Three-roller centralizer

Abstract

The application discloses a three-roller centralizer, which comprises a body, rollers are uniformly arranged on the surface of the middle part of the body, corresponding roller shafts are installed on the rollers, fixed blocks are sleeved on the two ends of the roller shafts, the fixed blocks are embedded on the body and fixed, notches are arranged at the fixed block mounting positions on the body, the fixed blocks are placed in the notches, clamping key mounting grooves are arranged in the middle parts of the right-angle sides of the fixed blocks, wedge blocks are arranged on the right-angle sides of the fixed blocks, the wedge blocks are located in the notches, clamping grooves are arranged on one side of the wedge blocks, the clamping grooves and the clamping key mounting grooves are correspondingly arranged and cooperated to form a space, and clamping keys are arranged in the space, the application realizes non-interval assembly, ensures that there is no interval between the parts of the assembled product, improves the reliability of the product, and the interval will cause the product to vibrate and generate impact load, so that the product will be quickly damaged.

Description

Technical Field

[0001] This invention relates to the field of drilling downhole tool improvement technology, specifically a three-roller centralizer. Background Technology

[0002] The purpose of a three-roller centralizer: It is a type of drilling stabilizer, characterized by three self-rotating rollers mounted on its body. During normal drilling, the centralizer rotates with the drill bit, while the rollers rotate in the opposite direction by rubbing against the well wall. This greatly reduces the frictional resistance between the tool and the well wall. At the same time, the wear-resistant rollers can also adjust the wellbore diameter to the standard wellbore size when in contact with the well wall. Whether drilling vertical or directional wells, the centralizer can ensure that the drill string or casing can be run into the correct wellbore diameter.

[0003] Currently, domestically used centralizers mainly consist of a body, roller shaft, fixing blocks, rollers, and bolts. The rollers rotate by passing through the upper and lower fixing blocks via the roller shaft, while the fixing blocks are inserted into the body via a keyway connection. As the downhole environment becomes increasingly complex, the operating conditions of centralizers downhole have become more demanding. During use, the connecting key on the body often wears down, causing the fixing blocks and rollers to fall downhole and cause accidents. Secondly, existing roller installations require the roller shaft to pass through the upper fixing block, roller, and lower fixing block, necessitating the machining of a long roller shaft mounting groove on the body for assembly, which is time-consuming, labor-intensive, and costly. The existing structure lacks a wedging device, resulting in gaps between assembled parts. During use, these gaps quickly increase, significantly reducing product lifespan. Other centralizers with wedging structures use screws for pre-tightening; however, these screws are constantly under stress during use, leading to fatigue fracture and loosening, potentially causing parts to fall to the bottom of the well and resulting in drilling accidents. Summary of the Invention

[0004] The purpose of this invention is to provide a high-performance, non-falling three-roller centering device that can save product costs, shorten the processing cycle, and reduce assembly difficulty, thereby overcoming the defects and deficiencies mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a three-roller straightener, comprising a body, rollers evenly arranged on the middle surface of the body, corresponding roller shafts mounted on the rollers, and fixing blocks sleeved at both ends of the roller shafts, the fixing blocks being embedded into the body and fixed.

[0006] A notch is provided at the mounting position of the fixing block on the main body to facilitate the placement of the fixing block into the notch;

[0007] A key mounting groove is provided in the middle of the right-angle side of the fixing block, and a wedge block is provided on the right-angle side of the fixing block. The wedge block is located in the notch. A slot is provided on one side of the wedge block. The slot and the key mounting groove are positioned corresponding to each other and cooperate to form a space. A key is provided in the space.

[0008] As a further aspect of the present invention: the cross-section of the notch is a right-angled trapezoidal structure; the cross-section of the fixing block is a right-angled trapezoidal structure, and the acute-angled side of the fixing block is inserted into and aligned with the acute-angled side of the notch.

[0009] As a further aspect of the present invention: a lower mounting groove is provided at the bottom of the right-angle side of the fixing block, and an adjusting shim is provided in the lower mounting groove; the corresponding side of the wedge block is an inclined surface, and the wedge block and the adjusting shim are interference fit.

