crane

Abstract

This disclosure relates to a crane, comprising: a chassis, a turntable, a mast, a boom, and a luffing mechanism. The turntable is rotatably mounted on the chassis. The mast and the boom are rotatably mounted on the turntable. The mast is connected to the boom via a second traction member. The luffing mechanism is mounted on the turntable for luffing the boom. The luffing mechanism includes: a connecting frame mounted on the turntable; a guide pulley assembly mounted on the connecting frame; a luffing pulley assembly mounted on the turntable and positioned below the guide pulley assembly; and a rope drive component for leading out and driving a luffing rope connected to the mast, and causing the luffing rope to pass through the guide pulley assembly and the luffing pulley assembly.

Description

Technical Field

[0001] This disclosure relates to the field of construction machinery, and more particularly to a crane. Background Technology

[0002] Construction efficiency is a critical technical indicator in engineering applications. With the continuous changes in construction scenarios, such as green petrochemical upgrades and municipal construction, higher demands are being placed on the adaptability of cranes to operate in confined spaces and their construction efficiency.

[0003] According to national standards defining the main structures of cranes under different operating conditions, crane operating conditions include standard operating conditions without a superlift mechanism and superlift operating conditions with a superlift mechanism. Cranes operating under these two conditions differ in structural form and working principle. Compared to superlift operating conditions, standard operating conditions do not require disassembly and reassembly of the superlift device, have fewer components, lower costs, higher operating efficiency, and better adaptability to operating in confined spaces.

[0004] In the luffing system of a standard-condition crane, the luffing pulley block is installed at the rear of the turntable and connected to the mast head via the luffing wire rope. A key indicator of the luffing system's capability is the luffing torque, which is equal to the product of the luffing force and the lever arm. To further improve the overall stability of the crane under standard conditions, an additional counterweight is added at the rear of the turntable to enhance the crane's anti-overturning moment. Summary of the Invention

[0005] The inventors discovered that the luffing system of a standard working crane is limited by its capacity and overall stability. Raising a long boom is difficult, limiting its maximum boom length and preventing the crane from reaching its maximum lifting capacity. Increasing the luffing winch torque by increasing its pulling force requires increasing the output power of the winch's reducer, which places higher demands on the load-bearing capacity of the mast and luffing wire rope. Increasing the luffing boom length by increasing the mast and turntable length necessitates lengthening both the turntable and mast. Whether developing a new product or modifying an existing one, both methods significantly increase the R&D cycle and cost of the crawler crane.

[0006] In view of this, embodiments of the present disclosure provide a crane that can improve the luffing system capability of the entire machine under standard operating conditions.

[0007] In one aspect of this disclosure, a crane is provided, comprising: a chassis, a turntable, a mast, a boom, and a luffing mechanism. The turntable is rotatably mounted on the chassis. The mast and the boom are rotatably mounted on the turntable. The mast is connected to the boom via a second traction member. The luffing mechanism is mounted on the turntable for realizing the luffing of the boom. The luffing mechanism includes:

[0008] A connecting frame is mounted on the turntable;

[0009] The guide pulley assembly is mounted on the connecting frame;

[0010] A variable amplitude pulley assembly is mounted on the turntable and is positioned lower than the guide pulley assembly; and

[0011] A rope drive component is used to lead out and drive the luffing rope connected to the mast, and to make the luffing rope pass around the guide pulley assembly and the luffing pulley assembly.

[0012] In some embodiments, the projection point of the guide pulley assembly on the boom's luffing plane is D; the projection point of the connection between the luffing pulley assembly and the turntable on the boom's luffing plane is C; the projection point of the connection between the mast and the luffing rope on the boom's luffing plane is A; and the projection point of the connection between the mast and the turntable on the boom's luffing plane is B. Within at least a portion of the mast's working stroke, projection point D is located on the side of the line AC connecting the projection points away from projection point B.

[0013] In some embodiments, throughout the entire working stroke of the mast, projection point D is located on the side of the line AC connecting projection points that is furthest from projection point B.

[0014] In some embodiments, the connecting bracket is detachably mounted on the turntable.

[0015] In some embodiments, the connecting frame is connected to the rear of the turntable.

