Stator heat dissipation structure of oil-cooled motor

Abstract

The invention provides an oil-cooled motor stator heat dissipation structure. The oil-cooled motor stator heat dissipation structure comprises a stator iron core, a shunt ring and an oil injection assembly which are sequentially arranged in the axial direction. A plurality of cooling liquid flow channels extending in the axial direction are evenly distributed on the peripheral wall of the stator core, a plurality of transition channels communicating with the cooling liquid flow channels are evenly distributed in the flow dividing ring in the circumferential direction, and a plurality of first oil injection channels and second oil injection channels are evenly distributed in the oil injection assembly in the circumferential direction. The included angles between the axes of the first oil injection channel and the second oil injection channel and the axis of the stator core are not consistent; a flow guide piece is arranged in the transition channel; when the flow speed of the cooling liquid in the transition channel is smaller than a threshold value, the flow guide piece limits the cooling liquid in the transition channel from flowing into the first oil injection channel; and when the flow speed of the cooling liquid in the transition channel is greater than a threshold value, the cooling liquid in the transition channel can overcome the limitation of the flow guide piece so as to flow into the first oil injection channel. The spraying angle of the cooling liquid can be changed to achieve a better cooling effect.

Description

Technical Field

[0001] The invention relates to the field of motors, and in particular to an oil-cooled motor stator heat dissipation structure. Background Art

[0002] With the continuous development of new energy vehicles and the gradual increase in market demand for new energy vehicle driving capabilities, the motors of new energy vehicles need to continuously improve their speed, torque density and power density while gradually compressing their volume. The higher the speed, torque density and power density of the motor, the higher the heat it generates. Therefore, the heat dissipation and cooling structure of the motor are essential for the reliable, stable and efficient operation of the motor. At present, the cooling methods of motors are divided into air cooling, water cooling and oil cooling. The oil cooling method has become the first choice for high-performance motor cooling due to its natural electrical insulation and high degree of freedom in structural design.

[0003] Take a motor as an example. Its rated working condition is 65kw. When it is at a rated speed of 12000rpm, copper loss accounts for about 20% of the total loss, and iron loss accounts for about 53% of the total loss. At this time, the iron core is the main source of heat. When the peak working condition is 120kW and the speed is 1600rpm, copper loss accounts for about 93% of the total loss, and iron loss accounts for about 6% of the total loss. At this time, the winding is the main source of heat. It can be seen that under different working conditions, the parts that need to be cooled first for the motor are different, and the prior art often cannot perform efficient cooling work on the iron core and winding separately. Furthermore, when the overall power of the motor is reduced, the amount of oil entering its coolant will decrease. The traditional motor winding cooling method cannot adjust the spray angle of the coolant. In this way, when the speed of the coolant sprayed from the oil spray hole is reduced, the angle of its injection into the winding will tend to be vertical, resulting in a smaller coverage of the coolant on the winding, resulting in poor cooling effect. Summary of the invention

[0004] In order to overcome the problem that the prior art cannot adjust the spray angle of the coolant when cooling the stator core end winding, the present invention provides an oil-cooled motor stator heat dissipation structure, wherein a plurality of axially extending coolant flow channels are evenly distributed on the outer peripheral wall of the stator core, a plurality of transition channels connected to the coolant flow channels are evenly distributed along the circumferential direction on the diverter ring, and a plurality of first and second oil injection channels are evenly distributed along the circumferential direction on the oil injection assembly, the first and second oil injection channels are arranged in parallel, and the axes of the first and second oil injection channels are inconsistent with the axis of the stator core. A guide is provided in the transition channel; when the coolant flow rate in the transition channel is less than a threshold value, the guide will limit the coolant in the transition channel from flowing into the first oil injection channel; the coolant flows out from the second oil injection channel, thereby spraying on the stator core end winding at a small angle, so that the coolant can flow along the outer surface of the stator core end winding, covering more surface area, and improving the uniformity of cooling. When the coolant flow rate in the transition channel is greater than the threshold value, the coolant in the transition channel can overcome the restriction of the guide member and flow into the first oil injection channel. Thus, the coolant is injected onto the stator core end winding at a large angle, which can maximize the impact force between the coolant and the surface of the stator core end winding, quickly break the thermal boundary layer on the surface of the stator core end winding, thereby improving the heat exchange efficiency and quickly taking away the heat generated by the stator core end winding, which is suitable for high load conditions.

