Electromechanical parking brake system with mutually coupled redundant service brake and parking brake

Abstract

An electromechanical parking brake system with a mutually coupled redundant service brake and parking brake, the electromechanical parking brake system comprising a brake assembly, an MGU housing, a service brake motor and gear reduction mechanism assembly, a gear system bearing bracket, an ECU controller assembly, a sealing cover plate, and a parking motor and gear reduction mechanism assembly, wherein the service brake motor and gear reduction mechanism assembly comprises service brake first-stage and second-stage reduction gear train mounting mechanisms and bearings; and the parking motor and gear reduction mechanism assembly comprises parking first-stage and second-stage reduction worm gear mechanisms and mounting bearings. The braking torques of a service brake and a parking brake are mutually coupled, two systems can share a brake output gear shaft assembly, the service brake and the parking brake can be operated independently, and the parking brake may also assist the service brake when needed. This design improves the safety and reliability of the brake system.

Description

A redundant electromechanical parking brake system with mutually coupled service and parking brakes. Technical Field

[0001] This invention relates to the field of automotive electromechanical parking brake technology, specifically to an electromechanical parking brake system in which driving and parking brakes are coupled and redundant. Background Technology

[0002] Electromechanical braking (EMB) systems use an electric motor as the driving source of braking force. Through a mechanical transmission mechanism, the motor's power is converted into braking force, clamping the vehicle's brake discs or drums to achieve braking. Compared to traditional hydraulic braking systems, EMB systems offer faster response times and more precise control, enabling more efficient energy recovery and superior braking performance.

[0003] Electromechanical braking systems consist of two components: a service brake and a parking brake. The service brake, typically using one or two motors, is a known existing technology. The parking brake usually uses a separate parking motor to drive a system with a one-way self-locking mechanism (one-way bearing, worm gear, lead screw, etc.) for parking, or it can be driven by a ratchet and pawl mechanism via a solenoid valve.

[0004] CN 117905881 A discloses a parking locking mechanism for an electromechanical brake actuator, including an electromagnetic locking assembly disposed within a motor housing and a locking disc fixed to the drive shaft of a drive motor. The locking disc has multiple locking holes evenly distributed circumferentially. The electromagnetic locking assembly includes an electromagnetic drive telescopic component and a locking head connected to the output end of the electromagnetic drive telescopic component, with the locking head extending into the locking holes. Using the above-mentioned parking locking mechanism and working method for an electromechanical brake actuator, locking is achieved through the electromagnetic locking assembly in conjunction with the locking disc fixed to the drive gear shaft. Due to the low torque of the drive gear, the impact on the locking head is relatively small, extending the service life of the mechanism. The disadvantages are: 1. The electromagnetic locking assembly, including a bistable electromagnet, dual electromagnetic coils, an iron core, and a locking head structure, is relatively complex, and the added current sensor and magnetic field strength sensor are costly; 2. There is a risk of misalignment between the multiple evenly distributed locking holes on the locking disc and the electromagnetic drive telescopic locking head, leading to parking failure.

[0005] CN 117905879 A discloses an electromechanical parking self-locking mechanism, control method, and vehicle. The electromechanical parking self-locking mechanism includes: a controller, a brake motor, a ratchet, and a pawl. The controller is connected to a solenoid valve, and the end of the solenoid valve has a push rod. When the solenoid valve is energized, the push rod extends to push the pawl, restricting the ratchet's reverse rotation, thus locking the vehicle. When the solenoid valve is de-energized, the push rod retracts and disengages from the pawl, allowing the ratchet to rotate in both directions, thus unlocking the vehicle. The structure is simple, requiring no sensors and reducing production costs. Disadvantages include: 1. The need for precise control and verification of the service and parking brakes, and the risk of premature, difficult, or jammed disengagement of the pawl and ratchet. 2. The pawl-ratchet locking mechanism cannot guarantee locking in any parking position, and the limited number of ratchet teeth leads to attenuation of parking force.

[0006] Furthermore, regardless of the parking structure mentioned above, there are certain problems:

[0007] All parking mechanisms require the service brake to engage first, and then the parking mechanism to lock. This parking method only works if the service brake is functioning properly. If the service brake fails, parking cannot be completed, and the parking system loses its braking safety redundancy.

[0008] The service brake and parking brake are relatively independent, which means that the two systems must consider their own clamping force requirements, placing higher demands on the motors and acceleration mechanisms of their respective systems, resulting in a relatively complex system and higher energy consumption.

[0009] When current electromechanical braking uses force control, the absence of a force sensor leads to complex control algorithms and an inability to achieve precise control.

