RU2452653C2 - Screw propeller of kalashnikov's design - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: screw propeller comprises a hub, adjoined blades, a water scoop and water intake vanes. The blades are of convex-concave cross section. Working surfaces of blades are made in the form of spiral sections and with an angle of inclination to the lower edges of the blades. The screw surface has a hollow truncated cone, where blades are installed. The profile of the blades, evenly swirling by 180 degrees, monotonously reduces when moving away from the screw axis.

EFFECT: increased propeller thrust.

2 cl, 3 dwg

Description

Technical field

The invention relates to the technology of propulsion devices for surface and underwater transport, can be used on passenger, transport, warships, submarines, boats, yachts and torpedoes.

State of the art

The closest in technical essence to the proposed device is the propeller of the patent of the Russian Federation under the number RU 2108265 C1. Due to the hub containing the blades of a convex-concave section with a screw surface, they are cup-shaped, in which the angle of inclination to the axis of the screw monotonously decreases with distance from the axis, while the screw surface of the blades has the shape of a parabola. The rotation of this screw allows you to increase traction due to the forced direction of the water captured by the blades along the axis of the screw. The disadvantages of this propeller are expanding scattered jets into the outer space, the additional mass of water and the attachment of flows created by centrifugal force are not fully involved, which reduces thrust efficiency, and as a result low efficiency.

Disclosure of invention

The invention is intended to solve the technical problem of increasing propeller thrust. The technical result is achieved due to the fact that the propeller of FIG. 1 contains 1 hub with 5 upper edges of the blades attached to it, blades 4 of a convex-concave section with a screw surface, monotonously decreasing with distance from the axis. The lower 6 edges of the blades are monolithically connected with a 2 hollow truncated cone, at the beginning of which there are 3 water inlets, at the very beginning of the water intake around the circumference there are 7 water intake blades that direct water to 4 blades. The turbulent perturbed stream that breaks out of the water intake, the blades redirect back to the blades with their rear edges, since during rotation they create a visor, the erupting stream, when faced with an obstacle, is dumped again onto the blades. The screw can be on the vessel both inside the hull and external - Fig. 1, outside the hull with 1 hub, like many propellers. Each of these 4 blades has a certain curved profile formed by the suction and discharge surfaces, as well as the incoming and outgoing edges. The blade is convex-concave and, twisting uniformly in a spiral, narrows, if it touches the truncated cone of Fig. 1, or does not constrict, if it concerns the cylinder, by hydrodynamic and strength characteristics. The blades have 5 upper edge and 6 lower edge. The line connecting the extreme, farthest points of the incoming and outgoing edges forms a suction and discharge surface. The advantages of these blades are that their profile provides a fairly uniform distribution of pressure on the suction and discharge surfaces of the blades with a sufficiently small profile resistance, as well as the fact that they have a reduced rarefaction peak at the incoming edge due to the curvature of the upper edge and the twisted blade inside the screw cone . The profile of the blade is such that the line forming the suction surface has a constant curvature from the input edge to the output edge. The line forming the injection surface has a concave portion of the blade and a convex portion of the outside. Due to the concave curvature of the discharge surface of the blades and a convex outside between the blades, a minimum of space is formed, which forces the flow to go in a given direction and prevents water from dispersing, which significantly increases the flow power. The device of the rotor blades, passing through the entire length, allows you to use their feature in the direction, discharge, focusing of the flow and helps to improve the hydrodynamic characteristics of the screw. According to the present invention, the hydraulic propeller blade has an inlet edge and an outlet edge, as well as a pumping and convex suction surface. The section of the line forming the suction surface is made convex and curved. Due to a significant shift of the inflection point of the line forming the injection surface to the outgoing edge, it was possible to increase the curvature of the concave portion of the injection surface and, accordingly, increase the peak of positive pressure in the front of the blade. The presence of a peak in positive pressure on the discharge surface allows, while maintaining the predetermined discharge force of the blade, to reduce the resistance of the suction surface and, accordingly, the rarefaction value on this surface, which means that the flow velocity increases. The ratio of the curvature of the suction and discharge surfaces in the region of the inlet edge determines the value of the angle of the shockless inlet for a given value of the injection force and allows to achieve the absence of rarefaction peaks in the region of the inlet edge for a given operating mode of the hydraulic propulsion device.

