Electronic mechanical braking device with long service life and high efficiency

Abstract

The invention relates to an electronic mechanical braking device, in particular to a long-service-life efficient electronic mechanical braking device, and aims to overcome the defect that in the prior art, resistance exists in axial movement of a movement conversion mechanism, and consequently the braking efficiency is reduced. The long-service-life efficient electronic mechanical braking device comprises a driving motor, a fixed sleeve, a planetary roller mechanism, a front shell, an output shaft and a damping reduction mechanism. The planetary roller mechanism comprises an input shaft, a roller frame and N planetary rollers, and N is greater than 2; the roller frame comprises a fixing frame and a gear ring, one end of the fixing frame is fixedly connected with the output shaft, and the gear ring is rotatably connected with the fixing frame and used for limiting axial movement of the planetary roller relative to the fixing frame. External threads or annular grooves matched with the external threads or the annular grooves in the input shaft are formed in the middle parts of the planetary rollers; the damping reduction mechanism comprises a first oil hole and a second oil hole which are formed in the two ends of the fixing frame respectively.

Description

Technical Field

[0001] The present invention relates to an electromechanical braking device, and more particularly to a long-life and high-efficiency electromechanical braking device. Background Art

[0002] With the rapid development of automotive technology, the electromechanical braking system (EMB) has the tendency to replace the current traditional hydraulic braking system due to its outstanding advantages such as simple system, fast braking response speed, and high efficiency.

[0003] The EMB electromechanical brake outputs braking power through a driving mechanism, drives a motion conversion mechanism to rotate, and the motion conversion mechanism pushes a braking force output element to perform non-rotating axial translational motion to achieve vehicle driving braking. In the existing electromechanical braking device, the front and rear chambers on both sides of the motion conversion mechanism are independent. During the rotation of the motion conversion mechanism, the front and rear chambers will form a closed cavity, causing the air pressure in the front and rear chambers to change, thereby preventing the axial movement of the motion conversion mechanism and resulting in a reduction in braking efficiency. Summary of the Invention

[0004] The object of the present invention is to solve the deficiency in the prior art that there is resistance to the axial movement of the motion conversion mechanism, resulting in a reduction in braking efficiency, and to provide a long-life and high-efficiency electromechanical braking device.

[0005] To achieve the above object, the technical solution provided by the present invention is as follows:

[0006] A long-life and high-efficiency electronic mechanical brake device, which is special in that it includes: a drive motor, a fixed sleeve, a planetary roller mechanism, a front housing, an output shaft and a damping reduction mechanism; the front housing is connected to one end of the fixed sleeve to form a sealed chamber; the sealed chamber is filled with lubricating oil or grease; the output shaft is arranged in the sealed chamber, and one end extends out of the sealed chamber; the planetary roller mechanism includes an input shaft, a roller frame and N planetary rollers, N>2 and is an integer; the input shaft is coaxially arranged in the fixed sleeve, one end of the input shaft is rotatably connected to the output shaft, and the other end extends out of the sealed chamber, and the input shaft is provided with an external thread or an annular groove; the roller frame is coaxially sleeved on the input shaft, and the roller frame includes a fixed frame arranged along the circumference of the input shaft and a gear ring nested inside the fixed frame, one end of the fixed frame is fixedly connected to the other end of the output shaft, and the inner wall of the fixed frame is fixedly connected to two locating rings arranged at intervals; a gap is provided between the outer wall of the gear ring and the fixed frame, and the two ends are rotatably abutted against the two locating rings, and the inner wall of the gear ring and the outer walls of the two ends of the planetary rollers are provided with matching annular tooth grooves at corresponding positions to limit axial movement between the two; N planetary rollers are arranged along the circumference of the input shaft, and the two ends are rotatably connected to the two locating rings respectively; the planetary rollers are provided corresponding to the external threads or annular grooves of the input shaft, and the middle part thereof is provided with an external thread or annular groove matching the external thread on the input shaft, or the middle part thereof is provided with an external thread matching the annular groove on the input shaft;

[0007] The non-rotating axis of the output shaft can be moved forward and backward by at least one of the following structures:

[0008] a. The output shaft and the input shaft are eccentrically arranged;

[0009] b.Anti-rotation keyway or non-circular cross section is used between the fixing frame and the fixing sleeve;

[0010] The output end of the drive motor is connected to the other end of the input shaft, and is used to drive the input shaft to rotate, thereby driving the non-orbital rotation of N planetary rollers. The planetary rollers in turn drive the ring gear, the fixed frame and the output shaft to move forward and backward along the axial direction of the input shaft; the damping reduction mechanism includes a first oil hole arranged at one end of the fixed frame, and a second oil hole at the other end, and the first oil hole and the second oil hole are respectively connected to the sealed cavity.

