Spring self-resetting electric actuator

Abstract

This invention provides a spring-driven self-resetting electric actuator, comprising a housing, a motor, and a gear assembly. The housing has a mating shaft that passes through it, with one end for mounting a self-centering connector, which in turn mounts a valve stem. The motor is mounted on the housing and has an output shaft. The gear assembly is mounted on the housing, with one end meshing with the output shaft gear and the other end meshing with the mating shaft. The motor drives the gear assembly to rotate the valve stem to open and close the valve. This spring-driven self-resetting electric actuator utilizes the motor's stall capability to brake the valve stem, eliminating the need for an electromagnetic brake. It meets the requirements for installation in both forward and reverse directions, enabling the electric actuator to simultaneously perform reset-opening and reset-closed valve functions. Furthermore, the self-centering connector can accommodate valve stems of different sizes while maintaining concentricity between the valve stem and the self-centering connector.

Description

Technical Field

[0001] This invention relates to the field of valve control technology in air conditioning systems of nuclear power plants, specifically to a spring-driven self-resetting electric actuator. Background Technology

[0002] In the design of ventilation and air conditioning systems in nuclear power plants, dampers are typically used to regulate airflow, isolate air, or prevent backflow. When a fire occurs in a room, flames may invade the air ducts, requiring the timely closure of fire dampers to cut off ventilation lines, control the spread of fire, and isolate fire-prone areas. Therefore, an electrically operated actuator is needed that allows the valve to automatically reset under specific conditions, such as power failure.

[0003] The current working principle of electric actuators is as follows: after being powered on, the motor power is disconnected by a limit switch when the motor reaches the fully open or fully closed position. At the same time, the electromagnetic brake is energized to brake the output shaft. After power loss, the electromagnetic brake is de-energized, and the return spring drives the output shaft to return to its original position.

[0004] Existing electric actuators have the following shortcomings:

[0005] 1. Electric actuators require braking components such as electromagnetic brakes and limit switches that transmit control signals to the electromagnetic brakes, which leads to complex structures, larger sizes, and higher costs for electric actuators.

[0006] 2. The mechanical and electrical structures of the electric actuator for resetting the valve and the electric actuator for resetting the valve are different. That is, an electric actuator can only reset in one direction, such as resetting the valve open or resetting the valve closed, and cannot have the functions of resetting the valve open and resetting the valve closed at the same time.

[0007] 3. Electric actuators use return springs to achieve the reset function. Therefore, the return springs need to be pre-tightened. In some structures, the return spring is mounted on the output shaft, while in others, the output shaft and transmission parts are not detachable. This makes it difficult to pre-tighten the return spring, and special equipment must be used to pre-tighten the spring before assembling it with the transmission parts.

[0008] 4. The connection structure between the output shaft of the electric actuator and the valve stem varies. Some use a keyed connection or a square-headed connection, which keeps the output shaft and valve stem concentric. However, different valve stem sizes require a custom-made output shaft. Others use a clamp connection, which can accommodate valve stems of different sizes, but the concentricity between the output shaft and valve stem is poor.

[0009] Based on this, this application proposes a spring self-resetting electric actuator to solve the above-mentioned technical problems. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to overcome the defects of existing electric actuators, such as complex structure, single reset, and difficulty in implementing the reset function, and to provide a spring self-resetting electric actuator.

[0011] The present invention solves the above-mentioned technical problems through the following technical solution:

[0012] This invention provides a spring-driven self-resetting electric actuator, characterized in that it includes:

[0013] The housing has a mating shaft that passes through it. The end of the mating shaft is used to install a self-centering connector, which is used to install a valve stem.

[0014] The motor is mounted on the housing and has an output shaft;

[0015] A gear assembly is mounted on the housing, with one end meshing with the output shaft gear and the other end meshing with the mating shaft. The motor is used to drive the gear assembly to rotate the valve stem to open and close the valve.

[0016] According to one embodiment of the present invention, the self-centering connector is detachably connected to the mating shaft;

[0017] Both ends of the mating shaft are the mounting ends of the valve stem.

[0018] According to one embodiment of the present invention, the self-centering connector includes a bracket, a positioning ring, an inner claw, and an outer claw, wherein the positioning ring is provided with at least one positioning pin, and the positioning ring is mounted on the mating shaft;

[0019] The inner jaw and the outer jaw are installed in the bracket by a threaded connector and are used to bring them close together in the bracket to form a closed jaw. The jaw is coaxial with the positioning ring and is used to lock the valve stem.

[0020] According to one embodiment of the present invention, the inner claw has a first opening, and the outer claw has a second opening on the side facing the inner claw, the first opening and the second opening cooperating to form the jaws.

