Electrical control brake system transmission mechanism

Abstract

The application discloses a kind of electric control brake system transmission mechanism, including motor, motor includes rotor, rotor is connected with rotor cover, motor is equipped with motor base, rotor cover one end is fixedly connected with motor base;Motor is further equipped with ball screw, ball screw includes screw shaft and nut, screw shaft is cooperated with nut, screw shaft one end is located in motor base and is contacted with motor base;Motor base and screw shaft are equipped with the limiting structure that keeps ball screw from loosening, nut is connected with plunger, plunger extends from motor, the electric control brake system transmission mechanism of the application is used, and the number of parts is less, and the limiting effect is reliable, and the application cost is low.

Description

Technical Field

[0001] This invention belongs to the field of braking system technology, specifically, it relates to a transmission mechanism for an electronically controlled braking system. Background Technology

[0002] In existing electric braking systems, how to effectively limit the movement of the transmission mechanism has always been a design challenge that needs to be solved.

[0003] Currently, the limiting structure of the transmission mechanism is achieved by assembling a pressure plate on the lead screw shaft and using the pressure plate to compress the double-layer retaining ring to achieve axial limiting of the transmission mechanism. This structure uses a large number of parts, the assembly process is difficult, and the material cost is high. Alternatively, a baffle with a flange can be designed, and the retaining ring is arranged inside the flange of the baffle. The rotor tube presses the double-layer retaining ring to achieve axial limiting of the transmission mechanism. This type of baffle has a complex forming process and high development and manufacturing costs.

[0004] Patent CN115257673A, published on November 1, 2022, discloses a transmission structure for an electric power booster with a speed reduction device. The speed reduction device's gear ring is rotatably connected to an adapter frame via a bearing. One end of the lead screw nut is fixedly connected to the gear ring, and the other end is rotatably connected to the adapter frame via a bearing. The lead screw shaft is rotatably connected to the lead screw nut via steel balls, and the front end of the lead screw shaft is fixedly connected to a limiting component. This transmission structure cannot reduce the number of parts, lacks reliable limiting functionality, and does not reduce costs. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing an electric braking system transmission mechanism with fewer components, reliable limiting effect, and low application cost.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The transmission mechanism of the electric braking system includes a motor, which includes a rotor connected to a rotor sleeve. A motor base is located inside the motor, and one end of the rotor sleeve is fixedly connected to the motor base. A ball screw is also located inside the motor, comprising a screw shaft and a nut. The screw shaft mates with the nut, and one end of the screw shaft is located inside the motor base and in contact with it. A limiting structure is provided between the motor base and the screw shaft to prevent the ball screw from loosening. A plunger is connected to the nut, and the plunger extends from the motor.

[0007] The limiting structure includes a boss located on the inner side of one end of the motor base. A baffle is sleeved on the lead screw shaft. A retaining ring is provided between the boss and the baffle. The two sides of the retaining ring contact one side of the boss and the end face of the baffle, respectively. The end of the rotor sleeve extends into the motor base and contacts the other side of the boss. The rotor sleeve is fixedly connected to the motor base.

[0008] The lead screw shaft includes a support journal, on which an inner spline sleeve is provided. The inner spline sleeve is interference-fitted with the lead screw shaft. An outer spline sleeve is provided outside the inner spline sleeve. The outer spline sleeve is located inside the motor base and is interference-fitted with the motor base. The outer spline sleeve is connected to the inner spline sleeve.

[0009] The inner spline sleeve is provided with a first step, and a washer is provided on the first step. A rubber pad is provided between the baffle and the washer. A second step is provided on the baffle, and the rubber pad is sleeved on the second step. The baffle, baffle, rubber pad and washer are arranged coaxially in sequence.

[0010] The outer diameter of the retaining ring is larger than the inner diameter of the boss, and the inner diameter of the retaining ring is smaller than the outer diameter of the baffle.

