Electric machine and powertrain based on the electric machine

Abstract

The utility model discloses a kind of motor and power system based on the motor, protruding rib is set on the end plate of rotor, rotate using rotor to drive protruding rib, drive cooling lubricating oil to form forced circulation in air gap, not only significantly strengthen the heat transfer efficiency of rotor and stator, effectively control rotor temperature rise and permanent magnet demagnetization risk, simultaneously improve the lubrication condition of moving part, and avoid the energy consumption and complexity brought by additional oil pump;Through the integration design of motor shell and half gear box body, and the communication oil channel of sealing plate and gear box, shared lubrication system is constructed, cooling lubricating oil circulation sharing and heat dissipation cooperation are realized, both simplify overall structure and improve system reliability;Under the premise of basically not increasing volume and weight, synchronous realization of the comprehensive benefits of heat dissipation performance improvement, system structure simplification and manufacturing cost reduction, especially suitable for space limited, power density requirement high application scene.

Description

Technical Field

[0001] This utility model belongs to the technical field of motor cooling structure, specifically relating to a motor and a power system based on the motor. Background Technology

[0002] Electric motorcycles typically use permanent magnet synchronous motors as their power source. These motors generate heat during operation, and if heat is not dissipated in time, it can accumulate and potentially burn out the motor. The heat in a permanent magnet synchronous motor primarily comes from the stator. Therefore, existing motorcycle permanent magnet synchronous motors generally have heat sinks or water-cooling structures on the motor housing to dissipate the heat generated by the stator through heat conduction from the housing. However, during operation, the permanent magnets on the rotor also generate heat due to eddy currents induced by the high-frequency magnetic field. Although the heat generated is relatively less than that from the stator, the circumferential gap between the rotor and stator, and the limited ability of the cylindrical rotor to dissipate lubricating oil from the lower parts of the motor, can lead to overheating of the rotor due to difficulty in heat transfer to the stator and motor housing. This can easily cause demagnetization of the permanent magnets, resulting in decreased motor performance or even motor failure. Chinese patent CN210246487U discloses a built-in motor cooling device for electric motorcycles. This patent achieves the circulation and spraying of lubricating oil inside the motor through additional oil lines, oil pumps, and oil injectors. Although this can improve the heat exchange efficiency between the motor interior and the motor housing, thereby reducing the temperature of the stator and rotor, the structure is not only relatively complex, but also increases the overall energy consumption of the motor due to the presence of the oil pump, resulting in poor practicality. Therefore, it is necessary to improve the cooling and lubrication structure of the motor. Summary of the Invention

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of this utility model is to provide an electric motor and a power system based on the electric motor, to solve the technical problem of complex cooling and lubrication structures in existing electric motors, and to achieve the effect of improving the heat dissipation performance and stability of the electric motor.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The motor includes a rotor, which includes a motor shaft, an iron core, and an end plate. The motor shaft passes through the inner holes of the iron core and the end plate and is connected to rotate synchronously. The end plate is located on one axial side of the iron core, and the side of the end plate away from the iron core has a rib. The motor contains cooling and lubricating oil. When the rotor rotates, the rib rotates with the end plate, causing the cooling and lubricating oil to flow circumferentially.

[0005] Furthermore, the rib extends radially along the end plate and has a certain degree of bending or flexural range.

[0006] Furthermore, the rib extends from the inner hole of the end plate to the outer surface of the end plate.

[0007] Furthermore, the end plate has multiple raised ribs that are evenly distributed circumferentially.

[0008] Furthermore, weight-reducing holes are provided on the end plate.

[0009] Furthermore, the motor housing is equipped with heat dissipation fins or a water-cooling structure.

[0010] This utility model also includes a power system, which includes the motor as described above. The motor housing includes a cylindrical shell, and the stator and rotor of the motor are disposed inside the shell. One end of the shell is detachably connected to an end cover, and the other end is integrally formed with a sealing plate. A gearbox is provided on the side of the sealing plate away from the shell. Half of the gearbox is integrally formed on the side of the sealing plate away from the shell. A shaft hole communicating with the inner cavity of the gearbox is provided through the sealing plate. The motor shaft passes through the shaft hole and extends into the inner cavity of the gearbox and is connected to the gearbox for transmission.

