A cycloidal gear back-off device

Abstract

This invention belongs to the field of downhole tools for oil drilling, specifically relating to a cycloidal gear reverser. The cycloidal gear reverser has an input shaft rotatably mounted within a housing. The lower end of the input shaft is fixedly connected to the upper end of an eccentric shaft assembly. A cycloidal wheel is fitted onto the eccentric block of the eccentric shaft assembly, and the circumferentially arranged external teeth of the cycloidal wheel connect with the internal teeth arranged on the inner wall of the housing. The upper end of a pin assembly is connected to the cycloidal wheel, and the lower end of the pin assembly is fixedly connected to an output shaft, which is rotatably mounted within the housing. The cycloidal gear reverser of this invention, through the cooperation of the eccentric shaft assembly, cycloidal wheel, and pin assembly, achieves higher strength, not only improving service life but also increasing the reverse torque transmitted to the stuck fish, thereby improving the efficiency and effectiveness of fish unblocking and expanding the range of wellbore sizes that the reverser can be used in.

Description

Technical Field

[0001] This invention belongs to the field of downhole tools for oil drilling, and specifically relates to a cycloidal gear reverser. Background Technology

[0002] During drilling operations, stuck drill bits and broken drill bits often occur, which can leave drill bits or other tools downhole. These left-down drill bits or other tools are called "fish that have fallen into the well."

[0003] Fish can be retrieved by two methods: direct retrieval and retrieval after unblocking. Direct retrieval involves using specialized tools to lift the fish directly. For fish that cannot be retrieved directly, a segmented, inverted-locking method is often used (i.e., the fish needs to be unblocked, forming multiple segments). A specialized inverted-locking tool is used to connect the fish, and this tool transmits reverse torque to the fish, unblocking it. This allows for segmented retrieval. However, the inverted-locking tool requires numerous inverted-locking drill rods, which need to be manufactured separately, increasing the cost of use.

[0004] Existing technologies have also proposed planetary gear reversers to achieve segmented retrieval, but they still have the following shortcomings: First, the reverser has low unblocking efficiency; second, the reverser is not suitable for large-diameter wells.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] To address the technical problems existing in the prior art, this invention provides a cycloidal gear reverser. The cycloidal gear reverser of this invention, through the cooperation of an eccentric shaft assembly, a cycloidal wheel, and a pin assembly, achieves higher strength, not only improving service life but also increasing the reverse torque transmitted to the fish, thereby improving the efficiency and effectiveness of fish unblocking and expanding the range of well sizes that the reverser can be used in.

[0007] This invention includes the following technical solutions:

[0008] The present invention provides a cycloidal gear reverser, comprising a housing, wherein an axially fixed input shaft, an eccentric shaft assembly, a cycloidal wheel, a pin assembly and an output shaft are disposed within the housing, and an anchoring block is disposed on the outer wall of the housing;

[0009] The input shaft is rotatably disposed within the housing. The lower end of the input shaft is fixedly connected to the upper end of the eccentric shaft assembly. The cycloidal wheel is sleeved on the eccentric block of the eccentric shaft assembly. The circumferentially arranged external teeth of the cycloidal wheel are connected to the internal teeth arranged on the inner wall of the housing.

[0010] The cycloidal wheel is connected to the upper end of the pin assembly, and the lower end of the pin assembly is fixedly connected to the output shaft. The output shaft is rotatably disposed within the housing.

[0011] Furthermore, at least two eccentric blocks are provided.

[0012] Furthermore, the eccentric shaft assembly includes an eccentric shaft and eccentric blocks, with two eccentric blocks of different heights disposed at both radial ends of the eccentric shaft.

[0013] Furthermore, the pin assembly includes a connecting shaft and pins, with the axial ends of several pins connected to the axial ends of the connecting shaft. The pins are used to connect the cycloidal wheel, and the connecting shaft is used to connect the output shaft.

[0014] Furthermore, multiple pins are provided, and the multiple pins are evenly distributed.

[0015] Furthermore, the cycloidal wheel has a transmission hole at its center for connecting to the input shaft, and the cycloidal wheel also has a pin hole for connecting to a pin shaft.

