A device for preventing reverse rotation of the polished rod in a screw pump.

Abstract

This invention provides a device for preventing reverse rotation of the guide rod in a screw pump. The device includes a main body, a toothed block, and a limiting post. The main body has a toothed block groove and a fastening hole penetrating the main body. The toothed block is shaped to match the toothed block groove and is detachably mounted in the groove. The toothed block has a groove extending along its axis for receiving the guide rod, and the groove has protruding teeth facing the hollow area of ​​the groove. The protruding teeth include strip-shaped teeth extending parallel to the axis. The limiting post is mounted in the fastening hole and extends at least a predetermined length in a direction perpendicular to the axis. This predetermined length ensures that the limiting post can abut against a base for supporting the drive device when the device is mounted on the guide rod. The device for preventing reverse rotation of the guide rod in a screw pump provided by this invention has many advantages, including simple structure, low cost, and high reliability.

Description

Technical Field

[0001] This invention relates to the field of oilfield equipment, and more specifically to a device for preventing the polished rod of a screw pump from reversing. Background Technology

[0002] Screw pumps are mainly used in industrial applications for pumping viscous liquids, and are also used for extracting heavy oil and sandy viscous oil. Screw pumps are positive displacement pumps with many advantages, such as small size, simple structure, and light weight. A screw pump mainly consists of a drive motor, reducer, drive shaft, stator, and rotor. During operation, the rotor is driven by the motor and rotates within the stator. The rotor and stator form several sealed cavities that are not interconnected. Due to the rotation of the rotor, these sealed cavities move axially from the suction end to the discharge end, and the medium continuously flows from the suction end to the discharge end within the cavities.

[0003] When a screw pump's drive motor operates under heavy load for extended periods, its bearings can become damaged, necessitating replacement of the screw pump drive head. Currently, drive head replacement typically involves using a crane to lift the polished mast for unloading, releasing the torque before replacing the drive head. Without a crane, this torque cannot be released, and the polished mast in the well can easily reverse during drive head replacement, potentially causing personal injury. Therefore, it is necessary to research and develop a device that can prevent the polished mast from reversing and safely remove the drive motor without using a crane to lift it.

[0004] Currently, several devices exist in the industry to prevent reverse rotation of the guide rod. The main types include ratchet and pawl mechanisms, friction-type anti-reverse devices, and hydraulic anti-reverse systems. The ratchet-pawl anti-reverse device mounts the pawl on a fixed spindle for free rotation. The ratchet and pawl are typically externally meshed. The pawl is placed around the ratchet, and springs ensure proper meshing between the pawl and the teeth. This device utilizes the unidirectional rotation characteristic of the ratchet and pawl mechanism to prevent reverse rotation. It has a simple structure, low cost, and can be installed at any point in the transmission chain. However, its disadvantages include the inability to automatically release reverse rotation, resulting in impact. During oil extraction, the pawl's impact and friction against the ratchet generate continuous noise and frictional heat. The friction-type anti-reverse device consists of a brake shoe and an overrunning clutch that identifies forward and reverse rotation. The brake shoe is riveted to the brake body, and the two brake bodies are bolted together to tighten the outer ring. When rotating forward, the device is inactive. During reverse rotation, it acts as a damper, limiting the speed and achieving the anti-reverse effect. However, the clamping bolts must be adjusted to achieve the required braking and speed limiting effect. Because manual adjustment is required, over-tightening and ineffective braking often occur. The hydraulic anti-reverse device is installed inside the gearbox and consists of a one-way clutch and a hydraulic wheel. When the sucker rod reverses, it drives the clutch and hydraulic wheel to rotate. At this time, the oil in the gearbox enters the channel of the hydraulic wheel and rotates with it. The channel has a large inlet and a small outlet. During rotation, the oil pressure in the channel gradually increases, consuming some energy and generating a high-speed jet at the outlet, producing a reverse torque that prevents the sucker rod from reversing. It has advantages such as high reliability and smooth operation, but the device is relatively expensive.

