阅读说明：本技术 单卷筒双吊点铸造起重机起升系统 (Hoisting system of single-drum double-hoisting-point casting crane ) 是由 郭振山 秦义校 焦倩倩 谷金朋 张灏 张洋洋 于 2020-06-04 设计创作，主要内容包括：本发明涉及单卷筒双吊点铸造起重机起升系统,属于重型装备领域。其特征是利用一个双联卷筒同时驱动两套滑轮组实现钢包或吊具的升降运动。该起升系统两套滑轮组共用一套驱动系统,可实现两滑轮组同步升降,避免了两套驱动系统因电机不同步而导致的两滑轮组不同步的问题。钢丝绳一头固定在卷筒上,另一头绕过定、动滑轮组到均衡杠杆一侧连接,均衡杠杆可实现两根钢丝绳均衡受力且安全可靠。当两套滑轮系统之一发生故障,另一套仍能继续短时间工作,以一半升降速度完成本次起吊作业,此时均衡杠杆的支撑弹簧可减缓钢丝绳断裂的冲击。该发明在实现不频繁使用的铸造起重机起吊功能的情况下,可以减少制造成本。(The invention relates to a lifting system of a single-drum double-lifting-point casting crane, belonging to the field of heavy equipment. The lifting mechanism is characterized in that a duplex winding drum is used for simultaneously driving two sets of pulley blocks to realize the lifting motion of a ladle or a lifting appliance. Two sets of pulley blocks of the lifting system share one set of driving system, synchronous lifting of the two pulley blocks can be achieved, and the problem that the two pulley blocks of the two sets of driving systems are asynchronous due to the fact that motors are asynchronous is solved. One end of each steel wire rope is fixed on the winding drum, the other end of each steel wire rope is connected to one side of the balancing lever by bypassing the fixed pulley block and the movable pulley block, and the balancing lever can realize balanced stress of the two steel wire ropes and is safe and reliable. When one of the two pulley systems breaks down, the other pulley system can still work for a short time, the lifting operation is completed at a half lifting speed, and the support spring of the balance lever can reduce the impact of the breakage of the steel wire rope. The invention can reduce the manufacturing cost under the condition of realizing the hoisting function of the casting crane which is not frequently used.)

1. Single reel double hoisting point foundry crane plays to rise system, includes duplex reel, four standing block, two running block and balanced lever, its characterized in that: synchronous lifting of the two winding systems is realized by using a duplex winding drum through a winding mode of a steel wire rope, namely synchronous lifting of the lifting points of the two movable pulley blocks is realized.

2. The single spool dual hoist point ladle crane hoisting system of claim 1 wherein: two steel wire ropes are wound on the winding drum, each steel wire rope is wound on the two groups of fixed pulleys and the two groups of movable pulleys simultaneously, and when one steel wire rope fails, the other steel wire rope can complete the lifting at a half lifting speed.

3. The single spool dual hoist point ladle crane hoisting system of claim 1 wherein: the two winding systems are the same in winding mode and are symmetrically arranged, and finally are connected through the balance lever, when the steel wire rope is broken, the winding mode can keep balance, and the steel ladle cannot be dislocated along the y direction.

4. The single spool dual hoist point ladle crane hoisting system of claim 1 wherein: the two sides of the balance lever are supported by springs, so that when a steel wire rope is broken, a certain buffering effect can be achieved, and the tilting amplitude of the balance lever is reduced.

Technical Field

The invention relates to a single-drum double-lifting-point casting crane lifting system which is suitable for a pouring crane with lower use frequency, less pouring times and relatively smaller lifting rated load.

Background

At present, a hoisting mechanism of a crane is generally arranged in a mode that one or two motors are connected with a high-speed shaft of a speed reducer through a coupler to drive two winding drums, the two winding drums are respectively wound with a steel wire rope, and the steel wire rope is wound or released, so that the steel ladle or a lifting appliance is lifted and lowered. However, for some cranes with relatively small hoisting capacity, low use frequency and low working grade, the cost is high by adopting the winding mode of the winding drum steel wire rope, the arrangement methods of the two sets of steel wire rope winding systems are independent respectively, and the problem that the hoisting points of the two sets of movable pulleys are not synchronous easily occurs in the hoisting or descending process.

The crane lifting system mainly functions in converting motion forms and transferring energy, but has different requirements for cranes with different working grades.

In summary, different hoisting systems are equipped for cranes with different working grades, so that the manufacturing cost of the crane can be reduced on the premise of ensuring safety, the structure of the crane is simplified, and the frequency of faults or accidents of the crane can be reduced.

Disclosure of Invention

The invention aims to provide a single-reel double-lifting-point casting crane lifting system, which realizes that one reel drives two sets of pulley blocks to synchronously lift two lifting points, enables the crane to normally work on the premise of safety, and reduces the manufacturing and maintenance cost. The safety performance of the crane is considered while the hoisting operation is completed. When one steel wire rope is broken in the hoisting process of the crane, the other steel wire rope can still finish the operation at half the hoisting speed, and the buffer spring plays a role in the breaking process of the steel wire rope. After the hoisting is completed, the steel wire rope needs to be completely replaced.

