Motor stator cooled by oil passing through grooves

Abstract

The invention requests to protect a motor stator with oil passing through grooves for cooling, the motor stator comprises a shell, an iron core and a winding, the iron core is cylindrical, the shell is arranged outside the iron core, the annular inner wall of the iron core is provided with a plurality of stator grooves, each stator groove is arranged along the axial direction of the iron core in a penetrating manner, and the winding is arranged in the stator groove. A plurality of oil holes are formed in the groove bottom of each stator groove in the radial direction, circumferential oil way grooves are formed in the positions, at the oil holes in different axial positions, of the annular outer wall of the iron core in the circumferential direction, and a plurality of axial oil way grooves are formed between every two adjacent circumferential oil way grooves. An oil inlet is formed in the position, between the two circumferential oil way grooves which are farthest away from each other, of the shell. The oil holes are communicated through the circumferential oil way grooves and the axial oil way grooves, and therefore after cooling oil enters from the oil inlet, large-area cooling can be conducted on the surface of the iron core firstly; the cooling oil enters the stator slots through the oil holes, so that the cooling oil is directly sprayed to the windings in the stator slots; and finally, axially spraying and cooling the end winding.

Description

Technical Field

[0001] The present invention relates to the technical field of electric motors, and more particularly to an electric motor stator with oil cooling in a slot. Background Art

[0002] Oil-cooled motors are relative to traditional water-cooled motors. Their motor refrigerant medium and heat exchange method are different from those of water-cooled motors. The oil cooling method can directly contact the motor windings to cool them down.

[0003] At present, the prior art, for example, the invention patent with publication number CN115566842A discloses a series oblique oil spray cooling structure of an oil-cooled motor, which includes "including a casing, an outer wall of the casing is provided with an oil inlet, an oil separation core lamination is provided inside the casing, cooling core laminations are provided on both sides of the oil separation core lamination, oil spray laminations are provided on one side of the two cooling core laminations, slot insulation paper is inserted and installed on one side of the oil spray lamination, windings are provided on the inner side of the slot insulation paper, nozzles are provided on the outer edge of the oil spray lamination, and a process gasket core is provided on the outer side of the oil spray lamination, According to the process requirements, a process gasket core that avoids the nozzle can be set on the outside of the oil-spraying lamination. When in use: the cooling oil is injected from the oil inlet on the casing into the middle oil-separating core lamination, distributed 360 degrees along the circumference, and then flows into the cooling channel on the surface of the cooling core lamination and then moves axially, and finally flows to the oil-spraying lamination, and is sprayed through the nozzle to the end of the winding for cooling. "Although the winding is cooled by oil cooling, the oil can only be sprayed from the nozzles on both sides of the core, and can only directly cool the ends of both sides of the winding. Such cooling effect is still not direct enough, resulting in insufficient cooling efficiency.

[0004] Therefore, how to improve the cooling efficiency of the motor is exactly the technical problem to be solved by this application. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention proposes a motor stator with oil cooling in the slots. By providing oil grooves and connecting grooves, cooling oil can enter the stator slots more stably and continuously. The provision of the oil grooves and connecting grooves increases the contact area between the cooling oil and the surface of the iron core, thereby improving the cooling efficiency.

[0006] The present invention provides a motor stator with oil cooling in the slot, and the technical solution is as follows:

[0007] The invention discloses a motor stator with oil cooling in the slot, comprising a shell, an iron core and a winding. The iron core is cylindrical, the shell is arranged outside the iron core, a plurality of stator slots are opened on the annular inner wall of the iron core, each stator slot is opened through the axial direction of the iron core, and the winding is arranged in the stator slot.

[0008] A plurality of oil holes are radially provided at the bottom of each stator slot, and each oil hole radially penetrates from the bottom of the stator slot to the annular outer wall of the iron core. The number and position of the oil holes on each stator slot are consistent, and circumferential oil path grooves are circumferentially provided on the annular outer wall of the iron core at the oil holes at different axial positions, and each circumferential oil path groove is used to connect the oil holes at the same axial position.

[0009] A plurality of axial oil passage grooves are arranged between adjacent circumferential oil passage grooves.

[0010] The housing is provided with an oil inlet at the middle position of the two circumferential oil grooves which are farthest apart. The oil inlet is used for cooling oil to enter and enter each stator slot through the circumferential oil groove, the axial oil groove and the oil hole.

