Electric cathead device based on servo motor driving

Abstract

The electric cathead device based on servo motor driving is provided with a cathead body, the cathead body comprises a cathead base, an electric cylinder assembly is installed on the cathead base in an integrated and modularized mode, the servo motor serves as a power source of the electric cylinder assembly, and lifting displacement of a movable pulley block installed at the power output top end of the electric cylinder assembly is achieved; a fixed pulley block is further installed on one side of the cathead base, the fixed end of the steel wire rope lock is connected with the cathead base, and the free end of the steel wire rope lock winds around the movable pulley block from bottom to top, then winds out of the bottom of the fixed pulley block and finally is connected with a dragged object to achieve dragging displacement of the steel wire rope lock. The electric drive cathead is adopted to replace a hydraulic drive head to achieve dragging of the steel wire rope, the problems of environmental pollution and potential safety hazards existing in the hydraulic drive cathead are solved, the control precision is high, the response speed is high, reliability is good, and integrated control is easy to achieve; the modular design is achieved, the structure is compact, safe, reliable, economical and practical.

Description

Technical Field

[0001] The invention belongs to the technical field of oil drilling machinery and equipment, and in particular relates to an electric cathead device driven by a servo motor. Background Art

[0002] The cathead is a mechanized tool for oil drilling rigs at the wellhead. It is used in conjunction with a lifting tong to make and break out drilling tools such as drill pipes, drill collars, and casing on land and offshore drilling rigs.

[0003] Currently, most catheads used in oil drilling rigs are hydraulically driven. This type of drive often results in environmental pollution caused by hydraulic oil leakage, and high-pressure hydraulic oil leakage also poses a safety hazard. To address this, the following technical solution is proposed. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide an electric cathead device driven by a servo motor, which uses an electric cathead instead of a liquid-driven cathead to drag the wire rope, thereby solving the environmental pollution problems and safety hazards of the liquid-driven cathead.

[0005] The technical solution adopted by the present invention is: an electric cathead device driven by a servo motor, comprising a cathead main body, the cathead main body including a cathead base, the cathead base integrated with and modularly installed with an electric cylinder assembly, the electric cylinder assembly adopts a servo motor as a power source to realize the lifting and lowering displacement of the movable pulley group installed at the top of the power output of the electric cylinder assembly; a fixed pulley group is also installed on one side of the cathead base, the fixed end of the wire rope lock is connected to the cathead base, the free end passes around the movable pulley group from bottom to top, and then comes out from the bottom of the fixed pulley group, and finally connected to the towed object to realize the dragging displacement of the wire rope lock.

[0006] In the above technical solution, further: the servo motor is decelerated by the reduction mechanism and driven by the spiral transmission pair in sequence to realize the lifting and lowering displacement of the movable pulley group, and the reduction mechanism is used to increase the output torque of the servo motor.

[0007] In the above technical solution, further: the reduction mechanism is composed of a planetary reducer and a gear reducer in sequence; the helical transmission pair is composed of a roller nut as power input and a screw shaft as power output; the power output shaft of the gear reducer is connected to the roller nut to realize the linear lifting displacement of the screw shaft, and the screw shaft drives the movable pulley group to realize the lifting displacement of the movable pulley group.

[0008] In the above technical solution, further: the servo motor is an explosion-proof servo motor.

[0009] In the above technical solution, further: it also includes: a control system, the control system has an explosion-proof control box, the servo drive, brake resistor, and control loop are encapsulated in the explosion-proof control box; a display control screen is integrated outside the explosion-proof control box, and the display control screen is connected to the input end of the control loop; the output end of the control loop is connected to the input end of the servo drive, the servo drive is connected to the power line of the servo motor, the servo motor is also connected to the encoder line of the servo drive, and the brake resistor is connected to the DC bus of the servo drive; it also includes a torque sensor, a speed sensor and a monitoring system, the output ends of the torque sensor and the speed sensor are connected to the input end of the monitoring system, and the output end of the monitoring system is connected to the input end of the display control screen.

