Compact drive structure for automotive brake

Abstract

The utility model discloses a compact drive structure for automobile brake relates to automobile brake equipment technical field, including motor and reduction gear box, the reduction gear box is built -in with two -stage planetary gear reduction system, be equipped with the first -stage sun wheel, the first -stage planet disk and two -stage planet disk that connect gradually in the reduction gear box, the first -stage sun wheel, the first -stage planet disk and two -stage planet disk are connected on output shaft. The utility model discloses through the unique structure design, will two -stage planetary gear reduction system and motor direct -link, has realized the high -degree integration, has reduced the space occupation greatly, has saved the space for the actuator assembly design of line control brake system, has realized the miniaturization and integration of brake system, is very friendly to the narrow car wheel edge installation environment.

Description

Technical Field

[0001] This utility model relates to the field of automotive braking equipment technology, and in particular to a compact drive structure for automotive braking. Background Technology

[0002] Electromechanical braking systems eliminate the traditional hydraulic braking force transmission method, directly driving the brakes with an electric motor to clamp the vehicle's brake discs or drums, thereby achieving braking. Its main advantages include short braking response time, high control precision, energy saving and environmental friendliness, enabling more efficient energy recovery and superior braking performance.

[0003] Electromechanical braking systems consist of two components: service brakes and parking brakes. To adapt to different application scenarios in passenger cars, commercial vehicles, or multi-purpose vehicles, electromechanical braking systems are developing towards lightweight, compact, redundant safety design, and intelligence.

[0004] Patent number "CN219115422U" discloses an electromechanical braking system and vehicle. In this system, a motor transmits power to the input end of a conversion structure via a transmission structure. The conversion structure converts the rotational motion of the input end into linear motion at its output end. The output end of the conversion structure drives a piston to move linearly, pushing the brake pads against the brake disc to achieve braking. The motor drives a first gear, which in turn drives a second gear, which in turn drives a third gear. The planetary gear system includes a sun gear, planet gears, a ring gear, and a planet carrier. The ring gear is fixed to a housing. The third gear drives the sun gear via a connecting shaft, which in turn drives the planet gears, which in turn drive the planet carrier, which in turn drives the ball screw. This transmission structure can achieve a large transmission ratio within a relatively small space. Furthermore, the ring gear is fixed to the housing via multiple connecting keys, simplifying installation and allowing for quick and easy installation. The multiple connecting keys are evenly distributed along the circumference of the ring gear, ensuring a stable and secure installation on the housing.

[0005] The above solutions are all relatively advanced actuator solutions in current automotive brake-by-wire systems. However, their shortcomings or defects are as follows: the driving and parking functions both require a single motor to provide power and torque, and the performance requirements of the motor are strict, requiring a relatively large torque motor, which in turn makes the motor's size too large, resulting in an overall actuator size that is too large, making size layout difficult, occupying a lot of space, and having a non-compact structure. This is also not friendly to the narrow installation environment around the car wheel. Utility Model Content

[0006] To address the shortcomings of existing technologies, this utility model proposes a compact drive structure for automotive braking, providing a drive assembly solution that is space-saving, highly integrated, compact, and low-cost.

[0007] The technical solution of this utility model is as follows: A compact drive structure for automobile braking includes a reduction gearbox and a motor with an output shaft. The reduction gearbox has a first-stage sun gear, a first-stage planetary disk, and a second-stage planetary disk connected in sequence. The first-stage sun gear, the first-stage planetary disk, and the second-stage planetary disk are coaxially connected to the output shaft.

[0008] Preferably, the output shaft of the motor is a two-stage stepped shaft, comprising a first shaft segment closer to the motor and a second shaft segment farther from the motor; the first-stage sun gear is fixedly connected to the first shaft segment of the output shaft, and the first-stage planetary disk and the second-stage planetary disk are both rotatably connected to the second shaft segment of the output shaft.

