CN211141346U

CN211141346U - Hoisting machinery for shipbuilding

Info

Publication number: CN211141346U
Application number: CN201920971188.2U
Authority: CN
Inventors: 王宝琳
Original assignee: China Merchants Heavy Industry Jiangsu Co Ltd
Current assignee: China Merchants Heavy Industry Jiangsu Co Ltd
Priority date: 2019-05-25
Filing date: 2019-06-26
Publication date: 2020-07-31
Anticipated expiration: 2029-06-26
Also published as: CN210393455U; CN210393452U

Abstract

The hoisting machinery for shipbuilding is characterized in that upper trolleys are respectively and independently arranged on two sides of a main beam of the hoisting machinery, each upper trolley respectively and independently passes through an upper rail arranged on the edge of the upper surface of the main beam of the hoisting machinery and a lower rail arranged on the lower edge of the side surface of the main beam of the hoisting machinery, and an inward or upward-inclined moment is provided through an inclined angle formed by the rails so as to prevent the upper trolleys from overturning. The dolly can be independently supported through the butt effect with orbital on foretell each, need not the physics between the dolly on each and connects, therefore, the utility model discloses a structure, its whole highly is less than current structure, can reduce the manufacturing cost in order to reduce the workshop of the roof height in hoisting machinery place workshop. The utility model discloses an go up the dolly structure and can drive alone respectively, therefore its flexibility is superior to prior art equally.

Description

Hoisting machinery for shipbuilding

Technical Field

The utility model relates to a shipbuilding equipment field particularly, relates to a hoisting machinery for shipbuilding.

Background

With the advent of the construction of luxury cruise ships, some shipyards have begun to build indoor docks for luxury cruise ship construction in pursuit of construction environment and project schedule. A double-beam shipbuilding gantry crane is required in an indoor dock. The hoisting height of the shipbuilding gantry crane needs to meet the requirement on the height of a constructed cruise ship. Meanwhile, since increasing the height of the indoor dock shop increases the construction cost thereof, it is necessary to impose a certain limit on the total height of the hoist.

The integral upper trolley needs to penetrate through the lower trolley under the requirement of the turnover process, so that the total height of the integral upper trolley is above the lower trolley. However, the crane for constructing the cruise ship cannot adopt the integral upper trolley scheme of the outdoor gantry crane due to the limitation of the above-mentioned indoor dock for constructing the cruise ship on the total height of the crane.

Furthermore, considering the large number of thin plate sections, profile sections and special sections in the construction process of the luxury cruise ship, the sections have higher requirements on the flexibility of the arrangement of the lifting hooks when the lifting process is established. Thus, the existing crane also has difficulty meeting this flexibility requirement.

SUMMERY OF THE UTILITY MODEL

The utility model discloses to prior art not enough, provide a hoisting machinery for shipbuilding, it has got rid of two connection structure who goes up between the dolly on the hoisting machinery for two go up the dolly can realize supporting through the independent connection effect with the girder respectively, with the height that reduces the dolly, reduce cost. The utility model discloses specifically adopt following technical scheme.

To achieve the above object, a hoisting machine for shipbuilding is provided, which includes: the upper trolley is arranged on two sides of a main beam of the hoisting machinery and comprises at least one pair of mutually independent trolleys; the rail is arranged on the surface edge of a main beam of the hoisting machine, has an inclined angle, is used for connecting the upper trolley and provides inward or upward inclined moment for the upper trolley connected with the rail so as to prevent the upper trolley from overturning; and the flexible hinge is abutted between the lower part of a main beam of the hoisting machine and the supporting leg of the hoisting machine and is used for offsetting or buffering an outward or downward inclined moment applied to the main beam by the upper trolley.

