A propeller drive assembly for transferring a torque between an engine and at least one propeller of a water surface vessel includes a plurality of lubrication clients. The propeller drive assembly includes a first lubrication system arranged to house a first lubricant, dedicated for lubrication of at least one first of the lubrication clients, and a second lubrication system arranged to house a second lubricant, dedicated for lubrication of at least one second of the lubrication clients, the at least one second lubrication client includes a seal arranged to seal the second lubrication system from a body of water surrounding at least a portion of the propeller drive assembly, the second lubrication system being arranged to transport the second lubricant to the seal.

A sealing device for a drive shaft is disclosed and described. The sealing device for a drive shaft comprises a housing disposed to surround the drive shaft between the inner space and the outer space, a plurality of sealing members axially separated from each other between the housing and the drive shaft to seal between the housing and the drive shaft, fixing ring members interposed between the plurality of sealing members to maintain the separation distance between the sealing members, and a fixing member secured to the housing to apply an axial pressure to the plurality of sealing members and fixing ring members, wherein a concave-convex section is formed on at least one of the close surfaces of the fixing ring member and the sealing member, which face each other.

A gear mounting assembly is for causing rotation of a propeller on a marine drive. The assembly includes a driveshaft; a first bevel gear on the driveshaft, wherein rotation of the driveshaft causes rotation of the first bevel gear; a propeller shaft for supporting the propeller such that rotation of the propeller shaft causes rotation of the propeller; a gear hub on the propeller shaft; a second bevel gear on the gear hub, wherein the second bevel gear is engaged with the first bevel gear such that rotation of the driveshaft causes rotation of the gear hub, which thereby causes rotation of the propeller shaft; and an adapter facilitating relative rotation between the propeller shaft and the gear hub when the gear hub is caused to rotate by the driveshaft.

A gear mounting assembly is for causing rotation of a propeller on a marine drive. The assembly includes a driveshaft; a first bevel gear on the driveshaft, wherein rotation of the driveshaft causes rotation of the first bevel gear; a propeller shaft for supporting the propeller such that rotation of the propeller shaft causes rotation of the propeller; a gear hub on the propeller shaft; a second bevel gear on the gear hub, wherein the second bevel gear is engaged with the first bevel gear such that rotation of the driveshaft causes rotation of the gear hub, which thereby causes rotation of the propeller shaft; and an adapter facilitating relative rotation between the propeller shaft and the gear hub when the gear hub is caused to rotate by the driveshaft.

A marine propulsion system for shallow waters, swamps, savannahs and the like includes a rotating propeller shaft supporting a propeller. An anti-cavitation body defines a partial cylinder having a longitudinal axis adjacent to the propeller. The propeller generates a vacuum between the anti-cavitation body and a surface of a water body. First and second wings adjacent to edges of the anti-cavitation body are generally planar and operatively angled towards the bottom of a water body. The first and second wings are adjusted to run below the water body surface and seal the anti-cavitation body to maintain generated vacuum. A first thread is cut in a first helical direction at an end of the rotating propeller shaft adjacent the propeller, and slightly more distal therefrom a second thread is cut in a second helical direction opposed to the first thread helical direction. The second thread drives matter away from the bearing.

A monitor and alarm system is provided for a marine vessel having a rotatable propeller drive shaft supported by one or more water-cooled bearings contained in strut barrels mounted on struts extending from the vessel hull or in stern tube assemblies. A heat sensor on the hull senses the ambient temperature of the water surrounding the vessel and one or more sensors on one or more bearings sense the temperature of the bearings. The sensed temperatures are electrically communicated via wires or wirelessly to gauges for monitoring and to a processing unit. The processing unit compares the sensed temperatures and generates a signal to an alarm device to initiate a bearing overheat warning or alarm if the differential between the bearing temperature and the ambient water temperature exceeds a predetermined amount.

A propeller drive assembly for transferring a torque between an engine and at least one propeller of a water surface vessel includes a plurality of lubrication clients. The propeller drive assembly includes a first lubrication system arranged to house a first lubricant, dedicated for lubrication of at least one first of the lubrication clients, and a second lubrication system arranged to house a second lubricant, dedicated for lubrication of at least one second of the lubrication clients, the at least one second lubrication client includes a seal arranged to seal the second lubrication system from a body of water surrounding at least a portion of the propeller drive assembly, the second lubrication system being arranged to transport the second lubricant to the seal.

A strut mounted gear box for counter rotating propellers. The gear box is strut mounted for securement to the hull of a boat. A main input shaft is coupled to a propulsion component of a boat with a distal end secured to an idler gear cage assembly located within the gear box. The main input shaft transfers torque and rotation from the propulsion component to an idler gear cage assembly. An inner tail shaft is coupled to the main input shaft and arranged to rotate the inner tail shaft in a first direction. A counter shaft is coupled to the idler gear cage assembly and arranged to rotate the counter shaft in a second direction. A first propeller is secured to the inner tail shaft providing rotation in the first direction; and a second propeller is secured to the counter shaft allowing rotation in the second direction.

An outboard propulsion system comprising an engine configured to receive oil; an oil pan configured to receive oil from the engine; and an oil reservoir configured to receive oil from the oil pan and provide oil to the engine, in use.

The arrangement comprises a seal (500) sealing a cylindrical rotating part (100) passing through an opening in a support structure in the vessel (10) against a medium (W). The seal (500) comprises a package of annular seal rings (510, 520, 530). Each seal ring (510, 520, 530) comprises a seal part (512, 522, 532) being supported in a corresponding seal support part (511, 521, 531). The seal support part (511) in the first seal ring (510) positioned closest to the medium (W) has the form of a cylinder (511A) provided with an annular flange (511B) at one end of the cylinder (511A). The outer surface of the cylinder (511A) is supported and sealed with an auxiliary seal (610) against the inner circumference of the opening. The annular flange (511B) is supported against the support structure (83) surrounding the opening. There are adjusting means (900) for adjusting the position of the first seal support part (511) in relation to the support structure (83) surrounding the opening in order to relocate the seal (500) in an axial direction in relation to the rotating part (31, 100).