Planetary gear structure for an electric actuator

Abstract

The utility model relates to an electric actuator planetary gear structure, include: gear box, end cover, input shaft, planetary gear reduction mechanism and output shaft. Be provided with the installation cavity in the gear box, the planetary gear reduction mechanism is installed in the installation cavity, the other end of gear box is provided with first axle hole, the output shaft rotatable is installed in the first axle hole, and the first axle hole is installed with sealing element, and the end cover is installed in the end of gear box, is used for sealing installation cavity, and the end of end cover near gear box is provided with sealing ring groove, and the sealing ring groove is provided with sealing ring, and the end of gear box is provided with the convex stripe with sealing cover ring groove cooperation. The utility model discloses through setting up sealing ring groove, sealing ring and convex stripe in the end cover and gear box junction, has improved the waterproof, dustproof capacity of gear box in the side of end cover, has improved the dustproof, the ability of preventing impurity invasion of gear box through setting up sealing element in the output shaft side of gear box, and the combination of both has improved the dustproof, waterproof performance of gear box.

Description

Technical Field

[0001] This utility model relates to the field of speed reducer technology, and in particular to a planetary gear structure for an electric actuator. Background Technology

[0002] With the continuous development of industrial automation, electric actuators are being used more and more widely in various industrial scenarios. They achieve precise operation and control of equipment such as valves through electric drive. As the core transmission component of electric actuators, the performance of the gearbox directly affects the operating efficiency and stability of the actuator.

[0003] Most existing electric actuators use gearboxes with an eccentric design. Their transmission structure includes a servo motor, a two-stage reducer, and a worm gear assembly. The worm gear passes through bushings in the front and rear cover plates and can slide back and forth. Transmission control is achieved through the engagement or disengagement of the worm gear and worm wheel. This type of eccentric gearbox has significant drawbacks: firstly, the overall structure is complex, requiring high precision in component assembly, and is susceptible to damage from external factors such as dust and water, affecting transmission stability; secondly, the eccentric layout results in a large gearbox size, occupying excessive space in space-constrained industrial equipment installation scenarios, causing inconvenience for installation, operation, and equipment integration. Summary of the Invention

[0004] The purpose of this utility model is to provide a planetary gear structure for an electric actuator to solve the problem of dust and water stains easily entering the gearbox.

[0005] To achieve the above objectives, this utility model discloses a planetary gear structure for an electric actuator, comprising: a gearbox, an end cover, an input shaft, a planetary gear reduction mechanism, and an output shaft. The gearbox has an installation cavity, and one end of the gearbox has an opening communicating with the installation cavity. The planetary gear reduction mechanism is installed within the installation cavity. The other end of the gearbox has a first shaft hole communicating with the installation cavity. The output shaft is rotatably installed within the first shaft hole. A seal is installed at the end of the first shaft hole away from the installation cavity, and the seal is positioned between the first shaft hole and the output shaft. The end cover is installed at the end of the gearbox to seal the installation cavity. A sealing ring groove is formed at the end of the end cover near the gearbox, and a sealing ring is provided within the sealing ring groove. The end of the gearbox has a protrusion that mates with the sealing ring groove. A second shaft hole is formed on the end cover, and the input shaft is rotatably installed within the second shaft hole. The input shaft is drive-connected to the planetary gear reduction mechanism, and the planetary gear reduction mechanism is drive-connected to the output shaft.

[0006] Preferably, the planetary gear reduction mechanism is a four-stage planetary reduction mechanism.

[0007] Preferably, the sidewall of the mounting cavity is provided with an internal gear ring. The planetary gear reduction mechanism includes a first-stage sun gear, multiple first-stage planetary gears, a first-stage planetary carrier, a second-stage sun gear, multiple second-stage planetary gears, a second-stage planetary carrier, a third-stage sun gear, multiple third-stage planetary gears, a third-stage planetary carrier, a fourth-stage sun gear, and multiple fourth-stage planetary gears. The first-stage sun gear is integrally formed with the input shaft. The first-stage planetary gears are rotatably mounted on the first-stage planetary carrier. The first-stage sun gear meshes with the first-stage planetary gears and with the internal gear ring. The second-stage sun gear is located at the bottom of the first-stage planetary carrier and is integrally formed with it. The second-stage planetary gears are rotatably mounted on the second-stage planetary carrier. The second-stage sun gear meshes with the second-stage planetary gears and with the internal gear ring. The third-stage sun gear is located at the bottom of the second-stage planetary carrier and is integrally formed with it. The third-stage planetary gears are rotatably mounted on the third-stage planetary carrier. The third-stage sun gear meshes with the third-stage planetary gears and with the internal gear ring. The fourth-stage sun gear is located at the bottom of the third-stage planetary support and is integrally formed with the third-stage planetary support. The fourth-stage planetary gear is rotatably mounted on the output shaft. The fourth-stage sun gear meshes with the fourth-stage planetary gear, and the fourth-stage planetary gear meshes with the internal gear ring.

