To disassemble the gearmotor, unscrew the screws securing the gear cover and remove it together with the limit switch panel. Then, the screws securing the gearbox housing to the motor housing are unscrewed and disconnected. Take out the motor armature. To remove the gearbox gear, unscrew the crank fastening nut, remove the retaining ring from the axle and remove the axle with the gear and washers from the housing.
The procedure for disassembling gearmotors manufactured by VNR is similar to that described above for domestic gearmotors. Only when disassembling, it must be borne in mind that the front bearing of the armature shaft is pressed into the cover with an interference fit. Therefore, to clean the collector, it is not recommended to disconnect the motor armature from the cover.
After disassembly, the internal cavities of the electric motor are blown with compressed air to remove deposits of coal dust and the technical condition of the parts of the gearmotor is checked. The brushes should move freely, without jamming, in the brush holders, and the springs should firmly press the brushes to the collector. The latter is cleaned with sandpaper with a grain size of 10 - M40, and then wiped with a clean rag, lightly greased with technical petroleum jelly. If the collector is badly burned or worn out, then it is better to replace the gearmotor with a new one. Check for signs of seizing on the necks of the armature shaft. If necessary, clean them with the same sandpaper.
The assembly of the gearmotor is carried out in the reverse order of disassembly. When assembling, the brushes are removed from the collector so as not to break them and not damage their edges, and the anchor is inserted into the housing with extreme care, avoiding hitting the poles so as not to break them. After assembly, it is recommended to tap the motor housing with a wooden hammer to center the bearings, and then check it on the stand. When installing the crank, it must be positioned so that in the final position it is parallel to the short arm of the cleaner and directed towards the electric motor.