A method of decreasing tire pressure includes opening a wheel valve (22) to allow pressurized air from a tire (10) to be directed to a first valve assembly (14) and to atmosphere. A target pressure is selected for a fluid control conduit (28). The fluid conduit (28) is in fluid communication with the first valve assembly (14) and a second or control valve assembly (30). The pressure in the fluid conduit (28) is measured. If the measured pressure is greater than the target pressure, then the second valve assembly (30) is de-energized. If the measured pressure is less than the target pressure, then the second valve assembly (30) is energized. A valve (42) prone to leak under very low temperatures may be subjected to repeated cycles of pressure application and pressure release in order to form a fluid-tight seal.

Vehicle systems and components are set forth, which aim to reduce rolling friction caused in part by the contact between the vehicle's tires and the ground surface over which the vehicle is traversing. These systems and/or components thereof may increase the overall fuel efficiency of a vehicle. In the examples provided, the systems and/or components change the tread contact patch of one or more tires during movement of the vehicle.

A fore-aft self-balancing personal transportation device having a single wheel structure with multiple air chambers and air pressure equalization between the air chambers. Embodiments include dual tires on a single rim structure, or a single tire structure with multiple lobes, etc. Air passage between the air chambers may be internal through the rim or external via an air hose or related structure. The air chambers may be tubed or tubeless. Several different embodiments are disclosed.

A wireless sensor for a wheel end assembly of a heavy-duty vehicle is provided. The wheel end assembly includes a wheel hub and a hub cap mounted on the wheel hub. The sensor includes mounting means disposed in the hub cap. Sensing means are mounted on the mounting means to sense at least one condition of the vehicle. A processor is mounted on the mounting means and is electrically connected to the sensing means to process data from the sensing means. Communication means are mounted on the mounting means and are electrically connected to the processor to communicate the processed data to a user. An electrical energy storage device is mounted on the mounting means and is electrically connected to the sensing means, the processor and the communication means, enabling the sensor to be independent from the vehicle power supply. The sensor also accommodates components of a tire inflation system.

An air maintenance tire pump simulator that simulates the environment of an air maintenance tire system is provided. The simulator includes at least one pneumatic cylinder, a structure that forms a closed cavity, and a pneumatic conduit extending between and fluidly connecting the pneumatic cylinder and the closed cavity. A cam is operably connected to a motor, and is also operably connected to the pneumatic cylinder. Engagement of the motor actuates rotation of the cam, which in turn actuates operation of the pneumatic cylinder to increase a pressure in the closed cavity. A method of simulating an air maintenance tire system is also provided.

An air-ride axle/suspension system for a heavy-duty vehicle. A frame and at least a pair of suspension assemblies support opposite ends of an axle for movement relative to the frame. An air spring is associated with one of the suspension assemblies that establishes a first relative position between the axle and the frame as a function of fluid pressure in the air spring. A tire and wheel assembly is operatively mounted to an end portion of the axle associated with the air spring. A sensor detects an inflation condition of the tire and wheel assembly. A venting system exhausts fluid pressure from the air spring to establish a second relative position between the axle and the frame that is different than the first relative position in response to detecting a predetermined inflation condition of the tire and wheel assembly.

A method for detecting a leak in a pressure vessel of a system including a plurality of pressure vessels in fluid communication with a common header comprises: reducing a fluid pressure in the common header to a first predetermined value below an operating pressure of the plurality of pressure vessels; gradually adding fluid to the common header at a first flow rate to increase the fluid pressure in the common header from the first predetermined value; monitoring, after gradually adding the fluid to the common header, the fluid pressure in the common header; and determining, based on the fluid pressure in the common header after gradually adding the fluid to the common header, a leak in at least one pressure vessel of the plurality of pressure vessels.

A method and system for servicing a vehicle in accordance with pre-determined maintenance settings is provided. Maintenance settings can be communicated to a vehicle maintenance tool via a communication device and the vehicle maintenance tool can interact with the vehicle in accordance with the maintenance settings.

A method and system for servicing a vehicle in accordance with pre-determined maintenance settings is provided. Maintenance settings can be communicated to a vehicle maintenance tool via a communication device and the vehicle maintenance tool can interact with the vehicle in accordance with the maintenance settings.

A method for managing pressure in one or more tires installed on a vehicle includes: determining, by an electronic control unit, a pressure parameter value based on one or more measured pressures; and commanding, by the electronic control unit and based on the pressure parameter value, at least one control valve to an open position to conduct fluid from an air source and to inflate the one or more tires.