Patent Publication Number: US-9849957-B1

Title: Systems and steering actuators for steering outboard marine engines

Description:
FIELD 
     The present disclosure relates to outboard marine engines and more particularly to systems and steering actuators for steering outboard marine engines. 
     BACKGROUND 
     The following U.S. Patent Applications are incorporated herein by reference, in entirety. 
     U.S. Pat. No. 7,255,616 discloses a steering system for a marine propulsion device that eliminates the need for two support pins and provides a hydraulic cylinder with a protuberance and an opening which cooperate with each other to allow a hydraulic cylinder&#39;s system to be supported by a single pin for rotation about a pivot axis. The single pin allows the hydraulic cylinder to be supported by an inner transom plate in a manner that allows it to rotate in conformance with movement of a steering arm of a marine propulsion device. 
     U.S. Pat. No. 7,150,664 discloses a steering actuator system for an outboard motor that connects an actuator member to guide rails which are, in turn, attached to a motive member such as a hydraulic cylinder. The hydraulic cylinder moves along a first axis with the guide rail extending in a direction perpendicular to the first axis. An actuator member is movable along the guide rail in a direction parallel to a second axis and perpendicular to the first axis. The actuator member is attached to a steering arm of the outboard motor. 
     U.S. Pat. No. 6,821,168 discloses an outboard motor that is provided with an internally contained cylinder and moveable piston. The piston is caused to move by changes in differential pressure between first and second cavities within the cylinder. By adding a hydraulic pump and a steering valve, the hydraulic steering system described in U.S. Pat. No. 6,402,577 is converted to a power hydraulic steering system by adding a hydraulic pump and a steering valve to a manual hydraulic steering system. 
     U.S. Pat. No. 6,402,577 discloses a hydraulic steering system in which a steering actuator is an integral portion of the support structure of a marine propulsion system. A steering arm is contained completely within the support structure of the marine propulsion system and disposed about its steering axis. An extension of the steering arm extends into a sliding joint which has a linear component and a rotational component which allow the extension of the steering arm to move relative to a moveable second portion of the steering actuator. The moveable second portion of the steering actuator moves linearly within a cylinder cavity formed in a first portion of the steering actuator. 
     U.S. Pat. No. 6,276,977 discloses a hydraulic actuator for an outboard motor system in which the cylinder and piston of the actuator are disposed within a cylindrical cavity inside a cylindrical portion of a swivel bracket. The piston within the cylinder of the actuator is attached to at least one rod that extends through clearance holes of a clamp bracket and is connectable to a steering arm of an outboard motor. The one or more rods attached to the piston are aligned coaxially with an axis of rotation about which the swivel bracket rotates when the outboard motor is trimmed. As a result, no relative movement occurs between the outboard motor, the rod attached to the piston of the actuator, and the swivel bracket during rotation of the outboard motor about the axis of rotation. 
     U.S. Pat. No. 6,113,444 discloses a rotary actuator used to steer a watercraft with an outboard motor. First and second brackets are attached to the outboard motor and the transom of the watercraft, respectively. The rotary actuator can be a hydraulic rotary actuator and either the rotor portion or stator portion of the rotary actuator can be attached to the outboard motor with the other portion being attached to the transom. A hydraulic pump is used to provide pressurized fluid to the actuator and a valve is used to selectively direct the pressurized fluid to one of two ports in the rotary actuator to select the directional rotation and speed between the stator portion and the rotor portion. 
     U.S. Pat. No. 5,392,690 discloses a marine hydraulic system for operation of a power steering assembly that includes a pressure accumulator to provide pressurized hydraulic fluid and valving that permits the transfer of hydraulic fluid within the cylinder to provide efficient use of hydraulic fluid. 