[0021] According to one embodiment of the present invention, the gear assembly includes a first gear, a second gear, and a third gear, wherein one end of the first gear meshes with the output shaft, and the other end meshes with the second gear;

[0022] The gear assembly further includes a reset mechanism, one end of which meshes with the second gear and the other end of which meshes with the third gear;

[0023] The outer periphery of the mating shaft is provided with a sector gear, one end of the third gear meshes with the sector gear, and two spaced adjusting screws are also provided on one side of the mating shaft, one end of the two adjusting screws facing the two end faces of the sector gear, for limiting the rotation position of the sector gear.

[0024] According to one embodiment of the present invention, the reset mechanism includes a manual shaft, on which a fourth gear is sleeved, one end of the fourth gear meshing with the second gear and the other end meshing with the third gear.

[0025] According to one embodiment of the present invention, the reset mechanism further includes a reset spring, which is sleeved on the manual shaft and located above the fourth gear.

[0026] According to one embodiment of the present invention, a locking mechanism is further included, the locking mechanism including a locking shaft, a torsion spring sleeved on the locking shaft, and a locking plate sleeved on the outside of the torsion spring, the locking plate having a first state and a second state under the rotation of the locking shaft;

[0027] In the first state, one end of the locking plate is engaged with the second gear to lock the position of the valve stem;

[0028] In the second state, the locking plate disengages from the second gear under the rotation of the torsion spring to unlock.

[0029] According to one embodiment of the present invention, the locking plate is tapered at one end facing the second gear for insertion into the tooth gap between adjacent teeth of the second gear.

[0030] According to one embodiment of the present invention, a micro switch is further provided inside the housing, and a stroke cam is further sleeved outside the mating shaft. The output end of the micro switch faces the stroke cam for switching the motor.

[0031] The positive and progressive effects of this invention are as follows:

[0032] The spring self-resetting electric actuator of the present invention has at least the following advantages:

[0033] 1. The valve stem is braked by using the motor as a stall mechanism, eliminating the need for an electromagnetic brake.

[0034] Second, it meets the installation requirements in both forward and reverse directions, enabling the electric actuator to simultaneously perform the functions of resetting the valve to open and resetting the valve to close.

[0035] Third, the return spring adopts a detachable structure, which is convenient for disassembly and assembly, and the pre-tightening operation is simpler.

[0036] Fourth, the self-centering connector can accommodate valve stems of different sizes while keeping the valve stem concentric with the self-centering connector. Attached Figure Description

[0037] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0038] Figure 1 This is a schematic diagram of the structure of the spring self-resetting electric actuator of the present invention;

[0039] Figure 2 for Figure 1 A schematic diagram of the spring self-resetting electric actuator from another angle;

[0040] Figure 3 This is a schematic diagram of the internal structure of the spring self-resetting electric actuator of the present invention;

[0041] Figure 4 This is a schematic diagram illustrating the fit between the self-centering connector and the valve stem of the present invention.

[0042] Figure 5 This is an exploded structural diagram of the self-centering connector of the present invention;

[0043] Figure 6 This is a schematic diagram of the gear assembly and output shaft of the present invention in terms of their engagement and transmission.

[0044] Figure 7 This is a schematic diagram of the engagement structure between the gear assembly and the locking mechanism of the present invention at an angle;

[0045] Figure 8 This is a schematic diagram of another engagement angle between the gear assembly and the locking mechanism of the present invention.

[0046] 10. Housing; 110. Self-centering connector; 111. Bracket; 112. Locating ring; 113. Inner jaw; 114. Outer jaw; 115. Locating pin; 116. Jaw; 117. First opening; 118. Second opening; 119. Sector gear; 1190. Adjusting screw; 120. Valve stem; 130. Microswitch; 140. Stroke cam; 150. Mating shaft;

[0047] 20. Motor; 210. Output shaft;

[0048] 30. Gear assembly; 310. First gear; 320. Second gear; 330. Third gear; 340. Reset mechanism; 341. Manual shaft; 342. Fourth gear; 343. Reset spring;

[0049] 40. Locking mechanism; 410. Locking shaft; 420. Torsion spring; 430. Locking plate. Detailed Implementation

[0050] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0051] Embodiments of the invention will now be described in detail with reference to the accompanying drawings. Preferred embodiments of the invention will now be described in detail, examples of which are illustrated in the drawings. Wherever possible, the same reference numerals will be used in all the drawings to denote the same or similar parts. Furthermore, although the terminology used herein is selected from commonly known and used terminology, some terms mentioned in this specification may have been chosen by the applicant at his or her discretion, and their detailed meanings are explained in the relevant sections of the description herein. Moreover, the invention should be understood not only by the actual terms used, but also by the meaning implied by each term.

