Linear electric actuator with overload protection

Abstract

This utility model discloses a linear electric actuator with overload protection, including a housing, a drive motor mounted on the housing, an overload protection mechanism mounted on the drive motor, and an actuator mounted on the output shaft end of the drive motor. The overload protection mechanism includes a mounting base, with fixed plates fixedly connected to both sides of the bottom of the mounting base. A fixed ring is fixedly installed inside the mounting base, and two elastic plates are fixedly connected to the inner side of the fixed ring. A connecting plate is fixedly connected between the two elastic plates. This belongs to the technical field of linear electric actuators. In this linear electric actuator with overload protection, the first and second metal plates deform upon heating, causing the entire actuator to bend upwards. The deformation of the first and second metal plates moves the connecting plate, which in turn moves the moving contact, causing the stationary contact to separate from the moving contact, disconnecting the power supply to the drive motor and providing excellent overload protection for the drive motor.

Description

Technical Field

[0001] This utility model relates to the technical field of linear electric actuators, specifically a linear electric actuator with overload protection. Background Technology

[0002] Linear electric actuators are core actuators in industrial automation systems, mainly used to convert control signals into linear motion to drive valves, baffles and other equipment for precise adjustment. In the existing technology, when a linear electric actuator is used under abnormal load, the motor is prone to overload and failure, and the protection effect on the motor is not ideal.

[0003] For example, patent publication number CN220152006U describes a linear electric actuator that replaces an electrothermal actuator and includes: a housing; a motor installed within the housing; a gear reduction mechanism installed within the housing with its primary gear fixed to the output shaft of the motor; and an actuator comprising a screw and a nut, the actuator gear of the gear reduction mechanism being fixed to the nut, the nut being threaded onto the screw, and the screw being retractably mounted on the housing. This linear electric actuator allows for control of the stroke and thrust via a host computer. Replacing the existing electrothermal sensor with a linear electric actuator significantly reduces system costs and provides good control. However, this linear electric actuator suffers from a problem where, under abnormal loads, the motor is prone to overload and failure, resulting in insufficient motor protection. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a linear electric actuator with overload protection, which solves the problem that when a linear electric actuator experiences abnormal loads during use, the motor is prone to overload and failure, and the protection effect on the motor is not ideal.

[0005] To achieve the above objectives, this utility model is implemented through the following technical solution: a linear electric actuator with overload protection, including a housing, a drive motor mounted on the housing, an overload protection mechanism mounted on the drive motor, and an actuator mounted on the output shaft end of the drive motor;

[0006] The overload protection mechanism includes a mounting base, with fixed plates fixedly connected to both sides of the bottom of the mounting base. A fixed ring is fixedly installed inside the mounting base, and two elastic plates are fixedly connected to the inner side of the fixed ring. A connecting plate is fixedly connected between the two elastic plates. A stationary contact is provided at the bottom of the connecting plate, and a moving contact is fixedly connected to the bottom surface of the connecting plate. A first metal plate is provided at the top of the connecting plate, and a second metal plate is fixedly connected to the top of the first metal plate. Fixed bolts and support frames are respectively provided at both ends of the first and second metal plates, and mounting bolts are provided on the support frames.

[0007] Preferably, the mounting base is fixedly mounted on the drive motor by a fixing plate, and the mounting base is connected to the inside of the drive motor, so that the temperature inside the drive motor can enter the interior of the mounting base.

[0008] Preferably, the coefficient of thermal expansion of the first metal sheet is greater than that of the second metal sheet, and the first metal sheet and the second metal sheet are welded together so that the first metal sheet and the second metal sheet can form a thermal bimetallic sheet and bend upward.

[0009] Preferably, one end of the first metal sheet and the second metal sheet are fixedly mounted on the connecting plate by fixing bolts, and the other end of the first metal sheet and the second metal sheet are fixedly connected to the support frame.

[0010] Preferably, the support frame is disposed inside the mounting base, and the support frame is fixedly connected to the inner wall of the mounting base by mounting bolts, so that one end of the first metal sheet and the second metal sheet can be fixed by the support frame.

[0011] Preferably, the actuator includes a worm gear with a worm wheel on one side. A driving gear is fixedly connected to the bottom end of the worm wheel, and a driven gear is provided on one side of the driving gear. Both ends of the worm gear are rotatably connected to the inner wall of the housing via bearings. The worm gear meshes with the worm wheel. A nut is fixedly connected to the driven gear, and a screw is threadedly connected inside the nut. A guide block is fixedly connected to the top end of the screw, and a guide rod is slidably connected to the guide block. An output rod is fixedly connected to the bottom end of the screw, enabling the self-locking function to maintain the load position and reduce the burden of restarting the drive motor.

