Driving and braking integrated electric wheel system adopting multi-connecting-rod type braking

Abstract

The invention discloses a driving and braking integrated electric wheel system with a multi-connecting-rod type braking function. A wheel unit, a planetary gear reducer, a multi-connecting-rod type braking system, a hub motor, a wheel support and an electromagnetic clutch are integrated. According to the system, the working state of a hub motor is controlled to be matched with an electromagnetic clutch to conduct multi-mode switching, the five working modes of driving, pure electric braking, composite braking, reversing braking and parking braking can be achieved, a gear ring structure is machined on the inner edge of a rim of a wheel unit, the utilization rate of the space in a wheel is increased, and the service life of the wheel unit is prolonged. Meanwhile, the hub motor serves as a multiplex power source for driving and braking work and is matched with a multi-connecting-rod transmission scheme adopted by the braking system, the driving and braking integrated function can be achieved, the energy utilization rate of the whole vehicle is improved, a conventional braking execution motor and a speed reducer thereof are omitted, sprung mass is greatly reduced, and the cost is reduced. The control performance and the driving smoothness of the whole vehicle can be improved, and great significance is achieved for high-integration and modularization research of the distributed driving technology.

Description

Technical Field

[0001] The present invention relates to an integrated drive and brake electric wheel system for electric vehicles, and in particular to an integrated drive and brake electric wheel system that integrates a wheel unit, a planetary gear reducer, a multi-link brake system, a hub motor, a wheel bracket, and an electromagnetic clutch, can realize power reuse of the drive and brake systems, and has multiple working modes. Background Art

[0002] The intelligent chassis roadmap for passenger electric vehicles, released in 2022, stipulates that intelligent chassis will develop toward distributed actuators and integrated control. By 2025, integrated control of both lateral and longitudinal drive and braking will be achieved. To this end, the drive system configuration is evolving from centralized to distributed. Currently, the key research focus for universities and companies is how to achieve highly integrated and modular designs that combine in-wheel motors with braking and suspension systems to form a compact electric wheel system.

[0003] Currently, the mainstream configuration of electric wheel systems utilizes an in-wheel motor (IWM) + electro-mechanical brake (EMB) system for an integrated design. However, since the EMB system itself requires a separate actuator motor and reducer for operation, this results in a large space requirement, excessive unsprung mass, poor ride smoothness and handling stability, and difficulty in arranging redundant safety solutions. With the continuous advancement of in-wheel motor technology, the actuator motor and reducer used in EMB systems often only operate under specific braking conditions. Under other conditions, they do not benefit vehicle performance and instead increase vehicle weight, reducing vehicle economics. In-wheel motors inherently have a four-quadrant operating characteristic range and require a planetary gear reducer for operation. If the vehicle's drive and brake systems could share a single "motor + reducer" mechanism, forming an integrated drive and brake system, achieving power reuse for both drive and brake operations while meeting the various functional requirements of existing system solutions, this would significantly save wheelside space and reduce unsprung mass, helping to address the difficulties in arranging redundant solutions and achieving lightweighting in electric wheel systems.

[0004] In summary, the current automotive industry urgently needs an electric wheel system with a highly integrated design that can realize power reuse for driving and braking and has a multi-mode switching function and an integrated driving and braking system. Summary of the Invention

[0005] Based on the background of the times, this paper designs an integrated drive-braking electric wheel system that integrates a wheel unit, a wheel bracket, a hub motor, a planetary gear reducer, an electronic wedge brake, and an electromagnetic clutch, which can realize power reuse of the drive and brake systems and has multiple working modes.

[0006] The technical solution of the present invention is: a multi-link brake drive-brake integrated electric wheel system, characterized by comprising:

[0007] A wheel unit (100) includes a tire (110), a rim (120), and a brake disc (130), and is mainly used to support vehicle load and transmit driving and braking torques. A gear ring structure is directly processed on the inner edge of the rim and cooperates with a planetary gear reducer to improve the utilization rate of the space inside the wheel.

[0008] The planetary gear reducer (200) comprises a stepped shaft (210), a locking nut (220), a sun gear (230), a planet carrier (240), and a planetary gear (250), and works in conjunction with a gear ring structure on the inner edge of a wheel rim of a wheel unit (100) to transmit torque output by a hub motor to achieve deceleration and torque increase, and works in conjunction with an electromagnetic clutch to achieve drive and brake multi-mode switching and power reuse through a planetary gear train transmission;

[0009] A multi-link brake system (300) includes a multi-link brake actuator (310), a ball nut (320), a ball screw (330), a latch (340), and a positioning washer (350). Each multi-link brake system (300) is equipped with two multi-link brake actuators (310), which are arranged symmetrically in an upper and lower direction and use a multi-link transmission scheme to perform a braking function, and are used to provide a braking torque in a braking condition of the multi-link brake integrated drive and brake electric wheel system.

[0010] The wheel hub motor (400) adopts a low-speed inner rotor motor, including a wheel hub motor rotor (410), a wheel hub motor stator and a housing (420), and is mainly used to provide the driving and braking operating torque of the multi-link brake integrated electric wheel system, and serves as the sole power source for driving and braking. The wheel hub motor is integrally mounted and fixed in the deep hole in the middle of the wheel bracket;

[0011] The wheel bracket (500) is mainly used to connect the multi-link brake drive-brake integrated electric wheel system and the vehicle suspension to transmit force and torque. A deep hole is provided in the middle for installing the wheel hub motor. The upper and lower ends are respectively provided with guide rail structures to play a guiding role and limit the movement trajectory of the brake support in the multi-link brake system (300);

[0012] The electromagnetic clutch (600) comprises a roller (610), a clutch outer hub (620), a clutch inner hub (630), a movable coil seat (640), an electromagnetic clutch upper cover (650), a movable coil winding (660), an electromagnetic clutch return rubber block (670), a fixed coil winding (680), and a locking latch (690). The electromagnetic clutch (600) is fixed to the housing of the hub motor (400) by screws. The hub motor (400) cooperates with the hub motor (400) to control the rotational freedom of the planetary carrier of the planetary gear reducer (200) and realize the switching of driving and braking multiple modes.

[0013] Preferably, the wheel unit (100) is characterized in that it comprises:

[0014] Tire (110), used to carry the load of the entire vehicle and transmit ground force and torque;

[0015] The rim (120) is mounted on the front end of the stepped shaft of the planetary gear reducer (200) through a positioning through-hole provided in the middle of the spoke and is positioned by a bearing. A gear ring structure is machined on the inner edge of the rim to cooperate with the planetary gear reducer (200) for operation, and a bolt hole is provided on the outer edge for mounting a brake disc.

[0016] The brake disc (130) is mounted on the outer edge of the wheel rim (120) by means of bolts, adopts inner ring braking, and leaves a braking gap with the friction lining of the multi-link brake system (300).

[0017] Preferably, the planetary gear reducer (200) is characterized in that it comprises:

[0018] The stepped shaft (210) is mainly used to connect and carry the various components in the planetary gear reducer (200) and provides a positioning function through the shaft shoulder. The front end is provided with a thread, the middle part is provided with a keyway for installing a flat key, and the rear end is provided with a spline for connecting with the hub motor (400) to transmit torque.

[0019] A locking nut (220) is mounted on the front threaded section of the stepped shaft (210) and cooperates with the bearing to axially fix the rim (120) and the stepped shaft (210);

[0020] The sun gear (230) has a keyway at its center, is connected to the stepped shaft (210) via a flat key, is axially positioned using a shaft shoulder, and is meshed with the planetary gear for transmission;

[0021] The planetary gear (250) is mounted on the planetary carrier via a bearing and is axially fixed via a nut and a lock ring;

[0022] The planet carrier (240) is mounted on the stepped shaft (210) via a bearing and positioned via a shaft shoulder. A planetary gear (250) is mounted on the front end and is driven by the meshing relationship between the planetary gear (250) and the sun gear (230). An external spline is machined in the middle portion and is connected to the ball screw of the multi-link brake system (300) to transmit torque. An externally extending hollow shaft structure is provided at the rear end to connect to the electromagnetic clutch (600).

[0023] Preferably, the multi-link brake system (300) is characterized in that it comprises:

[0024] The ball screw (330) has a through hole in the middle portion thereof for passing through the stepped shaft (210) and is connected to the spline section in the middle portion of the planetary carrier (240). Axial and radial positioning is achieved by means of bearings and locking rings.

[0025] The ball nut (320) cooperates with the ball screw (380). When the ball screw (380) rotates around the axis, the ball nut (370) moves in a axial direction without rotating itself.

[0026] The multi-link brake actuator (310) is the main part of the multi-link brake system (300), including a friction lining (311), a brake caliper (312), a brake rocker arm (313), a brake guide rod (314), a return spring (315), a brake support (316), a latch (317), and a positioning gasket (318). Each multi-link brake system (300) is equipped with two multi-link brake actuators (310), which are arranged symmetrically in an upper and lower direction. The position relationship between the brake caliper (312), the brake rocker arm (313), and the brake guide rod (314) is A-shaped. The multi-link transmission scheme is used to perform the braking function. The whole is respectively installed on the upper and lower sides of the ball nut (320), and the braking function is achieved by utilizing the translation of the ball nut (320).

[0027] Preferably, the multi-link brake actuator (300) is characterized by comprising:

[0028] The brake support (316) is fixedly connected to the ball nut (320) and is mainly used to carry and connect the various components of the multi-link brake actuator (300). A guide groove is provided in the middle to cooperate with the guide rail provided on the wheel bracket (500). When the ball screw (380) rotates around the axis, it moves axially along with the ball nut (370). Two cylindrical pin seats are provided on the top to hook with the spring;

[0029] There are two brake rocker arms (313), which are mounted on the brake support (316) through a cylindrical pin at the bottom. A cylindrical pin hole and an opening structure are provided in the middle for mounting a latch and a brake guide rod. A cylindrical pin is provided at the top for mounting a brake caliper. A spring hook is provided on the inner side. When viewed along the axial direction of the stepped shaft (210), the overall structure is symmetrical and the shape is relatively wide to ensure good mechanical properties under braking conditions.

[0030] There are two brake calipers (312) installed on the top of the brake rocker arm (313) through a cylindrical pin. When the brake is in operation, the brake calipers (312) move closer to each other as the brake rocker arm (313) swings. A groove is provided in the middle for mounting a friction lining.

[0031] There are two friction linings (311) installed in a groove provided in the middle of the brake caliper (312). The friction linings (311) are horseshoe-shaped and have a braking gap with the brake disc (130) in a non-braking condition.