Optionally, in the hoisting machinery for shipbuilding, the main beam includes two beams parallel to each other; the rail on the surface of each main beam comprises an upper rail and a lower rail respectively, wherein the upper rail is arranged on the outer edge of the upper surface of the main beam, and the lower rail is arranged on the lower edge of the outer side surface of the main beam; each go up no physical structure connection between the dolly, each go up the dolly respectively independent be provided with walking wheel and anti-disengaging device, walking wheel and anti-disengaging device butt respectively go up track and lower track, make it maintains to go up the dolly the outside of girder.

Optionally, in the hoisting machinery for shipbuilding, the traveling wheels are disposed on the upper portion of the upper trolley, and the lower surfaces of the traveling wheels abut against the upper end surface of the upper rail, so as to bear the upper trolley and the hoisting weight of the upper trolley and drive the upper trolley to travel along the upper rail.

Optionally, in the hoisting machine for shipbuilding, the anti-dropping device includes an upper idler wheel disposed at a lower edge of the traveling wheel, and the upper idler wheel is installed in a direction perpendicular to the traveling wheel and abuts against an inner side of the upper rail, so as to provide an inward moment to the upper trolley to prevent the upper trolley from overturning.

Optionally, in the hoisting machinery for shipbuilding, a guard plate is fixed to the inner side of the travelling wheel, an ear plate bent inward is arranged at the lower end of the guard plate, the lower surface of the ear plate does not exceed the lower side edge of the travelling wheel, and a wheel shaft of the upper idler wheel passes through the ear plate to fix the upper idler wheel on the lower side of the inner edge of the travelling wheel.

Optionally, in the hoisting machine for shipbuilding, an inverted triangle support is connected between the upper portion and the lower portion of the upper trolley, the traveling wheel is fixed to one side, close to the edge of the main beam, of the upper end of the inverted triangle support, the lower idler wheel is fixed to one side, close to the edge of the main beam, of the lower end of the inverted triangle support, the lower idler wheel abuts against the outer side end face of the lower rail along the radial direction of the lower idler wheel, and the distance between the lower portion of the upper trolley and the outer side face of the main beam is maintained.

Optionally, in the hoisting machinery for shipbuilding, the cross sections of the upper rail and the lower rail are both i-shaped, and each of the upper rail and the lower rail includes two parallel platforms and a rail web connected between the two platforms; the lower surface of the lower side platform of the upper rail and the upper surface of the main beam are further provided with a gasket, the upper surface of the lower side platform is further abutted with a pressing block, the pressing block and the gasket are penetrated through by bolts to be fixedly connected to the upper surface of the main beam, and the lower side platform of the upper rail is pressed on the main beam in an inward inclined mode.

Optionally, in the hoisting machinery for shipbuilding, the support legs are flexible legs.

Optionally, in the hoisting machinery for shipbuilding, the flexible legs include two groups respectively disposed below the two main beams, each group of flexible legs includes at least two groups respectively disposed at two ends of the main beam, and the flexible legs are connected to each other in a door shape.

Advantageous effects

The utility model discloses a hoisting machinery has saved physical connection structure between the dolly on each that sets up on it, and the dolly can independent operation respectively on each. Each upper trolley is connected to the outer side of a main beam of hoisting machinery such as a double-beam shipbuilding gantry crane and the like through respective anti-falling devices and travelling wheels, so that the upper trolleys are driven, a moment for preventing the upper trolleys from overturning is provided, and the upper trolleys and the hoisting weights thereof are borne. Because go up no physical connection between the dolly, therefore, the utility model discloses a structure, its whole highly is less than current structure, can reduce the manufacturing cost in order to reduce the workshop of the roof height in hoisting machinery place workshop. The utility model discloses an go up the dolly structure and can drive alone respectively, therefore its flexibility is superior to prior art equally.

The utility model discloses well upper and lower track and/or lower track are provided with inclination, and this inclination can provide ascending moment of inside or slope to the last dolly that the girder is connected, in order to prevent go up the dolly and topple. Therefore, the utility model discloses can to each go up the independent direction and the support of providing of dolly, prevent go up the dolly and overturn.

