10 | −5 | 0 | 5 | 10 | 15 | 20 | 25 | 30 | 35 | 40 | 45 | 50 | 55 | 60 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Correct gas pressure MPa | 10.5 | 10.8 | 11.1 | 11.4 | 11.6 | 11.9 | 12.2 | 12.4 | 12.7 | 13.0 | 13.2 | 13.5 | 13.8 | 14.1 | 14.4 |
Work sequence (checking and adjusting the pressure)
- Move the robot to the home posture and turn off the controller power.
- Remove the cover and plug from the gas inlet and insert the quick joint.
- Check that all valves on the gas charging device are closed, then attach the device to the quick joint.
- Check the surface temperature of the gas balancer and read the pressure.
- Release or add gas until the pressure matches the table.
- Remove the quick joint, refit the plug and cover at the specified torque, and turn the power back on.
Consult the manufacturer's service department about the gas charging device.
Safety precautions
- Use nitrogen gas only. Never put any other gas in.
- High concentrations of nitrogen can cause suffocation. Ventilate the area well while you work.
- Before starting, always confirm that the L-axis motor brake is working, or that the L arm is fixed so that it cannot rotate. If the L axis loses its holding force, for example because the brake is released, the balancer extends and swings the L arm, which is very dangerous.
- Follow the laws and local regulations on high-pressure gas.
- A very small amount of seal oil may seep from the bottom of the balancer.
Source: Based on YASKAWA manual HW1484423.