CN108105293B - Brake actuator, automobile brake system and electric automobile - Google Patents

Abstract

The utility model relates to a brake actuator, car braking system and electric automobile, this brake actuator includes the casing, hold the motor in the casing respectively, torque transmission device and screw-nut cooperation mechanism, the output torque of motor passes through torque transmission device and transmits to screw-nut cooperation mechanism so that the stopper work, torque transmission device includes planet wheel reduction gears, in this planet wheel reduction gears, the sun gear links to each other with the output shaft transmission of motor, the planet carrier links to each other with the screw drive of screw-nut cooperation mechanism, brake actuator still includes the electromagnetic braking ware that is used for the power output shaft locking of output shaft or planet carrier or releases the locking, lock output shaft or power output shaft when electromagnetic braking ware loses the electricity, release output shaft or power output shaft when electromagnetic braking ware is electrified. The brake actuator as described above is not only simple in structure but also has the effects of rapid signal transmission, fast braking response and sensitive response by using mechanical and electrical connections.

Description

Brake actuator, automobile brake system and electric automobile

Technical Field

The disclosure relates to the technical field of vehicles, in particular to a brake actuator, an automobile brake system and an electric automobile.

Background

In a traditional hydraulic or pneumatic braking system, the obvious defects of complex gas-liquid pipelines, difficult maintenance, complex arrangement structure, slow braking dynamic response, lower braking comfort performance and the like exist. For example, in a hydraulic brake system, a rebound vibration phenomenon occurs in a brake pedal when an anti-lock brake system is operated, which affects brake comfort. For another example, because the brake pedal mechanism is directly connected with the brake transmission device and the brake actuating device, the impact force generated when the vehicle collides can be directly transmitted into the cab through the brake system, and the safety performance of the automobile is seriously affected. Therefore, in view of the above problems, various electromechanical brake systems having a simple structure, a fast braking dynamic response, and excellent braking comfort and safety performance as compared to hydraulic or pneumatic brake systems have been developed in recent years.

Disclosure of Invention

The problem of this disclosure solution is to provide a simple structure and brake actuator, car braking system and electric automobile that braking dynamic response is fast.

In order to achieve the above object, according to one aspect of the present disclosure, there is provided a brake actuator including a housing torque, a motor torque, a torque transmission device, and a screw-nut engagement mechanism, each of which is accommodated in the housing torque, an output torque of the motor torque being transmitted to the screw-nut engagement mechanism through the torque transmission device to operate a brake, the torque transmission device including a planetary reduction mechanism torque in which a sun gear torque is drivingly connected to an output shaft torque of the motor torque, and a carrier torque is drivingly connected to a screw torque of the screw-nut engagement mechanism, the brake actuator further including an electromagnetic brake torque for locking or unlocking the output shaft torque or a power output shaft of the carrier torque, the output shaft torque or the power output shaft being locked when the electromagnetic brake torque is de-energized, releasing the output shaft torque or the power output shaft when the electromagnetic brake torque is energized.

Alternatively, the electromagnetic brake torque is connected to an output shaft torque of the motor torque for locking or unlocking the output shaft.

Alternatively, the electromagnetic brake torque includes an electromagnetic drive portion torque and a brake portion torque that is arranged at an interval from the electromagnetic drive portion torque and is connected to the output shaft torque, the electromagnetic drive portion torque includes an electromagnetic coil and a permanent magnet, the electromagnetic drive portion torque adsorbs the brake portion torque when the electromagnetic brake torque is de-energized, and the electromagnetic drive portion torque releases the brake portion torque when the electromagnetic brake torque is energized.

Optionally, the lead screw comprises a small-diameter section in transmission connection with the planet carrier and a large-diameter section matched with a nut of the lead screw nut matching mechanism, a thrust bearing is arranged on a connecting portion of the small-diameter section and the large-diameter section, and a step used for abutting against a static end of the thrust bearing is formed on the shell.

Optionally, the screw comprises a small diameter section in transmission connection with the planet carrier and a large diameter section matched with a nut of the screw nut matching mechanism, a thrust bearing is arranged on a connecting part of the small diameter section and the large diameter section, the small diameter section is supported in a shaft hole of the shell through a bearing or a shaft sleeve, and a flange of the bearing or the shaft sleeve abuts against an end wall of the shaft hole close to the large diameter section, so that a static end of the thrust bearing can abut against the flange of the bearing or the shaft sleeve.

Optionally, the screw-nut matching mechanism is a planetary roller screw mechanism torque, the planetary roller screw mechanism torque includes a screw torque, rollers and a nut torque, the rollers are respectively in threaded matching with the screw torque and the nut torque, roller gears are arranged at two ends of the rollers, an inner gear meshed with each roller gear is arranged on an inner circumferential surface of the nut torque or an outer gear meshed with each roller gear is arranged on an outer circumferential surface of the screw torque, and the nut torque is movable along an axial direction of the output shaft torque relative to the screw torque.

Optionally, the casing torque includes a first casing part torque detachably connected, the first casing part torque has a first opening and a first chamber containing torque for containing the motor torque and the electromagnetic brake torque and a second chamber containing torque for containing the planet wheel speed reducing mechanism torque are formed in the first casing part torque, the first chamber containing torque and the second chamber containing torque are communicated, and the screw nut matching mechanism extends out of the first opening.

Optionally, the housing torque further includes a second housing portion torque having a second opening, a third accommodating cavity torque for accommodating the screw nut matching mechanism is formed in the second housing portion torque, the first opening corresponds to the second opening, and when the first housing portion torque is matched with the second housing portion torque, the second accommodating cavity torque is communicated with the third accommodating cavity torque.

Optionally, the second housing portion torque is a floating caliper housing, and an inner friction plate torque and an outer friction plate torque for friction fit with the brake disc are arranged in the second accommodating cavity torque.

Through the technical scheme, the electromechanical brake actuator is adopted without arranging a gas-liquid brake pipeline, so that the structure is simple, the output torque of the motor is reliably transmitted to the screw nut matching mechanism through the torque transmission device, the friction plate can be effectively driven to clamp the brake disc, and the effects of rapid signal transmission, quick brake response and sensitive response are achieved.

Through the technical scheme, the electromechanical brake actuator is adopted without arranging a gas-liquid brake pipeline, so that the structure is simple, the output torque of the motor is reliably transmitted to the screw nut matching mechanism through the torque transmission device, the friction plate can be effectively driven to clamp the brake disc, and the effects of rapid signal transmission, quick brake response and sensitive response are achieved.

According to another aspect of the present disclosure, there is also provided a vehicle brake system including a brake provided with a brake actuator as described above.

Optionally, the brake includes a brake disc, a friction plate for friction fit with the brake disc is disposed in the brake actuator, and the screw-nut fit mechanism can drive the friction plate to clamp the brake disc.

According to still another aspect of the present disclosure, there is also provided an electric vehicle including the vehicle brake system as described above.

