A chain tightening method for scraper conveyor

Abstract

The present invention discloses a chain tightening method for a scraper conveyor, which belongs to the field of scraper conveyors. The method is a chain tightening method using a torque-limited deceleration permanent magnet variable frequency drive system. The torque-limited deceleration permanent magnet variable frequency drive system includes a drive unit, a brake, a frequency converter and a controller. The drive unit includes a permanent magnet synchronous motor and a gear transmission unit with a deceleration setting. The method includes the following steps: S10, controlling the permanent magnet synchronous motor to rotate at a low speed through the frequency converter to drive the tail sprocket of the scraper conveyor to rotate and complete the chain lifting action; S20, using a brake to brake the entire drive unit; S30, releasing the braking torque of the permanent magnet synchronous motor, and powering off the frequency converter; S40, manually intervening to connect the chain and complete the chain tightening work. The present invention uses a brake to brake the entire drive unit during the manual intervention process, releases the torque of the permanent magnet synchronous motor, and powers off the frequency converter, which can ensure the absolute safety and reliability of personnel in the chain connection process.

Description

Technical Field

[0001] The invention belongs to the field of scraper conveyors, and in particular relates to a chain tightening method for scraper conveyors. Background Art

[0002] As one of the "three machines" indispensable for the comprehensive mining face in underground coal mines, the scraper conveyor not only transports coal and materials, but also serves as the running track for the coal mining machine. The quality of its performance directly affects the efficiency of the entire underground mining.

[0003] Scraper conveyor is a continuous transport machine with chain as traction mechanism, and is currently the only transport equipment in longwall coal mining face. Chain is an elastic element, and will deform elastically after a period of use. It is necessary to tighten the chain regularly to ensure that the chain runs under appropriate tension.

[0004] In the existing chain tightening method for scraper conveyors, during the chain tightening process, the drive system needs to be separately equipped with a chain tightening motor, which provides power for the hydraulic motor, and the hydraulic motor is used to achieve the functions of slow chain tightening and maintenance. The hydraulic motor makes the structure of the entire drive unit more complicated, and also requires a supporting hydraulic source, which places more demands on peripheral supporting equipment. At the same time, when manual intervention is required for chain connection, the personal safety of the operator must be guaranteed, and more complex chain tightening tooling is often required to ensure that the scraper conveyor does not rotate suddenly, which makes the operation complicated and the work efficiency low. Summary of the invention

[0005] In order to solve the above problems, the present invention adopts the following technical solutions:

[0006] A chain tightening method for a scraper conveyor is a chain tightening method using a torque-limited deceleration permanent magnet variable frequency drive system, the torque-limited deceleration permanent magnet variable frequency drive system comprises a drive unit, a brake, a frequency converter and a controller, the drive unit comprises a permanent magnet synchronous motor and a gear transmission unit with a deceleration arrangement, the permanent magnet synchronous motor is drivingly connected to the input end of the gear transmission unit, the brake is arranged at the output end of the gear transmission unit, the frequency converter is electrically connected to the permanent magnet synchronous motor and the controller respectively, and the chain tightening method comprises the following steps:

[0007] S10, control the permanent magnet synchronous motor to rotate at a low speed through the frequency converter to drive the tail sprocket of the scraper conveyor to rotate and complete the chain lifting action;

[0008] S20, using a brake to brake the entire drive unit;

[0009] S30, release the permanent magnet synchronous motor braking torque, and power off the inverter;

[0010] S40, manual intervention is performed to connect the chain and complete the chain tightening work.

[0011] Furthermore, the gear transmission part includes a planetary gear transmission mechanism with a reduction gear arrangement, a sun gear of the planetary gear transmission mechanism is connected to an output end of the permanent magnet synchronous motor, and a planet carrier of the planetary gear transmission mechanism serves as an output end.

[0012] Furthermore, the torque-limiting deceleration permanent magnet variable frequency drive system also includes a torque-limiting protection unit, which is arranged between the inner gear ring of the planetary gear transmission mechanism and the outer shell of the planetary gear transmission mechanism, and is used to control the transmission torque during the transmission process of the planetary gear transmission mechanism and to achieve overload protection.

