Gearbox for core drilling rig

Abstract

The utility model relates to the technical field of core drilling, especially to a gearbox for core drilling machine. The gearbox comprises a box body, an input shaft, an intermediate rotating shaft, an output shaft and a shift fork mechanism. The input shaft is provided with a driving gear. The intermediate rotating shaft is provided with a driven gear, a clutch gear and an inner-outer connecting gear in sequence from top to bottom. The driving gear and the driven gear are in mesh with each other. The clutch gear rotates with the intermediate rotating shaft and moves up and down along the axial direction of the intermediate rotating shaft. The inner surface of the inner-outer connecting gear towards the clutch gear end is provided with internal teeth, and the outer surface of the inner-outer connecting gear away from the clutch gear end is provided with external teeth. The output shaft is provided with a second gear and a first gear in sequence from top to bottom along the axial direction. The shift fork mechanism drives the clutch gear to move up and down along the axial direction of the intermediate rotating shaft. The gearbox can switch the output shaft between low-speed rotation and high-speed rotation, so that the drill rod can meet various working requirements of low-speed heavy load and high-speed light load, and the working range of the drilling machine is improved.

Description

Technical Field

[0001] This utility model relates to the field of core drilling technology, and in particular to a gearbox for a core drilling machine. Background Technology

[0002] A core drilling rig is a specialized piece of equipment used to extract core samples from geological formations. It is widely used in geological exploration, construction engineering, mining, and other fields. A power system drives the drill bit to rotate, cutting and breaking the rock. Simultaneously, the drill pipe propels the drill bit to a predetermined depth. During drilling, the core samples are collected in a core tube inside the drill bit. As drilling deepens, the core samples are continuously extracted into the core tube, and finally, a hoisting system removes the core tube and the core samples from the ground.

[0003] The gearbox of a core drilling rig is used to adjust the speed and torque of the power system to meet the varying drilling speed and torque requirements under different geological conditions. Small, portable drilling rigs typically use mechanical gearboxes. Mechanical gearboxes generally achieve speed changes through gear meshing; however, the gear ratios in existing core drilling rig gearboxes are fixed, resulting in constant power output. This prevents core drilling rigs from simultaneously meeting the demands of low-speed heavy-load and high-speed light-load operations, significantly limiting their application range. Utility Model Content

[0004] The purpose of this invention is to overcome the above-mentioned defects in the existing technology and propose a gearbox for core drilling rigs that can switch the output shaft between low-speed and high-speed rotation, so that the drill rod can meet various working requirements such as low-speed heavy load and high-speed light load, thereby improving the working range of the drilling rig.

[0005] The technical solution of this utility model is: a gearbox for a core drilling machine, comprising a gearbox body, wherein the gearbox body further comprises:

[0006] An input shaft, on which a drive gear is mounted;

[0007] An intermediate rotating shaft has a driven gear, a clutch gear, and inner and outer connecting gears arranged sequentially from top to bottom along its shaft. The driving gear and the driven gear mesh with each other. The clutch gear rotates together with the intermediate rotating shaft and moves up and down along the axial direction of the intermediate rotating shaft. There is an annular gap between the inner wall of the inner and outer connecting gears facing the clutch gear and the outer wall of the intermediate rotating shaft. The inner surface of the inner and outer connecting gears facing the clutch gear end has internal teeth, and the outer surface of the inner and outer connecting gears facing away from the clutch gear end has external teeth.

[0008] The output shaft has a second gear and a first gear arranged sequentially along its top-to-bottom direction.

[0009] The shift fork mechanism moves the clutch gear up and down axially along the central rotating shaft.

[0010] The input shaft, intermediate rotating shaft, and output shaft are all housed inside the housing. One end of the shift fork mechanism is located inside the housing, while the other end is located outside the housing.

[0011] In this invention, when the shift fork mechanism moves the clutch gear to the uppermost end of its vertical movement range, the clutch gear and the second gear mesh with each other, thereby achieving low-speed rotation of the output shaft.

[0012] When the clutch gear of the shift fork mechanism is shifted into the annular gap between the inner and outer connecting gears and the intermediate rotating shaft, the clutch gear meshes with the inner gear of the intermediate rotating shaft, and the outer gear of the intermediate rotating shaft meshes with the first gear, thereby achieving high-speed rotation of the output shaft.

