Swivel drive assembly

Information

  • Patent Grant
  • 6503109
  • Patent Number
    6,503,109
  • Date Filed
    Wednesday, July 19, 2000
    24 years ago
  • Date Issued
    Tuesday, January 7, 2003
    21 years ago
Abstract
A swivel drive assembly for an electrically powered boat. The swivel drive assembly comprising a housing which has a propeller shaft extending therethrough and a propeller mechanically coupled to the propeller shaft. The swivel drive assembly further includes a turning post having a hollow interior mechanically coupled to the housing. A drive shaft is mechanically coupled to the propeller shaft and is disposed within the hollow interior of the turning post and the housing. The swivel drive assembly further includes an electric motor mechanically coupled to the drive shaft and operable to spin the propeller thereby. In this respect, the rotation of the turning post is operative to point the housing and the propeller in a desired direction to facilitate steering of the boat.
Description




CROSS-REFERENCE TO RELATED APPLICATIONS




(Not Applicable)




STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT




(Not Applicable)




BACKGROUND OF THE INVENTION




The present invention generally relates to a propulsion system for an electric boat, and more particularly to a swivel drive assembly.




Electric boats typically use a direct drive system for propulsion. In such a system, a propeller of the boat is attached to a propeller shaft which extends from the bottom thereof. The propeller shaft extends through the bottom of the boat via a stuffing box which prevents water from entering the boat. Disposed on an end of the propeller shaft opposite the propeller is a pulley. The pulley is coupled to an electric motor via a belt. Accordingly, as the electric motor rotates, the propeller shaft rotates thereby spinning the propeller and pushing the electric boat. By controlling the direction of rotation and speed of the electric motor, it is possible to control the speed and direction of the boat.




In order to maneuver the electric boat, there is typically provided at least one rudder, preferably two. Typically, the rudder is disposed aft of the propeller. By turning the rudder, water flowing thereover will be redirected thereby turning the boat. However, in order for the rudder of the electric boat to be effective, it is necessary for the electric boat to maintain a minimum speed. In this respect, water must flow over the rudder of the electric boat at a prescribed rate in order for the electric boat to turn. At slow speeds, the electric boat will become difficult to handle thereby resulting in an increase of danger to the passengers of the boat because water is not flowing over the rudder at the prescribed rate.




Additionally, as previously mentioned, the prior art direct drive system for the electric boat comprises an elongate propeller shaft extending through the bottom of the boat to the electric motor. The electric motor is mounted to the boat through the use of brackets such that the pulley of the propeller shaft, as well as the drive belt of the electric motor are disposed within a housing in the interior of the electric boat. The housing typically consumes valuable interior space of the electric boat that could be used for passengers.




The present invention addresses the above-mentioned deficiencies in the prior art direct drive systems for electric boats by providing a swivel drive system. The swivel drive system of the present invention consumes less interior space than the conventional direct drive system thereby providing extra interior room for passengers. Additionally, the swivel drive system, constructed in accordance with the preferred embodiment of the present invention, provides an assembly which greatly enhances the maneuverability of the electric boat at slow speeds. In this respect, the swivel drive system is capable of positioning the propeller of the electric boat in a direction which facilitates turning.




BRIEF SUMMARY OF THE INVENTION




A swivel drive assembly for an electrically powered boat. The swivel drive assembly comprising a housing which has a propeller shaft extending therethrough and a propeller mechanically coupled to the propeller shaft. The swivel drive assembly further includes a turning post having a hollow interior mechanically coupled to the housing. A drive shaft is mechanically coupled to the propeller shaft and is disposed within the hollow interior of the turning post and the housing. The swivel drive assembly further includes an electric motor mechanically coupled to the drive shaft and operable to spin the propeller thereby. In this respect, the rotation of the turning post is operative to point the housing and the propeller in a desired direction to facilitate steering of the boat.