[0013] Furthermore, the torque limiting protection unit includes:

[0014] A torque limiting protective shell which forms a closed space with the shell of the planetary gear transmission mechanism;

[0015] a hydraulic unit in communication with the enclosed space;

[0016] A plurality of pairs of friction plates and dual steel plates are arranged alternately in sequence, wherein the friction plates and the dual steel plates are both located in the enclosed space; the friction plates are fixedly mounted on the inner gear ring, and the dual steel plates are fixedly mounted on the inner wall of the torque limiting protection shell;

[0017] Among them, when the planetary gear transmission mechanism performs torque transmission, when the liquid pressure in the torque limiting protection shell reaches a preset value, the liquid pressure drives the friction plate and the dual steel plate to contact to achieve torque transmission; when the input or load torque of the planetary gear transmission mechanism is greater than the friction torque between the friction plate and the dual steel plate, the friction plate and the dual steel plate slide relative to each other to achieve overload protection.

[0018] Furthermore, the torque-limiting deceleration permanent magnet variable frequency drive system also includes a shell, which has an independently arranged drive cavity and transmission cavity, the permanent magnet synchronous motor is located in the drive cavity, the planetary gear transmission mechanism and the torque-limiting protective shell are located in the transmission cavity, and the outer shell of the planetary gear transmission mechanism is the inner wall of the transmission cavity.

[0019] Furthermore, the planetary gear transmission mechanism is a two-stage reduction mechanism, which includes a first-stage parallel cylindrical gear reduction mechanism and a first-stage planetary reduction mechanism. The output end of the first-stage parallel cylindrical gear reduction mechanism is drivingly connected to the sun gear of the first-stage planetary reduction mechanism, and the planet carrier of the first-stage planetary reduction mechanism is the output end; the friction plate is fixedly mounted on the inner gear ring of the first-stage planetary reduction mechanism through a first connecting member, and the dual steel plate is fixedly mounted on the inner wall of the transmission cavity through a second connecting member.

[0020] Furthermore, one of the friction plate and the dual steel plate is provided with inner teeth, and the other of the friction plate and the dual steel plate is provided with outer teeth, and the inner teeth and the outer teeth are used for connecting the friction plate and the first connecting member, and the dual steel plate and the second connecting member.

[0021] Furthermore, the brake disc is located on a side of the rotor shaft of the permanent magnet synchronous motor away from the output end and is fixedly connected to the rotor shaft of the permanent magnet synchronous motor, and the brake piston is mounted on the inner wall of the driving cavity.

[0022] Furthermore, the hydraulic brake and the hydraulic unit share the same hydraulic station.

[0023] Beneficial effects:

[0024] The present invention provides a chain tightening method for a scraper conveyor, which is a brand-new chain tightening method. The chain tightening function of the scraper conveyor can be realized by utilizing the characteristics of low speed and high torque of the permanent magnet synchronous motor and the stepless speed regulation function of the frequency converter. After the permanent magnet synchronous motor and the frequency converter cooperate to complete the chain lifting action, manual intervention is required to connect the chain. During the manual intervention process, the brake is used to brake the entire drive unit, and the torque of the permanent magnet synchronous motor is released. The frequency converter is powered off, which can ensure the absolute safety and reliability of personnel during the chain connecting process.

[0025] In addition, the chain tightening method of the present invention realizes the chain tightening function through the built-in brake of the torque-limiting deceleration permanent magnet variable frequency drive system and the cooperation between the permanent magnet synchronous motor and the frequency converter, which greatly simplifies the equipment structure, reduces the equipment volume, and reduces the dependence on external matching. The drive, control and braking of the equipment itself are fully utilized to fully realize the related functions of the original drive, greatly reduce the components of the drive system, reduce the equipment cost, and reduce the dependence on peripheral matching equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The overall structural diagram of the scraper conveyor equipped with a torque-limited deceleration permanent magnet variable frequency drive system;

[0027] Figure 2 It is the overall structural diagram of the torque-limited deceleration permanent magnet variable frequency drive system;

[0028] Among them, 1. sprocket; 2. chain ring; 3. scraper; 4. middle groove; 5. permanent magnet synchronous motor; 6. torque limiting protection part; 7. gear transmission part; 8. brake. DETAILED DESCRIPTION