[0016] In some embodiments, the connecting frame is detachably connected to the rear vertical end face of the turntable and is located on the side of the plane containing the rear vertical end face away from the boom.

[0017] In some embodiments, the connecting frame includes a truss structure.

[0018] In some embodiments, the crane further includes:

[0019] The counterweight mounting device is connected to the connecting frame; and

[0020] A counterweight system, mounted on the counterweight mounting device, is configured to provide counterweight to the crane.

[0021] In some embodiments, the counterweight mounting device includes:

[0022] The mounting frame has one end rotatably connected to the connecting frame, and the other end connected to the connecting frame via a first tensioning member;

[0023] The first traction member is located on the upper side of the mounting frame, and the counterweight system is adjustablely mounted on the mounting frame.

[0024] In some embodiments, the counterweight mounting device further includes:

[0025] A movable mechanism, movably mounted on the mounting frame; and

[0026] The lifting mechanism is mounted on the moving mechanism and connected to the counterweight system.

[0027] In some embodiments, the counterweight mounting device further includes:

[0028] A drive mechanism, connected between the moving mechanism and the connecting frame, is configured to drive the moving mechanism to move relative to the connecting frame on the surface of the mounting frame.

[0029] In some embodiments, the moving mechanism moves in a direction parallel to the horizontal plane and perpendicular to the luffing axis of the boom.

[0030] In some embodiments, the connecting frame includes:

[0031] A truss beam has a first end, a second end, and a third end; the first end is connected to the turntable; the second end and the third end are respectively connected to the mounting frame and the first tension member.

[0032] A support rod is located on the lower side of the truss beam. One end of the support rod is connected to the turntable, and the other end is connected to the truss beam or the mounting frame.

[0033] In some embodiments, the guide pulley assembly is located at the third end.

[0034] In some embodiments, the counterweight mounting device is detachably connected to the connecting frame.

[0035] Therefore, according to the embodiments of this disclosure, a connecting frame and a luffing pulley assembly are provided on the turntable, and a guide pulley assembly is provided on the connecting frame. The tension drive component leads out the luffing rope to connect to the mast, and the luffing rope passes around the guide pulley assembly and the luffing pulley assembly. Since the luffing pulley assembly is positioned lower than the guide pulley assembly, the rope exit point of the luffing rope leading to the mast is raised. Compared to the related technology where the rope exit point is lower and directly leads from the luffing pulley assembly to the mast, the lever arm of the luffing rope can be increased, thereby increasing the luffing torque without increasing the tension of the luffing rope. This is beneficial for improving the luffing system capacity and reducing the requirements for the load-bearing capacity and length of the mast, luffing rope, and turntable, thus also helping to reduce costs. Attached Figure Description

[0036] The accompanying drawings, which form part of this specification, illustrate embodiments of this disclosure and, together with the specification, serve to explain the principles of this disclosure.

[0037] This disclosure will become clearer with reference to the accompanying drawings and the following detailed description, wherein:

[0038] Figure 1 These are structural schematic diagrams of some embodiments of the crane according to the present disclosure;

[0039] Figure 2 This is a schematic diagram showing the counterweight adjustment and the projection points of each component on the luffing plane according to the crane embodiment of this disclosure.

[0040] Figure 3 This is an enlarged schematic diagram of the rear region of the turntable according to an embodiment of the crane disclosed herein;

[0041] Figure 4 yes Figure 3 A schematic diagram of the force analysis;

[0042] Figure 5 yes Figure 4 Schematic diagram of force analysis of the connecting frame;

[0043] Figure 6 This is a structural diagram of the crane embodiment according to the present disclosure when dismantling the counterweight mounting device and counterweight system;

[0044] Figure 7 This is a structural diagram of the crane embodiment according to the present disclosure during the dismantling of the connecting frame and guide pulley assembly.

[0045] It should be understood that the dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale. Furthermore, the same or similar reference numerals denote the same or similar components. Detailed Implementation

[0046] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the present disclosure or its application or use. The present disclosure may be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that the present disclosure will be thorough and complete, and will fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless specifically stated otherwise, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0047] The terms "first," "second," and similar words used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Words such as "including" or "contains" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well. Terms such as "above," "below," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, this relative positional relationship may also change accordingly.

