Overload protection device of electric actuating mechanism

Abstract

The utility model discloses an overload protection device for an electric actuating mechanism, which is characterized in that the overload protection device for the electric actuating mechanism comprises an upper shell, a lower shell, a motor fixed on the lower shell, a motor gear arranged on a motor shaft, an intermediate gear meshed with the motor gear, and a worm shaft fixed on a central hole of the intermediate gear, the worm is installed on the worm shaft, the worm gear is meshed with the worm, the gear shaft is installed on a center hole of the worm gear, the main gear is meshed with the gear shaft, the output shaft is installed on a center hole of the main gear, the output shaft fixing plate is fixed to the lower shell, and the microswitch fixing plate is installed on the output shaft fixing plate. The microswitch is fixed on the microswitch fixing plate, the spring is installed in an inner hole of the worm, the sliding plate is installed in a clamping groove in the outer side of the worm, and the cam is fixed on the sliding plate. When the motor runs, the motor gear, the intermediate gear, the worm shaft, the worm, the worm gear, the gear shaft, the main gear and the output shaft are driven to rotate. In the operation process, when the torque of the output shaft exceeds the safe torque, the axial stress of the worm is larger than the elastic force of the spring, the worm slides on the worm shaft, the sliding plate drives the cam to move, the microswitch is triggered, the power supply of the motor is cut off, the operation of the electric actuating mechanism is stopped, and the overload protection function is achieved; and the electric actuating mechanism immediately restores the running state.

Description

Technical field:

[0001] The utility model belongs to the field of electric actuators, in particular to an overload protection device for rotary electric actuators. Background technology:

[0002] The existing electric actuators have the following disadvantages: 1. The overload protection of the existing electric actuators is achieved through the overheat protection of the motor, which is not sensitive to the load and can only trigger the shutdown protection after the excessive load continues for a period of time. 2. After the existing electric actuators are shut down due to overload, when the load is reduced, they cannot resume operation immediately and need to wait for the motor to cool down before resuming operation. Utility model content:

[0003] The purpose of the utility model is to provide an electric actuator overload protection device with simple structure, sensitive response and reliable operation, thus overcoming the shortcomings and deficiencies of the existing common electric actuator overload protection.

[0004] In order to achieve the above-mentioned purpose, the technical scheme of the utility model is: an overload protection device for an electric actuator, comprising an upper housing, a lower housing, a motor fixed on the lower housing, a motor gear mounted on the motor shaft, an intermediate gear meshing with the motor gear, a worm shaft fixed on the center hole of the intermediate gear, a worm mounted on the worm shaft, a worm wheel meshing with the worm, a gear shaft mounted on the center hole of the worm wheel, a main gear meshing with the gear shaft, an output shaft mounted on the center hole of the main gear, an output shaft fixing plate fixed on the lower housing, a micro switch fixing plate mounted on the output shaft fixing plate, micro switches A and B fixed on the micro switch fixing plate, a spring mounted in the inner hole of the worm, a slide plate mounted on the outer slot of the worm, and cams A and B fixed on the slide plate. Two keyways are symmetrically arranged on the worm shaft, and the worm is mounted on the worm shaft by connecting key A and connecting key B. A circular hole is arranged inside the worm, and the spring is mounted in the worm hole by a spring gasket and a snap ring. A slot is arranged on the outer side of the worm, and the slide plate is mounted in the slot of the worm.

[0005] According to the utility model, the following effects can be achieved:

[0006] When the electric actuator is powered on, the motor drives the motor gear, intermediate gear, worm shaft, worm, worm wheel, gear shaft, main gear, and output shaft to rotate. When the motor is running in the forward direction, when the external load is greater than the safe load, the spring is compressed, the worm slides on the worm shaft, drives the slide plate and cam B to move, cam B touches the micro switch B, cuts off the power supply, and realizes overload protection. When the motor is running in the reverse direction, when the external load is greater than the safe load, the spring is compressed, the worm slides on the worm shaft, drives the slide plate and cam A to move, cam A touches the micro switch A, cuts off the power supply, and realizes overload protection. After the load returns to normal, the electric actuator immediately resumes operation. Description of the drawings:

[0007] Figure 1 This is a schematic diagram of the structure of the utility model

[0008] Figure 2 This is the exploded diagram of the utility model structure

[0009] Figure 3 Schematic diagram of the worm structure in the utility model

[0010] Figure 4 The exploded diagram of the worm structure in the utility model

[0011] Figure 5 This is the appearance diagram of the structure of the utility model

[0012] exist Figure 1 Among them, 1 is the motor, 2 is the reduction box, 3 is the reduction box fixing plate, 4 is the motor gear, 5 is the intermediate gear, 6 is the bearing cover, 7 is the worm gear, 8 is the output shaft, 9 is the main gear, 10 is the lower housing, 11 is the output shaft fixing plate, 12-1 is the micro switch A, 12-2 is the micro switch B, 13 is the worm bearing fixing plate, 14 is the micro switch fixing plate, 15-1 is the cam A, 15-2 is the cam B, and 16 is the worm.

[0013] Figure 2 Among them, 1 is the motor, 2 is the reduction box, 3 is the reduction box fixing plate, 4 is the motor gear, 5 is the intermediate gear, 6 is the bearing cover, 7 is the worm gear, 8 is the output shaft, 9 is the main gear, 10 is the lower housing, 12-1 is the micro switch A, 12-2 is the micro switch B, 13 is the worm bearing fixing plate, 15-1 is the cam A, 15-2 is the cam B, 16 is the worm, 17 is the front bearing of the worm shaft, 18 is the slide plate, 19 is the upper housing, 20 is the rear bearing of the worm shaft, 21 is the spring, 22 is the worm shaft, 23 is the upper bearing of the gear shaft, 24 is the gear shaft, 25 is the lower bearing of the gear shaft, 26 is the upper bearing of the output shaft, and 27 is the lower bearing of the output shaft.

[0014] exist Figure 3Among them, 15-1 is cam A, 15-2 is cam B, 16 is worm, 18 is slide plate, 21 is spring, 22 is worm shaft, and 28 is worm bushing.

[0015] exist Figure 4 Among them, 15-1 is cam A, 15-2 is cam B, 16 is worm, 18 is slide plate, 21 is spring, 22 is worm shaft, 28 is worm bushing, 29-1 is connecting key A, 29-2 is connecting key B, 30 is spring washer, and 31 is retaining ring.

[0016] exist Figure 5 This is the appearance diagram of the electric actuator of the utility model. Specific implementation method:

[0017] The utility model is described in detail below with reference to the accompanying drawings:

[0018] It includes an upper shell 19, a lower shell 10, a motor 1 fixed on the lower shell, a motor gear 4 installed on the motor shaft, an intermediate gear 5 meshing with the motor gear, a worm shaft 22 fixed on the center hole of the intermediate gear, a worm 16 installed on the worm shaft, a worm wheel 7 meshing with the worm, a gear shaft 24 installed on the center hole of the worm wheel, a main gear 9 meshing with the gear shaft, an output shaft 8 installed on the center hole of the main gear, an output shaft fixing plate 11 fixed on the lower shell, a microswitch fixing plate 14 installed on the output shaft fixing plate, microswitches A12-1 and microswitches B12-2 fixed on the microswitch fixing plate, a spring 21 installed in the inner hole of the worm, a slide plate 18 installed in the outer slot of the worm, and cams A15-1 and B15-2 fixed on the slide plate.

[0019] When the motor (1) is running in the forward direction (clockwise, Figure 2 The arrow in the middle indicates the direction), driving the motor gear (4) to rotate clockwise ( Figure 2 The middle arrow indicates the direction), the intermediate gear (5) and the worm (16) rotate counterclockwise ( Figure 2 The arrow in the middle indicates the direction), the worm gear (7) and the gear shaft (24) rotate clockwise ( Figure 2 The arrow in the middle indicates the direction), the main gear (9) and the output shaft (8) rotate counterclockwise ( Figure 2 The arrow in the middle indicates the direction). When the output shaft (8) is overloaded, the reaction force of the worm wheel (7) pushes the worm (16) to compress the spring (21) and move ( Figure 2 The middle arrow indicates the direction), driving the cam B (15-2) to touch the micro switch B (12-2), disconnecting the power supply of the motor (1) to achieve overload protection. When the overload of the output shaft (8) is eliminated, the compressed spring (22) pushes the worm (16) to drive the cam B (15-2) to reset, and the overload protection is released.

