Parking driving mechanism for EPB parking and driving method

Abstract

The invention discloses a parking driving mechanism for EPB parking. The driving mechanism comprises a driving mechanism shell, a motor and a transmission mechanism. The driving mechanism shell is used for supporting and protecting the whole parking driving mechanism and comprises a shell body, an upper end cover and a motor end cover. The motor is used for outputting torque to the parking driving mechanism; the transmission mechanism is a multi-stage gear set and is used for outputting torque input by the motor through the multi-stage gear set. During use, a current signal is input through a pin of the shell, the motor rotates after receiving the current signal and begins to transmit torque to the motor gear, the motor gear drives the first-stage transmission wheel and the second-stage transmission wheel to rotate through power input by the first-stage transmission wheel and transmit power to the planetary gear set, and the planetary gear set is meshed with an inner gear ring of the shell. And the output shaft is driven to rotate to transmit torque. The invention further discloses a driving method using the parking driving mechanism.

Description

Technical Field

[0001] The present invention belongs to the technical field of automotive braking and parking, and relates to a parking drive mechanism and a driving method for EPB parking. Background Art

[0002] An electronic parking brake is applied to a vehicle braking system. With the increasingly widespread application of vehicle mechanical electronics, new requirements are put forward for the electronic parking brake system.

[0003] The original electronic parking brake system has low transmission efficiency, poor stability and relatively high noise, which will affect the comfort experience of drivers and passengers during parking. By changing the gearbox transmission structure, it is beneficial to improve the transmission efficiency, reduce the noise performance and improve the riding comfort during parking.

[0004] The NVH performance of the product of the prior art CN210623540U is average, the wear resistance is relatively poor, which affects the product life, and the welding stability during the product assembly process is poor, resulting in an increase in the scrap rate of parts. Summary of the Invention

[0005] In order to solve the deficiencies of the prior art, the purpose of the present invention is to provide a parking drive mechanism and a driving method for EPB parking, which can meet the parking requirements of the vehicle, improve the transmission efficiency during vehicle parking transmission, reduce the vibration during the transmission process, reduce the noise performance and improve the riding comfort. The present invention changes the original plastic internal gear ring integrally formed with the housing to embed a metal internal gear ring into the housing by insert injection molding. The metal internal gear ring has an anti-rotation feature, high gear precision and good wear resistance, improves the noise, extends the product life and reduces the scrap rate of parts.

[0006] The present invention provides a parking drive mechanism for EPB parking, and the parking drive mechanism includes: a drive mechanism housing, a motor, and a transmission mechanism;

[0007] The drive mechanism housing is used to support and protect the entire parking drive mechanism, and includes a housing, an upper end cover, and a motor end cover; the upper end cover and the motor end cover are respectively fixedly connected to the housing by welding to form a semi-closed cavity; a housing bushing and a signal transmission interface formed by injection molding are further provided on the housing; the housing bushing is used to connect with the parking brake housing, and the signal transmission interface is used for signal transmission;

[0008] An internal gear ring cooperating with the planetary gear set is installed on the housing. The internal gear ring is fixedly connected to the housing in an injection-molded and embedded form and is wrapped outside the planetary gear set; the internal gear ring is made of metal material;

[0009] The transmission mechanism is a multi-stage gear set, including: a first-stage transmission gear set, a second-stage transmission gear set, and a planetary gear set; the aforementioned gear sets include multiple gears or multiple groups of gears, including a motor gear, a first-stage transmission gear, a second-stage transmission gear, a planetary gear, and an internal gear ring; among them, the first-stage transmission gear set includes the motor gear and the first transmission driven gear in the first-stage transmission gear; the second-stage transmission gear set includes the first transmission driving gear in the first-stage transmission gear and the second transmission driven gear in the second-stage transmission gear; the planetary gear set includes the second transmission driving gear in the second-stage transmission gear, the planetary gear, and the internal gear ring; the transmission mechanism is used to output the torque input by the motor through the multi-stage gear set;

[0010] The housing is also provided with a motor mounting boss and a housing pin; the axes of the motor mounting boss, the housing pin, and the internal gear ring are arranged parallel to each other; both sides of the motor mounting boss are provided with pins, and the pins are used for fixedly connecting with the power pins of the motor, and the pins are fixedly connected with the housing by insert molding.