[0016] Furthermore, the eccentric block is provided inside the transmission hole, and a roller is provided between the eccentric block and the transmission hole.

[0017] Furthermore, the outer wall of the housing is provided with upper and lower opposing snap-fit ​​grooves, and the upper and lower ends of the anchor block are respectively connected in the snap-fit ​​grooves; the outer wall of the housing located between the two upper and lower opposing snap-fit ​​grooves is sloping in the circumferential direction.

[0018] Furthermore, at least two sets of anchor blocks are provided; the anchor blocks of each set are evenly arranged around the circumference of the shell.

[0019] Furthermore, the housing includes a first housing, a second housing, and a third housing. The lower end of the first housing is connected to the upper end of the second housing, the lower end of the second housing is connected to the upper end of the third housing, and the inner wall of the second housing is provided with the internal teeth.

[0020] Furthermore, the outer wall of the first housing is provided with an anchoring block, and the outer wall of the third housing is provided with an anchoring block.

[0021] By adopting the above technical solution, the present invention has the following advantages:

[0022] 1. The cycloidal gear reverser of the present invention has higher strength through the cooperation of the eccentric shaft assembly, cycloidal wheel and pin assembly, which not only improves the service life, but also improves the reverse torque transmitted to the fish, thereby improving the efficiency and effectiveness of fish unblocking, and expanding the range of well sizes in which the reverser can be used.

[0023] 2. The cycloidal gear reverser of the present invention has the advantages of simple structure, easy manufacturing and low cost.

[0024] 3. Compared with hydraulic reversers, the cycloidal gear reverser of the present invention can achieve continuous reversers, which has the advantage of improving the efficiency of unblocking.

[0025] 4. The cycloidal gear reverser of the present invention can provide a reverse torque greater than the torque of the drill rod thread, and ensure that the deceleration and torque-increasing structure has sufficient strength, effectively replacing the reverse-threaded drill rod. The retrieval and unblocking operation can be completed using a conventional forward-threaded drill rod, which not only improves the on-site work efficiency, but also reduces the cost.

[0026] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0027] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of a cycloidal gear reverser in an embodiment of the present invention;

[0029] Figure 2 This is a cross-sectional view of a cycloidal gear reverser according to an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the eccentric shaft assembly in an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the pin assembly in an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the cycloidal wheel in an embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of the connection between the cycloidal wheel and the eccentric block in an embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of the structure of the shell connecting the anchor block in an embodiment of the present invention;

[0035] Figure 8 This is a schematic diagram of the initial state of the anchor block in an embodiment of the present invention;

[0036] Figure 9 This is a schematic diagram showing the state of the anchor block after it slides relative to the shell in an embodiment of the present invention;

[0037] Figure 10 This is a schematic diagram of the structure of the second housing in an embodiment of the present invention;

[0038] In the diagram, 10-shell, 11-first shell, 12-second shell, 13-third shell, 101-internal tooth;

[0039] 20 - Input axis;

[0040] 30 - Eccentric shaft assembly; 31 - Eccentric shaft; 32 - Eccentric block;

[0041] 60-Cycloidal wheel, 61-External tooth, 62-Transmission hole, 63-Pin hole;

[0042] 70 - Pin assembly, 71 - Connecting shaft, 72 - Pin;

[0043] 80 - Output shaft;

[0044] 90-Anchoring block;

[0045] 100-roller;

[0046] 110-Card slot;

[0047] 120 - First bearing;

[0048] 130 - Second bearing;

[0049] 140 - Top connector;

[0050] 150-lower connector;

[0051] 160-screw;

[0052] 170 - Pin sleeve. Detailed Implementation

[0053] The following description provides many different embodiments or examples for implementing various features of the invention. The elements and arrangements described in the specific examples below are only for concise expression of the invention and are merely examples, not intended to limit the invention.

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] The existing reverse-locking devices suffer from low unblocking efficiency and are unsuitable for large-diameter wells, mainly due to:

[0056] (1) Existing reversers are mostly used for sucker rods, and the counter torque provided is less than the thread turn torque of the fish;

[0057] (2) Under high torque, the commonly used involute gear structure has insufficient strength due to the limitation of wellbore size.