[0012] This invention provides a linear electric actuator with overload protection. Compared with the prior art, it has the following advantages:

[0013] 1. This linear electric actuator with overload protection deforms due to heat on the first and second metal plates, causing the whole to bend upward. The deformation of the first and second metal plates causes the connecting plate to move, which in turn causes the moving contact to move, separating the stationary contact from the moving contact and disconnecting the power supply to the drive motor, thus providing good overload protection for the drive motor.

[0014] 2. This linear electric actuator with overload protection drives a worm gear to rotate via a drive motor. The rotation of the worm gear drives the worm wheel to rotate, which in turn drives the drive gear to rotate. The drive gear then drives the driven gear to rotate, which in turn drives the nut to rotate. The rotation of the nut then drives the screw to move, which in turn drives the output rod to move. This allows the self-locking function of the worm gear and worm wheel to maintain the load position and reduces the burden of restarting the drive motor. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the overload protection mechanism of this utility model;

[0017] Figure 3 This is a schematic diagram of the internal structure of the mounting base of this utility model;

[0018] Figure 4 This is a schematic diagram of the actuator structure of this utility model.

[0019] In the diagram: 1. Housing; 2. Overload protection mechanism; 201. Mounting base; 202. Fixing plate; 203. Fixing ring; 204. Elastic sheet; 205. Connecting plate; 206. Stationary contact; 207. Moving contact; 208. First metal sheet; 209. Second metal sheet; 210. Fixing bolt; 211. Support frame; 212. Mounting bolt; 3. Drive motor; 4. Actuator; 401. Worm gear; 402. Worm wheel; 403. Driving gear; 404. Driven gear; 405. Nut; 406. Screw; 407. Guide block; 408. Guide rod; 409. Output rod. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Please see Figures 1-3 This utility model provides a technical solution: a linear electric actuator with overload protection, including a housing 1, a drive motor 3 mounted on the housing 1, an overload protection mechanism 2 mounted on the drive motor 3, and an actuator 4 mounted on the output shaft end of the drive motor 3. The overload protection mechanism 2 can disconnect the power supply to the drive motor 3 when the load is abnormal or a fault occurs, thus providing good overload protection for the drive motor 3.

[0022] Overload protection mechanism 2 includes a mounting base 201, which is fixedly mounted on the drive motor 3 via a fixing plate 202. The mounting base 201 is internally connected to the drive motor 3, allowing the internal temperature of the drive motor 3 to enter the mounting base 201. Fixing plates 202 are fixedly connected to both sides of the bottom of the mounting base 201. A fixing ring 203 is fixedly installed inside the mounting base 201. Two elastic plates 204 are fixedly connected to the inner side of the fixing ring 203. A connecting plate 205 is fixedly connected between the two elastic plates 204. The elastic plates 204 can use their elasticity to reset the connecting plate 205. A stationary contact 206 is provided at the bottom of the connecting plate 205, and a moving contact 207 is fixedly connected to the bottom surface of the connecting plate 205. A first metal plate 208 is provided at the top of the connecting plate 205, and a second metal plate 209 is fixedly connected to the top of the first metal plate 208. The thermal expansion of the first metal plate 208... The coefficient of thermal expansion is greater than that of the second metal sheet 209. The first metal sheet 208 and the second metal sheet 209 are welded together, so that the first metal sheet 208 and the second metal sheet 209 can form a thermal bimetallic sheet structure and deform and bend upward. The first metal sheet 208 and the second metal sheet 209 are respectively provided with fixing bolts 210 and support frames 211 at both ends. One end of the first metal sheet 208 and the second metal sheet 209 is fixedly installed on the connecting plate 205 by fixing bolts 210. The other end of the first metal sheet 208 and the second metal sheet 209 is fixedly connected to the support frame 211. The support frame 211 is provided with mounting bolts 212. The support frame 211 is located inside the mounting base 201. The support frame 211 is fixedly connected to the inner wall of the mounting base 201 by mounting bolts 212, so that one end of the first metal sheet 208 and the second metal sheet 209 can be fixed by the support frame 211.

[0023] Please see Figure 1 and Figure 4The actuator 4 includes a worm gear 401, the end of which is fixedly connected to the output shaft end of the drive motor 3. A worm wheel 402 is provided on one side of the worm gear 401, and a driving gear 403 is fixedly connected to the bottom end of the worm wheel 402. A driven gear 404 is provided on one side of the driving gear 403. Both ends of the worm gear 401 are rotatably connected to the inner wall of the housing 1 via bearings. The worm gear 401 meshes with the worm wheel 402. A nut 405 is fixedly connected to the driven gear 404, and a screw 406 is threaded into the nut 405. A guide block 407 is fixedly connected to the top end of the screw 406, and a guide rod 408 is slidably connected to the guide block 407. The screw 406 is guided by an output rod 409 fixedly connected to its bottom end. The output rod 409 can drive the worm gear 401 to rotate via the drive motor 3. The rotation of the worm gear 401 drives the worm wheel 402 to rotate, which in turn drives the drive gear 403 to rotate. The drive gear 403 drives the driven gear 404 to rotate, which in turn drives the nut 405 to rotate. The rotation of the nut 405 drives the screw 406 to move, which in turn drives the output rod 409 to move. This allows the self-locking function of the worm wheel 402 and the worm gear 401 to maintain the load position and reduces the restart burden on the drive motor 3.

