Middle friction type double-acting-force self-adaptive variable-speed electric driving system

Abstract

The invention discloses a middle friction type double-acting-force self-adaptive variable-speed electric driving system which has all the advantages of a double-acting-force self-adaptive variable-speed electric driving system, a node of slow-gear return power of the structure is located near the axial middle of an inner ring of a clutch and is the same as the position acting on a second group of elastic pieces, the response sensitivity is improved, and the service life of the system is prolonged. The structure is simple and compact, jamming and time delay in the gear shifting process are further avoided, gear shifting of a speed change system is sensitive, and pause is avoided; meanwhile, the slow-gear traction force return position is located near the axial middle of the driven part, when resistance is increased, the separation process of the clutch is achieved by compressing all the elastic assemblies instead of releasing a set of elastic assemblies, and therefore separation of the clutch is fast, and the problem that the efficiency is reduced due to redundant friction is solved.

Description

Technical Field

[0001] The invention relates to a motor vehicle transmission, in particular to a centrally mounted friction type double-acting force adaptive speed-changing electric drive system. Background Art

[0002] The operation of electric vehicles depends first on the electric drive system. The electric drive system has achieved a deep integration of mechanical and electric drive power components. It is the core component of driving and all the devices needed to provide power for electric vehicles. The electric drive system is mainly composed of four parts: drive motor, transmission, power converter and controller. Its performance and efficiency directly affect the power, economy and comfort of electric vehicles. The size and weight of the drive motor and transmission will also affect the overall efficiency of electric vehicles. The power converter and controller are closely related to the safe and reliable operation of electric vehicles.

[0003] Although the electric drive system with only a reduction transmission can make the torque output generated by the motor direct and smooth, it cannot take into account the power and economy of pure electric vehicles at the same time. This is because the drive motor cannot be at a high-efficiency working point in most working conditions during driving, especially at the highest or lowest speed and low load conditions. Due to the large reduction transmission ratio, there is no room for improvement after the speed reaches the limit, causing the electric vehicle to be at a higher speed critical point when cruising. The speed is restricted, and the efficiency generally drops below 60-70%. The power loss is large, the high-speed economy is not high, the vehicle's power, economy and comfort are poor, and the on-board electric energy is seriously wasted, which reduces the driving range. In addition, the electric drive system with only a reduction transmission structure is not conducive to the use of high-efficiency and lightweight drive motors.

[0004] Compared with the electric drive system equipped with a gearbox, the gearbox has less power output loss, that is, it can provide higher driving torque in the constant torque area, higher speed in the constant power area, and achieve high torque and high efficiency under low-speed and heavy-load conditions. What's better is that the timing of the electric motor power burst can be selected to optimize and improve the power output efficiency of the drive motor, enhance the continuous acceleration performance, and have a wider high-efficiency platform. It can fully meet the requirements of various complex working conditions such as vehicle acceleration, climbing and high-speed driving, greatly improve power, economy and comfort, and help reduce manufacturing and use costs, reduce battery capacity, lightweight and reduce volume, reduce vehicle weight and many other advantages that are difficult to achieve with only a reduction gearbox.

[0005] As products are upgraded, users' pursuit of performance, efficiency and range, as well as their sensitivity to weight and cost, decrease, and matching variable-speed transmissions should be the future development trend of electric motorcycle transmission systems.

[0006] There are many patent documents from 2013 to 2019. For example, the Chinese patent (zl 201310389721, name: multi-cam adaptive multi-speed automatic transmission, etc.) discloses a variety of transmission systems that use conical friction pairs combined with preload control transmission. The system uses the motor output power and driving resistance properties, through the friction transmission component, through the end cam clutch mechanism, and through the overrunning clutch to change the transmission route, and selects high-speed or low-speed gear according to the load adaptively to switch gears. The outer surface of the friction transmission component is designed to be a conical body, and the inner ring of the friction ring is constructed into a conical hole structure that matches the conical surface. The elastic element at the right end of the friction transmission component pushes the friction transmission component into the conical hole to achieve power combination. The end cam at the left end of the friction transmission component is pushed by the load to leave the conical hole to achieve power separation. In the end cam clutch mechanism described in the document, the part responsible for performing separation and combination is composed of the friction transmission component and the elastic element.

[0007] The speed change system of this structure breaks through the traditional electric vehicle transmission speed change structure, but there are still many technical problems:

[0008] 1. When the load transmitted by the friction pair transmission setting in the adaptive cam clutch mechanism is equal to and less than the transmission torque, after the friction pair transmission mechanism components are separated, the traction force and the driving resistance are relative and interactive, and are converted into the same direction axial synthetic pressure through the transmission mechanism, pressing the elastic element disc spring. After the elastic element disc spring is axially compressed, the elastic element characteristics will increase the reverse elastic force while pushing back the moving components in the friction pair transmission mechanism. The friction pair will be adhered for a short time, making it difficult for the friction pair transmission mechanism to achieve rapid separation and combination, which will accelerate the wear of the friction pair, resulting in uneven gear shifting and affecting the service life of the friction pair transmission mechanism. In particular, when the relative effects of traction and driving resistance on the friction transmission components increase to equal to and greater than the transmission torque limit, the reverse elastic push-back is more prominent. There are engineering principles and structural issues on how to reduce the reverse rebound caused by the increase in elastic force after the elastic element is compressed; 2. The friction pair transmission mechanism and the elastic element are arranged in a sequential manner, which has structural problems such as occupying a large space, transmitting small power, and low efficiency; 3. Since the mechanism does not have a transfer mechanism, the structure is complex, which is not conducive to lightweight and integration; 4. The process of calibrating the clutch transmission torque and speed of the friction pair transmission mechanism and the motor's efficient power target is complex and takes too long; 5. The friction transmission components do not have an instantaneous repeated locking mechanism that can adapt to the bumpy and washboard roads; 6. The mechanism has engineering problems such as timely synchronous control of the controller.

