A rotary chuck for an electric drill in a coal mine underground

Abstract

The application discloses a rotary chuck for an electric drilling machine in a coal mine underground, which comprises a chuck outer shell, a tubular mounting seat, a servo motor and a matched electric cylinder, a rotating shaft, a torque transmission disc, a conical slip, a chuck piston, a compression disc spring, a reset disc spring, a disc spring supporting plate, a thrust bearing, a load bearing, a limiting tooth assembly and a tooth lever assembly; when the servo-driven electric cylinder is advanced, the chuck piston is axially moved, the conical slip is radially moved to clamp the drill rod, and the disc spring supporting plate clamps the limiting tooth assembly; when the electric cylinder is retracted, the tooth lever assembly radially moves the limiting tooth to reset the disc spring to push back the chuck piston, and the conical slip is opened. The application simplifies the overall system complexity of the electric drilling machine, makes the chuck action more accurate and timely, makes the action monitoring more intuitive and simple, can provide sufficient clamping force for the slip, effectively reduces the number of parts rotating with the main shaft and the rotating mass, improves the dynamic balance quality of the main shaft, realizes internal movement and external static, and is more conducive to the transmission of electric signals.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of coal mine machinery, and relates to a rotary chuck for an electric drilling machine. BACKGROUND

[0002] The chuck is an important component of a drilling machine in a coal mine and is an indispensable important component in a water exploration and drilling process. The chuck is installed on a power head or a rotary device and used as a clamping device of the drilling machine. The chuck mainly clamps a drilling tool and provides torque and axial force to the drilling tool. Currently, a conventional drilling machine usually adopts a hydraulic rubber cylinder type chuck. The hydraulic pressure is a power source, and the rubber cylinder type structure is tightened by oil pressure and loosened by a spring. With the development of electric drilling machines, the conventional chuck cannot meet the requirements of the electric drilling machine on the size of the holding force, the response speed and accuracy of clamping and loosening in the drilling process of the drilling rod. At the same time, due to the system characteristics of the electric drilling machine, the hydraulic system will increase the system failure rate, so an electric chuck is urgently needed. SUMMARY

[0003] In view of the deficiencies in the prior art, the present application aims to provide a rotary chuck for an electric drilling machine in a coal mine, which overcomes the deficiency that the existing hydraulic chuck cannot be used efficiently and accurately with an electric drilling machine.

[0004] To solve the above technical problems, the present application adopts the following technical solutions:

[0005] A rotary chuck for an electric drilling machine in a coal mine, comprising a chuck outer shell, a tubular mounting seat, a servo motor and a matched electric cylinder, a rotating shaft, a torque transmission disc, a conical slip, a chuck piston, a compression disc spring, a reset disc spring, a disc spring support plate, a thrust bearing, a load bearing, a limiting tooth assembly and a tooth lever assembly.

[0006] The chuck outer shell comprises a cylindrical shell, a front end cover and a rear end cover installed at both ends of the cylindrical shell and having a central through hole, and thrust bearings are installed on the inner walls of the front end cover and the rear end cover; the tubular mounting seat is coaxially fixed in the middle rear part of the chuck outer shell; the servo motor is installed on the outer sidewall of the cylindrical shell, the electric cylinder matched with the servo motor is arranged in the annular space between the cylindrical shell and the tubular mounting seat, and the electric cylinder is parallel to the axis of the tubular mounting seat.

[0007] The rotating shaft is arranged in the tubular mounting seat and a load bearing is arranged between the rotating shaft and the tubular mounting seat, the rear end of the rotating shaft is connected with the main shaft of the rotary device through the torque transmission disc, and the rear edge of the rotating shaft abuts against the thrust bearing on the inner wall of the rear end cover; the conical slip is coaxially arranged between the front end cover and the rotating shaft, the rear end of the conical slip is placed in a plurality of slip grooves arranged on the front end surface of the rotating shaft, and the front end of the conical slip is placed in a slip groove on the slip rotating support plate, and the slip rotating support plate abuts against the thrust bearing on the inner wall of the front end cover.

[0008] The chuck piston sleeve is outside the conical slip and the rotating shaft, the front conical inner wall of the chuck piston corresponds to the conical slip, and the rear inner wall of the chuck piston is fixed to the rotating shaft through the piston key in the front part of the rotating shaft; a thrust bearing, a disc spring support plate II, a compression disc spring and a disc spring support plate III are sequentially arranged between the rear end of the chuck piston and the electric cylinder and are sleeved outside the tubular mounting seat; a thrust bearing, a disc spring support plate I and a reset disc spring are sequentially arranged between the front end of the chuck piston and the front end cover.