In the preferred embodiment of the present invention, the housing further comprises a gear mechanism mechanically coupled to the propeller shaft and the drive shaft. In this respect, the gear mechanism comprises a first bevel gear mechanically coupled to the propeller shaft and a second bevel gear mechanically coupled to the drive shaft and cooperatively engaged to the first bevel gear. Typically, the first and second bevel gears are spiral cut bevel gears in order to reduce noise and vibration of the swivel drive assembly.




In order to prevent water from entering the electric boat, the swivel drive assembly of the present invention further includes a seal mounted to the boat. The seal has an interior bore sized slightly larger than the turning post such that the turning post is extensible through the seal. The seal may include a vibration dampening member configured to reduce vibrations between the swivel drive assembly and the boat. Typically, the dampening member is formed from an elastomeric material.




In the preferred embodiment of the present invention, the seal has a housing with a hollow interior and the dampening member is disposed therein. The dampening member is formed with a cylindrical bore extending therethrough. The seal further includes a cylindrical bushing disposed within the cylindrical bore of the dampening member. The bushing has a hollow interior sized slightly larger than the turning post such that the turning post is extensible therethrough. Additionally, the seal may further include an oil seal disposed adjacent to the bushing and the turning post in order to prevent water from entering the boat from the space between the turning post and the bushing. The seal may further include a bearing disposed adjacent to the bushing and the turning post in order to facilitate rotation of the turning post.




The swivel drive assembly of the present invention may further include a motor mount attached to the electric motor and the turning post. In this respect, as the motor mount is rotated, the turning post is rotated thereby pointing the propeller in the desired direction to steer the boat. Additionally, the electric motor may include an output shaft mechanically coupled to the drive shaft through the use of a spline coupling.




In accordance with the present invention there is provided a method of controlling vibrations in an electrically powered boat having an electric motor, a drive shaft, a propeller shaft, a propeller, and a vibration dampening member. The method comprises attaching the vibration dampening member to the electric boat. Next, the electric motor is coupled to the vibration dampening member and the drive shaft is attached to the electric motor. The drive shaft is extended through the vibration dampening member and mechanically coupled to the propeller shaft. Next, the propeller is attached to the propeller shaft and spun by the electric motor such that vibrations may be created. In the preferred embodiment, the dampening member will reduce the vibrations caused by the spinning of the electric motor and the propeller. In the preferred embodiment, a gear mechanism mechanically couples the drive shaft to the propeller shaft. In this respect, the gear mechanism comprises a first spiral cut bevel gear and a second spiral cut bevel gear which are capable of reducing vibration and noise within the swivel drive assembly of the present invention.











BRIEF DESCRIPTION OF THE DRAWINGS




These as well as other features of the present invention will become more apparent upon reference to the drawings wherein:





FIG. 1

is a cross-sectional view of an electric boat using a prior art method of propulsion;





FIG. 2

is a cross-sectional view of the electric boat shown in

FIG. 1

using a swivel drive assembly of the present invention as the method of propulsion;





FIG. 3

is a perspective view of a seal and motor for the swivel drive assembly of the present invention;





FIG. 4

is a cross-sectional view of the upper portion of the swivel drive assembly of the present invention;





FIG. 5

is a cross-sectional view of the lower portion of the swivel drive assembly of the present invention; and





FIG. 6

is a cross-sectional view of the swivel drive assembly constructed in accordance with the present invention.











DETAILED DESCRIPTION OF THE INVENTION




Referring now to the drawings wherein the showings are for purposes of illustrating a preferred embodiment of the present invention only, and not for purposes of limiting the same,

FIG. 1

is a cross-sectional view of an electric boat


10


having a prior art propulsion system


12


. Specifically, the prior art propulsion system


12


includes a propeller


14


attached to a propeller shaft


16


that extends from a bottom


11


of the boat


10


. The propeller shaft


16


extends through a stuffing box


18


which prevents water from entering the interior of the boat


10


. Typically, the stuffing box


18


contains a seal which allows the propeller shaft


16


to rotate, while preventing water from entering the boat


10


. A deficiency with the stuffing box


18


is the tendency to leak. Additionally, the seal in the stuffing box


18


may fail thereby leading to water entering the boat


10


.




