A single bearing motor structure for an electromechanical brake (EMB) system

Abstract

The utility model relates to the technical field of wire control brake system, concretely relates to a single bearing motor structure for mechanical electronic brake EMB system, include: rotor subassembly, rotor subassembly has an output shaft, and only sets up a support bearing on the output shaft, and the inner ring of support bearing is pressed into the outer surface of output shaft through interference fit, bearing play adjustment mechanism, bearing play adjustment mechanism installs on the output shaft, and bearing play adjustment mechanism and the two end faces adjacent to support bearing are inlaid, change the play of support bearing through the movement of bearing play adjustment mechanism along the output shaft direction, in the utility model, adopt single bearing support structure, distinguish from traditional double bearing support, effectively simplify the motor structure, reduce the axial size, make the motor more compact, be suitable for installing and using in the limited space.

Description

Technical Field

[0001] This utility model relates to the field of brake-by-wire system technology, and in particular to a single-bearing motor structure for an electromechanical braking (EMB) system. Background Technology

[0002] The EMB system abandons the traditional hydraulic or pneumatic transmission method and directly drives the actuator through an electric motor to achieve braking. It has significant advantages such as fast response speed, high control precision, and easy integration, and is of great significance for improving the safety performance and braking efficiency of automobiles and realizing autonomous driving functions.

[0003] As the core power source of the EMB system, the motor's performance and structure directly affect the reliability and efficiency of the entire braking system. In traditional motor designs, the rotor support structure typically employs a dual-bearing arrangement, with a bearing installed at each end of the motor shaft. While this design can ensure stable rotor operation to a certain extent, it reveals numerous drawbacks when applied to EMB systems.

[0004] First, from a spatial layout perspective, the traditional dual-bearing motor structure results in a large axial dimension. In automotive braking systems, especially EMB systems, the need for compact integration with brake actuators, sensors, and other components places extremely stringent space requirements. A large axial motor dimension not only increases the installation difficulty of the EMB system within the vehicle but may also affect the overall layout rationality of the braking system, limiting its flexible arrangement within limited space and making it difficult to meet the modern automotive design requirements for lightweighting, miniaturization, and efficient space utilization.

[0005] Secondly, in terms of cost, the dual-bearing motor structure has significant disadvantages. On the one hand, the use of two bearings increases material costs. As a key component of the motor, bearings are relatively expensive, especially in EMB systems where high precision and reliability are required, where the quality standards for the selected bearings are more stringent, further increasing costs. On the other hand, from the perspective of production processes and assembly procedures, the installation of dual bearings requires additional steps and more complex assembly processes. This not only increases time and labor costs in the production process but may also affect the overall performance and reliability of the motor due to the accumulation of errors during assembly, leading to increased maintenance costs in the later stages.

[0006] Therefore, this application develops a single-bearing motor structure for an electromechanical braking (EMB) system to solve the problems existing in the prior art. Utility Model Content

[0007] The purpose of this invention is to provide a single-bearing motor structure for an electromechanical braking (EMB) system, in order to solve the problem that dual-bearing EMB motors are not suitable for placement on a vehicle in the prior art.

[0008] The technical solution of this utility model is: a single-bearing motor structure for an electromechanical braking (EMB) system, comprising:

[0009] A rotor assembly having an output shaft and a single support bearing on the output shaft, wherein the inner ring of the support bearing is press-fitted to the outer surface of the output shaft by an interference fit.

[0010] A bearing clearance adjustment mechanism is installed on the output shaft and is in contact with the two adjacent end faces of the support bearing. The clearance of the support bearing is changed by moving the bearing clearance adjustment mechanism along the output shaft.

[0011] Preferably, the supporting bearing is a four-point angular contact ball bearing.

[0012] Preferably, the bearing clearance adjustment mechanism is installed on the outer surface of the output shaft via a threaded connection, and the axial displacement of the bearing clearance adjustment mechanism is controlled by torque.

[0013] Preferably, the output shaft of the rotor assembly is sequentially press-fitted with the support bearing, the bearing clearance adjustment mechanism, the gear, and the sensing magnet.

[0014] Preferably, the motor has an output torque ≤1Nm and a rotor core height ≤15mm.

