A counterweight adjustment mechanism and a pumping unit

Abstract

The present invention relates to the technical field of pumping units, and discloses a counterweight adjustment mechanism and a pumping unit. The counterweight adjustment mechanism includes: two counterweight blocks, which are arranged on opposite sides of the crank and can move radially along the crank; the crank, which can rotate around its end; an adjustment assembly, which is connected to the two counterweight blocks and drives the two counterweight blocks to move alternately and intermittently; a drive assembly, which has a first state and a second state and can switch between the first state and the second state; when the drive assembly is in the first state, as the crank rotates, the adjustment assembly cooperates with the drive assembly to drive the two counterweight blocks to move alternately and intermittently. The pumping unit includes the counterweight adjustment mechanism. Through the above solution, the present invention can solve the technical problem that the balance blocks in the related art cannot match the dynamic requirements of well parameters.

Description

Technical Field

[0001] The present invention relates to the technical field of pumping units, and particularly to a counterweight adjustment mechanism and a pumping unit. Background Art

[0002] A pumping unit is a key device used to extract crude oil from oil wells in oil exploitation, and is commonly found in onshore oil fields and offshore platforms. Its core function is to transmit the ground power to the downhole pump, overcome the oil reservoir pressure, and lift the crude oil to the ground.

[0003] In order to offset the inertial force and torque fluctuation generated by the force difference during the up and down strokes when the pumping unit operates, the existing pumping units usually set balance weights. However, in the related art, the balance weights only adapt to a single working condition and cannot match the dynamic requirements of the oil well parameters. Summary of the Invention

[0004] The present invention discloses a counterweight adjustment mechanism and a pumping unit to solve the technical problem that the balance weights in the related art cannot match the dynamic requirements of the oil well parameters.

[0005] To solve the above problems, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention discloses a counterweight adjustment mechanism applied to a pumping unit, including:

[0007] Two counterweight blocks are arranged on opposite sides of the crank and can move radially along the crank;

[0008] The crank can rotate around its end;

[0009] An adjustment assembly is connected to the two counterweight blocks to drive the two counterweight blocks to move alternately and intermittently;

[0010] A drive assembly has a first state and a second state and can switch between the first state and the second state; when the drive assembly is in the first state, as the crank rotates, the adjustment assembly cooperates with the drive assembly to drive the two counterweight blocks to move alternately and intermittently.

[0011] In some solutions, the adjustment assembly includes a rotating member and two adjusting members;

[0012] The two adjusting members are respectively arranged inside the crank and are respectively connected to the counterweight blocks to drive the counterweight blocks to move radially along the crank;

[0013] The rotating member is rotatably arranged inside the crank, and as the rotating member rotates, it intermittently contacts the two adjusting members, thereby driving the two counterweight blocks to move alternately and intermittently.

[0014] In some solutions, the adjusting member includes a first worm gear, a first worm, and a first lead screw;

[0015] The first lead screw is cooperatively connected with the counterweight and is connected to the center of the first worm gear; the first worm is meshed with the first worm gear;

[0016] As the rotating member rotates, the rotating member alternately contacts the two first worms and drives the first worms to rotate.

[0017] In some solutions, the rotating member includes a rotating part and two gears;

[0018] The gears are connected to the first worms, the rotating part has external teeth, and during the rotation of the rotating part, the external teeth are respectively meshed with the two gears;

[0019] Wherein, when the driving assembly is in the first state, as the crank rotates, the rotating part intermittently contacts the driving assembly to drive the rotating part to rotate intermittently.

[0020] In some solutions, the driving assembly includes a driving member and an abutting part, and the driving member is used to drive the abutting part to move so as to switch between the first state and the second state;

[0021] Wherein, a plurality of protrusions are arranged on one side of the rotating part along its circumferential direction; when the driving assembly is in the first state, as the crank rotates, the plurality of protrusions respectively contact the abutting part to drive the rotating part to rotate intermittently.

[0022] In some solutions, the driving member includes a second worm gear, a second worm, a second lead screw and a driving part;

[0023] The second lead screw is cooperatively connected with the abutting part and is connected to the center of the second worm gear; the second worm is meshed with the second worm gear, and the output shaft of the driving part is connected to the second worm and is used to drive the second worm to rotate.