[0009] Therefore, in order to solve the above problems, the inventor of this patent has improved the above-mentioned speed change mechanism and adopted two groups of speed change elastic parts. When the transmission is in fast gear, the running resistance is used to act on the cam pair to push the second group of elastic elements to release the first group of elastic elements (the first group of elastic elements can also be pressed at the same time) to disengage the clutch; when the transmission is in slow gear, the traction force is used to press the first and second groups of elastic elements (disc springs) through the low-speed cam pair to keep the clutch disengaged. The two properties of traction and running resistance are fully utilized, and the friction pair transmission mechanism is calibrated to adjust the transmission load limit scheme. By abandoning many energy-consuming mechanisms, actuators, sensors and complex algorithms, the transmission mechanism is realized. Smooth and soft separation and combination, two different power outputs are transmitted, and the requirements of various complex working conditions such as vehicle acceleration, climbing and high-speed driving are met.

[0010] However, when the inventor tested the above scheme, he found that the node position where power is transmitted between the inner ring of the clutch and the transmission shaft sleeve basically coincides with the node position where the traction force of the slow gear mechanism enters. The structure is complex and occupies a large space. In addition, both the driving resistance and the traction force need to pass through the power transmission position to reach the second group of elastic elements, which causes interference between the power transmission route and the driving resistance and the low-speed gear traction force. Therefore, jamming and delays will occur during the gear shifting process, resulting in insensitive gear shifting of the transmission system and a sense of frustration.

[0011] Especially for the structure that uses the transmission shaft sleeve to directly output power, the position where the low-speed gear transmission shaft sleeve transmits the slow gear traction force back to the inner ring of the clutch is far away from the position acting on the second group of elastic elements, so that after the structure reacts, it causes further jamming and delay in the gear switching process, making the transmission system shifting not sensitive enough and causing a sense of frustration.

[0012] Therefore, it is necessary to improve the aforementioned automatic transmission device suitable for electric vehicles to save space and avoid interference between the power transmission route and the driving resistance and the traction of the low-speed gear. Therefore, it is possible to avoid jamming and delays in the gear shifting process, so that the gear shifting system is sensitive and does not feel jerky. At the same time, for the friction plate clutch, it is expected that all friction plates can transmit torque evenly to ensure long-term use of the system and improve transmission efficiency. Summary of the invention

[0013] In view of this, the purpose of the present invention is to provide a centrally mounted friction type dual-force adaptive speed-changing electric drive system, which adds a reverse gear transmission mechanism with strong adaptability. The device can not only adapt to changes in driving resistance and automatically shift gears without cutting off the driving force, but also solve the problem of high-efficiency forward and reverse driving on roads under complex conditions under bidirectional driving conditions. The device has a simple and compact configuration, and cooperates smoothly and naturally with the cam adaptive automatic speed-changing mechanism, thereby reducing manufacturing costs and ensuring transmission stability.

[0014] The centrally mounted friction dual-force adaptive speed-changing electric drive system of the present invention comprises a housing and a speed-changing system;

[0015] The transmission system comprises a power input mechanism, a main shaft, a main transmission mechanism, a low-speed gear transmission mechanism and a reverse gear transmission mechanism; the main transmission mechanism comprises a friction clutch and a transmission sleeve outerly disposed on the main shaft, the power input mechanism inputs power to the active member of the friction clutch, the driven member of the friction clutch transmits power to the transmission sleeve, and the transmission sleeve outputs power through a power output active member;

[0016] The driven member of the friction clutch and the transmission sleeve or / and the transmission sleeve itself form a transmission through at least one first axial cam pair;

[0017] The friction clutch is set to an axial preload force to engage it. When the transmission sleeve outputs power, the first axial cam pair generates an axial component force while transmitting the power. The axial component force is opposite to the axial preload force and has a tendency to overcome the axial preload force to release the friction clutch.

[0018] The low-speed gear transmission mechanism overtakes when the main transmission mechanism is transmitting; the drive motor simultaneously transmits power to the low-speed gear transmission mechanism, and the low-speed gear transmission mechanism transmits the low-speed gear power to the follower of the friction clutch through the second axial cam pair, and the part of the follower of the friction clutch for receiving the low-speed gear power is located near the axial middle of the follower.

[0019] Further, the low-speed gear transmission mechanism includes a low-speed gear shaft and an overrunning clutch arranged on the low-speed gear shaft, and also includes a low-speed gear transmission sleeve for transmitting power from the low-speed gear shaft to the driven member of the friction clutch, and the low-speed gear transmission sleeve is provided with at least one second axial cam pair. The low-speed gear transmission mechanism includes a low-speed gear shaft and an overrunning clutch arranged on the low-speed gear shaft, and also includes a low-speed gear transmission sleeve for transmitting power from the low-speed gear shaft to the driven member of the friction clutch, and the low-speed gear transmission sleeve is provided with at least one second axial cam pair.

[0020] Furthermore, the axial preload is applied by an elastic member, which includes a first elastic member and a second elastic member. The first elastic member applies the axial preload to the friction clutch, and the second elastic member applies the preload to the low-speed gear transmission sleeve. At the same time, the preload acts on the first elastic member as a basis for applying the preload of the first elastic member. The position of the low-speed gear transmission sleeve that transmits power to the driven member of the friction plate clutch is located between the first elastic member and the second elastic member.

[0021] Furthermore, the friction clutch is a friction plate clutch, the active part of the friction plate clutch includes an outer ring and an active friction plate, and the driven part includes an inner ring and a driven friction plate;

[0022] The outer ring includes a first bracket, a second bracket and a support column, the support column is multiple and distributed in the circumferential direction and fixedly connected between the first bracket and the second bracket, and the active friction plate is passed through the support column;

[0023] The inner ring is a hollow cylindrical structure; the first elastic member and the second elastic member are located in the hollow of the inner ring;

[0024] The rotor of the driving motor is a hollow structure, the friction plate clutch is located inside the hollow structure of the rotor, and the first bracket and the second bracket are respectively fixedly connected to the two axial ends of the rotor to form a transmission fit.

