An oil-cooled structure for motor stator

Abstract

This utility model relates to an oil-cooling structure for a motor stator, comprising an annular oil inlet groove and multiple deflecting oil channels. The annular oil inlet groove is disposed on the outer circumferential surface of the stator core. Multiple deflecting oil channels of the same shape and size are respectively disposed on both sides of the axial direction of the annular oil inlet groove. The multiple deflecting oil channels include at least two branch oil channels evenly distributed along the circumference of the stator core. The branch oil channels include an inlet oil channel, an outlet oil channel, and a serpentine oil channel. The inlet oil channel and the outlet oil channel extend along a first direction, which is parallel to the axial direction of the annular oil inlet groove. The first end of the serpentine oil channel is connected to the annular oil inlet groove through the inlet oil channel, and the second end is connected to the outlet oil channel, which extends to the axial end of the stator core. The flow rate and velocity in each branch oil channel of the above-mentioned motor stator oil-cooling structure are easily guaranteed, allowing the cooling lubricating oil to flow fully through the stator core, increasing the turbulence during the flow process, thereby improving the heat exchange capacity of the stator core and ensuring the high continuous performance of the drive motor of new energy commercial vehicles.

Description

Technical Field

[0001] This utility model relates to the field of drive motor technology, and more specifically, to a motor stator oil cooling structure. Background Technology

[0002] The current mainstream oil-cooled motor adopts a cooling scheme that couples indirect heat exchange through the yoke oil passage with direct heat exchange through spraying at the winding ends. That is, oil passages are opened in the stator core so that the cooling lubricating oil can indirectly carry away the heat introduced into the motor housing from the motor stator, and the cooling lubricating oil flows out from the yoke oil passage and sprays onto the winding ends.

[0003] However, existing yoke oil passages often have insufficient heat exchange capacity, with a low convective heat transfer coefficient, preventing the cooling system from supporting higher sustained performance. Therefore, improving the heat exchange capacity of the yoke oil passages through structural design is an urgent problem to be solved in the current new energy commercial vehicle drive motors. Utility Model Content

[0004] The purpose of this invention is to provide an oil-cooled structure for a motor stator to improve the heat exchange capacity of the oil channels in the yoke of the stator core.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] An oil-cooled stator structure for an electric motor, disposed on the stator core of the motor, comprising:

[0007] An annular oil inlet groove is provided on the outer circumferential surface of the stator core;

[0008] The stator core has multiple return oil channels, each with the same shape and size, arranged on both sides of the annular oil inlet groove on its outer circumferential surface. Each return oil channel includes X branch oil channels evenly distributed along the circumference of the stator core, where X is a natural number greater than or equal to 2. Each branch oil channel includes an inlet oil channel, an outlet oil channel, and a serpentine oil channel. Both the inlet oil channel and the outlet oil channel extend along a first direction, which is parallel to the axial direction of the annular oil inlet groove. The first end of the serpentine oil channel is connected to the annular oil inlet groove through the inlet oil channel, and the second end of the serpentine oil channel is connected to the outlet oil channel. The outlet oil channel extends to the axial end of the stator core.

[0009] In one embodiment of this application, the serpentine oil passage includes N serpentine units and N-1 connecting oil passages, where N is a natural number greater than or equal to 2. The serpentine units are arranged at intervals along the first direction, and the serpentine units are connected in series through the connecting oil passages to form the serpentine oil passage. The two serpentine units at both ends of the serpentine oil passage are respectively connected to the inlet oil passage and the outlet oil passage.

[0010] In one embodiment of this application, the serpentine unit includes M straight oil channels and M-1 rotary oil channels, where M is an odd number greater than or equal to 3. The straight oil channels are arranged in parallel at intervals and extend along a first direction or a second direction. The second direction is perpendicular to the axial direction of the annular oil inlet groove. The rotary oil channels are alternately connected to both ends of the straight oil channels along the arrangement direction of the straight oil channels to connect the straight oil channels in series to form the serpentine unit. The connecting oil channels are alternately connected between two adjacent serpentine units along the arrangement direction of the serpentine units.

[0011] In one embodiment of this application, the inlet oil passage, the outlet oil passage, the connecting oil passage, and the straight oil passage all extend along the first direction.

[0012] In one embodiment of this application, the stator core is assembled in a predetermined order from an inlet / outlet and connecting oil passage section, a rotating oil passage section, a straight oil passage section, and an annular oil inlet groove section. The inlet / outlet and connecting oil passage section is provided with a first oil passage groove structure in the circumferential direction to form the inlet oil passage, the outlet oil passage, and the connecting oil passage. The rotating oil passage section is provided with a second oil passage groove structure in the circumferential direction to form the rotating oil passage. The straight oil passage section is provided with a third oil passage groove structure in the circumferential direction to form the straight oil passage. The diameter of the annular oil inlet groove section is less than or equal to the minimum distance between the first oil passage groove structure, the second oil passage groove structure, and the third oil passage groove structure and the axis of the stator core.

