Energy-saving device for pod propeller

Abstract

The utility model relates to an energy-saving device for a pod propulsor, which comprises a hub cap fin, a hub cap, a propeller hub, a propeller and a pod propulsor underwater structure, the front end of the propeller hub of the propeller is fixedly connected with the hub cap and the hub cap fin, and the hub cap and the hub cap fin can coaxially rotate along with the propeller; the radius of the hub cap fin is 0.25 times that of the propeller; the geometric pitch angle of the root of the propeller blade is epsilon, and the pitch angle alpha-epsilon of the fin blade of the hub cap fin is approximately equal to 0; the fin inclination angle gamma of the hub cap fin is formed by fixing the hub cap fin after the hub cap fin rotates by + / -30 degrees in the rotation direction. By adopting the energy-saving device for the pod thruster, the pressure drop at the rear part of the propeller hub is reduced, the resistance of the whole propeller is reduced, and the thrust of the propeller is increased; in addition, the hub cap fins can reduce the torque of the propeller and increase the thrust effect, and the energy-saving effect is achieved.

Description

Technical Field

[0001] The utility model relates to a ship pod propeller, in particular to an energy-saving device for the pod propeller. Background Art

[0002] Pod thruster is a new type of special thruster, which belongs to the high-tech field of ship electric propulsion. The design of the propulsion device adopts a pod-type structure, breaking through the propulsion design pattern of "diesel engine plus open transmission shaft system". The use of pod-type electric propulsion reduces the water resource pollution problem caused by fuel emissions. The pod thruster is a combination of a propulsion motor and a propeller installed in a davit housing, and this assembly (propulsion motor, davit housing, propeller) is "suspended" at the stern with a rotating base, and the hull only needs to provide the power required by the propulsion motor. The direction of travel of the ship can be changed by rotating the pod thruster 360°.

[0003] The propulsion method of the pod propulsion system is to use the reaction force generated by the propeller pushing the water backward as thrust. The water flow is affected by the propeller of the pod propulsion system to obtain an additional force in the opposite direction of the thrust. The force of the water mass accelerating backward offsets part of the propeller thrust, thereby reducing the propulsion efficiency of the pod propulsion system. The propeller of the pod propulsion system adopts a keyless fitting method, and the propeller assembly consists of a hub, blades and a hub cap. In order to maximize the propulsion efficiency and reduce the energy loss caused by the backward movement of the water mass, a single-blade fin is welded or bolted to the propulsion module shell at home and abroad to disrupt the stable flow field of the propeller rotating and accelerating backward, but this structure generally has the following problems:

[0004] 1. The hub cap fin is installed at the propulsion motor housing by welding or bolting. The propulsion motor has a large span, and the propulsion motors of pod thrusters of different power levels have different lengths, generally in the range of 3.25 to 5.8 meters. The energy-saving effect of the hub cap fin arranged at the motor housing is relatively low, and the propulsion efficiency is improved by about 0.8%;

[0005] 2. Since the hub cap fin is connected to the motor housing by welding or bolting, and steel materials are used, electrolytic corrosion is prone to occur at the welding or bolting joints in the seawater environment, causing thrust loss, reducing propulsion efficiency, and affecting navigation economy.

[0006] Therefore, it is necessary to design an energy-saving device for pod thrusters, which not only has a simple structure, is easy to process and manufacture, and has low cost, but can also improve the propulsion efficiency of the pod thrusters, reduce the vibration and noise of the propellers, and improve the overall performance of the ship. Summary of the invention

[0007] The utility model aims to provide an energy-saving device for a pod propeller, which improves the propulsion efficiency of the pod propeller, reduces the exciting force and noise of the pod propeller, and improves the comfort of the ship by installing a hub cap fin at the existing propeller hub cap.

[0008] To achieve the above-mentioned purpose, the technical solution of the utility model is: an energy-saving device for a pod propeller, comprising: a hub cap fin, a hub cap, a hub, a propeller, and an underwater structure of a pod propeller, the front end of the propeller hub is fixedly connected with a hub cap and a hub cap fin, and the hub cap and the hub cap fin can rotate coaxially with the propeller; the radius of the hub cap fin is 0.25 times the radius of the propeller; the geometric pitch angle of the root of the propeller blade is ε, and the pitch angle of the fin blade of the hub cap fin is α-ε≈0; the fin inclination angle γ of the hub cap fin is that the fin of the hub cap fin is fixed after rotating ±30° along the rotation direction.

[0009] Furthermore, the hub cap fin and the hub cap are an integrally cast structure, and the propeller hub and the propeller are an integrally cast structure.