[0005] Therefore, it is still necessary to develop a device that is simple in structure, low in cost, and highly reliable to prevent the smooth rod of the screw pump from reversing. Summary of the Invention

[0006] The purpose of this invention is to provide a device for preventing the smooth rod of a screw pump from reversing in order to solve the above-mentioned problems existing in the prior art.

[0007] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0008] According to one aspect of the present invention, a device for preventing reverse rotation of the feed screw of a screw pump is provided, the device comprising:

[0009] The main body is provided with toothed grooves and fastening holes that penetrate the main body;

[0010] The tooth block has an outer shape that matches the shape of the tooth block groove and is detachably installed in the tooth block groove. The tooth block has a groove extending along the axis for receiving the optical rod. The groove is provided with protruding teeth protruding toward the hollow area of ​​the groove. The protruding teeth include strip-shaped protruding teeth extending parallel to the axis.

[0011] A limiting post is installed in a fastening hole and extends at least a predetermined length in a direction perpendicular to the axis. The predetermined length ensures that the limiting post can abut against the base used to support the drive device when the device is installed on the guide rod.

[0012] According to one embodiment of the present invention, the main body includes a detachable first half and a second half, the first half and the second half are joined together and tooth block grooves and fastening holes are symmetrically provided on both sides of the mating surface, and the tooth block includes a symmetrically arranged first tooth block portion and a second tooth block portion.

[0013] According to one embodiment of the invention, each of the first half and the second half includes a tooth block groove.

[0014] According to one embodiment of the present invention, each of the first half and the second half includes two tooth block slots arranged at intervals from top to bottom, one tooth block slot receiving a tooth block having strip-shaped protrusions parallel to the axis, and the other tooth block slot receiving a tooth block having annular protrusions.

[0015] According to one embodiment of the present invention, the tooth block groove includes an upper section, a middle section and a lower section, wherein the middle section is smaller than the upper and lower sections in the direction perpendicular to the axis and larger than the upper and lower sections in the direction parallel to the axis.

[0016] According to one embodiment of the present invention, the upper section, middle section and lower section are all square grooves.

[0017] According to one embodiment of the present invention, the first half and the second half further include unloading holes that extend from the outer surfaces of the first half and the second half into the tooth block groove.

[0018] According to one embodiment of the invention, the device further includes a fastener that is installed in a portion of the fastening hole.

[0019] According to one embodiment of the present invention, a portion of the fastening hole is provided with a hexagonal recess near the outer surface of the first half and the second half, the recess being recessed from the outer surface to a predetermined depth, and the limiting post is provided with a hexagonal limiting part that can be installed into the recess.

[0020] According to one embodiment of the present invention, the device includes two limiting posts, which are installed in two fastening holes arranged diagonally. Each limiting post includes a post body and a fastening nut. One end of the post body is threaded, and the threaded ends of the two limiting posts protrude from two opposite outer surfaces of the main body, respectively.

[0021] According to one embodiment of the invention, the tooth block is made of a material that is harder than the body.

[0022] By adopting the above technical solution, the present invention has at least the following beneficial effects:

[0023] This invention uses detachable tooth blocks, which can be made of stronger materials, thus reducing costs and ensuring sufficient strength.

[0024] The tooth block is designed to be detachable, allowing for the use of tooth blocks with different groove sizes for different sized optical rods, thus broadening its applicability. Moreover, when a tooth block is damaged, it can be replaced individually.

[0025] The overall structure is simple, without the use of complex electronic or hydraulic control components, resulting in greater reliability and stability, and lower cost.

[0026] The device can be equipped with two different types of tooth blocks, which can simultaneously prevent the guide rod from reversing and falling. Attached Figure Description

[0027] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0028] Figure 1 This is a side view of a device for preventing the screw rod of a screw pump from reversing, according to an embodiment of the present invention.

[0029] Figure 2 This is a top view of a device for preventing the rotor of a screw pump from reversing, according to an embodiment of the present invention.

