Thermostat main ball valve of automobile engine and its electric actuator, multi-stage gear transmission mechanism

Abstract

The present invention discloses a multi-stage gear transmission mechanism of a main ball valve electric actuator, comprising a motor, a planetary gear set and a planetary carrier, wherein the planetary gear set comprises a gear ring, a sun gear and a plurality of planetary gears; a rotating wheel is fixed on one side of the sun gear; an output shaft on the planetary carrier passes through the center of the sun gear and the rotating wheel and can rotate relative to the sun gear and the rotating wheel; the planetary shaft on the planetary wheel is fixedly connected to the star disk; the worm rotating wheel on the output shaft of the motor is meshed or the two are connected by gear transmission; the rotation of the worm drives the rotating wheel and the sun gear to rotate; the rotation of the sun gear drives the planetary gear to revolve around the axis of the sun gear and drives the planetary carrier to rotate. The multi-stage gear transmission mechanism has a compact structure, occupies a small space, and has a large output torque; the multi-stage gear transmission mechanism is applied to the electric actuator, which can greatly reduce the volume of the electric actuator, and the electric actuator has a high load-bearing capacity, a large speed ratio, a stable transmission, a high transmission efficiency, and a large output torque.

Description

Technical Field

[0001] The present invention relates to the field of ball valve type thermostats of intelligent thermal management systems for automobile engines, and more specifically, to a thermostat main ball valve of an automobile engine and an electric actuator and a multi-stage gear transmission mechanism thereof. Background Art

[0002] In the new form of the automotive industry, as more and more automakers turn their attention to the "new four modernizations", there is a wide demand for the "electrification" application of automatic valve actuators such as engine temperature control and battery cooling. It is particularly important to achieve compact actuator structure, high reliability, high torque, low current, and low manufacturing cost under harsh temperature and vibration environments. The existing electric control actuators for the main ball valve of the intelligent thermal management system of automobile engines on the market generally include electrical devices such as a box, a cover plate, a DC brushed motor, a worm gear and multi-stage spur gear transmission system, and a position sensor. The Chinese patent with patent application number CN201610804853.X discloses an actuator that is driven by a fixed multi-axis spur gear, has low torque density, and is large in size. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a thermostat main ball valve of an automobile engine and an electric actuator thereof, and a multi-stage gear transmission mechanism. The multi-stage gear transmission mechanism has a compact structure, occupies a small space, has smooth transmission, high transmission efficiency, and large output torque.

[0004] To achieve the above-mentioned object, the present invention provides the following technical solution: a multi-stage gear transmission mechanism of a main ball valve electric actuator, comprising a motor, a planetary gear set and a planet carrier, wherein the planetary gear set comprises a gear ring and a sun gear arranged inside the gear ring, a plurality of planetary gears are arranged between the gear ring and the sun gear, the inner sides of the plurality of planetary gears are all meshed with the sun gear, and the outer sides of the plurality of planetary gears are all meshed with the annular inner teeth on the gear ring; a rotating wheel is also fixed or integrally formed on one side of the sun gear along the axial direction of the sun gear;

[0005] The planet carrier comprises an output shaft, the middle part of which extends radially along the output shaft to form a star disk; the output shaft passes through the center of the sun gear and the rotating wheel and can rotate relative to the sun gear and the rotating wheel; a planet shaft is also rotatably arranged at the central part of the planet gear, and one end of the planet shaft close to the star disk is fixedly connected to the star disk;