[0010] Therefore, there is currently a lack of a design scheme with dual redundancy for driving and parking brakes, where braking and parking torques are coupled together, so that the electronic parking function can still operate normally even if one motor fails, or the power distribution between the two motors can be performed. Summary of the Invention

[0011] The purpose of this invention is to provide an electromechanical parking brake system with redundant coupling of driving and parking brakes, in order to solve the problems mentioned in the background art.

[0012] To achieve the above objectives, the present invention provides the following technical solution:

[0013] An electromechanical parking brake system with redundant coupling of service and parking brakes includes a brake assembly, a service brake motor and gear reduction mechanism assembly with a service brake secondary reduction output gear, a gear system bearing bracket connected to the brake assembly, an ECU controller assembly, and a parking motor and gear reduction mechanism assembly with a parking secondary reduction input worm gear. A secondary reduction gear system mounting shaft is rotatably mounted on the gear system bearing bracket. The service brake secondary reduction output gear and the parking secondary reduction input worm gear are jointly mounted on the secondary reduction gear system mounting shaft, and the parking secondary reduction input worm gear and the service brake secondary reduction output gear are coupled.

[0014] Preferably, the parking brake secondary reduction input worm gear has a protrusion on its spoke end face, and the service brake secondary reduction output gear has a concave block on its spoke end face. The protrusion and concave block abut against each other. The parking brake secondary reduction input worm gear is rotatably connected to the secondary reduction gear system mounting shaft, and the service brake secondary reduction output gear is fixedly connected to the secondary reduction gear system mounting shaft. Further preferably, the number of protrusions and concave blocks is not limited; it can be one, two, three, or even more.

[0015] Preferably, the ECU controller assembly is electrically connected to the service brake motor and gear reduction mechanism assembly and the parking motor and gear reduction mechanism assembly. The ECU controller assembly communicates with the vehicle via a CAN bus.

[0016] Preferably, the service brake motor and gear reduction mechanism assembly includes a service brake motor and a first-stage reduction gear system mounting shaft. A first-stage reduction input gear is sleeved on the output shaft of the service brake motor. A first-stage reduction output gear and a second-stage reduction input gear are sleeved on the first-stage reduction gear system mounting shaft. The first-stage reduction output gear meshes with the first-stage reduction input gear, and the second-stage reduction input gear meshes with the second-stage reduction output gear.

[0017] The first-stage reduction gear system mounting shaft has first-stage reduction gear system mounting bearings at both ends; the second-stage reduction gear system mounting shaft also has second-stage reduction gear system mounting bearings at both ends. More preferably, a first-stage reduction gear system mounting bearing is provided between the first-stage reduction gear system mounting shaft and the MGU housing, with the inner ring of the first-stage reduction gear system mounting bearing fixedly connected to the first-stage reduction gear system mounting shaft, and the outer ring of the first-stage reduction gear system mounting bearing fixedly connected to the MGU housing. Even more preferably, the reduction gear system mounting shaft is fixedly mounted on the MGU housing and the gear system bearing bracket via second-stage reduction gear system mounting bearings.

[0018] Preferably, the parking motor and gear reduction mechanism assembly includes a parking brake motor, a parking primary reduction input worm gear, and a parking secondary reduction input worm gear. The parking primary reduction input worm gear is fixedly connected to the output shaft of the parking brake motor. A parking primary reduction input worm wheel is fixedly mounted on the parking secondary reduction input worm gear. The parking primary reduction input worm wheel meshes with the parking primary reduction input worm gear, and the parking secondary reduction input worm gear meshes with the parking secondary reduction input worm wheel.

[0019] The parking secondary reduction input worm gear is equipped with secondary reduction worm gear mounting bearings at both ends. Specifically, a secondary reduction worm gear mounting bearing is provided between the parking secondary reduction input worm gear and the MGU housing. The inner ring of the secondary reduction worm gear mounting bearing is fixedly connected to the parking secondary reduction input worm gear, and the outer ring of the secondary reduction worm gear mounting bearing is fixedly connected to the MGU housing.

[0020] Preferably, the spoke end face of the parking secondary reduction input worm gear is provided with a first concave groove, and the first concave groove is provided with a first protrusion and a second protrusion. The spoke end face of the service brake secondary reduction output gear is provided with a second concave groove, and the second concave groove is provided with a first concave block and a second concave block corresponding to the first protrusion and the second protrusion. The first protrusion and the second protrusion extend into the second concave groove and abut against the sides of the first concave block and the second concave block.

