A power-failure reset electric actuator

Abstract

A power-failure reset electric actuator disclosed by the present invention comprises an electric actuator, a gearbox, an electromagnetic clutch and a spring resetter. The electromagnetic clutch includes a first half clutch and a second half clutch. The first half clutch is provided with a first toothed disc and a reset spring. The second half clutch is provided with a second toothed disc and an electromagnetic coil. The second half clutch is cooperatively connected with the spring resetter. The spring resetter includes a main shaft, a rack and a spring assembly. One end of the rack abuts against the spring assembly, and the other end of the rack is in transmission connection with the main shaft. A connecting shaft is movably arranged in the second half clutch, and the second toothed disc is in transmission connection with the main shaft through the connecting shaft. When the electromagnetic coil is powered on, the first toothed disc meshes with the second toothed disc, and the connecting shaft drives the main shaft to rotate. The rotation of the main shaft causes the rack to compress the spring assembly. When the electromagnetic coil is powered off, the reset spring resets, the first toothed disc is disengaged from the second toothed disc, and the reset of the spring assembly drives the rack to move, and the main shaft rotates back, realizing the power-failure reset function.

Description

Technical Field

[0001] The present invention relates to the technical field of electric actuators, and particularly to a power-failure reset electric actuator. Background Art

[0002] Electric actuators are key devices widely used in various industrial systems to drive valves to open and close. The reliability and stability of their operation will directly affect the performance level and overall safety of the entire system. Conventional electric actuators mainly consist of two major parts: a drive unit and a transmission mechanism. The transmission mechanism usually includes a reduction mechanism and an output shaft. The drive unit usually uses high-performance servo motors, stepper motors, or permanent magnet synchronous direct drive motors. The reduction mechanism includes components such as gearboxes and worm gears. Its main function is to convert the high-speed low-torque output of the motor into a low-speed high-torque mechanical motion suitable for valve operation.

[0003] When the motor receives an instruction from the control system, it will start to operate. The rotational motion of the motor is converted into an output form (linear or rotational) suitable for the valve through the reduction mechanism. After reaching the target position, the motor stops operating. Some models of electric actuators are also equipped with a self-locking function, which can maintain the valve state (such as fully open, fully closed, or intermediate adjustment). However, electric actuators highly rely on power supply, which brings certain risks in the actual operation process. Once a sudden accident or other unforeseen factors cause a sudden power outage in the power system, the electric actuator will no longer be able to perform its function of adjusting the valve. In this case, the valve cannot be adjusted to a position that meets the safety requirements, easily leading to valve out-of-control, and further causing a series of safety risks and property losses. To cope with this special situation, electric actuators are usually also equipped with a handwheel for manual control in case of insufficient power supply or faults. Nevertheless, if the operator fails to perform manual operation in time, there will still be potential safety hazards. In addition, the torque required for manual operation is relatively large, the operation process is laborious, and the efficiency of manual operation is relatively low, making it difficult to meet the rapid response requirements in case of emergencies. Therefore, it is necessary to make improvements. Summary of the Invention

[0004] The purpose of the present invention is to provide a power-failure reset electric actuator in view of the defects and deficiencies of the prior art. Its structure is simple and reasonable, and it is convenient to operate. When power fails, the first tooth disc disengages from the second tooth disc under the action of the reset spring, blocking the power of the gearbox to the main shaft, and the compressed spring assembly resets, causing the main shaft to rotate, thereby driving the valve to close. If the electric actuator loses power, the valve will automatically close.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] An electric actuator with power-off reset according to the present invention includes an electric actuator, a gearbox, an electromagnetic clutch, and a spring resetter. The electric actuator is drivingly connected to the electromagnetic clutch through the gearbox. The electromagnetic clutch includes a first half clutch and a second half clutch that are separately arranged. The first half clutch is drivingly connected to the gearbox. A first gear disk is fixedly arranged on the first half clutch. A second gear disk that cooperates with the first gear disk is rotatably arranged on the second half clutch. A reset spring is arranged on the first half clutch. An electromagnetic coil is arranged inside the second half clutch. The second half clutch is cooperatively connected to the spring resetter. The spring resetter includes a main shaft, a rack, and a spring assembly. One end of the rack abuts against the spring assembly, and the other end of the rack is drivingly connected to the main shaft. A connecting shaft is also movably arranged inside the second half clutch. The second gear disk is drivingly connected to the main shaft through the connecting shaft. When the electromagnetic coil is energized, an electromagnetic attraction force is generated between the first half clutch and the second half clutch, causing the first gear disk and the second gear disk to engage. The connecting shaft drives the main shaft to rotate, and the main shaft drives the rack to compress the spring assembly. When the electromagnetic coil is de-energized, the first half clutch is reset under the action of the reset spring, the first gear disk and the second gear disk are disengaged, and the reset of the spring assembly drives the rack to move, causing the main shaft to perform a rotary motion to achieve reset.