[0013] In one embodiment of this application, the inlet / outlet and connecting oil passage section is formed by stacking multiple A-type laminations, and the A-type laminations are evenly distributed with multiple first punches at circumferential intervals, the number of the first punches being X;

[0014] The rotary oil passage section is composed of multiple B-type laminations stacked together. The B-type laminations are provided with multiple second punches and multiple slots alternately in the circumferential direction. The shape and size of the second punches are the same as the first punches. The radial dimension of the slots is the same as the radial dimension of the second punches. The circumferential dimension of the slots is more than twice the circumferential dimension of the second punches. At least one slot is provided between two adjacent second punches.

[0015] The straight oil passage section is formed by stacking multiple C-shaped laminations. The C-shaped laminations have multiple third holes evenly distributed around their circumference. The shape and size of the third holes are the same as the first holes. The number of third holes is X×M.

[0016] The annular oil inlet groove section is composed of multiple D-shaped laminations stacked together. The diameter of the D-shaped lamination is less than or equal to the minimum distance between the first punch, the second punch, and the third punch and the axis of the stator core.

[0017] In one embodiment of this application, the inlet and outlet connecting oil passage section, the rotary oil passage section and the straight oil passage section are respectively provided with positioning hole structures. The inlet and outlet connecting oil passage section, the rotary oil passage section and the straight oil passage section are arranged in a preset order and the positioning hole structures are aligned so that the first oil passage groove structure, the second oil passage groove structure and the third oil passage groove structure are connected to form the multi-folding oil passage.

[0018] In one embodiment of this application, a centripetal nozzle is provided at the end of the outlet oil passage away from the serpentine oil passage. The centripetal nozzle has an oil injection hole extending from one end to the other end. The centripetal nozzle includes an axial section and a centripetal section connected to the axial section. The axial section is inserted into the outlet oil passage. The centripetal section is inclined towards the axis of the stator core from the end connected to the axial section. The angle β between the centripetal section and the axial section satisfies 120°≤β≤135°.

[0019] In one embodiment of this application, a housing is further included, the housing being interference-fitted with the stator core, and an oil inlet is provided at a position corresponding to the annular oil inlet groove of the stator core.

[0020] In one embodiment of this application, an oil distribution ring is provided on the inner sidewall of the end of the housing, and an oil collecting ring cavity is formed between the oil distribution ring and the inner sidewall of the end of the housing. The oil collecting ring cavity is connected to the end of the outlet oil passage away from the serpentine oil passage. A plurality of oil outlet holes are provided on the oil distribution ring along the circumferential direction. One end of the oil outlet hole is connected to the oil collecting ring cavity, and the other end is directed toward the axial direction of the stator core.

[0021] As can be seen from the above technical solution, this utility model discloses a motor stator oil cooling structure. The motor stator oil cooling structure is disposed on the motor stator core. The motor stator oil cooling structure includes an annular oil inlet groove and multiple folding oil channels. The annular oil inlet groove is disposed on the outer circumferential surface of the stator core. Multiple folding oil channels of the same shape and size are respectively disposed on both sides of the axial direction of the annular oil inlet groove on the outer circumferential surface of the stator core. The multiple folding oil channels include X branch oil channels evenly distributed along the circumference of the stator core, where X is a natural number greater than or equal to 2. The branch oil channels include an inlet oil channel, an outlet oil channel, and a serpentine oil channel. The inlet oil channel and the outlet oil channel both extend along a first direction. The first direction satisfies the condition of parallelism with the axial direction of the annular oil inlet groove. The first end of the serpentine oil channel is connected to the annular oil inlet groove through the inlet oil channel, and the second end of the serpentine oil channel is connected to the outlet oil channel. The outlet oil channel extends to the axial end of the stator core.

[0022] The aforementioned motor stator oil cooling structure features a multi-reversal oil channel consisting of multiple circumferentially distributed branch oil channels on both sides of the annular oil inlet groove. The branch oil channels extend directly from the annular oil inlet groove to the end of the stator core, resulting in a simple path. The flow rate and velocity in each branch oil channel are easily guaranteed. The serpentine oil channels in the branch oil channels allow the cooling lubricating oil to flow fully through the stator core, increasing the turbulence generated during the flow process due to the reversal, thereby improving the heat exchange capacity of the stator core and ensuring the high continuous performance of the drive motor for new energy commercial vehicles. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the stator core having the stator oil-cooling structure provided in one embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of an oil-cooled motor stator provided in one embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the branch oil passage of a motor stator oil cooling structure provided in one embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of multiple core stacked segments of a stator core having the stator oil-cooling structure provided in one embodiment of the present invention.

