Motor, electric drive assembly system, vehicle, and method for cooling a motor

Abstract

The present disclosure relates to a motor, an electric drive assembly system, a vehicle, and a method for cooling a motor, the motor comprising: a rotor having a rotor shaft rotating about a rotation axis; a stator including a core and stator coils located at axial ends of the core; and a cooling system including a fluid supply channel provided in the rotor shaft; a plurality of groups of fluid outlet channels disposed on the rotor shaft and corresponding to the stator coils; and a fluid storage channel provided in a central portion of the rotor shaft and fluidly communicating with the fluid supply channel and the fluid outlet channel, the fluid supply channel being adjacent to at least one of the plurality of groups of fluid outlet channels and extending at least partially into the fluid storage channel, and cooling fluid flowing out of the fluid supply channel enters the fluid storage channel and then flows out of the fluid outlet channel to cool the stator coils.

Description

[Technical Field]

[0001] The present disclosure relates to a motor having a cooling system, an electric drive assembly system including such a motor, a vehicle including such an electric drive assembly system, and a method for cooling such a motor. [Background technology]

[0002] A typical motor comprises a rotor and a stator, the rotor being rotatable relative to the stator, and the motor may be an electrical rotating machine in the form of an alternator, an electric motor, or a reversible motor, which can operate in two modes.

[0003] Motors can generate a significant amount of heat during operation, and overheating can rapidly degrade the insulation of the motor windings. Another problem is that the permanent magnets in the rotor lose their magnetic properties (are demagnetized) when they overheat, reducing efficiency.

[0004] Therefore, cooling the internal motor components (such as the rotor) and external motor components (such as the housing and stator) is important to ensure proper operation of the motor, increase its power density, and extend its lifespan. Summary of the Invention

[0005] To address the above problems and needs, the present disclosure proposes a novel motor, electric drive assembly system, vehicle, and method for cooling a motor, which solves the above problems and produces other technical effects by employing the following technical features:

[0006] In one aspect, the present disclosure provides a motor including a rotor, a stator, and a cooling system, together with a rotor shaft rotating about a rotation axis, wherein the stator includes a core and stator coils located at axial ends of the core, and the cooling system includes a fluid supply channel provided in the rotor shaft, a plurality of groups of fluid outlet channels disposed on the rotor shaft and corresponding to the stator coils, and a fluid storage channel provided in a central portion of the rotor shaft and in fluid communication with the fluid supply channel and the fluid outlet channel; The fluid supply channel is adjacent to at least one of the plurality of groups of fluid outlet channels and extends at least partially into the fluid storage channel, such that cooling fluid flowing out of the fluid supply channel enters the fluid storage channel and then flows out of the fluid outlet channel to cool the stator coil.

[0007] According to the above feature, the fluid supply channel is disposed adjacent to at least one of the groups of fluid outlet channels and extends at least partially into the fluid storage channel, so that the cooling fluid flowing out of the fluid supply channel enters the fluid storage channel, and the flow of the cooling fluid in the fluid storage channel cools the rotor shaft, thereby cooling the rotor. After filling the fluid storage channel, the cooling fluid flows out of the fluid outlet channel and cools the stator coil.

[0008] Additionally, because the fluid supply channel extends at least partially into the fluid storage channel, cooling fluid exiting the fluid supply channel is prevented from exiting the fluid outlet channel directly, but instead must pass through the fluid storage channel and therefore must cool the rotor shaft before exiting the fluid outlet channel.

[0009] The stator includes a core and stator coils located at both axial ends of the core, where the stator coils are an important component of the stator, and in the case of a motor, an increase in the temperature of the stator coils (usually made of a metal material such as copper) can lead to a decrease in the efficiency of the motor. Therefore, ensuring that the temperature of the stator coils remains stable to avoid overheating is important for improving the efficiency of the motor.

[0010] Furthermore, the fluid supply channel is located adjacent to at least one of the groups of fluid outlet channels and extends at least partially into the fluid storage channel, so that the cooling fluid flowing out of the fluid supply channel enters the fluid storage channel and flows along the axial direction of the fluid storage channel under the action of centrifugal force until it uniformly fills the fluid storage channel. Compared with other possible solutions in which the fluid supply channel is located in the central part of the rotor shaft, resulting in uneven distribution of the cooling fluid from the center to both sides, the above-mentioned features proposed in the present disclosure can effectively solve this problem because the cooling fluid flowing out of the fluid supply channel flows only along one side after entering the fluid storage channel. During the flow process, the cooling fluid is naturally distributed evenly until it fills the entire fluid storage channel, thus achieving a more uniform heat dissipation effect.

[0011] Furthermore, the cooling fluid is oil to cool the rotor and stator during operation. Compared to thermal conduction, which uses a conductive liquid such as water or ethylene glycol to cool the motor's outer housing, oil cooling allows the oil to directly enter the rotor and stator for heat dissipation by thermal convection, thereby achieving higher cooling efficiency.

[0012] In some embodiments, the plurality of groups of fluid outlet channels includes a first group of fluid outlet channels and a second group of fluid outlet channels respectively positioned at opposite ends of the rotor shaft corresponding to the stator coils.