[0024] During operation, the stationary contact 206 and the moving contact 207 are in contact, and the drive motor 3 drives the worm gear 401 to rotate. The rotation of the worm gear 401 drives the worm wheel 402 to rotate. The rotation of the worm wheel 402 drives the drive gear 403 to rotate. The rotation of the drive gear 403 drives the driven gear 404 to rotate. The rotation of the driven gear 404 drives the nut 405 to rotate. The rotation of the nut 405 drives the screw 406 to move. The movement of the screw 406 drives the output rod 409 to move, thus performing linear motion.

[0025] Under abnormal load, the first metal sheet 208 and the second metal sheet 209 deform due to heat. Since the coefficient of thermal expansion of the first metal sheet 208 is greater than that of the second metal sheet 209, the deformation of the first metal sheet 208 is larger, causing the whole sheet to bend upward. The deformation of the first metal sheet 208 and the second metal sheet 209 causes the connecting plate 205 to move. The movement of the connecting plate 205 causes the moving contact 207 to move, causing the stationary contact 206 to separate from the moving contact 207, disconnecting the power supply to the drive motor 3, and providing good overload protection for the drive motor 3.

[0026] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

Claims

1. Straight stroke electric actuator with overload protection comprising a housing (1), characterized in that: A drive motor (3) is installed on the outer casing (1), an overload protection mechanism (2) is installed on the drive motor (3), and an actuator (4) is installed at the end of the output shaft of the drive motor (3). The overload protection mechanism (2) includes a mounting base (201), with fixed plates (202) fixedly connected to both sides of the bottom of the mounting base (201). A fixed ring (203) is fixedly installed inside the mounting base (201). Two elastic plates (204) are fixedly connected to the inner side of the fixed ring (203). A connecting plate (205) is fixedly connected between the two elastic plates (204). A stationary contact (206) is provided at the bottom of the connecting plate (205). A moving contact (207) is fixedly connected to the bottom surface of the connecting plate (205). A first metal plate (208) is provided at the top of the connecting plate (205). A second metal plate (209) is fixedly connected to the top of the first metal plate (208). Fixed bolts (210) and support frames (211) are provided at both ends of the first metal plate (208) and the second metal plate (209). Mounting bolts (212) are provided on the support frame (211).

2. A straight stroke electric actuator with overload protection according to claim 1, characterized in that: The mounting base (201) is fixedly mounted on the drive motor (3) by a fixing plate (202), and the mounting base (201) is connected to the inside of the drive motor (3).

3. A straight stroke electric actuator with overload protection according to claim 1 characterized by: The coefficient of thermal expansion of the first metal sheet (208) is greater than that of the second metal sheet (209), and the first metal sheet (208) and the second metal sheet (209) are welded together.

4. A straight stroke electric actuator with overload protection according to claim 1 characterized by: One end of the first metal sheet (208) and the second metal sheet (209) are fixedly mounted on the connecting plate (205) by fixing bolts (210), and the other end of the first metal sheet (208) and the second metal sheet (209) are fixedly connected to the support frame (211).

5. A straight stroke electric actuator with overload protection according to claim 1 characterized by: The support frame (211) is located inside the mounting base (201), and the support frame (211) is fixedly connected to the inner wall of the mounting base (201) by mounting bolts (212).

6. A straight stroke electric actuator with overload protection according to claim 1 characterized by: The actuator (4) includes a worm (401), a worm wheel (402) is provided on one side of the worm (401), a drive gear (403) is fixedly connected to the bottom end of the worm wheel (402), and a driven gear (404) is provided on one side of the drive gear (403).

7. A straight stroke electric actuator with overload protection according to claim 6, characterized in that: The two ends of the worm (401) are rotatably connected to the inner wall of the outer shell (1) through bearings, and the worm (401) meshes with the worm wheel (402).

8. A straight stroke electric actuator with overload protection according to claim 6, characterized in that: A nut (405) is fixedly connected to the driven gear (404), a screw (406) is threaded inside the nut (405), a guide block (407) is fixedly connected to the top of the screw (406), a guide rod (408) is slidably connected to the guide block (407), and an output rod (409) is fixedly connected to the bottom of the screw (406).

Images