Cam-type electromechanical brake and vehicle

Abstract

The present invention discloses a cam-type electromechanical brake and a vehicle, belonging to the technical field of electromechanical brakes. The cam-type electromechanical brake includes a caliper component. A driven bracket is slidably arranged in the caliper housing. A driven bearing is embedded in the driven bracket. An installation groove is recessed in the middle of the driven bracket. The braking unit includes a housing, a first driving mechanism and two camshafts. The lower ends of the camshafts are rotatably arranged in the housing, and the upper ends of the camshafts pass through the driven bearing and are rotatably arranged in the caliper housing. The first driving mechanism is used to drive the camshafts to push the driven bracket to move in a direction close to or away from the friction plate through the driven bearing, and the two camshafts rotate towards each other. The clearance adjustment unit includes a stud, a bracket nut with an open cavity and a nut sealing plate. The stud is rotatably arranged in the installation groove, the bracket nut is threadedly connected to the stud, and the nut sealing plate is used to push the friction plate. The structure of the present invention is compact, the cost is low, and the clearance adjustment accuracy is high.

Description

Technical Field

[0001] The present invention relates to the technical field of electromechanical brakes, and particularly to a cam-type electromechanical brake and a vehicle. Background Art

[0002] Braking is an important function that must be available when a vehicle is in use. The quality of braking performance not only affects braking comfort, but also plays a decisive role in the safety of the vehicle. From the perspective of the structure of the brake, it mainly includes two categories: drum brakes and disc brakes. The latter has largely replaced the former in passenger cars due to its performance advantages such as heat dissipation and installation. From the perspective of the drive and transmission forms, it mainly includes two categories: hydraulic and electromechanical. The former is still widely used at present due to its relatively mature technology, but due to the disadvantages of easy leakage of the hydraulic circuit and slow braking response, with the rapid development of electric vehicles, the latter electromechanical brake has attracted great attention.

[0003] Among them, the electromechanical brake does not require hydraulic oil, has a fast response speed, and more accurate braking force control, and is an excellent brake for electric vehicle by-wire braking. The existing electromechanical brake with a lead screw configuration has a large volume and high manufacturing cost. The cam-type electromechanical brake is essentially a variable transmission ratio mechanism, which can set a larger transmission ratio range during the idle stroke to reduce the braking process time. Under the same braking intensity, the cam-type electromechanical brake requires a lower motor power, thereby reducing the system costs such as the corresponding motor drive circuit wiring harness connectors, and reducing the vehicle energy consumption.

[0004] The cam-type electromechanical brake has the following related problems and is analyzed in detail:

[0005] First is the problem of wear compensation of the brake pads. The braking process stops the brake disc by the friction generated by the relative sliding between the brake pads and the brake disc. The relative sliding friction will cause the brake pads to wear and become thinner, and the wear amount is generally between 10 - 20 mm. During braking, when the brake pads are pressed against the brake disc, axial deformation will occur, and the axial deformation amount is between 0.1 - 1 mm. The brake pads and the brake disc generally maintain a gap of 0.1 - 0.5 mm on both sides when there is no braking. During the braking process, whether it is a ball screw, a wedge block or a cam, the two parts of distance that need to move are the axial deformation and the gap. When the friction pads are worn, the braking action distance will increase greatly. In particular, limited by the lift of the cam, when the brake pads are worn, the cam brake will not be able to press the brake pads against the brake disc with the predetermined clamping force.

[0006] Secondly, there is the problem of excessive contact stress in the cam pair. According to the different follower types, the cam pair includes at least three types: pointed tip, flat bottom, and roller. In the first two types, there is relative sliding between the cam and the follower, which will generate a large frictional resistance and cause wear, so they are not suitable for adoption. For the roller-type cam, according to the current patent documents CN105143706A, CN101003254A, and CN114270068A, both the cam and the roller are in "external meshing". According to Hertz's formula, the composite curvature radius between the two is smaller than the curvature radius of any one of them at this point, and the smaller the composite curvature radius, the greater the contact stress generated. For a relatively strong braking intensity, the force required to press the brake pad onto the brake disc is between 20 - 50 kN. The large contact stress poses high requirements for the cam material and process.

[0007] Size problem: By increasing the radii of the cam and the roller, the composite curvature radius can be increased, and the contact stress can be reduced. Therefore, when the materials and processes (allowable contact stress) of the cam and the roller are determined, there is a contradiction between the contact stress and the structural size, and the roller and the cam are arranged separately in a straight line, resulting in a relatively large size along the axial direction of the brake disc.

[0008] To solve the contradiction between the contact stress and the structural size, the method adopted in the patent document CN105143706 is to add a stage of lever transmission after the cam, so as to reduce the acting force on the cam pair, and thus smaller sizes can be used under the condition of ensuring strength, but this inevitably makes the structure more complex.

[0009] To solve the problem of wear clearance compensation, the patent document CN101003254 designs a set of compensation devices. In theory, this scheme can achieve clearance compensation after wear. However, in fact, the clearance compensation occurs exactly when the clamping force is the largest, and the clearance compensation device often has low efficiency in order to ensure the characteristic of one-way self-locking. Therefore, the driving force required for compensation will be much greater than the driving force during normal braking.

