Abstract: A device for maintaining inflation pressure within a tire interior of a tire mounted on a rotating wheel with a rim. The device includes a compressor with piston penetrateably mountable on the wheel rim or in communication with a valve stem that incorporates air delivery to the compressor as mounted within the tire. The piston is in communication with a compressible piston driver having a distal end in contact with the inner floor of the mounted tire where the outer side of the tire contacts the ground once every revolution of the wheel. Repeated deformation of the rotating tire where it contacts the ground outside the distal end of the driver is transferred to the air compressor through a piston compression stroke. When such ground contact is not occurring, centrifugal force causes radial movement to accomplish the intake stroke of the piston. In this repetitious manner a small amount of air is forced into the tire during each rotation thereof when needed to maintain desired inflation pressure.

Abstract: A device for automatically maintaining desired air pressure within a vehicle tire utilizes deformation of the rotating tire where it contacts the road surface to operate an air compressor. The air compressor is formed in the wheel and connected to the tire, the compressor responsive to deformation of the tire causing compressed air to pass into the tire. The compressor is preferably of a reciprocating piston type having a cylinder adapted to receive a sliding piston, the piston preferably slidably received within a plunger in contact with the inside of the tire. A spring is preferably disposed between the plunger and the piston to limit the motion of the piston to a fixed displacement less than the deformation of the tire, such that the tire inflation system is operable for a wide range of deformations of the tire.

Abstract: A device for automatically maintaining desired air pressure within a vehicle tire utilizes inertial forces from changes in vehicle speed. The device includes a flywheel attached to and concentric with the vehicle wheel but free to rotate relative the wheel, and an air compressor attached to the vehicle wheel and connected to the tire, the compressor piston responsive to rotation of the flywheel with respect to the vehicle wheel to pass air into the tire. Preferably a connecting rod converts the rotation of the flywheel relative the wheel into the reciprocating sliding of a piston to operate the air compressor. Additionally, a centrifugal intake valve is preferably provided that seals off the inlet passageway to the air compressor when the vehicle is stopped or moving slowly to prevent contaminants from entering.

Abstract: A device for maintaining a desired inflation pressure within the tire utilizes a motor and air compressor disposed upon the rotating wheel to eliminate the requirement for a rotary pneumatic joint. The air compressor provides a source of air for maintaining inflation pressure and is driven by a DC motor. The motor is, in turn, driven by a generator which is partially disposed upon the rotating wheel and partially disposed upon a non-rotating portion of the vehicle. A stationary magnet attached to a non-rotating portion of the vehicle defines the generator's stator. Windings which define the generator's armature are formed upon a substrate which is applied to the rotating wheel such that the windings pass within close proximity to the stationary magnet. The air compressor may alternatively be mechanically driven directly by the rotation of the wheel.