Ev motor housing refers to the motor with diameter less than 160 mm or rated power less than 750 watts or with special performance and special purpose. Micromotor is a combination of high-tech industries in motor, microelectronics, power electronics, computer, automatic control, precision machinery, new materials and other disciplines. In particular, the application of electronic technology and new material technology has promoted the technological progress of micro motor.
Ev motor housing is not a complete cylinder. There are many lugs and other auxiliary structures on the cylinder. The wall thickness of each part of the casting changes greatly, and the stress of the casting during cooling and solidification will be relatively large. Previously, the deformation trend of castings could not be accurately predicted. The diameter difference of the straight end of the poured Ev motor housing casting is 15mm, and the ovality is serious. By setting annular casting ribs at the straight end, the diameter error of the straight end is within 1mm.
At the two long columns on the outside of the barrel, a "U" shape structure is formed locally, and the deformation here is also great. The distance between the two columns is not reduced during mold manufacturing, so that the casting size just conforms to the nominal size. For the arc part between the two columns at the upper end of the aluminum shell casting, the thickness of the rear wall after processing is required to be 12mm in the drawing and 5 ~ 7mm after actual processing. The problem is solved by setting the reverse deformation and increasing the arc thickness of 5mm to the axis of the cylinder.
