Brake drive mechanism

Abstract

The application relates to the technical field of vehicle braking, in particular to a brake driving mechanism. The brake driving mechanism comprises a motor (4), a speed reducer (3), a linear moving mechanism (5), an encoder (9), a pressure sensor (7) and a driving controller (10). The driving controller (10) receives the signal of the encoder (9) to determine the extension position of the linear moving mechanism (5), and determines the actual brake force through the signal from the pressure sensor (7), and adjusts the current of the motor (4) in real time by comparing the target brake force, so that precise braking is realized. In this way, the force feedback function is further increased, and direct and real-time detection of the output thrust is realized. Compared with the torque estimation by the motor (4) current, the direct measurement mode eliminates the error caused by the transmission efficiency fluctuation, is higher in control precision and better in safety.

Description

Technical Field

[0001] This application relates to the field of vehicle braking technology, and in particular to a brake drive mechanism. Background Technology

[0002] As the automotive industry moves towards electrification and intelligentization, traditional hydraulic braking systems are gradually being replaced by drive-by-wire chassis technology. Among these, electronic mechanical braking (EMB) systems, by eliminating hydraulic lines, brake fluid, and vacuum boosters, offer advantages such as fast response, simple structure, ease of integration, and environmental friendliness, making them the main development direction for future automotive braking systems.

[0003] Existing electromechanical brake drive mechanisms typically include a motor, a reducer, and a lead screw and nut mechanism. Their working principle is generally as follows: the controller controls the motor to rotate; after the reducer reduces speed and increases torque, it drives the lead screw and nut mechanism to convert the rotational motion into linear motion, thereby pushing the brake pads to clamp the brake disc and generate braking force.

[0004] However, precise pressure control during braking is crucial for vehicle comfort and safety (e.g., enabling ABS anti-lock braking). Existing low-cost solutions typically estimate the output braking force by detecting the motor current (current loop control). However, due to friction, wear, and efficiency fluctuations caused by temperature changes in the transmission mechanism, the non-linear relationship between current and actual braking force leads to significant estimation errors, making high-precision closed-loop control difficult to achieve. Utility Model Content

[0005] In view of this, the present invention proposes a brake drive mechanism, which aims to improve the accuracy of brake control.

[0006] The present invention provides a brake drive mechanism comprising a motor, a reducer, a linear motion mechanism, an encoder, a pressure sensor, and a drive controller. The input end of the reducer is connected to the motor shaft; the linear motion mechanism includes a lead screw and a lead screw nut, the lead screw nut being disposed outside the lead screw and configured to convert the rotational motion of the lead screw into linear motion; the lead screw is connected to the output end of the reducer via a transmission assembly; the encoder is configured to detect the rotational parameters of the motor; the pressure sensor is configured to detect the thrust of the lead screw; the drive controller is electrically connected to the motor and signal-connected to the encoder and the pressure sensor.

[0007] In a preferred embodiment of the brake drive mechanism provided by this utility model, the input end and output end of the reducer are located on the same axial end side, and the output end is coaxially arranged around the outside of the input end.

[0008] In a preferred embodiment of the brake drive mechanism provided by this utility model, the transmission assembly includes a driving wheel and a driven wheel rotatably disposed on the housing assembly, the axes of the driving wheel and the driven wheel being parallel; wherein, a motor is disposed on one side of the driving wheel and a reducer is disposed on the other side, the rotating shaft of the motor coaxially passes through the driving wheel and is connected to the input end of the reducer, and the output end of the reducer is connected to the driving wheel; the shaft hole of the driven wheel is connected to the lead screw.

[0009] In a preferred embodiment of the brake drive mechanism provided by this utility model, the housing assembly includes a base and an end seat. The base has a first mounting groove and a second mounting groove inside, and a mounting cylinder is provided at the bottom of the second mounting groove. The reducer is installed in the first mounting groove, and a pressure sensor is installed in the second mounting groove. The mounting cylinder passes through the inner hole of the pressure sensor, and a first bearing is provided inside the mounting cylinder. The inner ring of the first bearing is connected to the end of the lead screw. The end seat is connected to the top surface of the base and forms a mounting cavity with the base. The driving wheel and the driven wheel are disposed within the mounting cavity.