[0052] Please refer to Figures 1 to 8 The present invention proposes a spring self-resetting electric actuator, including a housing 10, a motor 20 and a gear assembly 30. The housing 10 is provided with a mating shaft 150, which passes through the housing 10. The end of the mating shaft 150 is used to install a self-centering connector 110, which is used to install a valve stem 120.

[0053] Specifically, the housing 10 has an inner cavity for accommodating the motor 20 and the gear assembly 30, and the housing 10 is provided with a mating shaft 150 for detachably installing the self-centering connector 110.

[0054] The motor 20 is mounted on the housing 10 and has an output shaft 210. The motor 20 is located inside the housing 10 and is used to drive the valve stem 120 to rotate, thereby controlling the opening and closing of the valve.

[0055] The gear assembly 30 is mounted on the housing 10, with one end meshing with the output shaft 210 gear and the other end meshing with the mating shaft 150. The motor 20 is used to drive the gear assembly 30 to rotate the valve stem 120 to open and close the valve.

[0056] It should be noted that this invention does not use braking components such as electromagnetic brakes, but utilizes a motor 20 to open and close the valve. This simplifies the electric actuator, meets the design requirements for miniaturization, and helps reduce costs. Moreover, compared to electromagnetic brakes, the motor 20 has higher motion stability, thus making the electric actuator of this invention safer to operate.

[0057] In one embodiment, the self-centering connector 110 is detachably connected to the housing 10. Both opposite ends of the mating shaft 150 are mounting ends of the valve stem 120.

[0058] Multiple snap-fit ​​blocks are provided circumferentially at opposite ends of the mating shaft 150, and snap-fit ​​grooves are formed between adjacent snap-fit ​​blocks. One end of the self-centering connector 110 is provided with a snap-fit ​​groove to engage with a positioning block. The self-centering connector 110 is snapped into the snap-fit ​​groove by the positioning block so that it can be detachably installed with the mating shaft 150.

[0059] Reference Figures 1 to 4 Both ends of the shaft 150 can be fitted with self-centering connectors 110. Thus, when the self-centering connector 110 of the electric actuator is installed on the first side of the housing 10, the electric actuator electrically opens the valve and closes it upon power failure. Conversely, when the self-centering connector 110 of the electric actuator is installed on the second side of the housing 10, the electric actuator electrically closes the valve and opens it upon power failure. Therefore, the electric actuator of this invention allows for installation in both forward and reverse directions, simultaneously fulfilling the functions of resetting and opening the valve, thus broadening its applicability.

[0060] Please refer to Figure 5 In one embodiment, the self-centering connector 110 includes a bracket 111, a positioning ring 112, an inner jaw 113, and an outer jaw 114. The positioning ring 112 is provided with at least one positioning pin 115 and is mounted on a mating shaft. The inner jaw 113 and the outer jaw 114 are mounted in the bracket 111 by threaded connections and are used to bring themselves close together to form a closed jaw 116 in the bracket 111. The jaw 116 is coaxial with the positioning ring 112 and is used to engage the valve stem 120.

[0061] The bracket 111 has a cavity for accommodating the inner claw 113 and the outer claw 114. The bottom of the bracket 111 is provided with a mating hole, and the aforementioned positioning block is provided on the outer periphery of the mating hole. The bracket 111 is provided at the end of the mating shaft 150 through the mating hole and the positioning block to connect with the mating shaft 150.

[0062] The inner jaw 113 and outer jaw 114 are connected to the bracket 111 via two threaded connectors. When the inner jaw 113 and outer jaw 114 are installed facing each other and move towards each other, a closed jaw 116 is formed to accommodate the valve stem 120. The inner jaw 113 and outer jaw 114 are mounted on the positioning ring 112 by pins. The two pins are spaced 180 degrees apart on the positioning ring 112. Therefore, the inner jaw 113 and outer jaw 114 can move equally in opposite directions around the geometric center of the positioning ring 112, forming a closed jaw 116 concentric with the geometric center of the positioning ring 112 to accommodate valve stems 120 with different envelope sizes. The positioning ring 112 is also mounted on the bracket 111. During installation, the valve stem 120 is automatically centered and can accommodate valve stems 120 of different sizes due to the combined action of the positioning ring 112, inner jaw 113, and outer jaw 114.

