KR101506644B1 - Automatic electricity taking system and method for rubber tyred container gantry crane - Google Patents

Abstract

An automatic feeding system and method of a gantry crane equipped with a rubber tire is a technique used for fixing a gantry power for a container terminal or a container yard during the transition from fuel to electricity. The automatic feed system according to the present invention includes a feeder cart, a contact device, a traction device, and a feed frame. The contact device and the traction device are completely separated. The contact device and the feed cart are separated / do. To allow the cart to smoothly enter the track, to prevent damage to the part due to no fundamental impact on the course of the orbit; After the contact device completes the entry of the cart, the cart and the contact device are separated and the cart is pulled by the elastic pulling device so that the current collector carbon brush can be smoothly and stably introduced and drawn, To compensate for the positional deviation of 1 meter in the vertical direction and to solve the problem that the current collecting cart can not be normally used due to uneven penetration in the container yard.

Description

TECHNICAL FIELD [0001] The present invention relates to an automatic feeding system and a method of a gantry crane equipped with a rubber tire,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gantry crane for a container terminal or a container yard, and more particularly to a new type of feeding system and method used in a gantry crane equipped with a rubber tire.

As the price of oil increases and the demand for environmental protection improves, it is becoming a trend to convert the power of rubber gantry mounted gantry cranes (RTG) from fuel to electric power. One important piece of technology that drives RTG by power is how to supply mains power to RTGs that travel long distances.

Currently, the most widely used method is to provide a power supply frame next to the main part of the RTG, a sliding contact line to communicate with the main power source on the power feeding frame, and a current collecting cart to move together with the RTG. The cart is electrically connected to the gantry crane, a current collector is installed on the cart, and a carbon brush is provided at an end of the current collector. At the time of power supply, the current collecting cart is installed on the feed frame, and the electric power on the sliding contact line is supplied to the RTG by connecting the carbon brush and the sliding contact wire.

The technical problem to be solved in this process is how to install the cart on the feed frame and implement the synchronization of the feeding of the cart and the RTG.

The most conventional method is to take an artificial working method, in which a cart is installed on a feed frame and then a plug of the cart is inserted on the RTG to allow the two to be electrically connected, To the sliding contact line. This type of artificial operation has high time and man power consumption and low efficiency. Especially on a rainy day, it is less safe to operate the plug because of the risk of electric shock.

In the Chinese patent application specification with application number 200910050482.0, an automatic cart contact structure is disclosed. In feeding, a contact device connected on the RTG pushes the cart horizontally, causing the cart to press the plate of the feed frame, And the cart draws up the cart by pulling up the guide plate by the forward pulling force under the action of one inclined guide plate installed on the feed frame to raise the component to the predetermined height and implement the orbit entry of the cart, The current collector is then guided into the sliding contact wire by means of a single trumpet-shaped guide to realize automatic feed.

