BOAT WITH A PAIR OF TURBINE ENGINES AND A CONFIGURABLE PROPELLER DRIVE SYSTEM FOR INDEPENDENTLY DRIVING A PAIR OF PROPELLERS FROM THE TURBINE ENGINES

Abstract

A boat including first and second turbine engines each having a rotor, first and second propeller assemblies each having a propeller shaft configured with a propeller pulley and a propeller, and a configurable propeller drive system including first and second configurable propeller drives each configured to drive a selected one of the first and second propeller pulleys from a corresponding one of the rotors of the first and second turbine engines. The first and second turbine engines may be air-cooled and mounted inline along the center of the hull. Each configurable propeller drive may include an intermediate pulley and multiple drive belts for driving a selected propeller pulley from each rotor via an intermediate pulley. The drive belts may be swapped so that either turbine engine may drive either propeller. The turbine engines may be air-cooled and may have reversible orientations.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to boating, and more specifically to a boat with a pair of turbine engines and a configurable propeller drive system for independently driving a pair of propellers from the turbine engines.

Description of the Related Art

Many waterways, including lakes and rivers and the like, particularly those located along borders between different states or nations, are often patrolled by boats operated by authorities such as border patrol officers. In some cases the border patrol presence is necessary to minimize illegal activity, such as human trafficking, illegal immigration, smuggling of illicit drugs, etc. The Rio Grande River is one such example of a navigable waterway located along the Texas border between Mexico and the United States. In order to facilitate effective law enforcement, border patrol boats need to be as fast as possible to reach an active area of interest in a minimal amount of time. In addition, border patrol boats should be easy to maintain to maximize effectiveness while minimizing cost.

Conventional boats used for border patrol are expensive to maintain and yet not sufficiently fast. Most conventional boats include one or more outboard motors that are unable to achieve speeds in excess of about 60 knots which is less than about 70 miles per hour (mph). In addition, conventional boat configurations often use water-cooled motors that require intake of the water for cooling. The water, however, often contains high levels of particulate and other corrosive substances that rapidly degrade the boat motors rendering them very expensive to maintain or replace.

BRIEF DESCRIPTION OF THE DRAWINGS

The benefits, features, and advantages of the present invention will become better understood with regard to the following description, and accompanying drawings, in which:

FIG. 1 is a simplified top view of a boat implemented according to one embodiment with a pair of turbine engines and a configurable propeller drive system for independently driving a pair of propellers.

FIG. 2 is a simplified top view of a boat implemented according to another embodiment that is substantially identical as the boat of FIG. 1 in which similar parts or components assume identical reference numbers, and in which a pair of drive belts driving propeller shaft pulleys are swapped.

FIG. 3 is a simplified top view of a boat implemented according to another embodiment that is substantially identical as the boat of FIG. 1 in which similar parts or components assume identical reference numbers, and in which the orientation of both turbine engines are reversed.

FIG. 4 is a simplified top view of a boat implemented according to another embodiment that is substantially identical as the boat of FIG. 3 in which similar parts or components assume identical reference numbers, and in which a pair of drive belts driving propeller shaft pulleys are swapped.

FIG. 5 is a simplified top view of a boat implemented according to another embodiment that is substantially similar as the boats of FIGS. 1-4 in which similar parts or components assume identical reference numbers, and in which the turbine engines are offset from center.

FIG. 6 is a simplified top view, a corresponding simplified side view, and a corresponding simplified front view of an outline of the turbine engine and the corresponding intermediate drive assembly of FIG. 1 according to one embodiment.

FIG. 7 is a more detailed diagram of a drive pulley configuration that may be used for selected ones up to all of the pulley and belt configurations shown for the boats of FIGS. 1-5 according to one embodiment.

FIG. 8 is a simplified rear view diagram of a steering system implemented according to one embodiment mounted to the transom of a boat, such as any of the boats of FIGS. 1-5 previously described.

FIG. 9 is a simplified rear view diagram of the transom of a boat illustrating the thrust tubes and corresponding propellers positioned for a full left-hand turn.

FIG. 10 is a simplified rear view diagram of the transom of a boat illustrating the thrust tubes and corresponding propellers positioned for a full right-hand turn.

DETAILED DESCRIPTION

A boat as described herein includes a hull, first and second turbine engines mounted within the hull each having a rotor, first and second propeller assemblies provided within the hull each having a propeller shaft configured with a propeller pulley and a propeller, and first and second configurable propeller drive each configured to drive a selected one of the first and second propeller pulleys from a corresponding one of the rotors of the first and second turbine engines. The first and second turbine engines may be air-cooled turbine engines.

Each configurable propeller drive may include an intermediate pulley, a first drive belt provided to drive the intermediate pulley from a rotor of a corresponding turbine engine, and a second drive belt provided to drive a selected one of the first second propeller pulleys from the intermediate pulley. The second drive belts of the configurable propeller drives may be swapped so that either turbine engine may drive either propeller.

