Coaxial automobile electronic mechanical brake

Abstract

The utility model discloses a coaxial automobile electronic mechanical brake which comprises a brake caliper, a motor, a speed reducer assembly and a ball screw assembly, the ball screw assembly is arranged in a shell of the brake caliper, and one end of the ball screw assembly abuts against a brake pad in the brake caliper; the other end of the ball screw assembly is connected with an output shaft of the speed reducer assembly, the speed reducer assembly is fixedly connected with a shell of a brake caliper, the input end of the speed reducer assembly is connected into an output shaft of the motor, and the output shaft of the motor and the ball screw assembly are coaxially arranged. The tail end of the motor is connected with a control unit assembly, and the motor is electrically connected with the control unit assembly. The device is reasonable in layout, simple in structure, easy to disassemble, low in horizontal space occupancy rate and more suitable for the installation environment with narrow horizontal space.

Description

Technical Field

[0001] The utility model relates to the technical field of electro-mechanical brakes, and particularly relates to a coaxial automotive electro-mechanical brake. Background Art

[0002] An automotive brake is a braking device for an automobile. Almost all the brakes used in automobiles are friction brakes, which can be divided into two major categories: drum brakes and disc brakes. The rotating element in the friction pair of a drum brake is a brake drum, and its working surface is a cylindrical surface; the rotating element of a disc brake is a rotating brake disc, with its end face as the working surface.

[0003] Electro-mechanical braking (EMB) is an advanced automotive braking technology that combines electronics and mechanical technologies to provide a safer, more efficient, and more environmentally friendly braking solution. In modern automotive technology, the importance of EMB is reflected in the following aspects:

[0004] Faster response speed: The EMB system uses electronic sensors and actuators to control braking, which can provide a faster response speed compared with traditional hydraulic braking systems. This helps to reduce the braking distance and improve driving safety.

[0005] More precise braking force control: Through electronic control, EMB can precisely adjust the braking force of each wheel. This precise control helps to improve the stability and maneuverability of the vehicle, especially under different road conditions and vehicle loads.

[0006] Energy recovery: In electric vehicles and hybrid vehicles, the EMB system can recover energy during braking, convert it into electrical energy and store it, thereby improving energy efficiency and extending the driving range.

[0007] Reduced maintenance requirements: Since the EMB system reduces many mechanical components in traditional hydraulic braking systems, such as hydraulic pipelines and seals, its maintenance requirements are low, reducing the maintenance cost.

[0008] Support for autonomous driving technology: With the development of autonomous driving technology, the EMB system is more easily integrated with the autonomous driving system, providing more precise vehicle control and improving the overall safety performance.

[0009] Environmentally friendly: The EMB system reduces the use of brake fluid, thereby reducing the risk of environmental pollution. This is of great significance for promoting the sustainable development of the automotive industry.

[0010] Improved vehicle performance: Through faster response speed and more precise braking force control, EMB helps to improve the dynamic performance of the vehicle, providing a better driving experience for the driver.

[0011] Generally speaking, electro-mechanical braking (EMB) is an important innovation in modern automotive technology. It not only improves driving safety but also supports the development of electric vehicles and autonomous driving technologies, contributing to a more environmentally friendly and efficient automotive future.

[0012] As disclosed in the patent number "CN221678704U" for "An electro-mechanical braking actuator with a force sensor", the upper housing is fixedly connected to the lower housing. The motor assembly is installed on the lower housing, and the caliper body is installed at one end of the lower housing away from the upper housing. A brake disc is provided inside the caliper body, and friction pads are provided on both sides of the brake disc. A ball screw assembly is provided inside the caliper body. A sun gear assembly and planet gears are installed inside the lower housing. A planet carrier with an output shaft assembly is provided between the planet gears and the ball screw assembly. A force sensor is fixedly provided inside the upper housing. A shaft rod coaxially arranged with the planet carrier with an output shaft assembly is provided inside the sun gear assembly. One end of the shaft rod is spline-connected to the end of the ball screw, and the other end of the shaft rod abuts against the force sensor.

[0013] In the above solution, the motor and the ball screw are arranged in a parallel-axis manner, resulting in a large horizontal space occupation and making it difficult to apply in an assembly environment with a narrow horizontal space. Utility Model Content

[0014] Aiming at the deficiencies of the prior art, the purpose of the present utility model is to provide an electro-mechanical brake that can be installed in a narrow horizontal space.

