Abstract: A propeller drive having coaxially aligned propellers separately operable or operable in unison in the same rotary direction. Independent operation of each propeller or operation of both in unison for maximum speed provides an efficient propeller drive for a marine vessel.

Abstract: Transmission for a single engine drive for dual concentric propellers in a straight or V-drive arrangement with the straight-drive including four shafts and nine gears and the V-drive adding two more shafts and four more gears.

Abstract: A seal arrangement for controlling any large bearing clearance in the vicinity of a propeller shaft, such as for a propeller drive system for ships with two concentric propeller shafts rotating in opposite directions. The seal arrangement has a housing ring for supporting the sealing lips and a supporting ring for supporting the housing ring and defining a clearance therebetween. This clearance can be sealed and maintained by using elastic ring walls disposed between and interconnecting the housing to the supporting ring, so that compensation can be achieved for changes in the clearance during rotation of the propeller shaft.

Abstract: A marine drive (10, 310) has two counter-rotating propellers (12 and 14, 312 and 314). Inner and outer concentric counter-rotating propeller shafts (40 and 42, 340 and 338) are supported by a spool (38, 336) in the lower horizontal bore (28, 328). Passages are provided in the housing for communicating lubrication and/or exhaust with the horizontal bore. Locking structure (50, 404) holds the driven gears and bearings in place in the lower horizontal bore.

Abstract: A shifting mechanism for an outboard drive of a watercraft provides reduced coupling shock when the forward gears are engaged by a dual clutch assembly, as well as provides for consistent and quick engagement of the clutch assembly with the gear. The shifting mechanism involves a first gear and a corresponding first clutch, and a second gear and a corresponding second clutch. A plunger carries the first and second clutches which are arranged on the plunger at unequal distances from their respective gears. This nonuniform spacial relationship between the clutches and gears causes one clutch to engage its corresponding gear before the other clutch engages its corresponding gear. The staggered engagement decreases shock on the transmission and permits quicker engagement between the clutches and gears.

Abstract: A marine drive (10) has two counter-rotating surface operating propellers (12 and 14). A planing plate (230) extends rearwardly from the drive housing (20) above the propellers (12 and 14) and pushes down on the surface of the water during initial boat acceleration to in turn lower the bow and aid in getting the boat up on plane. Right and left inclined splash plates (240 and 242) along the sides of the housing (20) extend from the torpedo portion (188) rearwardly and upwardly at an incline and meet the planing plate (230).

Abstract: A marine drive (10) has two counter-rotating surface operating propellers (12 and 14). The drive has a vertical X-dimension (254) in the range of about 13 inches to 19 inches in combination with a shaft-spacing dimension (258) in the range of about 8 inches to 15 inches in combination with a surfacing dimension .gtoreq. zero. In one embodiment, the shaft-spacing dimension is 13.5 inches, the vertical X-dimension is 16 inches, and the surfacing dimension is 2 inches.

Abstract: A multi-propeller drive system having a single input shaft for connection an engine system, a differential gear assembly for dividing the driving force from the input drive shaft between a pair of output shafts and a pair of laterally spaced propellers driven by the output shafts of the differential gear assembly. The differential gear assembly operates in a manner wherein one output shaft, if required, is permitted to revolve at a different rate than the other output shaft. A pair of brake mechanisms acting on the output shafts of the differential gear assembly enable an operator to control the rotational speed of the respective propellers without modifying the engine speed or transmission settings.

Abstract: A shifting mechanism for an outboard drive of a watercraft provides a simple and compact transmission, as well as streamlines a lower unit of the outboard drive to reduce fluidic drag. The shifting mechanism is located on a drive train generally aligned along a vertical axis and above a propulsion shaft of the lower unit. The drive train includes a rotatable input shaft which is driven by a motor. The transmission of the shifting mechanism, which is located above a cavitation plate of the housing of the outboard drive, selectively couples the input shaft and a drive shaft. The drive shaft in turn is coupled to the propulsion shaft. The transmission includes a clutch which is slidably connected to the drive shaft to move along the vertical axis into and out of direct engagement with the input shaft.

Abstract: A ship, in particular a deep-draft vessel configured for travel on the oceans or great lakes, can have a hull with two concentrically rotating propeller shafts passing through the hull, and rotate in opposite directions to one another. The ship will generally have seals between the propeller shafts, and between the propeller shafts and the hull. In general, it is necessary to lubricate and cool the sealing surfaces of the individual seals, so that the useful life of the individual seals is prolonged, and the risk of failure of the seals is reduced. For the effective lubrication of highly-stressed seals of propeller drive systems for ships with two concentric propellers rotating in opposite directions, a forced feed lubrication system with circulating lubricating oil has been found to be advantageous.

