A soft-start auxiliary belt rotation device for air compressor and working method thereof

Abstract

The present invention relates to an air compressor soft-start auxiliary belt rotation device and its operating method. The air compressor includes a compressor and a motor driving the compressor. The motor is connected to a power supply busbar via a power supply relay. The auxiliary belt rotation device includes a cylinder, a turbofan, a turbofan bearing, and a turbofan shaft disc. The rotating outer ring of the turbofan bearing is fixedly connected to the turbofan. The turbofan shaft disc is also fixedly connected to the rotating outer ring of the turbofan bearing. The fixed inner ring of the turbofan bearing is connected to the piston of the cylinder. The air inlet of the cylinder is connected to a main air path or a lifting air path via a connecting pipeline. The turbofan jet on the turbofan is also connected to the main air path or the lifting air path. The motor shaft disc is fixed to the drive shaft of the motor. The contact and engagement between the turbofan shaft disc and the motor shaft disc controls the motor to achieve pre-start of the motor driven by the turbofan at the initial startup stage. The present application can assist in pre-starting the motor, achieve delayed power-on of the motor, thereby reducing current and improving the operating stability and safety of the air compressor.

Description

Technical Field

[0001] The present invention relates to the technical field of rail vehicle braking devices, in particular to a belt-turning device for assisting an air compressor in soft starting, and a working method thereof. Background Art

[0002] An air compressor, whose full name is air compressor, is a device used to compress gas. It provides air source power and is the core equipment of the pneumatic system. It is a device that converts the mechanical energy of the prime mover (usually an electric motor or a diesel engine) into gas pressure energy. It is a compressed air pressure generating device.

[0003] Existing brake main air compressors use squirrel-cage three-phase asynchronous motors, which offer advantages such as simple structure, durability, high efficiency, and excellent performance. However, their starting current can be as high as 10 times the rated current or even higher, while traditional step-down soft-start systems can generally only reduce the starting current to around 2-4 times the rated current, causing significant damage to the motor, which in turn affects its stability and service life. Furthermore, vehicle design must consider the capacity of auxiliary systems and the operating conditions of other vehicle loads, such as setting a delayed start timer to prevent damage to other vehicle equipment caused by excessive inrush current.

[0004] Therefore, the introduction of auxiliary systems needs to be considered during vehicle design to further reduce the starting current. Summary of the Invention

[0005] The purpose of the present invention is to provide an air compressor soft start auxiliary belt rotation device and its working method, which can assist the pre-start of the motor, realize delayed power-on of the motor to reduce current, and improve the working stability and safety of the air compressor.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] The present invention provides an air compressor soft-start auxiliary belt rotation device for rail transit trains, wherein the air compressor includes a compressor and a motor driving the compressor, the motor being connected to a power supply bus through a power supply relay, the auxiliary belt rotation device including a cylinder, a turbofan, a turbofan bearing, and a turbofan shaft disc, the rotating outer ring of the turbofan bearing being fixedly connected to the turbofan, the turbofan shaft disc being also fixedly connected to the rotating outer ring of the turbofan bearing, the fixed inner ring of the turbofan bearing being connected to the piston of the cylinder, the air inlet of the cylinder being connected to a total air path or a lifting air path through a connecting pipeline, the turbofan jet port on the turbofan being also connected to the total air path or the lifting air path, a motor shaft disc being fixed on the transmission shaft of the motor, and the motor being controlled to achieve pre-start of the motor driven by the turbofan at the initial stage of startup through the contact and engagement between the turbofan shaft disc and the motor shaft disc.

[0008] For the above technical solution, the applicant has further optimization measures.

[0009] Optionally, the cylinder includes a cylinder body, a piston, a connecting rod and a return spring, the piston is arranged in the cylinder body, the cylinder body includes a front top surface, a rear bottom surface and a cylindrical circumferential surface in the middle, one end of the connecting rod is fixedly connected to the piston, and the other end passes through the front top surface of the cylinder body and is fixedly connected to the fixed inner ring of the turbofan bearing, the cylinder body is provided with the air inlet, and the air inlet is connected to the main air path or the lifting air path through a connecting pipeline, and the return spring is arranged between the inner side wall of the front top surface and the front side surface of the piston.

[0010] Furthermore, the cylinder includes a connecting column, which is coaxially arranged with the turbofan bearing. The connecting column is open on one side, and the edge of the open side is fixedly connected to the fixed inner ring of the turbofan bearing, and the outer wall of the closed side is fixedly connected to the other end of the connecting rod.