[0011] Furthermore, a limiting boss is provided at the other end of the input shaft for limiting the roller frame;

[0012] The limiting boss is close to one end face of the roller frame and cooperates with the other end face of the fixing frame, and a first boss is provided on it, and the other end face of the fixing frame is provided with a second boss. The first boss and the second boss cooperate with each other to prevent the planetary roller from excessive rotation and causing the thread to be stuck.

[0013] Furthermore, a mounting cavity is provided on the output shaft along the axis, and one end of the input shaft is nested in the mounting cavity.

[0014] Further, the damping reduction mechanism further includes at least one of the following three structures:

[0015] a. At least one through groove opened on the outer side of the fixed frame or the inner side of the fixed sleeve, and the through groove is a spiral groove or an axial straight groove;

[0016] b. A first air hole opened radially on the input shaft, a second air hole opened radially on the output shaft, and a connection hole opened axially on the input shaft and communicating the first air hole and the outside of one end of the input shaft;

[0017] c. A second air hole opened radially on the output shaft.

[0018] Further, the first air hole is located at the other end of the input shaft and close to the position of its external thread or annular groove;

[0019] The second air hole is located at the other end of the output shaft;

[0020] The connection hole is a central blind hole communicating one end of the input shaft; or, the connection hole is a central through hole, and a plug is provided near the other end of the input shaft;

[0021] The first oil hole includes a plurality of through holes respectively located between adjacent planetary rollers, and the second oil hole includes one group or two groups of through holes, and each group of through holes includes a plurality of through holes respectively located between adjacent planetary rollers.

[0022] Further, first arc grooves are respectively provided on both end faces of the ring gear, second arc grooves are correspondingly provided on the end faces of the two positioning rings close to the ring gear, and ball bearings are arranged in the first arc grooves and the second arc grooves.

[0023] Further, the N planetary rollers are evenly distributed along the circumference of the positioning ring;

[0024] External threads are provided on the input shaft, annular grooves matched with the external threads of the input shaft are arranged in the middle of the planetary rollers, and the adjacent planetary rollers are axially offset by 1 / N of the pitch of the external threads of the input shaft in sequence along the axial direction of the input shaft.

[0025] Further, the drive motor includes a stator structure and a rotor structure; the drive motor is provided as a single motor or a dual motor;

[0026] The stator structure of the dual motor is a double stator, and the rotor structure is a single rotor or a double rotor;

[0027] The rotor structure of the drive motor is a hollow structure, including a hollow rotor shaft sleeved on the fixed sleeve, and the hollow rotor shaft is connected to the other end of the input shaft;

[0028] A gap is provided between the fixed sleeve and the hollow rotor shaft.

[0029] Further, a braking force transmission shaft is provided at the front end of the output shaft, and the braking force transmission shaft is coaxial with the input shaft;

[0030] Said N = 8;

[0031] A dynamic sealing structure is provided between the output shaft and the front housing.

[0032] Further, a support guide sleeve is provided between one end of the input shaft and the inner wall of the output shaft. The input shaft is rotatably connected to the support guide sleeve through a bearing, and the support guide sleeve is slidably matched with the inner side wall of the installation cavity.