[0009] The limiting tooth assembly is installed on the inner wall of the cylindrical shell and is located in front of the electric cylinder and the disc spring support plate III; when the electric cylinder is extended forward to push the chuck piston to extrude the conical slip and clamp the drill rod, the outer edge protrusion of the disc spring support plate III is fixed by the limiting tooth assembly, at this time, the compression disc spring is in a compressed state, which can continuously provide pressure to the chuck piston, so that the conical slip obtains continuous and stable downward pressure to clamp the drill rod; when the electric cylinder is retracted, the tooth lever assembly can radially extrude the limiting tooth assembly to release the disc spring support plate III, and the reset disc spring pushes the chuck piston backward to loosen the conical slip and the drill rod.

[0010] The present application also comprises the following technical features:

[0011] Specifically, the annular edge of the outer edge of the rear end of the tubular mounting seat is welded to the inner wall of the rear end of the cylindrical shell to fix the cylindrical shell and the tubular mounting seat.

[0012] Specifically, the rear end of the rotating shaft is coaxially connected with a torque transmission disc; the side wall of the rotating shaft is a plurality of annular grooves to accommodate the bearing; the rotating shaft is formed by a plurality of rotating shaft units which are threadedly connected at the annular grooves to accommodate the bearing; a plurality of piston keys are arranged on the front end of the rotating shaft to connect with the chuck piston; the slip groove on the front end of the rotating shaft is a plurality of and is uniformly distributed in the circumferential direction and is opposite to the protrusions on the rear end of the conical slip.

[0013] Specifically, the conical slip is formed by a plurality of conical slip bodies which are circumferentially surrounded, and the slip spring is arranged between adjacent conical slip bodies; when the slip piston pushes each conical slip body to be radially close to each other, the slip spring is compressed; when the slip piston no longer extrudes the conical slip, the slip spring is reset; the conical surface of the outer wall of the conical slip is tapered from front to back; a plurality of protrusions are arranged on the front end surface of the conical slip to be opposite to the slip grooves on the slip rotating support plate.

[0014] Specifically, the inner wall of the front end cover and the rear end cover is provided with an annular groove to accommodate the thrust bearing; the rear end surface of the disc spring support plate I and the front end surface of the chuck piston are provided with opposite annular grooves to accommodate the thrust bearing; the rear end surface of the chuck piston and the front end surface of the disc spring support plate II are provided with opposite annular grooves to accommodate the thrust bearing.

[0015] Specifically, the electric cylinder has a plurality of and is uniformly distributed in the circumferential direction along the inner wall of the cylindrical shell, each electric cylinder corresponds to a set of limiting tooth assemblies and a set of tooth lever assemblies.

[0016] Specifically, the limiting click assembly includes a limiting click, a click limiting block, a click reset spring and a click side wing; the click limiting block is fixed on the inner wall of the cylindrical shell, and a slot-shaped sliding rail is arranged on the side wall of the click limiting block, which is along the radial direction of the cylindrical shell; the limiting click is arranged between the two click limiting blocks, and the two ends of the limiting click are arranged in the slot-shaped sliding rail of the click limiting block; the click reset spring is arranged between the limiting click and the cylindrical shell; the click side wing is connected to the middle and rear parts of the two sides of the limiting click, the middle and rear parts of the click side wing are flat, and the front part of the click side wing is inclined, which is inclined from the rear to the front along the direction close to the inner wall of the cylindrical shell; the tooth shape of the limiting click is a right triangle, and the hypotenuse is backward and the straight side is forward, so that the disc spring support plate III can move forward along the limiting click and can be clamped when the disc spring support plate III is clamped.

[0017] Specifically, the click lever assembly includes a click lever and a lever spring; the click lever includes two levers, an end shaft and a middle connecting rod; the two levers are parallel to each other, the middle connecting rod is vertically connected to the middle of the two levers, the end shaft is vertically connected to the ends of the two levers, and the end shaft vertically penetrates the front end of the electric cylinder, and the lever can rotate around the end shaft; the two ends of the lever spring are connected to the middle connecting rod and the front end of the electric cylinder respectively, the lever spring can pull the circular end head of the lever close to the front end of the electric cylinder, and the distance between the two levers is less than the diameter of the circular end head of the front end of the electric cylinder, so that the circular end head can limit the amplitude of the forward rotation of the two levers.

[0018] Specifically, when the electric cylinder extends forward, the two levers correspond to the two click side wings respectively, and the levers will rotate backward and tilt after being blocked by the click side wings, and the lever end head will move forward against the bottom surface of the click side wing; when the electric cylinder moves forward, the two levers are reset to the circular end head close to the front end of the electric cylinder under the action of the lever spring after the levers move away from the click side wings;

[0019] When the electric cylinder retracts backward, the inclined surface of the front part of the click side wing will press the lever backward, so that the lever is tightly close to the circular end head of the front end of the electric cylinder, and the lever applies a pushing force to the click side wing, so that the limiting click compresses the click reset spring and moves radially, so that the disc spring support plate III is separated from the limiting click and moves backward with the electric cylinder, and the lever successively passes through the inclined surface and the bottom flat surface of the middle and rear parts of the click side wing to continuously apply a pushing force to the limiting click to make it move radially until the disc spring support plate III moves backward to move away from the limiting click.