[0013] A second upper end cover is provided on the upper surface of the box above the middle rotating shaft, and a second lower end cover is provided on the lower surface of the box below the middle rotating shaft.

[0014] The upper and lower ends of the intermediate rotating shaft are rotatably connected to the housing via bearings.

[0015] The second lower end cover is fixed with an oil cup and an oil pump. The oil pump draws out the lubricating oil from the oil cup and sends it into the housing through the oil pipe.

[0016] The clutch gear is connected to the intermediate rotating shaft via a spline.

[0017] The upper part of the clutch gear is provided with an annular groove, and the shift fork mechanism is connected to the clutch gear through the annular groove.

[0018] The shift fork mechanism includes:

[0019] The first shift fork lever is located on the outside of the housing. One end of the lever, facing the housing, has a cone head and is connected to the side of the housing via a positioning plate. The other end of the lever, facing away from the housing, is connected to a handle. A sliding rod is slidably provided inside the handle. One end of the sliding rod is connected to the cone head and is located on the outside of the handle. A spring is connected between the sliding rod and the inner hole of the handle. The other end of the first shift fork lever is connected to the second shift fork lever via a connecting shaft.

[0020] The second shift fork is located inside the housing. One end of it is connected to the first shift fork, and the other end, facing the clutch gear, is provided with a shift fork. The shift fork is set in an annular groove.

[0021] The positioning plate is arc-shaped and fixed to the side of the box. It has two positioning holes. When the cone is inserted into the positioning hole, the first shift fork rod and the box are connected by a limiting constraint.

[0022] The top end of the output shaft is connected to the upper surface of the housing through the first upper end cover, and the bottom end of the output shaft is connected to the lower surface of the housing through the first lower end cover. Oil seals are provided at the connection points between the output shaft and the first upper end cover and the first lower end cover.

[0023] The top and bottom ends of the output shaft are rotatably connected to the housing via bearings.

[0024] The output shaft is connected to the first gear and the second gear via splines, and the bottom end of the output shaft is fixedly connected to the drill rod via a tapered thread.

[0025] The gearbox mounting plate is located on the rear side of the housing, and a sliding plate is located on the side of the drilling rig facing the gearbox. The gearbox mounting plate and the sliding plate can slide relative to each other in the horizontal direction to adjust the horizontal position of the gearbox; the sliding plate and the drilling rig can slide relative to each other in the vertical direction to adjust the vertical position of the gearbox.

[0026] The front side of the box has an openable lid.

[0027] The beneficial effects of this utility model are:

[0028] (1) This application uses a shifting mechanism to enable the transmission of torque between the intermediate rotating shaft and the output shaft through different meshing gear sets. During the transmission of rotational power through different meshing gear sets, the output shaft can switch between low-speed rotation and high-speed rotation, so that the drill pipe can meet various working requirements of low-speed heavy load and high-speed light load, thereby improving the working range of the drilling rig. The gearbox has a wide speed range, is suitable for various working scenarios, and has strong adaptability.

[0029] (2) Through the gear shifting adjustment of the gearbox, when the output shaft drives the drill pipe to rotate at high speed, high-speed drilling is achieved; when the working load is too large, such as when encountering hard rocks during drilling, the output shaft drives the drill pipe to rotate at low speed, increasing the torque and protecting the drill bit by drilling at low speed.

[0030] (3) When the output shaft needs to rotate at low speed, the power output from the power source is transmitted to the output shaft through two-stage reduction: the first-stage reduction is achieved during the meshing of the drive gear and the driven gear; the second-stage reduction is achieved during the meshing of the clutch gear and the second gear. Through the two-stage reduction process, the low-speed rotation of the output shaft and the drill rod can be effectively achieved, so that the drill rod rotating at low speed has the characteristics of large load-bearing capacity, torsion resistance, and impact resistance, which is suitable for drilling in complex geological conditions.