[0015] The technical solution of the present utility model is as follows:

[0016] A coaxial automotive electro-mechanical brake includes a brake caliper, a motor, a reducer assembly, and a ball screw assembly. The ball screw assembly is placed inside the housing of the brake caliper. One end of the ball screw assembly abuts against the brake pads inside the brake caliper. The other end of the ball screw assembly is connected to the output shaft of the reducer assembly. The reducer assembly is detachably and fixedly connected to the housing of the brake caliper. The input end of the reducer assembly is connected to the output shaft of the motor. The output shaft of the motor is coaxially arranged with the ball screw assembly. The tail end of the motor is connected to a control unit assembly, and the motor is electrically connected to the control unit assembly.

[0017] Preferably, the reducer assembly includes a first-stage planetary gear set, a second-stage planetary gear set, and a reducer housing. The inner wall of the reducer housing is provided with an internal gear ring. The first-stage planetary gear set and the second-stage planetary gear set are placed inside the reducer housing and mesh with the internal gear ring. The internal gear ring and the reducer housing are an integral structure. The output shaft of the motor is connected to the input end of the first-stage planetary gear set. The output shaft of the first-stage planetary gear set is connected to the input end of the second-stage planetary gear set. The output shaft of the second-stage planetary gear set is connected to and drives the ball screw assembly.

[0018] Preferably, the module of the first-stage planetary gear set and the second-stage planetary gear set is the same; since the two-stage planetary gears are designed with the same module, the two-stage planetary gear sets can share the same internal gear ring.

[0019] Preferably, a friction gasket is provided on one side of the first-stage planetary gear set close to the motor.

[0020] Preferably, a needle thrust bearing is provided on one side of the second-stage planetary gear set close to the ball screw assembly.

[0021] Preferably, the ball screw assembly includes a ball screw, a screw nut, and a piston. The screw nut is sleeved on one end of the ball screw, the other end of the ball screw is connected to the output shaft of the reducer assembly, the screw nut is nested into one end of the piston, and the other end of the piston abuts against the brake pad of the brake caliper.

[0022] Preferably, the ratio of the length a to the width b of the brake is 2 - 4:1, and the preferred length-width ratio is 3:1, with a more reasonable layout.

[0023] Preferably, the ratio of the length c of the brake caliper to the length d of the reducer assembly is 2 - 4:1. Preferably, the ratio of the length of the brake caliper to the length of the reducer assembly is 2.5:1, with a more reasonable layout.

[0024] Preferably, the reduction ratio of the reducer assembly is greater than or equal to 30:1, with a good torque amplification effect.

[0025] Compared with the prior art, the advantages of the present utility model are:

[0026] The present utility model proposes a coaxial layout method for the motor, reducer, and ball screw to adapt to the narrow installation environment in the horizontal direction.

[0027] The structure of the present utility model is simple. A split design is adopted among the reducer assembly, the brake caliper, and the motor, making it easy to disassemble and assemble, facilitating processing, installation, and subsequent maintenance.

[0028] The control unit assembly of the present utility model is directly integrated at the tail end of the motor, directly detecting and controlling the motor speed and torque.

[0029] The internal gear ring of the present utility model is directly integrally formed with the reducer housing.

[0030] The following further describes the detailed structure of the present utility model in conjunction with the drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is the overall external view of the present utility model;

[0032] Figure 2Explosion schematic diagram of the present utility model;

[0033] Figure 3 Cross-sectional view of the present utility model;

[0034] Figure 4 Dimension correspondence diagram of the present utility model.

[0035] Names of each component and corresponding serial numbers: 1. Brake caliper; 11. Ball screw; 12. Screw nut; 13. Piston; 2. Reducer assembly; 21. Reducer housing; 22. First-stage planetary gear set; 23. Second-stage planetary gear set; 24. Friction gasket; 25. Needle thrust bearing; 3. Motor; 4. Control unit; a. Brake length; b. Brake width; c. Length of the brake caliper; d. Total length of the reducer. Specific embodiments

[0036] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Usually, the components of the embodiments of the present utility model described and illustrated herein can be arranged and designed in various different configurations. The following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the present utility model claimed, but merely represents selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the scope of protection of the present utility model.