Each of the turbine engines may have a reversible orientation in which each configurable propeller drive includes first and second intermediate pulleys. The first drive belt is provided to drive either one of the first or the second intermediate pulleys from the rotor depending upon the orientation of the respective turbine engine, and the second drive belt is provided to drive a selected one of the propeller pulleys from the first intermediate pulley.

The first and second turbine engines may be mounted relative to a longitudinal centerline between a bow and a stern of the hull, in which the first turbine engine is mounted between the bow and the second turbine engine, and wherein the second turbine engine is mounted between the first turbine engine and the stern of the hull. The first and second turbine engines may be mounted inline in parallel with the longitudinal centerline of the hull. At least one of the first and second turbine engines may be mounted at an offset relative to the longitudinal centerline of the hull. The first configurable propeller drive may include at least one intermediate pulley positioned below the first turbine engine and the second configurable propeller drive may include at least one intermediate pulley positioned below the second turbine engine.

The first propeller assembly may be positioned on a port side of the hull and the second propeller assembly may be positioned on a starboard side of the hull. Each propeller assembly may include a thrust tube that contains a corresponding propeller shaft for directing the corresponding propeller. The boat may include a steering system mounted to the transom that constrains the first and second thrust tubes to swing together in tandem substantially in parallel with a bottom side of the hull towards the port side or the starboard side of the hull.

FIG. 1 is a simplified top view of a boat 100 implemented according to one embodiment with a pair of turbine engines (or simply “turbines”) 102 and 104 and a configurable propeller drive system for independently driving a pair of propellers 132 and 138. The boat 100 may be configured according to any one of several different boat configurations, such as V-hull boats, flat bottom boats, catamarans, etc. The boat 100 includes a hull 110 having a front end referred to herein as a bow 112 and a back end referred to herein as a stern 114. The back-most section of the stern 114 is referred to herein as a transom 116. A dashed line represents a centerline C_L from a center of the bow 112 to a center of the transom 116 at the stern 114 that divides the hull 110 between a port side 111 on the left and a starboard side 113 on the right for purposes of reference.

In one embodiment, each of the turbine engines 102 and 104 are air-cooled engines including an air intake labeled “IN” and an exhaust labeled “EXH,” in which an intermediate arrow symbol represents the direction of airflow though the respective turbine engine during operation. The arrow symbol also illustrates the mounting orientation of the respective turbine engine. The turbine engine 102 includes a rotor 122 and the turbine engine 104 includes a rotor 124. In the illustrated configuration of FIG. 1, the turbine engines 102 and 104 are mounted generally inline within the hull 110 each aligned in parallel with the centerline C_L with their rotors 122 and 124 facing each other.

Each of the turbine engines 102 and 104 may be a T53 air-cooled gas turbine engine, such as the Lycoming T53 turboshaft engine. The T53 turbine engine is air-cooled, lightweight, and relatively powerful and has often been used in helicopters and fixed-wing aircraft and the like. The T53 turbine engine may be configured to generate over 800 horsepower (hp) at over 21,000 revolutions per minute (rpm). As further described herein, the high rotational speed of each of the turbine engines 102 and 104 is geared down to a rotational speed suitable for the propellers 132 and 138 providing the thrust power for the boat 100. In one embodiment, the maximum rotational speed of the propellers 132 and 138 is about 5,000 to 7,000 rpm to achieve a maximum speed of about 96 knots or about 110 mph.

A propeller assembly 126 includes a propeller shaft 106, an elongated propeller pulley 130, the propeller 132, and a thrust tube 134. The propeller pulley 130 is mounted on one end and the propeller 132 is mounted on the other end of the propeller shaft 106. The propeller shaft 106 is inserted within a hollow center portion of the thrust tube 134 in such a manner so that the propeller shaft 106 rotates freely within the thrust tube 134. Similarly, a substantially similar propeller assembly 128 includes a propeller shaft 108, an elongated propeller pulley 136, a propeller 138, and a thrust tube 139. The propeller pulley 136 is mounted on one end and the propeller 138 is mounted on the other end of the propeller shaft 108. The propeller shaft 108 is inserted within a hollow center portion of the thrust tube 139 in such a manner so that the propeller shaft 108 rotates freely within the thrust tube 139.

The boat 100 is an inboard engine configuration with surface piercing propeller drives. The propeller assembly 126 is located on the port side 111 of the hull 112, whereas the propeller assembly 128 is located on the starboard side 113 of the hull 112. The propeller assembly 126 and the propeller assembly 128 are positioned so that the thrust tubes 134 and 139 and corresponding propeller shafts 106 and 108, respectively, protrude through the transom 116 to position both of the propellers 132 and 138 in the water at the rear of the hull 112. In this manner, during operation when the propeller pulleys 130 and 136 are rotated by rotors of the turbine engines 102 and 104, the propeller shafts 106 and 108 rotate the corresponding propellers 132 and 138 to propel the boat 100.