[0011] The upper end cover is fixedly connected to the housing, and the upper end cover is respectively provided with an axial limit feature of the first-stage transmission gear and an axial limit feature of the second-stage transmission gear for the first-stage transmission gear and the second-stage transmission gear; grease lubrication is adopted between the first-stage transmission gear and the second-stage transmission gear and the upper end cover; a grease cavity is correspondingly arranged on the upper end cover for storing lubricating grease to prevent the grease from splashing out under the action of centrifugal force during the rotation of the gears; the grease cavity is arranged on the inner end surface of the upper end cover by an injection molding integral with the upper end cover.

[0012] The motor and the transmission mechanism are installed in a semi-closed cavity inside the driving mechanism housing;

[0013] The motor is installed between the housing of the driving mechanism housing and the motor end cover, and a wave spring is also arranged between the motor and the motor end cover. The motor is radially positioned and axially positioned through the housing and the wave spring respectively;

[0014] The motor shaft of the motor passes through a through hole preset in the middle of the housing and extends out.

[0015] The motor gear is installed on the motor shaft with an interference fit and can rotate with the rotation of the motor shaft;

[0016] The first-stage transmission wheel is mounted on a housing pin fixed to the housing, and the first-stage transmission wheel can rotate freely on the housing pin; the first-stage transmission wheel further includes a first transmission driven wheel with a larger diameter in the upper part and a first transmission driving wheel with a smaller diameter in the lower part, which are coaxially arranged; the sizes of the first transmission driven wheel and the first transmission driving wheel are determined according to the actual internal space size of the housing, the size of the motor gear, the distance between the motor gear, the sizes and distances of other gears, etc., to ensure that the first transmission driven wheel can be closely meshed with the motor gear without slipping; the first transmission driven wheel is meshed with the motor gear in a matching manner and can rotate with the rotation of the motor gear, thereby driving the first transmission driving wheel to rotate;

[0017] The second-stage transmission wheel is mounted on an end cover pin fixed to the upper end cover, and the second-stage transmission wheel can rotate freely on the end cover pin; the second-stage transmission wheel further includes a second transmission driven wheel with a larger diameter in the upper part and a second transmission driving wheel with a smaller diameter in the lower part, which are coaxially arranged. The second transmission driving wheel is made of metal material and is integrally formed with the second transmission driven wheel by insert molding; the sizes of the second transmission driven wheel and the second transmission driving wheel are determined according to the actual internal space size of the housing, the size of the first transmission driving wheel, and the distance between the first transmission driving wheel, to ensure that the second transmission driven wheel can be closely meshed with the first transmission driving wheel without slipping; the second transmission driven wheel is meshed with the first transmission driving wheel in a matching manner, and when the first transmission driving wheel rotates, it drives the second transmission driven wheel to rotate; the second transmission driving wheel serves as the sun gear of the planetary gear set and is used to drive the planetary gear set to move; a grease storage feature is arranged on the end face of the second transmission driven wheel in the second-stage transmission wheel, and grease is stored through cooperation with the second-stage transmission wheel axial limit feature provided on the upper end cover. When the grease stored in the grease storage feature of the second-stage transmission wheel generates centrifugal force due to the rotation of the gear, the grease will be blocked by the grease storage feature to prevent the grease from being thrown out during rotation.

[0018] The parking drive mechanism includes at least one set of planetary gear sets; the planetary gear sets are arranged at the end of the transmission mechanism, and the transmission mechanism is driven by a motor and transmits torque to a first-stage transmission gear set and a second-stage transmission gear set in sequence, and finally outputs the torque of the drive mechanism through the planetary gear sets; the planetary gear sets further include a second transmission driving wheel, at least three planetary gears, an output shaft assembly, and an internal gear ring; the output shaft assembly is made of metal, and output shaft pins matching the number of the planetary gears are arranged thereon. The planetary gears are coaxially positioned and installed on the output shaft assembly through the output shaft pins and can rotate on the output shaft pins. The output shaft pins are press-fitted into the inner hole of the output shaft assembly with interference. Torque is input from the second transmission driving wheel and finally output through the output shaft; specifically, the torque output feature of the output shaft adopts the form of an inner hole and is coaxially arranged with the planetary gear set; the torque output feature of the output shaft is located at the middle position of the output shaft assembly, and rib features are distributed on the inner hole of the torque output feature of the output shaft. The rib features are concave spline features and cooperate with the protruding spline features of the brake caliper to output torque.