[0031] (4) By setting up oil cups and oil pumps, this application ensures the lubrication of the gear set in the gearbox, prolongs the service life of the gears, and improves the performance and service life of the gearbox. Attached Figure Description

[0032] Figure 1This is a first three-dimensional structural schematic diagram of the gearbox described in this utility model;

[0033] Figure 2 This is a second three-dimensional structural schematic diagram of the gearbox described in this utility model;

[0034] Figure 3 This is a schematic diagram of the internal main structure of the gearbox described in this utility model;

[0035] Figure 4 yes Figure 3 Sectional view along axis AA;

[0036] Figure 5 yes Figure 3 BB-direction sectional view;

[0037] Figure 6 This is a structural diagram of the input shaft, intermediate rotating shaft, and output shaft;

[0038] Figure 7 This is a schematic diagram of the clutch gear and shift fork mechanism;

[0039] Figure 8 This is a schematic diagram of the shift fork mechanism;

[0040] Figure 9 This is a schematic diagram of the output shaft;

[0041] Figure 10 This is a schematic diagram of the internal and external connecting gears;

[0042] Figure 11 This is a schematic diagram of the gearbox of this utility model installed on the drilling rig;

[0043] Figure 12 This is a schematic diagram of the connection between the gearbox and the drilling tower described in this utility model.

[0044] In the diagram: 1. Housing; 2. Housing cover; 3. First lower end cover; 4. Output shaft; 401. Spline; 402. Tapered thread; 5. Oil cup; 6. Oil pump; 7. Second lower end cover; 8. Gearbox mounting plate; 9. Oil pipe; 10. Shift mechanism; 1001. Shift fork; 1002. Positioning plate; 1003. Handle; 1004. First shift fork lever; 1005. Connecting shaft; 1006. Second shift fork lever; 1007. Cone; 11. First upper end cover; 12. Second upper end cover; 13. Input shaft ; 14 Intermediate rotating shaft; 15 Driving gear; 16 Deep groove ball bearing; 17 Driven gear; 18 Nylon retaining ring; 19 Clutch gear; 1901 Annular groove; 20 Inner and outer connecting gears; 2001 Gear body; 2002 Internal gear; 2003 External gear; 21 Bearing housing; 22 First oil seal; 23 Tapered roller bearing; 24 First gear; 25 Second gear; 26 Cylindrical roller bearing; 27 Second oil seal; 28 Drill tower; 29 Gearbox. Detailed Implementation

[0045] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0046] Specific details are set forth in the following description to provide a full understanding of the present invention. However, the present invention can be implemented in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0047] like Figure 1 and Figure 2 As shown, the gearbox for a core drilling machine according to this invention includes a housing 1, an input shaft 13, an intermediate rotating shaft 14, an output shaft 4, and a shifting mechanism 10. The input shaft 13 is connected to the output shaft of the power source. The input shaft 13 and the intermediate rotating shaft 14 are driven by gear meshing, and the intermediate rotating shaft 14 and the output shaft 4 are also driven by gear meshing. The shifting mechanism 10 acts on the intermediate rotating shaft, realizing the transmission connection between the intermediate rotating shaft 14 and the output shaft 4 through different gear meshing pairs, thereby realizing the speed adjustment of the output shaft and enabling the output shaft to switch arbitrarily between high-speed and low-speed rotation.

[0048] In this embodiment, the box body is made of one piece of cast iron sand casting, which improves the structural rigidity and strength of the box body, and has stronger overall torsional and impact resistance, thus avoiding welding deformation.

[0049] The top end of the output shaft 4 is connected to the top surface of the housing 1 via the first upper end cover 11, and the bottom end of the output shaft 4 is connected to the bottom surface of the housing 1 via the first lower end cover 3. A bearing and an oil seal are provided between the upper end of the output shaft 4 and the top surface of the housing, and a bearing and an oil seal are provided between the lower end of the output shaft 4 and the bottom surface of the housing. The first upper end cover and the first lower end cover serve to seal the bearings and also limit their movement.

[0050] A second upper cover 12 is fixed to the top surface of the housing 1 above the top of the intermediate rotating shaft 14, and a second lower cover 7 is fixed to the bottom surface of the housing 1 below the bottom of the intermediate rotating shaft 14. A bearing and an oil seal are provided between the top of the intermediate rotating shaft 14 and the top surface of the housing, and a bearing and an oil seal are provided between the bottom of the intermediate rotating shaft 14 and the bottom surface of the housing. The second upper cover 12 and the second lower cover 7 serve a sealing function and also limit the bearing position.

[0051] The bottom surface of the second lower end cover 7 is fixed with an oil cup 5 and an oil pump 6. The oil pump 6 draws out the lubricating oil from the oil cup 5 and injects it into the housing 1 through the oil pipe 9 to provide lubricating oil for the rotation of the gears in the gearbox, thereby extending the service life of the gears and improving the service life of the gearbox.