[0013] According to the above feature, the first group of fluid outlet channels and the second group of fluid outlet channels are respectively arranged at positions on both ends of the rotor shaft corresponding to the stator coils, so that the outlet cooling fluid more directly enters the stator coils and cools the stator coils. Optionally, the inner walls of the first group of fluid outlet channels and the second group of fluid outlet channels may have substantially the same inner diameter.

[0014] In some embodiments, the rotor shaft comprises a hollow cylindrical body and first and second portions on opposite sides of the cylindrical body, the cylindrical body comprising an inner wall, an outer wall, and a plurality of groups of fluid outlet channels throughout the inner and outer walls, and the inner wall between the first group of fluid outlet channels and the second group of fluid outlet channels is provided with a groove portion for forming a fluid storage channel, and the fluid supply channel is inserted in the first portion so as to enter the fluid storage channel and extends at least partially beyond the first group of fluid outlet channels in the direction of the rotation axis.

[0015] According to the above feature, the inner diameter of the inner wall between the first group of fluid outlet channels and the second group of fluid outlet channels is larger than the inner diameters of the first group of fluid outlet channels and the second group of fluid outlet channels, which means that a groove portion is provided on the inner wall between the two fluid outlet channels to form a storage channel for the cooling fluid.

[0016] In some embodiments, the fluid supply channel extends no more than one-third of the length of the cylinder in the direction of the axis of rotation.

[0017] According to the above feature, in combination with the feature of having a fluid supply channel adjacent to at least one of the groups of fluid outlet channels, to ensure uniform distribution of the cooling fluid within the fluid storage channel, the fluid supply channel should be located close to the end of the rotor shaft, i.e., the fluid supply channel should extend no more than 1 / 3 of the length of the tubular body. In alternative embodiments, the fluid supply channel may extend no more than 1 / 4, 1 / 5, 1 / 6, or 1 / 3 to 1 / 2 of the length of the tubular body in the direction of the rotation axis.

[0018] In some embodiments, the inlets of the first and / or second groups of fluid outlet channels are radially inward relative to an inner wall between the first and second groups of fluid outlet channels.

[0019] According to the above feature, the inner diameter of the inlet of the first group of fluid outlet channels and / or the second group of fluid outlet channels is smaller than the inner diameter of the fluid storage channel, which means that a groove is formed in the inner wall between the inlets of the two fluid outlet channels to form a storage channel for cooling the fluid.

[0020] In some embodiments, steps are provided on the inner wall of the cylindrical body between the first group of fluid outlet channels and the second group of fluid outlet channels and adjacent to each of the first group of fluid outlet channels and the second group of fluid outlet channels to form grooves.

[0021] According to the above features, steps are provided at corresponding positions to form a step transition between the fluid storage channel and the fluid outlet channel, wherein the height of the steps corresponds to the depth of the groove, and the surface between the steps and the inlet of the fluid outlet channel may extend parallel to the axial direction, so that the cooling fluid overflowing from the fluid storage channel flows substantially axially towards the inlet of the fluid outlet channel.

[0022] In some embodiments, the inner walls of the cylinder in the first group of fluid outlet channels and the second group of fluid outlet channels are inclined.

[0023] According to the above features, the inner walls of the cylindrical body in the first group of fluid outlet channels and the second group of fluid outlet channels may be arranged as inclined surfaces that can be directly connected to the inlets of the first group of fluid outlet channels and the second group of fluid outlet channels, allowing the cooling fluid overflowing from the fluid storage channel to flow directly out from the inlets of the fluid outlet channels.

[0024] In some embodiments, the first group of fluid outlet channels and / or the second group of fluid outlet channels extend at an angle to the axis of rotation.

[0025] According to the above feature, the first group of fluid outlet channels and / or the second group of fluid outlet channels extend at an angle relative to the rotation axis, the angle being in the range of 0 degrees to 90 degrees (inclusive). At an angle of 0 degrees, the first group of fluid outlet channels and / or the second group of fluid outlet channels are parallel to the rotation axis, and at an angle of 90 degrees, the first group of fluid outlet channels and / or the second group of fluid outlet channels are perpendicular to the rotation axis. At an angle greater than 0 degrees and less than 90 degrees, the first group of fluid outlet channels and / or the second group of fluid outlet channels are inclined relative to the rotation axis, and the cooling fluid flows out of the inclined fluid outlet channels.

[0026] When the rotor shaft is operating, i.e., rotating around the rotation axis, the cooling fluid that has flowed into the fluid outflow channel flows out along the fluid outflow channel under the action of centrifugal force, and here, by adjusting the inclination angle of the fluid outflow channel, the component of centrifugal force in the extension direction of the fluid outflow channel can be adjusted accordingly, and the flow rate of the cooling fluid discharged or released from the fluid outflow channel can be adjusted.

[0027] Furthermore, from another perspective, the inclination angle of the fluid outlet channel can also affect the coverage of the cooling fluid at the inlet of the fluid outlet channel, thereby affecting the amount of liquid that flows out. For example, when the liquid level in the rotor shaft is low, the area of ​​the fluid coverage hole is small, resulting in a small amount of liquid being discharged; when the liquid level on the rotor shaft is high, the area of ​​the fluid coverage hole is large, resulting in a large amount of liquid being discharged.

