Dual-lead electronic brake assembly

Abstract

The utility model provides a double-lead electronic brake assembly which solves the problems that an existing electronic brake system is limited in power amplification transmission and brake stroke and needs large power to achieve large brake force output when the stroke is large. According to the double-lead electronic braking assembly, the double-lead unit is matched with the switching unit, two-section braking in the braking process is achieved, the first section is threaded lead, the second lead transmission shaft, the rolling body and the first lead screw rotate synchronously, the rolling body does not rotate along a rail groove, the output piston slides in the output hole, and the output piston is driven to rotate synchronously. Large-stroke rapid small-torque transmission is realized; when the resistance borne by the thread lead is larger than the pre-tightening force of the spring, the spiral lead entering the track groove, the first lead screw does not rotate any more, the second lead transmission shaft rotates to drive all the rolling bodies to rotate along the track groove, all the rolling bodies spirally ascend during rotation, the first lead screw is pushed to move, and then the output piston is pushed to move; and small-stroke and high-torque transmission is realized.

Description

Technical Field

[0001] This utility model relates to braking systems, specifically to a dual-lead electronic braking assembly. Background Technology

[0002] With the rapid development of automobile and rail locomotive technology, the continuous increase in traffic volume and density, and the gradual increase in vehicle speed, the requirements for the safety and reliability of automobiles and locomotives are becoming increasingly stringent. Whether the braking systems of automobiles and locomotives can realize the driver's braking intentions and the requirements for unmanned automatic drive-by-wire control in real time, quickly and effectively has become a key issue affecting road traffic safety.

[0003] Traditional hydraulic braking systems are complex, slow in braking response, and bulky. They are difficult to install and assemble on a vehicle, and have high manufacturing and maintenance costs. Electronic braking systems have emerged to address these shortcomings. They not only overcome the inherent defects of hydraulic braking systems but also have significant advantages such as system simplicity, small size, fast braking response, and high efficiency.

[0004] Currently, commonly used electronic braking systems include ball screws, planetary roller screws, and cam drives. These systems primarily convert rotary motion into translational motion to provide braking force and ultimately achieve vehicle braking. However, existing electronic braking systems suffer from limitations in power amplification and transmission stroke, resulting in significant brake pad wear during braking and requiring substantial power to achieve large braking force output and a long travel distance. Utility Model Content

[0005] The purpose of this invention is to solve the technical problems of existing electronic braking systems, such as power amplification and transmission, limited braking stroke, and the need for greater power to achieve greater braking force output at a larger stroke, and to provide a dual-lead electronic braking assembly.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A dual-lead electronic braking assembly is characterized by comprising a brake housing, and an input unit, a dual-lead unit, a switching unit, and an output unit built into the brake housing.

[0008] The input unit includes a drive motor;

[0009] The output unit includes an output piston that is provided with internal or external threads and slides in conjunction with the output hole of the brake housing;

[0010] The dual-lead unit includes a first lead screw, a second lead drive shaft, and X rolling elements, where X ≥ 2. The right end of the second lead drive shaft is connected to the output end of the input unit. The X rolling elements are positioned between the left large end face of the second lead drive shaft and the right large end face of the first lead screw. A track with a helix angle is provided on the left large end face and / or the right large end face. The track has N concentric rings, each ring including M circumferentially distributed track slots with identical structural dimensions, where N ≥ 1, M ≥ 1, X = N × M, and N and M are not simultaneously 1. One rolling element is placed in each track slot. The selection of the helix angle satisfies the following conditions: the lowest point of all track slots is located in the same plane, and the highest point of all track slots is located in the same plane.

[0011] The first lead screw is threadedly connected to the output piston; the thread lead of the output piston is greater than the helical lead of the track groove.

[0012] The switching unit is used to switch the output piston between large-stroke, fast, low-torque transmission and small-stroke, high-torque transmission.

