Double-motor stepless speed change electric drive system

Abstract

The invention relates to the technical field of transmission, in particular to a double-motor stepless speed change electric drive system. The double-motor stepless speed change electric drive system comprises a first motor, a second motor, a planetary gear train, a pedal crankshaft, a sun wheel overrun clutch and a gear ring overrun clutch. The sun gear and / or the gear ring are / is set as power input, and the planet carrier is set as power output; a rotor of the first motor can be connected with the sun gear, and a rotor of the second motor can be connected with the gear ring through the gear ring overrunning clutch. The gear ring is locked by the gear ring overrun clutch and can only rotate in the forward direction. The pedal crank shaft is connected with the sun gear through the sun gear overrun clutch so that torque can only be transmitted from the pedal crank shaft to the sun gear. Therefore, the double motors can cooperate with the planetary gear train to jointly meet the speed change requirement.

Description

Technical Field

[0001] The present invention relates to the field of transmission technology, and in particular to a dual-motor continuously variable speed electric drive system. Background Art

[0002] Electric bicycles, also known as hybrid bicycles or ebikes, are more and more popular in the market in recent years because they combine the characteristics of bicycle sports and leisure and are easy and labor-saving. Most of the existing electric drive systems of electric power-assisted bicycles can only provide power, and the riding speed is adjusted through the speed change system on the bicycle. The speed change function of the products of a few manufacturers is to achieve the step-by-step speed adjustment of the electric drive system through the traditional gear shifting technology.

[0003] The electric drive systems of most electric bicycles on the market include separate motors and speed change mechanisms, and their speed change methods are single and cannot meet the needs of more usage scenarios. Summary of the invention

[0004] The objectives of the present invention include, for example, providing a dual-motor continuously variable electric drive system that can use dual motors in conjunction with a planetary gear system to jointly meet speed change requirements.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] In a first aspect, the present invention provides a dual-motor continuously variable speed electric drive system, comprising:

[0007] A first motor, a second motor, a planetary gear train, a pedal crankshaft, a sun gear overrunning clutch, and a ring gear overrunning clutch;

[0008] The planetary gear train comprises planetary gears, a sun gear, a ring gear, and a planet carrier; the planetary gears are circumferentially arranged around the sun gear, and the planetary gears are meshed with the sun gear and the ring gear respectively; and the sun gear and / or the ring gear are configured as power input, and the planet carrier is configured as power output;

[0009] The rotor of the first motor can be connected to the sun gear, and the rotor of the second motor can be connected to the ring gear through the ring gear overrunning clutch;

[0010] The pedal crankshaft is connected to the sun gear through the sun gear overrunning clutch, so that when torque is input from the pedal crankshaft, the sun gear overrunning clutch drives the sun gear to rotate synchronously, and when torque is input from the sun gear, the sun gear overrunning clutch idles, and the torque is not transmitted to the pedal crankshaft;

[0011] The ring gear overrunning clutch is configured such that when the second motor inputs torque, the ring gear overrunning clutch drives the ring gear to rotate synchronously, and when torque is input from the ring gear, the ring gear overrunning clutch idles and the torque is not transmitted to the second motor;

[0012] When the superimposed torque of the first motor and the pedal crankshaft at the sun gear is greater than the torque output by the second motor to the ring gear, the ring gear is decelerated until it is locked by the ring gear overrunning clutch;

[0013] When the superimposed torque of the first motor and the pedal crankshaft at the sun gear is less than or equal to the torque output by the second motor to the ring gear, the rotational speeds of the first motor and the second motor can be superimposed, and the rotational speed ratio between the pedal crankshaft and the planetary carrier can be continuously variable.

[0014] In an optional embodiment, the ring gear overrunning clutch is arranged on the ring gear or the rotor of the second motor.

[0015] In an optional embodiment, it also includes a first motor input gear and a second motor input gear; the rotor of the first motor is connected to the first motor input gear, and the first motor input gear can be connected to the sun gear; the rotor of the second motor is connected to the second motor input gear; the second motor input gear can be connected to the ring gear.

