LOWER ROLLING WHEEL WITH MUDDY WATER SEAL

摘要

PROBLEM TO BE SOLVED: To prevent the breakage of a lip seal when small stones directly collide therewith by arranging an approximately circular protective washer smaller than the outer diameter of the tread of a roller at both ends of a rolling wheel of a center-supported type with a roller mounted via the lip seal fitted into a shaft and a bearing in a crawler vehicle. SOLUTION: In a mobile crawler vehicle, a lip seal 2 and a ball bearing 3 are externally fitted around a shaft 1 center-supported on a truck frame 5 and a lower rolling wheel with the lip seal 2 and the ball bearing 3 internally fitted into a roller 4 is provided. In this case, a protective washer 7 with an outer diameterϕ3 for the lip seal 2 is fixed to the shaft 1 and provided a spaceδapart from both end faces 4b of the roller 4. The length L of the stepped portion of the shaft 1 is a fastening allowance D shorter than a value t3 which is obtained by adding the plate thickness t1 of the truck frame 5 to the plate thickness t2 of the protective washer 7. In this way, the shaft 1 is fastened with a bolt 9 to hold the protective washer 7 onto the stepped face of the shaft 1 and the truck frame 5.