[0032] There are two brake guide rods (314), each with a cylindrical pin hole at both ends, which are installed in the opening structure in the middle of the brake rocker arm (313) through a pin, and play a guiding role in the movement trajectory of the two brake rocker arms (313). The size of the brake guide rods (314) must ensure that they will not interfere with the brake disc (130) during movement;

[0033] A latch (317) is mounted in a cylindrical pin hole provided in the middle of the brake rocker arm (313), with both ends fixed by locking rings to provide radial positioning of the cylindrical pin hole of the brake guide rod (314);

[0034] There are four positioning washers (318) for providing axial positioning of the cylindrical pin hole of the brake guide rod (314);

[0035] There are two return springs (315) installed on the spring hooks provided on the brake rocker arm (313) and the brake support (316). When the brake is released, the return springs (315) are used to assist the return action of the brake rocker arm (313) to avoid incomplete separation of the friction lining (311) and the brake disc (130) due to insufficient return of the brake rocker arm (313).

[0036] Preferably, the hub motor (400) is characterized in that it comprises:

[0037] The hub motor rotor (410) has an output end connected to the rear end of the stepped shaft (210) via a spline for transmitting torque;

[0038] The hub motor stator and housing (420) are provided with threaded holes on the housing for mounting the electromagnetic clutch (600).

[0039] Preferably, the electromagnetic clutch (600) is characterized by comprising:

[0040] A roller (610) is mounted between the clutch outer hub and the clutch inner hub;

[0041] The clutch outer hub (620) is the main part of the electromagnetic clutch (600), with a through-hole structure in the middle and multiple arc grooves on the inner side for mounting the roller (610). Lugs are provided on both sides and are connected to the stator of the hub motor and the outer shell (420) by screws. A fixed coil seat is provided at the upper end for mounting the fixed coil winding and a small hole is provided for routing the wires.

[0042] The clutch inner hub (630) is an open annular structure as a whole, with multiple arc grooves on the outside for mounting the roller (610), and the inside is transitionally matched with the outside of the hollow shaft extending outward from the rear end of the planetary carrier (240), and a wedge structure is provided at the opening;

[0043] The movable coil seat (640) is arranged just above the fixed coil seat at the upper end of the clutch outer hub (620), has a deep hole in the middle and a bolt hole at the top for installing a locking pin;

[0044] The electromagnetic clutch upper cover (650) is mainly used to protect the upper components of the electromagnetic clutch (600), has a threaded bottom, and is installed on the top of the clutch outer hub (620);

[0045] A movable coil winding (660) is mounted on the movable coil base (640), and a magnetic field can be generated by energizing the movable coil winding (660);

[0046] The electromagnetic clutch return rubber block (670) has a through hole at its center and is installed between the movable coil winding (660) and the fixed coil seat at the upper end of the clutch outer hub (620). When the electromagnetic clutch (600) is in a locked state, the electromagnetic clutch return rubber block (670) is used to separate the movable coil winding (660) from the fixed coil seat at the upper end of the clutch outer hub (620).

[0047] The fixed coil winding (680) is mounted on the fixed coil seat at the upper end of the clutch outer hub (620) and has the same coil winding direction as the movable coil winding (660). When the fixed coil winding (680) and the movable coil winding (660) are energized in the same direction, the magnetic fields generated by the upper end of the fixed coil winding (680) and the lower end of the movable coil winding (660) are of opposite polarity and attract each other, causing the movable coil seat (640) to move downward and approach the fixed coil seat at the upper end of the clutch outer hub (620) and compress the electromagnetic clutch return rubber block (670). When the fixed coil winding (680) and the movable coil winding (660) are not energized, the magnetic field disappears. Due to the action of the electromagnetic clutch return rubber block (670), the separated movable coil winding (660) is separated from the fixed coil seat at the upper end of the clutch outer hub (620);

[0048] The locking pin (690) has a threaded hole on the top and is connected to the movable coil seat (640) by screws. The bottom is provided with a wedge structure. The shaft section passes through the fixed coil seat at the upper end of the clutch outer hub (620) and is arranged just above the opening of the clutch inner hub (630). When the fixed coil winding (680) and the movable coil winding (660) are energized in the same direction, due to the effect of the magnetic field, the movable coil seat (640) moves downward close to the fixed coil seat at the upper end of the clutch outer hub (620), causing the locking pin (690) to move to the upper end of the clutch inner hub (630). The electromagnetic clutch (600) is moved downward and inserted into the opening of the clutch inner hub (630). At this time, the clutch inner hub (630) is in the middle position and cannot rotate. At the same time, the inner diameter becomes larger and does not contact the outer ring of the hollow shaft extending outward from the rear end of the planetary carrier (240). When the electromagnetic clutch (600) is in a locked state, the fixed coil winding (680) and the movable coil winding (660) are not energized. Due to the action of the electromagnetic clutch return rubber block (670), the locking pin (690) moves upward and disengages from the opening of the clutch inner hub (630).

[0049] Preferably, it is characterized in that the working state of the electromagnetic clutch (600) includes:

[0050] In the locked state, the fixed coil winding (680) and the movable coil winding (660) are not energized, and there is no magnetic field. The movable coil seat (640) and the fixed coil seat at the upper end of the clutch outer hub (620) are separated due to the action of the electromagnetic clutch return rubber block (670), and the locking pin (690) is disengaged from the opening of the clutch inner hub (630). At this time, the inner ring of the clutch inner hub (630) is in contact with the outer ring of the hollow shaft extending outward from the rear end of the planetary carrier (240). When the planetary carrier (240) attempts to rotate, it will drive the clutch inner hub (630) to rotate. Due to the action of the roller (610), the inner diameter of the clutch inner hub (630) will become smaller, clamping the hollow shaft extending outward from the rear end of the planetary carrier (240) to generate friction, and this process has a self-amplifying effect, which is sufficient to prevent the planetary carrier (240) from rotating, forming a locking effect.

[0051] Active state, at this time, the fixed coil winding (680) and the movable coil winding (660) are energized and the current direction is the same. At this time, the magnetic fields generated by the upper end of the fixed coil winding (680) and the lower end of the movable coil winding (660) are opposite in polarity and attract each other, causing the movable coil seat (640) to move downward to approach the fixed coil seat at the upper end of the clutch outer hub (620) and compress the electromagnetic clutch return rubber block (670). The locking pin (690) will move downward and insert into the opening of the clutch inner hub (630), forcing the clutch inner hub (630) to be in the middle position and unable to rotate. At the same time, the inner diameter becomes larger and does not contact the outer ring of the hollow shaft extending outward from the rear end of the planetary carrier (240). At this time, the planetary carrier (240) can rotate freely.

[0052] Preferably, the feature is that the rotation direction reference system and the working mode include:

[0053] A rotation direction reference system is defined, wherein when the wheel unit (100) moves forward, the direction of the wheel unit (100) around its rotation axis is the positive rotation direction;

[0054] The operating modes of the multi-link brake integrated drive and brake electric wheel system are mainly divided into driving mode, pure electric braking mode, compound braking mode, reverse braking mode, and parking brake mode;

[0055] In the driving mode, the wheel hub motor (400) operates in the third quadrant, which is a negative speed and negative torque state, and the electromagnetic clutch (600) is in a locked state. At this time, the sun gear (230) rotates in reverse, and the gear ring on the inner edge of the rim (120) rotates forward, that is, the wheel unit (100) rotates forward, the planet carrier (240) is stationary, and the vehicle travels forward. If the wheel hub motor (400) operates in the first quadrant, which is a positive speed and positive torque state, the vehicle travels in reverse, and the transmission principle is the same;

[0056] In the pure electric braking mode, the wheel hub motor (400) operates in the second quadrant and is in a high efficiency range under medium and low vehicle speed braking conditions. The electric brake alone is sufficient to meet the braking requirements, and the energy utilization rate is higher. At this time, the wheel hub motor (400) is in a negative speed and positive torque state, and the electromagnetic clutch (600) is in a locked state. The sun gear (230) rotates in reverse and is in a deceleration state, and the gear ring on the inner edge of the rim (120) rotates in a forward direction and is in a deceleration state. That is, the wheel unit (100) rotates in a forward direction and is in a deceleration state, the planetary carrier (240) is stationary, and the vehicle is in a braking energy recovery state.

[0057] Compound braking mode is primarily used in braking scenarios at very low speeds and high speeds with high braking intensity. Due to the motor's operating characteristics and efficiency limitations in these scenarios, electric braking alone is insufficient to meet braking requirements. Therefore, mechanical friction braking is required in addition to electric braking to meet braking requirements. Compound braking mode is divided into efficiency-based compound braking mode and energy-saving compound braking mode, depending on whether the ratio of electric braking torque to mechanical friction braking torque is adjustable. This mode can be set according to the driver's preference.

[0058] The reverse braking mode works under the braking condition of the vehicle in reverse driving, because the hub motor (400) works in the fourth quadrant at this time, but because the vehicle speed is usually very low under the reverse braking condition, the hub motor (400) works in the low efficiency range, resulting in a low intensity of the electric brake alone, and completing a fast and efficient reverse braking action, so mechanical friction braking is introduced. At this time, the hub motor (400) is in a positive speed and negative torque state, and the electromagnetic clutch (600) is switched to an active state. The sun gear (230) rotates forward and is in a deceleration state, and the gear ring on the inner edge of the rim (120) rotates reversely and is in a deceleration state, that is, the wheel unit (100) is reversed and in a deceleration state, and the planetary carrier (240) is reversed, which will drive the ball screw (330) to reverse, and the ball nut (320) and the brake support (316) move backward. At this time, the friction lining (311) on the front side first contacts the brake disc (130). , so that the front brake rocker arm (313) swings forward, and under the action of the brake guide rod (314), the rear brake rocker arm (313) also swings forward, and finally the front and rear brake calipers (312) approach each other, and the multi-link brake actuator (310) clamps the brake disc (130) to achieve reverse braking. When the brake is canceled, the hub motor (400) is controlled to work in the first quadrant, which is a positive speed and positive torque. At this time, the planetary carrier (240) rotates forward, which will drive the ball screw (330) to rotate forward, and the ball nut (320) and the brake support (316) move forward until they return to the initial position. At the same time, the brake rocker arm (313) completes the return to the center under the action of the return spring (315), and the multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, so that the planetary carrier (240) is stationary, and the brake is released;

[0059] The parking brake mode is mainly divided into three types: flat ground parking brake, slope parking brake with the vehicle head facing up, and slope parking brake with the vehicle head facing down;