[0010] In summary, the existing cam-type electromechanical brake has a complex structure, large occupied volume, high cost, low reliability, and low clearance adjustment accuracy.

[0011] Therefore, there is an urgent need to provide a cam-type electromechanical brake to solve the above problems. Summary of the Invention

[0012] The purpose of the present invention is to provide a cam-type electromechanical brake and a vehicle, which have a compact and simple structure, low cost, high clearance adjustment accuracy, and high reliability.

[0013] To achieve the above purpose, the following technical solutions are provided:

[0014] The cam-type electromechanical brake includes:

[0015] A caliper component, including a caliper housing and a friction plate;

[0016] A driven bracket, slidably arranged in the caliper housing. A driven bearing is embedded in the driven bracket, and an installation groove is recessed in the middle of the driven bracket;

[0017] A braking unit, including a housing, a first driving mechanism and two camshafts. The housing is installed at the bottom of the caliper housing. The first driving mechanism is arranged in the housing. The lower end of the camshaft is rotatably arranged in the housing, and the upper end of the camshaft passes through the driven bearing and is rotatably arranged in the caliper housing. The first driving mechanism is in transmission connection with the two camshafts, and the two camshafts rotate towards each other to drive the camshaft to push the driven bracket to move in a direction close to or away from the friction plate through the driven bearing;

[0018] A clearance adjustment unit, including a stud, a bracket nut with an open cavity and a nut sealing plate. One end of the stud is rotatably arranged on the side wall of the installation groove. The bracket nut is threadedly connected to the stud and is located in the installation groove. The nut sealing plate seals the open cavity, and the area of the nut sealing plate is larger than the area of the open cavity. The nut sealing plate is used to push the friction plate.

[0019] As an alternative to the cam-type electromechanical brake, the first driving mechanism includes a first motor and a reduction and power distribution mechanism. The first motor is in transmission connection with the input end of the reduction and power distribution mechanism, and the lower end of the camshaft is connected to the output end of the reduction and power distribution mechanism.

[0020] As an alternative to the cam-type electromechanical brake, there are two camshafts. The reduction and power distribution mechanism includes two worm wheels and a worm with two sections of threads. The worm wheels are arranged at the lower ends of the camshafts. One end of the worm is connected to the first motor, and the other end of the worm meshes with the two worm wheels, and the rotation directions of the two camshafts are opposite.

[0021] As an alternative to the cam-type electromechanical brake, the output end of one of the reduction and power distribution mechanisms is in transmission connection with the stud.

[0022] As an alternative to the cam-type electromechanical brake, the clearance adjustment unit further includes a second driving mechanism, and the second driving mechanism is in transmission connection with the stud.

[0023] As an alternative to the cam - type electromechanical brake, the second driving mechanism includes a second motor, a driving gear, and a driven gear. The driven gear is installed at one end of the stud away from the bracket nut. The output shaft of the second motor is connected to the driving gear, and the driving gear meshes with the driven gear.

[0024] As an alternative to the cam - type electromechanical brake, the caliper housing is provided with a housing opening and a bearing hole. The driven bracket is horizontally installed in the housing opening, and the support bearing at the upper end of the camshaft is installed in the bearing hole. The rear cover is detachably connected to the housing opening.

[0025] As an alternative to the cam - type electromechanical brake, a jack is recessed at one end of the stud close to the rear cover.

[0026] As an alternative to the cam - type electromechanical brake, a wave spring is further included. The wave spring is arranged between the driven bracket and the side wall of the caliper housing.

[0027] As an alternative to the cam - type electromechanical brake, the braking unit further includes an angle sensor arranged at the tail end of the camshaft for measuring the rotation angle of the camshaft.

[0028] A vehicle includes a brake disc, a steering knuckle, and the cam - type electromechanical brake as described in any one of the above. The brake disc is rotatably arranged on the steering knuckle, and the cam - type electromechanical brake is installed on the steering knuckle for braking the brake disc.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] The cam - type electromechanical brake provided by the present invention uses a first driving mechanism to drive two camshafts to rotate towards each other, canceling the lateral component force of the cam, reducing the structural design burden, and further reducing the structural size; the double - cam itself also reduces the outer diameter of the cam compared with the single - cam, thereby reducing the size in the precession direction, increasing the span of the acting point, and thus increasing the stability of the braking clamping force (thrust); the profile surface of the camshaft is located inside the inner ring of the driven bearing of the driven bracket and presses against the inner ring. The camshaft pushes the driven bracket to move in a direction close to or away from the friction plate through the driven bearing. The cooperation between the profile surface of the camshaft and the inner ring of the driven bearing reduces a certain frictional loss to the driven bracket compared with the cam directly pressing on a plane. The contact surface between the cam and the inner ring of the driven bearing has a larger contact area (smaller curvature difference), improving the contact strength. Thus, the base circle radius of the cam can be reduced under the same strength requirements, reducing the size of the transmission system. In summary, on the one hand, the size of the cam - type electromechanical brake in the precession direction is shortened, the structure is more compact, and the occupied space is small; on the other hand, the contact between the camshaft and the inner diameter of the driven bearing is "internal meshing". According to Hertz's formula, the magnitude of the contact stress depends on the difference in the curvature radii at the contact point between the two. The smaller the difference in the curvature radii, the larger the combined curvature radius. Under the action of the same normal force, the contact stress is smaller, and the structural bearing capacity is stronger. Therefore, the contact stress between the two is greatly reduced, and there is no contradiction between the contact stress and the size.