[0021] Preferably, the first and second protrusions are positioned 180° apart, and the first and second concave blocks are also positioned 180° apart. The outer diameters of the first and second protrusions are smaller than the inner diameter of the secondary reduction output gear of the vehicle brake, but larger than the outer diameter of the gear sleeve. The two sets of protrusions and concave blocks cooperate with each other in a surface contact manner to transmit torque.

[0022] Preferably, both ends of the parking secondary reduction input worm gear are provided with a first protrusion and a second protrusion; both ends of the service brake secondary reduction output gear are provided with a first concave block and a second concave block.

[0023] Preferably, the parking secondary reduction input worm gear is connected to the secondary reduction gear system mounting shaft via a bearing or bushing. The parking secondary reduction input worm gear and the service brake secondary reduction output gear have no fixed assembly relationship. When the vehicle is under service braking, since the number of rotations of the service brake secondary reduction output gear is less than 1 / 2, there is a clearance between the first and second protrusions of the parking secondary reduction input worm gear and the first concave groove of the service brake secondary reduction output gear, which will not interfere with each other. Furthermore, when the vehicle starts, the parking secondary reduction input worm gear first returns to its initial position, and then the service brake secondary reduction output gear returns to its initial position. Therefore, the service brake and parking brake can work independently without affecting each other.

[0024] When the protrusions 1 and 2 at the end of the parking secondary reduction input worm gear of the parking motor and gear reduction mechanism assembly contact the sidewalls of the concave blocks 1 and 2 in the second concave groove of the service brake secondary reduction output gear, the two motors, the service brake motor and the parking brake motor, stop working, and parking is achieved through the self-locking function of the parking worm gear of the parking brake system.

[0025] The first-stage reduction input gear of the vehicle brake is fixedly connected to the output shaft of the vehicle brake motor. The first-stage reduction input gear, the second-stage reduction input gear, and the second-stage reduction output gear of the vehicle brake are fixedly connected to their respective mounting shafts by means of keyways, splines, etc., or are integrally formed. Each mounting shaft is equipped with bearings or bushings at both ends to reduce friction and improve efficiency.

[0026] To prevent incorrect installation, the protrusion features of the parking brake secondary reduction input worm gear and the concave features of the service brake secondary reduction output gear can be designed at two ends (upper and lower surfaces), with two protrusion and concave structures set at each end, so that there is no need to distinguish the installation direction.

[0027] When the vehicle is performing normal service braking, the service brake motor drives the first and second stage gear reduction mechanisms of the service brake to output braking torque through the second stage reduction gear shaft, thereby driving the brake actuator to achieve the braking function. When the vehicle needs braking force exceeding that of normal braking under certain special operating conditions, the parking brake motor drives the worm wheel to rotate through the worm gear reduction mechanism. When the protrusion at the end of the worm wheel contacts the protrusion in the groove at the end of the second stage reduction output gear of the service brake, it outputs a superimposed torque with the service brake system to meet the braking force requirements under extreme braking conditions.

[0028] When the service brake is released and the parking brake is needed, the parking motor drives the worm gear to rotate. When the protrusion at the end of the parking secondary reduction worm gear contacts the concave block in the groove of the service brake secondary gear, both motors stop working, and parking is achieved through the worm gear of the parking system. When the vehicle requires a larger parking force under some special working conditions, in addition to the clamping force generated by the service brake, the parking motor can also apply a certain clamping force through its own reduction mechanism, which is superimposed on the clamping force of the service brake to achieve a larger parking force.

[0029] When the service brake system fails, the parking motor drives the worm gear to rotate through its own reduction mechanism. When the protrusion at the end of the worm gear contacts the protrusion in the groove of the service brake reduction gear, it drives the service brake gear to rotate, thus still achieving a certain service braking function.

[0030] Preferably, the parking brake secondary reduction input worm gear is rotatably connected to the secondary reduction gear system mounting shaft, the service brake secondary reduction output gear is fixedly connected to the secondary reduction gear system mounting shaft, the service brake secondary reduction output gear is drive-connected to the service brake motor and gear reduction mechanism assembly, and the parking brake secondary reduction input worm gear is drive-connected to the parking motor and gear reduction mechanism assembly.

[0031] Preferably, it also includes an MGU housing and a sealing cover plate, which together form a box with an accommodating cavity. The service brake motor and gear reduction mechanism assembly, the gear system bearing bracket, the ECU controller assembly, and the parking motor and gear reduction mechanism assembly are all placed in the accommodating cavity. The MGU housing is provided with a through hole for the drive input shaft of the brake assembly to extend into. The MGU housing is fixedly connected to the housing of the brake assembly.

