An underground electric actuator

Abstract

The present invention relates to the technical field of electric actuators, and specifically proposes an underground electric actuator; comprising an outer shell, the outer shell comprising a box body and an upper cover fixed at the port of the box body, an inner bracket fixed in the box body, and an actuator for driving a valve mounted on the inner bracket; an outer seal for sealing the assembly joint between the box body and the upper cover is also mounted outside the box body; the electric actuator provided by the present invention greatly improves the strength and stability of the fixation with the valve, and in addition, an outer seal is matched with the box body, and can synchronously realize the sealing of the assembly joint between the upper cover and the box body by the outer seal after being locked and fixed with the valve, and the sealing fit between the outer seal and the contact end of the outer shell is enhanced by expansion and extrusion, and at the same time, the sealing rubber ring is enabled to be embedded in the gap at the assembly joint, which greatly improves the overall sealing effect and enhances the durability and reliability of the electric actuator seal.

Description

Technical Field

[0001] The invention relates to the technical field of electric actuators, and specifically proposes an underground electric actuator. Background Art

[0002] An electric actuator is a device that converts electrical energy into mechanical motion. It is used to control the position of valves, baffles or similar equipment to control opening and closing and adjust the size of the channel opening. It is widely used in industrial automation systems, such as petroleum and natural gas, chemical, electric power, water treatment and other industries to achieve automatic control of the flow of media in pipelines.

[0003] The present invention provides an underground electric actuator. As the name implies, the electric actuator is installed underground or partially installed underground with valves and other equipment to meet the use requirements of specific scenarios. Compared with the installation environment of non-underground electric actuators, underground electric actuators have to face more challenges such as underground soil and moisture. Therefore, higher requirements are placed on the sealing of the electric actuator to prevent soil and water from entering the interior of the electric actuator, so as to ensure that the underground electric actuator operates accurately and stably in the underground environment.

[0004] Most of the existing electric actuators simply improve the sealing effect by installing sealing gaskets at the assembly joints of the shell shell. The underground electric actuator is in contact with the ground for a long time, and water and soil are easy to come into contact with the joints. If the installation ground is in a production and living area with many vibrations, the vibration of the surrounding environment will be indirectly transmitted to the electric actuator through the ground, and the durability and reliability of the sealing at the assembly joints of the shell shell of the underground electric actuator cannot be guaranteed. Summary of the invention

[0005] In order to solve the above problems, the present invention provides an underground electric actuator for solving the problems mentioned in the above background technology.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions: an underground electric actuator, which is used to drive a valve; it includes an outer shell, which includes a box body and an upper cover fixed at the port of the box body, an inner bracket is fixed in the box body, and an actuator for driving the valve is assembled on the inner bracket; the bottom end of the box body is used to be matched and fixed on the fixed end of the valve; the actuator includes a damping motor, a multi-stage gear system for transmitting the output of the damping motor, an actuator output shaft for realizing the opening and closing of the valve, and a limit switch for limiting the rotation angle range of the actuator output shaft, and the actuator output shaft is exposed from the box body; the damping motor drives the actuator output shaft to rotate through the multi-stage gear system, and when the actuator output shaft triggers the limit switch, the damping motor stops rotating.

[0007] An external seal for sealing the assembly joint between the box body and the upper cover is also installed outside the box body. When the bottom end of the box body is fixed on the fixed end of the valve, the external seal is synchronously sealed at the assembly joint between the box body and the upper cover, and the sealing pressure of the external seal on the assembly joint is increased to the maximum state; when the box body and the valve are loosened and fixed, the external seal can be separated from the assembly joint.

[0008] Preferably, the ends of the box body and the upper cover are butted against each other through polygonal flanges of the same size; the outer seal comprises a sealing sleeve which is sleeved on the periphery of the polygonal flange of the box body, and a sealing rubber ring which is in complete contact with the side wall of the polygonal flange of the box body is fixed on the inner wall of the sealing sleeve; the sealing sleeve is connected to a sliding sleeve which is sleeved and slid on the box body, and a tube end face which is in contact with the fixed end face outside the box body is provided on the end of the sliding sleeve which is away from the sealing sleeve, and when the box body is butt-jointed and fixed to the fixed end of the valve, the fixed end of the valve presses the tube end face of the sliding sleeve against the fixed end face of the box body, and the sealing rubber ring moves to seal at the assembly joint between the box body and the upper cover.

