DESC:TECHNICAL FIELD
The present disclosure relates to mechanical engineering. More particularly, the present disclosure relates to drive system and method for electric mobility.
BACKGROUND
The increasing demand for electric mobility has led to remarkable advancements in drive systems for electric vehicles, which seek to improve their overall performance, efficiency, and control. Two-wheel electric vehicles, specifically motorcycles and electric scooters, require specialized drive systems that can effectively transmit power to the wheels while maintaining a lightweight and compact design.
However, traditional drive systems used in electric mobility face certain limitations. These systems often incorporate complex configurations, involving multiple gears, shafts, and clutches, which contribute to increased weight and reduced efficiency. The intricate nature of these systems adds manufacturing complexity, maintenance challenges, and cost implications.
Furthermore, achieving optimal gear ratios for acceleration and deceleration poses a significant challenge in traditional drive systems. The selection and engagement of appropriate gears to deliver the required torque and speed during various riding conditions are complex and time-consuming processes. This can result in suboptimal performance and compromised efficiency.
There is a need for a technology that addresses the aforementioned limitations such as complex configurations, leading to increased weight, reduced efficiency, achieving optimal gear ratios for acceleration and deceleration.
SUMMARY
In one aspect of the present disclosure, a drive system for electric mobility is provided.
The drive system includes a housing fixed to a wheel of an electric mobility. The drive system further includes first, and second motors mounted within the housing, wherein the first and second motors are circumferential flux permanent magnet (CFPM) motors. The drive system further includes a transmission disposed between the first and second motors. The drive system further includes a differential unit coupled to the transmission. The drive system further includes the first motor comprising a stator having an excitation coil and a rotor having permanent magnets spaced apart along its outer peripheral surface, wherein the rotor further comprises a gear along its inner peripheral surface and the second motor comprising a stator having permanent magnets and a rotor having an excitation coil, wherein the rotor further comprises a plurality of permanent magnets spaced apart along its inner peripheral surface and a gear along its outer peripheral surface, the transmission comprising a carrier coupled to a differential unit housing and planetary gears engaged with the gears of the first and second motors, wherein rotation of the first or second motor causes the planetary gears to rotate, thereby rotating the carrier, wherein the first and/or second motors are selectively or simultaneously operated under the control of a controller to enable accelerating and decelerating with changes of gear ratios, and wherein the differential unit applies power to wheels mounted on both ends of a drive shaft according to the operations of the first and second motors.
In some aspects of the present disclosure, the drive system further includes a one-way bearing coupled to the rotor of the first motor, wherein the one-way bearing prevents reverse rotation of the first motor when the second motor operates.
In some aspects of the present disclosure, the carrier is coupled to a wheel of a two-wheel electric mobility.
In some aspects of the present disclosure, the first and second motors are controlled by the controller according to a driver's control.

BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, show certain aspects of the subject matter disclosed herein and, together with the description, help explain some of the principles associated with the disclosed implementations. In the drawing,
Figure 1 illustrates a drive system for electric mobility, in accordance with an aspect of the present disclosure;
Figures 2, 3 & 4 are a longitudinal sectional view depicting a coupling relation between a transmission and a first motor of the drive of figure 1 in accordance with an aspect of the present disclosure;
Figure 5 is an exemplary view depicting a state in which a carrier of the drive system, in accordance with an aspect of the present disclosure; and
Figure 6 is a sectional view depicting a one-way bearing coupled to the ring gear of the rotor of a first motor, in accordance with an aspect of the present disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Various embodiments of the disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure. Thus, the following description and drawings are illustrative and are not to be construed as limiting. Numerous specific details are described to provide a thorough understanding of the disclosure. However, in certain instances, known details are not described in order to avoid obscuring the description.
References to one or an embodiment in the present disclosure can be references to the same embodiment or any embodiment; and, such references mean at least one of the embodiments.
Reference to "one embodiment", "an embodiment", “one aspect”, “some aspects”, “an aspect” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others.
The terms used in this specification generally have their ordinary meanings in the art, within the context of the disclosure, and in the specific context where each term is used. Alternative language and synonyms may be used for any one or more of the terms discussed herein, and no special significance should be placed upon whether or not a term is elaborated or discussed herein. In some cases, synonyms for certain terms are provided.
A recital of one or more synonyms does not exclude the use of other synonyms.
The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and is not intended to further limit the scope and meaning of the disclosure or of any example term. Likewise, the disclosure is not limited to various embodiments given in this specification. Without intent to limit the scope of the disclosure, examples of instruments, apparatus, methods and their related results according to the embodiments of the present disclosure are given below. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the disclosure. Unless otherwise defined, technical and scientific terms used herein have the meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In the case of conflict, the present document, including definitions will control.
Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or can be learned by practice of the herein disclosed principles. The features and advantages of the disclosure can be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the disclosure will become more fully apparent from the following description and appended claims, or can be learned by the practice of the principles set forth herein.
As mentioned before, there is a need for technology that overcomes these drawbacks, such as complex configurations, leading to increased weight, reduced efficiency, achieving optimal gear ratios for acceleration and deceleration. The present disclosure therefore provides a drive system for electric mobility offers a lightweight, efficient, and compact design tailored specifically for two-wheel vehicles. The drive system of present disclosure leverages CFPM motors, a transmission with variable gear ratios, and a differential unit to deliver optimal performance and control. The drive system also has the potential to significantly enhance the electric mobility landscape by improving efficiency, range, and overall driving experience for two-wheel electric vehicles.
Figure 1 illustrates a drive system for electric mobility 100, in accordance with an aspect of the present disclosure. Figure 2 is a longitudinal sectional view depicting a coupling relation between the transmission 230 and the first motor 210 of the drive 100 of figure 1 in accordance with an aspect of the present disclosure. The drive system 100 may include a housing 201 that may be fixed to a wheel of an electric mobility.
The drive system 100 may further include first and second motors 210 and 220, mounted within the housing 201. In some aspects of the present disclosure, the first and second motors 210 and 220 may be a circumferential flux permanent magnet (CFPM) motors. The said gears engage with planetary gears located on a carrier, which is part of the system that passes through the central drive shaft. Further enables the transmission of power from the motors to the drive shaft and, subsequently, to the differential gear.
The drive system 100 may further include a transmission 230 that is disposed between the first and second motors 210 and 220.
The drive system 100 may further include a differential unit 300 that may be coupled to the transmission 230.
The first motor 210 may include a stator having an excitation coil 211 and a rotor 210a that may have permanent magnets 212 spaced apart along the outer peripheral surface. The rotor 210a may further include a gear 213 along an inner peripheral surface.
The second motor 220 comprising a stator 220a having permanent magnets and a rotor 222 having an excitation coil 221.
The rotor 222 may further include a plurality of permanent magnets spaced apart along an inner peripheral surface and a gear 223 along an outer peripheral surface of the rotor 222.
The transmission 230 may include a carrier 231 that is coupled to a differential unit housing 301 and planetary gears 232 engaged with the gears 213 and 223 of the first and second motors 210 and 220.
In some aspects of the present disclosure, rotation of the first or second motor 210 and 220 may facilitates the planetary gears 232 to rotate, thereby rotating the carrier 231. In some aspects of the present disclosure, the carrier 231 may include a hole that facilitates to pass the drive shaft 303.
In some aspects of the present disclosure, the first and/or second motors 210 and 220 may be selectively or simultaneously operated under the control of a controller to enable accelerating and decelerating with changes of gear ratios.
In some aspects of the present disclosure, the differential unit 300 applies power to wheels mounted on both ends of a drive shaft 303 according to the operations of the first and second motors 210 and 220.
The drive system 100 may further include a one-way bearing 205 that may be coupled with the rotor 210a of the first motor 210. The one-way bearing 205 may prevents reverse rotation of the first motor 210 when the second motor 220 operates.
In some aspects of the present disclosure, the carrier 231 may be coupled with a wheel 310 of a two-wheel electric mobility.