[0013] Furthermore, a small groove is provided along the bottom of the track groove on the left large end face and / or the right large end face, and the width of the small groove is smaller than the width of the rolling element;

[0014] The switching unit includes a pull rod, a spring, and a one-way bearing or needle roller bearing, a thrust bearing, and a spring seat sleeved on the pull rod; the first lead screw and the second lead drive shaft are sleeved on the pull rod, and pull rod stops are respectively provided at both ends of the pull rod; one end of the thrust bearing abuts against the left pull rod stop, and the other end abuts against the left end face of the spring seat; the second lead drive shaft abuts against the right pull rod stop; one end of the spring abuts against the first lead screw, and the other end abuts against the spring seat; the one-way bearing or needle roller bearing, the spring seat, and the spring are sleeved on the pull rod from the inside to the outside.

[0015] Furthermore, the input unit also includes a gear reduction assembly connected to the output end of the drive motor, the gear reduction assembly being placed inside or outside the drive motor cavity; the right end of the second lead transmission shaft is connected to the output end of the gear reduction assembly.

[0016] Furthermore, the drive motor is an external rotor motor, the gear reduction assembly is placed inside the drive motor cavity, and an electromagnetic actuator is provided on the brake housing;

[0017] The outer rotor of the drive motor has multiple locking grooves evenly distributed circumferentially on its circumferential surface. One side of each locking groove has an angled edge. The output shaft of the electromagnetic actuator cooperates with the locking groove to stop the drive motor from rotating. Alternatively, a pawl is connected to the output shaft of the electromagnetic actuator. The pawl cooperates with the locking groove to stop the drive motor from rotating.

[0018] Alternatively, multiple locking grooves are evenly distributed along the circumference on the outer circumference of the second lead drive shaft, with an oblique angle on one side of each locking groove. The output shaft of the electromagnetic actuator or a pawl connected to the output shaft cooperates with the locking groove to stop the drive motor from rotating. Alternatively, a pawl is connected to the output shaft of the electromagnetic actuator, and the pawl cooperates with the locking groove to stop the drive motor from rotating.

[0019] Furthermore, the switching unit also includes a sliding washer sleeved on the pull rod, with one end of the sliding washer abutting against the pull rod stop on the right side and the other end abutting against the second lead drive shaft.

[0020] Furthermore, the track is set on the large end face on the right side of the first lead screw, and N=2, M=2; the rolling element is a rolling ball or a rolling column, and the shape of the track groove is adapted to the outer wall of the rolling ball or rolling column;

[0021] A rolling element retainer is provided between the large end face on the left side of the second lead drive shaft and the large end face on the right side of the first lead screw. Four rolling balls or rolling columns are provided, and all of them are located in the limiting holes opened on the rolling element retainer.

[0022] Furthermore, the switching unit also includes a bearing sleeved on the pull rod, the bearing being located in the inner cavity of the second lead drive shaft.

[0023] Furthermore, a sensor is arranged on the brake housing, and multiple protrusions are evenly distributed circumferentially along the edge of the large end face on the right side of the first lead screw. The protrusions are arranged radially or axially, and the sensing part of the sensor is arranged corresponding to the position of the protrusion.

[0024] Furthermore, a guide groove is provided axially on the inner wall of the output hole of the brake housing, and a guide block is provided on the outer wall of the output piston, with the guide block slidably assembled in the guide groove.

[0025] Furthermore, a track is also provided on the left large end face of the second lead drive shaft corresponding to the track on the right large end face of the first lead screw, and the rolling element is located in the track groove of both tracks.

[0026] Compared with the prior art, the beneficial effects of this utility model are:

[0027] (1) The present invention provides a dual-lead electronic braking assembly that realizes two-stage braking during the braking process through a dual-lead unit. First, the first lead, namely the threaded lead where the first lead screw meshes with the output piston, works. The second lead drive shaft, rolling elements, and the first lead screw rotate synchronously. The rolling elements play the role of transmitting torque and do not rotate along the track groove. When the torque is transmitted to the output piston, the output piston will slide in the output hole, realizing a large stroke, fast, and small torque transmission. When the resistance of the threaded lead is greater than the preload of the spring, it is switched by the switching unit to enter the second lead, namely the spiral lead of the track groove. At this time, the first lead screw no longer rotates. When the second lead drive shaft rotates, it will drive all the rolling elements to rotate along the track groove from the deepest part of each track groove. Because each track groove has a helical helix angle, all the rolling elements spiral upward when rotating, pushing the first lead screw to move, and then pushing the output piston to move, realizing a small stroke and high torque transmission. This solves the technical problems of existing electronic braking systems, such as power amplification and transmission, limited braking stroke, and the need for large power to achieve large braking force output at a large stroke.