[0019] A space for placing the second transmission driving wheel is formed among multiple planetary gears. The second transmission driving wheel serves as the sun gear of the planetary gear set, meshes with the planetary gears, drives the planetary gears to mesh and rotate in the internal gear ring, and drives the output shaft to rotate and transmit torque.

[0020] The present invention also proposes a parking drive method realized by the above parking drive mechanism. The method includes the following steps:

[0021] Step 1: The motor starts to rotate and generate torque when receiving the current input by the pin, and drives the motor gear press-fitted on the motor shaft to rotate and generate torque.

[0022] Step 2: The motor gear rotates to drive the first transmission driven wheel meshing with it to rotate, and the first transmission driving wheel then transmits the torque to the second transmission driven wheel. Since the second transmission driven wheel and the second transmission driving wheel are integrated by insert molding, the torque is then transmitted to the second transmission driving wheel.

[0023] Step 3: The second transmission driving wheel transmits the torque to the planetary gears. The planetary gears are coaxially arranged on the output shaft assembly, and the planetary gears mesh with the internal gear ring. Since the internal gear ring is injection molded in the housing, it will not rotate. All the planetary gears will drive the output shaft assembly to rotate. Finally, the output shaft assembly rotates and transmits the torque to the protruding spline of the brake caliper that cooperates with the torque output feature of the output shaft, and finally generates a braking torque through the caliper to realize the parking function.

[0024] In the prior art, the internal gear ring in the housing still adopts a plastic structure. During the injection molding process, the accuracy of the internal gear ring cannot be guaranteed, which will lead to poor NVH (noise, vibration, and harshness) performance. Moreover, since the internal gear ring is made of plastic and the planet gears are powder metallurgy metal parts, wear will occur after the parking mechanism is pulled and released multiple times. This will cause the gear backlash to increase, further affecting the NVH performance and the riding comfort. At the same time, the wear will also reduce the lifespan of the parts. In contrast, in the present invention, the direct injection molding solution for the internal gear ring is not considered. Instead, the internal gear ring is made by powder metallurgy process and then injected into the housing through an injection molding solution. The internal gear ring adopts a diamond structure to prevent rotation. The present invention can ensure the accuracy of the internal gear ring and also guarantee wear resistance, which is beneficial to improving the NVH performance, reducing wear, and increasing the transmission efficiency and lifespan of the parts.

[0025] In the previous structure, the housing had no welding positioning features. The present invention adds welding positioning features to the housing, such as Figure 13 As shown, when the motor end cover is welded to the housing, these welding positioning features can cooperate with the outer ring of the motor end cover to prevent the motor end cover from shaking during welding, ensuring the positioning of the parts during welding and improving the stability of the welding process.

[0026] The beneficial effects of the present invention include:

[0027] 1. Improve the noise level during EPB parking and enhance the riding comfort.

[0028] 2. Increase the transmission efficiency during parking, reduce energy loss, and improve the braking efficiency.

[0029] 3. Improve the wear resistance of the planetary gear train in the EPB actuator and extend the lifespan.

[0030] 4. Improve the stability of the welding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0032] Figure 1 It is a schematic diagram of the overall structure of the parking drive mechanism of the present invention.

[0033] Figure 2 It is a schematic diagram of the internal transmission structure of the parking drive mechanism of the present invention.

[0034] Figure 3 It is a schematic diagram of the internal planetary gear set structure of the parking drive mechanism of the present invention.

[0035] Figure 4 This is a sectional view of the parking drive mechanism of the present invention.

[0036] Figure 5 This is a schematic structural diagram of the interior of the parking drive mechanism of the present invention after removing the gears.

[0037] Figure 6 This is a schematic structural diagram of the internal gear ring in the housing of the present invention.

[0038] Figure 7 This is a schematic structural diagram of the housing of the present invention from one angle.

[0039] Figure 8 This is a schematic structural diagram of the housing of the present invention from another angle.

[0040] Figure 9 This is a schematic structural diagram of the interior of the upper end cover of the present invention.

[0041] Figure 10 This is a schematic structural diagram of the secondary transmission wheel of the present invention from one angle.

[0042] Figure 11 This is a schematic structural diagram of the output shaft assembly of the present invention from one angle.

[0043] Figure 12 This is a schematic structural diagram of the planetary gear set of the present invention.

[0044] Figure 13 This is a schematic structural diagram of the welding positioning feature position of the present invention.