[0024] In some solutions, a column is arranged along the radial direction inside the crank, a plurality of clamping parts are respectively arranged along the radial direction on the opposite sides of the column, and the counterweight is provided with a clamping part cooperating with the clamping parts;

[0025] Wherein, the clamping part has a notch penetrating along the radial direction of the crank, and as the counterweight moves, the clamping part passes through the notch to be clamped into different clamping parts.

[0026] In some solutions, the clamping part includes an intermediate part and two moving parts, and the two moving parts are arranged on the opposite sides of the intermediate part through elastic parts and can move towards or away from each other.

[0027] In some solutions, the moving part has a first bending structure, and the clamping part has a second bending structure; when the clamping part abuts against the clamping part, the first bending structure and the second bending structure abut and limit the position;

[0028] And / or, inclined guiding surfaces are respectively arranged at the end parts of the two moving parts.

[0029] In a second aspect, the present invention discloses a pumping unit, which includes the counterweight adjustment mechanism in the first aspect.

[0030] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0031] For the counterweight adjustment mechanism of the present invention, when the position of the counterweight block needs to be adjusted, the driving assembly switches to the first state. As the crank rotates, the cooperation between the driving assembly and the adjustment assembly drives the two counterweight blocks to move alternately and intermittently, and the unilateral counterweight is adjusted separately in different time periods, which can avoid the instantaneous mechanical impact load and resonance risk caused by the synchronous movement of the two counterweight blocks during the rotation of the crank. Moreover, moving the two counterweight blocks intermittently allows the pumping unit to perform dynamic error compensation and cross-verification through sensor feedback between two operations (such as evaluating the balance effect after adjusting one counterweight block and then correcting the other counterweight block), reducing the overshoot and oscillation of the adjustment trajectory, achieving a more stable progressive dynamic balance on the premise of ensuring the adjustment accuracy, and further matching the dynamic requirements of the oil well parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0033] Figure 1 is a schematic structural diagram of a pumping unit disclosed in some embodiments of the present invention;

[0034] Figure 2 is a schematic structural diagram of the counterweight adjustment mechanism disclosed in some embodiments of the present invention;

[0035] Figure 3 is a schematic structural diagram of a counterweight block disclosed in some embodiments of the present invention;

[0036] Figure 4 is Figure 3 an enlarged view of part A in

[0037] Figure 5 is an axonometric view of a crank disclosed in some embodiments of the present invention;

[0038] Figure 6 is Figure 5 an enlarged view of part B in

[0039] Figure 7 is a schematic connection diagram of the adjustment assembly and the counterweight block disclosed in some embodiments of the present invention;

[0040] Figure 8 is a partial axonometric view of an adjustment assembly disclosed in some embodiments of the present invention;

[0041] Figure 9 is a schematic structural diagram of a drive assembly disclosed in some embodiments of the present invention.

[0042] In the figure:

[0043] 100 - Counterweight adjustment mechanism, 110 - Counterweight block, 111 - Clamping part, 112 - Moving part, 113 - Intermediate part, 114 - First bending structure, 115 - Guide surface, 120 - Crank, 121 - Column, 122 - Clamping part, 123 - Second bending structure, 124 - Notch, 130 - Adjustment assembly, 131 - First lead screw, 132 - First worm, 133 - First worm gear, 134 - Gear, 135 - Rotating part, 136 - External teeth, 137 - Protrusion, 140 - Drive assembly, 141 - Abutting part, 142 - Second lead screw, 143 - Second worm gear, 144 - Driving part, 145 - Second worm;

[0044] 200 - Pumping unit. Detailed implementation manners

[0045] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other implementation manners obtained by those of ordinary skill in the art without creative efforts shall fall within the scope protected by the present invention.

[0046] The terms "first", "second", etc. in the specification and claims of the present invention are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data may be interchanged under appropriate circumstances so that the embodiments of the present invention can be implemented in an order different from those illustrated or described herein, and the objects distinguished by "first", "second", etc. are usually of the same category, and do not limit the number of objects. For example, the first object may be one or multiple.

[0047] The inventor found in use that in order to offset the inertial force and torque fluctuation generated by the difference in force during the up and down strokes when the pumping unit operates, the existing pumping units usually set balance weights. However, in the related art, the balance weights can only be adjusted in the non - working state, only adapt to a single working condition, and cannot match the dynamic requirements of the oil well parameters.

