Small angle grinders are power tools that we often use in our daily lives, but the maintenance of angle grinders is usually ignored, so I would like to remind everyone that they also need to be maintained in the process of use.
1. Always check whether the power cord connection is firm, whether the plug is loose, and whether the switching action is flexible and reliable.
2. Check whether the brush is worn too short, and replace the brush in time to prevent excessive sparks or burn the armature due to poor brush contact.
3. Pay attention to check that the air inlet and air outlet of the tool are not clogged, and remove oil and dust from any part of the tool.
4. Grease should be added in time.
5. If the tool fails, send it to the manufacturer or designated maintenance office for overhaul.If the tool is damaged due to abnormal use or human error in disassembly and repair, the manufacturer generally will not repair or exchange it free of charge.
6. Check the marking of the angle grinder.The angle grinders that cannot be used are: unmarked, those that cannot be clearly marked, and those that cannot be verified, regardless of whether they have shortcomings or not.
7. Check the shortcomings of angle grinding.There are two inspection methods: visual inspection, directly use your eyes to observe the surface of the angle grinder for cracks and other problems; percussion inspection, which is the main part of the inspection of the angle grinder, the method is to beat the angle grinder with a wooden mallet.If there is no problem with the angle grinder, it should be a crisp sound, if there is other sound, it indicates that there is a problem.
8. Check the rotational strength of the angle grinder.Use the same kind of angle grinders of the same batch of models for spot checks on the strength of rotation, and angle grinders that have not been tested must not be installed and used.
Electric brushes can be used in DC motors or AC commutator motors, such as general-purpose power tools, such as hand drills and angle grinders.It is used to cooperate with the commutator to realize the current commutation of the motor. It is a sliding contact body for the motor (except for the squirrel cage motor) to conduct current.In a DC motor, it is also responsible for the task of commuting (rectifying) the alternating electromotive force induced in the armature winding.Practice has proved that the reliability of motor operation depends to a large extent on the performance of the brush.
Leakage repair
Common faults that cause leakage of angle grinders are: stator leakage, rotor leakage, brush seat leakage (angle grinder with metal shell) and internal wire damage.
1) Remove the brush to determine whether the stator, brush holder and internal wires are leaking.
2) Disconnect the connection line between the stator and the brush holder to determine whether the brush holder is leaking electricity.
3) Independently measure whether the rotor is leaking electricity.
The rotor and brush holder can only be replaced for leakage, and the stator can be rewound or replaced.
First, disassemble and check if the wiring skin is damaged. Use a multimeter to detect the chassis, and then take out the rotor and measure it. It can be measured whether the rotor is leaking or the stator is leaking. The rotor can only be replaced. The stator leaks to see if the carbon brush powder and other debris accumulate too much and the leakage is caused. Clean it up and then measure it. The leakage means that the stator winding is not insulated well, and see if the winding is connected to the shell or wet. If not, it can only be rewound.
The fault and troubleshooting method of the angle grinder. The angle grinder uses a series excitation motor. The characteristic of this motor is that it has two carbon brushes and a commutator on the rotor.
The most common burned-out parts of this kind of motor are the commutator and the end of the rotor winding.
If the commutator is burned, the pressure of the carbon brush is generally not enough.When the motor is working, if the current continues to be large, the carbon brush will wear out quickly. After a long time, the carbon brush will become shorter, the pressure will become smaller, and the contact resistance will be very large. At this time, the heat on the surface of the commutator will be very serious.
If the winding part is burned, it means that the angle grinder puts a lot of pressure on the workpiece while working, the friction force is very large, and the motor is in an overloaded state for too long.It is also because the current is too strong.
Post time: Nov-11-2022
