Planetary transmission device for electric actuator

Abstract

The utility model discloses a planetary transmission device for an electric actuator, which relates to the technical field of valve actuators and comprises a central shaft, an electric worm gear, a first sun gear, a first planet gear, a second sun gear, a second planet gear, a manual worm gear and an output shaft assembly. The output shaft assembly is provided with a first pin shaft, the first pin shaft is sleeved with the second planet gear, the second sun gear is coaxially arranged on the outer side of the output shaft assembly and meshed with the second planet gear, and the first sun gear is coaxially arranged above the second sun gear and meshed with the first planet gear. The outer sides of the first planet gear and the second planet gear are meshed with an inner ring of the manual worm gear, an inner ring of the electric worm gear is meshed with the first sun gear, a needle bearing is arranged between the center shaft and the first sun gear, and a mechanical indicating dial is arranged at the upper end of the center shaft. Manual operation can be carried out without arranging an additional switching mechanism, and the opening degree of the valve can be effectively indicated.

Description

Technical Field

[0001] The utility model relates to the technical field of valve actuators, and particularly relates to a planetary transmission device for an electric actuator. Background Art

[0002] A valve electric actuator is a mechatronic industrial device used in conjunction with a valve to control the opening and closing of the valve. It mainly applies a certain torque to the valve to achieve the purpose of fully opening and completely closing the valve.

[0003] The existing electric actuators have the following problems: 1. Usually, a design integrating electric and manual control is adopted, which can take into account the advantages of convenient and fast electric control and strong stability of manual control. However, this design requires the design of an electric and manual switching mechanism, which increases the complexity of the machine and the production cost; 2. Usually, a display mechanism for conveniently observing and displaying the valve opening is provided. This display mechanism mostly uses a digital display screen in cooperation with an internal sensor for display. However, the sensor is easily affected by temperature and the like, resulting in inaccurate display of the valve opening and affecting the precise control of the valve. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the utility model provides a planetary transmission device for an electric actuator.

[0005] The technical solution provided by the utility model is as follows:

[0006] A planetary transmission device for an electric actuator includes a central shaft, an electric worm gear, a first sun gear, a first planet gear, a second sun gear, a second planet gear, a manual worm gear, and an output shaft assembly. The output shaft assembly is coaxially arranged at the lower end of the central shaft. The output shaft assembly is provided with a first pin shaft. The second planet gear is sleeved on the first pin shaft. The second sun gear is coaxially arranged outside the output shaft assembly and meshes with the second planet gear. The first sun gear is coaxially arranged above the second sun gear and meshes with the first planet gear. The outer sides of the first planet gear and the second planet gear mesh with the inner ring of the manual worm gear. The inner ring of the electric worm gear meshes with the first sun gear. A needle roller bearing is arranged between the central shaft and the first sun gear. A mechanical indicating disk is arranged at the upper end of the central shaft.

[0007] A planet carrier is arranged outside the second sun gear. The side part of the planet carrier extends to form an extension part. The extension part separates the first planet gear and the second planet gear. A second pin shaft is arranged on the extension part. The first planet gear is sleeved on the second pin shaft.

[0008] A shaft circlip for elastic retaining is arranged on the upper side of the central shaft where it is located on the needle roller bearing.

[0009] An O-ring seal is arranged above the shaft circlip for elastic retaining. The upper section of the central shaft where it is located on the O-ring seal forms an explosion-proof section.

[0010] A nylon gasket sleeve is provided between the electric worm gear and the first planet gear.

[0011] The output shaft assembly is provided with a connection groove connected to the valve stem, and internal teeth meshing with the valve stem are provided in the connection groove.

[0012] The output shaft assembly is circumferentially provided with a limit protrusion for preventing its excessive rotation.

[0013] The beneficial effects of the present utility model: By coaxially arranging an electric worm gear and a manual worm gear above and below the central shaft, and transmitting power through the sun gear and planet gears, the electric and manual controls are completely separated, and manual operation can be carried out without setting an additional switching mechanism. The structure is simple and the production cost is low. By arranging a needle roller bearing between the central shaft and the first sun gear, and a mechanical indicator disk is provided at the upper end of the central shaft. When the electric worm gear rotates to drive the first sun gear to rotate, the central shaft will not rotate therewith. The central shaft only rotates coaxially with the output shaft assembly. The mechanical indicator disk can effectively indicate the rotation of the output shaft, thereby displaying the opening degree of the valve, and is not easily affected by factors such as temperature, ensuring the precise control of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic cross-sectional structure diagram of an embodiment of the present utility model;

[0015] Figure 2 It is a partial three-dimensional structure diagram of an embodiment of the present utility model;

[0016] Figure 3 It is an assembly schematic diagram of an embodiment of the present utility model installed on an electric actuator. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The following further describes the embodiments of the present utility model with reference to the drawings.

[0018] As Figure 1-2 shown, a planetary transmission device for an electric actuator includes a central shaft 1, an electric worm gear 7, a first sun gear 6, a first planet gear 9, a second sun gear 12, a second planet gear 16, a manual worm gear 18, and an output shaft assembly 13.

[0019] The output shaft assembly 13 is coaxially sleeved on the outer side of the lower end of the central shaft 1 and rotates coaxially with the central shaft 1. The output shaft assembly 13 is provided with a first pin shaft 17. The second planet gear 12 is sleeved on the first pin shaft 17. The second sun gear 12 is coaxially arranged on the outer side of the output shaft assembly 13. One end of the second planet gear 16 meshes with the second sun gear 12, and the other end meshes with the inner ring of the manual worm gear 18. The manual worm gear 18, the second planet gear 16, and the second sun gear 12 together constitute the manual part of the transmission device. As Figure 3As shown, when the planetary transmission is assembled to the electric actuator, the manual worm gear 18 meshes with the manual worm 105. By rotating the manual worm 105 to drive the manual worm gear 18 to rotate, the output shaft assembly 13 can be driven to rotate.