The feed system of this structure realizes the entry of the cart into the track through the contact device pressure, the forward force of the RTG and the inclination of the slope guide plate, so that the guide plate of the swash plate can simultaneously fix the vertical position and the horizontal position , The contact device should provide a sufficiently large horizontal pressure (about 750KG) for the cart so as to ensure that the cart is in close contact with the guide plate during the entire guiding phase. However, in lifting the cart up to a predetermined height in the up-and-down direction through the inclined guide plate, the lifting force is only a vertical upward force component generated only with respect to the pressure perpendicular to the plate surface of the cart lifting wheel, Large forward tractive force should be provided. If the cart is subjected to a specific force analysis, the cart moves forward at a constant speed, and when the elevating wheel touches the inclined guide plate, an impact force is generated on the inclined guide plate, (50KG or more) of the frictional force generated between the joint ball and the back plate due to the cart pressure and the frictional force between the raising wheel and the inclined guide plate The force acting on the rising wheel is more than 220KG because the angle of the sloping guide plate is 22 degrees and the force acting on the rising wheel is more than 220KG, Since the generated impact force is 4 to 5 times greater than the normal force, A large impact force of 1 ton was generated. As a result, since the cart was not used a few times and the lifting parts of the lifting wheel were deformed several times, the cart was not lifted to a predetermined height, causing an accident that the driving wheel and the guide wheel hit the orbit. A linear motion ball bearing which generates a tilting moment in a clockwise direction by the impact force acting on the cart frame and slides up and down, and a vertical base outer spherical bearing The impact force greatly affects the lifetime and stability of the device. In addition, since there is an equilibrium of various forces in the course of the overall orbit, if a change occurs in one force, it may fail to enter the orbit (for example, the contact pressure of the contact device is insufficient or the RTG is shaken) The demand is very high. The power that pressurizes the cart to the back plate is pressurized air, which is supplied to a cylinder, a direction selector valve, a pneumatic valve, a pressure limiting valve, an air pipe, a pump connecting part, a motor, a belt, The air pressure is insufficient even if a malfunction of the air conditioner occurs. The reliability of the pneumatic system itself is not high, and this design should use a pneumatic system with a relatively low resistance in order to activate the elasticity of the retractable arm during RTG driving. As a result, the overall system is influenced by the reliability of the most important entry and exit process of the cart. Also, the traction of the cart is realized through the contact device. In the course of running in the first half, the contact device presses the cart on the feed frame, the load of the feed frame is small and the base settling is small. However, in the case of RTG work, the load is 200 tons, and after long use of the main, the column base mainly has a relatively large sedimentation (or thermal insulation), and the sedimentation difference mainly on the base of the column base is more than 40 cm However, the cart provided by the above system can not be operated in a place where the sedimentation is severe because the up and down floating range at the end of the contact device is only ± 10 cm, and the cart can not be used for the linear ball bearing slide rigidity restriction, There is a defect in the design itself because the floating range can not be increased due to limitations on the size of the fin.

SUMMARY OF THE INVENTION The present invention provides a system and method for feeding a gantry crane equipped with a rubber tire, which is designed to solve the above problems and can overcome design defects and improve the reliability of the overall system through the provision of an independent contact device and a traction device .

The above objects of the present invention are realized through the following technical solutions.

In the automatic feed system of the gantry crane equipped with a rubber tire according to the present invention,

A current collecting cart including a frame, a guiding wheel, a traveling wheel, a current collector, and a sensor part, wherein the current collector and the cable of the sensor part are connected to the gantry crane;

A sliding contact line and a cart traveling wheel guide rail, and a collecting traveling cart guide portion located at an intermediate portion and an end portion, wherein the guide portion includes two upper and lower groups of guide grooves and a back plate, A gantry crane provided with a fixing guide plate; And

Wherein the gantry cranes are connected to both ends of a collecting cart including at least an elastic gyro so that the cart is automatically positioned in the middle of the feed frame in the guide portion and the collecting cart is pulled in the middle portion and moved together with the gantry cranes Apparatus,

The automatic feed system

Wherein the contact device includes a vertically moving mechanism, a horizontal stretching mechanism, and a coupling mechanism capable of realizing the connecting and separating function of the contact device and the electric collecting cart, Are connected to each other or separated from each other via a coupling mechanism in the up-and-down moving mechanism operation, and after the separation, the current collecting cart stops on the feeding frame through the guide wheel and the driving wheel;

The towing device and the contact device are separated from each other.

Completion and supplementation of the above description of the technique, the present invention further applies the following technical measures or any combination of these measures.

The coupling mechanism includes a first coupling part connected to the current collecting cart and a second coupling part connected to the contact device. When the first coupling part and the second coupling part move in opposite directions, , And the separation operation of both moves in the reverse direction.

The opening of the guide groove of the power supply frame guide portion faces upward. The rail openings of the intermediate guide rails can be both upwardly and downwardly directed, and if the openings are up, the current collecting carts in the guide and intermediate sections use the same group of guide wheels and traveling wheels; If one of the middle portion upper and lower guide rails faces downward, the current collecting cart is provided with two sets of independent guide wheels and a driving wheel, and is used for guide guide grooves and intermediate guide rails, respectively.

The up-and-down moving mechanism may be provided at a connecting end of the contact device and the gantry crane, or may be provided at a contact device and a traveling cart coupling stage. The up-down moving mechanism may include a guide position fixing mechanism, It is a guide rail.

The up-and-down moving mechanism is a cylinder, a hydraulic cylinder, a push rod, a pull rod, a worm gear mechanism, or a sprocket chain mechanism.

The horizontal extending / retracting mechanism is a double arm translating mechanism, a single arm translating mechanism, a stretching / translating mechanism, a guide rail type translating mechanism, or a trunk beam type feed arm translating mechanism.

