Abstract: A pumping device is used with a pneumatic tire mounted on a tire rim to keep the pneumatic tire from becoming underinflated. The pumping device includes a housing attached to the tire rim, a dynamic mass mechanically confined to rotational movement relative to the housing and the tire rim, the dynamic mass moving in response to a minimum angular velocity of the tire rim and pumping ambient air into the housing, an intake port for ambient air to enter the housing, and an exhaust port for forcing pressurized air into a tire cavity of the pneumatic tire for restoring air loss from an inflation volume within the tire cavity.

Abstract: A pumping device is used with a pneumatic tire mounted on a tire rim to keep the pneumatic tire from becoming underinflated. The pumping device includes a housing attached to the tire rim, a dynamic mass mechanically confined to radial movement relative to the housing and the tire rim, an intake port for ambient to enter the housing, and an exhaust port for forcing air into a tire cavity of the pneumatic tire for restoring air loss from an inflation volume within the tire cavity.

Abstract: A pumping device is used with a pneumatic tire mounted on a tire rim to keep the pneumatic tire from becoming underinflated. The pumping device includes a housing attached to the tire rim, a dynamic mass mechanically confined to linear movement relative to the housing and the tire rim, the dynamic mass moving in response to shock loads transferred from the tire rim to the dynamic mass and pumping ambient air into the housing, an intake port for ambient air to enter the housing, and an exhaust port for forcing pressurized air into a tire cavity of the pneumatic tire for restoring air loss from an inflation volume within the tire cavity.