[0048] The following combines the attached Figures 1 to 9 , and through specific embodiments and their application scenarios, a counterweight adjustment mechanism 100 and a pumping unit 200 provided by the present invention are described in detail.

[0049] Some embodiments of the present invention provide a counterweight adjustment mechanism 100, which is applied to a pumping unit and includes a crank 120, an adjustment assembly 130, a drive assembly 140, and two counterweights 110.

[0050] As Figure 2 shown, the two counterweights 110 are disposed on opposite sides of the crank 120. The design of symmetrically arranging the two counterweights 110 on both sides of the crank 120 can offset the rotational centrifugal force through symmetric counterweights, significantly improving the dynamic balance of the crank 120.

[0051] As Figure 2 shown, the two counterweights 110 can move radially along the crank 120. The radial movement function enables the counterweights 110 to adjust the position of the counterweights 110 on the crank 120 according to the well parameters, so as to play a role in adjusting the length of the force arm, balancing the dynamic load, offsetting the asymmetric inertial forces of external loads such as the sucker rod and the liquid column, and reducing the torque fluctuation and vibration during the rotation of the crank 120.

[0052] As Figure 1 shown, the crank 120 can rotate around its end. In this embodiment, the rotating end of the crank 120 is connected to the speed reducer of the pumping unit, and the crank 120 is driven to rotate by the power of the pumping unit motor. Moreover, the crank 120 is also connected to the walking beam of the pumping unit through a rod, so as to drive the walking beam to rotate through the rotation of the crank 120, for the purpose of oil production.

[0053] As Figure 7 shown, the adjustment assembly 130 is connected to the two counterweights 110 and drives the two counterweights 110 to move alternately and intermittently. The adjustment assembly 130 drives the two counterweights 110 to move alternately and intermittently, and adjusts the unilateral counterweight separately in different time periods, which can avoid the instantaneous mechanical impact load and resonance risk caused by the synchronous movement of the two counterweights 110 during the rotation of the crank 120. Moreover, moving the two counterweights 110 intermittently allows the pumping unit to perform dynamic error compensation and cross-verification through sensor feedback between two actions (such as evaluating the balance effect after adjusting one counterweight 110 and then correcting the other counterweight 110), reducing the overshoot and oscillation of the adjustment trajectory, and achieving a more stable progressive dynamic balance on the premise of ensuring the adjustment accuracy.

[0054] As Figure 9As shown, the drive assembly 140 has a first state and a second state, and can switch between the first state and the second state; when the drive assembly 140 is in the first state, as the crank 120 rotates, the adjustment assembly 130 cooperates with the drive assembly 140 to drive the two counterweights 110 to move alternately and intermittently. When the drive assembly 140 is in the first state, the kinetic energy of the rotation of the crank 120 is used to trigger the adjustment assembly 130 at different times to drive the counterweights 110 on both sides to move alternately, which not only avoids the sudden increase in power and mechanical interference during synchronous adjustment, but also matches the angular velocity of the crank 120 through intermittent actions, so that the counterweight adjustment naturally fits the change of the system inertia, thus achieving precise balance without an additional independent power source.

[0055] Correspondingly, when the drive assembly 140 is in the second state, the crank 120 will not contact the adjustment assembly 130 during rotation, and thus the movement of the counterweight 110 cannot be adjusted.

[0056] Preferably in this embodiment, the drive assembly 140 is located at the lower stroke position of the crank 120. At the lower stroke, the crank 120 is at a low position, and the drive assembly 140 can be directly fixed to the ground foundation without additional high-altitude brackets or suspension structures, reducing the installation complexity. At the lower stroke stage, the gravitational potential energy of the crank 120 and the sucker rod system reaches the peak, and the drive assembly 140 utilizes this gravitational potential energy to be converted into the kinetic energy required to adjust the counterweight 110, reducing the load on the motor that drives the rotation of the crank 120.

[0057] As Figure 7 shown, the adjustment mechanism includes a rotating member and two adjustment members. The two adjustment members are respectively arranged inside the crank 120 and are respectively connected to the counterweights 110 to drive the counterweights 110 to move radially along the crank 120. The two adjustment members respectively drive the two counterweights 110 to move. Compared with the method of using one adjustment member to control the movement of the two counterweights 110, the load on the adjustment member is smaller. Moreover, the two adjustment members can achieve the purpose of driving the two counterweights 110 to move alternately.

