A drill rod height adjusting assembly for a rotary drilling rig

Abstract

The present application is suitable for rotary drilling rig technical field, provide a kind of rotary drilling rig with drill rod height adjusting assembly, include rotary drilling rig, still include support arm, set up in rotary drilling rig, support arm is equipped with rotary power mechanism and guide wheel, by stress optimization, reduce equipment load, effectively share the tension of winch unit, reduce the stress concentration of key components, reduce fatigue damage risk, prolong the service life of equipment, hydraulic oil is adjusted flow by control valve, realize damping buffering effect avoid drill rod falls or ascending speed too fast to improve construction precision, reduce impact and vibration, always provide support guide to drill rod, avoid swing or deviation, operation stability is stronger, by the control of electromagnet energization and de-energization, realize seamless switching, so that braking process is more flexible, automation, improve the precision of operation process, ensure the accurate control of drill rod position, by automatic limiting mechanism, even if power failure occurs, drill rod can also be guaranteed not to fall.

Description

Technical Field

[0001] This invention belongs to the field of rotary drilling rig technology, and particularly relates to a drill rod height adjustment component for rotary drilling rigs. Background Technology

[0002] Rotary drilling rigs are construction machines suitable for hole-forming operations in building foundation engineering. They are mainly applicable to construction in soil layers such as sand, cohesive soil, and silty soil, and are widely used in various foundation constructions such as cast-in-place piles, continuous walls, and foundation reinforcement. Compared with traditional impact drills or rotary drills, rotary drilling rigs have advantages such as fast drilling speed, high hole quality, strong adaptability, simple operation, and low noise and vibration. The drill rod is a steel pipe with threads at the tail, used to connect the drilling rig's surface equipment and the drilling equipment or bottom hole device located at the bottom of the well. The purpose of the drill rod is to transport drilling mud to the drill bit and raise, lower, or rotate the bottom hole device together with the drill bit. The rotary drilling rig drives the drill bit to rotate and cut the soil layer through hydraulic power, and uses a winch system to lift the cuttings, achieving efficient drilling operations.

[0003] The drill rods used in existing rotary drilling rigs have their extension and retraction height adjusted by a winch. The extension and retraction resistance of the drill rod is directly reflected by the power head onto the wire rope. The winch needs to output a huge pulling force to lock the drill rod, which accelerates wire rope fatigue and breakage. At the same time, it increases the overflow loss of the winch's hydraulic system, resulting in high energy consumption. Summary of the Invention

[0004] The purpose of this invention is to provide a drill rod height adjustment component for rotary drilling rigs, aiming to solve the problems of existing rotary drilling rigs where the height of the drill rod is adjusted by extension and retraction of the drill rod through a winch. The extension and retraction resistance of the drill rod is directly reflected by the power head onto the wire rope, requiring the winch to output a large pulling force to lock the drill rod, which accelerates wire rope fatigue and breakage. At the same time, it increases the overflow loss of the winch's hydraulic system and results in high energy consumption.

[0005] This invention is implemented as follows: a drill rod height adjustment assembly for a rotary drilling rig, comprising a rotary drilling rig, and further comprising:

[0006] A support arm is mounted on a rotary drilling rig, and a rotary power mechanism and guide wheels are installed on the support arm.

[0007] A drill pipe assembly is mounted on a support arm. The drill pipe assembly includes a support frame and a drill pipe body, which is powered by a rotary power mechanism.

[0008] A hydraulic support assembly, disposed on the drill pipe assembly and the support arm, is used to provide hydraulic support for the drill pipe assembly. The hydraulic support assembly includes:

[0009] The support mechanism, installed on the support frame and support arm, is used to provide auxiliary support for the support frame;

[0010] The hydraulic mechanism, mounted on the support mechanism and support arm, is used to cooperate with the support mechanism to deliver hydraulic oil.

[0011] A winch assembly, located on the rotary drilling rig away from the support arm, is used to adjust the height of the drill rod assembly. The winch assembly includes a winch unit and a braking unit.

[0012] As a further embodiment of the present invention, the support frame is slidably fitted on the support arm, a positioning column is fixedly installed on the support arm, the support frame and the positioning column are slidably fitted, a positioning groove is provided on the support arm for limiting the movement stroke of the support frame, and the drill rod body is rotatably fitted on the support frame.

