A reaming apparatus for oil exploration

Abstract

This invention belongs to the field of oil well drilling and reaming technology, specifically relating to a reaming device for oil well development. It includes a connecting drill pipe with a front-end drilling section and a rear-end reaming section connected to it. A central drilling section is connected to the bottom of the front-end drilling section. The front-end drilling section includes a front-end drill body with multiple detachable front-end drill plate assemblies arranged around its periphery. The rear-end reaming section has multiple stabilizing support assemblies, with two stabilizing support assemblies forming a group, and their ends connected to reaming drill plate assemblies. An adjustment drive assembly is located in the middle of the rear-end reaming section, used to adjust the distance between each reaming drill plate assembly and the central axis of the connecting drill pipe. This invention adapts to the reinforcement needs of different formations, especially loose formations, effectively increasing the wellbore diameter while maintaining a smooth transition of the wellbore trajectory, without requiring frequent drill bit changes, achieving a linear and gradual change in borehole diameter.

Description

Technical Field

[0001] This invention belongs to the field of oil well drilling and reaming technology, specifically relating to a reaming device for oil well development. Background Technology

[0002] In oil drilling, the formation structure varies significantly with increasing well depth. Particularly in some deep well sections, there are loose, fractured, or unstable formations. These formations are prone to wellbore instability, collapse, or diameter reduction, severely impacting the safety and efficiency of drilling operations. To ensure long-term wellbore stability, casing is typically installed and cement is injected into the corresponding well sections to form a complete cement protective layer and other reinforcing structures, effectively strengthening the wellbore.

[0003] To achieve sufficient cement sheath coverage and reinforcement, it is often necessary to enlarge the borehole diameter in the target formation to increase the thickness of the cement sheath and improve its sealing capacity and support strength for loose formations. However, traditional reaming processes and equipment have certain limitations in application. Most reaming tools produce abrupt changes in borehole diameter, which can easily form steps or abrupt changes in diameter within the wellbore. For example, utility model patent application number 202223082927.3 discloses a reamer for oil extraction, which is equipped with a reamer cutter fixing unit. A telescopic column fixing seat is used to fix the telescopic column, which drives the reamer cutter fixing seat to move, thereby buffering the reamer cutter fixing seat. The reamer cutter is used for reaming, a buffer spring is used for buffering, a protective sleeve is used to protect the reamer cutter fixing seat, a protective plate is used to facilitate maintenance of the buffer assembly to protect the cutter, and a cutting tool fixing seat is used to fix the cutting tool, which is used to ream the oil well.

[0004] Such abrupt changes in pore size can disrupt the normal upward flow of drilling fluid, leading to localized eddies, pressure fluctuations, or cuttings accumulation, thereby affecting wellbore cleaning and even inducing complex downhole conditions. Simultaneously, during cement injection, drastic changes in pore size can also affect the fluidity and displacement efficiency of the cement slurry, easily causing uneven distribution of the cement sheath and reduced bonding quality, thus weakening its reinforcing effect on the wellbore. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a borehole enlargement device for oil exploration that can adapt to the reinforcement needs of different formations, especially loose formations. While effectively enlarging the wellbore diameter, it maintains a smooth transition of the wellbore trajectory and does not require frequent drill bit replacements, thus achieving a linear and gradual change in borehole diameter.

[0006] The objective of this invention is achieved as follows: an oil drilling reaming device includes a connecting drill rod, on which a front end drilling section and a rear end reaming section are connected. The front end drilling section is connected to the lower end of the connecting drill rod, and a central drilling section is connected to the bottom of the front end drilling section. The front-end drilling section includes a front-end drill body, and multiple detachable front-end drill plate assemblies are evenly arranged on the periphery of the front-end drill body with its central axis as the center. The rear end reaming section is provided with multiple stabilizing support components. Two of the stabilizing support components are grouped together and their ends are connected to reaming drill plate components. The multiple reaming drill plate components are evenly distributed around the central axis of the connecting drill rod. An adjustment drive component is provided in the middle of the rear end reaming section. The adjustment drive component is used to adjust the distance between each reaming drill plate component and the central axis of the connecting drill rod.