[0010] In a preferred embodiment of the brake drive mechanism provided by this utility model, the reducer is a planetary reducer, which is provided with a sun gear, an internal gear ring and a planet carrier. The input end of the reducer is formed at one shaft end of the sun gear and the output end of the reducer is formed at one shaft end of the planet carrier.

[0011] In a preferred embodiment of the brake drive mechanism provided by this utility model, an axial end face of the planetary carrier is connected to the end face of the drive wheel by bolts.

[0012] In a preferred embodiment of the brake drive mechanism provided by this utility model, the brake drive mechanism further includes a thrust bearing connected to one end of the driven wheel and the other end in close contact with the pressure sensor, so as to transmit the axial thrust of the lead screw to the pressure sensor.

[0013] In a preferred embodiment of the brake drive mechanism provided by this utility model, the rotating shaft is formed with a cylindrical portion, which is connected to the shaft hole of the inner rotor of the motor. The cylindrical portion has an opening facing away from the drive wheel. The brake drive mechanism also includes a housing and a brake. The bottom end of the housing is connected to the end seat, and its inner sidewall is connected to the outer stator of the motor. One end of the brake is connected to the inner side of the cylindrical portion, and the other end is connected to the housing. The entire brake is located within the axial height range of the outer stator, and the brake is also electrically connected to the drive controller.

[0014] In a preferred embodiment of the brake drive mechanism provided by this utility model, the reducer is a harmonic reducer, the input end of the reducer is formed on one shaft end of the wave generator, and the output end of the reducer is formed on one shaft end of the flexible wheel.

[0015] In a preferred embodiment of the brake drive mechanism provided by this utility model, the linear movement mechanism further includes a cylinder, a slide rod, and a transition flange. One end of the cylinder is connected to the top surface of the end seat, and its inner wall has a first limiting portion parallel to the axial direction. The outer wall of the slide rod has a second limiting portion, which slides and limits the movement of the second limiting portion with the first limiting portion, and the inner wall of the slide rod is connected to the threaded nut. The transition flange has a central hole through which one end of the cylinder passes and connects to the cylinder, and it also connects to a fixing seat of the brake device. The brake device includes a brake disc and brake pads disposed opposite to each other. The brake disc is adapted to be connected to a wheel, and the brake pads are floatingly connected to the outer end of the slide rod.

[0016] In the brake drive mechanism provided by this utility model, when the brake drive mechanism outputs thrust, the lead screw of the linear moving mechanism experiences a huge reverse axial force. This force is transmitted to the driven wheel through the lead screw, and the driven wheel then directly presses this force onto the pressure sensor. The drive controller receives signals from the encoder to determine the extension position of the linear moving mechanism and uses signals from the pressure sensor to determine the actual braking force. By comparing the target braking force, the motor current is adjusted in real time to achieve precise braking. This further enhances the force feedback function, enabling direct, real-time detection of the output thrust. Compared to estimating torque through motor current, this direct measurement method eliminates errors caused by transmission efficiency fluctuations, resulting in higher control accuracy and better safety. Attached Figure Description

[0017] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can more clearly understand the above and other features and advantages of the present invention, in which:

[0018] Figure 1 This is a schematic diagram of the external structure of the brake drive mechanism in this embodiment.

[0019] Figure 2 This is a cross-sectional structural diagram of the brake drive mechanism in this embodiment.

[0020] Figure 3 This is a schematic diagram of the internal structure of the brake drive mechanism in this embodiment.

[0021] Figure 4 This is a schematic diagram of the base structure of the brake drive mechanism in this embodiment.

[0022] Figure 5This is a schematic diagram of the installation structure of the transmission assembly of the brake drive mechanism in this embodiment.

[0023] Figure 6 This is a schematic diagram of the assembly structure of the reducer of the brake drive mechanism in this embodiment.

[0024] Figure 7 This is an exploded view of the linear movement mechanism of the brake drive mechanism in this embodiment.

[0025] Figure 8 This is a schematic diagram showing the assembly relationship between the motor and the brake in the brake drive mechanism of this embodiment.

[0026] Figure 9 This is a schematic diagram of the control relationship of the brake drive mechanism in this embodiment.