[0009] Preferably, raised fillets are evenly distributed on the side walls of the polygonal flange of the upper cover, and a notch groove for insertion is provided on the sealing rubber ring to match each raised fillet. The notch groove is open on the side of the sealing rubber ring facing the upper cover and on the side wall in contact with the polygonal flange of the box body, and the width of the notch groove gradually decreases in the direction of insertion of the raised fillet.

[0010] Preferably, the outer end surface of the box body is provided with a clamping seat that is clamped with the fixed end of the valve, and a plurality of clamping grooves are distributed on the clamping seat; an avoidance groove is provided in each clamping groove on the clamping seat; an avoidance window that avoids the clamping seat is provided on the end surface of the sliding sleeve; a plurality of pressure-bearing plates that correspond to the plurality of avoidance grooves one by one are provided in the avoidance window; when the clamping seat is clamped and fixed on the fixed end of the valve, each pressure-bearing plate is pressed by the valve in the avoidance groove at the corresponding position.

[0011] Preferably, an embedded fixing portion for fixing with a fixed end of the valve is embedded in the box body; the embedded fixing portion includes an embedded lining plate embedded in the box body, and a plurality of threaded inserts are embedded and placed on the embedded lining plate, and the plurality of threaded inserts are all embedded and fixed on the box body and exposed from one end of the clamping seat, and the plurality of threaded inserts and the plurality of clamping grooves are alternately distributed in the same circumferential direction.

[0012] Preferably, the inner bracket includes an upper plate fixed adjacent to the port of the box body and a lower plate fixed to the inner end surface of the box body, and a plurality of columns are fixedly connected between the upper plate and the lower plate; the damping motor and the limit switch are both fixed on the upper plate, and the multi-stage gear train is assembled between the upper plate and the lower plate; the execution output shaft is rotatably mounted on the upper plate and the lower plate through bearings.

[0013] Preferably, the multi-stage gear train includes a primary gear set, a secondary gear set, a tertiary gear set, a fourth gear set and a fifth gear set, which are all rotatably mounted between the upper plate and the lower plate, the primary gear set is fixed on the output shaft of the damping motor, the primary gear set, the secondary gear set, the tertiary gear set, the fourth gear set and the fifth gear set are meshed in sequence, and a large gear meshing with the fifth gear set is fixed on the execution output shaft.

[0014] Preferably, two cams staggered in the circumferential direction are fixed along the axis of the execution output shaft; the limit switch is equipped with a switch contact strip that can contact the two cams accordingly, and when the cam is separated from the switch contact strip, the switch contact strip automatically rebounds and resets.

[0015] Preferably, an axial hole is opened on the clamping seat at the center of the circumferential distribution of the plurality of threaded inserts, the actuator output shaft extends into the axial hole, and one end of the actuator output shaft extending into the axial hole is provided with a polygonal socket for docking and inserting the valve shaft.

[0016] Preferably, the limit switch is provided with a wiring board, an external wiring harness is electrically connected and fixed to the wiring board, and the external wiring harness passes through the box body and extends to the outside.

[0017] The above technical scheme has the following advantages or beneficial effects: the present invention provides an underground electric actuator, which adopts a box body as a fixed base, and the box body and the valve fixed end adopt a matching clip-on design. An embedded fixing part made of metal material and locked and fixed with the valve fixed end is embedded in the box body, which greatly improves the strength and stability of the fixation with the valve. In addition, on the basis of using a sealing gasket or the like as an internal seal, an external seal is assembled with the box body, and the sealing of the assembly joint between the upper cover and the box body can be achieved synchronously after being locked and fixed with the valve. The sealing fit between the external seal and the contact end of the outer shell is enhanced by expansion and extrusion, and at the same time, the sealing rubber ring can be embedded in the gap at the assembly joint, which greatly improves the overall sealing effect and enhances the durability and reliability of the electric actuator seal. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention and its features, configurations and advantages will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings. The same reference numerals indicate the same parts throughout the drawings, which are not drawn to scale, with emphasis on illustrating the subject matter of the present invention.

[0019] Figure 1 It is a three-dimensional structural schematic diagram of an underground electric actuator provided by the present invention.

[0020] Figure 2It is a three-dimensional structural diagram of an underground electric actuator provided by the present invention from another perspective.