Furthermore, because the utility model discloses an go up the dolly and adopt independent connection structure to be connected to the girder respectively, therefore can be according to the hoist and mount technology needs of special segmentation in atress and moment scope, adjust respectively with the position of dolly on the girder down to each. Owing to can realize solitary control to last dolly, the utility model discloses can adapt to luxurious mail steamer and carry on the in-process, more meticulous operation is applicable to the required gesture fine setting of going on the segmentation of hoist and mount of different mounted position. The utility model discloses the independent dolly arrangement of going up that adopts provides the possibility for this kind of fine setting.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, together with the embodiments of the invention for the purpose of explanation and not limitation of the invention. In the drawings:

FIG. 1 is a schematic view of the overall structure of an indoor double-beam shipbuilding gantry crane with an independent upper trolley, which is applied to the utility model;

FIG. 2 is a schematic view of the connection structure of the upper trolley in the double-beam shipbuilding gantry crane;

FIG. 3 is an enlarged view of a portion of the area I in FIG. 2;

FIG. 4 is an enlarged view of a portion of region II of FIG. 2;

FIG. 5 is a schematic view of the plan arrangement of the upper/lower trolleys in the gantry crane for twin-beam shipbuilding in FIG. 1;

fig. 6 is a schematic diagram of the structure of two main beams in the double-beam shipbuilding gantry crane.

In the drawings, 1 denotes a main beam; 2 denotes a second main beam; 3 represents a lower trolley; 4 represents an upper trolley; 5 denotes a second upper carriage; 6 denotes a second flexible hinge; 7 denotes a first flexible hinge; 8 denotes a flexible leg; 9 denotes an upper rail; 11 denotes an upper idler; 12 denotes a road wheel; 13 denotes a lower idler; and 14, a lower track.

Detailed Description

In order to make the purpose and technical solution of the embodiments of the present invention clearer, the following description will clearly and completely describe the technical solution of the embodiments of the present invention by combining the drawings of the embodiments of the present invention. It is to be understood that the embodiments described are only some of the embodiments of the present invention, and not all of them. All other embodiments, which can be obtained by a person skilled in the art without any inventive work based on the described embodiments of the present invention, belong to the protection scope of the present invention.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The meaning of "inside and outside" in the present invention means that, with respect to the hoisting machine itself, the direction pointing to the inside of the main beam or the middle position of the plurality of main beams is inside, otherwise outside; and not to the specific limitations of the device mechanism of the present invention.

The utility model discloses in the meaning of "left and right" indicate that the user is just to hoisting machinery itself, and the one end of hoisting machinery's girder is left under this visual angle, and the other end is the right side, and is not right the utility model discloses a specific injecing of device mechanism.

The term "connected" as used herein may mean either a direct connection between elements or an indirect connection between elements through other elements.

The utility model discloses in the meaning of "upper and lower" mean that the user is just to hoisting machinery itself, is promptly for last by the direction of the directional girder in ground, otherwise promptly for down, and not right the utility model discloses a device mechanism's specific limited.

The utility model provides a hoisting machinery for shipbuilding, it can respectively independent setting in 1 both sides of girder of hoisting machinery, still can confirm its concrete quantity and set up the position according to the hoist and mount demand. Each go up the dolly respectively independent be provided with:

the traveling wheels 12 are arranged on one side of the upper trolley close to the edge of the main beam 1 and used for driving the upper trolley to independently run along the track on the edge of the main beam 1;

the anti-falling device is abutted to the track at the edge of the main beam 1 to prevent the upper trolley from overturning.

The crane mechanism of the free-standing upper trolley can be, but is not limited to, a gantry crane, a beam crane, a bridge crane or a traveling crane. Taking the double-beam shipbuilding gantry crane shown in fig. 1 as an example, the utility model provides a trolley can be installed outside the girder.