[0033] Advantages of the present invention:

[0034] 1. In the present invention, the roller frame is split into two structures, a fixed frame and a gear ring. A gap is provided between the gear ring and the fixed frame and they are movably connected, reducing the rotational resistance between the planetary roller and the roller frame. When the roller frame moves axially, sealed cavities are formed on both sides, resulting in damping when the roller frame moves axially at high speed. Therefore, the present invention provides a first oil hole and a second oil hole at both ends of the fixed frame, reducing the resistance of lubricating oil or grease flowing between the first cavity and the second cavity, facilitating the axial movement of the output shaft, the roller frame, and the planetary roller, making the movement of the roller frame more stable, reducing the noise during the movement process, and during the movement process, the lubricating oil or grease is sprayed through the first oil hole and the second oil hole between the planetary roller and the input shaft and the gear ring to lubricate moving parts such as the planetary roller, the input shaft, the gear ring, the roller frame, and the output shaft, further reducing the movement resistance, improving the force transmission efficiency. Compared with the existing mechanical braking device, the force transmission efficiency of the present invention is increased by more than 10%. Under the same input force, the present invention has a higher output force. The planetary roller structure is made more stable through the gear ring structure and can withstand a higher input force. At the same time, the service life of the electro-mechanical braking device is increased, and the number of repeated uses is far greater than 1.2 million times. The lubricating oil or grease enters the periphery of the planetary roller, conducts the heat generated by its movement and releases it along the front housing, improving the heat dissipation effect.

[0035] 2. In the present invention, balls are provided between the two ends of the gear ring and the two positioning rings, changing the original sliding fit between the planetary roller and the teeth of the roller frame to a rolling fit of the planetary roller through the gear ring and the fixed frame, improving the transmission efficiency.

[0036] 3. The present invention uses a planetary roller mechanism as the braking force transmission mechanism. The annular groove of the planetary roller is matched with the external thread of the input shaft, and the adjacent planetary rollers are axially spaced along the input shaft by 1 / N of the pitch of the external thread of the input shaft, ensuring that it can move axially along the input shaft.

[0037] 4. One end of the input shaft of the present invention is sleeved with a bearing and a support guide sleeve, and the axial movement of the output shaft is guided and supported by sliding connection of the support guide sleeve with the inner side wall of the installation cavity.

[0038] 5. The rotor of the driving motor of the present invention is designed as a hollow structure, and the driving motor is sleeved on the fixed sleeve, making full use of the space, reducing the volume of the electro-mechanical braking device, and realizing miniaturization. The driving motor can be a single motor or a dual motor; the dual motor can adopt a coaxial double-stator single-rotor or double-stator double-rotor structure to achieve design redundancy and improve the reliability of the overall device.

[0039] 6. The present invention adopts a dynamic sealing structure between the output shaft and the front housing to ensure the sealing performance of the sealing cavity, prevent the lubricating oil or grease in the sealing cavity from leaking out, and prevent external impurities from entering the sealing cavity, which affects the normal operation of the device.

[0040] 7. The present invention has the characteristics of compact structure, large output braking force, convenient installation and high reliability. Description of the Drawings

[0041] Figure 1 is a schematic structural diagram of the first embodiment of the present invention;

[0042] Figure 2 is a schematic diagram of the movement state of the roller frame in the first embodiment of the present invention;

[0043] Figure 3 is a schematic structural diagram of the roller frame in the first embodiment of the present invention;

[0044] Figure 4 is a schematic structural diagram of the position of the first oil hole in the first embodiment of the present invention;

[0045] Figure 5 is a schematic structural diagram of the position of the second oil hole in the first embodiment of the present invention;

[0046] Figure 6 is Figure 3 an enlarged schematic structural diagram at I in

[0047] Figure 7 is a schematic structural diagram of the planetary roller in the first embodiment of the present invention.

[0048] Description of the Reference Numerals:

[0049] 1 - Fixed sleeve, 2 - Input shaft, 3 - Tapered bearing, 4 - Planetary roller, 5 - Positioning ring, 6 - Roller frame, 61 - Second boss, 62 - Ring gear, 63 - Ball, 7 - Output shaft, 8 - Front housing, 9 - Driving motor, 10 - First screw, 11 - Hollow rotor shaft, 12 - Brake force transmission shaft, 13 - Rotary lip seal, 14 - Deep groove ball bearing, 15 - First boss, 17 - Slide sleeve, 18 - Sensor connecting shaft, 19 - Stator structure, 20 - Rotor structure, 21 - Stud, 22 - O-ring, 23 - Seal ring, 24 - Round nut, 25 - Lock washer, 27 - Outer shell, 28 - Second cavity, 29 - First cavity, 30 - First air hole, 31 - Second air hole, 32 - Connecting hole, 33 - First oil hole, 34 - Second oil hole, 35 - Support guide sleeve, 36 - Bearing. Detailed implementation mode

[0050] As Figure 1 and Figure 2 shown, a long-life and high-efficiency electromechanical braking device of the present invention includes a driving motor 9, a fixed sleeve 1, a planetary roller mechanism, a front housing 8, an output shaft 7 and a damping reduction mechanism.

