Variable pitch propeller with optimum hub to tip diameter ratio

Abstract

The present invention relates to a controllable pitch propeller capable of changing the pitch of the blade according to the navigation conditions of the ship, and particularly, to a controllable pitch propeller having an optimum hub to tip diameter ratio, which is capable of reducing the size of the hub in order to have a high efficiency close to the propulsive efficiency of a fixed pitch propeller (FPP). In order to achieve the above-mentioned object, the present invention relates to a controllable pitch propeller comprising a hub mounted at the propulsion shaft of the ship and a blade mounted at the circumference of the hub and having a variable pitch, and is technically characterized by an H / D ratio of the diameter (H) of the propeller to the diameter (D) of the hub of 0.170-0.2.

Description

Technical Field

[0001] This disclosure relates to a variable pitch propeller capable of changing the blade pitch according to the operating conditions of the ship, and more specifically, to a variable pitch propeller with an optimal hub diameter ratio, wherein the hub size can be reduced to achieve high efficiency with propulsion efficiency close to that of a fixed pitch propeller (FPP). Background Technology

[0002] A propulsion system is a device that propels a ship by converting the power of a propulsion engine transmitted through a shaft into thrust. Marine propulsion systems include propellers, jet propellers, rotors, and Voith-Schneider propellers. Among these, propellers are the most widely used due to their high propulsion efficiency, simple structure, and low manufacturing cost compared to other types of propulsion devices.

[0003] Propellers can also be classified by performance, for example: fixed pitch propellers (FPP), in which the propeller blades are fixed to a hub connected to a rotating shaft; controllable pitch propellers (CPP), in which the propeller blades can move in a hub connected to a rotating shaft to adjust the pitch angle; counter-rotating propellers (CRP), which recover rotational force from the front propeller and convert it into thrust by using a rear propeller that rotates in the opposite direction to the front propeller, etc.

[0004] In low-speed vessels (such as large commercial ships and tankers), propeller efficiency and fuel efficiency are important factors. Therefore, fixed-pitch propellers that can operate at a constant ship speed are typically installed on low-speed vessels.

[0005] Recently, due to the strengthening of various marine environmental regulations to address issues such as environmental pollution, there is a problem that ships cannot meet various marine environmental regulations when operating with fixed-pitch propellers designed to improve fuel efficiency.

[0006] Meanwhile, in the case of conventional controllable pitch propellers where the blade pitch can be changed according to the ship's operating conditions, the facilities and equipment for changing the blade angle should be installed in the hub. Therefore, there are disadvantages: the hub size becomes larger than that of a fixed pitch propeller. Additionally, the airfoil is not optimized for a specific pitch because it should operate at various pitches. Thus, a problem with conventional controllable pitch propellers is that their propulsion efficiency is 4% to 8% lower than that of fixed pitch propellers. Moreover, due to the increased manufacturing costs caused by the complex handling of controllable pitch propellers, applying them to low-speed vessels is not very effective.

[0007] At the same time, it is necessary to modify the operating conditions of low-speed vessels to comply with various marine environmental regulations and operate them appropriately. Furthermore, although the propeller pitch should be effectively adjusted according to changes in operating conditions, it is difficult to apply this due to drawbacks such as increased unit cost and reduced propulsion efficiency.

[0008] The drive mechanism of a conventional controllable pitch propeller will be described in detail below.

[0009] Figure 1 This is a conceptual diagram showing the drive mechanism of a controllable pitch propeller according to the prior art. Figure 2 yes Figure 1 An exploded view of the controllable pitch propeller shown. Figures 3A to 3C This is a conceptual diagram illustrating the relationship between the blade pitch and hydraulic pressure.

[0010] like Figure 1 As shown, the controllable pitch propeller 10 has a plurality of blades 20 mounted at equal angles around the hub 30, and the crosshead 31 moves in the longitudinal direction of the hub 30 according to the flow of hydraulic oil supplied through hydraulic lines extending into the hub 30.

[0011] The crosshead 31 has a columnar structure with as many side surfaces as the number of blades 20. As an example, when the number of blades 20 mounted on the hub 30 is four, a crosshead 31 with a quadrilateral prism structure is provided. Moreover, when the number of blades 20 is five, the crosshead may have a pentagonal prism structure.

[0012] Simultaneously, the blade carrier 23 is fixed to the blade shank 21. With the pin 25 formed in the blade carrier 23 mating with the crosshead 31, the crosshead 31 moves forward and backward in the longitudinal direction of the hub 30 under hydraulic pressure. Therefore, the blade pitch is changed by the mating structure of the crosshead 31 and the pin 25.

[0013] like Figure 2 As shown, a sliding groove 33 is formed on the side surface of the crosshead 31 in a direction perpendicular to the centerline of the propulsion shaft 1 (i.e., the longitudinal direction of the hub 30).

[0014] The sliding shoe 35 is positioned in the sliding groove 33, and the pin 25 is inserted into the sliding shoe 35.

[0015] In the case of the controllable pitch propeller 10 according to the prior art, the crosshead 31 moves forward and backward along the longitudinal direction of the hub 30 (i.e., the centerline of the propeller shaft 1) by hydraulic pressure. In this case, as... Figures 3A to 3CAs shown, the sliding shoe 35 moves in the vertical direction relative to the centerline of the propulsion shaft 1 (i.e., the longitudinal direction of the sliding groove 33). Simultaneously, as the crosshead 31 moves along the centerline of the propulsion shaft 1, the pin 25 rotates with the center point of the blade carrier 23 as the origin.

[0016] In other words, as the pin 25 moves in the vertical direction of the sliding groove 33 as the crosshead 31 moves forward and backward, the blade 20, which is rotatably mounted around the hub 30, rotates to adjust the blade pitch.

[0017] As described above, in the case of the drive mechanism of a conventional controllable pitch propeller 10, the pin 25 moves along the sliding groove 33 formed perpendicular to the centerline of the propeller shaft 1, while adjusting the blade pitch together with the crosshead 31, which moves forward and backward along the centerline of the propeller shaft 1. In this case, in order to sufficiently guarantee the adjustable range of the blade pitch, the length of the sliding groove 33 in the vertical direction should be sufficiently guaranteed. Therefore, the crosshead 31 should be enlarged, and when the crosshead 31 is enlarged, there is a problem that the hub 30 of the propeller is also enlarged.

[0018] Furthermore, when the sliding groove 33 is formed in the rotation direction of the controllable pitch thruster 10, the direction of the resistance generated by the rotation of the thruster 10 is almost the same as the longitudinal direction of the sliding groove 33.

[0019] Therefore, in order to maintain the blade pitch, the crosshead 31 should be fixed by hydraulic pressure so as not to move in the direction of the propulsion shaft. In order to fix the movement of the crosshead 31 by hydraulic pressure as described above, the required performance (flow rate and pressure) of the hydraulic system should be very high, which leads to the problem of increased cost of the hydraulic system.

[0020] Meanwhile, the pin 25 of the conventional controllable pitch propeller 10 can rotate approximately 70 degrees. Therefore, the variable range of the propeller pitch is also approximately ±35 degrees, thus offering the advantage of a wide pitch angle adjustment range. However, there is a disadvantage: installing a controllable pitch propeller with a hub larger than required, because its variable range is wider than needed depending on the type of vessel.

[0021] As mentioned above, in conventional controllable pitch propellers, as the size of the crosshead increases according to the structure of the slide and the capacity of the hydraulic system increases, the hub is formed to be larger than the diameter of the propeller.

[0022] As an example, Figure 10 The left thruster shown illustrates the structure of a conventional controllable pitch thruster and has an H / D ratio of 0.206. Here, H is the diameter of the hub, and D is the diameter of the thruster.

[0023] [Related Literature]

[0024] [Patent Literature]

[0025] Japanese Patent Publication No. 2020-0015347 (Publication Date: January 30, 2020)

[0026] Japanese Patent Publication No. 2017-190020 (Publication Date: October 19, 2017)

[0027] Korean Patent Publication No. 10-2016-0116224 (Publication Date: October 7, 2016) Summary of the Invention

[0028] This disclosure is designed to solve the problems of the prior art as described above, and therefore relates to providing a controllable pitch propeller capable of changing the blade pitch according to operating conditions by configuring the propeller blades to be variable within two pitch ranges. This disclosure also relates to providing a controllable pitch propeller with an optimal hub diameter ratio that minimizes the increase in hub size and exhibits high propulsion efficiency approaching that of a fixed-pitch propeller.

[0029] This disclosure for achieving the above objectives relates to a controllable pitch propeller comprising a hub mounted on a propulsion shaft of a ship and blades mounted around the hub and having a variable pitch, wherein the H / D ratio of the propeller diameter H to the hub diameter D is 0.170 to 0.2.