[0020] A planet carrier 11 is provided outside the second sun gear 12. An extension part 15 extends outward from the side of the planet carrier 11. A second pin shaft 10 is provided on the extension part 15. The first planet gear 9 is sleeved on the second pin shaft 10. The extension part 15 serves to separate the first planet gear and the second planet gear, ensuring that their rotations do not interfere with each other. The first sun gear 6 is coaxially provided above the second sun gear 12. A needle roller bearing 5 is provided between the central shaft 1 and the first sun gear 6. The needle roller bearing 5 enables the central shaft not to rotate when the first sun gear rotates. The lower end of the first sun gear 6 meshes with the first planet gear 9, and the upper end meshes with the electric worm gear 7. One side of the first planet gear 9 relative to the first sun gear 6 meshes with the inner ring of the manual worm gear 18. As Figure 3 shown, when the planetary transmission is assembled to the electric actuator, the electric worm gear 7 meshes with the electric worm 104. The transmission process of the electric part is as follows: the rotation of the electric worm 104 drives the electric worm gear 7 to rotate, which drives the first planet gear 9 to rotate. The rotation of the first planet gear 9 drives the second planet gear 12 to rotate through the transmission of the manual worm gear 18, and finally drives the output shaft assembly 13 to rotate.

[0021] In this embodiment, a mechanical indicating disk 2 is provided at the upper end of the central shaft 1. Since the central shaft 1 rotates coaxially with the output shaft assembly 13, the mechanical indicating disk 2 can accurately display the rotation angle of the output shaft assembly 13, thereby accurately displaying the opening degree of the valve. An axial circlip 4 is provided at the upper side of the central shaft 1 where it is located on the needle roller bearing 5. The axial circlip 4 prevents the needle roller bearing 5 from axially moving. An O-ring seal 3 is provided above the axial circlip 4. The upper section of the central shaft 1 where it is located above the O-ring seal 3 forms an explosion-proof section. As Figure 3 shown, when the planetary transmission is assembled in the installation groove of the electric actuator, the explosion-proof section of the central shaft 1 extends out of the installation groove. The O-ring seal 3 prevents dust and other impurities from entering the installation groove and affecting the transmission of the mechanical structure. The upper end of the central shaft 1 extends to the digital display screen 102. The mechanical indicating disk 2 is close to the digital display screen 102, which is conducive to comparing with the digital display data to achieve precise control.

[0022] In this embodiment, a nylon spacer sleeve 8 is provided between the electric worm gear 7 and the first planet gear 9. The upper and lower ends of the nylon spacer sleeve 8 respectively press against the electric worm gear 7 and the first planet gear 9, playing a role of support and separation.

[0023] In this embodiment, the output shaft assembly 13 is provided with a connection groove for connecting with the valve stem of the valve. An internal tooth 14 that meshes with the valve stem of the valve is provided in the connection groove. It is connected to the valve stem of the valve in a meshing manner, ensuring stable transmission.

[0024] In this embodiment, the output shaft assembly 13 is circumferentially provided with a limiting protrusion 15, and the limiting protrusion 15 is used to prevent the output shaft assembly 13 from rotating excessively, so as to avoid the transmission jamming or even jamming caused by the excessive rotation of the output shaft assembly 13.

[0025] The embodiments should not be construed as limitations of the present invention, and any non-creative improvements based on the spirit of the present invention should be regarded as within the protection scope of the present invention.

Claims

1. A planetary transmission device for an electric actuator, characterized in that: It includes a central shaft, an electric worm gear, a first sun gear, a first planetary gear, a second sun gear, a second planetary gear, a manual worm gear, and an output shaft assembly. The output shaft assembly is coaxially arranged at the lower end of the central shaft. The output shaft assembly is provided with a first pin shaft. The second planetary gear is sleeved on the first pin shaft. The second sun gear is coaxially arranged on the outside of the output shaft assembly and meshes with the second planetary gear. The first sun gear is coaxially arranged above the second sun gear and meshes with the first planetary gear. The outer sides of the first and second planetary gears are meshed with the inner ring of the manual worm gear, and the inner ring of the electric worm gear is meshed with the first sun gear. A needle bearing is arranged between the central shaft and the first sun gear, and a mechanical indicator plate is arranged at the upper end of the central shaft.

2. A planetary transmission device for an electric actuator according to claim 1, characterized in that: A planet carrier is disposed outside the second sun gear, and a side portion of the planet carrier extends to form an extension portion, the extension portion separates the first planetary gear and the second planetary gear, a second pin is disposed on the extension portion, and the first planetary gear is sleeved on the second pin.

3. A planetary transmission device for an electric actuator according to claim 1, characterized in that: The central shaft is provided with a shaft elastic retaining ring at the upper side of the needle bearing.

4. A planetary transmission device for an electric actuator according to claim 3, characterized in that: An O-type sealing ring is arranged above the shaft elastic retaining ring, and the central shaft is located at the upper section of the O-type sealing ring to form a flameproof section.

5. The planetary transmission device for an electric actuator according to claim 1, characterized in that: A nylon bushing is provided between the electric worm gear and the first planetary gear.

6. A planetary transmission device for an electric actuator according to claim 1, characterized in that: The output shaft assembly is provided with a connecting groove connected to the valve stem, and the connecting groove is provided with internal teeth meshing with the valve stem.

7. A planetary transmission device for an electric actuator according to claim 1, characterized in that: The output shaft assembly is circumferentially provided with a limiting protrusion for preventing the output shaft assembly from excessive rotation.

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