[0051] One end of the front housing 8 is connected to the fixed sleeve 1 to form a sealed cavity, and an O-ring 22 is provided at the connection between the front housing 8 and the fixed sleeve 1; part of the sealed cavity is filled with lubricating oil or grease.

[0052] The output shaft 7 is arranged in the sealed cavity, one end extends out of the sealed cavity, and a brake force transmission shaft 12 is arranged at the end. An installation cavity is opened along the axis of the output shaft 7, and the brake force transmission shaft 12 is coaxially arranged or eccentrically arranged with the outer circle of the output shaft 7.

[0053] As Figure 3 shown, the planetary roller mechanism includes an input shaft 2, a roller frame 6 and N planetary rollers 4, N > 2 and is an integer. In this embodiment, N = 8, as Figure 7 shown; the input shaft 2 is arranged in the sealed cavity, coaxial with the fixed sleeve 1 and the brake force transmission shaft 12, one end is nested in the installation cavity of the output shaft 7 and is eccentrically arranged with its outer circle, and the eccentric distance d is 1 mm to 3 mm. The outer side wall of the input shaft 2 is provided with an external thread. In this embodiment, a support guide sleeve 35 is arranged between one end of the input shaft 2 and the inner wall of the output shaft 7. The input shaft 2 is rotatably connected with the support guide sleeve 35 through a bearing 36. The support guide sleeve 35 is slidably matched with the inner side wall of the installation cavity to increase the radial support of the input shaft 2 and serve as the axial guide of the output shaft 7. The support guide sleeve 35 is preferably made of wear-resistant materials such as copper, polytetrafluoroethylene or nylon.

[0054] A tapered bearing 3 is sleeved on the other end of the input shaft 2, and a rotary lip seal 13 is provided between the tapered bearing 3 and the inner side wall of the other end of the fixed sleeve 1; the end of the other end of the input shaft 2 extends out of the sealing cavity and is connected to the output end of the driving motor 9.

[0055] The roller frame 6 is coaxially sleeved on the input shaft 2 and is located between the fixed sleeve 1 and the external thread of the input shaft 2. The roller frame 6 includes a fixed frame arranged along the circumferential direction of the input shaft 2 and a gear ring 62 nested inside the fixed frame and movably connected to the fixed frame. The fixed frame and the fixed sleeve 1 adopt a precise sliding fit with a small gap. One end of the fixed frame is fixedly connected to the other end of the output shaft 7 by a first screw 10. The first screw 10 is an M3 screw. Two positioning rings 5 are fixedly connected to the inner wall of the fixed frame at intervals.

[0056] Both ends of the 8 planetary rollers 4 are respectively movably connected to the two positioning rings 5 and are arranged along the circumferential direction of the input shaft 2, so that the planetary rollers 4, the roller frame 6 and the output shaft 7 form an integral structure. The planetary rollers 4 can only rotate but cannot revolve. Therefore, by adjusting the pitch of the input shaft 2, the thread self-locking of the input shaft 2 can be realized. The non-revolution of the planetary rollers 4 makes the accuracy of the braking control higher. Preferably, the 8 planetary rollers 4 are evenly distributed along the circumference of the positioning ring 5; an external thread or an annular groove matching the external thread of the input shaft 2 is provided in the middle of each planetary roller 4. Annular tooth grooves are provided at the corresponding positions on the outer wall of the two ends of the inner wall of the gear ring 62 and the planetary roller 4 to limit the axial movement between the two. First arc grooves are respectively arranged on the two end faces of the gear ring 62. As Figure 6 shown, second arc grooves are correspondingly arranged on the end faces of the two positioning rings 5 close to the gear ring 62. Ball bearings 63 are arranged in the first arc grooves and the second arc grooves, so that the gear ring 62 is in rolling connection with the fixed frame, further reducing the rotation resistance of the planetary rollers 4. A gap is provided between the gear ring 62 and the fixed frame; in this embodiment, the 8 planetary rollers 4 are evenly distributed along the circumference, and the axial difference between adjacent planetary rollers 4 along the input shaft 2 is 1 / N of the pitch of the external thread on the input shaft 2, where N is the number of planetary rollers. In this embodiment, it is 1 / 8, realizing the meshing of the 8 planetary rollers with the external thread of the spiral lead angle of the outer wall of the input shaft 2 in the axial direction.