     U.S. Pat. No. 5,376,029 discloses a control valve for a pressurized fluid-operated system, such as a marine power steering system, which includes a housing having an inlet and at least one outlet, with one or more work ports located therebetween. Pressurized fluid is supplied to the inlet, and a spool member is mounted within the housing for controlling the supply of pressurized fluid to a work-performing system, such as the extendible and retractable rod of a hydraulic cylinder assembly. The spool member includes structure for blocking the one or more work ports when the spool member is in its neutral position, when it is desired not to operate the system. This prevents the cylinder from being exposed to reservoir fluid when the spool member is in its neutral position. 
     U.S. Pat. No. 5,074,193 discloses a marine hydraulic system for operation of a power steering assembly that includes a pressure accumulator to provide pressurized hydraulic fluid and valving that permits the transfer of hydraulic fluid within the cylinder to provide efficient use of hydraulic fluid. 
     U.S. Pat. No. 4,362,515 discloses an improved steering system having a guide tube fixed to the end of the outer casing of a steering cable. A link rod connects between the steering arm and the inner core of the steering cable. A guide means is fixed with respect to the transom support means to guide the linear movement of the inner core. A limiting means limits the range of movement of the inner core and a restoring means moves the steerable drive unit from the extreme range of the range of movement of the ram. 
     SUMMARY 
     This Summary is provided to introduce a selection of concepts that are further described herein below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. 
     In certain examples, a steering actuator is for steering an outboard marine engine about a steering axis. The steering actuator comprises a housing; a piston device that is disposed in the housing, wherein hydraulic actuation of the piston device causes the outboard marine engine to pivot about the steering axis; and a valve device that is disposed in the housing. The valve device controls a flow of a hydraulic fluid to a first side of the piston device to move the piston device in a first piston direction in the housing and to an opposite, second side of the piston device to move the piston device in an opposite, second piston direction in the housing. Movement of the piston device in the first piston direction causes the outboard marine engine to pivot in a first pivot direction and movement of the piston device in the second piston direction causes the outboard marine engine to pivot in an opposite, second pivot direction. Advantageously, a rigid position reference link that rigidly connects the valve device to the piston device is entirely disposed in the housing. Corresponding systems are disclosed having the steering actuator for steering an outboard marine engine about a steering axis. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure is described with reference to the following drawing Figures. The same numbers are used throughout the drawing Figures to reference like features and like components. 
         FIG. 1  is a perspective view of an outboard marine engine having a steering actuator. 
         FIG. 2  is an exploded view of an exemplary steering actuator. 
         FIG. 3  is a sectional view, showing the steering actuator in a neutral position. 
         FIG. 4A  is a sectional view of the steering actuator, showing movement of a valve device into a first position. 
         FIG. 4B  is a closer sectional view of the valve device shown in  FIG. 4A . 
         FIG. 4C  is a sectional view of the steering actuator, showing the valve device back in the neutral position after pivoting movement of the outboard marine engine in a first pivot direction. 
         FIG. 5A  is a sectional view of the steering actuator, showing movement of the valve device into a second position, opposite the first position shown in  FIG. 4A . 
         FIG. 5B  is a closer sectional view of the valve device shown in  FIG. 5A . 
         FIG. 5C  is a sectional view of the steering actuator, showing the valve device back in the neutral position after pivoting movement of the outboard marine engine in a second pivot direction. 
         FIG. 6  is a schematic view of an exemplary system for steering the outboard marine engine. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
       FIG. 1  depicts an outboard marine engine  10  and a conventional transom plate  12  for mounting the outboard marine engine  10  on the stern of a marine vessel. A pair of conventional trim cylinders  14  (only one is shown in  FIG. 1 ) are configured to trim the outboard marine engine  10  about a horizontal trim axis  11 . A steering actuator  16  is configured to steer the outboard marine engine  10  about a vertical steering axis  18 .  FIG. 1  shows the steering actuator  16  and  FIG. 6  shows a control system  20  for the steering actuator  16 . Examples of the steering actuator  16  and the control system  20  are the primary focus of the present disclosure.  FIG. 2  shows the steering actuator  16  in exploded view.  FIGS. 3-5C  depict the steering actuator  16  during various operational positions, which occur as the control system  20  causes the outboard marine engine  10  to pivot in first and second pivot directions about the vertical steering axis  18 , as will be explained further herein below. 
