A rotatable shaft (22) slidingly rotatable supported in the circumferential direction in a slide bearing (16) formed of a porous sintered alloy-made bushing having pores (30) impregnated with a lubricating material (31), slide bearing grease (24) supplied between the slide bearing (16) and the shaft (22) and containing base oil, characterised by the base oil having a lower dynamic viscosity than that of the lubricating material (31) and exuding under a load of said shaft (22) to form an oil film (35) between said slide bearing (16) and said shaft (22), the slide bearing grease being (24) added with at least a solid lubricant (33).