[0011] Furthermore, the sealing plate has oil channels that communicate with the inner cavity of the motor and the inner cavity of the gearbox respectively. The motor is arranged horizontally, and in the vertical direction, the two ends of the oil channels are close to the bottom of the inner cavity of the motor and the bottom of the inner cavity of the gearbox respectively, so that the motor and the gearbox can exchange cooling lubricating oil through the oil channels.

[0012] Furthermore, the gearbox is equipped with multiple rotating gears to form a multi-stage transmission. The gears that serve as the input of the multi-stage transmission are synchronously connected to the motor shaft, and the shafts of the gears that serve as the output of the multi-stage transmission extend out of the gearbox. At least one gear inside the gearbox is vertically close to the bottom of the gearbox's inner cavity.

[0013] Furthermore, vertically, the bottom of the gearbox's inner cavity is a concave arc surface and concentric with the adjacent gears.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The motor described in this utility model innovatively transforms the end plate of the rotor into an impeller structure by setting protruding ribs. This allows the motor's own rotational power to drive the internal cooling and lubricating oil to form a circumferential circulation, overcoming the traditional difficulty in rotor heat dissipation. It enhances the efficiency of heat transfer from the rotor and stator to the outer casing, fundamentally suppressing rotor temperature rise and the risk of permanent magnet demagnetization, while significantly improving the lubrication conditions of the internal moving parts of the motor. The entire solution is an improvement on existing motors, eliminating the need for an additional oil pump or external circulation cooling system, thus reducing system complexity and cost. Furthermore, the integrated wheel structure and dynamic balancing weight-reduction structure effectively improve space utilization. This solution also eliminates complex oil circuits and control units, resulting in a simple, reliable, low-energy-consumption, and low-cost structure, which is beneficial for improving the motor's heat dissipation capacity, operational reliability, and service life.

[0015] 2. The power system described in this utility model achieves deep integration of the power system in terms of physical structure by designing the motor sealing plate and half of the gearbox as an integral molding structure. This eliminates the need for independent flanges, fasteners, and sealing structures required for the traditional connection between the motor and gearbox, simplifying the overall structure and reducing the number of parts and assembly steps. This not only effectively reduces manufacturing costs and weight, but more importantly, it eliminates the potential risk of cooling and lubricating oil leakage at the connection point, improving the structural rigidity, sealing reliability, and space compactness of the integrated motor and gearbox, providing a solid foundation for the miniaturization and high reliability design of the product.

[0016] 3. The power system described in this utility model connects the inner cavity of the motor and the inner cavity of the gearbox by setting a connecting oil passage on the sealing plate, thus constructing a shared lubrication and heat dissipation system. This system allows the motor and gearbox to automatically exchange and circulate shared cooling and lubricating oil, providing cooling and lubrication for the motor and meeting the lubrication and heat dissipation needs of the gearbox. It eliminates the complexity of designing separate lubrication systems for the motor and gearbox, and eliminates the rotary seal structure at the motor shaft extension, simplifying the structure, reducing manufacturing costs and failure rates. At the same time, it achieves synergy in thermal management between the two, allowing the heat inside the motor to be dissipated through the gearbox shell.

[0017] 4. The power system described in this utility model has internal cooling and lubricating oil that can increase the service life of the motor shaft sealing oil seal, prevent water damage due to seal failure during motor use, and significantly extend the service life of the motor bearings, thereby improving system reliability. Attached Figure Description