[0029] Example 1

[0030] refer to Figure 1-2A chain tightening method for a scraper conveyor is a chain tightening method using a torque-limited deceleration permanent magnet variable frequency drive system. The torque-limited deceleration permanent magnet variable frequency drive system includes a drive unit, a brake 8, a frequency converter and a controller. The drive unit includes a permanent magnet synchronous motor 5 and a gear transmission unit 7 with a deceleration arrangement. The permanent magnet synchronous motor 5 is drivingly connected to the input end of the gear transmission unit 7. The brake 8 is arranged at the output end of the gear transmission unit 7. The frequency converter is electrically connected to the permanent magnet synchronous motor 5 and the controller respectively. The chain tightening method includes the following steps:

[0031] S10, controlling the permanent magnet synchronous motor 5 to rotate at a low speed through the frequency converter to drive the tail sprocket of the scraper conveyor to rotate, thereby completing the chain lifting action;

[0032] S20, using the brake 8 to brake the entire drive unit;

[0033] S30, release the braking torque of the permanent magnet synchronous motor 5, and cut off the power supply of the inverter to ensure the absolute safety of personnel during the chain connection process;

[0034] S40, manual intervention is performed to connect the chain and complete the chain tightening work.

[0035] In the scraper conveyor of this embodiment, the power is input by the permanent magnet synchronous motor 5, transmitted to the sprocket shaft of the scraper 3 conveyor through the gear transmission part 7, driving the sprocket 1 to rotate, the chain ring 2 on the sprocket 1 is tightened, driving the scraper 3 on the middle groove 4 to move, thereby realizing the transportation of materials such as coal.

[0036] The permanent magnet synchronous motor 5 adopted in this embodiment has the characteristics of high torque density, compact structure and small size, large starting torque, strong overload capacity and high efficiency and energy saving, especially in low-speed and heavy-load starting. At the same time, the load response of the permanent magnet synchronous motor 5 is more sensitive than that of the asynchronous motor, and the starting current is smaller than that of the asynchronous motor (6-7 times the rated current), which has less impact on the power grid and lower capacity requirements for the front-end equipment.

[0037] The planetary gear transmission mechanism used in this embodiment utilizes the characteristics of gear transmission to not only achieve the effect of reducing speed and increasing torque, thereby further reducing the size of the permanent magnet synchronous motor 5, but also achieves an optimized design of the overall structural layout, making the heat dissipation system of the whole machine more efficient and reasonable.

[0038] In addition, the design rated speed of the permanent magnet synchronous motor 5 is significantly lower than that of the asynchronous motor. This is a good solution to the problem that "the asynchronous motor mainly uses a 4-pole motor with a rated speed of 1480r / min, a high input speed, and a high input end seal linear speed, which makes the oil leakage at the input end of the gearbox a frequent failure point." As the speed decreases, the linear speed of the skeleton seal will also be greatly reduced, and the service life of the skeleton seal will be greatly improved, thereby improving the overall reliability of the equipment.

[0039] In this embodiment, the gear transmission part 7 includes a planetary gear transmission mechanism with a reduction arrangement, the sun gear of the planetary gear transmission mechanism is connected to the output end of the permanent magnet synchronous motor 5, and the planet carrier of the planetary gear transmission mechanism serves as the output end.

[0040] By utilizing the gear transmission characteristics, not only the effect of reducing speed and increasing torque is achieved, thereby further reducing the size of the permanent magnet synchronous motor 5, but also the optimization design of the overall structural layout is achieved, thereby making the heat dissipation system of the whole machine more efficient and reasonable.

[0041] In order to better achieve the continuous guarantee of the set output torque within a certain period of time, meet more load conditions to protect the drive equipment, and reduce the number of shutdowns and downtime, this embodiment is further configured on the basis of embodiment 1.

[0042] In this embodiment, the torque-limited deceleration permanent magnet variable frequency drive system further includes a torque-limited protection unit 6, which is arranged between the inner gear ring of the planetary gear transmission mechanism and the outer shell of the planetary gear transmission mechanism, and is used to control the transmission torque during the transmission process of the planetary gear transmission mechanism and to achieve overload protection;

[0043] The torque limiting protection unit 6 comprises:

[0044] A torque limiting protective shell that forms a closed space with the shell of the planetary gear transmission mechanism;

[0045] A hydraulic unit in communication with the confined space;

[0046] Multiple pairs of friction plates and dual steel plates are arranged alternately in sequence, and both the friction plates and the dual steel plates are located in a closed space; the friction plates are fixedly mounted on the inner gear ring, and the dual steel plates are fixedly mounted on the inner wall of the torque limiting protection shell;

[0047] Among them, when the planetary gear transmission mechanism transmits torque, when the liquid pressure in the torque limit protection shell reaches a preset value, the liquid pressure drives the friction plate and the dual steel plate to contact to achieve torque transmission; when the input or load torque of the planetary gear transmission mechanism is greater than the friction torque between the friction plate and the dual steel plate, the friction plate and the dual steel plate slide relative to each other to achieve overload protection.