[0032] The present invention will be further explained and described below:

[0033] The technical problem this invention aims to solve is to improve the safety and reliability of electromechanical braking systems, particularly the redundant safety features in the event of a braking system failure. This redundancy design includes three aspects, ensuring that the parking brake system can still provide braking force even if the main service braking system fails, thus ensuring vehicle safety.

[0034] Firstly, there is redundancy in the mechanical transmission systems of the service braking system and the parking braking system;

[0035] Secondly, the coupling and decoupling of braking torque. In this invention, the service brake and parking brake are mutually coupled, and the two systems can share the brake output gear shaft assembly. The service brake and parking brake can work independently, and the parking brake can also assist the service brake when needed. This design improves the efficiency and reliability of the braking system.

[0036] Thirdly, there is redundancy in the motor drive controller ECU. The ECU is connected to the electromechanical brake assembly via the CAN bus, providing dual control protection to ensure that the braking system can still work normally when a single control system fails.

[0037] Compared with the prior art, the beneficial effects of the present invention are:

[0038] 1. Redundant Safety Function: The electromechanical braking system design of this invention includes redundant braking modes to address the vehicle braking and deceleration problem in the event of brake system failure, thereby improving vehicle safety. This redundant design ensures that even if the main service braking system fails, the parking brake system can still provide braking force, ensuring vehicle safety.

[0039] 2. Coupling and Decoupling of Braking Torque: In this invention, the braking torques of the service brake and parking brake are coupled together. The two systems can share the brake output gear shaft assembly, and the service brake and parking brake can be operated independently. Simultaneously, the parking brake can assist the service brake when needed. This design improves the efficiency and reliability of the braking system.

[0040] 3. Miniaturized and integrated design: By arranging the parking brake motor and the service brake motor in parallel, adopting a high-ratio two-stage worm gear transmission mechanism, and using a shared output gear shaft assembly, the present invention reduces the structural layout size, realizes the miniaturization and integration of the system, and helps to adapt to narrow wheel space.

[0041] 4. Advantages and application prospects: The electromechanical braking system of the present invention is particularly suitable for wheel-side braking systems of modern vehicles due to its advantages such as small size, fast response, reliable performance and safety and environmental protection.

[0042] In summary, an electromechanical brake with redundant coupling of driving and parking braking torques provides an efficient, safe, and responsive braking solution through its unique design, suitable for advanced driver assistance systems (ADAS) and autonomous driving systems in modern automobiles.

[0043] The detailed structure of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0044] Figure 1 is a schematic diagram of the overall structure of an electromechanical parking brake system with mutually coupled redundancy of driving and parking brakes according to the present invention.

[0045] Figure 2 is a schematic diagram of the driving and parking brake components of the present invention;

[0046] Figure 3 is a schematic diagram of the vehicle and parking brake reduction gear transmission mechanism of the present invention;

[0047] Figure 4 is a schematic diagram of the driving and parking brake coupling gear assembly of the present invention;

[0048] Figure 5 is a schematic diagram of the parking two-stage reduction input worm gear belt bearing assembly of the present invention;

[0049] Figure 6 is a schematic diagram of the two-stage reduction output gear assembly for the vehicle braking system of the present invention;

[0050] Figure 7 is a schematic diagram of the structure of the driving and parking brake coupling gear assembly (a pair of protrusions and concave blocks) of the present invention;

[0051] Figure 8 is a schematic diagram of the structure of the driving and parking brake coupling gear assembly (three pairs of protrusions and concave blocks) of the present invention;

[0052] The components include: 1. Brake assembly; 2. MGU housing; 3. Service brake motor and gear reduction mechanism assembly; 4. Gear system bearing bracket; 5. ECU controller assembly; 6. Sealing cover; 7. Parking motor and gear reduction mechanism assembly;

[0053] 31. Service brake motor; 32. Service brake primary reduction input gear; 33. Service brake primary reduction output gear; 34. Service brake secondary reduction input gear; 35. Service brake secondary reduction output gear; 36. Primary reduction gear system with mounting bearing; 37. Secondary reduction gear system with mounting bearing; 38. Primary reduction gear system with mounting shaft; 39. Secondary reduction gear system with mounting shaft; 310. Concave block one; 311. Gear sleeve; 312. Concave block two; 313. Second concave groove;