The action effect of the automobile brake system and the electric automobile of the present disclosure is the same as that of the brake actuator described above, and therefore, the detailed description thereof is omitted herein for the sake of avoiding redundancy.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

fig. 1 is a schematic structural diagram of a brake actuator provided in a first exemplary embodiment of the present disclosure;

FIG. 2 is a first schematic structural diagram of a brake actuator provided in accordance with a first exemplary embodiment of the present disclosure;

FIG. 3 is a second schematic structural diagram of a brake actuator provided in accordance with an exemplary first embodiment of the present disclosure;

fig. 4 is a structural view of a motor in a brake actuator provided in an exemplary first embodiment of the present disclosure;

fig. 5 is a structural schematic diagram of a planetary gear speed reduction mechanism in a brake actuator provided in an exemplary first embodiment of the present disclosure;

fig. 6 is a structural schematic diagram of a brake actuator provided in a second exemplary embodiment of the present disclosure;

fig. 7 is a structural schematic diagram of a brake actuator provided in a third exemplary embodiment of the present disclosure;

fig. 8 is a schematic structural view of a brake actuator according to an exemplary third embodiment of the present disclosure, in which a motor is connected to an electromagnetic brake;

fig. 9 is a schematic view of a partial structure of a brake actuator according to a fourth exemplary embodiment of the present disclosure;

FIG. 10 is a schematic view of another portion of a brake actuator according to a fourth exemplary embodiment of the present disclosure;

fig. 11 is a schematic structural view illustrating a connection between a motor and an electromagnetic brake in a brake actuator according to a fourth exemplary embodiment of the present disclosure;

FIG. 12 is a schematic diagram of a portion of another brake actuator provided in accordance with a fourth exemplary embodiment of the present disclosure;

fig. 13 is another partial structural schematic diagram of another brake actuator provided in accordance with a fourth exemplary embodiment of the present disclosure.

Detailed Description

The following detailed description of specific embodiments of the present disclosure is provided in connection with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

In the present disclosure, the use of directional terms such as "inner and outer" means inner and outer with respect to the profile of the corresponding component, unless stated to the contrary.

As shown in fig. 1 to 12, the brake actuator provided by the four exemplary embodiments of the present disclosure can effectively drive a friction plate to clamp a brake disc by a simple structure, effectively improve the braking response time of an automobile, and improve the performance such as comfort and operability. Here, for similar structures, effects, and the like in the four exemplary embodiments, in order to avoid repetition, redundant description is not given in the case that the detailed description has been given before.

As shown in fig. 1 to 5, the brake actuator provided according to the first embodiment includes a housing 100, a motor 101, a torque transmission device, and a lead screw nut fitting mechanism respectively accommodated in the housing 100, the output torque of the motor 101 is transmitted to the lead screw nut fitting mechanism through the torque transmission device to operate the brake, the torque transmission device comprises a drive gear set 102 and a plurality of planetary reduction mechanisms 103, the transmission gear set 102 includes a driven gear 1021 and a plurality of driving gears 1022 respectively engaged with the driven gear 1021, in the planetary gear speed reducing mechanism 103, each sun gear 1031 is in transmission connection with the output shaft 1011 of the corresponding motor 101, each planet carrier 1032 is in transmission connection with the corresponding driving gear 1022, each ring gear 1034 is fixed in the housing 100, and a lead screw 1061 of the lead screw nut matching mechanism is in transmission connection with the driven gear 1021.

The brake can be a disc brake, comprises a brake disc and a friction plate in friction fit with the brake disc, and the friction plate can be driven by a lead screw nut matching mechanism to clamp the brake disc, so that service braking or parking braking is realized. Specifically, here, the magnitude of the output torque of the electronic control unit to the motor 101 may be controlled according to the braking force of the brake pedal and the braking stroke. In addition, the sun gear 1031 is in transmission connection with the output shaft 1011 of the corresponding motor 101, and each planet carrier 1032 is in transmission connection with the corresponding driving gear 1022 through key connection, spline connection or the like, and the transmission connection between the sun gear 1031 and the motor 101, and between the planet carrier 1032 and the driving gear 1022 can also be realized through a form of profile fit. The torque output by each motor 101 is transmitted to the sun gear 1031 in the corresponding planetary gear speed reduction mechanism 103, transmitted to the driving gear 1022 of the transmission gear set 102 via the planetary gears 1033 and the planetary carrier 1032, and finally transmitted to the screw-nut matching mechanism via the driven gear 1021 engaged with each driving gear 1022, so that the nut 1062 of the screw-nut matching mechanism can drive the friction plate 104 to clamp the brake disc 105, thereby realizing service braking. As described above, the friction plate 104 is effectively driven to clamp the brake disc 105 by the simple brake actuator, so that the brake response time of the automobile can be effectively improved, and the effects of rapid signal transmission and sensitive response are achieved. In addition, mechanical and electronic connection structures are used for eliminating mechanical and pneumatic connection between the brake pedal and the brake actuating mechanism, so that the rebound phenomenon of the brake pedal is avoided during braking, and the performances such as comfort, operability and the like are improved. In addition, the plurality of planetary gear speed reducing mechanisms 103 and the transmission gear set 102 are in transmission fit, so that torque can be transmitted to the screw 1061 of the screw nut matching mechanism more reliably, the transmission efficiency is high, reliable power output is effectively guaranteed, and the energy-saving effect is achieved.

Alternatively, as shown in fig. 2 to 4, at least one of the motors 101 includes a motor portion 1012 for outputting torque and a motor locking portion 1013 for locking or unlocking an output shaft 1011 of the motor portion 1012, which are respectively provided in a motor housing 1010. Thus, the parking brake is achieved by locking or unlocking the motor unit 1012 by the motor locking unit 1013. Here, the motor locking part 1013 may adopt various reasonable arrangements as long as the output shaft 1011 of the motor part 1012 can be locked or unlocked. For example, the motor locking part 1013 may be a clamp for clamping the output shaft 1011 or a lock for snapping into the output shaft 1011. However, the present disclosure is not limited thereto, and the output shaft 1011 of the motor 101 may be locked or unlocked by an electromagnetic brake, which is a member known in the art, for example.

Alternatively, the motor locking portion 1013 includes an inner friction plate 1017 connected to the output shaft 1011, an outer friction plate 1018 connected to the motor housing 1010, and a locking portion and an electromagnetic driving portion, the locking portion driving the electromagnetic driving portion to move so that the outer friction plate 1018 is frictionally engaged with the inner friction plate 1017 to lock the output shaft 1011 when power is lost, and the electromagnetic driving portion moving in a direction overcoming the locking force of the locking portion so that the outer friction plate 1018 is frictionally disengaged from the inner friction plate 1017 to release the output shaft 1011 when power is supplied. Here, the inner friction plate 1017 and the outer friction plate 1018 may be configured according to actual requirements, for example, a plurality of first contact plates protrude radially outward from an outer surface of the inner friction plate 1017, a plurality of second contact plates protrude radially inward from an inner surface of the outer friction plate 1018, and the first contact plates and the second contact plates are spaced apart in a moving direction when power is supplied. In order to increase the friction between the first contact plate and the second contact plate, a plurality of concave-convex structures which are matched with each other may be arranged on the opposite side surfaces of the first contact plate and the second contact plate. For another example, the inner friction plate 1017 and the outer friction plate 1018 may be formed as first and second brake blocks having mating shaped opposing surfaces, the outer friction plate 1018 mating with the opposing surface of the inner friction plate 1017 when power is lost.

