Electric actuator for a marine steering system

Patent metadata

Field	Value
Publication number	US-2024326972-A1
Application number	US-202418616439-A
Country	US
Kind code	A1
Filing date	Mar 26, 2024
Priority date	Mar 28, 2023
Publication date	Oct 3, 2024
Grant date	—

Abstract

A marine steering system includes a marine propulsion unit, a steering tiller having a first end and a second end opposite the first end and being pivotably coupled to the marine propulsion unit proximate the second end, and an electric actuator. The electric actuator includes an output shaft, a motor that drives rotation of the output shaft about an axis, and a driven assembly pivotably coupled with the steering tiller proximate the first end and operably coupled with the output shaft, such that rotation of the output shaft by the motor drives axial movement of the driven assembly relative to the output shaft and the motor to steer the marine propulsion unit via the steering tiller.

First claim

What is claimed is:

1 . A marine steering system, comprising:
a marine propulsion unit; a steering tiller having a first end and a second end opposite the first end and being pivotably coupled to the marine propulsion unit proximate the second end; and an electric actuator, comprising:
an output shaft;
a motor that drives rotation of the output shaft about an axis; and
a driven assembly pivotably coupled with the steering tiller proximate the first end and operably coupled with the output shaft, such that rotation of the output shaft by the motor drives axial movement of the driven assembly relative to the output shaft and the motor to steer the marine propulsion unit via the steering tiller.

2 . The marine steering system of claim 1 , wherein the driven assembly comprises:
a housing; and a nut tube that is housed by and fixed relative to the housing and that receives a central screw that is fixedly coupled with the output shaft therein, wherein the nut tube is translatable along the axis in response to the motor rotating the output shaft.

3 . The marine steering system of claim 2 , wherein the marine steering system includes a roller screw assembly that comprises:
the central screw fixedly coupled with the output shaft; the nut tube that receives the central screw therein; and a plurality of rollers disposed radially between the central screw and the nut tube and configured to engage the central screw and the nut tube.

4 . The marine steering system of claim 3 , wherein the plurality of rollers are non-translatably connected with the central screw, such that the axial position of each of the plurality of rollers is fixed relative to the central screw.

5 . The marine steering system of claim 2 , wherein the motor is arranged external to the housing.

6 . The marine steering system of claim 1 , wherein the motor is axially offset from the entirety of the driven assembly.

7 . The marine steering system of claim 6 , wherein the motor and the output shaft are coaxially aligned, such that the motor and the output shaft rotate about the axis.

8 . The marine steering system of claim 1 , wherein the motor includes a stator and a rotor that is configured to rotate relative to the stator about a rotor axis that is radially offset from the axis about which the output shaft rotates.

9 . The marine steering system of claim 8 , wherein the motor is drivably connected to the output shaft via a gearset.

10 . The marine steering system of claim 8 , wherein the motor is drivably connected to the output shaft via a belt.

11 . The marine steering system of claim 2 , wherein the driven assembly comprises:
a pivot plate pivotably coupled to the housing and operable to pivot relative to the housing about a pivot plate axis that is parallel to the axis about which the output shaft rotates, wherein the steering tiller is pivotably coupled with the driven assembly via a pivotal coupling with the pivot plate, such that the pivot plate is operable to pivot relative to the housing about the pivot plate axis, and the steering tiller is operable to pivot relative to the pivot plate.

12 . The marine steering system of claim 11 , wherein the electric actuator further comprises:
a support structure having a support arm axially offset from the housing and configured to inhibit axial movement of the output shaft, wherein the motor is housed by the support arm, such that axial movement of the motor relative to the support arm is inhibited.

13 . The marine steering system of claim 12 , wherein the electric actuator further comprises:
a mounting shaft coupled to the support structure and configured to facilitate pivotal movement of the support structure, the motor, the output shaft, and the housing about a pivot axis that extends parallel to the axis and is radially offset from the axis and the pivot plate axis.

14 . The marine steering system of claim 13 , wherein a full stroke actuation of the electric actuator prompts pivotal movement of the support structure, the motor, the output shaft, and the housing about the pivot axis, pivotal movement of the pivot plate relative to the housing about the pivot plate axis, pivotal movement of the steering tiller relative to the pivot plate, and pivotal movement of the steering tiller relative to the marine propulsion unit.

15 . The marine steering system of claim 1 , wherein the marine propulsion unit is an engine.

16 . An electric actuator for a marine steering system, comprising:
a housing; a first output shaft extending axially outward from the housing in a first axial direction; a first motor arranged external to the housing and drivingly engaged with the first output shaft, such that the first motor is operable to drive rotation of the first output shaft about an axis; and a roller screw assembly arranged within the housing and coupled to the first output shaft, the roller screw assembly having a nut tube fixed relative to the housing and a central screw received by the nut tube, wherein the nut tube is axially translatable in response to the first motor rotating the first output shaft and the central screw about the axis.

17 . The electric actuator of claim 16 , further comprising:
a second output shaft coupled with the roller screw assembly and extending axially outward from the housing in a second axial direction opposite the first axial direction; and a second motor arranged external to the housing and drivingly engaged with the second output shaft.

18 . The electric actuator of claim 16 , further comprising:
a pivot plate pivotably coupled to the housing and operable to pivot relative to the housing about a pivot plate axis that is parallel to the axis about which the first output shaft rotates, the pivot plate being configured to have a steering tiller of the marine steering system pivotably coupled thereto.

19 . The electric actuator of claim 16 , wherein rotation of the first output shaft prompts axial translation of the nut tube relative to the first motor.

20 . A marine steering system, comprising:
a marine propulsion unit; a steering tiller having a first end and a second end opposite the first end and being pivotably coupled to the marine propulsion unit proximate the second end; and an electric actuator, comprising:
a housing;
a pivot plate pivotably coupled with the housing and operable to pivot relative to the housing about a pivot plate axis, wherein the steering tiller is pivotably coupled with the pivot plate proximate the first end of the steering tiller, such that the pivot plate is operable to pivot relative to the housing about the pivot plate axis, and the steering tiller is operable to pivot relative to the pivot plate;
a first output shaft extending axially outward from the housing in a first axial direction;
a second output shaft extending axially outward from the housing in a second axial direction opposite the first axial direction;
a first motor arranged external to the housing and drivingly engaged with the first output shaft, such that the first motor is operable to drive rotation of the first output shaft about an axis;
a second motor arranged external to the housing and drivingly engaged with the second output shaft, such that the second motor is operable to drive rotation of the second output shaft about the axis; and
a roller screw assembly arranged within the housing and coupled to the first and second output shafts, the roller screw assembly having a nut tube fixed relative to the housing and

Assignees

• Schaeffler Technologies Ag

Inventors

• Hooker Craig

Classifications

• B63H20/10

  Means enabling trim or tilt, or lifting of the propulsion element when an obstruction is hit; Control of trim or tilt · CPC title

• B63H20/12 Primary

  Means enabling steering · CPC title