[0007] Further, a transmission disk is also movably arranged inside the second half clutch. The second gear disk is arranged on the transmission disk and fixedly connected to the transmission disk. A first external gear ring is arranged on the outer wall of the connecting shaft. A first internal gear ring that cooperates with the first external gear ring is arranged on the inner wall of the transmission disk. The upper end of the connecting shaft extends into the first half clutch.

[0008] Further, a second internal gear ring is arranged on the inner wall of the connecting shaft. A second external gear ring that cooperates with the second internal gear ring is arranged on the upper end of the main shaft.

[0009] Further, a valve position transmitter is also arranged on the gearbox. The valve position transmitter is electrically connected to the electric actuator. The connecting shaft is hollow. A displacement rod is arranged inside the connecting shaft. A gap is formed between the displacement rod and the connecting shaft. The lower end of the displacement rod is fixedly connected to the main shaft. The upper end of the displacement rod extends into the valve position transmitter and is connected to the valve position transmitter.

[0010] Further, a bushing is fixedly arranged on the upper end of the first half clutch. The bushing extends into the gearbox and is drivingly connected to the gearbox.

[0011] Further, the electromagnetic clutch further includes a sheath. The first half clutch and the second half clutch are both placed inside the sheath.

[0012] Furthermore, the spring resetter further includes a housing and a limit block. Sealing caps are provided at both ends of the housing. The housing and the sealing caps cooperate to form an accommodation space. The main shaft, the rack, and the spring assembly are all arranged in the accommodation space. The limit block is sleeved on the main shaft.

[0013] Furthermore, a bushing is also arranged between the limit block and the housing.

[0014] Furthermore, a spring seat is arranged at one end of the rack away from the main shaft. One end of the spring assembly abuts against the spring seat, and the other end of the spring assembly abuts against the sealing cap.

[0015] Furthermore, a plurality of tooth grooves are arranged on the rack, and a third external tooth ring that cooperates with the tooth grooves is arranged on the main shaft.

[0016] The beneficial effects of the present invention are as follows: When the electric actuator controls the valve to be in a fully open state or a partially open state through the electromagnetic clutch, if a sudden power supply interruption occurs, that is, a power failure occurs. At this time, the first gear disk disengages from the second gear disk under the action of the return spring, and the power of the gearbox cannot be transmitted to the main shaft. In this state, the originally compressed spring assembly will gradually return to the uncompressed state by virtue of its own elastic force. This reset process will directly drive the main shaft to generate a rotary motion, and the rotary motion of the main shaft will further drive the connected valve to perform a closing action. That is, if a power failure occurs during the opening action of the electric actuator, the valve will automatically close. Because once a power failure occurs, not only a single part is affected, but it is very likely that other pipelines of the entire system will also fall into a power failure state at the same time. In this case, the fluid transmission must be immediately cut off to avoid potential safety hazards.