In one embodiment, the thrust tubes 134 and 139 may be mounted in a fixed position to the hull 110 so that the corresponding propellers 132 and 138 are in fixed positions on either side of the hull 110. In an alternative embodiment as further described herein, the propeller assemblies 126 and 128 are pivotally and slidably mounted to swing together in tandem substantially in parallel with a bottom side of the hull 110 towards the port side 111 or towards the starboard side 113 for steering the boat 100. Thus, as one propeller is moved away from the centerline C_L, the other propeller is moved towards the centerline C_L to steer the boat 110 in one direction, and vice-versa to steer the boat 110 in the opposite direction.

The boat 100 further includes a configurable propeller drive system that enables each of the turbine engines 102 and 104 to drive either one of the propellers 132 or 138 via the propeller assemblies 126 and 128. The configurable propeller drive system includes a first configurable propeller drive 140 for the turbine engine 102 and a second configurable propeller drive 150 for the turbine engine 104. In one embodiment, the first configurable propeller drive 140 includes an intermediate drive assembly 142 and a pair of drive belts 144 and 146, and the second configurable propeller drive 150 includes an intermediate drive assembly 152 and a pair of drive belts 154 and 156. Each of the intermediate drive assemblies 142 and 152 is mounted below a corresponding one of the turbine engines 102 and 104, respectively, and includes at least one pulley, a drive shaft, and a shaft tube. As shown, the intermediate drive assembly 142 is positioned below the turbine engine 102 and includes a first intermediate pulley 143 and a second intermediate pulley 145 mounted on either end of an intermediate drive shaft 147. In a similar manner, the intermediate drive assembly 152 is positioned below the turbine engine 104 and includes a first intermediate pulley 153 and a second intermediate pulley 155 mounted on either end of a intermediate drive shaft 157. Corresponding shaft tubes 141 and 151 (shown in FIG. 5) are provided for mounting each of the intermediate drive assemblies 142 and 152 to the hull 110, but are not shown in FIGS. 1-4 since hidden below each of the turbine engines 102 and 104.

In one embodiment, the rotors 122 and 124 of the turbine engines 102 and 104, the intermediate pulleys 143 and 145 of the intermediate drive assembly 142, the intermediate pulleys 153 and 155 of the intermediate drive assembly 122, and the propeller pulleys 130 and 136 of the propeller assemblies 126 and 128 are configured as cylindrical bodies with outer surfaces configured to optimize frictional interaction with corresponding drive belts to maximize transfer of rotary motion. The drive belt 144 is formed as a sturdy flexible loop that is configured to interface the outer surface of the rotor 122 and to interface the outer surface of the intermediate pulley 143 (or the outer surface of the intermediate pulley 145 when the position of the turbine engine 102 is reversed as further described herein) of the intermediate drive assembly 142 to transfer rotary motion of the rotor 122 to the intermediate pulley 143 (or to the intermediate pulley 145). Similarly, the drive belt 146 is formed as a sturdy flexible loop that is configured to interface the outer surface of the intermediate pulley 143 and the outer surface of the propeller pulley 130 (or the outer surface of the propeller pulley 136) to transfer rotary motion of the intermediate pulley 143 to the propeller pulley 130 (or to the propeller pulley 136). In this manner, the rotary motion of the rotor 122 is transferred to the propeller pulley 130 (or to the propeller pulley 136) and thus to the propeller 132 (or the propeller 138) via the propeller shaft 106 (or via the propeller shaft 108).

In a similar manner, the drive belt 154 is formed as a sturdy flexible loop that is configured to interface the outer surface of the rotor 124 and to interface the outer surface of the intermediate pulley 153 (or the outer surface of the intermediate pulley 155 when the position of the turbine engine 104 is reversed as further described herein) of the intermediate drive assembly 152 to transfer rotary motion of the rotor 124 to the intermediate pulley 153 (or to the intermediate pulley 155). Similarly, the drive belt 156 is formed as a sturdy flexible loop that is configured to interface the outer surface of the intermediate pulley 153 and the outer surface of the propeller pulley 136 (or the outer surface of the propeller pulley 130) to transfer rotary motion of the intermediate pulley 153 (or the intermediate pulley 155) to the propeller pulley 136 (or to the propeller pulley 130). In this manner, the rotary motion of the rotor 124 is transferred to the propeller pulley 136 (or to the propeller pulley 130) and thus to the propeller 138 (or the propeller 132) via the propeller shaft 108 (or the propeller shaft 106).

