The connection between bucket wheel reducer output shaft (hereinafter referred to as the bucket wheel) and drive reducer internal planetary frame is expanding sleeve connection. Because of inconvenient maintenance and replacement, according to the working condition, the expansion sleeve connection was replaced by spline connection. Comparing with the expansion sleeve connection, the spline connection has the advantages of compact structure, stable operation, safe and reliable, more convenient maintenance and quick change, striving for valid time, improving work efficiency.