[0054] 71. Parking brake motor; 72. Parking primary reduction input worm gear; 73. Parking primary reduction input worm wheel; 74. Parking secondary reduction input worm gear; 75. Secondary reduction worm gear mounting bearing; 76. Parking secondary reduction input worm wheel; 77. Protrusion 1; 78. Protrusion 2; 79. Secondary reduction input worm wheel bearing; 710. First concave groove. Detailed Implementation

[0055] As shown in Figures 1-2, the electromechanical parking brake system with redundant coupling of service and parking brakes comprises a brake assembly 1, an MGU housing 2, a service brake motor and gear reduction mechanism assembly 3, a gear system bearing bracket 4, an ECU controller assembly 5, a sealing cover 6, and a parking motor and gear reduction mechanism assembly 7. This invention reduces the structural layout size by arranging the parking brake motor 71 and the service brake motor 31 in parallel and using a high-ratio two-stage worm gear transmission mechanism to change the direction of braking force transmission, thereby achieving a shared output gear shaft assembly 39. This results in miniaturization and integration of the system, which helps to adapt to the narrow wheel space of vehicles.

[0056] The ECU controller assembly 5 is connected to the electromechanical brake assembly via the CAN bus, providing dual control protection to ensure that the braking system can still function normally when a single control system fails.

[0057] The ECU controller assembly 5 has fault detection and alarm functions. The system should be able to detect power supply faults, brake signal faults, control system faults, and electromechanical braking system assembly faults, and display alarm errors through the instrument panel when a fault is detected.

[0058] The brake assembly 1 is fixed to the MGU housing 2 by a threaded fixing structure at its end. The service brake motor and parking motor assembly 3 are installed and fixed by the fixing and limiting structure on the MGU housing 2. The service gear reduction mechanism and parking gear reduction mechanism are fixed to the MGU housing 2 by the gear system bearing bracket 4. The sealing cover 6 and ECU controller assembly 5 are fixed to the MGU housing 2 by threaded connection.

[0059] Specifically, the actuator of brake assembly 1 is a ball screw or other torque conversion mechanism.

[0060] Specifically, the service brake gear reduction mechanism assembly 3 includes a service brake primary reduction input gear 32, a service brake primary reduction output gear 33, a service brake secondary reduction input gear 34, a service brake secondary reduction output gear 35, and mounting shafts and bearings for the primary and secondary reduction gear systems. The parking gear reduction mechanism assembly 7 includes parking primary and secondary reduction input worm gears and bearings, and parking secondary reduction input worm gears and bearings.

[0061] Specifically, the first-stage reduction input gear 32 of the service brake is fixedly connected to the output shaft of the service brake motor 31. The first-stage reduction input gear 32, the second-stage reduction input gear 33, and the second-stage reduction output gear 34 of the service brake are fixedly connected to their respective mounting shafts by means of keyways, splines, etc., or are forged into one piece. Bearings or bushings are installed at both ends of each mounting shaft to reduce friction and improve efficiency.

[0062] Specifically, the parking brake secondary reduction worm gear 76 is connected to the service brake secondary reduction gear system mounting shaft 39 via a bearing or bushing. The two protrusions of the parking brake secondary reduction input worm gear 76 are tightly fitted with the two concave blocks in the second concave groove 313 of the service brake secondary reduction gear 35. When the vehicle is under service braking, the service brake motor 31 drives the gear reduction system to work. The parking brake motor 71, as a redundant backup, does not need to work synchronously. Furthermore, since the second-stage reduction gear needs to rotate 1 / 2 turn for the two protrusions of the parking second-stage reduction input worm gear 76 to contact the other side of the two concave blocks of the service brake second-stage reduction gear 35, the second-stage reduction mechanism designed in this invention has a working rotation number of less than 1 / 2 turn for the second-stage reduction gear. The two protrusions of the parking second-stage reduction input worm gear 76 and the two concave blocks in the second concave groove 313 of the service brake second-stage reduction gear 35 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 second-stage reduction input worm gear 76 returns to its initial position first, and then the second-stage reduction gear returns to its initial position. Therefore, the service brake and the parking brake can work independently without affecting each other.

[0063] Specifically, the parking secondary reduction input worm gear has two protrusions at 180° to each other at its end; the service brake secondary reduction gear 35 has a second concave groove 313 at its end, and the second groove 313 also has two concave features at 180° to each other, which cooperate with each other; preferably, in order to prevent incorrect installation, the protrusion features of the parking secondary reduction input worm gear and the service brake secondary reduction gear can be distributed at two ends, so that there is no need to distinguish the installation direction.