In the double-beam shipbuilding gantry crane, the two beams 1 of the double-beam structure comprise two beams which are parallel to each other, generally, in order to realize the balance of stress, an upper rail 9 and a lower rail 14 are respectively arranged on the outer edge of the upper surface and the lower edge of the outer side surface of each beam 1, the travelling wheel 12 and the anti-drop device of the upper trolley are respectively abutted against the upper rail 9 and the lower rail 14, so that the upper trolley is maintained at the outer side of the beam 1, and the stress conditions of the two beams are kept basically symmetrical.

Connection structure between twin beams shipbuilding portal crane and the last dolly specifically can be designed to include under an implementation:

the upper trolley upper track 9 is fixedly arranged on the upper surface of the main beam along the length direction of the main beam, namely the surface of a wing plate of the main beam, and is close to the outer edge of the main beam;

the upper trolley travelling wheels 12 are arranged on one side, close to the main beam, of the upper part of the upper trolley, and the lower surfaces of the upper trolley travelling wheels 12 abut against the upper end surface of the upper trolley upper rail 9 and are used for bearing the upper trolley and the hoisting weight thereof and driving the upper trolley to travel along the upper trolley upper rail 9;

the upper trolley lower rail 14 is fixedly arranged on the outer side surface of the main beam along the length direction of the main beam, namely the web plate surface of the main beam, and is close to the lower side edge of the main beam;

and the anti-falling device is connected with the upper trolley and the main beam and is used for keeping the connection between the upper trolley and the main beam from overturning.

Therefore, the utility model discloses can install the dolly in independence more than two respectively on two girders of first girder 1 and second girder 2 of mutual parallel arrangement for mutual independence and must not connect into a whole through physical structure between the dolly in two. Thus, each upper trolley can be respectively balanced with the dead weight thereof and the hanging weight of the upper trolley by the anti-falling device and the walking wheels 12 which are connected with the upper trolley, and the main beam on which the upper trolley is arranged bears the torsion moment required by the stability maintenance of the upper trolley connected with the outer side of the main beam.

Specifically, in one embodiment, the above-described torque moment required to maintain the upper carriage stable can be achieved by the anti-slip device constituted by the upper idler 11 shown in fig. 3. The upper idler wheel 11 is arranged at the lower side edge of the travelling wheel 12, and the mounting direction of the upper idler wheel is perpendicular to the travelling wheel 12 so as to abut against the inner side of the upper rail 9, so that inward moment is provided for the upper trolley, and the upper trolley is prevented from overturning.

Further, referring to fig. 4, the above anti-falling device may further include a lower idler 13 disposed at a side of the lower portion of the upper cart close to the main beam, the lower idler 13 being abutted against an outer end surface of the lower rail 14 of the upper cart along a radial direction thereof, for maintaining a distance between the lower portion of the upper cart and the outer side surface of the main beam, and providing an outward or upward-inclined moment to the upper cart to prevent the upper cart from overturning.

Although the arrangement scheme of the anti-falling device of the independent upper trolley can generate certain torsional moment for respective

main beams

1 and 2 and needs to check and change the structural design of the gantry crane, the construction cost of an indoor dock can be greatly reduced due to the reduction of the overall height of the gantry crane.

Further, in the double-beam shipbuilding gantry crane, in order to realize the independent control of the upper trolley, the first upper trolley 4 and the second upper trolley 5 can be respectively connected to a traveling encoder and an electric control system. The walking encoder is used for converting the positions of the first upper trolley 4 and/or the second upper trolley 5 connected with the walking encoder relative to the first main beam 1 and/or the second main beam 2 into codes; the electric control system is used for controlling the driving of the upper trolley travelling wheels 12 connected with the first upper trolley 4 and/or the second upper trolley 5 according to the codes of the travelling encoders on the first upper trolley 4 and/or the second upper trolley 5 so as to keep the first upper trolley 4 and the second upper trolley 5 running synchronously.

