Electronic mechanical calipers for brake-by-wire system and brake method

Abstract

The invention provides an electronic mechanical caliper for a brake-by-wire system and a braking method. The electronic mechanical caliper for the brake-by-wire system comprises a horizontal gear assembly, a planetary gear set, a reinforcement bearing structure and a caliper body. The reinforcement bearing structure comprises a reinforcement assembly, a screw rod and a piston; the screw is provided with external threads, and the inner cavity is provided with a spline hole which is matched with a spline shaft with an external spline; the piston can axially move, the front side of the piston is the rear end of the screw rod, and the rear end of the piston is used for abutting against the friction plate for braking. A sectional type propelling structure is adopted, when the first section is used for eliminating idle stroke, rotation is converted into linear motion through thread transmission, and when the second section is used for clamping, rotation motion is converted into linear motion through a reinforcement bearing structure; power transmission is achieved through the horizontal gear assembly and the planetary gear assembly, a two-stage braking mode is achieved through the reinforcement bearing structure, after the assemblies are combined together to be matched, the structural size of a product is greatly reduced, and arrangement is compact.

Description

Technical Field

[0001] The invention relates to a braking technology, in particular to an electronic mechanical caliper driven by a motor. Background Art

[0002] At present, the disc brakes of vehicles on the market are mainly divided into two categories: pneumatic and hydraulic according to the different power transmission media. However, pneumatic and hydraulic brake systems generally have problems such as complex structure, environmental pollution, slow response, and complex control, and cannot adapt to the development trend of intelligent and wire-controlled vehicles in the future. Therefore, the present invention aims to design an electronic mechanical caliper for a wire-controlled brake system to replace traditional pneumatic and hydraulic brakes.

[0003] Electromechanical calipers (or electric mechanical calipers) are mainly used in automotive braking systems. They control the clamping and release of brake discs through electric motors, which are smarter and more efficient than traditional manual or pneumatic calipers. Its advantages include precise control, reduced wear, reduced weight and integrated design.

[0004] However, existing electronic mechanical calipers also have certain problems in application. That is, the structure is not compact enough, and multiple components cannot be installed together to reduce space occupancy; secondly, the effect of rapid contact of the friction plate in the front section and increased thrust in the rear section is not formed during braking, which limits the braking effect. Summary of the invention

[0005] In order to solve the problems existing in the above-mentioned technologies, the present invention provides a technology that arranges multiple components compactly to reduce the occupied space, and realizes two stages of different propulsion forms to improve the braking effect.

[0006] The present invention provides an electronic mechanical caliper for a wire-controlled brake system, comprising: A spur gear assembly receives power from the motor; a planetary gear set connected to the spur gear assembly to receive rotational power; The force-enhancing bearing structure comprises a force-enhancing component, a screw and a piston; the screw is driven by a planetary gear set; the screw has an external thread; the force-enhancing component is sequentially arranged with a support plate, a rolling element and an active plate from front to back, the support plate and the active plate have a raceway with a varying depth that matches the rolling element; the external thread of the screw forms a thread pair with the internal thread of the active plate; the piston can move axially, the front side of the piston is the rear end of the screw, and the rear end of the piston is used to abut against a friction plate for braking; The caliper body is provided with a friction plate for braking, and the friction plate is arranged on one side of the force-enhancing bearing structure.

[0007] Preferably, it further comprises a spline shaft; the screw has an inner cavity; the inner cavity has a spline hole, and the spline hole cooperates with a spline shaft with external splines.

[0008] Preferably, it further comprises a motor, a lower shell and an upper shell, wherein the upper shell is detachably connected to the lower shell; the inlay has a mounting portion, and the lower shell is detachably connected to the mounting portion; The lower housing is used to install the motor, the spur gear assembly, the planetary gear set, the spline shaft and the force-enhancing bearing structure.