[0011] In summary, the above technical scheme has the following beneficial effects: the present application opens a number of oil holes at the bottom of the stator slot, and opens a circumferential oil path groove and an axial oil path groove on the annular outer wall of the core, thereby connecting the various oil holes, so that after the cooling oil enters from the oil inlet, it will first fill the circumferential oil path groove and the axial oil path groove, so that the cooling oil is stored in the fluidity of the core surface, and these cooling oils will cool the core surface over a large area; then the cooling oil will enter the stator slot through each oil hole, thereby directly spraying the winding in the stator slot to achieve high-speed convection heat exchange; finally, the cooling oil in the stator slot will be sprayed at high speed from both sides of the stator slot to form axial spray cooling of the end winding. By opening the circumferential oil path groove and the axial oil path groove, multiple oil holes can be supported to discharge oil, which increases the flow rate of the cooling oil, and the circumferential oil path groove and the axial oil path groove have the function of temporarily storing cooling oil, making the spraying of the cooling oil in the oil hole more stable, avoiding the situation where the oil pump is unstable and causing a large change in the cooling oil flow rate, thereby improving the cooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of an exploded view of a motor stator with oil cooling in the slot;

[0013] Figure 2 A schematic diagram of an iron core of a motor stator with oil cooling in the slot;

[0014] Figure 3 A schematic diagram of a circumferential oil groove and an axial oil groove of a motor stator with oil cooling in the groove;

[0015] Figure 4 A schematic diagram of a temporary storage slot and a connecting slot of a motor stator with oil cooling in the slot;

[0016] Figure 5 A schematic diagram of insulating paper for a motor stator with oil cooling in the slot;

[0017] Figure 6It is a schematic diagram of a side view of insulating paper of a motor stator with oil cooling in the slot;

[0018] Figure 7 A schematic diagram of insulating paper in a stator slot of a motor with oil cooling in the slot;

[0019] Figure 8 A schematic diagram of an oil inlet of a motor stator with oil cooling in a slot;

[0020] Fig. 9 A schematic diagram of an exploded view of the iron core of a motor stator with oil cooling in the slot;

[0021] Fig.10 It is a schematic diagram of the end face punching of a motor stator with oil cooling in the slot;

[0022] Fig.11 It is a schematic diagram of a lower hole punching plate of a motor stator with oil cooling in the slot;

[0023] Fig.12 A schematic diagram of an upper hole punching plate of a motor stator with oil cooling in the slot;

[0024] Fig.13 The present invention is a schematic diagram of a connecting punching sheet of a motor stator with oil cooling in the slot.

[0025] Figure numerals: 10, housing; 11, oil inlet; 20, iron core; 21, stator slot; 22, oil hole; 221, inlet hole; 222, outlet hole; 23, circumferential oil path groove; 24, axial oil path groove; 25, temporary storage groove; 26, connecting groove; 27, end face punching sheet; 28, lower hole punching sheet; 29, upper hole punching sheet; 210, connecting punching sheet; 30, winding; 40, insulating paper; 41, bottom surface; 42, left side surface; 43, right side surface; 44, left connecting surface; 45, right connecting surface; 46, left fixed surface; 47, right fixed surface. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] like Figure 1-Figure 3As shown, a motor stator with oil cooling in the slot includes a housing 10, an iron core 20 and a winding 30. The iron core 20 is cylindrical. The housing 10 is arranged outside the iron core 20. The annular inner wall of the iron core 20 is provided with a plurality of stator slots 21. Each stator slot 21 is opened along the axial direction of the iron core 20. The winding 30 is arranged in the stator slot 21. The bottom of each stator slot 21 is provided with a plurality of oil holes 22 in the radial direction. Each oil hole 22 is radially penetrated from the bottom of the stator slot 21 to the annular outer wall of the iron core 20. The oil hole 22 on each stator slot 21 is provided with a plurality of oil holes 22 in the radial direction. The number and position of the oil holes 22 are consistent. The annular outer wall of the iron core 20 is provided with circumferential oil grooves 23 at the oil holes 22 at different axial positions. Each circumferential oil groove 23 is used to connect the oil holes 22 at the same axial position. A plurality of axial oil grooves 24 are provided between adjacent circumferential oil grooves 23. The housing 10 is provided with an oil inlet 11 at the middle position of the two circumferential oil grooves 23 that are farthest apart. The oil inlet 11 is used for cooling oil to enter and enter each stator slot 21 through the circumferential oil grooves 23, the axial oil grooves 24 and the oil holes 22.