[0010] Among them, the display control screen is used to send control instructions and display the system status; it is used to realize parameter display and setting, and adjust the servo motor output torque and speed as needed to adapt to the dragging requirements under different load conditions; the control loop is used to generate PWM signals or digital instructions to adjust the output current / voltage of the servo driver; the servo driver is used to convert DC power into three-phase AC power and drive the servo motor to rotate; the servo motor feedback speed, position and direction signals to realize closed-loop control; specifically: the servo motor acts as an actuator, and is connected to the servo driver through its power lines U, V, W and encoder feedback lines A, B, Z phases; the braking resistor consumes the regenerative energy generated when the motor decelerates to prevent the bus voltage from exceeding the threshold; the speed sensor measures the motor speed, and the torque sensor measures the motor output shaft torque, which is converted into electrical signals. The monitoring system collects sensor data, issues an over-limit alarm and displays a real-time curve.

[0011] In the above technical solution, further: the control system is also electrically connected to the upper limit switch and the lower limit switch through wires. The upper limit switch and the lower limit switch are magnetic switches and are respectively installed near the upper and lower limit positions of the screw shaft movement trajectory; the magnetic switch detects whether the screw shaft has reached the limit position by sensing the position of a specific magnetic component on the screw shaft, thereby realizing automatic start and stop control of the lifting and lowering limit positions of the screw shaft.

[0012] In the above technical solution, further: a vertically upward electric cylinder assembly is installed in the cathead base, and the electric cylinder assembly is fixedly connected to the cathead base through the cylinder body; the upper limit switch and the lower limit switch are fixedly installed on the side wall of the cylinder body.

[0013] In the above technical solution, further: it also includes a rotating pin, and the fixed pulley group is installed on the side of the cathead base so that it can swing left and right through the rotating pin. The swingable fixed pulley group is used to adapt to different pulling directions of the wire rope lock; the cathead base is also provided with a limit block or an arc groove, and the limit block or arc groove is used to limit the left and right displacement swing of the fixed pulley group.

[0014] In the above technical solution, further: it also includes a guide frame, the guide frame is slidably adapted to be connected to the movable pulley group, and the guide frame provides a linear guide for the lifting displacement of the movable pulley group.

[0015] In the above technical solution, further: it also includes a rope clamp seat, and the wire rope lock is fixedly connected to the cat head base through the rope clamp seat.

[0016] The advantages of the present invention compared with the prior art are:

[0017] 1. The electric drive mode of the present invention effectively avoids the environmental pollution and safety hazards caused by hydraulic drive, while improving the control accuracy and response speed of the cathead.

[0018] 2. The reduction mechanism composed of the planetary reducer and the gear reducer of the present invention significantly improves the output torque of the servo motor, meeting the high torque requirement for the lifting and displacement of the screw shaft. The high torque output ensures that the device can still work stably and reliably under heavy load or harsh working conditions; the coordinated winding method of the wire rope lock on the movable and fixed pulley sets works together to achieve labor-saving load; the spiral transmission pair has the advantages of high transmission efficiency and good self-locking performance, so that the lifting and displacement of the screw shaft can be dragged efficiently, labor-savingly and stably.

[0019] 3. The present invention adopts a service motor as a power source and is used in conjunction with a collaborative control system to facilitate high-precision automatic control and intelligent monitoring, ensuring the position accuracy, safety and reliability of the operation.

[0020] 4. The electric cylinder assembly of the present invention integrates the servo motor, planetary reducer, gear reducer and screw shaft into one, with modular installation, compact structure and easy maintenance. It meets the control requirements of high efficiency and high precision, effectively reduces accident risks and maintenance costs, and improves the overall operating efficiency of the device.

[0021] 5. The explosion-proof servo motor of the present invention is combined with an explosion-proof control box, which has high safety and adaptability to harsh environments. It not only meets the explosion-proof requirements of the operating area, but also allows the user to observe and set relevant control system parameters through the display control screen, and adjust the servo motor output torque and speed as needed to meet the dragging requirements under different load conditions.

[0022] 6. The control system of the present invention is electrically connected to the upper limit switch and the lower limit switch. When the screw shaft moves to the limit position, the upper and lower limit switches send electrical signals to the control system to stop the equipment in time, thereby playing a safety protection role.

[0023] 7. The fixed pulley block of the present invention can swing left and right around the cathead base, so that the fixed pulley block can adapt to different pulling directions of the wire rope, reduce wire rope wear and transmission efficiency loss caused by angle deviation, and have an anti-overswing function to prevent the wire rope from falling out of the groove or equipment damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the main view of the present invention;

[0025] Figure 2 for Figure 1 Main view of the electric cylinder assembly;

[0026] Figure 3 for Figure 1 Main perspective view of the medium explosion-proof control box;

[0027] Figure 4 for Figure 3 Side view of;

[0028] Figure 5 This is a block diagram of the connection principle of the control system of the present invention.