The upper trolleys 4 and 5 can also be adjusted together with the lower trolley 3 under certain conditions according to the sectional hoisting process requirement and the stress distribution of the lifting hook so as to meet the hoisting requirements of different sections and special sections. When the ship is carried in a subsection mode, the positions of the upper trolley and the lower trolley can be finely adjusted in a limited mode, so that the alignment is convenient and accurate, and the subsection carrying efficiency is improved. Particularly, the independent upper trolleys 4 and 5 can be independently arranged on the

main beams

1 and 2 at two sides, the lower trolleys are arranged on the main beams at two sides through two tracks, the running of the upper trolleys and the running of the lower trolleys are not interfered with each other, and the height of the upper trolley mechanism and the lower trolley mechanism on the main beams can be ensured to meet the requirement of an indoor dock workshop on the height of a gantry crane.

Referring to fig. 5, the upper trolley connecting structure may be configured to arrange a plurality of upper trolleys on different

main beams

1 and 2 according to the hoisting process requirement. Because the upper trolley is independently arranged, a certain torsional moment is added to the

main beams

1 and 2. Therefore, referring to fig. 6, a first flexible hinge 7, a second flexible hinge 6 may also be arranged on the flexible leg 8. The flexible hinge is abutted between the lower part of a main beam of the hoisting machine and the support leg of the hoisting machine and used for offsetting or buffering the outward or downward inclined moment applied to the main beam by the upper trolley. The flexible legs are respectively arranged at two groups below the two main beams, each group of flexible legs comprises at least two flexible legs respectively arranged at two ends of the main beams, and the flexible legs are connected in a door shape.

More specifically, reference is made to the partial schematic diagrams shown in fig. 2, 3 and 4. In one implementation, the upper trolley track 9 may be inclined toward the inner side of the main beam to reduce the acting force of the upper backup wheel on the upper trolley track 9. According to the structure, a gasket is arranged between the lower end face of the upper trolley upper rail 9 and the upper surface of the main beam, the lower surface of the gasket is fixed to the outer edge of the main beam, an angle inclined towards the inner side of the main beam is arranged on the upper surface of the gasket, the height of the outer side of the gasket is higher than that of the inner side of the main beam, the lower end face of the upper trolley upper rail 9 is fixed to the upper surface of the gasket through bolts, and the upper trolley upper rail 9 is kept inclined towards the inner side of the main beam. At this time, a guard plate may be further fixed on the inner side or inner and outer sides of the traveling wheel 12, an inwardly bent ear plate is provided at the lower end of the guard plate, the lower surface of the ear plate is not more than the lower side edge of the traveling wheel 12, and a wheel shaft of the upper idler wheel 11 passes through the ear plate to fix the upper idler wheel 11 on the lower side of the inner edge of the traveling wheel 12. Thus, the upper idler 11 can abut against the inner upper portion of the upper rail 9 inclined inward, and a larger torsional moment can be achieved as needed, thereby further maintaining the stability of the upper carriage structure.

In one implementation mode, the upper part and the lower part of the upper trolley can be connected through an inverted triangle support shown in fig. 2, the upper trolley traveling wheels 12, the lower idler wheels 13 and/or the anti-falling devices are arranged on the same side of the inverted triangle support and used for providing moment for supporting the upper trolley not to overturn, and the other side of the inverted triangle support is used for supporting the hoisting weight of the upper trolley.

On the inverted triangle support, an upper idler wheel 11 on the lower side of the upper trolley travelling wheel 12 is further used as an anti-drop device. The upper idler wheel 11 is abutted against the inner side end face of the upper trolley upper track 9 along the radial direction of the upper idler wheel and is used for providing inward moment for the upper trolley so as to prevent the upper trolley from overturning.

