A conversion device for directional drilling of drill bits

Abstract

The present invention provides a conversion device for directional drilling of a drill bit, belonging to the technical field of directional drilling rigs. It includes a first housing and a second housing. One end of the second housing is inclined and communicatively arranged at one end of the first housing. A universal shaft is freely rotatably arranged in the second housing, and the front end of the universal shaft is used to drive the drill bit to rotate. A transmission shaft is rotatably arranged in the first housing and the transmission shaft can slide axially. An external spline is arranged at the front end of the transmission shaft, and a spline sleeve matching with the external spline is sleeved on the front end of the transmission shaft. The spline sleeve is connected to the rear end of the universal shaft. A straight-tooth external gear is installed on the transmission shaft behind the external spline, and a straight-tooth internal gear is fixedly arranged in the first housing. As a connecting piece between the drill bit and the drilling rig, the present invention can realize the directional drilling function of the directional drilling rig only by making adaptive modifications to the ordinary drilling rig, without using an expensive directional drilling rig, greatly reducing the procurement cost and improving the utilization rate of the ordinary drilling rig.

Description

Technical Field

[0001] The present invention relates to the technical field of directional drilling rigs, and particularly relates to a conversion device for directional drilling of drill bits. Background Art

[0002] The deep-hole drill rig for coal mines is a new generation of crawler-mounted drilling equipment for water exploration, gas exploration, fault exploration, roof caving, water injection, etc. It is mainly used for implementing dense-shaped boreholes in soft rock or coal seams with outburst prevention measures required in the driving face, and is also applicable to other occasions. During the borehole construction process in coal mines, due to the self-weight of the drill pipe and encountering rocks, etc., the drill pipe will generate an arc, resulting in a deviation between the linear effect of the formed borehole and the design. Especially in directional boreholes and deep-hole boreholes, the deviation is more obvious, causing serious inconsistencies between the actual construction and the design.

[0003] Although the directional drilling rigs on the current market can meet the basic requirements of directional drilling, their core directional technologies all use downhole motors to control the angle for directional drilling. The cost of the whole set of special equipment is expensive. The price of the directional drilling rig is generally more than three times that of ordinary drilling rigs, and the low utilization rate of ordinary drilling rigs will cause waste of resources. If the function of directional drilling can be realized by using ordinary drilling rigs, it will surely effectively improve the utilization rate of ordinary drilling rigs and reduce costs. Summary of the Invention

[0004] In view of this, the present invention provides a conversion device for directional drilling of drill bits. As a connecting piece between the drill bit and the drilling rig, only by making adaptive modifications to the ordinary drilling rig can the directional drilling function of the directional drilling rig be realized. There is no need to use an expensive directional drilling rig, which greatly reduces the procurement cost and can improve the utilization rate of ordinary drilling rigs.

[0005] To solve the above technical problems, the present invention provides a conversion device for directional drilling of drill bits, including a first housing and a second housing. One end of the second housing is inclined and communicated with one end of the first housing. A universal shaft is freely rotatably arranged in the second housing, and the front end of the universal shaft is used to drive the drill bit to rotate; a transmission shaft is rotatably arranged in the first housing and the transmission shaft can slide axially. An external spline is arranged at the front end of the transmission shaft, and a spline sleeve matching with the external spline is sleeved on the front end of the transmission shaft. The spline sleeve is connected with the rear end of the universal shaft. The rear end of the transmission shaft is driven by a drill pipe matching with it. A straight-tooth external gear is installed on the transmission shaft behind the external spline, and a straight-tooth internal gear is fixedly arranged in the first housing;

[0006] When the drill pipe drives the transmission shaft to normally push forward for drilling, the external spline and the spline sleeve are in a fully engaged state, and the straight-tooth external gear and the straight-tooth internal gear are in a disengaged state; when the drill pipe is pulled backward to facilitate directional drilling, the external spline and the spline sleeve are in a semi-engaged state, and the straight-tooth external gear and the straight-tooth internal gear are in an engaged state.

[0007] The present invention realizes that the rotation of the transmission shaft can only be transmitted to the drill bit through the universal joint, and cannot drive the first housing to rotate, so as to facilitate normal forward drilling by fully engaging the external spline at the front end of the transmission shaft with the spline sleeve and disengaging the external spur gear from the internal spur gear; at the same time, by semi-engaging the external spline at the end of the transmission shaft with the spline sleeve and engaging the external spur gear with the internal spur gear, the transmission shaft is locked with the first housing, and then when the drill pipe drives the transmission shaft to rotate, the first housing can be synchronously driven to rotate, achieving the purpose of adjusting the tool face angle to facilitate the realization of the directional function. As a connecting piece between the drill bit and the drill rig, the present invention can realize the directional drilling function of the directional drill rig only by making adaptive modifications to the ordinary drill rig, without using expensive directional drill rigs, greatly reducing the procurement cost and improving the utilization rate of the ordinary drill rig.

