Abstract: A constant pressure vehicle tire inflation system includes an air supply source. A first wheel valve is in fluid communication with a first tire of the vehicle, and a second wheel valve is in fluid communication with a second tire of the vehicle. A pneumatic conduit extends between and is in fluid communication with the air supply source and the wheel valves. At least a portion of the pneumatic conduit remains charged with air from at least one of the supply source and the tires. The system includes means for distributing air flow between the pneumatic conduit and the first and second wheel valves, in which the wheel valves and the means selectively maintain fluid communication between the first and second tires and the pneumatic conduit to provide pneumatic balancing between the tires, and the wheel valves provide emergency protection when a tire experiences significant pressure loss.

Abstract: A vehicle tire inflation system includes an air supply that is connected to a vehicle tire by a pneumatic conduit. A pump that is independent of and pneumatically parallel to the vehicle air supply includes an inlet and an outlet. The pump inlet receives air from atmosphere, the pump compresses the air, and the pump outlet is fluidly connected to the pneumatic conduit. When the air pressure in the pneumatic conduit drops below a predetermined level, compressed air from the pump is introduced into the pneumatic conduit, thus increasing the air pressure in the conduit to increase the air pressure that is available to the tire. A reservoir tank, which is also independent of the vehicle air supply, may be in fluid communication with the pump outlet and the pneumatic conduit.

Abstract: A temperature warning system for a vehicle includes a thermal plug disposed on the wheel end assembly of the vehicle. The thermal plug is in fluid communication with an air supply and with a flow sensor. The flow sensor is operatively connected to a warning light or indicator. Excessive heat in the axle spindle end and/or the wheel end assembly causes a fusible material in the thermal plug to melt allowing air to flow from the air supply through the thermal plug thus activating the flow sensor. The flow sensor in turn activates the warning light or indicator alerting the driver of the vehicle of a problem condition at the wheel end assembly and/or axle spindle.