A variable speed drive traction system for a coal mine rack rail locomotive

Abstract

The invention provides a variable speed drive traction system for a rack rail clamping locomotive in a coal mine, comprising a variable frequency motor, a bevel gear box, a two-stage gearbox assembly, a multi-stage parallel shaft reducer and a rack rail driving wheel; the variable frequency motor and the input end of the bevel gear box body are connected by a flange, the output shaft of the variable frequency motor and the input shaft of the bevel gear box are connected by a spline, the output shaft of the bevel gear box changes the output direction through a bevel gear pair, and turns 90 degrees; the output end of the bevel gear box and the two-stage gearbox assembly body are connected by a flange, the output shaft of the bevel gear box and the input shaft of the two-stage gearbox assembly are connected by a spline, and the two-stage gearbox assembly is connected by a spline. The output end of the assembly is connected to the input end of the multi-stage parallel shaft reducer by a flange, the output shaft of the two-stage gearbox assembly is connected to the input shaft of the multi-stage parallel shaft reducer, and the output shaft of the multi-stage parallel shaft reducer is connected to the rack driving wheel by a flange; the present invention adds a two-stage gearbox between the traction motor and the driving wheel, and sets a low-speed gear and a high-speed gear to better adapt to high-load conditions and high-speed conditions, thereby enhancing the adaptability of the locomotive equipment to the environment; at the same time, the locomotive equipment has a larger load capacity under high-load conditions, a faster speed under high-speed conditions, and higher operating efficiency and work efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of rack rail locomotives, and relates to a driving and traction system for a locomotive, in particular to a variable speed driving and traction system for a coal mine rack rail locomotive. Background Art

[0002] At present, most of the rack rail locomotives used in China use explosion-proof lead-acid batteries as the power source and variable frequency motors as the traction drive equipment. Due to the characteristics of the motor, it has a constant torque output within the rated speed and a constant power output outside the rated speed. Figure 1 As shown, the power of the motor is constant, and the rated torque corresponding to the rated speed point will be adapted according to the reduction ratio of the maximum load condition of the locomotive. When the traction required for the maximum load condition of the locomotive is very large, the rated speed of the motor will be very small, and the rated speed of the locomotive at this time will be very small; when the locomotive needs to run at high speed under horizontal conditions, due to the weak magnetic speed limit of the motor, its maximum speed is at most 3 times the rated speed, which becomes the biggest obstacle to the environmental adaptability of electric traction related equipment.

[0003] Due to the safety needs of coal mines, the transmission of the rack rail locomotive must not have a neutral gear phenomenon when parking, power off, or fluid outage. This is an essential failure safety requirement for coal mine rack rail locomotives. Therefore, the meshing of the gears and the drive shaft in the transmission of the rack rail locomotive cannot use the toothed sleeve clutch structure in the manual transmission, because the input shaft and the input shaft of the rack rail locomotive in the parking brake state are both non-rotatable, and the toothed sleeve clutch cannot engage; at the same time, the multi-plate clutch structure in the automatic transmission cannot be used, because the multi-plate clutch is in a normally open state and only engages when working, which does not meet the failure safety requirements. Summary of the invention

[0004] The object of the present invention is to provide a variable speed drive traction system for a rack rail locomotive, which can meet high-speed working conditions while meeting large load conditions, thereby improving the environmental adaptability of the locomotive.