Alternatively, as shown in fig. 4, the electromagnetic driving portion includes an electromagnetic coil 1014 and a ring magnet 1015, the locking portion is a spring 1016, the motor locking portion 1013 further includes a one-way clutch 1019 to which the inner friction plate 1017 is fixed and which is drivingly connected to the output shaft 1011, the ring magnet 1015 is engaged with a part of an inner peripheral surface of the electromagnetic coil 1014 to be able to expand and contract with respect to the electromagnetic coil 1014, the spring 1016 is provided on the inner peripheral surface of the electromagnetic coil 1014 and fixed to an inner end of the motor housing 1010 and a side end surface of the ring magnet 1015, the inner friction plate 1017 and the outer friction plate 1018 are provided on the other side of the ring magnet 1015 and are spaced from each other in an axial direction of the output shaft, when power is lost, the spring 1016 drives the ring magnet 1015 to push the outer friction plate 1018 so that the outer friction plate 1018 is frictionally engaged with the inner friction plate 1017, thereby locking the output shaft 1011 of the motor unit 1012 by the one-way clutch 1019. When energized, the ring magnet 1015 moves in a direction against the spring force of the spring 1016 to disengage the outer friction sheet 1018, such that the outer friction sheet 1018 is out of frictional engagement with the inner friction sheet 1017. The parking brake function is thereby reliably realized by the motor 101 configured as described above.

As shown in fig. 1 to 3, optionally, the lead screw 1061 includes a small diameter section in transmission connection with the driven gear 1021 and a large diameter section in cooperation with a nut 1062 of the lead screw nut cooperation mechanism, a thrust bearing 107 is disposed on a connection portion of the small diameter section and the large diameter section, and a step 1006 for abutting against a stationary end of the thrust bearing 107 is formed on the housing 100. Here, the small diameter section may be supported in the housing 100 by a sliding bearing, a rolling bearing, or a wear reduction copper bush 108, so that the wear of the lead screw 1061 can be reduced to protect the lead screw 1061. In addition, in a non-operating state of the brake actuator, an axial gap may be provided between the thrust bearing 107 and the step 1006, so that, in operation, the thrust bearing 107 can be brought into contact with the step 1006 by a reaction force of the nut 1062 against the lead screw 1061, and the thrust bearing 107 is provided to receive an axial load, thereby having a function of restricting an axial displacement of the lead screw 1061 with respect to the housing 100.

Optionally, the screw-nut matching mechanism is a planetary roller screw mechanism 106, the planetary roller screw mechanism 106 includes a screw 1061, rollers, and a nut 1062, the rollers are respectively in threaded matching with the screw 1061 and the nut 1062, and two ends of the rollers are provided with roller gears, an inner gear engaged with each roller gear is provided on an inner circumferential surface of the nut 1062 or an outer gear engaged with each roller gear is provided on an outer circumferential surface of the screw 1061, and the nut 1062 is movable relative to the screw 1061 along an axial direction of the output shaft 1011. The planetary roller screw mechanism 106 with the structure has the advantages of large bearing load, strong shock resistance, high transmission precision and long service life. Here, the roller gears at both ends of the roller can ensure the synchronism of transmission between the roller and the screw 1061 and the nut 1062, and can ensure that the pitch circle of the gear is pure rolling, thereby avoiding the interference phenomenon caused by the slippage of a part of the roller. In the above-described configuration, the gear meshing with the roller gear is provided on the inner circumferential surface of the nut 1062, but the present disclosure is not limited thereto, and for example, in the case where no internal gear is provided on the inner circumferential surface of the nut 1062, an external gear meshing with the roller gear may be provided on the corresponding outer circumferential surface of the screw 1061. Further alternatively, the screw nut engaging mechanism may be a ball screw nut mechanism, a slide screw nut mechanism, or the like.

Alternatively, as shown in fig. 1 to 3, the planetary reduction gear 103 and the motor 101 are formed into power output groups, and the power output groups are respectively provided with two groups in the housing 100 and are symmetrically arranged on two sides of the screw-nut matching mechanism. The specific arrangement structure of the planetary gear speed reduction mechanisms 103 in the two power output groups employed therein is the same, and at least one of the two motors 101 may be provided with the motor locking portion 1013 as described above. The torque reduced and increased in speed by each planetary reduction mechanism 103 is reliably transmitted to the screw 1061 of the screw-nut engagement mechanism via the driven gear 1021 of the transmission gear set 102. However, the present disclosure is not limited thereto, and the number of power output groups may be appropriately designed according to actual circumstances.

Optionally, the power output sets are respectively arranged in parallel with the screw nut matching mechanisms. Therefore, the brake actuator has the advantages of compact integral structure and small occupied installation space.

Optionally, the transmission gear set 102 includes an idler gear 1023 engaged between the drive gear 1022 and the driven gear 1021 to properly arrange the transmission ratios of the transmission gear set 102 according to the assembly environment.

Optionally, the housing 100 includes a first housing portion 1001 and a second housing portion 1002 that are detachably connected, a first accommodating cavity 1003 for accommodating the screw nut matching mechanism and having a first opening, a second accommodating cavity 1004 symmetrically disposed on two sides of the first accommodating cavity 1003 for accommodating the power output group, and a third accommodating cavity 1005 for accommodating the transmission gear set 102 and having a second opening, where the third accommodating cavity 1005 is respectively communicated with the first accommodating cavity 1003 and the second accommodating cavity 1004, the second housing portion 1002 is matched with the first housing portion 1001 to seal the second opening of the third accommodating cavity 1005, and the first opening and the second opening are disposed at two ends of the first housing portion 1001. The brake actuator as described above is of a modular structure as a whole, is compact in arrangement structure, can be reasonably arranged in a limited installation space, and has the effects of simple assembly and convenient maintenance.

According to a first embodiment, a brake is provided in a vehicle brake system, wherein the brake is provided with a brake actuator as described above. Optionally, the brake includes a brake disc 105, a friction plate 104 for friction engagement with the brake disc 105 is disposed in the brake actuator, and the screw nut engagement mechanism is capable of driving the friction plate 104 to clamp the brake disc 105. The brake caliper of the brake may be a floating caliper, and the housing 100 of the brake actuator is fixed on the floating caliper, or the floating caliper housing and the housing 100 are integrally formed, so that the torque output by the motor 101 is transmitted to the screw 1061 of the screw nut matching mechanism through the planetary gear speed reducing mechanism 103 and the transmission gear set 102 in sequence, and the driving nut 1062 pushes the friction plate 104 in the floating caliper to enable the inner friction plate 1041 and the outer friction plate 1042 to clamp the brake disc 105, thereby implementing service braking. In addition, when the parking brake is performed, the motor 101 is de-energized, the ring magnet 1015 is driven by the spring 1016 of the motor locking part 1013 to push the outer friction sheet 1018, so that the outer friction sheet 1018 is in friction fit with the inner friction sheet 1017, and the output shaft 1011 of the motor part 1012 is locked under the action of the one-way clutch 1019, thereby realizing the parking brake.

According to a first embodiment, an electric vehicle is provided that includes the vehicle brake system described above. The friction plate 104 can be effectively driven to clamp the brake disc 105 through the brake actuator with the simple structure, so that the braking response time of the automobile can be effectively prolonged, and the effects of rapid signal transmission and sensitive response are achieved.

A first embodiment of the present disclosure is described above with reference to fig. 1 to 5, and a second embodiment of the present disclosure is specifically described below with reference to fig. 6.

As shown in fig. 6, a brake actuator according to a second embodiment of the present disclosure includes a housing 200, a motor 201 accommodated in the housing 200, a torque transmission mechanism, and a plurality of screw-nut engagement mechanisms, wherein an output torque of the motor 201 is transmitted to each of the screw-nut engagement mechanisms through the torque transmission mechanism, so as to operate a brake, each of the screw-nut engagement mechanisms is provided with a first transmission gear 2062 drivingly connected to a screw 2061, and a second transmission gear 2033 meshed with each of the first transmission gears 2062 is provided on the torque transmission mechanism, so that a position of the nut 2063 of each of the screw-nut engagement mechanisms can be synchronously adjusted in an axial direction.

