HUB-INTEGRATED INFLATION SYSTEM
A hub-integrated inflation system which functions to convert relative motion at the wheel end (e.g., between the axle and the hub or wheel) into a pumping motion. The relative motion is then converted into mechanical or electrical energy, which can be used to actuate a pump of an inflator.
1 . An inflation system for a wheel mounted to a vehicle, comprising:
a cam defining:
a radially inward surface encircling an axis of rotation of the wheel; and
a radially outward surface; and
a pump system comprising:
an actuator coupled to the radially-outward surface; and
a pump coupled to the actuator;
wherein the pump system:
is mounted to the wheel; and
during wheel rotation, is operable in a power receiving mode, wherein:
the pump system harvests energy from relative motion of the actuator and the pump; and
the pump system and the cam rotate relative to the vehicle at different angular velocities.
2 . The wheel inflation system of claim 1 , wherein the cam encircles a cam retention element, which:
defines an arcuate surface coaxially aligned with the wheel axis of rotation; and
does not continuously rotate relative to the vehicle during wheel rotation.
3 . The wheel inflation system of claim 2 , wherein the cam rotates without slipping relative to the arcuate surface when the pump system is in the power receiving mode.
4 . The wheel inflation system of claim 2 , wherein the cam retention element remains static relative to the vehicle due to a torque applied by an eccentric mass during wheel rotation.
5 . The wheel inflation system of claim 2 , wherein the radially inward surface is symmetrical.
6 . The wheel inflation system of claim 1 , wherein the cam traverses a path around the wheel axis of rotation when the pump system is in the power receiving mode.
7 . The wheel inflation system of claim 1 , wherein the pump system defines a pressurized air outlet fluidly connected to a tire.
8 . A wheel inflation system comprising:
a cam arranged within a hub of a wheel and rotatably encircling a wheel axis of rotation;
a pump mounted to the hub, the pump comprising a piston contacting a surface of the cam and operable between:
a first mode, wherein relative motion between the pump and the cam drives pump actuation;
a second mode, wherein the pump is retained in a substantially static position relative to the cam.
9 . The wheel inflation system of claim 8 , wherein the cam defines a central axis offset from the wheel axis of rotation.
10 . The wheel inflation system of claim 8 , wherein the cam comprises a floating cam and translates about an axle of the wheel in the first mode.
11 . The wheel inflation system of claim 10 , wherein the cam is substantially statically retained relative to the pump by the piston in the second mode.
12 . The wheel inflation system of claim 8 , wherein the cam is statically retained by biasing the piston toward the wheel axis of rotation.
13 . The wheel inflation system of claim 8 , further comprising a bearing spacer, wherein the cam encircles and rides upon the bearing spacer.
14 . The wheel inflation system of claim 8 , wherein the cam encircles a wheel axle.
15 . The wheel inflation system of claim 8 , wherein the cam comprises a two-lobed cam.
16 . A wheel inflation system comprising:
a pumping system driven by wheel rotation, the pumping system operable between a pumping mode and a non-pumping mode, the pumping system comprising:
a floating cam defining an outer arcuate surface and an inner arcuate surface; and
a pump coupled to the outer arcuate surface of the floating cam;
wherein in the pumping mode:
the floating cam translates relative to the wheel; and
relative motion of the outer arcuate surface and the pump drives pump actuation.
17 . The system of claim 16 , wherein the pumping system is mounted within a lubricant cavity of a hub of the wheel.
18 . The system of claim 16 , wherein the floating cam has a nonuniform mass distribution.
19 . The system of claim 16 , wherein:
in the non-pumping mode, a point defined by the floating cam follows a circular path relative to a rotational axis of the wheel; and
in the pumping mode, the point defined by the floating cam follows a non-circular path relative to the rotational axis of the wheel.
20 . The system of claim 16 , wherein the floating cam encircles a bearing spacer mounted to an axle of the wheel.