CN115489704A

CN115489704A - Pyramid-like energy-saving hub cap

Info

Publication number: CN115489704A
Application number: CN202211292632.0A
Authority: CN
Inventors: 刘洋浩; 黄少锋; 孙海素; 杨博; 陈康
Original assignee: Shanghai Sidarui Ship Sea Engineering Service Co ltd
Current assignee: Shanghai Sidarui Ship Sea Engineering Service Co ltd
Priority date: 2022-10-21
Filing date: 2022-10-21
Publication date: 2022-12-20

Abstract

The invention discloses a prismoid-like energy-saving hub cap which is arranged behind a propeller on a ship; the device comprises side walls which are distributed annularly and a rear wall which is used for sealing an opening at the rear end of each side wall; the side wall and the rear wall enclose an accommodating cavity; the front end of the side wall is a circular end part, the rear wall is a polygon with rounded corners, and the intersection of two adjacent sides of the polygon is a rounded corner structure; the number of the sides of the polygon is the same as the number of the blades of the propeller; the side wall and the rear wall are integrally formed. The invention can obtain 0.5-1% of energy-saving benefit; the structure is simple, and the design and the manufacture are convenient.

Description

Pyramid-like energy-saving hub cap

Technical Field

The invention relates to the technical field of ships, in particular to a frustum pyramid type energy-saving hub cap.

Background

In all the civil operation ships, the propeller is the most widely applied propulsion form. On the premise of taking the propeller as a propeller, the energy-saving principle of the ship energy-saving device is divided into three categories from the hydrodynamic characteristics. Firstly, the forward flow of the propeller is changed, so that the efficiency of the whole propulsion system is improved, such as a front propeller guide vane, a front propeller guide pipe and the like; secondly, the design forms of the propeller, such as trim optimization, a new blade section design form and the like, are changed; and thirdly, recovering the rotation energy loss in the propeller wake vortex. The design applies the third energy-saving principle. The existing energy-saving device for recovering the energy loss of the wake vortex mainly comprises a twisted rudder, a hub cap fin, a rudder with a thrust fin and the like. However, the structures of the numerous wake vortex recovery energy-saving devices are complex, the process requirement is high, the maintenance is difficult, the design difficulty is high, and meanwhile, the existing energy-saving devices are added with new structures on the basis of the original structures, so that the corresponding cost is also increased.

In the prior art, devices for recovering the rotation energy of the propeller wake vortex are mainly divided into two attached body forms.

The first kind of attached body is hub cap fin, and the energy-saving attached body is fixed at the tail end of a propeller shaft, rotates along with the propeller, and disturbs water flow through blades on the energy-saving attached body to achieve the purpose of saving energy. The energy-saving target is mainly realized by the upper blades, various radial distributions, such as camber, blade width, pitch, trim, lateral inclination and the like, need to be considered in the blade design process, and the considerable energy-saving effect can be generated only by reasonable distribution, and if the distribution is not reasonable enough, even a negative effect can be generated, the design difficulty is high. Simultaneously, according to the intensity requirement, the thickness radial distribution of blade also needs to carry out reasonable design, need carry out complicated finite element intensity analysis even in order to ensure its safety when ship uses, and this has also increaseed the design degree of difficulty and design cycle undoubtedly. In addition, according to the test measurement result, the energy-saving effect of the energy-saving appendage is usually about 1%, and a very high performance improvement is not achieved through a complicated design process, so that the energy-saving appendage has a low cost performance.

The second is an appendage structure attached to the rudder, such as a rudder ball, twisted rudder, etc. The structure is a fixed structure and does not need to rotate, so that power driving is not needed, the main principle of energy saving is that the additional thrust borne by the appendage when the appendage rotates in the wake of the propeller is larger than the resistance caused by the appendage, or the resistance received by the rudder is reduced due to the appendage, but the appendage is added or the shape is changed to adapt to the rotating wake of the propeller. However such are rigidly fixed to the rudder blade,

the energy-saving device mainly adopts direct sailing during test measurement, can capture the energy-saving effect, and has the advantages that in the real ship sailing process, the rudder needs to be steered at a certain rudder angle to run for balancing the deflection effect of the propeller and the sailing requirements such as steering, and under the working conditions, the energy-saving device fails, and the additional body resistance is increased on the basis of failure in a less additional installation state. Therefore, the energy-saving effect of the energy-saving device is discounted on the basis of test measurement by comprehensively considering the energy-saving device. In addition, because the structure of the rudder is the characteristic of the external skin of the internal skeleton and the rigid connection form of the rudder, the structural design form which is compatible with the strength also becomes one of the limiting factors. The energy saving effect of such an energy saving device is about 1%.