Referring to

FIG. 1

, the propeller shaft


16


extends upwardly from the stuffing box


18


into the interior of the boat


10


. Attached to an end of the propeller shaft


16


, opposite the propeller


14


, is a first pulley


20


. A belt


22


wraps around the first pulley


20


and attaches to a second pulley


24


attached to a drive shaft


26


of an electric motor


28


. In this respect, the electric motor


28


rotates the drive shaft


26


thereby turning the second pulley


24


. As the belt


22


rotates, the first pulley


20


, propeller shaft


16


, and propeller


14


rotate thereby resulting in propulsion of the boat


10


.




As seen in

FIG. 1

, the propeller shaft


16


extends upwardly into the boat


10


thereby consuming interior space. Additionally, the electric motor


28


is mounted near the end of the propeller shaft


16


such that the electric motor


28


consumes interior space of the boat


10


. In fact, often times the manufacturer of the electric boat


10


will include a housing


29


to cover the prior art propulsion system


12


. For example, the housing


29


may be the steering console for the boat


10


. The prior art propulsion system


12


for electric boats is disadvantaged because it consumes valuable interior space.




In order to steer the electric boat


10


with the prior art propulsion system


12


, a rudder


30


is mounted aft of the propeller


14


. The rudder


30


is operative to direct the flow of water created by the movement of the boat


10


. Often times, in order to increase effectiveness, the boat


10


may be provided with twin rudders


30


positioned in a side-by-side configuration. In order for the rudder


30


to be effective, the boat


10


must be moving at a minimum speed such that water is flowing over the rudder


30


at a prescribed rate. If the electric boat


10


is not moving fast enough, then the flow of water over the rudder


30


is not adequate and the electric boat


10


loses steerage. Accordingly, a problem exists while docking the electric boat


10


where the operator of the boat will need to go slowly into the dock in order to make a safe landing. If the boat


10


docks to slowly, then the boat


10


will lose steerage. Alternatively, if the boat


10


is moving quickly, then there is the risk of damage to the boat


10


from colliding with the dock. Therefore docking an electric boat can be a difficult task for the operator because the correct speed must be used.




The present invention addresses the above-mentioned deficiencies in the prior art propulsion system


12


by providing a swivel drive assembly


100


that facilitates maneuvering an electric boat


102


. Specifically, as seen in

FIG. 2

, the swivel drive assembly


100


is positioned near the location of the rudder


30


of the electric boat


10


having the prior art propulsion system


12


. The swivel drive assembly


100


can rotate such that the assembly


100


can direct the flow of water propelled therefrom to turn the boat


102


(as will be further explained below). The swivel drive assembly


100


is linked to a steering wheel


104


of the boat


102


through a steering cable


106


. In this respect, the operator of the boat


102


can turn the wheel


104


to rotate the swivel drive assembly


100


. In addition to facilitating the steering of the boat


102


, the swivel drive assembly


100


provides a compact propulsion unit for the boat


102


. Specifically, the swivel drive assembly


100


can be mounted in the stern of the boat


102


to conserve space. Accordingly, as seen in

FIG. 2

, the electric boat


102


equipped with the swivel drive assembly


100


of the present invention has more interior room than the electric boat


10


with the prior art propulsion system


12


.




Referring to

FIGS. 4 and 6

, the swivel drive assembly


100


is mounted to the hull


108


of the boat


102


. Specifically, the hull


108


, at the location of the swivel drive assembly


100


, comprises an outer fiberglass layer


110


, an inner fiberglass layer


114


, and a plywood layer


112


sandwiched therebetween. The plywood layer


112


is bonded to both the inner and outer fiberglass layers


110


,


114


such that a unitary structure is formed thereby. Disposed within apertures of the plywood layer


112


and projecting upwardly through the inner layer


114


into the interior of the boat


102


are mounting bolts


116


. Each of the mounting bolts


116


is placed within the plywood layer


112


before bonding the same between the inner and outer fiberglass layers


110


,


114


. The mounting bolts


116


are used to attach swivel drive assembly


100


to the hull


108


of the boat


102


, as will be further explained below.




