| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the capacity of a grease basin by the portion of the volume of a spacer, and reduce the quantity of grease to be filled and the filling time by inserting the spacer formed of a deformable elastic body into the cylindrical grease basin. SOLUTION: A lateral pair of boss parts 31 are integrally provided on the base end part 15a of a boom 15 through a central pipe 29. Bearings 33 are press fitted to the inside surfaces of the boss parts 31. A spring 14 as a resin- made elastic body is inserted into a grease basin part 45. The spring 13 is formed in such a manner that the outer diameter R is smaller than the inside diameter D of the central pipe 29 and the inside diameter R0 is larger than the outer diameter D0 of a pin 11 in free state, so that it never obstructs the insertion of the pin 11 or the supply of grease to the boss parts 31. The spacer 13 is arranged in the grease basin part 45, whereby the capacity of the grease basin part 45 is reduced by the portion of the volume of the spacer 13.</p> |