Abstract: A seal arrangement for controlling any large bearing clearance in the vicinity of a propeller shaft, such as for a propeller drive system for ships with two concentric propeller shafts rotating in opposite directions, has a housing ring for supporting the sealing lips and a supporting ring for supporting the housing ring and defining a clearance therebetween. This clearance can be sealed, and maintained by using elastic ring walls disposed between and interconnecting the housing to the supporting ring, so that compensation can be achieved for changes in the clearance during rotation of the propeller shaft.

Abstract: A marine drive (10) has a spool (36) positioned in the lower horizonal bore (28) and supporting a dual propeller shaft assembly (38, 40). An exhaust passage (130) includes a passage (132) in the drive housing (26) communicating with the horizontal bore (28) at the spool (36), and a spool exhaust passage (134) passing exhaust rearwardly through the spool to the propeller through-hub exhaust passages (136, 138), providing through-hub exhaust through dual propellers (12, 14). An oil passage (152) in the housing (26) communicates with the horizontal bore (28) forwardly of the exhaust passage (132) and lubricates the dual propeller shaft assembly.

Abstract: A marine drive (10) has two counter-rotating surface operating propellers (12 and 14). The upper end (302) of the leading edge (288) of the skeg (194) is spaced forwardly of the lower end (310) of the trailing edge (306) of the skeg (194) by a horizontal distance greater than the horizontal length of the torpedo (188), for full rudder control. The skeg (194) has a first zone (318) with outer surface profiles (12P-15P) which are continuous and define continuous skeg sidewalls (320, 322) therealong. The skeg (194) has a second zone (324) above the first zone (318) and with outer surface profiles (9P-11P) along horizontal cross-sections, which profiles are discontinuous and define skeg sidewalls with openings (192, 193) therein. The horizontal cross-sections along the second zone (324) have discontinuous gaps (332, 333, 336) therein defining a cored passage (196) within the skeg (194) communicating with the openings (192, 193) in the sidewalls (320, 322).

Abstract: A marine drive is provided with a large volume anode, about 30 cubic inches, for galvanic protection. The anode (230) is a brick-like block member tapered along each of its height, width and length dimensions. The drive housing has an anode-mounting section (232) extending rearwardly therefrom and has a downwardly opening cavity (234) of substantially the same shape and volume as the anode, and receiving the anode in nested flush relation.

Abstract: A tandem propeller assembly for use with a marine propulsion unit is disclosed wherein a single shock-absorber assembly is utilized to assure damping effects for both propellers so as to protect the propulsion system from being damaged when either propeller is obstructed by drifting wood or other debris. Each of the preferred embodiments disclosed provides a simple structure for absorbing impacts upon either propeller in a tandem propeller assembly while minimizing any increase in the surface area of contact with the water which would increase the propulsion resistance and would result in speed loss.

Abstract: A two-stage submersible propulsor unit comprises a shroud having a water inlet and a water outlet, a shaft assembly centrally mounted within the shroud, an upstream and a downstream propeller, each of which includes a separate hub rotatably mounted on the shaft assembly, first and second electric motors separately rotating the upstream and the downstream propellers. Each motor includes a rotor mounted around the outer periphery of one of the propellers and a stator mounted around the shroud, and first and second thrust bearing assemblies for absorbing the thrust load generated between the hubs of the first and second propellers and the shaft assembly. Both thrust bearing assemblies are contained within a housing located on the downstream end of the shaft assembly.

Abstract: A strut mounted, counter rotation marine propeller propulsion system of the single engine is provided including a depending propeller shaft strut from which aligned front and rear propeller shafts are supported including remote ends disposed exteriorly of the strut and having front and rear propellers, respectively, mounted thereon and adjacent ends drivingly interconnected through the utilization of bevel gearing within a journal hub carried by the lower end of the strut. The forward extremity of the front propeller shaft is removably coupled to the rear end of a rearwardly and downwardly inclined power shaft journaled through the bottom of the associated hull and the strut includes horizontally outwardly projecting and forwardly and upwardly inclined opposite side water deflector plates for smoothing out the water discharge, in conjunction with the strut itself, from the front propeller.

Abstract: A marine drive (10) has two counter-rotating surface operating propellers (12 and 14). An upper adaptor spool (48) has a lower threaded outer portion (50) mating with a threaded portion (46) of the vertical bore (26) of the drive housing (20) and supporting the upper gear (42) for rotation about the driveshaft (36) and supporting the driveshaft (36) for rotation within the adaptor spool (48). Vertical bore structure enables assembly from above of the majority of the vertical drive train components into a one-piece unitary integrally cast housing. The vertical distance between the adaptor spool (48) and the lower bearing (118) supporting the vertical driveshaft (36) is about equal to propeller radius. The lower concentric counter-rotating propeller shafts (156, 158) are spaced from the upper input shaft (28) by a distance along the driveshaft (36) in the range of about 9 to 15 inches.