[0009] Preferably, the spur gear assembly comprises a motor gear, a bridge gear and a large gear which are meshed and connected in sequence; The lower shell has a main body tube, a transition tube and a side tube that are connected to each other. The motor gear is arranged in the side tube, the bridge gear is arranged in the transition tube, and the large gear is arranged in the main body tube; the motor is connected to the motor gear; The spline shaft, planetary gear set and force-enhancing bearing structure are also arranged in the main body tube.

[0010] Preferably, the planetary gear set comprises a planet carrier, planetary gears, a sun gear and an inner gear ring, the sun gear is arranged at the center of the planet carrier, the sun gear is meshed with a plurality of planetary gears, the planetary gears are meshed with the inner gear ring, and the inner gear ring is mounted on the planet carrier; The front end of the sun gear is connected to the middle part of the large gear, and the rear end of the sun gear is connected to the spline shaft.

[0011] Preferably, the lower housing is connected to the mounting portion via connecting bolts; One side of the caliper body is provided with a caliper frame, and the caliper frame is used for being installed on a vehicle; The large gear is equipped with a retaining spring I and a ball bearing; The planetary gear is equipped with a needle bearing 1 and a retaining spring 1; The sun gear is matched with a needle bearing II; the sun gear is connected to the large gear through a pin shaft to transmit torque; The bridge gear is equipped with a needle bearing III; The caliper body is provided with a mounting hole portion, the mounting hole portion is used for mounting the force-enhancing bearing structure, and a dust cover is provided at the rear end opening of the mounting hole portion.

[0012] Preferably, it further comprises a retaining sleeve; the active disc comprises a disc body and a screw sleeve, and the screw sleeve has a second needle roller bearing at a position close to the disc body; the screw sleeve passes through the inner hole of the retaining sleeve, and a wave spring II is provided between the retaining sleeve and the second needle roller bearing; A first needle bearing is provided between the end of the screw sleeve and the annular portion of the screw; A retaining spring II, a washer and a wave spring I are arranged in sequence between the retaining sleeve and the first needle roller bearing.

[0013] Preferably, the rear end of the screw rod has a protrusion, and the protrusion cooperates with the piston through a bearing structure.

[0014] A guide pin is arranged at the rear end head of the screw rod, the front end of the guide pin is fixed at the middle part of the rear end of the screw rod, and the rear end of the guide pin is rotatably matched with the mounting blind hole of the piston.

[0015] The guide pin has a bushing at the position where it is installed in the mounting blind hole.

[0016] The bearing structure is a cylindrical roller bearing.

[0017] Preferably, the wave spring I is a single-turn wave spring, and the wave spring II is a multi-turn wave spring.

[0018] Hemispherical grooves are arranged on both sides of the piston, and steel balls are arranged in the grooves, and the steel balls are slidably matched with the caliper body.

[0019] Preferably, the raceways are three evenly distributed raceways arranged based on a spiral line, and the raceways cooperate with the rolling elements to convert the torque input by the active disk into an axial thrust; The rolling elements are arranged on a cage.

[0020] The beneficial effects of the present invention are: 1. The present invention adopts a segmented propulsion structure. The first segment is to convert rotation into linear motion by thread transmission when eliminating idle travel, and the second segment is to convert rotation into linear motion by a force-enhancing bearing structure when clamping; 2. The present invention realizes power transmission through a flat gear assembly and a planetary gear assembly, and realizes a two-stage braking method through a force-enhancing bearing structure. After these components are combined together, the structural size of the product is greatly reduced and the arrangement is compact.

[0021] 3. The motor, spur gear assembly, planetary gear set, spline shaft and force-enhancing bearing structure are integrated into one component by setting the lower housing and the upper housing. These components are closely matched and closed. The housing is directly mounted on the caliper body and works in conjunction with the friction plate.