[0060] When the vehicle is in a flat ground parking brake condition, the vehicle is stationary. At this time, the hub motor (400) is controlled to work in the first quadrant, and the working point torque is small. At the same time, the electromagnetic clutch (600) is in an active state. At this time, the sun gear (230) rotates forward. Since the wheel unit (100) belongs to a large inertia system, the inner ring gear structure of the rim (120) will be accompanied by slight shaking and can be regarded as stationary. The planetary carrier (240) rotates forward, which will drive the ball screw (330) to rotate forward. The ball nut (320) and the brake support (316) move forward. At this time, the rear friction lining (311) first contacts the brake disc (130), thereby causing the rear brake rocker arm (313) to swing backward. Under the action of the brake guide rod (314), the front brake rocker arm (313) also swings backward, and finally the front and rear brake calipers (312) approach each other, and the multi-link brake actuator (310) clamps the brake disc (1 30), after being fully clamped, the electromagnetic clutch (600) switches to a locked state to realize the flat ground parking brake function. When the brake is canceled, the electromagnetic clutch (600) is first controlled to switch to an active state, and the hub motor (400) is controlled to work in the third quadrant, which is a negative speed and negative torque. The sun gear (230) reverses. Since the vehicle belongs to a large inertia system, it can be regarded as stationary in a short time, that is, the inner ring gear of the rim (120) is stationary. At this time, the planetary carrier (240) reverses, which will drive the ball screw (330) to reverse, and the ball nut (320) and the brake support (316) move backward until they return to the initial position. At the same time, the brake rocker (313) completes the return to the original position under the action of the return spring (315), and the multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to a locked state, so that the planetary carrier (240) is stationary, and the brake is released;

[0061] When the vehicle is in a parking brake condition on a slope with the front of the vehicle facing upward, the vehicle tends to reverse backward, which can be compared to the reverse braking mode. The hub motor (400) is controlled to be in the fourth quadrant. At this time, the hub motor (400) is in a positive speed negative torque state. At the same time, the electromagnetic clutch (600) is switched to an active state. The sun gear (230) rotates forward and is in a deceleration state. The gear ring on the inner edge of the rim (120) rotates reversely and is in a deceleration state. That is, the wheel unit (100) rotates reversely and is in a deceleration state. The planetary carrier (240) rotates reversely, which drives the ball screw (330) to reverse. The ball nut (320) and the brake support (316) move backward. At this time, the friction lining (311) on the front side first contacts the brake disc (130), thereby causing the brake rocker arm (313) on the front side to swing forward. Under the action of the brake guide rod (314), the brake rocker arm (313) on the rear side also swings forward, and finally the front and rear wheels are reversed. The two brake calipers (312) are close to each other, and the multi-link brake actuator (310) clamps the brake disc (130) to achieve parking brake on a slope with the front of the vehicle facing upward. When the brake is released, the hub motor (400) is controlled to work in the first quadrant, which is positive speed and positive torque. The sun gear (230) rotates forward. Since the vehicle belongs to a large inertia system, it can be regarded as stationary in a short period of time, that is, the inner ring gear of the rim (120) is stationary. At this time, the planetary carrier (240) rotates forward, which will drive the ball screw (330) to rotate forward. The ball nut (320) and the brake support (316) move forward until they return to the initial position. At the same time, the brake rocker (313) completes the return to the original position under the action of the return spring (315). The multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, making the planetary carrier (240) stationary, and achieving brake release.

[0062] When the vehicle is in a parking brake condition on a slope with the front of the vehicle facing downward, the vehicle tends to move forward, which can be compared to a compound braking mode. The hub motor (400) is controlled to be in the second quadrant. At this time, the hub motor (400) is in a negative speed positive torque state. At the same time, the electromagnetic clutch (600) is switched to an active state. The sun gear (230) rotates in reverse and is in a deceleration state. The gear ring on the inner edge of the rim (120) rotates forward and is in a deceleration state. That is, the wheel unit (100) rotates forward and is in a deceleration state. The planetary carrier (240) rotates forward, which will drive the ball screw (330) to rotate forward. The ball nut (320) and the brake support (316) move forward. At this time, the friction lining (311) on the rear side first contacts the brake disc (130), thereby causing the brake rocker arm (313) on the rear side to swing backward. Under the action of the brake guide rod (314), the brake rocker arm (313) on the front side also swings backward, and finally the front and rear sides are rotated in a reverse direction. The two brake calipers (312) are close to each other, and the multi-link brake actuator (310) clamps the brake disc (130) to achieve parking brake on a slope with the front of the vehicle facing downward. When the brake is released, the hub motor (400) is controlled to operate in the third quadrant, which is a negative speed and negative torque. The sun gear (230) rotates forward. Since the vehicle belongs to a large inertia system, it can be regarded as stationary for a short time, that is, the inner ring gear of the rim (120) is stationary. At this time, the planetary carrier (240) reverses, which will drive the ball screw (330) to reverse, and the ball nut (320) and the brake support (316) move backward until they return to the initial position. At the same time, the brake rocker (313) completes the return to the original position under the action of the return spring (315). The multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, making the planetary carrier (240) stationary, and achieving brake release.

[0063] Preferably, the compound braking mode of the multi-link brake integrated driving and braking electric wheel system is characterized by comprising:

[0064] The compound braking mode is divided into an efficiency-type compound braking mode and an energy-saving compound braking mode according to whether the ratio of the electric braking torque to the mechanical friction braking torque is adjustable, and can be set according to the driver's own preferences;

[0065] In the performance-oriented compound braking mode, the electric braking torque and the mechanical friction braking torque are distributed in a fixed ratio, and the proportion of the mechanical braking torque to the total braking torque reaches the maximum. The main focus is on vehicle driving performance and driving pleasure.

[0066] In energy-saving compound braking mode, electric braking torque and mechanical friction braking torque are distributed in a variable ratio. While meeting braking requirements, as much braking torque as possible is allocated to electric braking. This achieves energy-saving driving through brake energy recovery and improves vehicle economy.

[0067] The invention discloses a control method for an efficient composite braking mode, wherein the hub motor (400) is controlled to be in the second quadrant, at which time the hub motor (400) is in a negative speed and positive torque state, and the electromagnetic clutch (600) is controlled to be in an active state throughout the entire process, the sun gear (230) rotates in the reverse direction and is in a deceleration state, and the gear ring on the inner edge of the rim (120) rotates in the forward direction and is in a deceleration state, that is, the wheel unit (100) rotates in the forward direction and is in a deceleration state, and the planet carrier (240) rotates in the forward direction, which drives the ball screw (330) to rotate in the forward direction, and the ball nut (320) and the brake support (3 16) moves forward, at this time, the rear friction lining (311) first contacts the brake disc (130), thereby causing the rear brake rocker arm (313) to swing backward, and under the action of the brake guide rod (314), the front brake rocker arm (313) also swings backward, eventually causing the front and rear brake calipers (312) to approach each other, and the multi-link brake actuator (310) clamps the brake disc (130), realizing efficient composite braking. At this time, the braking torque of the entire vehicle is provided by both mechanical friction braking and electric braking, and the ratio of the torques of the two is a fixed value. λ is related to the design parameters of the internal components of the multi-link brake actuator (310), such as the transmission ratio and mechanical efficiency. The ratio of the output torque of the hub motor (400) to the total braking torque is The total braking torque output can be controlled by adjusting the torque output of the hub motor (400). When the brake is released, the hub motor (400) is controlled to operate in the third quadrant, which is a negative speed and negative torque. At this time, the planetary carrier (240) reverses, which drives the ball screw (330) to reverse, and the ball nut (320) and the brake support (316) move backward until they return to the initial position. At the same time, the brake rocker arm (313) is returned to the center position under the action of the return spring (315), and the multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, so that the planetary carrier (240) is stationary, and the brake is released.

[0068] The invention discloses a control method for an energy-saving composite braking mode, wherein the hub motor (400) is controlled to operate in the second quadrant. At this time, the hub motor (400) is in a negative speed positive torque state. Unlike the efficiency composite braking mode, the electromagnetic clutch (600) is not in an active state throughout the entire process, but its state switching is controlled in real time according to the target ratio of the electric braking torque to the mechanical friction braking torque. Since in the composite braking mode, the ratio of the mechanical friction braking to the total braking torque depends on the position of the brake support (316), that is, the position of the ball nut (320), and thus depends on the angle rotated by the ball screw (330), that is, the angle rotated by the planet carrier (240), the electromagnetic clutch (600) is first controlled to be in an active state, and the planet carrier (240) starts to rotate forward. After the planet carrier (240) rotates through a certain angle, the electromagnetic clutch (600) is quickly controlled to switch to a locked state, and the position of the planet carrier (240) at this time is fixed, so that the mechanical friction braking torque and the electric braking torque can be controlled to be in any ratio. The ratio of the output torque of the hub motor (400) to the total braking torque is An energy-saving composite braking mode is realized. At this time, the total braking torque output can be controlled by adjusting the torque output of the hub motor (400). When the brake is canceled, the hub motor (400) is controlled to operate in the third quadrant, which is a negative speed and negative torque. At this time, the planetary carrier (240) reverses, which drives the ball screw (330) to reverse, and the ball nut (320) and the brake support (316) move backward until they return to the initial position. At the same time, the brake rocker arm (313) completes the return to the original position under the action of the return spring (315), and the multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, so that the planetary carrier (240) is stationary, and the brake is released.

[0069] Beneficial effects of the present invention:

[0070] 1. The present invention provides a multi-link brake integrated drive and brake electric wheel system, which integrates a wheel unit, a planetary gear reducer, a multi-link brake system, a hub motor, a wheel bracket, and an electromagnetic clutch. This is conducive to the modular design of distributed drive. The corresponding electric wheel system can be directly selected according to the application scenario requirements of various types of vehicles, reducing the development cost of the entire vehicle and realizing personalized design.

[0071] 2. The present invention provides an integrated driving and braking electric wheel system with a multi-link brake. The hub motor serves as the power source for both driving and braking, realizing the power reuse function of driving and braking, which can improve the energy utilization rate of the entire vehicle, eliminate the conventional brake actuator motor and its reducer, and greatly reduce the unsprung mass, which is beneficial to improving the vehicle's handling and driving comfort, saving wheel side space, and helping to solve the problem of difficult layout of the electric wheel system.

[0072] 3. The present invention provides a multi-link braking integrated drive and braking electric wheel system, which cleverly adopts a multi-link transmission scheme to achieve the braking function. Compared with the wedge braking scheme, it can avoid the problem of difficult braking return, and at the same time has better heat dissipation performance, which is conducive to improving the braking performance of the entire vehicle.

[0073] 4. The present invention provides a multi-link braking integrated drive and braking electric wheel system, which can realize five working modes: driving, pure electric braking, compound braking, reverse braking, and parking braking. Among them, the compound braking mode can adopt different control strategies to realize two functions: efficiency-type compound braking mode and energy-saving compound braking mode. The parking brake is also divided into three types according to the application scenario: flat ground parking brake, slope parking brake with the vehicle head facing up, and slope parking brake with the vehicle head facing down, which has a wide range of applications.