[0027] The reference numerals in the attached figures are as follows:

[0028] 1-Housing assembly; 11-Base; 111-First mounting slot; 112-Second mounting slot; 1121-Mounting cylinder; 12-End seat; 13-Gland; 14-Pressure ring; 15-Housing; 16-End cover; 17-Adapter flange;

[0029] 2-Transmission assembly; 21-Driving wheel; 22-Driven wheel;

[0030] 3-Reducer; 301-Input end; 302-Output end; 31-Sun gear; 32-Internal gear ring; 33-Planet carrier;

[0031] 4-Motor; 41-Shaft; 411-Cylinder; 42-Inner rotor; 43-Outer stator;

[0032] 5-Linear movement mechanism; 51-Lead screw; 52-Cylinder body; 521-First limiting part; 53-Slide rod; 531-Second limiting part; 54-Lead nut sleeve;

[0033] 61-First bearing; 62-Second bearing; 63-Third bearing; 64-Fourth bearing; 65-Thrust bearing;

[0034] 7-Pressure sensor; 8-Brake; 9-Encoder; 10-Drive controller. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0036] It should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "connection" and "setup" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0037] Furthermore, it should be understood in the description of this application that the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0038] This embodiment provides a brake drive mechanism, mainly applied to automotive electromechanical braking systems (EMB). Through a highly integrated mechatronics design, this mechanism achieves precise closed-loop control of braking force, efficient transmission, and high reliability under complex operating conditions. The brake drive mechanism is composed of a power unit (motor 4), a reduction and torque amplification unit (reducer 3), a transmission conversion unit (transmission assembly 2), and an execution monitoring unit (pressure sensor 7 and encoder 9).

[0039] Combination Figures 1 to 3 The power source for this brake drive mechanism is a motor 4, which inputs rotational power to the reducer 3 via its shaft 41. To achieve a compact axial layout, the input end 301 and output end 302 of the reducer 3 are located on the same axial end side, with the output end 302 coaxially surrounding the input end 301. After being reduced in speed and torque by the reducer 3, the power is transmitted through a parallel shaft via a transmission assembly 2 consisting of a driving wheel 21 and a driven wheel 22. The driven wheel 22 drives the lead screw 51 in the linear motion mechanism 5 to rotate. The lead screw 51 cooperates with the lead nut 54, converting the rotational motion into linear reciprocating motion of the lead nut 54 and the connected slide rod 53. The outer end of the slide rod 53 is connected to the brake device via an adapter flange 17, pushing the brake pads to press against the brake disc to generate braking force.

[0040] In this embodiment, the braking device includes a brake disc and brake pads disposed opposite to each other. The brake disc is adapted to be connected to the wheel, and the brake pads are floatingly connected to the outer end of the slide bar 53. The central hole of the adapter flange 17 allows one end of the cylinder 52 of the linear moving mechanism 5 to pass through and be connected to the cylinder 52. The adapter flange 17 is also connected to the fixing seat of the braking device.

[0041] The brake drive mechanism adopts a highly integrated parallel shaft layout in its overall design. (Refer to...) Figure 1 The main body of the equipment is supported by the housing assembly 1, which mainly includes a base 11 and an end seat 12.

[0042] The base 11, as the main load-bearing component, has specific internal mounting space. Specifically, combined with... Figures 2 to 4 The base 11 has a first mounting groove 111 and a mounting cylinder 1121 inside. The first mounting groove 111 is located at the bottom of the base 11 and is used to accommodate the reducer 3; the mounting cylinder 1121 is used to support the end of the lead screw 51. The end seat 12 is connected to the top surface of the base 11, and the two are fastened together to form a closed or semi-closed mounting cavity. This mounting cavity is mainly used to accommodate the transmission assembly 2 (i.e., the driving wheel 21 and the driven wheel 22). The housing 15 of the motor 4 is connected to the end seat 12. From the outside, the motor 4, the end seat 12, and the base 11 are arranged axially in sequence, with a compact structure.

[0043] The core of this embodiment lies in its unique "through-shaft" transmission design. Combined with... Figure 3 and Figure 5 The transmission assembly 2 includes a driving pulley 21 and a driven pulley 22 arranged parallel to each other within the mounting cavity. Although the driving pulley 21 and driven pulley 22 in the attached drawings are illustrated using gear meshing as an example, the driving pulley 21 and driven pulley 22 can also be selected as synchronous pulleys to form a belt drive. The axes of the driving pulley 21 and driven pulley 22 are parallel.

