CN105270587A - Screw propeller - Google Patents

Abstract

The invention discloses a propeller which has a center point and is adapted to rotate with a rotation axis passing through the center point. A propeller includes multiple blades. Each blade has a central reference line. A projection of the central reference line on a virtual plane perpendicular to the axis of rotation has first and second opposite ends, the second end is located between the first end and the center point, and the reference line passes through the second end and the center point. The distance between the first end and the center point is R, and the distance between any position on the projection of the central reference line and the center point is r. The skew angle relative to the reference line between any of the positions and the center point is y, where R≥r, y≥524.35x ⁶ -1995x ⁵ +2894.5x ⁴ -2041.4x ³ +815.68x ² -195.81x+15.84, and y≤524.35x ⁶ -1995x ⁵ +2894.5x ⁴ -2041.4x ³ +815.68x ² -195.81x +21.84.

Description

propeller

technical field

The present invention relates to a propeller, and in particular to a propeller suitable for ships.

Background technique

In recent years, developing countries have developed rapidly and their consumption power and demand for materials have continued to increase, making trade between countries increasingly active. In addition to relying on air freight, the trade between countries still needs to rely on ships for transportation of bulk or heavy goods. Therefore, the demand for ship transportation in various countries has continued to increase in recent years.

Most of the current ships use the propeller to drive the fluid to drive the hull to sail. Specifically, the propeller has multiple blades, and when the propeller rotates, there will be a pressure difference between the high-pressure surface and the low-pressure surface of the blades, and the pressure difference will form a propulsion force to make the hull move forward on the water surface. Generally speaking, the blades of the propeller need to have a sufficient area ratio (arearatio) to maintain good structural strength and provide sufficient propulsion for the hull. However, the weight and surface area of the blade with a relatively large area are relatively large, so It will increase the manufacturing cost and need to use larger power to drive the propeller to operate normally.

Contents of the invention

The object of the present invention is to provide a propeller whose blades can maintain good structural strength with a small area ratio (arearatio), and can provide sufficient propulsion for the hull.

To achieve the above objects, the propeller of the present invention has a center point and is adapted to rotate with a rotation axis passing through the center point. A propeller includes a plurality of blades. Each blade has a central reference line. A projection of the central reference line on a virtual plane perpendicular to the rotation axis has opposite first and second ends, the second end is located between the first end and the center point, and the reference line passes through the second end and the center point. The distance between the first end and the center point is R, and the distance between any position on the projection of the central reference line and the center point is r. The skew angle of the line between any position and the center point relative to the reference line is y,

R≥r, $x=\frac{r}{R}$

y≥524.35x ⁶ -1995x ⁵ +2894.5x ⁴ -2041.4x ³ +815.68x ² -195.81x+15.84, and

y≤524.35x ⁶ -1995x ⁵ +2894.5x ⁴ -2041.4x ³ +815.68x ² -195.81x+21.84.

In one embodiment of the present invention, the above-mentioned

y= ^{524.35x6-1995x5} + ^{2894.5x4-2041.4x3 + 815.68x2-195.81x +} 18.84.

In an embodiment of the present invention, each of the blades mentioned above is inclined relative to the virtual plane.

In an embodiment of the present invention, the circumference of the above-mentioned circular area on the virtual plane passes through the first end of each blade, the sum of the developed areas of these blades is A1, the area of the circular area is A2, and $0.45\≤\frac{A1}{A2}\≤0.7.$

In an embodiment of the present invention, the above-mentioned R is between 2 meters and 5 meters.

Based on the above, in the propeller of the present invention, the skew angle y of each blade is defined as greater than or equal to 524.35x ⁶ -1995x ⁵ +2894.5x ⁴ -2041.4x ³ +815.68x ² -195.81x+15.84 and less than or equal to 524.35x ⁶ -1995x ⁵ +2894.5x ⁴ -2041.4x ³ +815.68x ² -195.81x+21.84, where R is the distance from the first end of the projection of the central reference line of each blade to the central point of the propeller, and r is the distance from any position of the projection of the central reference line to the central point . In this way, the blade still has good structural strength and can provide sufficient propulsion for the hull even though it is designed to have a relatively small unfolded area ratio, so as to reduce the manufacturing cost of the propeller. In addition, because the blade can have a smaller unfolded area ratio as mentioned above, the weight of the propeller is reduced and the surface area of the blade is reduced, so the ship can drive the propeller to operate normally with less power, thereby saving the transportation cost of the ship.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

Description of drawings

Fig. 1 is a side view of a propeller of an embodiment of the present invention applied to a ship;

Fig. 2 is the front view of the propeller of Fig. 1;

Fig. 3 is a partial structural schematic diagram of the propeller of Fig. 2;

Fig. 4 is the distribution curve of the skew angle of the blade of Fig. 3;

Fig. 5 is a partial structural sectional view of the propeller of Fig. 1;

FIG. 6 is a cross-sectional view of each blade of FIG. 1 .