[0045] In the figure, 100 - upper end cover, 110 - end cover shaft pin, 120 - axial limit feature of the secondary transmission wheel, 130 - grease cavity, 140 - axial limit feature of the primary transmission wheel, 200 - housing, 210 - internal gear ring, 220 - pin, 230 - housing bushing, 240 - housing shaft pin, 250 - signal transmission mechanism, 260 - motor mounting boss, 270 - welding positioning feature, 300 - motor end cover, 400 - motor gear, 500 - primary transmission wheel, 510 - first transmission driven wheel, 520 - first transmission driving wheel, 600 - secondary transmission wheel, 610 - second transmission driven wheel, 620 - second transmission driving wheel, 630 - grease storage feature, 700 - planetary gear, 800 - output shaft assembly, 810 - output shaft pin, 820 - inner hole of the output shaft assembly, 830 - output torque feature of the output shaft, 840 - rib position feature, 900 - motor, 910 - motor shaft, 1000 - wave spring. Detailed implementation mode

[0046] The present invention will be further described in detail with reference to the following specific embodiments and accompanying drawings. The processes, conditions, experimental methods, etc. for implementing the present invention are all common knowledge and well-known general knowledge in the art except for the specifically mentioned content below, and there is no particular limitation in the present invention.

[0047] As Figure 1 shown, the present invention provides a parking drive mechanism for an EPB parking brake. The drive mechanism includes: a drive mechanism housing, a motor 900, and a transmission mechanism.

[0048] The drive mechanism housing is used to support and protect the entire parking drive mechanism, including a housing 200, an upper end cover 100, and a motor end cover 300.

[0049] The motor 900 is used to output torque to the parking drive mechanism.

[0050] The transmission mechanism is a multi-stage gear set, including: a first-stage transmission gear set, a second-stage transmission gear set, and a planetary gear set; the aforementioned gear set includes multiple gears / groups of gears, specifically including a motor gear 400, a first-stage transmission wheel 500, a second-stage transmission wheel 600, a planetary gear 700, and an internal gear ring 210, as Figure 2 shown; wherein, the first-stage transmission gear set includes the motor gear 400 and the first transmission driven wheel 510 in the first-stage transmission wheel 500; the second-stage transmission gear set includes the first transmission driving wheel 520 in the first-stage transmission wheel 500 and the second transmission driven wheel 610 in the second-stage transmission wheel 600; the planetary gear set includes the second transmission driving wheel 620 in the second-stage transmission wheel 600, the planetary gear 700, and the internal gear ring 210; and is used to output the torque input by the motor 900 through the multi-stage gear set.

[0051] The upper end cover 100 and the motor end cover 300 are fixedly connected to the housing 200 by welding. Specifically, the upper end cover 100 is connected to the housing 200 by laser welding, and the motor end cover 300 is connected to the housing 200 by ultrasonic welding; a housing bushing 230 and a signal transmission mechanism 250 are also provided on the housing, as Figure 5 shown; the housing bushing 230 is used to be connected to the parking brake housing, and the signal transmission mechanism 250 is used for signal transmission.

[0052] As Figure 6 、 Figure 7As shown, a motor mounting boss 260 and a housing pin 240 are further arranged on the housing 200; the axes of the motor mounting boss 260, the housing pin 240, and the internal gear ring 210 are arranged parallel to each other; pins 220 are arranged on both sides of the motor mounting boss 260, and the pins 220 are used for fixedly connecting with the power pins of the motor. The pins 220 are fixedly connected with the housing 200 by insert molding.

[0053] As Figure 9 shown, the upper end cover 100 is fixedly connected with the housing 200. An axial limit feature 140 of the first-stage transmission wheel 500 and an axial limit feature 120 of the second-stage transmission wheel 600 are respectively arranged on the upper end cover 100; grease lubrication is adopted between the first-stage transmission wheel 500 and the second-stage transmission wheel 600 and the upper end cover 100; a grease cavity 130 is correspondingly arranged on the upper end cover 100 for storing lubricating grease to prevent the grease from splashing out under the action of centrifugal force during the rotation of the gears; the grease cavity 130 is arranged on the inner end surface of the upper end cover 100 by being injection-molded integrally with the upper end cover 100.

