Brake and vehicle electric drive system

Abstract

The invention provides a brake and an electric drive system for a vehicle, the brake is used for braking a transmission shaft of the electric drive system, and the brake comprises: a housing comprising a first housing and a second housing; the friction disc is mechanically and rotationally coupled with the transmission shaft and rotates along with the transmission shaft; the driving disc is arranged on one side of the friction disc in the axial direction and contained in the shell in a non-rotating but axial moving mode, and the end face, facing the first shell, of the driving disc and the first shell define a first liquid cooling channel; the fixed disc is arranged on the other side of the friction disc in the axial direction and is fixedly contained in the shell, and the end face, facing the second shell, of the fixed disc and the second shell define a second liquid cooling channel; the gear ring is arranged outside the driving disc in a sleeving mode and contained in the shell in a non-axial-moving mode, and internal threads matched with the external threads on the outer peripheral face of the driving disc are arranged on the inner peripheral face of the gear ring; and an actuating device for rotating the ring gear.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric drive, in particular to a brake and an electric drive system for vehicle comprising the same. BACKGROUND

[0002] In an electric passenger vehicle, a brake, such as a caliper brake, is usually arranged at the wheel side. In order to ensure effective braking, especially in the case of high-speed driving, the size of the brake friction disc can be increased. However, the increase in size of the wheel-side brake will adversely affect the space utilization and handling performance of the passenger vehicle.

[0003] In addition, the wheel-side brake may face problems such as large weight and volume, large influence of external environment (such as ice, snow, water, mud, etc.) on braking performance, easy rusting and abnormal noise, insufficient continuous braking reliability due to high brake disc temperature of 600℃ or above, and random emission of harmful solid particles generated by brake friction.

[0004] It should be noted that the content introduced here is only background information related to the present application, and does not necessarily belong to the prior art. SUMMARY

[0005] According to different aspects, the purpose of the present application is to provide a brake which can be integrated in an electric drive system and an electric drive system for vehicle.

[0006] In addition, the present application also aims to solve or alleviate other technical problems existing in the prior art.

[0007] According to a first aspect of the present application, a brake for braking a transmission shaft of an electric drive system is provided, comprising: a housing comprising a first housing and a second housing; a friction disc mechanically rotationally coupled with the transmission shaft and rotating with the transmission shaft; a drive disc arranged on one side of the friction disc in an axial direction and non-rotatably but axially movably accommodated in the housing, wherein an end surface of the drive disc facing the first housing defines a first liquid cooling channel with the first housing; a fixed disc arranged on the other side of the friction disc in an axial direction and fixedly accommodated in the housing, wherein an end surface of the fixed disc facing the second housing defines a second liquid cooling channel with the second housing; a gear ring sleeved on the outside of the drive disc and non-axially movably accommodated in the housing, an inner thread being provided on an inner circumferential surface of the gear ring and cooperating with an outer thread on an outer circumferential surface of the drive disc; an actuating device for rotating the gear ring, The rotation of the gear ring drives the drive disk to move axially toward the friction disk, thereby clamping the friction disk between the drive disk and the fixed disk, and thus braking the transmission shaft through the friction between the drive disk, the fixed disk and the friction disk. Alternatively, the rotation of the gear ring drives the drive disc to move axially away from the friction disc, thereby releasing the friction disc clamped between the drive disc and the fixed disc, and thus releasing the brake on the drive shaft.

[0008] In some embodiments, optionally, a plurality of first diversion ribs are provided on at least one of the end face of the drive disk facing the first housing and the end face of the first housing facing the drive disk, and a plurality of concentric first branch channels are formed by the first diversion ribs, wherein one of the radially farthest first branch channel and the radially nearest first branch channel is connected to the inlet of the first liquid cooling channel, and the other of the radially farthest first branch channel and the radially nearest first branch channel is connected to the outlet of the first liquid cooling channel, and the coolant flowing in through the inlet of the first liquid cooling channel is diverted to the first branch channel; And / or, a second diversion rib is provided on at least one of the end face of the fixed disk facing the second housing and the end face of the second housing facing the fixed disk, and a plurality of concentric second branch channels are formed by the second diversion rib, wherein the second branch channel is a deflection branch channel, and the coolant flowing in through the inlet of the second liquid cooling channel is diverted into the second branch channel.

[0009] In some embodiments, optionally, the inlet for coolant inflow of the first liquid cooling channel and the inlet for coolant inflow of the second liquid cooling channel are connected to the outside through the same inlet interface; And / or, the outlet for coolant outflow of the first liquid cooling channel and the outlet for coolant outflow of the second liquid cooling channel are connected to the outside through the same outlet interface.

[0010] In some embodiments, the second housing may optionally include a receiving chamber for accommodating the fixed disk, wherein the outer peripheral surface and hub of the fixed disk are welded to the side wall of the receiving chamber, and the end face of the fixed disk and the bottom wall of the receiving chamber define the second liquid cooling channel.

[0011] In some embodiments, optionally, one of the drive disk and the housing is provided with an axially extending limiting protrusion, and the other of the drive disk and the housing is provided with an axially extending limiting groove. The drive disk is circumferentially limited by accommodating the limiting protrusion in the limiting groove.

