An electronic mechanical brake system based on coupling of service and parking brake by gear belt

Abstract

The utility model belongs to the field of automobile electronic mechanical brake system discloses a kind of electronic mechanical brake system of driving and parking brake coupling based on gear belt, and the system includes: driving brake motor, belt wheel system, planetary gear train, parking brake motor and its transmission assembly, wherein, driving brake motor output end is fixedly equipped input gear, the output gear of belt wheel system is assembled in the sun gear input shaft of planetary gear train, gear belt is engaged between input gear and output gear, to realize deceleration and damping, planetary gear train is nested in the gear recess of output gear, driving brake torque is output via planet carrier output shaft, driving and parking brake share output shaft, compact structure, realize high transmission ratio, high torque output, meet electric vehicle high braking performance demand, gear belt has shock absorption and load sharing function, reduce noise, improve gear train durability life, double motor parallel arrangement and share output shaft design, significantly reduce axial and radial space, with high integration, high reliability and low maintenance cost advantage.

Description

Technical Field

[0001] This utility model relates to the field of automotive electromechanical braking systems, specifically to an electromechanical braking system based on gear belt coupling of driving and parking brakes. Background Technology

[0002] With the rapid development of automotive electrification and intelligence, electromechanical braking systems, as a replacement for traditional hydraulic braking systems, are gradually becoming the development trend of automotive braking systems due to their advantages such as fast response speed, high control precision, and high system integration. Electromechanical braking systems typically include two functional modules: service brake and parking brake. The service brake is responsible for deceleration and stopping the vehicle during travel, while the parking brake is responsible for maintaining the vehicle's position after it stops. Currently, the service brake and parking brake in electromechanical braking systems are usually implemented using independent designs.

[0003] CN117922522A discloses a parking brake actuator and an electromechanical brake actuator, including a parking brake motor, a parking reduction mechanism, a parking limit gear, and a parking gear. The output end of the parking brake motor is driven by the input end of the parking reduction mechanism, and the output end of the parking reduction mechanism is driven by the parking limit gear. The parking gear meshes with or disengages with the parking limit gear. While this structure achieves the parking brake function, it requires an additional independent parking actuator outside the service braking system, increasing the overall size of the braking system.

[0004] CN221698698U discloses a similar parking brake actuator, which also uses an independent parking brake motor and reduction mechanism. Although it has improved in terms of safety and response time, it still does not solve the problem of low integration between the service brake and parking brake systems.

[0005] Regarding the application of planetary gear transmission mechanisms, CN106090085A discloses a differential planetary actuator for a vehicle electronic parking brake system, including a brake caliper assembly and an actuator. The actuator employs differential planetary components, including a first sun gear, planet gears, a planet carrier, and a first internal gear ring. Although this solution utilizes a planetary gear mechanism to improve transmission efficiency, it primarily targets the parking brake function and does not consider the coupling design with the service brake.

[0006] The applicant's previous utility model patent application CN119796151A disclosed an electromechanical parking brake system with redundant coupling of driving and parking brakes. It includes a driving brake motor and gear reduction mechanism assembly with a two-stage reduction output gear for driving brake. This transmission system uses a two-stage reduction gear, which occupies a large space and has a small transmission ratio. Therefore, it is necessary to design a device with a more compact structure and higher integration.

[0007] In summary, the main problems with existing technologies are as follows: Firstly, traditional electromechanical braking systems typically design service braking and parking braking functions separately, resulting in complex system structures, large size, and increased weight. Secondly, even some solutions that attempt to integrate service and parking brakes often suffer from complex transmission systems, low transmission efficiency, and insufficient structural compactness. Especially within limited installation space, achieving a high-ratio, highly integrated service and parking brake coupling system remains a pressing technical challenge. Furthermore, existing electromechanical braking systems, when implementing the parking function, usually require an additional independent parking actuator outside the main braking system structure. This not only increases the overall size and axial / radial dimensions of the brake but also affects the structural compactness and reliability of the braking system. Utility Model Content

[0008] In view of the problems of large space occupation, low integration and small transmission ratio of existing electromechanical braking systems, this utility model provides an electromechanical braking system based on gear belt coupling of driving and parking brakes.