[0028] The present application opens a plurality of oil holes 22 at the bottom of the stator slot 21, and opens a circumferential oil path groove 23 and an axial oil path groove 24 on the annular outer wall of the core 20, thereby connecting the oil holes 22. In this way, after the cooling oil enters from the oil inlet 11, it will first fill the circumferential oil path groove 23 and the axial oil path groove 24, so that the cooling oil is stored in the fluidity of the surface of the core 20, and the cooling oil will cool the surface of the core 20 over a large area; then the cooling oil will enter the stator slot 21 through the oil holes 22, thereby directly spraying the winding 30 in the stator slot 21 to achieve high-speed convection heat exchange; finally, the cooling oil in the stator slot 21 will be sprayed at high speed from both sides of the stator slot 21, forming axial spray cooling of the end winding 30. By opening the circumferential oil groove 23 and the axial oil groove 24, oil can be supported to flow out of multiple oil holes 22, thereby increasing the flow rate of the cooling oil. The circumferential oil groove 23 and the axial oil groove 24 have the function of temporarily storing the cooling oil, making the injection of the cooling oil in the oil hole 22 more stable, thus avoiding the situation where the cooling oil flow rate changes greatly due to the instability of the oil pump, thereby improving the cooling efficiency.

[0029] like Figure 4 As shown, a temporary storage groove 25 and a connecting groove 26 are provided at the bottom of the stator slot 21 near the outer ring of the core 20 . The inner side of the temporary storage groove 25 is connected to the stator slot 21 through the connecting groove 26 , and the outer side of the temporary storage groove 25 is connected to the oil hole 22 .

[0030] If the oil hole 22 is directly opened from the bottom of the stator slot 21 and extends to the outer surface of the core 20, the winding 30 and the oil hole 22 are directly connected, so that the winding 30 will block the oil hole 22, so that the cooling oil in the oil hole 22 does not flow smoothly, and the cooling oil is dispersed through the oil hole 22, and it does not enter the stator slot 21 in a point-like manner, which is not uniform, affecting the cooling efficiency. The present application is provided with a temporary storage groove 25 and a connecting groove 26, and the temporary storage groove 25 and the connecting groove 26 are opened axially and correspond to the bottom of the stator slot 21, so that the cooling oil in the oil hole 22 can first flow into the temporary storage groove 25, and then the cooling oil flows through the temporary storage groove 25 and flows along the axial ends. The cooling oil in the temporary storage groove 25 can flow into the stator slot 21 linearly through the connecting groove 26. When the flow rate is large, the cooling oil can also be sprayed to the two ends of the winding 30 through the two axial ends of the temporary storage groove 25 to cool the two ends of the winding 30.

[0031] The width of the connecting groove 26 is smaller than the width of the temporary storage groove 25 .

[0032] The cooling oil first enters the wider temporary storage groove 25 through the oil hole 22, and then is sprayed onto the winding 30 through the narrower connecting groove 26, thereby increasing the flow rate of the cooling oil spray and changing the point spray of the oil hole 22 into the linear spray of the connecting groove 26, so that the entire winding 30 can be evenly cooled.

[0033] The width of the temporary storage slot 25 is the same as the width of the stator slot 21. This arrangement can facilitate stator processing.

[0034] The width of the communication groove 26 is less than or equal to half of the width of the stator slot 21 .

[0035] The width of the connecting groove 26 is greater than or equal to one quarter of the width of the stator slot 21 .

[0036] The connecting groove 26 is located in the middle of the stator slot 21. The function of the connecting groove 26 is to allow the cooling oil in the temporary storage groove 25 to be sprayed into the stator slot 21 in a linear manner. The smaller the width of the connecting groove 26, the smaller the flow rate of the cooling oil spray and the faster the flow rate; the wider the connecting groove 26, the larger the flow rate and the slower the flow rate. In order to stabilize the flow rate, the width cannot be too large, and in order to ensure the cooling efficiency, the width cannot be too small. Therefore, the width range of the connecting groove 26 is greater than or equal to one quarter of the width of the stator slot 21 and less than or equal to one half of the width of the stator slot 21. Preferably, the width of the connecting groove 26 is one half of the width of the stator slot 21.

[0037] like Figure 5 and Figure 6 As shown, an insulating paper 40 is also included. The insulating paper 40 is arranged in the stator slot 21 to guide the cooling oil in the stator slot 21 to flow toward the axial ends of the stator slot 21.