[0064] As shown in Figure 2, the service brake motor and gear reduction mechanism assembly 3 includes a service brake primary reduction input gear 32, a service brake primary reduction output gear 33, a service brake secondary reduction input gear 34, a service brake secondary reduction output gear 35, a primary reduction gear system mounting bearing 36, and a secondary reduction gear system mounting shaft and mounting bearing 37. The parking gear reduction mechanism assembly includes a parking primary reduction input worm 72, a parking primary reduction input worm wheel 73, a parking secondary reduction input worm 74, a secondary reduction worm mounting bearing 75, and a parking secondary reduction input worm wheel with mounting bearing assembly 76. The inner ring of the primary reduction gear system mounting bearing 36 is fixedly connected to the primary reduction gear system mounting shaft 38, and the outer ring of the primary reduction gear system mounting bearing 36 is fixedly connected to the MGU housing 2. The secondary reduction gear system mounting shaft 39 is fixedly mounted on the MGU housing 2 and the gear system bearing bracket 4 through the secondary reduction gear system mounting shaft and mounting bearing 37.

[0065] Specifically, the first-stage reduction input gear 32 of the service brake is fixedly connected to the output shaft of the service brake motor 31. The first-stage reduction input gear 32, the second-stage reduction input gear 34, and the second-stage reduction output gear 35 of the service brake are fixedly connected to their respective mounting shafts by means of keyways, splines, etc., or are integrally formed. Bearings or bushings are installed at both ends of each mounting shaft to reduce friction and improve efficiency.

[0066] Specifically, the parking motor and gear reduction mechanism assembly 7 includes a parking brake motor 71, a parking primary reduction input worm gear 72, and a parking secondary reduction input worm gear 74. The parking primary reduction input worm gear 72 is fixedly connected to the output shaft of the parking brake motor 71. A parking primary reduction input worm wheel 73 is fixedly mounted on the parking secondary reduction input worm gear 74. The parking primary reduction input worm wheel 73 meshes with the parking primary reduction input worm gear 72. The parking secondary reduction input worm gear 74 meshes with the parking secondary reduction input worm wheel 76.

[0067] Specifically, a secondary reduction worm gear mounting bearing 75 is provided between the parking secondary reduction input worm gear 74 and the MGU housing. The inner ring of the secondary reduction worm gear mounting bearing 75 is fixedly connected to the parking secondary reduction input worm gear 74, and the outer ring of the secondary reduction worm gear mounting bearing 75 is fixedly connected to the MGU housing.

[0068] Specifically, the parking secondary reduction input worm 74 is provided with either a keyway or a spline for fixing and installing the parking primary reduction input worm 73.

[0069] Specifically, the parking secondary reduction input worm gear 74 and the parking primary reduction input worm wheel 73 are forged into one piece.

[0070] As shown in Figures 3-6, the spoke end face of the parking secondary reduction input worm gear is provided with a first concave groove 710, in which a first protrusion 77 and a second protrusion 78 are provided. The spoke end face of the service brake secondary reduction output gear 35 is provided with a second concave groove 313, in which a first concave block 310 and a second concave block 312 corresponding to the first protrusion 77 and the second protrusion 78 are provided. The first protrusion 77 and the second protrusion 78 extend into the second concave groove 313 and abut against the first concave block 310 and the second concave block 312. The number of protrusions and concave blocks is not limited; it can be one, two, three, or even more. This is only an example.

[0071] The parking secondary reduction input worm gear 76 is connected to the secondary reduction gear system mounting shaft 39 via a bearing or bushing. The parking secondary reduction input worm gear 76 and the service brake secondary reduction output gear 35 have no fixed assembly relationship. When the vehicle is under service braking, since the number of rotations of the service brake secondary reduction output gear 35 is less than 1 / 2, the first protrusion 77 and the second protrusion 78 of the secondary reduction input worm gear 76 and the first concave block 310 and the second protrusion 312 in the second concave groove 313 of the secondary reduction output gear 35 have clearance and will not interfere with each other. Furthermore, when the vehicle starts, the parking secondary reduction input worm gear 76 first returns to its initial position, and then the secondary reduction output gear 35 returns to its initial position. Therefore, the service brake and the parking brake can work independently without affecting each other.

[0072] The first protrusion 77 and the second protrusion 78 in the first concave groove 710 at the end of the parking secondary reduction input worm gear 76 are arranged at 180° relative to each other; the first concave block 310 and the second concave block 312 in the second concave groove 313 at the end of the service brake secondary reduction gear 35 are also arranged at 180° relative to each other. The outer diameter of the first protrusion 77 and the second protrusion 78 is smaller than the inner diameter of the secondary reduction output gear 35 and larger than the outer diameter of the gear sleeve 311. The two sets of protrusions and concave blocks cooperate with each other to transmit torque in a surface contact manner.