[0030] Furthermore, according to a preferred embodiment of this disclosure, when the tanker is a low-speed vessel, the H / D ratio is 0.170 to 0.190.

[0031] Furthermore, according to a preferred embodiment of this disclosure, when the bulk carrier is a low-speed vessel, the H / D ratio is 0.185 to 0.20.

[0032] As described above, the controllable pitch propeller with an optimal hub diameter ratio according to this disclosure is configured to vary with a blade pitch suitable for the operating conditions when the operating conditions need to be changed due to various marine environmental regulations, and the hydraulic pressure required to change the blade pitch can be reduced as the pin moves along a guide groove formed diagonally relative to the longitudinal direction of the propulsion shaft. Since the blade pitch can be changed even with such a small hydraulic pressure, the capacity of the hydraulic system is reduced, and therefore the hub size can be reduced.

[0033] Furthermore, when the guide groove is formed in the diagonal direction of the propulsion shaft, the size of the crosshead can be reduced, and therefore the size of the hub can be configured to be smaller than that of a conventional controllable pitch propeller hub.

[0034] In this way, there are the following advantages: by changing the drive mechanism of the controllable pitch propeller, the size of the hub H / D can be reduced by 5% to 15% compared with the hub size of a conventional controllable pitch propeller, and it has the advantage of being able to reduce the structure by about 25% when the propeller material is changed and replaced. Attached Figure Description

[0035] Figure 1 This is a conceptual diagram showing the drive mechanism of a controllable pitch propeller according to the prior art.

[0036] Figure 2 yes Figure 1 An exploded view of the controllable pitch propeller shown.

[0037] Figures 3A to 3C This is a conceptual diagram illustrating the relationship between the blade pitch and hydraulic pressure.

[0038] Figure 4 This is a perspective view showing a controllable pitch propeller according to an embodiment of the present disclosure.

[0039] Figure 5 yes Figure 4 An exploded perspective view of the controllable pitch propeller shown.

[0040] Figures 6A to 6C This is a conceptual diagram illustrating the relationship between the blade pitch and hydraulic pressure.

[0041] Figure 7 This is a conceptual diagram showing the force acting on a pin moving along a diagonal guide groove.

[0042] Figure 8 It is a graph showing the pitch and hydraulic pressure based on the movement of the crosshead.

[0043] Figure 9 This is a conceptual diagram comparing the side surface of the crosshead of a controllable pitch propeller according to an embodiment of the present disclosure with the side surface of the crosshead of a conventional controllable pitch propeller.

[0044] Figure 10 This is a comparison diagram comparing the hub of a controllable pitch propeller according to the prior art with the hub of a controllable pitch propeller according to an embodiment of the present disclosure.

[0045] Figure 11 This is a conceptual diagram showing the end grooves formed at both ends of the guide groove.

[0046] Figure 12 This is a conceptual diagram showing the forces acting on a pin moving along the end groove and guide groove.

[0047] Figure 13It shows the sliding boot installed. Figure 12 An exploded perspective view of an example pin shown.

[0048] Figure 14 It shows Figure 13 The diagram shows a conceptual representation of the relationship between the sliding shoe and the second guide groove following the pin.

[0049] Figure 15 This is a conceptual diagram illustrating a controllable pitch thruster with a sliding locking block according to an embodiment of the present disclosure.

[0050] Figure 16 yes Figure 15 The cross-sectional view of the sliding lock block shown.

[0051] Figure 17 yes Figure 15 The exploded perspective view of the sliding lock block shown.

[0052] Figure 18 This is a conceptual diagram illustrating the operational relationships of the sliding lock blocks.

[0053] Figure 19 This is a conceptual diagram illustrating a controllable pitch propeller according to an embodiment of the present disclosure.

[0054] Figure 20 It shows the installation on Figure 19 A conceptual diagram of the hydraulic locking unit on the oil distribution box.

[0055] Figure 21 It shows Figure 20 A conceptual diagram of the operation of the hydraulic locking unit.

[0056] Figure 22 It is a conceptual diagram showing the operational relationship of the piston, crosshead, and hydraulic locking unit at dead center.

[0057] Figure 23 This is a conceptual diagram illustrating a controllable pitch thruster with a locking slider according to an embodiment of the present disclosure.

[0058] Figure 24 This is a conceptual diagram illustrating the locking and unlocking relationship of a locking slider based on the movement path of the pin that moves forward and backward according to the crosshead.

[0059] Figure 25 This is a detailed view showing the deformation relationship of the locking slider based on the connection between the locking block and the locking slider.

[0060] Figure 26 This is a cross-sectional view showing the state in which the piston moves backward according to the operation of the hydraulic system of the controllable pitch propeller according to an embodiment of the present disclosure.

[0061] Figure 27 It is a cross-sectional view showing the state in which the piston moves forward by the elastic force of the coil spring when the hydraulic pressure is released.

[0062] Figure 28 This is a conceptual diagram comparing a hydraulic circuit having a server hydraulic cylinder body according to an embodiment of the present disclosure with a conventional hydraulic circuit.

[0063] Figure 29 It shows Figure 26 A conceptual diagram of a modified example of a hydraulic system shown.

[0064] Figure 30 This is a conceptual diagram illustrating a hydraulic system with a switching valve according to an embodiment of the present disclosure.

[0065] Figure 31 It is shown in such Figure 26 The diagram shown is a conceptual representation of a hydraulic system with a switching valve, in which the helical spring is installed inside the cylinder. Detailed Implementation

[0066] In the following, preferred embodiments of the controllable pitch propeller of this disclosure will be described in detail with reference to the accompanying drawings, in the order of the drive mechanism, the diameter ratio of the hub and the blades, the locking device at the center of each dead point, and the hydraulic system.

[0067] [Drive mechanism for controllable pitch propeller]

[0068] Figure 4 This is a perspective view showing a controllable pitch propeller according to an embodiment of the present disclosure. Figure 5 yes Figure 4 An exploded perspective view of the controllable pitch propeller shown. Figures 6A to 6C This is a conceptual diagram illustrating the relationship between the blade pitch and hydraulic pressure. Figure 7 This is a conceptual diagram showing the force acting on a pin moving along a diagonal guide groove. Figure 8 It is a graph showing the pitch change and the magnitude of hydraulic pressure based on the movement of the crosshead. Figure 9 This is a conceptual diagram comparing the side surface of the crosshead of a controllable pitch propeller according to an embodiment of the present disclosure with the side surface of the crosshead of a conventional controllable pitch propeller.

[0069] like Figure 4 As shown, the controllable pitch propeller 100, mounted on the end of the propulsion shaft extending to the stern, includes a hub 130 connected to the propulsion shaft and a plurality of blades 120 mounted around the hub 130, capable of adjusting two pitch angles.

[0070] The drive mechanism of the controllable pitch propeller configured as described above will be described in detail below.

[0071] like Figure 4 and Figure 5 As shown, a crosshead 131, movable in the longitudinal direction of the hub 130, is embedded in the hub 130. Guide grooves 133 are formed on each side of the crosshead 131 in the direction of movement of the crosshead 131, i.e., diagonally opposite to the centerline of the propulsion shaft. A pin 125 is inserted into the guide grooves 133.

[0072] As described above, the blade carrier 123 is fixed to the blade shank 121. The pin 125 formed in the blade carrier 123 is inserted into the guide groove 133 of the crosshead 131.

[0073] As the crosshead 131 moves in the longitudinal direction of the hub 130, the pin 125 moves along the diagonal guide groove 133. The blade carrier 123 rotates by moving the pin 125 between the two ends of the guide groove 133 (i.e., the top dead center 133H and the bottom dead center 133L), and the blade pitch changes according to the rotation of the blade carrier 123.

[0074] like Figure 7 As shown, when the pin 125 also moves along the guide groove 133 according to the forward and backward movement of the crosshead 131, the pitch change of the blade 120 and the magnitude of the hydraulic pressure can be calculated by the following equations 1 and 2.

[0075] [Equation 1]

[0076]

[0077] [Equation 2]

[0078]

[0079]

[0080] Here, T sp Spindle torque, F′ cyl : Hydraulic pressure of the hydraulic system, d str : Stroke of the hydraulic system, θ s : Guide groove angle, θ′ R θ: principal axis angle range, r p : The distance from the pin to the center point of the spindle.

[0081] As can be seen from Equations 1 and 2, when the variable angle range of the pitch is small and the moving distance of the crosshead 131 (i.e. the stroke of the hydraulic system 140) is long, the load on the hydraulic system 140 decreases.

