Automatic and manual safety switching device for valve actuator

Abstract

This invention discloses an automatic / manual safety switching device for a valve actuator, comprising: a housing containing a rotating main shaft; an automatic locking component, a manual locking component, and a controller mounted on the outer wall of the housing; a trigger switch electrically connected to the controller on the manual locking component; an automatic drive mechanism for automatically driving the main shaft to rotate, and the automatic drive mechanism is electrically connected to the controller; a rotating sleeve that rotates with the main shaft; a manual drive mechanism that can be engaged or disengaged from the rotating sleeve; and a switching handle assembly for pushing the rotating sleeve toward the manual drive mechanism to engage with it in manual drive mode, or for pushing the rotating sleeve away from it to disengage it in automatic drive mode. This device enables safe, simple, and efficient switching between automatic and manual modes.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of valve driving device, more particularly to an automatic and manual safety switching device of valve actuator. BACKGROUND

[0002] The electric valve actuator is a machine driven by electric energy to drive the valve. The valve actuator generally has a manual mode, which is used to switch the valve actuator to the manual mode when the electric actuator cannot be used or in an emergency, so as to manually control the valve.

[0003] At present, the manufacturers of intelligent electric actuators generally adopt the following two ways to switch between electric and manual modes: one is to use differential gear planetary gear transmission to realize the switching between electric and manual modes. This switching mechanism is too complex, which is not conducive to the processing and assembly of the actuator. The other is to manually switch between electric and manual modes. In this way, if power supply is suddenly restored during manual operation, the motor drives the spindle to rotate, thereby causing the hand wheel to rotate, which is easy to cause personal injury.

[0004] Therefore, how to provide a safe, simple and efficient automatic and manual safety switching device of valve actuator is a problem to be solved by those skilled in the art. SUMMARY

[0005] Therefore, the present application provides a safe, simple and efficient automatic and manual safety switching device of valve actuator.

[0006] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0007] An automatic and manual safety switching device of valve actuator, comprising:

[0008] A housing, a spindle for driving the opening and closing of the valve is rotatably installed inside the housing, an automatic clamping piece, a manual clamping piece and a controller are respectively installed on the outer wall of the housing, and a trigger switch electrically connected with the controller is arranged on the manual clamping piece;

[0009] An automatic driving mechanism, which is arranged on the housing and is used to automatically drive the rotation of the spindle, and the automatic driving mechanism is electrically connected with the controller;

[0010] A rotating shaft sleeve, which is slidably sleeved on the spindle and can rotate with the spindle;

[0011] A manual driving mechanism, which is arranged on the housing and can be combined or separated with the rotating shaft sleeve;

[0012] The switching handle assembly is rotatably installed on the shell and is used to push the rotating shaft sleeve to move towards the manual driving mechanism to realize the manual driving mode of the main shaft by combining the rotating shaft sleeve with the manual driving mechanism, or push the rotating shaft sleeve to move away from the manual driving mechanism to realize the automatic driving mode of the main shaft by separating the rotating shaft sleeve from the manual driving mechanism;

[0013] When in the manual driving mode, the switching handle assembly is clamped with the manual clamping part and triggers the trigger switch to generate a first electric signal, and the controller disconnects the power supply of the automatic driving mechanism according to the first electric signal; when in the automatic driving mode, the switching handle assembly is separated from the trigger switch and clamped with the automatic clamping part, the trigger switch generates a second electric signal, and the controller connects the power supply of the automatic driving mechanism according to the second electric signal.

[0014] Compared with the prior art, the automatic and manual safety switching device of the valve actuator provided by the technical scheme can realize the automatic opening or closing operation of the valve when the actuator can be normally powered, and can realize the manual opening or closing operation of the valve when the actuator encounters a power failure.

[0015] Therefore, the device realizes efficient switching between electric and manual states through the switching handle assembly in the case of emergency power failure, realizes opening and closing of the valve by manual operation, and prevents accidents. The automatic and manual clamping members can position and clamp the switching handle assembly during operation, avoiding misoperation of personnel during operation. Meanwhile, the safety of personnel during manual operation of the valve is ensured due to the control of the trigger switch.

[0016] Further, the automatic driving mechanism comprises:

[0017] A driving motor is fixed on the shell, and the driving motor is electrically connected with the controller.