[0058] Based on this, this embodiment provides a cycloidal gear reverser, such as... Figure 1 , Figure 2 As shown, the device includes a housing 10, within which are arranged an axially fixed input shaft 20, an eccentric shaft assembly 30, a cycloidal wheel 60, a pin assembly 70, and an output shaft 80. An anchoring block 90 is provided on the outer wall of the housing 10.

[0059] Here, axial fixation should be understood as the input shaft 20, eccentric shaft assembly 30, cycloidal wheel 60, pin assembly 70 and output shaft 80 being fixed in the axial direction of the housing 10 and not having any movement in the axial direction.

[0060] The input shaft 20 is rotatably disposed inside the housing 10. The lower end of the input shaft 20 is fixedly connected to the upper end of the eccentric shaft assembly 30. The cycloidal wheel 60 is sleeved on the eccentric block 32 of the eccentric shaft assembly 30. The circumferentially arranged external teeth 61 of the cycloidal wheel 60 are connected to the internal teeth 101 arranged on the inner wall of the housing 10.

[0061] More specifically, the external teeth 61 of the cycloidal wheel 60 are engaged with the internal teeth 101 provided on the inner wall of the housing 10.

[0062] The cycloidal wheel 60 is connected to the upper end of the pin assembly 70, and the lower end of the pin assembly 70 is fixedly connected to the output shaft 80. The output shaft 80 is rotatably disposed within the housing 10.

[0063] The present invention utilizes the cooperation of the eccentric shaft assembly 30, the cycloidal wheel 60, the pin assembly 70 and the internal teeth 101 of the housing 10 to convert the forward rotation of the input shaft 20 into the reverse rotation of the output shaft 80, thereby achieving the function of releasing the fish from the trap.

[0064] The size of the reverse clamp is limited by the wellbore size. Compared to the reverse clamp with an involute gear structure used in the same wellbore, the reverse clamp provides less reverse torque, resulting in low unblocking efficiency and short service life. The reverse clamp of this embodiment, because it can provide greater reverse torque, not only improves unblocking efficiency but also extends service life.

[0065] In the axial direction of the housing 10, the input shaft 20, eccentric shaft assembly 30, cycloidal wheel 60, pin assembly 70, and output shaft 80 need to be fixed to ensure that the input shaft 20, eccentric shaft assembly 30, cycloidal wheel 60, pin assembly 70, and output shaft 80 do not move in the axial direction of the housing 10; at the same time, in the circumferential direction of the housing, the input shaft 20, eccentric shaft assembly 30, cycloidal wheel 60, pin assembly 70, and output shaft 80 all need to rotate circumferentially.

[0066] To achieve the goal of the input shaft 20, eccentric shaft assembly 30, cycloidal wheel 60, pin assembly 70, and output shaft 80 having circumferential rotation but no axial movement, a possible connection method is to provide a first limiting boss on the housing 10. Figure 2 (Not marked in the text), while the second limiting boss, which is used to cooperate with the first limiting boss, is set on the connection structure that connects the input shaft 20, the eccentric shaft assembly 30, the cycloidal wheel 60, the pin assembly 70 and the output shaft 80 into one unit.

[0067] For example, such as Figure 2 As shown, at least two first limiting bosses are required. The second limiting boss that cooperates with the first limiting boss located above can be set on the eccentric shaft assembly 30 or on the input shaft 20. The second limiting boss that cooperates with the first limiting boss located below can be set on the pin assembly 70 or on the output shaft 80.

[0068] like Figure 2 As shown, in this embodiment, the upper end of the input shaft 20 is also connected to an upper connector 140, and the lower end of the output shaft 80 is also connected to a lower connector 150. When the buckling device of this embodiment is used, the lower end needs to be connected to a buckling tool. Specifically, the output shaft 80 can be directly connected to the buckling tool, or the lower connector 150 can be connected to the buckling tool. The buckling tool is used to connect with the fish. It should be noted that the buckling tool is a conventional structure used in this field, so it will not be described in detail here.