[0011] The nut is located inside the rotor sleeve. Both one end of the nut and the inner side of the plunger end are threaded, and the nut is threadedly connected to the plunger.

[0012] The end of the support journal is a spherical structure, and the middle part of the motor base is provided with an arc-shaped groove, and the end of the support journal contacts the arc-shaped groove.

[0013] The retaining ring is a double-layered retaining ring, and there is a gap between the two ends of the retaining ring.

[0014] The motor includes a motor housing, with a first bearing and a second bearing respectively provided at both ends of the motor housing. The outer sides of the first bearing and the second bearing are fixedly connected to the motor housing. The motor base is fixedly connected to the inner side of the first bearing, and the rotor sleeve is fixedly connected to the inner side of the second bearing.

[0015] The motor housing is provided with an assembly fixture, which includes a fixture base, a fixture pressure plate on one side of the fixture base, and an installation block in the middle of the fixture pressure plate. One end of the installation block abuts against the retaining ring.

[0016] The technical advantages of this invention are as follows: Compared with the prior art, the transmission mechanism of the electric control braking system of this invention optimizes the limiting structure of the shaft components of the transmission mechanism, simplifies the structure of the baffle, reduces the number of parts, lowers material costs, and simplifies the baffle forming process, thus reducing manufacturing costs. A boss is designed inside the motor base to confine the retaining ring between the boss and the baffle. The reasonable arrangement of the retaining ring effectively prevents axial movement of the transmission mechanism, achieving reliable axial limiting of the ball screw and related components. The reasonable design of the retaining ring structure reduces assembly difficulty and improves assembly efficiency. The reasonable layout of each component ensures reliable connection, and the overall structure provides reliable transmission and stable operation. Attached Figure Description

[0017] This manual includes the following figures, which illustrate the following: Figure 1 This is a cross-sectional schematic diagram of the transmission mechanism of the electric control braking system of the present invention; Figure 2 yes Figure 1 Enlarged view of the internal structure of the motor base; Figure 3 This is an exploded disassembly diagram of the transmission mechanism of the present invention; Figure 4-1 and Figure 4-2 This is a schematic diagram of the installation process of the retaining ring of the present invention; Figure 5 This is a schematic diagram of the structure of a retaining ring used in this invention.

[0018] The markings in the diagram are as follows: 1. Motor; 2. Ball screw; 201. Nut; 202. Screw shaft; 203. Support journal; 3. Motor base; 301. Boss; 302. Arc groove; 5. Rotor; 6. Rotor sleeve; 7. Rubber pad; 8. Baffle; 9. Retaining ring; 10. Washer; 11. Piston; 12. Inner spline sleeve; 13. Outer spline sleeve; 14. First step; 15. Second step; 16. First bearing; 17. Second bearing; 18. Motor housing; 19. Tooling base; 20. Tooling pressure plate; 21. Mounting block one; 22. Mounting block two. Detailed Implementation

[0019] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention, and to facilitate its implementation.

[0020] like Figures 1 to 5 As shown, the transmission mechanism of the electric braking system includes a motor 1, which includes a rotor 5 connected to a rotor sleeve 6. A motor base 3 is provided inside the motor 1, and one end of the rotor sleeve 6 is fixedly connected to the motor base 3. A ball screw 2 is also provided inside the motor 1, which includes a screw shaft 202 and a nut 201. The screw shaft 202 and the nut 201 cooperate, and one end of the screw shaft 202 is located inside the motor base 3 and in contact with the motor base 3. A limiting structure is provided between the motor base 3 and the screw shaft 202 to keep the ball screw from loosening. A plunger 11 is connected to the nut 201 and extends out of the motor 1.