[0082] Meanwhile, rod 141R is connected to the rear end of crosshead 131, and piston 141 of hydraulic system 140 is fixed to the end of rod 141R. Piston 141 is located within cylinder 143 of hydraulic system 140 formed at the rear end of hub 130.

[0083] Additionally, a hydraulic line 145 extending into the hub 130 communicates with the interior of the cylinder 143 via a piston 141. Therefore, hydraulic oil flows into or out of the cylinder 143 through the hydraulic line 145. When hydraulic oil flows into or out of the inner rear portion of the cylinder 143 relative to the piston 141, the piston 141 moves forward or backward. Consequently, the crosshead 131 connected to the piston 141 also moves forward and backward under hydraulic pressure.

[0084] In the following text, reference will be made to Figures 6A to 6C Describes the variable relationship between the blade pitch and the stroke expansion and contraction of the hydraulic system.

[0085] like Figure 6A As shown, when hydraulic oil is introduced into the rear of piston 141 to extend the stroke of the hydraulic system, piston 141 moves forward under hydraulic pressure, i.e., in the arc direction. As piston 141 moves, crosshead 131 also moves in the arc direction. Therefore, pin 125 moves to the top dead center 133H of guide groove 133, and as pin 125 moves, blade 120... Figure 6A The blade 120 rotates clockwise as shown in the attached diagram. When pin 125 rotates and is positioned at the top dead center 133H, the blade 120 is in its maximum clockwise rotation state.

[0086] In this state, when hydraulic oil is introduced to the front of piston 141 and simultaneously discharged from the rear of piston 141, piston 141 moves backward. As piston 141 moves backward, pin 125 moves along guide groove 133 from top dead center 133H to bottom dead center 133L.

[0087] At this time, according to the movement of pin 125, blade 120... Figure 6B Rotate counterclockwise as shown. When the hydraulic system's stroke is contracted to its maximum value, that is, when the piston 141 has moved backward to its maximum value within the cylinder 143, the pin 125 is located at the lower dead center 133L of the guide groove 133, as shown. Figure 6C As shown. As described above, according to the movement of pin 125, blade 120 is located at the point where it has rotated counterclockwise to its maximum value.

[0088] As described above, when the pin 125 connected to the blade 120 moves along the guide groove 133 formed diagonally relative to the propulsion shaft, the two pitches corresponding to the top dead center 133H and the bottom dead center 133L can be changed.

[0089] Based on this drive mechanism, it can be seen that the greater the slope and the longer the length of the guide groove 133, the wider the variable range of the propeller pitch. However, in this case, it can be seen from Equation 2 that the hydraulic pressure should increase, and therefore, the size of the hydraulic system increases. Furthermore, in this case, with the increase in the crosshead 131, there is a problem of reduced propulsion efficiency of the thruster.

[0090] Therefore, in the controllable pitch propeller according to the embodiments of the present disclosure, the variable range of the two pitches of the blades is preferably limited to within 10 degrees.

[0091] Figure 8 It is a graph that shows the magnitude of the hydraulic pressure required based on the blade angle of a controllable pitch propeller.

[0092] according to Figure 8 The graphs shown indicate that when the variable range of the blade pitch is within ±10 degrees as in the embodiments of this disclosure, the required hydraulic pressure is approximately 100 kN. On the other hand, when the variable range of the blade pitch is within ±35 degrees, as in the conventional controllable pitch propeller 10, the required hydraulic pressure is 580 kN to 720 kN.

[0093] As described above, in the case of a controllable pitch propeller according to an embodiment of the present disclosure, the required hydraulic pressure can be reduced by limiting the variable range of the blade pitch to within ±10 degrees. Furthermore, the size of the hub 130 is reduced by positioning the guide groove 133 of the crosshead 131 diagonally relative to the propulsion shaft, and thus the blade pitch can be varied to suit the two types of operating conditions of low-speed vessels.

[0094] like Figure 9 As shown in (A), in the side surface of the crosshead 131 of the controllable pitch propeller 100 configured in this way, the guide groove 133 is formed diagonally relative to the propulsion shaft. Therefore, only the portion forming the guide groove 133 has a protruding structure that matches the pin 125. The crosshead 131 has a structure protruding in the lateral direction, as many as the number of blades. Therefore, the crosshead 131 has a short distance D1 from its center to its outermost edge, resulting in a small side cross-section. Figure 9 As shown in (B), a sliding groove 33 is formed on the side surface of the conventional crosshead 31 in the direction perpendicular to the propulsion shaft. Therefore, the distance D2 from the center of the crosshead 31 to the outermost edge is longer than the distance of the controllable pitch propeller of the embodiment of this disclosure. As a result, the side cross-section of the crosshead 31 becomes larger.

[0095] As described above, as the cross-sectional area of ​​the crosshead 31 increases, the diameter of the hub 30 also increases. Furthermore, the hub diameter of the controllable pitch propeller according to the embodiments of this disclosure is relatively smaller than that of a conventional controllable pitch propeller, thereby increasing the propulsion efficiency to near the level of a fixed pitch propeller.

[0096] [Diameter ratio of hub to blade]

[0097] Figure 10 This is a comparison diagram comparing the hub of a controllable pitch propeller according to the prior art with the hub of a controllable pitch propeller according to an embodiment of the present disclosure.

[0098] Figure 10 The thrusters shown illustrate a conventional controllable pitch thruster (left thruster) and a controllable pitch thruster (right thruster). The conventional controllable pitch thruster includes a crosshead with a vertical sliding groove according to the prior art, while the controllable pitch thruster includes a crosshead with a diagonal guide groove according to an embodiment of this disclosure.

[0099] In the case of a controllable pitch propeller with a diameter D of 8700 mm, the hub diameter H of a conventional controllable pitch propeller is 1790 mm, and the diameter ratio H / D is 0.206. On the other hand, the hub diameter H of the controllable pitch propeller according to the embodiment of this disclosure is 1610 mm, and the diameter ratio H / D is 0.185. Therefore, the diameter ratio can be reduced by approximately 10% compared to that of a conventional controllable pitch propeller.

[0100] At the same time, the safety factor decreases as the wheel hub diameter decreases. Specifically, the safety factor decreases by approximately 30% when the wheel hub diameter decreases by 10%, and by approximately 40% when the wheel hub diameter decreases by 15%.

[0101] Here, the safety factor represents an assessment of the fatigue strength under repeated loads due to the structural characteristics of the propeller and hub.

[0102] Typically, in the case of conventional controllable pitch propellers, the reduction can be as high as 15% considering the safety margin.

[0103] Therefore, when having the same propeller diameter D, the hub diameter H of the controllable pitch propeller according to this disclosure can be reduced by 5% to 15% compared to the hub diameter H of a conventional controllable pitch propeller.

[0104] Furthermore, in the case of a controllable pitch propeller with a mechanism according to this disclosure, if a suitable material for the propeller is selected and replaced, the hub diameter can be reduced by up to 20% compared to a conventional controllable pitch propeller.

[0105] Table 1 below shows the hub diameter / propeller diameter ratio of a fixed pitch propeller (FPP) and a controllable pitch propeller according to embodiments of the present disclosure, depending on the type and size of the low-speed vessel.

[0106] [Table 1]

[0107]

[0108]

[0109] As described above, in the controllable pitch propeller according to the embodiments of the present disclosure, the hub diameter can be reduced such that, taking into account a 40% reduction in safety factor, the H / D ratio is 0.165 to 0.190 for tankers and 0.180 to 0.200 for bulk carriers.

[0110] [First embodiment of the locking device at each stop point]

[0111] The following describes four types of embodiments of the locking device. Among them, the locking device according to the first embodiment relates to a structure in which end grooves are formed at both ends of the guide groove (i.e., the upper stop and the lower stop), in which the pin can be positioned in the direction of the advance axis.

[0112] Figure 11 This is a conceptual diagram showing the end grooves formed at both ends of the guide groove. Figure 12 This is a conceptual diagram showing the forces acting on a pin moving along the end groove and guide groove. Figure 13 It shows the sliding boot installed. Figure 12 An exploded perspective view of an example pin shown. Figure 14 It shows Figure 13 The diagram shows a conceptual representation of the relationship between the sliding shoe and the second guide groove following the pin.

[0113] like Figure 11 As shown, the end groove 135 is further formed at both ends of the guide groove 133 in the outward direction of the guide groove 133 along the center line of the propulsion shaft.