[0054] The motor 900 and the transmission mechanism are installed inside the driving mechanism housing; the motor 900 is installed between the housing 200 of the driving mechanism housing and the motor end cover 300. A wave spring 1000 is further arranged between the motor 900 and the motor end cover 300. The motor 900 is radially positioned and axially positioned through the housing 200 and the wave spring 1000 respectively; the motor shaft 910 of the motor extends out through a through hole preset in the middle of the housing.

[0055] The transmission mechanism further includes a motor gear 400, a first-stage transmission wheel 500, a second-stage transmission wheel 600, and a planetary gear 700; the motor gear 400 is installed on the motor shaft 910 by interference fit and can rotate with the rotation of the motor shaft 910;

[0056] The first-stage transmission wheel 500 is installed on a housing pin 240 fixed in the housing 200. The first-stage transmission wheel 500 can rotate freely on the housing pin 240. The first-stage transmission wheel 500 includes a first transmission driven wheel 510 and a first transmission driving wheel 520 formed integrally.

[0057] The second-stage transmission wheel 600 is installed on an end cover pin 110 fixed to the upper end cover 100. The second-stage transmission wheel 600 can rotate freely on the end cover pin 110. The second-stage transmission wheel 600 includes a second transmission driven wheel 610 and a second transmission driving wheel 620. As Figure 10As shown, a grease storage feature 630 is arranged on the end face of the second transmission driven wheel 610 in the secondary transmission wheel 600. Grease is stored through cooperation with the axial limit feature 120 of the secondary transmission wheel provided on the upper end cover. When the grease stored in the grease storage feature 630 of the secondary transmission wheel 600 generates centrifugal force due to the rotation of the gear, the grease will be blocked by the grease storage feature 630 to prevent the grease from being thrown out during rotation.

[0058] As Figure 4 shown, the first transmission driven wheel 510 and the first transmission driving wheel 520 are coaxially arranged; the diameter of the first transmission driven wheel 510 is larger than that of the first transmission driving wheel 520; the first transmission driven wheel 510 is meshed with the motor gear 400 in a matching manner and can rotate along with the rotation of the motor gear 400, thereby driving the first transmission driving wheel 520 to rotate.

[0059] The second transmission driven wheel 610 and the second transmission driving wheel 620 are coaxially arranged; the diameter of the second transmission driven wheel 610 is larger than that of the second transmission driving wheel 620; the second transmission driven wheel 610 is meshed with the first transmission driving wheel 520 in a matching manner. When the first transmission driving wheel 520 rotates, it drives the second transmission driven wheel 610 to rotate; the second transmission driving wheel 620 serves as the sun gear of the planetary gear set and is used to drive the planetary gear set to move.

[0060] The planetary gear set further includes a second transmission driving wheel 620, at least three planetary gears 700, an output shaft assembly 800, and an internal gear ring 210; output shaft pins 810 matching the number of planetary gears are arranged on the output shaft assembly 800. The output shaft pins 810 are press-fitted into the inner hole 820 of the output shaft assembly with an interference fit. The planetary gears 700 are positioned through the output shaft pins 810 and placed on the output shaft assembly 800, as Figure 3 、 Figure 12 shown.

[0061] As Figure 11 shown, the output shaft assembly 800 is placed on the plane of the housing 200 and can rotate freely. Torque is input through the second transmission driving wheel 620 and finally output through the torque output feature 830 of the output shaft; the torque output feature 830 of the output shaft is arranged coaxially with the planetary gear set in the form of an inner hole; the torque output feature 830 of the output shaft is located at the middle position of the output shaft assembly 800. Spline features 840 are distributed on the inner hole of the torque output feature 830 of the output shaft. The spline features 840 are concave spline features and cooperate with the protruding spline features of the brake caliper to output torque.

[0062] Inside the housing, an internal gear ring 210 that wraps around the outside of the planetary gear set and meshes with the planetary gear 700 is also fixedly arranged by injection molding.

[0063] A space for placing the second transmission driving wheel 620 is formed among multiple planetary gears 700. The second transmission driving wheel 620 serves as the sun gear of the planetary gear set, meshes with the planetary gears 700, drives the planetary gears 700 to mesh and rotate in the internal gear ring 210, and drives the output shaft assembly 800 to rotate and transmit torque.

[0064] During actual use, a current signal is input through the housing pin 220. After receiving the current signal, the motor 900 rotates and starts to transmit torque to the motor gear 400. The motor gear 400 drives the first-stage transmission wheel 500. The second-stage transmission wheel 600 starts to rotate by the power input from the first-stage transmission wheel 500 and transmits power to the planetary gear set. The planetary gear set meshes with the internal gear ring 210 of the housing and drives the output shaft assembly 800 to rotate and transmit torque.

