WATERCRAFT STEERING SYSTEM, AND WATERCRAFT

• US 20080119094A1
• Filed: 11/19/2007
• Published: 05/22/2008
• Est. Priority Date: 11/17/2006
• Status: Active Grant

• Current Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Original Assignee: Yamaha Marine Kabushiki Kaisha
• Inventors: Uchiyama, Ryuji, Mizutani, Makoto
• Granted Patent: US 8,162,706 B2
• Time in Patent Office: Days
• US Class Current: 440/53
• CPC Class Codes: B63H 20/12 Means enabling steering
• CPC Class Codes: B63H 25/02 Initiating means for steering , for slowing down, otherwise than by use of propulsive elements, or for dynamic anchoring
• CPC Class Codes: B63H 25/20 by mechanical means
• CPC Class Codes: B63H 25/24 by electrical means
• CPC Class Codes: B63H 25/42 Steering or dynamic anchoring by propulsive elements by jets B63H25/46; Steering or dynamic anchoring by propellers used therefor only; Steering or dynamic anchoring by rudders carrying propellers

Abstract

A watercraft can have an electric motor mounted on a screw bar extending in a right/left direction. The electric motor can move along the screw bar in the right/left direction to steer an outboard motor, or another part of a different marine propulsion system. One or more springs can be provided at the ends of the screw bar. When the outboard motor whose steered angle exists in a predetermined angle range including the maximum steered angle is steered back to a neutral position, either one of the springs presses the electric motor toward the center of the screw bar to assist the steering torque of the electric motor.

Claims

1. A steering system for a watercraft which pivots a watercraft propulsion unit laterally relative to a hull of the watercraft, to move the propulsion unit from a neutral position to a right/left direction by driving force of a steering actuator, the steering system comprising steering assist means for generating predetermined urging force in a direction toward the neutral position when the watercraft propulsion unit is steered toward at least one of the right direction and the left direction relative to the neutral position.

2. The watercraft steering system according to claim 1, wherein the steering assist means applies the urging force to the steering actuator when a steered angle of the watercraft propulsion unit is in a predetermined angle range including the maximum steered angle.

3. The watercraft steering system according to claim 1, wherein the steering assist means applies the urging force in an opposite direction relative to a direction in which propeller rotation reaction force is generated when the watercraft propulsion unit is driven.

4. The watercraft steering system according to claim 1, wherein the watercraft steering system comprises has a shaft whose axial direction is arranged along the right/left direction of the watercraft hull, the steering actuator is disposed movably along the axial direction of the shaft, and wherein the steering assist means comprises urging means disposed at end portions of the shaft and for pressing the steering actuator in the direction toward the neutral position.

5. The watercraft steering system according to claim 1, wherein the watercraft steering system has the steering actuator disposed on a shaft, a joint bracket attached to the steering actuator, and a swivel shaft whose axis is a pivot center for the joint bracket and for the watercraft propulsion unit, and wherein the steering assist means are urging means for moving the steering actuator parallel in a forward direction of the watercraft hull.

6. The watercraft steering system according to claim 1, wherein the steering assist means comprises urging means disposed in a steered direction of the watercraft propulsion unit and for pressing a portion of the watercraft propulsion unit when the watercraft steering unit is steered.

7. The watercraft steering system according to claim 4, wherein the urging means comprise at least one of a cylinder and piston combination, a coil spring and a torsion spring.

8. The watercraft steering system according to claim 1, wherein the steering actuator is an electrically operable actuator.

9. The watercraft steering system according to claim 1 in combination with a watercraft propulsion unit according mounted to a watercraft.

10. A steering system for a watercraft which pivots a watercraft propulsion unit laterally relative to a hull of the watercraft between a neutral position and right and left positions with a steering actuator, the steering system comprising a steering assist device configured to generate a predetermined force in a direction toward the neutral position when the watercraft propulsion unit is steered toward at least one of the right direction and the left direction relative to the neutral position.

11. The watercraft steering system according to claim 10, wherein the steering assist device is configured to apply the predetermined force to the steering actuator when a steered angle of the watercraft propulsion unit is in a predetermined angle range including the maximum steered angle.

12. The watercraft steering system according to claim 10, wherein the steering assist device is configured to apply the predetermined force in an opposite direction relative to a direction in which propeller rotation reaction force is generated when the watercraft propulsion unit is driven.

13. The watercraft steering system according to claim 10, wherein the watercraft steering system comprises has a shaft whose axial direction is arranged along the right/left direction of the watercraft hull, the steering actuator is disposed movably along the axial direction of the shaft, and wherein the steering assist device comprises an urging device disposed at end portions of the shaft and configured to press the steering actuator in the direction toward the neutral position.

14. The watercraft steering system according to claim 10, wherein the steering actuator is disposed on a shaft, the watercraft steering system further comprising a joint bracket attached to the steering actuator, and a swivel shaft whose axis is a pivot center for the joint bracket and for the watercraft propulsion unit, and wherein the steering assist device comprises an urging device configured to move the steering actuator parallel in a forward direction of the watercraft hull.

15. The watercraft steering system according to claim 10, wherein the steering assist device comprises an urging device disposed in a steered direction of the watercraft propulsion unit and configured to press a portion of the watercraft propulsion unit when the watercraft steering unit is steered.

16. The watercraft steering system according to claim 15, wherein the urging device comprises at least one of a cylinder and piston combination, a coil spring, and a torsion spring.

17. The watercraft steering system according to claim 10, wherein the steering actuator is an electrically operable actuator.

18. The watercraft steering system according to claim 10 in combination with a watercraft propulsion unit according mounted to a watercraft.