| 摘要 |
PROBLEM TO BE SOLVED: To provide a negative pressure booster capable of securing smooth sliding of a valve cylinder and preventing the generation of abnormal sound by preventing a stick-slip phenomenon of a seal lip.SOLUTION: In a negative pressure booster, bearing bush 9 made of elastic material, which slidably supports the outer peripheral surface of a valve cylinder 10 connected to a booster piston 5, is mounted to a bearing cylinder 12 provided on a rear wall of a booster shell 1, the inner peripheral surface of the bearing bush 9 is provided with a grease reservoir 35 for holding lubrication grease g, and the rear end of the bearing bush 9 is provided with a seal lip 13 decreased in thickness to be elastically brought into close contact with the outer peripheral surface of the valve cylinder, which is integrally connected thereto. The inner peripheral surface of the seal lip 13 is provided with an extension grease reservoir 35 continuously communicated with the grease reservoir 35 for holding the lubrication grease g common to that in the grease reservoir 35. |
