Redundant electromechanical parking brake system with mutually coupled service and parking brakes

Abstract

The present invention relates to the field of vehicle technology, specifically an electronic mechanical braking system. Disclosed is an electronic mechanical braking system with redundantly coupled service and parking braking torques. The system comprises a brake assembly, a MGU and 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. The service brake gear reduction mechanism assembly includes mounting mechanisms and bearings for the primary and secondary service brake reduction gear systems, while the parking brake gear reduction mechanism assembly includes primary and secondary parking reduction worm gear mechanisms and mounting bearings. The braking torques of the service and parking brakes of the present invention are mutually coupled, allowing the two systems to share a brake output gear shaft assembly. Service and parking brakes can be operated independently, and the parking brake can also assist service braking when needed. This design improves the safety and reliability of the braking system.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile electronic mechanical parking brakes, in particular to an electronic mechanical parking brake system with redundant mutually coupled driving and parking brakes. Background Art

[0002] Electromechanical braking (EMB) systems use an electric motor as the braking force source. A mechanical transmission mechanism converts the motor's power into braking force, clamping the vehicle's brake disc or drum to achieve braking. Compared to traditional hydraulic braking systems, EMB offers faster response and more precise control, enabling more efficient energy recovery and superior braking performance.

[0003] Electromechanical brake systems consist of two components: the service brake and the parking brake. The service brake typically utilizes a single or dual electric motor, a known prior art. The parking brake typically uses a separate parking motor to drive a system with a one-way self-locking mechanism (such as a one-way bearing, worm gear, or lead screw), or a solenoid valve to drive a ratchet and pawl mechanism.

[0004] CN 117905881 A discloses a parking lock mechanism for an electronic mechanical brake actuator, comprising an electromagnetic locking assembly disposed within a motor housing and a locking disk fixed to the drive shaft of a drive motor. The locking disk is provided with multiple locking holes evenly distributed around the circumference. The electromagnetic locking assembly includes an electromagnetically driven telescopic component and a locking head connected to the output end of the electromagnetically driven telescopic component, with the locking head extending into the locking holes. Using this parking lock mechanism and operating method for an electronic mechanical brake actuator, the electromagnetic locking assembly cooperates with the locking disk fixed to the drive gear shaft to achieve locking. Due to the low torque of the drive gear, the impact on the locking head is minimal, extending the service life of the mechanism. However, the following disadvantages are: 1. The electromagnetic locking assembly, including a bistable electromagnet, dual electromagnetic coils, an iron core, and a locking head, is relatively complex, and the additional current sensor and magnetic field strength sensor are costly. 2. There is a risk of misalignment between the multiple locking holes evenly distributed around the circumference of the locking disk and the electromagnetically driven telescopic locking head, resulting in a parking failure.

[0005] CN 117905879 A discloses an electronic mechanical parking self-locking mechanism, a control method and a vehicle. The electronic mechanical parking self-locking mechanism includes: a controller, a brake motor, a controller, a ratchet and a pawl. The controller is connected to a solenoid valve, and a push rod is provided at the end of the solenoid valve. When the solenoid valve is energized, the push rod extends to push the pawl to limit the reverse rotation of the ratchet, which is in a locked state. When the solenoid valve is de-energized, the push rod retracts and disengages from the pawl, and the ratchet can rotate forward and backward, which is in an unlocked state. The structure is simple and does not require a sensor, which reduces production costs. The disadvantages are: 1. It is necessary to accurately control the inspection and verification of the service brake and the parking brake, and there is a risk that the pawl and the ratchet gear will disengage too early, be difficult to disengage, or become stuck. 2. The locking mechanism using the pawl and ratchet cannot ensure that the parking is locked at any position. Due to the limited number of ratchet teeth, the parking force is attenuated.

[0006] And no matter which parking structure is used, there are certain problems:

[0007] All parking mechanisms require the service brake to be applied first, and then the parking mechanism is locked. This parking method requires the service brake to function normally before the parking brake can work. Once the service brake fails, parking cannot be completed, and the parking mechanism also loses the brake safety redundancy function.