[0052] The shift mechanism 10 is rotatably mounted on the side wall of the housing 1, with one end extending into the housing 1 and acting on the intermediate rotating shaft 14. The other end of the shift mechanism 10 is located outside the housing 1. By operating the shift mechanism 10, the position of the clutch gear on the intermediate rotating shaft 14 is changed, thereby changing the gear meshing between the intermediate rotating shaft 14 and the output shaft 4, thus enabling the output shaft 4 to switch between high speed and low speed.

[0053] A cover 2 is provided on the front side of the gearbox 1, and the cover 2 is openable. During drilling, the cover 2 can be opened to observe the meshing of the gears inside the gearbox, so as to detect faults in the transmission process in a timely manner and carry out maintenance.

[0054] like Figures 3 to 6 As shown, the top end of the input shaft 13 is located outside the housing 1, and the lower end of the input shaft 13 is located inside the housing 1. A bearing seat is provided inside the housing 1, and a bearing is installed in the bearing seat to facilitate the rotational connection between the input shaft 13 and the housing 1. A drive gear 10 is fixed to the end of the input shaft 13 located inside the housing. When the power source drives the input shaft 13 to rotate, it drives the drive gear 10 to rotate.

[0055] The top end of the intermediate rotating shaft 14 is rotatably connected to the housing 1 via a deep groove ball bearing 16. The bottom end of the intermediate rotating shaft 14 is rotatably connected to the bearing chamber 20.

[0056] A driven gear 17 is fixed to the upper end of the intermediate rotating shaft 14, and the driving gear 15 on the input shaft 13 meshes with the driven gear 17. Through the meshing between the driving gear 15 and the driven gear 17, the intermediate rotating shaft 14 is driven to rotate.

[0057] The number of teeth on the driven gear 17 is greater than the number of teeth on the driving gear 15. In this embodiment, the driving gear 15 has 25 teeth and the driven gear 17 has 55 teeth. Therefore, when the driving gear 15 drives the driven gear 17 to rotate, a first-stage deceleration is achieved.

[0058] A nylon retaining ring 18 is fixed on the intermediate rotating shaft 14 below the driven gear 17. A magnet is installed inside the nylon retaining ring 18. After the clutch gear moves upward, the magnetic attraction of the magnet connects the clutch gear and the nylon retaining ring 18 to prevent the clutch gear from falling.

[0059] An inner and outer connecting gear 20 is provided at the lower end of the intermediate rotating shaft 14 and above the bearing chamber 21. The inner and outer connecting gear 20 is sleeved on the outside of the intermediate rotating shaft 14. There is an annular gap between the inner surface of ...

[0060] Therefore, when the clutch gear is at the top of its movable range, the inner and outer connecting gears 20 do not rotate with the intermediate rotating shaft 14. When the clutch gear moves downward into the annular gap between the inner and outer connecting gears 20 and the intermediate rotating shaft 14, the clutch gear can drive the inner and outer connecting gears 20 to rotate through gear meshing.

[0061] A clutch gear 19 is provided on the intermediate rotating shaft 14 between the driven gear 17 and the inner and outer connecting gears 20. During the rotation of the intermediate rotating shaft 14, the clutch gear 19 can be driven to rotate together with it; at the same time, the clutch gear 19 can also reciprocate along the axial direction of the intermediate rotating shaft 14. The axial reciprocating movement of the clutch gear 19 is achieved by the shifting mechanism 10.

[0062] In this embodiment, the clutch gear 19 adopts an external gear structure, and the clutch gear 19 is connected to the intermediate rotating shaft 14 via a spline. During the rotation of the intermediate rotating shaft 14, torque is transmitted to the clutch gear 19 through the spline. Figure 7 As shown, the upper part of the clutch gear 19 is provided with an annular groove 1901, and the shift fork of the shift mechanism is located in the annular groove 1901. During the up and down movement of the shift fork, the clutch gear 19 is driven to move up and down along the axial direction of the intermediate rotating shaft 14 through the contact between the shift fork and the connecting ring.