In one embodiment, the outer drive surfaces of the rotors 122 and 124 and the outer drive surfaces of the intermediate pulley 143, 145, 153, 155, 130, and 136 are toothed, and the inner drive surfaces of the drive belts 144, 146, 154, and 156 are also toothed in a complementary fashion to minimize slippage and maximize power transfer efficiency. As described further below, idler pulleys or the like may be included for each of the drive belts 144, 146, 154, and 156 as further described herein. It is noted that the drive belts 144 and 154 may be identical and interchangeable, and that the drive belts 146 and 156 may be identical and interchangeable.

FIG. 2 is a simplified top view of a boat 200 implemented according to another embodiment that is substantially identical as the boat 100 in which similar parts or components assume identical reference numbers. In fact, the boat 200 is the same as the boat 100 except that the drive belt 146 is moved to instead drive the propeller pulley 136 of the propeller assembly 128 and the drive belt 156 is moved to instead drive the propeller pulley 130 of the propeller assembly 126. In this manner, the rotary motion of the rotor 122 of the turbine engine 102 is instead transferred to the propeller pulley 136 (instead of the propeller pulley 130) and thus to the propeller 138 via the propeller shaft 108 (instead of the propeller 132 via the propeller shaft 106). Likewise, the rotary motion of the rotor 124 of the turbine engine 104 is instead transferred to the propeller pulley 130 (instead of the propeller pulley 136) and thus to the propeller 132 via the propeller shaft 106 (instead of the propeller 138 via the propeller shaft 108). Operation of the boat 200 is similar to that of the boat 100, except that the rotational direction of each of the propellers 132 and 138 is reversed.

FIG. 3 is a simplified top view of a boat 300 implemented according to another embodiment that is substantially identical as the boat 100 in which similar parts or components assume identical reference numbers. In fact, the boat 300 is the same as the boat 100 except that the orientations of both of the turbine engines 102 and 104 are reversed and the drive belts 144 and 154 are moved accordingly. The position of the turbine engine 102 is reversed so that the rotor 122 is positioned above the intermediate pulley 145 of the intermediate drive assembly 142 instead of the intermediate pulley 143. The drive belt 144 is moved to interface the rotor 122 with the intermediate pulley 145 (instead of the intermediate pulley 143). Similarly, the position of the turbine engine 104 is reversed so that the rotor 124 is positioned above the intermediate pulley 155 of the intermediate drive assembly 152 instead of the intermediate pulley 153. The drive belt 154 is moved to interface the rotor 124 with the intermediate pulley 155 (instead of the intermediate pulley 153). Since the intermediate pulleys 143 and 145 are configured to rotate together via the intermediate drive shaft 147 and since the intermediate pulleys 153 and 155 are configured to rotate together via the intermediate drive shaft 157, operation of the boat 300 is substantially similar to that of the boat 200 except that the rotational direction of each of the propellers 132 and 138 is reversed.

FIG. 4 is a simplified top view of a boat 400 implemented according to another embodiment that is substantially identical as the boat 300 in which similar parts or components assume identical reference numbers. In fact, the boat 400 has the same configuration as that of the boat 300 except that the drive belt 146 is moved to drive the propeller pulley 136 of the propeller assembly 128 and the drive belt 156 is moved to drive the propeller pulley 130 of the propeller assembly 126. Operation of the boat 400 is similar to that of the boat 300, except that the rotational direction of each of the propellers 132 and 138 is reversed.

FIG. 5 is a simplified top view of a boat 500 implemented according to another embodiment that is substantially similar as the boats 100-400 in which similar parts or components assume identical reference numbers. The boat 500 has a similar configuration as that of the boat 100 except that the turbine engine 102 is offset from the centerline C_L toward the port side 111 and the turbine engine 104 is offset from the centerline C_L toward the starboard side 113. The drive belt 144 is appropriately sized to enable the rotor 122 to drive either one of the intermediate pulley 143 or 145 depending upon the orientation of the turbine engine 102, and the drive belt 154 is appropriately sized to enable the rotor 124 to drive either one of the intermediate pulleys 153 or 155 depending upon the orientation of the turbine engine 104.

Although the turbine engine 102 is shown offset toward the port side 111 and the turbine engine 104 is shown offset toward the starboard side 113, the opposite is contemplated in which the turbine engine 102 may instead be offset toward the starboard side 113 while the turbine engine 104 is offset toward the port side 111. In fact, many other alternative configurations are contemplated depending upon the desired configuration of the boat 500. In other embodiments, only one of the turbine engines 102 or 104 is offset in either direction, both of the turbine engines 102 and 104 may be offset in the same direction, the amount of offset for either one or both of the turbine engines 102 or 104 may be any suitable distance that is relatively small or large, etc. The relative locations of other boat equipment (not shown) may be adjusted to achieve a balanced configuration in any of these contemplated embodiments. In any of these embodiments, the orientations of the turbine engines 102 or 104 may be reversed as shown by the boat 300 of FIG. 3.