[0021] The motor 1 converts power into the extension and retraction of the plunger 11 via the ball screw 2 transmission pair. The ball screw 2 includes a screw shaft 202, a nut 201, and steel balls. The screw shaft 202 is rotatably connected to the nut 201 via the steel balls. The ball screw 2 converts rotation into linear movement of the nut 201. The forward and reverse rotation of the screw shaft 202 realizes the extension and retraction of the plunger 11, thereby realizing the pressure build-up and pressure release process of the plunger 11. The boss 301, the retaining ring 9, and the baffle 8 constitute the limiting structure of this transmission mechanism to ensure transmission stability.

[0022] like Figure 2 As shown, the limiting structure includes a boss 301, which is located on the inner side of one end of the motor base 3. A baffle 8 is sleeved on the lead screw shaft 202. A retaining ring 9 is provided between the boss 301 and the baffle 8. The two sides of the retaining ring 9 contact one side of the boss 301 and the end of the baffle 8, respectively. The end of the rotor sleeve 6 extends into the motor base 3 and is fixedly connected to the other side of the boss 301. The boss 301 is an annular boss, and the boss 301 and the motor base 3 are an integral structure. The retaining ring 9 is arranged between the boss 301 and the baffle 8 of the motor base 3. In its natural state, the inner diameter of the retaining ring 9 is smaller than the outer diameter of the baffle 8, and the outer diameter of the retaining ring 9 is larger than the inner diameter of the boss 301. The retaining ring 9 is blocked in both axial directions, which effectively prevents the axial movement of the lead screw shaft, spline sleeve, buffer assembly or baffle 8, thereby realizing the axial limit of the ball screw 2 and related components, and preventing the transmission mechanism of the electric control braking system from disengaging from the motor 1. The design of the boss 301 not only limits the installation of the retaining ring 9 and ensures the stability of the transmission components, but also increases the welding area of ​​the rotor sleeve 6 and the motor base 3, improving the stability of the connection between the two.

[0023] like Figure 2 As shown, the lead screw shaft 202 includes a support journal 203, on which an inner spline sleeve 12 is provided. The inner spline sleeve 12 is interference-fitted with the lead screw shaft 202. An outer spline sleeve 13 is provided outside the inner spline sleeve 12. The outer spline sleeve 13 is located inside the motor base 3 and is interference-fitted with the motor base 3. The outer spline sleeve 13 is connected to the inner spline sleeve 12. The inner spline sleeve 12 is interference-pressed onto the support journal 203 of the lead screw shaft 202 and is fixedly connected to the lead screw shaft 202. The outer spline sleeve 13 is interference-fitted or interference-welded to the motor base 3. The inner spline sleeve 12 and the outer spline sleeve 13 transmit torque through spline and tooth profile engagement, thereby converting the torque into linear motion of the nut 201 through the ball screw.

[0024] like Figure 3As shown, the inner spline sleeve 12 has a first step 14, a washer 10 is provided on the first step 14, a rubber pad 7 is provided between the baffle 8 and the washer 10, the baffle 8 has a second step 15, and the rubber pad 7 is fitted on the second step 15. The retaining ring 9, the baffle 8, the rubber pad 7 and the washer 10 are arranged coaxially in sequence. The first step 14 provides an installation position for the washer 10, and the second step 15 provides an installation position for the rubber pad 7. The baffle 8 and the boss 301 form the installation area of ​​the retaining ring 9, which can ensure the axial limit of the entire transmission head. The baffle 8 and the lead screw shaft 202 are coaxially assembled, and the two can move axially relative to each other. The baffle 8 has a stepped structure and is a stamped part. Its structural design is simple, and it is easier to form, which greatly reduces the product development cost. Washer 10 is located at the end of inner spline sleeve 12, or it can be integrated with inner spline sleeve 12. Washer 10 can buffer the load changes during the transmission of ball screw 2, reduce excessive compressive force that may be generated during transmission, and protect inner spline sleeve 12 and outer spline sleeve 13. Rubber pad 7 is made of rubber, spring, or a combination of rubber and spring. Rubber pad 7 is installed between baffle 8 and washer 10, and plays a buffering role for the transmission mechanism.