[0005] The present invention adopts the following technical solutions.

[0006] An oil-cooled motor stator heat dissipation structure, comprising:

[0007] A stator core, a shunt ring and an oil injection assembly are sequentially arranged along the axial direction;

[0008] The outer peripheral wall of the stator core is uniformly provided with a plurality of axially extending coolant flow channels, the diverter ring is uniformly provided with a plurality of transition channels connected with the coolant flow channels in the circumferential direction, the oil injection assembly is uniformly provided with a plurality of first oil injection channels and second oil injection channels in the circumferential direction, the first oil injection channel and the second oil injection channel are arranged in parallel, and the included angles of the axes of the first oil injection channel and the second oil injection channel and the axis of the stator core are inconsistent;

[0009] A flow guide is provided in the transition channel;

[0010] When the coolant flow rate in the transition channel is less than a threshold value, the guide member will restrict the coolant in the transition channel from flowing into the first oil injection channel;

[0011] When the coolant flow rate in the transition channel is greater than a threshold value, the coolant in the transition channel can overcome the restriction of the guide member and flow into the first oil injection channel.

[0012] Preferably, the coolant flow channel comprises a straight flow channel and a zigzag flow channel arranged in parallel, an adjustment ring is rotatably connected to the stator core, a flow block is provided on the adjustment ring, and the flow block can shield the straight flow channel and / or the zigzag flow channel.

[0013] Preferably, the stator core comprises a plurality of first punching sheets stacked in sequence, a plurality of positioning keys distributed along the circumferential direction are provided on the outer side of the first punching sheets, and the coolant flow channel is located between adjacent positioning keys.

[0014] Preferably, the projection positions of the inlet and outlet of the zigzag flow channel on the horizontal plane do not overlap, and the cooling oil flows in from the inlet of the zigzag flow channel, turns back, and then flows out from the outlet of the zigzag flow channel.

[0015] Preferably, a spoiler is provided on the outer side of the first punching sheet and is located in the zigzag flow channel to control the flow direction of the coolant.

[0016] Preferably, the diverter ring is provided with an annular confluence groove, and the confluence groove is located between the transition channel and the coolant channel.

[0017] Preferably, the angle between the axis of the first oil injection channel and the axis of the stator core is greater than the angle between the axis of the second oil injection channel and the axis of the stator core, and the flow guide is a spring embedded in the transition channel.

[0018] Preferably, the fuel injection assembly includes a plurality of second punching sheets stacked in sequence, the second punching sheets are coaxially arranged with the stator core, the second punching sheets are provided with a plurality of groups of first fuel injection holes for forming a first fuel injection channel, and a plurality of groups of second fuel injection holes for forming a second fuel injection channel.

[0019] Preferably, the first fuel injection channel and the second fuel injection channel each include m fuel injection branch channels, and m is greater than or equal to 2.

[0020] The beneficial effects of the present invention are:

[0021] The present invention provides an oil-cooled motor stator heat dissipation structure, wherein a plurality of axially extending coolant flow channels are evenly distributed on the outer peripheral wall of the stator core, a plurality of transition channels connected to the coolant flow channels are evenly distributed on the diverter ring along the circumferential direction, a plurality of first oil injection channels and second oil injection channels are evenly distributed on the oil injection assembly along the circumferential direction, the first oil injection channel and the second oil injection channel are arranged in parallel, and the angles between the axes of the first oil injection channel and the second oil injection channel and the axis of the stator core are inconsistent. A flow guide is arranged in the transition channel.

