| 摘要 |
The present invention provides a castor comprising a wheel (10) having an axial central bore and an inner portion (13) in the vicinity around the bore, a hub (30) adapted coaxially and at least partially within the central bore of the wheel (10), the hub (30) comprising radially protruding labyrinths (31) adapted to cover at least partly the side surface of the inner portion (13) of the wheel (10), and a single ball bearing (20) adapted to connect the hub (30) to the wheel (10) so that the bearing (20) is protected from external impurities by the labyrinths (31), whereby the bearing (20) provides assisted rotational movement between the hub (30) and the wheel (10). The castor (1) has been provided with radial clearance (40) between the hub (30) and inner portion (13) of the wheel (10), the clearance (40) being dimensioned to provide a flexing zone for accommodating elastic deformations of the wheel (10) upon external later-al impacts subjected thereto, wherein the hub (30) is adapted to provide radial sup-port for the inner portion (13) of the elastically deformed wheel (10). |