[0007] Furthermore, the front-end drill body is provided with a first threaded connector at the top and a second threaded connector at the bottom. The front-end drilled portion is connected to the lower end of the connecting drill rod through the first threaded connector, and the central drilled portion is connected to the bottom of the front-end drilled portion through the second threaded connector.

[0008] Furthermore, the central drilling section includes a central drill body, on which multiple inclined drill plates are provided on the side and a threaded connector is provided on the top; the threaded connector is connected to the second threaded joint, and the multiple inclined drill plates are evenly distributed around the central axis of the central drill body.

[0009] Furthermore, the front-end drill plate assembly includes a first drill plate, on the outer side of which a plurality of first drill bits are disposed; the front-end drill body is provided with a plurality of stabilizing slots, and the inner side of the first drill plate is provided with a stabilizing insert plate adapted to the stabilizing slots; the number of stabilizing slots corresponds to the number of the front-end drill plate assemblies.

[0010] Furthermore, the first drill plate is L-shaped in general, and a fixed base is provided on the top surface of the front drill body. A locking bolt is provided at the upper end of the first drill plate, and the locking bolt is connected to the fixed base.

[0011] Furthermore, limit stops are provided on the left and right end faces of the tail end of the drill plate, and multiple limit baffles are provided on the bottom surface of the front drill body. Multiple baffles are provided on the limit baffles, and multiple baffles are provided on the limit baffles, which are adapted to the size of the limit stops. The lower end of the first drill plate can be limited by embedding the limit stops into the baffles.

[0012] Furthermore, the rear reaming section includes a reaming main connector connected to the connecting drill pipe, and the stabilizing support assembly includes a fixed support arm connected to the side of the reaming main connector, the fixed support arm being slidably connected to a movable support arm; the end of the movable support arm is connected to the reaming drill plate assembly; the upper end of the connecting drill pipe is provided with a connecting end pipe, through which it is connected to other drilling drill pipes.

[0013] Furthermore, the reaming drill plate assembly includes a second drill plate, on which a plurality of second drill bits are uniformly arranged along its length; the end of the movable support arm is connected to the second drill plate.

[0014] Furthermore, the adjustment drive assembly includes an adjustment cap and an adjustment guide fixedly disposed on the side of the main borehole reaming connector. An adjustment screw is slidably connected inside the adjustment guide, and the end of the adjustment screw is connected to the borehole reaming plate assembly. One end of the adjustment cap is rotatably connected to the adjustment guide, and the other end is threadedly connected to the adjustment screw. The adjustment screw can be moved by rotating the adjustment cap.

[0015] Furthermore, a fixed ring seat is connected to the fixed support arm, and an adjusting drive gear ring is rotatably mounted on the fixed ring seat, which meshes with the adjusting cap; an adjusting drive worm gear is rotatably mounted on the reaming main pipe, and an adjusting drive gear is fixedly connected to the adjusting drive worm gear via a shaft, which meshes with the fixed ring seat; an adjusting drive motor is also mounted on the reaming main pipe, and an adjusting drive worm is connected to the adjusting drive worm, which meshes with the adjusting drive worm gear; the position of the reaming drill plate assembly can be automatically adjusted and controlled through the operation of the adjusting drive motor, which is convenient, quick, stable and efficient.