[0048] In this embodiment, the torque-limited deceleration permanent magnet variable frequency drive system also includes a shell, which has independently arranged drive chamber and transmission chamber, the permanent magnet synchronous motor 5 is located in the drive chamber, the planetary gear transmission mechanism and the torque-limiting protection shell are located in the transmission chamber, and the outer shell of the planetary gear transmission mechanism is the inner wall of the transmission chamber.

[0049] Among them, the driving shaft or gear shaft and other rotating parts in the planetary gear transmission mechanism are rotationally sealed and connected with the torque limiting protection shell.

[0050] Specifically, the shell structure in the overall drive system is optimized and designed, so that the drive unit can be installed in left and right modes by adjusting the combination of various components, which greatly facilitates users' needs for different installation types.

[0051] In this embodiment, the planetary gear transmission mechanism is a two-stage reduction mechanism, which includes a first-stage parallel cylindrical gear reduction mechanism and a first-stage planetary reduction mechanism. The output end of the first-stage parallel cylindrical gear reduction mechanism is drivingly connected to the sun gear of the first-stage planetary reduction mechanism, and the planet carrier of the first-stage planetary reduction mechanism is the output end; the friction plate is fixedly mounted on the inner gear ring of the first-stage planetary reduction mechanism through a first connecting member, and the dual steel plate is fixedly mounted on the inner wall of the transmission cavity through a second connecting member.

[0052] Specifically, the gear transmission unit 7 is a two-stage gear reducer. The first reduction mechanism and the second reduction mechanism are respectively composed of a cylindrical gear reduction mechanism and a first planetary reduction mechanism. They are mainly responsible for transmitting the speed and torque of the permanent magnet synchronous motor 5 to the next stage, thereby reducing the output speed and increasing the output torque.

[0053] The torque-limited deceleration permanent magnet variable frequency drive system provided in the present embodiment is small in size and compact in structure. The prior art realizes similar functions of the product with an overall volume increased by 2 to 3 times and a weight increased by more than 2 times. The chain tightening method of the scraper conveyor provided in the present embodiment is more suitable for working conditions with compact working environment, limited space, large impact load and high reliability requirements.

[0054] In this embodiment, one of the friction plate and the dual steel plate is provided with internal teeth, and the other of the friction plate and the dual steel plate is provided with external teeth. The internal teeth and the external teeth are used for connecting the friction plate with the first connecting member and the dual steel plate with the second connecting member.

[0055] Among them, the friction plate and the dual steel plate are both annular structures. According to actual usage, it is preferred that the outer ring of the friction plate is provided with external teeth, and the inner ring of the dual steel plate is provided with internal teeth.

[0056] Specifically, the planetary gear transmission mechanism includes four parts: a sun gear, a planetary gear, a planetary carrier and an inner gear ring. The planetary carrier is connected to the sprocket 1 of the scraper 3 conveyor, and the sun gear is connected to the output shaft of the upper gear transmission part 7. The torque limit protection part 6 transmits the output torque and speed of the upper stage to the inner gear ring, and then to the planetary carrier, and the planetary carrier outputs torque and speed.

[0057] The torque limit protection part 6 is mainly composed of a friction pair consisting of multiple pairs of staggered friction plates and dual steel plates, a torque limit protection shell (annular oil cylinder) and corresponding seals. The friction plate is used as a moving plate, connected to the inner gear ring of the planetary gear train, and moves with it;

[0058] The dual steel plate is used as a static plate and is connected to the inner wall of the transmission cavity (reducer housing) through internal teeth. The dynamic plate and the static plate are arranged alternately to form a friction pair, and the space between the friction plate and the dual steel plate is filled with hydraulic oil.

