Steering system for use in turning steerable vehicle wheels
A steering system for use in turning steerable vehicle wheels includes a one-piece output unit connected to a steering wheel such that rotation of the steering wheel urges the output unit to rotate about an axis. The output unit has an output shaft coupled to the steerable vehicle wheels such that rotation of the output unit affects steering of the steerable vehicle wheels. The output unit supports a planetary gear. A sun gear is connected to an electric motor such that torque from the electric motor urges the sun gear to rotate relative to the output unit. The sun gear is meshed with the planetary gear such that rotation of the sun gear urges the planetary gear to rotate and orbit the sun gear. The output unit is urged to rotate about the axis in response to the planetary gear rotating and orbiting the sun gear.
1 . A steering system for use in turning steerable vehicle wheels, the steering system comprising:
a one-piece output unit connected to a steering wheel such that rotation of the steering wheel urges the output unit to rotate about an axis, the output unit having an output shaft coupled to the steerable vehicle wheels such that rotation of the output unit affects steering of the steerable vehicle wheels, the output unit supporting at least one planetary gear;
a sun gear connected to an electric motor such that torque from the electric motor urges the sun gear to rotate relative to the output unit, the sun gear being meshed with the at least one planetary gear such that rotation of the sun gear urges the at least one planetary gear to rotate and orbit the sun gear, the output unit being urged to rotate about the axis in response to the at least one planetary gear rotating and orbiting the sun gear; and
a pinion meshing with external teeth of the output unit, the pinion connecting the output unit to the steering wheel.
2 . The steering system recited in claim 1 , wherein the external teeth at least partially circumferentially surround the output shaft.
3 . The steering system recited in claim 1 , wherein the at least one planetary gear is in a housing, the at least one planetary gear meshing with internal teeth of the housing.
4 . The steering system recited in claim 1 , wherein the sun gear extends into a recess of the output unit.
5 . The steering system recited in claim 4 , wherein the output unit includes at least one window extending radially therethrough, the at least one planetary gear extending through the at least one window such that the at least one planetary gear meshes with teeth that circumferentially surround the carrier.
6 . The steering system recited in claim 5 , wherein the at least one planetary gear is a plurality of planetary gears, the at least one window being a plurality of windows, the output unit supporting the plurality of planetary gears, each planetary gear being received in a corresponding window of the output unit.
7 . The steering system recited in claim 5 , wherein the at least one planetary gear meshes with the sun gear in a first portion of the recess, the sun gear being rotatably supported in a second portion of the recess via a bearing, the first portion having a larger diameter than the second portion.
8 . The steering system recited in claim 1 , wherein the at least one planetary gear extends through a window of the output unit, the window extending radially through the output unit.
9 . The steering system recited in claim 8 , wherein the planetary gear is connected to the output unit and maintained in the window via a shaft that extends in the direction of the axis.
10 . The steering system recited in claim 1 , further comprising an electrically powered steering unit comprising the electric motor and a gearbox, the output unit being at least partially in a housing of the gearbox.
11 . A steering system for use in turning steerable vehicle wheels, the steering system comprising:
a one-piece output unit having
a carrier for a planetary gear stage, the carrier being connected to an electric motor such that the electric motor urges the output unit to rotate about an axis via the carrier,
a worm wheel extending along the axis from an axial end face of the carrier, the worm wheel being connected to a steering wheel via a pinon such that rotation of the steering wheel urges the output unit to rotate about the axis, and
an output shaft extending along the axis from the axial end face of the carrier, the output shaft being configured to be coupled to the steerable vehicle wheels such that rotation of the output unit affects steering of the steerable vehicle wheels.
12 . The steering system recited in claim 11 , further comprising an electrically powered steering unit comprising the electric motor and a gearbox, the output unit being at least partially in a housing of the gearbox.
13 . The steering system recited in claim 11 , further comprising a sun gear connected to the electric motor such that torque from the electric motor urges the sun gear to rotate relative to the output unit, the sun gear being meshed with a plurality of planetary gears such that rotation of the sun gear urges the planetary gears to rotate and orbit the sun gear, the output unit supporting the planetary gears, the output unit being urged to rotate about the axis in response to the planetary gears rotating and orbiting the sun gear.
14 . The steering system recited in claim 13 , wherein the planetary gears extending through corresponding windows in the carrier such that the planetary gears mesh with teeth that circumferentially surround the carrier.
15 . The steering system recited in claim 11 , wherein the worm wheel at least partially circumferentially surrounds the output shaft.