[0021] Figure 3 It is a three-dimensional assembly diagram of an underground electric actuator provided by the present invention when an upper cover and an outer sealing member are not assembled.

[0022] Figure 4 It is a three-dimensional structural diagram of the assembly structure of the inner bracket and the actuator and the relative position relationship with the embedded fixing part.

[0023] Figure 5 yes Figure 4 A three-dimensional structural diagram of the assembly structure shown in the second viewing angle.

[0024] Figure 6 It is a three-dimensional structural diagram of the actuator (excluding the damping motor) and the lower plate assembly.

[0025] Figure 7 It is a three-dimensional structural diagram of the box.

[0026] Figure 8 It is a three-dimensional structure diagram of the box from another perspective.

[0027] Fig. 9 It is a three-dimensional structural diagram of the embedded fixing part.

[0028] Fig.10 It is a three-dimensional structural diagram of the upper cover.

[0029] Fig.11 It is a three-dimensional assembly drawing of the output shaft.

[0030] Fig.12 It is a three-dimensional structural diagram of the outer seal.

[0031] In the figure: 1, housing; 11, box body; 111, snap-fit ​​seat; 1111, snap-fit ​​groove; 1112, avoidance groove; 112, embedded fixing part; 1121, embedded lining plate; 1122, threaded insert; 113 shaft hole; 114, harness hole; 12, upper cover; 121, raised insert; 2, inner bracket; 21, upper plate; 22, lower plate; 23, column; 3, actuator; 31, damping motor; 32, multi-stage gear train; 321, primary gear set; 322, secondary gear set; 323. Three-stage gear set; 324. Four-stage gear set; 325. Five-stage gear set; 33. Executive output shaft; 331. Large gear; 332. Cam; 333. Multi-angle socket; 34. Limit switch; 341. Terminal block; 342. Switch contact strip; 343. Roller; 35. External wiring harness; 351. Wire harness sleeve; 4. External seal; 41. Sealing sleeve; 411. Sealing rubber ring; 412. Notch groove; 42. Sliding sleeve; 421. Avoidance window; 422. Pressure plate. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0034] like Figure 1 , Figure 7 , Figure 8 and Fig.10 As shown, an underground electric actuator, in the present invention, the electric actuator is used as a switch type control actuator to drive a valve, so that the valve can be switched on or off; the electric actuator comprises a housing 1, the housing 1 comprises a box body 11 and an upper cover 12, the box body 11 and the upper cover 12 are both integrally injection molded plastic parts, the box body 11 and the upper cover 12 are butt-jointed and assembled by a polygonal flange with the same size and structure, the polygonal flange is specifically a regular hexagonal flange; and is fixed and locked by bolts; the box body 11 serves as the overall base of the electric actuator, the box body 11 The outer end surface is provided with a clamping seat 111 which is clamped with the fixed end of the valve. The clamping seat 111 is circular, and an axial hole 113 is opened at the center of the clamping seat 111 on the box body 11. Four clamping grooves 1111 are evenly distributed around the circumference of the axial hole 113 on the clamping seat 111. The clamping grooves 1111 match the contour of the clamping part of the fixed end of the controlled valve. The clamping seat 111 is clamped with the fixed end of the valve, which improves the stability of the docking installation on the one hand, and realizes the precise alignment between the valve plate axis and the axial hole 113 of the valve on the other hand.

[0035] like Figure 3 , Figure 4 , Figure 5 , Figure 8 and Fig. 9As shown, the box body 11 needs to be further locked at the fixed end of the valve by bolts. In order to ensure the locking strength, an embedded fixing part 112 for fixing with the fixed end of the valve is embedded in the box body 11; the embedded fixing part 112 includes an embedded lining plate 1121 embedded in the box body 11, the embedded lining plate 1121 is circular, and four embedded holes are evenly distributed on the circumference of the embedded lining plate 1121. A threaded insert 1122 is correspondingly embedded and placed in each embedded hole on the embedded lining plate 1121. The embedded lining plate 1121 and the threaded insert 1122 are both iron metal parts. The embedded lining plate 1121 can make the four threaded inserts 112 2 is evenly dispersed and positioned. During the injection molding process of the box body 11, the embedded fixing portion 112 is positioned as a whole in the mold cavity for the injection molding of the box body 11. After the box body 11 is injection molded, the embedded lining plate 1121 is completely injection-molded and hidden in the box body 11. The threaded insert 1122 is provided with an external thread, which improves the bonding degree with the plastic part of the box body 11. The threaded insert 1122 is also processed with a screw hole for matching screw locking. One end of the screw holes of the four threaded inserts 1122 are all exposed from one end of the clamping seat 111, and the four threaded inserts 1122 and the four clamping grooves 1111 are evenly and alternately distributed in the circumferential direction of the shaft hole 113.