[0016] In an optional embodiment, it further includes a first motor idler gear and a second motor idler gear; the first motor input gear is connected to the sun gear via the first motor idler gear; and the second motor input gear can be connected to the ring gear via the second motor idler gear.

[0017] In an optional embodiment, the first motor idler wheel and the second motor idler wheel can be coaxially arranged.

[0018] In an optional embodiment, the ring gear overrunning clutch is arranged on the second motor idler gear.

[0019] In an optional embodiment, the planetary gear train and the pedal crank shaft are kept coaxially arranged.

[0020] In an optional embodiment, the pedal crank shaft passes through the center of the planetary carrier.

[0021] In an optional embodiment, the sun gear overrunning clutch and the planetary gear train are both mounted on the pedal crankshaft.

[0022] In an optional embodiment, the first motor and the second motor are arranged symmetrically.

[0023] The beneficial effects of the embodiments of the present invention include, for example:

[0024] The dual-motor continuously variable electric drive system of this scheme includes a first motor, a second motor, a planetary gear system, a pedal crankshaft, a sun gear overrunning clutch, and a ring gear overrunning clutch. The pedal crankshaft and the sun gear of the speed-changing planetary gear system transmit motion and torque through the sun gear overrunning clutch, and the torque can only be transmitted from the pedal crankshaft to the sun gear. The ring gear is locked by the ring gear overrunning clutch, and the ring gear can only rotate in one direction. The torque of the first motor can be superimposed on the torque of the pedal crankshaft. Specifically, when the sum of the superimposed torques of the first motor and the pedal crankshaft after the planetary gear system is greater than the torque of the second motor after the planetary gear system, the ring gear is decelerated until it is locked by the ring gear overrunning clutch. When the sum of the superimposed torques of the first motor and the pedal crankshaft after the planetary gear system is less than or equal to the torque of the second motor after the planetary gear system, the speeds of the first motor and the second motor can be superimposed, and the speed ratio between the output shafts of the pedal crankshaft can achieve stepless speed change. In this way, the dual-motor continuously variable electric drive system can achieve continuously variable speed, and such a system has the advantages of simple structure, easy use and convenient operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 This is a schematic structural diagram of a dual-motor continuously variable speed electric drive system according to a first embodiment of the present invention;

[0027] Figure 2 Schematic diagram of the structure of a dual-motor continuously variable speed electric drive system according to a second embodiment of the present invention;

[0028] Figure 3 Schematic diagram of the structure of a dual-motor continuously variable electric drive system according to embodiment 3 of the present invention.

[0029] Icons: 110 - first motor; 120 - second motor; 200 - planetary gear train; 210 - planetary gear; 220 - sun gear; 230 - ring gear; 240 - planet carrier; 300 - pedal crankshaft; 400 - sun gear overrunning clutch; 500 - ring gear overrunning clutch; 710 - first motor input gear; 720 - second motor input gear; 810 - first motor idler; 820 - second motor idler. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0033] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0035] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0036] Embodiment 1

[0037] Please refer to Figure 1 The present embodiment provides a dual-motor continuously variable electric drive system, including a first motor 110, a second motor 120, a planetary gear train 200, a pedal crankshaft 300, a sun gear overrunning clutch 400, and a ring gear overrunning clutch 500.

[0038] The planetary gear train 200 includes a planetary gear 210, a sun gear 220, a ring gear 230, and a planet carrier 240; the planetary gear 210 is circumferentially arranged around the sun gear 220, and the planetary gear 210 is meshed with the sun gear 220 and the ring gear 230 respectively; and the sun gear 220 and / or the ring gear 230 are configured as power input, and the planet carrier 240 is configured as power output;

[0039] The rotor of the first motor 110 can be connected to the sun gear 220 , and the rotor of the second motor 120 can be connected to the ring gear 230 via the ring gear overrunning clutch 500 ;