[0006] A worm is installed on the output shaft of the motor, and the worm is meshed with the rotating wheel or the two are connected by a gear transmission; the rotation of the worm drives the rotating wheel and the sun gear to rotate; the rotation of the sun gear drives the planetary gear to rotate, and the planetary gear can revolve around the axis of the sun gear and drive the planetary carrier to rotate. At the same time, the planetary gear can also rotate around its own axis, and the rotation of the planetary carrier further drives the output shaft to rotate. In the above technical scheme, when the worm at the output end of the motor is meshed with the wheel, the worm and the wheel form a primary transmission, and the planetary gear set is a secondary transmission; when the worm at the output end of the motor is meshed with the gear, a primary transmission is formed between the worm and the gear, a secondary transmission is formed between the gear and the wheel, and the planetary gear set is a tertiary transmission; the output shaft of the motor rotates to drive the worm to rotate, the rotation of the worm drives the wheel to rotate, or the worm drives the wheel to rotate through the gear, the wheel drives the sun gear to rotate, the sun gear drives the planetary gear to revolve around the axis of the sun gear, and the planetary gear drives the star disk and the shaft to rotate; compared with the multi-stage spur gear transmission scheme of the traditional actuator, the multi-stage gear transmission mechanism has a compact structure, occupies a small space, has a smooth transmission, high transmission efficiency, and a large output torque density; the multi-stage gear transmission design of the worm and the planetary gear set achieves smooth rotation of the output shaft.

[0007] Preferably, the worm and the rotating wheel are connected via a gear set, the gear set includes at least two gears, and the worm rotates to drive the gear set and the rotating wheel through the transmission effect of the gear set. The rotation of the worm drives the gears on the gear set to rotate, the rotation of the gear drives the rotating wheel to rotate, the rotating wheel drives the sun gear to rotate, the sun gear drives the planetary gear to revolve around the sun gear axis, and the planetary gear drives the star disk and the rotating shaft to rotate.

[0008] Preferably, the gear set includes a first gear and a second gear coaxially arranged with the first gear, and the first gear and the second gear are fixedly connected or integrally formed, the first gear meshes with the worm, and the second gear meshes with the rotating wheel.

[0009] Preferably, the outer diameter of the first gear is greater than the outer diameter of the second gear.

[0010] Preferably, the outer diameter of the rotating wheel is larger than the outer diameter of the second gear.

[0011] Preferably, the side wall of the rotating wheel near the sun wheel extends in the direction of the sun wheel with an annular plate portion for contacting with the planetary wheel; the star disk is provided with a plurality of third grooves matching with the planetary shaft, the planetary shaft is inserted into the third groove and fixedly connected with the third groove, and the third groove extends in the direction of the planetary wheel with an annular protrusion for contacting with the planetary wheel; the annular plate portion cooperates with the annular protrusion to limit the planetary wheel between the two. A gap is maintained between the planetary wheel and the rotating wheel, and between the planetary wheel and the star disk to avoid friction caused by contact with the rotating wheel and the star disk when the planetary wheel rotates, and the planetary shaft can also be integrally coated with the star disk by injection molding.

[0012] Preferably, the outer diameter of the planetary gear is smaller than the outer diameter of the sun gear.

[0013] The main ball valve electric actuator comprises a box body with an opening on one side and a box cover for sealing the box body, and is characterized in that: it also includes the multi-stage gear transmission mechanism of the main ball valve electric actuator as described above, and the motor, planetary gear set and planetary carrier are installed in the box body; one end of the output shaft on the planetary carrier is rotatably connected to the bottom wall of the box body, and the other end of the output shaft on the planetary carrier passes through the box cover and is rotatably connected to the box cover, and the gear ring is fixed on the box cover; a magnetic position sensor is also installed on the inner side of the bottom wall of the box body near the end position of the output shaft, and a magnetic disk matching the magnetic position sensor is installed on the end of the output shaft of the planetary carrier near the magnetic position sensor. Applying the above-mentioned multi-stage gear transmission mechanism to the electric actuator can greatly reduce the size of the electric actuator, and the electric actuator has high load-bearing capacity, large speed ratio, safe performance, smooth transmission, high transmission efficiency, and large output torque; In the above-mentioned technical scheme, the magnetic disc is installed on the output shaft of the planetary carrier, compared with the traditional scheme of installing it on the output gear shaft: 1. The scheme of installing the magnetic disc on the planetary carrier has a simpler process installation and no risk of damaging the gear; 2. The magnetic disc is installed on the output shaft of the planetary carrier and cooperates with the position sensor on the PCB board to realize the angle detection and feedback of the output shaft.