[0011] Optionally, the air inlet on the cylinder body is opened on the rear bottom surface of the cylinder body or the rear side of the cylindrical circumference, and the cylinder body is also provided with an air outlet, which is set at the front side of the cylindrical circumference of the cylinder body, and the air outlet is connected to the turbofan jet port, and the turbofan jet port corresponds to the blast to blow the turbofan to rotate.

[0012] Furthermore, the auxiliary belt rotation device is divided into a working state and a standby state according to whether the turbofan shaft disc is in contact with the motor shaft disc, wherein:

[0013] The auxiliary belt rotation device is in a standby state, the turbofan shaft disc and the motor shaft disc are in a disengaged state, the return spring at the cylinder body is in a tensioned state, and the air outlet is located at the front side of the piston;

[0014] The auxiliary belt rotation device is in a working state, the turbofan shaft disc is in contact with the motor shaft disc for transmission, the return spring at the cylinder body is in a compressed state, and the air outlet is located at the rear side of the piston;

[0015] When the auxiliary belt rotation device switches from the standby state to the working state, the high-pressure gas sent from the main air path or the lifting air path enters the cylinder body from the air inlet, and then the high-pressure gas pushes the piston to the front side to start moving, driving the connecting rod to push the turbofan bearing together with the turbofan and the turbofan shaft disc to move toward the motor shaft disc, so that the turbofan shaft disc contacts and transmits with the motor shaft disc. During this working state switching process, when the piston continues to move forward through the air outlet, the air path of the air outlet is opened and high-pressure gas is sent to the turbofan jet port.

[0016] Furthermore, the air inlet is connected to the main air circuit or the lifting air circuit through two connecting pipelines, and each connecting pipeline is provided with a solenoid valve for controlling the on-off of the connecting pipeline and a minimum pressure valve for monitoring the internal pressure of the connecting pipeline.

[0017] Optionally, it also includes a main transmission gear, a secondary transmission gear, and a rotating rod, the rotating rod is arranged parallel to the axis of the transmission shaft of the motor, the main transmission gear is sleeved and fixed on the transmission shaft, the secondary transmission gear is sleeved and fixed on the rotating rod, the main transmission gear and the secondary transmission gear are engaged for transmission, the motor shaft disc is sleeved on the rotating rod and fixedly connected to the rotating rod, and the turbofan shaft disc is sleeved on the rear side of the rotating rod.

[0018] Optionally, the motor shaft disc and the turbofan shaft disc are coaxially arranged, and the motor shaft disc and the turbofan shaft disc have matching limiting grooves and limiting protrusions on the opposite sides, and the limiting grooves and the limiting protrusions engage to lock the motor shaft disc and the turbofan shaft disc.

[0019] Optionally, a speed sensor is also included, wherein the sensing end of the speed sensor is arranged at the rotating outer ring of the turbofan bearing, and is used to sense and detect the rotation speed of the rotating outer ring. The output end of the speed sensor is connected to the controller, and the controller controls the conduction of the power supply relay according to the speed signal returned by the speed sensor.

[0020] Furthermore, solenoid valves for controlling the on-off of the connecting pipelines are respectively provided in the connecting pipelines, the solenoid valves are connected to the control end of the controller, and the controller controls the disconnection of the solenoid valves according to the speed signal returned by the speed sensor.

[0021] In particular, the present invention further provides a working method of the air compressor soft start auxiliary belt rotation device based on the above-mentioned method, characterized in that the air compressor starts according to the following steps after receiving the start instruction:

[0022] Step 1: The motor is connected to the power supply busbar through two power supply relays connected in series. When the air compressor is started, the first power supply relay is turned on and the second power supply relay remains off. The circuit between the motor and the power supply busbar is open.

[0023] Step 2: The controller selects to open the gas circuit control solenoid valve of the corresponding connecting pipeline according to the gas pressure, that is:

[0024] When the rail vehicle is in normal operation and the total air pressure meets the demand, the controller controls the total air path solenoid valve to be connected, while the bow path solenoid valve remains disconnected, and the total air passes through the total air path minimum pressure valve and the total air path solenoid valve in turn and enters the cylinder body of the cylinder;

[0025] When the vehicle restarts, the total air pressure is insufficient and the vehicle needs to raise the bow first. At this time, there is air in the auxiliary bow raising air circuit. The controller controls the bow raising circuit solenoid valve to be connected, while the total air circuit solenoid valve remains disconnected. The total air passes through the bow raising air circuit, then passes through the bow raising circuit minimum pressure valve and bow raising circuit solenoid valve, and then enters the cylinder body.