[0018] A first worm is rotatably installed inside the shell, and one end of the first worm is fixedly connected with a driving shaft of the driving motor.

[0019] A first worm wheel is sleeved on the main shaft, and the first worm wheel is in meshing transmission connection with the first worm.

[0020] The beneficial effects produced by the above technical solutions are as follows: in the automatic mode, the driving motor works to drive the first worm to rotate, the first worm drives the first worm wheel to rotate, the first worm wheel drives the main shaft to rotate, and then the automatic rotation operation of the main shaft is realized through the driving motor. When the switching handle assembly is clamped on the manual clamping member, the trigger switch is contacted, a first electric signal is generated from the trigger switch, and the controller disconnects the power supply of the driving motor according to the first electric signal. When the manual operation is performed, the driving motor is suddenly powered on, the driving motor works, the manual driving mechanism is self-rotated, and then personnel injury is caused.

[0021] Further, the automatic driving mechanism comprises:

[0022] A second worm is rotatably installed on the shell, and a hand wheel is fixed at one end of the second worm.

[0023] A second worm wheel is sleeved on the main shaft, the second worm wheel is in meshing transmission connection with the second worm, a first poking convex tooth is fixed on one side surface of the second worm wheel, a second poking convex tooth is fixed on one side surface of the rotating shaft sleeve, and the first poking convex tooth and the second poking convex tooth are in poking connection.

[0024] The beneficial effects produced by the above technical solutions are as follows: in the manual mode, the operator rotates the hand wheel to drive the second worm to rotate, the second worm drives the second worm wheel to rotate, the first poking convex tooth on the second worm wheel pokes the second poking convex tooth on the rotating shaft sleeve, and then the rotating shaft sleeve is rotated, the rotating shaft sleeve drives the main shaft to rotate, and then the manual rotation operation of the main shaft is realized through the hand wheel.

[0025] Furthermore, the main shaft has multiple circumferentially oriented sliding grooves on its shaft wall, and the inner sleeve hole of the rotating bushing has multiple circumferentially oriented sliding protrusions on its hole wall, with the multiple sliding protrusions corresponding to and slidingly connected to the multiple sliding grooves one by one.

[0026] The beneficial effects of adopting the above technical solution are: the setting of the actuating convex belt and the actuating slide groove can not only enable the rotating sleeve to slide stably on the main shaft, thereby realizing the precise engagement or separation of the rotating sleeve and the second worm gear, but also enable the rotating sleeve to drive the main shaft to rotate by itself under the cooperation of the actuating convex belt and the actuating slide groove, thereby realizing the rotation operation of the main shaft in manual mode.

[0027] Furthermore, the main shaft is provided with a first shaft section and a second shaft section with successively increasing shaft diameters. The first worm gear is fixed on the second shaft section, and the second worm gear is sleeved on the first shaft section. Multiple actuating grooves are formed on the outer periphery of the second shaft section. The switching handle assembly includes:

[0028] A rotating rod is rotatably mounted on the housing, with one end extending out of the housing and the other end extending into the housing and located on the other side of the rotating bushing;

[0029] A switching handle lever, one end of which is fixedly connected to one end of the rotating rod, and the switching handle lever is engaged with the automatic locking component or the manual locking component. The switching handle lever can contact a trigger switch.

[0030] A cam, the top surface of which is fixedly connected to the other end of the rotating rod, and the convex end of which can contact the other side of the rotating bushing to push the rotating bushing to move toward the second worm gear, so that the first actuating convex tooth and the second actuating convex tooth are connected to achieve the manual drive mode of the main shaft;

[0031] A spring is sleeved on the first shaft section. One end of the spring abuts against the stop protrusion on the second worm gear, and the other end abuts against the right shoulder of the first shaft section. When the pushing side end face of the actuating protrusion slides out of the actuating groove, the pushing side end face pushes the other end of the spring to compress the spring. When the protrusion end disengages from the other side of the rotating shaft sleeve, the spring pushes the rotating shaft sleeve to move away from the second worm gear.

