Oil-cooled motor stator structure
By setting radial and axial cooling oil channels and an asymmetrical oil spray hole layout in the stator core, the problem of uneven cooling at the lower end of the flat wire motor windings is solved, achieving more efficient heat dissipation and more reliable motor operation.
Patent Information
- Application Number
- CN202211516572.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-11-30
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2042-11-30
AI Technical Summary
The existing oil-drenching cooling method for flat wire motors cannot effectively cool the lower end of the windings, resulting in excessive local temperature rise and uneven temperature distribution, which affects the motor's insulation and permanent magnets.
The stator structure of the oil-cooled motor adopts a stator core with radial and axial cooling oil channels, combined with an asymmetrical oil spray hole layout, to ensure that the cooling oil is evenly sprayed onto the winding ends, and heat dissipation is achieved through forced liquid cooling.
This improves the motor's heat dissipation efficiency, avoids excessive local temperature rise, reduces the risk of insulation degradation, and makes the motor more reliable and improves its performance.
Smart Images
Figure CN115800637B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of motor cooling. BACKGROUND
[0002] With the pursuit of motor performance, flat wire motors with high power density and high torque density have gradually become the focus of current research. However, high torque density and high power density also mean high heat generation. If the heat generated by the motor cannot be dissipated in time, the temperature of the motor will be too high. When the temperature of the motor is too high, it will affect the performance of the motor, and even damage the insulation and permanent magnet of the motor, so effective cooling of each heat generating part of the motor is needed to ensure the stable and safe operation of the motor.
[0003] The traditional air-cooled and water-cooled cooling method is that the heat generated by the motor is conducted to the motor case, and then the heat is taken away by air or cooling liquid. This cooling method cannot meet the cooling requirements of the flat wire motor at the present stage.
[0004] In order to improve the cooling effect of the flat wire motor, at the present stage, non-magnetic and non-conductive cooling oil is sprayed through the oil channel of the motor case or is spun to the end of the stator winding through the rotating shaft, or a fan is installed at one end of the stator winding to cool the flat wire motor. However, due to the influence of gravity, the motor case spraying device generally only sprays the upper half area of the winding end, and the lower half winding cannot be directly sprayed, but only the downward flow of the upper half cooling oil can cool the lower half winding, which will cause local temperature rise and uneven temperature distribution, which is easy to cause insulation deterioration. SUMMARY
[0005] The present application is to solve the problem of local temperature rise caused by the oil shower cooling method of the existing flat wire motor, which needs to add an oil retaining ring and cannot cool the lower end of the winding in time. A stator slot oil-cooled stator structure is provided.
[0006] 1. An oil-cooled motor stator structure, comprising: a stator core (9), a winding (8).
[0007] Its characterized in that, the stator core (9) is provided with an internal radial annular cooling oil channel (6) coaxial with it along its radial direction, and 48 axial cooling oil channels (7) parallel to the radial cooling oil channel (6) are arranged near the outer surface of the stator core along its axial direction. The end of the axial cooling oil channel (7) is near the end surface of the stator core. A ring-shaped cooling channel (3) coaxial with the outer surface of the stator core (9) is arranged along the radial direction of the stator core (9) at the end of the axial cooling oil channel (7), and the ring-shaped cooling channel (3) connects the axial cooling oil channels together. An inwardly extending radial cooling channel (4) parallel to the end surface of the stator core (9) and communicating with it is arranged on the inner surface of the ring-shaped cooling channel (3). A coordinate axis is established with the plane where the end surface of the stator core is located as the coordinate axis, and the center of the outer surface of the stator core is taken as the coordinate origin, the horizontal direction is taken as the X-axis, and the vertical direction is taken as the Y-axis. The inwardly extending radial cooling channel (4) is symmetrical about the Y-axis and asymmetric about the X-axis. Above the X-axis, the end of the inwardly extending radial cooling channel (4) is close to the outer surface of the end portion of the winding (8). Below the X-axis, the end of the inwardly extending radial cooling channel (4) is close to the middle position of the end portion of the winding (8). The inwardly extending radial cooling channel (4) is perpendicular to the axial cooling oil channel (7). A square slot (10) perpendicular to the inwardly extending radial cooling channel (4) is arranged at the end of the inwardly extending radial cooling channel (4). An oil shower hole perpendicular to the square slot (10) and communicating with it is arranged on the end surface of the stator core, and two oil shower holes are connected to each square slot (10). The oil shower holes above the X-axis are collectively referred to as upper end oil shower holes (1), and the oil shower holes below the X-axis are collectively referred to as lower end oil shower holes (5). An oil inlet hole (2) communicating with the internal radial annular cooling oil channel (6) is arranged on the outer surface of the stator core along the radial direction, which is a channel for cooling oil to enter the stator. The oil inlet hole (2) is in communication with an external cooling device. Further, the oil-cooled motor stator structure described in the application also needs an external cooling device to supply oil to the stator oil circuit and cool the cooling liquid. The oil outlet of the external cooling device is in communication with the oil inlet hole (2) on the stator core (9).