[0016] The beneficial effects of this invention: This invention provides an oil well reaming device. The connecting drill rod has a central drilling section, a front-end drilling section, and a rear-end reaming section distributed sequentially from bottom to top, with the overall size of each section increasing sequentially. The central drilling section and the front-end drilling section perform primary drilling, while the rear-end reaming section is used for drilling and reaming. The central drilling section is located at the bottom of the entire reaming device and has the smallest overall size. It is used for drilling at the very front center position, paving the way for subsequent drilling and compensating for any missing drilling at the center position of the front-end drilling section. The front-end drilling section includes a front-end drill body. Multiple detachable front-end drill plate assemblies are evenly arranged around the periphery of the front-end drill body with its central axis as the center. These front-end drill plate assemblies can be easily and quickly disassembled, replaced, and installed as needed, facilitating maintenance and adjustment of the drilling size. The rear reaming section is equipped with a stabilizing support component, a reaming drill plate assembly, and an adjusting drive component. Two of the stabilizing support components form a group, and their ends are connected to the reaming drill plate assembly to provide stable structural support for the reaming drill plate assembly. At the same time, the distance between each reaming drill plate assembly and the central axis of the connecting drill rod can be adjusted by the adjusting drive component, thereby achieving continuous linear adjustment of the overall size of the rear reaming section and achieving the purpose of linear reaming during drilling. The reaming equipment for oil development of this invention is adapted to the reinforcement needs of different formations, especially loose formations. While effectively increasing the wellbore diameter, it maintains a smooth transition of the wellbore trajectory and does not require frequent drill bit changes, achieving a linear and gradual change in the borehole diameter, ensuring smooth drilling fluid return and uniform cement slurry injection, and ultimately achieving the purpose of improving wellbore stability and ensuring drilling safety and quality. Attached Figure Description

[0017] 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. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of a borehole reamer used in oil extraction.

[0019] Figure 2 This is a schematic diagram of the structure of an oil drilling equipment after the drilling parts are separated.

[0020] Figure 3 This is a schematic diagram of the central drilling section of a reaming device used in oil extraction.

[0021] Figure 4 This is a schematic diagram of the structure of a borehole connection at the front end of a reaming device used in oil exploration.

[0022] Figure 5 This is a schematic diagram of a structure for oil extraction using a drilling section connected to the front end of a reaming device, from another perspective.

[0023] Figure 6 This is a schematic diagram of the structure of a drilling plate assembly connected to the front end of a borehole reaming device for oil exploration.

[0024] Figure 7 This is a schematic diagram of the structure of the rear end of a borehole reaming device used in oil exploration.

[0025] Figure 8 This is a schematic diagram of the structure of an oil drilling device using a hole-reaming equipment with an adjustable drive assembly. Detailed Implementation

[0026] The present invention will now be further described with reference to the accompanying drawings.

[0027] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0028] 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 a part of the embodiments of the present invention, and not all of them. 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.

[0029] It should be noted that in the embodiments of the present invention, all directional indications (such as up-down-left-right-forward-backward...) are only used to explain the relative positional relationship and movement between the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly. The connection can be a direct connection or an indirect connection.

[0030] like Figures 1-2 As shown, an oil drilling reaming device of the present invention includes a connecting drill rod 1, on which a front end drilling part 4 and a rear end reaming part 3 are connected. The front end drilling part 4 is connected to the lower end of the connecting drill rod 1, and a central drilling part 5 is connected to the bottom of the front end drilling part 4. The front-end drilling section 4 includes a front-end drill body 10, and a plurality of detachable front-end drill plate assemblies 9 are evenly arranged on the periphery of the front-end drill body 10 with its central axis as the center. The rear end reaming section 3 is provided with a plurality of stabilizing support components 6, two of the stabilizing support components 6 are grouped together and their ends are connected to a reaming drill plate assembly 8, and the plurality of reaming drill plate assemblies 8 are evenly distributed around the central axis of the connecting drill rod 1; the middle part of the rear end reaming section 3 is provided with an adjustment drive assembly 7, which is used to adjust the distance of each reaming drill plate assembly 8 from the central axis of the connecting drill rod 1.

[0031] Furthermore, in one embodiment, such as Figure 2 As shown, the front drill body 10 is provided with a first threaded connector 11 at the top and a second threaded connector 12 at the bottom. The front drill hole 4 is connected to the lower end of the connecting drill rod 1 through the first threaded connector 11, and the central drill hole 5 is connected to the bottom of the front drill hole 4 through the second threaded connector 12. The structure is simple and reasonable, the connection is stable and efficient, and the disassembly and assembly efficiency of the equipment is improved.