[0025] like Figure 2 As shown, the outer diameter of the retaining ring 9 is larger than the inner diameter of the boss 301, and the inner diameter of the retaining ring 9 is smaller than the outer diameter of the baffle 8. With this structure, the retaining ring 9 can be stably confined between the boss 301 and the baffle 8, preventing it from easily dislodging and ensuring its long-term reliable axial limiting function. During installation, the radial deformation function of the retaining ring 9 is also fully utilized, greatly facilitating the installation and positioning process. This structure has broad application prospects in the pressure-building module of hydraulic wire-controlled braking systems.

[0026] like Figure 1 As shown, the nut 201 is located inside the rotor sleeve 6. Both one end of the nut 201 and the inner side of the end of the plunger 11 are provided with threads, and the nut 201 is threadedly connected to the plunger 11. The end of the plunger 11 abuts against the nut 201 and is also threadedly connected to the nut 201. The connection between the nut 201 and the plunger 11 is stable and reliable, and can be easily disassembled and assembled.

[0027] like Figure 2 As shown, the end of the support journal 203 has a spherical structure, and the motor base 3 has an arc-shaped groove 302 in the middle, with the end of the support journal 203 contacting the arc-shaped groove 302. In this structure, the end of the lead screw 202 and the motor base 3 form a spherical pair structure. The end of the lead screw 202 has good force distribution and strong anti-overturning ability, ensuring automatic alignment of the lead screw 202, thereby ensuring reliable linearity of the movement of the nut 201 and the plunger 11. It also makes full use of space and improves structural compactness.

[0028] like Figure 5As shown, the retaining ring 9 is a double-layer retaining ring 9, with a gap between the two ends of the retaining ring 9. The retaining ring 9 is at least a single-layer annular elastic element, and can be a common retaining ring 9, a double-layer retaining ring 9, a wave spring, or a butterfly spring. The material of the retaining ring 9 is not limited to stainless steel. Due to the gap, the retaining ring 9 can be compressed and radially reduced during installation to facilitate its insertion from the rotor sleeve 6 into the installation position.

[0029] like Figure 1 As shown, the motor 1 includes a motor housing 18, with a first bearing 16 and a second bearing 17 at each end of the motor housing 18. The outer sides of both the first bearing 16 and the second bearing 17 are fixedly connected to the motor housing 18. The motor base 3 is fixedly connected to the inner side of the first bearing 16, and the rotor sleeve 6 is fixedly connected to the inner side of the second bearing 17. The bearings in the above structure ensure that the rotation of the rotor sleeve 6 and the motor base 3 does not drive the motor housing 18, and also provide support for the rotor sleeve 6 and the motor base 3.

[0030] like Figure 4-1 and Figure 4-2 As shown, an assembly fixture is provided on the outside of the motor housing 18. The assembly fixture includes a fixture base 19, a fixture pressure plate 20 on one side of the fixture base 19, and a mounting block in the middle of the fixture pressure plate 20. One end of the mounting block abuts against the retaining ring 9. This assembly fixture is suitable for the installation of double-layer retaining rings. The mounting blocks are divided into mounting block one 21 and mounting block two 22. The fixture base 19 and the fixture pressure plate 20 fix the motor 1 as a whole. The retaining ring 9 extends from the middle of the fixture pressure plate 20 and undergoes radial deformation under the pressure of the mounting block, entering the rotor sleeve 6. Since the inner diameter of the retaining ring 9 is smaller than the outer diameter of the baffle 8, the retaining ring 9 is blocked by the baffle 8 and then returns to its original position between the baffle 8 and the boss 301. The retaining ring 9 then reaches the installation position. The operation is simple and quick, and the assembly difficulty is low.