[0022] When the coolant flow rate in the transition channel is less than the threshold value, the guide member will limit the coolant in the transition channel from flowing into the first oil injection channel; the coolant flows out from the second oil injection channel, thereby spraying on the stator core end winding at a small angle, so that the coolant can flow along the outer surface of the stator core end winding, covering more surface area, and improving the uniformity of cooling. When the coolant flow rate in the transition channel is greater than the threshold value, the coolant in the transition channel can overcome the restriction of the guide member and flow into the first oil injection channel. Thus, the coolant is sprayed on the stator core end winding at a large angle, which can maximize the impact force between the coolant and the surface of the stator core end winding, quickly break the thermal boundary layer on the surface of the stator core end winding, thereby improving the heat exchange efficiency, and quickly taking away the heat generated by the stator core end winding, which is suitable for high load conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 It is a schematic diagram of the three-dimensional structure of an embodiment of the present invention;

[0025] Figure 2 A front view of an embodiment of the present invention;

[0026] Figure 3 for Figure 2 AA section view;

[0027] Figure 4 for Figure 2 BB section view;

[0028] Figure 5 for Figure 2 CC section view;

[0029] Figure 6 for Figure 2 DD section view;

[0030] Figure 7 It is a cross-sectional view of a first punching sheet in one embodiment of the present invention.

[0031] Description of reference numerals:

[0032] 1. stator core; 11. first punching plate; 111. positioning key; 112. spoiler block; 12. straight flow channel; 13. zigzag flow channel; 14. adjustment ring; 141. baffle block; 2. diverter ring; 21. transition channel; 211. guide piece; 22. confluence groove; 3. injection assembly; 31. first injection channel; 32. second injection channel; 33. second punching plate; 331. first injection hole; 332. second injection hole; 333. injection branch channel. DETAILED DESCRIPTION

[0033] The drawings are only used for illustrative purposes and should not be construed as limitations of this patent. In order to better illustrate this embodiment, some parts of the drawings may be omitted, enlarged, or reduced, and do not represent the size of the actual product.

[0034] For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the drawings. The technical solution of the present invention is further described below in conjunction with the drawings and embodiments.

[0035] An oil-cooled motor stator heat dissipation structure comprises a stator core 1, a shunt ring 2 and an oil injection assembly 3 which are sequentially arranged along the axial direction.

[0036] A plurality of axially extending coolant flow channels are evenly distributed on the outer peripheral wall of the stator core 1, a plurality of transition channels 21 connected to the coolant flow channels are evenly distributed along the circumferential direction on the diverter ring 2, a plurality of first oil injection channels 31 and second oil injection channels 32 are evenly distributed along the circumferential direction on the oil injection assembly 3, the first oil injection channel 31 and the second oil injection channel 32 are arranged in parallel, and the angles between the axes of the first oil injection channel 31 and the second oil injection channel 32 and the axis of the stator core 1 are inconsistent.

[0037] A guide member 211 is provided in the transition channel 21; when the coolant flow rate in the transition channel 21 is less than a threshold value, the guide member 211 will limit the coolant in the transition channel 21 from flowing into the first oil injection channel 31; when the coolant flow rate in the transition channel 21 is greater than the threshold value, the coolant in the transition channel 21 can overcome the restriction of the guide member 211 and flow into the first oil injection channel 31.

[0038] When the stator core 1 is cooled and dissipated, the coolant is sprayed out from the first oil spray channel 31 or the second oil spray channel 32 to cool and dissipate the heat of the winding ends or other components of the stator.

[0039] In some embodiments, the coolant flow channel includes a straight flow channel 12 and a zigzag flow channel 13 arranged in parallel, an adjustment ring 14 is rotatably connected to the stator core 1, and a baffle block 141 is provided on the adjustment ring 14. The baffle block 141 can shield the straight flow channel 12 and / or the zigzag flow channel 13.

[0040] When in use, the flow rate of the coolant flowing into the straight-line flow channel 12 and the folded-line flow channel 13 is regulated by rotating the adjusting ring 14 .

[0041] In some embodiments, the stator core 1 includes a plurality of first punching sheets 11 stacked in sequence, and a plurality of positioning keys 111 are provided on the outer side of the first punching sheet 11 distributed along the circumferential direction, and the coolant flow channel is located between adjacent positioning keys 111. The first punching sheets 11 are fixed by welding, and the positioning keys 111 also play a role in assisting alignment.

[0042] In some embodiments, a spoiler 112 located in the zigzag flow channel 13 is provided on the outer side of the first punching plate 11. The spoiler 112 significantly increases the contact area between the first punching plate 11 and the coolant, thereby improving the heat exchange efficiency.