[0008] The oil-cooled motor stator structure described in the application uses forced liquid cooling to dissipate heat from the stator core and the end portion of the winding, promptly removes the heat generated by the flat wire motor, and greatly improves the heat dissipation efficiency of the motor. Moreover, the asymmetric oil shower hole arrangement enables the cooling oil to promptly spray and cool the entire end portion, avoids the problem of local overheating, reduces the possibility of insulation degradation, makes the motor run more reliably, and further improves the performance of the motor. BRIEF DESCRIPTION OF DRAWINGS
[0009] Figure 1 The end surface perspective view of the oil-cooled motor stator structure described in the application;
[0010] Figure 2 The perspective view of the stator core;
[0011] Figure 3 Fig. 1 is a perspective view of a stator structure;
[0012] Figure 4 Fig. 2 is a perspective view of a stator core;
[0013] Figure 5 Fig. 3 is a schematic view of an end surface of a stator core;
[0014] Figure 6 Fig. 4 is a schematic view of assembly of a stator core and winding;
[0015] 1, upper oil shower hole; 2, stator core cooling oil inlet; 3, end surface radial annular cooling passage; 4, inwardly extending radial cooling passage; 5, lower oil shower hole; 6, radial annular cooling passage; 7, axial cooling passage; 8, stator winding; 9, stator core; 10, square slot; DETAILED DESCRIPTION
[0016] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.
[0017] Specific implementation one: refer to Figures 1 to 6 Specifically, the oil-cooled motor stator structure described in the embodiment includes: (9) a stator core and (8) a stator winding.
[0018] The stator winding is embedded in the stator core slot.
[0019] Its characterized in that, the stator core (9) is provided with an internal radial annular cooling oil channel (6) coaxial with it along its radial direction, and 48 axial cooling oil channels (7) parallel to the radial cooling oil channel (6) are provided at a position close to the outer surface of the stator core along its axial direction. The end of the axial cooling oil channel (7) is at a position close to the end surface of the stator core. A ring-shaped cooling channel (3) coaxial with the outer surface of the stator core (9) is provided at the end of the axial cooling oil channel (7) along the radial direction of the stator core (9), and the ring-shaped cooling channel (3) connects the axial cooling oil channels together. An inwardly extending radial cooling channel (4) parallel to the end surface of the stator core (9) and communicating with it is provided on the inner surface of the ring-shaped cooling channel (3). A coordinate axis is established with the plane where the end surface of the stator core is located as the coordinate axis, and the center of the outer surface of the stator core is taken as the coordinate origin, with the horizontal direction as the X-axis and the vertical direction as the Y-axis. The inwardly extending radial cooling channel (4) is Y-axis symmetric and X-axis asymmetric. Above the X-axis, the end of the inwardly extending radial cooling channel (4) is close to the outer surface of the end portion of the winding (8). Below the X-axis, the end of the inwardly extending radial cooling channel (4) is close to the middle position of the end portion of the winding (8). The inwardly extending radial cooling channel (4) is perpendicular to the axial cooling oil channel (7). A square slot (10) perpendicular to the inwardly extending radial cooling channel (4) is opened at the end of the inwardly extending radial cooling channel (4). Oil shower holes perpendicular to the square slot (10) and communicating with it are opened on the end surface of the stator core, with the upper end oil shower hole (1) above the X-axis and the lower end oil shower hole (5) below the X-axis. An oil inlet hole (2) communicating with the internal radial annular cooling oil channel (6) is opened on the outer surface of the stator core along the radial direction, which is a channel for the cooling oil to enter the stator and communicate with the external cooling oil pump.
[0020] Further, the oil-cooled motor stator structure described in the present application also needs an external cooling device to supply oil to the stator oil circuit and cool the cooling liquid. The oil outlet of the external cooling device communicates with the oil inlet hole (2) on the stator core (9).
[0021] The stator structure described in the present example only needs to process the core laminations into the required shape at the corresponding positions during actual processing, and finally stack them into the stator core structure, so that the oil cooling in the slots of the stator core can be realized.