[0063] Specifically, the inner jaw 113 has a first opening 117, and the outer jaw 114 has a second opening 118 on the side facing the inner jaw 113. The first opening 117 and the second opening 118 cooperate to form a jaw 116. The size of the jaw 116 is adjustable, so as to accommodate valve stems 120 of different sizes.

[0064] Please refer to Figures 6 to 8 In one embodiment, the gear assembly 30 includes a first gear 310, a second gear 320, and a third gear 330. One end of the first gear 310 meshes with the output shaft 210, and the other end meshes with the second gear 320. The gear assembly 30 also includes a reset mechanism 340, one end of which meshes with the second gear 320, and the other end of which meshes with the third gear 330.

[0065] It should be noted that the first gear 310, the second gear 320, and the third gear 330 are each mounted on a rotating shaft. Each of the first gear 310, the second gear 320, and the third gear 330 includes two gears of different sizes along the axial direction of the rotating shaft. Taking the first gear 310 as an example, the first gear 310 includes a large gear and a small gear spaced apart along the axial direction of the rotating shaft. The large gear and the small gear rotate synchronously. The large gear meshes with the output shaft 210, and the small gear meshes with the second gear 320. The second gear 320 and the third gear 330 are similar, and will not be described in detail here. This arrangement can reduce the space required for arranging the gear assembly 30.

[0066] A sector gear 119 is provided on the outer periphery of the mating shaft 150. One end of the third gear 330 meshes with the sector gear 119. Two spaced adjusting screws 1190 are also provided on one side of the mating shaft 150. One end of the two adjusting screws 1190 faces the two end faces of the sector gear 119 and is used to limit the rotation position of the sector gear 119.

[0067] The sector gear 119 has two side end faces, and each of the two adjusting screws 1190 corresponds to one side end face. When the sector gear 119 rotates due to the rotation of the output shaft 210 of the motor 20, the side end face of the sector gear 119 rotates toward the adjusting screw 1190 to abut against the end of the adjusting screw 1190, thereby stopping the rotation.

[0068] Furthermore, the reset mechanism 340 includes a manual shaft 341, on which a fourth gear 342 is sleeved. One end of the fourth gear 342 meshes with the second gear 320, and the other end meshes with the third gear 330.

[0069] That is, the valve stem 120 can be driven to rotate by the motor 20 or the manual shaft 341. Both methods are acceptable and can be adapted to different usage scenarios.

[0070] Furthermore, the reset mechanism 340 also includes a reset spring 343, which is sleeved on the manual shaft 341 and located above the fourth gear 342.

[0071] The reset spring 343 is used to automatically rotate the valve stem 120 to the initial position when the motor 20 loses power.

[0072] Please refer to Figure 6 and Figure 7 In one embodiment, a locking mechanism 40 is also included. The locking mechanism 40 includes a locking shaft 410, a torsion spring 420 sleeved on the locking shaft 410, and a locking plate 430 sleeved on the outside of the torsion spring 420. The locking plate 430 has a first state and a second state under the rotation of the locking shaft 410. In the first state, one end of the locking plate 430 is engaged with the second gear 320 to lock the position of the valve stem 120. In the second state, the locking plate 430 is disengaged from the second gear 320 under the rotation of the torsion spring 420 to unlock.

[0073] The locking mechanism 40 is used to limit the rotation position of the valve stem 120, thereby enabling manual locking.

[0074] Specifically, the locking plate 430 is tapered at one end facing the second gear 320 so as to be inserted into the tooth gap between adjacent teeth of the second gear 320.

[0075] It should be noted that during manual operation, if it is necessary to keep the position of the electric actuator unchanged, the locking shaft 410 can be manually rotated clockwise to make the locking plate 430 contact the backlash of the second gear 320. At this time, the manual handle is released, and the second gear 320 will rotate a small angle under the action of the return spring 343, pressing the locking plate 430, so that the top plate is limited by the bottom plate and does not move. The rotation of the return spring 343 will be braked, realizing the function of manual locking. When the electric actuator is activated again, the locking plate 430 is reset by the action of the torsion spring 420 and disengages from the second gear 320.

[0076] In one embodiment, a micro switch 130 is also provided inside the housing 10, and a stroke cam 140 is also sleeved outside the cooperating shaft 150. The output end of the micro switch 130 faces the stroke cam 140 for switching the motor 20.

[0077] The electric actuator is also equipped with a terminal block and a junction box cover for easy wiring. The junction box cover has multiple outlet holes to meet different needs. The electric actuator also includes a transformer to meet different voltage requirements.