[0029] In the figure: 1-cathead body, 2-control system, 101-cathead base, 102-fixed pulley block, 103-rotating pin, 104-electric cylinder assembly, 105-movable pulley block, 106-guide frame, 107-wire rope lock, 108-rope clamp; 201-explosion-proof control box, 202-servo drive, 203-display control panel, 204-brake resistor, 205-control circuit; 104-1-servo motor, 104-2-planetary reducer, 104-3-gear reducer, 104-4-cylinder body, 104-5-roller nut, 104-6-screw shaft, 104-7 upper limit switch, 104-8-lower limit switch. DETAILED DESCRIPTION

[0030] The following is a combination of the embodiments of the present invention Figure 1-4 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0031] (like Figure 1(As shown) An electric cathead device based on servo motor drive has a cathead body 1, the cathead body 1 includes a cathead base 101, the cathead base 101 is integrated and modularly installed with an electric cylinder assembly 104, the electric cylinder assembly 104 uses a servo motor 104-1 as a power source to achieve the lifting and displacement of the movable pulley group 105 installed at the top of the power output of the electric cylinder assembly 104; it should be noted that the servo motor 104-1 here is mainly a linear servo motor, that is, a linear servo motor is directly used to replace the hydraulic cylinder to achieve lifting and displacement drive. A fixed pulley group 102 is also installed on one side of the cathead base 101. The fixed end of the wire rope lock 107 is connected to the cathead base 101. After the free end passes around the movable pulley group 105 from bottom to top, it is wound out from the bottom of the fixed pulley group 102 and finally connected to the towed object to achieve the dragging displacement of the wire rope lock 107.

[0032] It should be noted that the present invention adopts an electric-driven cathead instead of a liquid-driven head to achieve the dragging of the wire rope lock 107, thereby solving the environmental pollution problems and safety hazards of the liquid-driven cathead. The electric drive method based on the servo motor 104-1 as the power source not only effectively avoids the environmental pollution and safety hazards caused by hydraulic drive, but also helps to improve the control accuracy and response speed of the cathead.

[0033] In the above embodiment, the servo motor 104-1 is further configured to achieve the lifting and lowering displacement of the movable pulley assembly 105 after being decelerated by a reduction mechanism and then driven by a helical transmission pair. The reduction mechanism is used to increase the output torque of the servo motor 104-1. It should be noted that the servo motor 104-1 described herein is a rotary servo motor. In this case, the power output shaft of the servo motor 104-1 is decelerated by the reduction mechanism and then driven by a helical transmission pair, converting the motor's rotational motion into linear motion to achieve the lifting and lowering displacement.

[0034] It should be noted that: the servo motor 104-1 of the present invention is combined with a reduction mechanism and a spiral transmission pair to realize the technical solution of the lifting and lowering displacement of the movable pulley group 105, and realizes micron-level positioning and trajectory tracking through high-precision closed-loop control; torque amplification and smooth transmission meet the requirements of heavy load and low speed; the servo motor 104-1 can withstand 3 times the rated torque load, and the inertial buffering effect of the reduction mechanism can reduce the load impact, optimize the dynamic response, and adapt to high-speed start-stop and complex trajectories; the compact structure design saves space and maintenance costs; the four core advantages significantly improve the performance and reliability of the dragging system.

[0035] (like Figure 2 As shown in the above embodiment, further: the reduction mechanism is composed of a planetary reducer 104-2 and a gear reducer 104-3 in sequence; the helical transmission pair is composed of a roller nut 104-5 as a power input and a screw shaft 104-6 as a power output.

[0036] Specifically, the power output shaft of the servo motor 104-1 is connected to the power input shaft of the planetary reducer 104-2, the power output end of the planetary reducer 104-2 is connected to the power input end of the gear reducer, and the power output end of the gear reducer 104-3 is connected to the roller nut 104-5, so as to realize the linear lifting displacement of the screw shaft 104-6 screwed with the roller nut 104-5, and then the screw shaft 104-6 drives the movable pulley group 105 to realize the lifting displacement of the movable pulley group 105.

