Patent attributes
A wheel end assembly includes a self-contained air pump mechanism that maintains tire pressure at a desired level. The pump mechanism includes a piston and cylinder assembly that rotate with the tire. A linkage assembly drives the piston within the cylinder as the wheel end assembly rotates to pump air into the tire via a valve. The linkage assembly includes a first link fixed to a non-rotating wheel end component and a second link that rotates relative to the first link and which is coupled to drive the piston within the cylinder. The tire valve is in fluid communication with the cylinder and automatically opens when air pressure in the tire falls below a predetermined level and automatically closes when the air pressure achieves the predetermined level. An atmospheric valve is in fluid communication with the cylinder, and automatically opens to recharge the cylinder once the initial pressure charge has been delivered to the tire.
