Energy-saving hub cap of prism type

Abstract

The application discloses a prismatic type energy-saving hub cap which is arranged behind a propeller of a ship and comprises a circumferentially distributed side wall and a rear wall used for sealing an opening at the rear end of the side wall; the side wall and the rear wall enclose a containing cavity; the front end of the side wall is a circular end, and the rear wall is a polygon with rounded corners, the intersection of two adjacent sides of the polygon is a rounded corner structure; the number of sides of the polygon is the same as the number of blades of the propeller; and the side wall and the rear wall are integrally formed. The application can obtain energy-saving benefits of 0.5-1%, and has the advantages of simple structure, easy design and manufacture.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ship technology, in particular to a prismatic energy-saving hub cap. BACKGROUND

[0002] Among all the existing civil operation ships, propeller is the most widely used propulsion form. Under the premise of propeller as the propeller, from the water power characteristics, the energy-saving principle of ship energy-saving device is divided into three categories. The first one is to change the flow in front of the propeller, so as to improve the efficiency of the whole propulsion system, such as pre-leaf and pre-duct. The second one is to change the design form of the propeller itself, such as optimizing the trim and designing the new blade section. The third one is to recover the rotational energy loss in the propeller tail vortex. The present design applies the third energy-saving principle. The existing energy-saving devices for recovering the energy loss in the propeller tail vortex mainly include twisted rudder, hub cap fin, rudder attached thrust fin, etc. However, the structure of many tail vortex recovery energy-saving devices is complex, the process requirement is high, the maintenance is not easy, the design difficulty is also great, and the existing energy-saving devices need to add new structures on the basis of the original structure, which also increases the corresponding cost.

[0003] In the prior art, the device for recovering the rotational energy of the propeller tail vortex mainly includes two types of appendages.

[0004] The first type of appendage is hub cap fin. The energy-saving appendage is fixed at the end of the propeller shaft and rotates with the propeller, which disturbs the water flow through the blades to achieve the purpose of energy saving. The energy-saving goal is mainly achieved by the blades. In the design process of the blades, various radial distributions need to be considered, such as camber, blade width, pitch, trim, skew, etc. The above distributions need to be reasonable in order to produce considerable energy-saving effect. If not reasonable enough, it may even have a negative effect, which has a great design difficulty. At the same time, according to the strength requirement, the thickness of the blade needs to be designed radially, and even complex finite element strength analysis needs to be carried out to ensure the safety of the actual ship application, which undoubtedly increases the design difficulty and design cycle. In addition, according to the test measurement results, the energy-saving effect of this energy-saving appendage is usually about 1%, and through the complex design process, it has not achieved high performance improvement, which can be said to have a low performance-price ratio.

[0005] The second type is the appendage structure attached to the rudder, such as rudder ball and twisted rudder. This type of structure is a fixed structure and does not need to rotate, so it does not need power drive. The main principle of energy saving is that the additional thrust received by the appendage when rotating in the propeller tail flow is greater than the resistance caused by its existence, or the resistance received by the rudder is reduced due to its existence. However, this type of rigidly fixed on the rudder blade,

[0006] In the test measurement, straight sailing is mostly adopted, and the energy saving effect can be captured, however, in the process of ship sailing, the rudder needs to be operated with a certain rudder angle to balance the propeller deflection effect and the turning sailing requirement, under such working conditions, the energy saving device is invalid, and moreover, the additional body resistance is increased compared with the state without the device. Therefore, the energy saving effect of the energy saving device needs to be discounted based on the test measurement. In addition, due to the characteristics of the internal skeleton and the external skin and the rigid connection form with the rudder, the structure design form considering the strength also becomes one of the limiting factors. The energy saving effect of the energy saving device is about 1%.

[0007] In addition, due to the design characteristics of the above two forms of complex tail vortex recovery energy saving devices, the design cycle is long, a large amount of calculation verification is needed, and a relatively ideal scheme is obtained. This is also one of the disadvantages of the prior art. SUMMARY

[0008] The technical problem to be solved by the present application is to overcome the above-mentioned defects existing in the prior art, and to provide a kind of energy saving hub cap of prismatic type.