[0078] by Figure 6 Taking the direction of the valve as an example, the electric actuator can achieve the effects of electric valve opening, valve closing upon power failure, manual valve opening, and manual locking. The specific operation procedure is as follows:

[0079] The electric valve opening process includes: the motor 20 is energized, and the output shaft 210 drives the first gear 310, the second gear 320, the fourth gear 342, the third gear 330, and the sector gear 119 to rotate, which in turn drives the valve stem 120 to rotate to the valve opening position. At this time, the valve stem 120 abuts against the end of the adjusting screw 1190. At the same time, the return spring 343 in the reset mechanism 340 is in a continuously energized state.

[0080] The power failure valve closing process includes: the motor 20 loses power, the reset spring 343 drives the third gear 330 and the sector gear 119 to rotate, so that the valve stem 120 automatically returns to the initial valve closing position.

[0081] The manual valve opening process includes: the handle rotates the manual shaft 341, the fourth gear 342 drives the third gear 330 and the sector gear 119 to rotate, so that the valve stem 120 rotates to the valve opening position.

[0082] The manual locking process includes: During manual operation, if the position of valve stem 120 needs to remain unchanged, the locking shaft 410 can be manually rotated. The locking shaft 410 drives the torsion spring 420 to rotate, causing the locking plate 430 to rise and engage with the backlash of the second gear 320. Then, the manual handle is released, and the second gear 320 rotates a small angle under the action of the return spring 343, pressing down on the locking plate 430. At the same time, the locking plate 430 is kept stationary by the limit of the base plate, and the return spring 343 is braked, thus achieving the manual locking function. When powered again, the locking plate 430 is reset by the action of the torsion spring 420 and disengages from the second gear 320.

[0083] This application uses specific terms to describe embodiments of the application. Terms such as "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the application. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0084] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A spring-driven self-resetting electric actuator, characterized in that, include: The housing has a mating shaft that passes through the housing. The end of the mating shaft is used to install a self-centering connector, which is used to install a valve stem. The motor is mounted on the housing and has an output shaft; A gear assembly is disposed on the housing, with one end meshing with the output shaft gear and the other end meshing with the mating shaft. The motor is used to drive the gear assembly to rotate the valve stem to open and close the valve. The gear assembly includes a first gear, a second gear, and a third gear. One end of the first gear meshes with the output shaft, and the other end meshes with the second gear. The gear assembly further includes a reset mechanism, one end of which meshes with the second gear and the other end of which meshes with the third gear; The outer periphery of the mating shaft is provided with a sector gear, one end of the third gear meshes with the sector gear, and two spaced adjusting screws are also provided on one side of the mating shaft, one end of the two adjusting screws facing the two end faces of the sector gear, for limiting the rotation position of the sector gear; The reset mechanism includes a manual shaft, on which a fourth gear is sleeved. One end of the fourth gear meshes with the second gear, and the other end meshes with the third gear. The reset mechanism also includes a reset spring, which is sleeved on the manual shaft and located above the fourth gear.

2. The spring self-resetting electric actuator according to claim 1, characterized in that, The self-centering connector is detachably connected to the mating shaft; Both ends of the mating shaft are the mounting ends of the valve stem.

3. The spring self-resetting electric actuator according to claim 2, characterized in that, The self-centering connector includes a bracket, a positioning ring, an inner claw, and an outer claw. The positioning ring is provided with at least one positioning pin and is installed on the mating shaft. The inner jaw and the outer jaw are installed in the bracket by a threaded connector and are used to bring them close together in the bracket to form a closed jaw. The jaw is coaxial with the positioning ring and is used to lock the valve stem.

4. The spring self-resetting electric actuator according to claim 3, characterized in that, The inner claw has a first opening, and the outer claw has a second opening on the side facing the inner claw. The first opening and the second opening cooperate to form the jaws.

5. The spring self-resetting electric actuator according to claim 1, characterized in that, It also includes a locking mechanism, which includes a locking shaft, a torsion spring sleeved on the locking shaft, and a locking plate sleeved on the outside of the torsion spring. The locking plate has a first state and a second state under the rotation of the locking shaft. In the first state, one end of the locking plate is engaged with the second gear to lock the position of the valve stem; In the second state, the locking plate disengages from the second gear under the rotation of the torsion spring to unlock.

6. The spring self-resetting electric actuator according to claim 5, characterized in that, The locking plate is tapered at one end facing the second gear, so as to be inserted into the gap between adjacent teeth of the second gear.

7. The spring self-resetting electric actuator according to claim 1, characterized in that, The housing is also equipped with a micro switch, and a stroke cam is also fitted outside the mating shaft. The output end of the micro switch faces the stroke cam to switch the motor on and off.

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