Tensioning wheel with fully-sealed dust-proof structure

The invention relates to a tensioning wheel with a fully-sealed dust-proof structure. The tensioning wheel with the fully-sealed dust-proof structure comprises a tensioning wheel (1), a wheel axle (2), a bearing (6), a dust cover (3), a bearing end cover (4) and a fixed mandrel (5), wherein an outer ring of the bearing (6) is in interference fit with an inner hole of the tensioning wheel (1); an inner ring of the bearing (6) is in interference fit with the wheel axle (2); an annular groove A (9) and an annular groove B (10) are sequentially formed in the other side of the inner hole of the tensioning wheel (1); an elastic collar (7) for the hole is embedded into the annular groove A (9); the dust cover (3) is mounted on one side of the tensioning wheel (1) in a matching way; the fixed mandrel (5) is connected with the wheel axle (2) through threads in a matching way from the other side of the tensioning wheel (1); the bearing end cover (4) sleeves the fixed mandrel (5); the bearing end cover (4) is propped against the side surface of the inner ring of the bearing (6). The tensioning wheel with the fully-sealed dust-proof structure has the advantages of being simple in structure, low in cost, stable in sealing performance and convenient in detachment and mounting.