The new positions of the turbine engines 102 and 104 in the illustrated configuration of the boat 500 expose the shaft tube 141 of the intermediate drive assembly 142 that supports the intermediate drive shaft 147 and the shaft tube 151 of the intermediate drive assembly 152 that supports the intermediate drive shaft 157. Although not specifically shown, the shaft tube 141 is mounted to a portion of the hull 110 and the intermediate drive shaft 147 rotates freely within the shaft tube 141, but the intermediate drive shaft 147 is otherwise constrained by the mounted shaft tube 141 from moving in x, y, and z free space directions relative to the hull 110. Similarly, the shaft tube 151 is mounted to a portion of the hull 110 and the intermediate drive shaft 157 rotates freely within the shaft tube 151, but the intermediate drive shaft 157 is otherwise constrained by the mounted shaft tube 151 from moving in x, y, and z free space directions relative to the hull 110.

The relative configurations of the boats 100, 200, 300, 400, and 500 (100-500) illustrate the complete flexibility of reversible turbine engines and a configurable propeller drive system for independently driving a pair of propellers as described herein. Drive belts are relatively easy to install and remove, so that for a given orientation of the turbine engines 102 and 104, either one of the propeller assemblies 126 and 128 and corresponding propellers 132 and 138 can be driven by either one of the turbine engines 102 and 104. It is noted that the configuration of each of the intermediate drive assemblies 142 and 152 include a pair of pulleys (143 and 145, or 153 and 155) positioned on opposite ends below the respective turbine engines 102 and 104 to allow the orientations of the turbine engines 102 and 104 to be reversed. Since each of the drive belts 146 and 156 may be swapped to drive either one of the propeller pulleys 130 and 136, however, each of the intermediate drive assemblies 142 and 152 may alternatively be configured with a single pulley positioned below the corresponding turbine engine rotor. In other words, there may be no need for reversing the orientations of the turbine engines 102 and 104 for a given configuration.

The turbine engines 102 and 104 may be aligned with the centerline C_L as illustrated by the boats 100-400, or either one or both of the turbine engines 102 and 104 may be positioned at an offset relative to the centerline C_L as shown and described for the boat 500 shown in FIG. 5. The drive belt configuration allows complete flexibility and configurability, since any change of distance between the rotor and the pulley of the corresponding intermediate drive assembly may be compensated by a change of drive belt size or adjustment of an idler pulley or the like. When distribution of weight for purposes of proper balance is a consideration, the turbine engines 102 and 104 may be offset by any suitable amounts in the same or opposite directions.

Turbine engines typically have only one direction of rotation. Assume, for example, that when facing the rotor end of either of the turbine engines 102 or 104, that the rotor 122 or 124 rotates clockwise. For the boat 100 shown in FIG. 1, when viewing the boat 100 from the transom 116, the propeller 132 rotates clockwise whereas the propeller 138 rotates counterclockwise. Thus, the propellers 132 and 138 rotate in the opposite rotational direction relative to each other. For the boat 200 shown in FIG. 2, when viewing the boat 100 from the transom 116, the propeller 132 rotates counterclockwise whereas the propeller 138 rotates clockwise, which is opposite that of the boat 100. Nonetheless, the propellers 132 and 138 again rotate in the opposite rotational direction relative to each other.

Although not shown, given the flexibility of the configuration, the turbine engines 102 and 104 may alternatively be mounted to have the same orientation, such that the rotors 122 and 124 are both pointed towards the bow 112 or both pointed towards the stern 114. In either case, when the turbine engines 102 and 104 have the same orientation the propellers 132 and 138 both rotate in the same direction. When the rotors 122 and 124 are both pointed towards the bow 112 and if each rotates in the clockwise direction relative to the respective turbines, then both propellers 132 and 138 rotate in the counterclockwise direction. When the rotors 122 and 124 are both pointed towards the stern 114 and if each rotates in the clockwise direction relative to the respective turbines, then both propellers 132 and 138 rotate in the clockwise direction. Although such a configuration is possible, it is usually desired to have the propellers 132 and 138 rotate in opposite directions to avoid an undesired yaw force toward the port direction or toward the starboard direction.