The swivel drive assembly


100


has an electric motor


118


as the drive mechanism. The electric motor


118


is typically connected to an electronic speed control and a set of batteries through power cable


120


. The batteries and speed control are operative to rotate an output shaft


122


of the electric motor


118


at a desired direction and rate.




The motor


118


is attached to a generally circular mounting plate


124


with multiple bolts


126


. The mounting plate


124


generally has the same diameter as the motor


118


, such that the motor


118


can be mounted directly thereon. The motor


118


is formed with threaded bores wherein each of the bolts


126


may be threaded therein. Specifically, each of the bolts


126


is placed through a respective aperture formed in the mounting plate


124


and threaded into the threaded bores of the motor


118


. By tightening the bolts


126


, the motor


118


is as secured to the mounting plate


124


. As seen in

FIG. 4

, the output shaft


122


of motor


118


is advanced through an aperture (not shown) formed in the center of the mounting plate


124


.




As seen in

FIG. 4

, the steering cable


106


is secured to one of the bolts


126


. The steering cable


106


comprises an outer sheath


128


disposed about an interior cable


130


. The end of the interior cable


130


is flattened and forms a flange which contains an aperture (not shown). The bolt


126


is projected through the aperture of the interior cable


130


such that the flattened portion of the interior cable


130


is sandwiched between a lower surface of the mounting plate


124


and the head of the bolt


126


. Typically, the bolt


126


that is attached to the interior cable


130


is tightened to a setting that allows the aperture of the interior cable


103


to rotate freely around the bolt


126


. In this respect, a set of washers may be placed between the head of the bolt


126


, mounting plate


124


and interior cable


130


to prevent binding of the interior cable


130


and facilitate rotation thereof around the bolt


126


. As will be further explained below, the advancement and retraction of the interior cable


130


from the sheath


128


is operative to rotate the swivel drive assembly


100


to turn the boat


102


.




Referring to

FIG. 4

, attached to the mounting plate


124


is a cylindrical turning post


132


having a hollow interior


134


. The turning post


132


is attached to the mounting plate


124


in a location whereat the turning post


132


is coaxially aligned with the output shaft


122


of the motor


118


. In this respect, the output shaft


122


is disposed within the hollow interior


134


of the turning post


132


. The turning post


132


is typically fabricated from a metallic material such as stainless steel tubing. Furthermore, the turning post


132


is attached to the mounting plate via a method (e.g., welding) which allows the turning post


132


to rotate as the mounting plate


124


is rotated.




In order to prevent water from entering the boat


102


and prevent vibrations of the electric motor


118


being transferred to the hull


108


of the boat


102


, the swivel drive assembly


100


includes a seal unit


136


mounted to the hull


108


. The seal unit


136


has a housing


138


formed from a metallic material. As seen in

FIGS. 4 and 6

, the housing


138


is generally cylindrical and encloses the turning post


132


. The housing


138


has a generally cylindrical body section


140


which transitions into a circular flange section


142


. Each of the bolts


116


projects upwardly through apertures formed in the flange section


142


of housing


138


in order to secure the seal unit


136


to the hull


108


of the boat


102


. The body section


140


of the housing


138


has a generally cylindrical interior surface


144


. In abutting contact with the interior surface


144


is a vibration dampening member


146


formed from an elastomeric material. The vibration dampening member


146


is generally cylindrical and is formed slightly smaller than the inner diameter of the body section


140


of housing


138


. In this respect, the dampening member


146


can be inserted or formed into the interior of the housing


138


. The dampening member


146


has a generally cylindrical bore


150


formed within the center thereof. The bore


150


is coaxially aligned with the with the output shaft


122


of the motor


118


and turning post


132


, as will be further explained below. The dampening member


146


is formed with a series of notches


148


formed on an interior surface of the bore


150


. The notches


148


are disposed circumferentially about the bore


150


and evenly spaced along the central axis thereof. As seen in

FIG. 4

, there are four notches


148


formed in the dampening member


146


. However, the number and size of the notches


148


may vary as desired. Because the dampening member


146


is formed from an elastomeric material, vibration from the motor


118


and other components of the swivel drive assembly


100


will be absorbed by the dampening member


146


are not transmitted to the hull


108


of the boat


102


.




