Retainer for rotary roller bit

Abstract

The present disclosure describes, in part, systems and structures for a rotary roller bit (100) having a body (102) and a rolling cone cutter (110), where the rolling cone cutter (110) is coupled to the body (102) through a bearing retention interface, the bearing retention interface includes a ball bearing (114) located in a closed passage between the body (102) and the rolling cone cutter (110). The ball bearing (114) is inserted through an opening (128) that is then filled with a retaining pin (120) having an engagement feature (210) that ensures that the retaining pin (120) is aligned relative to the closed passage and the ball bearing (114), thereby reducing wear within the rotary roller bit.

Description

Technical Field

[0001] This disclosure relates generally to drilling machines, and more specifically to a rotary roller cone drill bit having an improved retainer system to reduce wear on the drill bit and extend its life. Background Technology

[0002] A rotary roller cone drill bit is adapted to be connected as the lowest component of a rotary drill string. As the drill string rotates, the drill bit breaks up the formation to form a formation borehole. The drill bit comprises individual arms extending downwards at an angle from the body of the drill bit. The lower end of each arm is shaped to form a journal, which can serve as a spindle or bearing pin on which the cutting head rotates. The roller cone cutter is mounted on each bearing pin and adapted to rotate thereon. A separate bearing system facilitates the rotation of the roller cone cutter. The bearing system typically includes roller bearings, ball bearings, friction bearings, and / or combinations thereof. The roller cone cutter has cutting structures on its outer surface for breaking up the formation as the drill bit rotates.

[0003] Rotary roller cone drills operate under extremely harsh conditions, and their size and geometry are limited by their working characteristics. A method must be provided to lock the roller cone cutter onto the bearing pins. Typically, the locking function is achieved by a ball bearing system, although other systems also exist. Ball bearing systems are used to hold the roller cone on the bearing journal and can withstand axial and radial loads, or not.

[0004] Lada's PCT patent publication WO1999039075 (hereinafter referred to as '075) entitled "Rotary Cone Drill Bit Having a Ball Plug Weld with Hardfacing" describes an example system for maintaining a roller cone cutter on a rotary drill bit. Specifically, '075 describes a rotary roller cone drill bit having a roller cone cutter assembly mounted on a spindle extending from a support arm. A ball bearing is then inserted through an opening or hole in the support arm to rotatably secure the roller cone cutter to the corresponding spindle. A ball retainer plug is then inserted into a ball retainer channel, and a ball plug weld is formed to secure the ball retainer plug. '075 further details the wear-resistant overlay on the metal surface to minimize or prevent corrosion, such as applying the wear-resistant overlay to the weld surface to ensure the retainer pin remains in place.

[0005] Although the device described in document '075 is configured to hold the ball bearings and thus the roller cone cutter on the rotating roller cone bit assembly, the device and system described in document '075 cannot ensure that the pins are kept in the correct position and orientation during assembly and welding. Therefore, the device and system described in document '075 are not configured to prevent premature wear of the ball bearings and / or retainers, which could lead to failure of the rotating roller cone bit.

[0006] The examples disclosed herein are intended to overcome the aforementioned deficiencies. Summary of the Invention

[0007] A general aspect includes a rotary roller cone drill bit. The rotary roller cone drill bit has a drill body having an upper portion adapted for connection with a drill string to rotate the rotary roller cone drill bit. The drill bit also includes one or more support arms attached to and extending from the drill body from a position opposite the upper portion. Each of the one or more support arms may include a journal having a bearing surface, the journal projecting generally downward and inward relative to a corresponding support arm among the one or more support arms. The drill bit also includes one or more cutting roller cone assemblies, the number of which equals the number of support arms, each cutting roller cone assembly being rotatably mounted on one of the one or more support arms. The drill bit also includes an opening formed on the outer surface of each support arm, a ball retaining channel extending from the opening on the outer surface of the support arm, wherein a ball bearing can be inserted through the opening and the ball retaining channel to rotatably secure the corresponding cutting roller cone assembly to the journal, the opening potentially including a first engagement feature. The drill bit also includes a retaining pin configured to insert into the opening and the ball retaining channel. The retaining pin has: a first end configured to mate with the bearing surface; and a second end configured to engage with the opening, wherein the second end includes a second engagement feature configured to engage with the first engagement feature of the opening to align the retaining pin within the ball retaining channel.

[0008] One general aspect includes a retaining pin for a ball bearing in a rotary drill bit. The retaining pin has a first end configured to engage with the ball bearing and includes a first side surface on a first lateral side of the first end, a second side surface on a second lateral side of the first end opposite the first lateral side, and a tip at the first end having a bearing engagement surface with a profile corresponding to the shape of the ball bearing. The retaining pin also includes a second end configured to engage with an opening in the body of the rotary drill bit. The retaining pin further includes an engagement feature configured to align the retaining pin within the opening in the body relative to a bearing surface supporting the ball bearing. Attached Figure Description

[0009] Detailed description is provided with reference to the accompanying drawings. In the drawings, the leftmost numeral of the reference numeral first appears in the drawing for which that numeral appears. The same reference numerals are used in different drawings to indicate similar or identical items or features.