[0069] The eccentric block 32 needs to be connected to the cycloidal wheel 60. One eccentric block 32 needs to be connected to one cycloidal wheel 60, and the number of eccentric blocks 32 is equal to the number of cycloidal wheels 60. Since torque needs to be transmitted and torque direction achieved between the eccentric blocks 32 and the cycloidal wheels 60, in order to improve the strength of the connection between the eccentric shaft assembly 30 and the cycloidal wheels 60, in some embodiments, such as... Figure 3 As shown, at least two eccentric blocks 32 are provided; correspondingly, at least two cycloidal wheels 60 are provided.

[0070] To simplify the structure and save costs, in some embodiments, two eccentric blocks 32 are provided; specifically, the eccentric shaft assembly 30 with two eccentric blocks 32 can be as follows: Figure 3As shown, the eccentric shaft assembly 30 includes an eccentric shaft 31 and eccentric blocks 32. Two eccentric blocks 32 with different heights are provided at both ends of the radial direction of the eccentric shaft 31. The eccentric blocks 32 arranged in this way have the advantage of reducing radial runout. Alternatively, the two eccentric blocks 32 may not be provided at both ends of the radial direction.

[0071] It should be noted that the two radial ends should be understood as: Figure 3 In the middle, the two ends of any one diameter of the eccentric shaft 31.

[0072] It should be noted that the difference in height should be understood as: Figure 2 In the middle, the lowest point of the upper eccentric block 32 must be at least higher than the highest point of the lower eccentric block 32.

[0073] In some embodiments, in a structure with at least two cycloidal wheels 60, a spacer (not shown in the figure) is also provided between two adjacent cycloidal wheels 60. Specifically, the spacer is sleeved on the eccentric shaft 31 of the eccentric shaft assembly 30. The spacer separates the cycloidal wheel 60 located above it and the cycloidal wheel 60 located below it, which can prevent wear between two adjacent cycloidal wheels 60.

[0074] Figure 3 In this context, the eccentric shaft 31 may include a shaft with a larger diameter and a shaft with a smaller diameter; the shaft with the larger diameter is used to connect to the input shaft 20, and the shaft with the smaller diameter is used to set the eccentric block 32. Figure 3 The image shows a section of shaft with a smaller diameter equipped with two eccentric blocks 32.

[0075] More in detail, such as Figure 3 As shown, the eccentric shaft 31 includes a first eccentric shaft, a second eccentric shaft, and a third eccentric shaft connected in sequence. The diameter of the first eccentric shaft is smaller than the diameter of the second eccentric shaft, and the diameter of the second eccentric shaft is smaller than the diameter of the third eccentric shaft. Two eccentric blocks are connected to the first eccentric shaft.

[0076] The input shaft 20, eccentric shaft assembly 30, cycloidal wheel 60, pin assembly 70, and output shaft 80 are connected as a single unit. Besides being fixed by the cooperation of the first and second limiting bosses, they can also be further connected to the housing 10 via bearings; more specifically, as... Figure 2 As shown, the circumferential section of the eccentric shaft assembly 30 with a larger diameter is connected to the housing 10 via a first bearing 120.

[0077] Since the smaller diameter section of the eccentric shaft assembly 30 can also be connected to the pin assembly 70, it has the advantage of increasing the stability of the structure in which the input shaft 20, eccentric shaft assembly 30, cycloidal wheel 60, pin assembly 70 and output shaft 80 are connected as a whole; the specific connection method is that the end of the smaller diameter shaft is connected to the pin assembly 70 through the second bearing 130.

[0078] In some embodiments, such as Figure 4 As shown, the pin assembly 70 includes a connecting shaft 71 and pins 72. The axial ends of several pins 72 are connected to the axial ends of the connecting shaft 71. The pins 72 are used to connect the cycloidal wheel 60, and the connecting shaft 71 is used to connect the output shaft 80.

[0079] In order to enhance the shear resistance of the pin 72, further improve the connection strength between the pin assembly 70 and the cycloidal wheel 60, increase the transmitted torque, and achieve the advantage of improving the unblocking efficiency, in some embodiments, multiple pins 72 may be provided, and the multiple pins 72 are evenly arranged.