[0044] Combination Figure 3 The motor 4 is located on one side of the drive wheel 21 (e.g., above), and the reducer 3 is located on the other side of the drive wheel 21 (e.g., below, i.e., inside the base 11). The shaft 41 of the motor 4 is designed to be relatively long. It passes coaxially through the center hole of the drive wheel 21 and extends directly to the reducer 3 below, and connects to the input end 301 of the reducer 3.

[0045] In this preferred embodiment, combined with Figure 6The reducer 3 is a planetary reducer. The input end 301 and the output end 302 of the reducer 3 are located on the same axial end side of the reducer 3 itself (i.e., the side facing the driving gear 21). The input end 301 of the reducer 3 is one shaft end of the sun gear 31, which is directly connected to the rotating shaft 41 of the motor 4 passing through the driving gear 21. The output end 302 of the reducer 3 is one shaft end of the planet carrier 33, and this output end 302 is coaxially arranged around the outside of the input end 301.

[0046] Continue to refer to Figure 1 and Figure 2 An annular step is formed on the inner wall of the first mounting groove 111 of the base 11. One end of the internal gear ring 32 of the planetary reducer is supported on this annular step, which not only serves as an axial positioning function but also restricts the rotation of the internal gear ring 32. For further fixation, a pressure cap 13 is provided, with the inner end of the pressure cap 13 abutting against the other end of the internal gear ring 32. Bolts are passed through the pressure cap 13 and the internal gear ring 32 and locked onto the annular step, thereby firmly locking the internal gear ring 32 of the reducer 3 into the base 11.

[0047] The power output path is as follows: the motor 4 shaft 41 rotates → drives the sun gear 31 → the planet gears revolve within the fixed internal gear ring 32 → drive the planet carrier 33 to rotate.

[0048] Continue to refer to Figure 2 To ensure the stability of the planetary carrier 33's rotation, multiple sets of bearings are installed. The second bearing 62 is located between the outer side of the first shaft end of the planetary carrier 33 and the pressure cover 13. The third bearing 63 is located between the inner side of the first shaft end of the planetary carrier 33 and the sun gear 31, ensuring input and output coaxiality. The fourth bearing 64 is located between the second shaft end of the planetary carrier 33 (the end opposite to the driving gear 21) and the interior of the base 11. Furthermore, the output end 302 of the planetary carrier 33 is rigidly connected to the end face of the driving gear 21 by bolts. Therefore, the reduced torque is directly transmitted to the driving gear 21. The driving gear 21 drives the driven gear 22 to rotate, and the driven gear 22 is responsible for driving the linear motion mechanism 5.

[0049] This embodiment also provides a modified implementation based on a harmonic reducer. In certain scenarios with extremely high precision requirements or more limited axial space, the harmonic reducer 3 can be used. In this case, the wave generator of the harmonic reducer 3 serves as the input end 301, and its shaft hole is connected to the motor 4 shaft 41 passing through the drive wheel 21. The flexible wheel of the harmonic reducer 3 serves as the output end 302, and its end is connected to the drive wheel 21. Furthermore, the rigid wheel of the harmonic reducer 3 is fixed within the first mounting groove 111 of the base 11.

[0050] In this embodiment, motor 4 drives the wave generator to rotate, forcing the flex wheel to undergo elastic deformation and mesh with the rigid wheel through staggered teeth, thereby driving the flex wheel to output low-speed, high-torque. The harmonic reducer 3 has advantages such as a large single-stage reduction ratio, no backlash, and fewer parts, which can further improve the positioning accuracy of the brake drive mechanism. Utilizing the coaxial input and output and flat structure of the harmonic reducer, a layout where the input and output are on the same side is also achieved. The backlash-free characteristic of the harmonic reducer makes the braking force adjustment response more sensitive and lag-free.

[0051] Continue to refer to Figure 2 and Figure 3 One end of the lead screw 51 is coaxially fixed to the center of the driven wheel 22 and rotates together with the driven wheel 22. The end of the lead screw 51 is supported in the mounting sleeve 1121 of the base 11 by the first bearing 61 to bear the radial load.

[0052] Combination Figure 7 A cylinder 52 is connected to the top surface of the end seat 12. A first limiting part 521 parallel to the axial direction is machined on the inner wall of the cylinder 52. A lead screw nut 54 is fitted onto the lead screw 51, with its internal thread engaging with the lead screw 51, and a slide rod 53 connected to its external side. A second limiting part 531 is provided on the outer wall of the slide rod 53, engaging with the first limiting part 521 of the cylinder 52. When the lead screw 51 rotates, the slide rod 53 cannot rotate due to the limitation of the limiting part; the lead screw nut 54 and the slide rod 53 can only extend or retract axially, thereby achieving the output of thrust.

