Novel roller bit with buffer structure

Abstract

The invention relates to the technical field of roller bits, in particular to a novel roller bit with a buffer structure, which comprises a base body and at least one roller palm piece assembly, each roller palm piece assembly comprises a roller palm and a roller rotatably mounted on the roller palm, and the buffer structure is arranged between the base body and the roller palm. Through the buffer structure arranged between the base body and the bit leg, impact and vibration caused by stratum hardness change or cracks in the drilling process can be effectively absorbed and relieved through the buffer effect of elastic elements such as a spring, the instantaneous impact load on a bearing system and a movable sealing ring is remarkably reduced, and the service life of the bearing system is prolonged. Therefore, the reliability and the service life of the sealing system are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of roller cone drill bit technology, specifically a novel roller cone drill bit with a buffer structure. Background Technology

[0002] Roller cone bits, as an important drilling tool, are widely used in oil extraction, mining, and water well drilling. Modified versions can also be used for projects such as borehole reaming and pile foundation drilling. A roller cone bit mainly consists of a die and a cone. Formed by hot forging and machining, the die shaft diameter and the cone's inner bore form a sliding bearing system, which, together with a sealing system, forms a single die. Three single dies are welded together to form a complete roller cone bit. Based on the tooth structure, roller cone bits can be divided into steel-tooth and insert-tooth types. Steel-tooth roller cone bits have teeth milled from the cone body and undergo heat treatment and surface overlay with tungsten carbide to improve wear resistance, making them suitable for softer formations. Insert-tooth roller cone bits, on the other hand, have carbide teeth pressed into the cone surface, making them suitable for hard formations.

[0003] In downhole operations, roller cone bits connect to and rotate with screw drill strings or drill strings, breaking rock by crushing and scraping it with their teeth. Under high drilling pressure, the drill bit bears an immense load. In homogeneous formations, the drilling process is relatively smooth; however, when the formation contains heterogeneous conditions such as alternating layers of hard and soft materials and well-developed fractures, the drill bit experiences severe impacts. These impacts not only burden the bearing system but also severely affect the reliability of the sealing system. The sealing system typically uses an interference fit between a rubber seal ring and the shaft diameter to achieve dynamic sealing and prevent mud intrusion. Once the seal fails, the bearing system will rapidly deteriorate, leading to overall drill bit failure. Furthermore, impacts can easily cause carbide teeth to fracture, especially the outer teeth, which can cause drill bit diameter reduction, further exacerbating the risk of seal failure.

[0004] In existing roller cone drill bit structures, the tooth plates are fixed, with the three tooth plates welded together and directly connected to the drill string, lacking an effective buffering mechanism to cope with formation impacts. Therefore, in complex formation conditions, the service life and reliability of the drill bit are severely limited. To solve these problems, there is an urgent need to design a new type of roller cone drill bit with a buffering function to improve its adaptability and durability in heterogeneous, high-impact formations. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a novel roller cone drill bit with a buffer structure.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a novel roller cone drill bit with a buffer structure, comprising a base and at least one roller cone palm assembly, the roller cone palm assembly comprising a palm and a roller cone rotatably mounted thereon, and a buffer structure is provided between the base and the palm. The buffer structure includes a piston hole formed on the substrate, a piston slidably disposed in the piston hole, and an elastic element that provides elastic buffering force to the piston; The toothed palm has a small shaft connected to the piston, allowing the toothed palm assembly to move relative to the base via the buffer structure.

[0007] Preferably, the elastic element is a spring, which includes one or more combinations of helical springs, wave springs, or disc springs.

[0008] Preferably, the disc springs are arranged in pairs to increase the stroke, or in stacked combinations to increase the elastic modulus.

[0009] Preferably, a piston seal is provided between the piston and the piston bore.

[0010] Preferably, the buffer structure further includes a limiting ring for limiting the piston stroke, the limiting ring being mounted on the base by fixing bolts.

[0011] Preferably, the piston is made of bearing steel, wear-resistant alloy or hard alloy, and its outer contour is precision ground or hard chrome plated.

[0012] Preferably, the inner surface of the piston bore is subjected to nitriding or hard chrome plating.

[0013] Preferably, the surface of the small shaft of the tooth is treated with carburizing, nitriding, electroplating, or coating.

[0014] Preferably, the roller cone drill bit includes three roller cone palm assemblies, each of which is connected to the base via an independent buffer structure.

[0015] Preferably, the roller is provided with carbide cutting teeth and carbide back cone protective teeth.

[0016] The beneficial effects of this invention are as follows: By using a buffer structure between the base and the tooth, the invention effectively absorbs and mitigates the impact and vibration caused by changes in formation hardness or fractures during drilling, significantly reducing the instantaneous impact load on the bearing system and dynamic seal ring. This greatly improves the reliability and service life of the sealing system and avoids premature bearing damage due to seal failure. At the same time, this structure also reduces the impact on the carbide teeth, reducing the risk of tooth breakage. Ultimately, it improves the overall adaptability and working durability of the roller cone bit in complex heterogeneous formations, ensuring the stability and efficiency of the drilling process. Attached Figure Description

[0017] Figure 1This is a diagram of the single palm blade, toothed wheel, and toothed palm blade in this invention, connected by a bearing system and a sealing system. Figure 2 This is a schematic diagram of the structure of the present invention; Figure 3 This is a schematic diagram of the buffer structure in this invention; Figure 4 This is a schematic diagram of the structure of the helical spring in this invention; Figure 5 This is a schematic diagram of the disc spring in this invention; Figure 6 This is a schematic diagram of the piston structure in this invention; Figure 7 This is a schematic diagram of the limiting ring in this invention; Figure 8 This is a schematic diagram of the assembled buffer structure roller cone drill bit in this invention. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] The following is combined Figure 1 The algorithm process and its principles are described.