[0013] As a further aspect of the present invention, the support mechanism includes:

[0014] The large protective sleeve is fixedly installed on the support arm;

[0015] The middle casing slides onto the large casing;

[0016] The first sealing plug is fixedly installed at the bottom end of the middle casing, and the first sealing plug is slidably engaged with the large casing;

[0017] A fixing rod is fixedly installed on the support frame, and the fixing rod is slidably engaged with the middle protective sleeve.

[0018] The second sealing plug is fixedly installed at the bottom end of the fixed rod, and the second sealing plug slides in conjunction with the middle protective sleeve.

[0019] As a further embodiment of the present invention, the first sealing plug is in the shape of an annulus, and the size of the first sealing plug is larger than the size of the middle protective tube and the second sealing plug. The second sealing plug is in the shape of a disc, and the size is smaller than the size of the middle protective tube.

[0020] As a further aspect of the present invention, the hydraulic mechanism includes:

[0021] The electric control valve is fixedly installed on the large casing;

[0022] The delivery pipeline is fixedly installed on the electric control valve and the support arm;

[0023] An oil reservoir is fixedly installed on one side of the support arm. The oil reservoir is filled with hydraulic oil. A sealing plug is rotatably fitted on the oil reservoir, and a fixed plug is rotatably fitted on the top of the oil reservoir.

[0024] The oil inlet valve is fixedly installed on the oil storage tank and the delivery pipeline, connecting the oil storage tank and the delivery pipeline.

[0025] The oil outlet valve is fixedly installed on the oil storage tank and the delivery pipeline, connecting the oil storage tank and the delivery pipeline.

[0026] As a further embodiment of the present invention, both the inlet valve and the outlet valve are one-way valves. The oil reservoir, the outlet valve, the delivery pipeline, the electric control valve, and the large protective sleeve constitute the first hydraulic oil flow path, and the large protective sleeve, the electric control valve, the delivery pipeline, the inlet valve, and the oil reservoir constitute the second hydraulic oil flow path.

[0027] As a further aspect of the present invention, the hoisting unit includes:

[0028] The winch seat is fixedly installed on the rotary drilling rig on the side away from the support arm;

[0029] The motor is fixedly mounted on the winch base, and the output end of the motor is connected to a drive shaft, which is rotatably engaged with the winch base.

[0030] A steel rope is wound around the drive shaft, with one end fixedly connected to the drive shaft and the other end fixedly connected to the support frame.

[0031] The guide wheel is used to guide the steel rope.

[0032] As a further aspect of the present invention, the braking unit includes:

[0033] The electromagnet is fixedly installed on the winch base;

[0034] The brake friction device is rotatably fitted on the winch seat near the electromagnet.

[0035] A powerful magnet is fixedly installed on the brake friction unit to provide magnetic force to the electromagnet.

[0036] The rotating block is rotatably engaged with a brake friction device located away from the strong magnet.

[0037] A powerful spring, one end of which is fixedly mounted on the winch base and the other end is fixedly connected to the rotating block, is used to limit the movement of the brake friction device.

[0038] As a further embodiment of the present invention, the number of braking units is multiple sets, and the multiple sets of braking units are symmetrically distributed along the central axis of the winch seat, for braking and limiting the drive shaft.

[0039] This invention provides a drill rod height adjustment component for a rotary drilling rig. Through force optimization, it reduces equipment load, effectively distributes the tension of the winch unit, reduces stress concentration on key components, lowers the risk of fatigue damage, and extends equipment service life. The hydraulic oil flow is regulated by a control valve to achieve a damping buffer effect, preventing the drill rod from falling or rising too quickly, thus improving construction accuracy, reducing impact and vibration, and providing constant support and guidance for the drill rod to prevent swaying or deviation, resulting in stronger operational stability. Seamless switching is achieved through the control of the electromagnet's energization and de-energization, making the braking process more flexible and automated, improving the accuracy of the operation process, ensuring precise control of the drill rod position, and ensuring that the drill rod does not fall even in the event of a power failure through an automatic limit mechanism. Attached Figure Description

[0040] Figure 1 This is a three-dimensional structural schematic diagram of a drill rod height adjustment component for a rotary drilling rig provided in an embodiment of the present invention;

[0041] Figure 2 This is a partial structural diagram of the drill rod assembly of a rotary drilling rig height adjustment component provided in an embodiment of the present invention;

[0042] Figure 3 This is a partial structural diagram of the hydraulic support component of a drill rod height adjustment assembly for a rotary drilling rig provided in an embodiment of the present invention;

[0043] Figure 4 This invention provides a structural diagram of the support mechanism and hydraulic mechanism of a drill rod height adjustment assembly for a rotary drilling rig.