That is, the inverted-triangular bracket is connected between the upper part and the lower part of the upper trolley, and the walking wheels 12 are fixed at one side of the upper end of the inverted-triangular bracket, which is close to the edge of the main beam 1, and provide walking driving force; the lower idler wheel 13 is fixed at one side of the lower end of the inverted triangle bracket close to the main beam and is abutted against the end face of the outer side of the lower rail 14 along the radial direction of the lower idler wheel; the upper idler wheels 11 abut against the inner side of the upper rail 9, resist the inclination of the trolley to the outer side of the main beam, and provide outward or upward-inclined moment for the upper trolley so as to prevent the upper trolley from overturning.

In the above structure, the cross section of the upper trolley upper rail 9 and/or the upper trolley lower rail 14 may be i-shaped, and the two sides of the lower portion of the i-shaped rail are respectively abutted by structures such as bolts and press blocks to fix the lower portion of the i-shaped rail on the surface of the main beam.

Specifically, the I-shaped structure comprises two parallel platforms and a rail web connected between the two platforms, the platform on one side of the I-shaped structure is installed on and fixed on the surface of the main beam, and the platform on the other side of the I-shaped structure is abutted against the upper trolley and provides inward or upward-inclined moment for the upper trolley.

In particular, for the upper rail 9, the upper platform of the i-shaped structure and the inner side wall of the side platform abut against the upper trolley at the same time: the upper side platform is used for bearing the upper trolley and the hoisting weight thereof to run along the upper track 9; the inner side wall is used for resisting the moment of outward overturning and overturning of the upper trolley and guiding the upper trolley to run along the upper track 9. A gasket is arranged between the lower end face of the I-shaped structure and the upper surface of the main beam, the lower surface of the gasket is laid and fixed along the outer edge of the main beam, the upper surface of the gasket is provided with an angle inclined towards the inner side of the main beam, the height of the outer side of the gasket is higher than that of the inner side of the main beam, the lower end face of the upper rail 9 is fixed on the upper surface of the gasket, and the upper rail 9 is kept inclined towards the inner side of the main beam.

In a more specific mode, the lower surface of the lower platform of the upper rail 9 abuts against the upper surface of the gasket, the upper surface of the lower platform also abuts against a pressing block, and the pressing block and the gasket are penetrated by bolts to be fixedly connected to the upper surface of the main beam so as to press the lower platform of the upper rail 9 on the main beam in an inward inclined mode.

For the lower rail 14, an outer platform in the i-shaped structure of the lower rail is abutted to the lower part of the upper trolley outwards, so that the distance between the lower part of the upper trolley and the outer side surface of the main beam is maintained. The outer surface of the inner platform in the I-shaped structure is also abutted with a pressing piece, and the pressing piece is penetrated through by a bolt to be fixedly connected to the outer side face of the main beam, so that the inner platform of the lower rail 14 is pressed on the outer side face of the main beam in an inward inclined mode.

From this, the utility model discloses to dolly structure height above the present shipbuilding portal crane girder high and designed the scheme of arranging of dolly on two independencies of indoor twin beams shipbuilding portal crane. The upper trolleys are independently arranged on the main beams at the two sides. The upper trolley is fixed and walks through an upper idler wheel 11, a lower idler wheel 13 and an upper trolley walking wheel 12. The trolley structure is hung on the girder on one side through the upper idler wheel, the walking wheel and the lower idler wheel, the upper idler wheel and the lower idler wheel provide torque for preventing the trolley from overturning, and the whole weight of the upper trolley and the hoisting weight is borne by the travelling wheel driving trolley. The utility model discloses an upper and lower dolly adopts independent arrangement, for handling opposite sex segmentation and special segmentation provide convenience, can realize the adjustment to upper and lower dolly position on the girder. When boats and ships segmentation is carried on the utility model discloses also can finely tune the precision in order to improve the segmentation counterpoint about the dolly, improve and carry on efficiency.

The above description is only for the embodiments of the present invention, and the description is specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several changes and modifications can be made, which all fall within the scope of the present invention.

