Rotary chuck for underground coal mine electric drilling machine

Abstract

The invention discloses a rotary chuck for an underground coal mine electric drilling machine. The rotary chuck comprises a chuck outer shell, a tubular mounting seat, a servo motor, a matched electric cylinder, a rotating shaft, a torque transmission disc, a conical surface slip, a chuck piston, a pressing disc spring, a reset disc spring, a disc spring supporting plate, a thrust bearing, a carrying bearing, a limiting latch assembly and a latch shifting rod assembly. When the servo driving electric cylinder jacks forwards, the chuck piston is pushed to move axially, the conical surface slips move radially to clamp the drill rod, and meanwhile the disc spring supporting plate clamps the limiting latch assembly. When the electric cylinder retracts, the clamping tooth driving lever assembly radially drives the limiting clamping teeth, the reset disc spring pushes back the chuck piston, and meanwhile the conical surface slips are opened. The whole system complexity of the electrically-driven drilling machine is simplified, the chuck acts more accurately and timely, action monitoring is more visual and simpler, enough clamping force can be provided for the slip, the number of parts rotating along with the main shaft is effectively reduced, the rotating quality is effectively reduced, the dynamic balance quality of the main shaft is improved, internal moving and external static are achieved, and transmission of electric signals is better facilitated.

Description

Technical Field

[0001] The invention belongs to the field of coal mine machinery and relates to a rotary chuck for an electric drilling rig. Background Art

[0002] The chuck is an important component of underground drilling equipment in coal mines and an indispensable component in the process of water exploration and drilling. Installed on the power head or rotator as a drilling rig clamping device, the chuck's main function is to clamp the drill tool and provide torque and axial force to the drill tool. At present, conventional drilling rigs usually use hydraulic rubber cartridge chucks, in which hydraulic pressure is the power source, and the rubber cartridge structure is tightened by oil pressure and released by spring. With the development of electric drilling rigs, conventional chucks can no longer meet the requirements of electric drilling rigs for the holding force, clamping and releasing response speed, and accuracy during drilling of drill rods. At the same time, due to the system characteristics of electric drilling rigs, adding a hydraulic system will increase the system failure rate, so there is an urgent need for an electric chuck. Summary of the invention

[0003] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a rotary chuck for an electric drill in an underground coal mine, so as to overcome the deficiencies that the existing hydraulic chuck cannot be used efficiently and accurately with the electric drive drill.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0005] A rotary chuck for an underground electric drill in a coal mine, comprising a chuck outer shell, a tubular mounting seat, a servo motor and a matching electric cylinder, a rotating shaft, a torque transmission plate, 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 bearing, a limit clamping tooth assembly, and a clamping tooth lever assembly;

[0006] The chuck outer shell comprises a cylindrical shell, a front cover and a rear cover installed at both ends of the cylindrical shell and having a central through hole, and thrust bearings are installed at the center of the inner walls of the front cover and the rear cover; the tubular mounting seat is coaxially fixed in the middle and rear part of the chuck outer shell; the servo motor is installed on the outer wall of the cylindrical shell, and the electric cylinder connected to 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 bearing is installed between the two. The rear end of the rotating shaft is connected to the main shaft of the rotator through a torque transmission plate, 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, the front end of the conical slip is placed in the 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 is sleeved outside the conical surface slip and the rotating shaft, the conical inner wall of the front part of the chuck piston corresponds to the conical surface slip, and the rear inner wall of the chuck piston is fixedly connected to the rotating shaft through the piston key at the front part of the rotating shaft; a thrust bearing sleeved outside the tubular mounting seat, 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; 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 latch 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 extends forward to push the chuck piston to squeeze the conical slip to clamp the drill rod, the outer edge protrusion of the disc spring support plate III is fixed by the limiting latch tooth assembly. At this time, the clamping disc spring is in a compressed state and can continuously provide pressure to the chuck piston, so that the conical slip obtains a continuous and stable downward pressure to clamp the drill rod; when the electric cylinder is retracted, the latch tooth lever assembly can radially squeeze the limiting latch 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 invention also includes 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 to the torque transmission plate; the side wall of the rotating shaft is a plurality of annular grooves for fitting the load-bearing bearing, and the rotating shaft is formed by a plurality of rotating shaft units threadedly connected at the annular grooves so as to be able to fit the load-bearing bearing; the front end of the rotating shaft is provided with a plurality of circumferentially evenly distributed piston keys for connecting with the chuck piston; the front end of the rotating shaft has a plurality of circumferentially evenly distributed cava grooves which are opposite to the protrusions at the rear end of the conical cava one by one.