[0114] When the pin 125 reaches the upper dead center 133H or the lower dead center 133L of the guide groove 133, the pin 125, which moves along the guide groove 133, enters the end groove 135 extending from the upper dead center 133H or the end groove 135 extending from the lower dead center 133L through the movement of the crosshead 131, and is positioned. Conversely, it enters the guide groove 133 from the end groove 135 through the movement of the crosshead 131, and moves toward the opposite end groove 135.

[0115] Therefore, the end slot 135 is formed to communicate with the guide slot 133 in the slot structure, the length of which is ( Figure 12e) The radius of pin 125 is greater than or equal to the radius of pin 125 along the centerline of the propulsion shaft at both ends of guide groove 133. When pin 125 is positioned in end groove 135, more than half of the cross-sectional area of ​​pin 125 is positioned within end groove 135.

[0116] Therefore, when the pin 125 enters the end groove 135 and is positioned, the outer peripheral surface of the pin 125 does not contact the inner surface of the guide groove 133, but contacts the inner surface of the end groove 135.

[0117] In this configuration, even when the resistance generated during the rotation of the controllable pitch propeller 100 is transmitted to the pin 125 via the blade 120, the direction of the resistance and the longitudinal direction of the end slot 135 are perpendicular to each other, thus preventing the pin 125 from entering the guide slot 133 and moving along it due to the resistance. Since the pin 125 is positioned and locked in the end slot 135 in this manner, the blade pitch is prevented from changing due to the resistance. Furthermore, the hydraulic pressure of the hydraulic system 140, which restricts the flow of the crosshead 131, can be reduced accordingly, and the size of the hub 130 can be reduced.

[0118] When the end grooves 135 are formed at both ends of the guide groove 133, their movement distance is increased by more than the diameter of the pin 125 compared to the movement distance along the crosshead of the guide groove without end grooves. Figures 5 to 6C As shown. That is, as the end grooves 135 are formed at both ends of the guide groove 133, the stroke of the hydraulic system 140 is further increased beyond the diameter of the pin 125.

[0119] like Figure 12 As shown, when pin 125 moves along end groove 135 and guide groove 133 according to the forward and backward movement of crosshead 131, the pitch change of blade 120 and the magnitude of hydraulic pressure can be calculated by the following equation 3.

[0120] [Equation 3]

[0121] d astr =d str -2e

[0122]

[0123]

[0124]

[0125] Here, e represents the length of the end slot, and T represents the length of the end slot. sp Spindle torque, F′ cyl : Hydraulic pressure of the hydraulic system, d str The full stroke of the hydraulic system, d astr : The stroke used in hydraulic systems for pitch control, θs : Guide groove angle, θ′ R : Spindle angle range, r p : The distance from the pin to the center point of the spindle.

[0126] As can be seen from Equation 3, due to the small variable angle range of the pitch and the long travel distance of the crosshead 131 (i.e., the stroke of the hydraulic system 140), the load on the hydraulic system 140 is reduced. Furthermore, when the pin 125 is positioned and locked in the end groove 135 formed by extending to the top and bottom dead centers of the guide groove 133, the hydraulic pressure corresponding to the resistance can be greatly reduced, thereby significantly reducing the capacity of the hydraulic system 140.

[0127] At the same time, the pin 125 has such Figure 11 and Figure 12 The cylindrical structure is shown. Therefore, when an external impact or the like is suddenly applied to the pin 125 located in the end slot 135, the problem is that the blade pitch can be changed by moving it from the end slot 135 to the guide slot 133.

[0128] To solve this problem, such as Figure 13 and Figure 14 As shown, the sliding shoe 150 is mounted around the pin 125. Additionally, a second guide groove 137 for guiding the sliding shoe 150 along the pin 125 is formed in the crosshead 131.

[0129] Specifically, the sliding shoe 150 is divided into an upper sliding shoe 150 and a lower sliding shoe 150, and a groove 151 that contacts the outer peripheral surface of the pin 125 is formed on the facing surfaces of the upper and lower sliding shoes 150, such that the pin 125 is positioned between the upper and lower sliding shoes 150. Furthermore, on the outside of the groove 151, a coil spring 153 is positioned between the upper and lower sliding shoes 150 to compensate for changes in the width of the second guide groove 137 as the sliding shoe 150 moves along the second guide groove 137. Although not in Figure 13 and Figure 14 As shown, a groove or pin inserted into the end of the helical spring 153 is formed in the helical spring sheet to fix the position of the helical spring 153, so that the position of the helical spring can be fixed.

[0130] Meanwhile, a second guide groove 137 is formed on the side surface of the crosshead 131, and the aforementioned guide groove 133 is formed on the bottom surface of the second guide groove 137. Furthermore, with the pin 125 inserted into the sliding shoe 150 located in the second guide groove 137, the end of the pin 125 is inserted into the guide groove 133.

[0131] Here, the second guide groove 137 is divided into a diagonal portion 137S formed with the same slope as the diagonal of the guide groove 133 and an end portion 137E corresponding to the end grooves 135 formed at both ends of the guide groove 133. The end portion 137E is formed along the centerline of the propulsion shaft, similar to the end groove 135.

[0132] When the second guide groove 137 is formed in this manner and the crosshead 131 on which the sliding shoe 150 is mounted moves forward and backward via the operation of the hydraulic system 140, the pin 125 moves from the guide groove 133 to the end groove 135 or from the end groove 135 to the guide groove 133. Due to the movement of the pin 125, the sliding shoe 150 also moves along the diagonal portion 137S and the end portion 137E of the second guide groove 137.

[0133] Because the sliding shoe 150 has a structure surrounding the pin 125, the width of the second guide groove 137 is wider than the width of the guide groove 133. The end portion 137E of the second guide groove 137 corresponding to the end groove 135 is also formed to be longer than the length of the end groove 135. Figure 12 (e in the text)

[0134] In this structure, when the pin 125 is positioned in the end groove 135, the sliding shoe 150 is positioned at both ends 137E of the second guide groove 137. When positioned at the end portion 137E of the second guide groove 137 formed along the centerline of the propulsion shaft, the contact surface between the sliding shoe 150 and the end portion 137E of the second guide groove 137 is perpendicular to the rotation direction of the propeller 100.

[0135] Since the contact surface between the end of the sliding shoe 150 and the second guide groove 137 is perpendicular to the rotation direction of the thruster 100, the sliding shoe 150 will not deviate from the second guide groove 137 due to the impact even if an external impact is applied. Therefore, the pin 125 is also stably positioned in the end groove 135.

[0136] Simultaneously, as the sliding shoe 150 moves from the end portion 137E of the second guide groove 137 to the diagonal portion 137S or from the diagonal portion 137S to the end portion 137E, the width of the second guide groove 137 changes at the bend where the end portion 137E and the diagonal portion 137S meet. Therefore, when the sliding shoe 150 passes through the bend, the helical spring 153 located between the upper and lower sliding shoes 150 elastically deforms to compensate for the change in width. Thus, the sliding shoe 150 smoothly passes from the end portion 137E to the diagonal portion 137S or from the diagonal portion 137S to the end portion 137E.

[0137] In this way, end grooves 135 are formed at both ends of guide grooves 133, and pins 125 are positioned in end grooves 135 to reduce resistance to rotation of the pusher 100, thereby reducing the capacity of the hydraulic system 140. Furthermore, when the sliding shoe 150 is installed and pins 125 are positioned in end grooves 135, the outer surface of the sliding shoe 150 and the inner surface of the end of the second guide groove 137 are in surface contact, and thus can effectively prevent pins 125 from separating from end grooves 135 due to external impacts, etc.

[0138] [Second embodiment of the locking device at each stop point]

[0139] When the pin is positioned at the top dead center and bottom dead center during the forward and backward movement of the crosshead, the locking device according to the second embodiment described below locks the forward and backward movement of the crosshead, thereby preventing the blade pitch from changing due to external resistance and impact.

[0140] The locking device according to the second embodiment is the locking device of the first embodiment described above (in... Figures 11 to 14 The locking mechanism of the second embodiment is different from that of the first embodiment. When describing the locking device of the second embodiment, it can be configured such that the locking device of the first embodiment may or may not be added to the locking device of the second embodiment. The locking device of the second embodiment is described below with reference to the accompanying drawings, in which the locking device of the first embodiment is added.

[0141] In the attached diagram, Figure 15 This is a conceptual diagram illustrating a controllable pitch propeller with a locking device according to an embodiment of the present disclosure. Figure 16 yes Figure 15 The cross-sectional view of the slider shown. Figure 17 yes Figure 15 The exploded perspective view of the slider shown. Figure 18 This is a conceptual diagram illustrating the operational relationships of the slider.