Symbol Description

50: ship

52: Power unit

60: water surface

100: Propeller

110: Shaft

120: blade

a, b, c: curve

A: axis of rotation

A1: Area and

A2: Area

B: area

C: center point

d: chord length

D: Direction

E1: first end

E2: second end

H: distance

L1: Projection of the central reference line

L2: baseline

L3: Online

L4: arch arc

P: position

r, R: distance

S: virtual plane

T: Thickness

y: skew angle

detailed description

Fig. 1 is a side view of a propeller according to an embodiment of the present invention applied to a ship. FIG. 2 is a front view of the propeller of FIG. 1 . Please refer to FIG. 1 and FIG. 2 , the propeller 100 of this embodiment is suitable to be configured on a ship 50 , such as a cargo ship or other types of ships. The propeller 100 includes a shaft portion 110 and a plurality of blades 120 , the blades 120 are connected to the shaft portion 110 in axisymmetric manner, and the shaft portion 110 is connected to the power device 52 of the ship 50 . The number of blades may be five as shown in FIG. 2 or other appropriate numbers, and the present invention is not limited thereto. When the ship 50 sails on the water surface 60 , the propeller 100 under the water surface 60 is driven by the power device 52 to rotate to generate propulsion to drive the ship 50 forward along the direction D.

Fig. 3 is a partial structural schematic diagram of the propeller in Fig. 2 . Please refer to FIG. 3 , the propeller 100 (marked in FIG. 1 and FIG. 2 ) of this embodiment has a center point C and is suitable for passing through a rotation axis (marked as rotation axis A in FIG. 1 ) passing through the center point C. The blades 120 provide propulsion for the vessel 50, wherein the axis of rotation A is parallel to said direction D. Each blade 120 has a center reference line which has a projection L1 on a virtual plane perpendicular to the axis A of rotation. The projection L1 of the central reference line has an opposite first end E1 and a second end E2, the second end E2 is located between the first end E1 and the center point C of the propeller 100, and a generating line (generating line) L2 passes through the first end E1. A straight line with two ends E2 and the center point C. The distance between the first end E1 and the central point C is R, and the distance between any position P on the projection L1 of the central reference line and the central point C is r, wherein R≥r and FIG. 3 only schematically shows a position P, and actually the position P can be any other position on the projection L1 of the central reference line. The skew angle of the line L3 between any position P and the center point C relative to the reference line L2 is y. The above-mentioned R value can be adjusted to an appropriate value between 2 meters and 5 meters according to the size, weight and other design parameters of the hull, but the present invention is not limited thereto.

FIG. 4 shows distribution curves of skew angles of the blades of FIG. 3 . In Fig. 4, curve a～curve c represent three distribution modes of the skew angle of the blade, and curve a is the function y=524.35x ⁶ -1995x ⁵ +2894.5x ⁴ -2041.4x ³ +815.68x ² -195.81x+21.84 , curve b is the function y=524.35x ⁶ -1995x ⁵ +2894.5x ⁴ -2041.4x ³ +815.68x ² -195.81x+15.84, curve c is the function y=524.35x ⁶ -1995x ⁵ +2894.5x ⁴ -2041.4x ³ +815.68x ² -195.81x+18.84. The skew angle y of this embodiment is defined as being between the function represented by the curve a and the function represented by the curve b. That is, the skew angle is defined as follows:

y≥524.35x ⁶ -1995x ⁵ +2894.5x ⁴ -2041.4x ³ +815.68x ² -195.81x+15.84,

y≤524.35x ⁶ -1995x ⁵ +2894.5x ⁴ -2041.4x ³ +815.68x ² -195.81x+21.84.