[0031] In the cam - type electromechanical brake provided by the present invention, one end of a stud is rotatably arranged in an installation groove recessed in the middle of the driven bracket. Rotating the stud makes the bracket nut drive the nut sealing plate to push the friction plate against the brake disc or release the brake disc. On the one hand, the stud and the bracket nut form a lead - screw and nut mechanism for compensating the gap between the friction plate and the brake disc after the friction plate wears, ensuring an accurate braking effect; on the other hand, the self - locking characteristic between the threads of the lead - screw and nut mechanism is utilized to ensure one - way transmission. Since the area of the nut sealing plate is larger than the area of the open cavity, the maximum thrust that the nut sealing plate can bear is increased.

[0032] The vehicle provided by the present invention is equipped with a cam - type electromechanical brake, which has a compact structure and excellent braking effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the content of the embodiments of the present invention and these drawings.

[0034] Figure 1 It is an assembly schematic diagram of installing the cam - type electromechanical brake in the present invention embodiment to the steering knuckle;

[0035] Figure 2 Explosion schematic diagram of the cam - type electromechanical brake installed on the steering knuckle in the embodiment of the present invention;

[0036] Figure 3 Assembly schematic diagram of the camshaft and the driven bracket in the embodiment of the present invention;

[0037] Figure 4 Is Figure 3 Cross - sectional view in the A - A direction of

[0038] Figure 5 Explosion schematic diagram of the camshaft and the driven bracket in the embodiment of the present invention;

[0039] Figure 6 Explosion schematic diagram of the driven bracket and the clearance adjustment unit in the embodiment of the present invention;

[0040] Figure 7 Explosion schematic diagram of the clearance adjustment unit in the embodiment of the present invention;

[0041] Figure 8 Structural schematic diagram of the cam - type electromechanical brake in the embodiment of the present invention (the caliper component is not shown);

[0042] Figure 9 Explosion schematic diagram of the first driving mechanism in the embodiment of the present invention;

[0043] Figure 10 Structural schematic diagram of the cam - type electromechanical brake in the embodiment of the present invention;

[0044] Figure 11 Is Figure 10 Cross - sectional view in the B - B direction of

[0045] Figure 12 Structural schematic diagram of the cam - type electromechanical brake in the embodiment of the present invention;

[0046] Figure 13 Is Figure 12 Cross - sectional view in the C - C direction of

[0047] Figure 14 Structural schematic diagram of the cam - type electromechanical brake in the embodiment of the present invention (the rear cover is not shown);

[0048] Figure 15 Structural schematic diagram of the first single - output and single - output reduction and power split mechanism in the embodiment of the present invention;

[0049] Figure 16 Structural schematic diagram of the second single - output and single - output reduction and power split mechanism in the embodiment of the present invention;

[0050] Figure 17 This is a schematic structural diagram of the third single-output speed reduction and power splitting mechanism in the embodiments of the present invention;

[0051] Figure 18 This is a schematic structural diagram of the fourth single-output speed reduction and power splitting mechanism in the embodiments of the present invention;

[0052] Figure 19 This is a schematic structural diagram of the fifth single-output speed reduction and power splitting mechanism in the embodiments of the present invention;

[0053] Figure 20 This is a schematic structural diagram of the first single-output double-output speed reduction and power splitting mechanism in the embodiments of the present invention;

[0054] Figure 21 This is a schematic structural diagram of the second single-output double-output speed reduction and power splitting mechanism in the embodiments of the present invention;

[0055] Figure 22 This is a schematic structural diagram of the third single-output double-output speed reduction and power splitting mechanism in the embodiments of the present invention;

[0056] Figure 23 This is a schematic structural diagram of the first driving mechanism of the first arrangement type in the embodiments of the present invention;

[0057] Figure 24 This is a schematic structural diagram of the first driving mechanism of the second arrangement type in the embodiments of the present invention;

[0058] Figure 25 This is a schematic structural diagram of the first driving mechanism of the third arrangement type in the embodiments of the present invention;

[0059] Figure 26 This is a schematic structural diagram of the first driving mechanism of the fourth arrangement type in the embodiments of the present invention;

[0060] Figure 27 This is a schematic structural diagram of the first driving mechanism of the fifth arrangement type in the embodiments of the present invention.

[0061] Reference numerals:

[0062] 100, cam-type electromechanical brake; 200, brake disc; 300, steering knuckle;

[0063] 1, caliper component; 2, driven bracket; 3, braking unit; 4, clearance adjustment unit; 5, wave spring;

[0064] 11, caliper housing; 111, housing opening; 112, bearing hole; 12, friction plate; 13, caliper bracket; 14, slide pillar; 15, snap ring; 16, setscrew; 17, rear cover; 18, cylindrical spring pin;

[0065] 21. Driven bearing; 22. Installation groove

[0066] 31. Machine housing; 32. First driving mechanism; 321. First motor; 322. Speed reduction and power distribution mechanism; 3221. Worm; 3222. Worm gear; 33. Camshaft; 34. Angle sensor; 35. Support bearing

[0067] 41. Stud; 42. Bracket nut; 43. Nut sealing plate; 44. Second driving mechanism; 441. Second motor; 442. Driving gear; 443. Driven gear; 45. Sealing ring Specific embodiments

[0068] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0069] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0070] In the description of the present invention, it should also be noted that unless otherwise clearly defined and limited, the terms "set" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0071] In the present invention, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include the first and second features not being in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is less than that of the second feature.

