The tire container gantry crane (hereinafter referred to as gantry crane) of a terminal company in Xiamen is manufactured by crane manufacturers such as Shanghai Zhenhua Port Machinery Co., Ltd. (ZPMC), Shanghai Port Machinery Heavy Industry Co., Ltd. (SPMC) and Noel Lifting Equipment (China) Co., Ltd. (Noel). For the anti-sway system of gantry crane spreader, each family adopts different methods and has its own characteristics. When the suspension point is braked, the goods will shake. How to prevent the shaking is a problem that all cranes have to deal with. For the gantry crane, the anti-sway system means that when the spreader lifts the container, the container can meet the recognized requirements for the container within a certain swing period under the condition that the trolley and the cart translate. A good anti-sway system can play a good anti-sway effect and greatly improve the labor productivity. The following is an analysis of several anti-sway systems used by portal cranes. 1 Traditional mechanical anti-roll device 1 1 The anti-roll device is installed under the small frame, which includes anti-roll steel wire rope, drum and torque limiter. The device can slow down the swing caused by the acceleration and deceleration of the car, thus improving the working efficiency. When the bottom of the spreader is 4 5 m off the ground and the car stops running at the rated speed for 5 s, the device can control the swing of the spreader! Within 5 cm. The layout and principle of 1 2 In order to reduce the swing of the spreader, in addition to adopting the wire rope winding mode that the lifting pulley on the frame deviates from the traction pulley on the spreader by a certain angle in the same plane (this wire rope mode has achieved a certain anti-swing effect), it is also equipped with a cycloidal pin wheel reducer with a torque limiter, a transmission chain, a drum with a one-way bearing and a brake. The role of one-way bearing is to make the drum rotate only in the winding direction of steel wire rope, and the unwinding direction of steel wire rope is locked with the transmission shaft. When the crane is working, the torque limiter is constantly energized, which always gives a pulling force to the anti-dumping wire rope, which is enough to roll up the loose anti-dumping wire rope. In the swing state of the spreader, the disc brake connected to the drum shaft applies tension to the anti-roll steel wire rope to prevent the spreader from swinging, and the resistance can be adjusted by setting the spring force. Repeat the above actions several times, so that the swing amplitude of the container and spreader is continuously reduced, and the anti-rolling effect is achieved. When the spreader descends, each moment limiter is subjected to a reverse force under the self-weight of the spreader. The inner and outer rings of one-way bearing are locked with each other, the shaft rotates, and the brake is opened. The tension of anti-roll steel wire rope is the blocking force of torque limiter and the reverse efficiency of mechanical transmission, and the anti-roll device works slightly. When the spreader stops lifting, the brake is locked, the inner and outer rings of the one-way bearing are engaged with each other, and the shaft is in a braking state. If the spreader swings due to other factors, the brake will produce damping effect and reduce the swing of the spreader. When the spreader rises, the tension generated by the weight of the spreader does not act on the anti-roll wire rope, and the torque limiter drives the drum to roll up the anti-roll wire rope. At this time, the one-way bearing is separated inside and outside, the rotating force does not act on the shaft, and the brake does not work. When the trolley is running (or combined with lifting), the brake is locked, the inner and outer rings of the one-way bearing are engaged and disengaged with each other, and the shaft is in a braking state. If the spreader swings due to other factors, the brake will produce damping effect, and at the same time, the torque limiter will continuously roll up the slack wire rope to reduce the swing of the spreader. 2 Hydraulic anti-rolling device 2 1 Composition of anti-rolling device The anti-rolling device consists of anti-rolling drum, anti-rolling wire rope, reversing pulley and transition pulley, hydraulic cylinder and a set of hydraulic system. The anti-roll drum is driven by the lifting drum through the open gear and runs synchronously. The hydraulic cylinder is placed on the hanger, and its pressure is provided by a group of hydraulic devices also placed on the hanger. The anti-rolling hydraulic system consists of the following five parts: oil inlet and oil outlet of the spreader, control valve block with hydraulic valve, pressure switch and four anti-rolling hydraulic valves. 6? 6 30 ? 6? 6 # lifting and transporting machinery? 6? 9 2007 (6) Cylinder, hydraulic accumulator and safety module. 