[0040] The pedal crankshaft 300 is connected to the sun gear 220 through the sun gear overrunning clutch 400, so that when the torque is input from the pedal crankshaft 300, the sun gear overrunning clutch 400 drives the sun gear 220 to rotate synchronously, and when the torque is input from the sun gear 220, the sun gear overrunning clutch 400 idles, and the torque is not transmitted to the pedal crankshaft 300;

[0041] The ring gear overrunning clutch 500 is configured such that when the second motor 120 inputs torque, the ring gear overrunning clutch 500 drives the ring gear 230 to rotate synchronously, and when the torque is input from the ring gear 230, the ring gear overrunning clutch 500 idles, and the torque is not transmitted to the second motor 120;

[0042] When the superimposed torque of the first motor 110 and the pedal crankshaft 300 at the sun gear 220 is greater than the torque output from the second motor 120 to the ring gear 230 , the ring gear 230 is decelerated until it is locked by the ring gear overrunning clutch 500 ;

[0043] When the superimposed torque of the first motor 110 and the pedal crankshaft 300 at the sun gear 220 is less than or equal to the torque output by the second motor 120 to the ring gear 230, the rotational speeds of the first motor 110 and the second motor 120 can be superimposed, and the rotational speed ratio between the pedal crankshaft 300 and the planetary carrier 240 can be continuously variable.

[0044] The dual-motor continuously variable electric drive system of this solution includes a first motor 110, a second motor 120, a planetary gear train 200, a pedal crankshaft 300, a sun gear overrunning clutch 400, and a ring gear overrunning clutch 500. The pedal crankshaft 300 and the sun gear 220 of the speed-changing planetary gear train 200 transmit motion and torque through the sun gear overrunning clutch 400, and the torque can only be transmitted from the pedal crankshaft 300 to the sun gear 220. The ring gear 230 is locked by the ring gear overrunning clutch 500, and the ring gear 230 can only rotate in one direction. The torque of the first motor 110 torque can be superimposed on the pedal crankshaft torque. Specifically, when the sum of the superimposed torques of the first motor 110 and the pedal crankshaft after the planetary gear train 200 is less than or equal to the torque of the second motor 120 after the planetary gear train 200, the rotation speeds of the first motor 110 and the second motor 120 can be superimposed, and the rotation speed ratio between the output shafts of the pedal crankshaft 300 can achieve stepless speed change. In this way, the dual-motor continuously variable electric drive system can achieve continuously variable speed, and such a system has the advantages of simple structure, easy use and convenient operation.

[0045] In an optional embodiment, the ring gear overrunning clutch 500 is arranged on the ring gear 230 or the rotor of the second motor 120. Figure 1 It can also be seen that in this embodiment, the ring gear overrunning clutch 500 is arranged on the ring gear 230 .

[0046] In an optional embodiment, the sun gear overrunning clutch 400 and the planetary gear 210 are both sleeved on the pedal crankshaft 300. This can further reduce the space occupied by the speed change system.

[0047] In an optional embodiment, the first motor 110 and the second motor 120 are arranged symmetrically, which is helpful to ensure the stability of the dual-motor continuously variable electric drive system during operation.

[0048] In an optional embodiment, it also includes a first motor input gear 710 and a second motor input gear 720; the rotor of the first motor 110 is connected to the first motor input gear 710, and the first motor input gear 710 can be connected to the sun gear 220; the rotor of the second motor 120 is connected to the second motor input gear 720; the second motor input gear 720 can be connected to the ring gear 230.

[0049] In an optional embodiment, the dual-motor continuously variable electric drive system further includes a first motor idler 810 and a second motor idler 820; the first motor input gear 710 is connected to the sun gear 220 via the first motor idler 810; and the second motor input gear 720 can be connected to the ring gear 230 via the second motor idler 820. The first motor idler 810 and the second motor idler 820 are used to change the direction of the output torque of the motor input gear, thereby ensuring the stability and reliability of the entire system.

[0050] from Figure 1 It can also be seen that in this embodiment, the ring gear overrunning clutch 500 is arranged between the ring gear 230 and the second motor idler gear 820.

[0051] In an optional embodiment, the first motor idler gear 810 and the second motor idler gear 820 can be coaxially arranged.