Here, the magnitude of the output torque of the electronic control unit to the motor 201 may be controlled according to the braking force and the braking stroke of the brake pedal. The torque transmission mechanism may have various structures as long as it can output the torque of the motor 201 to each of the screw-nut engaging mechanisms, and may be, for example, a gear transmission mechanism, a worm gear transmission mechanism, or the like. Here, the driving connection between the motor 201 and the torque transmission mechanism and the driving connection between the lead screw 2061 and the first driving gear 2062 of the lead screw nut matching mechanism can be realized by key connection or spline connection. As described above, the torque output from the motor 201 is transmitted to the lead screws 2061 of the respective lead screw-nut fitting mechanisms via the torque transmission mechanism, so that the nuts 2062 in driving engagement with the lead screws 2061 of the lead screw-nut fitting mechanisms can drive the friction plates 204 to clamp the brake disc 205, thereby realizing service braking. As described above, the friction plate 204 is effectively driven to clamp the brake disc 205 by the simple brake actuator, so that the brake response time of the automobile can be effectively improved, and the effects of rapid signal transmission and sensitive response are achieved. In addition, in the present embodiment, the plurality of screw-nut engagement mechanisms are driven by one motor 201 to adjust positions in the axial direction synchronously, so that the friction plates 204 can be stably pushed to reliably clamp the brake disc 205.

Alternatively, the torque transmission mechanism comprises a planetary gear train 202, the planetary gear train 202 comprises a sun gear 2021, a planet carrier 2022, planet gears 2023 and a gear ring 2024, the sun gear 2021 is in transmission connection with an output shaft 2011 of the motor 201, the planet gears 2023 are respectively meshed with the sun gear 2021 and the gear ring 2024, the gear ring 2024 is fixed in the housing 200, and the second transmission gear 2033 is coaxially arranged on the planet carrier 2022. Therefore, the output torque of the motor 201 is transmitted to the lead screw 2061 of each lead screw nut matching mechanism after being decelerated by the planetary gear train 202, that is, the output torque of the motor 201 is transmitted to the lead screw 2061 of each lead screw nut matching mechanism through the sun gear 2021, the planet gear 2023 and the planet carrier 2022, and then the output torque is transmitted to the lead screw 2061 of each lead screw nut matching mechanism through the second transmission gear 2033 which is in transmission connection with the planet carrier 2022 through a key, a spline connection or the like or is directly fixed on the planet carrier 2022, so that the nut 2063 of each lead screw nut matching mechanism can synchronously drive the friction plate 204 to clamp the brake disc 205, thereby realizing.

Alternatively, yet optionally, the torque transmitting mechanism comprises: a planetary gear train 202, the planetary gear train 202 including a sun gear 2021, a planet carrier 2022, planet gears 2023 and a gear ring 2024, the sun gear 2021 being in transmission connection with an output shaft 2011 of the motor 201, the planet gears 2023 being respectively engaged with the sun gear 2021 and the gear ring 2024, the gear ring 2024 being fixed in the housing 200, and a plurality of mounting shafts having the same interval from a central axis being provided on one side surface of the planet carrier 2022; a transmission gear train 203, wherein the transmission gear train 203 comprises a transmission ring gear 2031, a plurality of transmission ring gears 2032 and the second transmission gear 2033, each transmission ring gear 2032 is fixed on the corresponding mounting shaft and is engaged with the transmission ring gear 2031, and the second transmission gear 2033 is in transmission connection with or integrated with the transmission ring gear 2031. A large transmission ratio can thereby be achieved by means of the torque transmission mechanism as described above, and a greater braking force that meets the braking requirements can be achieved. However, the present disclosure is not limited thereto, and the torque transmission mechanism may have any other reasonable configuration as long as the output torque of the motor 201 can be transmitted to the screw rods 2061 of the respective screw-nut engagement mechanisms, and the nuts 2063 can synchronously drive the friction plates 204 (the inner friction plate 2041 and the outer friction plate 2042 clamp the brake disc 205).

Alternatively, each of the lead screws 2061 includes a small diameter section drivingly connected to the first transmission gear 2062 and a large diameter section engaged with the nut 2063 of the lead screw nut engaging mechanism, a thrust bearing is provided at a connecting portion of the small diameter section and the large diameter section, and a step for abutting against a stationary end of the thrust bearing is formed on the housing 200. Here, each of the lead screws 2061 may be supported in the housing 200 by a sliding bearing, a rolling bearing, or a wear-reducing copper bush, so that the wear of the lead screws 2061 can be reduced to protect the lead screws 2061. In addition, in the non-operating state of the brake actuator, an axial gap may be provided between the thrust bearing and the step, so that, in operation, the thrust bearing is brought into abutment with the step by the reaction force of the nut 2063 against the screw rod 2061, and the axial load is received by the thrust bearing, thereby having an effect of restricting the axial displacement of the screw rod 2061 relative to the housing 200.

Alternatively, as in the first embodiment, the screw-nut engagement mechanism is a planetary roller screw mechanism 206, the planetary roller screw mechanism 206 includes the screw 2061, rollers, and a nut 2063, the rollers are respectively screw-engaged with the screw 2061 and the nut 2063, roller gears are provided at both ends of the rollers, an internal gear engaged with each roller gear is provided on an inner circumferential surface of the nut 2063 or an external gear engaged with each roller gear is provided on an outer circumferential surface of the screw 2061, and the nut 2063 is movable in the axial direction of the output shaft 2011 with respect to the screw 2061. Therefore, the screw nut matching mechanism has the advantages of large bearing load, strong shock resistance, high transmission precision and long service life. Here, the roller gears at the two ends of the roller can ensure the synchronism of the transmission between the roller and the screw rod 2061 and the nut 2063, and can ensure that the pitch circle of the gear is pure rolling, thereby avoiding the interference phenomenon caused by the slippage of a part of the roller.

Optionally, the motor 201 is provided with a motor locking portion for locking or unlocking an output shaft 2011 of the motor 201. The motor locking unit locks or unlocks the output shaft 2011 of the motor 201, thereby realizing the parking brake of the brake actuator or unlocking the parking brake. However, the motor locking portion may have the same structure as the motor locking portion 1013 used in the first embodiment, that is, the motor 101 used in the first embodiment may be used as the motor 201 in the present embodiment. Alternatively, the motor locking portion may be, for example, an electromagnetic brake, which will be described in detail in the following third and fourth embodiments.

Alternatively, in order to ensure stable synchronous motion of two screw nut fitting mechanisms, the transmission gear train 203 is positioned between the planetary gear train 202 and the motor 201, and the screw nut fitting mechanisms are arranged in two and symmetrically arranged at two sides of the torque transmission mechanism. The two screw nut matching mechanisms adopted in the method have the same structure.

Optionally, the torque transmission mechanisms are respectively arranged in parallel with the lead screw nut matching mechanisms. Therefore, the brake actuator has the advantages of compact integral structure and small occupied installation space.