[0009] The technical solution of this utility model is: An electromechanical braking system based on gear belt coupling for vehicle and parking brakes includes a vehicle brake motor, a pulley system, a planetary gear system, a parking brake motor, and its transmission components. An input gear is fixedly mounted on the vehicle brake motor. The output gear in the pulley system is mounted on the sun gear input shaft of the planetary gear system. A gear belt is wound around the input and output gears and meshes with them. The planetary gear system is nested within the gear groove of the output gear. The torque of the vehicle brake motor is output through the planetary carrier output shaft of the planetary gear system. The parking brake motor is arranged parallel to the vehicle brake motor. The parking brake torque is output to the parking secondary reduction worm gear through a worm gear transmission assembly, and then output to the planetary carrier output shaft. The output gear and the parking secondary reduction worm gear are coupled. Both the vehicle brake motor and the parking brake motor transmit torque through the planetary carrier output shaft.

[0010] Preferably, the gear belt is a synchronous belt with a toothed structure on its inner circumference that meshes with the external teeth of the input gear and the output gear to transmit rotational power between the gears.

[0011] The planetary gear system includes a ring gear, a sun gear, planet gears, and a planet carrier. The sun gear is fixedly mounted on the sun gear input shaft and meshes with the planet gears. The planet gears are fixedly mounted on the planet carrier and mesh with the ring gear. The rotation of the planet carrier drives the output shaft of the planet carrier, which is fixed at its end, to output braking torque. The output gear is provided with a gear groove, the inner diameter of which is larger than the outer diameter of the ring gear. The planetary gear system is embedded in the groove cavity of the output gear.

[0012] The pulley system includes an input gear, a gear belt, and an output gear that mesh in sequence. One end of the input gear is fixedly provided with an input gear mounting bearing, and the output gear is fixedly assembled on the sun gear input shaft of the planetary gear system. At both ends of the sun gear input shaft, one end is provided with an output gear mounting bearing, and the other end is fixedly connected to the sun gear.

[0013] The transmission assembly includes a parking primary reduction worm gear, a parking primary reduction worm wheel, a parking secondary reduction worm gear, a parking secondary reduction worm wheel, and a parking secondary reduction worm wheel mounting bearing. The parking primary reduction worm gear is fixedly mounted on the output shaft of the parking brake motor. The parking primary reduction worm gear and the parking primary reduction worm wheel are coaxially arranged and rotate synchronously. The parking secondary reduction worm gear meshes with the parking secondary reduction worm wheel for transmission. Both ends of the parking secondary reduction worm gear are fixed by parking secondary reduction worm gear mounting bearings.

[0014] Preferably, the output gear is mounted on the sun gear input shaft, while the parking secondary reduction worm gear is mounted on the planetary carrier output shaft via a parking secondary reduction worm gear mounting bearing. The mating surfaces of the parking secondary reduction worm gear and the planetary carrier are respectively provided with worm gear end face teeth and planetary carrier end face teeth. The two end face teeth are symmetrically arranged in the circumferential direction. The torque is transmitted by close contact during rotation. The number of working rotations of the planetary carrier is less than 1 / 2 revolution.

[0015] Preferably, the parking secondary reduction worm gear rotates coaxially with the planetary carrier output shaft. During parking braking, torque is transmitted through the rotation and compression of the worm gear end face teeth and the planetary carrier end face teeth. The number of working rotations of the parking secondary reduction worm gear is less than 1 / 2 revolution.

[0016] Preferably, the gear ring is provided with a connecting key on its exterior and is assembled and fixed with the keyway on the gearbox housing.

[0017] Preferably, the sun gear input shaft is integrally formed with the sun gear or fixed by interference fit.

[0018] The parking brake primary reduction worm gear is fixedly connected to the parking brake motor. The parking brake primary reduction worm wheel is fixedly mounted on the parking brake secondary reduction worm gear via a keyway or spline. The parking brake secondary reduction worm gear has mounting bearings at both ends. The parking brake secondary reduction worm gear is fixedly connected to the parking brake primary reduction worm wheel or is forged into one piece.