[0048] In this disclosure, when a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediary device, or it may be not directly connected to the other devices but have an intermediary device.

[0049] All terms used in this disclosure (including technical or scientific terms) have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as a dictionary, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0050] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0051] like Figures 1 to 5 As shown, this disclosure provides a crane. The crane includes a chassis 11, a turntable 12, a mast 13, a boom 14, and a luffing mechanism 20.

[0052] The chassis 11 can be a tracked chassis or other types of chassis, such as a wheeled crane chassis or a ring rail chassis. The chassis 11 can move on the work site or be fixed to the work site. Depending on the type of chassis used, the crane can be a tracked crane, a truck crane, or a rail crane.

[0053] The turntable 12 is rotatably mounted on the chassis 11, for example, by means of a rotating body, and can rotate relative to the chassis 11 about a vertical axis perpendicular to the horizontal plane. Depending on the stability requirements of the crane, the turntable 12 may or may not be equipped with a fixed counterweight.

[0054] Both the mast 13 and the boom 14 are rotatably mounted on the turntable 12, and the mast 13 is connected to the boom 14 via a second traction member 15. The mast 13 can be a single mast or a pair. The boom 14 may include a main boom, and may also include a detachable auxiliary boom, etc., that can be mounted on the main boom.

[0055] The second traction component 15 can be a pull plate or a pull rope, etc. One end of the second traction component 15 can be connected to the boom head or boom body of the boom 14, and the other end can be connected to the end of the mast 13 away from the turntable 12. The number of second traction components 15 can be the same as the number of masts 13.

[0056] A luffing mechanism 20 is mounted on the turntable 12 to achieve luffing of the boom 14. The luffing mechanism 20 can rotate the mast 13 relative to the turntable 12 by pulling the mast 13. As the mast 13 rotates, the boom 14 is driven to luff via the second pulling member 15. The luffing range of the boom 14 corresponds to the entire working stroke of the mast 13.

[0057] The luffing mechanism 20 includes a connecting frame 21, a guide pulley assembly 22, a luffing pulley assembly 23, and a rope drive component 24. The connecting frame 21 is mounted on the turntable 12. The guide pulley assembly 22 is mounted on the connecting frame 21. The luffing pulley assembly 23 is mounted on the turntable 12, but at a lower position than the guide pulley assembly 22.

[0058] The rope drive component 24 is used to lead out and drive the luffing rope 25 connected to the mast 13, and to make the luffing rope 25 pass through the guide pulley assembly 22 and the luffing pulley assembly 23. The luffing rope 25 can be a wire rope or a rope made of other materials. The luffing rope 25 can be connected to a pulley block at the end of the mast 13. The rope drive component 24 may include a luffing winch mechanism driven by an electric motor or an internal combustion engine, and the luffing rope is wound up and down by the rotation of the drum of the luffing winch mechanism.

[0059] refer to Figure 1 The guide pulley assembly 22 can be located at the top of the connecting frame 21, or at other positions on the connecting frame 21, as long as its position is higher than that of the luffing pulley assembly 23. The luffing rope 25 passes around the guide pulley assembly 22 and the luffing pulley assembly 23, and can form a quadrilateral with the turntable 12 and the mast 13. In some embodiments, there are multiple guide pulley assemblies 22 located at different positions on the connecting frame 21, in which case the luffing rope 25 passes around the guide pulley assembly 22 and the luffing pulley assembly 23, and can form a polygon with more sides with the turntable 12 and the mast 13.

[0060] By extending and retracting the luffing rope 25 through the rope drive component 24, the length of the luffing rope between the guide pulley assembly 22 and the pulley block on the mast 13 can be reduced or increased. With the guide pulley assembly 22 and the turntable 12 remaining stationary, the mast 13 rotates relative to the turntable 12 as the luffing rope is extended or retracted, thereby driving the boom 14 to luff and adjusting the pitch angle of the boom 14.