[0057] A limit boss is arranged at the other end of the input shaft 2 for limiting the roller frame 6. The end face of the limit boss close to the roller frame 6 cooperates with the end face of the other end of the fixed frame, and a first boss 15 is arranged thereon. A second boss 61 is arranged on the end face of the other end of the fixed frame. The first boss 15 and the second boss 61 cooperate with each other to prevent the planetary rollers 4 from rotating excessively and causing the thread to jam.

[0058] To ensure the sealing performance of the sealing cavity, a dynamic sealing structure is provided between the output shaft 7 and the front housing 8; the dynamic sealing structure includes a sliding sleeve 17 and a sealing ring 23. The sliding sleeve 17 is arranged between the front housing 8 and the output shaft 7, and sealing rings 23 are provided between the sliding sleeve 17 and the output shaft 7 and between the sliding sleeve 17 and the front housing 8 respectively, to prevent external impurities (such as water, dust, etc.) from entering the sealing cavity and affecting the normal operation of the device. In addition, a stud 21 is provided on the end face of the end of the front housing 8 away from the fixed sleeve 1, which is convenient for assembly with other devices.

[0059] The drive motor 9 is used to drive the input shaft 2 to rotate, and then drive the N planetary rollers 4 to rotate self - rotatably. The self - rotation of the 8 planetary rollers 4 drives the ring gear 62 to rotate. The roller frame 6 is coaxially arranged with the input shaft 2. The outer circle of the output shaft 7 is eccentrically arranged with respect to the input shaft 2, and its installation cavity is coaxial with the input shaft 2. The fixed frame is fixedly connected to the output shaft 7, so that both the output shaft 7 and the fixed frame cannot rotate, thereby pushing the fixed frame and the output shaft 7 to perform a non - rotating axial translation movement along the axis direction of the output shaft 7 to achieve vehicle driving braking. As Figure 2 shown, the axial translation movement of the fixed frame divides the sealing cavity into a first cavity 29 and a second cavity 28 located at both ends of the roller frame 6.

[0060] The damping reduction mechanism is used to reduce the resistance of lubricating oil or grease or gas flowing back and forth in the sealing cavity (the first cavity 29 and the second cavity 28), make the movement of the roller frame 6 more stable, and reduce the noise during the movement; at the same time, the damping reduction mechanism can make the lubricating oil or grease flow in the fixed sleeve 1 along with the movement of the planetary roller mechanism to lubricate the moving parts such as the input shaft 2, planetary rollers 4, roller frame 6, output shaft 7, etc., and can evenly distribute the heat generated by the movement and release it through the housing.

[0061] The damping reduction mechanism includes a first oil hole 33 provided at one end of the fixed frame close to the output shaft 7, and a second oil hole 34 at the other end of the fixed frame. The first oil hole 33 and the second oil hole 34 are respectively communicated with the sealing cavity. The first oil hole 33 includes a plurality of through - holes located between adjacent planetary rollers 4. The second oil hole 34 includes one or two groups of through - holes, and each group of through - holes includes a plurality of through - holes located between adjacent planetary rollers 4. As Figure 4 and Figure 5 shown, in this embodiment, the second oil hole 34 includes two groups of through - holes with different diameters, and the first oil hole 33 includes N through - holes. The damping reduction mechanism further includes at least one of the following three structures:

[0062] The first one includes at least 1 through - groove opened on the outer side of the fixed frame or the inner side of the fixed sleeve 1. The through - groove is a spiral groove or an axial straight groove. Preferably, the through - groove is at least 3 circumferentially evenly distributed;