[0025] Furthermore, the low-speed gear transmission sleeve extends to the inside of the inner ring to form an inner extension section, and a radial protrusion is provided on the outer surface of the inner extension section. The first elastic member and the second elastic member are respectively set with preload forces and are arranged on both axial sides of the radial protrusion.

[0026] Furthermore, the first elastic member and the second elastic member are respectively the first speed change disc spring and the second speed change disc spring, and the first speed change disc spring and the second speed change disc spring are outermostly arranged on the inner extension section of the transmission shaft sleeve; the inner circle of the inner ring is provided with a limiting boss protruding inward, and the limiting boss is used to block the radial protrusion of the outer surface of the inner extension section at a set position toward the direction of the first elastic member.

[0027] Furthermore, the low-speed gear transmission mechanism also includes a low-speed gear intermediate driving gear, a low-speed gear intermediate driven gear and a low-speed gear driven gear; the outer ring of the friction plate clutch is in transmission cooperation with the low-speed gear intermediate driving gear, the low-speed gear intermediate driving gear is meshed with the low-speed gear intermediate driven gear, the low-speed gear intermediate driven gear is transmission-coordinated and arranged on the low-speed gear shaft, the inner ring of the overrunning clutch is in transmission cooperation with the low-speed gear shaft, and the outer ring of the overrunning clutch serves as the low-speed gear driving gear and is transmission-coordinated with the low-speed gear transmission shaft sleeve through the low-speed gear driven gear.

[0028] Further, the transmission sleeve is rotatably fitted onto the low-speed gear transmission sleeve; the power output active part is integrally formed or transmission-fitted to form a power output sleeve, the power output sleeve is transmission-fitted onto the transmission sleeve, and the outer circle is rotationally supported on the box body through a bearing, and the first bracket is axially outwardly necked and rotationally fitted onto the transmission sleeve;

[0029] The second bracket extends outward in the axial direction to form a second shaft sleeve section, and the second shaft sleeve section is rotatably supported by the main shaft and the box body.

[0030] Furthermore, an elastic preload is formed between adjacent active friction plates of the friction plate clutch through elastic pads; the driven friction plates are axially limited by elastic clips, and an elastic preload is also formed between the driven friction plates through second elastic pads; the elastic force of the second speed change disc spring is equal to or greater than the elastic force of the first speed change disc spring.

[0031] Furthermore, the elastic pad is an annular pad, and the diameter of the circle where the support rods are distributed is smaller than the outer diameter of the annular pad and larger than the inner diameter of the annular pad.

[0032] The beneficial effects of the present invention are as follows: the centrally mounted friction type dual-force adaptive speed-changing electric drive system of the present invention has all the advantages of the dual-force adaptive speed-changing electric drive system, adopts two sets of speed-changing elastic parts, fully utilizes the two properties of traction and driving resistance, realizes gear shifting and maintains driving in the corresponding gear under set conditions, transmits two different power outputs, and meets the requirements of various complex working conditions such as vehicle acceleration, climbing and high-speed driving; at the same time, the node position between the two sets of elastic parts is used as the slow gear power return position, which avoids the interference between the power output and the driving resistance and the traction force acting on the elastic parts, and makes the target of the driving resistance and the traction force acting on the elastic parts clearer, thereby not only saving the component layout space, but also avoiding the occurrence of jamming during the gear shifting process. and delay, so that the transmission system shifts sensitively and without a sense of jerkiness, thereby ensuring the power transmission efficiency of the transmission system; and, the structure can make the node for transmitting power located near the axial middle of the inner ring, the same as the position acting on the second group of elastic members, thereby improving the sensitivity of the response, which is not only simple and compact in structure, but also further avoids jamming and delay during the gear shifting process, thereby making the transmission system shift sensitive and without a sense of jerkiness; at the same time, the slow gear traction force return position is located near the axial middle of the driven member, and when the resistance increases, the clutch separation process is achieved by compressing all elastic components, rather than by releasing a group of elastic components, thereby making the clutch separation decisive and rapid, thereby avoiding the problem of reduced efficiency caused by excess friction. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0034] Figure 1 It is a schematic diagram of the axial cross-sectional structure of the present invention;

[0035] Figure 2 A cross-sectional view of one half of the clutch;

[0036] Figure 3 Schematic diagram of the installation structure of the active friction plate;

[0037] Figure 4 It is a schematic diagram of the structure of the elastic pad. DETAILED DESCRIPTION

[0038] like Figures 1 to 4 As shown: the central friction type dual-force adaptive speed-changing electric drive system of the present invention comprises a housing (a common structure in the mechanical field, not shown in the figure), a drive motor and a speed-changing system;

[0039] The speed change system includes a main shaft 1, a main transmission mechanism and a low-speed gear transmission mechanism; the main transmission mechanism includes a friction clutch and a transmission sleeve 6, the drive motor inputs power to the active part of the friction clutch, the driven part of the friction clutch transmits power to the transmission sleeve 6, and the driven part is located near its end to transmit power to the transmission sleeve 6, and the transmission sleeve 6 outputs power through a power output active part 3; the power output active part refers to the active part that continues to output power, and the power is generally received by the power output driven part, such as a sprocket, a pulley, etc., so that the present invention is a mid-mounted structure, which will not be repeated here;

[0040] The driven member of the friction clutch and the transmission sleeve 6 or / and the transmission sleeve itself form a transmission through at least one first axial cam pair 601;

[0041] The friction clutch is set to an axial preload force to engage it. When the transmission sleeve outputs power, the first axial cam pair 601 generates an axial force component while transmitting. The axial force component is opposite to the axial preload force and has a tendency to overcome the axial preload force to release the friction clutch.