[0009] The present application solves the above technical problems by the following technical solutions:

[0010] A kind of energy saving hub cap of prismatic type, it is arranged in the rear of the propeller on the ship;It includes the side wall distributed in a ring and the rear wall for enclosing the opening of the rear end of the side wall;The side wall and the rear wall enclose the containing cavity;The front end of the side wall is a circular end, and the rear wall is a polygon with rounded corners, the intersection of adjacent two sides of the polygon is a rounded corner structure;The number of sides of the polygon is the same as the number of propeller blades;The side wall and the rear wall are integrally formed.

[0011] The rear wall is a regular polygon with rounded corners.

[0012] The area of the rear wall is smaller than the area of the circular end of the front end of the side wall.

[0013] The outer surface of the side wall is a transition surface extending from the circular end of the front end of the side wall to the polygon structure of the rear wall.

[0014] The outer surface of the side wall is a convex transition surface.

[0015] The outer surface of the side wall is a concave transition surface.

[0016] The outer surface of the side wall is a flat transition surface.

[0017] The front end of the side wall is provided with a bolt slot;The bolt slot is distributed in a ring along the outer surface of the side wall.

[0018] A bolt hole is formed in the slot wall of the bolt slot.

[0019] When the frustum-type energy-saving hub cap is fixed behind the propeller, each vertex of the polygon of the rear wall has a phase corresponding relationship with the position of the propeller blade.

[0020] The beneficial effects of the present application are that the frustum-type energy-saving hub cap can achieve energy saving by weakening the energy loss of the hub vortex rotation, can obtain 0.5-1% energy saving benefit, and has simple structure, and is convenient for design and manufacture. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The figure is a perspective view of the preferred embodiment of the present application.

[0022] Figure 2 The figure is a front view of the preferred embodiment of the present application.

[0023] Figure 3 The figure is a rear view of the preferred embodiment of the present application. DETAILED DESCRIPTION

[0024] The following will take a preferred embodiment and combine the figures to more clearly and completely illustrate the present application.

[0025] As shown in Figure 1 , Figure 2 and Figure 3 , a frustum-type energy-saving hub cap is arranged behind the propeller of a ship; the hub cap comprises a circumferentially distributed side wall 10 and a rear wall 20 for sealing the opening of the rear end of the side wall; the side wall 10 and the rear wall 20 enclose a containing cavity. The containing cavity enclosed by the side wall and the rear wall is a cavity for accommodating a hydraulic nut.

[0026] The front end of the side wall 10 is a circular end, and the rear wall 20 is a polygon with rounded corners, and the intersection of adjacent two sides of the polygon is a rounded corner structure. The number of sides of the polygon is the same as the number of blades of the propeller.

[0027] The side wall 10 and the rear wall 20 are integrally formed.

[0028] In this embodiment, the rear wall 20 is a regular quadrilateral with rounded corners.

[0029] The area of the rear wall 20 is smaller than the area of the circular end of the front end of the side wall 10.

[0030] The outer surface of the side wall 10 is a transition surface extending from the circular end of the front end of the side wall to the polygon structure of the rear wall.

[0031] The transition surface can have various forms. In this embodiment, the outer surface of the side wall is a concave transition surface. In another embodiment, the outer surface of the side wall is a flat transition surface. In another embodiment, the outer surface of the side wall is a convex transition surface.

[0032] The front end of the side wall 10 is provided with a bolt groove 11; the bolt groove is distributed along the outer surface of the side wall. A bolt hole 12 is formed in the groove wall of the bolt groove 11.

[0033] When the frustum-type energy-saving hub cap is fixed behind the propeller, the vertices of the polygon of the rear wall have a phase correspondence relationship with the positions of the propeller blades.

[0034] The frustum-type energy-saving hub cap is cast and is an integrally formed structure.