[0008] Preferably, there are three first-stage planetary gears, three second-stage planetary gears, four third-stage planetary gears, and five fourth-stage planetary gears.

[0009] Preferably, the input shaft includes, from top to bottom, a first connecting part, a second connecting part, a first-stage sun gear, and a third connecting part. The first connecting part is used to connect to the motor, the second connecting part is rotatably connected to the end cover, and the third connecting part is rotatably connected to the first-stage planetary support.

[0010] Preferably, the first connecting part has a rectangular cross-sectional shape, and the second connecting part has a retaining ring groove on the side near the first connecting part.

[0011] Preferably, the sealing element is a skeleton oil seal.

[0012] Preferably, the input shaft has a hollow structure, and the first-stage planetary support, the second-stage planetary support, and the third-stage planetary support all have through holes in their middle sections, with the through holes being coaxially arranged with the input shaft.

[0013] Preferably, the end cover is provided with a mounting bracket for mounting a motor.

[0014] Preferably, the end cap is provided with a connecting lug on its periphery, the connecting lug having a first mounting hole, the end face of the gearbox extending peripherally to form a mounting surface, the mounting surface having a second mounting hole, the position of the second mounting hole corresponding to the first mounting hole, and the first mounting hole and the second mounting hole being connected by fasteners.

[0015] This utility model has the following beneficial effects: 1. This utility model improves the waterproof and dustproof capabilities of the gearbox on the end cover side by setting a sealing ring groove, sealing ring, and convex strip at the connection between the end cover and the gearbox; it also improves the gearbox's dustproof and impurity intrusion prevention capabilities by setting a seal on the output shaft side of the gearbox; the combination of the two improves the gearbox's dustproof and waterproof performance.

[0016] 2. The internal structure of the gearbox is compact, with the input shaft, first planetary support, second planetary support, third planetary support, and output shaft all coaxially arranged. Compared with eccentric gearboxes, the gearbox of this utility model is smaller in size. Attached Figure Description

[0017] Figure 1 This is a side view of the overall structure provided in a specific embodiment of the present utility model; Figure 2 This is a schematic front view of the overall structure provided in a specific embodiment of the present utility model; Figure 3 This is a cross-sectional schematic diagram of KK provided in a specific embodiment of this utility model; Figure 4 This is a partially enlarged schematic diagram of point A provided in a specific embodiment of this utility model; Figure 5 This is a cross-sectional schematic diagram of the planetary gear reduction mechanism provided in a specific embodiment of the present utility model; Figure 6 This is an overall exploded view provided in a specific embodiment of the present utility model; Figure 7 This is a schematic diagram of the input shaft provided in a specific embodiment of the present utility model; Figure 8 This is a schematic diagram of the primary planetary support and its structure provided in a specific embodiment of the present utility model; Figure 9 This is a schematic diagram of the secondary planetary support and its structure provided in a specific embodiment of the present utility model; Figure 10 This is a schematic diagram of a three-stage planetary support and its structure provided in a specific embodiment of this utility model.