[0142] like Figures 15 to 17 As shown, a rod 141R extending to the front of the piston 141 is positioned to pass through a crosshead 131 in its longitudinal direction. That is, the crosshead 131 is positioned around the rod 141R and can move in the longitudinal direction of the rod.

[0143] Simultaneously, slider 160 is positioned to move along rod 141R, and crosshead 131 is positioned within slider 160, but the length of slider 160 is longer than the length of crosshead 131. Therefore, crosshead 131 can move a length difference within slider 160 along rod 141R. When crosshead 131 has moved a length difference, crosshead 131 and slider 160 are in contact with each other.

[0144] In the structure of the locking device configured as described above, when the lever 141R moves via the operation of the hydraulic system 140, the slider 160 is positioned to contact the front stop 147F and the rear stop 147B. Therefore, the slider 160 moves together with the lever 141R. The crosshead 131 located within the slider 160 moves with the lever 141R, and contact with the crosshead 131 begins at the moment after the slider 160 has moved a certain length.

[0145] Meanwhile, an opening 161 is formed on the longitudinal side of the slider 160, allowing the pin 125 to be inserted into the guide groove 133 to move between the top dead center 133H and the bottom dead center 133L. Therefore, even if the slider 160 surrounds the crosshead 131, the pin 125 can move within the opening 161 of the slider 160, causing the blade pitch to change as described above.

[0146] Additionally, slider 160 moves along rod 141R in the same manner as piston 141, with both ends contacting front stop 147F and rear stop 147B. That is, slider 160 moves together with piston 141 according to the operation of hydraulic system 140. When the internal clearance G of slider 160 narrows and contacts each other, crosshead 131 located inside slider 160 moves along rod 141R together with slider 160.

[0147] Here, the description of the change in blade pitch based on the forward and backward movement of the crosshead is the same as that described above, and therefore will be omitted.

[0148] like Figure 18 As shown, the locking device according to the second embodiment includes: an elongated groove 163 formed on the side of the opening 161 in the longitudinal direction of the slider 160; two locking holes 139 formed in the crosshead 131 corresponding to the two ends of the elongated groove 163; and a plug 170 that, while supported on the inner surface of the hub 130, passes through the elongated groove 163, inserts into and locks the corresponding locking hole 139, and is withdrawn and unlocked. When the guide rail 165 formed in the elongated groove 163 of the slider 160 moves in the longitudinal direction, the plug 170 is inserted into or withdrawn from the locking hole 139.

[0149] More specifically, the spacing between the locking holes 139 formed in the crosshead 131 is the same as the distance between the top dead center 133H and the bottom dead center 133L of the pin 125. Therefore, when the pin 125 is at either the top dead center 133H or the bottom dead center 133L, the plug 170 corresponds to either of the two locking holes 139. Additionally, the plug 170 is inserted into the locking holes 139 to lock the slider 160 and the crosshead 131 together.

[0150] Meanwhile, with the slider 160 around the crosshead 131, a long groove 163 is formed in the longitudinal direction of the slider 160 for inserting the plug 170. Furthermore, when inserted into the long groove 163, the plug 170 is always provided with elasticity in the direction of insertion into the locking hole 139 via the coil spring 171.

[0151] Additionally, a pair of guide rails 165 are formed in an elongated groove 163 to guide the plug 170 upwards from the locking hole 139 of the crosshead 131. Furthermore, the elongated groove 163 is formed between the pair of guide rails 165. At both ends of the guide rails 165, inclined portions 165S are formed that gradually descend outwards. Therefore, when the plug 170 moves along the inclined portions 165S, it moves upwards or downwards to the position where the locking hole 139 is located.

[0152] On the two end surfaces of the plug 170 mounted on a pair of guide rails 165, inclined surfaces 170S are formed corresponding to the inclined portions 165S of the guide rails 165. Therefore, when the slider 160 moves forward and backward with the plug 170 positioned at the midpoint of the length of the guide rails 165, the plug 170 moves relative to the guide rails 165. Furthermore, upon reaching the inclined portion 165S of the guide rails 165, the plug 170 moves downward along the inclined portion 165S by the elastic force of the coil spring 171. Thus, the plug 170 is inserted into the locking hole 139 of the crosshead 131 through the elongated slot 163. Therefore, the crosshead 131 is locked to the slider 160.

[0153] As described above, when pin 125 is located at top dead center 133H and bottom dead center 133L, locking hole 139 is formed at the position corresponding to plug 170, and therefore, when plug 170 is pulled into locking hole 139, pin 125 is in the state of being at top dead center or bottom dead center. In this state, even if resistance or external impact is transmitted through pin 125, it can prevent pin 125 from separating from top dead center 133H or bottom dead center 133L.

[0154] Simultaneously, in the locked state where the plug 170 is inserted into the locking hole 139, when the slider 160 moves due to the internal gap G caused by the length difference of the crosshead 131, the plug 170 inserted into the locking hole 139 moves upward along the inclined portion 165S of the guide rail 165. Moreover, the plug 170 is pulled out from the locking hole 139 of the crosshead 131 and unlocked.

[0155] In this way, when the slider 160 moves to narrow the internal gap and contacts the crosshead 131 in the unlocked state (with the plug 170 withdrawn from the locking hole 139), the slider 160 and the crosshead 131 move together along the rod 141R. That is, when the crosshead 131 moves along the rod 141R in the unlocked state, the blade pitch changes.

[0156] In this state, when the plug 170, which moves along the guide rail 165, reaches the opposite end of the guide rail 165, it moves downward along the inclined portion 165S. The plug 170 is inserted through the elongated slot 163 into the locking hole 139 opposite to the crosshead 131 to be locked.

[0157] As described above, when the crosshead 131 moves and the pin 125 is positioned at the top dead center 133H and the bottom dead center 133L, the locking hole 139 is formed at the point corresponding to the plug 170. Therefore, when the plug 170 passes through the slot 163 and is inserted into the locking hole 139 of the crosshead 131, it means that the plug 170 is locked at the top dead center 133H or the bottom dead center 133L.

[0158] In this way, when pin 125 is at the top dead center 133H and bottom dead center 133L, plug 170 passes through slider 160 and is inserted into locking hole 139 of crosshead 131 to be locked. Therefore, crosshead 131 is restricted to slider 160, and slider 160 is restricted to rod 141R by front stop 147F and rear stop 147B. Thus, movement of crosshead 131 can be prevented by a force different from the hydraulic pressure of hydraulic system 140 (i.e., resistance generated by the rotation of thruster 100 and external impact).

[0159] Therefore, the blade pitch set by the top dead center 133H and the bottom dead center 133L can be prevented from shifting due to resistance and external impact.

[0160] [Third embodiment of the locking device at each stop point]

[0161] When the pin is positioned at the top dead center and bottom dead center during the forward and backward movement of the crosshead, the locking device according to the third embodiment described below locks the forward and backward movement of the crosshead, thereby preventing the blade pitch from changing due to external resistance and impact. In particular, the first embodiment of the locking device, the second embodiment described above, and the fourth embodiment described later are configured to be installed inside the hub, while the third embodiment of the locking device described below is installed on the propeller shaft.

[0162] In the attached diagram, Figure 19 This is a conceptual diagram illustrating a controllable pitch propeller according to an embodiment of the present disclosure. Figure 20 It shows the installation on Figure 19 A conceptual diagram of the hydraulic locking unit on the oil distribution box. Figure 21 It shows Figure 20 A conceptual diagram of the operation of the hydraulic locking unit. Figure 22 It is a conceptual diagram showing the operational relationship of the piston, crosshead, and hydraulic locking unit at dead center.

[0163] like Figure 19As shown, the blade 120 is mounted in the controllable pitch propeller 100 around the hub 130. The hub 130 is fixed to the end of the propeller shaft 1. Furthermore, the oil distribution box 190 is mounted on the propeller shaft 1.

[0164] Hydraulic oil in the hydraulic system 140 is formed in the oil distribution box 190 through its inlet and outlet ports 192A and 192B. The piston 141 moves forward and backward by the hydraulic oil flowing in and out through ports 192A and 192B. The structure of the propulsion shaft 1 and the movable hydraulic locking unit 191 installed inside the oil distribution box 190 to hydraulically lock the piston 141 will be described in detail below.

[0165] A hollow portion is formed inside the propulsion shaft 1, and a concentric hollow shaft 211 connected to the piston 141 is located within the hollow portion of the propulsion shaft 1. Furthermore, a first hydraulic line 145A is formed along the centerline of the hollow shaft 211, and the interval between the outer circumferential surface of the hollow shaft 211 and the hollow inner circumferential surface of the propulsion shaft 1 corresponds to a second hydraulic line 145B. The first hydraulic line 145A passes through the center of the piston 141 and communicates with the rear portion of the cylinder 143. The second hydraulic line 145B extends to the front portion of the piston 141 and communicates with the front portion of the cylinder 143.