[0052] In an optional embodiment, the planetary gear train 200, the pedal crankshaft 300, and the sun gear overrunning clutch 400 are coaxially arranged. Optionally, the pedal crankshaft 300 passes through the center of the planet carrier 240. The planet carrier 240 is sleeved on the pedal crankshaft 300, and the planet carrier 240 is not directly connected to the pedal crankshaft 300.

[0053] It should be noted that the pedal crankshaft 300 of the dual-motor continuously variable electric drive system can be superimposed with the torque of the first motor 110. The rotation speed of the pedal crankshaft 300 is directly proportional to the rotation speed of the first motor 110. During normal operation, the pedal crankshaft 300 can drive the rotor of the first motor 110 to rotate, but the first motor 110 cannot reversely drive the pedal crankshaft 300.

[0054] The ring gear 230 can only rotate in the forward direction. When the driving torque of the second motor 120 is insufficient to counteract the sum of the torques of the first motor 110 and the pedal crankshaft 300, the ring gear overrunning clutch 500 locks the ring gear 230 to prevent it from reversing.

[0055] The first motor 110 is connected to the sun gear 220 of the speed-changing planetary gear train 200 through a gear, and the second motor 120 is connected to the ring gear 230 of the speed-changing planetary gear train 200 through a gear. After the first motor 110 and the second motor 120 are coupled through the speed-changing gear row, stepless speed change between the pedal crankshaft 300 and the output shaft can be achieved. The output shaft (planet carrier 240) can reversely transmit power to the first motor 110 and the second motor 120 to achieve the power generation function.

[0056] It should be noted that, in other embodiments of the present invention, the first motor 110 and the second motor 120 may also be arranged in an asymmetric manner; further, the planetary gear system 200 and the pedal crankshaft 300 may also be arranged in a non-coaxial manner (specifically, the pedal crankshaft 300, the planetary carrier 240, and the sun gear overrunning clutch 400 may not be arranged on the same axis), and the planetary gear system 200 may not be mounted on the pedal crankshaft 300. This is just an example without specific limitation, as long as the dual-motor continuously variable electric drive system can achieve stable speed changes.

[0057] Embodiment 2

[0058] See also Figure 2 The scheme of this embodiment is substantially the same as that of the first embodiment, except that the dual-motor continuously variable speed electric drive system of this embodiment does not have the first motor idler gear 810 and the second motor idler gear 820, the first motor input gear 710 is directly meshed with the sun gear 220, and the second motor input gear 720 is connected to the ring gear 230 via the ring gear overrunning clutch 500. This further simplifies the speed change system.

[0059] Embodiment 3

[0060] See also Figure 3The scheme of this embodiment is substantially the same as that of the first embodiment, except that the ring gear overrunning clutch 500 of the dual-motor continuously variable electric drive system of this embodiment is not disposed between the ring gear 230 and the second motor idler 820, but the overrunning clutch is directly disposed on the second motor idler 820. This further simplifies the speed change system.

[0061] In summary, the embodiment of the present invention provides a dual-motor continuously variable speed electric drive system, which has at least the following advantages:

[0062] 1. Realize the stepless speed change function between the pedal crank shaft 300 and the output shaft;

[0063] 2. The output shaft can realize reverse driving capability, which can be used to recover energy during deceleration, reduce the braking load when going down a long slope, and generate electricity to replenish the battery, thereby extending the driving range.

[0064] 3. The planetary gear train 200 with the easy-to-process NGW configuration can greatly reduce the difficulty of manufacturing and processing, reduce the difficulty of assembly and installation, and obtain better cost advantages and better product quality.

[0065] 4. The application of the planetary gear train 200 makes the product design more compact and lighter.

[0066] 5. The use of the ring gear 230 clutch reduces the requirements on the motor, and a larger torque output can be obtained using a drive motor with a smaller torque.

[0067] 6. The first motor 110 can adopt a larger reduction ratio, and the second motor 120 can adopt a smaller reduction ratio. This can meet the vehicle's demand for large torque and high speed, and the motor speed is not too high.