[0028] (2) The present invention provides a dual-lead electronic braking assembly, which adopts an embedded setting of drive motor, gear reduction assembly and multi-layer concentric nested structure of switching unit and output piston, which can realize the flattening of structure and thus adapt to a smaller installation space.

[0029] (3) The dual-lead electronic braking assembly provided by this utility model is equipped with an electromagnetic actuator, and multiple locking slots are evenly distributed circumferentially on the outer rotor surface of the drive motor. The motor can be parked in the event of power failure by cooperating with the output shaft of the electromagnetic actuator and the locking slots. Alternatively, a pawl is connected to the output shaft of the electromagnetic actuator, and the pawl cooperates with the locking slots to achieve the motor parking function in the event of power failure. Alternatively, multiple locking slots are evenly distributed circumferentially on the outer circumferential surface of the second-lead drive shaft, and the motor parking function in the event of power failure is achieved by cooperating with the output shaft of the electromagnetic actuator or the pawl connected to the output shaft and the locking slots.

[0030] Furthermore, because the locking groove has an angle on one side, when the motor is powered on but the electromagnetic actuator is not, the motor locks when rotating in one direction, and when rotating in the other direction, the output shaft or pawl of the electromagnetic actuator can slide out along the angle of the locking groove, achieving active unlocking. For example, it locks when parked and automatically unlocks when braking.

[0031] (4) The dual-lead electronic braking assembly provided by this utility model has a small groove at the bottom of the track groove on the left large end face and / or the right large end face. The width of the small groove is smaller than the width of the rolling element. When the rolling element is a rolling ball, the original single-point contact between the rolling ball and the track groove becomes a double-point contact, which increases the load-bearing capacity. Attached Figure Description

[0032] Figure 1 This is a cross-sectional view of an embodiment of the dual-lead electronic braking assembly of the present invention in use.

[0033] Figure 2 This is a three-dimensional structural diagram of the second lead drive shaft in an embodiment of the present utility model;

[0034] Figure 3 This is a three-dimensional structural diagram of the second lead transmission shaft with a locking groove in an embodiment of the present invention;

[0035] Figure 4 This is a three-dimensional structural diagram of the first lead screw in this embodiment, showing the protrusions arranged axially.

[0036] Figure 5 This is a three-dimensional structural diagram of the first lead screw in this embodiment, showing the protrusions arranged radially.

[0037] Figure 6 This is a three-dimensional structural diagram of the rolling element cage in an embodiment of the present invention;

[0038] Figure 7 This is a schematic diagram illustrating the cooperation between the switching unit and the dual-lead unit in an embodiment of this utility model;

[0039] Figure 8 This is a three-dimensional structural diagram of the locking groove provided on the outer rotor of the drive motor in an embodiment of this utility model.

[0040] The annotations in the attached figures are explained as follows:

[0041] 01-Brake assembly, 011-Brake pad, 012-Housing, 013-Brake disc; 1-Brake housing, 2-Input unit, 21-Drive motor, 211-Locking groove; 22-Gear reduction assembly; 3-Dual lead unit, 31-Second lead drive shaft, 311-Left large end face; 32-Rolling element cage, 321-Limiting hole; 33-Rolling element, 34-First lead screw, 341-Right large end face, 342-Protrusion; 4-Switching unit, 41-Spring, 42-Pull rod, 43-Pull rod stop, 44-One-way bearing, 45-Thrust bearing, 46-Spring seat, 47-Bearing, 48-Sliding pad; 5-Output piston, 6-Electromagnetic actuator, 7-Sensor, 8-Railway groove, 81-Small groove. Detailed Implementation

[0042] The present invention will be further described below with reference to the accompanying drawings and exemplary embodiments.