[0032] The beneficial effects of adopting the above technical solution are as follows: In automatic mode, the switching handle is engaged with the automatic locking component. At this time, the cam's convex end moves away from the rotating sleeve, and the rotating sleeve moves to the left under the action of the spring, thus separating the rotating sleeve from the second worm gear. That is, the first and second actuating cams are in an unengaged actuating state. In this mode, the spindle can be automatically rotated by the drive motor. When manual mode is required, the operator rotates the switching handle to engage with the manual locking component. At this time, the cam's convex end contacts the rotating sleeve and pushes the rotating sleeve to the right. When the rotating sleeve moves, it compresses the spring, and the rotating sleeve engages with the second worm gear. That is, the first and second actuating cams are in an engaged actuating state. Then, in this mode, the spindle can be manually rotated by the handwheel. At the same time, the switching handle contacts the trigger switch, causing the trigger switch to generate a first electrical signal. The controller disconnects the power supply to the drive motor according to the first electrical signal, preventing the drive motor from being suddenly powered on during manual operation, which could cause the handwheel to rotate and cause injury.

[0033] Furthermore, the second shaft segment is provided with a limiting flange. When the spring pushes the rotating bushing to move away from the second worm gear, the stop side end face of the actuating convex band stops on the limiting flange.

[0034] The beneficial effects of adopting the above technical solution are: the limiting flange can limit the displacement of the rotating sleeve, that is, when the rotating sleeve stops on the limiting flange, the rotating sleeve and the cam can just be in contact. In this way, when the cam rotates, it can just push the rotating sleeve closer to the second worm gear, which can greatly reduce the idle stroke of the rotating sleeve and improve the operating efficiency.

[0035] Furthermore, the automatic locking component includes:

[0036] The first fixing seat is fixed to the top surface of the housing;

[0037] The first buckle plate is rotatably connected to the first fixed base, and the first buckle plate has a first locking slot that engages with the switching handle rod.

[0038] The manual locking component includes:

[0039] The second fixing base is fixed to the top surface of the housing, and the trigger switch is mounted on the second fixing base;

[0040] The second buckle plate is rotatably connected to the second fixed base, and the second buckle plate has a second locking slot for engaging with the switching handle rod.

[0041] The beneficial effects of adopting the above technical solution are: the first and second buckle plates can position and fix the switching handle lever, so that the position of the switching handle lever is fixed in automatic or manual mode, avoiding danger caused by misoperation.

[0042] Furthermore, a third worm gear is fitted on the main shaft, and a feedback worm and an angle encoder are rotatably mounted on the housing. The feedback worm is meshed with the third worm gear for transmission, and the rotating shaft of the angle encoder is fixedly connected to one end of the feedback worm for detecting the rotation angle of the main shaft.

[0043] The beneficial effects of adopting the above technical solution are: the rotation of the main shaft drives the rotation of the third worm gear, which in turn drives the rotation of the third worm, which in turn drives the rotation of the shaft of the angle encoder. Thus, the rotation angle of the main shaft can be detected by the angle encoder, allowing the staff to monitor the opening and closing status of the valve and the degree of valve opening in real time. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the internal structure of an automatic and manual safety switching device for a valve actuator provided by the present invention.

[0046] Figure 2 This is a diagram showing the switching handle assembly and the automatic locking mechanism engaged in automatic mode.

[0047] Figure 3 This is a diagram showing the switching handle assembly and manual locking mechanism engaged in manual mode.

[0048] Figure 4 This is a three-dimensional structural diagram of an automatic and manual safety switching device for a valve actuator provided by the present invention.

[0049] Figure 5 This is a schematic diagram from the first perspective when the second worm gear and the second worm wheel are in operation.

[0050] Figure 6 This is a schematic diagram from a second perspective when the second worm gear and the second worm wheel are in operation.

[0051] Figure 7 This is a schematic diagram of the present invention with the housing concealed.

[0052] Figure 8This is a schematic diagram from the first perspective of the first and second actuating teeth.

[0053] Figure 9 This is a schematic diagram from a second perspective of the first and second actuating teeth.

[0054] Figure 10 This is a schematic diagram from the first perspective when one side of the rotating bushing is stopped on the limiting flange.

[0055] Figure 11 This is a schematic diagram from a second perspective when one end of the rotating bushing is stopped on the limiting flange. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] See Figures 1-11 This invention discloses an automatic and manual safety switching device for a valve actuator, comprising:

[0058] The housing 1 has a main shaft 2 rotatably mounted inside the housing 1 for driving the valve opening and closing. An automatic locking component 3, a manual locking component 4, and a controller are respectively installed on the outer wall of the housing 1. The manual locking component 4 is equipped with a trigger switch 5 that is electrically connected to the controller.