[0012] In some embodiments, an elastic reset member may be included, with one end in contact with the drive shaft and the other end in contact with the friction disc, for use in axially resetting the friction disc to axially separate from the fixed disc or from the drive disc by means of an axial reset force.

[0013] In some embodiments, the drive disk and / or the fixed disk may optionally be made of aluminum-ceramic composite material or carbon-ceramic composite material; And / or, the friction disc includes a friction pad made of carbon fiber composite material.

[0014] In some embodiments, the actuation device may optionally include an actuating motor and a worm gear transmission mechanism, wherein the worm gear transmission mechanism includes a worm mechanically coupled to the actuating motor and worm gear teeth meshing with the helical teeth of the worm, the worm gear teeth being arranged on the outer peripheral surface of the gear ring.

[0015] In some embodiments, the drive shaft may optionally be the shaft of the drive motor of the electric drive system, the output shaft of the reducer of the electric drive system, or the output shaft of the differential of the reducer of the electric drive system.

[0016] Furthermore, according to a second aspect of this application, an electric drive system for vehicles is provided, comprising a drive motor, a reducer, and a brake according to any of the above embodiments, wherein the drive motor, the reducer, and the brake are detachably assembled.

[0017] According to some embodiments, the brake is compact in structure and has improved heat dissipation and cooling effect. Attached Figure Description

[0018] Referring to the accompanying drawings, the above and other features of this application will become apparent, wherein, Figure 1 A perspective view of the brake in its assembled state according to one embodiment is shown from a first-person perspective; Figure 2 It shows according to Figure 1 Exploded view of the brake; Figure 3 Shown from a second perspective according to Figure 1 A three-dimensional view of the brake; Figure 4 It shows according to Figure 3 Exploded view of the brake; Figure 5 A cross-sectional view of a brake according to one embodiment is shown; Figure 6 It shows the way Figure 5 A sectional view of the section line AA in the diagram; Figure 7 A front view of a brake according to one embodiment is shown; Figure 8 It shows the way Figure 7 A sectional view of the section line BB in the diagram; Figure 9 It shows the way Figure 8 A sectional view of the section line CC in the diagram; Figure 10 It shows the way Figure 8 A sectional view of the section line DD in the diagram; Figure 11 A schematic diagram of the architecture of an electric drive system according to one embodiment is shown; Figure 12 A schematic diagram of the architecture of an electric drive system according to another embodiment is shown; Figure 13 A schematic diagram of the architecture of an electric drive system according to another embodiment is shown. Detailed Implementation

[0019] It is readily understood that, based on the technical solution of this application, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of this application. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this application and should not be considered as the entirety of this application or as limitations or restrictions on the technical solution of this application.

[0020] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the structures shown in the accompanying drawings. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive. Furthermore, the terms "first," "second," "third," and similar expressions are used for descriptive and distinguishing purposes only and should not be construed as indicating or implying the relative importance of the corresponding components.

[0021] refer to Figures 1 to 4 The figures illustrate one embodiment of the brake provided in this application in perspective. Overall, the brake 1 includes a housing 10 and a friction disc 20, a drive disc 30, a fixed disc 40, and a gear ring 50 housed within its cavity.

[0022] The housing 10 includes a first housing 11 and a second housing 12, which are detachably connected by threaded fasteners, exemplarily secured by a plurality of bolts evenly distributed around the periphery. The drive shaft 2 of the electric drive system (see...) Figure 5The drive shaft 2 passes through the second housing 12 and is rotatably supported at the first housing 11 and the second housing 12, so as to achieve braking by friction between the friction disc 20 and the drive disc 30 and between the friction disc 20 and the fixed disc 40. Exemplarily, the end of the drive shaft 2 is supported at the first housing 11 and the second housing 12 by means of bearings. Further, a conductive element is arranged between the drive shaft 2 and the first housing 11 or the second housing 12, which is used to draw out the induced current on the drive shaft caused by changes in the magnetic field inside the motor. The conductive element is, for example, a conductive ring, which is sleeved on the outside of the drive shaft 2 and also serves a supporting function. Alternatively, the conductive element is a conductive wire or conductive sheet, which abuts between the drive shaft and the housing.

[0023] Here, the components that perform the friction braking function are enclosed in the housing 10. Compared to caliper brakes, this avoids the problem of indiscriminate emission of solid pollutant particles during braking and is protected from or significantly reduced by environmental weather conditions (such as rain, snow, dust, etc.), exhibiting better environmental tolerance and braking performance. Furthermore, compared to caliper brakes, the brake disc surface pressure of this brake is significantly reduced, resulting in more reliable braking performance.

[0024] It should be noted that the drive shaft mentioned here refers to the torque transmission shaft of an electric drive system. Taking an automotive electric drive system as an example, the drive motor and reducer of the electric drive system are mechanically coupled, and the reducer is mechanically coupled to the wheel hub, thereby forming a power transmission path. The drive motor can transmit its power to the wheel hub (when the drive motor acts as a driver to rotate the wheel hub) or absorb power from the wheel hub (when the drive motor acts as a generator for regenerative braking). Here, the drive shaft is either the rotating shaft of the drive motor or the output shaft of the reducer.