[0035] The frustum-type energy-saving hub cap of the present application is fixed behind the propeller by bolts, is rigidly connected with the propeller and rotates synchronously. The hub cap can effectively protect the hydraulic nut located in the accommodating cavity and protect the entire shaft system end. At the same time, the shape of the hub cap discards the common circular truncated cone shape and uses a frustum shape, thereby achieving the energy-saving goal.

[0036] When the propeller operates, the water flow at the position near the propeller hub also presents a polygon distribution with the same number of blades. When this flow characteristic reaches the frustum-type energy-saving hub cap, the side wall of the frustum-type energy-saving hub cap has a force acting on the water flow when passing through the convex ridge or groove with a certain inclination angle with the axial direction. This force reduces the rotational motion in the hub vortex. Correspondingly, the water flow also has a force acting on the side wall, so that the hub cap recovers a part of the torque for driving the propeller to rotate. This recovery of the torque achieves the energy-saving goal.

[0037] The frustum-type energy-saving hub cap of the present application achieves energy saving by reducing the rotational energy loss of the hub vortex. According to numerical analysis, the frustum-type energy-saving hub cap of the present application can obtain an energy-saving benefit of 0.5-1%.

[0038] The frustum-type energy-saving hub cap of the present application has the characteristics of simple structure and does not have complex-shaped blades. Therefore, it does not need to consider the radial distribution form of the six elements of the blades, and even less needs to perform finite element strength checking. Therefore, the design difficulty is greatly reduced. This solves the disadvantages of complex structure and design process in the prior art.

[0039] The frustum-type energy-saving hub cap of the present application is fixed behind the propeller by bolts, is rigidly connected with the propeller and rotates synchronously. This connection form avoids the connection form of being fixed to the rudder blade, such as dodging ball and twisting rudder, so that it can continuously and stably work at the rear of the propeller and recover energy.

[0040] The energy-saving hub cap of the prismatic type can obtain higher energy-saving effect than other energy-saving devices of the same type, and solves four disadvantages of design difficulty, complex structure, inability to work in energy-saving state for a long time, and long design cycle, and is a more reasonable new energy-saving device.

[0041] Although the specific embodiments of the present application are described above, those skilled in the art should understand that this is only an example, and the protection scope of the present application is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present application, and such changes and modifications all fall within the protection scope of the present application.

Claims

1. A kind of energy-saving hub cap of prismatic type, it is located in the rear of the propeller on ship;Its characterized in that, It includes a circumferentially distributed side wall and a rear wall for sealing the rear end opening of the side wall; the side wall and the rear wall enclose a containing cavity; the front end of the side wall is a circular end, and the rear wall is a regular polygon with rounded corners, and the intersection of the two adjacent sides of the polygon is a rounded corner structure; the number of sides of the polygon is the same as the number of blades of the propeller; the side wall and the rear wall are integrally formed; the outer surface of the side wall is a transition surface extending from the circular end of the front end of the side wall to the polygon structure of the rear wall; the outer surface of the side wall is a convex transition surface; or, the outer surface of the side wall is a concave transition surface; when the propeller is running, the water flow at the position near the hub of the propeller also presents a polygon-like distribution with the same number of blades as the propeller, and when the flow characteristics reach the prism-like energy-saving hub cap, the side wall of the prism-like energy-saving hub cap through the convex ridge or the concave groove with a certain inclination angle to the axial direction, the side wall has a force on the water flow, and the water flow also has a force on the side wall, so that the hub cap recovers a part of the torque to drive the propeller to rotate.

2. The pseudo-prism energy saving hubcap of claim 1, wherein, The area of the rear wall is smaller than the area of the circular end of the front end of the side wall.

3. The pseudo-prism energy saving hubcap of claim 1, wherein, The front end of the side wall is provided with a bolt groove; the bolt groove is circumferentially distributed along the outer surface of the side wall.

4. The pseudo-prism energy saving hubcap of claim 3, wherein, A bolt hole is formed in the groove wall of the bolt groove.

5. The pseudo-prism energy saving hubcap of claim 1, wherein, When the prism-like energy-saving hub cap is fixed to the rear of the propeller, the vertices of the polygon of the rear wall have a phase corresponding relationship with the positions of the blades of the propeller.

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