[0037] More specifically: the roller nut 104-5 is fixed to the cylinder body 104-4 through a bearing, and the roller nut 104-5 is only allowed to rotate, and the roller nut 104-5 cannot move axially. Therefore, the rotating roller nut 104-5 realizes the lifting and displacement of the screw shaft 104-6, and the lifting and lowering screw shaft 104-6 drives the movable pulley group 105 to lift and lower, realizing the dragging and displacement movement of the wire rope lock 107, thereby achieving the purpose of dragging the wellhead lifting tool and unhooking the pipe string.

[0038] It should be noted that the present invention's two-stage reduction mechanism, consisting of planetary reducer 104-2 and gear reducer 104-3, combined with the roller screw helical transmission pair consisting of roller nut 104-5 and screw shaft 104-6, significantly improves the performance and reliability of the movable pulley assembly 105 lifting system through its four core advantages: high torque density, high transmission accuracy, high dynamic response, long life, and low maintenance. This significantly increases the output torque of servo motor 104-1, meeting the low-speed, high-torque transmission requirements of screw shaft 104-6 for lifting and lowering. This high-torque output ensures stable and reliable operation of the device even under heavy loads or harsh operating conditions. The roller screw helical transmission pair, consisting of roller nut 104-5 and screw shaft 104-6, provides high-precision, long-life linear motion conversion. In conjunction with the winding method of the wire rope lock 107 on the movable and fixed pulley groups, effort-saving load is achieved; in addition, the spiral transmission pair of the present invention has the advantages of high transmission efficiency and good self-locking performance, so that the lifting and lowering displacement of the screw shaft 104-6 can be achieved efficiently, labor-savingly and stably by dragging displacement.

[0039] In the above embodiment, further: the servo motor 104 - 1 is an explosion-proof servo motor.

[0040] It should be noted that the present invention uses an explosion-proof servo motor in combination with the explosion-proof control box 201 described later, which has high safety, adaptability to harsh environments, and meets the explosion-proof requirements of the operating area. The use of an explosion-proof servo motor drive is highly safe and adaptable to harsh environments; the anti-interference ability makes the device stable in operation, reduces failures, and reduces maintenance costs; the explosion-proof standard compliance is high, meeting the use requirements of the oil drilling industry; the explosion-proof servo motor maintains its explosion-proof characteristics while still having high-precision control, fast response and high-efficiency output capabilities, which can meet the precise requirements of the electric cathead device for drag displacement; the explosion-proof servo motor is preferably used, with its high torque density and low inertia design, so that the device can still maintain stable dynamic performance when overloaded or quickly started and stopped; it is not only durable but also convenient and simplified maintenance process; and the modular design reduces the complexity and time cost of on-site maintenance.

[0041] (like Figure 3 、 Figure 4 、 Figure 5 (As shown in the above embodiment, further: it also includes a control system 2, the control system 2 has an explosion-proof control box 201, and the explosion-proof control box 201 encapsulates a servo driver 202, a brake resistor 204, and a control circuit 205. The explosion-proof control box 201 is integrated with a display control screen 203. The display control screen 203 is connected to the input end of the control circuit 205; the output end of the control circuit 205 is connected to the input end of the servo driver 202, the servo driver 202 is connected to the power line of the servo motor 104-1, the servo motor 104-1 is also connected to the encoder line of the servo driver 02, and the brake resistor 204 is connected to the DC bus of the servo driver 202; it also includes a torque sensor, a speed sensor and a monitoring system, the output ends of the torque sensor and the speed sensor are connected to the input end of the monitoring system, and the output end of the monitoring system is connected to the input end of the display control screen 203.

[0042] The display control screen 203 is used to send control commands and display system status; it is used to display and set parameters, and to adjust the servo motor's output torque and speed as needed to accommodate dragging requirements under different load conditions. The display control screen 203 includes a human-machine interface, with the display control screen 203 acting as a client and the PLC or servo driver 202 within the explosion-proof control box 201 acting as a server to implement read-write control. The control loop 205 is used to generate PWM signals or digital commands to adjust the output current / voltage of the servo driver 202, thereby adjusting the speed of the servo motor 104-1. The servo driver 202 is used to convert direct current (DC) into three-phase alternating current (AC) and drive the servo motor 104-1 to rotate. The servo motor 104-1 provides feedback of speed, position, and direction signals to achieve closed-loop control. Specifically, the servo motor 104-1, acting as an actuator, is connected to the servo driver 202 via its power lines U, V, and W and encoder feedback lines A, B, and Z. The braking resistor 204 consumes the regenerative energy generated when the motor decelerates to prevent the bus voltage from exceeding the threshold; the speed sensor measures the rotational speed of the servo motor 104-1, and the torque sensor measures the output shaft torque of the servo motor 104-1 and converts them into electrical signals; the monitoring system collects sensor data, issues an over-limit alarm, and displays a real-time curve.