[0036] like Figure 3 , Figure 4 and Figure 5 As shown, an inner bracket 2 is assembled in the box body 11, and the inner bracket 2 includes an upper plate 21 fixed adjacent to the port of the box body 11 by bolts and a lower plate 22 fixed to the inner end surface of the box body 11 by bolts, and a plurality of columns 23 are arranged between the upper plate 21 and the lower plate 22; the bottom end of the column 23 is inserted into the lower plate 22, and the top end of the column 23 is fixed to the upper plate 21 by screws. When the upper plate 21 and the lower plate 22 are both fixed to the box body 11, the plurality of columns 23 enhance the support of the lower plate 22 to the upper plate 21.

[0037] like Figure 3 , Figure 4 , Figure 5 , Figure 6 and Fig.11As shown, the inner bracket 2 is equipped with an actuator 3 for driving the valve; the actuator 3 includes a damping motor 31, a multi-stage gear train 32 for transmitting the output of the damping motor 31, an actuator output shaft 33 for realizing the opening and closing of the valve, and a limit switch 34 for limiting the rotation angle range of the actuator output shaft 33; in this embodiment, the damping motor 31 is specifically a 1w low-power AC motor; the actuator output shaft 33 is rotatably mounted on the upper plate 21 and the lower plate 22 through two bearings, and the actuator output shaft 33 extends into the shaft hole 113, and one end of the executive output shaft 33 extending into the shaft hole 113 is provided with a polygonal socket 333 for docking and inserting the valve plate shaft of the valve, and the polygonal socket 333 is specifically a regular octagon. Correspondingly, the cross-section of the valve plate shaft of the controlled valve is a regular octagon matching the polygonal socket 333. When the housing 11 is mounted on the fixed end of the valve through the clamping seat 111, the valve plate shaft can be aligned and plugged into the polygonal socket 333, thereby realizing synchronous linkage between the executive output shaft 33 and the valve plate shaft. The multi-stage gear train 32 includes a primary gear set 321, a secondary gear set 322, a tertiary gear set 323, a fourth gear set 324 and a fifth gear set 325, which are all rotatably mounted between the upper plate 21 and the lower plate 22. The primary gear set 321 is fixed on the output shaft of the damping motor 31. The primary gear set 321, the secondary gear set 322, the tertiary gear set 323, the fourth gear set 324 and the fifth gear set 325 are all equipped with gears of large and small sizes on the same shaft. The primary gear set 321, the secondary gear set 322, the tertiary gear set 323, the fourth gear set 324 and the fifth gear set 325 are meshed in sequence step by step, and the small-sized gear in the smaller gear set is meshed with the large-sized gear in the larger gear set. A large gear 331 meshing with the small-sized gear in the fifth gear set 325 is fixed on the execution output shaft 33. When the damping motor 31 is started, its output shaft rotates at high speed, and the output shaft 33 is rotated at low speed through the step-by-step reduction transmission of the multi-stage gear system 32 with five-stage transmission, and the small torque of the damping motor 31 can be amplified into a larger torque to generate a driving force sufficient to drive the valve plate to rotate.