[0018] Figure 1 This is a perspective view of the power system described in the embodiment; Figure 2 for Figure 1 The 3D view shown has the sealing plate hidden. Figure 3 This is a perspective view of the end plate described in the embodiment; Figure 4 This is a perspective view of the sealing plate and half of the gearbox as described in the embodiment; Figure 5 This is a front view of the sealing plate and half of the gearbox housing as described in the embodiment; Figure 6 For along Figure 5 Schematic diagram of the cross section of AA; Among them, the motor shaft is 1, the iron core is 2, the end plate is 3, the rib is 4, the weight reduction hole is 5, the heat dissipation fins are 6, the housing is 7, the sealing plate is 8, the stator is 9, the box is 10, the shaft hole is 11, the oil channel is 12, the gear is 13, the mounting position is 14, and the concave arc surface is 15. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0020] Example: Please see Figure 1 , Figure 2 and Figure 3 The motor and its rotor include a motor shaft 1, an iron core 2, and an end plate 3. The motor shaft 1 passes through the inner holes of the iron core 2 and the end plate 3 and is synchronously connected. The end plate 3 is located on one axial side of the iron core 2, and the side of the end plate 3 away from the iron core 2 has a rib 4. The motor contains cooling and lubricating oil, which fills a certain space inside the motor. When the rotor rotates, the rib 4 rotates with the end plate 3, causing the cooling and lubricating oil to flow circumferentially. In this embodiment, there are two end plates 3, located on both axial sides of the iron core 2 respectively. The end plates are made of aluminum alloy. The motor is placed horizontally with the rotor axis in place, and when the rotor rotates, at least a portion of the rib 4 can contact the cooling oil at the bottom of the motor to achieve an oil-throwing effect. The side of the end plate 3 facing the iron core 2 has two protruding linkage columns, which fit into the recessed linkage holes on the iron core 2 so that the end plate 3 rotates synchronously with the motor shaft 1 and the iron core 2.

[0021] The motor described in this utility model has a raised rib 4 on the side of the end plate 3 away from the iron core 2. When the end plate 3 rotates with the motor shaft 1, the raised rib 4 enhances the oil throwing effect of the rotor, causing the cooling lubricating oil to form a forced circumferential flow in the annular gap between the rotor and the stator 9. This not only significantly improves the efficiency of heat transfer from the rotor and stator 9 to the motor housing, effectively preventing the rotor from overheating due to heat accumulation, thus preventing demagnetization of the permanent magnet, but also improves the lubrication effect of the internal moving parts of the motor and reduces wear. The end plate 3 is an existing component of the motor used to limit the axial position of the iron core 2 and the permanent magnet. The raised rib 4 on its non-working surface makes full use of the existing structure and the spare space in the existing motor. It does not change other original structures of the motor. The overall structure is simple and effective, and there is no need to set up complicated devices such as oil pumps, oil lines and oil injectors. It fundamentally simplifies the system and avoids the problem of increased energy consumption caused by oil pumps. Therefore, this utility model effectively solves the problems of complex and high energy consumption of existing motor cooling and lubrication structures with low cost and structural modifications, which is beneficial to improving the heat dissipation performance, operational reliability and service life of motors. The structure hardly increases the overall size and weight of the motor, and has the outstanding advantages of simple and reliable structure, low energy consumption, low cost and strong practicality. Moreover, it can be adapted to existing air-cooled or water-cooled motors with minimal modifications to improve their heat dissipation bottlenecks. It is especially suitable for application scenarios with high requirements for size, weight and power density, such as electric motorcycles.

[0022] Please see Figure 2 and Figure 3 The rib 4 extends radially along the end plate 3 and has a certain degree of bending or curvature. This design makes the rib 4 form a shape similar to an inclined blade on the end plate 3, which optimizes the dynamic performance of the rib 4 when in contact with the cooling lubricating oil. Specifically, this design reduces the angle between the surface of the rib 4 and the rotation direction of the end plate 3 (i.e., the tangent direction of the corresponding position on the outer circle of the end plate 3), so that the rib 4 can more smoothly and efficiently "catch" and throw out the cooling lubricating oil when rotating, thereby significantly improving the oil throwing ability and flow guiding efficiency. At the same time, the bent or folded rib 4 can guide the oil flow to impact the stator 9 or the internal space at a better angle, reducing the energy loss and impact noise caused by the turbulence and splashing of the cooling lubricating oil, and achieving a balance between cooling effect and smooth operation.