[0014] Preferably, the gear ring is integrally formed with the box cover; or, the side wall of the box body extends in all directions to have a plurality of connecting plate parts for fixed connection with the box cover, each connecting plate part is provided with a mounting hole, and each mounting hole is embedded with a bushing. The gear ring and the box cover can be of one-piece or split design; the one-piece design reduces the number of parts, reduces the assembly process, and saves manufacturing costs; the split design can provide a variety of design and assembly solutions, and can be fixed on the box body or the box cover, increasing design flexibility. The mounting hole with a bushing can make the electric actuator suitable for harsh high temperature and vibration application environments.

[0015] A thermostat main ball valve of an automobile engine comprises the main ball valve electric actuator as described above.

[0016] In summary, the present invention has the following beneficial effects:

[0017] 1. The multi-stage gear transmission mechanism of the present invention has a compact structure, occupies a small space, has a stable transmission, high transmission efficiency, and a large output torque; through the multi-stage gear transmission design of the worm and the planetary gear set, the output shaft can rotate smoothly;

[0018] 2. Applying the above-mentioned multi-stage gear transmission mechanism to the electric actuator can greatly reduce the size of the electric actuator, and the electric actuator has high load-bearing capacity, large speed ratio, safe performance, stable transmission and high transmission efficiency;

[0019] 3. The magnetic disc of the electric actuator is installed on the planetary carrier, which makes the installation process simpler and has no risk of damaging the gears. The magnetic disc is installed on the output shaft of the planetary carrier and cooperates with the position sensor on the PCB board to realize the angle detection and feedback of the output shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the multi-stage gear transmission mechanism of the present invention;

[0021] Figure 2 It is a structural schematic diagram of the multi-stage gear transmission mechanism of the present invention without the gear ring;

[0022] Figure 3 It is a schematic diagram of the structure of the planetary gear set and the box cover assembly of the multi-stage gear transmission mechanism;

[0023] Figure 4 for Figure 3 The cross-sectional view along the AA direction;

[0024] Figure 5 It is a schematic diagram of the structure of the sun gear and the rotor;

[0025] Figure 6 A schematic diagram of the structure of the planetary gear, planetary carrier and box cover assembly;

[0026] Figure 7 It is a schematic diagram of the structure of the planet carrier;

[0027] Figure 8 It is a schematic diagram of the structure of the planetary gear set and the planetary carrier assembly;

[0028] Fig. 9 for Figure 8 The enlarged view of point A in the middle;

[0029] Fig.10 It is a structural schematic diagram of an electric actuator;

[0030] Fig.11 The schematic diagram of the structure of the electric actuator without the box cover;

[0031] Fig.12 It is a structural schematic diagram of the box cover;

[0032] Fig.13 It is a schematic diagram of the structure of the box.

[0033] Figure numerals: 1. motor; 2. planet carrier; 3. gear ring; 4. sun gear; 5. planetary gear; 6. rotating wheel; 7. output shaft; 8. star disk; 9. planetary shaft; 10. worm; 11. first gear; 12. second gear; 13. annular plate; 14. third groove; 15. annular protrusion; 16. casing; 17. casing cover; 18. first groove; 19. supporting plate; 20. extending plate; 21. second groove; 22. PCB board; 23. magnetic disk; 24. connecting plate; 25. mounting hole; 26. bushing. DETAILED DESCRIPTION

[0034] The present invention will be further described with reference to the accompanying drawings.