[0008] As a further improvement of the present invention, a partition with a sliding hole in the middle is arranged inside the first housing, and the partition is located behind the internal spur gear. The middle part of the transmission shaft is rotatably arranged in the sliding hole of the partition and can slide axially. After arranging the partition with a sliding hole in the middle inside the first housing, the transmission shaft can not only rotate freely in the sliding hole but also slide axially. At the same time, the torsional strength of the first housing is increased, and positioning is also provided for the subsequent normal forward drilling of the transmission shaft.

[0009] As a further improvement of the present invention, a limiting shoulder is arranged on the transmission shaft, and the limiting shoulder is located behind the partition. After arranging the limiting shoulder on the transmission shaft behind the partition, positioning is provided for the subsequent normal forward drilling of the transmission shaft.

[0010] As a further improvement of the present invention, in order to reduce the resistance when the transmission shaft rotates relative to the first housing, a first shaft sleeve is rotatably installed inside the first housing between the partition and the limiting shoulder. The front end of the first shaft sleeve is installed with rolling balls through a cage to achieve rolling movement between the front end of the first shaft sleeve and the limiting shoulder. A row or multiple rows of hemispherical grooves are formed on the circumferential surface of the first shaft sleeve, and rolling movement between the first shaft sleeve and the inner cavity of the first housing is realized through the rolling balls in the hemispherical grooves. The transmission shaft is rotatably arranged in the first housing through the first shaft sleeve, and the transmission shaft can slide axially.

[0011] As a further improvement of the present invention, in order to further reduce the resistance when the transmission shaft rotates relative to the first housing, a second shaft sleeve is fixedly installed on the transmission shaft behind the limiting shoulder. A row or multiple rows of hemispherical grooves are formed on the circumferential surface of the second shaft sleeve, and rolling movement between the second shaft sleeve and the inner cavity of the first housing is realized through the rolling balls in the hemispherical grooves.

[0012] As a further improvement of the present invention, an end cover is installed at the rear end of the first housing.

[0013] As a further improvement of the present invention, a seal is installed in the shaft hole of the end cover.

[0014] As a further improvement of the present invention, the first housing and the second housing are connected together by welding, threaded connection or flange connection.

[0015] In summary, compared with the prior art, the present application has at least one of the following beneficial technical effects:

[0016] 1. On the one hand, the present invention can utilize the forward propulsion of the drill pipe to directly transmit the rotational power of the drill rig to the drill bit through the universal shaft by the transmission shaft for normal forward drilling. On the other hand, it can utilize the backward pulling operation of the drill pipe to lock the transmission shaft and the first housing, and utilize the rotational power of the drill rig to adjust the tool face angle to achieve the directional function.

[0017] 2. The present invention can perform directional drilling without using a downhole positive displacement motor and a cable drill pipe, greatly reducing the cost.

[0018] 3. As a connecting member between the drill bit and the drill rig, the present invention can achieve the directional drilling function of the directional drill rig only by making adaptive modifications to an ordinary drill rig.

[0019] 4. The present invention has a simple and reliable structure, is convenient to maintain, and can be connected to the power head of the drill rig, greatly improving the drilling efficiency.

[0020] 5. The present invention can cooperate with a measurement-while-drilling device to monitor the change of the angle in real time and locate the drilling trajectory in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of the present invention in the normal forward drilling state;

[0022] Figure 2 is a schematic structural diagram of the present invention in the directional drilling state.

[0023] Reference Numerals:

[0024] 100, first housing;

[0025] 101, first bushing;

[0026] 102, cage;

[0027] 103, second bushing;

[0028] 104, end cap;

[0029] 105, seal;

[0030] 110, transmission shaft;

[0031] 120, external spline;

[0032] 130. Spline sleeve;

[0033] 140. External spur gear;

[0034] 150. Internal spur gear;

[0035] 160. Partition plate;

[0036] 170. Limit shoulder;

[0037] 200. Second housing;

[0038] 210. Cardan shaft;

[0039] 300. Drill pipe. Specific embodiments

[0040] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will combine the drawings of the embodiments of the present invention Figure 1 and 2 , and clearly and completely describe the technical solutions of the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art belong to the scope protected by the present invention.