[0009] Preferably, the motor has a fitting groove at one end near the output shaft, and the gearbox has an annular fitting protrusion at one end near the motor. The fitting protrusion is interference-fitted with the fitting groove, and a first bearing is provided between the fitting protrusion and the output shaft. The first bearing is interference-fitted with both the output shaft and the fitting protrusion.

[0010] Preferably, the motor has multiple buckles along the cylindrical surface near the output shaft end, and the gearbox housing has multiple buckle protrusions that cooperate with the buckles.

[0011] More preferably, the number of the buckles is three.

[0012] Preferably, the motor includes a stator and a rotor. The stator includes multiple stator cores and coil windings wound on the stator cores. The multiple stator cores are arranged side by side in a bent ring shape. The rotor surface is covered with magnetic pole plates. The rotor is located at the center of the stator core. The coil windings have drive wires led out from the front end of the stator core for connection to an external power source. The front end and rear end of the stator are respectively provided with a front injection molded part and a rear injection molded part. The front injection molded part has an extension block that wraps around the drive wire.

[0013] Preferably, the rotor includes a rotor core and a rotating shaft, the rotor core and the rotating shaft are an integral structure, and both the front injection molded part and the rear injection molded part are provided with output bearings. The rotating shaft is rotatably connected to the front injection molded part and the rear injection molded part through the output bearings.

[0014] Preferably, the drive shaft and the motor output shaft are an integral structure, and the part of the rotating shaft that extends out of the front injection molded part is the output shaft.

[0015] Preferably, the reduction gearbox includes a gearbox housing, with the first-stage planetary disk and the second-stage planetary disk housed within the gearbox housing. The first-stage planetary disk has multiple first-stage planetary gears, and the second-stage planetary disk has multiple second-stage planetary gears. The inner wall of the gearbox housing has internal gear rings that mesh with the first-stage and second-stage planetary gears respectively. A first-stage sun gear is fitted onto the output shaft of the motor. The first-stage sun gear meshes with the first-stage planetary gears at the center of the first-stage planetary disk. A second-stage sun gear is fixedly mounted on the side of the first-stage planetary disk away from the first-stage sun gear. The second-stage sun gear meshes with the second-stage planetary gears at the center of the second-stage planetary gears. An output gear is fixedly mounted on the side of the second-stage planetary disk away from the second-stage sun gear.

[0016] Preferably, the first-stage planetary disk is provided with multiple first-stage gear shafts, and the first-stage planetary gears are rotatably connected to the first-stage gear shafts; the second-stage planetary disk is provided with multiple second-stage gear shafts, and the second-stage planetary gears are rotatably connected to the second-stage gear shafts.

[0017] Preferably, a second bearing is provided between the secondary planetary disk and the gearbox housing, and needle roller bearings are provided between the secondary planetary disk, the primary planetary disk and the output shaft.

[0018] Preferably, a speed sensor is provided at the top end of the output shaft.

[0019] The beneficial effects of this utility model are as follows: 1. This utility model, through a unique structural design, combines a two-stage planetary gear reduction system and a motor for a high degree of integration. It achieves a direct connection between the two-stage planetary gear reduction system and the output shaft, and the output shaft is also the main shaft inside the two-stage planetary gear reduction system. This significantly reduces the size of the gearbox and the space occupied, saving space for the actuator assembly design of the brake-by-wire system. It realizes the miniaturization and integration of the braking system and is very friendly to the narrow wheel-side installation environment of automobiles.

[0020] 2. This utility model combines a two-stage planetary gear reduction system and a motor into a drive assembly unit. Under the same motor performance, the small torque of the motor is amplified into output through the planetary gear set, which greatly increases the output torque of the entire drive assembly unit. This significantly reduces the design difficulty of the gearbox transmission system that it is paired with, improves design efficiency and simplifies design difficulty, and achieves the braking requirement of small torque motor input and large torque output. It also significantly reduces the cost of the motor, and the highly integrated drive unit simplifies assembly difficulty and improves production efficiency.