[0020] The method for clamping and loosening the drill rod by the rotary chuck of the underground electric drilling machine, comprising the following steps:

[0021] When the chuck needs to clamp the drill rod, the servo motor receives the electrical signal to drive the axial movement of the electric cylinder, pushes the disc spring support plate III to extrude and compress the disc spring, and drives the axial movement of the chuck piston at the same time. At this time, the reset disc spring is compressed, the conical slip is moved towards the shaft under the drive of the chuck piston, when the drill rod is clamped, the electric cylinder stops the stroke; the outer edge of the disc spring support plate III is fixed by the limiting catch, at this time, the compressed disc spring is in a compressed state, which can continuously provide pressure to the chuck piston, so that the conical slip obtains continuous and stable downward pressure to clamp the drill rod;

[0022] When the drill rod needs to be loosened, the electric cylinder performs the recovery action, at this time, the front end of the electric cylinder pushes the lever to hard contact the side wing of the catch, the inclined surface of the lever pushes the limiting catch to move radially outward, at this time, the disc spring support plate III is released from the limiting catch, and the chuck piston, the compressed disc spring and the disc spring support plate are pushed to reset under the action of the reset disc spring; the conical slip is opened due to the action of the slip spring, at this time, the drill rod is loosened, and the electric cylinder returns to the initial state.

[0023] Compared with the prior art, the present application has the following technical effects:

[0024] The present application adds three groups of servo motors inside the chuck mechanism, thereby achieving the clamping and opening functions of the conventional chuck, canceling the hydraulic system in the chuck, and simplifying the overall system complexity of the electric drive drilling machine. Through the control of the servo motor, the chuck action is more accurate and timely, and the action monitoring is also more intuitive and simple. In order to avoid the characteristics that the motor cannot continuously and stably output high load, the compressed disc spring and the limiting catch assembly are added, which can replace the motor to provide sufficient clamping force to the slip when the chuck is working.

[0025] The present application effectively reduces the number and mass of rotating parts of the main shaft, for example, the chuck body, the motor, the disc spring and other parts do not rotate with the main shaft when working, which is beneficial to improve the dynamic balance quality of the main shaft and simplify the influencing factors in the design of the main shaft. Moreover, the mode of conducting electrical signals through the slip ring is avoided, the outer layer and the inner cavity are separated by the use of the thrust bearing and the bearing in the mechanism, a simpler structure feature of internal movement and external static is realized, which is more conducive to the transmission of electrical signals. Moreover, the design of the rubber cylinder is canceled, the chuck piston and the conical slip are slidably matched with the inclined surface to increase the force to push the slip radially, which can reduce the possibility of chuck failure and prolong the service life of the chuck. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a schematic diagram of the electric chuck.

[0027] Figure 2 It is a schematic diagram of the electric chuck.

[0028] Figure 3 It is a schematic diagram of the electric chuck.

[0029] Figure 4 This is a schematic diagram of the limit locking tooth assembly and the locking tooth lever assembly.

[0030] Figure 5 This is a schematic diagram of the rotating shaft and the torque transmission disc.

[0031] Figure 6 This is a schematic diagram of a rotating shaft unit.

[0032] Figure 7 This is a schematic diagram showing the forces acting on the conical slips and the chuck piston.

[0033] Figure 8 The graph shows the relationship between the radial force of the conical chuck, the axial displacement of the chuck piston, and the tilt angle.

[0034] Figure 9 This is a flowchart of the electric chuck's operation.

[0035] The meanings of the labels in the diagram are as follows:

[0036] 1. Chuck housing, 2. Front cover, 3. Servo motor, 4. Return disc spring, 5. Thrust bearing, 6. Conical jaws, 8. Jaw spring, 9. Chuck piston, 11. Disc spring support plate I, 12. Disc spring support plate II, 13. Disc spring support plate III, 14. Pressure disc spring, 15. Limiting jaw, 16. Electric cylinder, 17. Tubular mounting base, 18. Rotary shaft, 19. Bearing bearing, 22. Rotary shaft unit, 23. Jaw limiting block, 24. Jaw return spring, 25. Piston key, 26. Jaw rotating support plate, 27. Jaw lever, 28. Lever spring, 29. Jaw side wing, 30. Torque transmission plate. Detailed Implementation

[0037] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0038] Example 1:

[0039] like Figures 1 to 6 As shown, this embodiment provides a rotary chuck for an underground electric drilling rig in a coal mine, including a chuck housing 1, a tubular mounting base 17, a servo motor 3 and a matching electric cylinder 16, a rotating shaft 18, a torque transmission disc 30, a conical slip 6, a chuck piston 9, a clamping disc spring 14, a reset disc spring 4, a disc spring support plate, a thrust bearing 5, a load bearing 19, a limit chuck tooth assembly, and a chuck tooth lever assembly.