[0013] Specifically, the conical cava is circumferentially surrounded by a plurality of conical cava bodies, and a cava spring is arranged between adjacent conical cava bodies; when the cava piston pushes the conical cava bodies radially toward each other, the cava spring will be compressed, and when the cava piston no longer squeezes the conical cava, the cava spring will reset; the conical surface of the outer wall of the conical cava is in a shape of decreasing diameter from front to back; the front end surface of the conical cava is provided with a plurality of circumferentially evenly distributed protrusions to correspond one by one to the cava grooves on the cava rotating support plate.

[0014] Specifically, the inner walls of the front end cover and the rear end cover are both provided with annular grooves for accommodating the thrust bearing; the rear end face of the disc spring support plate I and the front end face of the chuck piston are both provided with relative annular grooves for accommodating the thrust bearing; the rear end face of the chuck piston and the front end face of the disc spring support plate II are both provided with relative annular grooves for accommodating the thrust bearing.

[0015] Specifically, there are a plurality of electric cylinders which are evenly distributed along the circumference of the inner wall of the cylindrical shell, and each electric cylinder corresponds to a group of limit locking gear assemblies and a group of locking gear lever assemblies.

[0016] Specifically, the limit gear assembly includes a limit gear, a gear limit block, a gear return spring and a gear side wing; the gear limit block is fixed to the inner wall of the cylindrical shell and a groove-shaped slide rail is provided on the side wall of the gear limit block, and the groove-shaped slide rail is radially along the cylindrical shell; the limit gear is arranged between the two gear limit blocks, and the two ends of the limit gear are arranged in the groove-shaped slide rail of the gear limit block; the gear return spring is arranged between the limit gear and the cylindrical shell; the gear side wing is connected to the middle and rear parts of both sides of the limit gear, the middle and rear bottom surface of the gear side wing is a plane, and the front part of the gear side wing is an inclined surface, which is inclined from the rear to the front edge close to the inner wall of the cylindrical shell; the tooth shape of the limit gear is a right triangle and the hypotenuse faces backward and the straight edge faces forward so that the disc spring support plate III can move forward along the limit gear and can clamp the outer edge protrusion of the disc spring support plate III when clamping the drill rod.

[0017] Specifically, the latching gear lever assembly includes a latching gear lever and a lever spring; the latching gear lever includes two levers, an end rotating shaft and a middle connecting rod; the two levers are parallel to each other, the middle connecting rod vertically connects the middle parts of the two levers, the end rotating shaft vertically connects the ends of the two levers, and the end rotating shaft vertically passes through the front end of the electric cylinder, and the lever can rotate around the end rotating shaft; the two ends of the lever spring are respectively connected to the middle connecting rod and the front end of the electric cylinder, the lever spring can pull the lever close to the circular end of the front end of the electric cylinder, and the distance between the two levers is smaller than the diameter of the circular end of the front end of the electric cylinder, so that the circular end can limit the forward rotation range of the two levers.

[0018] Specifically, when the electric cylinder extends and moves forward, the two levers correspond to the two latching tooth side wings respectively. After being blocked by the latching tooth side wings, the levers will rotate and tilt backward, and the ends of the levers will press against the bottom of the latching tooth side wings and move forward. After the levers move forward with the electric cylinder until they leave the latching tooth side wings, the two levers are reset to the round ends close to the front end of the electric cylinder under the action of the lever springs.

[0019] When the electric cylinder is retracted and moves backward, the inclined surface at the front of the tooth side wing will squeeze the lever backward so that the lever is close to the circular end head at the front end of the electric cylinder, and the lever applies thrust to the tooth side wing to make the limit tooth compress the tooth return spring and then move radially, so that the disc spring support plate III disengages from the limit tooth and moves backward with the electric cylinder, and the lever continuously applies thrust to the limit tooth through the inclined surface at the front of the tooth side wing and the bottom plane at the middle and rear part to make it move radially until the disc spring support plate III moves backward and leaves the limit tooth.