[0018] Explanation of symbols for main components: 100. Gearbox; 110. Internal gear ring; 120. Seal; 130. Raised bar; 200. End cover; 210. Mounting base; 220. Sealing ring groove; 230. Sealing ring; 240. Connecting ear; 300. Input shaft; 310. First connecting part; 320. Second connecting part; 321. Snap ring groove; 330. First-stage sun gear; 340. Third connecting part; 400. First-stage planetary carrier; 410. Second-stage sun gear; 420. First-stage planetary gear; 500. Second-stage planetary carrier; 510. Third-stage sun gear; 520. Second-stage planetary gear; 600. Third-stage planetary carrier; 610. Fourth-stage sun gear; 620. Third-stage planetary gear; 700. Output shaft; 710. Fourth-stage planetary gear; 800. Snap ring. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0020] like Figures 1-10 This utility model provides a planetary gear structure for an electric actuator, including: a gearbox 100, an end cover 200, an input shaft 300, a planetary gear reduction mechanism, and an output shaft 700. The gearbox 100 has an installation cavity. One end of the gearbox 100 has an opening communicating with the installation cavity. The installation cavity is cylindrical, and the opening is the same size as the cross-section of the installation cavity and is circular. The planetary gear reduction mechanism is installed in the installation cavity. The other end of the gearbox 100 has a first shaft hole communicating with the installation cavity. The output shaft 700 is rotatably installed in the first shaft hole. Two bearings are provided between the output shaft 700 and the first shaft hole. The two bearings are arranged along the axial direction of the output shaft 700. Bearing positions for installing the two bearings are provided near both ends of the first shaft hole. A retaining ring 800 is provided at the end of the output shaft 700 near the seal 120 to prevent the bearings from falling out of the first shaft hole. The seal 120 is installed at the end of the first shaft hole away from the installation cavity. The seal 120 is a skeleton oil seal. The seal 120 is located between the first shaft hole and the output shaft 700. The output shaft 700 passes through the inner ring of the skeleton oil seal. The skeleton oil seal can prevent external dust and impurities from entering the interior of the gearbox 100.

[0021] like Figures 3-4An end cap 200 is installed at the end of the gearbox 100 to seal the mounting cavity. A sealing ring groove 220 is provided at the end of the end cap 200 near the gearbox 100. The diameter of the sealing ring groove 220 is slightly larger than the diameter of the opening. A sealing ring 230 is provided in the sealing ring groove 220. The sealing ring 230 is a rubber sealing ring 230. A protrusion 130 is provided at the end of the gearbox 100 to cooperate with the sealing ring groove. The protrusion 130 is provided along the edge of the opening. After the end cap 200 is installed, the protrusion 130 is inserted into the sealing ring groove 220 and presses down the sealing ring 230 located in the sealing ring groove 220 to form a waterproof and dustproof sealing effect.

[0022] like Figure 6 The end cap 200 has a connecting lug 240 on its periphery. The connecting lug 240 is elongated and has a first mounting hole. The end face of the gearbox 100 extends peripherally to form a mounting surface, and a second mounting hole is provided on the mounting surface. The position of the second mounting hole corresponds to the first mounting hole. The first and second mounting holes are connected by fasteners, namely bolts and nuts. After the bolt passes through the first and second mounting holes, it is locked by the nut, thereby completing the installation of the end cap 200. In other embodiments, the first mounting hole can be a through hole, and the second mounting hole can be a threaded hole. This allows a bolt to pass through the first mounting hole and then be threaded into the second mounting hole, thereby fixing the end cap 200 and the gearbox 100. The end cover 200 has a second shaft hole, and the input shaft 300 is rotatably installed in the second shaft hole. The input shaft 300 is connected to the planetary gear reduction mechanism, and the planetary gear reduction mechanism is connected to the output shaft 700.

[0023] like Figure 7 The input shaft 300 includes, from top to bottom, a first connecting part 310, a second connecting part 320, a first-stage sun gear 330, and a third connecting part 340. The first connecting part 310, the second connecting part 320, the first-stage sun gear 330, and the third connecting part 340 are integrally formed. The first connecting part 310 is used to connect to the motor. The shape of the first connecting part 310 is a cylinder with a portion cut off along its axial direction on both sides, which can prevent slippage during the connection with the motor.

[0024] The second connecting part 320 is rotatably connected to the end cover 200. The second connecting part 320 is connected to the end cover 200 through a bearing. A retaining ring groove 321 is provided on the side of the second connecting part 320 near the first connecting part 310. That is, a retaining ring groove 321 is provided on the upper part of the second connecting part 320. A retaining ring 800 installed in the retaining ring groove 321 can position the input shaft 300 and restrict the axial movement of the input shaft 300. The third connecting part 340 is rotatably connected to the first planetary support 400. A through hole is provided in the middle of the first planetary support. The third connecting part 340 is connected to the through hole through a bearing. The end cover 200 and the first planetary support become two supports for the input shaft 300.