[0038] The insulating paper 40 includes a bottom surface 41, a left side surface 42, a right side surface 43, a left connecting surface 44, a right connecting surface 45, a left fixing surface 46 and a right fixing surface 47; the left side of the bottom surface 41 is connected to the left side surface 42, the left side surface 42 is connected to the left connecting surface 44, and the left connecting surface 44 is connected to the left fixing surface 46; the right side of the bottom surface 41 is connected to the right side surface 43, the right side surface 43 is connected to the right connecting surface 45, and the right connecting surface 45 is connected to the right fixing surface 47; the bottom surface 41 is located at the notch of the stator slot 21, the left side surface 42 and the right side surface 43 are respectively located at both sides of the stator slot 21, the left connecting surface 44 and the right connecting surface 45 are respectively located at both sides of the connecting slot 26, and the left fixing surface 46 and the right fixing surface 47 are respectively located at both sides of the temporary storage slot 25.

[0039] The insulating paper 40 of the present application is in a semi-open state, which is convenient for the cooling oil to enter the stator slot 21; the bottom closed position of the insulating paper 40 is located at the notch of the stator slot 21, which is used to isolate the cooling oil and allow the cooling oil to move along the axial direction of the stator slot 21; because the width of the connecting slot 26 is smaller than the width of the temporary storage slot 25, the upper part of the insulating paper 40 extends into the temporary storage slot 25 to form a bent state, thereby preventing the insulating paper 40 from being washed off by the cooling oil. The insulating paper 40 can have a certain expansion effect, cooperate with the oil cooling solution in the slot, cancel the stator paint dripping process, and further achieve a significant cost reduction of the stator.

[0040] like Figure 7 As shown, the axial length of the insulating paper 40 is greater than the axial length of the stator slot 21. The insulating paper 40 is longer than the stator slot 21, and both sides extend from both ends of the stator slot 21, thereby ensuring that the cooling oil is sprayed out from both ends of the stator slot 21.

[0041] Both ends of the insulating paper 40 in the axial direction extend beyond both ends of the stator slot 21 in the axial direction.

[0042] The lengths of the portions of the insulating paper 40 extending beyond the stator slots 21 at both axial ends are the same.

[0043] The insulating paper 40 is longer than the stator slot 21 and is symmetrically arranged in the stator slot 21 so that the protruding portions at both ends have the same length, thereby making the cooling oil sprayed out from both ends at the same angle and cooling effect.

[0044] The length of both ends of the insulating paper 40 extending beyond the stator slot 21 is between 2 and 5 centimeters.

[0045] like Figure 8As shown, the oil hole 22 includes an inlet hole 221 and an outlet hole 222. The inlet hole 221 is opened inward from the annular outer wall of the iron core 20, and the outlet hole 222 is opened from the temporary storage groove 25 to the annular outer wall of the iron core 20. The depths of the inlet hole 221 and the outlet hole 222 are both less than the distance between the temporary storage groove 25 and the annular outer wall of the iron core 20. The inlet hole 221 and the outlet hole 222 are staggered, and the facing ends of the inlet hole 221 and the outlet hole 222 are connected in the iron core 20. Because the iron core 20 is composed of multiple punching sheets, if the oil hole 22 is a single hole, it will lead to an incomplete punching sheet. Therefore, the oil hole 22 is designed as an inlet hole 221 and an outlet hole 222, so that each punching sheet has only a partial area with an opening to ensure the integrity of the punching sheet.

[0046] like Figure 9-13 As shown, specifically, the iron core 20 is composed of an end face punching sheet 27, a lower hole punching sheet 28, an upper hole punching sheet 29 and a connecting punching sheet 210. The end face punching sheet 27, the lower hole punching sheet 28, the upper hole punching sheet 29 and the connecting punching sheet 210 are all provided with stator slots 21, temporary storage slots 25 and connecting slots 26. The end face punching sheet 27 is located at both axial ends of the iron core 20. The inlet hole 221 area is formed by stacking a plurality of upper hole punching sheets 29 with inlet holes 221, and the outlet hole 222 area is formed by stacking a plurality of lower hole punching sheets 28 with outlet holes 222. The outer diameters of the lower hole punching sheet 28 and the upper hole punching sheet 29 are the same, and the outer diameter of the lower hole punching sheet 28 is smaller than that of the end face punching sheet 27 and the connecting punching sheet 210, so that a circumferential oil path groove 23 is formed in the area where the lower hole punching sheet 28 and the upper hole punching sheet 29 are located, and an axial oil path groove 24 is opened on the outer side of the annular connecting punching sheet 210.