[0043] Reference Figures 1-8This utility model discloses a dual-lead electronic braking assembly, including a brake housing 1, an input unit 2, a dual-lead unit 3, a switching unit 4, and an output unit built into the brake housing 1. A brake assembly 01 is connected to one side of the brake housing 1. The housing 012 of the brake assembly 01 is connected to the brake housing 1. A brake disc 013 is provided inside the housing 012. A brake pad 011 is provided on both sides of the brake disc 013. One of the brake pads 011 is used to cooperate with the output unit to achieve braking.

[0044] The output unit includes an output piston 5 with internal or external threads that slides into the output hole of the brake housing 1. In this embodiment, in order to achieve multi-layer concentric nesting to adapt to a smaller installation space, the output piston 5 is a hollow structure with internal threads on its inner wall and a guide block on its outer wall. The inner wall of the output hole of the brake housing 1 has a guide groove that mates with the guide block along the axial direction. The guide block is located in the guide groove. In this way, when driven by the thread, the output piston 5 can move along the axial direction, thereby squeezing the brake pad 011 and providing braking force.

[0045] The input unit 2 includes a drive motor 21 and a gear reduction assembly 22 connected to the output end of the drive motor 21. The gear reduction assembly 22 can be placed outside or inside the cavity of the drive motor 21. To reduce the overall volume of the input unit 2, in this embodiment, the drive motor 21 is an external rotor motor, and the gear reduction assembly 22 is a planetary gear reducer. The gear reduction assembly 22 is located inside the cavity of the drive motor 21. An electromagnetic actuator 6 is provided on the brake housing 1. In this embodiment, multiple locking grooves 211 are evenly distributed circumferentially on the circumferential surface of the external rotor of the drive motor 21, and their structure is as follows. Figure 8 As shown, the locking groove 211 cooperates with the output shaft of the electromagnetic actuator 6 to stop the rotation of the drive motor 21, thereby realizing the motor power failure parking function.

[0046] Of course, in other embodiments, a pawl can be connected to the output shaft of the electromagnetic actuator 6, and the drive motor 21 can be stopped by the pawl cooperating with the locking groove 211.

[0047] In other embodiments, a plurality of locking grooves 211 may be evenly distributed along the circumference on the outer peripheral surface of the second lead drive shaft 31, and their structure is as follows: Figure 3 As shown, the locking groove 211 cooperates with the output shaft of the electromagnetic actuator 6 to stop the rotation of the drive motor 21, or a pawl is connected to the output shaft of the electromagnetic actuator 6, and the pawl cooperates with the locking groove 211 to stop the rotation of the drive motor 21.

[0048] The locking groove 211 described above has an angle on one side. When the drive motor 21 is powered on but the electromagnetic actuator 6 is not powered on, the drive motor 21 is locked when it rotates in one direction, and when it rotates in the other direction, the output shaft of the electromagnetic actuator 6 or the pawl connected to the output shaft can slide out along the angle of the locking groove 211 to achieve active unlocking. In this way, it can be locked when parking and actively unlocked when braking.

[0049] The dual-lead unit 3 includes a first lead screw 34, a second lead drive shaft 31, and X rolling elements 33, where X ≥ 2, disposed between the right large end face 341 of the first lead screw 34 and the left large end face 311 of the second lead drive shaft 31. An external spline is provided at the right end of the second lead drive shaft 31, while an internal spline is provided at the output end of the gear reduction assembly 22. The connection between the two is achieved through the cooperation of the internal and external splines. An external thread is provided on the outer wall of the first lead screw 34, which is used to mesh with the internal thread of the output piston 5.