[0019] Compared with the prior art, the advantages of this utility model are: The system has a high transmission ratio, which increases the peak torque output of the brake motor and meets the high braking performance requirements of electric vehicles. The design of the gear belt drive and planetary gear drive structure significantly increases the braking torque output of the motor. When adapting to the braking torque capacity requirements of different vehicles, it is not necessary to increase the size of the brake motor, making the electromechanical braking system applicable to a wide range of vehicle models and easy to achieve product platform universality. The compact design allows for miniaturization of the transmission system, minimizing structural dimensions. The toothed belt output gear has a hollow structure, with the sun gear, planet gears, and internal gear ring directly nested within the output gear groove, saving space. The electromechanical braking system is limited by the space inside the wheel hub; the more compact the transmission system and the smaller the space, the more space and flexible installation methods the braking system can have. By reducing the number of gears and gear shafts in multi-stage gear transmissions, the system becomes lighter and less expensive. For the whole vehicle, the unsprung mass is reduced, which helps to improve the handling and comfort of the whole vehicle. The system exhibits low noise and excellent NVH (noise, vibration, and harshness) performance. Electric vehicles have higher NVH requirements than gasoline vehicles; the toothed belt designed in this invention can absorb vibration, reduce gear system noise, and improve overall vehicle comfort. High reliability and good durability. The planetary gear system has uniform load distribution, and combined with the shock absorption function of the toothed belt, it makes the planetary gear system transmission smoother, reduces gear meshing impact and tooth surface pitting, and improves the service life of the gear system.

[0020] The coupling and decoupling design of parking brake and service brake allows the transmission systems of service brake and parking brake to share an output shaft. This means that service brake torque output can be achieved independently, parking brake torque output can be achieved independently, or the torque output of service brake and parking brake can be superimposed. This meets the different braking requirements under complex driving conditions and improves the redundancy and safety of the braking system.

[0021] The detailed structure of this utility model will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of an electromechanical braking system that couples driving and parking brakes according to this utility model; Figure 2 This is a schematic diagram of the vehicle and parking brake coupling assembly of this utility model; Figure 3 This is a schematic diagram of the vehicle brake pulley system transmission mechanism of this utility model; Figure 4 This is a schematic diagram of the planetary gear transmission assembly of this utility model.

[0023] The components are as follows: 1. Service brake motor; 2. Input gear; 3. Gear belt; 4. Input gear mounting bearing; 5. Output gear mounting bearing; 6. Output gear; 7. Sun gear input shaft; 8. Gear ring; 9. Planetary gears; 10. Planetary carrier; 11. Parking secondary reduction worm gear; 12. Parking secondary reduction worm wheel; 13. Parking primary reduction worm wheel; 14. Parking primary reduction worm gear; 15. Parking brake motor; 16. Parking secondary reduction worm wheel mounting bearing; 17. Planetary carrier output shaft; 18. Worm wheel end face teeth; 19. Planetary carrier end face teeth; 20. Connecting key; 21. Sun gear; 22. Parking secondary reduction worm gear mounting bearing; 23. Gear groove; 40. Pulley system; 50. Planetary gear system. Detailed Implementation

[0024] like Figure 1-4 As shown, an electromechanical braking system based on gear belt coupling for both driving and parking brakes comprises a driving brake motor 1, a parking brake motor 15, a pulley system, a planetary gear system, a two-stage worm gear system, and mounting bearing assemblies. This invention arranges the parking brake motor 15 and driving brake motor 1 in parallel. The driving brake transmission gear system uses a pulley system, resulting in a high transmission ratio, low noise, and good NVH performance. Simultaneously, the planetary gear system increases the transmission ratio, ensuring uniform load distribution, smooth operation, and improved reliability and durability. The parking brake uses a high-ratio two-stage worm gear transmission mechanism to transmit braking torque. Furthermore, the output gear 6 is coupled with the parking brake's second-stage reduction worm gear. The torque of both the driving brake motor 1 and the parking brake motor 15 is output through the planetary carrier output shaft.

[0025] The pulley system includes an input gear 2, a gear belt 3, and an output gear 6. The input gear 2 is fixed on the output shaft of the service brake motor 1, and the input gear 2 meshes with the gear belt 3 and the output gear 6 in sequence. A sun gear input shaft 7 is coaxially mounted on the output gear 6.

[0026] The output gear 6 has a planetary gear system embedded in the gear groove 23, which reduces the structural layout size, realizes the miniaturization and integration of the system, and helps to reduce weight and improve braking torque.