Alternatively, as shown in fig. 6, the housing 200 includes a first housing portion 2001 and a second housing portion 2002 which are detachably connected, the first housing portion 2001 has a first opening and a second opening which are opposite to each other, a first accommodating chamber 2003 for accommodating the torque transmission mechanism is formed in the first housing portion 2001, and second accommodating chambers 2004 which are symmetrically arranged at both sides of the first accommodating chamber 2003 and are for accommodating the respective screw nut fitting mechanisms are formed, the first opening is formed at one side of the second accommodating chamber 2004 for the screw nut fitting mechanisms to pass through, the second opening is formed at the other side of the first accommodating chamber 2003 and the second accommodating chamber 2004, the second housing portion 2002 has a third opening which is opposite to the second opening, and a third accommodating chamber 2005 for accommodating the motor 201 is formed in the second housing portion 2002, when the first housing portion 2001 and the second housing portion 2002 are fitted, the first accommodating chamber 2003, the second accommodating chamber 2004, and the third accommodating chamber 2005 communicate with each other. The brake actuator as described above is of a modular structure as a whole, is compact in arrangement structure, can be reasonably arranged in a limited installation space, and has the effects of simple assembly and convenient maintenance.

According to a second embodiment, there is provided a vehicle brake system including a brake provided with the brake actuator of the second embodiment. Optionally, the brake includes a brake disc 205, a friction plate 204 for friction engagement with the brake disc 205 is disposed in the brake actuator, and the screw nut engagement mechanism is configured to drive the friction plate 204 to clamp the brake disc 205. The brake caliper of the brake may be a floating caliper to which the housing 200 of the brake actuator is fixed, or the floating caliper housing is integrally formed with the housing 200, and the position of the plurality of screw nut engagement mechanisms is synchronously adjusted in the axial direction by driving one motor 201, whereby the friction plates 204 can be stably pushed to reliably clamp the brake disc 205, and the braking efficiency can be improved.

An electric vehicle provided according to a second embodiment includes the vehicle brake system provided in the second embodiment described above. The friction plate 204 is effectively driven to clamp the brake disc 205 through the brake actuator with the simple structure, so that the brake response time of the automobile can be effectively prolonged, and the effects of rapid signal transmission and sensitive response are achieved.

The second embodiment of the present disclosure is described above with reference to fig. 6, and the third embodiment of the present disclosure is specifically described below with reference to fig. 7 and 8.

As shown in fig. 7 and 8, a brake actuator according to a third embodiment of the present disclosure includes a housing 300, a motor 301 respectively accommodated in the housing 300, a torque transmission device, and a screw-nut engagement mechanism, wherein an output torque of the motor 301 is transmitted to the screw-nut engagement mechanism through the torque transmission device to operate a brake, the torque transmission device includes a planetary reduction mechanism 302, in the planetary reduction mechanism 302, a sun gear 3021 is drivingly connected to an output shaft 3011 of the motor 301, a planet carrier 3022 is drivingly connected to a screw 3061 of the screw-nut engagement mechanism, the brake actuator further includes an electromagnetic brake 303 for locking or unlocking the output shaft 3011 or a power output shaft of the planet carrier 3022, the electromagnetic brake 303 locks or unlocks the output shaft 3011 or the power output shaft when power is lost, when the electromagnetic brake 303 is electrified, the output shaft 3011 or the power output shaft is released.

That is, at the time of service braking, the output torque of the motor 301 is transmitted to the lead screw 3061 of the lead screw-nut engagement mechanism via the sun gear 3021, the planet gear 3023, and the planet carrier 3022, and the nut 3062 is further caused to drive the friction plate 304 to clamp the brake disc 305, whereby service braking is achieved, and at the time of release of service braking, self-adjustment of the clearance can be achieved by de-energizing the motor 301, or by reversing the motor 301, so that the nut 3062 of the lead screw-nut engagement mechanism is returned, and self-adjustment of the brake clearance is performed. During parking braking, the output shaft 3011 of the motor 301 or the power output shaft of the planet carrier 3022 can be locked by the electromagnetic brake 303 losing power, so that the parking braking is realized. When the brake is released, the electromagnetic brake 303 may be energized to release the output shaft 3011 or the power output shaft, thereby releasing the parking brake. Here, the magnitude of the output torque of the electronic control unit to the motor 301 may be controlled according to the braking force and the braking stroke of the brake pedal. As described above, the friction plate 304 is effectively driven to clamp the brake disc 305 by the simple brake actuator, so that the brake response time of the automobile can be effectively improved, and the effects of rapid signal transmission and sensitive response are achieved.

In addition, the torque transmission device and/or the lead screw nut fitting mechanism may be provided in plural according to the actual requirement, for example, the number of the torque transmission device and the lead screw nut fitting mechanism may be set to be the same. Alternatively, the brake actuator of the present disclosure may be configured to drive a plurality of lead screw nut engaging mechanisms simultaneously through a torque transmission device, in which case the torque transmission device may include, for example, a form of drive gear set to adjust the appropriate gear ratio. Still alternatively, the brake actuator of the present disclosure may be configured to stably and reliably drive one screw-nut engaging mechanism through a plurality of torque transmission devices. The present embodiment is not particularly limited.

Alternatively, the electromagnetic brake 303 is connected to the output shaft 3011 of the motor 301 to lock or unlock the output shaft 3011, and a locking force of the electromagnetic brake 303 directly acts on the output shaft 3011 of the motor 301, thereby achieving high braking efficiency. The electromagnetic brake 303 may be a known component in the art, and mainly plays a role in transmitting power and controlling motion in a mechanical transmission system, and has the advantages of simple operation, sensitive response, reliable use, long service life, and the like.

For example, as shown in fig. 8, the electromagnetic brake 303 may alternatively include an electromagnetic driving portion 3031 and a braking portion 3032 arranged at a distance from the electromagnetic driving portion 3031 and connected to the output shaft 3011, the electromagnetic driving portion 3031 may include an electromagnetic coil and a permanent magnet, the electromagnetic driving portion 3031 may attract the braking portion 3032 when the electromagnetic brake 303 is de-energized, and the electromagnetic driving portion 3031 may release the braking portion 3032 when the electromagnetic brake 303 is energized. As described above, the output shaft 3011 of the motor 301 can be reliably locked. However, the present disclosure is not limited thereto, and the electromagnetic brake 303 may have any other reasonable structure as long as it can lock or unlock the output shaft 3011 of the motor 301. For example, the motor locking portion 1013 may have the same structure as that of the first embodiment, and may be provided inside the motor 301.

Optionally, the lead screw 3061 includes a small diameter section drivingly connected to the carrier 3022 and a large diameter section engaged with the nut 3062 of the lead screw nut engaging mechanism, a thrust bearing 307 is disposed on a connecting portion of the small diameter section and the large diameter section, and a step 3006 for abutting against a stationary end of the thrust bearing 307 is formed on the housing 300. The planet carrier 3022 and the lead screw 3061 may be in transmission connection through a spline fitting structure, but may also be in transmission connection through other profile fitting structures such as a key fitting structure. Here, each of the lead screws 3061 may be supported in the housing 300 by a sliding bearing, a rolling bearing, or a wear-reducing copper bush 308, so that the wear of the lead screws 3061 may be reduced to protect the lead screws 3061. Further, in the non-operating state of the brake actuator, since the axial gap may be provided between the thrust bearing 307 and the step 3006, when the brake actuator is operated, the thrust bearing 307 is brought into contact with the step 3006 by the reaction force of the nut 3062 against the screw 3061, and the thrust bearing 307 receives the axial load, thereby having a function of restricting the axial displacement of the screw 3061 relative to the housing 300.