[0028] In some embodiments, the first group of fluid outlet channels comprises a plurality of first guide holes adjacent to the first portion, the second group of fluid outlet channels comprises a plurality of second guide holes adjacent to the second portion, and the first guide holes and / or the second guide holes are circumferentially arranged along the rotor shaft.

[0029] According to the above features, the fluid outlet channel can take the form of a guide hole arranged circumferentially along the rotor shaft and at least partially over the entire inner wall of the rotor shaft, thereby allowing the cooling fluid of the fluid storage channel within the hollow rotor shaft to exit. Alternatively, the fluid outlet channel can also take other forms, for example allowing the fluid to exit from a conduit.

[0030] In some embodiments, the first guide hole and / or the second guide hole extend in a radial direction perpendicular to the axis of rotation.

[0031] In some embodiments, the first guide hole and / or the second guide hole extend at an angle relative to a radial direction perpendicular to the axis of rotation.

[0032] Similar to the above embodiment, the angled guide holes can adjust the velocity and volume of the cooling fluid outflow, thereby improving the flexibility and design margin of the cooling system. The number of first guide holes and / or second guide holes may be in the range of 2 to 10, for example, 2 to 6.

[0033] In another aspect, the present disclosure provides an electric drive assembly system including a housing and a motor as described above, wherein the rotor shaft is supported within the housing by at least one bearing.

[0034] In some embodiments, the electric drive assembly system further comprises a gear shaft rotatably fixedly connected to the rotor shaft, the gear shaft having opposite first and second ends and a fluid channel extending through the first and second ends, the second end being formed as a fluid supply channel.

[0035] Optionally, the gear shaft may be fixedly connected to the rotor shaft via splines.

[0036] In some embodiments, the electric drive assembly system further comprises a nozzle disposed at the first end in fluid communication with the fluid channel, the nozzle having a clearance fit with the fluid channel.

[0037] According to the above feature, the nozzle may be in fluid communication with the fluid channel, and the cooling fluid may be pumped through the nozzle into the fluid channel before ultimately entering the fluid supply channel.

[0038] In some embodiments, the fluid channel is provided with a stepped hole at the outlet of the nozzle, the inner diameter of the stepped hole being smaller than the radial dimension of the fluid channel and larger than the inner diameter of the nozzle orifice.

[0039] In one embodiment, the nozzle has a clearance fit with the fluid channel, which can allow a small amount of cooling fluid to leak through the clearance of the clearance fit. To prevent such leakage, according to the above feature, a stepped hole is disposed in the fluid channel at the outlet of the nozzle, which can block the cooling fluid and prevent it from backflowing and leaking through the clearance.

[0040] In some embodiments, the electric drive assembly system further comprises a bearing support structure for the rotor shaft and the gear shaft, the bearing support structure comprising a first bearing supporting the gear shaft at a first end, a second bearing supporting the rotor shaft at a first portion, and a third bearing supporting the rotor shaft at a second portion.

[0041] According to the above features, better support can be provided to the gear shaft, and the bearing support structure can provide sufficient support in the electric drive assembly system while preventing movement between the gear shaft and the rotor shaft, thereby improving the NVH performance of the entire vehicle.

[0042] In another aspect, the present disclosure further proposes a vehicle comprising the electric drive assembly system described above.

[0043] In yet another aspect, the present disclosure further proposes a method for cooling a motor, the method including the steps of cooling the stator coils by a cooling system and supplying fluid to the stator coils of the stator through a rotor shaft of the rotor, the cooling system including a fluid supply channel arranged in the rotor shaft, a plurality of groups of fluid outlet channels arranged on the rotor shaft and corresponding to the stator coils, and a fluid storage channel provided in a central portion of the rotor shaft and fluidically communicating with the fluid supply channel and the fluid outlet channel, the fluid supply channel being adjacent to at least one of the plurality of groups of fluid outlet channels and extending at least partially into the fluid storage channel, such that the cooling fluid flowing out of the fluid supply channel enters the fluid storage channel, and after filling the fluid storage channel, the cooling fluid flows out of the fluid outlet channel to cool the stator coils.

[0044] In some embodiments, the multiple groups of fluid outlet channels include a first group of fluid outlet channels and a second group of fluid outlet channels respectively positioned at opposite ends of the rotor shaft corresponding to the stator coils, and the first group of fluid outlet channels and / or the second group of fluid outlet channels extend at an angle to the rotational axis of the rotor shaft.

[0045] In some embodiments, the interior wall between the first group of fluid outlet channels and the second group of fluid outlet channels is provided with a groove to form a fluid storage channel.

[0046] According to the above features, the present disclosure further proposes a method for cooling a motor based on the proposed motor structure, which allows cooling both the stator coil and the rotor during operation of the motor via a flow of cooling fluid.