[0023] Please see Figure 2 and Figure 3 The rib 4 extends from the inner hole of the end plate 3 to the outer surface of the end plate 3. In this way, on the one hand, the contact and action area between the rib 4 and the cooling lubricating oil is increased to the maximum extent, so that the rib 4 can effectively push the cooling lubricating oil from the inner area near the motor shaft 1 to the outer edge of the end plate 3, thereby comprehensively enhancing the oil throwing ability and ensuring that the cooling lubricating oil can be delivered to a farther area. On the other hand, this structure acts like a reinforcing rib, improving the structural strength and rigidity of the rib 4 itself and the end plate 3 as a whole, so that it can withstand greater cooling lubricating oil load and centrifugal force under high-speed rotation, ensuring the mechanical reliability of long-term operation.

[0024] Please see Figure 2 and Figure 3 The end plate 3 has multiple raised ribs 4 that are evenly distributed circumferentially. This even circumferential distribution is key to ensuring the dynamic balance of the rotor, avoiding vibration and noise caused by uneven mass distribution during high-speed rotation, and ensuring the smoothness and reliability of motor operation. In addition, the multiple evenly distributed raised ribs 4 can continuously and smoothly push the cooling lubricating oil during the rotation cycle, forming a stable and uniform circumferential oil flow. This avoids the uneven flow that may be caused by single-point or local concentrated oil throwing, thereby improving the overall circulation efficiency and cooling uniformity of the cooling lubricating oil.

[0025] Please see Figure 2 and Figure 3The end plate 3 has weight-reduction holes 5. In this way, after the addition of the rib 4 to the end plate 3 increases the mass, the weight-reduction holes 5 directly reduce the overall weight of the end plate 3, which helps to compensate for the mass increase brought by the rib 4. More importantly, these weight-reduction holes 5 provide an effective means for fine adjustment of the rotor's dynamic balance. During the design verification and debugging stages, the number, position or size of the weight-reduction holes 5 can be adjusted to accurately compensate for the imbalance caused by manufacturing tolerances and material inhomogeneity, thereby optimizing the dynamic performance of the rotor. Understandably, it is necessary to repeat the process of assembly, disassembly, inspection, marking and processing when adjusting the dynamic balance. This design cleverly integrates the basic fixing function of the end plate 3, the cooling and lubrication function of the rib 4 and the dynamic balance adjustment function into one, which greatly improves the space utilization and functional integration of the components.

[0026] Please see Figure 1 and Figure 2 The motor housing is equipped with heat dissipation fins 6 or a water-cooling structure. The water-cooling structure is not shown in the figure. Understandably, the water-cooling structure includes a circulating water pipe attached to the housing or a water circulation channel based on the housing. In use, circulating cooling water is introduced into the circulating water pipe or water circulation channel to remove heat from the housing. Thus, the core of this invention lies in improving the flow of internal cooling lubricating oil to enhance the heat transfer path from the motor interior (especially the rotor) to the stator 9 and then to the housing. The heat dissipation bottleneck of traditional air-cooled or water-cooled motors is often that the rotor heat is difficult to transfer to the housing efficiently. This invention breaks through this bottleneck. The strong oil flow driven by the internal ribs 4 can quickly remove the heat from the rotor and stator 9 and transfer it to the housing. At this time, the heat dissipation fins 6 (air-cooled) or water-cooling structure on the housing can more efficiently dissipate this accumulated heat into the environment. The optimized flow of internal cooling lubricating oil and the external heat dissipation measures form a synergistic effect, jointly ensuring that both the stator 9 and the rotor are at a suitable operating temperature.