[0043] In some embodiments, the projected positions of the inlet and outlet of the zigzag flow channel 13 on the horizontal plane do not overlap, and the cooling oil flows in from the inlet of the zigzag flow channel 13, turns back, and then flows out from the outlet of the zigzag flow channel 13. By setting the position of the spoiler 112, the cooling oil flows in the zigzag flow channel 13 in a turning manner, which extends the flow path of the cooling oil, thereby achieving a better cooling effect on the stator core 1.

[0044] In some embodiments, a ring-shaped confluence groove 22 is provided on the diverter ring 2, and the confluence groove 22 is located between the transition channel 21 and the coolant channel. The coolant entering the coolant flow channel converges again in the confluence groove 22, flows and intersects in the confluence groove 22, and flows out of the transition channel 21, thereby improving the temperature consistency of the motor.

[0045] In some embodiments, the angle between the axis of the first oil injection channel 31 and the axis of the stator core 1 is greater than the angle between the axis of the second oil injection channel 32 and the axis of the stator core 1 , and the guide member 211 is a spring embedded in the transition channel 21 .

[0046] In some embodiments, the fuel injection assembly 3 includes a plurality of second punching sheets 33 stacked in sequence, the second punching sheets 33 are coaxially arranged with the stator core 1, and the second punching sheets 33 are provided with a plurality of groups of first fuel injection holes 331 for forming a first fuel injection channel 31, and a plurality of groups of second fuel injection holes 332 for forming a second fuel injection channel 32.

[0047] In some embodiments, the first oil injection channel 31 and the second oil injection channel 32 each include m oil injection branch channels, where m is greater than or equal to 2. By providing the oil injection branch channels 333, the cooling oil has a wider spray range when sprayed, so that the end windings of the stator core 1 have better cooling uniformity.

[0048] However, the prior art often fails to efficiently cool the core and windings separately. Furthermore, when the overall power of the motor decreases, the amount of coolant entering the motor will decrease. The traditional motor winding cooling method cannot adjust the spray angle of the coolant. Thus, when the speed of the coolant sprayed from the oil spray hole decreases, the angle at which the coolant enters the winding will tend to be vertical, resulting in a smaller coverage area of ​​the coolant on the winding, resulting in poor cooling effect.

[0049] At the same time, a coolant flow channel is provided on the stator core 1, and the cooling medium flows in the coolant flow channel, which can improve the heat dissipation capacity of the motor stator itself. At the same time, the outer cylindrical surface of the motor is a full circle, which can have good contact with the casing, which is conducive to production installation and transportation.

[0050] It can also adapt to different working conditions of the motor and make corresponding adjustments to the spray angle of the coolant. For example, a motor with a rated working condition of 65kW, when it is at a rated speed of 12000rpm, copper loss accounts for about 20% of the total loss, iron loss accounts for about 53% of the total loss, and the iron core is the main source of heat. When the peak working condition is 120kW and the speed is 16000rpm, copper loss accounts for about 93% of the total loss, iron loss accounts for about 6% of the total loss, and the winding is the main source of heat. It can be seen that under different working conditions, the parts of the motor that need to be cooled first are different, and the existing technology often cannot perform efficient cooling of the iron core and winding separately. At rated speed, the stator core 1 needs to be cooled first. By rotating the adjusting ring 14, the baffle block 141 blocks the entrance of the straight flow channel 12, so that the coolant mainly flows into the zigzag flow channel 13. The zigzag flow channel 13 allows the coolant to pass through the core at a lower speed and a longer distance, so that the coolant is fully in contact with the stator core 1 and the core is fully cooled. After that, the coolant flows into the transition channel 21. Since the coolant loses a part of its speed in the zigzag flow channel 13, the flow rate of the coolant cannot reach the threshold value, and can only push the spring 43 to turn outward with a small amplitude. Therefore, the spring 43 still maintains the position of limiting the coolant from being ejected from the first oil injection channel 31. The coolant will be ejected from the second oil injection channel 32, so as to be ejected at a small angle on the end winding of the stator core 1, so that the coolant can flow along the outer surface of the end winding of the stator core 1, covering more surface area and improving the uniformity of cooling.