[0005] The technical solution adopted by the present invention to achieve the above-mentioned purpose is:

[0006] A variable speed drive traction system for a coal mine rack rail clamping locomotive comprises a frequency conversion motor, a bevel gear box, a two-stage gearbox assembly, a multi-stage parallel shaft reducer and a rack rail driving wheel; the frequency conversion motor and the input end of the bevel gear box body are connected by a flange, the output shaft of the frequency conversion motor and the input shaft of the bevel gear box are connected by a spline, and the output shaft of the bevel gear box changes the output direction through a bevel gear pair to make a 90-degree turn; the output end of the bevel gear box and the two-stage gearbox assembly body are connected by a flange, the output shaft of the bevel gear box and the input shaft of the two-stage gearbox assembly are connected by a spline, the output end of the two-stage gearbox assembly and the input end of the multi-stage parallel shaft reducer are connected by a flange, the output shaft of the two-stage gearbox assembly is connected to the input shaft of the multi-stage parallel shaft reducer, and the output shaft of the multi-stage parallel shaft reducer is connected to the rack rail driving wheel by a flange.

[0007] The two-stage gearbox assembly includes an input shaft, a gearbox housing, a high-speed end rotary joint, a pinion, a clutch gear assembly, an output shaft, and a low-speed end rotary joint; the input shaft and the output shaft are respectively installed and fixed in the gearbox housing through two sets of tapered roller bearings, and respectively assume the functions of power input and power output. A clutch gear assembly and a pinion are respectively installed on the input shaft and the output shaft. The large gear tooth surface of the clutch gear assembly on the input shaft is meshed with the small gear tooth surface on the output shaft, and the small gear tooth surface on the input shaft is meshed with the large gear tooth surface of the clutch gear assembly on the output shaft. The high-speed end rotary joint is threadedly connected to the tail end of the output shaft, and the low-speed end rotary joint is threadedly connected to the tail end of the input shaft.

[0008] The clutch gear assembly includes an internal gear meshing sleeve, a gear sleeve pressure plate, a gear sleeve pressure plate spring, a gear sleeve meshing outer gear ring, a large gear, a friction plate inner gear seat, an outer gear friction plate, an inner gear friction plate, a friction plate outer inner seat, a friction plate pressure plate, a friction plate pressure plate spring, and a friction plate trigger plate; the gear sleeve meshing seat and the friction plate outer inner seat both have internal splines respectively installed on the transmission shaft and meshing with the external splines on the transmission shaft; the internal gear meshing sleeve has internal splines, which are installed on the gear sleeve meshing seat and meshing with the external splines of the gear sleeve meshing seat, and can slide left and right on the gear sleeve meshing seat; the gear sleeve pressure plate is fixed to the gear sleeve meshing seat by a gear sleeve pressure plate screw, and a force is applied to the internal gear meshing sleeve to press the internal gear meshing sleeve through the gear sleeve pressure plate spring; the meshing sleeve The outer gear ring and the friction plate inner gear seat are respectively arranged on both sides of the large gear and fixed by screws, and the inner gear engagement sleeve can mesh with the outer spline of the meshing outer gear ring when sliding to the meshing outer gear ring; the inner spline of the friction plate inner gear seat meshes with the outer spline of the outer gear friction plate; the inner spline of the inner gear friction plate meshes with the outer spline of the outer inner seat of the friction plate; the three outer gear friction plates and the four inner gear friction plates are arranged alternately, and the friction plate trigger plate is slidably installed on the outer inner seat of the friction plate; the friction plate pressure plate is fixed to one side of the outer inner seat of the friction plate by the friction plate pressure plate screw, and the friction plate pressure plate spring gives the friction plate trigger plate an elastic force to the other side, so that the friction plate trigger plate remains at the terminal on the other side; the elastic force of the gear sleeve pressure plate spring is much smaller than the elastic force of the friction plate pressure plate spring.

[0009] The present invention adds a two-stage gearbox between the traction motor and the driving wheel, and sets a low-speed gear and a high-speed gear to better adapt to high-load conditions and high-speed conditions, thereby enhancing the adaptability of the locomotive equipment to the environment; at the same time, the locomotive equipment has a larger load capacity under high-load conditions, a faster speed under high-speed conditions, and higher operating efficiency and work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the linear relationship between power, torque and speed of the variable frequency motor;

[0011] Figure 2 It is a schematic diagram of the mechanical structure of the drive traction system of the present invention;

[0012] Figure 3 It is a structural schematic diagram of the two-stage gearbox assembly in the present invention;

[0013] Figure 4 It is a structural schematic diagram of the clutch assembly in the two-stage transmission assembly of the present invention;

[0014] Figure 5 It is a control principle diagram of the two-stage gearbox assembly of the present invention.

