Patent ID: 7165815

Claim:
A wheel assembly, comprising a main body, two wheels, and two positioning shafts, wherein: the main body has two opposite sides each formed with a pivot hole; each of the two wheels is rotatably mounted on the main body and has a center formed with a step-shaped positioning hole; each of the two positioning shafts is mounted on a respective one of the two wheels and is combined with the main body; each of the two positioning shafts has a first end formed with a plurality of elastic positioning plates each extended through the positioning hole of the respective wheel and the respective pivot hole of the main body and each having a distal end formed with a hook-shaped locking portion locked on an inner side the respective pivot hole of the main body to lock each of the two positioning shafts on the main body; the wheel assembly further comprises two retaining rods each mounted in a respective one of the two positioning shafts to press each of the two positioning shafts on the main body; each of the two retaining rods has a first end formed with a retaining portion urged on the positioning plates of the respective positioning shaft to position the locking portion of each of the positioning plates on the inner side the respective pivot hole of the main body so as to lock each of the two positioning shafts on the main body; the first end of each of the two positioning shafts is formed with a plurality of slits located between the positioning plates; each of the two positioning shafts has an inside formed with a step-shaped limit hole axially extended through a whole length of each of the two positioning shafts and communicating with the slits, and each of the two retaining rods is mounted in the limit hole of the respective positioning shaft.