[0017] A displacement rod connected to the main shaft and a valve position transmitter connected in cooperation with the displacement rod are also provided. When the main shaft makes a rotary motion, the displacement rod connected to the main shaft will also make a rotary motion synchronously with the main shaft. After the system regains power supply and is powered on, the valve position transmitter will receive the rotation angle and displacement change of the displacement rod, and convert them into corresponding electrical signals and transmit them to the electric actuator to ensure that the electric actuator can receive the current valve position, thereby ensuring the normal operation and precise control of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of the present invention during operation;

[0019] Figure 2 is a schematic cross-sectional structural diagram of the present invention during operation;

[0020] Figure 3 is Figure 2 an enlarged schematic structural diagram of part A in

[0021] Figure 4 It is a schematic diagram of the exploded structure of the electromagnetic clutch and the spring returner;

[0022] Figure 5 is a schematic diagram of the structure when the first half clutch and the second half clutch are separated;

[0023] Figure 6 is a schematic diagram of the exploded structure of the first half of the clutch;

[0024] Figure 7 is a schematic diagram of the exploded structure of the second half of the clutch;

[0025] Figure 8 It is a schematic diagram of the structure of the main shaft.

[0026] Figures 1-8 In: 1. Electric actuator; 2. Gearbox; 3. Electromagnetic clutch; 31. First half clutch; 311. First toothed disc; 312. Return spring; 3121. Connecting column; 3122. Bolt; 313. Bushing; 314. First connecting sleeve; 3141. First ring groove; 315. Second connecting sleeve; 32. Second half clutch; 321. Second toothed disc; 322. Electromagnetic coil; 323. Connecting shaft; 3231. First outer gear ring; 3232. Second Inner gear ring; 324, transmission plate; 3241, first inner gear ring; 325, third connecting sleeve; 3251, second ring groove; 33, sleeve; 331, cover plate; 4, spring returner; 41, main shaft; 411, second outer gear ring; 412, third outer gear ring; 42, rack; 421, spring seat; 422, tooth groove; 43, spring assembly; 44, housing; 441, cover; 45, limit block; 46, bushing; 5, valve position transmitter; 51, displacement rod. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings.

[0028] like Figures 1-8 The electric actuator shown in FIG. 1 includes an electric actuator 1, a gear box 2, an electromagnetic clutch 3 and a spring resetter 4. The electric actuator 1 is connected to the electromagnetic clutch 3 through the gear box 2. Figure 5, the electromagnetic clutch 3 includes a first half-clutch 31 and a second half-clutch 32 which are separately arranged. The first half-clutch 31 is arranged above the second half-clutch 32. Preferably, in this embodiment, a bushing 313 is fixedly arranged at the upper end of the first half-clutch 31. The bushing 313 extends into the gearbox 2 and is in driving connection with the gearbox 2 to transmit power. A first tooth disc 311 is fixedly arranged at the lower end of the first half-clutch 31. A second tooth disc 321 which is matched with the first tooth disc 311 is rotatably arranged at the upper end of the second half-clutch 32. A return spring 312 is arranged on the first half-clutch 31. An electromagnetic coil 322 is arranged in the second half-clutch 32. The second half-clutch 32 is cooperatively connected with a spring reset device 4. The spring reset device 4 includes a main shaft 41, a rack 42 and a spring assembly 43. One end of the rack 42 abuts against the spring assembly 43, and the other end of the rack 42 is in driving connection with the main shaft 41. A connecting shaft 323 is also movably arranged in the second half-clutch 32. The second tooth disc 321 is in driving connection with the main shaft 41 through the connecting shaft 323. The main shaft 41 is in cooperation connection with a valve. Specifically, in this embodiment, referring to Figure 2 and Figure 4 , racks 42 which are matched with the main shaft 41 are arranged on both sides of the main shaft 41. A plurality of tooth grooves 422 are arranged on the rack 42. The tooth grooves 422 of the two racks 42 are arranged oppositely. By arranging the two racks 42, the transmission efficiency is higher. Both the first half-clutch 31 and the second half-clutch 32 are made of magnetic conductive materials. When the electromagnetic coil 322 is powered on, an electromagnetic attraction force is generated between the first half-clutch 31 and the second half-clutch 32. The electromagnetic attraction force makes the first half-clutch 31 move downward against the elastic force of the return spring 312, and the first tooth disc 311 meshes with the second tooth disc 321. The main shaft 41 is driven to rotate through the connecting shaft 323, so that the power of the gearbox 2 is transmitted to the main shaft 41, and further the valve opening is controlled. The main shaft 41 drives the rack 42 to move, so that the spring assembly 43 is compressed by force and stores energy; when the electromagnetic coil 322 is powered off, the first tooth disc 311 disengages from the second tooth disc 321 under the action of the return spring 312, and the power of the gearbox 2 cannot be transmitted to the main shaft 41. The spring assembly 43 releases the stored energy during the reset process, drives the rack 42 to move in the reverse direction, so that the main shaft 41 makes a rotary motion to realize reset, and drives the valve to close.