[0010] Figure 1 An example of a rotary roller cone drill bit with a retaining pin alignment system is illustrated according to at least one example.

[0011] Figure 2 A detailed cross-sectional view of a rotary roller cone drill bit according to the present disclosure is shown, in which a retaining pin with an alignment feature is shown.

[0012] Figure 3 A cross-sectional view of a rotary roller cone cutter according to the present disclosure is shown.

[0013] Figure 4 A cross-sectional view of a journal portion of a rotary roller cone drill bit according to the present disclosure is shown, the journal portion including a retaining pin having an alignment feature.

[0014] Figure 5 A perspective view of a retaining pin having an alignment feature according to the present disclosure is shown.

[0015] Figure 6 An end view of the retaining pin described herein according to this disclosure is illustrated, showing the bearing raceway portion and the alignment feature portion.

[0016] Figure 7 A detailed view of a retaining pin in a bearing channel of a rotary roller drill bit, according to the present disclosure, is shown. Detailed Implementation

[0017] Where possible, the same reference numerals will be used in all accompanying drawings to refer to the same or similar parts. In the accompanying drawings, the leftmost numeral of the reference numeral appears first in the drawing for which that reference numeral is used.

[0018] Figure 1 A rotary roller cone drill bit 100 with a retaining pin alignment system is illustrated according to at least one example. The rotary roller cone drill bit 100 is formed by a body 102 and one or more support arms 104, which together form an integral structure. The rotary roller cone drill bit 100 may also be referred to as a "roller cone rock drill bit" or a "rotary rock drill bit".

[0019] As the rotary roller cone cutter (roller cone cutter 110) rolls around the bottom of the borehole (not shown) by rotating the drill string (not shown) attached to the body 102, the rotary roller cone drill 100 performs cutting and drilling. The roller cone cutter 110 may include cutting elements that are part of the roller cone, such as milling cutting surfaces and / or embedded cutting inserts. The roller cone cutter 110 may also be referred to as a "rotary roller cone cutter" or "roller cone cutter". Each roller cone cutter 110 rotates about a corresponding journal 108, sometimes referred to as a spindle, with associated bearings 114, 116, 118, and 122 disposed therebetween. The roller cone cutter 110 and the journal 108 also interact at an interface 130 to provide additional load-bearing support for the roller cone cutter 110 during operation. The rotary roller cone drill 100 includes a body 102 having a tapered, flared upper portion adapted to be fixed to the lower end of the drill string. Three support arms 104 ( Figure 1 Two support arms (visible in the image) extend from the body 102. Each support arm 104 includes a roller cone cutter 110 rotatably mounted on one end of a journal 108. Each support arm 104 includes a journal 108 integrally formed with the support arm 104. The journal 108 is inclined downward and inward relative to the body 102 such that when the rotary roller cone bit 100 rotates, the roller cone cutter 110 engages with the bottom of the drill hole (not explicitly shown). For some applications, the journal 108 may also be inclined at an angle of zero to three degrees or four degrees or more in the direction of rotation of the rotary roller cone bit 100.

[0020] Each of the roller cone cutters 110 may include an insert 112 on its surface, which scrapes and chisels the sides and bottom of the borehole under the downhole forces applied to the rotating roller cone bit 100 via the drill string. The insert 112 may include a tungsten carbide insert press-fitted into the roller cone cutter 110. The insert 112 may also include a milled steel insert to form the cutting surface of the roller cone cutter 110. The resulting borehole debris is carried away from the bottom of the borehole by drilling fluid, which flows out from passages 106 adjacent to the lower portion of the body 102, such as through passages 124 and 126. The drilling fluid then flows upward to the surface through an annular space (not shown) formed between the rotating roller cone bit 100 and the sidewalls (not shown) of the borehole. Each of the three roller cone cutters 110 is generally constructed and mounted on its associated journal 108 in substantially the same manner. Therefore, only one support arm 104 and roller cone cutter 110 are described in detail. It should be understood that such descriptions also apply to other support arms 104 and toothed wheel cutters 110.

[0021] like Figure 1As shown, the roller cutter 110 has a generally cylindrical internal cavity for receiving the journal 108. Bearings 114, 116, 118, and 122 are positioned within the raceways and / or bearing surfaces of the roller cutter 110, allowing the roller cutter 110 to rotate about the journal 108. In some examples, one or more seals may be provided between the roller cutter 110 and the journal 108 to provide a fluid seal between the internal cavity and the journal 108.