[0040] The chuck outer shell 1 comprises a cylindrical shell, a front end cover 2 and a rear end cover which are installed at both ends of the cylindrical shell and have a central through hole, and a thrust bearing 5 is installed at the center of the inner wall of the front end cover 2 and the rear end cover; a tubular mounting seat 17 is coaxially fixed in the middle rear part of the chuck outer shell 1; a servo motor 3 is installed on the outer side wall of the cylindrical shell, and a matched electric cylinder 16 connected with the servo motor 3 is arranged in the annular space between the cylindrical shell and the tubular mounting seat 17, and the electric cylinder 16 is parallel to the axis of the tubular mounting seat 17.

[0041] A rotating shaft 18 is arranged in the tubular mounting seat 17, and a bearing 19 is arranged between the rotating shaft 18 and the tubular mounting seat 17, the rear end of the rotating shaft 18 is connected with the main shaft of the rotary table through a torque transmission disc 30, and the rear edge of the rotating shaft 18 abuts against the thrust bearing 5 on the inner wall of the rear end cover; a conical slip 6 is coaxially arranged between the front end cover 2 and the rotating shaft 18, the rear end of the conical slip 6 is arranged in a plurality of slip grooves arranged on the front end surface of the rotating shaft 18, and the front end of the conical slip 6 is arranged in a slip groove on a slip rotating support plate 26, and the slip rotating support plate 26 abuts against the thrust bearing 5 on the inner wall of the front end cover 2.

[0042] A chuck piston 9 is sleeved on the conical slip 6 and the rotating shaft 18, the conical inner wall of the front part of the chuck piston 9 corresponds to the conical slip 6, the rear inner wall of the chuck piston 9 is fixedly connected with the rotating shaft 18 through a piston key 25 arranged on the front part of the rotating shaft 18; a thrust bearing 5, a disc spring support plate II 12, a compression disc spring 14 and a disc spring support plate III 13 are sequentially arranged between the rear end of the chuck piston 9 and the electric cylinder 16 and are sleeved on the tubular mounting seat 17; a thrust bearing 5, a disc spring support plate I 11 and a reset disc spring 4 are sequentially arranged between the front end of the chuck piston 9 and the front end cover 2.

[0043] A limiting catch assembly is installed on the inner wall of the cylindrical shell and is located in front of the electric cylinder 16 and the disc spring support plate III 13, when the electric cylinder 16 extends forward to push the chuck piston 9 to extrude the conical slip 6 to clamp the drill rod, the outer edge protrusion of the disc spring support plate III 13 is fixed by the limiting catch assembly, at this time, the compression disc spring 14 is in a compressed state, and the chuck piston 9 can be continuously provided with pressure, so that the conical slip 6 obtains continuous and stable downward pressure to clamp the drill rod; when the electric cylinder 16 is retracted, the catch lever assembly can radially extrude the limiting catch assembly to release the disc spring support plate III 13, and the reset disc spring 4 pushes the chuck piston 9 backward to loosen the conical slip 6 and the drill rod.

[0044] Through the above scheme, when the motor receives an electric signal to start driving the electric cylinder 16 to push forward, the chuck piston 9 is axially moved, the conical slip 6 is radially moved to clamp the drill rod, and the outer edge protrusion of the disc spring support plate III 13 is clamped to the limiting catch assembly. When the electric cylinder 16 is retracted, the catch lever assembly radially drives the limiting catch to release the disc spring support plate III 13, and the reset disc spring 4 pushes the chuck piston 9 back, and the conical slip 6 is opened. When the main shaft of the rotary table rotates, only the chuck inner rotating shaft 18, the chuck piston 9 and the conical slip 6 are driven to rotate, and the chuck outer shell 1, the tubular mounting seat 17, the disc spring and the support plate remain stationary to reduce the rotational inertia of the electric chuck.

[0045] The annular edge of the rear end of the tubular mount 17 is welded to the inner wall of the rear end of the cylindrical shell to fix the cylindrical shell and the tubular mount 17.

[0046] The rear end of the rotating shaft 18 is coaxially connected to the torque transmission disc 30; the side wall of the rotating shaft 18 is provided with a plurality of annular grooves to accommodate the bearing 19; the rotating shaft 18 is formed by a plurality of rotating shaft units 22 which are threadedly connected at the annular grooves to accommodate the bearing 19; the front end of the rotating shaft 18 is provided with a plurality of piston keys 25 which are uniformly distributed in the circumferential direction to be connected to the chuck piston 9; the slip groove of the front end of the rotating shaft 18 is provided with a plurality of slip grooves which are uniformly distributed in the circumferential direction and are one-to-one corresponding to the protrusions of the rear end of the cone slip 6.