[0029] Specifically, the first half clutch 31 further includes a first connecting sleeve 314 and a second connecting sleeve 315. The second connecting sleeve 315 is sleeved outside the first connecting sleeve 314. The second connecting sleeve 315 and the first connecting sleeve 314 are fixedly connected through a connecting column 3121. A first annular groove 3141 is provided inside the first connecting sleeve 314. The upper end of the connecting column 3121 passes through the first annular groove 3141. A bolt 3122 is fixedly connected to the upper end of the connecting column 3121. The return spring 312 is sleeved on the upper end of the connecting column 3121. The upper end of the return spring 312 abuts against the bolt 3122, and the lower end of the return spring 312 abuts against the first annular groove 3141. When the first half clutch 31 moves downward under the action of electromagnetic suction, the connecting column 3121 moves downward synchronously, and the distance between the bolt 3122 and the first annular groove 3141 shortens, causing the return spring 312 to be compressed and store energy.

[0030] When the electric actuator 1 controls the valve to be in a fully open state or a partially open state through the electromagnetic clutch 3, if a sudden power supply interruption occurs, that is, a power failure phenomenon occurs. At this time, the first gear disk 311 disengages from the second gear disk 321 under the action of the return spring 312, and the power of the gearbox 2 cannot be transmitted to the main shaft 41. In this state, the originally compressed spring assembly 43 will gradually return to the uncompressed state by virtue of its own elastic force. This reset process will directly drive the main shaft 41 to generate a rotary motion, and the rotary motion of the main shaft 41 will further drive the connected valve to perform a closing action. That is, if a power failure occurs when the electric actuator 1 performs an opening action, the valve will automatically close. Because once a power failure occurs, not only a single part is affected, it is very likely that other pipelines of the entire system will also fall into a power failure state at the same time. In this case, the fluid transmission must be immediately cut off to avoid potential safety hazards.

[0031] Preferably, in this embodiment, refer to Figures 2-3 , a transmission disk 324 is also movably provided inside the second half clutch 32. The second gear disk 321 is provided on the transmission disk 324 and fixedly connected to the transmission disk 324. A first external gear ring 3231 is provided on the outer wall of the connecting shaft 323. A first internal gear ring 3241 that mates with the first external gear ring 3231 is provided on the inner wall of the transmission disk 324. The upper end of the connecting shaft 323 extends into the first half clutch 31. The first external gear ring 3231 and the first internal gear ring 3241 mesh to transmit power. When the second gear disk 321 rotates, it drives the transmission disk 324 and the connecting shaft 323 to rotate synchronously.

[0032] Preferably, in this embodiment, refer to Figure 7, the second half clutch 32 further includes a third connecting sleeve 325. A second annular groove 3251 is provided in the third connecting sleeve 325, and the electromagnetic coil 322 is placed in the second annular groove 3251. The connecting shaft 323 is hollow, and a second internal gear ring 3232 is provided on the inner wall of the connecting shaft 323. A second external gear ring 411 meshing with the second internal gear ring 3232 is provided at the upper end of the main shaft 41. The second internal gear ring 3232 and the second external gear ring 411 mesh to transmit power, and the rotation of the connecting shaft 323 drives the main shaft 41 to rotate synchronously.

[0033] Specifically, referring to Figures 2-3 , when the electric actuator 1 works, it transmits power to the gearbox 2. The gearbox 2 rotates, driving the sleeve 313 to rotate. The sleeve 313 is fixedly connected to the first half clutch 31, and the sleeve 313 drives the first half clutch 31 to rotate, thereby driving the first gear disk 311 to rotate. When the electromagnetic coil 322 is energized, the first gear disk 311 meshes with the second gear disk 321. The rotation of the first gear disk 311 drives the second gear disk 321 to rotate, and the rotation of the second gear disk 321 drives the connecting shaft 323 meshing with the second gear disk 321 to rotate. The rotation of the connecting shaft 323 drives the main shaft 41 to rotate synchronously.