[0010] As a further aspect of the present invention: elastic cylindrical pin holes are provided on the fixing block at the upper part of the key mounting groove and the wedge block at the upper part of the slot. The elastic cylindrical pin holes are connected to the corresponding key mounting groove and slot and are perpendicular to each other. An elastic cylindrical pin is installed in the elastic cylindrical pin hole, and the two elastic cylindrical pins hold the key in place, so that the key is located between the fixing block and the wedge block.

[0011] As a further aspect of the present invention: a spiral retaining ring is provided in the elastic cylindrical pin hole above the corresponding elastic cylindrical pin.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: First, the present invention has a simple structure, and the addition of adjusting shims greatly reduces the requirements for machining accuracy and makes maintenance more convenient. The product can be guaranteed to be seamless by replacing the adjusting shims. Second, this structure can easily achieve seamless assembly, ensuring that there are no gaps between the assembled product parts, thus improving the reliability of the product. Gaps can cause product vibration, generating impact loads and causing the product to fail quickly. Third, this structure can ensure that the product will never fall off, thus guaranteeing high reliability. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the structure of the present invention;

[0015] Figure 2 for Figure 1 A half-section view;

[0016] Figure 3 for Figure 1 Schematic diagram of the BB section;

[0017] Figure 4 for Figure 1 Schematic diagram of the CC section;

[0018] Figure 5 for Figure 4 Enlarged view of part A in the diagram;

[0019] Figure 6 This is a top view of the wedge block in this invention;

[0020] Figure 7 for Figure 6 Sectional view in;

[0021] Figure 8 This is a top view of the fixing block in this invention;

[0022] Figure 9 for Figure 8 The sectional view in the image.

[0023] In the diagram: 1. Body; 2. Roller; 3. Roller shaft; 4. Fixing block; 5. Wedging block; 6. Locking key; 7. Adjusting shim; 8. Elastic cylindrical pin hole; 9. Elastic cylindrical pin; 10. Spiral retaining ring; 1.1. Notch; 4.2. Locking key mounting slot; 5.1. Locking groove; Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Please see Figure 1-9 This embodiment provides a technical solution: a three-roller straightener, including a body 1, with rollers 2 evenly arranged on the middle surface of the body 1, and corresponding roller shafts 3 installed on the rollers 2. Fixing blocks 4 are sleeved at both ends of the roller shafts 3. A notch 1.1 is provided at the installation position of the fixing block 4 on the body 1 to facilitate the placement of the fixing block 4 into the notch 1.1. The fixing block 4 is embedded into the body 1 and fixed. The cross-section of the notch 1.1 is a right-angled trapezoidal structure. The cross-section of the fixing block 4 is a right-angled trapezoidal structure. The acute angle side of the fixing block 4 is inserted into the acute angle side of the notch 1.1 and aligned.

[0026] A key mounting groove 4.2 is provided in the middle of the right-angle side of the fixing block 4, and a wedge block 5 is provided in the right-angle side of the fixing block 4. The wedge block 5 is located in the notch 1.1. A slot 5.1 is provided on one side of the wedge block 5. The slot 5.1 corresponds to the key mounting groove 4.2 and cooperates with each other to form a space. A key 6 is provided in the space. An elastic cylindrical pin hole 8 is provided on the fixing block 4 above the key mounting groove 4.2 and the wedge block 5 above the slot 5.1. The elastic cylindrical pin hole 8 communicates with the corresponding key mounting groove 4.2 and slot 5.1 and is perpendicular to each other. An elastic cylindrical pin 9 is installed in the elastic cylindrical pin hole 8. The two elastic cylindrical pins 9 lock the key 6, so that the key 6 is located between the fixing block 4 and the wedge block 5. A spiral retaining ring 10 is provided in the elastic cylindrical pin hole 8 above the corresponding elastic cylindrical pin 9.

[0027] A lower mounting groove 4.1 is provided at the bottom of the right-angle side of the fixing block 4, and an adjusting shim 7 is provided in the lower mounting groove 4.1; the corresponding side of the wedge block 5 is an inclined surface, and the wedge block 5 and the adjusting shim 7 are interference fit.