[0026] Step 3: After the high-pressure gas enters the cylinder, it pushes the piston forward and drives the turbofan shaft disc to engage with the motor shaft disc. At the same time, the forward movement of the piston compresses the return spring. When the piston moves beyond the air outlet, the air outlet is opened, that is, the air outlet is connected to the external air path;

[0027] Step 4: High-pressure gas passes through the gas outlet and is ejected at the turbofan jet port, driving the turbofan to rotate, thereby driving the rotating outer ring of the turbofan bearing to rotate, and then the turbofan bearing drives the turbofan shaft disk fixed to it to rotate, and the rotation of the turbofan shaft disk drives the motor shaft disk and the motor drive shaft connected to the motor shaft disk to rotate;

[0028] During this process, the speed of the turbofan bearing is detected and fed back to the controller. When the speed reaches the preset speed, the second power supply relay is opened, and the power supply voltage gradually increases the output power to the motor from 0V or low voltage;

[0029] Step 5: When the turbofan reaches the set limit speed, the main air path solenoid valve or the lifting bow path solenoid valve in the connecting pipeline is cut off, and the piston at the cylinder returns due to the action of the return spring, driving the turbofan shaft disc to separate from the motor shaft disc, and the air outlet is closed as the piston moves backward;

[0030] Step 6: The power supply voltage continues to increase to the rated voltage, the air compressor gradually increases to the rated power, and the air compressor startup is completed.

[0031] The air compressor soft-start auxiliary belt rotation device and its working method of the present application are to control the introduction of airflow from the external main air path or the lifting bow air path to drive the turbofan, and then the turbofan rotates the drive shaft connected to the motor, thereby performing initial pre-start acceleration on the motor. After the motor reaches a certain initial speed, the air compressor power supply circuit is connected. This ensures that the initial power supply voltage does not need to be too high. The power supply voltage is then gradually increased to the rated voltage until the air compressor operates normally at the rated power. Due to the use of the device of the present application, the present invention has the following advantages compared with the existing technology:

[0032] (1) It can realize safe and effective soft start of air compressor with small impact current, overcoming the limitation of minimum starting voltage of traditional step-down starting method, and theoretically can realize zero voltage starting;

[0033] (2) The input air circuit of the present invention has two air sources to choose from: the total air circuit and the bow-lifting air circuit, so as to cope with the situation where there is no total air pressure when the vehicle is initially started, thereby improving the applicability of the present invention;

[0034] (3) The specially designed cylinder structure and air inlet and outlet design in the mechanical structure can make the turbofan shaft disc and the motor shaft disc engage first and then ventilate to start rotation, avoiding the introduction of additional control, reducing the device cost and control difficulty. Moreover, after the motor is pre-started and the motor drive shaft reaches a certain speed, the turbofan shaft disc and the motor shaft disc are automatically separated by cutting off the air path, avoiding the turbofan blocking the motor drive shaft and ensuring the stable operation of the air compressor.

[0035] (4) A minimum pressure valve is installed in the connecting pipeline connected to the main air circuit or the bow raising air circuit. Firstly, it can avoid the continuous air consumption in the main air circuit caused by the long-term opening of the electromagnetic valve failure. Secondly, it can avoid the air consumption caused by the electromagnetic valve failure during the bow raising process and affect the normal bow raising. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0037] Figure 1 2 is a schematic structural diagram of an air compressor soft-start auxiliary belt rotation device according to one embodiment of the present invention;

[0038] Figure 2 for Figure 1 The diagram shown is a partial enlarged schematic diagram of point A in the air compressor soft start auxiliary belt rotation device.