[0073] Preferably, to prevent incorrect installation, the protrusion features of the parking secondary reduction input worm gear 76 and the service brake secondary reduction gear 35 can be distributed at both ends (upper and lower surfaces), with two protrusions and two concaves provided at each end so that there is no need to distinguish the installation direction.

[0074] As shown in Figure 2, when the vehicle is performing normal service braking, the service brake motor 31 drives the first-stage reduction input gear 32 and the second-stage reduction input / output gear 34 of the service brake. The meshing of the two gears transmits the torque to the output shaft through the second-stage reduction gear 35, thereby transmitting the braking torque and driving the actuator of the brake assembly 1 to achieve the braking function.

[0075] Furthermore, when the vehicle requires braking force exceeding that of normal braking under certain special operating conditions, the parking brake motor 71 engages with the parking first-stage reduction input worm gear 72, and then reduces and amplifies the parking braking torque through the parking second-stage reduction input worm gear 74 and the second-stage reduction input worm gear 76. When the protrusion at the end of the parking second-stage reduction input worm gear 76 contacts the protrusion in the end groove of the service brake second-stage reduction output gear 35, it outputs a superimposed motor torque together with the service brake second-stage reduction output gear 35 to meet the braking force requirements under extreme braking conditions.

[0076] When the service brake is released and the parking brake is required, the parking brake motor 71 drives the parking first-stage reduction input worm 72 and the parking first-stage reduction input worm wheel 73, which then mesh with the parking second-stage reduction input worm 74 and the second-stage reduction input worm wheel 76 to output parking braking torque. When the two protrusions 77 and 78 at the end of the parking second-stage reduction input worm wheel 76 contact the sidewalls of the concave blocks 310 and 312 in the second concave groove 313 at the end of the service brake second-stage reduction output gear 35, the service brake motor 31 and the parking brake motor 71 stop working. Parking is achieved through the self-locking function of the parking worm wheel and worm of the parking brake system. Worm 74 is mounted and fixed to the MGU housing 2 via the second-stage reduction worm mounting bearing 75.

[0077] Furthermore, when the vehicle requires greater parking braking force under certain special operating conditions, in addition to the clamping force generated by the service brake motor 31, the parking brake motor 71 can also apply a certain clamping force through its own reduction mechanism to superimpose the clamping force of the service brake to achieve a greater parking force.

[0078] Furthermore, when the service brake system fails, the parking brake motor 71 drives the worm wheel 76 to rotate through its own worm gear reduction mechanism 72-74. When the protrusion at the end of the worm wheel 76 contacts the concave block of the second concave groove 313 of the service brake reduction gear, it drives the service brake gear 35 to rotate, thus still achieving a certain service braking function.

[0079] Furthermore, by adjusting the rotation angle range of the gears, the system can be adapted to ball screws with different leads, meeting different brake parameter requirements and achieving platform-based and universal application of the core components of the braking system. As shown in Figure 7, the protrusion and groove can also be a single pair. As shown in Figure 8, the protrusion and groove can also be three pairs.

[0080] With the braking stroke remaining constant, the increased rotational angle range of the mounting shaft in the two-stage reduction gear system allows for the adaptation of ball screw structures with smaller leads. The increased number of gear rotations allows for a greater piston extension stroke, reducing the overall system design complexity while broadening the design range and improving adaptability of other system components. For three-pair gear transmission mechanisms, fewer gear rotations and more even force distribution result in better mechanical properties and lower strength requirements, thus reducing gear manufacturing costs.

[0081] The above description is a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and concept of the present invention, should be covered within the scope of protection of the claims of the present invention.

Claims

1. An electromechanical parking brake system with redundant coupling of service and parking brakes, comprising a brake assembly (1), a service brake motor and gear reduction mechanism assembly (3) with a service brake secondary reduction output gear (35), a gear system bearing bracket (4) connected to the brake assembly (1), an ECU controller assembly (5), and a parking motor and gear reduction mechanism assembly (7) with a parking secondary reduction input worm gear (76), characterized in that: The gear system bearing bracket (4) is rotatably provided with a secondary reduction gear system mounting shaft (39). The service brake secondary reduction output gear (35) and the parking secondary reduction input worm gear (76) are jointly assembled on the secondary reduction gear system mounting shaft (39). The parking secondary reduction input worm gear (76) and the service brake secondary reduction output gear (35) are coupled.