[0020] The method for clamping and loosening a drill rod with a rotary chuck of an underground electric drill in a coal mine comprises the following steps:

[0021] When the chuck needs to clamp the drill pipe, the servo motor receives the electrical signal to drive the electric cylinder to move axially, pushes the disc spring support plate III to squeeze the compression disc spring, and drives the chuck piston to move axially at the same time. At this time, the reset disc spring is compressed, and the conical slip moves toward the axis driven by the chuck piston. When the drill pipe is clamped, the electric cylinder stops the stroke; the outer edge protrusion of the disc spring support plate III is fixed by the limit tooth. 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 a continuous and stable downward pressure to clamp the drill pipe;

[0022] When the drill rod needs to be loosened, the electric cylinder performs a recovery action. At this time, the lever at the front end of the electric cylinder first contacts the side wing of the latch tooth, and its inclined surface causes the lever to push the limit latch tooth to perform outward radial movement. At this time, the disc spring support plate III is free from the restriction of the limit latch tooth, and under the action of the reset disc spring, the chuck piston is pushed, the disc spring is compressed, and the disc spring support plate is reset; the conical slip is expanded due to the action of the slip spring, and the drill rod is loosened at this time, and the electric cylinder returns to its initial state.

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

[0024] The present invention achieves the clamping and opening functions of a conventional chuck by adding three sets of servo motors inside the chuck mechanism, eliminates the hydraulic system in the chuck, and simplifies the overall system complexity of the electric-driven drilling rig. By controlling the servo motor, the chuck action is more accurate and timely, and the action monitoring is more intuitive and simple. In order to avoid the characteristic that the motor cannot continuously and stably output high loads, a clamping disc spring and a limit tooth assembly are added, which can replace the motor to provide sufficient clamping force to the slip when the chuck is working.

[0025] The present invention effectively reduces the number of parts that rotate with the main shaft and the mass of the rotation. For example, the chuck body, motor, disc spring and other parts do not rotate with the main shaft during operation, which is beneficial to improving the dynamic balance quality of the main shaft and simplifying the influencing factors during the main shaft design. In addition, the method of conducting electrical signals by slip rings is avoided. The outer layer and the inner cavity are separated by the use of thrust bearings and load-bearing bearings in the mechanism, achieving a simpler structural feature of internal dynamic and external static, which is more conducive to the transmission of electrical signals. In addition, the design of the rubber cylinder is eliminated, and the radial displacement of the cava is promoted by the method of sliding the chuck piston and the conical cava with each other to cooperate with the inclined surface force increase, which can reduce the possibility of chuck failure and extend the service life of the chuck. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of electric chuck.

[0027] Figure 2 It is a schematic cross-sectional view of an electric chuck.

[0028] Figure 3 It is a cross-sectional view of the external stationary parts of the electric chuck body.

[0029] Figure 4 It is a schematic diagram of the limit latch assembly and the latch lever assembly.

[0030] Figure 5 Schematic diagram of the rotating shaft and torque transmission disk.

[0031] Figure 6 Schematic diagram of the rotating shaft unit.

[0032] Figure 7 It is a schematic diagram of the forces acting on the conical slip and the chuck piston.

[0033] Figure 8 It is a function diagram of the relationship between the radial force of the conical cava, the axial displacement of the chuck piston and the inclination angle.

[0034] Fig. 9 This is the working flow diagram of the electric chuck.

[0035] The meaning of each number in the figure is:

[0036] 1. Chuck shell, 2. Front cover, 3. Servo motor, 4. Reset disc spring, 5. Thrust bearing, 6. Conical cava, 8. Cava spring, 9. Chuck piston, 11. Disc spring support plate I, 12. Disc spring support plate II, 13. Disc spring support plate III, 14. Compression disc spring, 15. Limiting teeth, 16. Electric cylinder, 17. Tubular mounting seat, 18. Rotating shaft, 19. Load-bearing bearing, 22. Rotating shaft unit, 23. Gear limit block, 24. Gear reset spring, 25. Piston key, 26. Cava rotating support plate, 27. Gear lever, 28. Lever spring, 29. Gear side wing, 30. Torsion plate. DETAILED DESCRIPTION

[0037] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0038] Embodiment 1:

[0039] like Figures 1 to 6 As shown, this embodiment provides a rotary chuck for an underground electric drill in a coal mine, comprising a chuck outer shell 1, a tubular mounting seat 17, a servo motor 3 and a matching electric cylinder 16, a rotating shaft 18, a torque transmission plate 30, a conical cava 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 bearing 19, a limit gear assembly, and a gear lever assembly.