[0053] This embodiment connects the motor 4 and the reducer 3 by having the motor 4's shaft 41 pass through the drive wheel 21, so that the motor 4 and the reducer 3 are distributed on both sides of the gear plane, which greatly shortens the axial dimension of the brake drive mechanism; at the same time, the design of the reducer 3 with input and output on the same side makes the power transmission circuit extremely short, with good rigidity and compact structure.

[0054] In addition, continue to refer to Figure 1 and Figure 2 The housing assembly 1 may also be provided with an adapter flange 17, the central hole of which allows one end of the cylinder body 52 to pass through and connect to the cylinder body 52, and the adapter flange 17 is also connected to the mounting seat of the brake device.

[0055] In a preferred embodiment of the brake drive mechanism of this example, reference continues to... Figure 2 and Figure 3This section describes the force control structure of the integrated pressure sensor 7. Inside the base 11, in addition to the aforementioned mounting cylinder 1121, a second mounting groove 112 is formed. The pressure sensor 7 is an annular pressure sensor, its inner hole fitting around the outside of the mounting cylinder 1121, and the entire sensor is placed at the bottom of the second mounting groove 112. A pressure ring 14 is used to connect to the top of the base 11; for example, the pressure ring 14 can be screwed into the base 11 by threads, or the pressure ring 14 can be bolted to the base 11, pre-tightening or fixing the pressure sensor 7 axially within the groove. A thrust bearing 65 is provided on the shaft end of the driven wheel 22 facing the base 11. One side of the thrust bearing 65 is connected to the driven wheel 22, and the other side is in close contact with the force-bearing surface of the pressure sensor 7.

[0056] The control logic is as follows: the drive controller 10 receives the encoder 9 signal (to determine the position) and the pressure sensor 7 signal (to determine the actual braking force), and adjusts the motor 4 current in real time by comparing the target braking force to achieve precise braking.

[0057] When the brake drive mechanism outputs thrust, the lead screw 51 experiences a large reverse axial force. This force is transmitted to the driven wheel 22 via the lead screw 51, and the driven wheel 22 then directly presses this force onto the pressure sensor 7 via the thrust bearing 65. Thus, the brake drive mechanism of this embodiment further enhances force feedback functionality, making it particularly suitable for braking systems. It achieves direct, real-time detection of the output thrust. Compared to estimating torque through motor current, this direct measurement method eliminates errors caused by transmission efficiency fluctuations, resulting in higher control precision and better safety.

[0058] This embodiment focuses on the internal details of motor 4 and the detection feedback component, aiming to further reduce the size of the brake drive mechanism. Combined with Figure 8 The motor 4 can be configured with a built-in brake 8. Specifically, the shaft 41 of the motor 4 is not a solid long rod, but rather forms a cylindrical portion 411 with a large diameter. This cylindrical portion 411 is connected to the shaft hole of the rotor 42 inside the motor 4. The cylindrical portion 411 has an opening facing away from the drive wheel 21, forming an internal receiving space.

[0059] The electromagnetic brake 8 is installed in the space inside the cylinder 411. One end of the brake 8 is connected to the inside of the cylinder 411, and the other end is connected to the housing 15. The outer stator 43 of the motor 4 is fixed to the inner wall of the housing 15, and the bottom end of the housing 15 is connected to the end seat 12.

[0060] Thus, the brake drive mechanism of this embodiment has the following spatial advantages: the brake 8 is entirely located within the axial height range of the outer stator 43 (i.e., the brake 8 is "hidden" inside the rotor of the motor 4). This results in almost no increase in the axial length of the motor 4 after the addition of the brake 8 function. The brake 8 is also electrically connected to the drive controller 10.

[0061] Continue to refer to Figure 2 and Figure 3 An end cover 16 is connected to the top of the housing 15, forming an electrical cavity between the end cover 16 and the housing 15. The encoder 9 includes a reading head and a code disk. The code disk is mounted at the end of the shaft 41 of the motor 4, and the reading head is mounted inside the end cover 16. This encoder 9 is used to detect the rotational speed and angular position of the motor 4 and feeds the signal back to the drive controller 10, thereby calculating the displacement distance of the brake pads. This control is crucial during the elimination of brake gaps.