[0015] Preferably, the motor further includes a housing, a stator assembly, and an end cover. The outer ring of the support bearing is press-fitted into the bearing chamber of the end cover. The end cover is fixedly connected to the housing. The stator assembly is fixed to the inner wall of the housing and is arranged coaxially with the rotor assembly.

[0016] Compared with the prior art, the advantages of this utility model are:

[0017] (1) The single bearing support structure is adopted, which is different from the traditional double bearing support. This effectively simplifies the motor structure, reduces the axial dimension, and makes the motor more compact, making it suitable for installation and use in limited spaces.

[0018] (2) The bearing clearance adjustment mechanism is tightly installed on the outer surface of the output shaft by means of thread engagement. The bearing clearance can be precisely controlled by rotation adjustment, thereby realizing fine adjustment of the support bearing clearance and ensuring the stability and running accuracy of the rotor when the motor rotates at high speed.

[0019] (3) The radial and axial clearances of the bearing can be adjusted by the movement of the bearing clearance adjustment mechanism, which can significantly suppress radial runout, reduce high-frequency vibration, eliminate or reduce axial movement, avoid collision with end caps or seals, and reduce high-frequency noise and axial vibration. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0021] Figure 1 This is an exploded view of the single-bearing motor structure for an electromechanical braking EMB system described in this utility model.

[0022] Figure 2 This is a perspective view of a single-bearing motor structure for an electromechanical braking EMB system as described in this utility model;

[0023] Figure 3 This is a side sectional view of a single-bearing motor structure for an electromechanical braking (EMB) system according to the present invention.

[0024] The components include: 1. Rotor assembly; 11. Output shaft; 2. Support bearing; 3. Bearing clearance adjustment mechanism; 4. Gear; 5. Sensing magnet; 6. Housing; 7. Stator assembly; 8. End cover. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to specific embodiments:

[0026] like Figures 1-3 As shown, a single-bearing motor structure for an electromechanical braking (EMB) system includes a rotor assembly 1 and a bearing clearance adjustment mechanism 3. The rotor assembly 1 has an output shaft 11, which is the core component for the motor rotor's rotation. Only one support bearing 2 is mounted on the output shaft 11, unlike traditional double-bearing support structures. This simplifies the motor structure and reduces the axial dimension. The inner ring of the support bearing 2 is tightly press-fitted to the outer surface of the output shaft 11 via an interference fit, ensuring a stable connection between the bearing and the output shaft 11 to support the rotational movement of the rotor assembly 1. The bearing clearance adjustment mechanism 3 is mounted on the output shaft 11, adjacent to the support bearing 2, and ensures a tight fit with the end face of the support bearing 2. By adjusting the bearing clearance adjustment mechanism 3, it can be moved axially along the output shaft 11, thereby changing the clearance of the support bearing 2. Specifically, when the adjustment mechanism moves towards the support bearing 2, it compresses the internal clearance of the bearing, reducing the clearance; conversely, when the adjustment mechanism moves away from the support bearing 2, the internal clearance of the bearing increases, and the clearance increases accordingly.

[0027] Specifically, the support bearing 2 used to support the rotational motion of the rotor assembly 1 is a four-point angular contact ball bearing. The four-point angular contact ball bearing can simultaneously withstand combined loads from the radial and axial directions, ensuring the stability and reliability of the motor under high-speed rotation and complex working conditions. Furthermore, the motor is suitable for working conditions where the output torque does not exceed 1 Nm. At the same time, the height of the rotor core is limited to no more than 15 mm, ensuring that the motor can still achieve efficient and stable torque output in a compact space.

[0028] In this embodiment, the bearing clearance adjustment mechanism 3 is tightly installed on the outer surface of the output shaft 11 by means of thread engagement. By rotating, it can move precisely along the axial direction of the output shaft 11. During the adjustment process, the axial displacement of the bearing clearance adjustment mechanism 3 is precisely controlled by applying a specific torque, thereby realizing the fine adjustment of the clearance of the support bearing 2 and ensuring the stability and running accuracy of the rotor when the motor is rotating at high speed.