[0040] The chuck outer shell 1 includes 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 thrust bearings 5 ​​are installed in the center of the inner walls of the front end cover 2 and the rear end cover; a tubular mounting seat 17 is coaxially fixed in the middle and rear part of the chuck outer shell 1; a servo motor 3 is installed on the outer wall of the cylindrical shell, and an electric cylinder 16 connected to the servo motor 3 is arranged in the annular space between the cylindrical shell and the tubular mounting seat 17, and the axis of the electric cylinder 16 is parallel to that of the tubular mounting seat 17.

[0041] The rotating shaft 18 is arranged in the tubular mounting seat 17 and a load-bearing bearing 19 is installed between the two. The rear end of the rotating shaft 18 is connected to the main shaft of the rotator through the torque transmission plate 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; the conical cava 6 is coaxially arranged between the front end cover 2 and the rotating shaft 18, the rear end of the conical cava 6 is placed in a plurality of cava grooves set on the front end surface of the rotating shaft 18, and the front end of the conical cava 6 is placed in the cava groove on the cava rotating support plate 26, and the cava rotating support plate 26 abuts against the thrust bearing 5 on the inner wall of the front end cover 2.

[0042] The chuck piston 9 is sleeved on the outside of 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, and the rear inner wall of the chuck piston 9 is fixedly connected to the rotating shaft 18 through the piston key 25 at the front part of the rotating shaft 18; the thrust bearing 5, disc spring support plate II12, clamping disc spring 14, and disc spring support plate III13 sleeved on the outside of the tubular mounting seat 17 are arranged in sequence between the rear end of the chuck piston 9 and the electric cylinder 16; the thrust bearing 5, disc spring support plate I11, and reset disc spring 4 are arranged in sequence between the front end of the chuck piston 9 and the front end cover 2.

[0043] The limiting tooth 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 III13. 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 protrusion of the disc spring support plate III13 is fixed by the limiting tooth assembly. At this time, the clamping disc spring 14 is in a compressed state, which can continuously provide pressure to the chuck piston 9, so that the conical slip 6 obtains a continuous and stable downward pressure to clamp the drill rod; when the electric cylinder 16 is retracted, the tooth lever assembly can radially squeeze the limiting tooth assembly to release the disc spring support plate III13, and the reset disc spring 4 pushes the chuck piston 9 backward to loosen the conical slip 6 and the drill rod.

[0044] By adopting the above scheme, when the motor receives the electrical signal and starts to drive the electric cylinder 16 to push forward, it pushes the chuck piston 9 to move axially, pushes the conical slip 6 to move radially to clamp the drill pipe, and at the same time, the outer edge of the disc spring support plate III13 bulges to clamp the limit clamping gear assembly. When the electric cylinder 16 is retracted, the clamping gear lever assembly radially moves the limit clamping gear, the reset disc spring 4 pushes back the chuck piston 9, and at the same time, the conical slip 6 opens. When the main shaft of the rotator rotates, it only drives the rotating shaft 18, the chuck piston 9 and the conical slip 6 in the chuck to rotate, and the chuck outer shell 1, the tubular mounting seat 17, the disc spring, the support plate, etc. remain stationary to reduce the rotational inertia of the electric chuck.

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

[0046] The rear end of the rotating shaft 18 is coaxially connected to the torque transmission plate 30; the side wall of the rotating shaft 18 is a plurality of annular grooves for fitting the load-bearing bearing 19, and the rotating shaft 18 is formed by a plurality of rotating shaft units 22 threadedly connected at the annular grooves so as to realize fitting the load-bearing bearing 19; the front end of the rotating shaft 18 is provided with a plurality of circumferentially evenly distributed piston keys 25 for connecting with the chuck piston 9; the front end of the rotating shaft 18 has a plurality of circumferentially evenly distributed cava grooves and is one-to-one opposite to the protrusions at the rear end of the conical cava 6.