2. The electromechanical parking brake system with mutually coupled and redundant driving and parking brakes as described in claim 1, characterized in that, The parking secondary reduction input worm gear (76) has a protrusion on its spoke end face, and the service brake secondary reduction output gear (35) has a concave block on its spoke end face. The protrusion and the concave block abut against each other. The parking secondary reduction input worm gear (76) is rotatably connected to the secondary reduction gear system mounting shaft (39), and the service brake secondary reduction output gear (35) is fixedly connected to the secondary reduction gear system mounting shaft (39).

3. The electromechanical parking brake system with mutually coupled and redundant driving and parking brakes as described in claim 1, characterized in that, The ECU controller assembly (5) is electrically connected to the service brake motor and gear reduction mechanism assembly (3) and the parking motor and gear reduction mechanism assembly (7).

4. The electromechanical parking brake system with mutually coupled and redundant service and parking brakes as described in any one of claims 1-3, characterized in that: The vehicle brake motor and gear reduction mechanism assembly (3) includes a vehicle brake motor (31) and a first-stage reduction gear system mounting shaft (38). A first-stage reduction input gear (32) for vehicle brake is sleeved on the output shaft of the vehicle brake motor (31). A first-stage reduction output gear (33) for vehicle brake and a second-stage reduction input gear (34) for vehicle brake are sleeved on the first-stage reduction gear system mounting shaft (38). The first-stage reduction output gear (33) for vehicle brake meshes with the first-stage reduction input gear (32) for vehicle brake, and the second-stage reduction input gear (34) for vehicle brake meshes with the second-stage reduction output gear (35) for vehicle brake.

5. The electromechanical parking brake system with mutually coupled redundancy of service and parking brakes as described in claim 4, characterized in that: The first-stage reduction gear system mounting shaft (38) is provided with first-stage reduction gear system mounting bearings (36) at both ends; the second-stage reduction gear system mounting shaft (39) is provided with second-stage reduction gear system mounting bearings (37) at both ends.

6. The electromechanical parking brake system with mutually coupled redundancy of service and parking brakes as described in any one of claims 1-3, characterized in that: The parking motor and gear reduction mechanism assembly (7) includes a parking brake motor (71), a parking first-stage reduction input worm gear (72), and a parking second-stage reduction input worm gear (74). The parking first-stage reduction input worm gear (72) is fixedly connected to the output shaft of the parking brake motor (71). A parking first-stage reduction input worm wheel (73) is fixedly provided on the parking second-stage reduction input worm gear (74). The parking first-stage reduction input worm wheel (73) meshes with the parking first-stage reduction input worm gear (72). The parking second-stage reduction input worm gear (74) meshes with the parking second-stage reduction input worm wheel (76).

7. The electromechanical parking brake system with mutually coupled and redundant service and parking brakes as described in any one of claims 1-3, characterized in that: The spoke end face of the parking secondary reduction input worm gear (76) is provided with a first concave groove, and the first concave groove is provided with a first protrusion (77) and a second protrusion (78). The spoke end face of the service brake secondary reduction output gear (35) is provided with a second concave groove, and the second concave groove is provided with a first concave block (310) and a second concave block (312) corresponding to the first protrusion (77) and the second protrusion (78).

8. The electromechanical parking brake system with mutually coupled redundancy of service and parking brakes as described in claim 7, characterized in that: The first protrusion (77) and the second protrusion (78) are set at 180° relative to each other, and the first concave block (310) and the second concave block (312) are also set at 180° relative to each other. The outer diameter of the first protrusion (77) and the second protrusion (78) is smaller than the inner diameter of the second-stage reduction output gear (35) of the vehicle braking system.

9. The electromechanical parking brake system with mutually coupled redundancy of service and parking brakes as described in claim 8, characterized in that: Both ends of the parking secondary reduction input worm gear (76) are provided with a first protrusion (77) and a second protrusion (78); both ends of the service brake secondary reduction output gear (35) are provided with a first concave block (310) and a second concave block (312).

10. The electromechanical parking brake system with mutually coupled and redundant service and parking brakes according to any one of claims 1-3, characterized in that: It also includes an MGU housing (2) and a sealing cover (6), which together form a box with a cavity. The service brake motor and gear reduction mechanism assembly (3), the gear system bearing bracket (4), the ECU controller assembly (5), and the parking motor and gear reduction mechanism assembly (7) are all placed in the cavity. The MGU housing (2) has a through hole for the drive input shaft of the brake assembly (1) to extend into. The MGU housing (2) is fixedly connected to the housing of the brake assembly (1).

Images