[0027] Please see Figure 1 , Figure 2 and Figure 4This utility model also includes a power system containing the aforementioned motor. In the power system, the motor housing includes a cylindrical shell 7, and the motor stator 9 and rotor are disposed inside the shell 7. One end of the shell 7 is detachably connected to an end cover, and the other end is integrally formed with a sealing plate 8. A gearbox is provided on the side of the sealing plate 8 away from the shell 7. The gearbox is also known as a reducer or gearbox on a motorcycle. Half of the gearbox 10 is integrally formed on the side of the sealing plate 8 away from the shell. A shaft hole 11 communicating with the inner cavity of the gearbox is provided through the sealing plate 8. The motor shaft 1 passes through the shaft hole 11 and extends into the inner cavity of the gearbox for transmission connection. The gearbox is generally a split structure, with the opposite end faces of the two halves of the box 10 sealed together and fastened together with bolts. The attached figure only shows one half of the box 10 where the gearbox and the sealing plate 8 are integrated. In this way, the independent connecting flange and sealing structure between the motor sealing plate 8 and the gearbox in the traditional design are eliminated, and the two components are combined into one. This not only simplifies the overall structure, reduces the number of parts and assembly steps, and lowers the manufacturing cost, but also fundamentally eliminates the potential leakage point at the connection between the motor and the gearbox, significantly improves the rigidity of the connection and the sealing reliability, and makes the integration of the motor and the transmission system more compact and robust.

[0028] Please see Figure 1 , Figure 5 and Figure 6 The sealing plate 8 has oil channels 12 that communicate with the inner cavities of the motor and the gearbox, respectively. The motor is positioned horizontally, and vertically, the two ends of the oil channels 12 are located near the bottom of the inner cavities of the motor and the gearbox, respectively, allowing the motor and gearbox to exchange cooling and lubricating oil through the oil channels 12. This design enables the motor and gearbox to share cooling and lubricating oil, offering several advantages: First, it simplifies the system, requiring only an oil filling hole, an oil outlet, and an oil sight glass on the motor housing or gearbox to serve both cavities; second, it improves cooling and lubrication... The oil can flow and exchange naturally between the two chambers. The heat generated by the meshing of gears 13 in the gearbox can be carried to the motor through the cooling lubricating oil and finally dissipated through the heat dissipation structure of the motor housing, thus achieving auxiliary cooling of the transmission system. Furthermore, it lubricates the bearings and moving parts inside the motor. Therefore, this structure achieves a high degree of unity between the two functions of lubrication and heat dissipation, avoiding the complexity of setting up independent lubrication and cooling systems for the motor and gearbox. At the same time, it can also eliminate the need for the dynamic seal structure between the motor sealing plate 8 and the gearbox input shaft, further reducing costs and failure rates.

[0029] Please see Figure 1 , Figure 2 and Figure 5The gearbox contains multiple rotating gears 13 forming a multi-stage transmission. The gears 13 serving as inputs to the multi-stage transmission are synchronously connected to the motor shaft 1. The shafts of the gears 13 serving as outputs extend sealed out of the gearbox. At least one gear 13 is vertically positioned near the bottom of the gearbox's inner cavity. In this embodiment, there are three gears 13 in the gearbox: the gear 13 serving as input and the gear 13 serving as output, which are vertically positioned near the bottom of the gearbox's inner cavity. The accompanying drawings only show the gear 13 connected to the motor shaft 1 and the gearbox body 10. The mounting position 14 is used to install two other gears 13. In this way, under the premise of sharing the cooling lubricating oil, the gearbox itself has effective lubrication capability. When the gear 13 near the bottom of the inner cavity of the gearbox rotates, it will stir up the cooling lubricating oil and throw it to the surroundings, forming oil mist or splash, thereby lubricating the meshing points of each gear 13 and bearings. This not only ensures sufficient lubrication of the gearbox transmission pair and reduces wear, but also greatly enhances the heat exchange between the cooling lubricating oil and the gears 13 and the housing 10 due to the violent stirring of the cooling lubricating oil, further improving the heat dissipation capability of the gearbox itself.

[0030] Please see Figure 1 and Figure 5 Vertically, the bottom of the gearbox's inner cavity is a concave arc surface 15, concentric with the adjacent gear 13. In this way, the concave arc surface 15 matches the tooth profile of the gear 13, which can minimize the gap between the gear 13 and the bottom of the gearbox's inner cavity. This allows the gear 13 near the bottom to penetrate deeper into the cooling lubricating oil, and can "scoop up" and carry away more cooling lubricating oil during rotation. The concentric design ensures that the gap between the gear 13 and the arc bottom is uniform, which is conducive to forming a stable and efficient oil pumping action. It continuously and smoothly throws the cooling lubricating oil at the bottom upward, achieving more thorough and uniform lubrication and more effective heat exchange and cooling throughout the entire gearbox, while also helping to reduce oil churning losses.