[0044] Figure 5 This is a structural diagram of the winch assembly of a rotary drilling rig height adjustment assembly provided in an embodiment of the present invention;

[0045] Figure 6 This invention provides a drill rod height adjustment assembly for a rotary drilling rig. Figure 5 Enlarged view of point A in the middle.

[0046] In the attached diagram: 1. Support arm; 11. Rotary power mechanism; 12. Guide wheel; 2. Drill pipe assembly; 21. Support frame; 22. Drill pipe body; 3. Hydraulic support assembly; 31. Support mechanism; 311. Large casing; 312. Middle casing; 313. First sealing plug; 314. Fixed rod; 315. Second sealing plug; 32. Hydraulic mechanism; 321. Electric control valve; 322. Delivery pipeline; 323. Oil tank; 324. Inlet valve; 325. Outlet valve; 4. Hoisting assembly; 41. Hoisting unit; 411. Hoisting seat; 412. Motor; 413. Drive shaft; 414. Steel rope; 42. Braking unit; 421. Electromagnet; 422. Braking friction device; 423. Powerful magnet; 424. Rotating block; 425. Powerful spring. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0048] It is understood that the terms “first” and “second” as used herein may be used to describe various elements, but unless otherwise stated, these elements are not limited by these terms. These terms are used only to distinguish one element from another.

[0049] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0050] like Figures 1 to 6 As shown, an embodiment of the present invention provides a drill rod height adjustment assembly for a rotary drilling rig, comprising a rotary drilling rig and further comprising:

[0051] Support arm 1 is mounted on a rotary drilling rig. Rotary power mechanism 11 and guide wheel 12 are installed on support arm 1.

[0052] Drill pipe assembly 2 is mounted on support arm 1. Drill pipe assembly 2 includes support frame 21 and drill pipe body 22. Drill pipe body 22 is powered by rotary power mechanism 11.

[0053] Hydraulic support assembly 3, disposed on drill pipe assembly 2 and support arm 1, is used to provide hydraulic support for drill pipe assembly 2. Hydraulic support assembly 3 includes:

[0054] A support mechanism 31 is provided on the support frame 21 and the support arm 1, and is used to provide auxiliary support for the support frame 21.

[0055] The hydraulic mechanism 32 is mounted on the support mechanism 31 and the support arm 1, and is used to cooperate with the support mechanism 31 to transport hydraulic oil.

[0056] The winch assembly 4 is located on the rotary drilling rig on the side away from the support arm 1 and is used to adjust the height of the drill rod assembly 2. The winch assembly 4 includes a winch unit 41 and a braking unit 42.

[0057] Furthermore, as a further embodiment of the present invention, the support frame 21 is slidably fitted on the support arm 1, a positioning column is fixedly installed on the support arm 1, the support frame 21 is slidably fitted with the positioning column, and a positioning groove is provided on the support arm 1 for limiting the movement stroke of the support frame 21. The drill rod body 22 is rotatably fitted on the support frame 21.

[0058] In this embodiment of the invention, in practical application, the component is installed on a rotary drilling rig. During drilling operations, the support arm 1 serves as a supporting component, and the rotary power mechanism 11 outputs power to drive the drill rod body 22 to rotate the drill bit for drilling operations. The winch unit 41 adjusts the height of the drill rod body 22, thereby adjusting the drilling depth. The hydraulic support component 3 always maintains an auxiliary supporting force on the drill rod body 22, thereby reducing the pulling force of the winch unit 41 and further alleviating fatigue. Due to the design of the braking unit 42, it has a braking and limiting effect on the winch unit 41, which can keep the drill rod body 22 restricted in a certain position. With the cooperation of the hydraulic support component 3, the safety and stability of drilling operations are greatly increased.