It has been proved by experiments that by defining the above-mentioned skew angles of the blades 120 of the propeller 100, the cavitation phenomenon occurring at the periphery of the blades 120 can be effectively suppressed or delayed, and the blades 120 can be designed to have a smaller expansion area ratio ( arearatio) still has good structural strength and can provide sufficient propulsion for the hull of the ship 50, so as to reduce the manufacturing cost of the propeller 100. In addition, since the blades 120 can have a smaller expansion area ratio as mentioned above, the weight of the propeller 100 is reduced and the surface area of the blades 120 is reduced, so the ship 50 can drive the propeller 100 to operate normally with less power, thereby saving the ship. transportation cost. Furthermore, the deflection angles of the blades 120 of the propeller 100 are defined above to reduce the exciting force generated by the operation of the propeller 100 when the ship 50 is sailing. In a preferred embodiment, the skew angle of each blade 120 is defined as a function conforming to the curve b, but the present invention is not limited thereto.

Fig. 5 is a partial structural sectional view of the propeller in Fig. 1 . Further, in the propeller 100 of the present embodiment, the blade 120 is, for example, rake relative to the virtual plane (marked as virtual plane S in FIG. 5) as shown in FIG. 1 and FIG. Structural strength of paddle 100 . In addition, in this embodiment, the circumference of the circular area B (shown in FIG. 2 ) on the virtual plane S passes through the first end E1 of each blade 120 (marked in FIG. 3 ), and the expanded area of these blades 120 The sum is A1, and the area of the circular region B is A2. The expansion area ratio of the blade 120 is, for example, defined as the ratio of A1 and A2, and in this embodiment, its range is, for example: The weight of the propeller 100 is reduced and the surface area of the blade 120 is reduced with the resulting smaller developed area ratio. However, the present invention does not limit the magnitude of this ratio.

Other design parameters of each blade 120 in this embodiment will be illustrated below with reference to the accompanying drawings. FIG. 6 is a cross-sectional view of the blade of FIG. 1 . Please refer to FIG. 6, in the present embodiment, each blade 120 has a camberline (camberline) L4, and the distance H between the camberline L4 and the reference line L2 is defined as the camber height (camber) of the blade 120, but the present invention It is not limited to this.

To sum up, in the propeller of the present invention, the skew angle y of each blade is defined as greater than or equal to 524.35x ⁶ -1995x ⁵ +2894.5x ⁴ -2041.4x ³ +815.68x ² -195.81x+15.84 and Less than or equal to 524.35x ⁶ -1995x ⁵ +2894.5x ⁴ -2041.4x ³ +815.68x ² -195.81x+21.84, where R is the distance from the first end of the projection of the central reference line of each blade to the central point of the propeller, and r is the distance from any position of the projection of the central reference line to the central point . This can effectively suppress or delay the cavitation phenomenon occurring at the periphery of the blade, and enable the blade to still have good structural strength and provide sufficient propulsion for the hull to reduce the propeller manufacturing cost. In addition, because the blade can have a smaller unfolded area ratio as mentioned above, the weight of the propeller is reduced and the surface area of the blade is reduced, so the ship can drive the propeller to operate normally with less power, thereby saving the transportation cost of the ship. Furthermore, each blade of the propeller can be designed to be skewed, so as to further increase the structural strength of the propeller.

Although the present invention has been disclosed in conjunction with the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention should be defined by the appended claims.

Claims (5)

1. a propeller, this propeller has a center-point and is suitable for rotating with the pivot center by this center-point, and this propeller comprises:

Multiple blade, respectively this blade has a center reference line, this center reference line has one first relative end and one second end perpendicular to the projection on a virtual plane of this pivot center, this second end is between this first end and this center-point, one datum line is by this second end and this center-point, the distance of this first end and this center-point is R, any position in this projection of this center reference line and the distance of this center-point are r, the online angle of skew relative to this datum line of this any position and this center-point is y, wherein R>=r

Y>=524.35x ⁶-1995x ⁵+ 2894.5x ⁴-2041.4x ³+ 815.68x ²-195.81x+15.84, and

y≤524.35x ⁶-1995x ⁵+2894.5x ⁴-2041.4x ³+815.68x ²-195.81x+21.84。

2. propeller as claimed in claim 1, wherein

y＝524.35x ⁶-1995x ⁵+2894.5x ⁴-2041.4x ³+815.68x ²-195.81x+18.84。

3. propeller as claimed in claim 1, wherein respectively this blade relative to this virtual plane deflection.

4. propeller as claimed in claim 1, the circumference of the border circular areas wherein on this virtual plane by this first end of each this blade, the developed area of those blades and be A1, the area of this border circular areas is A2, and $0.45\≤\frac{A1}{A2}\≤0.7.$

5. propeller as claimed in claim 1, wherein R is between 2 meters and 5 meters.