[0063] The second one, as Figure 5As shown, it includes a first air hole 30 radially opened on the input shaft 2, a second air hole 31 radially opened on the output shaft 7, and a connecting hole 32 axially opened on the input shaft 2 and communicating the first air hole 30 and the second air hole 31; preferably, the second air hole 31 is close to the other end of the output shaft 7; the first air hole 30 is located at the other end of the input shaft 2 near its external thread; in this embodiment, the connecting hole 32 is designed to communicate with the central blind hole at one end of the input shaft 2; in other embodiments, the connecting hole 32 can also be a central through hole. When the connecting hole 32 is designed as a central through hole, a plug needs to be provided near the other end of the input shaft 2; during the translational movement of the output shaft 7, the first air hole 30 is always in the sealed cavity;

[0064] The third type includes a second air hole 31 radially opened on the output shaft 7. During the translational movement of the output shaft 7, the second air hole 31 is always in the sealed cavity.

[0065] The braking device of this embodiment further includes a housing 27 arranged outside the driving motor 9 and the fixed sleeve 1, and one end of the housing 27 is connected to the front housing 8.

[0066] The driving motor 9 of this embodiment is a single motor, including a stator structure 19 and a rotor structure 20. As Figure 1 shown, the stator structure 19 of the driving motor 9 is arranged on the front housing 8. In other embodiments, the stator structure 19 of the driving motor 9 can also be arranged on the housing 27. The rotor structure 20 of the driving motor 9 is a hollow structure. The rotor structure 20 is connected to the other end of the input shaft 2 through a hollow rotor shaft 11 sleeved on the fixed sleeve 1. The hollow rotor shaft 11 and the other end of the input shaft 2 are connected by splines. The other end of the input shaft 2 extends out of the hollow rotor shaft 11, and a round nut 24 is sleeved on the end of the other end. A lock washer 25 is arranged between the round nut 24 and the end face of the hollow rotor shaft 11; there is a gap between the fixed sleeve 1 and the hollow rotor shaft 11, and the hollow rotor shaft 11 is directly or indirectly fixed to the housing 27 through a deep groove ball bearing 14.

[0067] The braking device further includes a control unit arranged at the other end of the housing 27. The control unit includes an induction magnet and a circuit board. A sensor connecting shaft 18 is provided at the end of the other end of the input shaft 2 for arranging the induction magnet. The circuit board is arranged on the housing 27 and behind the induction magnet. A magnetic induction element is provided at the position opposite to the induction magnet on the circuit board. The magnetic induction element can identify the strength of the radial N / S magnetic field of the induction magnet during movement, and the circuit board is used to analyze and calculate the stroke of the translational movement of the output shaft 7 and perform real-time control.

[0068] The braking action process of the braking device of this embodiment is as follows:

[0069] During the driving process, when the driver steps on the brake pedal, the drive motor 9 starts. The rotor structure 20 drives the input shaft 2 to rotate through the hollow rotor shaft 11. The rotation of the input shaft 2 drives multiple planetary rollers 4 to rotate on their own axes. Since the roller frame 6 that cooperates with the multiple planetary rollers 4 is connected to the output shaft 7, and the outer circle of the output shaft 7 and the central axis of the input shaft 2 are arranged non-coaxially, and the installation cavity is coaxial with the input shaft 2, the multiple planetary rollers 4 rotate and sequentially push the ring gear 62, the ball 63, the fixed frame, and the output shaft 7 to move translationally along the axis of the output shaft 7 towards the end close to the braking force transmission shaft 12. The braking force transmission shaft 12 at one end of the output shaft 7 is fixedly connected to the vehicle braking mechanism, thereby realizing vehicle driving braking.

[0070] The present invention can achieve a larger braking force output with a smaller structure and ensure high-efficiency braking force output; the planetary roller 4 can only rotate on its own axis and cannot revolve, which can realize the screw self-locking of the input shaft 2 to achieve the parking braking function, integrating the driving braking and parking braking functions, canceling the existing locking through the clutch, reducing the manufacturing cost, and reducing the volume; the fixed sleeve 1 is hermetically connected to the front housing 8, which can not only realize the sealing of the lubricating oil but also prevent water or impurities from entering the sealed cavity and affecting the force transmission effect.

