The stacker-reclaimer of Guizhou Qianbei Power Plant had long suffered from frequent oil leakage of the hydraulic coupling. A WF-CT400090 permanent magnet coupling was adopted, which was installed and put into operation on September 15, 2020 and has been running ever since with remarkable results. Relevant experience is specially summarized as follows.

II. Equipment Description of Permanent Magnet Coupling

1.Equipment Model: CT400090;

2.Installation Type: Horizontal Installation;

3.Functional Features: Torque-limiting type;

4.Usage Location: Reclaimer Bucket Wheel No.1

5.Motor Parameters: 75kW/1480rpm

III. Installation Description

1.Reserve a shaft end spacing of 180mm between the motor and reducer during design;

2.The installation is similar to that of a coupling;

Check the gaps on both sides; the error shall not exceed 0.5mm.

4.Installation Legend

IV. Commissioning Operation Status

1.After startup, the motor and the connected conductor disc quickly reach the rated speed of the motor. The rotating speed of the permanent magnet connected to the load gradually increases and finally stabilizes at a constant speed, completing the starting process.

2.Smooth operation with extremely low vibration;

3.The speed of the load is 2% slightly lower than that of the motor.

V. Usage and Maintenance

1.Adaptable to various harsh environments, unaffected by dust, temperature, muddy water;

2.No bearings or other wearing parts are required, and no maintenance is needed as with coupling products.

VI. Overload Protection

1.The torque-limiting permanent magnet coupling can realize the overload protection function during operation. When the load is suddenly overloaded or locked, it can quickly widen the gap between the magnetic disc and the conductor disc, cutting off torque transmission between the motor and the load. This makes the motor run under no load and protects the motor.

2.None of the above situations have occurred so far, and the operation remains stable.