[0074] 5. The present invention provides a multi-link brake integrated drive and brake electric wheel system. The gear ring structure is directly processed on the inner edge of the rim and works in conjunction with a planetary gear reducer to fully utilize the space inside the wheel. At the same time, the rim itself serves as the housing of the planetary gear reducer, eliminating the need for an additional planetary gear reducer housing, thereby reducing the unsprung mass and saving space inside the wheel. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 This is a schematic structural diagram of the multi-link brake integrated drive and brake electric wheel system of the present invention;

[0076] Figure 2 This is a schematic diagram of the structural principle of the multi-link brake integrated drive and brake electric wheel of the present invention;

[0077] Figure 3 A side view of a multi-link brake actuator of a multi-link brake integrated drive and brake electric wheel system according to the present invention;

[0078] Figure 4 This is a cross-sectional view of the electromagnetic clutch of the multi-link brake integrated drive and brake electric wheel system of the present invention;

[0079] Figure 5 This is a schematic diagram of the working principle of the compound braking mode of the multi-link braking integrated drive and brake electric wheel system of the present invention;

[0080] Figure 6 This is a schematic diagram of the working principle of the reverse braking mode of the multi-link braking integrated drive and brake electric wheel system described in the present invention. DETAILED DESCRIPTION

[0081] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0082] The present invention proposes a multi-link brake drive and brake integrated electric wheel system, the specific structure of which is as follows: Figure 1 As shown, the structural principle is as follows Figure 2 As shown, it mainly includes: a wheel unit (100), a planetary gear reducer (200), a multi-link brake system (300), a hub motor (400), a wheel bracket (500), and an electromagnetic clutch (600).

[0083] The wheel unit (100) comprises a tire (110), a rim (120), and a brake disc (130), and is mainly used to support vehicle load and transmit driving and braking torques. A gear ring structure is directly processed on the inner edge of the rim and cooperates with a planetary gear reducer to improve the utilization rate of the space inside the wheel.

[0084] The tire (110) is used to carry the load of the entire vehicle and transmit ground force and torque; the rim (120) is installed on the front end of the stepped shaft of the planetary gear reducer (200) through a positioning through hole provided in the middle of the spoke and is positioned by a bearing; the inner edge of the rim is processed with a gear ring structure for cooperating with the planetary gear reducer (200) to work, and the outer edge is provided with bolt holes for installing a brake disc; the brake disc (130) is installed on the outer edge of the rim (120) by bolts, adopts inner ring braking, and leaves a braking gap with the friction lining of the multi-link brake system (300).

[0085] The planetary gear reducer (200) comprises a stepped shaft (210), a locking nut (220), a sun gear (230), a planet carrier (240), and a planetary gear (250), and works in conjunction with a gear ring structure on the inner edge of a wheel rim of a wheel unit (100) to transmit the torque output by a hub motor to achieve deceleration and torque increase, and works in conjunction with an electromagnetic clutch to achieve drive and brake multi-mode switching and power reuse through a planetary gear train transmission.

[0086] The stepped shaft (210) is mainly used to connect and carry various components in the planetary gear reducer (200), and provides a positioning function through a shaft shoulder. The front end is provided with a thread, the middle part is provided with a keyway for installing a flat key, and the rear end is provided with a spline, which is connected to the hub motor (400) to transmit torque; the locking nut (220) is installed on the front end threaded section of the stepped shaft (210), cooperates with the bearing to axially fix the rim (120) and the stepped shaft (210); the sun gear (230) is provided with a keyway in the center, is connected to the stepped shaft (210) through a flat key, and is engaged with the shaft shoulder. The planetary gear (250) is axially positioned and meshed with the planetary gear for transmission; wherein the planetary gear (250) is mounted on the planetary carrier via a bearing and is axially fixed via a nut and a lock ring; wherein the planetary carrier (240) is mounted on the stepped shaft (210) via a bearing and is positioned via a shaft shoulder; the planetary gear (250) is mounted at the front end and is driven by the meshing relationship between the planetary gear (250) and the sun gear (230); an external spline is machined in the middle portion and is connected to the ball screw of the multi-link brake system (300) for transmitting torque; and an outwardly extending hollow shaft structure is provided at the rear end to be connected to the electromagnetic clutch (600).

[0087] The multi-link brake system (300) is mainly as follows Figure 1 、 Figure 3 As shown, it includes a multi-link brake actuator (310), a ball nut (320), a ball screw (330), a pin (340), and a positioning washer (350). Each multi-link brake system (300) is equipped with two multi-link brake actuators (310), which are arranged symmetrically in an upper and lower direction. A multi-link transmission scheme is used to perform a braking function, and is used to provide a braking torque for the braking working condition of the multi-link brake drive-brake integrated electric wheel system.

[0088] The ball screw (330) is provided with a through hole in the middle portion thereof to pass through the stepped shaft (210), and is connected to the spline section in the middle portion of the planetary carrier (240), and axial and radial positioning is achieved by means of bearings and locking rings; the ball nut (320) cooperates with the ball screw (380), and when the ball screw (380) rotates around the axis, the ball nut (370) will move in a axial direction without rotating itself; the multi-link brake actuator (310) is the main part of the multi-link brake system (300), and includes a friction lining (311), a brake caliper (312), a brake A rocker arm (313), a brake guide rod (314), a return spring (315), a brake support (316), a latch (317), and a positioning gasket (318). Each multi-link brake system (300) is equipped with two multi-link brake actuators (310), which are arranged symmetrically in an upper and lower direction. The position relationship between the brake caliper (312), the brake rocker arm (313), and the brake guide rod (314) is A-shaped. A multi-link transmission scheme is used to perform the braking function. The whole is respectively installed on the upper and lower sides of the ball nut (320), and the braking function is achieved by utilizing the translation of the ball nut (320).

[0089] The brake support (316) is fixedly connected to the ball nut (320) and is mainly used to carry and connect the various components of the multi-link brake actuator (300). A guide groove is provided in the middle to cooperate with the guide rail provided on the wheel bracket (500). When the ball screw (380) rotates around the axis, it moves axially together with the ball nut (370). Two cylindrical pin seats are provided on the top to be hooked with the spring. There are two brake rocker arms (313) installed on the brake support (316) through the bottom cylindrical pin. A cylindrical pin hole and an opening structure are provided in the middle to The mounting pin and the brake guide rod are provided with a cylindrical pin on the top for mounting a brake caliper, and a spring hook is provided on the inner side. When viewed along the axial direction of the stepped shaft (210), the overall structure is symmetrical and the shape is relatively wide to ensure good mechanical properties under braking conditions. There are two brake calipers (312) mounted on the top of the brake rocker arm (313) through the cylindrical pin. When in braking condition, they move closer to each other as the brake rocker arm (313) swings. A groove is provided in the middle for mounting a friction lining. There are two friction linings (311) mounted on the brake caliper (312). The groove provided in the middle is horseshoe-shaped as a whole, and a braking gap is left with the brake disc (130) in the non-braking condition; wherein the brake guide rods (314) are two in total, with cylindrical pin holes at both ends, and are installed in the opening structure in the middle of the brake rocker arm (313) through a pin, which guides the movement trajectory of the two brake rocker arms (313). The size of the brake guide rod (314) must ensure that it will not interfere with the brake disc (130) during its movement; wherein the pin (317) is installed in the cylindrical pin hole provided in the middle of the brake rocker arm (313), and is installed at both ends through a pin. The locking ring is fixed to provide radial positioning of the cylindrical pin hole of the brake guide rod (314); wherein the positioning gaskets (318), there are four in total, are used to provide axial positioning of the cylindrical pin hole of the brake guide rod (314); wherein the return springs (315), there are two in total, are installed on the spring hooks provided on the brake rocker arm (313) and the brake support (316), and are used to assist the return action of the brake rocker arm (313) when the brake is released, so as to avoid incomplete separation of the friction lining (311) and the brake disc (130) due to insufficient return of the brake rocker arm (313).

[0090] The hub motor (400) adopts a low-speed inner rotor motor, including a hub motor rotor (410), a hub motor stator and a housing (420), and is mainly used to provide the driving and braking execution torque of the multi-link brake integrated electric wheel system for driving and braking conditions, and serves as the sole power source for driving and braking operations. The hub motor is integrally installed and fixed in the deep hole in the middle of the wheel bracket.

[0091] The output end of the hub motor rotor (410) is connected to the rear end of the stepped shaft (210) via a spline for transmitting torque; and the hub motor stator and the housing (420) are provided with threaded holes in the housing for mounting the electromagnetic clutch (600).

[0092] The wheel bracket (500) is mainly used to connect the multi-link brake drive-brake integrated electric wheel system and the vehicle suspension to transmit force and torque. A deep hole is provided in the middle for installing the hub motor. At the same time, guide rail structures are provided at the upper and lower ends to play a guiding role and limit the movement trajectory of the brake support in the multi-link brake system (300).

[0093] The electromagnetic clutch (600) is mainly as follows Figure 1 、 Figure 4 As shown, it includes a roller (610), a clutch outer hub (620), a clutch inner hub (630), a movable coil seat (640), an electromagnetic clutch upper cover (650), a movable coil winding (660), an electromagnetic clutch return rubber block (670), a fixed coil winding (680), and a locking pin (690), which are fixed to the housing of the hub motor (400) by screws. The hub motor (400) works in conjunction with the hub motor to control the rotational freedom of the planetary carrier of the planetary gear reducer (200) and realize the switching of the driving and braking multiple modes.

[0094] The roller (610) is installed between the clutch outer hub and the clutch inner hub; the clutch outer hub (620) is the main part of the electromagnetic clutch (600), the middle part is a through-hole structure, and a plurality of arc grooves are provided on the inner side for installing the roller (610), and lugs are provided on both sides, which are connected to the stator of the hub motor and the outer shell (420) by screws, and a fixed coil seat is provided on the upper end for installing the fixed coil winding, and a small hole is provided for routing; the clutch inner hub (630) is an open ring structure as a whole, and a plurality of arc grooves are provided on the outer side for installing the roller (610), The inner side is transitionally matched with the outer side of the hollow shaft extending outward from the rear end of the planetary carrier (240), and a wedge structure is provided at the opening; wherein the movable coil seat (640) is arranged directly above the fixed coil seat at the upper end of the clutch outer hub (620), and a deep hole is provided in the middle and a bolt hole is provided on the top for installing a locking pin; wherein the electromagnetic clutch upper cover (650) is mainly used to protect the components at the upper end of the electromagnetic clutch (600), and a thread is provided at the bottom and is installed on the top of the clutch outer hub (620); wherein the movable coil winding (660) is installed on the movable coil seat (640), and the movable coil winding (660) is screwed. When energized, a magnetic field can be generated; wherein the electromagnetic clutch return rubber block (670) has a through hole at its center and is installed between the movable coil winding (660) and the fixed coil seat at the upper end of the clutch outer hub (620); when the electromagnetic clutch (600) is in a locked state, the electromagnetic clutch return rubber block (670) is used to separate the movable coil winding (660) from the fixed coil seat at the upper end of the clutch outer hub (620); wherein the fixed coil winding (680) is installed at the fixed coil seat at the upper end of the clutch outer hub (620) and has the same winding direction as the movable coil winding (660); when the fixed coil winding (6 When the power supply direction of the fixed coil winding (680) is the same as that of the movable coil winding (660), the magnetic fields generated by the upper end of the fixed coil winding (680) and the lower end of the movable coil winding (660) are opposite, and they attract each other, causing the movable coil seat (640) to move downward, approach the fixed coil seat at the upper end of the clutch outer hub (620), and compress the electromagnetic clutch return rubber block (670). When the fixed coil winding (680) and the movable coil winding (660) are not powered, the magnetic field disappears, and due to the action of the electromagnetic clutch return rubber block (670), the separated movable coil winding (660) is separated from the fixed coil seat at the upper end of the clutch outer hub (620);The locking pin (690) is provided with a threaded hole at the top and is connected to the movable coil seat (640) by screws. The bottom is provided with a wedge structure. The shaft section passes through the fixed coil seat at the upper end of the clutch outer hub (620) and is arranged just above the opening of the clutch inner hub (630). When the fixed coil winding (680) and the movable coil winding (660) are energized in the same direction, due to the effect of the magnetic field, the movable coil seat (640) moves downward close to the fixed coil seat at the upper end of the clutch outer hub (620), so that the locking pin (690) ) moves downward and inserts into the opening of the clutch inner hub (630). At this time, the clutch inner hub (630) will be in the middle position and cannot rotate. At the same time, the inner diameter becomes larger and does not contact the outer ring of the hollow shaft extending outward from the rear end of the planetary carrier (240). When the electromagnetic clutch (600) is in the locked state, the fixed coil winding (680) and the movable coil winding (660) are not energized. Due to the action of the electromagnetic clutch return rubber block (670), the locking pin (690) moves upward and disengages from the opening of the clutch inner hub (630).