[0042] The low-speed gear transmission mechanism overtakes when the main transmission mechanism is transmitting, which means that the low-speed gear transmission mechanism needs to include an overrunning clutch. When the main transmission mechanism is transmitting, the overrunning clutch overtakes, and when the slow gear is transmitting, the overrunning clutch is engaged, which will not be repeated here; the driving motor simultaneously transmits power to the low-speed gear transmission mechanism, and the low-speed gear transmission mechanism transmits the low-speed gear power to the driven member of the friction clutch through the second axial cam pair 401, and the driven member of the friction clutch for receiving the low-speed gear power is located near the axial middle of the driven member, and the axial middle means that the driven member has a certain axial length, and the slow gear traction force is transmitted to the driven member from the middle, and the power transmission part of the main transmission mechanism (which is also the output part of the slow gear power) is located at the end of the driven member, so that the two avoid interference, and the pre-tightening force of the two elastic members provides a structure so that the clutch is separated by the elastic member compression method, thereby ensuring the smoothness and stability of the gear shifting.

[0043] In this embodiment, the low-speed gear transmission mechanism includes a low-speed gear shaft 7 and an overrunning clutch 8 arranged on the low-speed gear shaft 7, and also includes a low-speed gear transmission sleeve 4 for transmitting power from the low-speed gear shaft to the driven member of the friction clutch, and the low-speed gear transmission sleeve 4 is provided with at least one second axial cam pair 401;

[0044] The driving motor transmits power to the low-speed gear shaft 7 at the same time, that is, when the low-speed gear is transmitted, the power of the overrunning clutch 8 is transmitted to the driven member of the friction clutch through the second axial cam pair 401; when the power is transmitted only through the main transmission mechanism, after the transmission ratio of the low-speed gear transmission mechanism is set, the power output by the driven member of the friction clutch is transmitted to the overrunning clutch 8 through the second axial cam pair 401 in the reverse direction (the reverse direction of the second axial cam pair 401 can be a meshing transmission) to make the overrunning clutch 8 overtake, thereby avoiding transmission interference. When the resistance reaches the set value, the axial component force generated by the first axial cam pair 601 overcomes the axial preload force, so that the friction clutch is disengaged and the drive is engaged. The force is transmitted to the overrunning clutch and the second axial cam pair 401 through the low-speed gear shaft, and then to the driven member of the friction clutch and then to the transmission shaft sleeve 6, so that the slow gear power is output. Therefore, when the slow gear is transmitted, the second axial cam transmits the traction force from the slow gear, and the generated axial component force acts on the friction clutch to overcome the preload force. The axial component force generated by the reaction of the driving resistance during the power transmission of the first axial cam pair 601 is also used to overcome the preload force. Therefore, the traction force and the driving resistance act on the preload force together, which has better reliability and better avoids the problem of repeated engagement and disconnection of the friction clutch, and is suitable for driving on roads with poor conditions.

[0045] As shown in the figure, the low-speed gear transmission sleeve 4 is a segmented structure, with one or more second axial cam pairs 401 passing between the segments, and a second axial cam pair 401 can also be set between the low-speed gear transmission sleeve 4 and the driven member (middle part). Similarly, when multiple axial cam pairs are set, during low-speed gear transmission, the axial component force acts on the driven member to overcome the axial preload force, thereby achieving the effect of keeping the clutch separated.

[0046] The active part of the friction clutch can be the outer ring and accessories or the inner ring and accessories according to the requirements of the transmission layout. Similarly, the driven part can also be the inner ring and accessories or the outer ring and accessories. Under normal conditions, in order to meet the support of the main shaft 1 and the transmission needs of the transmission sleeve, the driven part should be the inner ring and accessories, and the active part should be the outer ring and accessories.

[0047] As shown in the figure, the driven member of the friction clutch is the inner ring 19, which is necked to form an extended sleeve section and is matched with the transmission sleeve 6 through the extended sleeve section, generally through a first axial cam pair (which can be a spiral cam pair or an end cam pair); the transmission sleeve 6 itself is a segmented structure, and the segments are matched with each other through one or more first axial cam pairs 601. The setting of multiple cam pairs can make the speed transmission smoother and more stable;

[0048] As shown in the figure, in this embodiment, the inner ring 16 of the friction clutch and the transmission sleeve 6 are matched through a first axial cam pair; and the transmission sleeve 6 outputs power through the active power output member (in this embodiment, the active sprocket), and the active power output member forms an output sleeve, which is outer-mounted on the transmission sleeve 6 and matched with the transmission (through the axial cam pair, which is generally understood as a first axial cam pair); the axial cam pair here is an axial cam (including an end face cam or a spiral cam) that cooperates with each other. When the transmission sleeve transmits power, the first axial cam pair 601 generates two components in the axial and circumferential directions, wherein the circumferential direction component outputs power, and the axial component is opposite to the axial preload and has a tendency to overcome the axial preload, that is, the rotation direction of the axial cam pair (including the second axial cam pair described below) is related to the power output rotation direction. Based on the above records, those skilled in the art can know which rotation direction of the axial cam pair can apply which direction of axial component, on the premise of knowing the power output direction, and will not repeat it here;

[0049] The active power output member is generally located near the middle of the present invention, which is conducive to realizing the layout of the mid-mounted structure. The power can be transmitted over a long distance through a series of mechanical transmission pairs to form a mid-mounted rear-drive structure, which will not be described in detail here;