[0038] like Figure 3 , Figure 4 , Figure 5 and Figure 6As shown, the limit switch 34 is fixed to the upper plate 21 through a fixing plate, the damping motor 31 is electrically connected to the limit switch 34, a terminal block 341 is provided on the limit switch 34, an external wiring harness 35 is electrically connected and fixed to the terminal block 341, a wiring harness hole 114 with an internal threaded screw is provided on the side wall of the box body 11, the external wiring harness 35 passes through the upper plate 21 and the lower plate 22 in turn, and extends to the outside through the wiring harness hole 114, the external wiring harness 35 is externally connected to a controller for sending a control command electrical signal to the damping motor 31, in order to ensure the sealing at the wiring harness hole 114, a wiring harness sleeve 351 with an external threaded screw is mounted on the external wiring harness 35, and the wiring harness sleeve 351 is threadedly connected to the wiring harness hole 114. Two cams 332 are fixed along the axis of the execution output shaft 33, and the offset angle of the two cams 332 is specifically 45°; the limit switch 34 is equipped with a switch contact strip 342 that can contact the two cams 332 accordingly, and there are two switch contact strips 342 that can contact the two cams 332 accordingly. In order to reduce the running resistance of the cam 332 rotating with the execution output shaft 33 when the cam 332 contacts the switch contact strip 342, a roller 343 is rotatably installed on the switch contact strip 342, and the switch contact strip 342 actually contacts the cam 332 through the roller 343. The switch contact strip 342 is made of spring steel. Therefore, when the cam 332 is separated from the switch contact strip 342, the switch contact strip 342 automatically rebounds and resets. In addition, when the far travel point of the cam 332 just contacts the roller 343, that is, the switch contact strip 342 is pressed and deformed to the maximum, the switch contact strip 342 causes the limit switch 34 to send a corresponding control signal, so that the output shaft of the damping motor 31 stops rotating.

[0039] In the actual working process, when the valve needs to be opened, the controller sends a corresponding control electrical signal to the damping motor 31, and the damping motor 31 starts after receiving the control electrical signal. Under the transmission of the multi-stage gear system 32, the execution output shaft 33 is driven to rotate stably at a low speed, and the execution output shaft 33 synchronously drives the valve plate to rotate through the docked valve plate shaft, so that the valve plate gradually opens the passage of the valve. In the present invention, when the far travel point of the upper cam 332 just contacts the rollers 343 of the corresponding two switch contact strips 342, the two pressed switch contact strips 342 send a stop signal to the damping motor 31 through the limit switch 34, and the damping motor 31, under the action of its own damping force, the damping motor The output shaft of the motor 31 responds instantly and stops rotating, the valve plate makes the valve channel fully open, and the valve is just in a fully open state; when the valve needs to be closed again, the controller sends a control electrical signal to the damping motor 31 again, executes the output shaft 33 to rotate again, and drives the valve plate to rotate, the upper cam 332 and the switch contact strip 342 are gradually separated, and when the far travel point of the lower cam 332 just rotates to contact with the other two switch contact strips 342, the switch contact strip 342 is triggered to send a stop signal to the damping motor 31 through the limit switch 34 again, the damping motor 31 pauses, and the valve plate makes the valve channel fully closed, and the valve is just in a fully closed state.

[0040] like Figure 1 and Figure 2 As shown, the present invention provides an underground electric actuator, which is half buried or fully buried underground. In order to enhance the overall sealing, when the electric actuator is assembled, the electrical components are basically hidden in the housing 1. The position where special attention should be paid to the sealing is located at the joint between the box body 11 and the upper cover 12. Therefore, the box body 11 is also equipped with an external seal 4 for sealing the joint between the box body 11 and the upper cover 12. Of course, in the conventional way, a sealing gasket can be installed between the box body 11 and the upper cover 12.

[0041] like Figure 1 , Figure 2 and Fig.12As shown, the outer seal 4 includes a sealing sleeve 41 which is sleeved on the periphery of the polygonal flange of the box body 11, and a sealing rubber ring 411 which is completely in contact with the side wall of the polygonal flange of the box body 11 is fixed on the inner wall of the sealing sleeve 41; raised molding strips 121 are evenly distributed on the side wall of the polygonal flange of the upper cover 12, and the raised molding strips 121 are integrally injection molded with the upper cover 12, and a notch groove 412 for insertion is arranged on the sealing rubber ring 411 in alignment with each raised molding strip 121, and the notch groove 412 is opened at the side of the sealing rubber ring 411 facing the upper cover 12 and on the side wall in contact with the polygonal flange of the box body 11, and the width of the notch groove 412 gradually decreases in the direction of insertion of the raised molding strip 121. The sealing sleeve 41 is connected to a sliding sleeve 42 which is sleeved and slides on the box body 11, and the end of the sliding sleeve 42 away from the sealing sleeve 41 is provided with a tube end face for contacting the fixed end face outside the box body 11; each clamping groove 1111 on the clamping seat 111 is provided with an avoidance groove 1112; an avoidance window 421 for avoiding the clamping seat 111 is provided on the tube end face of the sliding sleeve 42; four pressure plates 422 which correspond to the four avoidance grooves 1112 one by one are provided in the avoidance window 421.