Alternatively, as shown in fig. 7, the lead screw 3061 may further include a small diameter section drivingly connected to the carrier 3022 and a large diameter section engaged with the nut 3062 of the lead screw nut engaging mechanism, a thrust bearing 307 is disposed at a connecting portion of the small diameter section and the large diameter section, the small diameter section is supported in the shaft hole of the housing 300 by a bearing or bushing 308, and a flange of the bearing or bushing 308 abuts on an end wall of the shaft hole close to the large diameter section, so that a stationary end of the thrust bearing 307 can abut on the flange of the bearing or bushing 308. Here, the end wall of the housing 300 against which the flange of the bearing or bushing 308 abuts may be the step 3006 as described above, thereby having a function of limiting the axial displacement of the lead screw 3061 relative to the housing 300 by receiving the axial load by providing the thrust bearing 307.

The screw nut matching mechanism is a planetary roller screw mechanism 306, and the planetary roller screw mechanism 306 has the advantages of large bearing load, strong impact resistance, high transmission precision and long service life. The planetary roller screw mechanism 306 converts the rotational motion of the screw 3061 into linear motion of the nut 3062. Specifically, alternatively, as in the case of the planetary roller screw mechanism provided in the first and second embodiments, the planetary roller screw mechanism 306 includes a screw 3061, rollers that are screw-engaged with the screw 3061 and the nut 3062, respectively, and roller gears are provided at both ends of the rollers, an internal gear that meshes with each of the roller gears 306is provided on an inner circumferential surface of the nut 3062 or an external gear that meshes with each of the roller gears is provided on an outer circumferential surface of the screw 3061, and the nut 3062 is movable in the axial direction of the output shaft 3011 with respect to the screw 3061. Here, the roller gears at both ends of the roller can ensure the synchronism of the transmission between the roller and the screw 3061 and the nut 3062, and can ensure that the pitch circle of the gear is pure rolling, thereby avoiding the interference phenomenon caused by the slippage of a part of the roller. In the above-described configuration, the gear meshing with the roller gear is provided on the inner circumferential surface of the nut 3062, but the present disclosure is not limited thereto, and for example, in the case where no internal gear is provided on the inner circumferential surface of the nut 3062, an external gear meshing with the roller gear may be provided on the corresponding outer circumferential surface of the screw 3061. Further alternatively, the screw nut engaging mechanism may be a ball screw nut mechanism, a slide screw nut mechanism, or the like.

Optionally, the housing 300 includes a first housing portion 3001 detachably connected, the first housing portion 3001 has a first opening and a first accommodating cavity 3003 for accommodating the motor 301 and the electromagnetic brake 303 and a second accommodating cavity 3004 for accommodating the planetary gear reduction mechanism 302 are formed in the first housing portion 3001, the first accommodating cavity 3003 and the second accommodating cavity 3004 are communicated, and the screw nut matching mechanism extends out of the first opening. In addition, optionally, the housing 300 further includes a second housing portion 3002 having a second opening, a third accommodating cavity 3005 for accommodating the screw nut fitting mechanism is formed in the second housing portion 3002, the first opening corresponds to the second opening, and when the first housing portion 3001 and the second housing portion 3002 are fitted, the second accommodating cavity 3004 communicates with the third accommodating cavity 3005. The brake actuator as described above is of a modular structure as a whole, is compact in arrangement structure, can be reasonably arranged in a limited installation space, and has the effects of simple assembly and convenient maintenance.

Alternatively, the second housing portion 3002 is a floating caliper housing, and the second housing cavity 3004 has an inner friction plate 3041 and an outer friction plate 3042 disposed therein for frictional engagement with the brake disk 305. That is, the outer friction plate 3042 is fixed in the floating caliper housing, and when the inner friction plate 3042 is driven to move by the nut 3062 of the screw-nut engagement mechanism, the inner friction plate 3042 comes into contact with the brake disc 305, and then the floating caliper housing moves together with the first housing portion 3001 by the reaction force of the nut 3062, so that the outer friction plate 3042 fixed in the caliper housing comes into contact with the brake disc 305, thereby reliably braking the brake disc 305. When the service brake is released, the self-adjustment of the clearance of the brake can be realized by powering off the motor 301, or the self-adjustment of the clearance of the brake can be performed by reversely rotating the motor 301, so that the nut 3062 of the screw-nut matching mechanism returns.

A third embodiment of the present disclosure provides an automotive brake system including a brake provided with the brake actuator of the third embodiment. In this automobile brake system, the output shaft 3011 of the motor 301 is locked or unlocked by the electromagnetic brake 303, and thus a reliable parking function can be realized. Optionally, the brake includes a brake disc 305, a friction plate 304 is disposed in the brake actuator for friction engagement with the brake disc 305, and the screw nut engagement mechanism is configured to drive the friction plate 304 to clamp the brake disc 305. Here, the housing 300 of the brake actuator may be an integrally formed caliper housing, or may be assembled to the caliper housing, thereby effectively improving the braking response time of the vehicle and improving the braking efficiency.

An electric vehicle according to a third embodiment of the present disclosure includes the vehicle brake system according to the third embodiment. The brake actuator with a simple structure can effectively drive the friction plate 304 to clamp the brake disc 305, thereby improving the braking response time of the automobile and having the effects of rapid signal transmission and sensitive response.

The third embodiment of the present disclosure is described above with reference to fig. 7 and 8, and the fourth embodiment of the present disclosure is specifically described below with reference to fig. 9 to 13.

As shown in fig. 9 to 13, a brake actuator according to a fourth embodiment of the present disclosure includes a housing 400, a motor 401, a worm gear speed reducing mechanism 402, and a lead screw nut matching mechanism, which are respectively accommodated in the housing 400, wherein an output torque of the motor 401 is transmitted to the lead screw nut matching mechanism through the worm gear speed reducing mechanism 402 to operate a brake, a worm 4021 of the worm gear speed reducing mechanism 402 is in transmission connection with an output shaft 4011 of the motor 401, and a main shaft of a worm gear 4022 of the worm gear speed reducing mechanism 402 is in transmission connection with a lead screw 4061 of the lead screw nut matching mechanism.

Wherein, worm gear speed reducing mechanism 402 has that the drive ratio is big, bearing capacity is high, the transmission is steady, the vibration is little and noise low grade advantage, through the lead screw 4061 that transmits motor 401's output torque to lead screw nut cooperation mechanism via worm gear speed reducing mechanism 402 for nut 4062 can effectively drive friction disc 404 and press from both sides tightly brake disc 405, thereby can effectively improve the braking response time of car, has the effect that signal transmission is quick and the reaction is sensitive. Here, the motor 401 and the worm 4021 of the worm gear reduction mechanism 402, the worm gear 4022 of the worm gear reduction mechanism 402, and the lead screw 4061 of the lead screw nut engagement mechanism may be drivingly connected by using a key connection, a spline connection, or the like, or may be realized by various types of surface engagement for transmitting mechanical torque. In addition, the magnitude of the output torque of the electronic control unit to the motor 401 can be controlled according to the braking force of the brake pedal and the braking stroke.

Optionally, the brake actuator further includes a motor locking device for locking or unlocking the output shaft 4011 of the motor 401, the output shaft 4011 is locked when the motor locking device is de-energized, and the output shaft 4011 is released when the motor locking device is energized, whereby the parking brake can be reliably implemented. Here, the motor locking device may have various reasonable structures, and for example, the following two embodiments may be adopted.