[0039] The following are the descriptions of the reference numerals:

[0040] 1. Motor, 2. Drive shaft, 3. Rotating rod, 4. Turbofan jet nozzle, 5. Turbofan, 6. Turbofan bearing, 61. Rotating outer ring, 62. Fixed inner ring, 7. Motor shaft disc, 8. Cylinder, 81. Cylinder body, 82. Piston, 83. Connecting rod, 84. Return spring, 85. Connecting column, 9. Turbofan shaft disc, 10. Speed ​​sensor, 11. One-way valve, 12. Main air path solenoid valve, 13. Main air path minimum pressure valve, 14. Lifting bow path solenoid valve, 15. Lifting bow path minimum pressure valve, 16. First power supply relay, 17. Second power supply relay, 18. Air inlet, 19. Air outlet, 20. Main transmission gear, 21. Auxiliary transmission gear. DETAILED DESCRIPTION

[0041] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0042] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] This embodiment describes an air compressor soft start auxiliary belt rotation device for rail transit trains, the air compressor includes a compressor, a motor 1 that drives the compressor, and a motor 1 that drives the compressor. Figure 1 and 2 As shown, the motor 1 is connected to the power supply bus through the first power supply relay 16 and the second power supply relay 17. The auxiliary belt rotation device includes a cylinder 8, a turbofan 5, a turbofan bearing 6, and a turbofan shaft disc 9. The rotating outer ring 61 of the turbofan bearing 6 is fixedly connected to the turbofan 5. The turbofan shaft disc 9 is also fixedly connected to the rotating outer ring 61 of the turbofan bearing 6. The fixed inner ring 62 of the turbofan bearing 6 is connected to the piston 82 of the cylinder 8. The air inlet 18 of the cylinder 8 is connected to the main air path or the lifting air path through a connecting pipeline. The turbofan jet port 4 on the turbofan 5 is also connected to the main air path or the lifting air path. A motor shaft disc 7 is fixed on the drive shaft 2 of the motor 1. The contact and engagement between the turbofan shaft disc 9 and the motor shaft disc 7 controls the motor 1 to achieve pre-start of the motor 1 driven by the turbofan 5 at the initial startup stage.

[0045] The air compressor soft-start auxiliary belt rotation device of this embodiment controls the introduction of airflow from the external total air path or the lifting air path to drive the turbofan 5, and then rotates the transmission shaft 2 connected to the motor 1 through the turbofan 5, thereby performing initial pre-start acceleration on the motor 1. After the motor 1 has a certain initial speed, the air compressor power supply circuit is connected, so that the initial power supply voltage does not need to be too high. Subsequently, the power supply voltage is gradually increased to the rated voltage until the air compressor operates normally at the rated power.

[0046] For the selection of high-pressure gas source, the air inlet 18 is connected to the main air path or the lifting air path through two connecting pipelines respectively. In one connecting pipeline connected to the main air path, a main air path solenoid valve 12 for controlling the connection of the connecting pipeline and a main air path minimum pressure valve 13 for monitoring the internal pressure of the connecting pipeline are respectively provided. In the other connecting pipeline connected to the lifting air path, a lifting path solenoid valve 14 for controlling the connection of the connecting pipeline and a lifting path minimum pressure valve 15 for monitoring the internal pressure of the connecting pipeline are respectively provided.

[0047] In this way, as far as the input air circuit is concerned, there are two air sources to choose from, namely the total air circuit and the bow-lift air circuit. Especially when the rail vehicle is initially started, there is no wind in the total air circuit, and air can be introduced through the bow-lift air circuit to cope with the situation where there is no total air pressure when the vehicle is initially started, thereby improving the applicability of the present invention.

[0048] A total airway minimum pressure valve 13, installed in the connecting line to the total airway, monitors the air pressure in that connecting line and prevents it from being opened while the vehicle's air compressor is already running. This prevents continuous air consumption in the total airway caused by a faulty solenoid valve. Furthermore, a bow-raising minimum pressure valve 15, installed in the connecting line to the bow-raising airway, monitors the air pressure in that connecting line and prevents it from being opened while the vehicle's air compressor is already running. This prevents air consumption caused by a faulty solenoid valve during the bow-raising process from affecting normal bow-raising.

[0049] As for the structure of the cylinder 8, the specially designed structure of the cylinder 8 and the design of the air inlet and outlet 19 can make the turbofan shaft disc 9 and the motor shaft disc 7 engage first and then ventilate and start rotating, avoiding the introduction of additional control, reducing the device cost and control difficulty, and after the motor 1 is pre-started and the motor 1 drive shaft 2 reaches a certain speed, the turbofan shaft disc 9 and the motor shaft disc 7 are automatically separated by cutting off the air path, avoiding the turbofan 5 from blocking the rotation of the motor 1 drive shaft 2, and ensuring the stable operation of the air compressor.