The seal unit


136


further includes a generally cylindrical bronze bushing


152


to support the turning post


132


. The bushing


152


is disposed within the bore


150


of the vibration dampening member


146


. The bushing


152


is formed with a series of grooves


154


disposed about the outer surface thereof. More specifically, the grooves


154


are formed complementary to the notches


148


of the of the dampening member


146


such that the notches


148


lock with the grooves


154


and the bushing


152


is retained within the bore


150


of the dampening member


146


. As previously mentioned, the number of grooves


154


and notches


148


may vary in order to properly retain the bushing


152


within the dampening member


146


and prevent push out thereof. The inner diameter of the bushing


152


is sized slightly larger than the outer diameter of the turning post


132


such that the turning post


132


is in contact with the bushing


152


when extended there through, as seen in FIG.


6


. In this respect, the bushing


152


provides a surface that the turning post


132


rotates against. As will be recognized by those of ordinary skill in the art, the bushing


152


is fabricated from bronze to reduce corrosion.




Disposed on an upper portion


156


of the bushing


152


is an annular oil seal


158


and an annular bearing


160


. As seen in

FIG. 4

, the annular oil seal


158


is disposed within the interior of the bushing


152


such that it is in contact with both the turning post


132


and the bushing


152


. The oil seal


158


is circumferentially disposed about the interior diameter of the bushing


152


and the outer diameter of the turning post


132


. In this respect, the oil seal


158


provides a watertight seal that prevents water between turning post


132


and bushing


152


from entering the boat


102


. Accordingly, water outside the hull


108


that leaks through the space between the turning post


132


and bushing


152


at outer fiberglass layer


110


is prevented from entering the boat


102


by the oil seal


158


.




The bearing


160


is circumferentially disposed about the top portion


156


of the bushing


152


and is in abutting contact with the lower surface of the mounting plate


124


. The bearing


160


is attached to both the bushing


152


and the mounting plate


124


and provides free rotation of the mounting plate


124


with respect to the bushing


152


. Therefore, the mounting plate


124


with motor


118


can freely rotate on the top of the bushing


152


. Additionally, because the turning post


132


is fixedly attached to the mounting plate


124


, the turning post


132


can rotate within the bushing


152


. The bearing


160


may comprise ball bearings in order to facilitate the rotation of the mounting plate


124


.




As previously mentioned, the output shaft


122


extends downwardly from the motor


118


into the interior


134


of the turning post


132


. Disposed on the end of the output shaft


122


opposite the motor


118


is a cylindrical spline coupling


170


. The spline coupling is operative to join the output shaft


122


with a cylindrical drive shaft


172


, as seen in FIG.


4


. As seen in

FIGS. 4 and 6

, the drive shaft


172


extends downwardly through the interior


134


of the turning post


132


and is coaxially aligned therein. In the preferred embodiment of the present invention, the drive shaft


172


is fabricated from a metallic material such as stainless steel.




Referring to

FIGS. 5 and 6

, the turning post


132


is fixedly attached to a shroud


174


that is disposed in the water outside the hull


108


of the boat


102


. The turning post


132


is attached to the shroud


174


in a manner that provides a water tight seal. In this respect, water cannot enter the interior


134


of the turning post


132


through the attachment of the turning a post


132


with the shroud


174


. The interior


134


will therefore remain dry, as well as the drive shaft


172


.




The shroud


174


is fixedly attached to the turning post


132


such that as the turning post


132


is rotated, the shroud


174


will also rotate. Referring to

FIG. 5

, the shroud


174


is formed with an upper cavity


178


and a lower cavity


180


. An annular upper drive shaft bearing


176


is disposed in the upper cavity to support the drive shaft


172


as it extends through the upper cavity


178


. Disposed in the lower cavity


180


is a lower drive shaft bearing


182


which supports a lower end


184


of the drive shaft


172


.