[0080] In some embodiments, such as Figure 5 As shown, the cycloidal wheel 60 has a transmission hole 62 at its center for connecting to the eccentric shaft assembly 30, and the cycloidal wheel 60 also has a pin hole 63 for connecting to the pin 72. The position of the pin hole 63 on the cycloidal wheel 60 is not limited, as long as the pin hole 63 corresponds to the pin 72 and the eccentricity, the purpose of this invention can be achieved.

[0081] It should be noted that there are no restrictions on the specific positions of the transmission hole 62 and the pin hole 63. Any position that can achieve the function of the present invention should be within the protection scope of the present invention.

[0082] Figure 5 In this configuration, the specific positions of the transmission hole 62 and the pin hole 63 can be such that the transmission hole 62 is provided at the center of the cycloidal wheel 60, and the pin hole 63 is axially arranged around the cycloidal wheel 60.

[0083] For example, the specific structure of the transmission hole 62 of the cycloidal wheel 60 can be that the diameter of the transmission hole 62 is equal to the diameter of the eccentric shaft 31 (specifically, it can be the shaft with the smaller diameter mentioned above) connecting the eccentric block 32 plus twice the eccentricity of the eccentric block 32.

[0084] For example, the specific structure of the pin hole 63 of the cycloidal wheel 60 can be that the diameter of the pin hole 63 is equal to the pin 72 plus twice the eccentricity of the eccentric block 32.

[0085] For example, the specific structure of the external tooth 61 of the cycloidal wheel 60 can be that the tooth profile of the cycloidal wheel and the cycloidal gear housing are both cycloidal or equidistant curves; it can be understood that the tooth profile of the external tooth of the cycloidal tooth 61 is a curve formed by the cycloidal, and this curve is translated outward or inward by a certain distance.

[0086] In some embodiments, the eccentric block 32 is disposed within the transmission hole 62; the eccentric block 32 may be directly disposed within the transmission hole 62, in which case the outer diameter of the eccentric block 32 is adapted to the inner diameter of the transmission hole 62.

[0087] In some embodiments, to reduce friction between the transmission hole 62 and the eccentric block 32 and improve service life, such as Figure 6 As shown, a roller 100 is provided between the eccentric block 32 and the transmission hole 62.

[0088] In some embodiments, to improve the stress on the pin 72 of the pin assembly 70 and prevent the pin 72 from breaking, such as... Figure 2 As shown, a pin sleeve 170 is also provided; after the end of the pin 72 passes through the pin holes 63 of several cycloidal wheels 60, the pin sleeve 170 is connected to the end of the pin 72. In order to connect with the pin 72, the pin sleeve 170 is also provided with holes for connecting the pin 72.

[0089] In more detail, Figure 4 The diagram shows a pin assembly 70 with a plurality of pins 72. The connecting shaft 71 includes a first connecting shaft and a second connecting shaft connected to each other. The diameter of the first connecting shaft is smaller than the diameter of the second connecting shaft. The second connecting shaft has a connecting hole for connecting the eccentric shaft 31 of the eccentric shaft assembly 30. The plurality of pins 72 are evenly arranged around the connecting hole.

[0090] In order to convert the forward rotation of the input shaft 20 into the reverse rotation of the output shaft 80, the internal teeth 101 of the housing 10 must cooperate to achieve this function. The premise is that the housing 10 needs to be fixed. Therefore, before the buckle releases the buckle in this embodiment, the housing 10 needs to be fixed to the well wall. In this embodiment, the housing 10 is fixed by setting the anchor block 90.

[0091] In some embodiments, such as Figure 2 , Figure 7 As shown, the outer wall of the housing 10 is provided with vertically opposite snap-fit ​​grooves 110, and the upper and lower ends of the anchor block 90 are respectively connected to the vertically opposite snap-fit ​​grooves 110; Figure 8 , Figure 9 As shown, the outer wall of the housing 10 is sloped in the circumferential direction between two oppositely arranged snap-fit ​​grooves 110.