[0022] 4. The lower housing arranges the spur gear set reasonably through the main cylinder, transition cylinder and side cylinder, and integrates the motor at the side position, which greatly reduces the axial length occupied. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the overall structure of an electronic mechanical caliper for a wire-controlled brake system of the present invention; Figure 2 It is a structural schematic diagram of an overall structural exploded view of an electronic mechanical caliper for a wire-controlled brake system of the present invention; Figure 3 It is a structural schematic diagram of an overall structure of an electronic mechanical caliper for a wire-controlled brake system according to the present invention from one perspective; Figure 4 The invention is an electronic mechanical caliper for a wire-controlled brake system. Figure 3 A structural diagram of a CC cross-sectional view; Figure 5 The invention is an electronic mechanical caliper for a wire-controlled brake system. Figure 3 A structural diagram of a DD cross-sectional view; Figure 6 It is a schematic structural diagram of the decomposed structure of a force-enhancing bearing of an electronic mechanical caliper for a brake-by-wire system according to the present invention; Figure 7 It is a structural schematic diagram of a force-enhancing bearing structure of an electronic mechanical caliper for a brake-by-wire system according to the present invention from one perspective; Figure 8 The invention is an electronic mechanical caliper for a wire-controlled brake system. Figure 7 Structural schematic diagram of the EE cross-sectional view of the force-enhancing bearing structure; Fig. 9 It is a schematic diagram of the structure of a planetary gear set of an electronic mechanical caliper for a brake-by-wire system according to the present invention; Fig.10 It is a structural schematic diagram of a planetary gear set of an electronic mechanical caliper for a brake-by-wire system according to the present invention from one perspective; Fig.11 The invention is an electronic mechanical caliper for a wire-controlled brake system. Fig.10 Structural diagram of the FF cross-section of the planetary gear set; Fig.12 It is a schematic diagram of the exploded structure of a spur gear assembly of an electronic mechanical caliper for a brake-by-wire system according to the present invention; Fig.13 It is a structural schematic diagram of a spur gear assembly of an electronic mechanical caliper for a brake-by-wire system according to the present invention from one perspective; Fig.14 The invention is an electronic mechanical caliper for a wire-controlled brake system. Fig.13 Structural schematic diagram of the cross-sectional view of the spur gear assembly GG; Fig.15 It is an enlarged view of an active disc and a supporting disc of an electronic mechanical caliper used in a wire-controlled brake system of the present invention.

[0024] Description of reference numerals: 100-flat gear assembly; 200-planetary gear set; 300-spline shaft; 400-force-enhancing bearing structure; 500-caliper body; 600-motor; 700-lower housing; 800-upper housing; 900-installation part; 110-motor gear, 120-bridge gear; 130-large gear; 131-circlip I; 132-ball bearing; 210-planet carrier; 220-planet gear; 230-sun gear; 240-inner gear ring; 231-needle bearing I; 232-needle bearing II; 233-needle bearing III; 234-pin shaft; 410-force amplification component; 411-support plate; 412-rolling element; 4121-cage; 413-active plate; 4131-raceway; 4132-internal thread; 4133-plate body; 4134-screw sleeve; 414-second needle roller bearing; 415-wave spring II; 416-retaining sleeve; 417-first needle roller bearing; 4171-circlip II; 4172-gasket; 4173-wave spring I; 420-screw; 421-inner cavity; 4211-spline hole; 422-external thread; 423-protrusion; 424-bearing structure; 425-guide pin; 426-bushing; 430-piston; 431-groove; 432-steel ball; 433-mounting blind hole; 510-clamp frame; 520-mounting hole; 530-friction plate; 540-dust cover; 610-motor bearing; 710-main tube; 720-transition tube; 730-side tube; 740-connecting bolt. DETAILED DESCRIPTION

[0025] Embodiment 1:

