A magnetic transmission down-the-hole impactor

Abstract

The invention discloses a magnetic transmission down-the-hole impactor, belonging to the technical field of downhole tools. The magnetic transmission down-the-hole impactor includes an ejection trigger device, which is arranged between a rotor piston and an outer shell, connected to the rotor piston by a bearing, an ejection boss and a central axis clearance, and connected to the outer shell by an ejection control spring. When receiving the thrust from the central axis, the spring is compressed, and the ejection piece is ejected to generate friction with the well wall, thereby triggering the differential speed of the outer fan-shaped stator magnet and the inner fan-shaped rotor magnet; the magnetic transmission device is composed of an outer shell, an outer fan-shaped stator magnet, a rotor piston and an inner fan-shaped rotor magnet. The outer fan-shaped stator magnet and the inner fan-shaped rotor magnet are arranged in a regular pattern. When there is a differential speed between the two, an impact force will be generated; the central axis is displaced in linkage, and when encountering hard rock, the drilling speed of the drill bit is slow, and the central axis and the central axis limit joint generate a relative displacement through a long key, thereby generating thrust for the ejection piece. The present invention is different from the traditional hydraulic and pneumatic impactor. It uses strong magnets for magnetic transmission. While improving the drilling efficiency, it does not require a hydraulic pump to provide additional pressure or an air compressor to provide high-pressure airflow. It is a new type of down-the-hole impactor. The present invention can achieve the purpose of changing the impactor frequency by changing the number of magnetic pole pairs.

Description

Technical Field

[0001] The present invention relates to a down-the-hole impactor, and the technical field belongs to the technical field of downhole tools, and specifically to a magnetic transmission down-the-hole impactor. Background Art

[0002] Hammer drilling technology is a drilling method that combines impact drilling and rotary drilling. The combined action of rotation and impact can break rocks together and complement each other to give full play to their respective advantages. There are two types of mainstream down-the-hole hammers. The gas-driven down-the-hole hammer is called pneumatic down-the-hole impact drilling technology; the liquid-driven down-the-hole hammer is called hydraulic down-the-hole impact drilling technology.

[0003] The two are different in technology, but both require working medium to drive. Pneumatic down-the-hole impactors require an external air compressor, while hydraulic down-the-hole impactors require relatively high pressure from the hydraulic pump. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a down-the-hole impactor that does not rely on additional working medium, so as to solve the problem that additional medium cannot be provided or is difficult to provide in some existing occasions.

[0005] To achieve the above objectives, an embodiment of the present invention provides a magnetic transmission down-the-hole impactor.

[0006] The invention discloses a magnetic transmission down-the-hole impactor, belonging to the technical field of downhole tools. The magnetic transmission down-the-hole impactor includes an ejection trigger device, which is arranged between a rotor piston and a housing, connected to the rotor piston by a bearing, an ejection boss and a central axis clearance, and connected to the housing by an ejection control spring. When receiving the thrust from the central axis, the spring is compressed, and the ejection piece is ejected to generate friction with the well wall, thereby triggering the differential speed of the outer fan-shaped stator magnet and the inner fan-shaped rotor magnet; the magnetic transmission device is composed of a housing, an outer fan-shaped stator magnet, a rotor piston and an inner fan-shaped rotor magnet. The outer fan-shaped stator magnet and the inner fan-shaped rotor magnet are arranged according to a rule. When there is a differential speed between the two, an impact force will be generated; the central axis displacement is linked, encountering hard rock, the drilling speed of the drill bit is slow, and the central axis and the central axis limit joint generate a relative displacement through a long key, thereby generating a thrust to the ejection piece. The present invention is different from the traditional hydraulic and pneumatic impactor. It uses magnetic transmission, while improving the drilling efficiency, it does not require a hydraulic pump to provide additional pressure or an air compressor to provide high-pressure airflow, and is a new type of down-the-hole impactor. The present invention can achieve the purpose of changing the frequency of the impactor by changing the number of magnetic pole pairs.

[0007] The technical solution of the present invention is:

[0008] 1. A magnetic transmission down-the-hole impactor, which consists of an upper joint, a middle shaft limiter, a middle shaft guide key, a shell, a limit spring, a limit ring, an ejector, an ejection control spring, an ejection boss, a thrust bearing, an outer fan-shaped stator magnet, an inner fan-shaped rotor magnet, a travel guide key, a rotor piston, a middle shaft, a drill guide key, and a drill bit. The upper joint is connected to the center shaft limiter by threads, and has a clearance fit with the limit ring; the center shaft guide key is interference fit with the center shaft, and has a clearance fit with the center shaft limiter, and the outer shell is clearance fit with the ejector; the stroke guide key is interference fit with the rotor piston, and has a clearance fit with the center shaft; the inner sector rotor magnet is threadedly fastened to the rotor piston; the drill bit is interference fit with the outer shell, has a clearance fit with the drill bit guide key, and has a clearance fit with the center shaft; the center shaft is clearance fit with the drill bit guide key, and has a clearance fit with the center shaft; the center shaft is clearance fit with the drill bit guide key, the two halves of the center shaft limiter joints are closed and fastened with the four center shaft guide long keys by the upper joint through threads, and power is transmitted to the center shaft limiter joint, the ejector boss is connected to the center shaft by a thrust bearing, and a certain thrust is required to be preset, the spacing between the outer sector stator magnet and the inner sector rotor magnet is fixed, and the axial distance varies, and the inner and outer magnets are strong magnets, such as neodymium iron boron magnets;

[0009] 2. The middle shaft and the middle shaft limit joint transmit power through the middle shaft guide long key, and the three require a sealed connection.

[0010] 3. The middle shaft retracts itself by compressing the limit spring, and then pushes out the ejector; it extends itself by the tension of the limit spring, and then the ejector retracts due to the tension of the ejection control spring.