[0059] The specific working process of the torque limiting protection unit 6 is:

[0060] When the motor torque is output to the sun gear through the gear transmission unit 7, the sun gear drives the planetary gear to rotate. In the initial state, there is a certain gap between the dual steel plate and the friction plate. At this time, the friction resistance torque of the inner gear ring to the planetary gear is not large, so the transmitted load torque is small; the inner gear ring starts to move under the rotation of the planetary gear, and the output torque of the planetary carrier is very small at this time; when the oil pressure in the torque limit protection shell (annular oil cylinder) increases, the friction plate approaches the dual steel plate under the action of the oil pressure, so that the contact pressure between the dual steel plate and the friction plate increases, and the friction resistance torque of the inner gear ring to the planetary gear also increases, so that the output torque transmitted by the planetary carrier also increases, the output shaft is gradually driven, and the dual steel plate and the friction plate are gradually combined.

[0061] When the load torque is too large and exceeds the maximum torque that the friction plate and the dual steel plate can transmit, the friction plate and the dual steel plate will slide relative to each other to achieve the overload protection function;

[0062] When the load returns to normal, the friction plate and the dual steel plate can also ensure rapid recovery of engagement.

[0063] The torque limiting protection unit 6 in this embodiment utilizes the unique advantages of liquid viscous torque limiting, and can continuously guarantee the set output torque within a certain period of time, meet more load conditions to protect the drive equipment while reducing the number of shutdowns and downtime, and solves the problem of other torque limiting products that the output is disconnected after the set value is reached, and the equipment needs to be started with load or full load when it is restarted.

[0064] At the same time, the liquid viscosity torque limiter is set between the drive unit and the load, which can block all impact loads transmitted from the load side to the drive unit, better protect the components of the entire drive unit, and rely on the characteristics of the inverter and permanent magnet synchronous motor during the equipment startup process. The liquid viscosity control system is greatly simplified, and it plays a role in overload protection and impact protection during equipment operation.

[0065] The chain tightening method for the scraper conveyor provided in this embodiment is highly efficient and energy-saving with reduced overall costs. The permanent magnet synchronous motor rotor has its own magnetic field and does not require excitation loss. It can maintain a high power factor and efficiency at each load point, and reduces the transmission chain of the original transmission system, reducing energy losses. Therefore, the permanent magnet drive system is more energy-efficient during equipment operation. At the same time, due to its small size and compact structure, it has little dependence on peripheral supporting equipment and has a lower overall supporting cost.

[0066] In order to improve safety performance, in this embodiment, the brake 8 is a hydraulic brake, which includes a brake disc and a brake piston. The brake disc is located on the side of the rotor shaft of the permanent magnet synchronous motor away from the output end and is fixedly connected to the rotor shaft of the permanent magnet synchronous motor. The brake piston is installed on the inner wall of the drive chamber, and the hydraulic brake shares the same hydraulic station with the hydraulic unit.

[0067] In other embodiments, according to actual usage, the brake 8 can also be a pneumatic brake, an electric brake, a mechanical brake, or other types of brakes.

[0068] The chain tightening method for the scraper conveyor provided in this embodiment fully utilizes the drive, control and braking of the equipment itself to fully realize the relevant functions of the original drive, greatly reduces the components of the drive system, reduces equipment costs, and reduces dependence on peripheral supporting equipment.

[0069] The electric control system composed of frequency converter and controller can realize macro control of load, realize multi-machine linkage power balance, and multi-machine logic startup. It mainly deals with non-sudden load processing. At the same time, it can monitor the operation status of the equipment in real time, and each drive unit communicates with each other, and executes different logic strategies according to the operation status of each drive unit. The operation process is recorded and stored, including status parameters, alarm parameters, and fault parameters, and the relevant data can be uploaded to the host computer for unified data processing and automatic management.