[0022] The gear cutter 110 is held on a journal 108 by a plurality of ball bearings 114 inserted through openings in a support arm 104 that include ball channels 128 in the journal 108. The ball bearings 114 are arranged in a ring array within co-associated ball raceways in the journal 108 and the gear cutter 110. After insertion, the ball bearings 114 prevent the gear cutter from disengaging from the journal 108. A retaining pin 120 is then inserted into the ball channels 128 to block them. The retaining pin 120 serves to hold the gear cutter 110 on the journal 108 by holding the ball bearings 114 in place. The retaining pin 120 may be welded to the opening in the support arm 104 to provide a fluid barrier between the ball channels 128 and the exterior of the support arm 104. This welding also retains the retaining pin 120 within the ball channels 128. Welding techniques applicable to rotary roller drill bits 100 include, but are not limited to, gas shielded metal arc welding (GMAW), TIG, gas shielded tungsten arc welding (GTAW) or "helium arc welding", manual arc welding (SMAW) or "arc welding", oxy-fuel welding (OFW), oxy-fuel spot welding (OFSW) and high-velocity oxy-fuel (HVHVOFOF).

[0023] The journal 108 of the rotary roller cone drill bit 100 includes a bearing pin (e.g., a bearing) 122 on which the roller cone cutter 110 is mounted. The bearing 122 may include a thrust pad, and may include a first thrust pad on the journal 108 and a second thrust pad on the roller cone cutter 110. Multiple bearing systems are located within a bearing region between the roller cone cutter 110 and the journal 108. The bearing systems within the bearing region include an outer roller bearing 116, an inner roller bearing 118, and a thrust pad (e.g., bearing 122). The bearing systems facilitate rotation of the roller cone cutter 110 as the drill bit is rotated by the drill string and moves through the formation in the borehole. An annular groove is provided on the roller cone cutter 110 to receive a ball bearing 114. A ball channel 128 extends from the support arm 104 to a position radially aligned with the groove in the roller cone cutter 110. The ball channel 128 allows the ball bearing 114 to be inserted into the annular passage and secures the gear cutter 110 to the journal 108. After the ball bearing 114 is installed in place, the ball channel 128 is closed by retaining pins 120 that are held in place by welding.

[0024] Therefore, the rotary roller cone drill 100 has a body 102 configured to rotate about a longitudinal axis and may include at least one support arm 104. The rotary roller cone drill 100 also includes a journal 108 extending from at least one support arm 104 and defining a first passage 132 surrounding the exterior of the journal 108, and an opening through the journal 108 to the first passage 132 may include a first engagement feature (e.g., a ball bearing 114). The rotary roller cone drill 100 also includes a roller cone cutter 110 rotatably mounted on the journal 108 and defining a second passage 134 surrounding the interior of the roller cone cutter 110. The rotary roller cone drill 100 also includes a retaining member (e.g., a ball bearing 114) located in the first passage 132 and the second passage 134. The rotary roller drill bit 100 also includes a retaining pin 120 configured to insert into an opening. The retaining pin 120 has: a first end configured to engage with a first passage 132 and a retaining member; a second end opposite to the first end configured to engage with the opening; and a second engagement feature configured to engage with the first engagement feature of the opening and configured to align the retaining pin 120 relative to the first passage within the opening (e.g., ...). Figures 5 to 7 (As shown).

[0025] In some examples, the retaining member may include a ball bearing 114 disposed within the region defined by the first passage 132 and the second passage 134, and wherein a first end of the retaining pin 120 may include a bearing surface having a profile configured to engage with the ball bearing 114. This profile may include a radial profile extending along a first direction perpendicular to the length of the retaining pin and tangential to the bearing surface when the retaining pin 120 is inserted into the opening (e.g., as shown in the image). Figure 7 (As illustrated). The first end may include a first side and a second side disposed on the lateral side of the retaining pin 120, the first side and the second side being disposed at a non-zero angle relative to each other. The first end may include a trapezoidal profile defined between the first side, the second side, an inner edge adjacent to the inner diameter of the first passage 132 when the retaining pin 120 is inserted into the opening, and an outer edge adjacent to the outer diameter of the first passage 132 when the retaining pin 120 is inserted into the opening. The first cross-sectional area of ​​the intermediate portion of the retaining pin 120 between the first end and the second end is smaller than the second cross-sectional area of ​​the first end and the third cross-sectional area of ​​the second end (e.g., as shown). Figure 5(As illustrated). The second engagement feature may include a protrusion, and the first engagement feature may include a complementary concave structure of the protrusion, the complementary concave structure being configured to receive the protrusion along a single orientation of the retaining pin 120. The first and second engagement features define a slot for receiving a key, the key being configured to orient the retaining pin along a single orientation when the retaining pin 120 is inserted into the opening.

[0026] A typical bearing system for rotatably mounting the rotary cutter 110 on a journal 108 may include one or more radial bearings and one or more thrust bearings. The radial bearings are typically located between the outer diameter of the spindle and the inner surface of a cavity adjacent to the spindle. The thrust bearings and / or thrust bearing surfaces are typically located between the end of the journal 108 opposite the associated support arm 104 and an adjacent portion of the cavity formed in the rotary cutter 110. For some applications, a shoulder may be formed on the outside of the journal 108, and a corresponding shoulder may be formed inside the cavity, with the thrust bearing and / or thrust bearing surfaces positioned between these two shoulders.

