External gearbox of electric actuator and electric actuator

Abstract

The utility model discloses an external gear box of an electric actuator. The external gear box comprises a bottom shell, a connecting plate, an inner gear ring, a sun gear, a flange output shaft and a plurality of planet gears. The bottom shell is provided with an output shaft hole, the connecting plate is fixed to the open end of the bottom shell and provided with an input shaft hole, the inner gear ring is clamped and fixed between the bottom shell and the connecting plate and is in sealing fit with the bottom shell and the connecting plate, and the sun gear comprises a gear and the connecting plate which is coaxially connected with the gear and penetrates out of the input shaft hole. The planet gears are arranged between the sun gear and the inner gear ring in a surrounding mode and meshed with the sun gear and the inner gear ring. The flange output shaft comprises a flange plate connected with the planet wheel and an output shaft which is coaxially connected with the flange plate and rotatably supported in the output shaft hole. The external gear box adopts a coaxial structure, is small in occupied space, convenient to operate and capable of effectively preventing water and dust. The utility model further discloses an electric actuator with the external gear box, the overall size of the electric actuator is small, and the installation space can be saved.

Description

Technical Field

[0001] The utility model relates to the technical field of electric actuators, in particular to an electric actuator externally connected to a gear box and the electric actuator. Background Art

[0002] With the continuous development of industrial automation, electric actuators have been widely used in various industrial applications. They are driven by electricity to achieve operational control of various valves and other equipment.

[0003] The external gearbox of the existing electric actuator is often an eccentric structure. For example, the utility model patent with the announcement number CN219994519U discloses an electric actuator, which includes: a mounting base, a servo motor and a secondary reducer that are driven by each other are provided on the mounting base, an actuator shaft is passed through the bottom of the mounting base, the actuator shaft is driven by the secondary reducer, a worm is passed through the mounting base, a front cover plate and a rear cover plate are provided on the mounting base, and shaft sleeves are provided on the inner sides of the front cover plate and the rear cover plate. The rear end of the worm is inserted into the rear sleeve, the front end of the worm is passed through the front sleeve, and the front end of the worm passes through the front cover plate forward, and the worm can slide back and forth in the two sleeves. A worm wheel is fixed on the outer side of the actuator shaft, the worm and the worm wheel are meshed for transmission, and the worm can be separated from the worm wheel after rotating and moving backward, a clamping joint is provided on the front end of the worm, and an annular positioning groove is provided on the side wall of the front part of the worm, and a self-locking indexing pin is screwed on one side of the front cover plate, and the pin of the self-locking indexing pin can pass through the annular positioning groove horizontally. This type of electric actuator has a complex structure, is easily affected by dust or water stains, is large in size, occupies a lot of space, and brings certain inconveniences to operation. Utility Model Content

[0004] One of the purposes of the utility model is to provide an electric actuator with an external gear box, which adopts a coaxial structure, occupies a small space, is easy to operate, and is effectively waterproof and dustproof. The second purpose of the utility model is to provide an actuator to improve the efficiency of use and the convenience of operation.

[0005] In order to achieve the above-mentioned purpose, the technical solution proposed by the utility model is:

[0006] The utility model provides an external gear box for an electric actuator, which includes a bottom shell, a connecting plate, an inner gear ring, a sun gear, a flange output shaft and a plurality of planetary gears. One end of the bottom shell is open and the other end is provided with an output shaft hole. The connecting plate is fixed to the open end of the bottom shell, and is provided with an input shaft hole. The inner gear ring is clamped and fixed between the bottom shell and the connecting plate, and is sealed with the bottom shell and the connecting plate. The sun gear includes a coaxially connected input shaft and a gear, the sun gear is coaxially arranged in the inner gear ring, and the input shaft passes through the connecting plate from the input shaft hole. A plurality of planetary gears are arranged around the sun gear and the inner gear ring, and mesh with the sun gear and the inner gear ring. The flange output shaft includes a coaxially connected flange and an output shaft, the output shaft is rotatably supported in the output shaft hole, and the flange is connected to the planetary gear. The sun gear rotates and drives the planetary gear to rotate while revolving, and the planetary gear revolves and drives the flange output shaft to rotate.

[0007] Preferably, the input shaft is a shaft with a non-circular cross-section, such as a square shaft.

[0008] Preferably, the planetary gear comprises: a planetary gear meshing with the inner ring gear and the sun gear, a first bearing fixed in the planetary gear, and a planetary shaft connecting the first bearing and the flange.