[0059] It should be noted that the rotary power mechanism 11 and the drill pipe body 22 are both mature solutions of the prior art and are common knowledge to those skilled in the art, so they will not be described in detail here.

[0060] like Figures 1 to 6 As shown, in a further embodiment of the present invention, the support mechanism 31 includes:

[0061] Large casing 311 is fixedly installed on support arm 1;

[0062] The middle casing 312 is slidably fitted onto the large casing 311;

[0063] The first sealing plug 313 is fixedly installed at the bottom end of the middle protective sleeve 312, and the first sealing plug 313 is slidably engaged with the large protective sleeve 311;

[0064] The fixing rod 314 is fixedly installed on the support frame 21, and the fixing rod 314 is slidably engaged with the middle protective sleeve 312.

[0065] The second sealing plug 315 is fixedly installed at the bottom end of the fixing rod 314, and the second sealing plug 315 slides in conjunction with the middle protective sleeve 312;

[0066] Furthermore, as a further embodiment of the present invention, the first sealing plug 313 is annular in shape, and the size of the first sealing plug 313 is larger than the size of the middle protective sleeve 312 and the second sealing plug 315. The second sealing plug 315 is disc-shaped and smaller than the size of the middle protective sleeve 312.

[0067] In this embodiment of the invention, during actual application, as the drill pipe body 22 descends and extends, the fixing rod 314 and the second sealing plug 315 both move downward within the middle casing 312. When the second sealing plug 315 contacts the middle casing 312, the middle casing 312 also moves downward along with the fixing rod 314. The middle casing 312 and the first sealing plug 313 move and extend within the large casing 311. The positions of the three casings move synchronously according to the movement of the drill pipe body 22 and the support frame 21, always maintaining a supporting effect on the drill pipe body 22, further increasing the stability of the movement of the drill pipe body 22.

[0068] like Figures 1 to 6 As shown, in a further embodiment of the present invention, the hydraulic mechanism 32 includes:

[0069] The electric control valve 321 is fixedly installed on the large casing 311;

[0070] The delivery pipeline 322 is fixedly installed on the electric control valve 321 and the support arm 1;

[0071] The oil reservoir 323 is fixedly installed on one side of the support arm 1. The oil reservoir 323 is filled with hydraulic oil. A sealing plug is rotatably fitted on the oil reservoir 323, and a fixed plug is rotatably fitted on the top of the oil reservoir 323.

[0072] The oil inlet valve 324 is fixedly installed on the oil storage tank 323 and the delivery pipeline 322, so that the oil storage tank 323 is connected to the delivery pipeline 322;

[0073] An oil outlet valve 325 is fixedly installed on an oil storage tank 323 and a delivery pipeline 322, so that the oil storage tank 323 is connected to the delivery pipeline 322;

[0074] Furthermore, as a further embodiment of the present invention, both the inlet valve 324 and the outlet valve 325 are one-way valves. The oil tank 323, the outlet valve 325, the delivery pipeline 322, the electric control valve 321, and the large protective sleeve 311 constitute the first hydraulic oil flow path. The large protective sleeve 311, the electric control valve 321, the delivery pipeline 322, the inlet valve 324, and the oil tank 323 constitute the second hydraulic oil flow path.

[0075] In this embodiment of the invention, during practical application, as the first sealing plug 313 moves downward, the hydraulic oil in the casing flows through the electric control valve 321 into the delivery pipeline 322, the inlet valve 324, and the oil storage tank 323. After the second sealing plug 315 comes into contact with the middle casing 312, the second sealing plug 315 seals the first sealing plug 313. The middle casing 312 drives the first sealing plug 313 to continue downward. The flow of hydraulic oil maintains better stability of the drill rod body 22 and also prevents the drill rod body 22 from moving too fast. During the upward movement of the drill rod body 22, the hydraulic oil inside the oil storage tank 323 flows into the casing due to the suction force of the first sealing plug 313 and the second sealing plug 315, maintaining auxiliary support for the movement of the drill rod body 22, thereby completing the height adjustment.

[0076] It should be noted that the electric control valve 321, the oil inlet valve 324, and the oil outlet valve 325 are all mature solutions in the prior art and are common knowledge to those skilled in the art, so they will not be described in detail here.