The towing device includes a traction elastic gyrope, a protective stiffness gyrope and a ring hook mechanism, the elastic gyrope and the rigid gyrope forming a gyrope group, each being provided at both ends of the collecting cart, Connected to the current collecting cart through a ring hook mechanism, and connected to the gantry crane at the other end.

The width of the guide portion gradually decreases from forward to backward, the rear end of the guide portion communicates with the guide groove, and the width of the rear end of the guide portion is the same as the guide groove.

According to the present invention, there is provided an automatic power feeding method for a gantry crane equipped with a rubber tire, comprising the following steps.

1) confirming that the Gantry crane moves to the sliding contact line frame guide and the current collecting cart is connected to the contact device through the coupling mechanism;

2) The horizontally extending and contracted mechanism of the contact device is operated to push the current collecting cart parallel to the feed frame until the guide wheels of the current collecting cart are positioned on the back plate in front of the guide groove of the feed frame, Stopping the horizontal push operation;

3) The up-and-down movement mechanism of the contact device is operated to drive the coupling mechanism and the current collecting cart to move up and down along the back plate so that the guide wheel and the running wheel enter into the guide groove, step;

4) the up-and-down moving mechanism is continuously moved down so that the coupling mechanism is completely separated, and the cart stops on the feed frame;

5) operating the horizontal stretching mechanism to recover the contact device; And

6) The gantry crane pulls the current collecting cart through the traction device to allow the current collecting cart to advance to the middle of the sliding contact line, so that the horizontal direction of the guide wheel disposed in the horizontal direction And the cart is continuously advanced so that the carbon brush of the current collector on the cart is smoothly guided to the sliding contact line to be connected to the sliding contact line, After the energy is transferred to the gantry crane through the current collecting cart, the gantry crane can be immediately switched to mains power.

In the present invention, precise position fixation in the vertical and horizontal directions of the cart is implemented step by step through two independent mechanisms to ensure smoothness and reliability of entry into the cart track on the design, The damage was avoided; Since the cart and the contact device are separated and the cart is pulled through the elastic pulling device after the orbit enters, the carbon brush of the current collecting device can be reliably and reliably introduced to the safety sliding contact line, that is, Even if it is big, it can be used normally, is adaptable, and has active activity.

Are included in the scope of the present invention.

1 is a structural view of a cart and a contact device according to the present invention;
2 is another structural view of the cart and the contact device according to the present invention.
3 is another structural view of the cart and contact device according to the present invention.
4 is another structural view of the cart and contact device according to the present invention.
5 is another structural view of the cart and contact device according to the present invention.
6 is another structural view of the cart and contact device according to the present invention.
7 is another structural view of the cart and contact device according to the present invention.
Figs. 8 and 9 are views showing the structure of a cart and a feed frame according to the present invention. Fig.
10 is an enlarged view of a portion A in Fig.
10 is an enlarged view of a portion B in Fig.
12 is a structural view of a power supply frame guide unit according to the present invention.
Figs. 13 to 17 are diagrams showing a process of entering the current collecting cart track. Fig.

Example  One

In the automatic feed system of the gantry crane equipped with a rubber tire shown in Fig. 1, the current collecting cart 1 is connected on the contact device via a coupling mechanism, and on the current collecting cart 1, a guide wheel 12, An apparatus 11 is provided. In the contact device, the horizontal stretching mechanism 2 is provided with two symmetrical adjustment arms 21, which are located between the mounting frame 23 and the cart, and between the two adjustment arms, a telescopic rod 24 and a push rod 22 . The push rod implements lateral movement of the cart through varying the distance between the two adjustment arms. The up-down moving push rod mechanism 3 is provided between the contact device and the coupling mechanism, and is connected to the second coupling part of the coupling mechanism, and the first coupling part of the coupling mechanism is connected on the current collecting cart. The second coupling part faces up and causes the first coupling part to engage the second coupling part or to be displaced downwardly from one another.

Both ends of the current collecting cart 1 are connected to the RTG via the traction device 4 to implement traction, and one of the elastic rope for traction, the rigid rope for protection, the elastic rope, and the rope of one group must be elastic shall.

