Adaptive stabilizer bar with cycloidal drive
An improved adaptive stabilizer bar is provided. The stabilizer bar includes a cycloidal drive between first and second portions of a divided torsion bar. The cycloidal drive includes a cycloidal gear assembly that provides a significant mechanical advantage, allowing relatively small electric motors to be used. In addition, the cycloidal gear assembly has a relatively small physical footprint, particularly when compared to a planetary gear assembly, for example.
1. An adaptive stabilizer bar comprising:
a divided torsion bar having mutually facing ends;
a cycloidal drive disposed between the mutually facing ends of the divided torsion bar, wherein the cycloidal drive includes an electric motor coupled to a cycloidal gear assembly to rotate a first portion of the divided torsion bar relative to a second portion of the divided torsion bar, wherein the cycloidal gear assembly includes:
a cam drive gear intermeshed with an input gear that is rotatable by the electric motor,
a cam shaft that rotates in unison with the cam drive gear,
first and second cycloidal gears that oscillate by operation of the cam shaft, and
a ring gear surrounding at least one of the first and second cycloidal gears,
wherein the cam shaft includes a first cam for engaging the first cycloidal gear and includes a second cam for engaging the second cycloidal gear, the second cam being axially offset from the first cam.
2. The adaptive stabilizer bar of claim 1 , wherein the first cam rotates 180-degrees of out phase from the second cam.
3. The adaptive stabilizer bar of claim 1 , wherein the divided torsion bar includes first and second longitudinal segments connected to first and second arm segments, respectively.
4. The adaptive stabilizer bar of claim 3 , wherein the divided torsion bar is subjected to torsional forces when the first and second arm segments move relative to one another.
5. The adaptive stabilizer bar of claim 1 , wherein the cycloidal gear assembly is housed within a gearbox housing, and wherein the electric motor is housed within a motor housing that extends from an exterior portion of the gearbox housing.
6. The adaptive stabilizer bar of claim 5 , wherein the gearbox housing includes first and second co-axial openings for a first half-bar and a second half-bar of the divided torsion bar.
7. The adaptive stabilizer bar of claim 1 , wherein each of the first and second cycloidal gears include a plurality of lobes along an outer periphery thereof.
8. An adaptive stabilizer bar comprising:
a divided torsion bar having mutually facing ends;
a cycloidal drive disposed between the mutually facing ends of the divided torsion bar, wherein the cycloidal drive includes an electric motor coupled to a cycloidal gear assembly to rotate a first portion of the divided torsion bar relative to a second portion of the divided torsion bar, wherein the cycloidal gear assembly includes:
a cam drive gear intermeshed with an input gear that is rotatable by the electric motor,
a cam shaft that rotates in unison with the cam drive gear,
first and second cycloidal gears that oscillate by operation of the cam shaft,
a ring gear surrounding at least one of the first and second cycloidal gears, and
a plurality of rollers sandwiched between an outer portion of the second cycloidal gear and an inner portion of an output gear.
9. The adaptive stabilizer bar of claim 8 , wherein the output gear includes a conical body that narrows from a first outer diameter to a second outer diameter.
10. An adaptive stabilizer bar comprising:
a divided torsion bar coupled to first and second arm segments, the first arm segment being disposed at a first end of the divided torsion bar for mounting to a first vehicle wheel, the second arm segment disposed at a second end of the divided torsion bar for mounting to a second vehicle wheel, wherein the divided torsion bar includes a first half-bar and a second half-bar and is subjected to a torsional load when the first and second arm segments move relative to each another;
a cycloidal drive disposed between the first half-bar and the second-half bar, the cycloidal drive being operable to rotate the first half-bar relative to the second half-bar by operation of an actuator that is mechanically coupled to the cycloidal drive, wherein the cycloidal drive includes:
a cam drive gear intermeshed with an input gear that is rotatable by the actuator,
a cam shaft that rotates in unison with the cam drive gear,
first and second cycloidal gears that oscillate by operation of the cam shaft, and
a ring gear surrounding at least one of the first and second cycloidal gears,
wherein the cam shaft includes a first cam for engaging the first cycloidal gear and includes a second cam for engaging the second cycloidal gear, the second cam being axially offset from the first cam.
11. The adaptive stabilizer bar of claim 10 , wherein the cycloidal drive includes a gearbox housing, and wherein the actuator is housed within a motor housing that extends from an exterior portion of the gearbox housing.
12. The adaptive stabilizer bar of claim 10 , wherein the gearbox housing includes first and second co-axial openings for the first half-bar and the second half-bar, respectively.
13. An adaptive stabilizer bar comprising:
a divided torsion bar coupled to first and second arm segments, the first arm segment being disposed at a first end of the divided torsion bar for mounting to a first vehicle wheel, the second arm segment disposed at a second end of the divided torsion bar for mounting to a second vehicle wheel, wherein the divided torsion bar includes a first half-bar and a second half-bar and is subjected to a torsional load when the first and second arm segments move relative to each another;
a cycloidal drive disposed between the first half-bar and the second-half bar, the cycloidal drive being operable to rotate the first half-bar relative to the second half-bar by operation of an actuator that is mechanically coupled to the cycloidal drive, wherein the cycloidal drive includes:
a cam drive gear intermeshed with an input gear that is rotatable by the actuator,
a cam shaft that rotates in unison with the cam drive gear,
first and second cycloidal gears that oscillate by operation of the cam shaft,
a ring gear surrounding at least one of the first and second cycloidal gears, and
a plurality of rollers sandwiched between an outer portion of the second cycloidal gear and an inner portion of an output gear.
14. A cycloidal drive for an adaptive stabilizer bar, the cycloidal drive comprising:
an electrical motor within a motor housing; and
a cycloidal gear assembly within a gearbox housing, the electrical motor being coupled to the cycloidal gear assembly via an input gear, wherein the gearbox housing includes first and second co-axial openings for a first half-bar and a second half-bar of a divided torsion bar,
wherein the cycloidal gear assembly includes a cam drive gear intermeshed with the input gear, a cam shaft that rotates in unison with the cam drive gear, first and second cycloidal gears that oscillate by operation of the cam shaft, and a ring gear surrounding at least one of the first and second cycloidal gears,
wherein the cam shaft includes a first cam for engaging the first cycloidal gear and includes a second cam for engaging the second cycloidal gear, the second cam being axially offset from the first cam.
15. The cycloidal drive of claim 14 , wherein the cycloidal drive includes a gearbox housing, and wherein the actuator is housed within a motor housing that extends from an exterior portion of the gearbox housing.
16. The cycloidal drive of claim 14 , wherein the gearbox housing includes first and second co-axial openings for the first half-bar and the second half-bar, respectively.
17. A cycloidal drive for an adaptive stabilizer bar, the cycloidal drive comprising:
an electrical motor within a motor housing; and
a cycloidal gear assembly within a gearbox housing, the electrical motor being coupled to the cycloidal gear assembly via an input gear, wherein the gearbox housing includes first and second co-axial openings for a first half-bar and a second half-bar of a divided torsion bar,
wherein the cycloidal gear assembly includes:
a cam drive gear intermeshed with the input gear,
a cam shaft that rotates in unison with the cam drive gear,
first and second cycloidal gears that oscillate by operation of the cam shaft,
a ring gear surrounding at least one of the first and second cycloidal gears, and
a plurality of rollers sandwiched between an outer portion of the second cycloidal gear and an inner portion of an output gear.