[0050] A track with a helical helix angle is provided on the left large end face 311 and / or the right large end face 341. The track has N concentric rings, and each ring includes M circumferentially distributed track grooves 8 with identical structural dimensions, where N≥1, M≥1, and X=N×M. To ensure rotational balance, N and M are not both 1. Small grooves 81 are provided along the bottom of the track grooves 8 on the left large end face 311 and / or the right large end face 341. The width of the small grooves 81 is less than the width of the rolling element 33. The structure of the small grooves 81 is as follows: Figure 2 , Figure 3 as well as Figure 5 As shown. Each track groove 8 contains a rolling element 33, and the helix angle is selected to satisfy the following conditions: the lowest points of all track grooves 8 are located in the same plane, and the highest points of all track grooves 8 are located in the same plane. In this embodiment, as... Figure 2 As shown, a track with a helix angle is provided on the right large end face 341 of the first lead screw 34. In this embodiment, N=2, M=2, X=4, and as... Figure 4 and Figure 5 As shown, a track is also provided on the left large end face 311 of the second lead drive shaft 31, corresponding to the track on the right large end face 341 of the first lead screw 34. The rolling element 33 is located in the track groove 8 of both tracks. The rolling element 33 can be in the form of a rolling ball or a rolling column, and the shape of the track groove 8 is adapted to the outer wall of the rolling ball or rolling column. In this embodiment, in order to make the rolling smoother, the rolling element 33 is in the form of a rolling ball, and the shape of the track groove 8 is adapted to the outer wall of the rolling ball.

[0051] All rolling elements 33 are initially located at the deepest part of the track groove 8. When the rolling elements 33 rotate along the track groove 8, all rolling elements 33 have the same angular velocity. Thus, the rolling elements 33 rise synchronously with the rotation, thereby pushing the first lead screw 34, and subsequently pushing the output piston 5. Because the rolling elements 33 roll within the track groove 8, a rolling element retainer 32 is provided between the left large end face 311 and the right large end face 341 to prevent them from colliding with each other. Its structure is as follows: Figure 6 As shown, it has four limiting holes 321, and the four rolling elements 33 are all located in the limiting holes 321.

[0052] The switching unit 4 is used to switch the output piston 5 between large-stroke, fast, low-torque transmission and small-stroke, high-torque transmission. It includes a pull rod 42, a first-lead screw 34, and a second-lead drive shaft 31, both of which are hollow structures and are fitted onto the pull rod 42. Pull rod stops 43 are provided at both ends of the pull rod 42. The left pull rod stop 43 is threaded to the left end of the pull rod 42, while the right pull rod stop 43 is integrally formed with the pull rod 42. The second-lead drive shaft 31 abuts against the right pull rod stop 43. To prevent excessive wear on the second-lead drive shaft 31 caused by the right pull rod stop 43, a sliding washer 48 is fitted onto the pull rod 42, with one end abutting against the right pull rod stop 43 and the other end abutting against the second-lead drive shaft 31.

[0053] A one-way bearing 44 or a needle roller bearing, a spring seat 46, and a spring 41 are sequentially fitted on the pull rod 42 from the inside out. In this embodiment, the pull rod 42 is fitted with a one-way bearing 44. A thrust bearing 45 is also fitted on the pull rod 42, with one end abutting against the pull rod stop 43 on the left side and the other end abutting against the left end face of the spring seat 46. One end of the spring 41 abuts against the first lead screw 34 and the other end abuts against the spring seat 46.

[0054] Because the second lead drive shaft 31 needs to transmit the power of the input unit 2 to the first lead screw 34, its transmission stability is crucial. In order to ensure its smooth rotation, a bearing 47 is also sleeved on the pull rod 42, and the bearing 47 is located in the inner cavity of the second lead drive shaft 31.

[0055] Because the position of the output piston 5 is not convenient for setting up a sensor 7 to monitor its movement, in this embodiment, a sensor 7 is arranged on the brake housing 1, and multiple protrusions 342 are evenly distributed circumferentially along the edge of the large end face 341 on the right side of the first lead screw 34. The protrusions 342 are arranged axially or radially, and their structures are as follows: Figure 4 and Figure 5As shown, the sensing part of the sensor 7 is set at the position of the protrusion 342. In this way, by detecting the rotation frequency of the protrusion 342, the distance that the output piston 5 has moved when it is in the thread lead can be indirectly known.