[0008] The service brake and parking brake are relatively independent, which means that the two systems need to consider their respective clamping force requirements separately, placing higher requirements on the motors and acceleration mechanisms of each system, resulting in a relatively complex system and high energy consumption;

[0009] When current electronic mechanical brakes use force control, if a force sensor is not installed, the subsequent control algorithm will become complicated and precise control will not be achieved;

[0010] Therefore, there is currently a lack of a dual-redundancy design for driving and parking brakes, in which the braking and parking torques are coupled to each other, and the normal operation of the electronic parking function can be guaranteed after one of the motors fails, or dual-motor power distribution is performed. Summary of the Invention

[0011] The object of the present invention is to provide an electromechanical parking brake system with redundant mutually coupled service and parking brakes, so as to solve the problems raised in the above background technology.

[0012] To achieve the above object, the present invention provides the following technical solutions:

[0013] An electronic mechanical parking brake system with redundant mutually coupled service and parking brakes includes a brake assembly, a service brake motor and gear reduction mechanism assembly provided 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 provided with a parking secondary reduction input worm gear. A secondary reduction gear system mounting shaft is rotatably provided on the gear system bearing bracket. The service brake secondary reduction output gear and the parking secondary reduction input worm gear are jointly assembled on the secondary reduction gear system mounting shaft. The parking secondary reduction input worm gear is coupled to the service brake secondary reduction output gear.

[0014] 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 signals with the entire vehicle via a CAN bus.

[0015] Preferably, the service brake motor and gear reduction mechanism assembly includes a service brake motor and a first-stage reduction gear system mounting shaft, the output shaft of the service brake motor is sleeved with a service brake first-stage reduction input gear, the first-stage reduction gear system mounting shaft is sleeved with a service brake first-stage reduction output gear and a service brake second-stage reduction input gear, the service brake first-stage reduction output gear is meshed with the service brake first-stage reduction input gear, and the service brake second-stage reduction input gear is meshed with the service brake second-stage reduction output gear.

[0016] The primary reduction gear train mounting shaft is provided with primary reduction gear train mounting bearings at both ends; the secondary reduction gear train mounting bearings are also provided at both ends. Further preferably, a primary reduction gear train mounting bearing is provided between the primary reduction gear train mounting shaft and the MGU housing. The inner ring of the primary reduction gear train mounting bearing is fixedly connected to the primary reduction gear train mounting shaft, while the outer ring of the primary reduction gear train mounting bearing is fixedly connected to the MGU housing. Further preferably, the reduction gear train mounting shaft is fixedly mounted to the MGU housing and the gear system bearing bracket via the secondary reduction gear train mounting bearing.

[0017] Preferably, the parking motor and gear reduction mechanism assembly includes a parking brake motor, a parking first-stage reduction input worm and a parking second-stage reduction input worm, the parking first-stage reduction input worm is fixedly connected to the output shaft of the parking brake motor, the parking second-stage reduction input worm is fixedly provided with a parking first-stage reduction input worm wheel, the parking first-stage reduction input worm wheel is engaged with the parking first-stage reduction input worm, and the parking second-stage reduction input worm is engaged with the parking second-stage reduction input worm wheel.

[0018] Secondary reduction worm mounting bearings are provided at both ends of the secondary parking reduction input worm. Specifically, a secondary reduction worm mounting bearing is provided between the secondary parking reduction input worm and the MGU housing. The inner ring of the secondary reduction worm mounting bearing is fixedly connected to the secondary parking reduction input worm, and the outer ring of the secondary reduction worm mounting bearing is fixedly connected to the MGU housing.

[0019] Preferably, the spoke end face of the parking brake secondary reduction input worm wheel is provided with a first concave groove, and the first concave groove is provided with a protrusion 1 and a protrusion 2. 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 concave block 1 and a concave block 2 corresponding to the protrusion 1 and the protrusion 2. The protrusion 1 and the protrusion 2 extend into the second concave groove and abut against the side surfaces of the concave block 1 and the concave block 2.

[0020] Preferably, the first and second protrusions are arranged at 180° relative to each other, and the first and second concave blocks are also arranged at 180° relative to each other. The outer diameters of the first and second protrusions are smaller than the inner diameter of the service brake secondary reduction output gear and 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.

[0021] Preferably, both ends of the parking secondary reduction input worm gear are provided with a convex block 1 and a convex block 2; both ends of the service brake secondary reduction output gear are provided with a concave block 1 and a concave block 2.