     Referring now to  FIGS. 2 and 6 , the steering actuator  16  includes a housing  22  that contains a piston device  24  and a valve device  26 . Hydraulic actuation of the piston device  24  causes the outboard marine engine  10  to pivot in the first pivot direction (shown in  FIG. 4C ) about the vertical steering axis  18  and alternately to pivot in the opposite second pivot direction (shown in  FIG. 5C ) about the vertical steering axis  18 . The valve device  26  controls the hydraulic actuation of the piston device  24  by controlling a flow of hydraulic fluid to first and second sides  28 ,  30  of the piston device  24  to thereby cause movement the piston device  24  in first and opposite, second piston directions in the housing  22 . Detailed structural and operational features of the piston device  24  and the valve device  26  will be further described herein below with reference it  FIGS. 3-5C . 
     The housing  22  defines parallel, axially-extending first and second cavities  32 ,  34 , which are best seen in  FIGS. 3-5C . The piston device  24  is disposed in the first cavity  32  and the valve device  26  is disposed in the second cavity  34 . A further described herein below, the valve device  26  moves amongst three positions within the second cavity  34 , including a neutral position (shown in  FIGS. 3, 4C, 5C and 6 ) wherein the valve device  26  directs a flow of hydraulic fluid from a pump  36  back to a hydraulic fluid supply tank  38 , a first valve position (shown in  FIGS. 4A and 4B ) wherein the valve device  26  directs the flow of hydraulic fluid to a first side  40  of the piston device  24 , and a second valve position (shown in  FIGS. 5A and 58 ) wherein the valve device  26  directs the flow of hydraulic fluid to a second side  42  of the piston device  24 . 
     Referring now to  FIG. 6 , the control system  20  includes a computer controller  120  that is programmable and includes a computer processor, software, memory (i.e. computer storage) and an associated input/output (interface) device. The processor loads and executes software, which can be stored in the memory. Executing the software controls the control system  20  to operate as described herein in further detail below. The processor can comprise a microprocessor and/or other circuitry that receives and executes software. The processor can be implemented within a single device, but can also be distributed across multiple processing devices and/or subsystems that cooperate in executing program instructions. Examples include general purpose central processing units, application specific processors, and logic devices, as well as any other processing device, combination of processing devices, and/or variations thereof. The controller  120  can be located anywhere with respect to the outboard marine engine  10  and associated marine vessel and can communicate with various components of the control system  20  via wired and/or wireless links, examples of which are shown in  FIG. 6 . The controller  120  can have one or more microprocessors that are located together or remotely from each other in the control system  20  or remotely from the system  20 . 
     The memory can include any storage media that is readable by the processor and capable of storing software. The memory can include volatile and/or non-volatile removable and or non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules, or other data. The memory can be implemented as a single storage device but may also be implemented across multiple storage devices or subsystems. The memory can further include additional elements such as a controller capable of communicating with the processor. Examples of storage media include random access memory, read only memory, magnetic discs, optical discs, flash memory discs, virtual and/or non-virtual, magnetic cassettes, magnetic tape, magnetic disc storage, or other magnetic storage devices, or any other medium which can be used to store the desired information that may be accessed by an instruction execution system, as well as any combination or variation thereof, or any other type of storage media. In some implementations, the storage media can be non-transitory storage media. 