[0027] Thrust bearings and / or radial bearings may be formed as an integral part of journal 108. For some applications, roller bearings may be provided between the outer diameter of journal 108 and adjacent portions of the cavity to support radial loads transmitted from the gear cutter 110 to the spindle. For other applications, bushings may be provided between the outer diameter of journal 108 and adjacent portions of gear cutter 110 to withstand such radial loads.

[0028] This specification specifically addresses the scenario where the ball bearing 114 collides with the retaining pin 120 of the rotating roller drill bit 100. Therefore, the retaining pin 120 includes an engagement feature ( Figure 1 (Not shown in the image), this engagement feature ensures that the retaining pin 120 is welded along the intended orientation. The engagement feature, along with the corresponding interlocking or mating geometry of the retaining pin 120 and the support arm 104, ensures that the retaining pin 120 is welded along the intended orientation, thereby preventing the ball bearing 114 from colliding with the retaining pin 120 or causing it to wear unevenly.

[0029] The openings in retaining pin 120 and support arm 104 include a slot design to ensure precise positioning of retaining pin 120 during assembly of rotary roller bit 100. The slot design ensures that retaining pin 120 is welded along a predetermined orientation, with the bearing contact surface of retaining pin 120 correctly aligned with the ball bearing raceway defined by journal 108 and roller cutter 110. This engagement feature ensures the pin is welded along a predetermined orientation, which ensures the correct positioning and orientation of the ball bearing engagement surface of retaining pin 120 to prevent ball bearing 114 from colliding with retaining pin 120 or causing uneven wear. The welded retaining pin 120 can then be treated or coated with wear-resistant surfacing to extend the life of rotary roller bit 100. Wear-resistant surfacing of metal surfaces and substrates is a well-known technique for minimizing or preventing corrosion and abrasion of metal surfaces or substrates. Wear-resistant surfacing is generally defined as applying a layer of hard, wear-resistant material to a less wear-resistant surface or substrate through electroplating, welding, spraying, or other well-known metal deposition techniques. In the oil and gas industry, wear-resistant surfacing is frequently used to extend the service life of drill bits and other downhole tools. Carbides and their various alloys are among the more widely used wear-resistant surfacing materials for protecting drill bits and other downhole tools associated with oil and gas well drilling and production.

[0030] The engagement feature of the retaining pin 120 may include a slot or first engagement feature on the body of the rotary roller drill bit 100, and a corresponding protrusion or second engagement feature configured to mate with the first engagement feature (e.g., as described herein with respect to...). Figure 7 (As shown and described). The first and second engagement features may have any geometry, shape, or configuration, but the first and second engagement features only allow the retaining pin 120 to be fully inserted into the ball channel 128 when properly aligned. Improper alignment will cause the retaining pin 120 to fail to be fully seated and protrude from the ball channel 128. The slot design of the first and second engagement features, or other engagement features, ensures that the retaining pin 120 is welded along the intended orientation, thereby preventing the ball bearing 114 from colliding with the retaining pin 120 or causing uneven wear during use.

[0031] The retaining pin 120 can be made of various materials and can be heat-treated along its entire length, or different parts or sections of the retaining pin 120 can be subjected to different heat treatments and / or surface treatments, for example, to increase the hardness of the ball bearing mating surfaces.

[0032] Figure 2A detailed cross-sectional view 200 of a rotary roller cone drill bit 100 according to the present disclosure is shown, illustrating a retaining pin 120 having alignment features (e.g., engagement features 210). As shown in detailed cross-sectional view 200, the roller cone cutter 110 is secured to a journal 108 using ball bearings 114. The ball bearings 114 engage with the inner raceway 216 of the journal 108 (such as an inner bearing raceway) and the outer raceway 218 of the roller cone cutter 110 to prevent the roller cone cutter 110 from being removed from the journal 108 after assembly.

[0033] During the assembly of the rotary roller cone drill bit 100, the roller cone cutter 110 is positioned above the journal 108, with bearings 116 and 118 located appropriately between the inner surface of the roller cone cutter 110 and the outer surface of the journal 108. Additionally, a bearing 122 or thrust washer may be positioned between the journal 108 and the roller cone cutter 110. A ball bearing 114 is inserted through a ball channel 128 to reach the inner raceway 216 and the outer raceway 218. After the ball bearing 114 is inserted through the ball channel 128, a retaining pin 120 is inserted to prevent the ball bearing 114 from dislodging and causing the roller cone cutter 110 to be removed from the journal 108. The retaining pin 120 can then be welded in place to prevent its removal from the ball channel 128.

[0034] The retaining pin 120 includes a first end 208, a second end 206, an intermediate portion 204, and an engagement feature 210. The first end 208 is configured to engage with the ball bearing 114 via an inner raceway 216, and the retaining pin 120 may include a first side surface 506 disposed on a first lateral side of the first end 208 (e.g., ...). Figures 5 to 7 (as depicted), and a second side surface 508 disposed on the second lateral side opposite to the first lateral side of the first end 208 (as shown). Figures 5 to 7 The bearing engagement surface (as depicted) and forming part of the inner raceway 216 may include a profile corresponding to the shape of the ball bearing 114. The bearing engagement surface may be surface-hardened. A first side may include a first plane, and a second side may include a second plane, wherein the first side is disposed at a non-zero angle relative to the second side. The retaining pin 120 also includes a second end 206 and an engagement feature 210, the second end being configured to engage with an opening in the body 102, the engagement feature being configured to align the retaining pin 120 within the opening in the body 102 relative to the bearing surface supporting the ball bearing 114.