[0037] Unless otherwise defined, the technical terms or scientific terms used in this disclosure shall have the ordinary meanings understood by those of ordinary skill in the art in the field to which this disclosure belongs. The words such as "including" or "comprising" used in this disclosure mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. The words such as "connected" or "coupled" are not limited to physical or mechanical connections, and may also include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left", and "right" are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0038] As Figures 1-4Shown: A coaxial automotive electromechanical brake, including a brake caliper 1, a motor 3, a reducer assembly 2 and a ball screw assembly. The ball screw assembly is placed inside the housing of the brake caliper 1, and one end of the ball screw assembly abuts against the brake pads inside the brake caliper 1; the other end of the ball screw assembly is connected to the output shaft of the reducer assembly 2, and the reducer assembly 2 is fixedly connected to the housing of the brake caliper 1. It should be noted that the reducer assembly 2 can be fixedly connected to the brake caliper 1 by existing detachable connection methods such as bolt connection. The input end of the reducer assembly 2 is connected to the output shaft of the motor 3, and the output shaft of the motor 3 is coaxially arranged with the ball screw assembly. The tail end of the motor 3 is connected with a control unit, and the motor 3 is electrically connected to the control unit 4. By coaxially arranging the motor 3 with the ball screw assembly inside the brake caliper 1, the width of the entire brake in the horizontal direction is only the width of the brake caliper 1, greatly reducing the space occupancy rate of the brake in the horizontal direction; further, by adopting a split design for the reducer assembly 2 and the brake caliper 1, the overall structure of the brake is greatly simplified, enabling the brake caliper 1 and the reducer assembly 2 to be processed and assembled step by step and simultaneously, improving the processing and production efficiency, and facilitating the disassembly and assembly process during subsequent maintenance and repair of the brake, reducing the difficulty of disassembling and assembling the brake, and indirectly improving the maintenance efficiency.

[0039] It should be noted that in the present utility model, the control unit 4 is directly fixedly connected to the motor 3. The control unit 4 directly collects the working information of the motor 3 and performs feedback control on the motor 3, saving the arrangement of a large number of sensors and sensing wire harnesses, simplifying the structure while reducing the production and processing costs, and making the control more stable and reliable.

[0040] Specifically, the speed reducer assembly 2 includes a first-stage planetary gear set 22, a second-stage planetary gear set 23 and a speed reducer housing 21. An internal gear ring is provided on the inner wall of the speed reducer housing 21. The first-stage planetary gear set 22 and the second-stage planetary gear set 23 are placed inside the speed reducer housing 21 and mesh with the internal gear ring. The internal gear ring and the speed reducer housing 21 are of an integral structure. The output shaft of the motor 3 is connected to the input end of the first-stage planetary gear set 22. The output shaft of the first-stage planetary gear set 22 is connected to the input end of the second-stage planetary gear set 23. The output shaft of the second-stage planetary gear set 23 is connected to and drives the ball screw assembly. By serially assembling the first-stage planetary gear set 22 and the second-stage planetary gear set 23, the advantages of a large reduction ratio and a low space occupancy rate of the planetary gear train are fully utilized, further restricting the volume of the speed reducer assembly 2. Further, the first-stage planetary gear set 22 and the second-stage planetary gear set 23 can be designed and manufactured with the same module, which not only reduces the design and manufacturing costs of the planetary gears, but also enables the first-stage planetary gear set 22 and the second-stage planetary gear set 23 to share the same internal gear ring, making the structure of the speed reducer housing 21 simpler and the integration of the speed reducer assembly 2 easier. While reducing the processing production cost, the processing and manufacturing efficiency of the brake is also improved.

[0041] Specifically, a friction gasket 24 is provided on the side of the first-stage planetary gear set 22 close to the motor 3. When assembled, the friction gasket 24 can be made to fit with the planet gears of the first-stage planetary gear set 22 through a spring or other pressing mechanisms, which can effectively limit the first-stage planetary gear set 22 and prevent the first-stage planetary gear set 22 from generating lateral movement during rotation.

[0042] Specifically, a needle roller thrust bearing 25 is provided on the side of the second-stage planetary gear set 23 close to the ball screw assembly. The sliding friction between the second-stage planetary gear set 23 and the ball screw assembly is converted into rolling friction, reducing the wear between the two.

[0043] Specifically, the ball screw assembly includes a ball screw 11, a screw nut 12 and a piston 13. The screw nut 12 is sleeved on one end of the ball screw 11. The other end of the ball screw 11 is connected to the output shaft of the speed reducer assembly 2. The screw nut 12 is nested into one end of the piston 13. The other end of the piston 13 abuts against the brake pads of the brake caliper 1. When the output shaft of the motor 3 generates a torque, after being amplified by the speed reducer assembly 2, the torque is transmitted to the ball screw 11. The rotation of the ball screw 11 drives the screw nut 12, the piston 13 and the brake pads to move along the axis of the ball screw 11, thereby realizing the clamping and loosening of the brake pads on the brake disc.