[0030] Figure 3 This is a schematic diagram of the main body of a device for preventing reverse rotation of the screw rod of a screw pump according to an embodiment of the present invention.

[0031] Figure 4 This is a schematic diagram of the tooth block of a device for preventing reverse rotation of the screw rod of a screw pump according to an embodiment of the present invention.

[0032] Figure 5 This is a side view and a cross-sectional view of some components of a device for preventing reverse rotation of the screw rod of a screw pump according to an embodiment of the present invention.

[0033] Explanation of reference numerals in the attached figures

[0034] 100 Main body, 100a First half, 100b Second half, 110 Tooth block groove, 120 Unloading hole, 130 Fastening hole, 200 Tooth block, 200a First tooth block section, 200b Second tooth block section, 210 Upper tooth block section, 211 Lower tooth block section, 212 Middle tooth block section, 220 Protruding tooth, 220' Protruding tooth, 300 Limiting post, 310 Column, 320 Fastening nut, 400 Fastener. Detailed Implementation

[0035] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. For example, terms such as “length,” “width,” “upper,” “lower,” “left,” “right,” “front,” “rear,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer” indicate orientations or positions based on the orientations or positions shown in the accompanying drawings and are for ease of description only, and should not be construed as limiting the technical solution.

[0037] The terms "comprising" and "having," and any variations thereof, used in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion; the terms "first," "second," etc., used in the specification, claims, and accompanying drawings are used to distinguish different objects, not to describe a particular order. "A plurality of" means two or more, unless otherwise explicitly specified.

[0038] In the description and claims of this invention and the foregoing drawings, when an element is referred to as "fixed to," "mounted to," "disposed on," or "connected to" another element, it can be located directly or indirectly on that other element. For example, when an element is referred to as "connected to" another element, it can be directly or indirectly connected to that other element.

[0039] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0040] In oilfield development, screw pumps are widely used in the extraction of heavy oil, sandy oil, and high-gas oil because they occupy little space, are easy to install, easy to operate, and consume little energy. A screw pump mainly consists of a drive motor, reducer, transmission shaft, stator, and rotor.

[0041] This invention provides a device for preventing the polished rod of a screw pump from reversing. When the screw pump drive unit needs to be replaced, in order to prevent personal injury caused by the polished rod reversing, the device according to the invention is installed on the polished rod and secured together with the support of the drive unit, thereby achieving the effect of preventing the polished rod from reversing. Figure 1 and Figure 2 A device for preventing reverse rotation of the screw rod of a screw pump according to an embodiment of the present invention is shown. The device generally includes a body 100, a toothed block 200, a limiting post 300, and a fastener 400.

[0042] The main body 100 includes a first half 100a and a second half 100b. The first half 100a and the second half 100b are symmetrically arranged along the mating surface and used together. Since the structures of the first half 100a and the second half 100b are symmetrical, only the structure of the first half 100a will be described in detail below.

[0043] refer to Figure 3 ,in Figure 3 The left part shows a schematic diagram of the first half 100a with the outer surface of the first half 100a as the main viewing direction. Figure 3 The right part shows a schematic diagram with the docking surface of the first half 100a as the main viewing direction.

[0044] The first half 100a has a first surface P1 located on the outside and a second surface P2 for mating with the second half 100b, the first surface P1 and the second surface P2 being disposed opposite to each other. The first half 100a has a toothed groove 110, which starts from the second surface P2 and extends toward the first surface P1. The toothed groove 110 does not penetrate the entire thickness of the first half 100a (i.e., the direction of the line connecting the first surface P1 and the second surface P2), but terminates between the first surface P1 and the second surface P2.