[0072] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0073] In the prior art, the cam-type electromechanical brake does not require hydraulic fluid, has a fast response speed, and more accurate braking force control, and is an excellent brake for electric vehicle by-wire braking. However, the existing cam-type electromechanical brake has the disadvantages of large structural occupied space volume, high cost, and low clearance adjustment accuracy.

[0074] In order to make the structure of the mechanical brake compact, low in cost, and high in clearance adjustment accuracy, this embodiment provides a cam-type electromechanical brake and a vehicle. The following will be combined with Figures 1 to 27 to describe the specific content of this embodiment in detail.

[0075] Embodiment 1

[0076] In this embodiment, the cam-type electromechanical brake 100 includes a caliper assembly 1, a driven bracket 2, a brake unit 3, and a clearance adjustment unit 4.

[0077] Among them, the caliper assembly 1 includes a caliper housing 11, a caliper bracket 13, a slide post 14, a snap ring 15, a rear cover 17, a friction plate 12, and a setscrew 16. The rear cover 17 is fixed to the caliper housing 11 by screws. The slide post 14 connects the caliper housing 11 and the caliper bracket 13 in series, enabling the caliper housing 11 to float and having a degree of freedom of movement in one direction. The cylindrical spring pin 18 is limited between the caliper housing 11 and the caliper bracket 13. The snap ring 15 is installed in the groove of the caliper bracket 13, and the friction plate 12 is installed therein. The two friction plates 12 squeeze the brake disc 200 to achieve braking. The caliper bracket 13 is installed on the steering knuckle 300 or the drive axle housing by screws.

[0078] The driven bracket 2 is slidably arranged in the caliper housing 11, and a driven bearing 21 is embedded in the driven bracket 2. The driven bracket 2 is recessed with a mounting groove 22 in the direction away from the friction plate 12 for mounting the gap adjustment unit 4, making the overall structure more compact and reducing the occupied space.

[0079] The brake unit 3 includes a housing 31, a first drive mechanism 32, and a camshaft 33 with support bearings 35 at its upper and lower ends. The housing 31 is screw-mounted to the bottom of the caliper housing 11. The first drive mechanism 32 is mounted within the housing 31. The lower end of the camshaft 33 is rotatably mounted within the housing 31 via the support bearing 35. The upper end of the camshaft 33 passes through the driven bearing 21 and is rotatably mounted within the caliper housing 11 via the support bearing 35. A push screw 16 is mounted at the top of the caliper housing 11, facilitating removal of the support bearing 35 at the upper end of the camshaft 33 by turning the push screw 16. (The caliper body is located above the camshaft's support bearing 35 and is equipped with threads and a push screw 16 for bearing removal.) The first drive mechanism 32 is in transmission connection with the camshaft 33, driving the camshaft 33 via the driven bearing 21 to push the driven bracket 2 toward or away from the friction plate 12. The clearance adjustment unit 4 includes a sealing ring 45, a stud 41, a bracket nut 42 with an open cavity, and a nut sealing plate 43. One end of the stud 41 is rotatably mounted on the sidewall of the mounting slot 22. The bracket nut 42 is threadedly connected to the stud 41. The nut sealing plate 43 seals the open cavity. The area of the nut sealing plate 43 is larger than that of the open cavity. The nut sealing plate 43 is used to push the friction plate 12 against the brake disc 200. The sealing ring 45 is used to seal the gap between the driven bracket 2 and the sidewall of the caliper housing 11.

[0080] Cam-type electromechanical brakes offer lower manufacturing costs and are easier to commercialize than screw-type mechanical brakes. Cams are essentially variable-ratio mechanisms, allowing for a wider range of transmission ratios during idle travel, thereby reducing braking time. For the same braking time, cam-type electromechanical brakes require less motor power, reducing system costs for the motor, electric drive circuitry, wiring harness connectors, and more, ultimately lowering vehicle energy consumption.

