| 摘要 |
PURPOSE:To make it possible to facilitate the exchange of grease, by forming a new grease filling structure and a used grease discharge structure having a lid, in the outer side surface part of a hollow seal member. CONSTITUTION:A grease nipple 6 provided in the outer surface part of an outer seal 4, pierces through both seal holding frame 4b and seal member 4a and reaches a grease filling section. A discharge hole 7 formed in the outer side surface part of the outer seal 4, reaches the grease filling section. Accordingly, the exchange of grease may be made in an extremely simple way through the grease nipple 6 and the discharge hole 7. |