[0026] like Figures 1 to 8 As shown, the present embodiment provides an electronic mechanical caliper for a brake-by-wire system, which includes a flat gear assembly 100, a planetary gear set 200, a force-enhancing bearing structure 400 and a caliper body 500; The flat gear assembly 100 receives power from the motor 600; The planetary gear set 200 is connected to the spur gear assembly 100 to receive rotational power; The force-enhancing bearing structure 400 includes a force-enhancing component 410, a screw 420 and a piston 430; the screw 420 is driven by the planetary gear set 200, and has an external thread 422; the force-enhancing component 410 sequentially arranges a support plate 411, a rolling body 412 and an active plate 413 from front to back, and the support plate 411 and the active plate 413 have a raceway 4131 with a varying depth that cooperates with the rolling body 412; the external thread 422 of the screw 420 and the internal thread 4132 of the active plate 413 form a thread pair; the piston 430 can move axially, the front side of the piston 430 is the rear end of the screw 420, and the rear end of the piston 430 is used to abut against the friction plate 530 for braking; The caliper body 500 has a friction plate 530 for braking, and the friction plate 530 is arranged on one side of the force-enhancing bearing structure 400. In the initial stage, there is a gap between the piston 430 and the friction plate 530.

[0027] The working process of the scheme of this embodiment is as follows: Power transmission: The flat gear assembly 100 receives power from the motor 600, and then transmits the rotational power to the screw 420 of the force-enhancing bearing structure 400 through the planetary gear set 200; then the following steps are performed: The first section is to eliminate the idle stroke (eliminate the gap). During this process: the horizontal thrust resistance of the piston 430 is F1. Under this resistance, the corresponding friction torque between the transmission thread pairs is M1; the internal friction torque of the force-enhancing bearing structure 400 is M2, and the friction torque of the active disk 413 during rotation is M3. The screw 420 starts to rotate under the input torque M4, and the driving torque of the screw 420 on the active disk 413 is equal to the friction torque M1 between the thread pairs; at the same time, because the active disk 413 is hindered by the friction torques M2 and M3, and M1 is smaller than the sum of M2 and M3, the active disk 413 remains stationary, and the screw 420 starts to move horizontally while rotating, pushing the piston 430 forward until the gap between the piston 430 and the friction plate 530 is completely eliminated, and then the piston 430 continues to move, and the clamping force F3 starts to increase from zero, and the corresponding resistance to the advancement of the piston 430 is the sum of F1 and F3, the friction torque M1 between the thread pairs, and the friction torque M2 increase simultaneously (the growth rate is smaller than M1), until the size of M1 is equal to the sum of M2 and M3, and this is the critical point at the end of the first stage of movement; The second section is the clamping stage, during which the clamping force F3 further increases, and the friction torque M1 between the threaded pairs increases at the same time. During this process, M1 is greater than the sum of M2 and M3. Driven by the friction torque M1, the active disk 413 rotates and advances horizontally together with the screw 420 until it reaches the target clamping force F4 and stops.

[0028] When the active disk 413 rotates, the raceway 4131 with varying depth contacts the rolling element 412 , which forces the active disk 413 to move in the axial direction. That is, the process of converting the rotational torque into the linear thrust is achieved through the cooperation between the active disk 413 and the rolling element 412 .

[0029] Embodiment 2:

[0030] This embodiment further includes a spline shaft 300; the screw rod 420 has an inner cavity 421; the inner cavity 421 has a spline hole 4211, and the spline hole 4211 cooperates with the spline shaft 300 with an external spline; This embodiment further includes a motor 600, a lower housing 700 and an upper housing 800, wherein the upper housing 800 is detachably connected to the lower housing 700; the caliper body 500 has a mounting portion 900, the lower housing 700 is detachably connected to the mounting portion 900, and the motor 600 is supported and installed by a motor bearing 610; The lower housing 700 is used to install the motor 600 , the spur gear assembly 100 , the planetary gear set 200 , the spline shaft 300 and the force-enhancing bearing structure 400 .

[0031] Through such a combination, multiple components are very compactly integrated inside the lower shell 700 and the upper shell 800; and the motor 600 is located at the side, and the power is transmitted to the planetary gear set 200 on the side through the flat gear assembly 100, and then transmitted to the spline shaft 300 and the screw 420, and the rotational power is converted into linear thrust through the force-enhancing bearing structure 400.