[0068] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A dual-motor continuously variable speed electric drive system, characterized in that: include: A first motor (110), a second motor (120), a planetary gear train (200), a pedal crankshaft (300), a sun gear overrunning clutch (400), and a ring gear overrunning clutch (500); The planetary gear train (200) comprises a planetary gear (210), a sun gear (220), a ring gear (230), and a planet carrier (240); the planetary gear (210) is circumferentially arranged around the sun gear (220), and the planetary gear (210) is meshed with the sun gear (220) and the ring gear (230) respectively; and the sun gear (220) and / or the ring gear (230) are configured as power input, and the planet carrier (240) is configured as power output; The rotor of the first motor (110) can be connected to the sun gear (220), and the rotor of the second motor (120) can be connected to the ring gear (230) via the ring gear overrunning clutch (500); The pedal crankshaft (300) is connected to the sun gear (220) via the sun gear overrunning clutch (400), so that when torque is input from the pedal crankshaft (300), the sun gear overrunning clutch (400) drives the sun gear (220) to rotate synchronously, and when torque is input from the sun gear (220), the sun gear overrunning clutch (400) idles and the torque is not transmitted to the pedal crankshaft (300); The ring gear overrunning clutch (500) is configured such that when the second motor (120) inputs torque, the ring gear overrunning clutch (500) drives the ring gear (230) to rotate synchronously, and when torque is input from the ring gear (230), the ring gear overrunning clutch (500) idles and the torque is not transmitted to the second motor (120); When the superimposed torque of the first motor (110) and the pedal crankshaft (300) at the sun gear (220) is greater than the torque output by the second motor (120) to the ring gear (230), the ring gear (230) is decelerated until it is locked by the ring gear overrunning clutch (500); When the superimposed torque of the first motor (110) and the pedal crankshaft (300) at the sun gear (220) is less than or equal to the torque output by the second motor (120) to the ring gear (230), the rotational speeds of the first motor (110) and the second motor (120) can be superimposed, and the rotational speed ratio between the pedal crankshaft (300) and the planetary carrier (240) can be continuously variable.

2. The dual-motor continuously variable electric drive system according to claim 1, characterized in that: The ring gear overrunning clutch (500) is arranged on the ring gear (230) or the rotor of the second motor (120).

3. The dual-motor continuously variable electric drive system according to claim 1 is characterized in that: It also includes a first motor input gear (710) and a second motor input gear (720); the rotor of the first motor (110) is connected to the first motor input gear (710), and the first motor input gear (710) can be connected to the sun gear (220); the rotor of the second motor (120) is connected to the second motor input gear (720); the second motor input gear (720) can be connected to the ring gear (230).

4. The dual-motor continuously variable speed electric drive system according to claim 3 is characterized in that: It also includes a first motor idler gear (810) and a second motor idler gear (820); the first motor input gear (710) is connected to the sun gear (220) via the first motor idler gear (810); and the second motor input gear (720) can be connected to the ring gear (230) via the second motor idler gear (820).

5. The dual-motor continuously variable speed electric drive system according to claim 4 is characterized in that: The first motor idler wheel (810) and the second motor idler wheel (820) can be coaxially arranged.

6. The dual-motor continuously variable speed electric drive system according to claim 4, characterized in that: The ring gear overrunning clutch (500) is arranged on the second motor idler gear (820).

7. The dual-motor continuously variable electric drive system according to claim 1, characterized in that: The planetary gear train (200) and the pedal crankshaft (300) are coaxially arranged.

8. The dual-motor continuously variable speed electric drive system according to claim 1, characterized in that: The pedal crankshaft (300) passes through the center of the planet carrier (240).

9. The dual-motor continuously variable speed electric drive system according to claim 1, characterized in that: The sun gear overrunning clutch (400) and the planetary gear (210) are both sleeved on the pedal crankshaft (300).

10. The dual-motor continuously variable speed electric drive system according to claim 1, characterized in that: The first motor (110) and the second motor (120) are arranged symmetrically.

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