[0047] In order to more clearly describe the technical solutions provided by some embodiments of the present disclosure, drawings of the embodiments are briefly described below. It is clear that the drawings in the following description do not limit the present disclosure, but are only relevant to some embodiments of the present disclosure. [Brief explanation of the drawings]

[0048] [Figure 1] FIG. 1 is a schematic diagram of a motor in accordance with at least one embodiment of the present disclosure. [Figure 2] FIG. 1 is a schematic diagram of an electric drive assembly system in accordance with at least one embodiment of the present disclosure. [Figure 3] 1 is a schematic diagram of the flow of cooling fluid from a fluid supply channel, through a fluid storage channel, and out a fluid outlet channel. [Figure 4] FIG. 1 is a schematic diagram of an electric drive assembly system according to one or more embodiments of the present disclosure. [Figure 5] FIG. 1 is a schematic diagram of an electric drive assembly system according to one or more embodiments of the present disclosure. [Figure 6] FIG. 1 is a schematic diagram of an electric drive assembly system according to one or more embodiments of the present disclosure. [Figure 7] FIG. 1 is a schematic diagram of an electric drive assembly system according to one or more embodiments of the present disclosure. [Figure 8] FIG. 1 is a schematic diagram of an electric drive assembly system according to one or more embodiments of the present disclosure. [Figure 9] 1 is a flowchart of a method for cooling a motor in accordance with at least one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0049] In order to make the objectives, technical solutions, and advantages of the present disclosure clearer, the technical solutions provided by some embodiments of the present disclosure are clearly and completely described below with reference to the drawings of specific embodiments of the present disclosure. In the drawings, the same symbols represent the same parts. It is important to note that the described embodiments are only some embodiments of the present disclosure, but not all embodiments. All other embodiments obtained by those skilled in the art based on the described embodiments of the present disclosure without creative work fall within the scope of protection of the present disclosure.

[0050] Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure belongs. The words “first,” “second,” and similar terms used in the specification and claims of the patent application of this disclosure do not denote order, quantity, or importance, but are merely used to distinguish between different components. Similarly, words such as “a” or “one” do not necessarily denote a quantitative limitation. The words “comprise,” “include,” or any other similar term mean that the element or object appearing before the term encompasses the elements or objects listed thereafter and their equivalents, but does not exclude other elements or objects. The words “connected” or “coupled” and similar terms are not limited to physical or mechanical connections, but may also include electrical connections, whether direct or indirect. Terms such as “top,” “bottom,” “left,” and “right” are used only to indicate relative positions; if the absolute positions of the described objects change, the relative positions may also change accordingly.

[0051] A typical motor comprises a rotor and a stator, and the motor may be an electric rotating machine in the form of an alternator, an electric motor, or a reversible motor capable of operating in two modes. The electronic components of a vehicle, particularly an electric vehicle, are powered by a battery, and the electric vehicle is driven by a traction motor. An electric vehicle may comprise numerous other components not described herein but known to those skilled in the art. Additionally, different types of vehicles, including motorcycles, airplanes, trucks, ships, and train engines, may be combined with the inventive concepts described herein.

[0052] When operating properly, a motor generates a significant amount of heat, which, if not dissipated in a timely manner, can cause the motor to overheat. When a motor overheats, the insulation performance of the motor windings rapidly deteriorates, affecting the safety and lifespan of the motor. Furthermore, the permanent magnets in the rotor lose their magnetic properties as they overheat, resulting in a decrease in efficiency. Therefore, it is necessary to cool the motor's internal components (such as the rotor) and external components (such as the housing and stator).

[0053] Several different approaches have been developed to meet the cooling needs of vehicle motors. For example, cooling circuits are formed by supplying cooling pipes to the rotor shaft and stator, and a coolant, such as oil, is typically used in this method. However, the construction of the components in such cooling circuits is usually complex.

[0054] Furthermore, liquids such as water or ethylene glycol may be used for cooling, but such liquids are conductive and cannot be introduced directly into the motor stator (they would short-circuit), so they may be used to cool only the outside of the motor housing by thermal conduction.

[0055] To overcome the shortcomings of the prior art, the present disclosure provides a novel motor, electric drive assembly system, vehicle, and method for cooling a motor with a cooling system, which has a simple structure and high heat dissipation efficiency, thereby increasing power density and extending life, and resulting in a permanent magnet that is cooler and less susceptible to demagnetization.

[0056] Electrification has become one of the major development trends in the automotive industry, and special attention has been paid to whether the electric drive assembly system that serves as the power system of electric vehicles is highly integrated, lightweight, and reliable.

[0057] The electric drive assembly system is a highly integrated electric drive system, and is typically composed of a motor, an inverter, and a retarder. The motor, inverter, and retarder of electric drive systems currently available on the market are typically manufactured separately, and the motor, retarder, and inverter are connected to each other via fasteners. Due to such separate configurations, the electric drive assembly system is large and heavy, and occupies a considerable amount of space in the overall layout of the vehicle.

[0058] Therefore, the present disclosure further proposes a highly integrated electric drive assembly system based on the above-mentioned motor.

[0059]

[0023] The embodiments of the present disclosure will be described in detail with reference to the drawings. It should be noted that in the drawings, components having substantially the same or similar structures and functions are denoted by the same reference numerals, and redundant descriptions thereof will be omitted.

[0060] Compared to the embodiments shown in the drawings, feasible embodiments within the scope of protection of the present disclosure may have fewer components, additional components not shown in any of the drawings, different components, differently arranged components, or differently connected components, etc. Furthermore, two or more components in the drawings may be implemented as a single component, or a single component shown in the drawings may be implemented as multiple separate components, without departing from the concepts disclosed in the present disclosure.