[0025] The planetary gear reduction mechanism is a four-stage planetary reduction mechanism. In other embodiments, the planetary gear reduction mechanism may also be a three-stage or five-stage planetary reduction mechanism.

[0026] like Figure 5 In this embodiment, an internal gear ring 110 is provided on the side wall of the mounting cavity, and the planetary gear reduction mechanism includes a first-stage sun gear 330, three first-stage planetary gears 420, a first-stage planetary carrier 400, a second-stage sun gear 410, three second-stage planetary gears 520, a second-stage planetary carrier 500, a third-stage sun gear 510, four third-stage planetary gears 620, a third-stage planetary carrier 600, a fourth-stage sun gear 610, and five fourth-stage planetary gears 710.

[0027] The first-stage sun gear 330 is integrated with the input shaft 300. The first-stage planet gear 420 is rotatably mounted on the first-stage planetary support 400. The first-stage sun gear 330 meshes with the first-stage planet gear 420. The first-stage planet gear 420 meshes with the internal gear ring 110. The first-stage sun gear 330 drives the first-stage planet gear 420 to rotate. The first-stage planet gear 420 rolls along the internal gear ring 110, driving the first-stage planetary support 400 to rotate.

[0028] The secondary sun gear 410 is located at the bottom of the primary planetary support 400 and is integrally formed with the primary planetary support 400. The secondary planetary gear 520 is rotatably mounted on the secondary planetary support 500. The secondary sun gear 410 meshes with the secondary planetary gear 520, and the secondary planetary gear 520 meshes with the internal gear ring 110. The secondary sun gear 410 drives the secondary planetary gear 520 to rotate, and the secondary planetary gear 520 rolls along the internal gear ring 110, driving the secondary planetary support 500 to rotate.

[0029] The third-stage sun gear 510 is located at the bottom of the second-stage planetary support 500 and is integrally formed with the second-stage planetary support 500. The third-stage planetary gear 620 is rotatably mounted on the third-stage planetary support 600. The third-stage sun gear 510 meshes with the third-stage planetary gear 620, and the third-stage planetary gear 620 meshes with the internal gear ring 110. The third-stage sun gear 510 drives the third-stage planetary gear 620 to rotate, and the third-stage planetary gear 620 rolls along the internal gear ring 110, driving the third-stage planetary support 600 to rotate. The fourth-stage sun gear 610 is located at the bottom of the third-stage planetary support 600 and is integrally formed with the third-stage planetary support 600. The fourth-stage planetary gear 710 is rotatably mounted on the output shaft 700. The fourth-stage sun gear 610 meshes with the fourth-stage planetary gear 710, and the fourth-stage planetary gear 710 meshes with the internal gear ring 110. The fourth-stage sun gear 610 drives the fourth-stage planetary gear 710 to rotate, and the fourth-stage planetary gear 710 rolls along the internal gear ring 110, driving the output shaft 700 to rotate.

[0030] The input shaft 300 has a hollow structure. Through holes are formed in the middle of the first-stage planetary support 400, the second-stage planetary support 500, and the third-stage planetary support 600. These through holes are coaxial with the input shaft 300. A shaft can be inserted into the through hole, and its end is fixedly connected to the top of the output shaft 700. The fixed connection can be made by welding or threading. This allows the rotation of the output shaft 700 to be controlled via this shaft. For example, the rotation of this shaft can be manually controlled, thereby driving the output shaft 700 to rotate, adding a manual control function to the output shaft 700.

[0031] like Figure 6 The end cover 200 is provided with a mounting base 210 for mounting the motor. The main body of the mounting base 210 is in the shape of a cuboid with a circular groove. A notch is provided on one side of the circular groove to connect to the side of the cuboid. The output shaft 700 is located at the notch. The upper surface of the mounting base 210 is provided with mounting holes. The mounting base 210 can improve the stability of motor installation.