[0032] Embodiment 3:

[0033] In this embodiment, Figure 12 to Figure 14 As shown, the flat gear assembly 100 comprises a motor gear 110, a bridge gear 120 and a large gear 130 which are meshed and connected in sequence; The lower housing 700 has a main body tube 710, a transition tube 720 and a side tube 730 which are connected to each other. The motor gear 110 is arranged in the side tube 730, the bridge gear 120 is arranged in the transition tube 720, and the large gear 130 is arranged in the main body tube 710; the motor 600 is connected to the motor gear 110; The spline shaft 300 , the planetary gear set 200 and the force-enhancing bearing structure 400 are also disposed in the main body tube 710 .

[0034] Embodiment 4:

[0035] like Figures 9 to 11As shown, the planetary gear set 200 comprises a planet carrier 210, planetary gears 220, a sun gear 230 and an inner gear ring 240. The sun gear 230 is arranged at the center of the planet carrier 210. The sun gear 230 meshes with a plurality of planetary gears 220. The planetary gears 220 mesh with the inner gear ring 240. The inner gear ring 240 is mounted on the planet carrier 210. The front end of the sun gear 230 is connected to the middle of the large gear 130 , that is, the front end of the sun gear 230 is fixedly connected to the large gear 130 , and the rear end of the sun gear 230 is connected to the spline shaft 300 .

[0036] Embodiment 5:

[0037] The lower housing 700 is connected to the mounting portion 900 via connecting bolts 740; One side of the clamp body 500 is provided with a clamp frame 510, and the clamp frame 510 is used to be installed on a vehicle; The large gear 130 is equipped with a retaining spring 1131 and a ball bearing 132; The planetary gear 220 is equipped with a needle bearing I231 and a retaining spring I131; The sun gear 230 is matched with a needle bearing II232; the sun gear 230 is connected to the middle part of the large gear 130 through a pin 234 to transmit torque; The bridge gear 120 is matched with a needle bearing III233; The caliper body 500 has a mounting hole 520 , and the mounting hole 520 is used for mounting the force-enhancing bearing structure 400 . A dust cover 540 is provided at the rear end opening of the mounting hole 520 .

[0038] Embodiment 6:

[0039] This embodiment also includes a retaining sleeve 416; the active disk 413 has a disk body 4133 and a screw sleeve 4134, and the screw sleeve 4134 has a second needle bearing 414 near the disk body 4133; the screw sleeve 4134 passes through the inner hole of the retaining sleeve 416, and a wave spring II415 is provided between the retaining sleeve 416 and the second needle bearing 414; the provision of the wave spring II415 can strengthen the pressure on the second needle bearing 414, so that the maximum friction torque overcome by the active disk 413 is adjusted; in the installed state, the retaining sleeve 416 is fixed in the caliper body 500 under the pressing action of the wave spring II415; The wave spring II415 supports the second needle roller bearing 414. When the active disk 413 moves axially toward the retaining sleeve 416, the wave spring is compressed, and the active disk 413 rotates through the second needle roller bearing 414. When the brake is released later, the wave spring is reset.

[0040] A first needle bearing 417 is provided between the end of the sleeve 4134 and the annular portion of the screw rod 420; the first needle bearing is used to prevent the screw rod 420 from directly contacting and rubbing against the retaining spring II4171 when rotating, and to prevent the screw rod 420 from getting stuck when contacting the active disk 413 under a large input torque when retreating to the rightmost end.

[0041] A retaining spring II4171, a washer 4172 and a wave spring I4173 are sequentially provided between the retaining sleeve 416 and the first needle roller bearing 417. The first needle roller bearing 417 is supported and stabilized by the wave spring, the annular portion of the screw rod 420 contacts the first needle roller bearing 417 to complete the rotation, and when the annular portion of the screw rod 420 moves axially, the first needle roller bearing 417 is stably supported by the characteristics of the wave spring.