Claims

1. A hoisting machine for shipbuilding, characterized by comprising:

the upper trolley is arranged on two sides of a main beam (1) of the hoisting machinery and comprises at least one pair of mutually independent trolleys;

the rail is arranged at the surface edge of a main beam (1) of the hoisting machine, has an inclined angle, is used for connecting the upper trolley and provides inward or upward inclined moment for the upper trolley connected with the rail so as to prevent the upper trolley from overturning;

the flexible hinge (6) is abutted between the lower part of the main beam (1) of the hoisting machine and the supporting leg of the hoisting machine and is used for offsetting or buffering the outward or downward inclined moment applied to the main beam (1) by the upper trolley.

2. Hoisting machine for shipbuilding according to claim 1, characterized in that said girder (1) comprises two parallel beams;

the track on the surface of each main beam (1) comprises an upper track (9) and a lower track (14), wherein the upper track (9) is arranged on the outer edge of the upper surface of the main beam, and the lower track (14) is arranged on the lower edge of the outer side surface of the main beam;

each go up no physical structure between the dolly and connect, each go up the dolly respectively independent be provided with walking wheel (12) and anticreep device, walking wheel (12) and anticreep device butt respectively go up track (9) and lower track (14), make it maintains to go up the dolly the outside of girder (1).

3. The shipbuilding hoisting machine according to claim 2, characterized in that the travelling wheels (12) are arranged at the upper part of the upper trolley, and the lower surface of the travelling wheels abuts against the upper end surface of the upper rail (9) and is used for carrying the upper trolley and the hoisting weight thereof and driving the upper trolley to travel along the upper rail (9).

4. The shipbuilding hoisting machine according to claim 2, wherein the anti-falling device includes an upper idler (11) provided at a lower side edge of the traveling wheel (12), the upper idler (11) being installed in a direction perpendicular to the traveling wheel (12) and abutting on an inner side of the upper rail (9) for providing an inward moment to the upper trolley to prevent the upper trolley from overturning.

5. The hoisting machine for shipbuilding according to claim 4, characterized in that a guard plate is fixed on the inner side of the travelling wheel (12), the lower end of the guard plate is provided with an ear plate which is bent inwards, the lower surface of the ear plate does not exceed the lower side edge of the travelling wheel (12), and the axle of the upper idler wheel (11) passes through the ear plate to fix the upper idler wheel (11) on the lower side of the inner edge of the travelling wheel (12).

6. The shipbuilding hoisting machine according to claim 5, characterized in that an inverted triangle support is connected between the upper portion and the lower portion of the upper trolley, the traveling wheels (12) are fixed to one side of the upper end of the inverted triangle support close to the edge of the main beam (1), a lower idler wheel (13) is further fixed to one side of the lower end of the inverted triangle support close to the main beam, and the lower idler wheel (13) abuts against the outer side end face of the lower rail (14) along the radial direction of the lower idler wheel to maintain the distance between the lower portion of the upper trolley and the outer side face of the main beam (1).

7. Marine crane according to claim 6, characterised in that the upper (9) and lower (14) rails are I-shaped in cross-section and comprise two platforms parallel to each other and a web connected between the two platforms;

a gasket is further arranged between the lower surface of the lower side platform of the upper rail (9) and the upper surface of the main beam (1), a pressing block is further abutted to the upper surface of the lower side platform, the pressing block and the gasket are penetrated through by bolts to be fixedly connected to the upper surface of the main beam, and the lower side platform of the upper rail (9) is pressed on the main beam in an inward inclined mode.

8. The shipbuilding hoisting machine of claim 7, wherein the support legs are flexible legs.

9. The hoisting machine for shipbuilding according to claim 8, wherein the flexible legs include two groups respectively disposed below the two girders, each group of flexible legs includes at least two groups respectively disposed at both ends of the girders, and the connection between the groups of flexible legs is door-shaped.