[0095] The electromagnetic clutch (600) has two working states, namely a locked state and an active state. In the locked state, the fixed coil winding (680) and the movable coil winding (660) are not energized, and there is no magnetic field. The movable coil seat (640) and the fixed coil seat at the upper end of the clutch outer hub (620) are separated due to the action of the electromagnetic clutch return rubber block (670). The locking pin (690) is disengaged from the opening of the clutch inner hub (630). At this time, the inner ring of the clutch inner hub (630) contacts the outer ring of the hollow shaft extending outward from the rear end of the planetary carrier (240). When the planetary carrier (240) attempts to rotate, it will drive the clutch inner hub (630) to rotate. Due to the action of the roller (610), the inner diameter of the clutch inner hub (630) will become smaller, clamping the hollow shaft extending outward from the rear end of the planetary carrier (240) to generate friction, and this process has a self-amplifying effect, which is sufficient to make the planetary carrier (240) rotate. The planet carrier (240) cannot rotate, forming a locking effect; in the active state, the fixed coil winding (680) and the movable coil winding (660) are energized and the current directions are the same. At this time, the magnetic fields generated by the upper end of the fixed coil winding (680) and the lower end of the movable coil winding (660) are of opposite polarity and attract each other, causing the movable coil seat (640) to move downward toward the fixed coil seat at the upper end of the clutch outer hub (620) and compress the electromagnetic clutch return rubber block (670). The locking pin (690) will move downward and insert into the opening of the clutch inner hub (630), forcing the clutch inner hub (630) to be in the middle position and unable to rotate. At the same time, the inner diameter becomes larger and does not contact the outer ring of the hollow shaft extending outward from the rear end of the planet carrier (240). At this time, the planet carrier (240) can rotate freely.

[0096] The multi-link brake drive-brake integrated electric wheel system needs to define a rotation direction reference system, and when the wheel unit (100) moves forward, its own direction around the rotation axis is the positive rotation direction.

[0097] The working modes of the multi-link braking integrated drive and brake electric wheel system are mainly divided into driving mode, pure electric braking mode, compound braking mode, reverse braking mode, and parking brake mode.

[0098] The driving mode is operated under the driving condition, the hub motor (400) operates in the third quadrant, which is a negative speed and negative torque state, and the electromagnetic clutch (600) is in a locked state. At this time, the sun gear (230) rotates in reverse, and the ring gear on the inner edge of the rim (120) rotates forward, that is, the wheel unit (100) rotates forward, the planet carrier (240) is stationary, and the vehicle travels forward. If the hub motor (400) operates in the first quadrant, which is a positive speed and positive torque state, the vehicle travels in reverse, and the transmission principle is the same;

[0099] The pure electric braking mode operates under medium and low vehicle speed braking conditions, the hub motor (400) operates in the second quadrant and is in a high efficiency range, the electric braking alone is sufficient to meet the braking requirements, and the energy utilization rate is higher, at this time the hub motor (400) is in a negative speed positive torque state, and the electromagnetic clutch (600) is in a locked state, the sun gear (230) rotates in reverse and is in a deceleration state, the gear ring on the inner edge of the rim (120) rotates forward and is in a deceleration state, that is, the wheel unit (100) rotates forward and is in a deceleration state, the planetary carrier (240) is stationary, and the vehicle is in a braking energy recovery state.

[0100] The working principle diagram of the compound braking mode is as follows: Figure 5As shown, it is mainly used in braking scenarios at extremely low vehicle speeds and braking scenarios at high speeds with high braking intensity. Due to the operating characteristics of the motor and the limitations of the motor efficiency in this scenario, electric braking alone is not enough to meet the braking needs. Therefore, it is necessary to introduce mechanical friction braking on the basis of electric braking to meet the braking needs. The compound braking mode is divided into an efficiency compound braking mode and an energy-saving compound braking mode according to whether the ratio of the electric braking torque to the mechanical friction braking torque is adjustable, which can be set according to the driver's own preferences. In the efficiency compound braking mode, the electric braking torque and the mechanical friction braking torque are distributed in a fixed ratio, and the proportion of the mechanical braking torque to the total braking torque reaches the maximum at this time, mainly pursuing the driving performance of the whole vehicle and experiencing the driving pleasure. In the energy-saving compound braking mode, the electric braking torque and the mechanical friction braking torque are distributed in a variable ratio. Under the premise of meeting the braking needs, as much braking torque as possible is allocated to the electric brake, and energy-saving driving is achieved through brake energy recovery, thereby improving the economy of the whole vehicle. The invention discloses a control method for a closed braking mode, wherein the wheel hub motor (400) is controlled to be in the second quadrant, at which time the wheel hub motor (400) is in a negative speed positive torque state, and the electromagnetic clutch (600) is controlled to be in an active state throughout the entire process, the sun gear (230) rotates in the reverse direction and is in a deceleration state, and the gear ring on the inner edge of the rim (120) rotates in the forward direction and is in a deceleration state, that is, the wheel unit (100) rotates in the forward direction and is in a deceleration state, and the planet carrier (240) rotates in the forward direction, which drives the ball screw (330) to rotate in the forward direction, and the ball nut (320) and the brake support (316) rotate in the forward direction. ) moves forward, at this time the rear friction lining (311) contacts the brake disc (130) first, thereby causing the rear brake rocker arm (313) to swing backward, and under the action of the brake guide rod (314), the front brake rocker arm (313) also swings backward, eventually causing the front and rear brake calipers (312) to approach each other, and the multi-link brake actuator (310) clamps the brake disc (130), realizing efficient composite braking. At this time, the braking torque of the entire vehicle is provided by both mechanical friction braking and electric braking, and the ratio of the torques of the two is a fixed value. λ is related to the design parameters of the internal components of the multi-link brake actuator (310), such as the transmission ratio and mechanical efficiency. The ratio of the output torque of the hub motor (400) to the total braking torque is The total braking torque output can be controlled by adjusting the torque output of the hub motor (400). When the brake is canceled, the hub motor (400) is controlled to operate in the third quadrant, which is a negative speed and negative torque. At this time, the planetary carrier (240) is reversed, which drives the ball screw (330) to reverse, and the ball nut (320) and the brake support (316) move backward until they return to the initial position. At the same time, the brake rocker (313) is returned to the center position under the action of the return spring (315). The multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, making the planetary carrier (240) stationary, and achieving brake release. In the energy-saving composite braking mode control method, the hub motor (400) is controlled to operate in the second quadrant. At this time, the hub motor (400) is in a negative speed and positive torque state. Unlike the efficiency-type compound braking mode, the electromagnetic clutch (600) is not in an active state throughout the entire process, but its state switching is controlled in real time according to the target ratio of the electric braking torque to the mechanical friction braking torque. Since in the compound braking mode, the ratio of the mechanical friction braking to the total braking torque depends on the position of the brake support (316), that is, the position of the ball nut (320), and thus depends on the angle of rotation of the ball screw (330), that is, the angle of rotation of the planetary carrier (240), the electromagnetic clutch (600) is first controlled to be in an active state, and the planetary carrier (240) starts to rotate forward. After it rotates a certain angle, the electromagnetic clutch (600) is quickly controlled to switch to a locked state, fixing the position of the planetary carrier (240) at this time, and the mechanical friction braking torque and the electric braking torque can be controlled to be in any ratio. The ratio of the output torque of the hub motor (400) to the total braking torque is An energy-saving composite braking mode is realized. At this time, the total braking torque output can be controlled by adjusting the torque output of the hub motor (400). When the brake is canceled, the hub motor (400) is controlled to operate in the third quadrant, which is a negative speed and negative torque. At this time, the planetary carrier (240) reverses, which drives the ball screw (330) to reverse, and the ball nut (320) and the brake support (316) move backward until they return to the initial position. At the same time, the brake rocker arm (313) completes the return to the original position under the action of the return spring (315), and the multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, so that the planetary carrier (240) is stationary, and the brake is released.

[0101] The reverse braking mode has a working principle diagram as shown below: Figure 6As shown, the vehicle works under the braking condition of reverse driving, because the hub motor (400) works in the fourth quadrant at this time, but because the vehicle speed is usually very low under the reverse braking condition, the hub motor (400) works in the low efficiency range, resulting in a low intensity of the separate electric braking, and completing a fast and efficient reverse braking action, so the mechanical friction brake is introduced. At this time, the hub motor (400) is in a positive speed and negative torque state, and the electromagnetic clutch (600) is switched to an active state. The sun gear (230) rotates forward and is in a deceleration state, and the gear ring on the inner edge of the rim (120) rotates reversely and is in a deceleration state, that is, the wheel unit (100) rotates reversely and is in a deceleration state, and the planetary carrier (240) rotates reversely, which will drive the ball screw (330) to reverse, and the ball nut (320) and the brake support (316) move backward. At this time, the friction lining (311) on the front side first contacts the brake disc (130), from The front brake rocker arm (313) swings forward, and under the action of the brake guide rod (314), the rear brake rocker arm (313) also swings forward, and finally the front and rear brake calipers (312) approach each other, and the multi-link brake actuator (310) clamps the brake disc (130) to achieve reverse braking. When the brake is canceled, the hub motor (400) is controlled to work in the first quadrant, which is a positive speed and positive torque. At this time, the planetary carrier (240) rotates forward, which will drive the ball screw (330) to rotate forward, and the ball nut (320) and the brake support (316) move forward until they return to the initial position. At the same time, the brake rocker arm (313) completes the return to the original position under the action of the return spring (315), and the multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, so that the planetary carrier (240) is stationary, and the brake is released.