[0022] Preferably, the parking secondary reduction input worm gear is connected to the secondary reduction gear system mounting shaft through a bearing or a bushing, and the parking secondary reduction input worm gear and the service brake secondary reduction output gear have no fixed assembly relationship. When the vehicle is in service braking, since the number of rotations of the service brake secondary reduction output gear is less than 1 / 2, the protrusions 1 and 2 of the parking secondary reduction input worm gear and the concave blocks 1 and convex blocks 2 in the first concave groove of the service brake secondary reduction output gear have a clearance margin and will not interfere with each other, and when the vehicle starts, the parking secondary reduction input worm gear first returns to its initial position, and the service brake secondary reduction output gear then returns to its initial position, so the service brake and the parking brake can work independently without affecting each other.

[0023] When the protrusions 1 and 2 at the ends of the parking secondary reduction input worm gear of the parking motor and gear reduction mechanism assembly contact the side walls of the concave blocks 1 and 2 in the second concave groove of the service brake secondary reduction output gear, both 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.

[0024] The service brake first-stage reduction input gear is fixedly connected to the output shaft of the service brake motor. The service brake first-stage reduction input gear, the service brake second-stage reduction input gear, and the service brake second-stage reduction output gear are fixedly connected to their respective mounting shafts through 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.

[0025] In order to prevent installation errors, the convex features of the parking secondary reduction input worm gear and the concave features of the service brake secondary reduction output gear can be designed at the two ends, with two convex and concave structures set at each end, so that there is no need to distinguish the installation direction.

[0026] When the vehicle performs conventional service braking, the service brake motor drives the first and second stage service brake gear reduction mechanisms to output the braking torque through the secondary reduction gear shaft, pushing the brake actuator to realize the braking function; when the vehicle requires braking force beyond conventional braking under some special working conditions, the parking brake motor drives the worm gear to rotate through the worm gear reduction mechanism. When the protrusion at the end of the worm gear contacts the protrusion in the groove at the end of the secondary reduction output gear of the service brake, the motor outputs the superimposed torque together with the service brake system to meet the braking force requirements under extreme braking conditions.

[0027] When the service brake is released and the parking brake is required, the parking motor drives the worm gear to rotate the worm wheel. When the protrusion at the end of the parking secondary reduction worm wheel contacts the concave block in the groove of the service brake secondary gear, the two 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 and superimpose the clamping force of the service brake to achieve a greater parking force.

[0028] 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, and a certain service brake function can still be achieved.

[0029] Preferably, the parking secondary reduction input worm gear is rotationally 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 transmission connected to the service brake motor and gear reduction mechanism assembly, and the parking secondary reduction input worm gear is transmission connected to the parking motor and gear reduction mechanism assembly.

[0030] Preferably, it also includes an MGU housing and a sealing cover plate, the MGU housing and the sealing cover plate are combined to form a box body 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, and the MGU housing is fixedly connected to the housing of the brake assembly.

[0031] The present invention will be further explained and illustrated below:

[0032] The technical problem addressed by this invention is to improve the safety and reliability of electromechanical brake systems, particularly by providing redundant safety features in the event of brake system failure. This redundant design encompasses three aspects, ensuring that the parking brake system can provide braking force even if the primary service brake system fails, thus ensuring vehicle safety.

[0033] First, the mechanical transmission system redundancy of the service brake system and the parking brake system;

[0034] Second, the coupling and decoupling of braking torque. The present invention couples the service and parking brakes, allowing the two systems to share a common brake output gear shaft assembly. Service and parking brakes can operate independently, while the parking brake can also assist service braking when needed. This design improves the efficiency and reliability of the braking system.

[0035] The third is the redundancy of the motor drive controller ECU. The ECU is connected to the electronic mechanical brake assembly through the CAN bus, providing dual control protection to ensure that the braking system can still work normally when a single control system fails.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. Redundant Safety Function: The electromechanical braking system of this invention incorporates a redundant braking mode to address vehicle deceleration issues in the event of a brake system failure, enhancing vehicle safety in the event of a brake system failure. This redundant design ensures that even if the primary service brake system fails, the parking brake system can still provide braking force, ensuring vehicle safety.