In addition, due to the design characteristics of the two types of complicated wake vortex recovery energy-saving devices, the design period is long, and a large amount of calculation verification is needed, so that a relatively ideal scheme is obtained. This is also one of the drawbacks of the prior art.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a frustum pyramid type energy-saving hub cap.

The invention solves the technical problems through the following technical scheme:

a prismoid-like energy-saving hub cap is arranged behind a propeller on a ship; the device comprises side walls which are distributed annularly and a rear wall which is used for sealing an opening at the rear end of each side wall; the side wall and the rear wall enclose an accommodating cavity; the front end of the side wall is a circular end part, the rear wall is a polygon with rounded corners, and the intersection of two adjacent sides of the polygon is a rounded corner structure; the number of the sides of the polygon is the same as the number of the blades of the propeller; the side wall and the rear wall are integrally formed.

The rear wall is a regular polygon with rounded corners.

The area of the rear wall is smaller than the area of the rounded end of the front end of the side wall.

The outer surface of the side wall is a transition surface extending from the rounded end of the front end of the side wall to the polygonal configuration of the rear wall.

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

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

The outer surface of the side wall is a straight transition surface.

The front end of the side wall is provided with a bolt groove; the bolt grooves are circumferentially distributed along the outer surface of the side wall.

And bolt holes are formed in the wall of the bolt groove.

When the frustum-shaped energy-saving hub cap is fixedly connected to the rear of the propeller, each vertex of the polygon of the rear wall has a phase corresponding relation with the position of the propeller blade.

The invention has the beneficial effects that: the prismoid-like energy-saving hub cap realizes energy saving by weakening the rotation energy loss of the hub vortex, and can obtain 0.5-1% of energy-saving benefit; the structure is simple, and the design and the manufacture are convenient. The frustum pyramid type energy-saving hub cap can obtain higher energy-saving effect than other energy-saving devices of the same type, simultaneously solves the four defects of difficult design, complex structure, incapability of working in an energy-saving state for a long time, longer design period and the like, and is a more reasonable novel energy-saving device.

Drawings

Fig. 1 is a perspective view of a preferred embodiment of the present invention.

Fig. 2 is a front view of the preferred embodiment of the present invention.

Fig. 3 is a rear view of the preferred embodiment of the present invention.

Detailed Description

The present invention will be more clearly and completely described in the following description of preferred embodiments, taken in conjunction with the accompanying drawings.

As shown in fig. 1, 2 and 3, a frustum pyramid-shaped energy-saving hub cap is arranged behind a propeller on a ship; the device comprises side walls 10 distributed annularly and a rear wall 20 used for sealing the rear end opening of the side walls; the side wall 10 and the rear wall 20 enclose a receiving cavity. The accommodating cavity enclosed by the side wall and the rear wall is a cavity for accommodating the hydraulic nut.

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 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 walls 10 and the rear wall 20 are integrally formed.

In the present embodiment, the rear wall 20 is a regular quadrangle having rounded corners.

The area of the rear wall 20 is smaller than the area of the rounded end of the front end of the side wall 10.

The outer surface of the side wall 10 is a transition surface extending from the rounded end of the front end of the side wall to the polygonal configuration of the rear wall.

The transition surface may take a variety of forms. In this embodiment, the outer surface of the sidewall is a concave transition surface. In another embodiment, the outer surface of the sidewall is a straight transition surface. In other embodiments, the outer surface of the sidewall is a convex transition surface.