[0061] For cranes, a key indicator of the luffing system's capability is the luffing torque. The luffing torque is equal to the product of the luffing force and the lever arm. (Reference) Figure 2 The dashed line with double arrows represents the lever arm L2' of the luffing system in the related art, while the solid line with double arrows represents the lever arm L2 of the luffing mechanism in the embodiment of this disclosure. Because the guide pulley assembly 22 located at the top of the connecting frame 21 is higher than the luffing pulley assembly 23 on the turntable, the lever arm L2 is greater than the lever arm L2'. Therefore, under the same luffing force, the embodiment of this disclosure can provide a higher luffing torque, thereby significantly improving the capability of the luffing system.

[0062] Compared to related technologies that directly guide the luffing pulley assembly to the lower rope exit point of the mast, the embodiments of this disclosure can increase the lever arm of the luffing rope, thereby increasing the luffing torque without increasing the tension of the luffing rope. This is beneficial for improving the luffing system capability and reducing the requirements for the load-bearing capacity and length of the mast, luffing rope, and turntable.

[0063] During the operation of the machine, by increasing the rope exit point of the luffing rope, the lever arm of the luffing rope is increased. This allows the use of mechanisms with smaller luffing forces, thereby reducing the requirements on the load-bearing capacity and length of the mast, luffing rope, and turntable, which helps to reduce costs and development cycle.

[0064] This disclosure is applicable to cranes operating under standard conditions without a super-lift mechanism. For example, in the national standard GB / T14560, the standard operating condition for a crawler crane is the operation of a crane without a super-lift mechanism. Cranes operating under standard conditions use far fewer components, resulting in lower costs for purchase, use, and transportation, and higher efficiency in assembly, disassembly, and operation. The luffing capability of the existing system can be enhanced through the luffing mechanism in this disclosure.

[0065] Figure 2 The plane shown is the luffing plane of boom 14. (Reference) Figure 1 and Figure 2The projection point of the guide pulley assembly 22 on the luffing plane of the boom 14 is D; the projection point of the connection position between the luffing pulley assembly 23 and the turntable 12 on the luffing plane of the boom 14 is C; the projection point of the connection position between the mast 13 and the luffing rope 25 on the luffing plane of the boom 14 is A; and the projection point of the connection position between the mast 13 and the turntable 12 on the luffing plane of the boom 14 is B.

[0066] As the mast 13 rotates, the projection point A also changes position accordingly. During at least a portion of the mast 13's working stroke, the projection point D is located on the side of the line AC connecting projection points away from projection point B. This ensures that the lever arm L2 is always greater than the lever arm L2' during at least a portion of the mast 13's working stroke, thereby allowing the luffing torque of the luffing rope to be raised within at least a portion of the luffing range of the boom 14. Preferably, during the entire working stroke of the mast 13 (e.g., ...), ... Figure 2 The working stroke of the middle mast 13 corresponds to a rotation angle of 90° to 100°, which allows the projection point D to be located on the side of the line AC connecting the projection points away from the projection point B.

[0067] refer to Figures 1 to 2 To improve the stability of the crane under standard operating conditions, in some embodiments, the crane further includes a counterweight mounting device 30 and a counterweight system 40. The counterweight mounting device 30 is connected to the connecting frame 21. The counterweight system 40 is disposed on the counterweight mounting device 30 and configured to provide counterweight to the crane. The counterweight system 40 may include one or more counterweight blocks, and the number of counterweight blocks may be increased or decreased, or the specifications of the counterweight blocks may be adjusted, as needed.

[0068] refer to Figure 2 and Figure 3 In some embodiments, the counterweight mounting device 30 includes a mounting frame 31. One end of the mounting frame 31 is rotatably connected to the connecting frame 21, and the other end is connected to the connecting frame 21 via a first pulling member 32. The first pulling member 32 is located on the upper side of the mounting frame 31, and the counterweight system 40 is adjustablely mounted on the mounting frame 31. The first pulling member 32 can be a pull plate or a pull rope.

[0069] Compared to the fixed counterweights commonly used in related technologies, the adjustable position of the counterweight system on the mounting frame allows for adjustments to the anti-overturning moment under the same counterweight conditions, tailored to actual needs. For simplicity, other components that can generate anti-overturning moments, such as the weight of the turntable, are temporarily ignored here. Figure 2 In the diagram, when the boom is on the right side, the track wheel on the right side of the chassis corresponds to the overturning line of the entire machine. For the counterweight system 40 located on the left side of the turntable, the distance from the counterweight system 40 to the overturning line of the entire machine is L1 or L1', depending on its specific position.