[0166] Therefore, when hydraulic oil flows into the cylinder 143 through the first hydraulic line 145A, the piston 141 moves forward and the stroke of the hydraulic system 140 extends. Additionally, the hydraulic oil filling the front portion of the cylinder 143 flows towards the oil distribution tank 190 through the second hydraulic line 145B. Conversely, when hydraulic oil flows into the cylinder 143 through the second hydraulic line 145B, the stroke of the hydraulic system 140 contracts, and the piston 141 moves backward. Furthermore, the hydraulic oil filling the rear portion of the cylinder 143 flows towards the oil distribution tank 190 through the first hydraulic line 145A.

[0167] The hollow shaft 211 connected to the piston 141 moves forward and backward together with the piston 141.

[0168] Meanwhile, the hydraulic locking unit 191 is installed inside the oil distribution box 190, and the hollow shaft 211 passes through the hydraulic locking unit 191 and extends to the front of the hydraulic locking unit 191.

[0169] At the same time, such as Figures 20 to 22 As shown, hydraulic oil flowing in through the first port 192A of the oil distribution box 190 flows to the front end of the hydraulic locking unit 191 and can flow to the first hydraulic line 145A, which is open at the end of the hollow shaft 211. Hydraulic oil introduced through the second port 192B flows to the rear end of the hydraulic locking unit 191 and can pass between the hydraulic locking unit 191 and the propulsion shaft 1 to flow to the second hydraulic line 145B.

[0170] Therefore, when hydraulic oil flows into the first port 192A, the hollow shaft 211 moves forward, and the piston 141 moves forward at the same time. At this time, when the hollow shaft 211 passes through the hydraulic locking unit 191, the front end of the hollow shaft 211 moves to the front of the hydraulic locking unit 191.

[0171] Conversely, when hydraulic oil flows through the second port 192B, the hollow shaft 211 moves backward, and at the same time, the piston 141 moves backward.

[0172] Here, the space formed on the inner arc-shaped side of the hydraulic locking unit 191, allowing the front end of the hollow shaft 211 to move, is referred to as the first chamber 193A. Additionally, the space between the rear end of the hydraulic locking unit 191 and the propulsion shaft 1 is referred to as the second chamber 193B.

[0173] Simultaneously, two locking rings 194A and 194B are located within the hydraulic locking unit 191 at a distance D3. The two locking rings 194A and 194B surround the hollow shaft 211. Additionally, two grooves 195A and 195B that mate with the locking rings 194A and 194B are formed on the hollow shaft 211 at a distance D4. The distance D4 between the grooves 195A and 195B corresponds to the sum of the distance D3 between the locking rings 194A and 194B and the distance between the top and bottom dead centers. Although not shown in the accompanying drawings, the locking rings 194A and 194B have a partially open structure, and their diameter can be elastically expanded or contracted.

[0174] Therefore, during the movement of the hollow shaft 211 and the piston 141, when the pin 125 is at top dead center 133H (when the stroke of the hydraulic system 140 is contracted to its maximum value), the first groove 195A formed on the front end side of the hollow shaft 211 matches the first locking ring 194A. When the pin 125 is at bottom dead center (when the stroke of the hydraulic system is extended to its maximum value), the second groove 195B formed along the length of the hollow shaft 211 matches the second locking ring 194B. Thus, when either the locking rings 194A or 194B matches either the grooves 195A or 195B, the hollow shaft 211, which moves together with the piston 141, stops moving. Therefore, the thruster pitch is locked so as not to be changed by resistance or external impact.

[0175] The structure of the hydraulic locking unit 191 will be described in detail below.

[0176] The hydraulic locking unit 191 is fixed to the interior of the propulsion shaft 1, and a first flow path 196A communicating with the first chamber 193A is formed at the front end of the hydraulic locking unit 191. A second flow path 196B communicating with the second chamber 193B is formed at the rear end of the hydraulic locking unit 191.

[0177] Furthermore, the first locking ring 194A is positioned corresponding to the front end of the hollow shaft 211, i.e., the first flow path 196A, and is also located around the hollow shaft 211. The second locking ring 194B is positioned corresponding to the second flow path 196B.

[0178] Additionally, a sliding lock 213 that moves along the hollow shaft 211 is mounted on the hydraulic locking unit 191. The two sliding locks 213 move in the longitudinal direction of the hollow shaft 211 respectively through the interaction of the hydraulic pressure of the hydraulic oil flowing into the hydraulic locking unit 191 via the first flow path 196A or the second flow path 196B and the elastic force of the support spring 215 supporting the sliding locks 213.

[0179] The sliding lock 213 has a retainer structure, and when moved in the longitudinal direction of the hollow shaft 211, the sliding lock locks around the locking rings 194A and 194B that mate with the slots 195A and 195B, thereby locking the locking rings 194A and 194B so that they do not deviate from the slots 195A and 195B. Additionally, the sliding lock 213 is positioned such that the locking rings 194A and 194B can be disengaged from the slots 195A and 195B. When both locking rings 194A and 194B are disengaged from the slots 195A and 195B, the hollow shaft 211 is in an unlocked state, allowing it to move forward and backward.

[0180] Meanwhile, the spring retainer 217 is fixed at the middle of the length of the hydraulic locking unit 191. The end portions of the support springs 215 located on both sides of the spring retainer 217 are inserted into the spring retainer 217 and supported by the spring retainer 217.

[0181] In the following text, reference will be made to Figures 20 to 22 The locking and unlocking relationship of the hydraulic locking unit configured as described above is described in detail.

[0182] like Figures 20 to 22 As shown, with the stroke of the hydraulic system 140 extended to its maximum value (pin at top dead center), hydraulic oil fills the rear of the cylinder 143, and the piston 141 is in the forward position, meaning the hollow shaft 211 is also in the forward position. At this time, as the hollow shaft 211 is positioned by moving forward into the interior of the first chamber 193A, the second locking ring 194B mates with the second groove 195B, and the sliding lock 213 surrounds the second locking ring 194B to prevent unlocking.

[0183] In this state, when hydraulic oil flows in through the second port 192B, it moves towards the rear end of the hydraulic locking unit 191 and flows into the second chamber 193B, thereby generating hydraulic pressure that causes the sliding lock 213 to move forward through the second flow path 196B. Additionally, when the sliding lock 213 moves forward and unlocks the second locking ring 194B, the hollow shaft 211 is in a movable state and moves backward, while hydraulic oil fills the front of the cylinder 143 through the second chamber 193B and the second hydraulic line 145B. Simultaneously, hydraulic oil located at the rear of the cylinder 143 flows out through the first hydraulic line 145A, the first chamber 193A, the first flow path 196A, and the first port 192A.

[0184] In this way, when the hollow shaft 211 moves backward, the first groove 195A of the hollow shaft 211 moves toward the first locking ring 194A, and the first locking ring 194A matches and is locked with the first groove 195A. This is the state where the stroke of the hydraulic system 140 is contracted to its maximum value, with the pin 125 positioned at the lower dead center 133L.

[0185] When the first locking ring 194A mates with the first slot 195A in this manner, the sliding lock 213 moves forward by the elastic force of the support spring 215 to surround the mating first locking ring 194A, thereby preventing unlocking.

[0186] As described above, when pin 125 is at top dead center or bottom dead center, hydraulic locking unit 191 maintains a locked state through matching grooves 195A, 195B and locking rings 194A, 194B, thereby preventing changes in the propeller pitch due to resistance caused by propeller rotation or external impacts. Furthermore, hydraulic locking unit 191 is unlocked by the hydraulic pressure of inflowing and outflowing hydraulic oil, causing the hydraulic system 140 to expand and contract during its stroke, allowing pin 125 to move from top dead center 133H to bottom dead center 133L or from bottom dead center 133L to top dead center 133H.

[0187] [Fourth embodiment of the locking device at each stop point]

[0188] The locking device according to the fourth embodiment described below locks the pin to prevent changes in the blade pitch due to external resistance, impact, etc., when the pin is positioned at the top dead center and bottom dead center. This includes the locking device of the first embodiment described above (in... Figures 11 to 14 The configuration of (in the first embodiment) will be omitted. Therefore, redundant descriptions of the configuration described in the first embodiment will be omitted.

[0189] In the attached diagram, Figure 23 This is a conceptual diagram illustrating a controllable pitch thruster with a locking slider according to an embodiment of the present disclosure. Figure 24This is a conceptual diagram illustrating the locking and unlocking relationship of a locking slider based on the movement path of the pin that moves forward and backward according to the crosshead. Figure 25 This is a detailed view showing the deformation relationship of the locking slider based on the connection between the locking block and the locking slider.