[0059] Automatic drive mechanism 6 is mounted on housing 1 and is used to automatically drive the spindle 2 to rotate. Automatic drive mechanism 6 is electrically connected to controller.

[0060] Rotate the bushing 7, which is slidably sleeved on the main shaft 2 and can rotate together with the main shaft 2;

[0061] Manual drive mechanism 8 is mounted on housing 1 and can be engaged or disengaged from rotating bushing 7.

[0062] The switching handle assembly 9 is rotatably mounted on the housing 1 and is used to push the rotating bushing 7 to move towards the manual drive mechanism 8 so that the rotating bushing 7 engages with the manual drive mechanism 8 to realize the manual drive mode of the spindle 2, or to push the rotating bushing 7 away from the manual drive mechanism 8 so that the rotating bushing 7 separates from the manual drive mechanism 8 to realize the automatic drive mode of the spindle 2.

[0063] When in manual drive mode, the switching handle assembly 9 engages with the manual locking piece 4 and triggers the trigger switch 5 to generate a first electrical signal. The controller disconnects the power supply to the automatic drive mechanism 6 according to the first electrical signal. When in automatic drive mode, the switching handle assembly 9 disengages from the trigger switch 5 and engages with the automatic locking piece 3. The trigger switch 5 generates a second electrical signal, and the controller connects the power supply to the automatic drive mechanism 6 according to the second electrical signal.

[0064] In a specific embodiment, the automatic drive mechanism 6 includes:

[0065] The drive motor is fixed on the housing 1 and is electrically connected to the controller.

[0066] The first worm gear 61 is rotatably installed inside the housing 1, and one end of the first worm gear 61 is fixedly connected to the drive shaft of the drive motor.

[0067] The first worm gear 62 is fixed on the main shaft 2 and is meshed with the first worm 61 for transmission.

[0068] The manual drive mechanism 8 includes:

[0069] The second worm gear 81 is rotatably mounted on the housing 1, and a handwheel 82 is fixed to one end of the second worm gear 81.

[0070] The second worm gear 83 is sleeved on the main shaft 2 and meshes with the second worm 81 for transmission. A first actuating tooth 831 is fixed on one side of the second worm gear 83 and a second actuating tooth 71 is fixed on one side of the rotating bushing 7. The first actuating tooth 831 and the second actuating tooth 71 are connected in a pulsating manner.

[0071] The main shaft 2 has multiple circumferentially opening sliding grooves 201 on its shaft wall, and the inner sleeve hole of the rotating bushing 7 has multiple circumferentially opening sliding bands 72 on its hole wall. The multiple sliding bands 72 are slidably connected to the multiple sliding grooves 201 in a one-to-one correspondence.

[0072] The main shaft 2 has a first shaft section 21 and a second shaft section 22 with successively increasing shaft diameters. A first worm gear 62 is fixed on the second shaft section 22, and a second worm gear 83 is fitted on the first shaft section 21. Multiple actuating grooves 201 are formed on the outer periphery of the second shaft section 22. The switching handle assembly 9 includes:

[0073] Rotating rod 91 is rotatably mounted on housing 1. One end of rotating rod 91 extends out of housing 1, and the other end extends into housing 1 and is located on the other side of rotating bushing 7.

[0074] Switching handle 92, one end of which is fixedly connected to one end of rotating rod 91, switching handle 92 is engaged with automatic locking component 3 or manual locking component 4, and switching handle 92 can contact trigger switch;

[0075] Cam 93, the top surface of cam 93 is fixedly connected to the other end of rotating rod 91, and the convex end 931 of cam 93 can contact the other side of rotating sleeve 7 to push rotating sleeve 7 to move towards the second worm gear 83, so that the first actuating tooth 831 and the second actuating tooth 71 are connected to achieve the manual drive mode of main shaft 2.

[0076] Spring 94 is sleeved on the first shaft section 21. One end of spring 94 abuts against the stop boss 10 on the second worm gear 83, and the other end abuts against the right shoulder 221 of the first shaft section 21. When the push side end face 721 of the actuating convex band 72 slides out of the actuating groove 201, the push side end face 721 pushes the other end of spring 94 to compress spring 94. When the convex end 931 disengages from the other side of the rotating shaft sleeve 7, spring 94 pushes the rotating shaft sleeve 7 to move away from the second worm gear 83.