[0042] The rear end of the screw rod 420 has a protrusion 423 , and the protrusion 423 cooperates with the piston 430 through a bearing structure 424 .

[0043] A guide pin 425 is provided at the rear end head of the screw rod 420 , and the front end of the guide pin 425 is fixed to the middle of the rear end of the screw rod 420 . The rear end of the guide pin 425 can be rotatably matched with the mounting blind hole 433 of the piston 430 .

[0044] The guide pin 425 has a bushing 426 at the position where it is installed in the mounting blind hole 433 .

[0045] The bearing structure 424 is a cylindrical roller bearing.

[0046] The wave spring I4173 is a single-turn wave spring, and the wave spring II415 is a multi-turn wave spring. The wave spring II415 can apply a load to the active disk 413 in the initial stage to increase the friction torque between the active disk 413 and the support disk 411; in addition, the wave spring I4173 can prevent the first needle bearing 417 from axial movement and limit the position.

[0047] The piston 430 is provided with hemispherical grooves 431 on both sides, and steel balls 432 are arranged in the grooves 431 , and the piston 430 is slidably matched with the caliper body 500 through the steel balls 432 .

[0048] like Fig.15 As shown, the raceways 4131 are three evenly distributed raceways arranged based on a spiral line, and the raceways 4131 cooperate with the rolling elements 412 to convert the torque input by the active disk 413 into an axial thrust; The rolling body 412 is arranged on a retaining frame 4121 .

[0049] The working process of the thrust conversion structure of this embodiment is as follows: The first section is to eliminate the idle stroke. During this process: the horizontal thrust resistance of the piston 430 is F1. Under this resistance, the corresponding friction torque between the transmission thread pairs is M1; the initial assembly state pressure of the wave spring II is F2, the internal friction torque of the force-enhancing bearing structure 400 is M2, and the friction torque of the needle bearing II to the active disk 413 is M3. The screw 420 starts to rotate under the input torque M4, and the driving torque of the screw 420 on the active disk 413 is equal to the friction torque M1 between the thread pairs; at the same time, because the active disk 413 is hindered by the friction torques M2 and M3, and M1 is smaller than the sum of M2 and M3, the active disk 413 remains stationary, and the screw 420 starts to move horizontally while rotating, pushing the piston 430 forward until the gap between the piston 430 and the friction plate 530 is completely eliminated, and then the piston 430 continues to move, and the clamping force F3 starts to increase from zero, and the corresponding resistance to the advancement of the piston 430 is the sum of F1 and F3, the friction torque M1 between the thread pairs, and the friction torque M2 increase simultaneously (the growth rate is smaller than M1), until the size of M1 is equal to the sum of M2 and M3, and this is the critical point at the end of the first stage of movement; The second stage is the clamping stage, during which: the clamping force F3 further increases, and the friction torque M1 between the threaded pairs increases simultaneously. During this process, M1 is greater than the sum of M2 and M3. Driven by the friction torque M1, the active disk 413 rotates and advances horizontally together with the screw 420 until the target clamping force F4 is reached and the drive stops. In this scheme, the friction torques M1, M2, and M3 are determined by the friction characteristics of the parts themselves and the loads they are subjected to. Therefore, in order to ensure the accuracy of the motion process, the friction coefficients of each component and the thrust resistance of the piston should be reasonably designed, and the lead P1 of the transmission thread and the lead P2 of the force-enhancing bearing should be reasonably designed (this parameter determines the slopes K1 and K2 of the growth of M1 and M2, and K1 should be greater than K2 during the growth process. At the same time, when designing the wave spring, the force value F2 should be fully calculated and verified.

[0050] The segmented propulsion motion is achieved by designing appropriate friction torque between thread transmission (constant in idle stroke, and increases with the increase of piston thrust when clamped) and the friction torque size during the movement of rolling elements in the force-enhancing bearing (constant in idle stroke, and can be adjusted by adjusting the force value of the wave spring, and increases with the increase of piston thrust when clamped).

