Nanyang DC motor repair commutator fault inspection and repair

Nanyang DC motor repair commutator fault inspection and repair
DC motor repair commutator inspection and repair The factors for poor contact include commutator step difference and insufficient roundness accuracy (note the step difference is the radius difference between the two commutator segments) Replacement The surface roughness of the commutator is too low. The surface of the commutator is scratched. The gap of the commutator is seriously uneven. The material strength and heat resistance of the commutator are unqualified.
Nanyang DC motor maintenance and repair methods for internal short circuit in the commutator
If a short circuit occurs inside the DC motor commutator, the following treatment methods must be adopted.
, open the binding hoop at the end of the coil on the commutator side.
Make sure to mark the mutual positions of the rotor windings, iron slots and commutator segments.
, Make iron hoops to prevent the commutator from loosening during maintenance. When making iron hoops, the number, thickness and width of the iron hoops should be determined according to the diameter and axial length of the commutator. Generally, thick steel plates are used to make iron hoops with a width of ~. First, wrap the commutator with two layers of epoxy glass cloth or an insulating board that is wider than the width of the iron hoop. Then wrap the iron hoop on the insulating board and tighten it with the bolts on the iron hoop. Commutator, so that the iron hoop hugs and tightens the commutator tightly.
Loosen the pressure ring of the commutator, take out the mica ring, and check that the short circuit point is not at this end of the commutator before removing the commutator. Check the condition of the shaped mica ring on the other side. If the shaped mica ring is firmly stuck, do not force it down. In addition, the surface condition of the shaped mica ring can also be directly inspected in the commutator. If it is found that there is a large amount of carbon powder and oil on the surface of the mica ring, wipe the surface of the mica ring clean with a white cloth dipped in alcohol. At the same time, wipe the carbon powder and oil on the commutator and mica sheets. For scorched marks on the mica ring, use a scraper to scrape off the scorched parts, and then wipe them clean with a white cloth dipped in alcohol. After thorough cleaning, use the power supply voltage to test the inter-chip resistance. After passing the test, put the cleaned shaped mica ring on, then set the shaped pressure ring, install the commutator, and finally use a test light to check the short circuit between the pieces until it is qualified.
If the mica ring is severely burned and the depth is very deep, the burned part must be completely dug out with an electrician's knife, and a groove must be dug around the faulty part to expose the new insulation. Then use epoxy resin glue and glass fiber cloth to fill the hollowed area flat. After curing, trim the surface to make it flat. After passing the test, it can be put into use again.
If the shaped mica ring is severely burned and cannot be repaired locally, then a new shaped mica ring must be made. After replacing the new mica ring, reassemble the commutator until the pressure test is passed. Then remove the iron hoop on the commutator, insert the rotor winding into the commutator slot, and weld with the commutator segments. Finally, after passing the pressure test, the surface of the commutator must be sealed.