[0035] Engaging feature 210 may include a second profile configured to engage with an opening in the body only along one orientation, so as to orient the retaining pin relative to the body when the retaining pin is inserted into the opening. In some examples, engaging feature 210 may include a protrusion that acts as a key to orient the retaining pin 120 relative to the ball channel 128, such that the bearing engagement surface is oriented tangentially to the inner raceway 216, so that the ball bearing 114 does not collide with the bearing engagement surface and does not cause uneven wear of the retaining pin 120. The protrusion may have a specific shape that engages with engaging feature 212 of the body 102 such that the retaining pin 120 can only be fully inserted when properly aligned. In some examples, engaging feature 210 may include a protrusion on the body 102 and / or a slot defined between the retaining pin 120 and the ball channel 128, such that a key can be inserted into the slot when the retaining pin 120 is properly aligned.

[0036] The first cross-sectional area of ​​the intermediate portion 204 between the first end 208 and the second end 206 is smaller than the second cross-sectional area of ​​the first end 208 and the third cross-sectional area of ​​the second end 206. In this way, the ball channel can be used as a conduit for fluids such as air or lubricant, allowing fluid to be transported via the journal 108 to achieve various purposes such as cooling, debris removal, and lubrication.

[0037] Therefore, as described herein, the rotary roller cone bit holding system includes a body 102 having an upper portion adapted for connection with a drill string to rotate a rotary roller cone bit 100. The rotary roller cone bit 100 also includes one or more support arms 104 attached to and extending from the body 102 from a position opposite the upper portion. Each of the one or more support arms 104 includes a journal 108 having a bearing surface, the journal 108 projecting generally downward and inward relative to a corresponding support arm among the one or more support arms. The rotary roller cone bit 100 also includes one or more roller cone cutters 110, the number of which equals the number of support arms 104, each roller cone cutter 110 being rotatably mounted on one of the one or more support arms 104. The rotary roller cone drill bit 100 also includes an opening formed on the outer surface of each support arm 104, through which a ball channel 128 extends from the opening on the outer surface of the support arm 104, wherein a ball bearing 114 can be inserted through the opening and the ball channel 128 to rotatably secure a corresponding roller cone cutter 110 to a journal 108. The opening may include a first profile. The rotary roller cone drill bit 100 also includes a retaining pin 120 configured to insert into the opening and the ball channel 128. The retaining pin includes: a first end portion 208 configured to mate with a bearing surface; a second end portion 206 configured to engage with the opening; and an engagement feature 210 having a second profile configured to engage with the first profile of the opening to align the retaining pin 120 within the ball retaining channel. In some examples, the depth position of the retaining pin 204 may be set and / or positioned based on the engagement of the first end portion 220 with the journal 108 at the bottom of the ball retaining channel.

[0038] In some examples, the engagement feature 210 may include a protrusion having a second profile, and the first profile may include a complementary concave structure or corresponding shape that matches the second profile. The first end portion 208 may include a first side surface and a second side surface disposed on the lateral side of the retaining pin, the first side surface and the second side surface being disposed at a non-zero angle relative to each other. The first end portion 208 may include a trapezoidal profile defined between the first side surface and the second side surface. The first end portion 208 may include a contact surface 220 having a radial profile extending along a first direction perpendicular to the length of the retaining pin 120 and tangential to a surface (e.g., inner raceway 216) when the retaining pin 120 is inserted into the opening. The retaining pin 120 may include a hardened surface located at the first end portion 208 for engaging with one or more ball bearings 114 located within the bearing surface. The first cross-sectional area of ​​the intermediate portion 204 of the retaining pin 120 between the first end portion 208 and the second end portion 206 is smaller than the second cross-sectional area of ​​the first end portion and the third cross-sectional area of ​​the second end portion.

[0039] Figure 3 A cross-sectional view 300 of the roller cone cutter 110 of the rotary roller cone drill 100 according to the present disclosure is illustrated. Bearing surfaces are provided on the internal cavity of the roller cone cutter 110 for receiving the bearings described herein. Bearing surfaces 308 and 310 may be configured to receive roller bearings, and bearing surface 306 may be configured to receive thrust bearings, bushings, or other such features. Other internal surfaces of the roller cone cutter 110 may serve as bearing surfaces, including thrust shoulders, additional raceways, and other features that may be provided on the roller cone cutter 110 and / or journal 108. Surface 304 may form part of a bearing raceway that captures a ball bearing 114 during assembly of the rotary roller cone drill 100. Surface 304 may have a profile (as can be seen from the cross-section) corresponding to the shape and size of the ball bearing 114, although in some examples, this size may be slightly larger than the diameter of the ball bearing. As illustrated, surface 304 may have a semi-circular shape or a shape corresponding to a partially circular cross-section.