[0077] The second shaft section 22 is provided with a limiting flange 222. When the spring 94 pushes the rotating bushing 7 to move away from the second worm gear 83, the stop side end face 722 of the pusher belt 72 stops on the limiting flange 222.

[0078] Automatic locking component 3 includes:

[0079] The first fixing seat 31 is fixed to the top surface of the housing 1;

[0080] The first buckle plate 32 is rotatably connected to the first fixed base 31. The first buckle plate 32 has a first locking slot 321 that engages with the switching handle 92.

[0081] Manual locking component 4 includes:

[0082] The second fixing seat 41 is fixed to the top surface of the housing 1, and the trigger switch 5 is installed on the second fixing seat 41;

[0083] The second buckle plate 42 is rotatably connected to the second fixed base 41, and the second buckle plate 42 has a second locking slot 421 that engages with the switching handle rod 92.

[0084] A third worm gear 11 is mounted on the main shaft 2. A feedback worm 12 and an angle encoder are rotatably mounted on the housing 1. The feedback worm 12 is meshed with the third worm gear 11 for transmission. The rotating shaft of the angle encoder is fixedly connected to one end of the feedback worm 12 and is used to detect the rotation angle of the main shaft 2.

[0085] This device can realize the automatic and manual drive rotation of the spindle, thereby realizing the automatic and manual opening or closing operation of the valve. The specific process is as follows:

[0086] Automatic mode (the device is not powered off and can be powered normally): the switching handle is locked in the first locking hole on the first latch plate. At this time, the cam's convex end is away from the rotating bushing. The rotating bushing moves to the left under the action of the spring, thereby separating the rotating bushing from the second worm gear. That is, the first and second actuating cams are in an unengaged actuating state. In this mode, the main shaft can be automatically rotated by the drive motor.

[0087] Manual Mode (This device cannot operate normally in the event of a power outage): Rotate the switching handle until it engages with the second locking slot on the second latch plate. At this time, the cam's convex end pushes the rotating sleeve to the right. As the rotating sleeve moves, it compresses the spring, engaging the second worm gear. This means the first and second actuating cams are in a engaged actuating state. In this mode, the main shaft can be manually rotated using the handwheel. Simultaneously, the switching handle contacts the trigger switch, generating a first electrical signal. The controller disconnects the power to the drive motor based on this signal, preventing the drive motor from suddenly energizing during manual operation, which could cause the handwheel to rotate and potentially result in injury.

[0088] After the valve is manually opened or closed and the device is powered normally, the switching handle is repositioned onto the first locking port. At this time, the switching handle is disengaged from the trigger switch, and the trigger switch generates a second electrical signal. The controller connects the power supply to the drive motor according to the second electrical signal, and then the valve is automatically closed or opened again through the drive motor.