[0065] As Figure 5 shown, on the housing 200, there are an internal gear ring 210, pins 220, a housing bushing 230, and a housing pin shaft 240. These parts are all injection molded into the housing 200. Among them, the internal gear ring 210 of the housing of the present invention is made of powder metallurgy material and injection molded into the housing 200. This can effectively improve the wear resistance of the previous solution that uses the same plastic material as the housing, and at the same time can also improve the noise level during gear transmission. In addition, it can also improve the transmission efficiency and greatly improve the performance of this mechanism.

[0066] As Figure 5 and Figure 6 shown, for the internal gear ring 210 of the present invention, instead of considering the direct injection molding solution, the internal gear ring 210 is made by powder metallurgy process and then injection molded into the housing 200 through an injection molding solution. The internal gear ring 210 adopts a diamond structure, which can prevent the internal gear ring 210 from rotating after being injection molded into the housing and play an anti-rotation role. Moreover, the minimum thickness of the internal gear ring 210 is 2 mm, which can ensure the precision of the internal gear ring 210. This is beneficial to improving the NVH performance. And by adopting a metal structure, it can reduce wear, improve the transmission efficiency and service life of parts.

[0067] In addition, the previous structure housing had no welding positioning features. The present invention adds welding positioning features on the housing 200. As Figure 13 shown, the welding positioning feature 270 is located at the connection between the housing 200 and the motor end cover 300, which can ensure the positioning of parts during welding and improve the stability of the welding process.

[0068] The protection scope of the present invention is not limited to the above embodiments. Without departing from the spirit and scope of the inventive concept, all changes and advantages that can be conceived by those skilled in the art are included in the present invention, and the appended claims are taken as the scope of protection.

Claims

1. A parking drive mechanism for EPB parking, characterized in that, The driving mechanism includes: a driving mechanism housing, a motor (900), and a transmission mechanism; The driving mechanism housing is used to support and protect the entire parking driving mechanism, and includes a housing (200), an upper end cover (100), and a motor end cover (300); The motor (900) is used to output torque to the parking driving mechanism; The transmission mechanism is a multi-stage gear set, including: a first-stage transmission gear set, a second-stage transmission gear set, and a planetary gear set; and outputs the torque input by the motor (900) through the multi-stage gear set.

2. The parking drive mechanism according to claim 1, characterized in that, The gear set includes a motor gear (400), a first-stage transmission wheel (500), a second-stage transmission wheel (600), a planetary gear (700), and an internal gear ring (210); wherein, the first-stage transmission gear set includes the motor gear (400) and the first transmission driven wheel (510) in the first-stage transmission wheel (500); the second-stage transmission gear set includes the first transmission driving wheel (520) in the first-stage transmission wheel (500) and the second transmission driven wheel (610) in the second-stage transmission wheel (600); the planetary gear set includes the second transmission driving wheel (620) in the second-stage transmission wheel (600), the planetary gear (700), and the internal gear ring (210).

3. The parking drive mechanism according to claim 1, characterized in that, The upper end cover (100) and the motor end cover (300) are fixedly connected to the housing (200) by welding and form a semi-closed cavity, and the motor (900) and the transmission mechanism are arranged in the cavity; and / or, The parking driving mechanism includes at least one set of planetary gear sets; the planetary gear sets are arranged at the end of the transmission mechanism, and the transmission mechanism is driven by the motor (900) and transmits the torque to the first-stage transmission gear set and the second-stage transmission gear set in sequence, and finally outputs the torque of the driving mechanism through the planetary gear sets.

4. The parking drive mechanism according to claim 1, characterized in that, An internal gear ring (210) that cooperates with the planetary gear set is installed on the housing (200), and the internal gear ring (210) is fixedly connected to the housing (200) in an injection-molded and inlaid form; the internal gear ring (210) is made of metal material.

5. The parking drive mechanism according to claim 4, characterized in that, The housing (200) is also provided with a motor mounting boss (260) and a housing pin (240); the axes of the motor mounting boss (260), the housing pin (240), and the internal gear ring (210) are arranged parallel to each other; Pin feet (220) are arranged on both sides of the motor mounting boss (260), and the pin feet (220) are used to fixedly connect with the power pin feet of the motor (900), and the pin feet (220) are fixedly connected to the housing (200) by insert injection molding.