[0045] exist Figure 3In the illustrated embodiment, each half is provided with upper and lower tooth block grooves 110. The size and shape of the upper and lower tooth block grooves 110 can be similar. Each tooth block groove 110 consists of three sections: upper, middle, and lower. The upper section is a rectangular groove with a smaller height H1 (as shown in the figure) and a larger length (i.e., in the left-right direction shown in the figure) and depth (i.e., along the line connecting the second surface P2 and the first surface P1). The middle section is also a rectangular groove with a height H2 that is significantly greater than the height H1 of the upper section, and a smaller length and depth. The lower section is also a rectangular groove with a height H3 that is similar to the height H1 of the upper section, and a larger length and depth than the middle section. That is to say, compared with the middle section, the upper and lower sections extend a greater distance toward the first surface P1 and to the left and right sides, thus forming a groove 110 that is deeper and longer at both ends and shallower and shorter in the middle.

[0046] The upper surface of the upper tooth block groove 110 can be flush with the top surface of the first half 100a (i.e., the groove is cut starting from the top surface of the first half 100a), which makes it easier to process. However, in other embodiments, the upper surface of the upper tooth block groove 110 can also be located within the base of the first half 100a. A spacer is provided between the upper tooth block groove 110 and the lower tooth block groove 110, and an arc-shaped groove is provided at the spacer. The shape and size of the arc-shaped groove are adapted to the size of the clamped optical rod. The lower surface of the lower tooth block groove 110 is separated from the bottom surface of the first half 100a by a distance. That is, the lower surface of the lower tooth block groove 110 is not located at the bottom surface of the first half 100a, but is located at a position higher than the bottom surface of the first half 100a, thereby ensuring that the lower tooth block groove 110 can provide stronger support for the tooth block 200 installed therein. Correspondingly, the portion between the lower surface of the lower tooth block groove 110 and the bottom surface of the first half 100a is also provided with an arc-shaped groove, the shape and size of which are adapted to the size of the clamped optical rod.

[0047] The first half 100a also has an unloading hole 120. Figure 3 In the illustrated embodiment, the first half 100a has two unloading holes 120. One unloading hole 120 extends from the first surface P1 to the middle section of the upper tooth block groove 110, preferably to the midpoint of the middle section. The other unloading hole 120 extends from the first surface P1 to the middle section of the lower tooth block groove 110, preferably to the midpoint of the middle section. When the tooth block groove 110 and the tooth block 200 are assembled and used together, the gap between them is filled with oil, making the tooth block 200 firmly sucked into the tooth block groove 110 and difficult to remove. In this case, a rod can be inserted from the unloading hole 120, and the rod can be used to push the tooth block 200 to remove it. It is understood that the number of unloading holes 120 here is not limiting, and more or fewer unloading holes 120 can be provided as needed.

[0048] The first half 100a also has a fastening hole 130. Figure 3 In the illustrated embodiment, the first half 100a has four fastening holes 130. The four fastening holes 130 are symmetrically arranged in pairs on both sides of the upper and lower threaded block grooves 110. Optionally, the fastening holes 130 that mate with the bolt heads may be machined with hexagonal edges near the outer surface. Figure 3 In the illustrated embodiment, hexagonal recesses are machined in the upper and lower fastening holes 130 located on the same side of the upper and lower tooth block grooves 110. The embedding depth of the hexagonal recesses can be approximately 5 mm. The limiting post 300 and the fastener 400 can be inserted into the fastening holes 130 to fasten the first half 100a, the second half 100b, and the guide rod between them together.

[0049] refer to Figure 2 and Figure 4 This diagram illustrates the structure of a tooth block 200 in a device for preventing reverse rotation of the screw rod of a screw pump according to the present invention. The tooth block 200 includes a first tooth block portion 200a and a second tooth block portion 200b. The shape and dimensions of each of the first tooth block portion 200a and the second tooth block portion 200b are adapted to the shape and dimensions of the tooth block groove 110. Since the first tooth block portion 200a and the second tooth block portion 200b are symmetrical, only the structure of the first tooth block portion 200a will be described in detail below. The top surface, bottom surface, and three side surfaces of the first tooth block portion 200a respectively abut against the corresponding surfaces of the tooth block groove 110. Another side surface of the first tooth block portion 200a (hereinafter referred to as the abutting side surface) abuts against the second tooth block portion 200b. The first tooth block portion 200a also includes an upper section 210, a middle section 212, and a lower section 211. The upper section 210, the middle section 212, and the lower section 211 are flush with the abutting surfaces. On other sides, the upper section 210 and the lower section 211 extend outwards more than the middle section 212. That is to say, the first tooth block portion 200a is thicker at both ends and thinner in the middle.