[0092] It should be understood that connecting one anchor block 90 requires a set of vertically opposite snap-fit ​​grooves 110, and connecting multiple anchor blocks 90 requires multiple sets of vertically opposite snap-fit ​​grooves; and multiple slope shapes are provided accordingly.

[0093] Figure 8 , Figure 9 In the middle, three anchor blocks 90 form a group, and a corresponding group of anchor blocks 90 needs to be connected. Three sets of vertically opposite snap-fit ​​grooves are provided on the housing 10; correspondingly, Figure 2 In the middle, a set of anchor blocks 90 are provided at both the upper and lower ends of the housing 10, which enables the housing 10 to have a better fixing effect.

[0094] Based on the structure of the housing 10 and the anchor block 90, after the reverse clamp is lowered into the well and connected to the fish in this embodiment, the housing 10 is rotated so that the housing 10 and the anchor block 90 have relative movement. The anchor block 90 slides on the outer wall of the housing 10, thereby anchoring itself to the well wall.

[0095] To further improve the anchoring effect, thereby increasing the torque and achieving the advantage of improved release efficiency. In some embodiments, such as Figure 2 , Figure 8 As shown, at least two sets of anchor blocks 90 are provided; the anchor blocks 90 in each set are evenly arranged around the circumference of the housing 10.

[0096] Figure 8 The diagram shows the connection between the anchor block 90 and the housing 10 when the anchor block 90 is anchored to the well wall; this is the position of the anchor block 90 before it slides relative to the housing 10. Figure 9 The image shows the position of the anchor block 90 after it has slid relative to the housing 10.

[0097] Figure 8 , Figure 9 In the diagram, three anchor blocks 90 are grouped together. Of course, the illustration is only illustrative. Groups of four, five, or other numbers of anchor blocks 90 should also be within the scope of protection of this invention. Figure 8 , Figure 9 The diagram also shows a screw 160 connected to the housing 10, which can limit the relative rotation of the anchor block 90; of course, the relative rotation of the anchor block 90 does not necessarily require the screw 160 to limit it, so the screw 160 may not be provided on the housing 10.

[0098] In order to reduce the assembly difficulty of the buckle in this embodiment and reduce the production cost, in some embodiments, the housing 10 includes a first housing 11, a second housing 12 and a third housing 13, the lower end of the first housing 11 is connected to the upper end of the second housing 12, and the lower end of the second housing 12 is connected to the upper end of the third housing 13.

[0099] Figure 10 The inner wall of the second housing 12 is provided with the inner teeth 101. Providing the inner teeth 101 on the second housing 12 makes it easier to assemble the buckle of this embodiment.

[0100] like Figure 2 As shown, the inner walls of the first housing 11 and the second housing 12 are both provided with a first limiting boss.

[0101] Figure 2 In this configuration, the connection between the first housing 11 and the second housing 12, as well as the connection between the second housing 12 and the third housing 13, can be achieved through male and female connectors. Specifically, the first housing 11 may have a male connector with external threads at its lower end, the second housing 12 may have female connectors with internal threads at both its upper and lower ends, and the third housing 13 may have a male connector with external threads at its upper end.

[0102] An anchoring block 90 is provided on the outer wall of the first housing 11, and an anchoring block 90 is provided on the outer wall of the third housing 13. There may be multiple anchoring blocks 90 provided on the outer wall of the first housing 11, and multiple anchoring blocks may be provided on the outer wall of the third housing 13.

[0103] The working process and principle of this invention:

[0104] In this embodiment, the upper end of the reverse threader is connected to a conventional drilling tool, and the lower end is connected to a special tool, which is then lowered into the well. It should be noted that the special tool can be an expansion threading tool.

[0105] When reversed, the reverser is rotated clockwise. At this time, the reverser rotates in the forward direction. Under the action of gravity, the anchoring block 90 contacts the well wall of the wellbore when the reverser rotates and slides counterclockwise relative to the shell 10 along the sloped slide under the action of friction, thereby increasing the outer diameter of the shell 10 and thus achieving the purpose of anchoring.

