This paper takes a heavy duty apron feeder that we provided for a domestic sintering plant as an example to analysis its operation faults. The essential parameter of this apron feeder is: conveying material is hot sintering ore, conveying capacity is 880t/h, material temperture is 750℃～850℃. Apron feeder usually used in normal working temperature, the connect between the shaft drive and sprocket wheel often use the casing swage connection. The casing swage connection is easy to installation and replacement and convenient to maintenance. Under the high temperature working condition, because the material expansion and contraction, the gap between main shaft and chain sprocket is large.

According to the analysis of the service conditions of the heavy duty apron feeder, the sinter transported is 750℃~850℃, and the material temperature is 400℃~ 500℃ when it reaches the unloading part of the main shaft after being cooled by the cool air of the blower in the transportation section. Therefore, the connection type of casing swage cannot be adopted. The analysis shows that the axial force on the main shaft sprocket can be ignored and the main bearing is radial force. In order to ensure the reliable connection when bearing large radial load, the main shaft is mounted between the driving main shaft and the sprocket wheel and support wheel. Key connection can be used in high temperature condition, reliable connection, easy loading and unloading, low processing cost. By means of key connection, the heavy plate feeder can effectively meet the high temperature conditions of the operation site and ensure the performance of the main machine.
Technicle pricinple and theoretical foundation
Due to the limition of the hot working condition, the main shaft device of heavy duty apron feeder changes the previous design type, changing the casing swage connection between the driving spindle and the driving sprocket and supporting wheel to the key connection, which can effectively overcome the high temperature conditions and ensure the smooth operation of the equipment.
After analyzing the field conditions of the apron feeder, the product was designed and the chain connection was selected as the connection mode of driving spindle, sprocket and support wheel. In the process of heavy duty apron feeder conveying material, the driving sprocket on the spindle device mainly bears the driving traction effect, but the axial force is small. The middle support wheel mainly plays a supporting and auxiliary traction role, the axial force is small. Therefore, in the overall design of the spindle device, the supporting wheel adopts the axial positioning method with one end as the shaft shoulder and the other end as the retaining ring and positioning screw. But in the sprocket part has adopted the axle shoulder and the axle sleeve localization way.
Process design, product drawing and manufacturing
After the design of shaft and parts is completed, the process design is carried out, including heat treatment process and machining process design. The processing method is optimized while the performance of parts is guaranteed to achieve the purpose of convenient processing and cost saving.