[0047] The conical slip 6 is circumferentially surrounded by a plurality of conical slip bodies, and a slip spring 8 is arranged between adjacent conical slip bodies; when the slip piston pushes the conical slip bodies radially close to each other, the slip spring 8 is compressed, and when the slip piston no longer squeezes the conical slip 6, the slip spring 8 is reset; the conical surface of the outer wall of the conical slip 6 is in a reduced diameter shape from front to back; the front end surface of the conical slip 6 is provided with a plurality of circumferentially evenly distributed protrusions to correspond to the slip grooves on the slip rotating support plate 26 one by one. Specifically, in this embodiment, there are three conical slip bodies, and three sets of slip springs 8 are installed accordingly.

[0048] The inner walls of the front end cover 2 and the rear end cover are both provided with annular grooves for accommodating the thrust bearing 5; the rear end face of the disc spring support plate I11 and the front end face of the chuck piston 9 are both provided with corresponding annular grooves for accommodating the thrust bearing 5; the rear end face of the chuck piston 9 and the front end face of the disc spring support plate II12 are both provided with corresponding annular grooves for accommodating the thrust bearing 5.

[0049] There are multiple electric cylinders 16 and they are evenly distributed along the circumference of the inner wall of the cylindrical shell. In this embodiment, three groups of servo motors and electric cylinders are provided, and each electric cylinder 16 corresponds to a group of limit locking gear components and a group of locking gear lever components.

[0050] The limit clamping tooth assembly includes a limit clamping tooth 15, a clamping tooth limit block 23, a clamping tooth return spring 24 and a clamping tooth side wing 29; the clamping tooth limit block 23 is fixed to the inner wall of the cylindrical shell and a grooved slide rail is provided on the side wall of the clamping tooth limit block 23, and the grooved slide rail is radially along the cylindrical shell; the limit clamping tooth 15 is arranged between the two clamping tooth limit blocks 23, and the two ends of the limit clamping tooth 15 are arranged in the grooved slide rail of the clamping tooth limit block 23; the clamping tooth return spring 24 is arranged between the limit clamping tooth 15 and the cylindrical shell shaped shell; the latch tooth side wing 29 is connected to the middle and rear parts of both sides of the limit latch tooth 15, the middle and rear bottom surface of the latch tooth side wing 29 is a plane, and the front part of the latch tooth side wing 29 is an inclined surface, which is inclined from the back to the front close to the inner wall of the cylindrical shell; the tooth shape of the limit latch tooth 15 is a right triangle with the hypotenuse facing backward and the straight edge facing forward so that the disc spring support plate III13 can move forward along the limit latch tooth 15 and can clamp the outer edge protrusion of the disc spring support plate III13 when clamping the drill pipe.

[0051] The latching gear lever assembly includes a latching gear lever 27 and a lever spring 28; the latching gear 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 vertically connects the middle parts of the two levers, the end shaft vertically connects the ends of the two levers, and the end shaft vertically passes through the front end of the electric cylinder 16, and the lever 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, the lever spring 28 can pull the lever close to the circular end of the front end of the electric cylinder 16, and the distance between the two levers is smaller 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 range of the two levers.

[0052] When the electric cylinder 16 extends and moves forward, the two levers correspond to the two latching tooth wings 29 respectively. After being blocked by the latching tooth wings 29, the levers will rotate and tilt backward, and the ends of the levers will press against the bottom of the latching tooth wings 29 and move forward. After the levers move forward with the electric cylinder 16 until they leave the latching tooth wings 29, the two levers are reset to the round ends close to the front end of the electric cylinder 16 under the action of the lever springs 28.

[0053] When the electric cylinder 16 is retracted and moves backward, the inclined surface at the front of the latch tooth side wing 29 will squeeze the lever backward so that the lever is close to the circular end head at the front end of the electric cylinder 16, and the lever applies a thrust to the latch tooth side wing 29 to cause the limit latch tooth 15 to compress the latch tooth return spring 24 and then move radially, thereby causing the disc spring support plate III13 to disengage from the limit latch tooth 15 and move backward with the electric cylinder 16, and the lever continuously applies a thrust to the limit latch tooth 15 through the inclined surface at the front of the latch tooth side wing 29 and the bottom plane at the middle and rear part to cause it to move radially until the disc spring support plate III13 moves backward to leave the limit latch tooth 15.