[0081] In short, for the cam-type electromechanical brake 100 provided by the present invention, the first driving mechanism 32 drives the two camshafts 33 to rotate, canceling the lateral component force of the cams, reducing the structural design burden, and further reducing the structural size; the double cams themselves also reduce the outer diameter of the cams compared with single cams, thereby reducing the size in the precession direction (but increasing the lateral size), increasing the span of the acting points, and thus increasing the stability of the braking clamping force (thrust); the profile surface of the camshaft 33 is located within the inner ring of the driven bearing 21 of the driven bracket 2 and presses against the inner ring. The camshaft 33 pushes the driven bracket 2 to move in a direction close to or away from the friction plate 12 through the driven bearing 21. The profile surface of the camshaft 33 cooperates with the inner ring of the driven bearing 21, reducing a certain frictional loss to the driven bracket compared with the cams directly pressing against a plane. The contact surface between the cam and the inner ring of the driven bearing has a larger contact area (smaller curvature difference), improving the contact strength, so that the base circle radius of the cam can be reduced under the same strength requirement, reducing the size of the transmission system. In summary, on the one hand, the size of the cam-type electromechanical brake 100 in the precession direction is shortened, the structure is more compact, and the occupied space is small; on the other hand, the contact between the camshaft 33 and the inner diameter of the driven bearing 21 is "internal meshing". According to Hertz's formula, the magnitude of the contact stress depends on the difference in the curvature radii at the contact point between the two. The smaller the difference in the curvature radii, the larger the combined curvature radius. Under the action of the same normal force, the contact stress is smaller, and the structural bearing capacity is stronger. Therefore, the contact stress between the two is greatly reduced, and there is no contradiction between the contact stress and the size. One end of the stud 41 is rotatably arranged in the installation groove 22 recessed in the middle of the driven bracket 2. Rotating the stud 41 causes the bracket nut 42 to drive the nut sealing plate 43 to push the friction plate 12 against the brake disc 200 or release the brake disc 200. On the one hand, the stud 41 and the bracket nut 42 form a lead screw and nut mechanism for compensating the gap between the friction plate 12 and the brake disc 200 after wear, ensuring an accurate braking effect; on the other hand, the self-locking characteristic between the threads of the lead screw and nut mechanism is utilized to ensure single-direction transmission. Since the area of the nut sealing plate 43 is larger than the area of the open cavity, the maximum thrust that the nut sealing plate 43 can bear is increased. The front adapter plate (nut sealing plate 42) of the clearance adjustment nut (bracket nut 42) expands the friction plate pressing area and the lateral span, enhancing the stability; at the same time, it serves as a seal for the clearance adjustment nut.

[0082] The clearance adjustment unit 4 is centrally arranged on the driven bracket 2 provided with double cams, reducing the size in the precession direction by about 50% compared with the general industry level. Due to a large amount of space saving (especially in the precession direction), the industry difficulty that the brake is too large to match the vehicle model application is overcome.

[0083] It is worth noting that the camshaft 33 at least includes an input end, a contour surface, a support surface and a sensor connecting section; the input end of the camshaft 33 is fixedly connected to the interface of the rotational output of the reduction transfer mechanism 322; the driven bearing 21 includes at least two contact surfaces, an inner ring and an outer ring; and the contact surface of the inner ring of the driven bearing 21 is in line contact with the contour surface of the camshaft 33; the driven bracket 2 at least includes a bearing mounting hole and a contact surface, and the bearing mounting hole of the driven bracket 2 cooperates with the outer ring of the driven bearing 21; the contact surface of the mounting groove 22 of the driven bracket 2 contacts one of the contact surfaces of the stud 41, and the driven bracket 21 has an opening-gap adjustment to place the tail extension shaft of the stud 41 into it, and a limit spring is used to limit the position of the stud 41 to realize the linkage between the gap adjustment mechanism and the cam transmission system.

[0084] The support bearing 35 includes at least an inner ring and an outer ring; the inner ring of the support bearing 35 cooperates with the contour curved surface of the camshaft 33 .

[0085] The housing opening 111 in the caliper housing 11 houses the driven bracket 2. The support bearings 35 of the camshaft 33 are positioned within the upper and lower bearing holes 112 within the housing opening 111. This design creates a highly integrated caliper housing, resulting in enhanced structural strength and a reduced number of components. The rear cover 17 of the housing opening 11 is easily removed to observe the cam's operation and troubleshoot any issues. Removal of the rear cover 17 facilitates manual clearance adjustment and allows for manual release of the parking brake.

[0086] Furthermore, a socket is recessed at one end of the stud 41 near the rear cover 17. Specifically, a hexagonal hole can be opened at the end of the extension shaft of the stud 41 to insert a wrench (required to open the rear cover 17) to achieve manual clearance adjustment and manual release of parking.

[0087] Furthermore, the first drive mechanism 32 includes a first motor 321 and a reduction gear transfer mechanism 322. The first motor 321 is in driving connection with the input end of the reduction gear transfer mechanism 322, and the lower end of the camshaft 33 is connected to the output end of the reduction gear transfer mechanism 322. The power of the first motor 321 is transmitted to the camshaft 33 via the reduction gear transfer mechanism 322.

[0088] For example, Figures 15 to 19As shown, the speed reduction and power splitting mechanism 322 includes a speed reducer configuration with a single input shaft and a single output shaft, having one input end and one output end. It can be, but is not limited to, a coaxial arrangement for the input and output ends. Available speed reducer forms include, for example, planetary gear reduction, harmonic gear reduction, etc. A coaxial connection form can also be considered as this speed reduction form; the input and output ends are parallel shafts in the opposite direction; the input and output ends are parallel shafts in the same direction, parallel shafts in the same direction; the input and output ends are in the form of intersecting shafts, such as bevel gears; the input and output ends are in the form of crossed shafts, such as worm gears. In addition, the speed reducer can be single-stage or multi-stage, and another form obtained by connecting two speed reduction forms in series is also included. For example, connecting a parallel shaft form and an intersecting shaft form in series can obtain a speed reducer in the form of crossed shafts, or it can also be in the form of multi-stage series, such as connecting two planetary gear speed reducers in series, which is also a coaxial form. In short, general speed reducers within the scope of this technical field and their simple combined connection forms are all included in the above situations.