FIG. 6 is a simplified top view, a corresponding simplified side view, and a corresponding simplified front view of an outline of the turbine engine 102 and the corresponding intermediate drive assembly 142 according to one embodiment. The turbine engine 102 and the intermediate drive assembly 142 are both shown floating relative to a cut-out bottom portion of the hull 110 of any of the boats 100-500. Although not explicitly shown, the configuration shown in FIG. 6 may be equally applied to the turbine engine 104 and the corresponding intermediate drive assembly 152. As previously described, the turbine engine 102 includes the rotor 122 and the intermediate drive assembly 142 includes intermediate pulleys 143 and 145 mounted on either end of the intermediate drive shaft 147 which is inserted within the shaft tube 141. The shaft tube 141 and a portion of the intermediate drive shaft 147 that are underneath the turbine engine 102 are shown with dotted lines in the top view, which are both positioned above the bottom portion of the hull 110. The drive belt 144 is provided to enable the rotor 122 to drive the intermediate pulley 143 of the intermediate drive assembly 142.

Although not explicitly shown, the orientation of the turbine engine 102 may be reversed and the drive belt 144 moved to enable the rotor 122 to drive the other intermediate pulley 145 of the intermediate drive assembly 142 as previously described. As shown in the side view of FIG. 6, the intermediate drive assembly 142 is positioned above the bottom portion of the hull 110. The drive belt 144 is shown as a drive interface between the rotor 122 and the intermediate pulley 143. As described in FIG. 5, the drive belt 144 is appropriately sized depending upon the relative offset of the turbine engine 102.

The front view of FIG. 6 depicts a front view of the turbine engine 102 with the rotor 122 driving the intermediate pulley 143 via the drive belt 144 positioned relative to the hull 110, which is shown as a V-shaped hull. The front view also shows the drive belt 146 and the propeller pulley 130 of the corresponding propeller assembly 126 to illustrate relative positioning between the turbine engine 102, the intermediate drive assembly 142, and the propeller assembly 126. The illustrated configuration equally applies to the drive belt 146 (or the drive belt 156) driving the propeller pulley 136 of the corresponding propeller assembly 128, except positioned on the other side of the intermediate pulley 143 (or the intermediate pulley 153).

The front view of FIG. 6 also includes a radius value rx for the rotor 122 and for each of the intermediate pulley 143 and 130 indicating the corresponding radius, in which “x” is an index from 1 to 3. As shown, the rotor 122 has a radius r1, the intermediate pulley 143 has a radius r2, and the propeller pulley 130 has a radius r3. It is noted that the Figures are not drawn to scale and thus do not show actual or relative sizes. The ratio of pairs of the radius values determines the relative rotational speed of the pulleys and ultimately the rotational speed of the propellers 132 and 134. In particular, the ratio r1/r2 determines the relative rotational speed of the intermediate pulley 143 relative to the rotor 122, and the ratio r2/r3 determines the relative rotational speed of the propeller pulley 130 relative to the intermediate pulley 143. The radius values are selected to gear down the rotational speed of the rotor 122 to the rotational speed of the corresponding propeller.

For a simplified example, suppose the maximum rotational speed of the rotor 122 is 20,000 rpm and it is desired that the corresponding propeller has a rotational speed of 5,000 rpm. The radii may be selected such that r2=2r1 and r3=2r2. In this manner, when the rotor 122 is rotating at 20,000 rpm, the intermediate pulley 143 rotates at 20,000*(r1/r2)=20,000*(1/2)=10,000 rpm, and the propeller pulley 130 rotates at 10,000*(r2/r3)=10,000(1/2)=5,000 rpm. The propeller (e.g., 132 or 138) thus rotates at the same rotational speed as the propeller pulley 130, or 5,000 rpm. The radii of the rotor of each of the turbine engines and each of the pulleys are selected to achieve the desired rotational speed of the propellers given the rotational speed of the rotor of the turbine engine. As before, the illustrated radius and ratio configurations equally apply to the rotor 124 of the turbine engine 104 driving either of the intermediate pulleys 153 or 155 which further drive either one of the propeller pulleys 130 or 136 based on the configuration of the drive belt 156 as previously described.

It is appreciated that it is possible to drive either of the propeller pulleys 130 or 136 directly from the rotor 122 of the turbine engine 102 or directly from the rotor 124 of the turbine engine 104 using a single drive belt. It is noted, however, that gearing down the rotation speed of each rotor to a maximum rotation speed of a propeller means that the radius of each rotor is significantly reduced and/or the radius of each of the propeller pulleys 130 and 136 is significantly increased. The intermediate intermediate pulley 143 (or 145) and 153 (or 155) provide a more practicable rotary motion transfer mechanism given the rotation speed of the rotors and the desired rotation speed of the propellers.