[0047] The cone slip 6 is formed by a plurality of cone slip bodies which are circumferentially surrounded, and the cone slip spring 8 is arranged between adjacent cone slip bodies; when the cone slip piston pushes the cone slip bodies to be radially close to each other, the cone slip spring 8 is compressed; when the cone slip piston no longer presses the cone slip 6, the cone slip spring 8 is reset; the cone surface of the outer wall of the cone slip 6 is tapered from front to rear; the front end surface of the cone slip 6 is provided with a plurality of protrusions which are uniformly distributed in the circumferential direction to be one-to-one corresponding to the slip grooves on the slip rotating plate 26. Specifically, in the embodiment, there are three cone slip bodies, and three sets of cone slip springs 8 are correspondingly arranged.

[0048] The inner wall of the front end cover 2 and the rear end cover is provided with an annular groove to accommodate the thrust bearing 5; the rear end surface of the disc spring plate I 11 and the front end surface of the chuck piston 9 are provided with corresponding annular grooves to accommodate the thrust bearing 5; the rear end surface of the chuck piston 9 and the front end surface of the disc spring plate II 12 are provided with corresponding annular grooves to accommodate the thrust bearing 5.

[0049] The electric cylinder 16 is provided with a plurality of electric cylinders which are uniformly distributed in the circumferential direction along the inner wall of the cylindrical shell; in the embodiment, three sets of servo motors and electric cylinders are arranged, and each electric cylinder 16 corresponds to a set of limiting teeth assembly and a set of tooth racking lever assembly.

[0050] The limiting teeth assembly includes the limiting teeth 15, the tooth limiting block 23, the tooth reset spring 24 and the tooth side wing 29; the tooth limiting block 23 is fixed to the inner wall of the cylindrical shell, and a slot-shaped sliding rail is arranged on the side wall of the tooth limiting block 23, which is radially along the cylindrical shell; the limiting teeth 15 are arranged between two tooth limiting blocks 23, and the two ends of the limiting teeth 15 are arranged in the slot-shaped sliding rail of the tooth limiting block 23; the tooth reset spring 24 is arranged between the limiting teeth 15 and the cylindrical shell; the tooth side wing 29 is connected to the middle and rear parts of the two sides of the limiting teeth 15, the bottom surface of the middle and rear parts of the tooth side wing 29 is a plane, and the front part of the tooth side wing 29 is an inclined surface which is inclined along the direction of approaching the inner wall of the cylindrical shell from rear to front; the tooth shape of the limiting teeth 15 is a right triangle, and the hypotenuse is directed backward and the straight side is directed forward, so that the disc spring plate III 13 can move forward along the limiting teeth 15 and can be clamped to the outer edge protrusion of the disc spring plate III 13 when clamping the drill rod.

[0051] The toothed lever assembly includes a toothed lever 27 and a lever spring 28. The toothed lever 27 includes two levers, an end pivot, and a middle connecting rod. The two levers are parallel to each other, the middle connecting rod is perpendicularly connected to the middle of the two levers, and the end pivot is perpendicularly connected to the ends of the two levers. The end pivot passes perpendicularly through the front end of the electric cylinder 16, and the levers can rotate around the end pivot. The lever spring 28 is connected at both ends to the middle connecting rod and the front end of the electric cylinder 16, respectively. The lever spring 28 can pull the levers close to the circular end of the front end of the electric cylinder 16, and the distance between the two levers is less than the diameter of the circular end of the front end of the electric cylinder 16, so that the circular end can limit the forward rotation of the two levers.

[0052] When the electric cylinder 16 extends and moves forward, the two levers correspond to the two toothed side wings 29 respectively. After the levers are blocked by the toothed side wings 29, they will rotate and tilt backward, and the end of the lever will move forward against the bottom of the toothed side wings 29. The levers move forward with the electric cylinder 16 until they leave the toothed side wings 29. Under the action of the lever spring 28, the two levers return to the round end near the front end of the electric cylinder 16.

[0053] When the electric cylinder 16 retracts and moves backward, the inclined surface at the front of the tooth side wing 29 will press the lever backward, causing the lever to press against the circular end of the electric cylinder 16. The lever applies a pushing force to the tooth side wing 29, causing the limiting tooth 15 to compress the tooth return spring 24 and move radially, thereby causing the disc spring support plate III13 to disengage from the limiting tooth 15 and move backward with the electric cylinder 16. The lever continuously applies a pushing force to the limiting tooth 15 through the inclined surface at the front of the tooth side wing 29 and the bottom plane at the middle and rear, causing it to move radially until the disc spring support plate III13 moves backward and leaves the limiting tooth 15.