6. The parking drive mechanism according to claim 3, characterized in that, On the upper end cover (100), there are respectively arranged an axial limit feature (140) of the first-stage transmission wheel (500) and an axial limit feature (120) of the second-stage transmission wheel (600); grease lubrication is adopted between the first-stage transmission wheel (500), the second-stage transmission wheel (600) and the upper end cover (100); a grease cavity (130) is correspondingly arranged on the upper end cover (100) for storing lubricating grease; the grease cavity (130) is arranged on the inner end face of the upper end cover (100) by an injection molding integral with the upper end cover (100).

7. The parking drive mechanism according to claim 2, characterized in that, The first-stage transmission wheel (500) is installed on a housing pin (240) fixed to the housing (200), and the first-stage transmission wheel (500) can rotate freely on the housing pin (240); the first-stage transmission wheel (500) includes an integrally formed first transmission driven wheel (510) and a first transmission driving wheel (520), and the first transmission driven wheel (510) and the first transmission driving wheel (520) are coaxially arranged; the first transmission driven wheel (510) is meshed with the motor gear (400) in a matching manner and can rotate with the rotation of the motor gear (400), so as to drive the first transmission driving wheel (520) to rotate.

8. The parking drive mechanism according to claim 2, characterized in that, The second-stage transmission wheel (600) includes two-stage gear structures, namely a second transmission driven wheel (610) and a second transmission driving wheel (620). The two-stage gears are coaxially arranged. The second transmission driving wheel (620) is made of metal material and is injection molded integrally with the second transmission driven wheel (610) in an insert form; on the end face of the second transmission driven wheel (610) in the second-stage transmission wheel (600), there is arranged a grease storage feature (630), and grease is stored through cooperation with the axial limit feature (120) of the second-stage transmission wheel arranged on the upper end cover. When the grease in the grease storage feature (630) of the second-stage transmission wheel (600) generates centrifugal force due to the rotation of the gears, the grease will be blocked by the grease storage feature (630) to prevent the grease from being thrown out during the rotation process.

9. The parking drive mechanism according to claim 2, characterized in that, The planetary gear set is arranged at the end of the transmission mechanism. The planetary gear set includes a second transmission driving wheel (620), an internal gear ring (210), planetary gears (700), and an output shaft assembly (800). The planetary gears (700) are coaxially installed on the output shaft pin (810) of the output shaft assembly (800) and can rotate freely. The output shaft pin (810) is press-fitted into the inner hole (820) of the output shaft assembly with an interference fit. The output shaft assembly (800) is placed on the plane of the housing (200) and can rotate freely. Torque is input through the second transmission driving wheel (620) and finally output through the output torque feature (830) of the output shaft; the output torque feature (830) of the output shaft is arranged coaxially with the planetary gear set in the form of an inner hole; the output torque feature (830) of the output shaft is located at the middle position of the output shaft assembly (800), and rib features (840) are distributed on the inner hole. The rib features (840) are concave spline features, which cooperate with the protruding spline features of the brake caliper to output torque. The output shaft assembly (800) is made of metal material. Three or more planetary gears (700) are installed on the output shaft assembly (800) to provide output torque for the output torque feature (830) of the output shaft.

10. A parking drive method implemented by using the parking drive mechanism according to any one of claims 1-9, characterized in that, The method includes the following steps: Step 1: The motor (900) starts to rotate and generate torque when it receives the current input from the pin (220), and drives the motor gear (400) press-fitted on the motor shaft (910) to rotate and generate torque. Step 2: The motor gear (400) rotates to drive the first transmission driven wheel (500) meshing with it to rotate. The first transmission driving wheel (520) then transmits the torque to the second transmission driven wheel (610), and further transmits it to the second transmission driving wheel (620). Step 3: The second transmission driving wheel (620) transmits the torque to the planetary gears (700). The planetary gears (700) are coaxially arranged on the output shaft assembly (800), and the planetary gears (700) mesh with the internal gear ring (210). The planetary gears (700) drive the output shaft assembly (800) to rotate. Finally, the output shaft assembly (800) rotates and transmits the torque to the protruding spline of the brake caliper that cooperates with the output torque feature (830) of the output shaft. Finally, the brake caliper generates a braking torque to achieve the parking function.

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