In some aspects of the present disclosure, the first and second motors 210 and 220 may be controlled by the controller according to a driver's control.
In some aspects of the present disclosure, the first and second motors 210 and 220 may rotate in the same direction as each other during operation, and the second motor 220 can be controlled to rotate in a reverse direction while the first motor 210 can be controlled to rotate at a low speed in a forward direction under the control of the controller.
In some aspects of the present disclosure, the permanent magnets 212 may be spaced apart from one another at given intervals along the outer peripheral surface of the rotor 210a, and the gear 213 may be disposed along the inner peripheral surface of the rotor 210a as shown in figure 2.
In some aspects of the present disclosure, the second motor 220 is supported against the housing 201 by means of a bearing so that it can rotate on the drive shaft 303.
In some aspects of the present disclosure, the first and second motors 210 and 220 may selectively or simultaneously operate under the control of a controller (not shown) to allow the electric mobility to perform accelerating and decelerating with changes of gear ratios.
FIG. 5 is an exemplary view depicting a state in which a carrier of the drive system 100, in accordance with an aspect of the present disclosure.
The drive system 100 may be coupled with at least one wheel of two-wheel electric mobility, and as shown in Figure 5. The carrier 231 may be coupled to the corresponding wheel 310 of the two-wheel electric mobility (not shown).
FIG. 6 is a sectional view depicting a one-way bearing 205 coupled to the ring gear of the rotor 210a of the first motor 210, in accordance with an aspect of the present disclosure. The one-way bearing 205 may prevents the first motor 210 from rotating in a reverse direction when the second motor 220 operates.
In some aspects of the present disclosure, the ring gear of the rotor 210a of the first motor 210 may be disposed rotatably inside the housing 201 in one direction by way of the one-way bearing 205, such that the first motor 210 prevents from rotating in a reverse direction when the second motor 220 operates.
In FIG. 6 illustrates the drive system 100 that include a reference numeral 206 represents a ratchet wheel, a reference numeral 206a a ratchet, and a reference numeral 207 a pawl.
In some aspects of the present disclosure, rotary force may be transmitted only in one direction by way of the operation of the pawl, and the ratchet wheel does not transfer motion in the opposite direction.
In operation, when electric mobility starts, the drive 100 may start driving by way of the operation of the second motor 220. When electricity may be supplied to the second motor 220, the rotor may rotate to allow the carrier 231 to rotate around the drive shaft 303 by way of the planetary gears 232 engaged with the gear thereof and may further transfer the rotary force to the differential unit housing 301. As a result, the differential gear 302 rotates to allow the drive shaft 303 to rotate. Upon the electric mobility starts, the second motor 220 may drive faster by the control of the controller. And the speeds associated with the first motor and the second motor may be integral with the revolutions per minute of an output side, such that the planetary gears 232 may not operate.
In some aspects of the present disclosure, to facilitate speed reduction in driving, contrarily, the rotating speeds of the first motor 210 and the second motor 220 may be gradually reduced by way of the controller.
In some aspects of the present disclosure, the drive system 100 may be configured to operate the drive shaft 303 with the first and second motors 210 and 220 and the carrier 231 having the planetary gears 232, such that the drive 100 is simple in configuration and becomes lightweight, thereby being implementable for the two-wheel electric mobility.
The implementation set forth in the foregoing description does not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Although a few variations have been described in detail above, other modifications or additions are possible. Further features and/or variations can be provided in addition to those set forth herein. For example, the implementation described can be directed to various combinations and sub combinations of the disclosed features and/or combinations and sub combinations of the several further features disclosed above. In addition, the logic flows depicted in the accompany figures and/or described herein do not necessarily require the order shown, or sequential order, to achieve desirable results. Other implementations may be within the scope of the following claims. ,CLAIMS:1. A single shaft drive for electric mobility, comprising:
a housing (301) having a drive shaft (303) rotatably disposed therein by means of a differential gear (302) connected to the driving shaft (303);
a first motor (210) having a stator (211) fixed to the inside of the housing (301), a rotor (210a) rotatably coupled to the housing (301), and a gear (213) disposed on the inner periphery of the rotor (210a);
a second motor (220) coupled to the housing (301) to be thus rotatable on the drive shaft (303) and having a rotor (222) and a gear (223) disposed on the outer periphery of the rotor (222); and
a carrier (231) fixedly coupled to the housing (301), passing the drive shaft (303) therethrough, and having planetary gears (232) rotatably disposed between the gear (213) of the first motor (210) and the gear (223) of the second motor (220).
2. The single shaft drive for electric mobility as claimed in claim 1, wherein the carrier (231) is coupled to a wheel (310).

3. The single shaft drive for electric mobility as claimed in claim 1, further comprises a one-way bearing (205) mounted inside the housing (301) to prevent the first motor (210) from rotating reversely when the second motor (220) operates.

4. The single shaft drive for electric mobility as claimed in claim 1, wherein the first motor (210) and the second motor (220) are circumferential flux permanent magnet (CFPM) motors.

5. The single shaft drive for electric mobility as claimed in claim 1, wherein the planetary gears (232) engage with both the gear (213) of the first motor (210) and the gear (223) of the second motor (220) to provide a differential speed between the two motors, facilitating smooth transitions in speed and torque distribution.

6. The single shaft drive for electric mobility as claimed in claim 1, further comprising a controller configured to selectively adjust the operational parameters of the first motor (210) and the second motor (220) based on the velocity and torque requirements dictated by the electric mobility’s current operating conditions.

7. The single shaft drive for electric mobility as claimed in claim 1, wherein the one-way bearing (205) is configured to lock in one direction of rotation to facilitate a ratcheting function that prevents reverse motion of the first motor (210) under load reversals.