[0050] Specifically, the cylinder 8 includes a cylinder body 81, a piston 82, a connecting rod 83 and a return spring 84. The piston 82 is arranged in the cylinder body 81. The cylinder body 81 includes a front top surface, a rear bottom surface and a cylindrical circumferential surface in the middle. One end of the connecting rod 83 is fixedly connected to the piston 82, and the other end passes through the front top surface of the cylinder body 81 and is fixedly connected to the fixed inner ring 62 of the turbofan bearing 6. The cylinder body 81 is provided with the air inlet 18, and the air inlet 18 is connected to the main air path or the lifting bow air path through a connecting pipeline. In order to ensure the reliability of the air path operation, a one-way valve 11 is also connected to the air inlet 18. The return spring 84 is arranged between the inner side wall of the front top surface and the front side surface of the piston 82. The air inlet 18 on the cylinder body 81 is opened on the rear bottom surface of the cylinder body 81 or the rear side of the cylindrical circumference. The cylinder body 81 is also provided with an air outlet 19. The air outlet 19 is set at the front side of the cylindrical circumference of the cylinder body 81, and the air outlet 19 is connected to the turbofan jet port 4. The turbofan jet port 4 corresponds to the blast to blow the turbofan 5 to rotate.

[0051] The auxiliary belt rotation device is divided into a working state and a standby state according to whether the turbofan shaft disc 9 and the motor shaft disc 7 are in contact or not, wherein:

[0052] The auxiliary belt rotation device is in a standby state, the turbofan shaft disc 9 and the motor shaft disc 7 are in a disengaged state, the return spring 84 at the cylinder body 81 is in a tensioned state, and the air outlet 19 is located in front of the piston 82;

[0053] The auxiliary belt rotation device is in the working state, the turbofan shaft disc 9 is in contact with the motor shaft disc 7 for transmission, the return spring 84 at the cylinder body 81 is in a compressed state, and the air outlet 19 is located at the rear side of the piston 82;

[0054] When the auxiliary belt rotation device switches from the standby state to the working state, the high-pressure gas sent from the main air path or the lifting air path enters the cylinder 81 through the air inlet 18, and then the high-pressure gas pushes the piston 82 to the front side to start moving, driving the connecting rod 83 to push the turbofan bearing 6 together with the turbofan 5 and the turbofan shaft disc 9 to move toward the motor shaft disc 7, so that the turbofan shaft disc 9 contacts and transmits with the motor shaft disc 7. During this working state switching process, when the piston 82 continues to move forward through the air outlet 19, the air path of the air outlet 19 is opened and high-pressure gas is sent to the turbofan jet port 4.

[0055] Structurally, in this embodiment, in order to better enable the piston 82 to combine with the connecting rod 83 to push the turbofan 5 and the turbofan shaft disc 9, the auxiliary belt rotation device is also provided with a connecting column 85 at the cylinder 8. The connecting column 85 is coaxially arranged with the turbofan bearing 6. The connecting column 85 is open on one side, and the edge of the open side is fixedly connected to the fixed inner ring 62 of the turbofan bearing 6, and the outer wall of the closed side is fixedly connected to the other end of the connecting rod 83.

[0056] In order to enable better transmission on the motor 1 side without affecting the normal operation of the motor 1 after startup, a main transmission gear 20, a secondary transmission gear 21, and a rotating rod 3 are also provided on the motor 1 side. The rotating rod 3 is arranged parallel to the axis of the transmission shaft 2 of the motor 1. The main transmission gear 20 is sleeved and fixed on the transmission shaft 2, and the secondary transmission gear 21 is sleeved and fixed on the rotating rod 3. The main transmission gear 20 and the secondary transmission gear 21 are engaged for transmission. The motor shaft disc 7 is sleeved on the rotating rod 3 and fixedly connected to the rotating rod 3. The turbofan shaft disc 9 is sleeved on the rear side of the rotating rod 3.

[0057] The motor shaft disc 7 and the turbofan shaft disc 9 are coaxially arranged. The motor shaft disc 7 and the turbofan shaft disc 9 have matching limiting grooves and limiting protrusions on the opposite sides thereof. The limiting grooves and limiting protrusions engage and lock the motor shaft disc 7 and the turbofan shaft disc 9. The shapes of the limiting grooves and limiting protrusions can be a cross groove and a cross protrusion, a bevel gear groove and a bevel gear-shaped protrusion, or other special-shaped protrusions, so as to achieve docking and locking of the motor shaft disc 7 and the turbofan shaft disc 9.