[0042] The outer seal 4 is a plastic part integrally injection-molded around the sealing rubber ring 411. When assembling the electric actuator, before installing the wiring harness sleeve 351, the outer seal 4 is first mounted on the box body 11. A window is provided on the side wall of the sliding sleeve 42 of the polygonal flange to avoid the wiring harness sleeve 351. The wiring harness sleeve 351 is then passed through the window and installed on the wiring harness hole 114. The assembly limit of the outer seal 4 by the box body 11 and the blocking of the outer seal 4 by the wiring harness sleeve 351 prevent the outer seal 4 from detaching from the box body 11.

[0043] When the electric actuator is docked and fixed to the fixed end of the controlled valve, the fixed end of the valve is clamped in the clamping groove 1111. At this time, the pressure plate 422 is located between the clamping seat 111 and the fixed end of the valve. Due to the contact resistance between the sealing rubber ring 411 and the multilateral flange, the pressure plate 422 does not completely fall into the avoidance groove 1112. When the four bolts are locked in the threaded insert 1122 in sequence to lock the box body 11 and the fixed end of the valve, the pressure plate 422 is squeezed in the avoidance groove 1112. The locking force causes the shell 1 and the outer seal 4 to move toward each other. The sealing rubber ring 411 crosses the assembly joint of the shell 1 and is sealed and wrapped on the multilateral flange of the upper cover 12. In the process of approaching toward each other, the raised insert strip 121 is inserted into the notch groove 412 at the corresponding position, and the raised fillet 121 plays the role of an expansion strip. The raised fillet 121 squeezes the notch groove 412 to maximize the contact force between the sealing rubber ring 411 and the polygonal flange, and the sealing rubber ring 411 is embedded in the tiny gap assembled between the box body 11 and the upper cover 12, which greatly enhances the sealing of the joint, thereby improving the overall sealing of the electric actuator, and can effectively prevent water and mud from entering the housing 1 and affecting the internal electrical components. In addition, the outer seal 4 is sealed synchronously with the fixed docking of the electric actuator and the valve. Only when the four fixing threads are completely removed, the outer seal 4 will be separated from the joint of the housing 1 to ensure the durability and reliability of the seal.

[0044] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0045] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "connect", "install", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0046] The above describes the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; any technician familiar with the art can make many possible changes and modifications without departing from the technical solution of the present invention, or modify them into equivalent embodiments with equivalent changes, which does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of protection of the technical solution of the present invention.

Claims

1. An underground electric actuator, the electric actuator being used to drive a valve; comprising a housing (1), the housing (1) comprising a box body (11) and an upper cover (12) fixed at a port of the box body (11), an inner bracket (2) being fixed in the box body (11), an actuator (3) for driving the valve being mounted on the inner bracket (2); characterized in that: The bottom end of the housing (11) is used for being matched and fixed to the fixed end of the valve; the actuator (3) comprises a damping motor (31), a multi-stage gear train (32) for transmitting the output of the damping motor (31), an actuator output shaft (33) for realizing the opening and closing of the valve, and a limit switch (34) for limiting the rotation angle range of the actuator output shaft (33), wherein the actuator output shaft (33) is exposed from the housing (11); the damping motor (31) drives the actuator output shaft (33) to rotate through the multi-stage gear train (32), and when the actuator output shaft (33) triggers the limit switch (34), the damping motor (31) stops rotating; The box body (11) is also provided with an outer sealing member (4) for sealing the assembly joint between the box body (11) and the upper cover (12); when the bottom end of the box body (11) is fixed to the fixed end of the valve, the outer sealing member (4) is simultaneously sealed at the assembly joint between the box body (11) and the upper cover (12), and the sealing pressure of the outer sealing member (4) on the assembly joint is increased to a maximum state; when the box body (11) and the valve are loosened and fixed, the outer sealing member (4) can be separated from the assembly joint; The ends of the box body (11) and the upper cover (12) are butted against each other via a polygonal flange of the same size; the outer sealing member (4) comprises a sealing sleeve (41) sleeved on the outer periphery of the polygonal flange of the box body (11); a sealing rubber ring (411) is fixed on the inner side wall of the sealing sleeve (41) and is in full contact with the side wall of the polygonal flange of the box body (11); the sealing sleeve (41) is connected to a sliding sleeve (42) sleeved and slid on the box body (11); an end of the sliding sleeve (42) away from the sealing sleeve (41) is provided with a tube end face for contacting an external fixed end face of the box body (11); when the box body (11) is butt-jointed and fixed to the fixed end of the valve, the fixed end of the valve presses the tube end face of the sliding sleeve (42) against the fixed end face of the box body (11), and the sealing rubber ring (411) moves to seal at the assembly joint between the box body (11) and the upper cover (12).