[0089] Exemplarily, as Figures 20 to 22 shown, the speed reduction and power splitting mechanism 322 includes a speed reducer configuration with a single input shaft and two output shafts, having one input end and two output ends. It can be, but is not limited to, a parallel shaft arrangement for the input and output ends; an intersecting shaft arrangement for the input and output ends; a crossed shaft arrangement for the input and output ends.

[0090] Furthermore, two camshafts 33 are provided. The speed reduction and power splitting mechanism 322 includes two worm wheels 3222 and a worm 3221 with two threaded sections. The worm wheels 3222 are arranged at the lower ends of the camshafts 33. One end of the worm 3221 is connected to the first motor 321, and the other end of the worm 3221 meshes with the two worm wheels 3222, and the rotation directions of the two camshafts 33 are opposite.

[0091] Exemplarily, in this embodiment, as Figure 9As shown in the figure, the worm gear 3222 includes a left worm gear and a right worm gear. The worm 3221 includes a worm main shaft, a left worm and a right worm, and the left worm and the right worm are coaxial. The left worm gear meshes with the left worm; the right worm gear meshes with the right worm. For the double cam-double worm gear, the worm gears of the left and right cams are in reverse, and together with the double cams that rotate in opposite directions, the axial component force acting on the worm is offset. The worm gear itself occupies a small size in the precession direction, which matches the overall design of the compressed size space. As shown in the figure, the thread helix directions of the left worm and the left worm gear are both left-handed, and the thread helix directions of the right worm and the right worm gear are both right-handed. The helix directions of the left and right worm gears are opposite, and the number of teeth of the left worm gear and the right worm gear is equal, and the number of heads of the left worm and the right worm is equal, so as to ensure that when the left and right worms rotate coaxially, the two worm gears rotate at the same speed in opposite directions, so that the lateral forces can cancel each other out when the camshaft 33 is clamped. When the helix angles of the left and right worms are equal and the torques on the worm gears are equal, the axial forces on the worm main shaft can also cancel each other out. The left worm and the right worm are supported on the housing 31 through bearings; the left worm and the right worm are fixedly connected to the worm main shaft through pins, and the worm main shaft is splined to the output shaft of the first motor. The first motor 321 is fixedly connected to the motor mounting plate through mounting screws; the motor mounting plate is then fixed to the housing 31 through screws. The left worm gear and the camshaft 33 on the left side are fixed through set screws and limit screws; similarly, the right worm gear and the camshaft 33 on the right side are fixed through set screws and limit screws. The contour surface of the camshaft 33 does not rotate continuously but only has a certain working range, and the camshaft 33 rotates back and forth during operation.

[0092] In some application scenarios, the worm gear can be designed to be self-locking. In this way, without major structural adjustments, the front wheels of the vehicle can be designed for pure service braking, and the rear wheels can be designed to have a parking function. Since the structure of the front and rear wheels changes little, the reuse rate of components is increased, and the mass production cost is further reduced (the parking function of other mechanical brakes often requires adding a set of mechanisms and an independent power source, resulting in increased complexity and cost).

[0093] In some other application scenarios, such as Figures 23 to 27 As shown in the figure, the first drive mechanism 32 also has various layout types.

[0094]

[0092] In some application scenarios, the worm gear can be designed to be self-locking. In this way, without major structural adjustments, the front wheels of the vehicle can be designed for pure service braking, and the rear wheels can be designed to have a parking function. Since the structure of the front and rear wheels changes little, the reuse rate of components is increased, and the mass production cost is further reduced (the parking function of other mechanical brakes often requires adding a set of mechanisms and an independent power source, resulting in increased complexity and cost).

[0093] In some other application scenarios, such as Figures 23 to 27 As shown in the figure, the first drive mechanism 32 also has various layout types.

[0094] For example Figure 23 As shown in the figure, the first motor 321 with a single output shaft is connected to the input shaft of the reducer, and the two output shafts of the reducer with double output shafts are respectively fixedly connected to the two worms 3221. The helix directions and meshing forms of the worm gears and the worms 3221 are the same as those in Figure 9 the scheme.

[0095] For example Figure 24 As shown in the figure, a first motor 321 with double output shafts is adopted. The two motor output shafts are connected to two reducers, and the speed ratios of the two reducers are the same, and the center distances of the parallel shafts are the same.

[0096] For example Figure 25As shown, the first motor 321 with a single output shaft is connected to the input shaft of the reducer, and the output shaft of the reducer is fixedly connected to the input gear; the input gear is engaged with the left gear and the idler gear, and the idler gear is engaged with the right gear. The number of teeth on the left and right gears is equal, which can ensure that the left and right gears output equal and opposite rotational motion.

[0097] For example Figure 26 As shown, the first motor 321 with a single output shaft is connected to the reducer input shaft, the reducer output shaft is fixedly connected to the intermediate worm, and the intermediate worm is engaged with the left and right worm wheels at the same time.

[0098] For example Figure 27 As shown, the first motor 321 with a single output shaft is connected to the reducer input shaft, the reducer output shaft is directly coaxially fixed to the right gear, and the left gear and the right gear are meshed and have the same number of teeth.