[0061] Figure 1 is a schematic diagram of a motor according to at least one embodiment of the present disclosure. Figure 2 is a schematic diagram of an electric drive assembly system according to at least one embodiment of the present disclosure. Figure 3 is a schematic diagram of the flow of cooling fluid from a fluid supply channel, through a fluid storage channel, and out a fluid outlet channel.

[0062] As shown in FIG. 1, the motor may include a rotor and a stator, with the rotor rotatable relative to the stator about a rotation axis. The rotor has a rotor shaft 2 that rotates about a rotation axis D. The stator includes a core and stator coils (not shown) located at both axial ends of the core. When the motor operates as an electric motor, the stator coils are excited to generate a drive magnetic field, which rotates the rotor shaft 2. Conversely, when the motor operates as a generator, the rotor shaft 2 is driven to rotate, generating an induced current in the stator coil. In either case, the drive current and the induced current cause the motor to generate a significant amount of heat during operation, which must be dissipated in a timely manner.

[0063] Therefore, the motor proposed in this disclosure includes a cooling system, which includes at least a fluid circuit in which heat is absorbed by a cooling fluid and dissipated through the cooling circuit. In the illustrated embodiment, the cooling fluid is oil, such as automatic transmission oil, lubricating oil, or any other similar oil. In other embodiments, other types of fluid may be used. In one example, the cooling system may further include a fluid pump that pumps the cooling fluid through the fluid circuit. In another example, instead of including any pump, the cooling system may use gears to agitate the oil, which then flows into the fluid channel through a conduit in the housing.

[0064] Specifically, the cooling system includes a fluid supply channel 3, multiple groups of fluid outlet channels 4, and a fluid storage channel 5. The fluid supply channel 3 is located within the rotor shaft 2, which is hollow and has one closed end and the other open end as shown in FIG. 1 , through which the fluid supply channel 3 can extend. The fluid supply channel 3 may be, for example, part of a gear shaft 7 of an electric drive assembly system (described in more detail below), or may be a fluid conduit extending within the rotor shaft 2.

[0065] The multiple groups of fluid outflow channels 4 are arranged on the rotor shaft 2 and correspond to the stator coils. In this embodiment, the multiple groups of fluid outflow channels 4 include a first group of fluid outflow channels 41 and a second group of fluid outflow channels 42, which are respectively arranged at both ends of the rotor shaft 2 corresponding to the stator coils. The fluid outflow channels 4 may be arranged throughout the entire rotor shaft 2. As shown in FIG. 1 , the rotor shaft 2 includes a hollow cylindrical body 21 and a first portion 22 and a second portion 23 on either side of the cylindrical body 21. The first portion 22 may be at least partially open, and the second portion 23 may be closed. Alternatively, both the first portion 22 and the second portion 23 may be partially open to facilitate the introduction and discharge of cooling fluid. The cylindrical body 21 includes an inner wall 211, an outer wall 212, and multiple groups of fluid outflow channels 4. The multiple groups of fluid outflow channels 4 are arranged throughout the entire inner wall 211 and the outer wall 212, for example, in the form of through holes.

[0066] The fluid storage channel 5 is disposed in the central portion of the rotor shaft 2 and is fluidly connected to the fluid supply channel 3 and the fluid outlet channel 4. As shown in FIG. 1 , a groove 6 is provided in an inner wall 211 between the first group of fluid outlet channels 41 and the second group of fluid outlet channels 42 to form the fluid storage channel 5. Specifically, the inner diameter of the inner wall 211 between the first group of fluid outlet channels 41 and the second group of fluid outlet channels 42 is larger than the inner diameter of the inner wall 211 of the tubular body 21 at the inlet of the first group of fluid outlet channels 41 or the second group of fluid outlet channels 42. In other words, the inlet of the first group of fluid outlet channels 41 and / or the second group of fluid outlet channels 42 is radially inward of the inner wall 211 between the first group of fluid outlet channels 41 and the second group of fluid outlet channels 42. The height of the fluid storage channel 5 is equal to the difference between the inner diameters.

[0067] The fluid supply channel 3 is adjacent to at least one of the multiple groups of fluid outlet channels 4 and extends at least partially into the fluid storage channel 5, so that cooling fluid exiting the fluid supply channel 3 enters the fluid storage channel 5 and then exits the fluid outlet channel 4 to cool the stator coil. As shown in FIG. 1, the fluid supply channel 3 is adjacent to a first group of fluid outlet channels 41.

[0068] It should be noted that the term "adjacent" as used in this disclosure refers to being close to or near it, and in terms of numerical definitions, "adjacent" can mean that the fluid supply channel 3 extends in the direction of the rotation axis D by no more than 1 / 3 of the length of the cylindrical body 21, for example no more than 1 / 4, no more than 1 / 5, no more than 1 / 6.

[0069] Optionally, the number of fluid outlet channels 4 in each group may be in the range of 2-10, for example 2-6.

[0070] 1, the fluid supply channel 3 is inserted into the first portion 22 of the rotor shaft 2 so as to enter the fluid storage channel 5 and extend at least partially beyond the first group of fluid outlet channels 41 in the direction of the rotation axis D. The fluid supply channel 3 may be part of a gear shaft, which will be described in more detail below.