[0015] Figure 1, variable frequency motor; 2, bevel gear box; 3, two-stage gearbox assembly; 4, multi-stage parallel shaft reducer; 5, rack drive wheel; 6, input shaft; 7, gearbox housing; 8, high-speed end rotary joint; 9, small gear; 10, clutch large gear assembly; 11, output shaft; 12, low-speed end rotary joint; 13, internal gear engagement sleeve; 14, gear sleeve pressure plate; 15, gear sleeve pressure plate screw; 16, gear sleeve pressure plate spring; 17, gear sleeve engagement seat; 1 8. Meshing outer gear ring; 19. Large gear; 20. Friction plate inner gear seat; 21. External gear friction plate; 22. Internal gear friction plate; 23. Friction plate outer and inner seats; 24. Friction plate pressure plate screw; 25. Friction plate pressure plate; 26. Friction plate pressure plate spring 27. Friction plate trigger plate; 28. Including OR gate type shuttle valve; 29. ​​Y-type three-position four-way solenoid reversing valve; 30. Pressure sensor; 31. Speed ​​sensor; 32. Speed ​​controller. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings:

[0017] A variable speed drive traction system for a coal mine rack rail locomotive, such as Figure 2 As shown, it includes a variable frequency motor 1, a bevel gear box 2, a two-stage gearbox assembly 3, a multi-stage parallel shaft reducer 4 and a rack driving wheel 5; the variable frequency motor 1 and the input end of the bevel gear box 2 are connected by flanges, the output shaft of the variable frequency motor 1 and the input shaft of the bevel gear box 2 are connected by splines, and the output shaft of the bevel gear box 2 changes the output direction through a bevel gear pair, turning 90 degrees; the output end of the bevel gear box 2 and the two-stage gearbox assembly 3 are connected by flanges, and the output shaft of the bevel gear box 2 and the input shaft of the two-stage gearbox assembly 3 are connected by splines The output end of the two-stage gearbox assembly 3 is connected to the input end of the multi-stage parallel shaft reducer 4 by a flange, the output shaft of the two-stage gearbox assembly 3 is connected to the input shaft of the multi-stage parallel shaft reducer, and the output shaft of the multi-stage parallel shaft reducer 4 is connected to the rack driving wheel 5 by a flange; the variable frequency motor 1 generates a certain torque and speed through the rotation of the output shaft, which is finally transmitted to the rack driving wheel 5 through the bevel gear box 2, the two-stage gearbox assembly 3, and the multi-stage parallel shaft reducer 4, so that the rack driving wheel 5 generates an amplified torque and a reduced speed.