[0058] In order to monitor the connection and conduction of the power supply circuit of the motor 1 and the state that the motor 1 reaches a specific speed (the turbofan 5 cannot keep up with the rotation and generates resistance), monitoring the rotation speed of the turbofan 5, the turbofan bearing 6, and the turbofan shaft disc 9 will undoubtedly be able to well reflect the rotation speed of the motor 1 drive shaft 2 after the motor shaft disc 7 and the turbofan shaft disc 9 are connected. Specifically, this embodiment detects the rotation speed of the turbofan bearing 6 by providing a speed sensor 10. Of course, the speed of the turbofan shaft disc 9 can also be directly detected, or the speed of the motor 1 side can be detected to solve the technical problem of speed detection.

[0059] In this embodiment, the sensing end of the speed sensor 10 is disposed at the rotating outer ring 61 of the turbofan bearing 6 for sensing and detecting the rotational speed of the rotating outer ring 61. The output end of the speed sensor 10 is connected to a controller, which controls the conduction of the power supply relay based on the rotational speed signal returned by the speed sensor 10. Solenoid valves for controlling the on / off state of the connecting pipelines are respectively disposed in the connecting pipelines. The solenoid valves are connected to the control end of the controller, which controls the disconnection of the solenoid valves based on the rotational speed signal returned by the speed sensor 10.

[0060] When the auxiliary belt rotation device of this embodiment is used to assist in starting the air compressor, the air compressor starts according to the following steps after receiving the start command:

[0061] (1) The first power supply relay 16 in the air compressor power supply circuit is turned on, and the second power supply relay 17 remains disconnected, and the circuit between the air compressor and the power supply bus is open;

[0062] (2) The controller selects to open the gas circuit control solenoid valve of the corresponding connecting pipeline according to the gas pressure, namely:

[0063] When the rail vehicle is in normal operation and the total air pressure meets the demand, the controller controls the total air path solenoid valve 12 to be turned on, while the bow path solenoid valve 14 remains off, and the total air passes through the total air path minimum pressure valve 13, the total air path solenoid valve 12, and the one-way valve 11 in sequence and enters the cylinder body 81 of the cylinder 8;

[0064] When the vehicle restarts, the total air pressure is insufficient and the vehicle needs to raise the bow first. At this time, there is air in the auxiliary bow raising air circuit. The controller controls the bow raising circuit solenoid valve 14 to be turned on, while the total air circuit solenoid valve 12 remains off. The total air flows through the bow raising circuit, passes through the bow raising circuit minimum pressure valve 15, the bow raising circuit solenoid valve 14, and the one-way valve 11, and enters the cylinder body 81 of the cylinder 8.

[0065] (3) After the high-pressure gas enters the cylinder 81, it pushes the piston 82 forward and drives the turbofan shaft disc 9 to engage with the motor shaft disc 7. At the same time, the forward movement of the piston 82 compresses the return spring 84. When the piston 82 moves beyond the air outlet 19, the air outlet 19 is opened, that is, the air outlet 19 is connected to the external air path;

[0066] (4) High-pressure gas is ejected from the turbofan jet port 4 through the gas outlet 19, pushing the turbofan 5 to rotate, thereby driving the rotating outer ring 61 of the turbofan bearing 6 to rotate, and then the turbofan bearing 6 drives the turbofan shaft disc 9 fixed thereto to rotate, and the rotation of the turbofan shaft disc 9 drives the motor shaft disc 7 and the rotating rod 3 fixed thereto to rotate, and drives the transmission shaft 2 of the motor 1 to rotate through the meshing auxiliary transmission gear 21 and the main transmission gear 20. In this process, the rotation speed of the rotating outer ring 61 of the turbofan bearing 6 is detected and fed back to the controller. When the speed reaches the preset speed (to ensure that the initial rotation speed of the motor 1 reaches a fixed value to prevent excessive starting current, and the user can configure this speed according to the specific type of motor 1), the second power supply relay 17 is turned on, and the power supply voltage is gradually increased from 0V (or low voltage) to output power to the motor 1;

[0067] (5) When the turbofan 5 reaches a certain speed, since the speed that the turbofan 5 can reach under the high-pressure gas drive is certain, there must be a limit value. When the motor 1 increases its speed under the external power supply, the drive shaft 2 of the motor 1 and the transmission of the turbofan 5 will be in an idle state. Therefore, it is necessary to cut off the main air path solenoid valve 12 or the lifting bow path solenoid valve 14 in the connecting pipeline of the air supply path of the auxiliary belt rotation device before or after this speed is reached. Because the air path is cut off, the piston 82 at the cylinder 8 returns due to the action of the return spring 84, driving the turbofan shaft disc 9 to separate from the motor shaft disc 7. As the piston 82 moves to the rear side, the piston 82 closes the air outlet 19 after moving past the position of the air outlet 19.