[0035] This embodiment discloses a main ball valve of a ball valve type thermostat of an automobile engine intelligent thermal management system and its electric actuator, a multi-stage gear transmission mechanism, such as Figures 1 to 4 As shown, the multi-stage gear transmission mechanism includes a motor 1, a planetary gear set and a planet carrier 2. The motor 1 is a brushed DC motor 1; the planetary gear set includes a gear ring 3 and a sun gear 4 arranged inside the gear ring 3. In the radial direction of the sun gear 4, a plurality of planetary gears 5 are arranged between the gear ring 3 and the sun gear 4. Figure 3 , Figure 4 and Figure 6 As shown, the inner sides of the plurality of planetary gears 5 are meshed with the sun gear 4, and the outer sides of the plurality of planetary gears 5 are meshed with the annular inner teeth on the gear ring 3; Figure 5 As shown, a runner 6 is fixed or integrally formed on one side of the sun gear 4 along the axial direction of the sun gear 4. The sun gear 4 and the runner 6 are coaxially arranged. Preferably, the outer diameter of the runner 6 is larger than the outer diameter of the sun gear 4. Figure 7 and Figure 8As shown, the planet carrier 2 includes an output shaft 7, the middle part of the output shaft 7 extends radially along the output shaft 7 to form a star disk 8; the output shaft 7 passes through the center of the sun gear 4 and the rotating wheel 6 and can rotate relative to the sun gear 4 and the rotating wheel 6, and in the axial direction of the sun gear 4, a plurality of planetary gears 5 are arranged between the second sun gear 4 and the star disk 8; a planetary shaft 9 which is relatively fixed to the planetary gear 5 is also rotatably arranged at the central part of the planetary gear 5, the planetary shaft 9 passes through the center of the planetary gear 5, and the planetary gear 5 can rotate relative to the planetary shaft 9, and one end of the planetary shaft 9 close to the star disk 8 is fixedly connected to the star disk 8, and the sun gear 4 drives the planetary gears 5 to rotate. The shaft 9 and the planetary gear 5 rotate simultaneously, so that the planetary shaft 9 and the planetary gear 5 remain in a relatively fixed state and revolve around the sun gear 4 together. Preferably, the outer diameter of the planetary gear 5 is smaller than the outer diameter of the sun gear 4. A worm 10 is installed on the output shaft of the motor 1, and the worm 10 is meshed with the rotating wheel 6 or the two are connected by a gear transmission. The rotation of the worm 10 drives the rotating wheel 6 and the sun gear 4 to rotate; the rotation of the sun gear 4 drives the planetary gear 5 to rotate, and the planetary gear 5 can revolve around the axial direction of the sun gear 4 and drive the planetary carrier 2 to rotate. At the same time, the planetary gear 5 can also rotate around its own axial direction, and the rotation of the planetary carrier 2 drives the output shaft 7 to rotate. In the above technical scheme, when the worm 10 at the output end of the motor 1 is meshed with the rotating wheel 6, the worm 10 and the rotating wheel 6 form a primary transmission, and the planetary gear set is a secondary transmission; when the worm 10 at the output end of the motor 1 is meshed with the gear, a primary transmission is formed between the worm 10 and the gear, a secondary transmission is formed between the gear and the rotating wheel 6, and the planetary gear set is a tertiary transmission; the output shaft 7 of the motor 1 rotates to drive the worm 10 to rotate, the worm 10 rotates to drive the rotating wheel 6 to rotate, or the worm 10 drives the rotating wheel 6 to rotate through the gear, the rotating wheel 6 drives the sun gear 4 to rotate, the sun gear 4 drives the planetary gear 5 to revolve around the sun gear 4, and the planetary gear 5 drives the star plate 8 and the rotating shaft to rotate; the multi-stage gear transmission mechanism has a compact structure, occupies a small space, has a smooth transmission, high transmission efficiency, and a large output torque; the multi-stage gear transmission design of the worm 10 and the planetary gear set realizes the smooth rotation of the output shaft 7.