[0034] Preferably, in this embodiment, a valve position transmitter 5 is further provided on the gearbox 2. The valve position transmitter 5 is electrically connected to the electric actuator 1. The valve position transmitter 5 is used to monitor the valve opening (position) in real time. A displacement rod 51 is provided in the connecting shaft 323. A gap is formed between the displacement rod 51 and the connecting shaft 323 to ensure that there is no interference between the two during movement. The lower end of the displacement rod 51 is fixedly connected to the main shaft 41, and the upper end of the displacement rod 51 extends into the valve position transmitter 5 and is connected to the valve position transmitter 5. Specifically, when the main shaft 41 rotates under the action of the driving force, it drives the displacement rod 51 to rotate synchronously. At this time, the valve position transmitter 5 will receive the rotation angle and displacement change of the displacement rod 51, and convert them into corresponding electrical signals and transmit them to the electric actuator 1, so that the electric actuator 1 can accurately control the opening or closing of the valve according to the received signals.

[0035] For the electric actuator 1, if the electric actuator 1 was in the open state before power failure and was suddenly closed due to power failure, then after the power is restored and restarted, the electric actuator 1 will face a problem that it cannot accurately determine the actual position of the valve. This uncertainty will bring potential risks. If the valve is already in the open position and the electric actuator 1 still rotates in the direction of opening the valve according to the instruction before power failure, it is very likely that due to excessive rotation, the internal parts will bear too much tensile force and be damaged seriously. In the present invention, a valve position transmitter 5 is provided to monitor the valve state. When the electric actuator 1 is restarted after being powered on, if the signal transmitted by the valve position transmitter 5 shows that the valve is already in the fully closed position, then the electric actuator 1 will only be able to perform the opening action and will not perform the closing action anymore, avoiding excessive rotation and causing damage to the internal parts.

[0036] Specifically, referring to Figures 2-3 , when the main shaft 41 makes a rotary motion, the displacement rod 51 connected to the main shaft 41 will also make a rotary motion synchronously with the main shaft 41. After the system regains power supply and is powered on, the valve position transmitter 5 will receive the rotation angle and displacement change of the displacement rod 51 and convert them into corresponding electrical signals to be transmitted to the electric actuator 1, so as to ensure that the electric actuator 1 can receive the current valve position, thereby ensuring the normal operation and precise control of the entire system.

[0037] Preferably, in this embodiment, referring to Figure 4 , the electromagnetic clutch 3 further includes a sheath 33. A cover plate 331 is provided at the upper end of the sheath 33. An accommodation cavity is formed inside the sheath 33 in cooperation with the cover plate 331. The first half clutch 31 and the second half clutch 32 are both placed in the accommodation cavity, playing a protective role to prevent dust and impurities from entering and affecting the use.

[0038] Preferably, in this embodiment, referring to Figure 4 , the spring returner 4 further includes a housing 44 and a limit block 45. Sealing covers 441 are provided at both ends of the housing 44. An accommodation space is formed by the housing 44 in cooperation with the sealing covers 441. The main shaft 41, the rack 42 and the spring assembly 43 are all arranged in the accommodation space. The limit block 45 is sleeved on the main shaft 41, playing a limiting role. Preferably, in this embodiment, a bushing 46 is further provided between the limit block 45 and the housing 44, which can effectively reduce the friction between the two and extend the service life.

[0039] Preferably, referring to Figure 8, a third external gear ring 412 that mates with the tooth groove 422 is provided on the main shaft 41, and the tooth groove 422 meshes with the third external gear ring 412 to transmit power. A spring seat 421 is provided at one end of the rack 42 away from the main shaft 41. One end of the spring assembly 43 abuts against the spring seat 421, and the other end of the spring assembly 43 abuts against the cover 441. The spring assembly 43 includes multiple groups of springs. Specifically, when the electromagnetic coil 322 is powered on and the main shaft 41 rotates under the action of the driving force, it drives the rack 42 to move, causing the spring assembly 43 to be compressed by force; when the electromagnetic coil 322 is powered off, the spring assembly 43 resets, driving the rack 42 to move in the direction close to the main shaft 41. The rack 42 drives the main shaft 41 to perform a rotary motion, causing the main shaft 41 to drive the valve to perform a closing action.