[0068] (6) The power supply voltage continues to increase to the rated voltage, the air compressor gradually increases to the rated power, and the air compressor startup is completed.

[0069] In summary, the auxiliary belt rotation device based on the present application can cooperate with the soft-start air compressor to achieve safe and effective soft starting of the air compressor, with small impact current, overcoming the limitation of the minimum starting voltage of the traditional step-down starting method, and theoretically achieving zero-voltage starting.

[0070] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. An air compressor soft start auxiliary belt rotation device, used in rail transit trains, the air compressor includes a compressor and a motor that drives it, the motor is connected to the power supply bus through a power supply relay, characterized in that: The auxiliary belt rotation device includes a cylinder, a turbofan, a turbofan bearing, and a turbofan shaft disc. The rotating outer ring of the turbofan bearing is fixedly connected to the turbofan, and the turbofan shaft disc is also fixedly connected to the rotating outer ring of the turbofan bearing. The fixed inner ring of the turbofan bearing is connected to the piston of the cylinder. The air inlet of the cylinder is connected to the main air path or the lifting air path through a connecting pipeline. The turbofan jet on the turbofan is also connected to the main air path or the lifting air path. A motor shaft disc is fixed to the drive shaft of the motor. The contact and engagement between the turbofan shaft disc and the motor shaft disc controls the motor to achieve motor pre-starting driven by the turbofan at the initial startup stage. The cylinder includes a cylinder body, a piston, a connecting rod and a return spring. The piston is arranged in the cylinder body. The cylinder body includes a front top surface, a rear bottom surface and a cylindrical circumferential surface in the middle. One end of the connecting rod is fixedly connected to the piston, and the other end passes through the front top surface of the cylinder body and is fixedly connected to the fixed inner ring of the turbofan bearing. The cylinder body is provided with the air inlet, and the air inlet is connected to the main air path or the lifting air path through a connecting pipeline. The return spring is arranged between the inner side wall of the front top surface and the front side surface of the piston.

2. The air compressor soft start auxiliary belt rotation device according to claim 1, characterized in that: The cylinder includes a connecting column, which is coaxially arranged with the turbofan bearing. The connecting column is open on one side, and the edge of the open side is fixedly connected to the fixed inner ring of the turbofan bearing, while the outer wall of the closed side is fixedly connected to the other end of the connecting rod.

3. The air compressor soft start auxiliary belt rotation device according to claim 1, characterized in that: The air inlet on the cylinder body is opened on the rear bottom surface of the cylinder body or the rear side of the cylindrical circumference. The cylinder body is also provided with an air outlet, which is set at the front side of the cylindrical circumference of the cylinder body, and the air outlet is connected to the turbofan jet port. The turbofan rotates in response to the blast from the turbofan jet port.

4. The air compressor soft start auxiliary belt rotation device according to claim 3, characterized in that: The auxiliary belt rotation device is divided into a working state and a standby state according to whether the turbofan shaft disc is in contact with the motor shaft disc, wherein: The auxiliary belt rotation device is in a standby state, the turbofan shaft disc and the motor shaft disc are in a disengaged state, the return spring at the cylinder body is in a tensioned state, and the air outlet is located at the front side of the piston; The auxiliary belt rotation device is in a working state, the turbofan shaft disc is in contact with the motor shaft disc for transmission, the return spring at the cylinder body is in a compressed state, and the air outlet is located at the rear side of the piston; When the auxiliary belt rotation device switches from the standby state to the working state, the high-pressure gas sent from the main air path or the lifting air path enters the cylinder body from the air inlet, and then the high-pressure gas pushes the piston to the front side to start moving, driving the connecting rod to push the turbofan bearing together with the turbofan and the turbofan shaft disc to move toward the motor shaft disc, so that the turbofan shaft disc contacts and transmits with the motor shaft disc. During this working state switching process, when the piston continues to move forward through the air outlet, the air path of the air outlet is opened and high-pressure gas is sent to the turbofan jet port.