[0071] To form the grooves 6, steps 61 may be provided on the inner wall 211 of the cylindrical body 21 between the first group of fluid outlet channels 41 and the second group of fluid outlet channels 42 and adjacent to each of the first group of fluid outlet channels 41 and the second group of fluid outlet channels 42. The steps 61 are formed by a step-like change in radial dimension. Furthermore, referring to FIGS. 1 and 2 together, the first group of fluid outlet channels 41 may include a plurality of first guide holes 43 adjacent to the first portion 22, and the second group of fluid outlet channels 42 may include a plurality of second guide holes 44 adjacent to the second portion 23. The plurality of first guide holes 43 and the plurality of second guide holes 44 are arranged circumferentially along the rotor shaft 2, and may each be six, uniformly distributed circumferentially. Furthermore, the first guide holes 43 and the second guide holes 44 extend in a radial direction perpendicular to the rotation axis D. Therefore, when the rotor shaft 2 rotates, the cooling fluid is discharged from the first guide hole 43 and the second guide hole 44 under the action of centrifugal force, thereby cooling the stator coil. The cooling fluid that has cooled the stator coil may be returned to a fluid pump or a heat exchanger (not shown) through a recovery channel (not shown) arranged in the motor, thereby forming a fluid circuit.

[0072] 2, the electric drive assembly system may include a housing 1, a first end cover 10, a second end cover 20, a gear shaft 7, a nozzle 8, and a motor, as described above, with the rotor shaft 2 of the motor supported within the housing 1 by a bearing support structure 9. The first end cover 10 and the second end cover 20 each fit into the housing 1 and are disposed opposite each other.

[0073] The gear shaft 7 is rotatably and fixedly connected to the rotor shaft 2 (e.g., via a splined connection). The gear shaft 7 has opposite first and second ends 71, 72 and a fluid channel 73 extending throughout the first and second ends 71, 72. The gear shaft 7 is thus also hollow, with the second end 72 formed as a fluid supply channel 3 that extends into the rotor shaft 2 and communicates with the fluid storage channel 5.

[0074] The gear shaft 7 may be connected to a retarder and / or an output shaft, thereby reducing the torque of the rotor shaft 2 and outputting the torque to drive the vehicle.

[0075] The nozzle 8 is disposed at the first end 71 of the gear shaft 7 and is in fluid communication with the fluid channel 73, through which the cooling fluid enters the fluid channel 73 and ultimately into the fluid supply channel 3. The nozzle 8 may be disposed on the first end cover 10 and may be generally cylindrical and coaxial with the gear shaft 7 and the rotor shaft 2. The nozzle 8 has a clearance fit with the fluid channel 73 when the motor is running, as the rotor shaft 2 and the gear shaft 7 rotate while the nozzle 8 is idle. As such, the clearance fit may allow a small amount of cooling fluid to leak through the gap. The leaked cooling fluid can be recovered via a return channel (not shown) disposed within the housing 1 without affecting the operation of other components in the electric drive assembly system.

[0076] The nozzle 8 may be connected to a fluid pump (not shown) so that the cooling fluid is pumped into the nozzle 8. Alternatively, the oil may also be agitated by the gears and flow into the fluid channel 73 through a conduit in the housing.

[0077] Referring again to FIG. 2, the bearing support structure 9 includes at least a first bearing 91 , a second bearing 92 , and a third bearing 93 .

[0078] A first bearing 91 supports the gear shaft 7 at the first end 71, and the first bearing 91 is attached to the first end cover 10. A second bearing 92 supports the rotor shaft 2 at the first portion 22, and the second bearing 92 is attached to the housing 1. A third bearing 93 supports the rotor shaft 2 at the second portion 23, and the third bearing 93 is attached to the second end cover 20. Alternatively, the second bearing 92 may support the second end 72 of the gear shaft 7 instead of supporting the first portion 22 of the rotor shaft 2.

[0079] In this embodiment, the first end cover 10 and the second end cover 20 are each fitted to the housing 1 and positioned opposite each other, the first end cover 10 and the second end cover 20 close the two end faces of the housing 1 respectively, and the motor and gear shaft 7 share the same housing without the need for an additional motor housing and / or gear housing.

[0080] Therefore, one housing 1 is used which is shared by the motor and the gear shaft, the gear shaft 7 is connected to the rotor shaft 2 via a spline, and the gear shaft 7 and the rotor shaft 2 are supported by three bearings, which establishes a reliable connection between the rotor shaft 2 and the gear shaft 7 to improve power transmission efficiency, while reducing the weight and overall dimensions of the electric drive assembly system and providing better support for the gear shaft 7; therefore, a support structure with at least three bearings can provide sufficient support for the electric drive assembly system while preventing movement between the two shafts.

[0081] Alternatively, the housing 1 may be formed by connecting two separate housings. For example, the motor housing and the gear housing may be two separate housings, and the motor housing and the gear housing may be fixedly connected to each other by screws.

[0082] Alternatively, the bearing support structure may comprise more than four bearings, for example four bearings, two of which support the rotor shaft 2 at either end in the region where the motor is located, and two of which support the gear shaft 7 at either end in the region where the gears are located.