[0038] 2. Coupling and Decoupling of Braking Torque: The braking torques of the service and parking brakes are coupled, allowing the two systems to share a common brake output gear shaft assembly. Service and parking brakes can be operated independently, while the parking brake can also assist service braking when needed. This design improves the efficiency and reliability of the braking system.

[0039] 3. Miniaturized and integrated design: The present invention arranges the parking brake motor and the service brake motor in parallel, adopts a high-speed-ratio two-stage worm gear transmission mechanism, and uses a shared output gear shaft assembly, thereby reducing the structural layout size, achieving miniaturization and integration of the system, and helping to adapt to the narrow wheel side space.

[0040] 4. Advantages and application prospects: The electronic mechanical 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, safety and environmental protection.

[0041] In summary, an electromechanical brake with redundantly coupled driving and parking braking torques provides an efficient, safe, and responsive braking solution through its unique design, which is suitable for advanced driver assistance systems (ADAS) and autonomous driving systems in modern vehicles.

[0042] The detailed structure of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic diagram of the overall structure of an electromechanical parking brake system with redundant coupled driving and parking brakes according to the present invention;

[0044] Figure 2 This is a schematic structural diagram of the service and parking brake assembly of the present invention;

[0045] Figure 3 Schematic diagram of the driving and parking brake reduction gear transmission mechanism of the present invention;

[0046] Figure 4 This is a schematic structural diagram of the driving and parking brake coupling gear assembly of the present invention;

[0047] Figure 5 This is a schematic diagram of the bearing assembly installed on the input worm gear belt of the parking secondary reduction gear of the present invention;

[0048] Figure 6 This is a schematic diagram of the service brake two-stage reduction output gear assembly of the present invention;

[0049] Among them: 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;

[0050] 31. Service brake motor; 32. Service brake first-stage reduction input gear; 33. Service brake first-stage reduction output gear; 34. Service brake second-stage reduction input gear; 35. Service brake second-stage reduction output gear; 36. First-stage reduction gear train mounting bearing; 37. Second-stage reduction gear train mounting bearing; 38. First-stage reduction gear train mounting shaft; 39. Second-stage reduction gear train mounting shaft; 310. Concave block 1; 311. Gear sleeve; 312. Concave block 2; 313. Second concave groove;

[0051] 71. Parking brake motor; 72. Parking first-stage reduction input worm; 73. Parking first-stage reduction input worm; 74. Parking second-stage reduction input worm; 75. Second-stage reduction worm mounting bearing; 76. Parking second-stage reduction input worm; 77. Bump 1; 78. Bump 2; 79. Second-stage reduction input worm bearing; 710. First concave groove. DETAILED DESCRIPTION

[0052] like Figure 1-2 As shown, the driving and parking brakes are coupled to each other redundantly, and the main components include a brake assembly 1, an MGU housing 2, a driving brake motor and gear reduction mechanism assembly 3, a gear system bearing bracket 4, an ECU controller assembly 5, a sealing cover plate 6 and a parking motor and gear reduction mechanism assembly 7. The present invention arranges the parking brake motor 71 in parallel with the driving brake motor 31 and adopts a high-speed ratio two-stage worm gear transmission mechanism to change the transmission direction of the braking force to realize a shared output gear shaft assembly 39, thereby reducing the structural layout size, realizing miniaturization and integration of the system, and helping to adapt to the narrow wheel side space of the vehicle.

[0053] The ECU controller assembly 5 is connected to the electronic mechanical brake assembly via the CAN bus, providing dual control protection to ensure that the brake system can still work normally when a single control system fails.

[0054] The ECU controller assembly 5 has fault detection and alarm functions. The system should be able to detect power supply failure, brake signal failure, control system failure and electronic mechanical brake system assembly failure, and display an alarm error through the instrument when a failure is detected.

[0055] The end of the brake assembly 1 is provided with a threaded fixing structure to be fixed to the MGU housing 2. The service brake motor and parking motor assembly 3 are installed and fixed through the fixing and limiting structures on the MGU housing 2. The service gear reduction mechanism and the parking gear reduction mechanism are fixed to the MGU housing 2 through the gear system bearing bracket 4. The sealing cover plate 6 and the ECU controller assembly 5 are fixed to the MGU housing 2 through threaded connections.

[0056] Specifically, the actuator of the brake assembly 1 is a ball screw or other torque conversion mechanism.