Abstract: A high-thrust, shock-resistant submersible propulsor unit comprises of a shroud having a water inlet and a water outlet, a shaft assembly centrally mounted within the shroud, and an upstream and a downstream propeller, each of which includes a separate hub rotatably mounted on the shaft assembly, first and second electric motors for independently rotating the upstream and the downstream propellers, wherein each motor includes a rotor mounted around the outer periphery of one of the propellers, and a stator mounted on the shroud around the rotor, and first and second bearing assemblies, each of which includes a thrust bearing disposed within the hubs of the upstream and downstream propellers in the shaft assembly, wherein the thrust bearings associated with the first and second bearing assemblies are located on opposite ends of the shaft assembly. Each of the bearing assemblies includes a removable cover which affords easy and separate access to the bearing contained in each.

Abstract: In a ships drive transmission, contra rotating propeller shafts are driven by powered means comprising concentric contra rotating drive elements, one of the shafts being connected thereto via epicyclic gearing. The propeller shafts are also coupled to each other through a part of the epicyclic gearing, to ensure equal loading.

Abstract: A leisure boat is provided in a round form having a diameter of about 1 to 2 meters, and includes propeller means provided at a position closer to its bow from the center of the boat and the bow and having a mechanism for changing its driving direction and sensor means provided on the outside of the boat for sensing external force. The sensor means is so connected to the propeller means that when the boat comes in contact or collision with another boat, etc., the sensor means detects the resulting external force to transmit it to the propeller means, thereby changing its driving direction.

Abstract: A marine propulsion system includes a steerable lower gearcase portion and a drive mechanism including a chain drive for driving dual counterrotating propellers. The dual propellers are rotatably mounted to the lower steerable gearcase portion by means of inner and outer coaxially extending propeller shafts. A sprocket is mounted to each propeller shaft, and first and second chain portions extend between the propeller shaft sprockets and a pair of upper drive sprockets, preferably disposed above the water line during boat operation. Coaxially extending inner and outer drive shafts are interconnected with the engine output shaft, and are adapted for counterrotation in response to rotation thereof. The coaxial drive shafts are interconnected with the upper drive sprockets for driving such sprockets in opposite rotational directions, thereby resulting in movement of the first and second chain portions in opposite directions.

Abstract: A marine drive (1) for a boat (3) includes a construction wherein a propeller supporting bearing device (29, 40) is disposed in a recess (28, 39) inside the propeller hub (23, 22). A bearing carrier (24, 37) is concentrically associated with a propeller shaft (20, 18). The carrier is provided with a rearwardly extending nose portion (27, 38) which is telescoped within the forwardly facing recess in an adjacent rearward propeller hub. The propeller shaft is journalled in the bearing device which is disposed between the carrier and the shaft and within the recess. In one aspect of the invention, the carrier is prevented from rotating about the shaft axis (17). In another aspect, a sealing device (26) is disposed between the propeller shaft and the rear end portion (8a) of an adjacent supporting gear case (8). In the embodiment disclosed, dual propellers and dual bearing carriers are utilized, with bearing carrier noses disposed in recesses in both propeller hubs.

Abstract: A boat steering mechanism contemplates the disposition of parallel side-by-side drive shafts outboard of the boat's fore and aft centerline. The shafts are supported for high speed rotation by drive sleeves which are in turn supported by members attached to the transom at effectively a single universal pivot point. Such attachment of the support members to the transom allows the props at the ends of the drive shafts to swing along a shared arc in response to being driven to port or starboard by steering pistons. This enables the props to be positioned, during a turn, so that their degree of immersion in the water through which the boat is being driven remains essentially constant despite the heeling of the boat in the turn.

Abstract: A marine drive unit (1) includes a lower torpedo housing (9). At least one propeller shaft (21) is mounted in the housing for rotation about a drive axis (17). The propeller shaft is driven by a driving gear (16) suitably connected to a marine engine (4) and mounted on the drive axis. A first forward thrust bearing (41) is disposed between the driving gear and the housing. In addition, a second forward thrust bearing (42) is disposed adjacent the forward end of the propeller shaft. A pre-loading device, in the present embodiment a washer-like Belleville spring (43) of a desired capacity, is disposed to provide an adjustable rearwardly biasing force on the second thrust bearing.

Abstract: A marine propulsion unit providing for steerable legs for the propeller of a boat which are rotatable in steering direction through 360.degree.. A transmission is provided having spiral bevel gears arranged so that for a constant direction of rotation bearing, loading for parts below the hull can be significantly reduced. There are provided two separate legs having a common drive each being rotatable in steering direction through 360.degree. so that reverse thrust can be achieved without changing the rotating direction of the thrusting propellers relative to their support.

Abstract: The invention involves an electromechanical mechanism for controlling the trim and tilt of an outboard motor mounted on outboard powered boats. Trim arms are pivotally mounted from brackets attached to a boat transom. The trim arms move the outboard motor prop housing relative to the boat transom and bottom of the boat by use of an electromechanical motor mechanism.

Abstract: A double propeller drive unit for boats having an inclined steering axis and a trim fin arrangement which is fixed to the cavitation plate of the drive unit, is disposed in the boundary region between the propellers, and is designed to balance torques acting on the drive unit.