[0022] The working principle of the present embodiment for oil cooling in the stator slots is as follows:
[0023] The stator oil cooling process is as follows: the cooling oil with low temperature enters the stator core (9) from the stator core (9) cooling oil inlet (2), flows into the radial annular channel (6) in the stator, then flows into the plurality of axial cooling channels (7) in parallel with the radial annular channel, flows through the axial cooling channels (7) to the end to flow into the end face radial annular cooling channel (3) near the stator end face, flows into the inwardly extending radial cooling channel (4) extending radially inwardly and parallel to the stator end face through the end face radial annular cooling channel (3), flows through the inwardly extending radial cooling channel (4) to the square groove (10) at the end of the inwardly extending radial cooling channel (4), and then is sprayed out from the plurality of axial oil injection holes in communication with the square groove to the surface of the winding end portion to cool the winding end portion.
[0024] In the specific implementation process, the application adopts an asymmetric structure design, establishes a coordinate axis with the plane where the stator core end face is located, takes the center of the outer surface of the stator core as the coordinate origin, takes the horizontal direction as the X axis, and takes the vertical direction as the Y axis. The inwardly extending radial cooling channel (4) is a Y axis symmetric and X axis asymmetric structure. Above the X axis, the end of the inwardly extending radial cooling channel (4) is close to the outer surface of the winding (8) end portion. Below the X axis, the end position of the inwardly extending radial cooling channel (4) is close to the middle position of the winding (8) end portion. In this way, the relative position of the oil spraying hole and the end portion winding is more reasonable, so that the entire end portion winding can be timely sprayed by the cooling oil to carry away a large amount of heat and avoid local overheating problems. In actual application, the position of the oil spraying hole can be changed as needed.
[0025] Although the application is described herein with reference to particular embodiments, it is to be understood that these embodiments are merely exemplary of the principles and applications of the present application. It is therefore to be understood that numerous modifications can be made to the illustrative embodiments and that other arrangements can be devised without departing from the spirit and scope of the present application as defined by the appended claims. It is to be understood that the features of the dependent claims can be combined with those of the parent application in the manner set forth in the description. It is also to be understood that features described with respect to one embodiment can be used in other embodiments.
Claims
1. A stator structure for an oil-cooled electric motor, comprising: The stator core (9) and winding (8) are characterized in that the stator core (9) has an internal radial annular cooling oil channel (6) coaxial with it along its radial direction, and 48 axial cooling oil channels (7) connected in parallel with the radial cooling oil channels (6) are provided along its axial direction near the outer surface of the stator core. The end of the axial cooling oil channel (7) is near the end face of the stator core. At the end of the axial cooling oil channel (7), an annular cooling channel (3) coaxial with the outer surface of the stator core (9) is provided along the radial direction of the stator core (9). The annular cooling channel (3) connects the axial cooling channels together. On the inner surface of the annular cooling channel (3), there is an inwardly extending radial cooling channel (4) parallel to and connected to the end face of the stator core (9). A coordinate axis is established with the plane where the end face of the stator core is located, with the center of the circle of the outer surface of the stator core as the origin, the horizontal direction as the X-axis, and the vertical direction as the Y-axis. The inwardly extending radial cooling channel The channel (4) is a Y-axis symmetrical and X-axis asymmetrical structure. Above the X-axis, the end of the inwardly extending radial cooling channel (4) is close to the outer surface of the winding (8) end. Below the X-axis, the end of the inwardly extending radial cooling channel (4) is close to the middle position of the winding (8) end. The inwardly extending radial cooling channel (4) is perpendicular to the axial cooling channel (7). A square groove (10) perpendicular to it is opened at the end of the inwardly extending radial cooling channel (4). An oil-drenching hole perpendicular to the square groove (10) and connected to it is opened on the end face of the stator core. Each square groove (10) is connected to two oil-spraying holes. Several oil-drenching holes above the X-axis are collectively referred to as upper oil-drenching holes (1), and several oil-drenching holes below the X-axis are collectively referred to as lower oil-drenching holes (5). An oil inlet hole (2) connected to the internal radial annular cooling oil channel (6) is opened on the outer surface of the stator core in the radial direction. It is the channel for cooling oil to enter the stator and is connected to the external cooling oil pump.
2. The oil-cooled motor stator structure according to claim 1, characterized in that, The stator winding is a flat wire hairpin winding.
3. The oil-cooled motor stator structure according to claim 1, characterized in that, The coolant is engine oil.
4. The oil-cooled motor stator structure according to claim 1, characterized in that, An external cooling system is required to supply oil to the stator cooling channels.