[0029] To further explain, the movement of the bearing clearance adjustment mechanism 3 can adjust the radial and axial clearances of the bearing. When the bearing clearance adjustment mechanism 3 is close to the support bearing 2, it indirectly reduces the radial clearance by axially compressing the inner ring of the bearing, changing the contact angle and contact stress distribution between the roller and the raceway. The axial force causes slight deformation of the inner ring, making the contact between the roller and the raceway tighter and increasing the radial stiffness. This can significantly suppress radial runout and reduce high-frequency vibration. At the same time, by adjusting the end face of the bearing clearance adjustment mechanism 3, the axial movement of the inner ring of the bearing is directly restricted, eliminating or reducing axial movement, avoiding collision with the end cover 8 or the seal, and reducing high-frequency noise and axial vibration.

[0030] Furthermore, on the output shaft 11 of the rotor assembly 1, each component is press-fitted sequentially in a specific order. Specifically, firstly, the support bearing 2 is tightly press-fitted onto the designated position of the output shaft 11 using an interference fit to support the rotational movement of the rotor assembly 1; then, the bearing clearance adjustment mechanism 3 is installed on the output shaft 11 via a threaded fit structure and arranged adjacent to the support bearing 2, so that the bearing clearance can be precisely controlled by rotating the adjustment mechanism; next, the gear 4 is press-fitted onto the output shaft 11 to transmit torque or realize mechanical transmission function; finally, the sensing magnet 5 is press-fitted onto the end of the output shaft 11 to cooperate with the sensor to monitor the rotor's speed, position and other key parameters in real time, ensuring the stable connection and precise positioning of each component on the output shaft 11.

[0031] Furthermore, the motor also includes a housing 6, a stator assembly 7, and an end cover 8. The outer ring of the support bearing 2 is tightly press-fitted into the pre-set bearing chamber inside the end cover 8 by an interference fit to ensure the stable installation of the bearing. The end cover 8 and the housing 6 are fixedly connected (such as by bolts or welding) to form the external support structure of the motor. The stator assembly 7 is firmly fixed to the inner wall of the housing 6 and is coaxially arranged with the rotor assembly 1, ensuring that the magnetic field distribution between the rotor and stator is uniform during motor operation, thereby improving the operating efficiency and stability of the motor.

[0032] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. It is obvious to those skilled in the art that this utility model is not limited to the details of the above exemplary embodiments, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and therefore, all changes falling within the meaning and scope of the equivalents of the claims are intended to be included within this utility model.

Claims

1. A single bearing motor structure for an electromechanical brake (EMB) system, characterized by, include: The rotor assembly (1) has an output shaft (11) and only one support bearing (2) is provided on the output shaft (11). The inner ring of the support bearing (2) is press-fitted to the outer surface of the output shaft (11) by an interference fit. The bearing clearance adjustment mechanism (3) is installed on the output shaft (11) and the two end faces of the bearing clearance adjustment mechanism (3) are in contact with the two end faces of the support bearing (2). The clearance of the support bearing (2) is changed by moving the bearing clearance adjustment mechanism (3) along the output shaft (11).

2. A single bearing motor structure for an electromechanical brake (EMB) system according to claim 1, characterized in that: The support bearing (2) is a four-point angular contact ball bearing.

3. A single bearing motor structure for an electromechanical brake (EMB) system according to claim 1, characterized in that: The bearing clearance adjustment mechanism (3) is installed on the outer surface of the output shaft (11) by threaded connection, and the axial displacement of the bearing clearance adjustment mechanism (3) is controlled by torque.

4. A single bearing motor structure for an electromechanical brake (EMB) system according to claim 1, characterized in that: The output shaft (11) of the rotor assembly (1) is sequentially press-fitted with the support bearing (2), bearing clearance adjustment mechanism (3), gear (4) and sensing magnet (5).

5. A single bearing motor structure for an electromechanical brake (EMB) system according to claim 1, characterized in that: The motor has an output torque of ≤1Nm and a rotor core height of ≤15mm.

6. A single bearing motor structure for an electromechanical brake (EMB) system according to claim 1, characterized in that: The motor also includes a housing (6), a stator assembly (7) and an end cover (8). The outer ring of the support bearing (2) is press-fitted into the bearing chamber of the end cover (8). The end cover (8) is fixedly connected to the housing (6). The stator assembly (7) is fixed to the inner wall of the housing (6) and is coaxially arranged with the rotor assembly (1).

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