In order to achieve the purpose, the hoisting system of the single-reel double-hoisting-point casting crane has the following scheme.

A single-reel double-hoisting-point casting crane hoisting system comprises a reel (1), a fixed pulley block (2), a fixed pulley block (3), a movable pulley block (4), a movable pulley block (5), a fixed pulley block (6), a fixed pulley block (7), a steel wire rope (8), a steel wire rope (9), a buffer spring (10) and a balance lever (11). The fixed pulley block (2) and the fixed pulley block (6) are composed of 3 fixed pulleys, and the fixed pulley block (3) and the fixed pulley block (7) are composed of 2 fixed pulleys and are fixed on the crane trolley frame through pin shafts. The winding drum (1) is connected with a fixed motor, a reducer and a brake on the trolley frame and is arranged reasonably. The movable pulley blocks (4) and (5) are composed of 4 pulleys. One section of the steel wire rope on the left side of the winding drum (1) is fixed on the winding drum, the other end of the steel wire rope downwards winds to a second pulley of the movable pulley block (5) through the guide pulley in the fixed pulley block (6), upwards winds to a middle pulley of the fixed pulley block (6), downwards winds to a third pulley of the movable pulley block (5), then winds to a last guide pulley on the right side of the fixed pulley block (3) through a last guide pulley of the fixed pulley block (6), downwards winds to a third pulley of the movable pulley block (4), upwards winds to a middle pulley of the fixed pulley block (3), downwards winds to a second pulley on the left side of the movable pulley block (4), and is most connected to a balance lever (3) fixed on a trolley frame of the crane, and primary winding of the system is completed. The other steel wire rope starts from the right side of the winding drum, one end of the other steel wire rope is fixed to the winding drum, and the other end of the other steel wire rope passes through the guide pulley. And the winding is symmetrical to the winding process and is finally connected to the other end of the equalizing lever (11). The two winding systems are connected through a balance lever (11) fixed on the trolley frame.

The calculation is described by taking a 100t casting crane of a low working grade as an example, and the specific analysis is as follows.

Two sets of pulley blocks share one group of driving system, namely the winding speed V of the steel wire rope is the same, and in order to ensure synchronous lifting, the same lifting speed of a heavy object is required, namely V₁=V₂。

The multiplying power m of the pulley block is = the moving speed of the rope/the ascending speed of the heavy object, so that the multiplying power of the two pulley blocks is the same. And the multiplying power of the pulley block is m =4 according to the winding mode of the steel wire rope.

The pulley has an efficiency of η =0.98,efficiency η of pulley block_z=0.97。

The maximum static tension Smax = P/(2 × 4 × 0.97 × 0.984) =139.71KN of the steel cord.

Fmin=D²σ≥NSmax=2.5×139.71KN=349.28KN。

Wherein Fmin is the minimum breaking tension of the selected wire rope bundles (7) and (8); smax is the maximum tension of the selected carbon fiber ropes (7) and (8); n is the safety coefficient of the system; the safety factor is taken as 2.5, and the tensile strength sigma of the steel wire is taken as 1400N/mm. Calculated minimum wire rope diameter D =15.80 mm.

The steel wire rope marked 166 x 19S is initially selected in view of the low frequency of use of the casting crane and at the same time to ensure the safety of the hoisting process.

Wire diameter = D/(n)_{Outer cover}+3.5) =16/(6+3.5) =1.68mm, the wire rope tensile stress is calculated.

σ_t=1.2S/(iπ²/4)=1.2×139.7×1000/(6×19×π×1.68²/4)=664N/mm＜[σ_t]。

The bending stress of the wire rope around the drum or sheave is calculated as follows.

σ_w=0.4E/D_min=0.4×2.06×10⁵×1.68/237=584N/mm＜[σ_w]The difference between the diameter of the winding drum and the diameter of the pulley is not large, so that the bending strength of the steel wire rope on the pulley is only calculated and checked.

Wherein E is the elastic modulus of the steel wire, and the value E =2.06 × 10⁵Mpa. Is the diameter of the wire, D_minIs the diameter of the pulley.

Minimum diameter D of pulley_min=(ht-1)d=(16-1)×15.80=240mm。

The major dimensions of the mandrel are determined, including diameter D, length L, and wall thickness h.

Diameter D of the drum_{Winding drum}=(ht-1)d=(14-1)×15.80=208mm。

Length L =2 (L) of single-layer twin roll₀+L₁+L₂)+L3=2676mm。

Wherein the hoisting height H =20m, the assembly pulley multiplying power m =4, the diameter D of the winding drum_{Winding drum}=208mm, spiral groove pitch t =18mm₁Length required for fixing rope endDegree, L₂Length of free portions of the two ends of the drum, L₃The length of the middle smooth surface of the duplex winding drum.

Drum wall thickness h =0.02D +8=12.1mm, calculated to meet the requirements.