[0051] In addition, when resetting is required, the motor reverses to drive the gears and thrust conversion structure to move in the opposite direction, and each stage corresponds to the clamping process one by one.

Claims

1. An electromechanical caliper for a brake-by-wire system, characterized in that: include: The flat gear assembly (100) receives power from the motor (600); A planetary gear set (200) connected to the spur gear assembly (100) to receive rotational power; A force-enhancing bearing structure (400) comprises a force-enhancing component (410), a screw (420) and a piston (430); the screw (420) is driven by a planetary gear set (200), and the screw (420) has an external thread (422); the force-enhancing component (410) is arranged with a support plate (411), a rolling body (412) and an active plate (413) in sequence from front to back, and the support plate (411) and the active plate (413) have a raceway (4131) with a varying depth that cooperates with the rolling body (412); the external thread (422) of the screw (420) and the internal thread (4132) of the active plate (413) form a thread pair; the piston (430) is capable of axial movement, the front side of the piston (430) is the rear end of the screw (420), and the rear end of the piston (430) is used to abut against a friction plate (530) for braking; The caliper body (500) has a friction plate (530) for braking, and the friction plate (530) is arranged on one side of the force-enhancing bearing structure (400).

2. The electromechanical caliper for a brake-by-wire system according to claim 1, characterized in that: It also includes a spline shaft (300); the screw rod (420) has an inner cavity (421); the inner cavity (421) has a spline hole (4211), and the spline hole (4211) cooperates with the spline shaft (300) with an external spline; It also comprises a motor (600), a lower housing (700) and an upper housing (800), wherein the upper housing (800) is detachably connected to the lower housing (700); the caliper body (500) has a mounting portion (900), and the lower housing (700) is detachably connected to the mounting portion (900); The lower housing (700) is used to install the motor (600), the spur gear assembly (100), the planetary gear set (200), the spline shaft (300) and the force-enhancing bearing structure (400).

3. The electromechanical caliper for a brake-by-wire system according to claim 2, characterized in that: The spur gear assembly (100) comprises a motor gear (110), a bridge gear (120) and a large gear (130) which are meshed and connected in sequence; The lower housing (700) comprises a main body tube (710), a transition tube (720) and a side tube (730) which are connected to each other; a motor gear (110) is arranged in the side tube (730); the bridge gear (120) is arranged in the transition tube (720); and the large gear (130) is arranged in the main body tube (710); the motor (600) is connected to the motor gear (110); The spline shaft (300), the planetary gear set (200) and the force-enhancing bearing structure (400) are also arranged in the main body tube (710).

4. The electromechanical caliper for a brake-by-wire system according to claim 3, characterized in that: The planetary gear set (200) comprises a planet carrier (210), planetary gears (220), a sun gear (230) and an inner gear ring (240); the sun gear (230) is arranged at the center of the planet carrier (210); the sun gear (230) is meshed with a plurality of planetary gears (220); the planetary gears (220) are meshed with the inner gear ring (240); and the inner gear ring (240) is mounted on the planet carrier (210); The front end of the sun gear (230) is connected to the middle of the large gear (130), and the rear end of the sun gear (230) is connected to the spline shaft (300).

5. The electromechanical caliper for a brake-by-wire system according to claim 4, characterized in that: The lower housing (700) is connected to the mounting portion (900) via connecting bolts (740); One side of the caliper body (500) is provided with a caliper frame (510), and the caliper frame (510) is used for being installed on a vehicle; The large gear (130) is equipped with a retaining spring I (131) and a ball bearing (132); The planetary wheel (220) is matched with a needle bearing I (231) and a retaining spring I (131); The sun gear (230) is matched with a needle bearing II (232); the sun gear (230) is connected to the large gear (130) via a pin shaft (234) to transmit torque; The bridge gear (120) is matched with a needle bearing III (233); The caliper body (500) is provided with a mounting hole portion (520), the mounting hole portion (520) being used for mounting the force-enhancing bearing structure (400), and a dust cover (540) is provided at the rear end opening of the mounting hole portion (520).