[0070] A key indicator of the machine's overall anti-overturning capability is its anti-overturning moment. The anti-overturning moment of the machine is equal to the product of the weight of the counterweight system and the distance from the counterweight system to the overturning line of the machine.

[0071] For example, during hoisting, when a large anti-overturning moment is required, the counterweight system 40 can be pushed to a position far from the turntable. After hoisting is completed, when such a large anti-overturning moment is not needed, and the additional counterweight needs to be off the ground when the entire machine is moved, lifting the counterweight system when it is in this position will easily cause the entire machine to tip backward. At this time, the counterweight system 40 can be moved back to a position closer to the turntable. At this time, the anti-overturning moment provided by the counterweight system is smaller, and it is not easy to tip over when the entire machine is moved and the counterweight system is off the ground, thus eliminating the need for repeated disassembly and assembly of the counterweight.

[0072] Because the counterweight system 40 can be moved, its anti-overturning distance is significantly increased. It can also be dynamically adjusted in real time according to the actual lifting load and different postures during the lifting process, ensuring that the center of gravity of the entire machine remains within a safer and more reasonable range while maintaining overall safety. Thus, this embodiment fully utilizes the connecting frame in the luffing mechanism to connect and fix the counterweight mounting device, simultaneously solving the two major challenges of limiting the boom length and performance improvement of the crane under standard operating conditions—the luffing system's capability and the overall machine's stability—through a relatively compact structure.

[0073] refer to Figure 3 and Figure 4 In some embodiments, the counterweight mounting device 30 further includes a moving mechanism 33 and a lifting mechanism 34. The moving mechanism 33 is movably mounted on the mounting frame 31. The moving mechanism 33 can be a trolley that moves on the upper surface of the mounting frame 31, and the trolley moves by rolling on the mounting frame 31 via rollers. The moving mechanism 33 can also slide directly on the mounting frame 31.

[0074] The lifting mechanism 34 is mounted on the moving mechanism 33 and connected to the counterweight system 40. The lifting mechanism 34 can lower the counterweight system 40 to the ground or lift it off the ground, facilitating adjustments to the counterweight system during installation to address uneven ground conditions or to meet the ground-level requirements during machine operation. The lifting mechanism 34 can utilize the extension and retraction of a lifting cylinder to achieve the lifting action, or it can employ other forms of lifting mechanisms, such as pneumatic or electric lifting mechanisms.

[0075] exist Figure 3The counterweight mounting device 30 may further include a drive mechanism 35. The drive mechanism 35 is connected between the moving mechanism 33 and the connecting frame 21, and is configured to drive the moving mechanism 33 to move relative to the connecting frame 21 on the surface of the mounting frame 31. The drive mechanism 35 may employ a hydraulic cylinder to push or pull the moving mechanism 33, or other types of drive mechanisms, such as pneumatic or electric push-pull mechanisms.

[0076] refer to Figure 2 In some embodiments, the moving direction v of the moving mechanism 33 is parallel to the horizontal plane and perpendicular to the luffing axis of the boom 14. This allows the moving device 33 to adjust the distance between the counterweight system and the turntable more quickly.

[0077] Figure 6 This is a structural diagram illustrating the removal of the counterweight mounting device and counterweight system according to an embodiment of the crane disclosed herein. (Reference) Figure 3 , Figure 4 and Figure 6 The counterweight mounting device 30 is detachably connected to the connecting frame 21. Thus, in some scenarios, the crane can be modified for use by removing the counterweight mounting device and the counterweight system. See the attached diagram for the disassembled configuration. Figure 6 At this point, space occupancy can be reduced while minimizing the risk of overturning.

[0078] exist Figure 2 In this configuration, the connecting frame 21 is connected to the tail 121 of the turntable 12. This facilitates the installation of a counterweight mounting device and a counterweight system, and also helps to increase the exit point of the luffing rope. The connecting frame 21 is detachably connected to the vertical end face of the tail of the turntable 12, and is located on the side of the plane containing the vertical end face of the tail away from the boom 14.