Alternatively, as shown in fig. 9 to 11, the motor locking device is an electromagnetic brake 407, the electromagnetic brake 407 is the same as the electromagnetic brake 303 provided in the third embodiment, that is, the electromagnetic brake 407 includes an electromagnetic driving portion 4071 and a braking portion 4072 that is arranged at a distance from the electromagnetic driving portion 4071 and is connected to the output shaft 4011, the electromagnetic driving portion 4071 includes an electromagnetic coil and a permanent magnet, the electromagnetic driving portion 4071 adsorbs the braking portion 4072 when the electromagnetic brake 407 is powered off, and the electromagnetic driving portion 4071 releases the braking portion 4072 when the electromagnetic brake 407 is powered on. As described above, the output shaft 4011 of the motor 401 can be reliably locked. However, the present disclosure is not limited thereto, and other electromagnetic brakes known in the art may be used as the motor locking device, which mainly serve to transmit power and control motion in a mechanical transmission system, and have the advantages of simple operation, sensitive response, reliable use, long service life, and the like.

Alternatively, similarly to the brake actuator provided in the first embodiment, the motor locking device is provided in the housing of the motor 401, and includes an inner friction plate connected to the output shaft 4011, an outer friction plate connected to the housing of the motor 401, a locking portion and an electromagnetic driving portion, when power is lost, the locking portion drives the electromagnetic driving portion to move so that the outer friction plate is in friction fit with the inner friction plate to lock the output shaft 4011, and when power is supplied, the electromagnetic driving portion moves in a direction overcoming a locking force of the locking portion so that the outer friction plate is out of friction fit with the inner friction plate to release the output shaft 4011. The contents of this portion have been described in detail in the brake actuator provided in the first embodiment described above, and a detailed description thereof is omitted here in order to avoid redundancy.

Optionally, the electromagnetic driving portion includes an electromagnetic coil and an annular magnet, the locking portion is a spring, the motor locking device further includes a one-way clutch fixed with the inner friction plate and in transmission connection with the output shaft 4011, the annular magnet is matched with a part of inner circumferential surface of the electromagnetic coil to be capable of extending and contracting relative to the electromagnetic coil, the spring is located on the inner circumferential surface of the electromagnetic coil and fixed on the inner end of the casing of the motor 401 and a side end surface of the annular magnet respectively, the inner friction plate and the outer friction plate are located on the other side of the annular magnet and are arranged at intervals along the axial direction of the output shaft 4011, when power is lost, the spring drives the annular magnet to push the outer friction plate so that the outer friction plate is in friction fit with the inner friction plate, and when power is supplied, the annular magnet moves in the direction overcoming the elastic force of the spring to separate from the outer friction, so that the outer friction plate is disengaged from the inner friction plate. Thus, the parking brake function is reliably realized by the motor 401 configured as described above.

Optionally, the brake actuator comprises a telescopic device for operating the brake, under the condition of service braking, the output torque of the motor 401 is transmitted to the screw-nut matching mechanism through the worm gear and worm speed reducing mechanism 402, so that the brake is operated to realize service braking, and under the condition of parking braking, the telescopic piece of the telescopic device enables the brake to be operated to realize parking braking. That is, during service braking, the output torque of the motor 401 is transmitted to the lead screw 4061 of the lead screw and nut engagement mechanism via the worm 4021 and the worm wheel 4022 of the worm gear and worm reduction mechanism 402, so that the nut 4062 can drive the friction plate 404 to clamp the brake disk 405, thereby realizing service braking. During parking braking, the brake is operated through the telescopic piece of the telescopic device to realize parking braking. The telescopic device can have a variety of possible configurations, for example an electric cylinder. The telescopic member of the telescopic device may directly drive the friction plate 404 to clamp the brake disk 405, or indirectly drive the friction plate 404 to clamp the brake disk 405 through the nut 4062 of the screw-nut fitting mechanism, which is not particularly limited herein.

Optionally, as shown in fig. 13, the telescopic device includes a parking motor 408, a planetary gear speed reducing mechanism 403, and a parking screw 409 serving as the telescopic member, where the parking screw 409 is in transmission connection with a parking output shaft 4081 of the parking motor 408 through the planetary gear speed reducing mechanism 403 and is capable of extending and retracting relative to the planetary gear speed reducing mechanism 403, the parking screw 409 is inserted through a central hole of the lead screw 4061 and is in threaded fit with the central hole so as to be capable of driving a nut 4062 of the lead screw nut matching mechanism, under parking braking, the lead screw 4061 is locked, and an output torque of the parking motor 408 is transmitted to the parking screw 409 through the planetary gear speed reducing mechanism 403 so as to be capable of driving the nut 4062 of the lead screw nut matching mechanism.

That is, during the vehicle braking, the parking motor 408 is not operated, and the starter motor 401 transmits the output torque to the lead screw 4061 of the lead screw-nut engagement mechanism through the worm gear reduction mechanism 402, so that the nut 4062 in driving engagement with the lead screw 4061 drives the friction plate 404 to clamp the brake disk 405. Wherein the ring gear 4034 of the planetary reduction mechanism 403 is fixed in the housing 400. When parking brake is performed during driving, the lead screw 4061 of the lead screw nut engagement mechanism is locked by a locking member such as a pin, and in this state, the parking output shaft 4081 of the parking motor 408 rotates forward, and the output torque thereof is transmitted to the parking screw 409 through the sun gear 4031, the planet gear 4033, and the planet carrier 4032 of the planet gear speed reduction mechanism 403, and at this time, since the lead screw 4061 that is screwed to the parking screw 409 is fixed to the housing 400, the parking screw 409 extends in the axial direction thereof to abut against the nut 4062 of the lead screw nut engagement mechanism, and the nut 4062 supplies pressure to the friction plate 404, thereby realizing parking brake. When the parking brake is directly applied, the parking screw 409 abuts the nut 4062, and the nut 4062 drives the friction plate 404 to clamp the brake disk 405. When the parking brake is released, the parking screw 409 is retracted relative to the planetary gear reduction mechanism 403 and separated from the nut 4062 by the reverse rotation of the parking output shaft 4081 of the parking motor 408, thereby releasing the parking brake.

Here, for example, the parking screw 409 may be engaged with the carrier 4032 of the planetary gear reduction mechanism 403 by a spline engagement structure, that is, the carrier 4032 is fixed with a spline housing 4035, one end of the parking screw 409 is formed as a spline shaft, and power transmission is achieved by engagement of the spline housing 4035 and the spline shaft. It should be noted here that the spline shaft on the parking screw 409 is axially movable relative to the spline housing 4035 to enable the parking screw 409 to move axially relative to the spline housing 4035 in cooperation with the threads of the lead screw 4061. However, the present disclosure is not limited thereto, and for example, the carrier 4032 and the parking screw 409 may achieve power transmission through a profile fitting structure, where it is necessary to provide the parking screw 409 to be axially movable with respect to the carrier 4032 while achieving power transmission. Further, the following configuration may be adopted. A sleeve with an internal thread can be fixed on the planet carrier 4032, an external thread matched with the internal thread of the sleeve is formed at one end of the parking screw 409, at the moment, an internal thread does not need to be formed in a central hole of the lead screw 4061 for penetrating through the parking screw 409, the parking screw 409 only needs to be in threaded fit with the sleeve to move relative to the sleeve, and therefore the inner friction plate 4041 and the outer friction plate 4042 clamp the brake disc 405 through the extrusion nut 4062, and parking braking is achieved accordingly.