[0050] The first tooth block portion 200a also has a groove that is generally semi-cylindrical. The diameter of the semi-cylindrical groove is approximately equal to the diameter of the optical rod to be clamped. The groove extends from the mating side of the first tooth block portion 200a toward the opposite side. A protruding tooth 220 is provided in the groove.

[0051] In some embodiments, as Figure 4 As shown in the left part, the protruding tooth 220 is an arc-shaped tooth extending circumferentially along the groove. Each arc-shaped tooth protrudes radially towards the central axis of the groove. This type of protruding tooth 220 prevents the polished rod from falling axially. This type of tooth block can be made of 20CrMoTi and 20# steel. The steel is carburized and quenched to achieve a surface hardness of HRC58-62. It adopts a wedge-type clamping structure, and the clamping force will increase with the longer the load.

[0052] In other embodiments, such as Figure 4 As shown in the right part, the protruding tooth 220' is a vertical tooth extending axially along the groove. Each vertical tooth also protrudes radially towards the central axis of the groove. This type of protruding tooth 220' prevents the polished rod from sliding circumferentially, thus preventing the polished rod from rotating. This tooth block can be made of 20CrMoTi and 20# steel. The steel is carburized and quenched, achieving a surface hardness of HRC58-62.

[0053] refer to Figure 5 , Figure 5 The left portion shows a schematic diagram of the assembly structure in which the tooth block 220 is installed in the tooth block slot 110, and the right portion shows a cross-sectional view taken along line AA of the left view. In the embodiment shown in this figure, a tooth block with vertical strip-shaped protrusions 220' is installed in the upper tooth block slot 110 to prevent the guide rod from sliding circumferentially, thus preventing the guide rod from rotating. A tooth block with arc-shaped protrusions 220 is installed in the lower tooth block slot 110 to prevent the guide rod from falling axially. However, it is conceivable that the types of tooth blocks provided in the upper and lower tooth block slots 110 can be interchanged. Alternatively, if the screw pump already has other structures for preventing the guide rod from falling, the tooth block with arc-shaped protrusions 220 described herein can be omitted, and only the tooth block with vertical strip-shaped protrusions 220' is provided. In this case, only one tooth block 200 can be used, and correspondingly, only one tooth block slot 110 can be provided in each half.

[0054] Depend on Figure 5 As can be seen, when the tooth blocks 220 are installed in the tooth block slots 110, the upper section 210 and lower section 211 of each tooth block 220 are inserted into the upper and lower sections of the tooth block slots 110, respectively, and the middle section 212 of the tooth block 220 is stuck in the middle section of the tooth block slots 110. To enhance the anti-reverse capability of the device, the tooth block slots and tooth blocks are generally square in shape. When the guide rod applies torque to the tooth block 220 to cause it to rotate, it cannot rotate because the corners of the tooth block 220 are stuck in the tooth block slots 110.

[0055] Return to reference Figure 1 and Figure 2 The device according to the invention for preventing reverse rotation of the screw rod of a screw pump further includes at least one limiting post 300. Figure 1-2In the illustrated embodiment, two limiting posts 300 are used. Each limiting post 300 generally includes a post body 310 and a fastening nut 320. The two limiting posts 300 are installed in two of the four fastening holes 130 arranged diagonally. One end of the limiting post 300 is provided with an external thread, the outer diameter of which can be, for example, 29 mm, and the pitch can be approximately 90 mm. A hexagonal angle is provided at a predetermined distance (e.g., 100 mm) from the threaded end, the size and dimensions of which are adapted to the hexagonal angle of the fastening hole 130 and are received in the hexagonal angle recess of the fastening hole 130. A columnar portion extending away from the threaded end is provided on the second side of the hexagonal angle, the length of which can be approximately 200 mm.