[0083] FIG. 3 is a schematic diagram of the flow of cooling fluid in this embodiment. As shown by the arrows in FIG. 3 , the cooling fluid, driven by, for example, a fluid pump (not shown), first enters the fluid channel 73 from the nozzle 8. Under the combined action of centrifugal force and the fluid pump, the cooling fluid flows substantially along the inner wall of the fluid channel 73 toward the fluid supply channel 3, enters the fluid storage channel 5, i.e., the groove 6, from one side of the first portion 22, accumulates there, and is uniformly distributed in the groove 6, thereby cooling the rotor shaft 2. After the accumulated cooling fluid fills the groove 6, the cooling fluid flows into the first guide hole 43 and the second guide hole 44 and is radially discharged from the first guide hole 43 and the second guide hole 44 under the action of centrifugal force, ultimately cooling the stator coil (not shown).

[0084] A motor according to at least one embodiment of the present disclosure, and an electric drive assembly system including such a motor, are described above with reference to Figures 1 to 3. Based on the inventive concepts introduced by this disclosure, alternative embodiments can be derived without departing from the scope of the present disclosure. Figures 4 to 8 are schematic diagrams of an electric drive assembly system according to one or more embodiments of the present disclosure.

[0085] For simplicity, in the following embodiments, particular emphasis will be placed on describing the differences from the previous embodiments, and identical components or features will be designated with the same or similar reference numerals.

[0086] 4, in an exemplary embodiment, to avoid leakage of the cooling fluid, the fluid channel 73 may further be provided with a stepped hole 74 at the outlet of the nozzle 8. The inner diameter of the stepped hole 74 is smaller than the radial dimension of the fluid channel 73 and larger than the inner diameter of the nozzle 8. Therefore, the cooling fluid entering the fluid channel 73 from the nozzle 8 cannot return to the loose-fitted component, preventing the cooling fluid from leaking through the gap.

[0087] As shown in FIG. 5 , in another embodiment, the first guide holes 43 and the second guide holes 44 extend at an acute angle relative to the radial direction, i.e., greater than 0 degrees and less than 90 degrees. The cooling fluid flows out through the inclined first guide holes 43 and second guide holes 44. Adjusting the inclination angle of the first guide holes 43 and second guide holes 44 can adjust the centrifugal force component in the extension direction of the first guide holes 43 and second guide holes 44, thereby adjusting the flow rate of the cooling fluid discharged or ejected from the first guide holes 43 and second guide holes 44. The inclination angle of the first guide holes 43 and second guide holes 44 also affects the reach of the cooling fluid at the inlet of the fluid outlet channel 4 and the amount of liquid flowing out.

[0088] In relation to the features of the embodiment shown in Figures 4 and 5, as shown in Figure 6, this embodiment has both the stepped hole 74 feature described above and the sloped first and second guide holes 43, 44 feature, and therefore provides the advantages of both of the above-mentioned embodiments.

[0089] 7, in yet another embodiment, the inner walls 211 of the cylindrical body 21 in the first group of fluid outlet channels 41 and the second group of fluid outlet channels 42 are inclined surfaces. The inclined surfaces may be directly connected to the inlets of the first group of fluid outlet channels 41 and the second group of fluid outlet channels 42, allowing the cooling fluid overflowing from the fluid storage channel 5 to flow directly out of the inlets of the fluid outlet channels without having to pass through a step. The inclined surfaces may be formed, for example, by chamfering.

[0090] The embodiment shown in FIG. 8 is based on the embodiment shown in FIG. 7, with the addition of the stepped hole 74 feature as described above, which will not be described again.

[0091] 9 is a flowchart of a method for cooling a motor. First, in step S01, the motor is started, and then the cooling system is started. Optionally, if a fluid pump is provided, the fluid pump may be started in step S01. Next, in step S02, the cooling system supplies fluid to the stator coil of the stator via the rotor shaft 2 of the rotor to cool the stator coil. A motor for implementing the above steps may include features of one or more of the above-described embodiments.

[0092] According to another aspect of the present disclosure, there is further provided a vehicle, for example, comprising the electric drive assembly system described above.

[0093] The vehicle may be, for example, a pure electric vehicle (BEV, battery electric vehicle), a hybrid vehicle (HEV, hybrid electric vehicle), a plug-in hybrid vehicle (PHEV, plug-in hybrid electric vehicle), a range extender electric vehicle (range extender electric vehicle), or a fuel cell electric vehicle (FCEV, fuel cell electric vehicle).

[0094] Although exemplary embodiments of the motor, electric drive assembly system, vehicle, and method for cooling a motor proposed in the present disclosure have been particularly described above with reference to preferred embodiments, those skilled in the art can understand that variations and modifications can be made to the above specific embodiments without departing from the spirit of the present disclosure. Furthermore, the various technical features and structures proposed in various aspects of the present disclosure can be combined in various ways without exceeding the protection scope of the present disclosure as defined by the appended claims.

Claims

1. a rotor having a rotor shaft that rotates around the rotation axis; a stator including a core and stator coils positioned at both axial ends of the core; 1. A cooling system comprising: a fluid supply channel provided in the rotor shaft; a plurality of groups of fluid outlet channels disposed on the rotor shaft and corresponding to the stator coils; and a fluid storage channel in the central portion of the rotor shaft, the fluid storage channel in fluid communication with the fluid supply channel and the fluid outlet channel; a cooling system comprising: wherein the fluid supply channel is adjacent to at least one of the plurality of groups of fluid outlet channels and extends at least partially into the fluid storage channel, and the cooling fluid exiting the fluid supply channel enters the fluid storage channel and then exits the fluid outlet channel to cool the stator coil.