Fixedly attached on the lower end


184


of the drive shaft


172


is a drive shaft bevel gear


186


. The drive shaft bevel gear


186


is in meshing engagement with a propeller shaft bevel gear


188


. As seen in

FIG. 5

, the propeller shaft bevel gear


188


is fixedly attached to a propeller shaft


190


. Accordingly ,the rotation of the drive shaft


172


will rotate the propeller shaft


190


via the drive shaft bevel gear


186


and the propeller shaft bevel gear


188


. In the preferred embodiment of the present invention, the drive shaft bevel gear


186


and the propeller shaft bevel gear


188


are both complementary spiral cut bevel gears. By utilizing spiral cut bevel gears, whine and vibration from the gears


186


,


188


are reduced and not transmitted into the boat


102


.




The propeller shaft


190


is generally perpendicular to the drive shaft


172


. The propeller shaft


190


is supported in the lower cavity


180


by a forward propeller shaft bearing


192


and an aft propeller shaft bearing


194


. Additionally, the propeller shaft bevel gear


188


is supported by a propeller shaft bevel gear bearing


196


. The propeller shaft


190


can therefore spin by the rotation of the drive shaft


172


. In order to prevent water from entering the lower cavity


180


of the shroud


174


, the propeller shaft


190


extends through a propeller shaft seal


198


. The propeller shaft seal


198


circumferentially surrounds the propeller shaft


190


to provide a water-tight seal, but still allow the rotation of the propeller shaft


190


. Attached to the end of the propeller shaft


190


extending from the propeller shaft seal


198


is a propeller


200


.




The shroud


174


is typically fabricated from fiberglass and shaped similar to the rudder


30


used in the prior art propulsion system


12


. By rotating the shroud


174


, it is therefore possible to steer the boat


102


from the water flowing there over. Additionally, when the propeller


200


is spinning, and the shroud


174


is rotated, then the propeller


200


will pointed in a direction that will turn the boat


102


. In this respect, by pointing the propeller


200


(as it is rotating) with the shroud


174


, it is easier to turn the boat


102


at slow speed. This allows for easy docking and maneuvering of the boat


102


.




In order to steer the boat


102


, the operator turns the steering wheel


104


in the desired direction which will correspondingly extend or retract the interior cable


130


of the steering cable


106


. The extension or retraction of the interior cable


130


will correspondingly rotate the mounting plate


124


and turning post


132


attached thereto. As previously mentioned, the shroud


174


will rotate with the rotation of the turning post


132


because they are attached together. The rotation of the shroud


174


will therefore point the propeller


200


in the desired direction to steer the boat


102


.




In addition to facilitating steerage of the boat


102


, the swivel drive assembly


100


of the present invention additionally consumes less interior space of the boat


102


than the prior art system


12


. As seen in

FIG. 2

, the swivel drive assembly


100


is mounted in the stern of the boat


102


which is typically used for storage. With the configuration of the present invention, the swivel drive assembly


100


consumes less interior space than the prior art propulsion system


12


. Additionally, by vertically mounting the electric motor


118


directly above the shroud


174


, the need for belt


22


and pulleys


20


and


24


is not needed thereby increasing the reliability and safety of the propulsion system for the electric boat


102


.




Additional modifications and improvements of the present invention may also be apparent to those of ordinary skill in the art such as using two swivel drive assemblies


100


in a side-by-side configuration. Thus, the particular combination of parts described and illustrated herein is intended to represent only certain embodiments of the present invention, and is not intended to serve as limitations of alternative devices within the spirit and scope of the invention.