[0079] In some embodiments, the connecting frame 21 includes a truss structure, which can reduce the weight of the connecting frame. (Reference) Figure 3 The connecting frame 21 may include a truss beam 211 and a support rod 212. The truss beam adopts a truss structure, which is lighter in weight. The truss beam 211 has a first end 211a, a second end 211b, and a third end 211c. The first end 211a is connected to the turntable 12, and the second end 211b and the third end 211c are respectively connected to the mounting frame 31 and the first tensioning member 32. The truss beam can be hinged to the rear of the turntable 12, and the height position of the guide pulley assembly can be easily adjusted, which also facilitates the installation or disassembly of the truss beam.

[0080] The support rod 212 is located below the truss beam 211. One end of the support rod 212 is connected to the turntable 12, and the other end is connected to the truss beam 211 or the mounting frame 31. This structure ensures the stability of the counterweight system 40 on the mounting frame 31. The support rod 212 provides stable support for the truss beam 211, and different lengths can be selected to match the position of the truss beam 211 as needed.

[0081] Figure 4 A simplified force analysis diagram of truss beam 211 is shown. For the counterweight system, the force F is exerted through the supporting action of support rod 212. z2 ) and the tension (force F) of the first traction member 32. i2 The action of the counterweight system 40 (force G) allows it to lift off the ground, thereby achieving the pushing function. The first traction member 32 is connected to the third end 211c of the truss beam 211, and the guide pulley assembly 22 can be set at the third end 211c. This structure with a common point of action allows the force F applied by the luffing rope 25 at the third end 211c to be... bf2 with force F i1 The directions are basically opposite, which can offset some of the interaction forces, resulting in a more reasonable force distribution and thus greater safety and reliability.

[0082] The truss beam 211 raises the exit point of the luffing rope 25 (i.e., the third end 211c), and the tension F of the first traction member 32... i1 And the tension F of the luffing rope 25 bf2 The angles between the forces and truss beam 211 are both relatively large, both being obtuse angles; therefore, neither of these forces will exert pressure on truss beam 211. Only the tension F of the luffing rope 25... bf1 The force F forms an acute angle with truss beam 211, which will exert pressure on truss beam 211. i1 and F bf2 The stress decomposition directions along truss beam 211 are all opposite to the compressive forces it bears, which can reduce the stress on truss beam 211, improve the stress distribution of structural components, make the overall stress distribution more reasonable, safer and more reliable, and make the structural components lighter. Figure 4 In the middle, force F i1 and F i2 Action and reaction forces are equal in magnitude and opposite in direction. z1 Heli F z2 These are action and reaction forces that are equal in magnitude and opposite in direction.

[0083] Specifically, refer to Figure 5 With the pulley axis of the guide pulley assembly as the center, the direction from the hinge point of the truss beam 211 on the turntable to this center is the y-axis, and the direction perpendicular to the y-axis is the x-axis. Force decomposition is performed in the coordinate system formed by the x-axis and y-axis. Force F i1 and F bf2 The component force F of the two on the x-axisi1x and F bf2x Forces in opposite directions can partially cancel each other out. Force F i1 and F bf1 The component force F of the two on the x-axis i1x and F bf1x Forces in opposite directions can partially cancel each other out. Force F i1 and F bf1 / F bf2 The component forces F of the three forces on the y-axis i1y and F bf1y / F bf2y Only the component force F in the middle bf1y It will exert pressure on truss beam 211, component force F i1y and F bf1y This arrangement counteracts some of the pressure in the opposite direction. This arrangement is more conducive to the stress distribution of structural components, resulting in a more rational, safer, and more reliable overall stress distribution, and lighter structural components.

[0084] Figure 7 This is a structural diagram illustrating the removal of the connecting frame and guide pulley assembly according to an embodiment of the crane disclosed herein. (Reference) Figure 6 and Figure 7 In some embodiments, the connecting frame 21 is detachably mounted on the turntable 12. In cases where the boom is short or lifting is not required, the crane can be restored to a conventional crane structure by removing the connecting frame and guide pulley assembly.