     The input/output device can include any one of a variety of conventional computer input/output interfaces for receiving electrical signals for input to the processor and for sending electrical signals from the processor to various components of the control system  20 . The controller  120 , via the noted input/output device, communicates with components of the outboard marine engine  10  via communication links, which as mentioned herein above can be wired or wireless links. As explained further herein below, the controller  120  is capable of monitoring and controlling operational characteristics of the outboard marine engine  10  by sending and/or receiving control signals via the various links shown in  FIG. 6 . Although the links are each shown as a single link, the term “link” can encompass one or a plurality of links that are each connected to one or more of the components of the control system  20 . 
     In some examples, the controller  120  is configured to receive inputs from a user input device  122 , which can for example include a conventional steering wheel, joystick, touch pad, touch screen and/or the like. Such input devices for inputting operator steering commands to a controller  120  are well known in the art and therefore are not further herein described. The controller  120  is configured to output control signals to the steering actuator  16  to for example control the valve device  26 , as further described herein below. In some example, the controller  120  is also or alternately configured to generate output command signals that control the valve device  26  based upon programming stored within the memory of the controller  120 , such as for example in stationkeeping modes, trolling modes, waypoint tracking modes, and/or the like, all of which are well-known by those having ordinary skill the art. 
     Referring to  FIGS. 2 and 6 , the valve device  26  includes an electrically-powered bidirectional motor  44  that is controlled by the controller  120  to cause rotation of an output shaft  46  about its own axis in a first rotational direction and to cause rotation of the output shaft  46  about its own axis in an opposite, second rotational direction. The output shaft  46  extends into and engages with a hollow output sleeve  48  via threads (best shown in  FIGS. 3-5C ) on the outer circumference of the output shaft  46  that mate with corresponding threads on the inner circumference of the hollow output sleeve  48 . The hollow output sleeve  48  extends into and is axially slideable with respect to a hollow spool  50  that is fixedly coupled to the bidirectional motor  44  via a threaded connector  52 . By the threaded connection, rotation of the output shaft  46  in the noted first rotational direction causes axial travel of the hollow output sleeve  48  out of the spool  50 . Rotation of the output shaft  46  in the noted second rotational direction causes opposite axial travel of the hollow output sleeve  48  into the spool  50 . 
     Referring to  FIGS. 2 and 6 , the outer circumference of the spool  50  defines oil passages  54   a ,  54   b ,  54   c  for conveying the flow of hydraulic fluid to the first side  28  of the piston device  24  (via  54   a ), to the second side  30  of the piston device  24  (via passage  54   c ) and back to the tank (via passage  54   b ). The oil passages  54   a ,  54   b ,  54   c  are best shown schematically in  FIG. 6 , but are also called out in  FIG. 2 . Fluid-tight wiper and seal combinations  56  are disposed on the outer circumference of the spool  50 , on opposite axial sides of the noted oil passages  54   a ,  54   b . Pairs of oppositely-oriented spring retainers  58  and Belleville washer springs  60  are disposed in a spring-receiving groove  62  formed in the outer circumference of the spool  50 . Bearings  64  are disposed on the output sleeve  48  and facilitate movement of the output sleeve  48  relative to the spool  50 . An end cap  66  is threadingly received in the second cavity  34  of the housing  22  and abuts against an end of the spool  50 . Additional fluid-tight seals  68  are disposed between the end cap  66  and the spool  50 . 
     The housing  22  has a hydraulic fluid inlet  70  to which an inlet fitting  72  is connected. The inlet fitting  72  couples an inlet line  74  to the inlet  70  for providing the flow of hydraulic fluid from the pump  36  to the valve device  26 . The housing  22  also has a hydraulic fluid outlet  76  to which an outlet fitting  78  is connected. The outlet fitting  78  couples an outlet line  80  to the outlet  76  for providing the flow of hydraulic fluid from the valve device  26  to the tank  38 . During assembly of the actuator  16 , the valve device  26  is inserted into one end of the second cavity  34  and the end cap  66  is threaded onto an opposite end of the second cavity  34  so as to place the valve device  26  in the noted neutral position. More specifically, threading of the end cap  66  onto the second cavity  34  forces the spool  50  to axially move to the left in the second cavity  34 . Unthreading the end cap  66  allows the spool  50  to move to the right in the second cavity  34 . The preferred start-up position for the valve device  26  is the neutral position wherein the passages  54   b  are aligned with the inlet  70  and outlet  76  so that hydraulic fluid from the pump  36  is returned back to the tank  38 . The housing  22  also has a grommeted wire passage  73  formed therein for passage of electrical wires for providing power to the bidirectional motor  44  and communication links for communicating position of the valve device  26  to the controller  120 . 