[0054] Example 2:

[0055] This embodiment provides a method for clamping and releasing drill rods using a rotary chuck on an underground electric drilling rig in a coal mine, such as... Figure 9 As shown, it includes the following steps:

[0056] When the chuck needs to clamp the drill rod, the servo motor receives an electrical signal and drives the electric cylinder to move axially, pushing the disc spring support plate III to squeeze and clamp the disc spring. At the same time, it drives the chuck piston to move axially. At this time, the return disc spring is compressed, and the conical slip moves towards the axis under the action of the chuck piston. When the drill rod is clamped, the electric cylinder stops its stroke. The limiting teeth are restricted and fixed in the tooth limiting block. They cooperate with the tooth return spring on the back and can only move radially. Since the tooth profile is right angled on one side and inclined on the other side, it can control the disc spring support plate III to move unidirectionally towards the front cover. After the electric cylinder stops its stroke, the outer edge protrusion of the disc spring support plate III is fixed by the limiting teeth. At this time, the clamping disc spring is in a compressed state, which can continuously provide pressure to the chuck piston, so that the conical slip obtains continuous and stable downward pressure to clamp the drill rod.

[0057] When the drill rod needs to be released, the electric cylinder retracts. At this time, the lever at the front end of the electric cylinder, which is fixed by the lever spring, first makes hard contact with the side wing of the chuck tooth. Its inclined surface causes the lever to push the limiting chuck tooth to move outward radially. At this time, the disc spring support plate III is released from the limitation of the limiting chuck tooth. Under the action of the reset disc spring, it pushes the chuck piston, the clamping disc spring, the disc spring support plate and other components to reset. Without the limitation of the chuck piston, the conical chuck is opened by the action of the chuck spring. At this time, the drill rod is released, and the electric cylinder and other components return to their initial state.

[0058] This embodiment is applicable to drill pipes of different diameters, but in order to ensure the reliability of clamping during use, it is necessary to replace the slips of different specifications.

[0059] In this invention, the angle between the chuck piston and the conical slips needs to be selected appropriately. For example... Figure 7 The figure shown is a simplified cross-sectional force diagram, where θ is the inclination angle and F a F is the axial force acting on the chuck piston. b F is the component of force perpendicular to the two contact surfaces, and F is the force of the radial pressure of the slip on the drill rod.

[0060]

[0061] like Figure 8 As shown, the horizontal axis represents the angle, and the left vertical axis represents the radial force of the valve. The thrust provided by the electric cylinder is fixed at F. a At the same time, the smaller the angle, the greater the force on the drill pipe. However, in actual use, excessive force on the drill pipe will cause deformation, while insufficient force will cause sliding friction, reducing rotational efficiency. Furthermore, the axial displacement of the chuck piston is limited by the internal space of the chuck; the smaller the angle, the greater the displacement. For example... Figure 8 The right-hand vertical axis represents the axial displacement L of the chuck piston. a The radial displacement of the slip from its initial state to its contact with the drill pipe.

[0062]

[0063] In the entire chuck system, both the return disc spring and the clamping disc spring obey Hooke's Law:

[0064] F 复 =K 复 ×ΔX 复

[0065] F 压 =K 压 ×ΔX 压

[0066] F 复 To represent the force exerted on the reset disc spring in its working state, ΔX1 represents the compression of the reset disc spring in its working state compared to its initial state, F 压For the force of the compressed disc spring working state, ΔX2 is the compression of the compressed disc spring working state.

[0067] In the system, the force relationship of the two groups of disc springs and the piston follows:

[0068] F 压 -F 复 = F,

[0069]

[0070] And the axial force F>0 of the piston in the working state also shows that the spring coefficient K of the compressed disc spring 复 cannot be too small. Moreover, the compression of the reset disc spring is equal to the maximum axial displacement L of the chuck piston, and the compression ΔX2 of the compressed disc spring is:

[0071]

[0072] Then the total stroke of the electric cylinder is ΔX, which can ensure that the slips can clamp the drill pipe:

[0073]

[0074] The preferred embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the specific details in the above-described embodiments. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, and these simple modifications all belong to the protection scope of the present application.

[0075] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, various possible combinations are not described again by the present application.

[0076] Furthermore, various different embodiments of the present application can also be combined in any manner, as long as they do not deviate from the technical concept of the present application, and they should also be considered as disclosed by the present application.