[0036] like Figure 2As shown, a gear set is also provided between the worm 10 and the rotating wheel 6, and a transmission connection is achieved through the gear set. The gear set includes at least two gears. The transmission effect of the gear set makes the worm 10 rotate to drive the gear set and the rotating wheel 6; preferably, the gear set includes a first gear 11 and a second gear 12 coaxially arranged with the first gear 11, and the first gear 11 and the second gear 12 are fixedly connected or integrally formed, the first gear 11 meshes with the worm 10, and the second gear 12 meshes with the rotating wheel 6. The rotation of the worm 10 drives the gears on the gear set to rotate, the rotation of the gear drives the rotating wheel 6 to rotate, the rotating wheel 6 drives the sun gear 4 to rotate, the sun gear 4 drives the planetary gear 5 to revolve around the axial direction of the sun gear 4, and the planetary gear 5 drives the star plate 8 and the rotating shaft to rotate. Preferably, the outer diameter of the first gear 11 is larger than the outer diameter of the second gear 12, and at the same time, the outer diameter of the second gear 12 is smaller than the outer diameter of the rotating wheel 6.

[0037] As a preference, Figure 5 , Figure 8 and Fig. 9 As shown, the side wall of the rotating wheel 6 near the sun wheel 4 extends toward the sun wheel 4 with an annular plate portion 13 for contacting with the planetary wheel 5; the star disk 8 is provided with a plurality of third grooves 14 for matching with the planetary shaft 9, the planetary shaft 9 is inserted into the third grooves 14 and fixedly connected with the third grooves 14, and the third grooves 14 extend toward the planetary wheel 5 with an annular protrusion 15 for contacting with the planetary wheel 5; the annular plate portion 13 and the annular protrusion 15 match to limit the planetary wheel 5 between the two. A gap is maintained between the planetary wheel 5 and the rotating wheel 6, and between the planetary wheel 5 and the star disk 8, so as to avoid friction caused by contact with the rotating wheel 6 and the star disk 8 when the planetary wheel 5 rotates.

[0038] Main ball valve electric actuator, such as Figures 10 to 13As shown, it includes a box body 16 with an opening on one side, and a box cover 17 for sealing the box body 16, and also includes the multi-stage gear transmission mechanism of the main ball valve electric actuator as described above, and the motor 1, the planetary gear set and the planetary carrier 2 are installed in the box body 16; the inner side of the bottom wall of the box body 16 forms a first groove 18 for accommodating and fixing the motor 1, and the two sides of the first groove 18 form support plates 19 for supporting the two ends of the motor 1, and the inner side of the bottom wall of the box body 16 is located on one side of the first groove 18. There are also two protruding plates 20 with arc-shaped cross-sections and oppositely arranged. One end of the output shaft 7 on the planetary carrier 2 is rotatably connected to the bottom wall of the box body 16. Specifically, the end of the output shaft 7 is rotatably connected between the two protruding plates 20 and is radially limited by the two protruding plates 20. The other end of the output shaft 7 on the planetary carrier 2 passes through the box cover 17 and is rotatably connected to the box cover 17. The box cover 17 is also provided with a The radial limiting star disk 8 is annular in shape of the second groove 21, the star disk 8 on the planetary carrier 2 is embedded in the second groove 21 and can rotate relative to the second groove 21, and a rotating shaft passes through the center of the first gear 11 and the second gear 12 on the gear set, one end of the rotating shaft is fixedly supported by the box body 16, and the other end of the rotating shaft is positioned and supported by the shaft hole of the box cover 17, and the gear ring 3 is fixed on the box cover 17; a PCB board 22 is installed on the inner side of the bottom wall of the box body 16 corresponding to the position of the protruding plate portion 20, the PCB board 22, and the PCB board 22 is provided with an avoidance groove for avoiding the protruding plate portion 20, the PCB board 22 is plugged into the PCB board 22 and fixedly connected to the bottom wall of the box body 16 by fasteners, and a magnetic position sensor is also installed on the PCB board 22 near the end position of the output shaft 7, and a magnetic cake 23 matching the magnetic position sensor is installed on the output shaft 7 of the planetary carrier 2 at one end near the position sensor. Applying the above-mentioned multi-stage gear transmission mechanism to the electric actuator can greatly reduce the size of the electric actuator, and the electric actuator has a high load-bearing capacity, a large speed ratio, safe performance, smooth transmission, high transmission efficiency, and a large output torque; in the above-mentioned technical scheme, the magnetic disc 23 is installed on the output shaft 7 of the planetary carrier 2, compared with the traditional scheme of installing it on the output gear shaft: 1. The scheme in which the magnetic disc 23 is installed on the planetary carrier 2 has a simpler process installation and no risk of damaging the gear; 2. The scheme in which the magnetic disc 23 is installed on the planetary carrier 2 cooperates with the magnetic position sensor on the PCB board 22 to realize the angle detection and feedback of the output shaft 7.