[0062] Combination Figure 9 In this embodiment, the control aspect of the brake drive mechanism includes an encoder 9 (for position / speed loop control) integrated at the tail of the motor 4 and a pressure sensor 7 (for force / current loop auxiliary control) integrated in the base 11. Furthermore, the drive controller 10 is electrically connected to the motor 4 and the brake 8, and signal-connected to the encoder 9 and the pressure sensor 7.

[0063] The working process of this brake drive mechanism includes:

[0064] (1) Braking request: The drive controller 10 receives the vehicle's braking signal.

[0065] (2) Action execution: The controller controls the rotation of the motor 4. After the motor shaft 41 is reduced in speed and torque is increased by the reducer 3, it drives the driving wheel 21 and the driven wheel 22 to rotate, which in turn drives the lead screw 51 to rotate.

[0066] (3) Thrust establishment: The lead screw 51 rotates to drive the slide bar 53 to extend linearly, eliminating the brake gap and causing the brake pads to press against the brake disc (at this time, the reading of the pressure sensor 7 begins to change abruptly).

[0067] (4) Closed-loop control: The encoder 9 provides real-time feedback on the rotation angle of the motor 4 and calculates the moving distance of the slide bar 53 to achieve rapid response. After contacting the brake disc, the actual clamping force signal detected by the pressure sensor 7 is fed back to the drive controller 10. The drive controller 10 fine-tunes the torque of the motor 4 according to the difference between the target pressure and the actual pressure until the target braking force is reached, thereby achieving precise braking force control.

[0068] (5) Parking mode: If the vehicle stops and parking is required, the drive controller 10 controls the brake 8 inside the motor 4 to engage, locking the motor 4 shaft 41 and locking the position of the lead screw 51. At this time, the motor 4 can be de-energized, and the braking force is maintained by the brake 8 to realize the parking function.

[0069] (6) Brake release: The controller controls the brake 8 to open, the motor 4 reverses, and drives the slide bar 53 to retract, thus releasing the brake.

[0070] In extreme low-temperature environments, the viscosity of the lubricating grease in the reducer 3 and transmission assembly 2 increases, leading to a significant increase in internal frictional resistance. At this time, the drive controller 10 no longer relies solely on the motor 4 current to estimate the braking force, but instead directly reads the value from the pressure sensor 7. The pressure sensor 7 directly senses the axial thrust transmitted back from the lead screw 51, and the drive controller 10 compensates for the output torque of the motor 4 in real time based on the measured pressure.

[0071] In emergency situations where ABS is triggered, the motor 4 can switch between forward and reverse rotation at extremely high speeds because the mechanism uses a lead screw 51 for direct drive in conjunction with a high-precision pressure sensor 7. The thrust bearing 65 transmits pressure changes instantaneously to the pressure sensor 7, and the drive controller 10 achieves high-frequency pressure closed-loop control.

[0072] When parking on a long slope, once the motor 4 drives the lead screw 51 to reach the target clamping force, the brake 8 actuates, locking the cylinder 411 of the motor 4 shaft. Even if the motor 4 is de-energized, the braking force can still be maintained through the mechanical structure of the lead screw 51.

[0073] In summary, the brake drive mechanism of this embodiment has high rigidity, compactness and force sensing capability, and can provide a brake drive mechanism with fast response speed, high control precision and small size that can be installed in the wheel hub for brake drive.

[0074] It should be understood that although this specification is described according to various embodiments, not every embodiment or implementation method contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0075] The above descriptions are merely illustrative embodiments of this application and are not intended to limit the scope of the embodiments of this application. Any equivalent changes, modifications, and combinations made by those skilled in the art without departing from the concept and principles of the embodiments of this application should fall within the protection scope of the embodiments of this application.

Claims

1. A brake drive mechanism, characterized in that, include: Motor (4); The reducer (3) has its input end (301) connected to the shaft (41) of the motor (4). The linear movement mechanism (5) includes a lead screw (51) and a lead screw sleeve (54), wherein the lead screw sleeve (54) is disposed outside the lead screw (51) and configured to convert the rotational motion of the lead screw (51) into linear motion; wherein the lead screw (51) is connected to the output end (302) of the reducer (3) via a transmission assembly (2). The encoder (9) is configured to detect the rotational parameters of the motor (4); A pressure sensor (7) is configured to detect the thrust of the lead screw (51); The drive controller (10) is electrically connected to the motor (4) and signal-connected to the encoder (9) and the pressure sensor (7).