[0089] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0090] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An automatic / manual safety switching device for a valve actuator, characterized in that, include: The housing (1) has a main shaft (2) for driving the valve opening and closing rotatably installed inside the housing (1). An automatic locking component (3), a manual locking component (4), and a controller are respectively installed on the outer wall of the housing (1). The manual locking component (4) is provided with a trigger switch (5) that is electrically connected to the controller. An automatic drive mechanism (6) is provided on the housing (1) for automatically driving the main shaft (2) to rotate. The automatic drive mechanism (6) is electrically connected to the controller. Rotary bushing (7), which is slidably sleeved on the main shaft (2) and can rotate together with the main shaft (2); Manual drive mechanism (8) is provided on the housing (1), and the manual drive mechanism (8) can be combined with or separated from the rotating bushing (7); A switching handle assembly (9) is rotatably mounted on the housing (1) and is used to push the rotating bushing (7) toward the manual drive mechanism (8) so that the rotating bushing (7) is engaged with the manual drive mechanism (8) to realize the manual drive mode of the spindle (2), or to push the rotating bushing (7) away from the manual drive mechanism (8) so that the rotating bushing (7) is separated from the manual drive mechanism (8) to realize the automatic drive mode of the spindle (2); When in manual drive mode, the switching handle assembly (9) engages with the manual locking piece (4) and triggers the trigger switch (5) to generate a first electrical signal. The controller disconnects the power supply to the automatic drive mechanism (6) according to the first electrical signal. When in automatic drive mode, the switching handle assembly (9) disengages from the trigger switch (5) and engages with the automatic locking piece (3). The trigger switch (5) generates a second electrical signal. The controller connects the power supply to the automatic drive mechanism (6) according to the second electrical signal. The automatic drive mechanism (6) includes: A drive motor is fixed on the housing (1) and electrically connected to the controller; The first worm (61) is rotatably mounted inside the housing (1), and one end of the first worm (61) is fixedly connected to the drive shaft of the drive motor. The first worm gear (62) is sleeved on the main shaft (2) and is meshed with the first worm (61) for transmission. The manual drive mechanism (8) includes: The second worm (81) is rotatably mounted on the housing (1), and a handwheel (82) is fixed at one end of the second worm (81). The second worm gear (83) is sleeved on the main shaft (2). The second worm gear (83) is meshed and connected to the second worm (81). A first actuating tooth (831) is fixed on one side of the second worm gear (83). A second actuating tooth (71) is fixed on one side of the rotating bushing (7). The first actuating tooth (831) and the second actuating tooth (71) are connected by a prying action. The main shaft (2) has a plurality of circumferentially open sliding grooves (201) on its shaft wall, and the inner sleeve hole of the rotating bushing (7) has a plurality of circumferentially open sliding protrusions (72) on its hole wall, and the plurality of sliding protrusions (72) and the plurality of sliding grooves (201) are slidably connected in a one-to-one correspondence. The main shaft (2) is provided with a first shaft section (21) and a second shaft section (22) with successively increasing shaft diameters. The first worm gear (62) is fixed on the second shaft section (22), and the second worm gear (83) is fitted on the first shaft section (21). A plurality of actuating grooves (201) are provided on the outer periphery of the second shaft section (22). The switching handle assembly (9) includes: Rotating rod (91), the rotating rod (91) is rotatably mounted on the housing (1), one end of the rotating rod (91) extends out of the housing (1), the other end extends into the housing (1) and is located on the other side of the rotating bushing (7); A switching handle (92) is fixedly connected at one end to one end of the rotating rod (91). The switching handle (92) is engaged with the automatic locking component (3) or the manual locking component (4). The switching handle (92) can contact the trigger switch. Cam (93), the top surface of the cam (93) is fixedly connected to the other end of the rotating rod (91), and the convex end (931) of the cam (93) can contact the other side of the rotating bushing (7) to push the rotating bushing (7) to move towards the second worm gear (83) so that the first actuating tooth (831) and the second actuating tooth (71) are connected to achieve the manual drive mode of the main shaft (2); Spring (94) is sleeved on the first shaft section (21). One end of the spring (94) abuts against the stop boss (10) on the second worm gear (83), and the other end abuts against the right shoulder (221) of the first shaft section (21). When the push side end face (721) of the actuating convex band (72) slides out of the actuating groove (201), the push side end face (721) pushes the other end of the spring (94) to compress the spring (94). When the convex end (931) disengages from the other side of the rotating bushing (7), the spring (94) pushes the rotating bushing (7) to move away from the second worm gear (83). The automatic locking component (3) includes: The first fixing seat (31) is fixed to the top surface of the housing (1); The first buckle plate (32) is rotatably connected to the first fixed base (31), and the first buckle plate (32) has a first locking slot (321) for engaging with the switching handle rod (92). The manual locking component (4) includes: The second fixing seat (41) is fixed on the top surface of the housing (1), and the trigger switch (5) is installed on the second fixing seat (41); The second buckle plate (42) is rotatably connected to the second fixed base (41), and the second buckle plate (42) has a second locking slot (421) that engages with the switching handle rod (92). The second shaft segment (22) is provided with a limiting flange (222). When the spring (94) pushes the rotating bushing (7) to move away from the second worm gear (83), the stop side end face (722) of the actuating convex band (72) stops on the limiting flange (222). The main shaft (2) is fitted with a third worm gear (11). A feedback worm (12) and an angle encoder are rotatably mounted on the housing (1). The feedback worm (12) is meshed with the third worm gear (11) for transmission. The rotating shaft of the angle encoder is fixedly connected to one end of the feedback worm (12) for detecting the rotation angle of the main shaft (2).

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