Outboard motors having steerable lower gearcase

1. An outboard motor comprising:

a powerhead configured to rotate a driveshaft;

a steering housing located below the powerhead;

a lower gearcase located below the steering housing and supporting a propeller shaft that is operably coupled to the driveshaft so that rotation of the driveshaft causes rotation of the propeller shaft, wherein the lower gearcase is steerable about a steering axis with respect to the steering housing;

a steering column fixed to the lower gearcase and extending upwardly into the steering housing, wherein the driveshaft or an extension thereof extends through the steering column and into the lower gearcase and operably into engagement with the propeller shaft; and

a steering actuator coupled to the steering housing, wherein the steering actuator comprises a piston that is movable back and forth in a cylinder, and wherein the piston is engaged with the steering column via a rack and pinion such that back and forth movement of the piston causes rotation of the steering column and the lower gearcase about the steering axis.

2. The outboard motor according to claim 1 , wherein the rack and pinion comprises a set of teeth on the piston that are meshed with a corresponding set of teeth on the steering column, and wherein the set of teeth on the piston are operably engaged with the set of teeth on the steering column such that back and forth linear movement of the set of teeth on the piston causes back and forth rotational movement of the teeth on the steering column about the steering axis.

3. The outboard motor according to claim 2 , wherein the steering housing comprises a center-column and wherein the steering column extends upwardly into a through-bore in the center-column, and wherein the driveshaft or the extension thereof extends through the steering column and the through-bore in the center-column.

4. The outboard motor according to claim 1 , wherein the steering column comprises a center column extending upwardly from a lower perimeter mounting flange, and wherein a through-bore extends through the center column and defines an open interior in the center column, and wherein the driveshaft or the extension thereof extends through the open interior of the center column, into the lower gearcase and into engagement with the propeller shaft.

5. The outboard motor according to claim 1 , wherein the steering actuator is hydraulically-actuated and wherein the piston is movable back and forth in the cylinder under pressure from hydraulic fluid supplied to the cylinder, and further comprising a pump that supplies the hydraulic fluid to the cylinder.

6. The outboard motor according to claim 1 , wherein the cylinder is formed through the steering housing.

7. The outboard motor according to claim 6 , wherein the cylinder is formed through opposing sidewalls on opposite sides of the steering housing.

8. The outboard motor according to claim 1 , further comprising seals on the piston, wherein the seals engage with a radially inner sidewall of the cylinder so as to define opposing fluid chambers in the cylinder, and further comprising an inlet on each of the opposing fluid chambers, respectively, via which the pump is configured to supply hydraulic fluid under pressure to the opposing fluid chambers and thereby cause the piston to forcibly move back and forth in the cylinder.

9. The outboard motor according to claim 8 , further comprising end caps mounted on the sidewalls of the steering housing and more particularly on opposite sides of the cylinder, enclosing the opposing fluid chambers.

10. The outboard motor according to claim 1 , further comprising a set of bearings that facilitate rotation of the steering column and lower gearcase with respect to the steering housing.

11. The outboard motor according to claim 1 , wherein the set of bearings comprises upper bearings located above the rack and pinion and a lower set of bearing located below the rack and pinion.

12. The outboard motor according to claim 11 , wherein the upper and lower bearings surround the steering column and are located radially between the steering column and the steering housing, and wherein the upper bearings are located between an upper bearing surface on the steering column and an inner bearing surface on the steering housing and wherein the lower bearings are located between a lower bearing surface on the steering column and a lower inner bearing surface on the steering housing.

13. The outboard motor according to claim 12 , wherein the upper and lower bearings each comprises inner and outer races containing tapered roller bearings that extend transversely with respect to the steering axis.

14. The outboard motor according to claim 1 , further comprising a driveshaft housing located above the steering housing.

15. An outboard motor comprising:

a powerhead configured to rotate a driveshaft;

a steering housing located below the powerhead;

a lower gearcase located below the steering housing and supporting a propeller shaft that is operably coupled to the driveshaft so that rotation of the driveshaft causes rotation of the propeller shaft, wherein the lower gearcase is steerable about a steering axis with respect to the steering housing;

a steering column fixed to the lower gearcase and extending upwardly into the steering housing, wherein the driveshaft or an extension thereof extends through the steering column and into the lower gearcase and operably into engagement with the propeller shaft; and

a steering actuator coupled to the steering housing, wherein the steering actuator comprises a piston that is movable back and forth in a cylinder, and wherein the piston is engaged with the steering column via a rack and pinion such that back and forth movement of the piston causes rotation of the steering column and the lower gearcase about the steering axis;

wherein the steering housing comprises a center-column and wherein the steering column extends upwardly into a through-bore in the center-column, and wherein the rack and pinion is located at least partially in the though-bore in the center column.

16. The outboard motor according to claim 15 , wherein piston is movable back and forth within the through-bore of the center-column, wherein the rack and pinion comprises a set of teeth on the piston that are meshed with a corresponding set of teeth on the steering column, and wherein the set of teeth on the piston are operably engaged with the set of teeth on the steering column such that back and forth linear movement of the set of teeth on the piston causes back and forth rotational movement of the teeth on the steering column about the steering axis.

17. The outboard motor according to claim 16 , wherein the cylinder is formed through opposing sidewalls on opposite sides of the steering housing, and wherein the piston is movable back and forth through the opposing sidewalls and into opposing end caps on the sidewalls.

18. The outboard motor according to claim 15 , further comprising a set of bearings that facilitate rotation of the steering column and lower gearcase with respect to the steering housing, wherein the set of bearings comprises upper bearings located above the rack and pinion and a lower set of bearing located below the rack and pinion.

19. The outboard motor according to claim 18 , wherein the upper and lower bearings surround the steering column and are located radially between the steering column and the steering housing, and wherein the upper bearings are located between an upper bearing surface on the steering column and an inner bearing surface on the steering housing and wherein the lower bearings are located between a lower bearing surface on the steering column and a lower inner bearing surface on the steering housing.

20. The outboard motor according to claim 19 , wherein the upper and lower bearings each comprises inner and outer races containing tapered roller bearings that extend transversely with respect to the steering axis.