A sliding contact line 53 and a cart traveling wheel guide rail are provided on the power feeding frame 5 (Figs. 8 and 9), and a current collecting cart guide part located at an intermediate portion and an end portion is included. And the horizontal direction cart position fixing guide plate 52 is provided in the guide groove. The openings of the guide grooves face upward and have a constant depth and must exceed the height of the guide wheel (Fig. 11). (Fig. 12) is added to the guide groove in order to make it easier for the user to enter the orbit, and the inclined guide plate 511 is provided in the guide portion, the width of the guide portion gradually decreases from forward to backward, The rear end and the guide groove are communicated, and the width of the rear end of the guide portion is the same as the guide groove. The width of the guide groove is slightly larger than the guide wheel so that the guide wheel smoothly enters the orbit even in a slightly inclined state.

In the mechanism shown in Fig. 9, vertically moving push rod mechanisms 3 are provided on both sides of the horizontal stretching and shrinking mechanism 2, so that vertical positional movement is more effective.

10 is a type of coupling mechanism. The hook structure 6 includes a hook on the contact device and a ring on the current collecting cart 1. A roller or a cylinder 7 may be additionally provided on one surface of the contact device in contact with the current collecting cart so that the contact device moves up and down with respect to the cart.

Example  2

Except that a double arm translation mechanism is used and an up-and-down moving push rod mechanism 3 is installed between the horizontal extending mechanism 2 and the gantry crane in the automatic feed system of the gantry-equipped gantry crane shown in Fig. 2 , And the remaining part is the same as that of the first embodiment.

Example  3

In the automatic feed system of the gantry-equipped gantry crane shown in Fig. 3, except that the lateral movement of the cart is realized by adjusting between the two adjustment arms 21 in the double arm translation mechanism through the crank connection rod mechanism 25 And the remaining part is the same as that of the second embodiment.

Example  4

In the automatic feed system of the gantry-equipped gantry crane shown in Fig. 4, the horizontal stretching mechanism 2 uses a stretching and translating mechanism, and includes a slight expansion and contraction node. The up-and-down moving push rod mechanism 3 is installed between the mounting frame 23 and the gantry crane, and the mounting frame slides up and down on the vertical slide rail, and provides the driving force in the up-down moving push rod mechanism 3. The remaining part is the same as that of the second embodiment.

Example  5

In the automatic feed system of the gantry-equipped gantry crane shown in Fig. 5, the horizontal stretching mechanism uses a trunk-beam type translating mechanism and pushes or pulls the cart through mutual electromagnetism between the connecting rods 26. [ The up-and-down moving push rod mechanism 3 is provided between the trunk-beam type translating mechanism and the coupling mechanism, and the mounting frame 23 can also be moved vertically. The remainder is the same as in Example 1.

Example  6

In the automatic feed system of the gantry crane equipped with a rubber tire shown in Fig. 6, the horizontal stretching mechanism 2 and the single arm translating mechanism are used. The single arm translating mechanism includes a swing arm 29, a support rod 27, 28, and the push rod 28 drives the swing arm to change the angle to implement translational motion. The remaining part is the same as that of the fourth embodiment.

Example  7

In the automatic feed system of the gantry-equipped gantry crane shown in Fig. 7, the horizontal stretching mechanism 2 uses a rail type translating mechanism, and the stretching arm slides in the guide hole to realize translation. The remaining part is the same as that of the fourth embodiment.

The feeding process of this system is as follows.

1) connecting the current collecting cart to the contact device through the coupling mechanism (Fig. 13);

2) The horizontal stretching mechanism is operated to push the current collecting carts parallel to the feeding frame side until the guide wheels of the current collecting cart are positioned on the guide grooves of the feeding frame (Fig. 14);

3) The up-and-down moving mechanism is operated to drive the coupling mechanism and the current collecting cart to move up and down so that the guide wheel enters the guide groove (Fig. 15);

4) The up-and-down moving mechanism is moved downwardly to disengage the coupling mechanism, and the cart stops on the feed frame (Fig. 16);

5) the horizontal stretching mechanism operates to retrieve the contact device (Fig. 17);

6) The gantry crane pulls the current collecting cart through the traction device to allow the current collecting cart to advance to the middle of the sliding contact line, so that the horizontal direction of the guide wheel disposed in the horizontal direction The movement amount in the direction of the cart is reduced to realize position fixation in the horizontal direction of the cart; The cart continues to advance and is connected to the sliding contact line through the trumpet opening 512 so that the carbon brush of the current collector on the cart is smoothly guided to the sliding contact line,

Further, the current collecting device is connected to the sliding contact line, so that the electric energy of the sliding contact line is transmitted to the gantry crane through the current collecting cart.