[0106] After anchoring, the housing 10 is fixed to the well wall, driving the input shaft 20 to rotate clockwise, which in turn drives the eccentric shaft assembly 30 to rotate clockwise. The two cycloidal wheels 60 form a small tooth difference gear transmission by meshing the external teeth 61 with the internal teeth 101 of the housing 10. The clockwise rotation of the eccentric shaft assembly 30 drives the two cycloidal wheels 60 to start rotating counterclockwise at a certain reduction ratio. The two cycloidal wheels 60 drive the pin 72 through the pin hole 63, thereby driving the pin assembly 70 to rotate counterclockwise. The pin assembly 70 drives the output shaft 80 connected at the bottom and the expansion buckle tool connected at the bottom to rotate counterclockwise, thus realizing the counterclockwise rotation of the fish and releasing the fish from the jam.

[0107] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0108] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of multiple components or the interaction between multiple components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0109] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0110] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A gerotor back-dropper, characterized by, Includes a housing (10), within which are arranged an axially fixed input shaft (20), an eccentric shaft assembly (30), a cycloidal wheel (60), a pin assembly (70), and an output shaft (80), and an anchor block (90) is provided on the outer wall of the housing (10); The input shaft (20) is rotatably disposed inside the housing (10). The lower end of the input shaft (20) is fixedly connected to the upper end of the eccentric shaft assembly (30). The cycloidal wheel (60) is sleeved on the eccentric block (32) of the eccentric shaft assembly (30). The circumferentially arranged external teeth (61) of the cycloidal wheel (60) are connected to the internal teeth (101) arranged on the inner wall of the housing (10). The cycloidal wheel (60) is connected to the upper end of the pin assembly (70), and the lower end of the pin assembly (70) is fixedly connected to the output shaft (80). The output shaft (80) is rotatably disposed within the housing (10).

2. The cycloidal gear reverser according to claim 1, characterized in that, At least two eccentric blocks (32) are provided.

3. A cycloidal gear reverser according to claim 2, characterized in that, The eccentric shaft assembly (30) includes an eccentric shaft (31) and eccentric blocks (32), with two eccentric blocks (32) of different heights arranged at both radial ends of the eccentric shaft (31).

4. A cycloidal gear reverser according to claim 1, characterized in that, The pin assembly (70) includes a connecting shaft (71) and pins (72), with the axial ends of several pins (72) connected to the axial ends of the connecting shaft (71). The pins (72) are used to connect the cycloidal wheel (60), and the connecting shaft (71) is used to connect the output shaft (80).

5. A cycloidal gear reverser according to claim 4, characterized in that, Multiple pins (72) are provided, and the multiple pins (72) are evenly distributed.

6. A cycloidal gear reverser according to claim 4, characterized in that, The cycloidal wheel (60) has a transmission hole (62) at its center for connecting the input shaft (20), and the cycloidal wheel (60) has a pin hole (63) for connecting with the pin (72).

7. A cycloidal gear reverser according to claim 6, characterized in that, The eccentric block (32) is provided inside the transmission hole (62), and a roller (100) is provided between the eccentric block (32) and the transmission hole (62).

8. A cycloidal gear reverser according to claim 1, characterized in that, The outer wall of the housing (10) is provided with upper and lower opposing snap-fit ​​grooves (110), and the upper and lower ends of the anchor block (90) are respectively connected in the snap-fit ​​grooves (110); the outer wall of the housing (10) located between the two upper and lower opposing snap-fit ​​grooves (110) is sloping in the circumferential direction.

9. A rotor for a gerotor pump according to claim 8, wherein At least two sets of anchor blocks (90) are provided; the anchor blocks (90) of each set are evenly arranged around the circumference of the shell (10).

10. A cycloidal gear reverser according to claim 1, characterized in that, The housing (10) includes a first housing (11), a second housing (12) and a third housing (13). The lower end of the first housing (11) is connected to the upper end of the second housing (12), and the lower end of the second housing (12) is connected to the upper end of the third housing (13). The inner wall of the second housing (12) is provided with the internal teeth (101).

11. A rotor for a gerotor according to claim 10, wherein An anchor block (90) is provided on the outer wall of the first housing (11), and an anchor block (90) is provided on the outer wall of the third housing (13).

Images