[0102] The parking brake mode is mainly divided into three types: flat ground parking brake, slope parking brake with the vehicle head facing upward, and slope parking brake with the vehicle head facing downward. When the vehicle is in the flat ground parking brake working condition, the vehicle is stationary, and the wheel hub motor (400) is controlled to work in the first quadrant, and the working point torque is small. At the same time, the electromagnetic clutch (600) is in an active state, and the sun gear (230) rotates forward. Since the wheel unit (100) belongs to a large inertia system, the inner edge of the wheel rim (120) is The ring structure will shake slightly and can be regarded as stationary, while the planet carrier (240) rotates forward, which will drive the ball screw (330) to rotate forward, and the ball nut (320) and the brake support (316) move forward. At this time, the friction lining (311) on the rear side first contacts the brake disc (130), thereby causing the brake rocker arm (313) on the rear side to swing backward. Under the action of the brake guide rod (314), the brake rocker arm (313) on the front side also swings backward, and finally the front and rear brake calipers (312) are moved forward. When the wheels are close to each other, the multi-link brake actuator (310) clamps the brake disc (130). After the wheels are fully clamped, the electromagnetic clutch (600) switches to a locked state to realize the flat ground parking brake function. When the brake is canceled, the electromagnetic clutch (600) is first controlled to switch to an active state, and the wheel hub motor (400) is controlled to work in the third quadrant, which is a negative speed and negative torque. The sun gear (230) is reversed. Since the vehicle belongs to a large inertia system, it can be regarded as stationary for a short time, that is, the wheel rim (12 0) The inner gear ring is stationary, and the planet carrier (240) reverses, which drives the ball screw (330) to reverse, and the ball nut (320) and the brake support (316) move backward until they return to the initial position. At the same time, the brake rocker (313) is returned to the center position under the action of the return spring (315), and the multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, making the planet carrier (240) stationary, and the brake is released;When the vehicle is in the parking brake working condition on the slope with the front of the vehicle facing upward, the vehicle has a tendency to reverse, which can be compared to the reverse braking mode. The hub motor (400) is controlled to be in the fourth quadrant. At this time, the hub motor (400) is in a positive speed negative torque state. At the same time, the electromagnetic clutch (600) is switched to an active state. The sun gear (230) rotates forward and is in a deceleration state. The gear ring on the inner edge of the rim (120) rotates reversely and is in a deceleration state. That is, the wheel unit (100) rotates reversely and is in a deceleration state. The planetary carrier (240) rotates reversely, which will drive the ball screw (330) to reverse. The ball nut (320) and the brake support (316) move backward. At this time, the friction lining (311) on the front side first contacts the brake disc (130), thereby causing the brake rocker arm (313) on the front side to swing forward. Under the action of the brake guide rod (314), the brake rocker arm (313) on the rear side also swings forward, and finally the brake rocker arm (313) on the rear side is rotated forward. The front and rear brake calipers (312) are close to each other, and the multi-link brake actuator (310) clamps the brake disc (130) to achieve parking brake on a slope with the front of the vehicle facing upward. When the brake is released, the hub motor (400) is controlled to work in the first quadrant, which is a positive speed and positive torque. The sun gear (230) rotates forward. Since the vehicle belongs to a large inertia system, it can be regarded as stationary in a short period of time, that is, the inner ring gear of the rim (120) is stationary. At this time, the planetary carrier (240) rotates forward, which will drive the ball screw (330) to rotate forward. The ball nut (320) and the brake support (316) move forward until they return to the initial position. At the same time, the brake rocker arm (313) is completed under the action of the return spring (315). The multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, making the planetary carrier (240) stationary, and the brake is released.When the vehicle is in the slope parking brake condition with the front of the vehicle facing downward, the vehicle tends to move forward, which can be compared to the compound braking mode. The hub motor (400) is controlled to be in the second quadrant. At this time, the hub motor (400) is in a negative speed positive torque state. At the same time, the electromagnetic clutch (600) is switched to an active state. The sun gear (230) rotates in reverse and is in a deceleration state. The gear ring on the inner edge of the rim (120) rotates forward and is in a deceleration state. That is, the wheel unit (100) rotates forward and is in a deceleration state. The planetary carrier (240) rotates forward, which will drive the ball screw (330) to rotate forward. The ball nut (320) and the brake support (316) move forward. At this time, the friction lining (311) on the rear side first contacts the brake disc (130), thereby causing the brake rocker arm (313) on the rear side to swing backward. Under the action of the brake guide rod (314), the brake rocker arm (313) on the front side also swings backward, and finally the brake rocker arm (313) on the front side is rotated backward. The front and rear brake calipers (312) are close to each other, and the multi-link brake actuator (310) clamps the brake disc (130) to achieve parking brake on a slope with the front of the vehicle facing downward. When the brake is released, the hub motor (400) is controlled to work in the third quadrant, which is a negative speed and negative torque. The sun gear (230) rotates forward. Since the vehicle belongs to a large inertia system, it can be regarded as stationary for a short period of time, that is, the inner ring gear of the rim (120) is stationary. At this time, the planetary carrier (240) reverses, which will drive the ball screw (330) to reverse, and the ball nut (320) and the brake support (316) move backward until they return to the initial position. At the same time, the brake rocker (313) completes the return to the original position under the action of the return spring (315). The multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, making the planetary carrier (240) stationary, and achieving brake release.

[0103] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and the embodiments. They can be applied to various fields suitable for the present invention. For those familiar with the art, further modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described here. Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and the embodiments. They can be applied to various fields suitable for the present invention. For those familiar with the art, further modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. The multi-link brake integrated drive and brake electric wheel system is characterized by: include: A wheel unit (100) includes a tire (110), a rim (120), and a brake disc (130), and is mainly used to support vehicle load and transmit driving and braking torques. A gear ring structure is directly processed on the inner edge of the rim and cooperates with a planetary gear reducer to improve the utilization rate of the space inside the wheel. The planetary gear reducer (200) comprises a stepped shaft (210), a locking nut (220), a sun gear (230), a planet carrier (240), and a planetary gear (250), and works in conjunction with a gear ring structure on the inner edge of a wheel rim of a wheel unit (100) to transmit torque output by a hub motor to achieve deceleration and torque increase, and works in conjunction with an electromagnetic clutch to achieve drive and brake multi-mode switching and power reuse through a planetary gear train transmission; A multi-link brake system (300) includes a multi-link brake actuator (310), a ball nut (320), a ball screw (330), a latch (340), and a positioning washer (350). Each multi-link brake system (300) is equipped with two multi-link brake actuators (310), which are arranged symmetrically in an upper and lower direction and use a multi-link transmission scheme to perform a braking function, and are used to provide a braking torque in a braking condition of the multi-link brake integrated drive and brake electric wheel system. The wheel hub motor (400) adopts a low-speed inner rotor motor, including a wheel hub motor rotor (410), a wheel hub motor stator and a housing (420), and is mainly used to provide the driving and braking operating torque of the multi-link brake integrated electric wheel system, and serves as the sole power source for driving and braking. The wheel hub motor is integrally mounted and fixed in the deep hole in the middle of the wheel bracket; The wheel bracket (500) is mainly used to connect the multi-link brake drive-brake integrated electric wheel system and the vehicle suspension to transmit force and torque. A deep hole is provided in the middle for installing the wheel hub motor. The upper and lower ends are respectively provided with guide rail structures to play a guiding role and limit the movement trajectory of the brake support in the multi-link brake system (300); The electromagnetic clutch (600) comprises a roller (610), a clutch outer hub (620), a clutch inner hub (630), a movable coil seat (640), an electromagnetic clutch upper cover (650), a movable coil winding (660), an electromagnetic clutch return rubber block (670), a fixed coil winding (680), and a locking latch (690). The electromagnetic clutch (600) is fixed to the housing of the hub motor (400) by screws. The hub motor (400) cooperates with the hub motor (400) to control the rotational freedom of the planetary carrier of the planetary gear reducer (200) and realize the switching of driving and braking multiple modes.

2. The multi-link brake integrated driving and braking electric wheel system according to claim 1, characterized in that: The wheel unit (100) is characterized by comprising: Tire (110), used to carry the load of the entire vehicle and transmit ground force and torque; The rim (120) is mounted on the front end of the stepped shaft of the planetary gear reducer (200) through a positioning through-hole provided in the middle of the spoke and is positioned by a bearing. A gear ring structure is machined on the inner edge of the rim to cooperate with the planetary gear reducer (200) for operation, and a bolt hole is provided on the outer edge for mounting a brake disc. The brake disc (130) is mounted on the outer edge of the wheel rim (120) by means of bolts, adopts inner ring braking, and leaves a braking gap with the friction lining of the multi-link brake system (300).

3. The multi-link brake drive-brake integrated electric wheel system according to claim 2, characterized in that: The planetary gear reducer (200) is characterized by comprising: The stepped shaft (210) is mainly used to connect and carry the various components in the planetary gear reducer (200) and provides a positioning function through the shaft shoulder. The front end is provided with a thread, the middle part is provided with a keyway for installing a flat key, and the rear end is provided with a spline for connecting with the hub motor (400) to transmit torque. A locking nut (220) is mounted on the front threaded section of the stepped shaft (210) and cooperates with the bearing to axially fix the rim (120) and the stepped shaft (210); The sun gear (230) has a keyway at its center, is connected to the stepped shaft (210) via a flat key, is axially positioned using a shaft shoulder, and is meshed with the planetary gear for transmission; The planetary gear (250) is mounted on the planetary carrier via a bearing and is axially fixed via a nut and a lock ring; The planet carrier (240) is mounted on the stepped shaft (210) via a bearing and positioned via a shaft shoulder. A planetary gear (250) is mounted on the front end and is driven by the meshing relationship between the planetary gear (250) and the sun gear (230). An external spline is machined in the middle portion and is connected to the ball screw of the multi-link brake system (300) for transmitting torque. An externally extending hollow shaft structure is provided at the rear end to connect with the electromagnetic clutch (600).

4. The multi-link brake drive-brake integrated electric wheel system according to claim 3, characterized in that: The multi-link brake system (300) is characterized by comprising: A ball screw (330) is provided with a through hole in the middle portion thereof for passing through the stepped shaft (210), and is connected to the spline section in the middle portion of the planetary carrier (240), and is positioned axially and radially by means of a bearing and a locking ring; The ball nut (320) cooperates with the ball screw (380). When the ball screw (380) rotates around the axis, the ball nut (370) moves in a axial direction without rotating itself. The multi-link brake actuator (310) is the main part of the multi-link brake system (300), including a friction lining (311), a brake caliper (312), a brake rocker arm (313), a brake guide rod (314), a return spring (315), a brake support (316), a latch (317), and a positioning gasket (318). Each multi-link brake system (300) is equipped with two multi-link brake actuators (310), which are arranged symmetrically in an upper and lower direction. The position relationship between the brake caliper (312), the brake rocker arm (313), and the brake guide rod (314) is A-shaped. The multi-link transmission scheme is used to perform the braking function. The whole is respectively installed on the upper and lower sides of the ball nut (320), and the braking function is achieved by utilizing the translation of the ball nut (320).