[0027] The two-stage worm gear transmission mechanism includes a parking primary reduction worm 14, a parking primary reduction worm wheel 13, a parking secondary reduction worm 11, a parking secondary reduction worm wheel 12, and a parking secondary reduction worm wheel mounting bearing 16. The parking primary reduction worm 14 is fixedly mounted on the output shaft of the parking brake motor 15. The parking primary reduction worm 14 meshes with the parking primary reduction worm wheel 13, and the parking secondary reduction worm 11 meshes with the parking secondary reduction worm wheel 12 in sequence. Both ends of the worm are fixed by mounting bearings.

[0028] The output gear 6 is mounted on the sun gear input shaft 7. The sun gear input shaft 7 and the sun gear 21 are integrally formed or press-fitted together. The output gear 6 drives the sun gear 21, the sun gear 21 drives the planet gears 9, and the planet gears 9 drive the planet carrier 10 to achieve torque transmission. The parking secondary reduction worm gear 11 is mounted on the planet carrier output shaft 17. The parking secondary reduction worm gear 11 and the planet carrier 10 have end face teeth on their mating surfaces. The parking secondary reduction worm gear 11 transmits power to the planet carrier 10 through the end face teeth. The output gear 6 and the parking secondary reduction worm gear 11 achieve a coupled design by jointly influencing the planetary gear system 50. This means that the driving braking torque output can be achieved independently, the parking braking torque output can be achieved independently, or the two torques can be superimposed.

[0029] Specifically, the planetary gear system includes a ring gear 8, a sun gear 21, planet gears 9, and a planet carrier 10. The sun gear 21 meshes with the planet gears 9, which are mounted on the planet carrier 20 and mesh with the ring gear 8. The planet carrier 10 rotates to drive the planet carrier output shaft 17, which is fixed at its end, to output braking torque.

[0030] Specifically, the output gear 6 of the pulley system is provided with a gear groove 23, the inner diameter of which is larger than the outer diameter of the planetary gear ring 8. The planetary gear is embedded inside the output gear 6, reducing the overall arrangement of the planetary gear system and reducing the height dimension by more than 20%, thus making the transmission system structure more compact. At the same time, the use of the planetary gear system achieves a larger transmission ratio and improves braking force.

[0031] Specifically, the gear ring 8 is externally fitted with a connecting key 20, which is assembled and fixed to the keyway on the gearbox housing.

[0032] Specifically, the vehicle brake input gear 2 is fixedly connected to the output shaft of the vehicle brake motor 1. The output gear 6 is fixedly connected to the sun gear input shaft 7. One end of the sun gear input shaft 7 is a mounting bearing 5, and the other end is a sun gear 21. The sun gear 21 and the sun gear input shaft 7 are integrally formed.

[0033] Optionally, the output gear 6 is fixedly connected to the sun gear input shaft 7 by means of splines or keyways, and the sun gear 21 is integrally formed or press-fitted to the sun gear input shaft 7.

[0034] Specifically, the two end face teeth 18 of the parking secondary reduction worm gear 12 are tightly engaged with the two end face teeth 19 of the planetary carrier 10. When the vehicle is under service braking, the service brake motor 1 drives the pulley system to work, and the parking brake motor 15, as a redundant backup, does not need to work synchronously. Furthermore, since the output gear 6 needs to rotate 1 / 2 turn before the two end face teeth of the parking secondary reduction worm gear 11 can contact the other side of the two end face teeth of the planetary carrier 10, the secondary reduction mechanism designed in this utility model has a working rotation number of less than 1 / 2 turn for the output gear 6. The two end face teeth of the parking secondary reduction worm gear 6 and the two end face teeth of the planetary carrier 10 have a clearance margin and will not interfere with each other. Moreover, when the vehicle starts, the parking brake can be released manually or automatically before the service brake, that is, the parking secondary reduction worm gear 11 returns to its initial position first, and then the output gear 6 returns to its initial position. Therefore, the service brake and the parking brake can work independently without affecting each other.

[0035] like Figure 2 As shown, the two worm gear end face teeth 18 of the parking secondary reduction worm gear 12 and the two gear end face teeth 19 of the planetary carrier are respectively arranged opposite each other at 180 degrees around the circumference and fit tightly together after assembly. The inner diameter of the gear groove of the output gear 6 is larger than the outer diameter of the gear ring 8 of the planetary gear system 50 and is fixedly fitted. The planetary carrier 10 and the planetary carrier output shaft 17 output braking torque.