5. The air compressor soft start auxiliary belt rotation device according to any one of claims 1 to 4, characterized in that: The air inlet is connected to the main air circuit or the bow-lifting air circuit through two connecting pipelines. A solenoid valve for controlling the on-off of the connecting pipeline and a minimum pressure valve for monitoring the internal pressure of the connecting pipeline are respectively provided in each connecting pipeline.

6. The air compressor soft start auxiliary belt rotation device according to claim 1, characterized in that: It also includes a main transmission gear, a secondary transmission gear, and a rotating rod. The rotating rod is arranged parallel to the axis of the transmission shaft of the motor. The main transmission gear is sleeved and fixed on the transmission shaft, and the secondary transmission gear is sleeved and fixed on the rotating rod. The main transmission gear and the secondary transmission gear are engaged for transmission. The motor shaft disc is sleeved on the rotating rod and fixedly connected to the rotating rod. The turbofan shaft disc is sleeved on the rear side of the rotating rod.

7. The air compressor soft start auxiliary belt rotation device according to claim 1 or 6, characterized in that: The motor shaft disc and the turbofan shaft disc are coaxially arranged, and the motor shaft disc and the turbofan shaft disc have matching limiting grooves and limiting protrusions on the opposite sides, and the limiting grooves and the limiting protrusions engage and lock the motor shaft disc and the turbofan shaft disc.

8. The air compressor soft start auxiliary belt rotation device according to claim 1, characterized in that: It also includes a speed sensor, the sensing end of the speed sensor is arranged at the rotating outer ring of the turbofan bearing, and is used to sense and detect the rotation speed of the rotating outer ring. The output end of the speed sensor is connected to the controller, and the controller controls the conduction of the power supply relay according to the speed signal returned by the speed sensor. Solenoid valves for controlling the on and off of the connecting pipelines are respectively provided in the connecting pipelines, and the solenoid valves are connected to the control end of the controller. The controller controls the disconnection of the solenoid valves according to the speed signal returned by the speed sensor.

9. A working method based on the air compressor soft start auxiliary belt rotation device according to any one of claims 1 to 8, characterized in that: After receiving the start command, the air compressor starts according to the following steps: Step 1: The motor is connected to the power supply busbar through two power supply relays connected in series. When the air compressor is started, the first power supply relay is turned on and the second power supply relay remains off. The circuit between the motor and the power supply busbar is open. Step 2: The controller selects to open the gas circuit control solenoid valve of the corresponding connecting pipeline according to the gas pressure, that is: When the rail vehicle is in normal operation and the total air pressure meets the demand, the controller controls the total air path solenoid valve to be connected, while the bow path solenoid valve remains disconnected, and the total air passes through the total air path minimum pressure valve and the total air path solenoid valve in turn and enters the cylinder body of the cylinder; When the vehicle restarts, the total air pressure is insufficient and the vehicle needs to raise the bow first. At this time, there is air in the auxiliary bow raising air circuit. The controller controls the bow raising circuit solenoid valve to be connected, while the total air circuit solenoid valve remains disconnected. The total air passes through the bow raising air circuit, then passes through the bow raising circuit minimum pressure valve and bow raising circuit solenoid valve, and then enters the cylinder body. Step 3: After the high-pressure gas enters the cylinder, it pushes the piston forward and drives the turbofan shaft disc to engage with the motor shaft disc. At the same time, the forward movement of the piston compresses the return spring. When the piston moves beyond the air outlet, the air outlet is opened, that is, the air outlet is connected to the external air path; Step 4: High-pressure gas passes through the gas outlet and is ejected at the turbofan jet port, driving the turbofan to rotate, thereby driving the rotating outer ring of the turbofan bearing to rotate, and then the turbofan bearing drives the turbofan shaft disk fixed to it to rotate, and the rotation of the turbofan shaft disk drives the motor shaft disk and the motor drive shaft connected to the motor shaft disk to rotate; During this process, the speed of the turbofan bearing is detected and fed back to the controller. When the speed reaches the preset speed, the second power supply relay is opened, and the power supply voltage gradually increases the output power to the motor from 0V or low voltage; Step 5: When the turbofan reaches the set limit speed, the main air path solenoid valve or the lifting bow path solenoid valve in the connecting pipeline is cut off, and the piston at the cylinder returns due to the action of the return spring, driving the turbofan shaft disc to separate from the motor shaft disc, and the air outlet is closed as the piston moves backward; Step 6: The power supply voltage continues to increase to the rated voltage, the air compressor gradually increases to the rated power, and the air compressor startup is completed.

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