5. The multi-link brake integrated driving and braking electric wheel system according to claim 4, characterized in that: The multi-link brake actuator (300) is characterized by comprising: The brake support (316) is fixedly connected to the ball nut (320) and is mainly used to carry and connect the various components of the multi-link brake actuator (300). A guide groove is provided in the middle to cooperate with the guide rail provided on the wheel bracket (500). When the ball screw (380) rotates around the axis, it moves axially along with the ball nut (370). Two cylindrical pin seats are provided on the top to hook with the spring; There are two brake rocker arms (313), which are mounted on the brake support (316) through a cylindrical pin at the bottom. A cylindrical pin hole and an opening structure are provided in the middle for mounting a latch and a brake guide rod. A cylindrical pin is provided at the top for mounting a brake caliper. A spring hook is provided on the inner side. When viewed along the axial direction of the stepped shaft (210), the overall structure is symmetrical and the shape is relatively wide to ensure good mechanical properties under braking conditions. There are two brake calipers (312) installed on the top of the brake rocker arm (313) through a cylindrical pin. When the brake is in operation, the brake calipers (312) move closer to each other as the brake rocker arm (313) swings. A groove is provided in the middle for mounting a friction lining. There are two friction linings (311) installed in a groove provided in the middle of the brake caliper (312). The friction linings (311) are horseshoe-shaped and have a braking gap with the brake disc (130) in a non-braking condition. There are two brake guide rods (314), each with a cylindrical pin hole at both ends, which are installed in the opening structure in the middle of the brake rocker arm (313) through a pin, and play a guiding role in the movement trajectory of the two brake rocker arms (313). The size of the brake guide rods (314) must ensure that they will not interfere with the brake disc (130) during movement; A latch (317) is mounted in a cylindrical pin hole provided in the middle of the brake rocker arm (313), with both ends fixed by locking rings to provide radial positioning of the cylindrical pin hole of the brake guide rod (314); There are four positioning washers (318) for providing axial positioning of the cylindrical pin hole of the brake guide rod (314); There are two return springs (315) installed on the spring hooks provided on the brake rocker arm (313) and the brake support (316). When the brake is released, the return springs (315) are used to assist the return action of the brake rocker arm (313) to avoid incomplete separation of the friction lining (311) and the brake disc (130) due to insufficient return of the brake rocker arm (313).

6. The multi-link brake drive-brake integrated electric wheel system according to claim 3, characterized in that: The hub motor (400) is characterized by comprising: The hub motor rotor (410) has an output end connected to the rear end of the stepped shaft (210) via a spline for transmitting torque; The hub motor stator and housing (420) are provided with threaded holes on the housing portion for installing the electromagnetic clutch (600).

7. The multi-link brake integrated driving and braking electric wheel system according to claim 6, characterized in that: The electromagnetic clutch (600) is characterized by comprising: A roller (610) is mounted between the clutch outer hub and the clutch inner hub; The clutch outer hub (620) is the main part of the electromagnetic clutch (600), with a through-hole structure in the middle and multiple arc grooves on the inner side for mounting the roller (610). Lugs are provided on both sides and are connected to the stator of the hub motor and the outer shell (420) by screws. A fixed coil seat is provided at the upper end for mounting the fixed coil winding and a small hole is provided for routing the wires. The clutch inner hub (630) is an open annular structure as a whole, with multiple arc grooves on the outside for mounting the roller (610), and the inside is transitionally matched with the outside of the hollow shaft extending outward from the rear end of the planetary carrier (240), and a wedge structure is provided at the opening; The movable coil seat (640) is arranged just above the fixed coil seat at the upper end of the clutch outer hub (620), has a deep hole in the middle and a bolt hole at the top for installing a locking pin; The electromagnetic clutch upper cover (650) is mainly used to protect the upper components of the electromagnetic clutch (600), has a threaded bottom, and is installed on the top of the clutch outer hub (620); A movable coil winding (660) is mounted on the movable coil base (640), and a magnetic field can be generated by energizing the movable coil winding (660); The electromagnetic clutch return rubber block (670) has a through hole at its center and is installed between the movable coil winding (660) and the fixed coil seat at the upper end of the clutch outer hub (620). When the electromagnetic clutch (600) is in a locked state, the electromagnetic clutch return rubber block (670) is used to separate the movable coil winding (660) from the fixed coil seat at the upper end of the clutch outer hub (620). The fixed coil winding (680) is mounted on the fixed coil seat at the upper end of the clutch outer hub (620) and has the same coil winding direction as the movable coil winding (660). When the fixed coil winding (680) and the movable coil winding (660) are energized in the same direction, the magnetic fields generated by the upper end of the fixed coil winding (680) and the lower end of the movable coil winding (660) are of opposite polarity and attract each other, causing the movable coil seat (640) to move downward and approach the fixed coil seat at the upper end of the clutch outer hub (620) and compress the electromagnetic clutch return rubber block (670). When the fixed coil winding (680) and the movable coil winding (660) are not energized, the magnetic field disappears. Due to the action of the electromagnetic clutch return rubber block (670), the separated movable coil winding (660) is separated from the fixed coil seat at the upper end of the clutch outer hub (620); The locking pin (690) has a threaded hole on the top and is connected to the movable coil seat (640) by screws. The bottom is provided with a wedge structure. The shaft section passes through the fixed coil seat at the upper end of the clutch outer hub (620) and is arranged just above the opening of the clutch inner hub (630). When the fixed coil winding (680) and the movable coil winding (660) are energized in the same direction, due to the effect of the magnetic field, the movable coil seat (640) moves downward close to the fixed coil seat at the upper end of the clutch outer hub (620), causing the locking pin (690) to move to the upper end of the clutch inner hub (630). The electromagnetic clutch (600) is moved downward and inserted into the opening of the clutch inner hub (630). At this time, the clutch inner hub (630) is in the middle position and cannot rotate. At the same time, the inner diameter becomes larger and does not contact the outer ring of the hollow shaft extending outward from the rear end of the planetary carrier (240). When the electromagnetic clutch (600) is in a locked state, the fixed coil winding (680) and the movable coil winding (660) are not energized. Due to the action of the electromagnetic clutch return rubber block (670), the locking pin (690) moves upward and disengages from the opening of the clutch inner hub (630).

8. The multi-link brake drive-brake integrated electric wheel system according to claim 7, characterized in that: The working state of the electromagnetic clutch (600) includes: In the locked state, the fixed coil winding (680) and the movable coil winding (660) are not energized, and there is no magnetic field. The movable coil seat (640) and the fixed coil seat at the upper end of the clutch outer hub (620) are separated due to the action of the electromagnetic clutch return rubber block (670), and the locking pin (690) is disengaged from the opening of the clutch inner hub (630). At this time, the inner ring of the clutch inner hub (630) is in contact with the outer ring of the hollow shaft extending outward from the rear end of the planetary carrier (240). When the planetary carrier (240) attempts to rotate, it will drive the clutch inner hub (630) to rotate. Due to the action of the roller (610), the inner diameter of the clutch inner hub (630) will become smaller, clamping the hollow shaft extending outward from the rear end of the planetary carrier (240) to generate friction, and this process has a self-amplifying effect, which is sufficient to prevent the planetary carrier (240) from rotating, forming a locking effect. Active state, at this time, the fixed coil winding (680) and the movable coil winding (660) are energized and the current direction is the same. At this time, the magnetic fields generated by the upper end of the fixed coil winding (680) and the lower end of the movable coil winding (660) are opposite in polarity and attract each other, causing the movable coil seat (640) to move downward to approach the fixed coil seat at the upper end of the clutch outer hub (620) and compress the electromagnetic clutch return rubber block (670). The locking pin (690) will move downward and insert into the opening of the clutch inner hub (630), forcing the clutch inner hub (630) to be in the middle position and unable to rotate. At the same time, the inner diameter becomes larger and does not contact the outer ring of the hollow shaft extending outward from the rear end of the planetary carrier (240). At this time, the planetary carrier (240) can rotate freely.