[0077] like Figures 1 to 6 As shown, in a further embodiment of the present invention, the hoisting unit 41 includes:

[0078] The winch seat 411 is fixedly installed on the rotary drilling rig on the side away from the support arm 1;

[0079] Motor 412 is fixedly mounted on winch base 411. The output end of motor 412 is connected to drive shaft 413, and drive shaft 413 is rotatably engaged with winch base 411.

[0080] Steel rope 414 is wound around drive shaft 413, with one end fixedly connected to drive shaft 413 and the other end fixedly connected to support frame 21;

[0081] Guide wheel 12 is used to guide steel rope 414;

[0082] In this embodiment of the invention, during practical application, the motor 412 starts and outputs power, causing the drive shaft 413 to rotate. When the drive shaft 413 rotates clockwise, the steel cable 414 is tightened, thereby driving the support frame 21 and the drill rod body 22 to move upward. When the drive shaft 413 rotates counterclockwise, the steel cable 414 loosens, and the drill rod body 22 and the support frame 21 fall naturally under the force of gravity. It should be noted that during the movement of the drill rod body 22, the electric control valve 321 needs to be kept in the open state. When the electric control valve 321 is closed, the drill rod body 22 is subject to the limiting force of hydraulic oil and cannot move.

[0083] like Figures 1 to 6 As shown, in a further embodiment of the present invention, the braking unit 42 includes:

[0084] Electromagnet 421 is fixedly installed on winch base 411;

[0085] The brake friction device 422 is rotatably fitted on the winch seat 411 on the side close to the electromagnet 421;

[0086] A powerful magnet 423 is fixedly installed on the brake friction unit 422 and is used to magnetically engage the electromagnet 421.

[0087] Rotating block 424 is rotatably engaged with brake friction 422 above the strong magnet 423;

[0088] A strong spring 425, one end of which is fixedly mounted on the winch base 411 and the other end is fixedly connected to the rotating block 424, is used to limit the brake friction device 422.

[0089] Furthermore, as a further embodiment of the present invention, the number of braking units 42 is multiple sets, and the multiple sets of braking units 42 are symmetrically distributed along the central axis of the winch seat 411, for braking and limiting the drive shaft 413.

[0090] In this embodiment of the invention, during practical application, when the drill rod body 22 moves, the electromagnet 421 is energized and repels the strong magnet 423, causing the brake friction device 422 to rotate under the force. At this time, the brake friction device 422 is not in contact with the drive shaft 413 and does not have a limiting effect on the drive shaft 413. The strong spring 425 stores energy under the force. When the drill rod body 22 stops moving, the electromagnet 421 is de-energized. At this time, the magnetic force disappears, the stored energy of the strong spring 425 is released, and the brake friction device 422 is pushed to firmly contact the drive shaft 413. The brake friction device 422 increases the frictional resistance of the drive shaft 413 rotation, thus completing the braking and limiting of it. In case of power failure, after the electromagnet 421 is de-energized, the brake friction device 422 will also actively limit the drive shaft 413, thereby ensuring better stability of the drill rod body 22 and preventing the drill rod body 22 from falling.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A drill rod height adjustment assembly for a rotary drilling rig, comprising a rotary drilling rig, characterized in that, Also includes: A support arm (1) is mounted on a rotary drilling rig, and a rotary power mechanism (11) and a guide wheel (12) are installed on the support arm (1). The drill pipe assembly (2) is mounted on the support arm (1). The drill pipe assembly (2) includes a support frame (21) and a drill pipe body (22). The drill pipe body (22) is powered by a rotary power mechanism (11). A hydraulic support assembly (3) is disposed on the drill pipe assembly (2) and the support arm (1) for hydraulically supporting the drill pipe assembly (2). The hydraulic support assembly (3) includes: A support mechanism (31) is provided on the support frame (21) and the support arm (1) for auxiliary support of the support frame (21); A hydraulic mechanism (32) is provided on the support mechanism (31) and the support arm (1) for cooperating with the support mechanism (31) to transport hydraulic oil; The winch assembly (4) is located on the rotary drilling rig on the side away from the support arm (1) and is used to adjust the height of the drill rod assembly (2). The winch assembly (4) includes a winch unit (41) and a braking unit (42).