[0011] 4. After the ejector is ejected and stuck on the well wall, the brake housing is applied.

[0012] The embodiments of the present invention have the following advantages:

[0013] 1. No need to provide additional working medium;

[0014] 2. In the soft bottom layer, the center axis is not enough to retract, and the magnetic impact will not be triggered. The drill bit can drill normally, saving energy;

[0015] 3. The structure is simple and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Structural schematic diagram provided for an embodiment of the utility model: 1. upper joint, 2. middle shaft limiter, 3. middle shaft guide key, 4. housing, 5. limit spring, 6. limit ring, 7. ejector, 8. ejector control spring, 9. ejector boss, 10. thrust bearing, 11. outer fan-shaped stator magnet, 12. inner fan-shaped rotor magnet, 13. travel guide key, 14. rotor piston, 15. middle shaft, 16. drill guide key, 17. drill;

[0017] Figure 2 Screenshot for AA;

[0018] Figure 3 Screenshot for BB;

[0019] Figure 4 Take screenshots for CC;

[0020] Figure 5 Screenshot for DD;

[0021] Figure 6 Screenshot for EE. DETAILED DESCRIPTION

[0022] The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0023] In addition, the accompanying drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The thickness and shape of each layer in the accompanying drawings do not reflect the actual scale, but are only for the convenience of explaining the content of the present disclosure.

[0024] like Figure 1 As shown, the utility model provides a magnetic transmission down-the-hole impactor, which is composed of an upper joint, a middle shaft limiter, a middle shaft guide key, an outer shell, a limit spring, a limit ring, an ejector, an ejection control spring, an ejection boss, a thrust bearing, an outer fan-shaped stator magnet, an inner fan-shaped rotor magnet, a travel guide key, a rotor piston, a middle shaft, a drill guide key, and a drill bit.

[0025] The upper joint is threadedly connected to the center shaft limiter and has a clearance fit with the limit ring; the center shaft guide key is interference fit with the center shaft and has a clearance fit with the center shaft limiter; the outer shell is clearance fit with the ejector; the stroke guide key is interference fit with the rotor piston and has a clearance fit with the center shaft; the inner fan-shaped rotor magnet is threadedly fastened to the rotor piston; the drill bit is interference fit with the outer shell and has a clearance fit with the drill guide key and the center shaft; the center shaft and the drill guide key are clearance fit.

[0026] The working process of a magnetic transmission down-the-hole impactor is as follows:

[0027] When encountering hard rock during drilling, the pressure transmitted by the drill bit increases, the middle shaft limit spring is compressed, the middle shaft retracts, driving the ejector boss, and the ejector boss inclined surface generates thrust for the ejector;

[0028] The ejection control spring is compressed, the ejector extends and generates friction on the well wall, the housing slows down, and a speed difference is formed with the rotor piston;

[0029] When there is a speed difference between the inner sector-shaped rotor magnet and the outer sector-shaped stator magnet, the corresponding area of ​​the magnetic pole changes, thereby generating a circulating magnetic force. When the axial component of the magnetic force is in the direction of the drill bit, it drives the rotor piston to hit the drill bit. When the axial component of the magnetic force is in the direction of the central axis limiter, it drives the rotor piston to retract, thus forming a certain frequency of hitting the drill bit.

[0030] After the drill bit hits the hard rock and breaks it, the pressure on the middle shaft is not enough to resist the elastic force generated by the middle shaft limit spring. The spring returns, the middle shaft extends, and the ejector retracts under the return of the ejection control spring, eliminating the friction with the well wall, and the drill bit drills normally.

[0031] The present invention mainly utilizes the strong magnetism of magnets such as neodymium iron boron to convert part of the rotary energy of the drill rod into impact. Drilling and impact use the same energy source, eliminating the need for additional media or additional pressure of the hydraulic pump.

[0032] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, these modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A magnetic transmission down-the-hole impactor, which is composed of an upper joint, a middle shaft limiter, a middle shaft guide key, a shell, a limit spring, a limit ring, an ejector, an ejection control spring, an ejection boss, a thrust bearing, an outer fan-shaped stator magnet, an inner fan-shaped rotor magnet, a travel guide key, a rotor piston, a middle shaft, a drill guide key, and a drill, and is characterized in that: The upper joint is connected to the center shaft limiter by threads and has a clearance fit with the limit ring; the center shaft guide key is interference fit with the center shaft and has a clearance fit with the center shaft limiter, and the outer shell is clearance fit with the ejector; the stroke guide key is interference fit with the rotor piston and has a clearance fit with the center shaft; the inner sector rotor magnet is threadedly fastened to the rotor piston; the drill bit is interference fit with the outer shell and has a clearance fit with the drill guide key and the center shaft; the center shaft is clearance fit with the drill guide key, and the two halves of the center shaft limiter are closed and fastened with the four center shaft guide keys by the upper joint through threads, and power is transmitted to the center shaft limiter, the ejector boss is connected to the center shaft through a thrust bearing, the radial spacing between the outer sector stator magnet and the inner sector rotor magnet is fixed, and the axial offset varies periodically, and the inner sector rotor magnet and the outer sector stator magnet are neodymium iron boron magnets.

2. A magnetic transmission down-the-hole impactor according to claim 1, characterized in that: The middle shaft and the middle shaft limiter transmit power through the middle shaft guide key, and the three require a sealed connection.

3. The magnetic transmission down-the-hole impactor according to claim 1, characterized in that: The ejector brakes the housing using spring tension.

4. A magnetic transmission down-the-hole impactor according to claim 3, characterized in that: After the ejector is braked, a speed difference is formed between it and the inner fan-shaped rotor magnet, thereby generating an impact force.

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