9. The multi-link brake drive-brake integrated electric wheel system according to claim 8, characterized in that: The rotation direction reference frames and operating modes include: A rotation direction reference system is defined, wherein when the wheel unit (100) moves forward, the direction of the wheel unit (100) around its rotation axis is the positive rotation direction; The operating modes of the multi-link brake integrated drive and brake electric wheel system are mainly divided into driving mode, pure electric braking mode, compound braking mode, reverse braking mode, and parking brake mode; In the driving mode, the wheel hub motor (400) operates in the third quadrant, which is a negative speed and negative torque state, and the electromagnetic clutch (600) is in a locked state. At this time, the sun gear (230) rotates in reverse, and the gear ring on the inner edge of the rim (120) rotates forward, that is, the wheel unit (100) rotates forward, the planet carrier (240) is stationary, and the vehicle travels forward. If the wheel hub motor (400) operates in the first quadrant, which is a positive speed and positive torque state, the vehicle travels in reverse, and the transmission principle is the same; In the pure electric braking mode, the wheel hub motor (400) operates in the second quadrant and is in a high efficiency range under medium and low vehicle speed braking conditions. The electric brake alone is sufficient to meet the braking requirements, and the energy utilization rate is higher. At this time, the wheel hub motor (400) is in a negative speed and positive torque state, and the electromagnetic clutch (600) is in a locked state. The sun gear (230) rotates in reverse and is in a deceleration state, and the gear ring on the inner edge of the rim (120) rotates in a forward direction and is in a deceleration state. That is, the wheel unit (100) rotates in a forward direction and is in a deceleration state, the planetary carrier (240) is stationary, and the vehicle is in a braking energy recovery state. Compound braking mode is primarily used in braking scenarios at very low speeds and high speeds with high braking intensity. Due to the motor's operating characteristics and efficiency limitations in these scenarios, electric braking alone is insufficient to meet braking requirements. Therefore, mechanical friction braking is required in addition to electric braking to meet braking requirements. Compound braking mode is divided into efficiency-based compound braking mode and energy-saving compound braking mode, depending on whether the ratio of electric braking torque to mechanical friction braking torque is adjustable. This mode can be set according to the driver's preference. The reverse braking mode works under the braking condition of the vehicle in reverse driving, because the hub motor (400) works in the fourth quadrant at this time, but because the vehicle speed is usually very low under the reverse braking condition, the hub motor (400) works in the low efficiency range, resulting in a low intensity of the electric brake alone, and completing a fast and efficient reverse braking action, so mechanical friction braking is introduced. At this time, the hub motor (400) is in a positive speed and negative torque state, and the electromagnetic clutch (600) is switched to an active state. The sun gear (230) rotates forward and is in a deceleration state, and the gear ring on the inner edge of the rim (120) rotates reversely and is in a deceleration state, that is, the wheel unit (100) is reversed and in a deceleration state, and the planetary carrier (240) is reversed, which will drive the ball screw (330) to reverse, and the ball nut (320) and the brake support (316) move backward. At this time, the friction lining (311) on the front side first contacts the brake disc (130). , so that the front brake rocker arm (313) swings forward, and under the action of the brake guide rod (314), the rear brake rocker arm (313) also swings forward, and finally the front and rear brake calipers (312) approach each other, and the multi-link brake actuator (310) clamps the brake disc (130) to achieve reverse braking. When the brake is canceled, the hub motor (400) is controlled to work in the first quadrant, which is a positive speed and positive torque. At this time, the planetary carrier (240) rotates forward, which will drive the ball screw (330) to rotate forward, and the ball nut (320) and the brake support (316) move forward until they return to the initial position. At the same time, the brake rocker arm (313) completes the return to the center under the action of the return spring (315), and the multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, so that the planetary carrier (240) is stationary, and the brake is released; The parking brake mode is mainly divided into three types: flat ground parking brake, slope parking brake with the vehicle head facing up, and slope parking brake with the vehicle head facing down; When the vehicle is in a flat ground parking brake condition, the vehicle is stationary. At this time, the hub motor (400) is controlled to work in the first quadrant, and the working point torque is small. At the same time, the electromagnetic clutch (600) is in an active state. At this time, the sun gear (230) rotates forward. Since the wheel unit (100) belongs to a large inertia system, the inner ring gear structure of the rim (120) will be accompanied by slight shaking and can be regarded as stationary. The planetary carrier (240) rotates forward, which will drive the ball screw (330) to rotate forward. The ball nut (320) and the brake support (316) move forward. At this time, the rear friction lining (311) first contacts the brake disc (130), thereby causing the rear brake rocker arm (313) to swing backward. Under the action of the brake guide rod (314), the front brake rocker arm (313) also swings backward, and finally the front and rear brake calipers (312) approach each other, and the multi-link brake actuator (310) clamps the brake disc (1 30), after being fully clamped, the electromagnetic clutch (600) switches to a locked state to realize the flat ground parking brake function. When the brake is canceled, the electromagnetic clutch (600) is first controlled to switch to an active state, and the hub motor (400) is controlled to work in the third quadrant, which is a negative speed and negative torque. The sun gear (230) reverses. Since the vehicle belongs to a large inertia system, it can be regarded as stationary in a short time, that is, the inner ring gear of the rim (120) is stationary. At this time, the planetary carrier (240) reverses, which will drive the ball screw (330) to reverse, and the ball nut (320) and the brake support (316) move backward until they return to the initial position. At the same time, the brake rocker (313) completes the return to the original position under the action of the return spring (315), and the multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to a locked state, so that the planetary carrier (240) is stationary, and the brake is released; When the vehicle is in a parking brake condition on a slope with the front of the vehicle facing upward, the vehicle tends to reverse backward, which can be compared to the reverse braking mode. The hub motor (400) is controlled to be in the fourth quadrant. At this time, the hub motor (400) is in a positive speed negative torque state. At the same time, the electromagnetic clutch (600) is switched to an active state. The sun gear (230) rotates forward and is in a deceleration state. The gear ring on the inner edge of the rim (120) rotates reversely and is in a deceleration state. That is, the wheel unit (100) rotates reversely and is in a deceleration state. The planetary carrier (240) rotates reversely, which drives the ball screw (330) to reverse. The ball nut (320) and the brake support (316) move backward. At this time, the friction lining (311) on the front side first contacts the brake disc (130), thereby causing the brake rocker arm (313) on the front side to swing forward. Under the action of the brake guide rod (314), the brake rocker arm (313) on the rear side also swings forward, and finally the front and rear wheels are reversed. The two brake calipers (312) are close to each other, and the multi-link brake actuator (310) clamps the brake disc (130) to achieve parking brake on a slope with the front of the vehicle facing upward. When the brake is released, the hub motor (400) is controlled to work in the first quadrant, which is positive speed and positive torque. The sun gear (230) rotates forward. Since the vehicle belongs to a large inertia system, it can be regarded as stationary in a short period of time, that is, the inner ring gear of the rim (120) is stationary. At this time, the planetary carrier (240) rotates forward, which will drive the ball screw (330) to rotate forward. The ball nut (320) and the brake support (316) move forward until they return to the initial position. At the same time, the brake rocker (313) completes the return to the original position under the action of the return spring (315). The multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, making the planetary carrier (240) stationary, and achieving brake release. When the vehicle is in a parking brake condition on a slope with the front of the vehicle facing downward, the vehicle tends to move forward, which can be compared to a compound braking mode. The hub motor (400) is controlled to be in the second quadrant. At this time, the hub motor (400) is in a negative speed positive torque state. At the same time, the electromagnetic clutch (600) is switched to an active state. The sun gear (230) rotates in reverse and is in a deceleration state. The gear ring on the inner edge of the rim (120) rotates forward and is in a deceleration state. That is, the wheel unit (100) rotates forward and is in a deceleration state. The planetary carrier (240) rotates forward, which will drive the ball screw (330) to rotate forward. The ball nut (320) and the brake support (316) move forward. At this time, the friction lining (311) on the rear side first contacts the brake disc (130), thereby causing the brake rocker arm (313) on the rear side to swing backward. Under the action of the brake guide rod (314), the brake rocker arm (313) on the front side also swings backward, and finally the front and rear sides are rotated in a reverse direction. The two brake calipers (312) are close to each other, and the multi-link brake actuator (310) clamps the brake disc (130) to achieve parking brake on a slope with the front of the vehicle facing downward. When the brake is released, the hub motor (400) is controlled to operate in the third quadrant, which is a negative speed and negative torque. The sun gear (230) rotates forward. Since the vehicle belongs to a large inertia system, it can be regarded as stationary for a short time, that is, the inner ring gear of the rim (120) is stationary. At this time, the planetary carrier (240) reverses, which will drive the ball screw (330) to reverse, and the ball nut (320) and the brake support (316) move backward until they return to the initial position. At the same time, the brake rocker (313) completes the return to the original position under the action of the return spring (315). The multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, making the planetary carrier (240) stationary, and achieving brake release.

10. The multi-link brake integrated driving and braking electric wheel system according to claim 9, characterized in that: The compound braking mode of the multi-link braking drive-braking integrated electric wheel system is characterized by comprising: The compound braking mode is divided into an efficiency-type compound braking mode and an energy-saving compound braking mode according to whether the ratio of the electric braking torque to the mechanical friction braking torque is adjustable, and can be set according to the driver's own preferences; In the performance-oriented compound braking mode, the electric braking torque and the mechanical friction braking torque are distributed in a fixed ratio, and the proportion of the mechanical braking torque to the total braking torque reaches the maximum. The main focus is on vehicle driving performance and driving pleasure. In energy-saving compound braking mode, electric braking torque and mechanical friction braking torque are distributed in a variable ratio. While meeting braking requirements, as much braking torque as possible is allocated to electric braking. This achieves energy-saving driving through brake energy recovery and improves vehicle economy. The invention discloses a control method for an efficient composite braking mode, wherein the hub motor (400) is controlled to be in the second quadrant, at which time the hub motor (400) is in a negative speed and positive torque state, and the electromagnetic clutch (600) is controlled to be in an active state throughout the entire process, the sun gear (230) rotates in the reverse direction and is in a deceleration state, and the gear ring on the inner edge of the rim (120) rotates in the forward direction and is in a deceleration state, that is, the wheel unit (100) rotates in the forward direction and is in a deceleration state, and the planet carrier (240) rotates in the forward direction, which drives the ball screw (330) to rotate in the forward direction, and the ball nut (320) and the brake support (3 16) moves forward, at this time, the rear friction lining (311) first contacts the brake disc (130), thereby causing the rear brake rocker arm (313) to swing backward, and under the action of the brake guide rod (314), the front brake rocker arm (313) also swings backward, eventually causing the front and rear brake calipers (312) to approach each other, and the multi-link brake actuator (310) clamps the brake disc (130), realizing efficient composite braking. At this time, the braking torque of the entire vehicle is provided by both mechanical friction braking and electric braking, and the ratio of the torques of the two is a fixed value. λ is related to the design parameters of the internal components of the multi-link brake actuator (310), such as the transmission ratio and mechanical efficiency. The ratio of the output torque of the hub motor (400) to the total braking torque is The total braking torque output can be controlled by adjusting the torque output of the hub motor (400). When the brake is released, the hub motor (400) is controlled to operate in the third quadrant, which is a negative speed and negative torque. At this time, the planetary carrier (240) reverses, which drives the ball screw (330) to reverse, and the ball nut (320) and the brake support (316) move backward until they return to the initial position. At the same time, the brake rocker arm (313) is returned to the center position under the action of the return spring (315), and the multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, so that the planetary carrier (240) is stationary, and the brake is released. The invention discloses a control method for an energy-saving composite braking mode, wherein the hub motor (400) is controlled to operate in the second quadrant. At this time, the hub motor (400) is in a negative speed positive torque state. Unlike the efficiency composite braking mode, the electromagnetic clutch (600) is not in an active state throughout the entire process, but its state switching is controlled in real time according to the target ratio of the electric braking torque to the mechanical friction braking torque. Since in the composite braking mode, the ratio of the mechanical friction braking to the total braking torque depends on the position of the brake support (316), that is, the position of the ball nut (320), and thus depends on the angle rotated by the ball screw (330), that is, the angle rotated by the planet carrier (240), the electromagnetic clutch (600) is first controlled to be in an active state, and the planet carrier (240) starts to rotate forward. After the planet carrier (240) rotates through a certain angle, the electromagnetic clutch (600) is quickly controlled to switch to a locked state, and the position of the planet carrier (240) at this time is fixed, so that the mechanical friction braking torque and the electric braking torque can be controlled to be in any ratio. The ratio of the output torque of the hub motor (400) to the total braking torque is An energy-saving composite braking mode is realized. At this time, the total braking torque output can be controlled by adjusting the torque output of the hub motor (400). When the brake is canceled, the hub motor (400) is controlled to operate in the third quadrant, which is a negative speed and negative torque. At this time, the planetary carrier (240) reverses, which drives the ball screw (330) to reverse, and the ball nut (320) and the brake support (316) move backward until they return to the initial position. At the same time, the brake rocker arm (313) completes the return to the original position under the action of the return spring (315), and the multi-link brake actuator (310) releases the brake disc (130). At this time, the electromagnetic clutch (600) switches back to the locked state, so that the planetary carrier (240) is stationary, and the brake is released.

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