[0099] Furthermore, in this embodiment, the gap adjustment unit 4 also includes a second drive mechanism 44 (serving as an independent power source), which is in transmission connection with the stud 41. The second drive mechanism 44 drives the stud 41 to rotate, thereby adjusting the wear gap resulting from wear of the friction plate 12. When the second drive mechanism 44 is not rotating, the stud 41 also does not rotate. The self-locking nature of the threads of the screw-nut mechanism maintains the bracket nut 42 in the adjusted position relative to the stud 41.

[0100] Further, if Figure 7 As shown, the second drive mechanism 44 includes a second motor 441, a driving gear 442, and a driven gear 443. The driven gear 443 is mounted on the end of the stud 41 away from the bracket nut 42. The output shaft of the second motor 441 is connected to the driving gear 442, and the driving gear 442 is meshed with the driven gear 443. Exemplarily, the second motor 441 is a servo motor or a steering gear, etc., and no further limitation is imposed here.

[0101] Furthermore, the diameter of the driving gear 442 is smaller than that of the driven gear 443 , which reduces the rotation speed of the driven gear 443 and increases the torque of the driven gear 443 , making it easier to reduce the power of the second motor 441 and to use a miniaturized motor for driving.

[0102] Furthermore, the cam-type electromechanical brake 100 includes a wave spring 5, which is positioned between the driven bracket 2 and the sidewall of the caliper housing 11. When the brake is released, the compressed wave spring 5 assists in returning the driven bracket 2 to its original position. The driven bracket 2 uses dual wave springs 5 for return, and a mounting slot for the wave spring 5 is located on the front wall of the caliper body, simplifying the return mechanism.

[0103] In this embodiment, the profile curve of the camshaft 33 on the left is symmetrical to the profile curve of the camshaft 33 on the right. When the two camshafts 33 rotate in opposite directions at the same speed, the vertical movement of the driven bearing 21 is the same, the vertical forces are superimposed, and the lateral forces are in opposite directions and cancel each other out. The lateral force cancellation can eliminate the friction of the driven bracket 2 when it moves in the caliper housing 11, avoiding poor movement. The driven bearing 21 can be selected from a needle bearing with a strong load-bearing capacity. The profile curve of the camshaft 33 and the inner diameter of the driven bearing 21 are only squeezed in the normal direction, and there is no wear caused by relative sliding, which is beneficial to improving the service life of the camshaft 33. The journal of the camshaft 33 is supported by four support bearings 35. The wave spring 5 is clamped between the driven bracket 2 and the caliper body, and resets the driven bracket 2 when the camshaft 33 rotates after clamping. The centers of curvature at the contact points of the camshaft 33 and the driven bearing 21 are on the same side. According to Hertz's formula, the comprehensive curvature radius is related to the difference between the curvature radii of the two. The smaller the difference in curvature radii, the larger the comprehensive curvature radius. Under the same normal force, the contact stress is smaller and the structural bearing capacity is stronger. Therefore, the structural size can be designed to be very small.

[0104] Braking unit 3 further includes an angle sensor 34, which is mounted at the rear end of camshaft 33 (sensor connection section). The fixed portion of angle sensor 34 is attached to housing 31 via bolts and nuts. In this embodiment, a SV01A103AEA01R0 rotary angle position sensor with a 10K trimming potentiometer is used. This angle measurement principle utilizes a sliding rheostat, offering reliable operation, long life, and low cost. The detected data is used to control the desired rotation angle of camshaft 33. Specifically, the rear end of camshaft 33 is connected to an extended shaft with a low-cost angle sensor (with a range of less than 360 degrees).

[0105] like Figure 5 Combine Figure 9 As shown, a worm gear, a set screw, and a bolt are fixed to the camshaft 33 to limit the cam's rotation angle. Bolts are deliberately chosen rather than completely hidden set screws because the protruding nut, combined with the track grooves in the reducer housing, limits the cam's rotation angle range, thus achieving mechanical rotational limit and preventing over-limit operation.

[0106] This embodiment also provides a vehicle, which includes a brake disc 200, a steering knuckle 300, and the aforementioned cam-type electromechanical brake 100. The brake disc 200 is rotatably mounted on the steering knuckle 300, and the cam-type electromechanical brake 100 is mounted on the steering knuckle 300 for braking the brake disc 200. The installation of the cam-type electromechanical brake 100 provides a compact structure and excellent braking effect.

[0107] Note that the cam-type electromechanical brake in this embodiment can be applied to, but is not limited to, rail transportation or aircraft landing gear, etc.

[0108] Embodiment 2

[0109] This embodiment provides a cam - type electromechanical brake 100. Compared with Embodiment 1, the basic structure of the cam - type electromechanical brake 100 provided in this embodiment is the same as that in Embodiment 1, and only the drive setting of the stud 41 is different. The structures that are the same as those in Embodiment 1 will not be described in detail in this embodiment.