[0020] like Figure 1 As shown in the figure, 1 is the toothed gear, 2 is the sliding bearing system, 3 is the locking steel ball, 4 is the toothed tooth, 5 is the carbide cutting tooth, 6 is the carbide back cone protective alloy, 7 is the rubber seal ring and sealing system, 8 is the lubricating oil supply channel, and 9 is the oil storage system.

[0021] The drill bit 1 and the tooth 4 are locked together by steel balls 3. The bearing system 2 bears the drilling pressure. When the drill bit 1 rotates, the dynamic seal rubber ring 7 isolates it from the external environment and bears the friction of the bearing system 2, ensuring oil lubrication of the bearing 2. The oil storage system 9 continuously supplies oil to the sliding bearing system 2 through the oil channel 8. Rock breaking is performed by the carbide cutting teeth 5, and the carbide back cone protective teeth 6 protect the back of the drill bit 1. If the rubber seal ring 7 fails, the bearing system 2 will quickly fail, and the drill bit will also quickly fail. The rubber sealing system is significantly affected by vibration.

[0022] Therefore, in order to ensure the service life of roller cone drill bits, a movable roller cone drill bit capable of buffering the impact of the bottom layer is now being designed. For example... Figure 2-8 As shown, the drill bit structure mainly includes a base 11 and three roller cone palm assemblies. Each roller cone palm assembly consists of a palm 4 and a roller cone 1 rotatably mounted thereon. Carbide cutting teeth 5 and carbide back cone protective teeth 6 are arranged on the roller cone 1.

[0023] The core buffer structure 10 is disposed between the base 11 and each tooth 4. Specifically, a piston bore 15 is machined on the base 11, the inner surface of which is finished and may be nitrided or electroplated with hard chrome to enhance wear resistance.

[0024] The piston 17 is precisely fitted inside the piston bore 15, and its outer contour is precision ground. The piston 17 can be made of bearing steel, wear-resistant alloys such as 9Cr18Mo, or cemented carbide, and its surface can also be electroplated with hard chrome. A piston seal 16 is provided between the piston 17 and the piston bore 15 to ensure sealing performance during sliding.

[0025] The elastic element 18 is installed behind the piston 17 and serves as the main component providing cushioning force. In this embodiment, the elastic element 18 can be a helical spring, or a wave spring or a disc spring can be selected according to actual needs. When using a disc spring, a mating combination can be used to increase the stroke, or a stacked combination can be used to increase the elastic modulus.

[0026] The small shaft 14 extending from the toothed palm 4 is connected to the piston 17. The surface of the small shaft 14 should be carburized, nitrided, electroplated or specially coated to enhance wear resistance.

[0027] The limiting ring 12 is mounted on the base 11 by the fixing bolt 13 to limit the maximum stroke of the piston 17 and prevent the assembly from disengaging.

[0028] During operation, when the drill bit 1 encounters a formation impact, the impact force is transmitted through the drill bit 1 and the toothed plate 4 to the small shaft 14, pushing the piston 17 to slide within the piston bore 15 and compress the elastic element 18. The elastic element 18 absorbs the impact energy through elastic deformation, enabling the entire drill bit toothed plate assembly to generate a buffer displacement relative to the base 11, thereby effectively protecting key components such as the bearing system 2 and the sealing ring 7, and significantly improving the service life and reliability of the drill bit in complex formations.

[0029] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A novel roller cone drill bit with a buffer structure, comprising a base (11) and at least one roller cone palm assembly, the roller cone palm assembly comprising a palm (4) and a roller cone (1) rotatably mounted thereon, characterized in that: A buffer structure (10) is provided between the base (11) and the tooth palm (4). The buffer structure (10) includes a piston hole (15) formed on the substrate (11), a piston (17) slidably disposed in the piston hole (15), and an elastic element (18) that provides elastic buffering force to the piston (17). The toothed palm (4) has a small shaft (14) connected to the piston (17), so that the toothed palm assembly can be moved relative to the base (11) by the buffer structure (10).

2. The novel roller cone drill bit with a buffer structure according to claim 1, characterized in that: The elastic element (18) is a spring, which includes one or more combinations of helical springs, wave springs or disc springs.

3. The novel roller cone drill bit with a buffer structure according to claim 2, characterized in that: The disc springs are used in a pairing combination to increase the stroke, or in a stacked combination to increase the elastic modulus.

4. The novel roller cone drill bit with a buffer structure according to claim 1, characterized in that: A piston seal (16) is provided between the piston (17) and the piston hole (15).

5. The novel roller cone drill bit with a buffer structure according to claim 1, characterized in that: The buffer structure (10) also includes a limiting ring (12) for limiting the stroke of the piston (17), the limiting ring (12) being mounted on the base (11) by a fixing bolt (13).

6. The novel roller cone drill bit with a buffer structure according to claim 1, characterized in that: The piston (17) is made of bearing steel, wear-resistant alloy or hard alloy, and its outer circle contour is precision ground and / or hard chrome plated.

7. The novel roller cone drill bit with a buffer structure according to claim 1, characterized in that: The inner surface of the piston hole (15) is nitrided or hard chrome plated.

8. The novel roller cone drill bit with a buffer structure according to claim 1, characterized in that: The surface of the small shaft (14) of the toothed palm (4) is treated with carburizing, nitriding, electroplating or coating.

9. The novel roller cone drill bit with a buffer structure according to claim 1, characterized in that: The roller cone drill bit includes three roller cone palm assemblies, each of which is connected to the base (11) via an independent buffer structure (10).

10. The novel roller cone drill bit with a buffer structure according to any one of claims 1 to 9, characterized in that: The roller (1) is provided with carbide cutting teeth (5) and carbide back cone protective teeth (6).

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