2. 2. The motor of claim 1, wherein the plurality of groups of fluid outlet channels include a first group of fluid outlet channels and a second group of fluid outlet channels respectively disposed at the positions on the opposite ends of the rotor shaft corresponding to the stator coils.

3. the rotor shaft comprises a hollow cylindrical body, a first portion and a second portion on opposite sides of the cylindrical body, the cylindrical body comprising an inner wall, an outer wall, and the plurality of groups of fluid outlet channels extending throughout the inner wall and the outer wall; and a groove for forming the fluid storage channel is provided on the inner wall between the first group of fluid outlet channels and the second group of fluid outlet channels; The motor of claim 2 , wherein the fluid supply channel is inserted into the first portion so as to enter the fluid storage channel and extend at least partially beyond the first group of fluid outlet channels in the direction of the rotation axis.

4. The motor of claim 3 , wherein the fluid supply channel extends in the direction of the axis of rotation no more than one-third of the length of the tubular body.

5. The motor of claim 3 , wherein the inlets of the first and / or second groups of fluid outlet channels are radially inward relative to the inner wall between the first and second groups of fluid outlet channels.

6. 6. The motor of claim 5, wherein a step is provided on the inner wall of the cylindrical body between the first group of fluid outlet channels and the second group of fluid outlet channels and adjacent to each of the first group of fluid outlet channels and the second group of fluid outlet channels to form the groove portion.

7. The motor of claim 5 , wherein the inner walls of the cylindrical body in the first group of fluid outlet channels and the second group of fluid outlet channels are inclined surfaces.

8. 8. A motor according to claim 3, wherein the first group of fluid outlet channels and / or the second group of fluid outlet channels extend at an angle to the axis of rotation.

9. 9. The motor of claim 8, wherein the first group of fluid outlet channels comprises a plurality of first guide holes adjacent the first portion, the second group of fluid outlet channels comprises a plurality of second guide holes adjacent the second portion, and the first guide holes and / or the second guide holes are circumferentially arranged along the rotor shaft.

10. The motor according to claim 9 , wherein the first guide hole and / or the second guide hole extend in a radial direction perpendicular to the rotation axis.

11. The motor according to claim 9 , wherein the first guide hole and / or the second guide hole extend at an angle with respect to a radial direction perpendicular to the rotation axis.

12. Housing and A motor according to any one of claims 1 to 11. wherein the rotor shaft is supported within the housing by at least one bearing.

13. a gear shaft rotatably and fixedly connected to the rotor shaft, the gear shaft having opposed first and second ends and a fluid channel extending through the first and second ends, the second end being formed as the fluid supply channel; The electric drive assembly system of claim 12 further comprising:

14. a nozzle disposed at the first end, in fluid communication with the fluid channel, and in a clearance fit with the fluid channel; The electric drive assembly system of claim 13 further comprising:

15. 15. The electric drive assembly system of claim 14, wherein the fluid channel is provided with a stepped hole at the outlet of the nozzle, and the inner diameter of the stepped hole is smaller than the radial dimension of the fluid channel and larger than the inner diameter of the nozzle orifice.

16. The rotor shaft may further include a bearing support structure for the rotor shaft and the gear shaft, the rotor shaft including a hollow cylindrical body and a first portion and a second portion on opposite sides of the cylindrical body, the bearing support structure including: a first bearing supporting the gear shaft at the first end; a second bearing supporting the rotor shaft at the first portion; a third bearing supporting the rotor shaft at the second portion; and The electric drive assembly system of claim 15, comprising:

17. A vehicle comprising an electric drive assembly system according to any one of claims 12 to 16.

18. cooling the stator coils with a cooling system and supplying fluid to the stator coils of the stator through a rotor shaft of a rotor, the cooling system comprising: a fluid supply channel disposed within the rotor shaft; a plurality of groups of fluid outlet channels disposed on the rotor shaft corresponding to the stator coils; and a fluid storage channel provided in the central portion of the rotor shaft and in fluid communication with the fluid supply channel and the fluid outlet channel. wherein the fluid supply channel is adjacent to at least one of the plurality of groups of fluid outlet channels and extends at least partially into the fluid storage channel, the cooling fluid flowing out of the fluid supply channel enters the fluid storage channel, and the cooling fluid fills the fluid storage channel before flowing out of the fluid outlet channel to cool the stator coil.

19. 19. The method of claim 18, wherein the plurality of groups of fluid outlet channels include a first group of fluid outlet channels and a second group of fluid outlet channels respectively disposed at the positions on opposite ends of the rotor shaft corresponding to the stator coils, and the first group of fluid outlet channels and / or the second group of fluid outlet channels extend at an angle relative to the rotational axis of the rotor shaft.

20. 20. The method of claim 19, wherein an inner wall between the first group of fluid outlet channels and the second group of fluid outlet channels is provided with a groove for forming the fluid storage channel.

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