[0021] 3. This utility model integrates the stator core and motor drive wires into a single structure by injection molding at both ends of the motor stator core. Without affecting the motor performance, it directly saves the motor housing, thereby drastically reducing the motor's external dimensions. This reduces the outer diameter of the motor, occupies less space, facilitates subsequent size arrangement, greatly reduces the design and development difficulty of the gearbox, increases the design freedom of the gearbox, and is friendly to the narrow installation environment of automobile wheel rims.

[0022] 4. This utility model forms a snap-fit ​​structure by direct injection molding on the motor and sets a matching snap-fit ​​protrusion on the gearbox housing; a fitting groove is set on the output shaft end face and a fitting protrusion is set on the gearbox housing; in order to realize the assembly between the gearbox and the motor. The design of the above structures is an integrated structure with the gearbox housing or the motor, which simplifies the manufacturing process, significantly improves the assembly efficiency, and also improves the space utilization. Attached Figure Description

[0023] Figure 1 This is an exploded view of the overall drive structure of this utility model; Figure 2 This is a cross-sectional view of the overall assembly of the drive structure of this utility model; Figure 3 This is a schematic diagram of the overall structure of the motor of this utility model; Figure 4 This is a schematic diagram of the structure of the motor of this utility model; Component names and serial numbers: 1. Gearbox; 11. First-stage sun gear; 12. First-stage planetary disk; 13. Second-stage planetary disk; 14. Second bearing; 15. Gearbox housing; 16. Needle roller bearing; 17. Second-stage gear shaft; 18. Second-stage planetary gear; 19. First-stage planetary gear; 110. First-stage gear shaft; 111. Second-stage sun gear; 112. Output gear; 113. Snap-fit ​​protrusion; 114. Engaging protrusion; 2. Motor; 21. Stator core; 22. Coil winding; 23. Rotor; 24. Magnetic pole plate; 25. Front injection molded part; 26. Rear injection molded part; 27. Motor bearing; 28. Output shaft; 281. First shaft section; 282. Second shaft section; 29. ​​Drive wire; 210. Buckle; 212. Protruding block; 213. Fitting groove; 3. First bearing. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can be arranged and designed in various different configurations. The following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely to illustrate selected embodiments of the utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0025] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning as understood by a person skilled in the art to which this disclosure pertains. The words “comprising” or “including” or similar terms used in this disclosure mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0026] like Figure 1 and Figure 2 As shown, a compact drive structure for automotive braking includes a motor 2 and a reduction gearbox 1. The reduction gearbox 1 includes a gearbox housing 15, a first-stage planetary disk 12, and a second-stage planetary disk 13. The first-stage planetary disk 12 and the second-stage planetary disk 13 are housed within the gearbox housing 15. The first-stage planetary disk 12 has multiple first-stage planetary gears 19, and the second-stage planetary disk 13 has multiple second-stage planetary gears 18. The inner wall of the gearbox housing 15 is provided with internal gear rings that mesh with the first-stage planetary gears 19 and the second-stage planetary gears 18, respectively. A first-stage sun gear 11 is fitted onto the output shaft of the motor 2. The first-stage sun gear 11 is located at the center of the first-stage planetary disk 12 and is adjacent to the first-stage planetary gears 19 and 18. 9. The first-stage planetary disk 12 is fixedly provided with a second-stage sun gear on the side away from the first-stage sun gear 11. The second-stage sun gear meshes with the second-stage planetary gear 18 at the center of the second-stage planetary disk 18. The output gear 112 is fixedly provided with a second-stage planetary disk 13 on the side away from the second-stage sun gear. The output shaft 28 of the motor 2 is a two-stage stepped shaft, including a first shaft section 281 close to the motor 2 and a second shaft section 282 away from the motor 2. The first-stage sun gear 11 is fixedly connected to the first shaft section 281 of the output shaft 28. The first-stage planetary disk 12, the second-stage sun gear, the second-stage planetary disk 13 and the output gear 112 are all rotatably connected to the second shaft section 282 of the output shaft 28.