2. The drill rod height adjustment assembly for a rotary drilling rig according to claim 1, characterized in that, The support frame (21) is slidably fitted on the support arm (1), and a positioning column is fixedly installed on the support arm (1). The support frame (21) is slidably fitted with the positioning column. A positioning groove is provided on the support arm (1) for limiting the movement stroke of the support frame (21). The drill rod body (22) is rotatably fitted on the support frame (21).

3. The drill rod height adjustment assembly for a rotary drilling rig according to claim 1, characterized in that, The support mechanism (31) includes: The large protective sleeve (311) is fixedly installed on the support arm (1); The middle casing (312) is slidably fitted onto the large casing (311); The first sealing plug (313) is fixedly installed at the bottom end of the middle protective sleeve (312), and the first sealing plug (313) slides in cooperation with the large protective sleeve (311); A fixing rod (314) is fixedly installed on the support frame (21), and the fixing rod (314) is slidably engaged with the middle protective sleeve (312); The second sealing plug (315) is fixedly installed at the bottom end of the fixing rod (314), and the second sealing plug (315) slides in cooperation with the middle protective sleeve (312).

4. The drill rod height adjustment assembly for a rotary drilling rig according to claim 3, characterized in that, The first sealing plug (313) is in the shape of an annulus and its size is larger than that of the middle protective sleeve (312) and the second sealing plug (315). The second sealing plug (315) is in the shape of a disc and its size is smaller than that of the middle protective sleeve (312).

5. The drill rod height adjustment assembly for a rotary drilling rig according to claim 3, characterized in that, The hydraulic mechanism (32) includes: An electric control valve (321) is fixedly installed on the large casing (311); The delivery pipeline (322) is fixedly installed on the electric control valve (321) and the support arm (1); The oil reservoir (323) is fixedly installed on one side of the support arm (1). The oil reservoir (323) is filled with hydraulic oil. A sealing plug is rotatably fitted on the oil reservoir (323). A fixed plug is rotatably fitted on the top of the oil reservoir (323). An oil inlet valve (324) is fixedly installed on the oil storage tank (323) and the delivery pipeline (322) to connect the oil storage tank (323) and the delivery pipeline (322); An oil outlet valve (325) is fixedly installed on the oil storage tank (323) and the delivery pipeline (322) to connect the oil storage tank (323) and the delivery pipeline (322).

6. The drill rod height adjustment assembly for a rotary drilling rig according to claim 5, characterized in that, The inlet valve (324) and outlet valve (325) are both one-way valves. The oil tank (323), outlet valve (325), delivery pipeline (322), electric control valve (321) and large casing (311) constitute the first hydraulic oil flow path. The large casing (311), electric control valve (321), delivery pipeline (322), inlet valve (324) and oil tank (323) constitute the second hydraulic oil flow path.

7. The drill rod height adjustment assembly for a rotary drilling rig according to claim 1, characterized in that, The hoisting unit (41) includes: The winch seat (411) is fixedly installed on the rotary drilling rig on the side away from the support arm (1); The motor (412) is fixedly mounted on the winch base (411), and the output end of the motor (412) is connected to the drive shaft (413), which is rotatably engaged with the winch base (411). A steel rope (414) is wound around the drive shaft (413), with one end fixedly connected to the drive shaft (413) and the other end fixedly connected to the support frame (21); The guide wheel (12) is used to guide the steel rope (414).

8. The drill rod height adjustment assembly for a rotary drilling rig according to claim 7, characterized in that, The braking unit (42) includes: An electromagnet (421) is fixedly installed on a winch base (411); The brake friction device (422) is rotatably fitted on the winch seat (411) on the side close to the electromagnet (421); A powerful magnet (423) is fixedly installed on the brake friction device (422) to provide magnetic force to the electromagnet (421); Rotating block (424) is rotatably fitted on brake friction device (422) above the strong magnet (423); A strong spring (425) is fixedly mounted on the winch seat (411) at one end and fixedly connected to the rotating block (424) at the other end, and is used to limit the brake friction device (422).

9. A drill rod height adjustment assembly for a rotary drilling rig according to claim 8, characterized in that, The number of braking units (42) is multiple sets, and the multiple sets of braking units (42) are symmetrically distributed along the central axis of the winch seat (411) for braking and limiting the drive shaft (413).

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