Coaxial structure of auxiliary wheels and primary wheel, has frame that is pivotally connected to axle, and primary wheel and auxiliary wheels inserted coaxially onto axle via bearings

摘要

The coaxial structure includes a frame (1A) that is pivotally connected to an axle (2A). A primary wheel (3A) and the auxiliary wheels (4A) are inserted coaxially onto the axle via bearings (31A,41A). The tires (32A,42A) of the primary and auxiliary wheels can be injection molded or casting molded.