2. The underground electric actuator according to claim 1, characterized in that: The side walls of the polygonal flange of the upper cover (12) are evenly distributed with raised fillets (121), and the sealing rubber ring (411) is provided with a notch groove (412) for insertion, which is aligned with each raised fillet groove (121). The notch groove (412) is opened at the side of the sealing rubber ring (411) facing the upper cover (12) and on the side wall in contact with the polygonal flange of the box body (11), and the width of the notch groove (412) gradually decreases in the direction of insertion facing the raised fillet groove (121).

3. The underground electric actuator according to claim 2, characterized in that: The outer end surface of the box body (11) is provided with a clamping seat (111) that is clamped with the fixed end of the valve, and a plurality of clamping grooves (1111) are distributed on the clamping seat (111); each clamping groove (1111) on the clamping seat (111) is provided with an avoidance groove (1112); the end surface of the sliding sleeve (42) is provided with an avoidance window (421) that avoids the clamping seat (111); a plurality of pressure-bearing plates (422) that correspond to the plurality of avoidance grooves (1112) are provided in the avoidance window (421); when the clamping seat (111) is clamped and fixed on the fixed end of the valve, each pressure-bearing plate (422) is pressed by the valve into the avoidance groove (1112) at a corresponding position.

4. The underground electric actuator according to claim 3, characterized in that: An embedded fixing portion (112) for fixing with a fixed end of a valve is integrally embedded in the box body (11); the embedded fixing portion (112) comprises an embedded lining plate (1121) embedded in the box body (11), a plurality of threaded inserts (1122) are embedded and placed on the embedded lining plate (1121), the plurality of threaded inserts (1122) are all embedded and fixed on the box body (11) and exposed from one end of the clamping seat (111), and the plurality of threaded inserts (1122) and the plurality of clamping grooves (1111) are alternately distributed in the same circumferential direction.

5. The underground electric actuator according to claim 1, characterized in that: The inner bracket (2) comprises an upper plate (21) fixed adjacent to an end of the box body (11) and a lower plate (22) fixed to an inner end surface of the box body (11); a plurality of columns (23) are fixedly connected between the upper plate (21) and the lower plate (22); the damping motor (31) and the limit switch (34) are both fixed on the upper plate (21); the multi-stage gear train (32) is assembled between the upper plate (21) and the lower plate (22); and the execution output shaft (33) is rotatably mounted on the upper plate (21) and the lower plate (22) via a bearing.

6. The underground electric actuator according to claim 5, characterized in that: The multi-stage gear train (32) comprises a primary gear set (321), a secondary gear set (322), a tertiary gear set (323), a fourth gear set (324) and a fifth gear set (325) which are all rotatably mounted between the upper plate (21) and the lower plate (22); the primary gear set (321) is fixed on the output shaft of the damping motor (31); the primary gear set (321), the secondary gear set (322), the tertiary gear set (323), the fourth gear set (324) and the fifth gear set (325) are meshed in sequence; and a large gear (331) meshing with the fifth gear set (325) is fixed on the execution output shaft (33).

7. The underground electric actuator according to claim 5, characterized in that: Two cams (332) are fixed along the axis of the execution output shaft (33) and are staggered in the circumferential direction. The limit switch (34) is equipped with a switch contact strip (342) that can contact the two cams (332) accordingly. When the cams (332) and the switch contact strip (342) are separated, the switch contact strip (342) automatically rebounds and resets.

8. The underground electric actuator according to claim 4, characterized in that: An axial hole (113) is provided on the clamping seat (111) at the center of the circumferential distribution of the plurality of threaded inserts (1122), the execution output shaft (33) extends into the axial hole (113), and one end of the execution output shaft (33) extending into the axial hole (113) is provided with a multi-angle socket (333) for butt-jointing and inserting the shaft of the valve.

9. The underground electric actuator according to claim 5, characterized in that: The limit switch (34) is provided with a wiring board (341), and an external wiring harness (35) is electrically connected and fixed to the wiring board (341), and the external wiring harness (35) passes through the box body (11) and extends to the outside.

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