[0063] like Figure 8 As shown, the shifting mechanism includes a shift fork 1001, a handle 1003, a first shift fork lever 1004, and a second shift fork lever 1006. The second shift fork lever 1006 is located inside the housing. One end of the second shift fork lever 1006, facing the side of the clutch gear 19, is connected to the shift fork 1001. The other end of the second shift fork lever 1006 is fixedly connected to one end of the first shift fork lever 1004 via a connecting shaft 1005. The first shift fork lever 1004 is located outside the housing. The other end of the first shift fork lever 1004, facing the side of the housing, has a conical head 1007. Correspondingly, an arc-shaped positioning plate 1002 is fixed to the side of the housing. The positioning plate 1002 has two positioning holes. The handle 1003 is connected to the end of the first shift fork lever 1004 facing away from the housing. The connecting shaft 1005 is rotatably connected to the housing.

[0064] The cone head 1007 is movably disposed within the handle 1003. In this embodiment, the sliding rod is slidably disposed within the inner hole of the handle 1003. The side of the sliding rod facing the housing has the cone head 1007, and the side of the sliding rod away from the housing is located outside the handle 1003, with a spring connecting the sliding rod to the inner hole.

[0065] During the rotation of handle 1003, the first shift fork 1004 and the connecting shaft 1005 are sequentially used to drive the second shift fork 1006 to rotate. As the second shift fork 1006 rotates with the connecting shaft 1005, the shift fork 1001 at its free end will also move up and down, thereby causing the shift fork 1001 to drive the clutch gear 19 to move up and down axially.

[0066] During the rotation of the first shift fork 1004, the positioning hole on the positioning plate 1002 limits and positions the rotation of the first shift fork 1004. While the first shift fork 1004 is rotating, the spring inside it remains compressed. When the first shift fork 1004 rotates to the first positioning hole on the positioning plate 1002, the cone 1007 automatically enters the first positioning hole under the force of the spring, fixing the first shift fork 1004 to the side of the housing. This achieves the positioning of the first shift fork 1004, the second shift fork 1006, and the shift fork 1001. At this time, the clutch gear rises to the top of its movable range and its position is fixed.

[0067] When the position of the clutch gear needs to be adjusted, pull the sliding rod to disengage the cone 1007 from the positioning hole. Then, rotate the handle 1003 to simultaneously rotate the first shift fork 1004 and the second shift fork 1006. At this time, the shift fork 1001 drives the clutch gear downwards. When the cone 1007 rotates to the second positioning hole, under the force of the spring, the cone 1007 automatically enters the second positioning hole, fixing the first shift fork 1004 to the side of the housing. This achieves the positioning of the first shift fork 1004, the second shift fork 1006, and the shift fork 1001. The clutch gear then descends to the lowest point of its movable range and its position is fixed.

[0068] A second oil seal 27 is provided at the rotatable connection between the output shaft 4 and the first upper end cover 11, and a first oil seal 22 is provided at the rotatable connection between the output shaft 4 and the first lower end cover 3. The upper end of the output shaft 4 is rotatably connected to the housing 1 via a cylindrical roller bearing 26. The lower middle part of the output shaft 4 is rotatably connected to the housing via a tapered roller bearing 23. The lower end of the output shaft 4 is located on the outside of the housing 1, and the bottom end of the output shaft 4 is provided with a tapered thread 402, which achieves a fixed connection between the output shaft 4 and the drill rod.

[0069] The upper end of the output shaft 4 is provided with a second gear 25 and a first gear 24 from top to bottom. Both the second gear 25 and the first gear 24 are connected to the output shaft 4 via splines 401. A spacer is provided between the first gear 25 and the second gear 24 to limit the movement of the two gears. During the rotation of the second gear 25 or the first gear 24, torque is transmitted to the output shaft 4 through the splines 401, thereby realizing the rotation of the output shaft 4.

[0070] When the shift fork 1001 of the gear shifting mechanism drives the clutch gear 19 to the maximum position of its movable range, the clutch gear 19 and the second gear 25 mesh with each other. At this time, while the driven gear 17 drives the clutch gear 19 to rotate, the torque is transmitted to the output shaft 4 through the meshing between the clutch gear 19 and the second gear 25. Since the number of teeth of the second gear 25 is greater than the number of teeth of the clutch gear 19, a two-stage reduction is achieved during the rotation of the clutch gear 19 and the second gear 25, and the torque of the output shaft 4 increases. At this time, the low-speed rotating output shaft 4 can drive the drill rod to meet the low-speed heavy-load working requirements.