[0050] In this embodiment, the axial preload is applied by an elastic member, which includes a first elastic member 10 and a second elastic member 18. The first elastic member 10 applies the axial preload to the friction clutch, and the second elastic member 18 applies a preload to the slow gear transmission sleeve 4. At the same time, the preload acts on the first elastic member 10 as a basis for applying the preload of the first elastic member; as shown in the figure, the first elastic member 10 directly applies a leftward preload to the inner ring 16 of the friction clutch, so that the clutch engages for transmission; the second elastic member 18 applies a leftward preload to the slow gear transmission sleeve 4 (a corresponding structure, such as an annular protrusion, is provided on the sleeve), and at the same time acts on the first elastic member 10 through the slow gear transmission sleeve 4 to form a stepped linkage structure; in this structure, when the driving resistance reaches the set value, the right end of the transmission sleeve 6 moves to The right movement squeezes the driven member to compress the first elastic member 10, and the friction clutch is disengaged; the slow gear transmission mechanism transmits power, and the slow gear power is transmitted to the slow gear transmission sleeve through the overrunning clutch 8. The slow gear transmission sleeve squeezes the second elastic member 18 through the second axial cam pair, and uses traction to keep the clutch separated, while transmitting power to the driven member. The driven member transmits power to the transmission sleeve 6, and continues to squeeze the driven member through the first axial cam pair 601, and uses the driving resistance to keep the clutch separated. In this structure, two elastic members are used to achieve the engagement and disengagement of the clutch, which can make the axial component force formed by the driving resistance mainly act on a part of the elastic member, and the clutch is separated by releasing. The stepped progressive elastic preload buffers the repeated compression of the elastic member caused by the unstable driving resistance on uneven roads, thereby reducing the possibility of repeated engagement and disengagement of the clutch.

[0051] In this embodiment, the active part of the friction clutch includes an outer ring and an active friction plate 14 arranged on the outer ring 17, and the driven part includes an inner ring 19 and a driven friction plate arranged on the inner ring, and the inner ring is a hollow cylindrical structure;

[0052] The outer ring of the friction plate clutch includes a first bracket 20, a second bracket 20a and a support column 17. The support column 17 is multiple and distributed in the circumferential direction and fixedly connected between the first bracket 20 and the second bracket 20a. The active friction plate 14 of the friction plate clutch is inserted through the support column. In this structure, the support column 17 is detachably connected to the first bracket 20 and the second bracket 20a, so that the length of the entire outer ring is adjustable. Different support column lengths are used according to different needs to set different numbers of active friction plates 14. The structure in which the active friction plate 14 is inserted through the support column makes the active friction plate move stably and evenly, which is more suitable for the speed change system of the present invention and ensures the sensitivity of speed change. At the same time, the adjustable length provides sufficient assembly space for the setting of two groups of elastic parts and is suitable for the pre-tightening structure of longer elastic parts.

[0053] The inner ring of the friction plate clutch is a hollow cylindrical structure; the first elastic member 10 and the second elastic member 18 are located in the hollow of the inner ring; as shown in the figure, the main shaft 1 passes through the drive system of the present invention from left to right to form a supporting foundation, and the main speed change mechanism (the first and second elastic members and a part of the slow gear transmission sleeve) is located in the space formed by the inner ring 19; the drive motor includes a motor stator 22 and a motor rotor 23, which is an inner rotor structure. As shown in the figure, the rotor of the drive motor is a hollow structure, and the friction plate clutch is located inside the hollow structure of the rotor. The first bracket and the second bracket are respectively fixedly connected to the axial ends of the rotor to form a transmission match; this structure makes the electric drive system compact as a whole and occupies a small space when used. The inner ring 19 of the hollow structure can transmit a large torque and is used to install some components, so that the structure of the clutch and the speed change mechanism is deeply optimized, forming partial or full inclusion and high integration, and the cooperation is smooth and natural, and there is no operation interference, which ensures that the speed change mechanism works efficiently under all working conditions and comprehensive road conditions.

[0054] As shown in the figure, the first bracket is outward (such as Figure 1 The left side as shown, that is, the outer side relative to the clutch) extends to form a first sleeve section, the second bracket extends to the other outer side (the right side as shown in the figure) to form a second sleeve section, the transmission sleeve 6 rotates and fits on the low-speed gear transmission sleeve 4, the first sleeve section rotates and fits on the transmission sleeve 6, and the low-speed gear intermediate driving gear 5 is transmission-fitted on the first sleeve section. As shown in the figure, the inner ring 19 is necked to form an inner ring sleeve and cooperates with the transmission sleeve 6 through a first axial cam pair 601. The inner ring sleeve and the transmission sleeve 6 are rotated and fitted together to fit on the low-speed gear transmission sleeve 4. In the above structure, each sleeve is sequentially sleeved, and is rotationally fitted or transmission-fitted as needed. It has good support stability, and the structure is simple and compact. It can be achieved through a simple mechanical connection, which will not be repeated here.

[0055] The second sleeve section is rotatably supported on the main shaft 1 and the housing. Figure 1As shown, the second shaft sleeve section extends to the right (based on the left and right of the structure shown in the figure) to form a set shape, and a stepped necking structure is formed between the axial direction and the second bracket 20a. The set position of the outer circle is supported on the box body through a bearing (not marked in the figure), and the set position of the inner circle is supported on the main shaft 1. Of course, the method of supporting the main shaft 1 generally needs to be implemented through an intermediate piece. As shown in the figure, the inner circle is supported on the main shaft 1 through a bearing and a bearing support 11 (the bearing support 11 also serves as the support base of the second elastic member) to form a supporting structure. The overall structure is stable and will not be repeated here. The structure of the bearing support 11 is adaptively manufactured according to the structures of the main shaft 1, the second shaft sleeve section and other components. The bearing support 1 and the main shaft 1 are circumferentially spaced. It can be fixed, for example, by a spline structure, to form a stable support, which will not be elaborated here; at the same time, parts of the first bracket and the second bracket are made into a sleeve structure, and finally the main box body and the power output shaft form direct and indirect support, and the additional bending moment generated by the torque is transmitted to the box body, which can transmit a large torque without bending deformation, and can greatly reduce the size of the component under the same load-bearing capacity conditions, and adapt to the hollow structure of the clutch; it achieves high torque, high speed and lightweight indicators, and also makes the speed change mechanism have better stability and low noise at high speed; this structure ensures the compactness of the overall structure of the drive system itself, which is conducive to the realization of the overall lightweight layout of the drive system.