[0010] Furthermore, a threaded hole is provided at the small end face of the hub for connecting the hub cap; the hub and the permanent magnet propulsion motor shaft are connected by oil pressure without a key.

[0011] Furthermore, the interior of the hub cap is a cavity, and the end surface of the hub cap is provided with bolt holes for connecting to the propeller hub, and the hub cap is connected to the propeller hub by installing bolts.

[0012] Furthermore, a circle of locking grooves is opened on the end face of the hub cap. After the hub cap is connected to the propeller hub through mounting bolts, stainless steel wire is used to mechanically prevent the mounting bolts from loosening to prevent the hub cap fin from flying off when the propeller rotates.

[0013] Furthermore, a sealing groove is provided on the end face of the hub cap for installing a sealing ring to prevent external seawater from entering the underwater structure of the pod thruster.

[0014] Furthermore, the upper end flange of the pod thruster underwater structure is connected to the slewing module by bolts, and the slewing module is rotatably connected to the pod thruster underwater structure via a slewing bearing.

[0015] Furthermore, the podded thruster underwater structure has a built-in permanent magnet propulsion motor, one end of which is connected to a propeller and a hub.

[0016] The beneficial effects of the utility model are:

[0017] 1. Due to the existence of the hub cap fin, the fluid is accelerated toward the trailing edge of the blade and the fin, causing the pressure on the pressure surface of the blade root to drop, and the pressure on the suction surface near its trailing edge also drops. This drop will continue along the entire blade profile until its leading edge; it rectifies the fluid near the hub cap fin and weakens the hub vortex, thereby increasing the pressure difference of the blade, that is, increasing the thrust.

[0018] 2. Since the fin blades have a certain angle of attack with the flow from the hub, lift and drag can be generated. The lift reduces the torque in the propeller's rotation direction.

[0019] 3. By utilizing the interference effect of the fin blades, although the hub cap fin itself does not generate thrust, the torque of the entire energy-saving device including the fin and propeller is reduced and the thrust is increased, thereby improving the characteristics of the propeller. The efficiency can be increased by 3% to 7%, which is more obvious for propellers with a relatively high pitch.

[0020] The energy-saving device for the pod propeller of the utility model can reduce the pressure drop at the rear of the hub, reduce the resistance of the entire propeller, and increase the propeller thrust; in addition, the hub cap fin can reduce the torque of the propeller, increase the thrust, achieve the effect of energy saving, and promote the development of energy-saving technology for pod propellers. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the installation of an energy-saving device for pod thrusters;

[0022] Figure 2 It is a three-dimensional diagram of the hub cap fin structure for the pod thruster;

[0023] Figure 3 It is a diagram of the arrangement of the hub cap fin structure for the pod thruster;

[0024] Figure 4 It is the structural arrangement diagram of the energy-saving device for the pod thruster;

[0025] In the figure, 1. hub cap fin, 2. hub cap, 3. propeller hub, 4. propeller, 5. pod thruster underwater structure, 6. locking groove, 7. mounting bolt, 8. sealing ring groove. DETAILED DESCRIPTION

[0026] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0027] like Figures 1 to 4 As shown, the utility model is an energy-saving device for a pod propeller, comprising: a hub cap fin 1, a hub cap 2, a hub 3, a propeller 4, a pod propeller underwater structure 5, a locking groove 6, a mounting bolt 7, and a sealing ring groove 8.

[0028] The upper end flange of the pod thruster underwater structure 5 is connected to the slewing module by bolts, and the slewing bearing in the slewing module rotates to realize the rotation of the pod thruster underwater structure 5; the pod thruster underwater structure 5 has a built-in permanent magnet propulsion motor, one end of which is connected to the propeller 4 and the hub 3, and the three-phase alternating current transmits electric energy to the permanent magnet propulsion motor through a power cable. Due to the presence of permanent magnets, the permanent magnet propulsion motor drives the propulsion motor shaft to rotate under the excitation of three-phase alternating current; as the frequency of the inverter changes, the propeller rotates at different speeds.

[0029] The hub cap 2 and the hub cap fin 1 are installed at the front end of the hub 3 of the propeller 4 and rotate coaxially with the propeller 4. When the pod propeller is sailing, the water flow on the surface of the hub cap 2 flows along the rotation direction of the propeller, forming a low pressure at the center of the hub cap 2, generating strong vortices and cavitation. The hub cap 2 is equipped with a hub cap fin 1 with a certain angle and shape. The radius of the hub cap fin 1 is 0.25 times the radius of the propeller; the geometric pitch angle of the root of the propeller 4 blades is ε, and the pitch angle of the fin blade of the hub cap fin 1 is α-ε≈0; the fin inclination angle γ of the hub cap fin 1 is that the fin of the hub cap fin is fixed after rotating ±30° along the rotation direction.