[0071] When the shift fork 1001 of the shift mechanism drives the clutch gear 19 to the bottom of its movable range, the clutch gear 19 enters the annular gap between the inner and outer connecting gears 20 and the intermediate rotating shaft 14.

[0072] like Figure 10 As shown, the inner and outer connecting gear 20 includes a cylindrical gear body 2001. There is an annular gap between the inner surface of the gear body 2001 and the outer surface of the intermediate rotating shaft 14. The inner surface of the gear body 2001 facing the clutch gear is provided with internal teeth 2002, and the outer side of the gear body 2001 away from the clutch gear is provided with external teeth 2003.

[0073] When the clutch gear 19 enters the annular gap between the inner and outer connecting gears 20 and the intermediate rotating shaft 14, the clutch gear 19 meshes with the internal gear 2002, while the external gear 2003 meshes with the first gear 24. As the clutch gear 19 rotates with the intermediate rotating shaft 14, the meshing between the clutch gear 19 and the internal gear 2002 drives the inner and outer connecting gears 20 to rotate. Because the number of teeth on the internal gear 2002 is greater than the number of teeth on the clutch gear 19, three-stage speed reduction is achieved during the meshing transmission process.

[0074] At this time, the meshing between the external gear 2003 and the first gear 24 drives the first gear 24 and the output shaft 4 to rotate. Since the number of teeth between the external gear 2003 and the first gear 24 is not much different, the high-speed rotation of the output shaft 4 is achieved. The high-speed rotating output shaft 4 can drive the drill rod to meet the working requirements of heavy speed and light load.

[0075] The connection structure between the gearbox and the drilling rig is as follows: Figure 11 and Figure 12 As shown, the gearbox 29 is slidably mounted on the drilling rig 28. Figure 1 As shown, a gearbox mounting plate 8 is fixed to the rear side of the gearbox housing 1 facing the drill tower, and a corresponding sliding plate is provided on the drill tower 28. Two symmetrically arranged horizontal guide sliders are located on the front side of the sliding plate facing the gearbox, forming a dovetail groove. The gearbox mounting plate 8 is slidably positioned within this dovetail groove, allowing for horizontal position adjustment of the gearbox. During operation, when core extraction is required, the gearbox can be moved to one side via horizontal movement, facilitating drill pipe extraction.

[0076] Correspondingly, a vertical slider is provided on the rear side of the slide plate, and the slider is slidably connected to the turret 28. In actual use, the vertical position of the gearbox 29 can be adjusted by sliding between the gearbox and the turret according to engineering needs. After the position of the gearbox 29 is adjusted, the slider is fixed to the turret 28 with bolts, and the gearbox fixing plate 8 is fixed to the slide plate, thereby fixing the position of the gearbox 29.

[0077] The working principle of the gearbox for this core drilling rig is as follows. The shift fork 1001 in the shift mechanism moves the clutch up and down, switching the meshing relationship between different transmission gear sets. The power source drives the input shaft 13 to rotate. The input shaft 13, through the meshing between the driving gear 15 and the driven gear 17, drives the intermediate rotating shaft 14 to rotate, thereby realizing the rotation of the clutch gear 19.

[0078] When the drilling rig requires high-speed drilling, the handle 1003 is turned, and the shift fork 1001 drives the clutch gear 19 downward into the inner hole of the inner and outer connecting gear 20. At this time, the clutch gear 19, through its meshing with the inner gear 2002 of the inner and outer connecting gear 20, drives the inner and outer connecting gear 20 to rotate. Simultaneously, the outer gear 2003 on the inner and outer connecting gear 20 rotates along with it. Through the meshing between the outer gear 2003 and the first gear 24, the first gear 24 and the output shaft 4 are driven to rotate, thereby realizing the high-speed rotation of the output shaft 4 and the drill rod fixedly connected to the output shaft 4, achieving high-speed drilling.

[0079] When encountering hard rocks or excessive loads, the shift fork 1001 drives the clutch gear 19 to the top of its movable range. At this time, the clutch gear 19 meshes with the second gear 25, while the inner and outer connecting gears 20 do not rotate with the intermediate rotating shaft 14, meaning they are in an inactive state. The rotation of the second gear 25 enables the output shaft 4 to rotate at low speed, achieving low-speed drilling to protect the drill string and increase torque. The gearbox proposed in this application enables the drilling rig to adapt to all operating scenarios, from light-load high-speed to heavy-load low-speed.

