Impeller casting shape and size

The shape and dimension inspection of impeller casting is to check whether the actual dimension of impeller blank casting falls within the specified dimensional tolerance zone of impeller blank casting.

a. Rim roundness error

Use the rotary shaft roundness measuring instrument to measure the roundness error of the inner and outer diameter of the wheel flange, and the roundness error is always controlled within 0.5mm.

b. Distance difference between adjacent blades

By measuring one by one with template and vernier caliper, the maximum distance error between adjacent cast impeller blades is 0.8mm, which is controlled within the maximum error of 1mm, meeting the technical requirements.

c. Flatness error

Use the clearance method to measure the flatness error of the upper and lower surfaces of the impeller, use the knife edge ruler to measure the straightness in all directions on the plane, and directly use the clearance method and the feeler gauge to obtain the error value. The maximum error is 1mm, which is controlled within 3mm and 5mm of the upper and lower machining allowance.

d. Dimensional inspection of casting impeller

Through the inspection of the main dimensions of the cast impeller blade, rim, spoke and hub and referring to the standard of dimensional tolerance and machining allowance of castings (GB / T6414-1999), the dimension of the impeller casting meets the technical requirements of cT4 ~ CT5, and the position dimension of the cast impeller blade can reach CT3.

After annealing, the impeller casting is delivered in the surface sand blowing state. After machining by the enterprise, the dynamic balance test shows that the impeller casting can fully meet the use requirements.