METHOD FOR ISOLATION OF MAGNET CORE SLOTS IN MOTOR ARMATURE Russian patent published in 2014 - IPC H02K15/10 H02K3/34 

FIELD: electricity.

SUBSTANCE: in the method for insulation of slots of the magnet cores in micromotor stators based on charging of electroinsulating material particles with electric charge and their precipitation into slots under action of the electric field, the new development lies in placement of the armature magnet cores in the centre of an elastic cylindrical dielectric cup that covers hermetically the outer surface of the armature magnet core, installation of two electrodes at a distance of 20-30 mm from end walls of the armature magnet core, filling of the above cup with electrophoretic compound with the following ratio of components (in mg/l): varnish PE-939 of C mark - (510÷255), 1% - liquid ammonia 1% - NH₄OH - (130÷190), ethyl cellosolve - C₄H₁₀O₂ - (120÷175), diethylene oxide (C₄H₈O₂) - the rest. Positive potential from the direct current source is supplied to the magnet core and negative potential from the above source is supplied to electrodes and at current density within the range of 2-10 mA/cm², electrophoretic precipitation of the film former is made to the slots, to end surfaces and a shaft of the magnet core armature within the period of rime defined as per the formula $$t=\frac{cd}{kj},$$ where c is density of enamel, kg/m³, d is thickness of slot insulation, m, k is current output solid residual, kg/A×s. In process of electrophoretic precipitation of the film former continuous rotation of electrophoretic compound is arranged opposite each slot at the end wall of the armature magnet core, for this purpose rectangular permanent magnets are placed opposite each slot and their end walls are placed from the magnet core end at the distance of 5-10 mm. When t time is over the armature magnet core is removed from electrophoretic compound and the film precipitated at the surface of the magnet core is subject to thermal treatment during 4-5 minutes at a temperature of 380-390°C. Insulation of the armature magnet core slots for electric motor AIR71V8 according to the claimed method allows attaining the technical result at thickness of the slot insulating film much thinner than thickness of the film obtained by the prototype method.

EFFECT: increase of breakdown voltage of the film 1,4 timers more than the breakdown voltage of the film obtained by the prototype method, receipt of higher, a sequence higher, adhesive and mechanical properties of the film with simultaneous reduction of labour intensity during slots isolation per 38 times.

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