[0056] Fastener 400 is installed into the remaining fastening hole 130 to secure the first half 100a and the second half 100b together. The fastener can be a combination of bolt and nut. The bolt head can be hexagonal to fit into the hexagonal recess of the fastening hole 130. This enhances the fastening strength and prevents the fastener from slipping.

[0057] In use, the device for preventing reverse rotation of the screw pump rod according to the present invention involves assembling the toothed block 200 into the corresponding toothed block groove 110, and then aligning the two main body halves containing the toothed block 200 to the two sides of the screw rod, so that the screw rod is locked in the grooves of the two opposing toothed blocks. A fastener 400, such as a fastening bolt, is inserted into the fastening hole 130 of the main body, and a nut is installed on the threaded end of the fastening bolt. A limiting post 300 is then installed into the corresponding fastening hole 130, and a nut is installed on the threaded end of the limiting post 300, with the columnar portion of the limiting post 300 abutting against the support post of the drive unit support base. After installing the device, the square clip and torque clip at the top of the drive unit are removed, and the connecting bolts between the drive unit and the support base are removed. The faulty drive unit is then removed and replaced with a new one. The drive unit is reconnected to the support base with bolts. The torque clip and square clip on the drive unit are then tightened. The anti-screw reverse rotation device is removed, completing the replacement of the drive unit.

[0058] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0059] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0060] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A device for preventing reverse rotation of the polished rod of a screw pump, characterized in that, include: The main body is provided with a toothed groove and a fastening hole penetrating the main body. The main body includes a detachable first half and a second half, which are joined together and the toothed groove and the fastening hole are symmetrically arranged on both sides of the mating surface. The tooth block has an outer shape that matches the shape of the tooth block groove and is detachably installed in the tooth block groove. The tooth block has a groove extending along the axis and for receiving the optical rod. The groove is provided with protruding teeth protruding toward the hollow area of ​​the groove. The protruding teeth include strip-shaped protruding teeth extending parallel to the axis. The tooth block includes a first tooth block portion and a second tooth block portion arranged symmetrically. A limiting post, which is installed in the fastening hole and extends at least a predetermined length in a direction perpendicular to the axis, ensures that the limiting post can abut against the base for supporting the drive device when the device is mounted on the optical rod. The tooth block groove includes an upper section, a middle section, and a lower section. The middle section is smaller than the upper and lower sections in the direction perpendicular to the axis, and larger than the upper and lower sections in the direction parallel to the axis. The upper, middle, and lower sections are all square grooves.

2. The apparatus according to claim 1, characterized in that, Each of the first half and the second half includes a tooth block groove.

3. The apparatus according to claim 1, characterized in that, Each of the first half and the second half includes two tooth block slots arranged at intervals from top to bottom, one of the tooth block slots receiving a tooth block having strip-shaped protrusions parallel to the axis, and the other tooth block slot receiving a tooth block having annular protrusions.

4. The apparatus according to claim 1, characterized in that, The first half and the second half also include unloading holes that extend from the outer surfaces of the first half and the second half into the tooth block groove.

5. The apparatus according to claim 1, characterized in that, The device also includes fasteners that are installed in a portion of the fastening holes.

6. The apparatus according to claim 1, characterized in that, A portion of the fastening holes has a hexagonal recess near the outer surfaces of the first and second halves. The recess is recessed to a predetermined depth from the outer surface, and the limiting post has a hexagonal limiting part that can be installed into the recess.

7. The apparatus according to claim 1, characterized in that, The device includes two limiting posts, which are installed in two fastening holes arranged diagonally. Each limiting post includes a post body and a fastening nut. One end of the post body is threaded, and the threaded ends of the two limiting posts protrude from two opposite outer surfaces of the main body, respectively.

8. The apparatus according to claim 1, characterized in that, The tooth block is made of a material that is harder than the main body.

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