Claims

1. A rotary chuck for an underground electric drilling rig in a coal mine, characterized in that, Includes chuck housing (1), tubular mounting base (17), servo motor (3) and matching electric cylinder (16), rotating shaft (18), torque transmission disc (30), conical chuck (6), chuck piston (9), clamping disc spring (14), reset disc spring (4), disc spring support plate, thrust bearing (5), load bearing (19), limit chuck tooth assembly, and chuck tooth lever assembly; The chuck housing (1) includes a cylindrical housing, a front end cover (2) and a rear end cover installed at both ends of the cylindrical housing with a central through hole. Thrust bearings (5) are installed at the center of the inner walls of the front end cover (2) and the rear end cover. The tubular mounting base (17) is coaxially fixed in the middle and rear part of the chuck housing (1). The servo motor (3) is installed on the outer wall of the cylindrical housing. The electric cylinder (16) connected to the servo motor (3) is located in the annular space between the cylindrical housing and the tubular mounting base (17). The electric cylinder (16) is parallel to the axis of the tubular mounting base (17). The rotating shaft (18) is located inside the tubular mounting base (17) and a bearing (19) is installed between them. The rear end of the rotating shaft (18) is connected to the main shaft of the rotary device through a torsion transmission plate (30). The rear edge of the rotating shaft (18) abuts against the thrust bearing (5) on the inner wall of the rear end cover. The conical slip (6) is coaxially located between the front end cover (2) and the rotating shaft (18). The rear end of the conical slip (6) is placed in multiple slip grooves provided on the front end face of the rotating shaft (18). The front end of the conical slip (6) is placed in the slip groove on the slip rotating support plate (26). The slip rotating support plate (26) abuts against the thrust bearing (5) on the inner wall of the front end cover (2). The chuck piston (9) is sleeved on the conical slip (6) and the rotating shaft (18). The conical inner wall of the front part of the chuck piston (9) corresponds to the conical slip (6). The inner wall of the rear part of the chuck piston (9) is fixed to the rotating shaft (18) through the piston key (25) at the front of the rotating shaft (18). Between the rear end of the chuck piston (9) and the electric cylinder (16), there are in sequence a thrust bearing (5), a disc spring support plate II (12), a clamping disc spring (14), and a disc spring support plate III (13) sleeved on the tubular mounting base (17). Between the front end of the chuck piston (9) and the front end cover (2), there are in sequence a thrust bearing (5), a disc spring support plate I (11), and a reset disc spring (4). The limiting tooth assembly is installed on the inner wall of the cylindrical housing and located in front of the electric cylinder (16) and the disc spring support plate III (13). When the electric cylinder (16) extends forward to push the chuck piston (9) to squeeze the conical slip (6) to clamp the drill rod, the outer edge of the disc spring support plate III (13) is fixed by the limiting tooth assembly. At this time, the pressing disc spring (14) is in a compressed state, which can continuously provide pressure to the chuck piston (9) so that the conical slip (6) can obtain a continuous and stable downward pressure to clamp the drill rod. When the electric cylinder (16) retracts, the tooth lever assembly can radially squeeze the limiting tooth assembly to release the disc spring support plate III (13), and the reset disc spring (4) pushes the chuck piston (9) backward to release the conical slip (6) and the drill rod.

2. The rotary chuck for underground electric drilling rigs in coal mines as described in claim 1, characterized in that, The annular edge of the outer rear end of the tubular mounting base (17) is welded to the inner wall of the rear end of the cylindrical shell to fix the cylindrical shell to the tubular mounting base (17).

3. The rotary chuck for underground electric drilling rigs in coal mines as described in claim 1, characterized in that, The rear end of the rotating shaft (18) is coaxially connected to the transmission disk (30); the side wall of the rotating shaft (18) has multiple annular grooves to accommodate the bearing (19); the rotating shaft (18) is formed by multiple rotating shaft units (22) threaded together at the annular grooves to accommodate the bearing (19); the front end of the rotating shaft (18) is provided with multiple circumferentially distributed piston keys (25) to connect with the chuck piston (9); the front end of the rotating shaft (18) has multiple circumferentially distributed slip grooves and is aligned with the protrusions at the rear end of the conical slip (6).

4. The rotary chuck for underground electric drilling rigs in coal mines as described in claim 1, characterized in that, The conical slip (6) is formed by multiple conical slip bodies circumferentially, and slip springs (8) are provided between adjacent conical slip bodies; when the slip piston pushes each conical slip body radially closer to each other, it will compress the slip springs (8); when the slip piston no longer squeezes the conical slip (6), the slip springs (8) will reset; the conical surface of the outer wall of the conical slip (6) is tapered from front to back; the front end face of the conical slip (6) is provided with multiple circumferentially distributed protrusions to correspond one-to-one with the slip grooves on the slip rotating support plate (26).

5. The rotary chuck for underground electric drilling rigs in coal mines as described in claim 1, characterized in that, The inner walls of the front end cover (2) and the rear end cover are provided with annular grooves to accommodate the thrust bearing (5); the rear end face of the disc spring support plate I (11) and the front end face of the chuck piston (9) are provided with opposite annular grooves to accommodate the thrust bearing (5); the rear end face of the chuck piston (9) and the front end face of the disc spring support plate II (12) are provided with opposite annular grooves to accommodate the thrust bearing (5).