[0056] During the braking process, this embodiment achieves two-stage braking. The first stage is the first lead, which is the thread lead of the output piston 5, that is, the distance the output piston 5 moves when the internal thread of the output piston 5 meshes with the external thread of the first lead screw 34. Then, there is the helical lead of the track groove 8, that is, the distance the rolling element 33 moves from the deepest part of the track groove 8 to the shallowest part. Because of the helix angle, the rolling element 33 is lifted and pushes the output piston 5 to move. The thread lead of the output piston 5 is greater than the helical lead of the track groove 8.

[0057] During braking, the first lead stroke operates first, and the second lead drive shaft 31, rolling elements 33, and the first lead screw 34 rotate synchronously. The rolling elements 33 transmit torque and do not rotate along the track groove 8. When the torque is transmitted to the output piston 5, the output piston 5 will slide in the output hole, realizing a large stroke, fast, and small torque transmission. When the resistance of the threaded lead stroke is greater than the preload of the spring 41, the switching unit 4 switches to the second lead stroke, i.e., the helical lead stroke of the track groove 8. At this time, the first lead screw 34 no longer rotates, and the rotation of the second lead drive shaft 31 will drive all the rolling elements 33 from the deepest part of each track groove 8 along the track. As the groove 8 rotates, because each track groove 8 has a helical helix angle, all rolling elements 33 spiral upwards during rotation, driving the first lead screw 34 to move, which in turn drives the output piston 5 to move, realizing a small stroke and high torque transmission. When braking is not required, the spring 41 gradually returns from the compressed state to the preloaded state. During the recovery process, under the action of the one-way bearing 44 and the thrust bearing 45, all rolling elements 33 rotate in the opposite direction along the track groove 8 back to the deepest part of the track groove 8. At this time, the first lead screw 34 will slowly move to the right to reset until the spring force of the spring 41 decreases to the preload value of the spring 41, at which point the first lead screw 34 rotates in the opposite direction to reset.

[0058] The embodiments described above are merely descriptions of specific implementations of this utility model and are not intended to limit the scope of this utility model. Various modifications and improvements made to the technical solutions of this utility model by those skilled in the art without departing from the spirit of this utility model should fall within the protection scope defined by the claims of this utility model.

Claims

1. A dual lead electronic brake assembly characterized by: The brake assembly comprises a brake housing (1), an input unit (2), a double-lead unit (3), a switching unit (4) and an output unit (3) arranged in the brake housing (1); The input unit (2) comprises a driving motor (21); The output unit comprises an output piston (5) provided with internal threads or external threads and slidingly fitted with an output hole of the brake housing (1); The double-lead unit (3) comprises a first-lead screw (34), a second-lead transmission shaft (31) and X rolling bodies (33), X≥2; the second-lead transmission shaft (31) is connected with an output end of the input unit (2); the X rolling bodies (33) are arranged between a left large end face (311) of the second-lead transmission shaft (31) and a right large end face (341) of the first-lead screw (34); the left large end face (311) and / or the right large end face (341) are provided with tracks with helix angles; the tracks have N concentric circles, each circle comprises M circumferentially distributed and identically sized track grooves (8), N≥1, M≥1, X=N×M, and N and M are not simultaneously 1; one rolling body (33) is arranged in each track groove (8); and the helix angles are selected to satisfy that the lowest points of all the track grooves (8) are located in the same plane, and the highest points of all the track grooves (8) are located in the same plane; The first-lead screw (34) is threadedly connected with the output piston (5); the thread lead of the output piston (5) is greater than the helix lead of the track grooves (8); The switching unit (4) is used to switch the output piston (5) between large-stroke fast-small-torque transmission and small-stroke large-torque transmission.

2. The double-lead electronic brake assembly according to claim 1, wherein: Small grooves (81) are arranged along the track grooves (8) at the bottoms of the track grooves (8) of the left large end face (311) and / or the right large end face (341); the widths of the small grooves (81) are smaller than the width of the rolling bodies (33); The switching unit (4) comprises a pull rod (42), a spring (41), a one-way bearing (44) or a needle bearing, a thrust bearing (45) and a spring seat (46) which are arranged on the pull rod (42); the first-lead screw (34) and the second-lead transmission shaft (31) are arranged on the pull rod (42); the pull rod (42) is provided with pull rod stops (43) at two ends thereof; the thrust bearing (45) is abutted against the left pull rod stop (43) at one end and against the left end face of the spring seat (46) at the other end; the second-lead transmission shaft (31) is abutted against the right pull rod stop (43); the spring (41) is abutted against the first-lead screw (34) at one end and against the spring seat (46) at the other end; the one-way bearing (44) or the needle bearing, the spring seat (46) and the spring (41) are arranged on the pull rod (42) from inside to outside.