[0027] Specifically, the motor 2 is provided with a fitting groove 213 at one end near the output shaft 28, and the gearbox 1 is provided with an annular fitting protrusion 114 at one end near the motor 2. The fitting protrusion 114 is interference-fitted with the fitting groove 213, and a first bearing 3 is provided between the fitting protrusion 114 and the output shaft 28. The first bearing 3 is interference-fitted with both the output shaft 28 and the fitting protrusion 114.

[0028] Specifically, the motor 2 has multiple latches 210 along its cylindrical surface near the output shaft 28, and the gearbox housing 15 has multiple latch protrusions 113 that cooperate with the latches 210. More preferably, the number of latches 210 is three. By forming the latches 210 directly during injection molding, not only can additional processing costs be saved, but the quick assembly and disassembly characteristics of the latch 210 structure are also very suitable for the scenario where the automotive brake motor 2 needs to be assembled in a confined space.

[0029] This utility model combines two fixing methods, a buckle 210 and a fitting groove 213, between the gearbox 1 and the motor 2 to connect, assemble, and position the motor 2 and the gearbox 1. It also restricts the degree of freedom, achieving both axial fixation and circumferential fixation to prevent rotation. This results in a compact structure, small space occupation, and high integration, realizing the miniaturization and integration of the braking system.

[0030] like Figure 3 and Figure 4 As shown, specifically, the motor 2 includes a stator and a rotor 23. The stator includes multiple stator cores 21 and coil windings 22 wound on the stator cores 21. The multiple stator cores 21 are arranged side by side in a bend to form a ring. The rotor 23 has magnetic pole plates 24 attached to its surface. The rotor 23 is located at the center of the stator cores 21. The coil windings 22 have drive wires 29 led out from the front end of the stator cores 21 for connection to an external power source. The front end and rear end of the stator are respectively provided with a front injection molded part 25 and a rear injection molded part 26. The front injection molded part 25 has an extension block 212 that wraps around the drive wires 29. This invention forms an integrated motor 2 structure by injection molding the front and rear ends of the stator core 21. The injection molded parts are attached to the front and rear ends of the stator core 21 to form end caps, while the stator core 21 can be directly exposed to serve as the outer shell of the motor 2. This integrated motor 2 structure saves the outer shell of the motor 2 without affecting the performance of the motor 2, thus greatly compressing the external size of the motor 2, reducing the outer diameter of the motor 2, occupying less space, providing convenience for subsequent size arrangement, greatly reducing the design and development difficulty of the gearbox 1, increasing the design freedom of the gearbox 1, and being very friendly to the narrow installation environment of automobile wheel side.

[0031] Specifically, the rotor 23 includes a rotor core and a rotating shaft. The rotor core and the rotating shaft are an integrated structure. Both the front injection molded part 25 and the rear injection molded part 26 are provided with output shaft bearings. The rotating shaft is rotatably connected to the front injection molded part 25 and the rear injection molded part 26 through the output shaft bearings, thereby achieving fixed constraint on both ends of the rotor 23 and making the motor 2 work stably and reliably.

[0032] Specifically, the drive shaft and the output shaft of the motor 2 are integrated into one unit, and the portion of the rotating shaft extending out of the front injection-molded part 25 is the output shaft 28. This simplifies the structure of the motor 2 and reduces the number of parts used for connection.

[0033] Specifically, the first-stage planetary disk 12 is provided with multiple first-stage gear shafts 110, and the first-stage planetary gear 19 is rotatably connected to the first-stage gear shafts 110; the second-stage planetary disk 13 is provided with multiple second-stage gear shafts 17, and the second-stage planetary gear 18 is rotatably connected to the second-stage gear shafts 17.

[0034] Specifically, a second bearing 1416 is provided between the secondary planetary disk 13 and the gearbox housing 15, and a needle roller bearing is provided between the secondary planetary disk 13, the primary planetary disk 12 and the output shaft 28.