On the same principle, when the cart is to be lowered on the feed frame after power feeding, it is very convenient because it requires only a few steps such as lateral movement, upward movement, hook movement, and movement in the lateral direction.

In the present invention, since the cart can be moved only according to a predetermined route, the cart can be stably completed with a small force and no shock is generated in the first half process. The track entry accuracy is high, that is, even if the vehicle body is slightly inclined, the orbit entry can be ensured; Since the contact and the traction are separated and the traction is completed using the elastic gyrope, the work can be carried out up to 1 m above the slope, and it is applied especially to the working environment where the settlement occurs in the RTG local part.

After completing the contact according to the present invention, that is, after completing the position fixation in the vertical direction on the feed frame of the cart, the contact device is immediately separated from the cart and recovered singly, (This pressure is generated by the reversing torque generated on the frame to overcome the cart gravity, through the guide plate for fixing the horizontal position, and it is only 5 to 15% of the weight of the cart, that is, 20KG or less), the moving space in the horizontal direction of the guide wheel is gradually reduced to fix the position of the cart in the horizontal direction, and then the current collector carbon brush enters the safety sliding contact line again by guiding action of the trumpet- ; In this case, the contact device only needs to contact and stop the current collecting cart, that is, both the up and down movement and the horizontal expansion and contraction operations are completed, and the reliability is greatly improved. And the cart is smooth and shock-free when both vertical and horizontal positioning operations are completed. In this way, the reliability of the first step is higher because the positioning of the two directions of up and down and horizontal directions is implemented, and then the introduction of the carbon brush of the current collector is completed again. Assuming that the traction rope length of the elastic traction device is about 3 meters and the maximum possible elongation (i.e., the stiffness rope length) is 0.2 meters, the possible elongation and vertical expansion / contraction of the cart in the vertical direction of the gantry crane are + 0.5 meter and ± 1 meter (3.2 * 3.2-3 * 3 = 1 * 1 + 0.5 * 0.5), and the extension of 0.2 meters is in the fully possible elastic deformation range and is restored to the initial length immediately after the external force is removed . In this case, the movable range of the gyro and the ring is generally in the middle position, and the range of possible position change of the cart with respect to the gantry crane of the cart in the horizontal direction and the vertical direction is 2 meters and 2 meters respectively, and the deflection (horizontal direction) (+/- 0.25) of the frame and mainly non-uniform sedimentation (i. E., Up and down direction) is at most 0.5 meters (+/- 0.25), the elastic gypsum is subjected to gantry crane deflection through the elastic deformation, It is possible to compensate for the deviation. Further, the center of the cart is generally located at a substantially same position as the center of the contact device due to the substantially similar pulling force in the forward and backward directions, In addition, the impact can be effectively mitigated. By virtue of the traction of the elastic rope, the elasticity and adaptability of the cart and the impact force exerted are superior to those of direct contact with relatively rigid contact devices.

The present invention can be applied not only to a new energy improvement item but also to a retrofit of an energy construction for manually operating a current collecting cart, that is, a slight modification to a manually operated cart, It is very easy to install the guide portion with the opening upward so that the cart can enter the track. If the guide portion and the RTG main body can be placed on the same base, accurate track entry of the cart can be ensured.

The up-and-down moving mechanism applied to the present invention can be realized by mechanisms other than the above-described push rod, cylinders, hydraulic cylinders, push rods, pull rods, mechanical transmission such as worm gear mechanisms, sprocket chain mechanisms, The type of equipment and the installation location of both can be selected by demand.

While the present invention has been shown and described with respect to specific embodiments thereof, the present invention is not limited to the above-described embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. Therefore, the scope of protection of the present invention conforms to the claims.