[0054] Embodiment 2:

[0055] This embodiment provides a method for clamping and loosening a drill rod with a rotary chuck of an underground electric drill in a coal mine, such as Fig. 9 As shown, the following steps are included:

[0056] When the chuck needs to clamp the drill pipe, the servo motor receives the electrical signal to drive the electric cylinder to move axially, push the disc spring support plate III to squeeze the compression disc spring, and drive the chuck piston to move axially at the same time. At this time, the reset disc spring is compressed, and the conical slip moves toward the axis driven by the chuck piston. When the drill pipe is clamped, the electric cylinder stops its stroke; the limit tooth is restricted and fixed in the tooth limit block, and can only make radial movement in cooperation with the tooth reset spring on the back, and because the tooth profile is right angled on one side and inclined on the other side, the disc spring support plate III can be controlled to make unidirectional axial movement toward the front end cover; after the electric cylinder stops its stroke, the outer edge protrusion of the disc spring support plate III is fixed by the limit tooth. 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 a continuous and stable downward pressure to clamp the drill pipe;

[0057] When the drill rod needs to be loosened, the electric cylinder performs a recovery action. At this time, the lever fixed by the lever spring at the front end of the electric cylinder first contacts the side wing of the tooth, and its inclined surface causes the lever to push the limit tooth to make an outward radial movement. At this time, the disc spring support plate III is free from the restriction of the limit tooth, and the chuck piston, the compression disc spring, the disc spring support plate and other components are pushed to reset under the action of the reset disc spring; without the restriction of the chuck piston, the conical slip is expanded due to the action of the slip spring, and the drill rod is loosened at this time, and the electric cylinder and other components return to their initial state.

[0058] This embodiment is applicable to drill rods of different diameters, but in order to ensure clamping reliability during use, slips of different specifications need to be replaced.

[0059] In the present invention, the inclination angle between the chuck piston and the conical slip needs to be selected at a suitable angle. Figure 7 The simplified cross-sectional force diagram is shown, where θ is the inclination angle, F a is the axial force on the chuck piston, F b is the component force perpendicular to the two contact surfaces, and F is the force of the slip radially pressing the drill pipe.

[0060]

[0061] like Figure 8 As shown, the horizontal axis is the angle, and the vertical axis on the left is the radial force of the slip. When the thrust provided by the electric cylinder is fixed at F a When the angle is smaller, the force on the drill rod is greater. However, in actual use, if the force on the drill rod is too large, it will deform. If the force is too small, it will cause sliding friction and reduce the rotation efficiency. In addition, the chuck piston is affected by the internal space of the chuck, and the axial displacement is limited. The smaller the angle, the greater the displacement. Figure 8 The vertical coordinate on the right side is the axial displacement of the chuck piston L, L a It is the radial displacement of the slip from the initial state to contacting the drill pipe.

[0062]

[0063] In the entire chuck system, the return disc spring and the compression disc spring follow Hooke's law:

[0064] F 复 =K 复 ×ΔX 复

[0065] F 压 =K 压 ×ΔX 压

[0066] F 复 is the force of the reset disc spring in the working state, ΔX1 is the compression of the reset disc spring in the working state compared with the initial state, F 压is the force on the compression disc spring in working state, and ΔX2 is the compression amount of the compression disc spring in working state.

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

[0068] F 压 -F 复 =F,

[0069]

[0070] And the axial force F of the piston in the working state is greater than 0, which also shows that the elastic coefficient K of the compression disc spring is 复 It cannot be too small. And the compression of the reset disc spring is equal to the maximum axial displacement L of the chuck piston, so the compression of the clamping disc spring ΔX2 is:

[0071]

[0072] Then when the total stroke of the electric cylinder is ΔX, it can be guaranteed that the slips can clamp the drill rod:

[0073]