2. The brake drive mechanism according to claim 1, characterized in that, The input end (301) and output end (302) of the reducer (3) are located on the same axial end side of itself, and the output end (302) is coaxially arranged around the outside of the input end (301).

3. The brake drive mechanism according to claim 1, characterized in that, The transmission assembly (2) includes a drive wheel (21) and a driven wheel (22) rotatably disposed on the housing assembly (1), the axes of the drive wheel (21) and the driven wheel (22) being parallel; The drive wheel (21) is provided with a motor (4) on one side and a reducer (3) on the other side. The shaft (41) of the motor (4) passes through the drive wheel (21) coaxially and is connected to the input end (301) of the reducer (3). The output end (302) of the reducer (3) is connected to the drive wheel (21). The driven wheel (22) is connected to the lead screw (51) through its shaft hole.

4. The brake drive mechanism according to claim 3, characterized in that, The housing assembly (1) includes: The base (11) has a first mounting groove (111) and a second mounting groove (112) inside it, and a mounting cylinder (1121) is provided at the bottom of the second mounting groove (112). The reducer (3) is installed in the first mounting groove (111), and a pressure sensor (7) is provided in the second mounting groove (112). The mounting cylinder (1121) passes through the inner hole of the pressure sensor (7), and a first bearing (61) is provided inside the mounting cylinder (1121). The inner ring of the first bearing (61) is connected to the end of the lead screw (51). An end seat (12) is connected to the top surface of the base (11) and forms a mounting cavity between the base (11) and the base (11), wherein the drive wheel (21) and the driven wheel (22) are disposed in the mounting cavity.

5. The brake drive mechanism according to claim 4, characterized in that, The reducer (3) is a planetary reducer, which is provided with a sun gear (31), an internal gear ring (32) and a planet carrier (33). The input end (301) of the reducer (3) is formed on one shaft end of the sun gear (31), and the output end (302) of the reducer (3) is formed on one shaft end of the planet carrier (33).

6. The brake drive mechanism according to claim 5, characterized in that, One axial end face of the planetary carrier (33) is bolted to the end face of the drive wheel (21).

7. The brake drive mechanism according to claim 4, characterized in that, The brake drive mechanism further includes: A thrust bearing (65) is connected to one end of the driven wheel (22) and the other end is in close contact with the pressure sensor (7) to transmit the axial thrust of the lead screw (51) to the pressure sensor (7).

8. The brake drive mechanism according to claim 4, characterized in that, The rotating shaft (41) has a cylindrical portion (411) connected to the shaft hole of the inner rotor (42) of the motor (4). The cylindrical portion (411) has an opening facing away from the drive wheel (21). The brake drive mechanism further includes: The housing (15) has its bottom end connected to the end seat (12) and its inner side wall connected to the outer stator (43) of the motor (4). The brake (8) is connected at one end to the inner side of the cylinder (411) and at the other end to the housing (15), and its entire body is located within the axial height range of the outer stator (43), and the brake (8) is also electrically connected to the drive controller (10).

9. The brake drive mechanism according to claim 1, characterized in that, The reducer (3) is a harmonic reducer. The input end (301) of the reducer (3) is formed on one shaft end of the wave generator, and the output end (302) of the reducer (3) is formed on one shaft end of the flex wheel.

10. The brake drive mechanism according to claim 4, characterized in that, The linear movement mechanism (5) further includes: The cylinder body (52) has one end connected to the top surface of the end seat (12), and its inner wall has a first limiting part (521) parallel to the axial direction. The slide rod (53) has a second limiting part (531) on its outer wall. The second limiting part (531) is slidably limited to the first limiting part (521), and the inner wall of the slide rod (53) is connected to the nut sleeve (54). The adapter flange (17) has a central hole through which one end of the cylinder body (52) passes and connects to the cylinder body (52), and it is also connected to the mounting base of the brake device; wherein the brake device includes a brake disc and brake pads arranged opposite to each other, the brake disc being adapted to be connected to a wheel, and the brake pads being floatingly connected to the outer end of the slide rod (53).

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