[0025] Specifically, in some embodiments, the drive shaft 2 serves as the shaft of the drive motor, and the brake 1 is arranged along the power transmission path between the drive motor and the reducer. In other embodiments, optionally, the drive shaft 2 serves as the shaft of the drive motor, the brake 1 is arranged along the power transmission path at one end of the drive motor, and the reducer is arranged at the other end of the drive motor. This arrangement, where the drive shaft 2 serves as the shaft of the drive motor, requires a relatively smaller braking torque from the brake for the same braking power demand, which is beneficial for the application of lighter brakes.

[0026] In some other embodiments, the drive shaft 2 may optionally be the output shaft of the reducer of the electric drive system, that is, the brake 1 is arranged between the reducer and the hub along the power transmission route.

[0027] In some other embodiments, the drive shaft 2 may optionally be the output shaft of the differential of the reducer, that is, the brake 1 is arranged between the differential and the wheel hub along the power transmission route.

[0028] Taking the aforementioned electric drive system for vehicles as an example, the brake proposed in this application enables an electric drive system with integrated braking function, where the common caliper brake is no longer installed at the wheel hub. This reduces unsprung mass, improving vehicle handling stability; furthermore, it lowers wheel moment of inertia, allowing for the use of lightweight brakes and facilitating deep integration with the electric drive system. Additionally, it significantly frees up space around the wheel hub, which is beneficial for the arrangement of suspension or steering mechanisms and the optimization of overall vehicle space.

[0029] Regarding the friction disc 20, it is mechanically coupled to the drive shaft 2, that is, the friction disc 20 and the drive shaft 2 are mechanically fixed, especially torsionally fixed, and the friction disc 20 rotates together with the drive shaft 2. Specifically, the friction disc 20 is fitted onto the outer peripheral surface of the drive shaft 2 with its central hub. The central hub of the friction disc 20 has an axially extending protrusion, and the outer peripheral surface of the drive shaft 2 has an axially extending groove for receiving the protrusion, so as to circumferentially limit the friction disc 20 and prevent it from rotating relative to the drive shaft 2. Alternatively, the outer peripheral surface of the drive shaft 2 has an axially extending protrusion, and the central hub of the friction disc 20 has an axially extending groove for receiving the protrusion, so as to circumferentially limit the friction disc 20 and prevent it from rotating relative to the drive shaft 2. Exemplarily, the friction disc 20 and the drive shaft 2 are splined.

[0030] In some embodiments, the drive shaft 2 may optionally be a solid drive shaft.

[0031] In some other embodiments, the drive shaft 2 may optionally be a hollow drive shaft, with a shaft seal plug embedded in its central hole to prevent coolant or other contaminants from flowing into it.

[0032] In some embodiments, the friction disk 20 may optionally include a metal disk 21 and friction pads 22, for example, riveted or bonded to both sides of the metal disk. The friction pads may be made of wear-resistant and high-temperature-resistant materials, such as carbon fiber composites, which also have the advantages of low density and low thermal conductivity.

[0033] Viewed axially, on one side of the friction disc 20 (in) Figure 2 A drive disc 30 is arranged on the lower side (in the middle), which is non-rotatable but axially movable; on the opposite side of the friction disc 20 (in Figure 2A fixed disk 40 is arranged on the upper side (center), which is stationary. When the drive disk 30 moves axially toward the friction disk 20, the friction disk 20 is clamped between the drive disk 30 and the fixed disk 40. The drive shaft 2 is braked by the friction between the drive disk 30 and the fixed disk 40 and the friction pads 22 on one side. Conversely, when the drive disk 30 moves axially away from the friction disk 20, the friction disk 20 clamped between the drive disk 30 and the fixed disk 40 is released, and the drive disk 30 and the fixed disk 40 disengage from the friction pads 21 on one side, thereby releasing the brake on the drive shaft 2. Therefore, the friction brake provided in this application can operate without applying lubricating oil between the friction surfaces, avoiding rotational drag losses caused by lubricating oil and the performance effects of lubricating oil under different environments.

[0034] In some embodiments, the drive disk 30 and the fixed disk 40 are made of materials with high thermal conductivity and wear resistance, such as aluminum alloy, carbon ceramic composite, aluminum ceramic composite, etc.

[0035] In some embodiments, the friction disc 20 is also equipped with an elastic reset member (not shown in the figure). One end of the elastic reset member contacts the friction disc 20, and the other end contacts the drive shaft 2, so as to drive the friction disc 20 away from the fixed disc 40 or the drive disc 30 through axial reset force, thereby preventing the friction disc from sticking to them. Exemplarily, the elastic reset member can be arranged in the axial gap between the hub of the metal disc 21 and both ends of the drive shaft 2. Here, the elastic reset member can be a spring, such as a coil spring, a diaphragm spring, a wave spring, etc.

[0036] The axial movement of the drive disc 30 is achieved through a gear ring 50 and an actuator 60. The gear ring 50 is coaxially sleeved on the outside of the drive disc 30. The gear ring cannot move axially, but it can be driven to rotate by the actuator 60. Specifically, an internal thread 51 is provided on the inner peripheral surface of the gear ring 50, and a corresponding external thread 31 is provided on the outer peripheral surface of the drive disc 30 to mate with the internal thread 51. Through the threaded engagement between the two, the rotation of the gear ring 50 is converted into the axial movement of the drive disc 30 toward or away from the friction disc 20. Advantageously, the self-locking effect of the threaded engagement ensures that the friction disc 20 is reliably clamped, thereby ensuring a stable braking effect. This also allows the brake to be used not only as a service brake but also as a parking brake.