[0074] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0075] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0076] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A rotary chuck for an electric drill in a coal mine. It is characterized in that It comprises a chuck outer shell (1), a tubular mounting seat (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 compression disc spring (14), a reset disc spring (4), a disc spring support plate, a thrust bearing (5), a load-bearing bearing (19), a limit clamping tooth assembly, and a clamping tooth lever assembly; The chuck outer shell (1) comprises a cylindrical shell, a front cover (2) and a rear cover which are installed at both ends of the cylindrical shell and have a central through hole, and thrust bearings (5) are installed at the center of the inner walls of the front cover (2) and the rear cover; the tubular mounting seat (17) is coaxially fixed at the middle and rear part of the chuck outer shell (1); the servo motor (3) is installed on the outer wall of the cylindrical shell, and the electric cylinder (16) matched with the servo motor (3) is arranged in the annular space between the cylindrical shell and the tubular mounting seat (17), and the axes of the electric cylinder (16) and the tubular mounting seat (17) are parallel; The rotating shaft (18) is arranged in the tubular mounting seat (17) and a load-bearing bearing (19) is installed between the two. The rear end of the rotating shaft (18) is connected to the main shaft of the rotator through a torque transmission plate (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; the 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 placed 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 placed 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); The chuck piston (9) is sleeved on the outside of 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 fixedly connected to the rotating shaft (18) through the piston key (25) at the front part of the rotating shaft (18); a thrust bearing (5) sleeved on the outside of the tubular mounting seat (17), 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); 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); The limit latching tooth 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 squeeze 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 limit latching tooth assembly. At this time, the compression disc spring (14) is in a compressed state and can continuously provide pressure to the chuck piston (9), so that the conical slip (6) obtains a continuous and stable downward pressure to clamp the drill rod; when the electric cylinder (16) is retracted, the latching tooth lever assembly can radially squeeze the limit latching tooth 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.

2. The rotary chuck for an underground electric drilling rig in a coal mine as claimed in claim 1, It is characterized in that The annular edge of the outer edge of the rear end of the tubular mounting seat (17) is welded to the inner wall of the rear end of the cylindrical shell to fix the cylindrical shell and the tubular mounting seat (17).

3. The rotary chuck for an underground electric drilling rig in a coal mine as claimed in claim 1, It is characterized in that 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 a plurality of annular grooves for fitting the load-bearing bearing (19); the rotating shaft (18) is formed by a plurality of rotating shaft units (22) threadedly connected at the annular grooves so as to fit the load-bearing bearing (19); the front end of the rotating shaft (18) is provided with a plurality of piston keys (25) evenly distributed in the circumferential direction for connecting with the chuck piston (9); the front end of the rotating shaft (18) has a plurality of circumferentially evenly distributed slip grooves and is opposite to the protrusions at the rear end of the conical slip groove (6) one by one.

4. The rotary chuck for an underground electric drilling rig in a coal mine as claimed in claim 1, It is characterized in that The conical slip (6) is circumferentially surrounded by a plurality of conical slip bodies, and a slip spring (8) is arranged between adjacent conical slip bodies; when the slip piston pushes the conical slip bodies radially toward each other, the slip spring (8) is compressed, and when the slip piston no longer squeezes the conical slip (6), the slip spring (8) is reset; the conical surface of the outer wall of the conical slip (6) is in a shape of decreasing diameter from front to back; the front end surface of the conical slip (6) is provided with a plurality of circumferentially evenly distributed protrusions to correspond one by one to the slip grooves on the slip rotating support plate (26).

5. The rotary chuck for an underground electric drilling rig in a coal mine as claimed in claim 1, It is characterized in that The inner walls of the front end cover (2) and the rear end cover are both provided with annular grooves for accommodating 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 both provided with corresponding annular grooves for accommodating 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 both provided with corresponding annular grooves for accommodating the thrust bearing (5).

6. The rotary chuck for an underground electric drilling rig in a coal mine as claimed in claim 1, It is characterized in that There are a plurality of electric cylinders (16) which are evenly distributed along the circumference of the inner wall of the cylindrical shell, and each electric cylinder (16) corresponds to a group of limit locking gear components and a group of locking gear lever components.