[0032] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A planetary gear structure for an electric actuator, characterized in that, include: Gearbox, end cover, input shaft, planetary gear reduction mechanism, and output shaft; The gearbox has an installation cavity. One end of the gearbox has an opening communicating with the installation cavity. The planetary gear reduction mechanism is installed in the installation cavity. The other end of the gearbox has a first shaft hole communicating with the installation cavity. The output shaft is rotatably installed in the first shaft hole. A seal is installed at the end of the first shaft hole away from the installation cavity. The seal is located between the first shaft hole and the output shaft. An end cover is installed at the end of the gearbox to seal the installation cavity. A sealing ring groove is provided at the end of the end cover near the gearbox. A sealing ring is provided in the sealing ring groove. The end of the gearbox has a protrusion that mates with the sealing ring groove. A second shaft hole is provided on the end cover. The input shaft is rotatably installed in the second shaft hole. The input shaft is driven by the planetary gear reduction mechanism. The planetary gear reduction mechanism is driven by the output shaft.

2. The planetary gear structure for an electric actuator according to claim 1, characterized in that: The planetary gear reduction mechanism is a four-stage planetary reduction mechanism.

3. The planetary gear structure for an electric actuator according to claim 1, characterized in that: The side wall of the mounting cavity is provided with an internal gear ring, and the planetary gear reduction mechanism includes a first-stage sun gear, multiple first-stage planetary gears, a first-stage planetary carrier, a second-stage sun gear, multiple second-stage planetary gears, a second-stage planetary carrier, a third-stage sun gear, multiple third-stage planetary gears, a third-stage planetary carrier, a fourth-stage sun gear, and multiple fourth-stage planetary gears. The first-stage sun gear is integrally formed with the input shaft, and the first-stage planetary gears are rotatably mounted on the first-stage planetary support. The first-stage sun gear meshes with the first-stage planetary gears, and the first-stage planetary gears mesh with the internal gear ring. The secondary sun gear is located at the bottom of the primary planetary support and is integrally formed with the primary planetary support. The secondary planetary gear is rotatably mounted on the secondary planetary support. The secondary sun gear meshes with the secondary planetary gear, and the secondary planetary gear meshes with the internal gear ring. The third-stage sun gear is located at the bottom of the second-stage planetary support and is integrally formed with the second-stage planetary support. The third-stage planetary gear is rotatably mounted on the third-stage planetary support. The third-stage sun gear meshes with the third-stage planetary gear, and the third-stage planetary gear meshes with the internal gear ring. The fourth-stage sun gear is located at the bottom of the third-stage planetary support and is integrally formed with the third-stage planetary support. The fourth-stage planetary gear is rotatably mounted on the output shaft. The fourth-stage sun gear meshes with the fourth-stage planetary gear, and the fourth-stage planetary gear meshes with the internal gear ring.

4. The planetary gear structure for an electric actuator according to claim 3, characterized in that: The first-stage planetary gear has three components, the second-stage planetary gear has three components, the third-stage planetary gear has four components, and the fourth-stage planetary gear has five components.

5. The planetary gear structure for an electric actuator according to claim 1, characterized in that: The input shaft comprises, from top to bottom, a first connecting part, a second connecting part, a first-stage sun gear, and a third connecting part. The first connecting part is used to connect to the motor, the second connecting part is rotatably connected to the end cover, and the third connecting part is rotatably connected to the first-stage planetary support.

6. The planetary gear structure for an electric actuator according to claim 5, characterized in that: The first connecting part has a rectangular cross-sectional shape, and the second connecting part has a retaining ring groove on the side near the first connecting part.

7. The planetary gear structure for an electric actuator according to claim 1, characterized in that: The sealing element is a skeleton oil seal.

8. The planetary gear structure for an electric actuator according to claim 6, characterized in that: The input shaft has a hollow structure, and the first-stage planetary support, the second-stage planetary support, and the third-stage planetary support all have through holes in their middle sections. The through holes are coaxially arranged with the input shaft.

9. The planetary gear structure for an electric actuator according to claim 1, characterized in that: The end cap is provided with a mounting bracket for installing the motor.

10. The planetary gear structure of an electric actuator according to claim 1, characterized in that: The end cap is provided with a connecting lug on its periphery, and a first mounting hole is provided on the connecting lug. The end face of the gearbox extends to the periphery to form a mounting surface, and a second mounting hole is provided on the mounting surface. The position of the second mounting hole corresponds to the position of the first mounting hole, and the first mounting hole and the second mounting hole are connected by fasteners.

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