[0036] like Figure 4 As shown, the planetary gear transmission assembly mainly includes a sun gear 21, planet gears 9, a ring gear 8, a planet carrier 10, and a planet carrier output shaft 17. The rotation of the sun gear 21 inputs torque to the vehicle brake motor, which is transmitted through the pulley system 40. This torque drives the planet gears 9 to rotate. The planet gears rotate around the sun gear 21 and the ring gear 8, driving the planet carrier 10 to rotate, which in turn drives the planet carrier output shaft 17 to rotate. This rotation is converted into linear motion of the brake piston through a motion conversion mechanism, thereby pressing the brake disc to generate braking force. The motion conversion mechanism can be a ball screw, planetary roller screw, etc.

[0037] Specifically, when the vehicle is performing regular service braking, the service brake motor 1 transmits torque to the sun gear 21 fixed on the output gear 6 through the pulley system 40. The rotation of the sun gear 21 drives the planet gears 9 to rotate. The planet gears rotate around the gear ring 8, which drives the planet carrier 10 to rotate, and drives the planet carrier output shaft 17 to rotate to output braking torque.

[0038] Specifically, when the vehicle is in regular parking braking mode, the parking brake motor 15 rotates through a two-stage worm gear transmission mechanism to input torque to the second-stage parking reduction worm gear 12. The two end face teeth 18 of the worm gear and the two end face teeth 19 of the planetary carrier 10 are closely engaged and rotate around the planetary carrier output shaft 17 to transmit power torque to the planetary carrier output shaft 17.

[0039] Specifically, the parking first-stage reduction worm gear 14 is fixedly connected to the parking brake motor 15, and the parking first-stage reduction worm wheel 13 is fixedly mounted on the parking second-stage reduction worm gear 11 through a keyway or spline. The parking second-stage reduction worm gear 11 is provided with mounting bearings at both ends.

[0040] Specifically, the parking secondary reduction worm gear 11 is fixedly connected to the parking primary reduction worm wheel 13 or is forged into one piece.

[0041] Furthermore, when the vehicle requires braking force exceeding that of normal braking under certain special operating conditions, the parking brake motor 15 engages with the parking first-stage reduction worm gear 13 through the parking first-stage reduction worm gear 14, and then reduces speed and increases torque through the parking second-stage reduction worm gear 11 and the parking second-stage reduction worm gear 12. When the end face teeth of the parking second-stage reduction worm gear 12 contact the end face teeth of the planetary carrier 10, it drives the planetary carrier 10 to rotate, thereby driving the output shaft 17 to rotate and apply the superimposed braking torque of the parking motor to meet the braking force requirements under extreme braking conditions.

[0042] When the service brake and parking brake are released, the two motors, service brake motor 1 and parking brake motor 15, stop working, and parking is achieved through the parking worm gear self-locking function of the parking brake system.

[0043] Furthermore, when the service brake system fails, the parking brake motor 15 drives the parking secondary reduction worm gear 12 to rotate through its own worm gear reduction mechanism. When the end face teeth of the parking secondary reduction worm gear 12 contact the end face teeth of the planetary carrier 10, it drives the output shaft 17 to transmit torque, thus still achieving a certain service braking function.

[0044] The above description is a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and concept of this utility model, should be covered within the protection scope of the claims of this utility model.

Claims

1. An electromechanical braking system based on a gear belt coupling for driving and parking brakes, comprising a driving brake motor (1), a pulley system, a planetary gear system, a parking brake motor (15), and its transmission components, wherein an input gear (2) is fixedly mounted on the driving brake motor (1), an output gear (6) in the pulley system (40) is mounted on the sun gear input shaft (7) of the planetary gear system (50), a gear belt (3) is arranged around the input gear (2) and the output gear (6) and meshes with the input gear (2) and the output gear (6), and the planetary gear system (50) is nested in the gear groove (23) of the output gear (6), characterized in that: The service brake motor (1) outputs torque through the planetary carrier output shaft (17) of the planetary gear system (50). The parking brake motor (15) is arranged in parallel with the service brake motor (1). The torque is transmitted to the parking secondary reduction worm gear (12) through the worm gear transmission assembly. The torque is output through the planetary carrier output shaft (17). The output gear (6) and the parking secondary reduction worm gear (12) are coupled. Both the service brake motor (1) and the parking brake motor (15) output torque through the planetary carrier output shaft (17).