[0009] Preferably, it also includes an extension rod, the sun gear is provided with a central through hole, one end of the extension rod penetrates through the central through hole and is fixedly connected to the flange output shaft.

[0010] Preferably, the connecting plate is detachably connected to the bottom shell via a first screw, and a screw slot engaging with the first screw is provided on the outer circumferential surface of the inner gear ring to limit the rotation of the inner gear ring.

[0011] Preferably, a first sealing ring is provided between the connecting plate and the inner gear ring, a second sealing ring is provided between the inner gear ring and the bottom shell, and an oil seal sleeved on the output shaft is provided in the output shaft hole.

[0012] Preferably, an annular step is provided on the outer circumference of the output shaft, and a first step surface facing the connection plate and a second step surface facing away from the connection plate are provided in the output shaft hole. A second bearing, a third bearing and a retaining ring are sleeved on the output shaft, the outer ring end face of the second bearing abuts against the first step surface, the inner ring end face of the second bearing abuts against the step surface of the annular step, the outer ring end face of the third bearing abuts against the second step surface, and the inner ring end face of the third bearing abuts against the retaining ring.

[0013] The utility model also provides an electric actuator, which includes an electric actuator body and an electric actuator external gear box of the utility model. The connecting plate of the external gear box is fixedly connected to the electric actuator body by a second screw, and the input shaft of the sun gear is connected to the power output shaft of the electric actuator body.

[0014] Preferably, a third sealing ring is provided between the connecting plate and the electric actuator body.

[0015] Preferably, the power output shaft of the electric actuator body is provided with a non-circular hole, and the input shaft of the sun gear is a non-circular cross-section shaft matching the non-circular hole.

[0016] By adopting the above technical solution, the beneficial effects of the utility model are as follows:

[0017] 1. The external gearbox of the electric actuator of the utility model adopts a planetary gear transmission system, and its input and output are coaxial. Compared with the existing eccentric external gearbox, it has a simpler structure and a smaller volume, which is conducive to saving installation space. And because other components are basically installed in the internal space formed by the connecting plate, the bottom shell and the inner gear ring, the effectiveness of waterproofing and dustproofing of the external gearbox can be ensured by strengthening the sealing between the three.

[0018] 2. The electric actuator of the utility model is equipped with the external gear box of the utility model, and its overall volume is smaller, which is conducive to saving installation space, and its use efficiency is also higher and the operation is more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a half-section schematic diagram of the electric actuator externally connected to the gear box of the first embodiment.

[0020] Figure 2 This is a schematic diagram of the exploded structure of the electric actuator externally connected to the gear box of Example 1.

[0021] Figure 3 It is a schematic diagram of the three-dimensional structure of the electric actuator of the second embodiment.

[0022] Figure 4 It is a front view schematic diagram of the electric actuator of the second embodiment.

[0023] Figure 5 It is a half-section schematic diagram of the electric actuator of the second embodiment.

[0024] Figure 6 This is a schematic diagram of the exploded structure of the electric actuator of the second embodiment.

[0025] Wherein: 1. bottom shell, 2. output shaft hole, 3. connecting plate, 4. input shaft hole, 5. inner gear ring, 6. sun gear, 7. input shaft, 8. gear, 9. planetary gear, 10. flange output shaft, 11. flange plate, 12. output shaft, 13. planetary gear, 14. first bearing, 15. planetary shaft, 16. extension rod, 17. center through hole, 18. first screw, 19. screw slot, 20. first sealing ring, 21. second sealing ring, 22. third sealing ring, 23. oil seal, 24. annular step, 25. first step surface, 26. second step surface, 27. second bearing, 28. third bearing, 29. retaining ring, 30. electric actuator body, 31. second screw, 32. non-circular hole, 33. power output shaft. DETAILED DESCRIPTION

[0026] The utility model is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0027] Embodiment 1