[0110] Furthermore, in this embodiment, the output end of one of the speed - reducing and power - splitting mechanisms 322 is in transmission connection with the stud 41. Therefore, through the cooperation of the first motor 321 and the speed - reducing and power - splitting mechanism 322, the first driving mechanism 32 can be used to drive the rotation of the camshaft 33 and also to drive the rotation of the stud 41, making the structure of the cam - type electromechanical brake 100 more compact and reducing the occupied area. It can be understood that the clearance adjustment can also adopt a non - independent power source, that is, it is driven by the cam power source (the first motor 321) to achieve automatic clearance adjustment. The independent power source for clearance adjustment can more precisely and actively adjust the clearance, and enables the clearance adjustment unit 4 to have a backup braking function in addition to the cam main motor (the first motor 321); two highly compact independent power source clearance adjustment mechanisms are designed. The independent / non - independent power source clearance adjustment unit 4 can be arranged in the recess (installation groove 22) of the driven bracket 2, that is, the outer shape spaces of the two clearance adjustment devices are basically the same.

[0111] Note that the cam - type electromechanical brake in this embodiment can be but is not limited to being applied to rail transit or aircraft landing gears, etc. The above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described here, and various obvious changes, re - adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, it can also include more other equivalent embodiments, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. Cam-type electromechanical brake, characterized in that, Comprising: A caliper component (1), including a caliper housing (11) and a friction plate (12); A driven bracket (2), slidably arranged within the caliper housing (11), the driven bracket (2) being embedded with a driven bearing (21), and a mounting groove (22) being recessed in the middle of the driven bracket (2); A braking unit (3), including a housing (31), a first driving mechanism (32) and two camshafts (33), the housing (31) being mounted at the bottom of the caliper housing (11), the first driving mechanism (32) being arranged within the housing (31), the lower end of the camshaft (33) being rotatably arranged within the housing (31), the upper end of the camshaft (33) passing through the driven bearing (21) and being rotatably arranged within the caliper housing (11), and the first driving mechanism (32) being in transmission connection with the two camshafts (33), the two camshafts (33) rotating towards each other for driving the camshaft (33) to push the driven bracket (2) to move in a direction close to or away from the friction plate (12) through the driven bearing (21); A clearance adjustment unit (4), including a stud (41), a bracket nut (42) with an open cavity, and a nut sealing plate (43), one end of the stud (41) being rotatably arranged on the side wall of the mounting groove (22), the bracket nut (42) being threadedly connected to the stud (41) and located within the mounting groove (22), the nut sealing plate (43) plugging the open cavity, and the area of the nut sealing plate (43) being larger than the area of the open cavity, the nut sealing plate (43) being used to push the friction plate (12).

2. The cam-type electromechanical brake according to claim 1, characterized in that, The first driving mechanism (32) includes a first motor (321) and a speed reduction and power splitting mechanism (322), the first motor (321) being in transmission connection with the input end of the speed reduction and power splitting mechanism (322), and the lower end of the camshaft (33) being connected to the output end of the speed reduction and power splitting mechanism (322).

3. The cam-type electromechanical brake according to claim 2, characterized in that, There are two camshafts (33), the speed reduction and power splitting mechanism (322) includes two worm wheels (3222) and a worm (3221) with two sections of threads, the worm wheels (3222) being arranged at the lower end of the camshaft (33), one end of the worm (3221) being connected to the first motor (321), the other end of the worm (3221) being meshed with the two worm wheels (3222), and the rotation directions of the two camshafts (33) being opposite.

4. The cam-type electromechanical brake according to claim 2, characterized in that, The output end of one of the speed reduction and power splitting mechanisms (322) is in transmission connection with the stud (41).

5. The cam - type electromechanical brake according to claim 2, characterized in that, The clearance adjustment unit (4) further includes a second driving mechanism (44), the second driving mechanism (44) being in transmission connection with the stud (41).

6. The cam - type electromechanical brake according to claim 5, characterized in that, The second driving mechanism (44) includes a second motor (441), a driving gear (442) and a driven gear (443). The driven gear (443) is mounted on one end of the stud (41) away from the bracket nut (42). The output shaft of the second motor (441) is connected to the driving gear (442), and the driving gear (442) meshes with the driven gear (443).

7. The cam-type electromechanical brake according to claim 1, characterized in that The caliper housing (11) is provided with a housing opening (111) and a bearing hole (112). The driven bracket (2) is horizontally mounted in the housing opening (111). The support bearing (35) at the upper end of the camshaft (33) is mounted in the bearing hole (112). The rear cover (17) is detachably connected to the housing opening (111).

8. The cam-type electromechanical brake according to claim 7, characterized in that, One end of the stud (41) close to the rear cover (17) is recessed with a jack.

9. The cam-type electromechanical brake according to any one of claims 1-8, characterized in that, It further includes a corrugated spring (5). The corrugated spring (5) is arranged between the driven bracket (2) and the side wall of the caliper housing (11).

10. The cam-type electromechanical brake according to claim 9, characterized in that, The braking unit (3) further includes an angle sensor (34). The angle sensor (34) is arranged at the tail end of the camshaft (33) for measuring the rotation angle of the camshaft (33).

11. A vehicle, characterized in that, It includes a brake disc (200), a steering knuckle (300) and the cam-type electromechanical brake according to any one of claims 1-10. The brake disc (200) is rotatably arranged on the steering knuckle (300). The cam-type electromechanical brake (100) is mounted on the steering knuckle (300) for braking the brake disc (200).

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