[0040] Figure 4 A cross-sectional view of a journal 108 of a rotary roller drill bit 100 according to the present disclosure is illustrated. The journal includes a retaining pin 120 with alignment features. The journal 108 includes an inner surface 402 that forms the inner portion of the raceway of a ball bearing 114. The inner surface 402 may have a similar profile (e.g., shape, profile, diameter, radius, etc.) to surface 304, and the surface 304 and the inner surface 402 together form the passageway or raceway of the ball bearing 114. The inner surface 402 may have a semi-circular cross-section as depicted, or may have other such shapes or geometries. The inner surface 402 and / or surface 304 may be surface-treated, greased, or otherwise treated to facilitate the rolling of the ball bearing 114 within the raceway.

[0041] The ball channel 128 intersects the inner surface 402, causing the inner surface 402 to be interrupted at the location of the ball channel 128. The retaining pin 120, more specifically, the first end 208 of the retaining pin 120, may partially or completely fill the gap in the inner surface 402. In some examples, the inner raceway 216 may be tangent to the inner surface 402 at the location of the ball channel 128. For ease of machining, the inner raceway 216 may have a profile corresponding to the ball bearing 114 (as depicted), but may not necessarily need to conform to the curvature of the bearing raceway. Instead, the bearing surface may be configured to be tangent only to the bearing raceway. In some examples, the first end 208 and the inner raceway 216 do not completely span the gap in the inner surface 402 formed by the ball channel 128. Instead, the width of the inner raceway 216 may be smaller than the width of the ball channel, such as... Figure 7 The description.

[0042] Figure 5 A perspective view of a retaining pin 120 having an engagement feature 514 according to the present disclosure is illustrated. The retaining pin 120 is configured to insert into an opening in the body of a rotating roller cone drill bit 100 to retain a ball bearing 114, thereby holding the roller cone cutter 110 in proper position on a journal 108. The retaining pin 120 has a first end portion 504 including a contact surface 502 configured to engage with a bearing raceway on which the ball bearing 114 runs. The retaining pin 120 also includes a second end portion 512 opposite the first end portion, configured to engage with a distal end of an opening in the body. The second end portion 512 includes an engagement feature 514 configured to engage with engagement features of the opening and / or the body / journal, and configured to align the retaining pin 120 relative to the bearing raceway within the opening.

[0043] The bearing surface has a profile configured to engage with the ball bearing 114. This profile may include a radial profile that extends along a first direction perpendicular to the length of the retaining pin and is tangent to the bearing surface when the retaining pin 120 is inserted into the opening. For ease of machining, the contact surface 502 may have a profile corresponding to the ball bearing 114 (as depicted), but may not necessarily need to conform to the curvature of the bearing raceway. Instead, the contact surface 502 may be configured to be tangent only to the bearing raceway and therefore perpendicular to the direction along the length of the retaining pin 120 from the first end to the second end.

[0044] The first end 504 may include a first side 506 and a second side 506 disposed on the lateral side of the first end 504 of the retaining pin 120 (e.g., ...). Figures 6 to 7 (As depicted), the first side 506 and the second side are arranged at a non-zero angle relative to each other. Therefore, the first end 504 may include a trapezoidal profile defined between the first side 506 and the second side 508, as shown. Figure 6 exemplified.

[0045] The first cross-sectional area of ​​the intermediate portion 510 of the retaining pin 120 between the first end 504 and the second end 512 is smaller than the second cross-sectional area of ​​the first end 504 and the third cross-sectional area of ​​the second end 512. In this way, the ball channel can be used as a conduit for fluids such as air or lubricant, allowing fluid to flow through the journal for various purposes such as cooling, debris removal, and lubrication, because the fluid can flow around the intermediate portion 510 of the retaining pin 120.

[0046] Engaging feature 514 may include a protrusion that engages with a slot or complementary concave structure of the protrusion positioned and / or defined in an opening in the body and configured to receive the protrusion along a single orientation of the retaining pin 120. Engaging feature 514 ensures that the retaining pin 120 is welded along a desired orientation. The engagement feature, along with the corresponding interlocking or mating geometry of the retaining pin 120 and the support arm 104, ensures that the retaining pin 120 is welded along a desired orientation, thereby preventing the ball bearing 114 from colliding with the retaining pin 120 or causing uneven wear. In some examples, the engagement feature may not be a protrusion, but rather a slot that engages with a protrusion defined in the opening. In some examples, the engagement feature may include a slot on the retaining pin 120 and a slot defined around the periphery of the opening for receiving a key configured to align the retaining pin along a single orientation when the retaining pin 120 is inserted into the opening.