[0032] Furthermore, in one embodiment, such as Figure 3 As shown, the central drilling section 5 includes a central drill body 13, on which multiple inclined drill plates 14 are provided on the side and a threaded connector 37 is provided on the top. The threaded connector 37 is connected to the second threaded joint 12. The multiple inclined drill plates 14 are evenly distributed around the central axis of the central drill body 13. The central drilling section 5 is located at the bottom of the entire reaming equipment and has the smallest overall size. It is used to perform drilling operations at the front center position, to pave the way for subsequent drilling, and to make up for the lack of drilling at the center position of the front drilling section 4.

[0033] Furthermore, in one embodiment, such as Figures 4-6 As shown, the front-end drill plate assembly 9 includes a first drill plate 15, on the outer side of which a plurality of first drill bits 17 are provided; the front-end drill body 10 is provided with a plurality of stabilizing slots 22, and the inner side of the first drill plate 15 is provided with stabilizing inserts 16 adapted to the stabilizing slots 22; the number of stabilizing slots 22 corresponds to the number of front-end drill plate assemblies 9, and the front-end drill plate assembly 9 is inserted into the corresponding stabilizing slots 22 through the stabilizing inserts 16 thereon to ensure the structural strength of the connection between it and the front-end drill body 10. When the front-end drilling section 4 performs rotary drilling operations, the first drill bits 17 thereon squeeze and cut the soil and rock layers to achieve stable and reliable drilling operations.

[0034] Furthermore, in one embodiment, such as Figure 4As shown, the first drill plate 15 is generally L-shaped. A fixed base 19 is provided on the top surface of the front drill body 10. A locking bolt 18 is provided at the upper end of the first drill plate 15, and the locking bolt 18 is connected to the fixed base 19. Through the connection between the locking bolt 18 and the fixed base 19, the fixed connection between the front drill plate assembly 9 and the front drill body 10 is realized. At the same time, it is convenient to install and disassemble the front drill plate assembly 9, so that the front drill plate assembly 9 can be easily and quickly disassembled, replaced and installed as needed, thereby improving work efficiency.

[0035] Furthermore, in one embodiment, such as Figures 5-6 As shown, limit stops 20 are provided on the left and right end faces of the tail end of the drill plate 15, and multiple limit baffles 21 are provided on the bottom surface of the front drill body 10. Multiple grooves adapted to the size of the limit stops 20 are provided on the limit baffles 21. By embedding the limit stops 20 into the grooves on the limit baffles 21, the lower end of the first drill plate 15 can be limited. Combined with the connection between the locking bolts 18 and the fixed connector 19, a fixed connection between the front drill plate assembly 9 and the front drill body 10 is achieved. Furthermore, by adjusting the insertion of the limit stops 20 into different grooves on the limit baffles 21, and coordinating different depths of the connection between the locking bolts 18 and the fixed connector 19, the distance between the central axis of the front drill plate assembly 9 and the front drill hole 4 can be adjusted, thereby controlling the overall drilling size of the front drill hole 4. This method is convenient, quick, and highly adaptable.

[0036] Furthermore, in one embodiment, such as Figure 7 As shown, the rear reaming section 3 includes a reaming main connector 24 connected to the connecting drill pipe 1. The stabilizing support assembly 6 includes a fixed support arm 32 connected to the side of the reaming main connector 24. The fixed support arm 32 is slidably connected to a movable support arm 31. The end of the movable support arm 31 is connected to the reaming drill plate assembly 8. The stabilizing support assembly 6 provides stable structural support for the reaming drill plate assembly 8. At the same time, the sliding connection between the movable support arm 31 and the fixed support arm 32 can adjust the distance between each reaming drill plate assembly 8 and the central axis of the reaming main connector 24, thereby adjusting the overall size of the rear reaming section 3. This, in conjunction with the front drilling section 4 and the central drilling section 5, enables drilling and reaming operations. The upper end of the connecting drill pipe 1 is provided with a connecting end pipe 2, which connects to other drilling drill pipes.