     Rotation of the output shaft  46  in the first rotational direction unthreads the output shaft  46  from the output sleeve  48  and thus causes axial, linear travel of the output sleeve  48  along the output shaft  46 , away from the bidirectional motor  44 . Rotation of the output shaft  46  in the first rotational direction thus moves the valve device  26  (including the spool  50 ) into the noted first valve position (shown in  FIGS. 4A and 4B ) wherein hydraulic fluid from the pump  36  is supplied to the first side  28  of the piston device  24 . 
     Rotation of the output shaft  46  in the opposite, second rotational direction threads the output shaft  46  into the output sleeve  48  and thus causes axial, linear travel of the output sleeve  48  along the output shaft  46 , towards the bidirectional motor  44 . Rotation of the output shaft in the second rotational direction thus moves the valve device  26  (including the spool  50 ) into the second valve position (shown in  FIGS. 5A and 5B ) wherein hydraulic fluid from the pump  36  is supplied to the second side  30  of the piston device  24 . 
     When the output shaft  46  is not rotating, the natural resiliency of the springs  58  and Belleville washer springs  60  biases the valve device (including the spool  50 ) into the neutral position (shown in  FIGS. 3, 4C and 5C ). As mentioned above, positioning the valve device  26  in the neutral position causes hydraulic fluid from the pump  36  to be returned back to the tank  38 . Movement of the spool  50  will cause corresponding movement of the bidirectional motor  44  and associated threaded connector  52  in a motor portion  82  of the second cavity  34 . 
     With continued reference to  FIG. 2 , the piston device  24  has a first piston  84  that is on a first side  86  of the piston device  24  and a second piston  88  that is on an opposite, second side of the piston device  24 . In this example, the piston device  24  also includes a center trunnion  92  that is disposed in the first cavity  32 , between the first and second pistons  84 ,  86 . A pivot pin  94  extends from the trunnion  92 , transversely with respect to the first cavity  32 , and is slidingly received in a transverse recess  93  formed in a vertical trunnion sleeve  96 . The pivot pint  94  is configured to couple with a steering arm  98  on the outboard marine engine  10 , as shown in dashed lines in  FIGS. 3-5C . Axial movement of the trunnion  92  in the first cavity  32  causes the trunnion sleeve  96  to rotate about its own axis, which in turn causes movement of the steering arm  98  and pivoting movement of the outboard marine engine  10  about the vertical steering axis  18 , as shown in  FIGS. 3-5C . Bearing combinations  99  facilitate sliding of the first and second pistons  84 ,  88  within the first cavity  32 . 
     Referring to  FIGS. 3-5C , a first hydraulic fluid passageway  100  (shown in dashed line) conveys the flow the hydraulic fluid in the housing  22  from the valve device  26  to the first side  28  of the piston device  24  to thereby increase hydraulic fluid pressure on the first side  28 . Increasing hydraulic fluid pressure on the first side  28  causes the first piston  84  to move, and thereby move the trunnion  92 , in the first piston direction (i.e. to the right in the figures). A second hydraulic fluid passageway  102  (shown in dashed line) conveys the flow of hydraulic fluid in the housing  22  from the valve device  26  to the second side  30  of the piston device  24  to thereby increase the hydraulic fluid pressure in the second side  30 . Increasing hydraulic fluid pressure on the second side  30  causes the second piston  88  to move, and thereby move the trunnion  96  in the opposite, second piston direction (i.e. to the left in the figures). As described, the flow of the hydraulic fluid to the first and second hydraulic fluid passageways  100 ,  102  is controlled by the valve device  26 . 