[0035] Specifically, a speed sensor is provided at the top end of the output shaft 28. This sensor is used to read the parameters of the motor 2, facilitating subsequent adjustment of the motor 2 by the braking system control layer.

[0036] Specific assembly process: This invention features a two-stage stepped shaft for the output shaft 28. The first shaft segment 281 is fitted with the first bearing 3 and the first-stage sun gear via a hole-shaft connection. The first shaft segment 281 and the bearing have an interference fit to fix and constrain the output shaft 28, ensuring smooth and reliable operation. The first shaft segment 281 and the first-stage sun gear also have an interference fit, with the first-stage sun gear press-fitted onto the first shaft segment 281 to transmit power. The first-stage sun gear meshes with the first-stage planetary gear 19. An internal gear ring is provided on the inner wall of the gearbox housing, meshing with the first-stage planetary gear 19. One end of the first-stage gear shaft 110 is press-fitted into a pre-drilled hole in the first-stage planetary disk, while the other end passes through the inner hole of the first-stage planetary gear 19 with a clearance fit. The first-stage planetary gear 19 meshes with the first-stage sun gear, driving the first-stage planetary disk to rotate. The second-stage sun gear and the first-stage planetary disk are integrated. The drive assembly unit features a single-stage planetary disk and a second-stage planetary gear 18 that mesh to transmit torque. Similarly, one end of the second-stage gear shaft 17 is press-fitted into a pre-drilled hole in the second-stage planetary disk 13, while the other end passes through a hole in the second-stage planetary gear 18 with a clearance fit. The output wheel and the second-stage planetary disk 13 are integrated, meaning the second-stage planetary gear 18 transmits torque to rotate the second-stage planetary disk 13, providing power output for the drive assembly. The second-stage planetary disk 13 has a bearing seat with a clearance fit to the inner ring of the bearing. The gearbox housing also has a bearing seat with a clearance fit to the outer ring of the bearing, fixing the second-stage planetary disk 13 for stable and reliable operation. The needle roller bearings are arranged in a parallel configuration along the output shaft 28, engaging with the second-stage stepped shaft of the motor 2 to constrain the output shaft and ensure stable and reliable operation. The motor 2's output terminals are encapsulated in plastic using injection molding to facilitate connection to the PCB circuit board. The motor 2 has an inner hole that mates with a cylindrical boss on one end of the gearbox housing to fix and constrain the entire planetary gear set. The other end of the gearbox housing also has an inner hole, providing a hole-shaft interface for externally connected parts and serving to constrain and fix the other end. The motor 2 has three latches 210, which mate with three bosses on the gearbox housing, securing the motor 2 and the gearbox housing in the axial direction. Through a unique structural design, the two-stage planetary gear reduction system and the motor 2 are organically combined, achieving a high degree of integration. The direct connection between the two-stage planetary gear reduction system and the output shaft 28, with the output shaft 28 also serving as the main axis within the system, significantly reduces the size of the gearbox and space requirements. This saves space for the actuator assembly design of the brake-by-wire system, achieving miniaturization and integration of the braking system, and is highly suitable for the confined space of automotive wheel wells.

[0037] The above description is a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and concept of this utility model, should be covered within the protection scope of the claims of this utility model.

Claims

1. A compact drive structure for automotive braking, comprising a reduction gearbox (1) and a motor (2) with an output shaft (28), characterized in that: The reduction gearbox (1) is provided with a first-stage sun gear (11), a first-stage planetary disk (12) and a second-stage planetary disk (13) connected in sequence. The first-stage sun gear (11), the first-stage planetary disk (12) and the second-stage planetary disk (13) are coaxially connected on the output shaft (28).

2. The compact drive structure for automotive braking according to claim 1, characterized in that: The output shaft (28) is a two-stage stepped shaft, including a first shaft section (281) close to the motor (2) and a second shaft section (282) away from the motor (2); the first-stage sun gear (11) is fixedly connected to the first shaft section (281) of the output shaft (28), and the first-stage planetary disk (12) and the second-stage planetary disk (13) are rotatably connected to the second shaft section (282) of the output shaft (28).

