An externally driven marine propulsion system

Abstract

The present invention provides an externally driven marine propulsion system, comprising a main engine shaft part enclosed inside a hull, and a propeller part installed at the bottom of the hull and outside the hull, wherein the main engine shaft part comprises an engine; a rotating main shaft is fixed on the engine rotating shaft, and a driving gear is arranged on the rotating main shaft; the propeller part is provided with an annular pipe housing enclosing the propeller; an opening is arranged in the pipe housing; a support seat is arranged at the opening for fixing the driving gear; a propeller pipe bearing is fixed on the inner ring of the pipe housing; the inner ring of the propeller pipe bearing is provided with a propeller pipe; the inner ring of the propeller pipe is uniformly fixedly provided with a plurality of propeller blades; and the outer ring of the propeller pipe is fixedly provided with an outer gear of the propeller pipe; and the outer gear of the propeller pipe is meshed with the driving gear. The propulsion system provided by the invention has excellent hydrodynamic performance and greatly improves flexibility.

Description

technical field [0001] The invention relates to the field of marine power design, in particular to an externally driven marine propulsion system. Background technique [0002] Existing ship propellers are mainly propellers, including some forms of propellers such as the most conventional open propellers. At present, most of the existing propellers work in the form of directly driving the blades by the rotating shaft, which severely limits the freedom of propeller blade design. The reason is that the small radius of the propeller in this direct shaft drive form requires a large thickness. At the same time, the contribution to the thrust is very small, and vortex is easily generated locally; in addition, most of the position of the propeller blade tip of the direct shaft drive is open, which will cause a three-dimensional wing effect, that is, there is a self-facing blade at the propeller blade tip. The lateral flow around the back of the blade affects the original excellent ...

AI Technical Summary

Problems solved by technology

At present, most of the existing propellers work in the form of directly driving the blades by the rotating shaft, which severely limits the freedom of propeller blade design. The reason is that the small radius of the propeller in this direct shaft drive form requires a large thickness. At the same time, the contribution to the thrust is very small, and vortex is easily generated locally; in addition, most of the position of the propeller blade tip of the direct shaft drive is open, which will cause a three-dimensional wing effect, that is, there is a self-facing blade at the propeller blade tip. The lateral flow around the back of the blade affects the original excellent airfoil characteristics, reduces the pressure difference on both sides of the blade, and disturbs the flow field near the blade tip; the torsional vibration problem of the shafting is also caused by this propulsion A problem that needs to be faced in the form; finally, the low-speed and large-diameter propeller can improve the propulsion efficiency, but the low-speed main engine that directly drives its operation requires a long stroke, and the main engine is large in size, which is not conducive to layout. The speed of the host needs to use a gearbox to reduce the output speed, which is inefficient and cumbersome

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