[0040] The above description is only a preferred embodiment of the present invention. Therefore, any equivalent changes or modifications made according to the structure, characteristics, and principles described in the scope of this invention patent application are included in the scope of this invention patent application.

Claims

1. An electric actuator with power-off reset, characterized in that: It includes an electric actuator, a gearbox, an electromagnetic clutch and a spring returner. The electric actuator is drivingly connected to the electromagnetic clutch through the gearbox. The electromagnetic clutch includes a first half clutch and a second half clutch which are separately arranged. The first half clutch is drivingly connected to the gearbox. A first toothed disc is fixedly arranged on the first half clutch. A second toothed disc which is matched with the first toothed disc is rotatably arranged on the second half clutch. A return spring is arranged on the first half clutch. An electromagnetic coil is arranged in the second half clutch. The second half clutch is cooperatively connected with the spring returner. The spring returner includes a main shaft, a rack and a spring assembly. One end of the rack abuts against the spring assembly, and the other end of the rack is drivingly connected to the main shaft. A connecting shaft is also movably arranged in the second half clutch. The second toothed disc is drivingly connected to the main shaft through the connecting shaft. When the electromagnetic coil is powered on, an electromagnetic attraction force is generated between the first half clutch and the second half clutch, so that the first toothed disc meshes with the second toothed disc, and the connecting shaft drives the main shaft to rotate. The main shaft drives the rack to compress the spring assembly. When the electromagnetic coil is powered off, the first half clutch resets under the action of the return spring, the first toothed disc is disengaged from the second toothed disc, and the reset of the spring assembly drives the rack to move, so that the main shaft makes a rotary motion to achieve reset.

2. The power-failure reset electric actuator according to claim 1, characterized in that: A transmission disc is also movably arranged in the second half clutch. The second toothed disc is arranged on the transmission disc and fixedly connected to the transmission disc. A first external toothed ring is arranged on the outer wall of the connecting shaft. A first internal toothed ring which is matched with the first external toothed ring is arranged on the inner wall of the transmission disc. The upper end of the connecting shaft extends into the first half clutch.

3. The power-off reset electric actuator according to claim 1, characterized in that: A second internal toothed ring is arranged on the inner wall of the connecting shaft. A second external toothed ring which is matched with the second internal toothed ring is arranged on the upper end of the main shaft.

4. The power-off reset electric actuator according to claim 1, characterized in that: A valve position transmitter is also arranged on the gearbox. The valve position transmitter is electrically connected to the electric actuator. The connecting shaft is hollow. A displacement rod is arranged in the connecting shaft. A gap is formed between the displacement rod and the connecting shaft. The lower end of the displacement rod is fixedly connected to the main shaft. The upper end of the displacement rod extends into the valve position transmitter and is connected to the valve position transmitter.

5. The power-off reset electric actuator according to claim 1, characterized in that: A bushing is fixedly arranged on the upper end of the first half clutch. The bushing extends into the gearbox and is drivingly connected to the gearbox.

6. The power-off reset electric actuator according to claim 1, characterized in that: The electromagnetic clutch further includes a sheath. The first half clutch and the second half clutch are both arranged in the sheath.

7. An electric actuator with power-off reset according to claim 1, characterized in that: The spring returner further includes a housing and a limit block. Seals are arranged at both ends of the housing. The housing and the seals cooperate to form an accommodation space. The main shaft, the rack and the spring assembly are all arranged in the accommodation space. The limit block is sleeved on the main shaft.

8. An electrically actuated mechanism with power-off reset according to claim 7, characterized in that: A bushing is also arranged between the limit block and the housing.

9. The power-off reset electric actuator according to claim 7, characterized in that: A spring seat is arranged at one end of the rack away from the main shaft. One end of the spring assembly abuts against the spring seat, and the other end of the spring assembly abuts against the seal.

10. A power-off reset electric actuator according to claim 1, characterized in that: A plurality of tooth grooves are arranged on the rack. A third external toothed ring which is matched with the tooth grooves is arranged on the main shaft.

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