[0070] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A chain tightening method for a scraper conveyor, characterized in that: The invention discloses a chain tightening method using a torque-limited deceleration permanent magnet variable frequency drive system, wherein the torque-limited deceleration permanent magnet variable frequency drive system comprises a drive unit, a brake, a frequency converter and a controller, wherein the drive unit comprises a permanent magnet synchronous motor and a gear transmission unit provided with a deceleration device, wherein the permanent magnet synchronous motor is drivingly connected to the input end of the gear transmission unit, the brake is provided at the output end of the gear transmission unit, the frequency converter is electrically connected to the permanent magnet synchronous motor and the controller respectively, and the chain tightening method comprises the following steps: S10, control the permanent magnet synchronous motor to rotate at a low speed through the frequency converter to drive the tail sprocket of the scraper conveyor to rotate and complete the chain lifting action; S20, using a brake to brake the entire drive unit; S30, release the permanent magnet synchronous motor braking torque, and power off the inverter; S40, manual intervention to connect the chain and complete the chain tightening work; The gear transmission part includes a planetary gear transmission mechanism with a reduction gear, the sun gear of the planetary gear transmission mechanism is connected to the output end of the permanent magnet synchronous motor, and the planet carrier of the planetary gear transmission mechanism serves as the output end; The torque-limited deceleration permanent magnet variable frequency drive system further includes a torque-limited protection unit, which is arranged between the inner gear ring of the planetary gear transmission mechanism and the outer shell of the planetary gear transmission mechanism, and is used to control the transmission torque during the transmission process of the planetary gear transmission mechanism and to achieve overload protection; The torque limiting protection unit comprises: A torque limiting protective shell which forms a closed space with the shell of the planetary gear transmission mechanism; a hydraulic unit in communication with the enclosed space; A plurality of pairs of friction plates and dual steel plates are arranged alternately in sequence, wherein the friction plates and the dual steel plates are both located in the enclosed space; the friction plates are fixedly mounted on the inner gear ring, and the dual steel plates are fixedly mounted on the inner wall of the torque limiting protection shell; Wherein, when the planetary gear transmission mechanism performs torque transmission, when the liquid pressure in the torque limiting protection shell reaches a preset value, the liquid pressure drives the friction plate and the dual steel plate to contact to achieve torque transmission; when the input or load torque of the planetary gear transmission mechanism is greater than the friction torque between the friction plate and the dual steel plate, the friction plate and the dual steel plate slide relative to each other to achieve overload protection; The torque-limited deceleration permanent magnet variable frequency drive system also includes a housing, wherein the housing has an independently arranged drive cavity and a transmission cavity, wherein the permanent magnet synchronous motor is located in the drive cavity, wherein the planetary gear transmission mechanism and the torque-limited protective shell are located in the transmission cavity, and wherein the outer shell of the planetary gear transmission mechanism is the inner wall of the transmission cavity; The electric control system composed of the frequency converter and the controller realizes macro control of the load, realizes the power balance of multi-machine linkage, and the logical startup of multi-machine. It mainly deals with the processing of non-sudden loads. At the same time, it can monitor the operating status of the equipment in real time, and the various drive parts communicate with each other, and execute different logical strategies according to the operating status of each drive part; the operation process is recorded and stored, including status parameters, alarm parameters, and fault parameters, and the relevant data is uploaded to the host computer for unified data processing and automatic management.

2. The chain tightening method of a scraper conveyor according to claim 1, characterized in that: The planetary gear transmission mechanism is a two-stage reduction mechanism, which includes a first-stage parallel cylindrical gear reduction mechanism and a first-stage planetary reduction mechanism. The output end of the first-stage parallel cylindrical gear reduction mechanism is drivingly connected to the sun gear of the first-stage planetary reduction mechanism, and the planet carrier of the first-stage planetary reduction mechanism is the output end; the friction plate is fixedly mounted on the inner gear ring of the first-stage planetary reduction mechanism through a first connecting member, and the dual steel plate is fixedly mounted on the inner wall of the transmission cavity through a second connecting member.

3. The chain tightening method of a scraper conveyor according to claim 2, characterized in that: One of the friction plate and the dual steel plate is provided with inner teeth, and the other of the friction plate and the dual steel plate is provided with outer teeth, and the inner teeth and the outer teeth are used for connecting the friction plate with the first connecting member, and the dual steel plate with the second connecting member.

4. The chain tightening method of a scraper conveyor according to claim 3, characterized in that: The brake is a hydraulic brake, which includes a brake disc and a brake piston. The brake disc is located on the side of the rotor shaft of the permanent magnet synchronous motor away from the output end and is fixedly connected to the rotor shaft of the permanent magnet synchronous motor. The brake piston is installed on the inner wall of the drive chamber.

5. The chain tightening method of a scraper conveyor according to claim 4, characterized in that: The hydraulic brake and the hydraulic unit share the same hydraulic station.

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