Optionally, the housing 400 includes a first housing portion 4001, a second housing portion 4002, and a third housing portion 4003, the first housing portion 4001 has a first opening and a second opening, a first accommodating cavity 4004 for accommodating the parking motor 408, the worm gear reduction mechanism 402, and the screw-nut fitting mechanism is formed in the first housing portion 4001, the second housing portion 4002 seals the first opening, the third housing portion 4003 has a third opening and is formed with a second accommodating cavity 4005 for accommodating the telescopic device, the second opening corresponds to the third opening, and the telescopic member spans the first accommodating cavity 4004 and the second accommodating cavity 4005. The first housing portion 4001 may be integrally formed with a floating caliper housing in which an inner friction plate 4041 and an outer friction plate 4042 are provided. The brake actuator as described above is of a modular structure as a whole, is compact in arrangement structure, can be reasonably arranged in a limited installation space, and has the effects of simple assembly and convenient maintenance.

Optionally, a thrust bearing 4010 is disposed between the turbine 4022 and the lead screw 4061. By providing the thrust bearing 4010 to receive the axial load, the axial displacement of the lead screw 4061 relative to the turbine 4022 is restricted.

Alternatively, the screw-nut engaging mechanism is a planetary roller screw mechanism 406, the planetary roller screw mechanism 406 includes a screw 4061, rollers, and a nut 4062, the rollers are respectively screw-engaged with the screw 4061 and the nut 4062, the rollers are provided with roller gears at both ends, an inner gear engaged with each roller gear is provided on an inner circumferential surface of the nut 4062 or an outer gear engaged with each roller gear is provided on an outer circumferential surface of the screw 4061, and the nut 4062 is movable in the axial direction of the output shaft 4011 relative to the screw 4061.

A brake system for an automobile according to a fourth embodiment of the present disclosure includes a brake provided with the brake actuator according to the fourth embodiment. Optionally, the brake includes a brake disc 405, a friction plate 404 for friction fit with the brake disc 405 is disposed in the brake actuator, and the screw nut fit mechanism is capable of driving the friction plate 404 to clamp the brake disc 405. Here, the caliper housing of the brake may be integrally formed with the housing 400 of the brake actuator, or the housing 400 may be assembled to the caliper housing, and the output torque of the motor 401 of the brake actuator is transmitted to the lead screw 4061 of the lead screw-nut fitting mechanism via the worm reduction gear 402, so that the nut 4062 can effectively drive the friction plate 404 to clamp the brake disc 405, thereby effectively improving the brake response time of the vehicle, and having the effects of rapid signal transmission and sensitive response.

A fourth embodiment of the present disclosure provides an electric vehicle including the vehicle brake system according to the fourth embodiment. The brake actuator adopting the modular structure can realize the service brake function and the parking brake function at the same time, improves the integration degree of the whole vehicle, has high transmission efficiency and good mechanical performance.

Four alternative embodiments of the present disclosure are described in detail with reference to the drawings, however, the present disclosure is not limited to the details of the embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

It should be noted that, in the foregoing embodiments, various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various combinations that are possible in the present disclosure are not described again.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.

Claims (10)

1. A brake actuator, characterized in that the brake actuator comprises a housing (300), an electric motor (301) accommodated in the housing (300), a torque transmission device and a screw-nut matching mechanism, wherein the output torque of the electric motor (301) is transmitted to the screw-nut matching mechanism through the torque transmission device to enable a brake to work, the torque transmission device comprises a planet wheel speed reducing mechanism (302), a sun wheel (3021) is in transmission connection with an output shaft (3011) of the electric motor (301), a planet carrier (3022) is in transmission connection with a screw (3061) of the screw-nut matching mechanism, the brake actuator further comprises an electromagnetic brake (303) used for locking or unlocking the output shaft (3011) or a power output shaft of the planet carrier (3022), and the output shaft (3011) or the power output shaft is locked when the electromagnetic brake (303) loses power, when the electromagnetic brake (303) is electrified, the output shaft (3011) or the power output shaft is released, the lead screw (3061) comprises a small-diameter section which is in transmission connection with the planet carrier (3022) and a large-diameter section which is matched with a nut (3062) of the lead screw nut matching mechanism, a thrust bearing (307) is arranged on the connection part of the small-diameter section and the large-diameter section,

the housing (300) is formed with a step (3006) for abutting against a stationary end of the thrust bearing (307), or,

the small diameter section is supported within a shaft bore of the housing (300) by a bearing or bushing (308), and a flange of the bearing or bushing (308) abuts against an end wall of the shaft bore adjacent the large diameter section to enable a stationary end of the thrust bearing (307) to abut against the flange of the bearing or bushing (308).

2. A brake actuator according to claim 1, wherein the electromagnetic brake (303) is connected to an output shaft (3011) of the motor (301) for locking or unlocking the output shaft.

3. The brake actuator according to claim 2, wherein the electromagnetic brake (303) comprises an electromagnetic drive portion (3031) and a brake portion (3032) arranged at a distance from the electromagnetic drive portion (3031) and connected to the output shaft (3011), the electromagnetic drive portion (3031) comprises an electromagnetic coil and a permanent magnet, the electromagnetic drive portion (3031) attracts the brake portion (3032) when the electromagnetic brake (303) is de-energized, and the electromagnetic drive portion (3031) releases the brake portion (3032) when the electromagnetic brake (303) is energized.

4. The brake actuator according to claim 1, wherein the screw-nut engaging mechanism is a planetary roller screw mechanism (306), the planetary roller screw mechanism (306) includes a screw (3061), rollers, and a nut (3062), the rollers are respectively screw-engaged with the screw (3061) and the nut (3062), roller gears are provided at both ends of the rollers, an internal gear engaged with each roller gear is provided on an inner circumferential surface of the nut (3062) or an external gear engaged with each roller gear is provided on an outer circumferential surface of the screw (3061), and the nut (3062) is movable in an axial direction of the output shaft (3011) relative to the screw (3061).

5. The brake actuator according to claim 1, wherein the housing (300) includes a first housing portion (3001) detachably connected, the first housing portion (3001) has a first opening, and a first housing cavity (3003) for housing the motor (301) and the electromagnetic brake (303) and a second housing cavity (3004) for housing the planetary gear reduction mechanism (302) are formed in the first housing portion (3001), the first housing cavity (3003) and the second housing cavity (3004) communicate, and the lead screw-nut engagement mechanism protrudes from the first opening.

6. The brake actuator according to claim 5, wherein the housing (300) further includes a second housing portion (3002) having a second opening, a third housing cavity (3005) for housing the screw-nut engagement mechanism is formed in the second housing portion (3002), the first opening and the second opening correspond, and when the first housing portion (3001) and the second housing portion (3002) are engaged, the second housing cavity (3004) communicates with the third housing cavity (3005).

7. A brake actuator according to claim 6, wherein the second housing portion (3002) is a floating caliper housing, and wherein an inner friction plate (3041) and an outer friction plate (3042) are provided within the second receiving cavity (3004) for frictional engagement with the brake disc.

8. A vehicle brake system, characterized in that it comprises a brake provided with a brake actuator according to any one of claims 1-7.

9. The automotive brake system of claim 8, wherein the brake comprises a brake disc (305), and wherein a friction plate (304) is disposed in the brake actuator for frictional engagement with the brake disc (305), and wherein the lead screw nut engagement mechanism is configured to drive the friction plate (304) to clamp the brake disc (305).

10. An electric vehicle, characterized in that it comprises a vehicle brake system according to claim 8 or 9.

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