[0020] When the motor (1) is running in reverse (counterclockwise, Figure 2 The middle arrow indicates the reverse direction), driving the motor gear (4) to rotate counterclockwise ( Figure 2 The middle arrow indicates the reverse direction), the intermediate gear (5) and the worm (16) rotate clockwise ( Figure 2 The middle arrow indicates the reverse direction), the worm wheel (7) and the gear shaft (24) rotate counterclockwise ( Figure 2 The arrow in the middle indicates the reverse direction), the main gear (9) and the output shaft (8) rotate clockwise ( Figure 2 The middle arrow indicates the reverse direction). When the output shaft (8) is overloaded with torque, the reaction force of the worm wheel (7) pushes the worm (16) to compress the spring (21) and move ( Figure 2 The middle arrow indicates the reverse direction), driving the cam A (15-1) to touch the micro switch A (12-1), disconnecting the power supply of the motor (1) to achieve overload protection. When the overload of the output shaft (8) is eliminated, the compressed spring (21) pushes the worm (16) to drive the cam A (15-1) to reset, and the overload protection is released. A spring (21) is used to achieve overload protection in the opening direction and the closing direction of the electric actuator.

Claims

1. An overload protection device for an electric actuator, characterized in that: The invention comprises an upper housing (19), a lower housing (10), a motor (1) fixed on the lower housing, a motor gear (4) mounted on the motor shaft, an intermediate gear (5) meshed with the motor gear, a worm shaft (22) fixed on the center hole of the intermediate gear, a worm (16) mounted on the worm shaft, a worm wheel (7) meshed with the worm, a gear shaft (24) mounted on the center hole of the worm wheel, a main gear (9) meshed with the gear shaft, an output shaft (8) mounted on the center hole of the main gear, an output shaft fixing plate (11) fixed on the lower housing, a micro switch fixing plate (14) mounted on the output shaft fixing plate, a micro switch A (12-1) and a micro switch B (12-2) fixed on the micro switch fixing plate, a spring (21) mounted in the inner hole of the worm, a slide plate (18) mounted on the outer slot of the worm, and a cam A (15-1) and a cam B (15-2) fixed on the slide plate.

2. The electric actuator overload protection device according to claim 1 is characterized in that: Two keyways are symmetrically arranged on the worm shaft (22), and the worm (16) is mounted on the worm shaft (22) via a connecting key A (29-1) and a connecting key B (29-2).

3. The electric actuator overload protection device according to claim 1 is characterized in that: A circular hole is arranged inside the worm (16), and a spring (21) is installed in the hole of the worm (16) through a spring washer (30) and a snap ring (31).

4. The electric actuator overload protection device according to claim 1 is characterized in that: A slot is arranged on the outside of the worm (16), a slide plate (18) is installed in the slot of the worm (16), and a cam A (15-1) and a cam B (15-2) are fixed on the slide plate (18).

5. The electric actuator overload protection device according to claim 1 is characterized in that: When the external load is greater than the safety load during the forward rotation of the motor, the spring (21) is compressed, the worm (16) slides on the worm shaft (22), driving the slide plate (18) and the cam B (15-2) to move, and the cam B (15-2) touches the micro switch B (12-2), cutting off the power supply and realizing overload protection.

6. The electric actuator overload protection device according to claim 1, characterized in that: When the external load is greater than the safety load during the reverse operation of the motor, the spring (21) is compressed, the worm (16) slides on the worm shaft (22), driving the slide plate (18) and the cam A (15-1) to move, and the cam A (15-1) touches the micro switch A (12-1), cutting off the power supply and realizing overload protection.

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