[0058] As Figure 7 shown, the rotating member is rotatably arranged inside the crank 120, and as the rotating member rotates, it intermittently contacts the two adjustment members, and thus drives the two counterweights 110 to move alternately and intermittently. The rotating member is the driving core, and by rotating and establishing an alternating cooperation between the two adjustment members and the drive assembly 140, the continuous rotation of the crank 120 is converted into the drive for the counterweights 110 on both sides.

[0059] As Figure 7 and Figure 8As shown in the figure, the adjusting member includes a first worm gear 133, a first worm 132, and a first lead screw 131. The first lead screw 131 is cooperatively connected to the counterweight 110 and is connected to the center of the first worm gear 133. The first worm 132 meshes with the first worm gear 133. As the rotating member rotates, the rotating member alternately contacts the two first worms 132 and drives the first worms 132 to rotate. When the worm rotates, due to the meshing of the worm and the worm gear, the worm gear and the lead screw are driven to rotate, and the lead screw is cooperatively connected to the counterweight 110, thereby driving the counterweight 110 to move. Moreover, by utilizing the self-locking characteristics of the worm gear and the worm, the unexpected displacement of the counterweight 110 caused by vibration or inertia can be eliminated.

[0060] As Figure 7 and Figure 8 shown in the figure, the rotating member includes a rotating part 135 and two gears 134. The gears 134 are connected to the first worms 132. The rotating part 135 has external teeth 136. During the rotation of the rotating part 135, the external teeth 136 respectively mesh with the two gears 134. Among them, when the driving assembly 140 is in the first state, as the crank 120 moves, the rotating part 135 intermittently contacts the driving assembly 140 to drive the rotating part 135 to rotate intermittently. When the driving assembly 140 is in the first state, as the crank 120 rotates, the rotating part 135 will intermittently contact the driving assembly 140, thereby causing the rotating part 135 to rotate intermittently. During the rotation process, the external teeth 136 of the rotating part 135 intermittently contact the two gears 134, and the gravitational potential energy generated during the rotation of the crank 120 is transmitted to the worm through the gears 134, so as to achieve the purpose of driving the two counterweights 110 to move alternately and intermittently.

[0061] As Figure 9 shown in the figure, the driving assembly 140 includes a driving member and an abutting part 141. The driving member is used to drive the abutting part 141 to move to switch between the first state and the second state. When the driving assembly 140 is in the first state, as the crank 120 rotates, the rotating part 135 intermittently contacts the abutting part 141, thereby driving the rotating part 135 to rotate intermittently, and finally achieving the purpose of driving the two counterweights 110 to move alternately and intermittently. When the driving assembly 140 is in the second state, the rotation of the crank 120 will not cause the rotating part 135 to contact the abutting part 141, so the rotating part 135 cannot be driven to rotate. The driving member drives the movement of the abutting part 141 to adjust the height of the abutting part 141, so that the abutting part 141 cooperates with the rotating part 135, or the rotating part 135 will not contact the rotating part 135.

[0062] As Figure 8As shown in the figure, a plurality of protrusions 137 are provided along the circumferential direction on one side of the rotating part 135; when the driving assembly 140 is in the first state, as the crank 120 rotates, the plurality of protrusions 137 respectively contact the abutting part 141 to drive the rotating part 135 to rotate intermittently. The periodic impact between the circumferentially arranged plurality of protrusions 137 and the abutting part 141 triggers a pure mechanical time-sharing drive. During the first rotation of the crank 120, one of the protrusions 137 impacts and triggers the abutting part 141 to drive one of the counterweights 110 to move; during the Nth rotation of the crank 120, one of the protrusions 137 impacts and triggers the abutting part 141 to drive the other counterweight 110 to move. By repeating the above steps, the two counterweights 110 are alternately and intermittently moved.

[0063] Wherein, N can be 2, 3, 4, 5 or more, and this embodiment does not limit this.

[0064] Preferably in this embodiment, the number of the protrusions 137 is four. By reasonably designing the position of the abutting part 141, the rotation angle of the rotating part 135 is 90 degrees after each protrusion 137 impacts the abutting part 141.