The front end of the side wall 10 is provided with a bolt groove 11; the bolt grooves are circumferentially distributed along the outer surface of the side wall. The wall of the bolt slot 11 is provided with a bolt hole 12.

The prismatic table energy-saving hub cap is formed by casting and is an integrally formed structure.

The frustum-like energy-saving hub cap is fixed behind the propeller through bolts, is rigidly connected with the propeller and synchronously rotates, and can effectively protect the hydraulic nuts in the accommodating cavities and protect the tail end of the whole shafting. Meanwhile, the hub cap has the appearance of a frustum instead of a common circular truncated cone, so that the aim of saving energy is fulfilled.

When the propeller runs, the water flow form at the position near the propeller hub also presents a polygon-like distribution with the same number of blades, when the flow characteristic reaches the frustum-like energy-saving hub cap, when the ridge or the groove of the side wall of the frustum-like energy-saving hub cap, which forms a certain inclination angle with the axial direction, the side wall acts on the water flow with force, the force reduces the rotary motion in the hub vortex, correspondingly, the water flow also acts on the side wall, so that the hub cap recovers a part of torque to drive the propeller to rotate, and the recovery of the part of torque realizes the aim of energy saving.

The frustum-shaped energy-saving hub cap realizes energy saving by weakening the rotation energy loss of the hub vortex. Through numerical analysis, the prismoid-like energy-saving hub cap can obtain 0.5-1% of energy-saving benefit.

The frustum pyramid-like energy-saving hub cap has the characteristic of simple structure, and does not have blades with complex shapes, so that the radial distribution form of six elements of the blades does not need to be considered, and the design difficulty is greatly reduced because finite element strength check is not required. The defect that the structural form and the design flow are complex in the prior art is overcome.

The frustum-like energy-saving hub cap is fixed behind the propeller through bolts, is rigidly connected with the propeller and synchronously rotates. The connection form avoids the connection form of fixing the hiding ball, the twisted rudder and the like on the rudder blade, thereby ensuring that the rudder blade can continuously and stably work right behind the propeller to recover energy.

The frustum pyramid type energy-saving hub cap can obtain higher energy-saving effect than other energy-saving devices of the same type, simultaneously solves the four defects of difficult design, complex structure, incapability of working in an energy-saving state for a long time, longer design period and the like, and is a more reasonable novel energy-saving device.

While specific embodiments of the invention have been described above, it will be understood by those skilled in the art that this is by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.

Claims

1. A prismoid-like energy-saving hub cap is arranged behind a propeller on a ship; the sealing device is characterized by comprising side walls distributed annularly and a rear wall used for sealing an opening at the rear end of each side wall; the side wall and the rear wall enclose an accommodating cavity; the front end of the side wall is a circular end part, the rear wall is a polygon with rounded corners, and the intersection of two adjacent sides of the polygon is a rounded corner structure; the number of the sides of the polygon is the same as the number of the blades of the propeller; the side walls and the rear wall are integrally formed.

2. The energy saving cap of claim 1, wherein the rear wall is a regular polygon with rounded corners.

3. The energy saving cap of claim 1, wherein the area of the rear wall is smaller than the area of the rounded end of the front end of the side wall.

4. The energy saving cap of claim 1, wherein the outer surface of the side wall is a transition surface extending from the rounded end of the front end of the side wall to the polygonal configuration of the rear wall.

5. The energy-conserving hub cap of claim 4, wherein the outer surface of the sidewall is a convex transition surface.

6. The energy saving cap of claim 4, wherein the outer surface of the sidewall is a concave transition surface.

7. The energy saving cap of claim 4, wherein the outer surface of the sidewall is a straight transition surface.

8. The frustum-shaped energy-saving hub cap as claimed in claim 1, wherein the front end of the side wall is provided with a bolt groove; the bolt grooves are circumferentially distributed along the outer surface of the side wall.

9. The energy-saving boss cap of claim 8, wherein the slot wall of the bolt slot has a bolt hole.

10. The energy-saving hub cap like a truncated pyramid of claim 1, wherein when the energy-saving hub cap like a truncated pyramid 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 blades.