[0043] It should be noted that: in addition to using the servo motor 104-1 as the power source, the present invention is used in combination with the collaborative control system 2 to facilitate the realization of high-precision automatic control and intelligent monitoring, ensuring the position accuracy, safety and reliability of the operation. The electrically driven cathead device can automatically complete the dragging and displacement tasks of different loads through preset programs and parameters, thereby improving work efficiency, safety and reliability. Equipped with sensors and monitoring systems, various parameters (such as torque, speed, etc.) in the dragging and displacement process are monitored in real time to ensure the safety and reliability of the operation. In addition, the display control screen 203 of the present invention observes and sets the relevant parameters of the control system, and adjusts the output torque and speed of the servo motor 104-1 according to demand to adapt to the dragging requirements under different load conditions.

[0044] In the above embodiment, further: the control system 2 is also electrically connected to the upper limit switch 104-7 and the lower limit switch 104-8 via wires. Specifically, the upper limit switch 104-7 and the lower limit switch 104-8 are connected to the limit input port of the servo driver 202. Preferably: the upper limit switch 104-7 and the lower limit switch 104-8 are magnetic switches, and the upper limit switch 104-7 and the lower limit switch 104-8 are respectively installed near the upper and lower limit positions of the motion trajectory of the screw shaft 104-6; the magnetic switches detect whether the screw shaft 104-6 has reached the limit position by sensing the position of a specific magnetic component on the screw shaft 104-6, thereby realizing automatic start and stop control of the lifting limit position of the screw shaft 104-6.

[0045] It should be noted that the servo driver 202 in the control system 2 of the present invention is electrically connected to the upper limit switch 104-7 and the lower limit switch 104-8 via wires. When the screw shaft 104-6 moves to the limit position, the upper and lower limit switches send electrical signals to the control system 2, stopping the equipment in time and providing safety protection. Specifically, the upper limit switch 104-7 is installed near the maximum extension position of the screw shaft 104-6, and the lower limit switch 104-8 is installed near the minimum extension position or fully retracted position of the screw shaft 104-6. The principle is as follows: the magnetic switch triggers the switching action by sensing the position of a magnetic element (such as a magnet) installed on the end of the screw shaft 104-6 or the movable pulley group 105. When the screw shaft 104-6 or the movable pulley group 105 moves to the upper limit or lower limit, the magnetic switch senses the magnetic element, triggers the switch, and outputs a signal to the control system 2. Based on the received signals, control system 2 determines the position of screw shaft 104-6 or movable pulley assembly 105 and controls the start, stop, or reverse rotation of servo motor 104-1 to prevent it from exceeding the safe travel range. Magnetic switches, the core technology of upper limit switch 104-7 and lower limit switch 104-8, offer significant advantages in industrial drag systems, particularly in explosion-proofing, corrosion resistance, and long life.

[0046] In the above embodiment, further: a vertically upward electric cylinder assembly 104 is installed in the cathead base 101, and the electric cylinder assembly 104 is fixedly connected to the cathead base 101 through the cylinder body 104-4; the upper limit switch 104-7 and the lower limit switch 104-8 are fixedly installed on the side wall of the cylinder body 104-4.

[0047] It should be noted that the electric cylinder assembly 104 of the present invention integrates the servo motor 104-1, the planetary reducer 104-2, the gear reducer 104-3, and the screw shaft 104-6 into one, with an integrated modular installation structure. The structure is compact and easy to maintain, while meeting the control requirements of high efficiency and high precision, effectively reducing the risk of accidents and maintenance costs, and improving the overall operating efficiency of the device.

[0048] In the above embodiment, further: it also includes a rotating pin 103, and the fixed pulley group 102 is installed on the side of the cathead base 101 so as to be able to swing left and right through the rotating pin 103. The swingable fixed pulley group 102 is used to adapt to different pulling directions of the wire rope lock 107; the cathead base 101 is also provided with a limit block or an arc groove, and the limit block or arc groove is used to limit the left and right displacement swing of the fixed pulley group 102.

