Power steering for an all terrain vehicle
An all-terrain vehicle including a frame having longitudinally-spaced ends defining a first longitudinal axis, and a power steering unit supported by the frame. The power steering unit has an output shaft which is held at its free end in an aperture, and rotates within a bearing.
1. A four wheel drive all-terrain vehicle, comprising:
a frame including longitudinally spaced-apart ends defining a first longitudinal axis, the frame comprising a frame front end portion;
a plurality of wheels operably coupled to the frame;
a steering linkage operatively coupled between an operator input steering portion and at least one of the plurality of wheels, the steering linkage comprising a lower steering assembly having a rotatable coupler and a fixed portion
front and rear differentials; and
a power steering assembly operatively coupled to the steering linkage, the power steering assembly comprising an electric motor and a gear box, the gear box comprising an input shaft and an output shaft, the input shaft being operatively coupled to the operator input steering portion, wherein, the rotatable coupler comprising a shaft which is supported at its free end, a bearing is positioned at the free end of the rotatable coupler shaft and the bearing is held within an aperture by the fixed portion of the lower steering assembly and the rotatable coupler shaft rotates relative to the bearing; and the aperture is integrated within the front differential housing.
2. The all-terrain vehicle of claim 1 , wherein the aperture is located at the top of the front differential housing.
3. The all-terrain vehicle of claim 1 , wherein the lower steering assembly further comprises a bearing cap which at least partially surrounds the bearing, and is fixed to the top of the front differential housing.
4. The all-terrain vehicle of claim 3 , wherein a Pitman arm is attached to the rotatable coupler shaft, above the bearing cap.
5. The all-terrain vehicle of claim 4 , wherein the top of the front differential is provided with a flange, profiled to receive the bearing and the bearing cap.
6. The all-terrain vehicle of claim 1 , further comprising a first bracket assembly for attaching the power steering assembly to the frame.
7. The all-terrain vehicle of claim 6 , wherein the lower steering assembly further comprises a bearing cap, and a second bracket assembly attached to the bearing cap and to the first bracket assembly, laterally supporting the output shaft.
8. A four wheel drive all-terrain vehicle, comprising:
a frame including longitudinally spaced-apart ends defining a first longitudinal axis, the frame comprising a frame front end portion;
a plurality of wheels operably coupled to the frame;
front and rear differentials;
a steering linkage operatively coupled between an operator input steering portion and at least one of the plurality of wheels, the steering linkage comprising a lower steering assembly having a rotatable coupler and a fixed portion;
a power steering assembly operatively coupled to the steering linkage, the power steering assembly comprising an electric motor and a gear box, the gear box comprising an input shaft and an output shaft, the input shaft being operatively coupled to the operator input steering portion, and the output shaft being operatively coupled to the lower steering assembly, the lower steering assembly having a bearing adjacent its free end; and
a bearing support flange supporting the output shaft bearing, the bearing support flange being provided on the front differential housing.
9. The all-terrain vehicle of claim 8 , wherein the rotatable coupler is comprised of a shaft which is supported at its free end.
10. The all-terrain vehicle of claim 9 , wherein the bearing is attached to the free end of the rotatable coupler shaft, and the bearing is held by the bearing support flange, and the rotatable coupler shaft rotates relative to the bearing.
11. The all-terrain vehicle of claim 10 , wherein the bearing support flange comprises an aperture and the bearing and the rotatable coupler shaft are held fixed within the aperture.
12. The all-terrain vehicle of claim 11 , wherein the aperture is located at the top of the front differential housing.
13. The all-terrain vehicle of claim 12 , wherein the support assembly further comprises a bearing cap which at least partially surrounds the bearing, and is fixed to the bearing support flange.
14. The all-terrain vehicle of claim 8 , wherein the rotatable coupler shaft is supported both vertically and laterally.
15. The all-terrain vehicle of claim 8 , wherein the output torque on the rotatable coupler shaft is at least 50 N-M.
16. The all-terrain vehicle of claim 15 , wherein the output torque on the rotatable coupler shaft is approximately 60 N-M.