[0018] The secondary gearbox assembly 3 is as follows: Figure 3As shown, it includes an input shaft 6, a gearbox housing 7, a high-speed end rotary joint 8, a pinion 9, a clutch gear assembly 10, an output shaft 11, and a low-speed end rotary joint 12; the input shaft 6 and the output shaft 11 are respectively fixed in the gearbox housing through two sets of tapered roller bearings, and respectively assume the functions of power input and power output. A clutch gear assembly 10 and a pinion 9 are respectively installed on the input shaft 6 and the output shaft 11. The large gear tooth surface of the clutch gear assembly 10 on the input shaft 6 is meshed with the tooth surface of the pinion 9 on the output shaft 11, and the tooth surface of the pinion 9 on the input shaft 6 is meshed with the tooth surface of the clutch gear assembly 10 on the output shaft 11. The high-speed end rotary joint 8 is connected to the tail end of the output shaft 11 by a thread, and the low-speed end rotary joint 12 is connected to the tail end of the input shaft 6 by a thread; the two pinions 9 and the two clutch gear assemblies 10 on the input end 6 and the output end 11 are meshed in pairs to form two gear pairs. The input side gear pair is a speed-increasing gear pair, and the output side gear pair is a speed-reducing gear pair. Since the clutch gear assembly 10 is in a normally closed state when the power is off and the fluid is cut off, that is, the two clutch gear assemblies 10 are in meshing state with the input end 6 and the output end 11 respectively, and maintain the same rotation speed; in the case of power off and fluid cut off, since the two gear pairs act together, a self-locking state is formed, and this state is the gearbox braking state; when the clutch gear assembly 10 on the output shaft 11 is supplied with fluid through the high-speed end rotary joint 8 and the output shaft 11, the large gear of the clutch gear assembly 10 is separated from the output shaft 11, at this time, the speed-increasing gear pair on the input side is running, and this state is the gearbox speed-increasing state; when the clutch gear assembly 10 on the input shaft 6 is supplied with fluid through the low-speed end rotary joint 12 and the input shaft 6, the large gear of the clutch gear assembly 10 is separated from the input shaft 6, and at this time, the speed-increasing gear pair on the output side is running, and this state is the gearbox speed-reducing state.

[0019] The clutch gear assembly 10 is as follows: Figure 4As shown, it includes an inner gear engagement sleeve 13, a sleeve pressure plate 14, a sleeve pressure plate screw 15, a sleeve pressure plate spring 16, a sleeve engagement seat 17, an engagement outer gear ring 18, a large gear 19, a friction plate inner gear seat 20, an outer gear friction plate 21, an inner gear friction plate 22, a friction plate outer inner seat 23, a friction plate pressure plate screw 24, a friction plate pressure plate 25, a friction plate pressure plate spring 26, and a friction plate trigger plate 27; the sleeve engagement seat 17 and the friction plate outer inner seat 23 are both provided with inner splines and are respectively installed on the transmission shaft, and mesh with the outer splines in the middle of the transmission shaft; so that the sleeve engagement seat 17 and the friction plate outer inner seat 23 are meshed with each other. The inner seat 23 can rotate synchronously with the transmission shaft; the inner gear engagement sleeve 13 has an inner spline, which is installed on the gear sleeve engagement seat 17, meshed with the outer spline of the gear sleeve engagement seat 17, and can slide left and right on the gear sleeve engagement seat 17, the gear sleeve pressure plate 14 is fixed to one end of the gear sleeve engagement seat 17 by the gear sleeve pressure plate screw 15, and the gear sleeve pressure plate spring 16 gives the inner gear engagement sleeve 13 an elastic force to the other side, pressing the inner gear engagement sleeve 13 to the other side; the meshing outer gear ring 18 and the friction plate inner gear seat 20 are respectively placed on both sides of the large gear 19, fixed by screws, the meshing outer gear ring 18, The large gear 19 and the friction plate inner tooth seat 20 can rotate freely and at the same speed. When the gear sleeve pressure plate spring 16 acts on one side, the inner tooth engagement sleeve 13 can mesh with the outer spline of the meshing outer gear ring 18 to meet the transmission torque requirement; the inner spline of the friction plate inner tooth seat 20 meshes with the outer spline of the outer tooth friction plate 21; the inner spline of the inner tooth friction plate 22 meshes with the outer spline of the friction plate outer inner seat 23; the three outer tooth friction plates 21 and the four inner tooth friction plates 22 are staggered so that friction can be generated on both sides of the friction plate; the friction plate trigger plate 27 is installed in cooperation with the outer and inner friction plates of the friction plate. The friction plate pressure plate 25 is fixed to one side of the friction plate outer inner seat 23 by the friction plate pressure plate screw 24, and gives the friction plate trigger plate 27 an elastic force toward the other side through the friction plate pressure plate spring 26, so that the friction plate trigger plate 27 maintains the other side terminal. When sliding to the final end, a certain pressure will be applied to the outer tooth friction plate 21 and the inner tooth friction plate 22, so that friction force is generated on both sides of the outer tooth friction plate 21 and the inner tooth friction plate 22, so as to meet the requirement of transmitting torque; the elastic force of the gear sleeve pressure plate spring 16 is much smaller than the elastic force of the friction plate pressure plate spring 26.