FIG. 7 is a more detailed diagram of a drive pulley configuration 700 that may be used for selected ones up to all of the pulley and belt configurations shown for the boats 100-500 according to one embodiment. The drive pulley configuration 700 includes a driving pulley 702, a driven pulley 704, an idler pulley 706, and a drive belt 708. The idler pulley 706 is shown in the engaged position to reduce slack of the drive belt 708 for operation. The idler pulley 706 is also shown in a disengaged position using dashed lines to loosen the drive belt 708 to allow the driving pulley 702 to rotate freely without rotating the driven pulley 704. Direction arrows indicate the rotational direction of the pulleys 702, 704, and 706, and the drive belt 708 when the idler pulley 706 is engaged as shown. When the idler pulley 706 is engaged, the driving pulley 702, the driven pulley 704, and the drive belt 708 rotate in the clockwise direction whereas the idler pulley 706 rotates in the counterclockwise direction. The outer drive surfaces of the driving pulley 702 and the driven pulley 704 and the inner drive surface of the drive belt 708 are toothed as shown to minimize slippage and optimize transfer of rotary motion during operation. The outer surface of the belt drive and the outer surface of the idler pulley 706 may be smooth and not toothed.

The drive pulley configuration 700 may be used for any up to all of the drive pulley and belt combinations of the boats 100-500 previously described. For example, the drive pulley configuration 700 may be used for the drive belt 146 between the intermediate pulley 143 and either 130 or 136 and for the drive belt 156 between the intermediate pulley 143 and either 130 or 136. The drive pulley configuration 700 may be used in addition, or in the alternative, to the drive belt 144 between the rotor 122 and the operative intermediate pulley 143 or 145, and to the drive belt 154 between the rotor 124 and the operative intermediate pulley 153 or 155. The drive pulley configuration 700 allows the corresponding drive belt to be loosened and replaced.

Assume, for example, that the drive pulley configuration 700 is applied to each of the drive belts 144, 146, 154, and 156 of the boats 100-500. In this case, each idler pulley is placed in the disengaged position to replace the corresponding drive belt (representing any of the drive belts 144, 146, 154, and 156) or when the boat is idle. When the turbine engines 102 and 104 are turned on, each idler pulley may remain in the disengaged position so that the rotors 122 and 124 do not drive the propeller pulleys 130 or 136 so that the propellers 132 and 138 do not rotate, such as when the boat is idling. When the turbine engines 102 and 104 are on and each idler pulley is engaged, the turbine engines 102 and 104 drive the propellers 132 and 138 to propel the boat.

FIG. 8 is a simplified rear view diagram of a steering system 800 implemented according to one embodiment mounted to the transom 116 of a boat, such as any of the boats 100-500 previously described. The steering system 800 is only briefly described herein but is more fully described in U.S. Pat. No. 7,316,595 issued Jan. 8, 2008, which is incorporated herein by reference in its entirety. Although any of the boats 100-500 may include a rudder or the like to facilitate steering, the boats 100-500 have an inboard engine configuration with surface piercing propeller drives and instead may be configured with the steering system 800 to minimize contact with the water. The propeller 132 mounted to the propeller shaft 106 within the thrust tube 134 is shown in the port side, and the propeller 138 mounted to the propeller shaft 108 within the thrust tube 139 is shown in the starboard side of the boat.

In one embodiment, the steering system 800 includes a center ball and ball cup assembly 802 having a center ball further mounted to a center of a steering link bar 804. The steering system 800 includes a port side hydraulic steering ram 806P and a port side steering anchor and bracket arm assembly 808P. The steering system 800 also includes a starboard side hydraulic steering ram 806S and a starboard side steering anchor and bracket arm assembly 808S. One end of the steering link bar 804 is pivotally linked to the thrust tube 134 and the other end of the steering link bar 804 is pivotally linked to the thrust tube 139. A bite bar 810P is provided on the port side and a similar bite bar 810S is provided on the starboard side. The hull 110 is shown as a V-shaped hull in which the bite bar 810P is positioned in parallel with a bottom side of the hull 110 on the port side, and in which the bite bar 810S is positioned in parallel with a bottom side of the hull 110 on the starboard side. Although not show, a tension spring configuration or the like forces the thrust tube 134 towards the bite bar 810P to limit travel of the thrust tube 134 along a path parallel with the bottom of the hull on the port side as illustrated by an arrow 812P, and also forces the thrust tube 139 towards the bite bar 810S to limit travel of the thrust tube 139 along a path parallel with the bottom of the hull on the starboard side as illustrated by an arrow 812S.

In operation, the steering system 800 moves both of the thrust tubes 134 and 139 together towards the port side to turn the boat left or moves both of the thrust tubes 134 and 139 together towards the starboard side to turn the boat right. Although not shown, a driver or operator of the boat manipulates a steering mechanism, such as a steering wheel or the like, to turn to the left or to the right. Steering apparatus (not) shown) linked to the steering system 800 responds by moving the thrust tubes 134 and 139 and thus the propellers 132 and 138, respectively, in accordance with the movement of the steering mechanism. When turning left, the thrust tube 134 slides along the bite bar 810P and is constrained to follow the path of arrow 812P in parallel with the bottom of the hull 110 upwards toward the left, while the thrust tube 139 slides along the bite bar 810S and is constrained to follow the path of arrow 812S in parallel with the bottom of the hull 110 downward towards the center. When turning right, the thrust tube 134 slides along the bite bar 810P and is constrained to follow the path of the arrow 812P in parallel with the bottom of the hull 110 downward towards the center, and the thrust tube 139 slides along the bite bar 810S and is constrained to follow the path of the arrow 812S in parallel with the bottom of the hull 110 upward towards the right.