[0065] As Figure 9 shown, the driving member includes a second worm gear 143, a second worm 145, a second lead screw 142 and a driving part 144. The second lead screw 142 is cooperatively connected with the abutting part 141 and is connected to the center of the second worm gear 143; the second worm 145 meshes with the second worm gear 143, and the output shaft of the driving part 144 is connected to the second worm 145 for driving the second worm 145 to rotate. The motor drives the second worm 145 to rotate. Since the second worm 145 meshes with the second worm gear 143, the second worm gear 143 drives the second lead screw 142 to rotate, driving the abutting part 141 to move, thereby enabling the driving assembly 140 to switch between the first state and the second state.

[0066] Moreover, by utilizing the self-locking characteristics of the second worm 145 and the second worm gear 143, the situation where the impact of the protrusion 137 on the abutting part 141 causes the displacement of the abutting part 141 can be avoided.

[0067] Preferably in this embodiment, the driving part 144 is a motor.

[0068] In this embodiment, the contact surface between the abutting part 141 and the protrusion 137 is an inclined surface. The inclined surface design significantly reduces the collision impact force through the principle of vector decomposition of force: when the protrusion 137 contacts the inclined surface of the abutting part 141, the collision force can be decomposed into a normal force perpendicular to the inclined surface and a tangential force parallel to the inclined surface, effectively reducing the instantaneous stress on the contact surface. At the same time, the tangential component force is converted into the axial thrust for driving the lead screw through the self-locking of the worm.

[0069] AsFigure 5 and Figure 6 As shown in Figure 6 , a column 121 is provided along the radial direction inside the crank 120. A plurality of clamping portions 122 are respectively provided on the opposite sides of the column 121 along its radial direction. The counterweight 110 is provided with a clamping member 111 that cooperates with the clamping portion 122. Through the cooperation of the clamping portion 122 and the clamping member 111, during the rotation of the crank 120, the counterweight 110 transmits the centrifugal force to the column 121 through the clamping portion 122, which can effectively inhibit the transverse shear overload of the counterweight 110 on the first lead screw 131 caused by the centrifugal force generated by the rotation of the crank 120, and avoid the thread stress concentration of the first lead screw 131 caused by bearing the transverse component force.

[0070] As Figure 6 shown in Figure 6 , the clamping portion 122 has a notch 124 that penetrates along the radial direction of the crank 120. As the counterweight 110 moves, the clamping member 111 is inserted into different clamping portions 122 through the notch 124. The notch 124 allows the clamping member 111 to quickly align with different clamping portions 122 as the counterweight 110 moves, so that the movement of the counterweight 110 along the radial direction of the crank 120 is not restricted, and the clamping member 111 can be inserted into different clamping portions 122 as the counterweight 110 moves.

[0071] As Figure 3 and Figure 4 shown in Figure 3 and Figure 4 , the clamping member 111 includes an intermediate portion 113 and two moving portions 112. The two moving portions 112 are provided on the opposite sides of the intermediate portion 113 through elastic members and can move towards or away from each other. During the process of the clamping member 111 passing through the notch 124, the two moving portions 112 are squeezed and move towards the intermediate portion 113. During this process, the elastic members store elastic potential energy. When the clamping member 111 passes through the notch 124, the elastic potential energy of the elastic members is released, driving the two moving portions 112 to move away from the intermediate portion 113 and move away from each other, so that the clamping member 111 abuts against the clamping portion 122.

[0072] Preferably in this embodiment, the elastic members are a plurality of springs. Specifically, the number of elastic members can be 1, 2, 3, 4 or more, and this embodiment does not limit this.

[0073] In this embodiment, wedge-shaped surfaces are respectively provided on the end faces of the two moving portions 112 away from the intermediate portion 113, so as to facilitate the two moving portions 112 to move towards the intermediate portion 113 during the process of the clamping member 111 passing through the notch 124.

[0074] As Figure 4 and Figure 6As shown, the moving part 112 has a first bending structure 114, and the clamping part 122 has a second bending structure 123; when the clamping member 111 abuts against the clamping part 122, the first bending structure 114 and the second bending structure 123 abut and limit each other. Through the two-way bending and interlocking design, when the clamping member 111 cooperates with the clamping part 122, the rigid surface contact of the first bending structure 114 and the second bending structure 123 directly transmits the centrifugal force generated by the rotation of the crank 120 to the column 121, thereby reducing the shear force of the first lead screw 131 and increasing the service life of the first lead screw 131.