[0056] In this embodiment, the low-speed gear transmission sleeve 4 extends to the inside of the inner ring 19 to form an inner extension section, and a protrusion 16 is provided on the outer surface of the inner extension section. The first elastic member 10 and the second elastic member 18 are respectively set with preload and are arranged on both axial sides of the protrusion; as shown in the figure, the protrusion 16 is an annular protrusion, which is used to separate the first elastic member 10 and the second elastic member 18. One end of the first elastic member presses against the annular protrusion, and the other end presses against the preload limiting shoulder formed by the necking of the inner ring. One end of the second elastic member presses against the annular protrusion, and the other end presses against a retaining ring outermost disposed on the main shaft. The retaining ring presses against the bearing support 11, which is a general structure in the mechanical field to form a complete speed change elastic mechanism.

[0057] In this embodiment, the first elastic member 10 and the second elastic member 18 are respectively the first speed disc spring and the second speed disc spring. The first speed disc spring is sleeved on the inner extension section of the transmission shaft sleeve, and the second speed disc spring is also sleeved on the inner extension section of the transmission shaft sleeve. Of course, the inner extension section can also end with a radial protrusion 16, and the second speed disc spring directly resists the radial protrusion 16, which will not be repeated here; the inner circle of the inner ring 19 is provided with an inwardly protruding limiting shoulder, and the limiting shoulder is used to block the radial protrusion on the outer surface of the inner extension section at a set position toward the direction of the first elastic member; as shown in the figure, the limiting shoulder forms a radially inward step for blocking the annular protrusion to ensure that the first elastic member 10 is limited in bearing the pressure of the second elastic member 18, and the preload force of the second elastic member can be conveniently set, and the preload force can be applied in a step-by-step manner while smoothly releasing the axial preload force when the driving resistance reaches the set value.

[0058] As shown in the figure, the low-speed gear transmission mechanism also includes a low-speed gear intermediate driving gear 5, a low-speed gear intermediate driven gear 9 and a low-speed gear driven gear 2; the outer ring of the friction plate clutch is in transmission cooperation with the low-speed gear intermediate driving gear 5, the low-speed gear intermediate driving gear 5 is meshed with the low-speed gear intermediate driven gear 9, the low-speed gear intermediate driven gear 9 is arranged on the low-speed gear shaft 7 in transmission cooperation, the inner ring of the overrunning clutch is in transmission cooperation with the low-speed gear shaft, the outer ring of the overrunning clutch 8 is used as the low-speed gear driving gear and is in transmission meshing with the low-speed gear driven gear 2, of course, the outer ring is an outer gear ring structure, which is not repeated here; the low-speed gear driven gear 2 is in transmission cooperation with the low-speed gear transmission shaft sleeve 4 (this embodiment is sleeve-connected and transmission cooperation), the overall structure is simple and compact, and the transmission route is clear and clear; the transmission cooperation between the above-mentioned gears and shafts can be achieved through a general transmission cooperation structure, such as key connection, integral forming, etc., which is not repeated here;

[0059] According to this structure, it can be concluded that the position setting of the overrunning clutch can be arbitrarily selected in the low-speed gear mechanism, for example, as the low-speed gear intermediate driving gear 5, the low-speed gear intermediate driven gear 9 and the low-speed gear driven gear 2, all of which can achieve the purpose of the invention, and will not be repeated here;

[0060] As shown in the figure, the active power output member 3 is sleeved on the transmission sleeve 6 and is located near the middle of the inner side of the low-speed driven gear 2, so that the present invention can be a mid-mounted structure output; the active power output member 3 forms a power output sleeve for receiving the output power of the transmission sleeve 6 and transmitting it to the active power output member 3, and the power output sleeve is sleeved on the transmission sleeve 6 in a transmission matching manner, and the two ends correspond to the box body to form a rotation support;

[0061] Different from the existing power output connection transmission, in this structure, a power output sleeve is used to output power to the sprocket. It has the required set length in the axial direction and the inner circle is supported on the transmission sleeve 6. The support is uniform and stable. The outer circle is supported on the box body, and cooperates with the inner circle of the transmission sleeve 6 to form a stable support from both inside and outside. Theoretically, it can be infinitely increased in the axial direction, so that the installation of the sprocket is stable, avoiding the occurrence of running clearance, ensuring the transmission efficiency while ensuring the installation support strength.

[0062] In the present invention, in addition to the bearing support, in order to ensure the compactness of the structure and the stability of the support, an oil channel or oil groove is set at the position of the direct rotational cooperation to reduce friction, which belongs to the general configuration in the field of mechanical transmission and will not be described in detail here;

[0063] An elastic preload is formed between adjacent active friction plates of the friction clutch through elastic pads; and an elastic clamp is used to axially limit the driven friction plate.

[0064] Structurally, the transmission shaft sleeve 6 is rotatably fitted onto the low-speed gear transmission shaft sleeve 4, the low-speed gear intermediate driving gear 5 is transmission-fitted or fixedly arranged on a low-speed intermediate driving gear shaft sleeve, the low-speed intermediate driving gear shaft sleeve and the first shaft sleeve section of the first bracket 20 are rotatably fitted onto the transmission shaft sleeve 6 together, and the various transmission shaft sleeves are rotatably fitted onto each other in layers, and the overall structure is compact and supports each other, so that the structure has good stability.