FIG. 9 is a simplified rear view diagram of the transom 116 of the boat illustrating the thrust tubes 134 and 139 and corresponding propellers 132 and 138 positioned for a full left-hand turn. Although not depicted, when the thrust tubes and propellers are so positioned, the hull 110 of the boat tilts towards the left causing the bow of the boat to veer or turn left.

FIG. 10 is a simplified rear view diagram of the transom 116 of the boat illustrating the thrust tubes 134 and 139 and corresponding propellers 132 and 138 positioned for a full right-hand turn. Although not depicted, when the thrust tubes and propellers are so positioned, the hull 110 of the boat tilts towards the right causing the bow of the boat to veer or turn right.

Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions and variations are possible and contemplated. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A boat, comprising:

a hull;

a first turbine engine having a rotor and a second turbine engine having a rotor, wherein both turbine engines are mounted within the hull;

a first propeller assembly provided within the hull comprising a first propeller shaft configured with a first propeller pulley and a first propeller;

a second propeller assembly provided within the hull comprising a second propeller shaft configured with a second propeller pulley and a second propeller; and

a configurable propeller drive system, comprising: a first configurable propeller drive configured to drive a selected one of the first and second propeller pulleys from the rotor of the first turbine engine; and a second configurable propeller drive configured to drive a selected one of the first and second propeller pulleys from the rotor of the second turbine engine.

2. The boat of claim 1,

wherein the first configurable propeller drive comprises: a first intermediate pulley; a first drive belt provided to drive the first intermediate pulley from the rotor of the first turbine engine; and a second drive belt provided to drive a selected one of the first second propeller pulleys from the first intermediate pulley; and

wherein the second configurable propeller drive comprises: a second intermediate pulley; a third drive belt provided to drive the second intermediate pulley from the rotor of the second turbine engine; and a fourth drive belt provided to drive a selected one of the first second propeller pulleys from the second intermediate pulley.

3. The boat of claim 1,

wherein each of the first and second turbine engines have a reversible orientation in which each turbine engine is mounted either in a first orientation or a second orientation;

wherein the first configurable propeller drive comprises: first and second intermediate pulleys mounted on either end of a first intermediate drive shaft; a first drive belt provided to drive the first intermediate pulley from the rotor of the first turbine engine when mounted in the first orientation, or to drive the second intermediate pulley from the rotor of the first turbine engine when mounted in the second orientation; and a second drive belt provided to drive a selected one of the first second propeller pulleys from the first intermediate pulley; and

wherein the second configurable propeller drive comprises: third and fourth intermediate pulleys mounted on either end of a second intermediate drive shaft; a third drive belt provided to drive the third intermediate pulley from the rotor of the second turbine engine when mounted in the first orientation, or to drive the fourth intermediate pulley from the rotor of the second turbine engine when mounted in the second orientation; and a fourth drive belt provided to drive a selected one of the first second propeller pulleys from the third intermediate pulley.

4. The boat of claim 1, wherein the first and second turbine engines are mounted relative to a longitudinal centerline between a bow and a stern of the hull, wherein the first turbine engine is mounted between the bow and the second turbine engine, and wherein the second turbine engine is mounted between the first turbine engine and the stern.

5. The boat of claim 4, wherein the first and second turbine engines are mounted inline in parallel with the longitudinal centerline of the hull.

6. The boat of claim 4, wherein at least one of the first and second turbine engines is mounted at an offset relative to the longitudinal centerline of the hull.

7. The boat of claim 4, wherein the first configurable propeller drive includes at least one intermediate pulley positioned below the first turbine engine and wherein the second configurable propeller drive includes at least one intermediate pulley positioned below the second turbine engine.

8. The boat of claim 4, wherein the first propeller assembly is positioned on a port side of the hull and wherein the second propeller assembly is positioned on a starboard side of the hull.

9. The boat of claim 8, further comprising:

the first propeller assembly comprising a first thrust tube that extends beyond a transom at the stern of the hull, wherein the first propeller shaft is provided within the first thrust tube;

the second propeller assembly comprising a second thrust tube that extends beyond the transom and wherein the second propeller shaft is provided within the second thrust tube; and

a steering system mounted to the transom that constrains the first and second thrust tubes to swing together in tandem substantially in parallel with a bottom side of the hull towards the port side or the starboard side of the hull.

10. The boat of claim 1, wherein the first and second turbine engines are air-cooled turbine engines.