     Referring to  FIG. 2 , a first removable end cap  104  is disposed on the first side of the piston device  24  and a second removable end cap  106  is disposed on the second side of the piston device  24 . The first and second end caps  104 ,  106  enclose the piston device  24  in the first cavity  32 . A first removable end plate  108  is disposed on the housing  22  and encloses the first end cap  104  in the housing  22 . A second removable end plate  110  is on the housing  22  and encloses the second end cap  106  in the housing  22 . A removable lower access panel  113  is connected to the housing  22  and encloses the first and second cavities  32 ,  34 , thus providing access to the piston device  24  and valve device  26  for servicing. 
     A rigid position reference link  112  rigidly connects that valve device  26  to the piston device  24 . The rigid position reference link  112  is entirely disposed in the housing  22 . In this example, the rigid position reference link  112  is an elongated bar that has a first end  114  that is threaded to the trunnion  92  and a second end  116  that is threaded a link bracket  118  that is affixed to the end of the spool  50 . As such, the trunnion  92  and spool  50  are fixed together, maintaining constant position reference between these respective components. 
     Operation of the steering actuator  16  will now be described with reference to  FIGS. 3-5C  and  FIG. 6 . 
       FIG. 3  depicts the valve device  26  in the neutral position wherein the valve device  26  is directing the flow of hydraulic fluid from the pump  36  back to the tank  38 . The flow of hydraulic fluid enters the inlet  70  via the inlet fitting  72  and is channeled through the oil passages  54   b  (see  FIG. 6 ) back to the tank  38  via the outlet  76  and outlet fitting  78 . In this position, the springs  58 ,  60  act on the spring receiving groove  62  in the spool  50  to bias the spool  50  into the neutral position. The bidirectional motor  44  and threaded connector  52  are also biased into a neutral position, since they are connected to the spool  50 . The pressure of the hydraulic fluid on the first and second sides  28 ,  30  of the piston device  24  is roughly equal and the outboard marine engine  10  is depicted in a straightforward orientation with respect to the vertical steering axis  18 . 
       FIG. 4A  depicts the steering actuator  16  upon an input to the controller  120  for steering movement of the outboard marine engine  10  in the first pivot direction. The controller  120  controls the bidirectional motor  44  to rotate the output shaft  46  in the noted first rotational direction, which causes axial travel of the output sleeve  48  out of the spool  50 , away from the bidirectional motor  44 . Initial movement of the output sleeve  48  (i.e. to the right in  FIG. 4A ) is prevented by the relative heavy weight of the outboard marine engine  10  acting against the end of the output sleeve  48 . That is, the output sleeve  48  is connected to the outboard marine engine  10  via the rigid position reference link  112  and the trunnion  92 . The force required to move the outboard marine engine  10  about the vertical steering axis  18  is greater than the force required to move the bidirectional motor  44 , threaded connector  52  and spool  50  reversely in the motor portion  82  of the second cavity  34 . As such, rotation of the bidirectional motor  44  in the first rotational direction causes the spool  50  and bidirectional motor  44  to move to the left in  FIG. 4A , which causes the oil passages  54   a  on the spool  50  to align with the inlet  70  and outlet  76 . This allows flow of hydraulic fluid from the pump  36  to the first hydraulic fluid passageway  100  and then into the first side  28  of the piston device  24 . As shown in  FIGS. 4B and 4C , increasing the flow of hydraulic fluid to the first side  28  of the piston device  24  via the first hydraulic fluid passageway  100  increases the pressure on the first side  28 , which acts on the first piston  84  and causes the first piston  84  to move the piston device  24  in the first piston direction (i.e. to the right in the figures), which in turn, causes the outboard marine engine  10  to pivot in a first pivot direction, as shown in dashed lines in  FIG. 4C . Once the requested pivoting movement of the outboard marine engine  10  is achieved (i.e. the requested pivoting movement that is input to the controller  120  via for example the input device  122 ), the controller  120  causes the bidirectional motor  44  to stop rotating the output shaft  46 , which allows the springs  60 ,  62  to re-center the spool  50  such that the oil passages  54   b  divert the flow of hydraulic fluid from the pump  36  back to the tank  38 , as shown in  FIGS. 4C and 6 . 