[0031] In summary, the core of the motor and power system based on this invention lies in achieving a synergistic improvement in the motor's heat dissipation and lubrication performance through structural innovation. This is primarily achieved by setting ribs 4 on the rotor end plate 3, using the rotor to drive the ribs 4 to rotate, thus forcing the cooling and lubricating oil to circulate in the air gap. This significantly enhances the heat transfer efficiency between the rotor and stator 9, effectively controlling rotor temperature rise and the risk of permanent magnet demagnetization, while also improving the lubrication of moving parts and avoiding the energy consumption and complexity associated with an additional oil pump. Secondly, through the integrated design of the motor housing and half of the gearbox housing 10, and the connecting oil passage between the sealing plate 8 and the gearbox, a shared lubrication system is constructed, realizing shared circulation of cooling and lubricating oil and synergistic heat dissipation. This simplifies the overall structure and improves system reliability. Without significantly increasing volume or weight, it simultaneously achieves the combined benefits of improved heat dissipation performance, simplified system structure, and reduced manufacturing costs, making it particularly suitable for applications with limited space and high power density requirements.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of this utility model that do not depart from the spirit and scope of this technical solution should be covered within the scope of the claims of this utility model.

Claims

1. An electric motor, characterized in that: The device includes a rotor, which comprises a motor shaft, an iron core, and an end plate. The motor shaft passes through the inner holes of the iron core and the end plate and is synchronously connected. The end plate is located on one axial side of the iron core, and the side of the end plate away from the iron core has a rib. The motor contains cooling and lubricating oil. When the rotor rotates, the rib rotates with the end plate, causing the cooling and lubricating oil to flow circumferentially.

2. The motor according to claim 1, characterized in that: The ribs extend radially along the end plate and have a certain degree of bending or curvature.

3. The motor according to claim 1, characterized in that: The rib extends from the inner hole of the end plate to the outer surface of the end plate.

4. The motor according to claim 1, characterized in that: There are multiple raised ribs on the end plate, which are evenly distributed circumferentially.

5. The motor according to claim 1, characterized in that: Weight reduction holes are provided on the end plate.

6. The motor according to claim 1, characterized in that: The motor housing is equipped with heat dissipation fins or a water-cooling structure.

7. A power system, characterized in that: The motor includes the motor as described in any one of claims 1-6, wherein the motor housing comprises a cylindrical housing, the stator and rotor of the motor are disposed within the housing, one end of the housing is detachably connected to an end cover, and the other end is integrally formed with a sealing plate, a gearbox is provided on the side of the sealing plate away from the housing, half of the gearbox is integrally formed on the side of the sealing plate away from the housing, and a shaft hole communicating with the inner cavity of the gearbox is provided through the sealing plate, the motor shaft passes through the shaft hole and extends into the inner cavity of the gearbox and is connected to the gearbox for transmission.

8. The power system according to claim 7, characterized in that: The sealing plate has oil channels that communicate with the inner cavity of the motor and the inner cavity of the gearbox respectively. The motor is arranged horizontally, and in the vertical direction, the two ends of the oil channels are close to the bottom of the inner cavity of the motor and the bottom of the inner cavity of the gearbox respectively, so that the motor and the gearbox can exchange cooling lubricating oil through the oil channels.

9. The power system according to claim 8, characterized in that: The gearbox contains multiple rotating gears that form a multi-stage transmission. The gears that serve as the input to the multi-stage transmission are synchronously connected to the motor shaft, and the shafts of the gears that serve as the output to the multi-stage transmission extend out of the gearbox. At least one gear inside the gearbox is vertically positioned near the bottom of the gearbox's inner cavity.

10. The power system according to claim 9, characterized in that: Vertically, the bottom of the gearbox's inner cavity is a concave arc surface and concentric with the adjacent gears.

Images