[0190] like Figure 23 As shown, guide groove 133, end groove 135, and second guide groove 137 are formed in crosshead 131. Pin 125 is inserted into guide groove 133 and moves between upper dead center 133H and lower dead center 133L of guide groove 133 as crosshead 131 moves forward and backward. At each dead center, pin 125 is inserted into or withdrawn from end groove 135.

[0191] Meanwhile, guide groove 133 and end groove 135 are formed at the bottom of second guide groove 137 in the same manner as the second guide groove 137 in the first embodiment. The diagonal portion 137S of the second guide groove 137 corresponds to guide groove 133, and the end portion 137E of the second guide groove 137 corresponds to end groove 135.

[0192] Furthermore, the locking device according to the fourth embodiment includes a protrusion 181 formed at the end portion 137E of the second guide groove 137 and a locking slider 180 surrounding the pin 125. The locking slider 180 of the locking device moves along the diagonal portion 137S and the end portion 137E of the second guide groove 137.

[0193] In the locking device of the fourth embodiment, the locking slider 180 is configured to replace the sliding shoe described in the first embodiment. Figure 13 (150 in the first embodiment). In the first embodiment, the sliding shoe 150 is positioned at the end portion 137E of the second guide groove 137 and has surface contact to prevent the pin 125 from moving due to resistance and impact. In the fourth embodiment, by matching the locking slider 180 and the protrusion 181 in addition to the surface contact function, the pin 125 can be prevented from moving due to resistance and impact more effectively.

[0194] The structure and organic connection between the protrusion 181 formed at the end portion 137E of the second guide groove 137 and the locking slider 180 will be described below.

[0195] like Figures 23 to 25 As shown, the end portion 137E is formed along the centerline of the propulsion shaft 1 at both ends of the second guide groove 137, and protrusions 181 are formed on the inner surfaces facing the end portion 137E. The ends of the protrusions 181 are configured to extend over the locking slider 180 in a hemispherical shape.

[0196] Meanwhile, when the crosshead 131 moves forward or backward under the hydraulic pressure of the hydraulic system 140, the locking slider 180 surrounding the pin 125 moves relative to the pin 125 along the end portion 137E and diagonal portion 137S of the second guide groove 137.

[0197] The locking slider 180 has the same structure as the sliding shoe 150 described in the first embodiment, and includes an upper locking slider 180 and a lower locking slider 180, wherein a pin 125 is inserted between the upper locking slider 180 and the lower locking slider 180. Thus, a groove 181I, which contacts the outer circumferential surface of the pin 125, is formed on the surface facing the upper locking slider 180 and the lower locking slider 180, allowing the pin 125 to be inserted between the upper locking slider 180 and the lower locking slider 180. A helical spring 183 supporting the upper locking slider 180 and the lower locking slider 180 is positioned on both sides of the groove 181I.

[0198] Additionally, the matching groove 181E of the matching protrusion 181 is formed on the outer surface of the upper locking slider 180, and on the outer surface of the lower locking slider 180 facing the inner surface of the second guide groove 137.

[0199] The locking slider 180, configured as described above, moves along the second guide groove 137 together with the movement of the pin 125. At this time, the outer surfaces of the upper and lower locking sliders 180 are positioned to face the inner surfaces of the second guide groove 137 in the diagonal portion 137S and end portion 137E. As the locking slider 180 passes the end portion 137E, the diagonal portion 137S, and the protrusion 181, the coil spring 183 extends and contracts as the width becomes narrower or wider, thereby changing the slope of the upper and lower locking sliders 180.

[0200] In other words, when the width of the locking slider 180 narrows as the locking slider 180 moves along the second guide groove 137 through the structure of the second guide groove 137 and the protrusion 181, the coil spring 183 located on the narrowing side in the front or rear of the pin 125 contracts, and the locking slider 180 moves from the end portion 137E to the diagonal portion 137S, or from the diagonal portion 137S to the end portion 137E, while compensating for the narrowing of the width.

[0201] Furthermore, in the structure in which the locking slider 180 moves in response to a change in the width of the second guide groove 137, since the width between the protrusions 181 is narrower than the width of the second guide groove 137 in the same manner, even when located at the portion forming the end 137E of the protrusion 181, the coil spring 183 contracts to pass through the protrusion 181, and the protrusion 181 and the matching groove 181E match each other to be locked.

[0202] In this state, when the crosshead 131 moves via the operation of the hydraulic system, the pin 125 moves along the guide groove 133, and the locking slider 180 also moves along the second guide groove 137 following the pin 125. When the locking slider 180, which mates with the protrusion 181, moves, the protrusion 181 separates from the mating groove 181E and unlocks.

[0203] In this way, compared with the locking device of the first embodiment, the locking device according to the fourth embodiment can increase the reliability of locking through the matching relationship between the protrusion 181 and the matching groove 181E and the surface contact.

[0204] [First Embodiment of a Hydraulic System]

[0205] Typically, in order to control the stroke of a hydraulic system, hydraulic ports are installed at the front and rear ends of the cylinder, and hydraulic oil flows into or out of the front or rear of the cylinder through the hydraulic ports, causing the piston to move and the stroke to be controlled.

[0206] The aforementioned controllable pitch actuator is configured to move the piston, while multiple hydraulic lines formed inside the rod are introduced or discharged relative to the piston to the front or rear of the cylinder to move the piston in the forward or backward direction. On the other hand, the hydraulic system, described below, is configured such that a helical spring for pressing the piston forward or backward is built into the cylinder, thereby replacing hydraulic pressure with elastic force.

[0207] In the attached diagram, Figure 26 This is a cross-sectional view showing the state of the piston moving backward during operation of the hydraulic system of a controllable pitch thruster according to an embodiment of the present disclosure. Figure 27 It is a cross-sectional view showing the state in which the piston moves forward by the elastic force of the coil spring when the hydraulic pressure is released. Figure 28 This is a conceptual diagram comparing a hydraulic circuit having a server hydraulic cylinder body according to an embodiment of the present disclosure with a conventional hydraulic circuit. Figure 29 It shows Figure 26 A conceptual diagram of a modified example of a hydraulic system shown.

[0208] like Figure 26 As shown, piston 141 is located in cylinder 143 of hydraulic system 140 connected to the rear end of hub 130, and rod 141R extending from piston 141 is connected to crosshead 131 by extending to the outside of cylinder 143.

[0209] When the interior of the cylinder 143 is divided based on the piston 141, the space formed in front of the piston 141 is referred to below as the "front chamber 149F", and the space formed behind the piston 141 is referred to as the "rear chamber 149B". Here, a compression coil spring 185 is located in the rear chamber 149B, and the coil spring 185 presses the piston 141, causing the piston 141 to move in the direction of the stroke extension of the hydraulic system 140, i.e., toward the arc shape.

[0210] Furthermore, the orifice 145O of ​​the hydraulic line 145 formed within the rod 141R is formed in front of the piston 141. Therefore, hydraulic oil supplied through the hydraulic line 145 fills the front chamber 149F to generate hydraulic pressure, causing the piston 141 to move rearward. In this way, when the piston 141 moves rearward under hydraulic pressure, the helical spring 185 located in the rear chamber 149B is pushed and contracts by the piston 141.

[0211] Simultaneously, when the supply of hydraulic oil through hydraulic line 145 is interrupted, hydraulic line 145... Figure 28 The control valve 187 shown opens, controlling the supply of hydraulic oil, and the hydraulic pressure applied to piston 141 is released, causing piston 141 to move forward by the elastic force of the compression coil spring 185. As piston 141 moves forward in this manner, the hydraulic oil filling the front chamber 149F is discharged through hydraulic line 145.

[0212] As described above, hydraulic oil is supplied to the rear chamber 149B via hydraulic line 145 extending to it. This shortens the stroke of hydraulic system 140, causing the crosshead 131 to move rearward and rotate the blade 120 counterclockwise. Conversely, when hydraulic line 145 is opened via control valve 187, the stroke of hydraulic system 140 is extended by the elastic force of helical spring 185, causing the crosshead 131 to move forward and rotate the blade 120 clockwise. In this way, the blade pitch can be changed by the hydraulic pressure of hydraulic system 140 and the elastic force of helical spring 185.

[0213] at the same time, Figure 29 yes Figures 26 to 28 The hydraulic system shown is a variant of the structure and is configured such that the helical spring 185 is located in the front chamber 149F and the hydraulic line 145 passes through the piston 141 to supply to the rear chamber 149B.