[0030] The interior of the hub cap 2 is a hollow cavity, and the end face of the hub cap 2 is provided with bolt holes for connecting to the propeller hub. After the end faces are connected, mechanical anti-loosening is adopted to prevent the hub cap fin from loosening; a sealing groove 8 is designed on the end face of the hub cap 2, in which a sealing ring can be installed to prevent seawater from entering the cavity and corroding the propeller 4 and the hub 3, making it difficult to disassemble.

[0031] The hub cap 2 is installed on the small end face of the hub of the propeller 4, which is easy to install; the fin blade line is linearly related to the propeller blade, the structure is simple and easy to process and manufacture, and the cost is low; it can be installed or replaced without docking.

[0032] The hub cap fin 1 and the hub cap 2 are integrally cast, and the propeller hub 3 and the propeller 4 are integrally cast; a threaded hole is arranged at the small end face of the propeller hub 3 for connecting the hub cap fin 1; a sealing ring groove 8 is opened at the end face of the hub cap 2, and a sealing ring needs to be installed in advance when installing the hub cap 2 to prevent external seawater from entering the underwater structure 5 of the pod propeller; a circle of locking grooves 6 is opened at the end face of the hub cap 2. After the hub cap 2 is connected to the propeller hub 3 through the mounting bolts 9, the mounting bolts 9 are mechanically prevented from loosening by stainless steel wire to prevent the hub cap fin from flying off when the propeller rotates. The propeller hub 3 and the motor shaft are connected by oil pressure keyless connection; the hub cap 2 is connected to the propeller hub 3 through the mounting bolts 9.

[0033] After power is turned on, the permanent magnet motor in the pod propulsion underwater structure 5 starts working, driving the propeller 4 and the hub cap fin to rotate. The pod propulsion underwater structure 5 is propelled in the water flow, and the load of the water flow acts on the hub cap 2, and the hub cap fin 1 rotates to form a stable vortex. The stable vortex acts on the propeller 4 to form a stable hydrodynamic force, reduce the vortex resistance of the propeller operation, improve the propulsion efficiency, and improve the economic efficiency of navigation. In this implementation case, only 4-blade hub cap fins are used for introduction, but this number should not be used as a limitation of the present invention.

Claims

1. An energy-saving device for a pod propulsion system, characterized in that: It includes a hub cap fin, a hub cap, a hub, a propeller, and a pod thruster underwater structure. The front end of the propeller hub is fixedly connected with a hub cap and a hub cap fin, and the hub cap and the hub cap fin can rotate coaxially with the propeller; the radius of the hub cap fin is 0.25 times the radius of the propeller; the geometric pitch angle of the propeller blade root is ε, and the pitch angle of the fin blade of the hub cap fin is α-ε≈0; the fin inclination angle γ of the hub cap fin is that the fin of the hub cap fin is fixed after rotating ±30° along the rotation direction.

2. The energy-saving device for a pod propulsion system according to claim 1, characterized in that: The hub cap fin and the hub cap are an integral casting structure, and the propeller hub and the propeller are an integral casting structure.

3. The energy-saving device for a pod propulsion system according to claim 1, characterized in that: A threaded hole is provided at the small end face of the hub for connecting the hub cap; the hub and the permanent magnet propulsion motor shaft are connected by oil pressure without key.

4. The energy-saving device for a pod propulsion system according to claim 1, characterized in that: The inside of the hub cap is a cavity, and the end surface of the hub cap is provided with bolt holes for connecting the propeller hub of the propeller. The hub cap is connected to the propeller hub by installing bolts.

5. The energy-saving device for a pod propulsion system according to claim 1, characterized in that: There is a circle of locking grooves on the end face of the hub cap. After the hub cap is connected to the propeller hub through mounting bolts, stainless steel wire is used to mechanically prevent the mounting bolts from loosening to prevent the hub cap and hub cap fin from flying off when the propeller rotates.

6. The energy-saving device for a pod propulsion system according to claim 1, characterized in that: The end face of the hub cap is provided with a sealing groove for installing a sealing ring to prevent external seawater from entering the underwater structure of the pod thruster.

7. The energy-saving device for a pod propulsion system according to claim 1, characterized in that: The upper end flange of the pod thruster underwater structure is connected to the slewing module through bolts, and the slewing module is rotatably connected to the pod thruster underwater structure through a slewing bearing.

8. The energy-saving device for a pod propulsion system according to claim 1, characterized in that: The podded propulsion underwater structure has a built-in permanent magnet propulsion motor, one end of which is connected to the propeller and hub.

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