[0037] Continue to refer to Figure 2 and Figure 4The actuation device 60 includes an actuator motor 61 and a worm gear transmission mechanism 62. The worm gear transmission mechanism 62 includes a worm 621 and worm gear teeth 622. The worm 621 is mechanically coupled to the shaft of the actuator motor 61. The worm gear teeth 622 are arranged on the outer peripheral surface of the gear ring 50, and the worm gear teeth 622 and the helical teeth of the worm 621 mesh, thereby driving the gear ring 50 to rotate by the rotation of the worm 621 around its own axis. Here, by controlling the rotation of the actuator motor 61, the rotation of the gear ring 50 and the resulting axial movement of the drive disc 30 can be precisely controlled, that is, the triggering or release of the brake can be precisely controlled. Furthermore, based on the self-locking effect, large transmission ratio, and high load-bearing capacity of the worm gear transmission mechanism, it is possible to ensure that the friction disc 20 is reliably clamped between the drive disc 30 and the fixed disc 40, thereby ensuring stable friction braking. Furthermore, the arrangement of the gear ring 50 and the worm gear transmission mechanism 60 in this way can significantly reduce the axial length of the brake 1, achieving a more compact spatial arrangement.

[0038] like Figure 1 and Figure 6 As shown, the actuator 61 and the worm gear 621 can be fixed by means of bearing supports 63. The supports 63 are detachably fixed to the housing 10 by bolts, and the worm gear 621 is rotatably supported at both ends in the grooves of the supports 63 by support members implemented as bearings or bushings about its own axis.

[0039] like Figure 2 and Figure 4 As shown, the worm gear teeth 622 can cover the entire outer peripheral surface of the gear ring 50. Alternatively, in other embodiments, the worm gear teeth 622 can occupy only a portion of the outer peripheral surface of the gear ring 50.

[0040] Furthermore, considering wear resistance, the worm 621, or at least the teeth of the worm 621, can be made of steel, and the worm gear teeth 622 can be made of copper-based material. Optionally, the external threads on the outer peripheral surface of the drive disc 30 can be integrally formed by casting steel into the body or by bolting.

[0041] It should be noted that the actuation device is not limited to the embodiments described herein, and can be modified in terms of structure and configuration as needed. For example only, instead of a worm gear drive, a gear drive, such as a spur or helical cylindrical gear drive, can be used to drive the gear ring 50 to rotate, thereby driving the disc 30 to move axially via the internal thread 51 of the gear ring 50 to clamp or release the friction disc 20.

[0042] Combination Figure 2 and Figure 4A limiting protrusion 32 is provided on the outer peripheral surface of the drive disk 30 in the region adjacent to the second housing 12, and a limiting groove 121 is provided on the inner wall of the second housing 12 facing the drive disk 30. The limiting protrusion and the limiting groove extend axially and engage with each other. In this way, the drive disk 30 is circumferentially limited to prevent relative rotation with the drive shaft and to guide the axial movement of the drive disk 30.

[0043] In some embodiments, optionally, an axially extending limiting groove is provided on the outer peripheral surface of the drive disk 30 in the region adjacent to the second housing 12, and an axially extending limiting protrusion is provided on the inner wall of the second housing 12 facing the drive disk 30, which engages with the limiting groove to circumferentially limit the drive disk 30 to prevent it from rotating relative to the drive shaft and to guide the axial movement of the drive disk 30.

[0044] In other embodiments, optionally, a limiting groove is provided on the outer peripheral surface of the drive disk 30 in the region adjacent to the first housing 11, and a limiting protrusion is provided on the inner wall of the first housing 11 facing the drive disk 30; or, a limiting protrusion is provided on the outer peripheral surface of the drive disk 30 in the region adjacent to the first housing 11, and a limiting groove is provided on the inner wall of the first housing 11 facing the drive disk 30. By engaging the limiting protrusion into the limiting groove, the drive disk 30 is circumferentially limited to prevent relative rotation with respect to the drive shaft, and the axial movement of the drive disk 30 is guided.

[0045] In other embodiments, optionally, a limiting groove is provided on the outer peripheral surface of the drive disk 30 in the region adjacent to the first housing 11 and the second housing 12, and a limiting protrusion is provided on the inner wall of the first housing 11 and the second housing 12 facing the drive disk 30. Alternatively, a limiting protrusion is provided on the outer peripheral surface of the drive disk 30 in the region adjacent to the first housing 11 and the second housing 12, and a limiting groove is provided on the inner wall of the first housing 11 and the second housing 12 facing the drive disk 30. By engaging the limiting protrusion into the limiting groove, the drive disk 30 is circumferentially limited to prevent relative rotation with respect to the drive shaft, and the axial movement of the drive disk 30 is guided.

