The motor for hydraulic oil pump is directly related to the energy conservation and emission reduction policy. Many national key projects and municipal projects must meet the requirements of IE3 energy efficiency assessment. However, for motor manufacturers, there are many bottleneck technologies to be broken, such as the measurement of loss and the impact of the motor. Determination of key factors of efficiency, causes of loss and quantitative analysis. The following Dalan motor small series first from the cause of the increase in loss, one by one for everyone to decompose and analyze.
Stator winding resistance is large:
(1) The wire has a large resistivity or a small wire diameter, an uneven wire diameter or a small number of turns;
(2) The wiring is incorrect or the welding is not strong;
(3) The actual number of turns is more than the design value.
Large stator current:
(1) Other losses are large;
(2) The three phases are unbalanced due to the asymmetry of the stator windings;
(3) The stator air gap is seriously uneven;
(4) Since the number of turns is less than the normal value, the resistance will be less than the normal value;
(5) The winding wiring is incorrect.
Rotor winding (or bar) resistance is large:
(1) The electrical resistivity of aluminum (copper) is large;
(2) There are air holes or impurities in the cast aluminum rotor bar or end ring, or local thin strips due to casting defects;
(3) The stator slots are not neat (expressed as slotted serrations), and there are staggered and reversed pieces, resulting in insufficient effective area of the rotor slots;
(4) Because the improper selection of cast aluminum parameters leads to loose structure of aluminum, which directly leads to an increase in resistivity;
(5) The material does not meet the requirements, for example, the ordinary aluminum rotor uses alloy aluminum;
(6) Use the wrong rotor and so on.
Large rotor current:
(1) using the wrong rotor;
(2) When the aluminum is cast, the wrong aluminum is used, for example, the alloy aluminum rotor uses ordinary aluminum;
(3) The rotor core is not laminated, resulting in a large area of aluminum between the sheets, resulting in excessive lateral current of the rotor.
Stray loss is large:
(1) improper selection of stator winding type or pitch;
(2) improper selection of the stator and rotor slots;
(3) The air gap is too small or severely uneven;
(4) The rotor bar and the core are severely short-circuited;
(5) The end of the stator winding is too long.
The number of core pieces is insufficient and the iron weight is not enough:
(1) The number of chips is insufficient (missing);
(2) The lamination pressure is small, not compacted, and the direct result is insufficient iron weight;
(3) The burr of the punching piece is large, and the iron weight cannot be guaranteed when the iron length is met;
(4) The paint is too thick and belongs to the direct quality problem of silicon steel sheet.
----- Editor-in-Chief: Dalan Oil Pump Motor 02-Procurement Consultant
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