When the steel wire rope is broken, the other steel wire rope bears load, the two sides are completely symmetrical, so that the stress of the steel wire rope is 2 times of the original stress, the change of the stressed cross section area of the steel wire rope is not considered, the multiplying power of the steel wire rope in a winding mode is m =2, and the maximum static tension Smax of the steel wire rope is enlarged by 2 times.

Then the calculated tensile stress sigma of the wire rope_t，Bending stress sigma of cable wire around drum or pulley_wIncrease to sigma_t=664N/mm×2=1328N/mm＜[σ_t]，σ_w=584N/mm×2=1168N/mm＜[σ_w]And the strength condition is still met, so that one steel wire rope can finish the lifting at the time without breaking.

When the steel wire rope is broken, the buffer spring is compressed and pulled at the same time, the lever length L and the deflection angle α are balanced, the elastic compression amount or the tensile amount lambda = L × tan α of the spring is calculated, at the moment, the balance lever is subjected to torsion, and the torsion resistant torque Me =2F is calculated_x× L/2, wherein F_x=k×λ。

Where k is the damping spring rate and λ is the equalizing lever deflection distance. The spring is statically deformed after the steel wire rope is broken, so the calculation is reasonable.

Drawings

Fig. 1 is a schematic winding diagram of a duplex drum hoisting mechanism, wherein (1) is a drum, (2), (3), (6) and (7) are fixed pulley blocks. (11) The balance lever, the movable pulley block (4) and the movable pulley block (5), the steel wire rope (8) and the steel wire rope (9) and the buffer spring (10) are adopted.

Fig. 2 is a sequence diagram of a wire rope passing around a pulley. Wherein (1) is a winding drum, and (2), (3), (6) and (7) are fixed pulley groups. (11) For balancing the lever, (4) and (5) are both movable pulley blocks, and (8) and (9) are steel wire ropes, wherein a1, a2, a3 and a4 … … a15 are the sequence and the direction of the steel wire rope (8) passing around the pulley, and b1, b2, b3 and b4 … … b15 are the sequence and the direction of the steel wire rope (9) passing around the pulley.

Fig. 3 is a schematic diagram of a conventional double-drum hoisting mechanism, in which (1) and (9) are drums, (2) and (6) are fixed pulley blocks, (4) and (5) are both movable pulley blocks, and (7) and (8) are steel wire ropes.

Detailed Description

In order that the technical contents of the invention can be more clearly understood, the detailed description is given of specific embodiments. The embodiment of a hoisting system of a single-drum double-hoisting-point casting crane.

A single-reel double-hoisting-point casting crane hoisting system comprises a reel (1), a fixed pulley block (2), a fixed pulley block (3), a movable pulley block (4), a movable pulley block (5), a fixed pulley block (6), a fixed pulley block (7), a steel wire rope (8), a steel wire rope (9), a buffer spring (10) and a balance lever (11). The fixed pulley block (2) and the fixed pulley block (6) are composed of 3 fixed pulleys, and the fixed pulley block (3) and the fixed pulley block (7) are composed of 2 fixed pulleys and are fixed on the crane trolley frame through pin shafts. The winding drum (1) is connected with a fixed motor, a reducer and a brake on the trolley frame and is arranged reasonably. The movable pulley blocks (4) and (5) are composed of 4 pulleys. One section of the left steel wire rope (8) on the winding drum (1) is fixed on the winding drum, the other end of the left steel wire rope is downwards wound to the second pulley of the movable pulley block (5) through the middle guide pulley of the fixed pulley block (6), upwards wound to the middle pulley of the fixed pulley block (6), downwards wound to the third pulley of the movable pulley block (5), then wound to the last guide pulley on the right side of the fixed pulley block (3) through the last guide pulley of the fixed pulley block (6), downwards wound to the third pulley of the movable pulley block (4), upwards wound to the middle pulley of the fixed pulley block (3), downwards wound to the second pulley on the left side of the movable pulley block (4), and finally connected to the balance lever (3) fixed on the crane trolley frame, so that the primary winding of the system is completed. The other steel wire rope (9) starts from the right side of the winding drum, one end of the other steel wire rope is fixed to the winding drum, and the other end of the other steel wire rope passes through the guide pulley. And the winding is symmetrical to the winding process and is finally connected to the other end of the equalizing lever (11). The two winding systems are connected through a balance lever (11) fixed on the trolley frame. The steel wire ropes (8) and (9) are wound on the two sets of pulley blocks, and the hoisting or lifting of the steel ladle or the lifting appliance is realized through the winding of the steel wire ropes. In the hoisting process, the pulley block has unbalanced stress, and when the condition occurs, the balance lever (3) can deflect, so that the aim of balancing the stress is achieved. If the steel wire rope (8) or (9) breaks during the hoisting process, the other steel wire rope can realize the hoisting process at half the hoisting speed. And at the moment of fracture, the buffer spring (10) is compressed or stretched, so that the impact can be relieved, and the tilting angle of the balance lever (11) is reduced.

The above embodiments are merely illustrative of several embodiments of the present invention, which are described in detail and detailed, but not construed as limiting the scope of the present invention. It should be noted that the hoisting system is not limited to double hook foundries, but the system described above is still applicable to other less frequently used cranes. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.