[0039] Preferably, the gear ring 3 and the box cover 17 are integrally formed; the gear ring 3 and the box cover 17 can be of an integral or split design; the integral design reduces the number of parts, reduces the assembly process, and saves manufacturing costs; the split design can provide a variety of design and assembly solutions, increasing design flexibility. In addition, the side wall of the box body 16 extends in all directions with a plurality of connecting plate portions 24 for fixed connection with the box cover 17, each connecting plate portion 24 is provided with a mounting hole 25, each mounting hole 25 is embedded with a bushing 26, and the mounting hole 25 with the bushing 26 can make the electric actuator suitable for harsh high temperature and vibration application environments.

[0040] The main ball valve of the thermostat of the automobile engine includes the main ball valve electric actuator described above, the inner spline hole of the output shaft 7 of the electric actuator is connected with the spline shaft of the main ball valve, the mounting hole 25 of the electric actuator is fixed with the mounting hole of the main ball valve by bolts, the magnetic position sensor on the PCB board 22 cooperates to realize the detection and feedback of the rotation angle of the output shaft 7, and the spline of the ball valve is linked to the output shaft 7 to realize the precise control of the ball valve opening. The electric actuator is mainly used on the main ball valve of the ball valve type thermostat of the automobile engine intelligent thermal management system. The electric actuator is used for the ball valve drive electric actuator with an angular position feedback signal of the ball valve type thermostat of the automobile engine, which can realize the precise control of the ball valve opening, thereby controlling the flow of the coolant to achieve more precise engine temperature control and maximize the fuel efficiency of the engine. By adopting a multi-stage gear transmission design including a worm gear 10 and a planetary gear set, the present invention achieves smooth transmission, compact structure, high transmission efficiency, high structural strength, high transmission reliability, long service life, large output torque, safe performance, relatively simple assembly scheme, and is suitable for application environments in engine compartments with harsh temperatures and vibrations.