3. The dual lead electronic brake assembly of claim 2, wherein: The input unit (2) further comprises a gear reduction assembly (22) connected with the output end of the driving motor (21), which is arranged in the cavity of the driving motor (21) or outside the cavity of the driving motor (21); the right end of the second lead transmission shaft (31) is connected with the output end of the gear reduction assembly (22).

4. The dual lead electronic brake assembly of claim 3, wherein: The driving motor (21) is an external rotor motor, the gear reduction assembly (22) is arranged in the cavity of the driving motor (21), and the brake shell (1) is provided with an electromagnetic actuator (6). A plurality of locking grooves (211) are uniformly arranged on the circumferential surface of the external rotor of the driving motor (21) in the circumferential direction, one side of the locking groove (211) is provided with an oblique angle, the output shaft of the electromagnetic actuator (6) is matched with the locking groove (211) to realize the rotation stopping of the driving motor (21); or, the output shaft of the electromagnetic actuator (6) is connected with a pawl, and the pawl is matched with the locking groove (211) to realize the rotation stopping of the driving motor (21). Or, a plurality of locking grooves (211) are uniformly arranged on the outer circumferential surface of the second lead transmission shaft (31) in the circumferential direction, one side of the locking groove (211) is provided with an oblique angle, the output shaft of the electromagnetic actuator (6) or the pawl connected with the output shaft is matched with the locking groove (211) to realize the rotation stopping of the driving motor (21); or, the output shaft of the electromagnetic actuator (6) is connected with a pawl, and the pawl is matched with the locking groove (211) to realize the rotation stopping of the driving motor (21).

5. The dual lead electronic brake assembly of claim 4, wherein: The switching unit (4) further comprises a sliding gasket (48) sleeved on the pull rod (42), one end of the sliding gasket (48) abuts against the right pull rod stop (43), and the other end abuts against the second lead transmission shaft (31).

6. The dual lead electronic brake assembly of claim 5, wherein: The track is arranged on the right large end surface (341) of the first lead screw (34), N=2, and M=2; the rolling body (33) is a rolling ball or a rolling column, and the shape of the track groove (8) is matched with the outer wall of the rolling ball or the rolling column; A rolling body retainer (32) is arranged between the left large end surface (311) of the second lead transmission shaft (31) and the right large end surface (341) of the first lead screw (34), the rolling ball or the rolling column is provided with four rolling balls or rolling columns, and the rolling balls or rolling columns are arranged in the limiting holes (321) formed in the rolling body retainer (32).

7. The dual lead electronic brake assembly of claim 6, wherein: The switching unit (4) further comprises a bearing (47) sleeved on the pull rod (42), and the bearing (47) is located in the inner cavity of the second lead transmission shaft (31).

8. The dual lead electronic brake assembly of claim 1, wherein: The brake shell (1) is provided with a sensor (7), a plurality of protrusions (342) are uniformly arranged on the edge of the right large end surface (341) of the first lead screw (34) in the circumferential direction, the protrusions (342) are arranged in the radial direction or the axial direction, and the sensing part of the sensor (7) is arranged at the position corresponding to the protrusions (342).

9. The dual lead electronic brake assembly of claim 7, wherein: A guide groove is formed in the inner wall of the output hole of the brake shell (1) in the axial direction, and a guide block is arranged on the outer wall of the output piston (5) and is slidably arranged in the guide groove.

10. The dual lead electronic brake assembly of claim 6, wherein: The left side large end face (311) of the second lead screw transmission shaft (31) is provided with a track corresponding to the track on the right side large end face (341) of the first lead screw (34), and the rolling body (33) is located in the track groove (8) of both.

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