[0020] When there is no pressure in the control hydraulic oil circuit, the gear sleeve pressure plate 14 pushes the internal gear engagement sleeve 13 to the position as shown in the figure. Figure 3 At the far right end shown, at this time, the inner teeth of the inner gear engagement sleeve 13 are meshed with the outer teeth of the gear sleeve engagement seat 17 and the outer teeth of the meshing outer gear ring 18 at the same time; and the friction plate pressure plate 25 pushes the friction plate trigger plate 27 to the far left end through the friction plate pressure plate spring 26, applying a certain pressure to the outer gear friction plate 21 and the inner gear friction plate 22, so that friction force is generated on both sides of the outer gear friction plate 21 and the inner gear friction plate 22, reaching a state where the friction plate outer inner seat 23 is meshed with the friction plate inner gear seat 20.

[0021] When the rail-tracked locomotive starts to drive and traction and the hydraulic oil circuit starts to supply fluid, Figure 3 As shown, the hydraulic oil will push the inner gear meshing sleeve 13 to the left and the friction plate trigger plate 27 to the right through the liquid supply hole; because the elastic force of the gear sleeve pressure plate spring 16 is much smaller than the elastic force of the friction plate pressure plate spring 26, the inner gear meshing sleeve 13 will act first, and the inner spline of the inner gear meshing sleeve 13 will be disengaged from the outer spline of the gear sleeve meshing seat 17. At this time, the braking state of the gearbox is completely achieved by the friction engagement between the friction plate inner gear seat 20, the outer gear friction plate 21, the inner gear friction plate 22, and the friction plate outer inner seat 23, so as to prevent the variable frequency motor 1 from slipping when the starting torque is too small; as the pressure of the control hydraulic oil circuit increases and the starting torque of the variable frequency motor 1 increases, the friction trigger plate 27 starts to move to the right, and before starting to move, there will be a certain amount of slippage between the outer gear friction plate 21 and the inner gear friction plate 22. At this time, the variable frequency motor 1 starts to act at an ultra-low frequency, and the starting torque reaches above the rated traction force, so that the locomotive equipment can be pulled normally.

[0022] When the rail-carrying locomotive stops, the frequency conversion motor 1 will reduce to an ultra-low frequency, so that the speed of the rail-carrying locomotive is reduced to nearly 0 speed, and the hydraulic oil circuit is controlled to start to cut off the fluid; at this time, the friction plate trigger plate 27 first starts to slide to the left, and exerts a certain pressure on the outer tooth friction plate 21 and the inner tooth friction plate 22, so that the two sides of the outer tooth friction plate 21 and the inner tooth friction plate 22 produce friction force, and then the friction plate inner tooth seat 20, the outer tooth friction plate 21, the inner tooth friction plate 22, and the friction plate outer inner seat 23 are in a friction meshing state. At this time, the gearbox is already in braking state to prevent the variable frequency motor 1 from running at an ultra-low frequency due to insufficient traction and slipping; when the pressure of the control hydraulic oil circuit is too low, the internal gear meshing sleeve 13 begins to slide to the right. Since the meshing of the internal and external splines requires a completely consistent rotation angle, there is a high probability that meshing will not occur at this time. At this time, since the internal gear meshing sleeve 13 will always generate a thrust to slide to the right, as long as the internal gear meshing sleeve 13 and the meshing external gear ring 18 have a certain rotational displacement, they can mesh instantly.