[0071] Embodiment 2

[0072] The difference from Embodiment 1 is that the drive motor 9 is a dual motor. In this embodiment, the dual motor adopts coaxial double stators and a single rotor to achieve the redundancy of the design and improve the reliability of the overall equipment. In other embodiments, the dual motor can also adopt coaxial double stators and double rotors.

[0073] Embodiment 3

[0074] The difference from Embodiment 1 and Embodiment 2 is that the outer sidewall of the input shaft 2 is provided with equally spaced annular grooves, and the middle part of the planetary roller 4 is provided with external threads that match them. The groove spacing of the annular grooves matches the pitch of the planetary roller 4.

[0075] Embodiment 4

[0076] The difference from Embodiment 1 is that in order to achieve miniaturization and non-rotating axial movement of the output shaft 7, the radial cross-section of the fixed frame is non-circular. Preferably, the outer peripheral radial cross-section of the fixed frame is polygonal, and the central hole of the fixed sleeve 1 is a polygon adapted to the outer periphery of the fixed frame. In other embodiments, at least one anti-rotation guiding key can also be provided on the outer sidewall of the fixed frame, and a guiding groove that cooperates with the guiding key is provided on the inner wall of the fixed sleeve 1, or the fixed frame and the fixed sleeve 1 adopt spline fit, so that the fixed frame can only move linearly along the axis and cannot rotate.

[0077] In order to better achieve the anti-rotation effect of the output shaft 7, the outer circumference of the output shaft 7 and the input shaft 2 can also be designed to be eccentrically arranged. The installation cavity is coaxial with the input shaft 2. At the same time, the fixing bracket and the fixing sleeve 1 are matched with an anti-rotation keyway or a non-circular cross-section. An anti-rotation key is provided between the output shaft 7 and the braking drive shaft 12.

Claims

1. A long-life and high-efficiency electromechanical braking device, characterized in that: It includes a driving motor (9), a fixed sleeve (1), a planetary roller mechanism, a front housing (8), an output shaft (7) and a damping reduction mechanism; One end of the front housing (8) is connected to the fixed sleeve (1) to form a sealed cavity; the sealed cavity is filled with lubricating oil or grease; the output shaft (7) is arranged in the sealed cavity, and one end extends out of the sealed cavity; The planetary roller mechanism includes an input shaft (2), a roller frame (6) and N planetary rollers (4), where N>2 and is an integer; The input shaft (2) is coaxially arranged in the fixed sleeve (1). One end of the input shaft (2) is rotatably connected to the output shaft (7), and the other end extends out of the sealed cavity. The input shaft (2) is provided with an external thread or an annular groove; The roller frame (6) is coaxially sleeved on the input shaft (2). The roller frame (6) includes a fixed frame arranged circumferentially along the input shaft (2) and a gear ring (62) nested inside the fixed frame. One end of the fixed frame is fixedly connected to the other end of the output shaft (7), and two positioning rings (5) are fixedly connected to the inner wall of the fixed frame at intervals; there is a gap between the outer wall of the gear ring (62) and the fixed frame, and both ends are rotatably abutted against the two positioning rings (5) respectively. Annular tooth grooves are provided at corresponding positions on the inner wall of the gear ring (62) and the outer walls of both ends of the planetary roller (4) to limit axial movement between the two; The N planetary rollers (4) are arranged circumferentially along the input shaft (2), and both ends are rotatably connected to the two positioning rings (5) respectively; the planetary rollers (4) are arranged corresponding to the external thread or annular groove of the input shaft (2), and an external thread or annular groove matching the external thread on the input shaft (2) is provided in the middle, or an external thread matching the annular groove on the input shaft (2) is provided in the middle; The non-rotating axial forward and backward movement of the output shaft (7) is realized by at least one of the following structures: a. The output shaft (7) and the input shaft (2) are eccentrically arranged; b. A non-rotating keyway or non-circular cross-section fit is adopted between the fixed frame and the fixed sleeve (1); The output end of the driving motor (9) is connected to the other end of the input shaft (2) to drive the input shaft (2) to rotate, drive the N planetary rollers (4) to rotate non-revolutionarily, and the planetary rollers (4) sequentially drive the gear ring (62), the fixed frame and the output shaft (7) to move axially forward and backward along the input shaft (2); The damping reduction mechanism includes a first oil hole (33) provided at one end of the fixed frame and a second oil hole (34) provided at the other end. The first oil hole (33) and the second oil hole (34) are respectively communicated with the sealed cavity.