6. The rotary chuck for underground electric drilling rigs in coal mines as described in claim 1, characterized in that, The electric cylinders (16) are multiple and evenly distributed along the inner wall of the cylindrical shell. Each electric cylinder (16) corresponds to a set of limiting tooth assemblies and a set of tooth lever assemblies.

7. The rotary chuck for underground electric drilling rigs in coal mines as described in claim 1, characterized in that, The limiting tooth assembly includes a limiting tooth (15), a tooth limiting block (23), a tooth return spring (24), and a tooth side wing (29); the tooth limiting block (23) is fixed to the inner wall of the cylindrical shell and has a grooved slide rail on its side wall, which is radially along the cylindrical shell; the limiting tooth (15) is located between two tooth limiting blocks (23), with both ends of the limiting tooth (15) located in the grooved slide rail of the tooth limiting block (23); the tooth return spring (24) is located on the limiting tooth. (15) Between the cylindrical shell; the toothed side wings (29) are connected to the middle and rear parts of the limiting toothed teeth (15). The bottom surface of the middle and rear part of the toothed side wings (29) is a plane, and the front part of the toothed side wings (29) is an inclined surface. The inclined surface is inclined from the rear to the front towards the inner wall of the cylindrical shell. The tooth shape of the limiting toothed teeth (15) is a right triangle with the hypotenuse facing backward and the straight side facing forward so that the disc spring support plate III (13) can move forward along the limiting toothed teeth (15) and can clamp the outer edge protrusion of the disc spring support plate III (13) when clamping the drill rod.

8. The rotary chuck for underground electric drilling rigs in coal mines as described in claim 7, characterized in that, The toothed lever assembly includes a toothed lever (27) and a lever spring (28); the toothed lever (27) includes two levers, an end shaft, and a middle connecting rod; the two levers are parallel to each other, the middle connecting rod is perpendicularly connected to the middle of the two levers, the end shaft is perpendicularly connected to the ends of the two levers, and the end shaft passes perpendicularly through the front end of the electric cylinder (16), and the levers can rotate around the end shaft; the two ends of the lever spring (28) are respectively connected to the middle connecting rod and the front end of the electric cylinder (16), and the lever spring (28) can pull the levers close to the circular end of the front end of the electric cylinder (16), and the distance between the two levers is less than the diameter of the circular end of the front end of the electric cylinder (16), so the circular end can limit the forward rotation of the two levers.

9. The rotary chuck for underground electric drilling rigs in coal mines as described in claim 8, characterized in that, When the electric cylinder (16) extends forward, the two levers correspond to the two toothed side wings (29) respectively. After the levers are blocked by the toothed side wings (29), they will rotate backward and tilt, and the end of the lever will abut against the bottom of the toothed side wings (29) and move forward. After the levers move forward with the electric cylinder (16) until the levers leave the toothed side wings (29), the two levers will return to the round end near the front end of the electric cylinder (16) under the action of the lever spring (28). When the electric cylinder (16) retracts and moves backward, the inclined surface at the front of the tooth side wing (29) will press the lever backward, causing the lever to press against the round end of the electric cylinder (16). The lever applies a thrust to the tooth side wing (29), causing the limiting tooth (15) to compress the tooth return spring (24) and move radially, thereby causing the disc spring support plate III (13) to disengage from the limiting tooth (15) and move backward with the electric cylinder (16). The lever continuously applies a thrust to the limiting tooth (15) through the inclined surface at the front of the tooth side wing (29) and the bottom plane at the middle and rear, causing it to move radially until the disc spring support plate III (13) moves backward and leaves the limiting tooth (15).

10. The method for clamping and releasing drill rods using a rotary chuck in an underground electric drilling rig in a coal mine, as described in claim 9, is characterized in that... Includes the following steps: When the chuck needs to clamp the drill rod, the servo motor receives an electrical signal and drives the electric cylinder to move axially, pushing the disc spring support plate III to squeeze and clamp the disc spring. At the same time, it drives the chuck piston to move axially. At this time, the return disc spring is compressed, and the conical slip moves towards the axis under the action of the chuck piston. When the drill rod is clamped, the electric cylinder stops its stroke. The outer edge protrusion of the disc spring support plate III is fixed by the limiting teeth. At this time, the clamping disc spring is in a compressed state, which can continuously provide pressure to the chuck piston, so that the conical slip obtains continuous and stable downward pressure to clamp the drill rod. When the drill rod needs to be released, the electric cylinder retracts. At this time, the lever at the front end of the electric cylinder first makes hard contact with the side wing of the chuck tooth. Its inclined surface causes the lever to push the limiting chuck tooth to move radially outward. At this time, the disc spring support plate III is released from the limitation of the limiting chuck tooth. Under the action of the reset disc spring, it pushes the chuck piston, presses the disc spring, and resets the disc spring support plate. The conical slip is opened due to the action of the slip spring. At this time, the drill rod is released, and the electric cylinder returns to the initial state.

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