[0023] After the rail-tracked locomotive stops, if the friction between the outer tooth friction plate 21 and the inner tooth friction plate 22 is insufficient, the inner tooth meshing sleeve 13 and the meshing outer gear ring 18 will have a certain displacement. At this time, their inner and outer splines will instantly mesh to supplement the torque requirement of the transmission shaft to the large gear 19, thereby improving safety and reliability. If the next time the rail-tracked locomotive is towed, it is still necessary to supply fluid to this group. Since the inner tooth meshing sleeve 13 and the meshing outer gear ring 18 are originally in a disengaged state, it will not affect the next time the rail-tracked locomotive is towed.

[0024] The secondary gearbox assembly 3 is connected to a control hydraulic oil circuit system, and the control hydraulic oil circuit system is as follows Figure 5 As shown, it includes an OR-type shuttle valve 28, a Y-type three-position four-way solenoid reversing valve 29, a pressure sensor 30, a speed sensor 31, and a speed controller 32; the output oil circuit of the Y-type three-position four-way solenoid reversing valve is respectively connected to the high-speed end rotary joint 8 and the low-speed end rotary joint 12 of the secondary gearbox assembly, and the two output oil circuits of the Y-type three-position four-way solenoid reversing valve 29 are also respectively connected to the two oil inlets of the OR-type shuttle valve 28, and the oil outlet of the OR-type shuttle valve 28 is connected to the pressure sensor 30, so that the pressure sensor 30 can detect the output oil circuit of the Y-type three-position four-way solenoid reversing valve 29. The hydraulic pressure on the medium and high pressure sides, the two electromagnets a and b on the Y-type three-position four-way electromagnetic reversing valve 29 respectively control the fluid supply to the high-speed end rotary joint 8 and the low-speed end rotary joint 12; the two electromagnets a and b are respectively connected to the speed controller 32 through cables, so that the speed controller 32 can control the electromagnets a and b; the pressure sensor 30 and the speed sensor 31 are connected to the speed controller 32 through cables, so that the pressure signal of the hydraulic system and the speed signal of the locomotive can be transmitted to the speed controller 32, thereby monitoring and controlling the running status of the locomotive.

[0025] The present invention improves the environmental adaptability of the ground rail rack locomotive drive traction system under heavy load and high speed working conditions by adding a secondary gearbox; a normally closed clutch with a gear sleeve combined with multiple friction plates is integrated in the secondary gearbox to realize the automatic shifting function and improve safety and reliability. The drive traction mechanism of the present invention uses a variable frequency motor as a power component. The variable frequency motor here is replaced by other power components such as a hydraulic motor and a pneumatic motor. The present invention can also achieve the same function.

Claims

1. A variable speed drive traction system for a coal mine rack rail locomotive, characterized in that: It includes a frequency conversion motor, a bevel gear box, a two-stage gearbox assembly, a multi-stage parallel shaft reducer and a rack driving wheel; the frequency conversion motor and the input end of the bevel gear box body are connected by flanges, the output shaft of the frequency conversion motor and the input shaft of the bevel gear box are connected by splines, and the output shaft of the bevel gear box changes the output direction through a bevel gear pair, turning 90 degrees; the output end of the bevel gear box and the two-stage gearbox assembly body are connected by flanges, the output shaft of the bevel gear box and the input shaft of the two-stage gearbox assembly are connected by splines, the output end of the two-stage gearbox assembly and the input end of the multi-stage parallel shaft reducer are connected by flanges, the output shaft of the two-stage gearbox assembly is connected to the input shaft of the multi-stage parallel shaft reducer, and the output shaft of the multi-stage parallel shaft reducer is connected to the rack driving wheel by flanges; the two-stage The gearbox assembly includes an input shaft, a gearbox housing, a high-speed end rotary joint, a pinion, a clutch gear assembly, an output shaft, and a low-speed end rotary joint; the input shaft and the output shaft are respectively fixed in the gearbox housing through two sets of tapered roller bearings, and respectively assume the functions of power input and power output; a clutch gear assembly and a pinion are respectively installed on the input shaft and the output shaft; the large gear tooth surface of the clutch gear assembly on the input shaft is meshed with the small gear tooth surface on the output shaft, and the small gear tooth surface on the input shaft is meshed with the large gear tooth surface of the clutch gear assembly on the output shaft; the high-speed end rotary joint is threadedly connected to the tail end of the output shaft, and the low-speed end rotary joint is threadedly connected to the tail end of the input shaft.