[0041] Referring to the drawings Figure 1 , a conversion device for directional drilling of a drill bit mainly includes a first housing 100 and a second housing 200. One end of the second housing 200 is inclined and communicated with one end of the first housing 100. The inclined angle is relative to the axis of the first housing 100, and the axis of the second housing 200 deviates by 1.25°. Of course, it can also be set to other angles according to needs; a cardan shaft 210 is rotatably arranged in the second housing 200, and the front end of the cardan shaft 210 is used to drive the drill bit to rotate. A transmission shaft 110 is rotatably arranged in the first housing 100 and the transmission shaft 110 can slide axially. An external spline 120 is provided at the front end of the transmission shaft 110. A spline sleeve 130 that cooperates with the external spline 120 is sleeved on the front end of the transmission shaft 110. The spline sleeve 130 is connected to the rear end of the cardan shaft 210, and the rear end of the transmission shaft 110 is driven by a drill pipe 300 that cooperates with it. An external spur gear 140 is installed on the transmission shaft 110 behind the external spline 120. An internal spur gear 150 is fixedly arranged in the first housing 100, and the external spur gear 140 and the internal spur gear 150 can cooperate with each other.

[0042] The conversion method of this conversion device is specifically as follows: As Figure 1As shown in the figure, when the drill pipe 300 drives the transmission shaft 110 to push forward and drill normally, the external spline 120 and the spline sleeve 130 are in a fully engaged state, and the straight-tooth external gear 140 and the straight-tooth internal gear 150 are in a disengaged state. At this time, the rotation of the transmission shaft 110 can only be transmitted to the drill bit through the universal shaft 210, and the first housing 100 cannot be driven to rotate; as Figure 2 shown in the figure, when the drill pipe 300 is pulled backward for directional drilling, the external spline 120 and the spline sleeve 130 are in a semi-engaged state, and the straight-tooth external gear 140 and the straight-tooth internal gear 150 are in an engaged state. At this time, the transmission shaft 110 and the first housing 100 are locked (cannot rotate relative to each other). Therefore, when the drill pipe 300 drives the transmission shaft 110 to rotate, the first housing 100 can be driven to rotate synchronously, achieving the purpose of adjusting the tool face angle to facilitate the realization of the directional function. As a connecting piece between the drill bit and the drill rig, the present invention can realize the directional drilling function of the directional drill rig only by making adaptive modifications to the ordinary drill rig, without using an expensive directional drill rig, greatly reducing the procurement cost and improving the utilization rate of the ordinary drill rig.

[0043] As Figure 1 shown in the figure, in order to increase the torsional strength of the first housing 100 and at the same time provide positioning for the subsequent normal forward pushing and drilling of the transmission shaft 110, a partition 160 with a sliding hole in the middle is provided inside the first housing 100, and the partition 160 is located behind the straight-tooth internal gear 150. The middle part of the transmission shaft 110 is rotatably arranged in the sliding hole of the partition 160 and can slide axially.

[0044] As Figure 1 shown in the figure, in order to provide a positioning position for the subsequent normal forward pushing and drilling of the transmission shaft 110, a limit shoulder 170 is provided on the transmission shaft 110, and the limit shoulder 170 is located behind the partition 160.

[0045] As Figure 1 shown in the figure, in order to reduce the resistance when the transmission shaft 110 rotates relative to the first housing 100, a first bushing 101 is rotatably installed inside the first housing 100 between the partition 160 and the limit shoulder 170, and a rolling ball is installed at the front end of the first bushing 101 through a cage 102 to achieve rolling motion between the front end of the first bushing 101 and the limit shoulder 170. The structure of the cage 102 can adopt the cage of a bearing in the prior art. A row or multiple rows of hemispherical grooves are provided on the circumferential surface of the first bushing 101 (the hemispherical grooves in each row are circumferentially distributed on the outer circle of the first bushing 101, and the hemispherical grooves are relatively conventional and not numbered in the figure), and rolling motion between the first bushing 101 and the inner cavity of the first housing 100 is achieved through the rolling balls in the hemispherical grooves. In this way, the transmission shaft 110 can be rotatably arranged in the first housing 100 through the first bushing 101 and the transmission shaft 110 can slide axially.