[0031] The working principle of the transmission mechanism of the electric control braking system is as follows: the ball screw 2 and the rotor 5 are arranged coaxially, the rotor sleeve 6 is welded to the motor base 3, and the motor base 3 is provided with a boss 301 supported by the rotor sleeve 6. After power is applied, the rotor 5 of the motor 1 rotates, driving the motor base 3 to rotate together. The motor base 3 is fixedly connected to the outer spline sleeve 13. The inner spline sleeve 12 and the outer spline sleeve 13 transmit torque through the spline. The inner spline sleeve 12 is press-fitted to the screw shaft 202. The rotor 5 transfers torque to the screw shaft 202 through the motor base 3, the inner spline sleeve 12, and the outer spline sleeve 13. The rotation of the screw shaft 202 drives the screw nut 201 of the screw shaft 202 to move forward / backward to realize the pressure build-up / pressure release of the plunger 11. In the above process, the retaining ring 9 is arranged between the boss 301 and the baffle 8. The inner diameter of the retaining ring 9 is larger than the outer diameter of the baffle 8, and the outer diameter of the retaining ring 9 is larger than the inner diameter of the boss 301 of the motor base 3. The retaining ring 9 is in a stable position, which prevents the axial movement of the lead screw shaft and achieves axial limit for the ball screw 2 and related components. At the same time, the rubber pad 7 is set between the washer 10 and the baffle 8 to buffer the transmission mechanism.

[0032] Example: Motor 1 is a brushless motor 1. After being powered on, it provides input torque to realize the rotation of rotor 5, rotor sleeve 6 and motor base 3. Motor base 3 transmits torque to lead screw shaft 202 through spline transmission. The torque transmission drives ball screw 2 to make linear motion. Nut 201 is fixedly connected to plunger 11. Under the drive of nut 201, plunger 11 makes linear motion to complete pressure building / depressurization, thereby realizing the control of hydraulic braking system.

[0033] The assembly process of retaining ring 9 using tooling is as follows: Figure 4-1 For the first stage of the assembly process of the retaining ring 9, the motor 1 is installed into the tooling base 19, and the tooling pressure plate 20 is pressed onto the tooling base 19. The tooling pressure plate 20 is designed with a tapered structure, and the opening is larger than the size of the straight section. The retaining ring 9 is naturally inserted into the opening of the tooling pressure plate 20. The mounting block 21 presses against the retaining ring 9 towards the straight section. After the mounting block 21 has completed the effective pressing stroke, the assembly process begins... Figure 4-2 In the second stage of the assembly process of the retaining ring 9, the mounting block 22 presses against the retaining ring 9 and continues to press it in until the retaining ring 9 contacts the baffle 8. The retaining ring 9 is pressed in further, and the rubber pad 7 enters a compressed state until the other side of the retaining ring 9 is completely separated from the boss 301 of the motor base 3. The retaining ring 9 returns to its natural state in the radial direction from the compressed state, while it remains in the compressed state in the axial direction. One side of the retaining ring 9 contacts the motor base 3, and the other side contacts the baffle 8. The entire system is in a stable state, and the ball screw 2 and its associated components are axially limited, ensuring that the ball screw 2 and its associated components do not come out of the motor 1.

[0034] Compared with existing technologies, the transmission mechanism of this electric braking system optimizes the limiting structure of the shaft components, simplifies the structure of the baffle 8, reduces the number of parts, and lowers material costs. The forming process of the baffle 8 is simple, reducing manufacturing and processing costs. A boss 301 is designed in the motor base 3 to restrict the retaining ring 9 between the boss 301 and the baffle 8. The reasonable arrangement of the retaining ring 9 can effectively prevent axial movement of the transmission mechanism and achieve reliable axial limiting of the ball screw 2 and related components. The reasonable structural design of the retaining ring 9 reduces assembly difficulty and improves assembly efficiency. The reasonable layout of each component and the reliable connection ensure reliable transmission and stable operation of the overall structure.