[0057] Specifically, the service brake gear reduction mechanism assembly 3 includes a service brake first-stage reduction input gear 32, a service brake first-stage reduction output gear 33, a service brake second-stage reduction input gear 34, a service brake second-stage reduction output gear 35, and mounting shafts and bearings for the first and second-stage reduction gear trains. The parking gear reduction mechanism assembly 7 includes the parking first-stage and second-stage reduction input worm gears and mounting bearings, and the parking second-stage reduction input worm gear and mounting bearings.

[0058] Specifically, the service brake first-stage reduction input gear 32 is fixedly connected to the output shaft of the service brake motor 31, and the service brake first-stage reduction input gear 32, the service brake second-stage reduction input gear 33, and the service brake second-stage reduction output gear 34 are fixedly connected to their respective mounting shafts through 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.

[0059] Specifically, the parking brake secondary reduction worm gear 76 is connected to the service brake secondary reduction gear system mounting shaft 39 through a bearing or a bushing, and the two protrusions of the parking 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 respectively. When the vehicle is in service braking, the service brake motor 31 drives the gear reduction system to work, and the parking brake motor 71, as a redundant backup, does not need to work synchronously. Moreover, since the secondary reduction gear needs to rotate 1 / 2 circle, the two protrusions of the parking secondary reduction input worm wheel 76 can contact the other side of the two concave blocks of the service brake secondary reduction gear 35. In the secondary reduction mechanism designed by the present invention, the working rotation number of the secondary reduction gear is less than 1 / 2 circle. The two protrusions of the parking secondary reduction input worm wheel 76 and the two concave blocks in the second concave groove 313 of the service brake secondary reduction gear 35 have a clearance margin and will not interfere with each other. Moreover, when the vehicle is started, the parking brake can be released manually or automatically before the service brake, that is, the parking secondary reduction input worm wheel 76 first returns to its initial position, and the secondary reduction gear then returns to its initial position. Therefore, the service brake and the parking brake can work independently without affecting each other.

[0060] Specifically, the end of the parking brake secondary reduction input worm gear is provided with two protrusions with an angle of 180° relative to each other; the end of the service brake secondary reduction gear 35 is provided with a second concave groove 313, and the second groove 313 also has two concave block features with an angle of 180° relative to each other, which cooperate with each other; preferably, in order to prevent installation errors, the protrusion features of the parking brake secondary reduction input worm gear and the service brake secondary reduction gear can be distributed at both ends, so that there is no need to distinguish the installation direction.

[0061] like Figure 2As shown, 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 train mounting bearing 36, a secondary reduction gear train mounting shaft, and a 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 a mounting bearing assembly 76. The inner ring of the primary reduction gear train mounting bearing 36 is fixedly connected to the primary reduction gear train mounting shaft 38, and the outer ring of the primary reduction gear train mounting bearing 36 is fixedly connected to the MGU housing 2. The secondary reduction gear train mounting shaft 39 is fixedly mounted to the MGU housing 2 and the gear system bearing bracket 4 via the secondary reduction gear train mounting shaft and the mounting bearing 37.

[0062] Specifically, the service brake first-stage reduction input gear 32 is fixedly connected to the output shaft of the service brake motor 31, and the service brake first-stage reduction input gear 32, the second-stage reduction input gear 34, and the second-stage reduction output gear 35 are fixedly connected to their respective mounting shafts through 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.

[0063] Specifically, the parking motor and gear reduction mechanism assembly 7 includes a parking brake motor 71, a parking first-stage reduction input worm 72 and a parking second-stage reduction input worm 74. The parking first-stage reduction input worm 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 wheel 74. The parking first-stage reduction input worm wheel 73 is engaged with the parking first-stage reduction input worm 72, and the parking second-stage reduction input worm wheel 74 is engaged with the parking second-stage reduction input worm wheel 76.

[0064] Specifically, a secondary reduction worm mounting bearing 75 is provided between the parking secondary reduction input worm 74 and the MGU housing. The inner ring of the secondary reduction worm mounting bearing 75 is fixedly connected to the parking secondary reduction input worm 74, and the outer ring of the secondary reduction worm mounting bearing 75 is fixedly connected to the MGU housing.

[0065] Specifically, the parking secondary reduction input worm 74 is provided with either a keyway or a spline for fixing the parking primary reduction input worm wheel 73 .