[0046] AsFigure 1 As shown, in order to further reduce the resistance when the transmission shaft 110 rotates relative to the first housing 100, a second bushing 103 is fixedly installed on the transmission shaft 110 behind the limit shoulder 170. A row or multiple rows of hemispherical grooves are formed on the circumferential surface of the second bushing 103 (the hemispherical grooves in each row are circumferentially distributed on the outer circular surface of the first bushing 101, and the hemispherical grooves are relatively conventional and not numbered in the figure), and rolling movement with the inner cavity of the first housing 100 is achieved through the balls (the balls are conventional spherical balls and not numbered in the figure) in the hemispherical grooves.

[0047] As Figure 1 shown, in order to achieve the sealing of the rear end of the first housing 100, an end cover 104 is installed at the rear end of the first housing 100.

[0048] As Figure 1 shown, in order to prevent dust and dirt from entering the inner cavity of the first housing 100, a seal 105 is installed in the shaft hole of the end cover 104.

[0049] As Figure 1 shown, in order to facilitate assembly and maintenance, the first housing 100 and the second housing 200 are connected together by a threaded connection. Of course, the first housing 100 and the second housing 200 can also be connected and fixed by other methods, such as welding or flange connection.

[0050] In the present invention, unless otherwise clearly defined and limited, for example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. Unless otherwise clearly defined, for those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0051] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle described in the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A conversion device for directional drilling of a drill bit, comprising a first housing (100) and a second housing (200), one end of the second housing (200) is inclined and communicated with one end of the first housing (100), and it is characterized in that: A universal shaft (210) is rotatably arranged freely within the second housing (200). The front end of the universal shaft (210) is used to drive the drill bit to rotate. A transmission shaft (110) is rotatably arranged within the first housing (100) and the transmission shaft (110) can slide axially. An external spline (120) is provided at the front end of the transmission shaft (110). A spline sleeve (130) that mates with the external spline (120) is sleeved on the front end of the transmission shaft (110). The spline sleeve (130) is connected to the rear end of the universal shaft (210). The rear end of the transmission shaft (110) is driven by a drill pipe (300) that mates with it. A straight-tooth external gear (140) is mounted on the transmission shaft (110) behind the external spline (120). A straight-tooth internal gear (150) is fixedly arranged within the first housing (100). When the drill pipe (300) drives the transmission shaft (110) to normally push forward for drilling, the external spline (120) and the spline sleeve (130) are in a fully engaged state, and the straight-tooth external gear (140) and the straight-tooth internal gear (150) are in a disengaged state. When the drill pipe (300) is pulled backward for directional drilling, the external spline (120) and the spline sleeve (130) are in a semi-engaged state, and the straight-tooth external gear (140) and the straight-tooth internal gear (150) are in an engaged state. A partition plate (160) with a sliding hole in the middle is arranged inside the first housing (100), and the partition plate (160) is located behind the straight-tooth internal gear (150). The middle part of the transmission shaft (110) is rotatably arranged in the sliding hole of the partition plate (160) and can slide axially. The first housing (100) and the second housing (200) are connected together by welding, or threaded connection, or flange connection.

2. The conversion device for directional drilling of a drill bit according to claim 1, characterized in that: A limit shoulder (170) is provided on the transmission shaft (110), and the limit shoulder (170) is located behind the partition plate (160).

3. The conversion device for directional drilling of a drill bit according to claim 2, characterized in that: A first shaft sleeve (101) is rotatably installed inside the first housing (100) between the partition plate (160) and the limit shoulder (170). A ball is installed at the front end of the first shaft sleeve (101) through a cage (102) to achieve rolling movement between the front end of the first shaft sleeve (101) and the limit shoulder (170). One row or multiple rows of hemispherical grooves are formed on the circumferential surface of the first shaft sleeve (101), and rolling movement between the first shaft sleeve (101) and the inner cavity of the first housing (100) is achieved through the balls in the hemispherical grooves. The transmission shaft (110) is rotatably arranged inside the first housing (100) through the first shaft sleeve (101), and the transmission shaft (110) can slide axially.

4. The conversion device for directional drilling of a drill bit according to claim 2, characterized in that: A second bushing (103) is fixedly installed on the transmission shaft (110) behind the limit shoulder (170). A row or multiple rows of hemispherical grooves are formed on the circumferential surface of the second bushing (103), and rolling movement between the inner cavity of the first housing (100) is achieved through the balls in the hemispherical grooves.

5. The conversion device for directional drilling of a drill bit according to any one of claims 1 to 4, characterized in that: An end cover (104) is installed at the rear end of the first housing (100).

6. The conversion device for directional drilling of a drill bit according to claim 5, characterized in that: A seal (105) is installed in the shaft hole of the end cover (104).

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