[0035] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. An electrically controlled brake system transmission mechanism characterized by: The transmission mechanism of the electric control braking system includes a motor (1), the motor (1) includes a rotor (5), the rotor (5) is connected to a rotor sleeve (6), the motor (1) is provided with a motor base (3), one end of the rotor sleeve (6) is fixedly connected to the motor base (3); the motor (1) is also provided with a ball screw (2), the ball screw (2) includes a screw shaft (202) and a screw nut (201); a limiting structure is provided between the motor base (3) and the screw shaft (202) to keep the ball screw from loosening; The limiting structure includes a boss (301), which is located on the inner side of one end of the motor base (3). A baffle (8) is sleeved on the lead screw shaft (202). A retaining ring (9) is provided between the boss (301) and the baffle (8). The two sides of the retaining ring (9) are in contact with one side of the boss (301) and the end face of the baffle (8), respectively. The end of the rotor sleeve (6) extends into the motor base (3) and contacts the other side of the boss (301).

2. The transmission mechanism of the electric braking system according to claim 1, characterized in that: The motor housing (18) is provided with an assembly fixture on its exterior. The assembly fixture includes a fixture base (19). A fixture pressure plate (20) is provided on one side of the fixture base (19). An installation block is provided in the middle of the fixture pressure plate (20). One end of the installation block abuts against the retaining ring (9).

3. The transmission mechanism of the electric control braking system according to claim 2, characterized in that: The mounting blocks are divided into mounting block one (21) and mounting block two (22). The tooling pressure plate (20) has a tapered structure, and the opening of the tooling pressure plate (20) is larger than the size of the straight section of the tooling pressure plate (20).

4. The transmission mechanism of the electric control braking system according to claim 1, characterized in that: In its natural state, the inner diameter of the retaining ring (9) is smaller than the outer diameter of the baffle (8), and the outer diameter of the retaining ring (9) is larger than the inner diameter of the boss (301). The retaining ring (9) is blocked in both axial directions.

5. The transmission mechanism of the electric braking system according to claim 1, characterized in that: The boss (301) is an annular boss. The boss (301) and the motor base (3) are an integral structure. The retaining ring (9) is arranged between the boss (301) and the baffle (8) of the motor base (3).

6. The transmission mechanism of the electric control braking system according to claim 1, characterized in that: The retaining ring (9) is a double-layer retaining ring, and there is a gap between the two ends of the retaining ring (9).

7. The transmission mechanism of the electric control braking system according to claim 1, characterized in that: The lead screw shaft (202) includes a support journal (203), on which an inner spline sleeve (12) is provided. The inner spline sleeve (12) is interference-fitted with the lead screw shaft (202). An outer spline sleeve (13) is provided outside the inner spline sleeve (12). The outer spline sleeve (13) is located inside the motor base (3). The outer spline sleeve (13) is interference-fitted with the motor base (3). The outer spline sleeve (13) is connected to the inner spline sleeve (12).

8. The transmission mechanism of the electric control braking system according to claim 7, characterized in that: The inner spline sleeve (12) is provided with a first step (14), and a washer (10) is provided on the first step (14). The baffle (8) is provided with a second step (15), and a rubber pad (7) is provided between the baffle (8) and the washer (10). The rubber pad (7) is sleeved on the second step (15), and the retaining ring (9), baffle (8), rubber pad (7) and washer (10) are arranged coaxially in sequence.

9. The transmission mechanism of the electrically controlled braking system according to claim 8, characterized in that: The motor (1) includes a motor housing (18), with a first bearing (16) and a second bearing (17) respectively at both ends of the motor housing (18). The outer sides of the first bearing (16) and the second bearing (17) are fixedly connected to the motor housing (18). The motor base (3) is fixedly connected to the inner side of the first bearing (16), and the rotor sleeve (6) is fixedly connected to the inner side of the second bearing (17).

10. The transmission mechanism of the electrically controlled braking system according to claim 9, characterized in that: The end of the support journal (203) is a spherical structure, and the middle part of the motor base (3) is provided with an arc groove (302), and the end of the support journal (203) contacts the arc groove (302).

Images