[0046] Combination Figure 2 , Figure 4 and Figure 5In its assembled state, the drive disk 30 is at least partially housed in the first receiving chamber 111 of the first housing 11, wherein an annular support protrusion 33 of the drive disk 30 is axially movably embedded between two concentric first support rings 1111 in the central region defining the first receiving chamber 111. A support member 112, such as a bearing or bushing, is arranged between the inner surface of the support protrusion 33 and the radially inward first support ring 1111 (which is farther from the central axis of the brake); a sealing ring is provided between the outer surface of the support protrusion 33 and the radially outward first support ring 1111 (which is farther from the central axis of the brake). Furthermore, an annular groove for receiving the sealing ring is provided on the outer peripheral surface of the drive disk 30 adjacent to the first housing 11, or an annular groove for receiving the sealing ring is provided on the first housing 11, wherein the sealing ring is pressed against the outer peripheral surface of the drive disk 30 and the first support ring 1111 defining the first receiving chamber 111.

[0047] Thus, the end face of the drive disk 30 facing the first housing 11 and the wall of the first receiving chamber 111 together define a first sealed chamber 113, which is used to contain coolant and its volume changes with the axial movement of the drive disk 30. That is, the drive disk 30 and the first housing 11 together define a first liquid cooling channel 70, thereby achieving heat dissipation and cooling of the drive disk 30 and the friction disk 20.

[0048] Furthermore, the stationary mounting plate 40 is at least partially housed in the second receiving chamber 122 of the second housing 12, which is defined by two concentric second support rings 1221. The mounting plate 40 is fitted with its hub and supported on the radially inner second support ring 1221 (closer to the central axis of the brake), and its outer peripheral surface is pressed against the radially outer second support ring 1221.

[0049] In some embodiments, the fixed disk 40 is welded to the side wall of the second receiving chamber 122 via its outer peripheral surface, i.e., welded to the second supporting protrusion 1221. For example, in Figure 5 As shown, the hub of the fixed disk 40 is tightly fitted and welded to the radially inner second support protrusion 1221, and a stepped portion is provided on the outer peripheral surface of the fixed disk 40 facing away from the friction disk 20, which is supported at the radially outer second support protrusion 1221 and welded thereto, thereby forming a welded portion 42. Thus, the end face of the fixed disk 40 facing the second housing 12 and the second housing 12 (specifically the bottom wall of the second receiving chamber 122) form a second sealed chamber 123, in which coolant is contained. That is, the fixed disk 40 and the bottom wall of the second receiving chamber 122 together define a second liquid cooling channel 80, thereby achieving heat dissipation and cooling of the fixed disk 40 and the friction disk 20.

[0050] Here, the welded portion 42 between the fixed disk 40 and the second housing 20 serves as both a fixing element and a sealing element, offering advantages in terms of structure and sealing reliability. However, it should be noted that the fixed disk 40 is not limited to the embodiment where a sealed chamber is formed with the second housing through the above-described welding method; it can also be modified as needed, for example, by using a sealing ring to construct the sealed chamber.

[0051] Here, by integrating liquid cooling channels into the brake, temperature can be effectively controlled, thermal fade of friction materials can be suppressed, service life can be extended, and braking stability can be guaranteed. Compared with common caliper-type wheel-side brakes, the risk of thermal failure and thermal fade can be significantly reduced, with the temperature of the friction braking components controlled to at least below 190°C. On the other hand, by arranging liquid cooling channels on the end faces of the drive disc and the fixed disc, a lightweight design can be achieved.

[0052] For example, the coolant may involve water. Alternatively, the coolant may consist of water, antifreeze, and additives, such as an ethylene glycol-based coolant.

[0053] Next, refer to Figures 7 to 10 The implementation methods of the two liquid cooling channels are described below.

[0054] Figure 9 In accordance with Figure 8 The cross-sectional view along section line CC shows the first liquid cooling channel 70. Multiple concentric annular first diversion ribs 34 are provided on the end face of the drive disc 30 facing the first housing 11 and the end face of the first housing 11 facing the drive disc 30, forming multiple concentric annular first branch channels 71. Among them, the radially furthest first branch channel 71 (which is furthest from the central axis of the brake, i.e., the outermost first branch channel) and the first inlet 72 of the first liquid cooling channel 70 (located in...) Figure 9 The first branch channel 71 (located on the lower side) is connected to the first outlet 73 of the first liquid cooling channel 70 (located on the lower side), while the first branch channel 71 at the radially closest end (which is closest to the central axis of the brake, i.e., the first branch channel at the center) is connected to the first outlet 73 of the first liquid cooling channel 70. Figure 9 (It is located on the upper side) connected. Based on the axial mobility of the drive disk 30 relative to the second housing 20, coolant can flow from one of the first branch channels 71 to the adjacent first branch channel 71 through the gap between the first branch rib 34 and the bottom wall of the first sealing chamber 113 or the gap between the drive disk 30 and the end face of the drive disk 30 facing the first housing 11. Here, the coolant flowing in from the radially furthest first branch channel 71 flows out from the radially closest first branch channel 71 after flowing through substantially the entire end face of the drive disk 40, which can achieve uniform and effective heat dissipation and cooling.

[0055] In some embodiments, the first diversion rib 34 may be integrally formed with the drive disk 40 or with the first housing 11. In other embodiments, the first diversion rib 34 may be fixed as a separate component at the drive disk 40 or at the first housing 11.