2. The electromechanical braking system based on gear belt coupling for driving and parking brakes according to claim 1, characterized in that: The gear belt (3) is a synchronous belt with a toothed structure on its inner circumference, which meshes with the outer teeth of the input gear (2) and the output gear (6) to transmit rotational power between the gears.

3. The electromechanical braking system based on gear belt coupling for driving and parking brakes according to claim 1, characterized in that: The planetary gear system (50) includes a gear ring (8), a sun gear (21), planet gears (9), and a planet carrier (10). The sun gear (21) is fixedly mounted on the sun gear input shaft (7) and meshes with the planet gears (9). The planet gears (9) are fixedly mounted on the planet carrier (10) and mesh with the gear ring (8). The planet carrier (10) rotates to drive the planet carrier output shaft (17) fixed at its end to output braking torque. The output gear (6) is provided with a gear groove (23), the inner diameter of which is larger than the outer diameter of the gear ring (8). The planetary gear system (50) is embedded in the cavity of the output gear groove (23).

4. The electromechanical braking system based on gear belt coupling for driving and parking brakes according to claim 1, characterized in that: The pulley system (40) includes an input gear (2), a gear belt (3), and an output gear (6) that mesh in sequence. One end of the input gear (2) is fixedly provided with an input gear mounting bearing (4), and the output gear (6) is fixedly mounted on the sun gear input shaft (7) of the planetary gear system (50). At both ends of the sun gear input shaft (7), one end is provided with an output gear mounting bearing (5), and the other end is fixedly connected to the sun gear (21).

5. The electromechanical braking system based on gear belt coupling for driving and parking brakes according to claim 1, characterized in that: The transmission assembly includes a parking first-stage reduction worm gear (14), a parking first-stage reduction worm wheel (13), a parking second-stage reduction worm gear (11), a parking second-stage reduction worm wheel (12), and a parking second-stage reduction worm wheel mounting bearing (16). The parking first-stage reduction worm gear (14) is fixedly mounted on the output shaft of the parking brake motor (15). The parking first-stage reduction worm gear (14) and the parking first-stage reduction worm wheel (13) are coaxially mounted and rotate synchronously. The parking second-stage reduction worm gear (11) meshes with the parking second-stage reduction worm wheel (12). Both ends of the parking second-stage reduction worm gear (11) are fixed by the parking second-stage reduction worm gear mounting bearing (22).

6. The electromechanical braking system based on gear belt coupling for driving and parking brakes according to claim 1, characterized in that: The output gear (6) is mounted on the sun gear input shaft (7), and the parking secondary reduction worm gear (12) is mounted on the planetary carrier output shaft (17) through the parking secondary reduction worm gear mounting bearing (16). The mating surfaces of the parking secondary reduction worm gear (12) and the planetary carrier (10) are respectively provided with worm gear end face teeth (18) and planetary carrier end face teeth (19). The two end face teeth are symmetrically arranged at 180° in the circumferential direction. The torque is transmitted by tightly fitting together during rotation. The number of working rotations of the planetary carrier (10) is less than 1 / 2 revolution.

7. The electromechanical braking system based on gear belt coupling for driving and parking brakes according to claim 1, characterized in that: The parking secondary reduction worm gear (12) rotates coaxially with the planetary carrier output shaft (17). During parking braking, the torque is transmitted through the rotation and compression of the worm gear end face teeth (18) and the planetary carrier end face teeth (19). The number of working rotations of the parking secondary reduction worm gear (12) is less than 1 / 2 rotation.

8. The electromechanical braking system based on gear belt coupling for driving and parking brakes according to claim 3, characterized in that, The gear ring (8) is externally provided with a connecting key (20) which is assembled and fixed with the keyway on the gearbox housing.

9. An electromechanical braking system based on a gear belt for coupling driving and parking brakes according to claim 1 or 3, characterized in that: The sun gear input shaft (7) and the sun gear (21) are integrally formed or fixed by interference fit.

10. An electromechanical braking system based on gear belt coupling for driving and parking brakes according to claim 5, characterized in that: The parking first-stage reduction worm gear (14) is fixedly connected to the parking brake motor (15). The parking first-stage reduction worm wheel (13) is fixedly mounted on the parking second-stage reduction worm gear (11) through a keyway or spline. The parking second-stage reduction worm gear (11) is provided with mounting bearings at both ends. The parking second-stage reduction worm gear (11) is fixedly connected to the parking first-stage reduction worm wheel (13) or forged into one piece.

Images