[0028] like Figure 1 and Figure 2 As shown, the electric actuator external gearbox of this embodiment includes: a bottom shell 1, a connecting plate 3, an inner gear ring 5, a sun gear 6, a flange output shaft 10, an extension rod 16 and six planetary gears 9. One end of the bottom shell 1 is open, and the other end is provided with an output shaft hole 2. The connecting plate 3 is fixed to the open end of the bottom shell 1 by three circumferentially evenly distributed first screws 18, and the connecting plate 3 is provided with an input shaft hole 4 coaxial with the output shaft hole 2. The inner gear ring 5 is clamped and fixed between the bottom shell 1 and the connecting plate 3, and the outer circumferential surface of the inner gear ring 5 is provided with a screw groove 19 that is engaged with the first screw 18. The screw groove 19 and the first screw 18 are used to limit the circumferential rotation of the inner gear ring 5, so that the connecting plate 3, the inner gear ring 5 and the bottom shell 1 are fixedly connected. The sun gear 6 is arranged in the inner gear ring 5 and is coaxial with the inner gear ring 5. The six planetary gears 9 are arranged around the sun gear 6 and the inner gear ring 5, and mesh with the sun gear 6 and the inner gear ring 5, so that the planetary gears 9 are driven to rotate while revolving around the sun gear 6 through the rotation of the sun gear 6. The flange output shaft 10 is rotatably connected with the six planetary gears 9 and the bottom shell 1, and is coaxial with the sun gear 6. The flange output shaft 10 is driven to rotate through the revolution of the planetary gears 9, thereby reducing the output speed and torque. The sun gear 6 is provided with a central through hole 17, and one end of the extension rod 16 is inserted through the central through hole 17 and fixedly connected to the flange output shaft 10. The extension rod 16 can synchronously transmit the rotation angle information of the flange output shaft 10 upward.

[0029] Specifically, the sun gear 6 of this embodiment includes: an input shaft 7 and a gear 8. The input shaft 7 and the gear 8 are coaxially connected, and the gear 8 is meshed with six planetary gears 9. The input shaft 7 is a non-circular cross-section shaft, preferably a square shaft. The input shaft 7 passes through the connecting plate 3 from the input shaft hole 4 for connecting the power input.

[0030] The planetary gear 9 includes: a planetary gear 13, a first bearing 14 and a planetary shaft 15. The planetary gear 13 is arranged between the sun gear 6 and the inner gear ring 5 and meshes with the sun gear 6 and the inner gear ring 5. The first bearing 14 is fixed in the planetary gear 13, and one end of the planetary shaft 15 is assembled in the first bearing 14. The first bearing 14 preferably adopts a needle bearing to facilitate the miniaturization of the external gear box. The flange output shaft 10 includes: a flange 11 and an output shaft 12. The flange 11 and the output shaft 12 are coaxially connected. The flange 11 is provided with six shaft holes, and the other end of the planetary shaft 15 is assembled in the shaft hole. The output shaft 12 is rotatably supported in the output shaft hole 2 through the second bearing 27 and the third bearing 28. The second bearing 27 and the third bearing 28 preferably adopt deep groove ball bearings. The provision of multiple bearings is conducive to improving the stability of the rotation of the flange output shaft 10.

[0031] In order to improve assembly efficiency, in this embodiment, a first step surface 25 facing the connecting plate 3 and a second step surface 26 facing away from the connecting plate 3 are provided in the output shaft hole 2, and an annular step 24 is provided on the outer peripheral surface of the output shaft 12 of the flange output shaft 10. During assembly, the second bearing 27 can be directly pressed between the first step surface 25 and the annular step 24 to achieve axial limit. The third bearing 28 is pressed to the second step surface 26 through a retaining ring 29 fixed on the output shaft 12 for axial limit. The assembly is simple, and there is no need to set too many fasteners.

[0032] In order to improve the sealing performance of the external gearbox, a first sealing ring 20 is arranged between the connecting plate 3 and the inner gear ring 5, and a second sealing ring 21 is arranged between the inner gear ring 5 and the bottom shell 1, which are responsible for waterproofing and dustproofing the mating surfaces. An oil seal 23 sleeved on the output shaft 12 is arranged in the output shaft hole 2, which is responsible for waterproofing and dustproofing the output part.

[0033] Embodiment 2

[0034] like Figure 3 to Figure 6 As shown, the electric actuator of this embodiment includes: an electric actuator body 20 and an electric actuator external gearbox of embodiment one. A non-circular hole 32 is provided at the axis center of the power output shaft 33 of the electric actuator body 30, which is plugged into and matched with the non-circular cross-section shaft of the external gearbox. The connecting plate 3 and the electric actuator body 30 are fixedly connected by a plurality of second screws 31 to achieve a fixed connection between the external gearbox and the electric actuator body 30, without the need to set a coupling to connect the power output shaft 33 of the electric actuator body 30 and the input shaft 7 of the external gearbox. At the same time, it is also convenient to seal between the electric actuator body 30 and the external gearbox. Only a third sealing ring 22 is set between the connecting plate 3 and the electric actuator body 30 to ensure that the mating surfaces of the two are effectively waterproof and dustproof.