The invention is illustrated by drawings, where Fig. 1 shows a cross-sectional view of a screw with one blade and water intake blades, the screw's suction diameter is larger than the ejector, smaller in diameter, the number of blades and water intake blades are distributed arbitrarily within the cone circumference, within reasonable limits. Figure 2 shows a profile view of the blade of a convex-concave section with a helical surface, monotonously decreasing with distance from the axis, if it relates to the shape of the truncated cone screw, while the screw surface of the blades is convex-concave and twisting 180 degrees uniformly in a spiral, tapers off. The line connecting the outermost, most distant points of the incoming and outgoing, is called the chord of the section and is the abscissa axis, from which the ordinates of the lines t ₁ max, forming a suction surface, and t ₂ max, forming a pushing surface are counted perpendicular to the chord. The length of the chord is indicated as A in shares. Thus, all blade lengths are determined by the chord in fractions B and C, and all thicknesses are determined by ordinates in fractions t ₁ max and t ₂ max. The advantage of this blade is that its profile provides a fairly uniform distribution of pressure along the suction and pushing surfaces with a sufficiently small profile resistance, as well as the fact that the blade has a reduced rarefaction peak at the incoming edge due to the presence of a smooth bend at the incoming upper 9 edge and lower 8 edge, as well as a twisted screw surface. Figure 3 shows the water intake blade, which is placed around the circumference of the water intake at an arbitrary angle and is fixed by its lower edge 10 to the surface of the screw. The upper curved edge 11 forms a suction surface, where the curvature of the suction surface is indicated at its widest point as t max, blades with the same, arbitrary height, with curved upper edges. The combination of four elements of the device, namely: a truncated cone, where the suction diameter of the cone is larger than the ejector, water intake, original blades with a small space between the external and internal suction and push surfaces and water intake blades, provide a technical result for a significant increase in efficiency and flow rate. The screw can be on the vessel both inside the hull and external - figure 1, outside the hull with a hub, like many propellers. The profile of the blades of the screw passing through the entire length of the cone allows you to use their feature in the direction, discharge, focusing of the flow and improves the hydrodynamic characteristics of the screw. According to the present invention, the hydraulic propeller blade has an input edge and an output edge, as well as a pumping and convex suction surface. The section of the line forming the suction surface is made convex and curved. Due to a significant shift of the inflection point of the line forming the injection surface toward the outgoing edge, it was possible to increase the curvature of the concave portion of the injection surface and, accordingly, increase the peak of positive pressure in the front of the blade. The presence of a peak in positive pressure on the discharge surface allows, while maintaining the predetermined discharge force of the blade, to reduce the resistance of the suction surface and, accordingly, the rarefaction value on this surface, which means that the flow velocity increases. The ratio of the curvature of the suction and discharge surfaces in the region of the incoming edge determines the magnitude of the angle of the shock-free entrance for a given value of the pumping force and allows to achieve the absence of rarefaction peaks in the region of the incoming edge for a given operating mode of the propulsion device. The device operates as follows. The rowing screw of figure 1, consisting of an elongated, truncated 2 cone, which rotates when 1 hub is rotated. When the screw rotates, the water intake 7 vanes discard water onto the 4 vanes, which are fixed to 1 hub, the vanes catch the flow and, sucking, direct it along the cone from the larger diameter of the screw to a smaller one. In the element of the intake, the perturbed turbulent flow escaping outward is again thrown onto the blades by the blades and the flow created by their rotation. The operation of the screw described above contributes to the formation of traction and greatly increases the efficiency of the power from connecting the streams to the blades into a single stream breaking out through a narrower diameter of the screw.

List of drawings

The invention is illustrated by drawings, which depict:

figure 1 - screw in the context, with one blade and water intake blades;

figure 2 is a section of a blade according to the invention;

figure 3 - water intake blade according to the invention.

The implementation of the invention

The invention relates to shipbuilding and is used as a mover of the vessel, bow thrusters and screw columns. In practice, the screw can be used in the construction of large vessels such as tankers, lighters, submarines, etc. and to small floating vehicles. The screw can be made in one piece, melted from a metal with a hydrophobic coating, or assembled from separate, component parts. The screw device is as follows. A 2 truncated cone is taken, 4 vanes are attached to it, which are fixed to 1 hub, 7 water vanes are attached around the circumference in a 3 water intake. When the hub rotates, all the elements of the device rotate together as a unit.

Claims (2)

1. A rowing screw containing a hub with attached blades of convex-concave section, with working surfaces in the form of spiral sections and with an angle of inclination to the lower edges of the blades, characterized in that the helical surface has a hollow truncated cone in which the blades are, profile which, spinning 180 ° uniformly in a spiral, decreases monotonically with distance from the axis of the screw, it has a water intake and water intake blades. 2. The propeller according to claim 1, characterized in that the space between the blades is limited, and all the blades are in a closed screw housing and has a difference in screw diameters, where the diameter of the suction surface of the screw at the reception is greater than the diameter at the outlet.

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