2. The long-life and high-efficiency electromechanical braking device according to claim 1, characterized in that: A limit boss is provided at the other end of the input shaft (2) for limiting the roller frame (6); The end face of the limit boss close to the roller frame (6) is matched with the end face of the other end of the fixed frame, and a first boss (15) is provided thereon. A second boss (61) is provided on the end face of the other end of the fixed frame. The first boss (15) and the second boss (61) cooperate with each other to prevent the threads from jamming due to excessive rotation of the planetary roller (4).

3. The long-life and high-efficiency electromechanical braking device according to claim 2, wherein: An installation cavity is axially formed on the output shaft (7), and one end of the input shaft (2) is nested in the installation cavity.

4. The long-life and high-efficiency electromechanical braking device according to claim 3, characterized in that, The damping reduction mechanism further includes at least one of the following three structures: a. At least one through groove opened on the outer side surface of the fixed frame or the inner side surface of the fixed sleeve (1), and the through groove is a spiral groove or an axial straight groove; b. A first air hole (30) radially opened on the input shaft (2), a second air hole (31) radially opened on the output shaft (7), and a connection hole (32) axially opened on the input shaft (2) and communicating the first air hole (30) with the outer side of one end of the input shaft (2); c. A second air hole (31) radially opened on the output shaft (7).

5. The long-life and high-efficiency electromechanical braking device according to claim 4, wherein: The first air hole (30) is located at the other end of the input shaft (2) and near its external thread or annular groove; The second air hole (31) is located at the other end of the output shaft (7); The connection hole (32) is a central blind hole communicating with one end of the input shaft (2); or, the connection hole (32) is a central through hole, and a plug is provided near the other end of the input shaft (2); The first oil holes (33) include a plurality of through holes respectively located between adjacent planetary rollers (4), and the second oil holes (34) include one or two groups of through holes, and each group of through holes includes a plurality of through holes respectively located between adjacent planetary rollers (4).

6. The long-life and high-efficiency electromechanical braking device according to any one of claims 1 to 5, wherein: First arc grooves are respectively arranged on the two end faces of the gear ring (62), second arc grooves are correspondingly arranged on the end faces of the two positioning rings (5) close to the gear ring (62), and ball bearings (63) are arranged in the first arc grooves and the second arc grooves.

7. The long-life and high-efficiency electromechanical braking device according to claim 6, wherein: The N planetary rollers (4) are evenly distributed along the circumference of the positioning ring (5); External threads are provided on the input shaft (2), an annular groove matching with the external threads of the input shaft (2) is arranged in the middle of the planetary roller (4), and the adjacent planetary rollers (4) are axially spaced by 1 / N of the pitch of the external threads of the input shaft (2) in sequence along the input shaft (2).

8. The long-life and high-efficiency electromechanical braking device according to claim 7, wherein: The driving motor (9) includes a stator structure (19) and a rotor structure (20); the driving motor (9) is arranged as a single motor or a dual motor; The stator structure (19) of the dual motor is a dual stator, and the rotor structure (20) is a single rotor or a dual rotor; The rotor structure (20) of the driving motor (9) is a hollow structure, including a hollow rotor shaft (11) sleeved on the fixed sleeve (1), and the hollow rotor shaft (11) is connected with the other end of the input shaft (2); A gap is provided between the fixed sleeve (1) and the hollow rotor shaft (11).

9. The long-life and high-efficiency electromechanical braking device according to claim 8, wherein: A brake force transmission shaft (12) is provided at the front end of the output shaft (7), and the brake force transmission shaft (12) is coaxial with the input shaft (2); where N = 8; A dynamic sealing structure is provided between the output shaft (7) and the front housing (8).

10. The long-life and high-efficiency electromechanical braking device according to claim 3, wherein: A support guide sleeve (35) is provided between one end of the input shaft (2) and the inner wall of the output shaft (7). The input shaft (2) is rotatably connected to the support guide sleeve (35) through a bearing (36), and the support guide sleeve (35) is slidably matched with the inner side wall of the installation cavity.

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