[0047] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A motor stator with oil cooling in the slot, comprising a housing (10), an iron core (20) and a winding (30), wherein the iron core (20) is cylindrical, the housing (10) is arranged outside the iron core (20), a plurality of stator slots (21) are formed on the annular inner wall of the iron core (20), each of the stator slots (21) is formed through the iron core (20) in the axial direction, and the winding (30) is arranged in the stator slot (21), characterized in that: A plurality of oil holes (22) are radially formed at the bottom of each stator slot (21), and each of the oil holes (22) radially penetrates from the bottom of the stator slot (21) to the annular outer wall of the iron core (20). The number and position of the oil holes (22) on each stator slot (21) are consistent. The annular outer wall of the iron core (20) is circumferentially formed with circumferential oil passage grooves (23) at the oil holes (22) at different axial positions, and each of the circumferential oil passage grooves (23) is used to connect the oil holes (22) at the same axial position. A plurality of axial oil passage grooves (24) are provided between adjacent circumferential oil passage grooves (23); The housing (10) is provided with an oil inlet (11) at a middle position between two circumferential oil grooves (23) that are farthest apart from each other. The oil inlet (11) is used for cooling oil to enter and enter each stator slot (21) through the circumferential oil groove (23), the axial oil groove (24) and the oil hole (22).

2. The motor stator with oil cooling in the slot according to claim 1, characterized in that: A temporary storage groove (25) and a connecting groove (26) are provided at the bottom of the stator groove (21) near the outer ring of the iron core (20); the inner side of the temporary storage groove (25) is connected to the stator groove (21) through the connecting groove (26), and the outer side of the temporary storage groove (25) is connected to the oil hole (22).

3. The motor stator with oil cooling in the slot according to claim 2, characterized in that: The width of the connecting groove (26) is smaller than the width of the temporary storage groove (25).

4. The motor stator with oil cooling in the slot according to claim 2, characterized in that: The width of the temporary storage slot (25) is the same as the width of the stator slot (21).

5. The motor stator with oil cooling in the slot according to claim 4, characterized in that: The width of the connecting groove (26) is less than or equal to half the width of the stator groove (21).

6. The motor stator with oil cooling in the slot according to claim 5, characterized in that: The width of the connecting groove (26) is greater than or equal to one quarter of the width of the stator groove (21).

7. The motor stator with oil cooling in the slot according to claim 3, characterized in that: Also included is insulating paper (40), which is arranged in the stator slot (21) and is used to guide cooling oil in the stator slot (21) to flow toward the axial ends of the stator slot (21).

8. The motor stator with oil cooling in the slot according to claim 7, characterized in that: The insulating paper (40) comprises a bottom surface (41), a left side surface (42), a right side surface (43), a left connecting surface (44), a right connecting surface (45), a left fixing surface (46) and a right fixing surface (47); The left side of the bottom surface (41) is connected to the left side surface (42), the left side surface (42) is connected to the left connecting surface (44), and the left connecting surface (44) is connected to the left fixing surface (46); The right side of the bottom surface (41) is connected to the right side surface (43), the right side surface (43) is connected to the right connecting surface (45), and the right connecting surface (45) is connected to the right fixing surface (47); The bottom surface (41) is located at the notch of the stator slot (21), the left side surface (42) and the right side surface (43) are respectively located at both sides of the stator slot (21), the left connecting surface (44) and the right connecting surface (45) are respectively located at both sides of the connecting slot (26), and the left fixing surface (46) and the right fixing surface (47) are respectively located at both sides of the temporary storage slot (25).

9. The motor stator with oil cooling in the slot according to claim 7, characterized in that: The axial length of the insulating paper (40) is greater than the axial length of the stator slot (21).

10. The motor stator with oil cooling in the slot according to any one of claims 1 to 9, characterized in that: The oil hole (22) comprises an inlet hole (221) and an outlet hole (222); the inlet hole (221) is opened inward from the annular outer wall of the iron core (20); the outlet hole (222) is opened from the temporary storage groove (25) toward the annular outer wall of the iron core (20); the depths of the inlet hole (221) and the outlet hole (222) are both less than the distance between the temporary storage groove (25) and the annular outer wall of the iron core (20); the inlet hole (221) and the outlet hole (222) are staggered; and the facing ends of the inlet hole (221) and the outlet hole (222) are connected in the iron core (20).

Images