[0066] Specifically, the parking secondary reduction input worm 74 and the parking primary reduction input worm wheel 73 are forged into one piece.

[0067] like Figure 3-6 As shown, the spoke end face of the parking brake secondary reduction input worm wheel is provided with a first concave groove 710, and the first concave groove 710 contains a protrusion 1 77 and a protrusion 2 78. The spoke end face of the service brake secondary reduction output gear 35 is provided with a second concave groove 313, and the second concave groove 313 contains a concave block 1 310 and a concave block 2 312 corresponding to the protrusion 1 77 and the protrusion 2 78. The protrusion 1 77 and the protrusion 2 78 extend into the second concave groove 313 and abut against the concave block 1 310 and the concave block 2 312.

[0068] The parking brake secondary reduction input worm gear 76 is connected to the secondary reduction gear system mounting shaft 39 through a bearing or a 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 in service braking, since the number of rotations of the service brake secondary reduction gear output gear 35 is less than 1 / 2, the protrusions 1 77 and 2 78 of the secondary reduction input worm gear 76 and the concave blocks 1 310 and 2 312 in the second concave groove 313 of the secondary reduction output gear 35 have a clearance margin and will not interfere with each other. When the vehicle is started, the parking secondary reduction input worm gear 76 first returns to its initial position, and the secondary reduction output gear 35 then returns to its initial position. Therefore, the service brake and the parking brake can work independently without affecting each other.

[0069] The protrusion 1 77 and the protrusion 2 78 in the first concave groove 710 at the end of the parking brake secondary reduction input worm gear 76 are arranged at 180° relative to each other; the concave block 1 310 and the concave block 2 312 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 protrusion 1 77 and the protrusion 2 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 groups of protrusions and concave blocks cooperate with each other in a surface contact manner to transmit torque.

[0070] Preferably, in order to prevent installation errors, the convex features of the parking brake secondary reduction input worm gear 76 and the service brake secondary reduction gear 35 can be distributed at both ends, with two convex blocks and concave blocks set at each end so that there is no need to distinguish the installation direction.

[0071] like Figure 2 As shown, when the vehicle performs conventional service braking, the service brake motor 31 drives the service brake first-stage reduction input gear 32 and the second-stage reduction input and output gear 34. The two-stage gears engage to transmit the torque to the output shaft through the second-stage reduction gear 35 to transmit the braking torque, thereby pushing the brake assembly 1 actuator to realize the braking function.

[0072] Furthermore, when the vehicle requires braking force exceeding that of conventional braking under certain special operating conditions, the parking brake motor 71 engages the parking brake input worm gear 72 with the parking brake input worm gear 76, which then decelerates and increases torque to input the parking braking torque. When the protrusion on the end of the parking brake input worm gear 76 contacts the protrusion in the groove on the end of the service brake output gear 35, the motor and the service brake output gear 35 work together to output the superimposed motor torque to meet the braking force requirements under extreme braking conditions.

[0073] When service braking is released and parking braking is required, the parking brake motor 71 drives the first-stage parking reduction input worm 72 and the first-stage parking reduction input worm wheel 73, which then engage and rotate to output the parking braking torque via the second-stage parking reduction input worm 74 and the second-stage parking reduction input worm wheel 76. When the two protrusions 1 77 and 2 78 on the ends of the second-stage parking reduction input worm wheel 76 respectively contact the sidewalls of the first and second recesses 310 and 312 within the second recessed groove 313 on the end of the service brake second-stage reduction output gear 35, both the service brake motor 31 and the parking brake motor 71 stop operating, and parking is achieved through the parking brake system's self-locking function. The parking worm 74 is mounted to the MGU housing 2 via the second-stage parking reduction worm mounting bearing 75.

[0074] Furthermore, when the vehicle requires a larger parking brake force under some special working 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 deceleration mechanism to superimpose the clamping force of the service brake to achieve a larger parking force.

[0075] 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. 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, and a certain service brake function can still be achieved.

[0076] The above is a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solutions and concepts of the present invention, should be covered by the scope of protection of the claims of the present invention.