[0035] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, those skilled in the art should understand that various changes in form and details of the present invention are within the scope of protection of the present invention without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. An electric actuator with an external gearbox, characterized in that: include: A bottom shell (1) having an open end and an output shaft hole (2) at the other end; A connecting plate (3) is provided with an input shaft hole (4), wherein the connecting plate (3) is fixed to the open end of the bottom shell (1); An inner gear ring (5) is clamped and fixed between the bottom shell (1) and the connecting plate (3), and is sealingly matched with the bottom shell (1) and the connecting plate (3); A sun gear (6) comprises an input shaft (7) and a gear (8) which are coaxially connected, wherein the sun gear (6) is coaxially arranged in the inner gear ring (5), and the input shaft (7) passes through the connecting plate (3) from the input shaft hole (4); A plurality of planetary gears (9) are disposed around the sun gear (6) and the inner gear ring (5), and mesh with the sun gear (6) and the inner gear ring (5); A flange output shaft (10) comprises a flange plate (11) and an output shaft (12) which are coaxially connected, wherein the output shaft (12) is rotatably supported in the output shaft hole (2), and the flange plate (11) is connected to the planetary gear (9); The sun gear (6) rotates and drives the planet gear (9) to revolve and rotate at the same time, and the planet gear (9) revolves and drives the flange output shaft (10) to rotate.

2. The electric actuator externally connected to a gear box according to claim 1, characterized in that: The input shaft (7) is a shaft with a non-circular cross-section.

3. The electric actuator externally connected to a gear box according to claim 1, characterized in that: The planetary gear (9) comprises: a planetary gear (13) meshing with the inner gear ring (5) and the sun gear (6), a first bearing (14) fixed in the planetary gear (13), and a planetary shaft (15) connecting the first bearing (14) and the flange (11).

4. The electric actuator externally connected to a gear box according to claim 1, characterized in that: It also includes an extension rod (16), the sun gear (6) is provided with a central through hole (17), one end of the extension rod (16) penetrates through the central through hole (17) and is fixedly connected to the flange output shaft (10).

5. The electric actuator externally connected to a gear box according to claim 1, characterized in that: The connecting plate (3) is detachably connected to the bottom shell (1) via a first screw (18), and the outer peripheral surface of the inner gear ring (5) is provided with a screw slot (19) that is engaged with the first screw (18) to limit the rotation of the inner gear ring (5).

6. The electric actuator externally connected to a gear box according to claim 1, characterized in that: A first sealing ring (20) is provided between the connecting plate (3) and the inner gear ring (5), a second sealing ring (21) is provided between the inner gear ring (5) and the bottom shell (1), and an oil seal (23) sleeved on the output shaft (12) is provided in the output shaft hole (2).

7. The electric actuator externally connected to a gear box according to claim 3, characterized in that: The outer circumferential surface of the output shaft (12) is provided with an annular step (24), and the output shaft hole (2) is provided with a first step surface (25) facing the connecting plate (3) and a second step surface (26) facing away from the connecting plate (3); the output shaft (12) is sleeved with a second bearing (27), a third bearing (28) and a retaining ring (29), the outer ring end surface of the second bearing (27) abuts against the first step surface (25), the inner ring end surface of the second bearing (27) abuts against the step surface of the annular step (24), the outer ring end surface of the third bearing (28) abuts against the second step surface (26), and the inner ring end surface of the third bearing (28) abuts against the retaining ring (29).

8. The electric actuator externally connected to a gear box according to claim 7, characterized in that: The first bearing (14) is a needle bearing, and the second bearing (27) and the third bearing (28) are deep groove ball bearings.

9. An electric actuator, characterized in that: It comprises an electric actuator body (30) and an electric actuator external gear box as claimed in any one of claims 1 to 8, wherein the connecting plate (3) is fixedly connected to the electric actuator body (30), and the input shaft (7) of the sun gear (6) is connected to the power output shaft (33) of the electric actuator body (30).

10. The electric actuator according to claim 9, characterized in that: A third sealing ring (22) is provided between the connecting plate (3) and the electric actuator body (30); a non-circular hole (32) is provided on the power output shaft (33) of the electric actuator body (30); and the input shaft (7) of the sun gear (6) is a non-circular cross-section shaft matching the non-circular hole (32).

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