[0028] The working principle and installation process of this embodiment are as follows:

[0029] The three-roller straightener provided in this embodiment uses a fixed block 4, a wedge block 5, a locking key 6, an elastic cylindrical pin 9, and a spiral retaining ring 10 to fix the rollers 2 and roller shafts 3 of the straightener. After the rollers 2 and roller shafts 3 are installed together with the fixed block 4, they are placed into the notch 1.1 of the main body 1. At this time, the locking key 6 is placed into the locking key mounting groove 4.2 of the fixed block 4, and the adjusting shim 7 is placed into the lower mounting groove 4.1 of the fixed block 4. Then, the wedge block 5 is pressed into the notch 1.1 of the main body 1. The lower end of the wedge block 5 has a certain slope. With a certain interference fit (i.e., the corresponding side of the wedge block 5 is an inclined surface, and the wedge block 5 and the adjusting shim 7 are interference fit), the fixing block 4 can be wedge-tightened to ensure that there is no gap after installation. Then, the retaining key 6 is pushed into the wedge block through the elastic cylindrical pin hole 8 on the fixing block 4. The retaining key 6 is then half in the fixing block 4 and half in the wedge block 5, forming a whole with the fixing block 4 and the wedge block 5. Then, the two elastic cylindrical pins 9 are installed into the corresponding elastic cylindrical pin holes 8 to block the retaining key 6, and the spiral retaining ring 10 is installed. The advantages of this structure are that the fixing device is assembled without any gaps, the elastic cylindrical pin 9 is not under any force, and there is no risk of it falling off or being damaged by fatigue. A spiral retaining ring 10 is also added to the elastic cylindrical pin 9 to ensure that it will never fall off, directly guaranteeing that the fixing block 4 and the wedge block 5 will never fall off. The only way it will fall off is if the entire locking key 6 is completely sheared. The force that the locking key 6 bears is only the centrifugal force generated by the rotation of the centralizer, which is far less than the shearing force that the locking key 6 can withstand. Therefore, this structure can guarantee that it will never fall off.

[0030] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A three-roller straightener, comprising a body (1), wherein rollers (2) are evenly arranged on the middle surface of the body (1), and corresponding roller shafts (3) are mounted on the rollers (2), and fixing blocks (4) are sleeved at both ends of the roller shafts (3), the fixing blocks (4) being embedded into the body (1) and fixed thereon, characterized in that: A notch (1.1) is provided at the mounting position of the fixing block (4) on the main body (1) to facilitate the placement of the fixing block (4) in the notch (1.1); A key mounting groove (4.2) is provided in the middle of the right-angle side of the fixing block (4), and a wedge block (5) is provided on the right-angle side of the fixing block (4). The wedge block (5) is located in the notch (1.1). A slot (5.1) is provided on one side of the wedge block (5). The slot (5.1) and the key mounting groove (4.2) are positioned corresponding to each other and cooperate to form a space. A key (6) is provided in the space. The cross-section of the notch (1.1) is a right trapezoidal structure; the cross-section of the fixing block (4) is a right trapezoidal structure, and the acute angle side of the fixing block (4) is inserted into the acute angle side of the notch (1.1) and aligned. A lower mounting groove (4.1) is provided at the bottom of the right-angle side of the fixing block (4), and an adjusting shim (7) is provided in the lower mounting groove (4.1); the corresponding side of the wedge block (5) is an inclined surface, and the wedge block (5) and the adjusting shim (7) are interference fit; On the fixing block (4) at the top of the key mounting groove (4.2) and on the wedge block (5) at the top of the slot (5.1), there are elastic cylindrical pin holes (8). The elastic cylindrical pin holes (8) are connected to the corresponding key mounting groove (4.2) and slot (5.1) and are perpendicular to each other. An elastic cylindrical pin (9) is installed in the elastic cylindrical pin hole (8). The two elastic cylindrical pins (9) hold the key (6) in place, so that the key (6) is located between the fixing block (4) and the wedge block (5).

2. A three-roller straightener according to claim 1, characterized in that: A spiral retaining ring (10) is provided in the elastic cylindrical pin hole (8) above the corresponding elastic cylindrical pin (9).

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