2 2 Working principle When the spreader swings laterally, the two hydraulic cylinders on one side of the swing direction are stretched out by tension, and the pressure increases, which leads to the increase of the tension of the two anti-swing ropes, thus limiting the swing amplitude. Two hydraulic cylinders on the other side, under the action of system oil pressure, the piston rod retracts, eliminating the slack of anti-sway rope. When the paver swings in opposite directions, the functions of the two groups of hydraulic cylinders are opposite. In this way, the swing of the spreader quickly decays until it stops. When the piston rod is extended, the hydraulic oil first flows back to the accumulator through the orifice. Due to throttling, the pressure in the oil cylinder rises, and when it reaches the set pressure of the overflow valve, the oil flows back to the accumulator through the main overflow valve. The pressure set by the safety valve determines the maximum pressure of the anti-roll hydraulic cylinder. The accumulator absorbs the pressure fluctuation caused by the anti-vibration cylinder action, and stores and provides pressure energy. When the pressure of the accumulator system reaches the set pressure of the accumulator safety valve, the hydraulic oil overflows and returns to the spreader tank. Most of the wire breakage or tension of anti-sway rope is caused by the abrasion of pulley edge. It is suggested that nylon pulley be used as pulley, and steel wire rope with high bending strength can be used as anti-sway rope. 3 Eight-rope bidirectional anti-sway technology 3 1 Eight hoisting rope winding system, which consists of hoisting drum, pulley and eight hoisting wire ropes. Eight rope ends of eight wire ropes are fixed on the drum through wire rope pressure plates and screws respectively. After the other eight rope ends of the wire rope respectively bypass the relevant pulleys on the trolley, every two rope ends are obliquely connected at the midpoint of the four sides of the special hanger with flower basket screws to form four equal isosceles triangles respectively. Working principle Using the geometric principle of triangle stability, the traditional lifting winding system is changed into four identical inverted triangle systems. Eight steel wires in the eight-rope winding system cross the hanger obliquely, and their horizontal component prevents the hanger from swinging in the direction of the cart and the car. The inverted triangle system improves the rigidity of the suspension system, that is, the trolley and hanger seem to be rigidly connected. When the car starts or brakes, the hanger (including goods) also brakes, which fundamentally eliminates the swing of the hanger. 4 Cross-winding mode of hoisting wire rope 4 1 Mechanism arrangement and working principle 4. Hoisting wire rope is directly wound from the drum to the pulley on the spreader frame (different from the normal winding mode). And then returns to the tilting mechanism of the spreader after passing through the transition and steering pulley on the frame. This arrangement fully considers the pulley lifting point on the trolley frame to move outward as far as possible, so as to realize that the horizontal component of the hoisting wire rope in the direction of the trolley frame is large enough, and the anti-rolling function of the spreader in the direction of the trolley frame can be realized by this component. When the spreader starts to swing, the horizontal component produced by the lifting wire rope on the other side will restrict the swing of the spreader. This arrangement has obvious anti-sway effect. The steel wire rope passes through fewer pulleys, and the four hoisting steel wires have the same length and uniform winding form, which can reduce the difficulty of maintenance work. The layout of the trolley is simplified, and the mechanism layout on the trolley frame is completely symmetrical, which avoids the eccentric load in the traditional design and makes the stress form of the structure more reasonable. The arrangement of wire ropes is completely symmetrical in the running direction of the trolley, and the stress included angle is the same at any lifting position, thus effectively achieving the anti-sway effect. Because the pulley that the hoisting wire rope passes through on the spreader adopts cross winding, the bending degree of the wire rope increases and the service life of the wire rope decreases accordingly. The above are several common ways to use the anti-sway system of wharf gantry crane. Of course, there are other ways, such as using a hydraulic cylinder to push the lifting pulley on the spreader frame to change the opening angle of the lifting wire rope, so as to change the horizontal component of the lifting wire rope and realize the anti-sway effect of the spreader. You can also try to change the lifting pulley under the trolley frame into a fulcrum movable mode, which moves with the change of lifting height, thus changing the angle of the wire rope. In a word, for container gantry crane, a good anti-sway device can improve the working efficiency. But the most important factor still depends on the driver's human factors. It is most important for drivers to be familiar with the condition of the machine and improve labor productivity under the condition of ensuring safety.