[0214] In this configuration, when hydraulic oil is supplied to the rear chamber 149B, the stroke of the hydraulic system 140 extends, and the blade 120 rotates clockwise while the crosshead 131 moves forward. Furthermore, when the hydraulic line 145 is opened via the control valve 187, the stroke of the hydraulic system 140 contracts due to the elastic force of the coil spring 185, and thus, the blade 120 rotates counterclockwise while the crosshead 131 moves backward.

[0215] at the same time, Figure 28 (A) illustrates a hydraulic circuit for expanding and contracting the stroke of a hydraulic system using hydraulic oil, and Figure 28 (B) shows a hydraulic circuit for expanding and contracting the hydraulic system during strokes via hydraulic oil and a helical spring.

[0216] like Figure 28 As shown in (A), hydraulic lines 145 should be connected to the front chamber 149F and the rear chamber 149B respectively, so that the hydraulic system 140 can expand and contract during its stroke via hydraulic oil, thus complicating the configuration of the hydraulic system. On the other hand, in a configuration where the hydraulic system 140 expands and contracts during its stroke via hydraulic oil and a coil spring 185, as... Figure 28 As shown in (B), the hydraulic line 145 is connected to either the front chamber 149F or the rear chamber 149B, and therefore, there is the advantage of simple configuration of the hydraulic system 140.

[0217] Because the configuration of the hydraulic system 140 installed in the hub 130 is simplified in this way, the size of the hub 130 can be reduced to represent high efficiency with a propulsion efficiency close to that of a fixed-pitch propeller.

[0218] [Second Embodiment of the Hydraulic System]

[0219] As described above, the controllable pitch propeller according to this disclosure is variable in two pitches.

[0220] In the case of conventional controllable pitch propellers, the pitch variation range is wide, and a hydraulic system capable of proportional control should be provided, since the pitch is typically controlled in five stages. On the other hand, when only two pitches are changed, as in this disclosure, the hydraulic system can be controlled by switching valves.

[0221] In the attached diagram, Figure 30 This is a conceptual diagram illustrating a hydraulic system with a switching valve according to an embodiment of the present disclosure. Figure 31 It shows that being in such a state Figure 26 The diagram shows a conceptual representation of a hydraulic system with a switching valve, in which a helical spring is mounted inside a cylinder.

[0222] like Figure 30As shown, two hydraulic lines 145A and 145B are connected to the cylinder 143 of the hydraulic system 140, which is mounted at the rear end of the wheel hub 130. The first hydraulic line 145A branches off and connects to a first switching valve 187A and a second switching valve 187B, and the second hydraulic line 145B also branches off and connects to both the first and second switching valves 187A and 187B. Here, the second on / off valve 187B corresponds to the emergency control valve.

[0223] In addition, the hydraulic oil supply line 223 extending from the oil pump 221 and the discharge line 225 extending from the oil tank 220 are respectively connected to the first switching valve 187A and the second switching valve 187B.

[0224] Therefore, the hydraulic oil supplied by the operation of the oil pump 221 is typically supplied to the cylinder 143 through the first switching valve 187A, which serves as the operation control valve. The hydraulic oil flowing out of the cylinder 143 is discharged into the oil tank 220 through the first switching valve 187A.

[0225] When hydraulic oil flows into or out of cylinder 143 in this manner through the operation of the first switching valve 187A or the second switching valve 187B, two-step control of the stroke extension or contraction of hydraulic system 140 is performed.

[0226] When the stroke of the hydraulic system 140 extends, the pin 125 is located at the top dead center 133H of the guide groove 133, and when the stroke retracts, the pin 125 is located at the bottom dead center 133L of the guide groove 133, thereby controlling the blade pitch to 2 pitch.

[0227] at the same time, Figure 31 The circuit diagram of the hydraulic system shown is configured such that when the hydraulic line 145 passes through the helical spring 185 (in... Figure 26 and Figure 27 When the piston 141 is installed inside the cylinder 143 and opened, it moves by the elastic force of the coil spring 185, as shown in the image. Figure 26 As shown in the diagram. In the same case, the first switching valve 187A, the second switching valve 187B, the oil pump 221, the oil tank 220, the hydraulic oil supply line 223, and the drain line 225, as described above, are installed in the same manner in a hydraulic line 145 extending to the cylinder 143.

[0228] In this configuration, when hydraulic oil is supplied through hydraulic line 145, piston 141 moves in the direction that compresses coil spring 185 as it flows into cylinder 143. Consequently, the stroke of hydraulic system 140 extends or contracts, and when hydraulic line 145 opens, the compressed coil spring 185 extends. Therefore, piston 141 moves in the direction that provides elastic force to coil spring 185, and hydraulic oil in cylinder 143 flows toward oil tank 220 through the open hydraulic line 145.

[0229] Figure 31 The hydraulic system 140 of the controllable pitch propeller 100 shown is also located at the upper dead center 133H of the guide groove 133 during the stroke extension, and the pin 125 is located at the lower dead center 133L of the guide groove 133 during the stroke retraction, thereby controlling the blade pitch to 2 pitches.

[0230] Meanwhile, as a switching valve, it can be configured as a solenoid valve, or alternatively, a valve capable of two-step control can be used, wherein the hydraulic line is opened or closed by the valve.

[0231] [Description of the reference mark]

[0232] 1: Propulsion Shaft

[0233] 100: Controllable Pitch Propeller

[0234] 120: Paddle

[0235] 121: Blade Handle

[0236] 123: Propeller Carrier

[0237] 124: Sales

[0238] 130: Wheel hub

[0239] 131: Crosshead

[0240] 133: Guide groove

[0241] 133H: Top dead center

[0242] 133L: Bottom dead center

[0243] 135: End slot

[0244] 137: Second guide groove

[0245] 137S: Diagonal portion

[0246] 137E: End portion

[0247] 139: Locking hole

[0248] 140: Hydraulic system

[0249] 141: Piston

[0250] 141R: Rod

[0251] 143: Cylinder block

[0252] 145: Hydraulic lines

[0253] 145A: First hydraulic line

[0254] 145B: Second hydraulic line

[0255] 147F: Front stop

[0256] 147B: Rear stop

[0257] 150: Sliding Boots

[0258] 150M: Upward sliding boot

[0259] 150L: Sliding Boots

[0260] 153: Coil Spring

[0261] 160: Slider

[0262] 161: Opening

[0263] 163: Long slot

[0264] 165: Guide rail

[0265] 165S: Inclined section

[0266] 170: Plug

[0267] 170S: Inclined surface

[0268] 171: Coil Spring

[0269] 180: Lock slider

[0270] 180H: Upper locking slider

[0271] 180L: Lower locking slider

[0272] 181: Protrusion

[0273] 183, 185: Coil springs

[0274] 187: Control valve

[0275] 187A187B: Switch valve

[0276] 190: Fuel Dispenser

[0277] 191: Hydraulic locking unit

[0278] 192A / 192B: Ports

[0279] 193A193B: Room

[0280] 194A194B: Locking ring

[0281] 195A195B: Slot

[0282] 196A196B: Flow path

[0283] 210: Sliding shaft

[0284] 211: Hollow Shaft

[0285] 213: Slide Lock

[0286] 215: Support spring

[0287] 217: Spring retainer

[0288] 220: Fuel tank

[0289] 221: Oil pump

[0290] 223: Supply pipeline

[0291] 225: Discharge pipeline

Claims

1. A controllable pitch propeller for low-speed vessels, the controllable pitch propeller comprising: A hub, which is mounted on the ship's propulsion shaft; A crosshead, said crosshead being at least partially received in the wheel hub; A blade, the blade being mounted around the hub and coupled to the crosshead, the blade having a variable pitch; and A blade carrier, which is mounted onto the blade. The crosshead is capable of moving along the longitudinal direction of the wheel hub. In this configuration, a pin formed in the propeller carrier is inserted into a guide groove, the guide groove being formed on each side of the crosshead, such that when the crosshead moves along the longitudinal direction of the hub, the pin moves along the guide groove. The guide groove extends diagonally relative to the centerline of the propulsion shaft, such that the movement of the pin along the guide groove causes the blade carrier to rotate, thereby changing the pitch of the blade. The crosshead has a cross shape, such that the H / D ratio of the diameter H of the hub to the diameter D of the thruster is 0.170 to 0.

2.

2. The controllable pitch propeller according to claim 1, wherein, When the tanker is the low-speed vessel, the H / D ratio is 0.170 to 0.

190.

3. The controllable pitch propeller according to claim 1, wherein, When the bulk carrier is the low-speed vessel, the H / D ratio is 0.185 to 0.20.

Images