       FIGS. 5A-5C  depict the steering actuator  16  during an input to the controller  120  for movement of the outboard marine engine  10  about the vertical pivot axis in the noted second pivot direction. 
       FIG. 5A  depicts a steering actuator  16  upon an input to the controller  120  for steering movement of the outboard marine engine  10  in the second pivot direction. The controller  120  controls the bidirectional motor  44  to rotate the output shaft  46  in the noted second rotational direction, which causes axial travel of the output sleeve  48  into the spool  50 , towards the bidirectional motor  44 . Initial movement of the output sleeve  48  (i.e. to the left in  FIG. 5A ) is prevented by the relative heavy weight of the outboard marine engine  10  acting against the end of the output sleeve  48 . That is, the output sleeve  48  is connected to the outboard marine engine  10  via the rigid position reference link  112  and the trunnion  92 . The force required to move the outboard marine engine  10  about the vertical steering axis  18  is greater than the force required to move the bidirectional motor  44 , threaded connector  52  and spool  50  in the motor portion  82  of the second cavity  34 . As such, rotation of the bidirectional motor  44  in the second rotational direction causes the spool  50  and bidirectional motor  44  to move to the right in  FIG. 5A , which causes the oil passages  54   c  on the spool  50  to align with the inlet  70  and outlet  76 . This allows flow of hydraulic fluid from the pump  36  to the second hydraulic fluid passageway  102  and then into the second side  30  of the piston device  24 . As shown by comparison of  FIGS. 5A, 5B  to  FIG. 5C , increasing the flow of hydraulic fluid to the second side  30  of the piston device  24  via the second hydraulic fluid passageway  102  increases the pressure on the second side  30 , which acts on the second piston  88  and causes the second piston  88  to move the piston device  24  in the second piston direction (i.e. to the left in the figures), which in turn, causes the outboard marine engine  10  to pivot in a first pivot direction, as shown in dashed lines in  FIG. 5C . Once the requested pivoted movement of the outboard marine engine  10  is achieved (i.e. the requested pivoting movement input to the controller  120  via for example the input device  122 ), the controller  120  causes the bidirectional motor  44  to stop rotating the output shaft  46 , which allows the springs  60 ,  62  to re-center the spool  50  such that the oil passages  54   b  divert the flow of hydraulic fluid from the pump  36  back to the tank  38 , as shown in  FIG. 5C . 
     Through research and development, the present inventors have determined that enclosing the steering actuator  16  in a housing  22 , including for example enclosing the piston device  24 , valve device  26 , and rigid positional reference link  112  in the housing  22  avoids improper installation and functionality instigated by boat builders and/or customers. Enclosing the electrical components and steering actuator  16  in the housing  22  protects the electrical components and steering actuator  16  from exposure to the elements, which can undesirably lead to water infiltration into the piston device  24 , valve device  26  and related hydraulic components. The examples shown in the figures is also much shorter in length than current steering actuators, which lessens packaging issues associated with assembly of the apparatus on the marine vessel. 
     In the above description, certain terms have been used for brevity, clarity, and understanding. No unnecessary limitations are to be inferred therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. The different systems and method steps described herein may be used alone or in combination with other systems and methods. It is to be expected that various equivalents, alternatives and modifications are possible within the scope of the appended claims.