[0044] The ratio of the length a to the width b of the brake is 2 - 4:1, and the length-width ratio of this embodiment is 3:1. The ratio of the length c of the brake caliper to the total length d of the speed reducer is 2 - 4:1, and the length ratio of this embodiment is 2.5:1. The above design layout is more reasonable and can better adapt to the assembly in a narrow installation environment in the horizontal direction.

[0045] Working process and principle: When braking is required, the operator manually or the program automatically issues a brake signal command. After the control unit 4 receives the brake signal command, it controls the motor 3 to rotate forward. The torque generated by the motor 3 is amplified by the speed reducer assembly 2 and then transmitted to the ball screw assembly. The ball screw 11 and the screw nut 12 convert the rotational motion into a linear motion, convert the torque into a thrust, and push the brake pads to gradually approach the brake disc through the piston 13, and cooperate with the fixed brake pads on the other side of the brake disc to clamp the brake disc to achieve the locking of the wheel. At the same time, during this process, the control unit 4 real-time collects the working data of the motor 3 and uses this to judge and feedback to control the working mode of the motor 3.

[0046] The above is the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model, according to the technical solution and its concept of the present utility model, makes equivalent substitutions or changes, and should be covered by the protection scope of the claims of the present utility model.

Claims

1. A coaxial electro-mechanical brake for automobiles, comprising a brake caliper (1), a motor (3), a reducer assembly (2) and a ball screw assembly, characterized in that: The ball screw assembly is placed inside the housing of the brake caliper (1), and one end of the ball screw assembly abuts against the brake pads inside the brake caliper (1); the other end of the ball screw assembly is connected to the output shaft of the speed reducer assembly (2), the speed reducer assembly (2) is detachably and fixedly connected to the housing of the brake caliper (1), the input end of the speed reducer assembly (2) is connected to the output shaft of the motor (3), the output shaft of the motor (3) is arranged coaxially with the ball screw assembly, a control unit (4) is connected to the tail end of the motor (3), and the motor (3) is electrically connected to the control unit (4).

2. The coaxial automotive electro-mechanical brake according to claim 1, wherein: The speed reducer assembly (2) includes a first-stage planetary gear set (22), a second-stage planetary gear set (23) and a speed reducer housing (21). An internal gear ring is provided on the inner wall of the speed reducer housing (21). The first-stage planetary gear set (22) and the second-stage planetary gear set (23) are placed inside the speed reducer housing (21) and mesh with the internal gear ring. The internal gear ring and the speed reducer housing (21) are of an integral structure. The output shaft of the motor (3) is connected to the input end of the first-stage planetary gear set (22), the output shaft of the first-stage planetary gear set (22) is connected to the input end of the second-stage planetary gear set (23), and the output shaft of the second-stage planetary gear set (23) is connected to and drives the ball screw assembly.

3. The coaxial automotive electromechanical brake according to claim 2, wherein: The module of the first-stage planetary gear set (22) and the second-stage planetary gear set (23) is the same.

4. The coaxial automotive electromechanical brake according to claim 2, characterized in that: A friction gasket (24) is provided on one side of the first-stage planetary gear set (22) close to the motor (3).

5. The coaxial automotive electromechanical brake according to claim 2, wherein: A needle thrust bearing (25) is provided on one side of the second-stage planetary gear set (23) close to the ball screw assembly.

6. The coaxial automotive electromechanical brake according to claim 1, wherein: The ball screw assembly includes a ball screw (11), a screw nut (12) and a piston (13). The screw nut (12) is sleeved on one end of the ball screw (11). The other end of the ball screw (11) is connected to the output shaft of the speed reducer assembly (2). The screw nut (12) is nested into one end of the piston (13), and the other end of the piston (13) abuts against the brake pads of the brake caliper (1).

7. A coaxial automotive electro-mechanical brake according to any one of claims 1-6, characterized in that: The ratio of the length a to the width b of the brake is 2 - 4:

1.

8. A coaxial automotive electromechanical brake according to any one of claims 1-6, characterized in that: The ratio of the length c of the brake caliper (1) to the length d of the speed reducer assembly (2) is 2 - 4:

1.

9. A coaxial automotive electromechanical brake according to any one of claims 1-6, characterized in that: The reduction ratio of the speed reducer assembly (2) is greater than or equal to 30:1.

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