[0085] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0086] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A crane, characterized in that Comprise: A chassis (11), a rotary table (12), a mast (13), an arm support (14) and a luffing mechanism (20), the rotary table (12) is rotatably arranged on the chassis (11), the mast (13) and the arm support (14) are rotatably arranged on the rotary table (12), the mast (13) is connected with the arm support (14) through a second pulling member (15), the luffing mechanism (20) is arranged on the rotary table (12) and is used for realizing luffing of the arm support (14); wherein, the luffing mechanism (20) comprises: A connecting frame (21) arranged on the rotary table (12); A guide sheave assembly (22) arranged on the connecting frame (21); A luffing sheave assembly (23) arranged on the rotary table (12) and lower than the arrangement position of the guide sheave assembly (22); and A pull rope driving component (24) used for leading out and driving a luffing pull rope (25) connected with the mast (13) and making the luffing pull rope (25) pass through the guide sheave assembly (22) and the luffing sheave assembly (23); Wherein, the projection point of the guide sheave assembly (22) on the luffing plane of the arm support (14) is D, the projection point of the connecting position of the luffing sheave assembly (23) and the rotary table (12) on the luffing plane of the arm support (14) is C, the projection point of the connecting position of the mast (13) and the luffing pull rope (25) on the luffing plane of the arm support (14) is A, and the projection point of the connecting position of the mast (13) and the rotary table (12) on the luffing plane of the arm support (14) is B; within at least part of the working stroke of the mast (13), the projection point D is located on the side of the projection point connecting line AC away from the projection point B.

2. The crane of claim 1, wherein, Within the whole working stroke of the mast (13), the projection point D is located on the side of the projection point connecting line AC away from the projection point B.

3. The crane of claim 1, wherein, The connecting frame (21) is detachably arranged on the rotary table (12).

4. The crane of claim 1, wherein, The connecting frame (21) is connected to the tail portion (121) of the rotary table (12).

5. The crane of claim 4, wherein, The connecting frame (21) is detachably connected with the tail vertical end surface of the rotary table (12) and is located on the side of the plane where the tail vertical end surface is away from the arm support (14).

6. The crane of claim 4, wherein, The connecting frame (21) comprises a truss structure.

7. The crane of claim 1, wherein, Further comprise: A counterweight mounting device (30) connected with the connecting frame (21); And A counterweight system (40) arranged on the counterweight mounting device (30) and configured to provide counterweight for the crane.

8. The crane of claim 7, wherein, The counterweight mounting device (30) comprises: A mounting frame (31) rotatably connected with one end of the connecting frame (21) and connected with the other end of the connecting frame (21) through a first pulling member (32); Wherein, the first pulling member (32) is located on the upper side of the mounting frame (31), and the counterweight system (40) is adjustably arranged on the mounting frame (31).

9. The crane of claim 8, wherein, The counterweight mounting device (30) further comprises: A moving mechanism (33) movably arranged on the mounting frame (31); and A lifting mechanism (34) is arranged on the moving mechanism (33) and connected with the counterweight system (40).

10. The crane of claim 9, wherein, The counterweight mounting device (30) further comprises: A driving mechanism (35) is connected between the moving mechanism (33) and the connecting frame (21) and configured to drive the moving mechanism (33) to move on the surface of the mounting frame (31) relative to the connecting frame (21).

11. The crane of claim 9, wherein, The moving direction of the moving mechanism (33) is parallel to the horizontal plane and perpendicular to the luffing axis of the boom (14).

12. The crane of claim 8, wherein, The connecting frame (21) comprises: A truss beam (211) having a first end (211a), a second end (211b) and a third end (211c), the first end (211a) being connected with the turntable (12), the second end (211b) and the third end (211c) being connected with the mounting frame (31) and the first pulling member (32) respectively; and A support rod (212) located on the lower side of the truss beam (211), one end of the support rod (212) being connected with the turntable (12) and the other end being connected with the truss beam (211) or the mounting frame (31).

13. The crane of claim 12, wherein, The guide pulley assembly (22) is located at the third end (211c).

14. The crane of claim 7, wherein, The counterweight mounting device (30) is detachably connected with the connecting frame (21).

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