[0080] The gearbox for core drilling rigs provided by this utility model has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model. The above description of the disclosed embodiments enables those skilled in the art to implement or use this utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this utility model. Therefore, this utility model is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A gearbox for a core drill, comprising a housing, characterized in that Also includes: An input shaft, on which a drive gear is mounted; The intermediate rotating shaft has a driven gear, a clutch gear, and inner and outer connecting gears arranged sequentially from top to bottom. The driving gear and the driven gear mesh with each other. The clutch gear rotates together with the intermediate rotating shaft and moves up and down along the axial direction of the intermediate rotating shaft. There is an annular gap between the inner wall of the inner and outer connecting gears facing the clutch gear and the outer wall of the intermediate rotating shaft. The inner surface of the inner and outer connecting gears facing the clutch gear has internal teeth, and the outer surface of the inner and outer connecting gears away from the clutch gear has external teeth. The output shaft has a second gear and a first gear arranged sequentially along its top-to-bottom direction. The shift fork mechanism moves the clutch gear up and down axially along the central rotating shaft. The input shaft, intermediate rotating shaft, and output shaft are all housed inside the housing. One end of the shift fork mechanism is located inside the housing, while the other end is located outside the housing.

2. The core drill gearbox according to claim 1, characterized in that When the shift fork mechanism moves the clutch gear to the uppermost end of its vertical movement range, the clutch gear and the second gear mesh with each other, realizing the low-speed rotation of the output shaft. When the clutch gear of the shift fork mechanism is shifted into the annular gap between the inner and outer connecting gears and the intermediate rotating shaft, the clutch gear meshes with the inner gear of the intermediate rotating shaft, and the outer gear of the intermediate rotating shaft meshes with the first gear, thereby achieving high-speed rotation of the output shaft.

3. The coring rig gearbox of claim 1, wherein, A second upper end cover is provided on the upper surface of the box above the middle rotating shaft, and a second lower end cover is provided on the lower surface of the box below the middle rotating shaft. The upper and lower ends of the intermediate rotating shaft are rotatably connected to the housing via bearings. The second lower end cover is fixed with an oil cup and an oil pump. The oil pump draws out the lubricating oil from the oil cup and sends it into the housing through the oil pipe.

4. The coring rig gearbox of claim 1, wherein, The clutch gear is connected to the intermediate rotating shaft via a spline. The upper part of the clutch gear is provided with an annular groove, and the shift fork mechanism is connected to the clutch gear through the annular groove.

5. The coring rig gearbox of claim 4, wherein, The shift fork mechanism includes: The first shift fork lever is located on the outside of the housing. One end of the lever, facing the housing, has a cone head. The other end of the lever, away from the housing, is connected to a handle. A sliding rod is slidably provided inside the handle. One end of the sliding rod is connected to the cone head. One end of the sliding rod is located on the outside of the handle. A spring is connected between the sliding rod and the inner hole of the handle. The other end of the first shift fork lever is connected to the second shift fork lever via a connecting shaft. The second shift fork is located inside the housing. One end of it is connected to the first shift fork, and the other end, facing the clutch gear, is provided with a shift fork. The shift fork is set in an annular groove. The positioning plate is arc-shaped and fixed to the side of the box. It has two positioning holes. When the cone head is inserted into the positioning hole, the first shift fork rod and the box are connected by a limiting constraint.

6. The coring rig gearbox of claim 1, wherein, The top end of the output shaft is connected to the upper surface of the housing through the first upper end cover, and the bottom end of the output shaft is connected to the lower surface of the housing through the first lower end cover. Oil seals are provided at the connection points between the output shaft and the first upper end cover and the first lower end cover. The top and bottom ends of the output shaft are rotatably connected to the housing via bearings. The output shaft is connected to the first gear and the second gear via splines, and the bottom end of the output shaft is fixedly connected to the drill rod via a tapered thread.

7. The coring rig gearbox of claim 1, wherein, The gearbox mounting plate is located on the rear side of the housing, and a sliding plate is located on the side of the drilling rig facing the gearbox. The gearbox mounting plate and the sliding plate can slide relative to each other in the horizontal direction to adjust the horizontal position of the gearbox; the sliding plate and the drilling rig can slide relative to each other in the vertical direction to adjust the vertical position of the gearbox. The front side of the box has an openable lid.

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