[0037] Furthermore, in one embodiment, such as Figure 7As shown, the reaming drill plate assembly 8 includes a second drill plate 23, on which a plurality of second drill bits 25 are uniformly arranged along its length direction; the end of the movable support arm 31 is connected to the second drill plate 23, and the position of the second drill plate 23 can be adjusted by the adjustment drive assembly 7, while the stabilizing support assembly 6 provides stable structural support for the reaming drill plate assembly 8.

[0038] Furthermore, in one embodiment, such as Figure 7 As shown, the adjustment drive assembly 7 includes an adjustment cap 30 and an adjustment guide tube 28 fixedly disposed on the side of the reaming main connector 24. An adjustment screw 29 is slidably connected inside the adjustment guide tube 28, and the end of the adjustment screw 29 is connected to the reaming drill plate assembly 8. One end of the adjustment cap 30 is rotatably connected to the adjustment guide tube 28, and the other end is threadedly connected to the adjustment screw 29. The adjustment screw 29 can be moved by rotating the adjustment cap 30, thereby adjusting the position of the reaming drill plate assembly 8 and realizing the adjustment of the overall size of the rear reaming section 3.

[0039] Furthermore, in one embodiment, such as Figure 7 , 8 As shown, a fixed ring seat 26 is connected to the fixed support arm 32, and an adjusting drive gear ring 27 is rotatably mounted on the fixed ring seat 26. The adjusting drive gear ring 27 is meshed with the adjusting cap 30. An adjusting drive worm gear 35 is rotatably mounted on the expanding main pipe 24. The adjusting drive worm gear 35 is fixedly connected to an adjusting drive gear 33 via a shaft, and the adjusting drive gear 33 is meshed with the fixed ring seat 26. An adjusting drive motor 34 is also mounted on the expanding main pipe 24. The adjusting drive motor 34 is connected to an adjusting drive worm 36, and the adjusting drive worm 36 meshes with the adjusting drive worm gear 35. The connection allows for automatic adjustment and control of the position of the reaming drill plate assembly 8 through the operation of the adjustment drive motor 34. This operation is convenient, quick, stable, and efficient. Specifically, when reaming is required, the adjustment drive motor 34 is activated to drive the adjustment drive worm gear 36 to rotate, which in turn drives the adjustment drive gear 33 to rotate. The adjustment drive gear 33 then drives the fixed ring seat 26 to rotate, which in turn drives the adjustment cap 30 to rotate, thereby moving the adjustment screw 29. This achieves the adjustment of the position of the reaming drill plate assembly 8 and the overall size adjustment of the rear reaming section 3.

[0040] In summary, this invention provides an oilfield reaming device. The connecting drill rod 1 has a central drilling section 5, a front-end drilling section 4, and a rear-end reaming section 3 arranged sequentially from bottom to top, with the overall dimensions of each section increasing sequentially. The central drilling section 5 and the front-end drilling section 4 perform primary drilling, while the rear-end reaming section 3 is used for both drilling and reaming. The central drilling section 5 is located at the bottom of the entire reaming device and has the smallest overall size. It is used for drilling at the very front center position, paving the way for subsequent drilling and compensating for any missing drilling at the center position of the front-end drilling section 4. The front-end drilling section 4 includes a front-end drill body 10. Multiple detachable front-end drill plate assemblies 9 are evenly arranged around the periphery of the front-end drill body 10 with its central axis as the center. These assemblies can be easily and quickly disassembled, replaced, and installed as needed, facilitating maintenance and adjustment of the drilling size. The rear reaming section 3 is equipped with a stabilizing support component 6, a reaming drill plate assembly 8, and an adjusting drive component 7. Two of the stabilizing support components 6 form a group, and their ends are connected to the reaming drill plate assembly 8 to provide stable structural support for the reaming drill plate assembly 8. At the same time, the distance between each of the reaming drill plate assemblies 8 and the central axis of the connecting drill rod 1 can be adjusted by the adjusting drive component 7, thereby realizing continuous linear adjustment of the overall size of the rear reaming section 3, achieving the purpose of linear reaming during drilling. The reaming equipment for oil development of this invention is adapted to the reinforcement needs of different formations, especially loose formations. While effectively increasing the wellbore diameter, it maintains a smooth transition of the wellbore trajectory and does not require frequent drill bit changes, achieving a linear and gradual change in the borehole diameter, ensuring smooth drilling fluid return and uniform cement slurry injection, and ultimately achieving the purpose of improving wellbore stability and ensuring drilling safety and quality.

