Abstract: In a vacuum booster for a vehicular brake, at least one of flat front attachment portion and flat rear attachment portion has a central disc portion which is concentric with a fitting cylindrical portion and plural side disc portions which are disposed around the central disc portion so as to be continuous with the central disc portion and to be spaced from each other. Bolts are inserted through at least a pair of side disc portions of the plural side disc portions.

Abstract: According to one embodiment, a vacuum booster includes a booster shell and a booster piston which divides an interior of the booster shell into a front vacuum chamber and a rear operation chamber. The vacuum booster further includes a valve cylinder in which a control valve controls a communication state of the operation chamber depending on a movement of an input rod. A bearing cylinder is provided on a rear wall of the booster shell. A bearing bush is mounted in the bearing cylinder to support the valve cylinder, and a seal lip is provided at a rear end of the bearing bush integrally therewith to contact elastically closely with the valve cylinder. A grease reservoir is provided in an inner surface of the bearing bush, and an extension grease reservoir is provided in an inner surface of the seal lip.

Abstract: According to one embodiment, a vacuum booster includes a booster shell and a booster piston which divides an interior of the booster shell into a front vacuum chamber and a rear operation chamber. The vacuum booster further includes a valve cylinder in which a control valve controls a communication state of the operation chamber depending on a movement of an input rod. A bearing cylinder is provided on a rear wall of the booster shell. A bearing bush is mounted in the bearing cylinder to support the valve cylinder, and a seal lip is provided at a rear end of the bearing bush integrally therewith to contact elastically closely with the valve cylinder. A grease reservoir is provided in an inner surface of the bearing bush, and an extension grease reservoir is provided in an inner surface of the seal lip.

Abstract: In a vacuum booster for a vehicular brake, at least one of flat front attachment portion and flat rear attachment portion has a central disc portion which is concentric with a fitting cylindrical portion and plural side disc portions which are disposed around the central disc portion so as to be continuous with the central disc portion and to be spaced from each other. Bolts are inserted through at least a pair of side disc portions of the plural side disc portions.