[0041] The specified directions in this specific embodiment are only for the convenience of describing the positional relationship and the coordination relationship between the components. The above is only a preferred embodiment of the present invention. The protection scope of the present invention is not limited to the above embodiment. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. The multi-stage gear transmission mechanism of the main ball valve electric actuator is characterized by: The invention comprises a motor (1), a planetary gear set and a planet carrier (2), wherein the planetary gear set comprises a gear ring (3) and a sun gear (4) arranged on the inner side of the gear ring (3), a plurality of planetary gears (5) are arranged between the gear ring (3) and the sun gear (4), the inner sides of the plurality of planetary gears (5) are all meshed with the sun gear (4), and the outer sides of the plurality of planetary gears (5) are all meshed with the annular internal teeth on the gear ring (3); a rotating wheel (6) is also fixed or integrally formed on one side of the sun gear (4) along the axial direction of the sun gear (4); The planet carrier (2) comprises an output shaft (7), the middle portion of the output shaft (7) extending in the radial direction of the output shaft (7) to form a star disk (8); the output shaft (7) passes through the center of the sun gear (4) and the rotating wheel (6) and can rotate relative to the sun gear (4) and the rotating wheel (6); a planet shaft (9) is also rotatably arranged at the central portion of the planet gear (5), and one end of the planet shaft (9) close to the star disk (8) is fixedly connected to the star disk (8); A worm (10) is mounted on the output shaft (7) of the motor (1), and the worm (10) is meshed with the rotating wheel (6) or the two are connected via a gear transmission; the rotation of the worm (10) drives the rotating wheel (6) and the sun gear (4) to rotate; the rotation of the sun gear (4) drives the planetary gear (5) to rotate, and the planetary gear (5) can revolve around the axis of the sun gear (4) and drive the planetary carrier (2) to rotate; at the same time, the planetary gear (5) can also rotate around its own axis, and the rotation of the planetary carrier (2) drives the output shaft (7) to rotate; The worm (10) and the rotating wheel (6) are connected to each other via a gear set, wherein the gear set comprises at least two gears, and the worm (10) rotates to drive the gear set and the rotating wheel (6) through the transmission effect of the gear set; The gear set comprises a first gear (11) and a second gear (12) coaxially arranged with the first gear (11), and the first gear (11) and the second gear (12) are fixedly connected or integrally formed, the first gear (11) is meshed with the worm (10), and the second gear (12) is meshed with the rotating wheel (6); The outer diameter of the first gear (11) is greater than the outer diameter of the second gear (12); The outer diameter of the rotating wheel (6) is greater than the outer diameter of the second gear (12); The outer diameter of the planetary gear (5) is smaller than the outer diameter of the sun gear (4).

2. The multi-stage gear transmission mechanism of the main ball valve electric actuator according to claim 1 is characterized in that: The side wall of the rotating wheel (6) close to the sun gear (4) extends in the direction of the sun gear (4) to form an annular plate portion (13) for abutting against the planetary gear (5); the star plate (8) is provided with a plurality of third grooves (14) matching with the planetary shafts (9); the planetary shafts (9) are inserted into the third grooves (14) and fixedly connected with the third grooves (14); the third grooves (14) extend in the direction of the planetary gear (5) to form an annular protrusion (15) for abutting against the planetary gear (5); the annular plate portion (13) matches with the annular protrusion (15) to limit the planetary gear (5) between the two.

3. The main ball valve electric actuator is characterized by: The invention comprises a box body (16) with an opening on one side and a box cover (17) for sealing the box body (16), and is characterized in that: it also comprises a multi-stage gear transmission mechanism of the main ball valve electric actuator as claimed in claim 1 or 2, wherein a motor (1), a planetary gear set and a planetary carrier (2) are installed in the box body (16); one end of the output shaft (7) on the planetary carrier (2) is rotatably connected to the bottom wall of the box body (16), and the other end of the output shaft (7) on the planetary carrier (2) passes through the box cover (17) and is rotatably connected to the box cover (17), and the gear ring (3) is fixed on the box cover (17); a position sensor is also installed at the end position of the output shaft (7) on the inner side of the bottom wall of the box body (16), and a magnetic disk (23) matching the position sensor is installed on the end of the output shaft (7) of the planetary carrier (2) near the position sensor.

4. The main ball valve electric actuator according to claim 3 is characterized in that: The gear ring (3) and the box cover (17) are integrally formed; or, the side wall of the box body (16) extends in all directions to have a plurality of connecting plate portions (24) for fixed connection with the box cover (17), each connecting plate portion (24) is provided with a mounting hole (25), and each mounting hole (25) is embedded with a bushing (26).

5. The main ball valve of the thermostat of the automobile engine is characterized by: It comprises the main ball valve electric actuator as claimed in claim 3.

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