3. A compact drive structure for automotive braking according to claim 1 or 2, characterized in that: The motor (2) has a fitting groove (213) at one end near the output shaft (28), and the gearbox (1) has a ring-shaped fitting protrusion (114) at one end near the motor (2). The fitting protrusion (114) is interference-fitted with the fitting groove (213), and a first bearing (3) is provided between the fitting protrusion (114) and the output shaft (28). The first bearing (3) is interference-fitted with both the output shaft (28) and the fitting protrusion (114).

4. A compact drive structure for automotive braking according to claim 1 or 2, characterized in that: The motor (2) has multiple buckles (210) along the cylindrical surface near the output shaft (28), and the gearbox (1) has multiple buckle protrusions (113) that cooperate with the buckles (210) on the outer surface.

5. A compact drive structure for automotive braking according to claim 1 or 2, characterized in that: The motor (2) includes a stator and a rotor (23). The stator includes multiple stator cores (21) and coil windings (22) wound on the stator cores (21). The multiple stator cores (21) are arranged side by side in a bend to form a ring. The rotor (23) has magnetic pole plates (24) attached to its surface. The rotor (23) is located at the center of the stator cores (21). The coil windings (22) have drive wires (29) led out from the front end of the stator cores (21) for connection with an external power source. The front end and rear end of the stator are respectively provided with a front injection molding part (25) and a rear injection molding part (26). The front injection molding part (25) has an extension block (212) that wraps around the drive wires (29).

6. A compact drive structure for automotive braking according to claim 5, characterized in that: The rotor (23) includes a rotor (23) core and a rotating shaft. The rotor (23) core and the rotating shaft are an integrated structure. Both the front injection molded part (25) and the rear injection molded part (26) are provided with output shaft (28) bearings. The rotating shaft is rotatably connected to the front injection molded part (25) and the rear injection molded part (26) through the output shaft (28) bearings.

7. A compact drive structure for automotive braking according to claim 1, 2, or 6, characterized in that: The reduction gearbox (1) also includes a gearbox housing (15). The first-stage planetary disk (12) and the second-stage planetary disk (13) are placed inside the gearbox housing (15). The first-stage planetary disk (12) is provided with multiple first-stage planetary gears (19). The second-stage planetary disk (13) is provided with multiple second-stage planetary gears (18). The inner wall of the gearbox housing (15) is provided with internal gear rings that mesh with the first-stage planetary gears (19) and the second-stage planetary gears (18) respectively. The output shaft (28) of the motor is fitted with a first-stage sun gear (11). The first-stage sun gear (11) is located at the center of the first-stage planetary disk (12) and meshes with the first-stage planetary gears (19). A second-stage sun gear (111) is fixedly provided on the side of the first-stage planetary disk (12) away from the first-stage sun gear (11). The second-stage sun gear (111) is located at the center of the second-stage planetary gears (18) and meshes with the second-stage planetary gears (18). An output gear (112) is fixedly provided on the side of the second-stage planetary disk (13) away from the second-stage sun gear (111).

8. A compact drive structure for automotive braking according to claim 7, characterized in that: The first-stage planetary disk (12) is provided with multiple first-stage gear shafts (110), and the first-stage planetary gear (19) is rotatably connected to the first-stage gear shafts (110); the second-stage planetary disk (13) is provided with multiple second-stage gear shafts (17), and the second-stage planetary gear (18) is rotatably connected to the second-stage gear shafts (17).

9. A compact drive structure for automotive braking according to claim 7, characterized in that: A second bearing (14) is provided between the secondary planetary disk (13) and the gearbox housing (15), and a needle roller bearing (16) is provided between the secondary planetary disk (13), the primary planetary disk (12) and the output shaft (28).

10. A compact drive structure for automotive braking according to claim 1, 2, 6, 8, or 9, characterized in that: A speed sensor is provided at the top of the output shaft (28).

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