Claims (9)

1. A current collecting cart comprising a guide wheel, a traveling wheel, a current collector, and a sensor component formed on a frame, wherein a current collector of the current collector of the current collector and a cable of the sensor component are connected to a gantry crane;
A gantry crane having a pair of upper and lower guide grooves and a back plate and a guide groove for fixing the horizontal position of the cart in the guide groove, A feed frame installed in the frame; And
Wherein the gantry cranes are connected to both ends of a collecting cart including at least an elastic gyro so that the cart is automatically positioned in the middle of the feed frame in the guide portion and the collecting cart is pulled in the middle portion and moved together with the gantry cranes Device;
And an automatic feed system for a gantry crane equipped with a rubber tire,
The automatic feed system further comprises a contact device installed on the side of the gantry crane,
The contact device comprises:
Horizontal stretching mechanism;
A coupling mechanism capable of implementing a connection and disconnection function of the contact device and the current collecting cart; And
And a vertical movement mechanism provided between the contact device and the coupling mechanism,
The contact device and the current collecting cart are connected to each other or separated from each other through the coupling mechanism during operation of the up-and-down moving mechanism. After the separation, the current collecting cart stops on the feed frame through the guide wheel and the traveling wheel,
Wherein the towing device and the contact device are separated from each other. The method according to claim 1,
The coupling mechanism includes a first coupling part connected to the current collecting cart and a second coupling part connected to the contact device. When the first coupling part and the second coupling part move in opposite directions, , And a separating operation of the gantry crane when moving in the reverse direction occurs. 3. The method of claim 2,
And the opening of the guide groove of the power supply frame guide portion is directed upward. The method of claim 3,
The up-and-down moving mechanism is provided at a connecting end of the contact device and the gantry crane, or is installed at the contact device and the traveling cart coupling stage. The up-and-down moving mechanism is provided with a guide position fixing mechanism, Wherein the gantry crane is a guide rail. 5. The method of claim 4,
Wherein the up-down movement mechanism is a cylinder, a hydraulic cylinder, a push rod, a pull rod, a worm gear mechanism, or a sprocket chain mechanism. 5. The method of claim 4,
The horizontal extending / retraction mechanism is a trunk-beam type translating mechanism that pushes or pulls a cart through mutual electromagnet mixing between a double arm translating mechanism, a single arm translating mechanism, a telescopic translating mechanism, a guide rail type translating mechanism, Automatic feeding system of gantry cranes with rubber tires. 7. The method according to any one of claims 4 to 6,
The towing device includes a traction elastic gyrope, a protective rigid gyrope, and a ring hook mechanism, wherein the elastic gypsum and rigid gyrope form a gyrope group, each of which is provided at each end of the collecting cart, Wherein the gantry crane is connected to a current collecting cart through a ring hook mechanism and the other end is connected to a gantry crane. 7. The method according to any one of claims 4 to 6,
Wherein a guide portion is formed at a front end of the guide groove and the width of the guide portion gradually decreases from forward to backward, the rear end of the guide portion communicates with the guide groove, and the rear end width of the guide portion is the same as the guide groove. Automatic feeding system of crane. A method of automatically feeding a gantry crane equipped with a rubber tire according to claim 2,
1) confirming that the Gantry crane moves to the sliding contact line frame guide and the current collecting cart is connected to the contact device through the coupling mechanism;
2) The horizontally extending and retracted mechanism of the contact device is operated to push the current collecting cart parallel to the feed frame side until the guide wheels of the current collecting cart are positioned on the back plate in front of the guide groove of the feed frame, Stopping the pushing operation;
3) The up-and-down movement mechanism of the contact device is operated to drive the coupling mechanism and the current collecting cart to move up and down along the back plate so that the guide wheel and the running wheel enter into the guide groove, step;
4) the up-and-down moving mechanism is continuously moved down so that the coupling mechanism is completely separated, and the cart stops on the feed frame;
5) operating the horizontal stretching mechanism to recover the contact device; And
6) The gantry crane pulls the current collecting cart through the traction device to allow the current collecting cart to advance to the middle of the sliding contact line, so that the horizontal direction of the guide wheel disposed in the horizontal direction The movement amount in the direction of the cart is reduced to realize position fixation in the horizontal direction of the cart; The cart continues to advance so that the carbon brush of the current collector on the cart is smoothly guided to the sliding contact line and is connected to the sliding contact line and after the electric energy of the sliding contact line is transmitted to the gantry crane through the current collecting cart, Wherein the gantry crane is connected to the gantry crane.

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