2. A variable speed drive traction system for a coal mine rack rail locomotive according to claim 1, characterized in that: The clutch gear assembly includes an internal gear meshing sleeve, a gear sleeve pressure plate, a gear sleeve pressure plate spring, a gear sleeve meshing seat, a gear sleeve meshing outer gear ring, a large gear, a friction plate inner gear seat, an outer gear friction plate, an inner gear friction plate, a friction plate outer inner seat, a friction plate pressure plate, a friction plate pressure plate spring, and a friction plate trigger plate; the gear sleeve meshing seat and the friction plate outer inner seat both have internal splines that are respectively installed on the transmission shaft and mesh with the external splines on the transmission shaft; the internal gear meshing sleeve has internal splines that are installed on the gear sleeve meshing seat and mesh with the external splines of the gear sleeve meshing seat and can slide left and right on the gear sleeve meshing seat; the gear sleeve pressure plate is fixed to the gear sleeve meshing seat with a gear sleeve pressure plate screw, and gives the internal gear meshing sleeve a certain amount of engagement through the gear sleeve pressure plate spring. The inner gear meshing sleeve is pressed by a force; the meshing outer gear ring and the friction plate inner gear seat are respectively arranged on both sides of the large gear and fixed by screws, and the inner gear meshing sleeve can mesh with the outer spline of the meshing outer gear ring when sliding to the meshing outer gear ring; the inner spline of the friction plate inner gear seat meshes with the outer spline of the outer gear friction plate; the inner spline of the inner gear friction plate meshes with the outer spline of the outer inner seat of the friction plate; the three outer gear friction plates and the four inner gear friction plates are arranged alternately, and the friction plate trigger plate is installed on the outer inner seat of the friction plate and can slide; the friction plate pressure plate is fixed to one side of the outer inner seat of the friction plate by the friction plate pressure plate screw, and the friction plate pressure plate spring gives the friction plate trigger plate an elastic force toward the other side, so that the friction plate trigger plate remains at the terminal on the other side.

3. A variable speed drive traction system for a coal mine rack rail locomotive according to claim 2, characterized in that: The elastic force of the gear sleeve pressure plate spring is much smaller than the elastic force of the friction plate pressure plate spring.

4. The variable speed drive traction system for a coal mine rack rail locomotive according to claim 1, characterized in that: The secondary gearbox assembly is connected to a control hydraulic oil circuit system, which includes an OR-type shuttle valve, a Y-type three-position four-way solenoid reversing valve, a pressure sensor, a speed sensor, and a speed controller; the output oil circuit of the Y-type three-position four-way solenoid reversing valve is respectively connected to the high-speed rotary joint and the low-speed rotary joint of the secondary gearbox assembly, and the two output oil circuits of the Y-type three-position four-way solenoid reversing valve are also respectively connected to the two oil inlets of the OR-type shuttle valve, and the oil outlet of the OR-type shuttle valve is connected to the pressure sensor. The two electromagnets on the Y-type three-position four-way solenoid reversing valve respectively control the fluid supply to the high-speed rotary joint and the low-speed rotary joint; the two electromagnets are respectively connected to the speed controller through cables, and the pressure sensor and the speed sensor are connected to the speed controller through cables. The pressure sensor collects the pressure signal of the hydraulic system, and the speed sensor collects the speed signal of the locomotive.

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