Morteng grounding carbon brushes are key components in rotating motors (such as generators and electric motors), primarily used to eliminate shaft currents, protect equipment safety, and assist monitoring systems. Their application scenarios and functions are as follows:
I.Core Functions and Effects
- When a generator or motor is running, asymmetry in the magnetic field (such as uneven air gaps or differences in coil impedance) can induce shaft voltage in the rotating shaft. If the shaft voltage breaks through the bearing oil film, it can form shaft current, leading to shaft bearing electrolysis, lubricant degradation, and even bearing failure.
- Morteng grounding carbon brushes short-circuit the rotor shaft to the machine housing, diverting shaft currents to ground and preventing them from flowing through the bearings. For example, large generators typically install grounding carbon brushes at the turbine end, while the excitation end bearings are fitted with insulating pads, forming the classic ‘excitation end insulation + turbine end grounding’ configuration.
II. Typical Application Scenarios
-Thermal/hydropower generators: Morteng grounding carbon brushes are installed at the turbine end, in conjunction with insulated bearings at the excitation end, to eliminate leakage magnetic induction shaft voltage. For example, in hydropower generators, thrust bearings rely solely on a thin oil film for insulation, and grounding the carbon brushes can prevent electrolysis of the bearing shells.
-Wind turbines: Used for generator rotors or surge protection systems, materials are often selected from metallic graphite (copper/silver-based), which offers high conductivity, wear resistance, and transient current resistance.
-High-voltage/variable-frequency motors: These have a higher risk of shaft current. For example, Tonghua Power Generation Company installed grounding carbon brushes on the drive end of the primary fan motor, using constant-pressure springs to maintain a zero potential, thereby resolving the issue that the original insulated bearings could not completely block shaft current.
-Railway transportation: In traction motors of electric locomotives or diesel locomotives, grounding carbon brushes eliminate static electricity accumulation during operation, protect bearings, and maintain electrical system stability.
Post time: Aug-01-2025