6. The electromechanical caliper for a brake-by-wire system according to claim 1, characterized in that: It also includes a retaining sleeve (416); the active disk (413) has a disk body (4133) and a threaded sleeve (4134); the threaded sleeve (4134) has a second needle roller bearing (414) at a position close to the disk body (4133); the threaded sleeve (4134) passes through the inner hole of the retaining sleeve (416); a wave spring II (415) is provided between the retaining sleeve (416) and the second needle roller bearing (414); A first needle roller bearing (417) is provided between the end of the screw sleeve (4134) and the annular portion of the screw rod (420); A retaining spring II (4171), a gasket (4172) and a wave spring I (4173) are provided in sequence between the retaining sleeve (416) and the first needle roller bearing (417).

7. The electromechanical caliper for a brake-by-wire system according to claim 6, characterized in that: The wave spring I (4173) is a single-turn wave spring, and the wave spring II (415) is a multi-turn wave spring; Hemispherical grooves (431) are provided on both sides of the piston (430), and steel balls (432) are arranged in the grooves (431) so as to be slidably matched with the caliper body (500) via the steel balls (432).

8. The electromechanical caliper for a brake-by-wire system according to claim 1, characterized in that: The rear end of the screw rod (420) has a protrusion (423), and the protrusion (423) cooperates with the piston (430) via a bearing structure (424); A guide pin (425) is provided at the rear end head of the screw rod (420), the front end of the guide pin (425) is fixed to the middle of the rear end of the screw rod (420), and the rear end of the guide pin (425) is rotatably matched with the mounting blind hole (433) of the piston (430); The guide pin (425) has a bushing (426) at the position where it is installed in the mounting blind hole (433); The bearing structure (424) is a cylindrical roller bearing.

9. The electromechanical caliper for a brake-by-wire system according to claim 1, characterized in that: The raceways (4131) are three evenly distributed raceways arranged based on a spiral line, and the raceways (4131) cooperate with the rolling bodies (412) to convert the torque input by the active disk (413) into an axial thrust; The rolling body (412) is arranged on a retaining frame (4121).

10. A braking method for an electronic mechanical caliper, characterized in that: The electronic mechanical caliper is an electronic mechanical caliper for a brake-by-wire system according to any one of claims 1 to 9; The braking method comprises the following steps: The first stage is to eliminate the idle stroke. During this process: the horizontal thrust resistance of the piston (430) is F1. Under this resistance, the corresponding friction torque between the transmission thread pairs is M1; the internal friction torque of the force-enhancing bearing structure (400) is M2, and the friction torque of the active disk (413) during rotation is M3; the screw (420) starts to rotate under the input torque M4, and the driving torque of the screw (420) on the active disk (413) is equal to the friction torque M1 between the thread pairs; at the same time, because the active disk (413) is hindered by the friction torques M2 and M3, and M1 is smaller than the sum of M2 and M3, 3, therefore, the active disk (413) remains stationary, and the screw (420) starts to move horizontally while rotating, pushing the piston (430) forward until the gap between the piston (430) and the friction plate (530) is completely eliminated, and then the piston (430) continues to move, and the clamping force F3 starts to increase from zero, and the corresponding resistance to the advancement of the piston (430) is the sum of F1 and F3, the friction torque M1 between the thread pair, and the friction torque M2 increase simultaneously, until the size of M1 is equal to the sum of M2 and M3, which is the critical point at the end of the first stage of movement; The second stage is the clamping stage, during which the clamping force F3 further increases, and the friction torque M1 between the threaded pair increases simultaneously. During this process, M1 is greater than the sum of M2 and M3. Driven by the friction torque M1, the active disk (413) rotates and advances horizontally together with the screw (420) until the target clamping force F4 is reached and the drive stops.

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