[0056] In some embodiments, the first diversion rib may be provided only on the end face of the drive disk 40 facing the first housing 11, or the first diversion rib may be provided only on the surface of the first housing 11 facing the drive disk 40.

[0057] from Figure 9 It can also be seen that a radially extending DC channel is provided at the first inlet 72 of the first liquid cooling channel 70, which is connected to the external liquid cooling circuit through the inlet interface 74; a radially extending DC channel is provided at the first outlet 73 of the first liquid cooling channel 70, which is connected to the external liquid cooling circuit through the outlet interface 75, so that the coolant in the brake 1 can be circulated through the suction pump or compressor in the external liquid cooling circuit.

[0058] It should be noted that the flow divider 34 and the first branch channel 71 in the liquid cooling circuit of the first sealed chamber 113 can also be non-concentric annular, such as eccentric or non-circular. As long as a liquid flow channel and fin-like structure are formed from the inlet to the outlet, and are evenly distributed on the side of the drive disk away from the friction disk, it is acceptable.

[0059] Figure 10 In accordance with Figure 8 The cross-sectional view along section line DD shows the second liquid cooling channel 80. Multiple concentric arc-shaped second diversion ribs 41 are provided on the end face of the fixed plate 40 facing the second housing 12, forming two concentric mirror-symmetrical second branch channels 81. These are folded branch channels. For clarity of layering, [the text abruptly ends here]. Figure 10 Only the second branch channel on the right side is marked with an appendix. Specifically, the coolant flowing in through the second inlet 82 of the second liquid cooling channel 80 flows through a radially extending direct current channel to the central region. In the central region, the coolant is split into two second branch channels 81 on the left and right sides and finally flows out at the second outlet 83. The fixed plate 40 is fixed relative to the second housing 12, and there is essentially no gap between the free end of the second branch rib and the bottom wall of the second sealed chamber 123. Therefore, the coolant can flow along a predetermined route through the second branch channels 81 before flowing out, thereby achieving uniform and effective cooling.

[0060] It should be noted that the embodiments of this application are not limited to the above-mentioned semi-circular reversing tributary channel, but can also be fan-shaped reversing tributary channel.

[0061] In some embodiments, the second diversion rib can be arranged on the surface of the second housing 12 facing the friction disk 20. Specifically, the second diversion rib is provided on the bottom wall of the second sealing chamber 123.

[0062] In other embodiments, the second diversion ribs can be provided on the end face of the fixed disk 40 facing the second housing 12 and the surface of the second housing 12 facing the friction disk 20, respectively.

[0063] It should be noted that the flow divider 34 and the first branch channel 71 in the liquid cooling circuit of the second sealed chamber 123 can also be non-circular, as long as they form a liquid flow channel from the inlet to the outlet and a fin-like structure, and are evenly distributed on the side of the fixed disk away from the friction disk.

[0064] refer to Figure 5 and Figure 8 The first inlet 72 of the first liquid cooling channel 70 and the second inlet 82 of the second liquid cooling channel are connected to the external liquid cooling circuit through the same inlet interface 74, and the first outlet 73 of the first liquid cooling channel 70 and the second outlet 83 of the second liquid cooling channel 80 are connected to the external liquid cooling circuit through the same outlet interface 75, thereby simplifying the layout of the liquid cooling pipeline.

[0065] It should be noted that the inlet and outlet of the first liquid cooling channel 70 and the inlet and outlet of the second liquid cooling channel 80 can be modified as needed. For example, it is feasible to connect only the first inlet 72 of the first liquid cooling channel 70 and the second inlet 82 of the second liquid cooling channel to the external liquid cooling circuit through the same inlet interface 74; or, connect only the first outlet 73 of the first liquid cooling channel 70 and the second outlet 83 of the second liquid cooling channel 80 to the external liquid cooling circuit through the same outlet interface 75; or, arrange the first inlet 72 and the first outlet 73 of the first liquid cooling channel 70 adjacent to each other; or, arrange the second inlet 82 and the second outlet 83 of the second liquid cooling channel adjacent to each other.

[0066] It should be noted that the above description of the first and second liquid cooling channels is merely illustrative and can be modified in terms of channel orientation and the structure of the flow dividers.

[0067] In summary, the brakes according to some embodiments can be integrated into the electric drive system, eliminating the need for wheel-side brakes and achieving an integrated configuration of vehicle drive and braking. Compared to open, air-cooled wheel-side brakes, these brakes are closed and liquid-cooled, significantly reducing the maximum temperature of the brake disc, for example, to only 1 / 3 of the maximum temperature of traditional brake discs. This significantly improves the overheating and heat fade problems of brakes during prolonged or repeated emergency braking, such as during automotive braking performance testing—AMS (AutoMotor and Sport) testing. Simultaneously, these brakes are unaffected by external environmental factors (such as ice, snow, water, mud, etc.), avoiding rust problems. The brake disc surface pressure is significantly reduced, improving abnormal noise and making braking performance more reliable. Furthermore, harmful particulate matter generated by braking friction is not emitted or is only emitted during maintenance, preventing environmental pollution. In the brakes according to some embodiments, the self-locking effect of the threaded fit ensures that the friction disc is reliably clamped, thereby guaranteeing stable braking action. In some embodiments of the brake, the worm gear transmission mechanism further ensures that the friction disc is reliably clamped between the drive disc and the fixed disc, thereby guaranteeing stable friction braking. In some embodiments of the brake, by modifying the corresponding liquid cooling channels, uniform and effective heat dissipation and cooling can be achieved while simplifying the piping layout.