Claims
  • 1. A swivel drive assembly for an electrically powered boat, the swivel drive assembly comprising:a rudder-shaped shroud to direct water flow to steer the boat; a propeller shaft extending through the shroud; a propeller attached to the propeller shaft; a straight tubular turning post attached to the shroud and rotatably mounted to the boat; a drive shaft extending within the turning post and the shroud, the drive shaft being mechanically coupled to the propeller shaft; and an electric motor mechanically coupled to the drive shaft, the rotation of the electric motor being operable to spin the propeller; wherein the rotation of the turning post is operative to point the propeller and the rudder shaped shroud in a desired direction in order to facilitate steering of the boat.
  • 2. The swivel drive assembly of claim 1 further comprising a gear mechanism mechanically coupling the propeller shaft to the drive shaft.
  • 3. The swivel drive assembly of claim 2 wherein the gear mechanism comprises a first bevel gear attached to the propeller shaft and a second bevel gear attached to the drive shaft and cooperatively engaged to the first bevel gear.
  • 4. The swivel drive assembly of claim 3 wherein the first and second bevel gears are spiral cut bevel gears.
  • 5. The swivel drive assembly of claim 1 further comprising a seal mounted to the boat, the seal having an interior bore sized slightly larger than the turning post such that the turning post is extensible through the seal, the centerline of the seal being in axial alignment with the centerline of the drive shaft.
  • 6. The swivel drive assembly of claim 5 wherein the seal comprises a vibration dampening member configured to reduce vibrations between the swivel drive assembly and the boat.
  • 7. The swivel drive assembly of claim 6 wherein the dampening member is formed from an elastomeric material.
  • 8. A swivel drive assembly for an electrically powered boat, the swivel drive assembly comprising:a shroud; a propeller shaft extending through the shroud; a propeller attached to the propeller shaft; a tubular turning post attached to the shroud and rotatably mounted to the boat; a drive shaft extending within the turning post and the shroud, the drive shaft being mechanically coupled to the propeller shaft; an electric motor mechanically coupled to the drive shaft, the rotation of the electric motor being operable to spin the propeller; and a seal mounted to the boat, the seal having an interior bore sized slightly larger than the turning post such that the turning post is extensible through the seal, the seal further comprising; a housing having a hollow interior; a dampening member disposed within the hollow interior of the housing, the dampening member being formed with a cylindrical bore extending there through; and a cylindrical bushing disposed within the cylindrical bore of the dampening member, the bushing having a hollow interior sized slightly larger than the turning post such that the turning post is extensible therethrough; wherein the rotation of the turning post is operative to point the propeller in a desired direction in order to facilitate steering of the boat.
  • 9. The swivel drive assembly of claim 8 wherein the seal further comprises an oil seal disposed adjacent to the bushing and the turning post in order to prevent water from entering the boat.
  • 10. The swivel drive assembly of claim 8 wherein the dampening member is formed from an elastomeric material.
  • 11. The swivel drive assembly of claim 8 wherein the seal further comprises a bearing disposed adjacent to the bushing and the turning post in order to facilitate rotation of the turning post.
  • 12. The swivel drive assembly of claim 1 further comprising a motor mount attached to the electric motor and the turning post wherein rotation of the motor mount rotates the turning post.
  • 13. The swivel drive assembly of claim 1 wherein the electric motor further comprises an output shaft mechanically coupled to the drive shaft.
  • 14. The swivel drive assembly of claim 13 further comprising a spline coupling mechanically coupling the output shaft to the drive shaft.
  • 15. A swivel drive assembly for a boat, the swivel drive assembly comprising:a housing having a hollow interior; a dampening member having an interior surface, the dampening member disposed within the hollow interior of the housing, the dampening member being formed with a cylindrical bore extending therethrough, the dampening member having at least one notch defining an upper, lower, and interior circumferential surface, the at least one notch being on the interior surface of the dampening member, the upper and lower surface providing vibration dampening in a direction perpendicular to the upper and lower surface, the interior circumferential surface providing vibration dampening in a direction perpendicular to the interior circumferential surface; and a cylindrical bushing disposed within the cylindrical bore of the dampening member, the bushing having a hollow interior sized slightly larger than a turning post such that the turning post is extensible therethrough, the cylindrical bushing having notches that engage the at least one notch of the dampening member.
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