[0075] As Figure 4 shown, inclined guiding surfaces 115 are respectively provided at the ends of the two moving parts 112. By arranging the inclined guiding surfaces 115 on the moving parts 112, the guiding part decomposes the radial pressure into a force for driving the moving parts 112 to move horizontally, thereby facilitating the two moving parts 112 to move towards each other to pass through the notch 124.

[0076] Some embodiments of the present invention further provide a pumping unit, as Figure 1 shown, including a counterweight adjustment mechanism 100.

[0077] The pumping unit further includes a walking beam, a balance beam, a motor, a reducer, and a connecting rod. The rotating end of the crank 120 is connected to the speed reducer of the pumping unit, and the crank 120 is driven to rotate by the power of the pumping unit motor. And, the crank 120 is also connected to the balance beam of the pumping unit through a rod, and the walking beam is arranged at the end of the balance beam. The balance beam is driven to rotate periodically by the rotation of the crank 120 to achieve the purpose of oil production.

[0078] In addition, it should be noted that the scope of the methods and devices in the embodiments of the present invention is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, the features described with reference to certain examples may be combined in other examples.

[0079] The above is only the specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention.

Claims

1. A counterweight adjustment mechanism is applied to a pumping unit, characterized in that, Comprising: Two counterweights, arranged on opposite sides of the crank and movable along the radial direction of the crank; The crank, which can rotate around its end; An adjustment assembly, connected to the two counterweights, driving the two counterweights to move alternately and intermittently; A driving assembly, having a first state and a second state, and capable of switching between the first state and the second state; when the driving assembly is in the first state, as the crank rotates, the adjustment assembly cooperates with the driving assembly to drive the two counterweights to move alternately and intermittently; The adjustment assembly includes a rotating member and two adjusting members; The two adjusting members are respectively arranged inside the crank and are respectively connected to the counterweights to drive the counterweights to move along the radial direction of the crank; The rotating member is rotatably arranged inside the crank, and as the rotating member rotates, it intermittently contacts the two adjusting members, thereby driving the two counterweights to move alternately and intermittently; The adjusting member includes a first worm gear, a first worm and a first lead screw; The first lead screw is cooperatively connected to the counterweight and is connected to the center of the first worm gear; the first worm meshes with the first worm gear; As the rotating member rotates, the rotating member alternately contacts the two first worms and drives the first worms to rotate; The rotating member includes a rotating part and two gears; The gears are connected to the first worms, the rotating part has external teeth, and during the rotation of the rotating part, the external teeth respectively mesh with the two gears; Wherein, when the driving assembly is in the first state, as the crank rotates, the rotating part intermittently contacts the driving assembly to drive the rotating part to rotate intermittently; The driving assembly includes a driving member and an abutting part, and the driving member is used to drive the abutting part to move to switch between the first state and the second state; Wherein, a plurality of protrusions are arranged along the circumferential direction on one side of the rotating part; when the driving assembly is in the first state, as the crank rotates, the plurality of protrusions respectively contact the abutting part to drive the rotating part to rotate intermittently.

2. The counterweight adjustment mechanism according to claim 1, characterized in that, The driving member includes a second worm gear, a second worm, a second lead screw and a driving part; The second lead screw is cooperatively connected to the abutting part and is connected to the center of the second worm gear; the second worm meshes with the second worm gear, and the output shaft of the driving part is connected to the second worm to drive the second worm to rotate.

3. A counterweight adjustment mechanism according to claim 1, characterized in that A column is arranged inside the crank along its radial direction, and a plurality of clamping parts are respectively arranged along the radial direction on opposite sides of the column, and the counterweight is provided with a clamping part cooperating with the clamping parts; Wherein, the clamping part has a notch penetrating along the radial direction of the crank, and as the counterweight moves, the clamping part passes through the notch to be clamped into different clamping parts.

4. A counterweight adjustment mechanism according to claim 3, characterized in that, The clamping part includes an intermediate part and two moving parts, and the two moving parts are arranged on opposite sides of the intermediate part through elastic members and can move towards or away from each other.

5. A counterweight adjustment mechanism according to claim 4, characterized in that, The moving part has a first bending structure, and the clamping part has a second bending structure; when the clamping member abuts against the clamping part, the first bending structure and the second bending structure abut and limit each other; And / or, inclined guiding surfaces are respectively provided at the end portions of the two moving parts.

6. A pumping unit, characterized in that, It includes the weight adjustment mechanism according to any one of claims 1-5.

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