[0041] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0042] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. An oil drilling reaming device, comprising a connecting drill pipe, characterized in that, The connecting drill rod is connected to a front drilling section and a rear enlarged hole section. The front drilling section is connected to the lower end of the connecting drill rod, and a central drilling section is connected to the bottom of the front drilling section. The front-end drilling section includes a front-end drill body, and multiple detachable front-end drill plate assemblies are evenly arranged on the periphery of the front-end drill body with its central axis as the center. The rear end reaming section is provided with multiple stabilizing support components. Two of the stabilizing support components are grouped together and their ends are connected to reaming drill plate components. The multiple reaming drill plate components are evenly distributed around the central axis of the connecting drill rod. An adjustment drive component is provided in the middle of the rear end reaming section. The adjustment drive component is used to adjust the distance between each reaming drill plate component and the central axis of the connecting drill rod.

2. The oil drilling reaming equipment as described in claim 1, characterized in that, The front-end drill body is provided with a first threaded joint at the top and a second threaded joint at the bottom.

3. The oil drilling reaming equipment as described in claim 2, characterized in that, The central drilling section includes a central drill body, on which multiple inclined drill plates are provided on the side and a threaded connector is provided on the top.

4. The oil drilling reaming equipment as described in claim 1, characterized in that, The front-end drill plate assembly includes a first drill plate, on the outer side of which a plurality of first drill bits are disposed; the front-end drill body is provided with a plurality of stabilizing slots, and the inner side of the first drill plate is provided with a stabilizing insert plate adapted to the stabilizing slots.

5. The oil drilling reaming equipment as described in claim 4, characterized in that, The first drill plate is L-shaped in general. A fixed base is provided on the top surface of the front drill body. A locking bolt is provided at the upper end of the first drill plate, and the locking bolt is connected to the fixed base.

6. The oil drilling reaming equipment as described in claim 5, characterized in that, Limiting rods are provided on the left and right end faces of the tail end of the drill plate, and multiple limiting baffles are provided on the bottom surface of the front drill body. Multiple baffles with corresponding grooves are provided on the limiting baffles.

7. The oil drilling reaming equipment as described in claim 1, characterized in that, The rear reaming section includes a reaming main connector connected to the connecting drill rod, and the stabilizing support assembly includes a fixed support arm connected to the side of the reaming main connector, and the fixed support arm is slidably connected to a movable support arm.

8. The oil drilling reaming equipment as described in claim 7, characterized in that, The hole-reaming drill plate assembly includes a second drill plate, on which a plurality of second drill bits are uniformly arranged along its length.

9. The oil drilling reaming equipment as described in claim 7, characterized in that, The adjustment drive assembly includes an adjustment cap and an adjustment guide fixedly disposed on the side of the main borehole reaming connector. An adjustment screw is slidably connected inside the adjustment guide, and the end of the adjustment screw is connected to the borehole reaming plate assembly. One end of the adjustment cap is rotatably connected to the adjustment guide, and the other end is threadedly connected to the adjustment screw.

10. The oil drilling reaming equipment as described in claim 9, characterized in that, A fixed ring seat is connected to the fixed support arm, and an adjusting drive gear ring is rotatably mounted on the fixed ring seat. The adjusting drive gear ring meshes with the adjusting cap. An adjusting drive worm gear is rotatably mounted on the expanding main pipe, and an adjusting drive gear is fixedly connected to the adjusting drive worm gear via a shaft. The adjusting drive gear meshes with the fixed ring seat. An adjusting drive motor is also mounted on the expanding main pipe, and an adjusting drive worm is connected to the adjusting drive worm. The adjusting drive worm meshes with the adjusting drive worm wheel.

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