[0068] Furthermore, according to the second aspect of this application, an electric drive system for vehicles is also proposed, the architecture of which is... Figure 11 , Figure 12 and Figure 13 It is shown schematically in the middle.

[0069] exist Figure 11 and Figure 12 The electric drive system 100 shown is a dual-motor electric drive system with integrated braking function. Its two drive motors 3, two reducers 4, and two brakes 1 provided according to any embodiment of this application are assembled into a single unit, for example, by means of a housing that detachably secures the aforementioned components. This further improves space utilization and thereby increases the integration of the electric drive controller, enhances vehicle braking performance and braking energy recovery efficiency, and reduces unsprung mass, thus improving vehicle handling performance.

[0070] exist Figure 11In the illustrated embodiment, the electric drive system 100 employs a fixed-axis gear transmission, with the motor shaft and output gear shaft arranged non-coaxially. A brake 1 is located at the front end of the drive motor 3's shaft, and the rear end is connected to a reducer 4. The brake 1 brakes the drive motor 3's shaft, and the reducer 4 mechanically rotates with the driven component (e.g., the wheel hub). In this architecture, for the same braking power requirement, the braking torque provided by the brake is relatively small, which is beneficial for the application of lighter brakes. Furthermore, by centrally arranging the two drive motors in the central area, it facilitates the arrangement of power supply lines and centralized heat dissipation of the motors.

[0071] exist Figure 12 In the illustrated embodiment, the electric drive system 100 employs a planetary gear transmission, with the motor shaft and output gear shaft arranged coaxially. Specifically, a brake 1 is arranged at the front end of the drive motor 3's shaft, and a reducer 4 is arranged at the rear end. The two brakes 1 are integrated in the middle area, which facilitates the arrangement of the liquid cooling channel and the corresponding pipelines.

[0072] In some embodiments not shown, the brake 1 of such a dual-motor electric drive system may optionally be arranged at the rear end of the shaft of the drive motor 3. Taking an automotive electric drive system as an example, the brake 1 may be arranged between the drive motor and the reducer for the same wheel.

[0073] In some other embodiments not shown, the brake 1 of this dual-motor electric drive system is optionally arranged at the output end of the reducer 4. Taking an automotive electric drive system as an example, the brake 1 is arranged outside the wheel hub but relatively close to the wheel hub.

[0074] exist Figure 13 In the illustrated embodiment, the electric drive system 100 is a single-motor electric drive system with integrated braking function. It comprises a drive motor 3, a reducer 4, a differential 5, and two brakes 1 provided according to any embodiment of this application, assembled into a single assembly. The two brakes are arranged on both sides of the differential 5. Using a single-motor drive reduces the number of parts in the electric drive system, thereby lowering costs. The single-motor electric drive system can employ a fixed-axis gear transmission with the motor shaft and output gear shaft not coaxial (e.g., ...). Figure 13 (As shown), a rotary gear transmission with the motor shaft and output gear shaft coaxial can also be used (not shown).

[0075] In some embodiments, the two drive motors are operable independently, meaning they can operate with different parameters (e.g., speed, torque) than each other, allowing the two driven components (e.g., wheel hubs) to rotate independently with different speeds and torques. Here, because the two drive motors can operate independently, precise electronic control replaces mechanical coupling, and dynamic speed and torque distribution significantly improves maneuverability.

[0076] For example, the drive motor 3 is an axial flux motor or a radial flux motor, which can be selected according to the axial length of the electric drive system and cost control.

[0077] For example, the reducer 4 can have a fixed gear ratio, such as a single-stage planetary gear reducer. When two drive motors are provided, on the one hand, a reducer with a fixed gear ratio can cover a larger range of driving torques; on the other hand, compared to a reducer with a multi-stage gear ratio, it allows the driven component to remain coupled to the drive unit at all times, facilitating operation.

[0078] It should be noted that the electric drive system for vehicles proposed herein can be applied to new energy vehicles. On the one hand, it can involve pure electric vehicles (whose power source is a rechargeable power battery, such as a lithium-ion battery, a fuel cell, or the like), and on the other hand, it can involve hybrid electric vehicles (whose power source includes an engine and a rechargeable power battery).

[0079] For example, the rear axle and / or front axle of the vehicle are drive axles, which include brakes or electric drive systems according to any of the above embodiments. Here, by removing the brakes from the wheel hubs and instead moving them outside the wheel hubs, specifically to the drive side, a drive axle with integrated braking function is achieved. On the one hand, removing the brakes from the wheel hubs reduces unsprung mass, which is beneficial for improving vehicle handling stability; on the other hand, the wheel rotational inertia is reduced, allowing for the application of lightweight brakes, which facilitates deep integration with the motor and electric drive controller. Furthermore, compared to wheel-side brakes, brakes integrated into the drive axle avoid the problem of indiscriminate emission of solid pollutant particles during friction braking, and are unaffected by environmental weather conditions (such as rain, snow, dust, etc.) or have their effects significantly reduced, exhibiting better environmental tolerance and braking performance. Finally, removing the brakes from the wheel hubs significantly frees up space around the wheel hubs, which is beneficial for the arrangement of suspension or steering mechanisms, optimization of overall vehicle space, and reduction of wheel wind resistance. In addition, if both the front and rear axles of the vehicle adopt one of the aforementioned dual-motor electric drive systems with integrated braking functions, from the perspective of the whole vehicle, the four-motor distributed torque vector control technology can significantly improve the vehicle's cornering performance, provide sensitive steering, and enhance driving quality and safety.