7. The rotary chuck for an underground electric drilling rig in a coal mine as claimed in claim 1, It is characterized in that The limit latch assembly comprises a limit latch (15), a latch stop block (23), a latch reset spring (24) and a latch side wing (29); the latch stop block (23) is fixed to the inner wall of the cylindrical shell and a grooved slide rail is provided on the side wall of the latch stop block (23), and the grooved slide rail is radially along the cylindrical shell; the limit latch (15) is arranged between the two latch stop blocks (23), and the two ends of the limit latch (15) are arranged in the grooved slide rail of the latch stop block (23); the latch reset spring (24) is arranged on the limit latch (15) and the cylindrical shell; the latch tooth side wings (29) are connected to the middle and rear parts of both sides of the limit latch tooth (15), the bottom surface of the middle and rear part of the latch tooth side wings (29) is a plane, and the front part of the latch tooth side wings (29) is an inclined surface, which is inclined from the back to the front and close to the inner wall of the cylindrical shell; the tooth shape of the limit latch tooth (15) is a right triangle with the hypotenuse facing backward and the straight edge facing forward so that the disc spring support plate III (13) can move forward along the limit latch tooth (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 an underground electric drilling rig in a coal mine as claimed in claim 7, It is characterized in that The latching gear lever assembly comprises a latching gear lever (27) and a lever spring (28); the latching gear lever (27) comprises two levers, an end rotating shaft and a middle connecting rod; the two levers are parallel to each other, the middle connecting rod vertically connects the middle parts of the two levers, the end rotating shaft vertically connects the ends of the two levers, and the end rotating shaft vertically passes through the front end of the electric cylinder (16), and the lever can rotate around the end rotating 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), the lever spring (28) can pull the lever close to the circular end of the front end of the electric cylinder (16), and the distance between the two levers is smaller than the diameter of the circular end of the front end of the electric cylinder (16), so that the circular end can limit the range of forward rotation of the two levers.

9. The rotary chuck for an underground electric drilling rig in a coal mine as claimed in claim 8, It is characterized in that When the electric cylinder (16) extends and moves forward, the two levers correspond to the two latching tooth side wings (29) respectively. After being blocked by the latching tooth side wings (29), the levers will rotate and tilt backward, and the ends of the levers will press against the bottom of the latching tooth side wings (29) and move forward. After the levers move forward with the electric cylinder (16) until they leave the latching tooth side wings (29), the two levers are reset to the round ends close to the front end of the electric cylinder (16) under the action of the lever springs (28); When the electric cylinder (16) is retracted and moves backward, the inclined surface at the front of the latch tooth side wing (29) will squeeze the lever backward so that the lever is close to the circular end of the front end of the electric cylinder (16), and the lever applies a thrust to the latch tooth side wing (29) so that the limit latch tooth (15) compresses the latch tooth return spring (24) and then moves radially, so that the disc spring support plate III (13) is separated from the limit latch tooth (15) and moves backward with the electric cylinder (16), and the lever applies a thrust to the limit latch tooth (15) through the inclined surface at the front of the latch tooth side wing (29) and the bottom plane at the middle and rear part to make it move radially until the disc spring support plate III (13) moves backward and leaves the limit latch tooth (15).

10. The method for clamping and releasing the drill rod with a rotary chuck of an underground electric drill in a coal mine as claimed in claim 9, It is characterized in that The following steps are involved: When the chuck needs to clamp the drill pipe, the servo motor receives the electrical signal to drive the electric cylinder to move axially, pushes the disc spring support plate III to squeeze the compression disc spring, and drives the chuck piston to move axially at the same time. At this time, the reset disc spring is compressed, and the conical slip moves toward the axis driven by the chuck piston. When the drill pipe is clamped, the electric cylinder stops the stroke; the outer edge protrusion of the disc spring support plate III is fixed by the limit tooth. 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 a continuous and stable downward pressure to clamp the drill pipe; When the drill rod needs to be loosened, the electric cylinder performs a recovery action. At this time, the lever at the front end of the electric cylinder first contacts the side wing of the latch tooth, and its inclined surface causes the lever to push the limit latch tooth to perform outward radial movement. At this time, the disc spring support plate III is free from the restriction of the limit latch tooth, and under the action of the reset disc spring, the chuck piston is pushed, the disc spring is compressed, and the disc spring support plate is reset; the conical slip is expanded due to the action of the slip spring, and the drill rod is loosened at this time, and the electric cylinder returns to its initial state.

Images