[0049] Specifically: the mounting hole of the fixed pulley block 102 is clearance-matched with the rotating pin 103, allowing the fixed pulley block 102 to swing. In order to limit excessive swinging, a limit block or an arc groove can be set on the cathead base 101 to limit the swing range of the fixed pulley block 102, preventing excessive swinging from causing the wire rope to fall out of the groove or damage the equipment. When the pulling direction of the wire rope lock 107 changes due to changes in drilling conditions (such as drill bit offset, wellhead angle adjustment), the fixed pulley block 102 automatically adjusts the angle by swinging to ensure that the wire rope always fits with the pulley groove. Therefore, the swing function enables the wire rope lock 107 to maintain the optimal force direction, reducing wire rope wear and transmission efficiency loss caused by angle deviation. In addition, the swing function of the fixed pulley block 102 can adapt to complex working conditions, improve transmission efficiency, avoid damage, extend the service life of the equipment, reduce maintenance costs, improve safety and reliability, and has a simple structure and is easy to maintain.

[0050] In the above embodiment, further: a guide frame 106 is also included, and the guide frame 106 is slidably adapted to be connected to the movable pulley group 105. The guide frame 106 provides a linear guide for the lifting displacement of the movable pulley group 105, ensuring the safety, efficiency and stability of the dragging displacement.

[0051] The above embodiment further includes a rope clamp 108, through which the wire rope lock 107 is fixedly connected to the cathead base 101. As the key connecting component between the wire rope lock 107 and the cathead base 101, the rope clamp 108 significantly improves the safety, reliability, and maintenance efficiency of the towing system through its three core advantages: structural optimization, mechanical reinforcement, and standardized installation.

[0052] The working principle of the present invention is as follows: before use, the electric cathead device is fixed to a suitable position on the drilling table of the oil drilling rig through the cathead base 101, and the wire rope lock 107 is connected to the wellhead tool (such as a lifting clamp) that needs to be towed. When in use: the servo motor 104-1 of the electric cylinder assembly 104 is used as a power source, and the servo motor 104-1 accurately controls its speed and direction by receiving instructions from the control system. The output shaft of the servo motor 104-1 is connected to the reduction mechanism, and the reduction mechanism converts the high-speed rotational motion of the servo motor 104-1 into the low-speed, high-torque rotational motion of the roller nut 104-5 through the planetary reducer 104-2 and the gear reducer 104-3. The design of the reduction mechanism is to increase the output torque to meet the torque requirements required for the lifting and lowering displacement of the screw shaft 104-6. The roller nut 104-5 cooperates with the screw shaft 104-6 to form a spiral transmission pair. The output shaft of gear reducer 104-3 is connected to roller nut 104-5. When roller nut 104-5 rotates, screw shaft 104-6 moves up and down along its axis. As screw shaft 104-6 moves up and down, movable pulley assembly 105 also moves up and down synchronously, thereby dragging wire rope 107. By controlling the rotation of servo motor 104-1, wire rope lock 107 pulls the tongs, enabling the make-up and break-out of drilling tools such as drill pipe, drill collars, and casing during oil drilling.

[0053] From the above description, it can be seen that the present invention preferably utilizes an explosion-proof servo motor as the power source. While meeting the requirements of existing hydraulically driven catheads, it effectively avoids the environmental pollution caused by hydraulic oil leakage and the safety hazards associated with high-pressure hydraulic oil leakage. Furthermore, the use of high-precision servo motor 104-1 significantly improves the control accuracy and response speed of the cathead, meeting the requirements. The coordinated reduction mechanism and the combination of movable and fixed pulleys effectively increase the operating load. Combined with a control system, it can adapt to towing requirements under varying load conditions.

[0054] In summary, the present invention has high control accuracy, fast response speed, good reliability, and is easy to implement integrated control. At the same time, it avoids the environmental pollution problems and safety hazards caused by hydraulic oil leakage in traditional hydraulic catheads; it has a modular design, compact structure, safety, reliability, economy and practicality.