[0047] The engagement feature 514 and its corresponding shape or receiving shape can also be used to set and ensure the correct depth placement of the retaining pin 120 within the ball channel. The engagement feature 514 can be fitted into a slot or recess machined around the periphery of an opening in the ball channel. The machining depth of the slot or recess allows the retaining pin 120 to be positioned at the correct depth when the engagement feature 514 bottoms out into the slot or recess after insertion into the ball channel. In this way, the retaining pin 120 can be easily oriented and correctly positioned relative to the depth in the ball channel without any careful measurement or fixtures, thereby ensuring precise placement of the retaining pin to extend its life and reduce wear at the retaining pin, preventing premature failure of the rotary drill bit.

[0048] At the second end 512, the retaining pin 120 includes a chamfered edge 516 and an outer surface 518. The chamfered edge 516 is used when welding the retaining pin 120 to the body of the rotary roller drill bit. The chamfered edge allows the weld to fill the chamfered space between the retaining pin 120 and the opening.

[0049] Figure 6 An end view of the retaining pin 120 described herein according to this disclosure is illustrated, showing the bearing raceway portion and the alignment feature. As shown, the engagement feature 514 protrudes such that when inserted into the opening, the engagement feature 514 only allows the retaining pin 120 to be fully inserted when correctly oriented. The sides of the first end are depicted, wherein the first side 506 and the second side 508 form a trapezoidal profile as described herein. The distance 606 between the first side 506 and the second side 508 at the bottom edge of the trapezoid (e.g., with) Figure 6 The distance 606 between adjacent inner raceways (corresponding to and adjacent to the inner diameter of the inner raceway 216) is less than the distance 604. The contact surface 602 can be from... Figure 6The edge shown at point 602 curves toward the bottom of the narrow section of the adjacent trapezoid (as illustrated in the figure).

[0050] The retaining pin 120, more specifically, the first end of the retaining pin 120, may partially or completely fill the gap in the bearing raceway, as described herein. In some examples, the contact surface 602 may be tangential to the bearing raceway at the location of the ball channel 128. For ease of machining, the contact surface 602 may have a profile corresponding to the ball bearing 114 (as depicted), but may not necessarily need to conform to the curvature of the bearing raceway. Instead, the contact surface 602 may be configured to be tangential only to the bearing raceway (and thus the contact surface is illustrated as a plane spanning the upper edge at 602). In some examples, the first end and the contact surface 602 do not completely span the gap in the bearing raceway formed by the ball channel. This allows for the use of a simplified profile at the first end and may also allow air or fluid to be blown along the ball channel into the space between the journal and the gear cutter.

[0051] Figure 7 A detailed view 700 illustrates a retaining pin 120 in a bearing channel of a rotary roller drill bit according to the present disclosure. Figure 7 Only a portion of the body 702 is shown. This portion of the body includes an opening 704 leading to the ball channel 128, as described herein. The opening 704 is defined in the body 702 by an engagement feature 706 that corresponds to the outline of the engagement feature 514 of the retaining pin 120. Although Figure 7 The specific shape and geometry of the engagement feature are shown, but other shapes and geometries are envisioned such that the retaining pin 120 can only be fully inserted into the opening 704 when it is correctly oriented.

[0052] As described above, the bearing raceway 708 is defined within the journal, and a gap exists on the surface of the bearing raceway 708 where it intersects with the ball channel 128. The width of the contact surface 602 of the retaining pin 120 is smaller than the width of the gap in the bearing raceway 708. Therefore, spaces 710 are left on both sides of the contact surface 602. This space accommodates the flat profile of the contact surface 602 (e.g., flat means tangential to the bearing raceway 708, rather than having a matching curvature), as described herein. In some examples, the retaining pin 120 may have a curved bearing surface that conforms to the curvature of the bearing raceway 708.

[0053] Industrial applicability

[0054] This disclosure provides systems and methods for securing the journal of a rotary roller cone drill bit, and specifically relates to a retaining pin and retaining pin geometry to achieve precise depth and positioning, as well as rotational orientation, of the retaining pin relative to a ball bearing used to retain the engagement between the roller cone cutter and the journal. The retaining pin includes a geometry of an engaging slot and a protrusion that engage only when correctly oriented, and also provides precise depth positioning of the retaining pin. Such systems and methods can be used to improve the performance and lifespan of one or more mechanical operations by reducing wear and extending the life of rotary roller cone drill bits, thereby reducing downtime and costs associated with drill bit maintenance and replacement. Therefore, the example systems and methods described above can provide substantial cost and time savings, and reduce the time and labor required for various activities at the work site, as well as other things that will become apparent to those skilled in the art.

[0055] While various aspects of this disclosure have been specifically shown and described with respect to the embodiments described above, those skilled in the art will understand that various additional embodiments can be contemplated by modifications to the disclosed machines, systems, and methods without departing from the spirit and scope of the disclosure. Such embodiments should be understood to fall within the scope of this disclosure as determined by the claims and any equivalents.