[0065] In this embodiment, an elastic preload is formed between adjacent active friction plates 14 of the friction plate clutch through an elastic pad 13. The elastic pad 13 is generally made of an elastic non-metallic material and has a set elasticity. As shown in the figure, the elastic pad is an annular pad, and the diameter of the circle where the support rods are distributed is smaller than the outer diameter of the annular pad and larger than the inner diameter of the annular pad, that is, the support rod needs to pass through the elastic pad. Figure 4As shown, the elastic pad 13 is an annular elastic rubber ring made of polyurethane material, and the annular elastic rubber ring is provided with a hole for the support column 17 to pass through, so as to ensure the installation stability of the elastic pad 13. The elastic pad 13 is arranged between adjacent active friction plates 14. When the active friction plate 14 is under pressure, it overcomes the elastic force of the elastic rubber ring and fits with the driven friction plate for transmission. When the pressure is released, the elasticity of the elastic rubber ring is used to make the active friction plate 14 return evenly and quickly to complete the shifting operation. At the same time, due to the arrangement of the elastic pad 13, each active friction plate is evenly stressed, and has synchronization when engaging and separating with the driven friction plate, so as to avoid that some friction plates are in a semi-friction state and affect the efficiency; because the annular area of ​​the elastic pad covers the support rod, the area of ​​the elastic pad acting on the active friction plate is increased, so as to ensure uniformity and the sensitivity of the clutch at the same time, and cooperate with the preload force structure of the double elastic element of the present invention, so as to further make the friction clutch more adaptable to the separation and engagement characteristics of the speed change mechanism of the present invention;

[0066] The driven friction plate 12 is axially limited by an elastic retaining ring 15. Figure 2 As shown, the cross-section of the elastic retaining ring 15 can be rectangular, circular, etc., and is installed in the installation groove corresponding to the inner ring 19 to limit the driven friction plate 12 to ensure that the movement of the inner ring 19 can drive the driven friction plate to move more flexibly and smoothly to complete the engagement and separation smoothly.

[0067] At the same time, the outer and inner ring loads of the clutch are made into a necked sleeve structure, and are ultimately supported by the housing and the main shaft (indirectly), transmitting the additional bending moment generated by the torque to the housing, which can transmit a large torque without bending deformation, greatly reducing the size of components under the same load-bearing capacity conditions, and adapting to the hollow structure of the clutch; achieving high torque, high speed and lightweight indicators, and also making the speed change mechanism have better stability and low noise at high speed; this structure ensures the compactness of the overall structure of the drive system itself, and is conducive to the overall lightweight layout of the drive system.

[0068] In this embodiment, the elastic force of the second speed-changing disc spring is equal to or greater than the elastic force of the first speed-changing disc spring, so as to ensure the pressing force on the first disc spring, thereby ensuring the normal operation of the system.

[0069] The above embodiments are only the best structures of the present invention and are not intended to limit the protection scope of the present invention. The schemes with some adjustments in the connection mode do not affect the realization of the purpose of the present invention.

[0070] The fast gear power transmission route of this embodiment is as follows:

[0071] Driving motor rotor → outer ring of friction clutch → inner ring of friction clutch → transmission sleeve → first axial cam pair → transmission sleeve → active power output member → output power;

[0072] At this time, the overrunning clutch overtakes, and the resistance transmission route is: active power output member → transmission sleeve → first axial cam pair → transmission sleeve → inner ring of friction clutch → first speed disc spring (which will also produce pressure on the second speed disc spring); when the driving resistance increases to a certain level, the resistance causes the axial force of the first axial cam pair to overcome the first speed disc spring (which will also produce pressure on the second speed disc spring) to move the inner ring of the friction clutch, thereby disengaging the friction clutch, and the power is transmitted through the following route, namely the low-speed gear power transmission route:

[0073] Driving motor rotor → outer ring of friction clutch → low-speed gear shaft → overrunning clutch → low-speed gear driven gear → low-speed transmission sleeve → second axial cam pair → middle part enters inner ring of friction clutch → transmission sleeve → first axial cam pair → active power output member → output power.

[0074] In the low-speed gear power transmission route, the axial force (driving resistance) generated by the first axial cam pair continues to act on the first speed disc spring, while the axial force (traction force) of the second axial cam pair acts on the second speed disc spring, and both are compressed (i.e. in the direction of clutch disengagement). That is, in the slow gear power transmission process, the slow gear traction force and driving resistance work together to prevent the compression of the speed disc spring from reciprocating compression during the low-speed gear transmission process, thereby preventing the clutch from repeatedly engaging during the slow gear power transmission process.

[0075] It can be seen from the above transmission route that when the present invention is in operation, the clutch is tightly fitted under the action of the first and second speed change disc springs to form an automatic speed change mechanism that maintains a certain pressure, thereby achieving the transmission purpose. At this time, the overrunning clutch is in an overrunning state.

[0076] When the motor vehicle starts, the resistance is greater than the driving force, and the resistance forces the first axial cam pair to produce axial displacement, and the clutch is disengaged after the first axial cam pair compresses the first speed disc spring; the low-speed gear start is automatically realized, the starting time is shortened, and the starting force is reduced. At the same time, the second speed disc spring is compressed based on the above principle. At the same time, the first speed disc spring and the second speed disc spring absorb the energy of the motion resistance torque to store potential energy for restoring the power transmission of the fast gear.

[0077] After successful starting, the driving resistance is reduced. When the axial component force is reduced to a pressure less than the pressure generated by the first speed disc spring (the second speed disc spring is under pressure at the same time), the pressure of the speed disc spring generated by the compression of the motion resistance is released. The first speed disc spring compresses and pushes the inner ring to complete the clutch's restoration to a tight fit state, and the low-speed overtaking clutch is in an overtaking state.

