Pumping device for seat of vehicle

A pumping device for a seat of a vehicle, the pumping device comprising:

• a cam mechanism rotating along with a lever;
• a clutch mechanism receiving power from the cam mechanism;
• a housing accommodating the cam mechanism and the clutch mechanism therein;
• a brake mechanism accommodated in the housing to receive power from the clutch mechanism, and configured such that a plurality of boss portions protrude along an outer circumferential surface thereof, outer end sides of the boss portions face an inner circumferential surface of the housing, and a pressing portion protruding from the clutch mechanism is disposed between two boss portions of the plurality of boss portions;
• and
• a brake roller provided at opposite sides of each of the boss portions of the brake mechanism to be disposed between a boss portion of the plurality of boss portions and the pressing portion, and configured such that an outermost point thereof is disposed outward more than the outer end sides of the boss portions based on a central axis of the brake mechanism, and the outermost point is brought into contact with the inner circumferential surface of the housing.