Impellers to drive vessels

Abstract

A vessel has an impeller mounted at the bow 2 of the vessel , which is driven by a shaft (5, Fig 4) connected to an engine. The impeller has a number of blades (3, Fig 3) mounted on a hub which when r

Description

Background All objects passing through a fluid experience drag exponentially in relation to their speed. There is "gliding drag" on a vessel's hull when gliding through water without its engine running. Problem When a propeller at the stern of a vessel is pushing it forwards extra drag is created because the vessel's propeller(s) take(s) water from in front, i.e. from around the hull. The water passing the hull just before it goes through the propeller is travelling nearly at the speed that it goes through the propeller, effectively dragging the vessel backwards. That drag effect is also present at further distances from the propeller(s), decreasing as the distance from the propellers increases. Propellers move vessels, but the drag they create prevents forward motion as much as would be the case if they didn't create "extra drag" in addition to "gliding drag". Solution to the problem Eliminate "extra drag" by use of Impellers which will not create drag extra to "gliding drag". What impellers will do Impellers will drive vessels efficiently. Summary of the invention The invention is of impellers for pulling vessels through water. An impeller is any arrangement of blades of any shape attached to a shaft, or more than one shaft on the same axis, that when rotated by a motor cause a flow of water to move away from the axis of the shaft by centrifugal force with the result that the vessel it is driving moves in the direction that the flow of water has come from with increasing speed until the power of the motor is matched by the "gliding drag" on its hull. The blades may be mounted on a surface and may extend beyond the perimeter of that surface, or the surface may be ridged. Introduction to the drawings Figure 1 shows impellers at both ends of a vessel. Figure 2 indicates a floating vessel the right hand impeller of which has a harness (1), which is part of the structure of the vessel, to push against. Impellers will usually be under the surface of the water and be in front of the equivalent of trunkated bulbous bows (2) which smoothly form part of the hull. The blades (3) may be mounted on a surface of any shape, for example conical (figure 3 side elevation, figure 4 section, and figure 5 front elevation; curved figure 6 section; or flat figure 7; or ridged figure 11 (4). Because impellers rotate they need to be balanced to keep wear to the impeller shaft bearings and engine driving the shaft(s) (5) to a minimum. Impellers may be made of rigid or semi rigid material or materials, and may be made with replaceable blades of when damage or wear occurs. The thrust of impellers can be taken as tension by the impeller shaft (5) restrained to the hull through its mountings, or a harness (1) fixed to the hull and / or superstructure may pass in front of the impeller to take forward thrust from the impeller. An impeller may be fixed forward relative to its bulbous bow backing (2), or to minimise bow wave effect at at different speeds, or depth below the water surface due to loading of the vessel, may be mounted on a projecting sleeve, figure 9 section (6). An impeller is any arrangement of blades of any shape attached to a shaft, or more than one shaft on the same axis, figure 9 section (5), or may have a gearing system within the impeller to increase the speed of rotation of the central part of the impeller; for example figure 10 section indicates cogged wheels (7) turned by and turning toothed tracks (8) which double the speed of rotation of the front part of the impeller. The cogged wheels will be housed on suitable bearings. When impellers are active water may break the surface causing splashing the air bubbles from which will act as lubricant between the water and hull thereby reducing drag particularly if the vessel has a flat bottom.

Claims

1) An impeller as any arrangement of blades or ridges of any shape attached to a shaft, preferably balanced in rotation, that when attached to a vessel's hull and rotated by an engine cause a flow of water to move away from the axis of the shaft by centrifugal force with the result that the vessel the impeller is part of moves in the direction from which the flow of water has come from.2) An impeller according to claim 1 may be mounted on a projectable sleeve.3) A harness of one or more structural elements may project from the hull and / or superstructure of the vessel passing in front of an impeller where it shall take thrust from the impeller through bearings or bearings to keep friction between the impeller and harness to a minimum.

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