[0078] During driving, the principle of automatic gear shifting follows the change of movement resistance in the same manner as above, and gear shifting can be achieved without cutting off the driving force, making the entire locomotive run smoothly, safely and with low consumption. The transmission route is also simplified, thus improving transmission efficiency. Of course, at this time, the reverse gear overtaking clutch overtakes and does not interfere with normal driving.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A central friction dual-force adaptive speed-changing electric drive system, characterized in that: It includes a box, a driving motor and a speed changing system; The speed change system includes a main shaft, a main transmission mechanism and a low-speed gear transmission mechanism; the main transmission mechanism includes a friction clutch and a transmission sleeve, the drive motor inputs power to the active part of the friction clutch, the driven part of the friction clutch transmits power to the transmission sleeve, and the transmission sleeve outputs power through a power output active part; The driven member of the friction clutch and the transmission sleeve or / and the transmission sleeve itself form a transmission through at least one first axial cam pair; The friction clutch is set to an axial preload force to engage it. When the transmission sleeve outputs power, the first axial cam pair generates an axial component force while transmitting the power. The axial component force is opposite to the axial preload force and has a tendency to overcome the axial preload force to release the friction clutch. The low-speed gear transmission mechanism overtakes when the main transmission mechanism is transmitting; the drive motor simultaneously transmits power to the low-speed gear transmission mechanism, and the low-speed gear transmission mechanism transmits the low-speed gear power to the follower of the friction clutch through the second axial cam pair, and the part of the follower of the friction clutch for receiving the low-speed gear power is located near the axial middle of the follower.

2. The centrally mounted friction dual-force adaptive speed-changing electric drive system according to claim 1 is characterized in that: The low-speed gear transmission mechanism includes a low-speed gear shaft and an overrunning clutch arranged on the low-speed gear shaft, and also includes a low-speed gear transmission sleeve for transmitting power from the low-speed gear shaft to the driven member of the friction clutch, and the low-speed gear transmission sleeve is provided with at least one second axial cam pair.

3. The centrally mounted friction dual-force adaptive speed-changing electric drive system according to claim 1 is characterized in that: The axial preload is applied by an elastic member, which includes a first elastic member and a second elastic member. The first elastic member applies the axial preload to the friction clutch, and the second elastic member applies a preload to the low-speed gear transmission sleeve. At the same time, the preload acts on the first elastic member as a basis for applying the preload of the first elastic member. The position where the low-speed gear transmission sleeve transmits power to the driven member of the friction plate clutch is located between the first elastic member and the second elastic member.

4. The centrally mounted friction dual-force adaptive speed-changing electric drive system according to claim 3 is characterized in that: The friction clutch is a friction plate clutch, the active part of the friction plate clutch includes an outer ring and an active friction plate, and the driven part includes an inner ring and a driven friction plate; The outer ring includes a first bracket, a second bracket and a support column, the support column is multiple and distributed in the circumferential direction and fixedly connected between the first bracket and the second bracket, and the active friction plate is passed through the support column; The inner ring is a hollow cylindrical structure; the first elastic member and the second elastic member are located in the hollow of the inner ring; The rotor of the driving motor is a hollow structure, the friction plate clutch is located inside the hollow structure of the rotor, and the first bracket and the second bracket are respectively fixedly connected to the two axial ends of the rotor to form a transmission fit.

5. The central friction dual-force adaptive speed-changing electric drive system according to claim 3 is characterized in that: The low-speed gear transmission sleeve extends to the inside of the inner ring to form an inner extension section, and a radial protrusion is provided on the outer surface of the inner extension section. The first elastic member and the second elastic member are respectively set with preload forces and are arranged on both axial sides of the radial protrusion.

6. The central friction dual-force adaptive speed-changing electric drive system according to claim 5 is characterized in that: The first elastic member and the second elastic member are respectively the first speed change disc spring and the second speed change disc spring, and the first speed change disc spring and the second speed change disc spring are outer-circled on the inner extension section of the transmission shaft sleeve; the inner circle of the inner ring is provided with an inwardly protruding limiting boss, and the limiting boss is used to block the radial protrusion of the outer surface of the inner extension section at a set position toward the direction of the first elastic member.

7. The centrally mounted friction dual-force adaptive speed-changing electric drive system according to claim 3 is characterized in that: The low-speed gear transmission mechanism also includes a low-speed gear intermediate driving gear, a low-speed gear intermediate driven gear and a low-speed gear driven gear; the outer ring of the friction plate clutch is in transmission cooperation with the low-speed gear intermediate driving gear, the low-speed gear intermediate driving gear is meshed with the low-speed gear intermediate driven gear, the low-speed gear intermediate driven gear is transmission-coordinated and arranged on the low-speed gear shaft, the inner ring of the overrunning clutch is in transmission cooperation with the low-speed gear shaft, and the outer ring of the overrunning clutch serves as the low-speed gear driving gear and is in transmission cooperation with the low-speed gear transmission shaft sleeve through the low-speed gear driven gear.

8. The central friction dual-force adaptive speed-changing electric drive system according to claim 2 is characterized in that: The transmission sleeve is rotatably fitted onto the low-speed gear transmission sleeve; the power output active part is integrally formed or transmission-fitted to form a power output sleeve, the power output sleeve is transmission-fitted onto the transmission sleeve, and the outer circle is rotationally supported on the box body through a bearing, and the first bracket is axially outwardly necked and rotationally fitted onto the transmission sleeve; The second bracket extends outward in the axial direction to form a second shaft sleeve section, and the second shaft sleeve section is rotatably supported by the main shaft and the box body.

9. The centrally mounted friction dual-force adaptive speed-changing electric drive system according to claim 7 is characterized in that: An elastic preload is formed between adjacent active friction plates of the friction plate clutch through elastic pads; the driven friction plates are axially limited by elastic clips, and an elastic preload is also formed between the driven friction plates through second elastic pads; the elastic force of the second speed change disc spring is equal to or greater than the elastic force of the first speed change disc spring.

10. The central friction dual-force adaptive speed-changing electric drive system according to claim 9 is characterized in that: The elastic pad is an annular pad, and the diameter of the circle where the support rods are distributed is smaller than the outer diameter of the annular pad and larger than the inner diameter of the annular pad.

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