[0051] At the peak speed, the winding needs to be cooled first. By rotating the adjusting ring 14, the baffle block 141 blocks the entrance of the zigzag flow channel 13, so that the coolant mainly flows through the straight flow channel 12. The straight flow channel 12 allows the coolant to flow through the stator core 1 at a faster speed, so that the coolant can be sprayed out at a lower temperature. After that, the coolant flows into the confluence groove 22. Since the coolant basically has no loss of speed in the straight flow channel 12, the speed of the coolant exceeds the threshold, which is enough to push the spring 43 to a large extent, so that the spring 43 releases the restriction on the first oil injection channel 31, and most of the coolant can be ejected from the first oil injection channel 31. When the coolant is sprayed from the first oil injection channel 31, it has a greater relative speed with the stator core 1, thereby significantly reducing the thickness of the thermal boundary layer on the surface of the end winding of the stator core 1, improving the heat exchange efficiency, and quickly taking away the heat generated by the end winding of the stator core 1, which is suitable for high load conditions.

[0052] The stator core 1 is also provided with a confluence groove 22, so that the coolant can flow into the transition channel 21 evenly, and the coolant is fully mixed in the confluence groove 22, thereby improving the heat dissipation capacity of the stator core 1 and improving the temperature consistency of the motor.

[0053] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An oil-cooled motor stator heat dissipation structure, characterized in that ,include: A stator core, a shunt ring and an oil injection assembly are sequentially arranged along the axial direction; The outer peripheral wall of the stator core is uniformly provided with a plurality of axially extending coolant flow channels, the diverter ring is uniformly provided with a plurality of transition channels connected with the coolant flow channels in the circumferential direction, the oil injection assembly is uniformly provided with a plurality of first oil injection channels and second oil injection channels in the circumferential direction, the first oil injection channel and the second oil injection channel are arranged in parallel, and the included angles of the axes of the first oil injection channel and the second oil injection channel and the axis of the stator core are inconsistent; A flow guide is provided in the transition channel; When the coolant flow rate in the transition channel is less than a threshold value, the guide member will restrict the coolant in the transition channel from flowing into the first oil injection channel; When the coolant flow rate in the transition channel is greater than a threshold value, the coolant in the transition channel can overcome the restriction of the guide member and flow into the first oil injection channel.

2. The oil-cooled motor stator heat dissipation structure according to claim 1, characterized in that: The coolant flow channel comprises a straight flow channel and a zigzag flow channel arranged in parallel, an adjusting ring is rotatably connected to the stator core, a flow block is provided on the adjusting ring, and the flow block can shield the straight flow channel and / or the zigzag flow channel.

3. The oil-cooled motor stator heat dissipation structure according to claim 2, characterized in that: The stator core comprises a plurality of first punching sheets stacked in sequence, a plurality of positioning keys distributed along the circumferential direction are arranged on the outer side of the first punching sheets, and the coolant flow channel is located between adjacent positioning keys.

4. The oil-cooled motor stator heat dissipation structure according to claim 2, characterized in that: The projection positions of the inlet and outlet of the zigzag flow channel on the horizontal plane do not overlap, and the cooling oil flows in from the inlet of the zigzag flow channel, turns back, and then flows out from the outlet of the zigzag flow channel.

5. The oil-cooled motor stator heat dissipation structure according to claim 3, characterized in that: A spoiler block is disposed on the outer side of the first punching sheet and is located in the zigzag flow channel to control the flow direction of the coolant.

6. The oil-cooled motor stator heat dissipation structure according to claim 1, characterized in that: The diverter ring is provided with an annular confluence groove, and the confluence groove is located between the transition channel and the coolant channel.

7. The oil-cooled motor stator heat dissipation structure according to claim 1, characterized in that: The angle between the axis of the first oil injection channel and the axis of the stator core is greater than the angle between the axis of the second oil injection channel and the axis of the stator core, and the flow guide is a spring embedded in the transition channel.

8. The oil-cooled motor stator heat dissipation structure according to claim 1, characterized in that: The fuel injection assembly includes a plurality of second punching sheets stacked in sequence, the second punching sheets are coaxially arranged with the stator core, and the second punching sheets are provided with a plurality of groups of first fuel injection holes for forming a first fuel injection channel, and a plurality of groups of second fuel injection holes for forming a second fuel injection channel.

9. The oil-cooled motor stator heat dissipation structure according to claim 8, characterized in that: The first fuel injection channel and the second fuel injection channel each include m fuel injection branch channels, where m is greater than or equal to 2.

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