Claims

1. A rotary roller cone drill bit (100), the rotary roller cone drill bit comprising: The drill bit body (102) has an upper portion adapted to be connected to a drill string to rotate the rotary roller drill bit (100); One or more support arms (104) are attached to the drill body (102) from a position opposite to the upper portion and extend from the drill body. Each of the one or more support arms (104) includes a journal (108) having a bearing surface. The journal (108) generally projects downward and inward relative to the corresponding support arm (104) of the one or more support arms. One or more cutting gear assemblies (110), the number of which is equal to the number of support arms (104), each cutting gear assembly (110) being rotatably mounted on one of the one or more support arms (104); An opening (704) is formed on the outer surface of each support arm (104), and a ball retaining channel (128) extends from the opening on the outer surface of the support arm (104), thereby allowing a ball bearing (114) to be inserted through the opening and the ball retaining channel (128) to rotatably secure a corresponding cutting gear assembly (110) to the journal (108). The opening includes a first engagement feature (212). and A retaining pin (120), configured to insert into the opening (704) and the ball retaining channel (128), the retaining pin (204) comprising: A first end (220) is configured to mate with the bearing surface; A second end portion (206) configured to engage with the opening (704), wherein the second end portion (206) includes a second engagement feature (210) configured to engage with a first engagement feature (212) of the opening (704) to align the retaining pin (120) within the ball retaining channel (128).

2. The rotary roller drill bit (100) according to claim 1, wherein the second engagement feature (210) includes a protrusion, and the first engagement feature (212) is configured to receive the protrusion along a single orientation of the retaining pin.

3. The rotary roller drill bit according to claim 1, wherein the first end (220) includes a first side (506) and a second side (508) disposed on the lateral side of the retaining pin (120), the first side (506) and the second side (508) being disposed at a non-zero angle relative to each other.

4. The rotary roller drill bit (100) according to claim 1, wherein the first engagement feature (212) includes a first geometry defined by the opening, and the second engagement feature (210) includes a second geometry configured to fit the first geometry.

5. The rotary roller drill bit (100) according to claim 1, wherein the first end (220) includes a second bearing surface (502) having a radial profile extending along a first direction perpendicular to the length of the retaining pin (120) and tangent to the bearing surface when the retaining pin (120) is inserted into the opening.

6. The rotary roller drill bit (100) according to claim 1, wherein the retaining pin (120) includes a hardened surface located at the first end (220) for engaging with one or more ball bearings (114) located within the bearing surface.

7. The rotary roller drill bit (100) according to claim 1, wherein the first cross-sectional area of ​​the intermediate portion (510) of the retaining pin (120) between the first end (220) and the second end (206) is smaller than the second cross-sectional area of ​​the first end and the third cross-sectional area of ​​the second end.

8. A rotary drill bit (100), the rotary drill bit comprising: The drill bit body (102) is configured to rotate about a longitudinal axis and includes at least one support arm (104). Journal (108), which extends from and defines the at least one support arm (104): A first passage (402) surrounds the outside of the journal (108); and An opening (704) extends through the journal (108) to the first passage (402), the opening including a first engagement feature (706). A roller cutter (110) is rotatably mounted on the journal (108) and defines a second passage (304) surrounding the interior of the roller cutter (110); A retaining member (114) is disposed in the first passage (402) and the second passage (304); and A retaining pin (120), configured to be inserted into the opening (704), the retaining pin (120) comprising: A first end (220) is configured to mate with the first passage (402) and the retaining member (114); A second end (206), opposite to the first end (220), is configured to engage with the opening; and The second engagement feature (514) is positioned at the second end and configured to engage with the first engagement feature (706) of the opening, and is configured to align the retaining pin (120) within the opening relative to the first passage.

9. The rotary drill bit (100) of claim 8, wherein the retaining member (114) comprises a ball bearing disposed in the region defined by the first passage (402) and the second passage (304), and wherein the first end of the retaining pin (120) comprises a bearing surface having a profile configured to engage the ball bearing.

10. The rotary drill bit (100) according to claim 9, wherein the profile includes a radial profile (502) extending along a first direction perpendicular to the length of the retaining pin (120) and tangent to the bearing surface when the retaining pin (120) is inserted into the opening.

11. The rotary drill bit (100) according to claim 8, wherein the first end (504) includes a first side (506) and a second side (508) disposed on the lateral side of the retaining pin, the first side and the second side being disposed at a non-zero angle relative to each other.

12. The rotary drill bit (100) of claim 8, wherein the first engagement feature (706) includes a first geometry defined by the opening, and the second engagement feature (514) includes a second geometry configured to fit the first geometry.

13. The rotary drill bit (100) according to claim 8, wherein the first cross-sectional area of ​​the intermediate portion (510) of the retaining pin (120) between the first end and the second end is smaller than the second cross-sectional area of ​​the first end and the third cross-sectional area of ​​the second end.

14. The rotary drill bit (100) according to claim 8, wherein the second engagement feature (514) includes a protrusion, and the first engagement feature (706) includes a complementary concave structure of the protrusion, the complementary concave structure being configured to receive the protrusion in a single orientation along the retaining pin (120).

15. The rotary drill bit (100) of claim 8, wherein the first engagement feature (706) and the second engagement feature (514) define a slot for receiving a key, the key being configured to orient the retaining pin (120) in a single orientation when the retaining pin (120) is inserted into the opening.

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