Claims

1. An electronic mechanical parking brake system with redundant driving and parking brake coupling, comprising a brake assembly (1), a driving brake motor and gear reduction mechanism assembly (3) provided with a driving 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) provided with a parking secondary reduction input worm gear (76), characterized in that: A secondary reduction gear system mounting shaft (39) is rotatably provided on the gear system bearing bracket (4), and 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, and the spoke end surface of the parking secondary reduction input worm gear (76) is provided with a convex block 1 (77) and a convex block 2 (78), and the spoke end surface of the service brake secondary reduction output gear (35) is provided with a concave block 1 (310) and a concave block 2 (312), and the convex block 1 (77) and the convex block 2 (78) are in contact with the side surfaces of the concave block 1 (310) and the concave block 2 (312). 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).

2. The electromechanical parking brake system with redundant coupled service and parking brakes according to 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).

3. The electromechanical parking brake system with redundant mutually coupled service and parking brakes according to claim 1 or 2, characterized in that: The service brake motor and gear reduction mechanism assembly (3) comprises a service brake motor (31) and a first-stage reduction gear system mounting shaft (38); a service brake first-stage reduction input gear (32) is sleeved on the output shaft of the service brake motor (31); a service brake first-stage reduction output gear (33) and a service brake second-stage reduction input gear (34) are sleeved on the first-stage reduction gear system mounting shaft (38); the service brake first-stage reduction output gear (33) is meshed with the service brake first-stage reduction input gear (32); and the service brake second-stage reduction input gear (34) is meshed with the service brake second-stage reduction output gear (35).

4. The electromechanical parking brake system with redundant mutually coupled service and parking brakes according to claim 3, characterized in that: Both ends of the first-stage reduction gear train mounting shaft (38) are provided with first-stage reduction gear train mounting bearings (36); and both ends of the second-stage reduction gear train mounting shaft (39) are provided with second-stage reduction gear train mounting bearings (37).

5. The electromechanical parking brake system with redundant mutually coupled service and parking brakes according to claim 1 or 2, 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 (72) and a parking second-stage reduction input worm (74), wherein the parking first-stage reduction input worm (72) is fixedly connected to the output shaft of the parking brake motor (71), and a parking first-stage reduction input worm wheel (73) is fixedly provided on the parking second-stage reduction input worm wheel (74), wherein the parking first-stage reduction input worm wheel (73) is meshed with the parking first-stage reduction input worm wheel (72), and the parking second-stage reduction input worm wheel (74) is meshed with the parking second-stage reduction input worm wheel (76).

6. The electromechanical parking brake system with redundant mutually coupled service and parking brakes according to claim 5, characterized in that: Two ends of the parking secondary reduction input worm (74) are provided with secondary reduction worm mounting bearings (75).

7. The electromechanical parking brake system with redundant mutually coupled service and parking brakes according to claim 1 or 2, characterized in that: The spoke end surface of the parking secondary reduction input worm wheel (76) is provided with a first concave groove, in which a convex block 1 (77) and a convex block 2 (78) are provided. The spoke end surface of the service brake secondary reduction output gear (35) is provided with a second concave groove, in which a concave block 1 (310) and a concave block 2 (312) corresponding to the convex block 1 (77) and the convex block 2 (78) are provided.

8. The electromechanical parking brake system with redundant mutually coupled service and parking brakes according to claim 7, characterized in that: The convex block 1 (77) and the convex block 2 (78) are arranged at 180 degrees relative to each other, and the concave block 1 (310) and the concave block 2 (312) are also arranged at 180 degrees relative to each other. The outer diameters of the convex block 1 (77) and the convex block 2 (78) are smaller than the inner diameter of the secondary reduction output gear (35) of the service brake.

9. The electromechanical parking brake system with redundant mutually coupled service and parking brakes according to claim 8, characterized in that: Both ends of the parking secondary reduction input worm wheel (76) are provided with a first convex block (77) and a second convex block (78); and both ends of the driving 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 redundant mutually coupled service and parking brakes according to claim 1, characterized in that: The invention also includes an MGU housing (2) and a sealing cover plate (6), wherein the MGU housing (2) and the sealing cover plate (6) are combined to form a box body with an accommodating cavity, wherein 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 accommodating cavity, and the MGU housing (2) is provided with a through hole for the drive input shaft of the brake assembly (1) to extend therethrough, and the MGU housing (2) is fixedly connected to the housing of the brake assembly (1).

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