[0080] Finally, it should be noted that the vehicle electric drive system according to this application may have the advantages and features described above with respect to the brake according to this application, and reference can be made accordingly to the description made with respect to the brake, which will not be repeated here.

[0081] It should be understood that all the above preferred embodiments are exemplary and not restrictive, and various modifications or variations made by those skilled in the art to the specific embodiments described above under the concept of this application should be within the scope of legal protection of this application.

Claims

1. A brake for braking the drive shaft of an electric drive system, characterized in that, The brake includes: The housing includes a first housing and a second housing; A friction disc, which is mechanically coupled to the drive shaft and rotates along with the drive shaft; A drive disk, which is axially arranged on one side of the friction disk and is non-rotatable but axially movable, is housed in the housing, wherein the end face of the drive disk facing the first housing defines a first liquid cooling channel with the first housing; A fixed disk is arranged axially on the other side of the friction disk and is fixedly housed in the housing, wherein the end face of the fixed disk facing the second housing defines a second liquid cooling channel with the second housing; A gear ring is sleeved on the outside of the drive disk and is housed in the housing without axial movement. The inner peripheral surface of the gear ring is provided with an internal thread that mates with the external thread on the outer peripheral surface of the drive disk. An actuator for rotating the gear ring. The rotation of the gear ring drives the drive disk to move axially toward the friction disk, thereby clamping the friction disk between the drive disk and the fixed disk, and thus braking the transmission shaft through the friction between the drive disk, the fixed disk and the friction disk. Alternatively, the rotation of the gear ring drives the drive disc to move axially away from the friction disc, thereby releasing the friction disc clamped between the drive disc and the fixed disc, and thus releasing the brake on the drive shaft.

2. The brake according to claim 1, characterized in that, A plurality of first diversion ribs are provided on at least one of the end face of the drive disk facing the first housing and the end face of the first housing facing the drive disk, and a plurality of concentric first branch channels are formed through the first diversion ribs. Among them, one of the radially farthest first branch channel and the radially nearest first branch channel is connected to the inlet of the first liquid cooling channel, and the other of the radially farthest first branch channel and the radially nearest first branch channel is connected to the outlet of the first liquid cooling channel. The coolant flowing in through the inlet of the first liquid cooling channel is diverted to the first branch channel. And / or, a second diversion rib is provided on at least one of the end face of the fixed disk facing the second housing and the end face of the second housing facing the fixed disk, and a plurality of concentric second branch channels are formed by the second diversion rib, wherein the second branch channel is a deflection branch channel, and the coolant flowing in through the inlet of the second liquid cooling channel is diverted into the second branch channel.

3. The brake according to claim 1, characterized in that, The inlet for coolant inflow of the first liquid cooling channel and the inlet for coolant inflow of the second liquid cooling channel are connected to the outside through the same inlet interface; And / or, the outlet for coolant outflow of the first liquid cooling channel and the outlet for coolant outflow of the second liquid cooling channel are connected to the outside through the same outlet interface.

4. The brake according to claim 1, characterized in that, The second housing has a receiving chamber for accommodating the fixed disk, wherein the outer peripheral surface and hub of the fixed disk are welded to the side wall of the receiving chamber, and the end face of the fixed disk and the bottom wall of the receiving chamber define the second liquid cooling channel.

5. The brake according to claim 1, characterized in that, One of the drive disk and the housing is provided with an axially extending limiting protrusion, and the other of the drive disk and the housing is provided with an axially extending limiting groove. By accommodating the limiting protrusion in the limiting groove, the drive disk is circumferentially limited.

6. The brake according to claim 1, characterized in that, It includes an elastic reset member, one end of which contacts the drive shaft and the other end of which contacts the friction disc, so as to drive the friction disc to axially separate from the fixed disc or from the drive disc by means of axial reset force.

7. The brake according to claim 1, characterized in that, The drive disk and / or the fixed disk are made of aluminum-ceramic composite material or carbon-ceramic composite material; And / or, the friction disc includes a friction pad made of carbon fiber composite material.

8. The brake according to claim 1, characterized in that, The actuation device includes an actuator motor and a worm gear transmission mechanism. The worm gear transmission mechanism includes a worm that is mechanically coupled to the actuator motor and worm gear teeth that mesh with the helical teeth of the worm. The worm gear teeth are arranged on the outer peripheral surface of the gear ring.

9. The brake according to claim 1, characterized in that, The drive shaft is the shaft of the drive motor of the electric drive system, the output shaft of the reducer of the electric drive system, or the output shaft of the differential of the reducer of the electric drive system.

10. An electric drive system for vehicles, characterized in that, It includes a drive motor, a reducer, and a brake according to any one of claims 1 to 9, wherein the drive motor, the reducer, and the brake are detachably assembled.

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