[0055] Each embodiment in this specification is described in a related manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications and equivalent replacements made within the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. An electric cathead device driven by a servo motor, comprising a cathead body (1), wherein the cathead body (1) includes a cathead base (101), and is characterized in that: The cathead base (101) is integrated and modularly installed with an electric cylinder assembly (104), and the electric cylinder assembly (104) adopts a servo motor (104-1) as a power source to realize the lifting and lowering displacement of a movable pulley group (105) installed at the power output top of the electric cylinder assembly (104); a fixed pulley group (102) is also installed on one side of the cathead base (101), and the fixed end of the wire rope lock (107) is connected to the cathead base (101), and the free end is wound around the movable pulley group (105) from bottom to top, and then wound out from the bottom of the fixed pulley group (102), and finally connected to the towed object to realize the dragging displacement of the wire rope lock (107).

2. The electric cathead device according to claim 1, characterized in that: The servo motor (104-1) is decelerated by a deceleration mechanism and then driven by a spiral transmission pair to achieve the lifting displacement of the movable pulley group (105). The deceleration mechanism is used to increase the output torque of the servo motor (104-1).

3. The electric cathead device according to claim 2, characterized in that: The reduction mechanism is composed of a planetary reducer (104-2) and a gear reducer (104-3) in sequence; the helical transmission pair is composed of a roller nut (104-5) as a power input and a screw shaft (104-6) as a power output; the power output shaft of the gear reducer (104-3) is connected to the roller nut (104-5) to achieve linear lifting displacement of the screw shaft (104-6), and the screw shaft (104-6) drives the movable pulley group (105) to achieve lifting displacement of the movable pulley group (105).

4. The electric cathead device according to any one of claims 1 to 3, characterized in that: The servo motor (104-1) is an explosion-proof servo motor.

5. The electric cathead device according to claim 4, characterized in that: The invention also includes a control system (2), wherein the control system (2) has an explosion-proof control box (201), wherein a servo driver (202), a brake resistor (204), and a control circuit (205) are encapsulated in the explosion-proof control box (201); a display control screen (203) is integrated outside the explosion-proof control box (201), and the display control screen (203) is connected to the input end of the control circuit (205); the output end of the control circuit (205) is connected to the input end of the servo driver (202), the servo driver (202) is connected to the power line of the servo motor (104-1), the servo motor (104-1) is also connected to the encoder line of the servo driver (02), and the brake resistor (204) is connected to the DC bus of the servo driver (202); and the invention also includes a torque sensor, a speed sensor, and a monitoring system, wherein the output ends of the torque sensor and the speed sensor are connected to the input end of the monitoring system, and the output end of the monitoring system is connected to the input end of the display control screen (203).

6. The electric cathead device according to claim 5, characterized in that: The control system (2) is also electrically connected to an upper limit switch (104-7) and a lower limit switch (104-8) via a wire. The upper limit switch (104-7) and the lower limit switch (104-8) are magnetic switches and are respectively installed near the upper and lower limit positions of the motion trajectory of the screw shaft (104-6). The magnetic switch detects whether the screw shaft (104-6) has reached the limit position by sensing the position of a specific magnetic component on the screw shaft (104-6), thereby realizing automatic start and stop control of the lifting limit position of the screw shaft (104-6).

7. The electric cathead device according to claim 6, characterized in that: An electric cylinder assembly (104) facing vertically upward is mounted inside the cathead base (101), and the electric cylinder assembly (104) is fixedly connected to the cathead base (101) via a cylinder body (104-4); the upper limit switch (104-7) and the lower limit switch (104-8) are fixedly mounted on the side wall of the cylinder body (104-4).

8. The electric cathead device according to claim 7, characterized in that: The invention also includes a rotating pin (103), and a fixed pulley group (102) is installed on the side of the cat head base (101) so as to be swingable left and right through the rotating pin (103). The swingable fixed pulley group (102) is used to adapt to different pulling directions of the wire rope lock (107); the cat head base (101) is also provided with a limit block or an arc groove, and the limit block or the arc groove is used to limit the left and right displacement swing of the fixed pulley group (102).

9. The electric cathead device according to claim 8, characterized in that: The invention also comprises a guide frame (106), wherein the guide frame (106) is slidably adapted to be connected to the movable pulley group (105), and the guide frame (106) provides a linear guide for the lifting displacement of the movable pulley group (105).

10. The electric cathead device according to claim 9, characterized in that: It also includes a rope clamp seat (108), and the wire rope lock (107) is fixedly connected to the cat head base (101) through the rope clamp seat (108).

Images