[0028] Figure 5 An exploded view of multiple core stacked segments of a stator core having a stator oil-cooling structure provided in one embodiment of the present invention;

[0029] Figure 6 A partial structural schematic diagram of the A-type lamination of the stator core having the stator oil-cooling structure provided in this embodiment of the utility model;

[0030] Figure 7 A partial structural schematic diagram of the B-type lamination of the stator core having the stator oil-cooling structure provided in this embodiment of the utility model;

[0031] Figure 8 A partial structural schematic diagram of the C-shaped lamination of the stator core having the stator oil-cooling structure provided in this embodiment of the utility model;

[0032] Figure 9A partial structural schematic diagram of the D-type lamination of the stator core having the stator oil-cooling structure provided in this embodiment of the utility model;

[0033] Figure 10 This is a schematic diagram showing the stacking sequence of the stator core stacking segments of a motor stator with an oil-cooled stator structure provided in one embodiment of the present invention.

[0034] Figure 11 This is a schematic diagram of the stacking sequence of the stator core stacking segments of a motor stator with an oil-cooled stator structure provided in another embodiment of the present invention.

[0035] Figure 12 A schematic diagram of multiple core stacked segments of a stator core having a stator oil-cooling structure provided in another embodiment of the present invention.

[0036] Figure 13 A schematic diagram of the branch oil passage of the motor stator oil cooling structure provided in another embodiment of this utility model;

[0037] Figure 14 This is a cross-sectional view of the stator core and housing assembly provided in one embodiment of the present invention;

[0038] Figure 15 This is a schematic diagram of the stator core and housing assembly structure provided in another embodiment of the present invention;

[0039] Figure 16 A cross-sectional view of the stator core and housing assembly provided in another embodiment of this utility model;

[0040] Figure 17 This is a schematic diagram of the structure of the centripetal nozzle provided in an embodiment of the present utility model;

[0041] Figure 18 A cross-sectional view of a centripetal nozzle provided in an embodiment of this utility model;

[0042] Figure 19 This is a cross-sectional view of the stator core and housing assembly provided in another embodiment of the present invention.

[0043] In the picture:

[0044] 100 is the stator core; 110 is the first core stacked section; 120 is the second core stacked section; 130 is a type A lamination; 131 is the first punch; 132 is the first positioning hole; 140 is a type B lamination; 141 is the second punch; 142 is a groove; 143 is the second positioning hole; 150 is a type C lamination; 151 is the third punch; 152 is the third positioning hole; 160 is a type D lamination; 161 is the fourth positioning hole.

[0045] 200 is an annular oil inlet groove;

[0046] 300 is a multi-turn oil passage; 310 is a branch oil passage; 311 is an inlet oil passage; 312 is an outlet oil passage; 313 is a serpentine oil passage; 3131 is a serpentine unit; 31311 is a straight oil passage; 31312 is a rotary oil passage; 3132 is a connecting oil passage.

[0047] 400 is the housing; 410 is the oil inlet; 420 is the oil distribution ring; 430 is the oil collecting ring cavity; 440 is the oil outlet.

[0048] 500 is the radial nozzle; 510 is the axial section; 520 is the radial section; 530 is the oil injection hole; 540 is the limiting step surface. Detailed Implementation

[0049] The core of this utility model is to provide a motor stator oil cooling structure. The structural design of this motor stator oil cooling structure enables it to improve the heat exchange capacity of the oil passages in the yoke of the stator core.

[0050] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0051] Please see Figures 1 to 3 .

[0052] This utility model discloses a motor stator oil cooling structure, which is used to be installed on the stator core 100 of the motor. The motor stator oil cooling structure includes an annular oil inlet groove 200 and a multi-folding oil channel 300.

[0053] The annular oil inlet groove 200 is provided on the outer circumferential surface of the stator core 100. The annular oil inlet groove 200 is an open groove, that is, it has a groove wall on the side close to the axis of the stator core 100 in the axial and radial directions, and an open groove opening on the side far away from the axis of the stator core 100 in the radial direction. This design is used to form a circumferentially closed annular oil inlet cavity with the inner wall of the housing 400 when the stator core 100 is assembled into the housing 400.

[0054] The annular oil inlet groove 200 is usually located at the center of the outer circumferential surface of the stator core 100, that is, the distance between the two side walls of the annular oil inlet groove 200 and the end face of the stator core 100 on the corresponding side is the same. The outer circumferential surface of the stator core 100 is provided with multiple return oil channels 300 of the same shape and size on both sides of the axial direction of the annular oil inlet groove 200. The multiple return oil channels 300 on both sides of the axial direction of the annular oil inlet groove 200 can be completely symmetrical about the annular oil inlet groove 200 or can adopt an asymmetrical structure. The multiple return oil channels 300 include X branch oil channels 310 evenly distributed along the circumference of the stator core 100, where X is a natural number greater than or equal to 2. It should be noted that each branch oil channel 310 should be distributed as much as possible around the stator core 100 in the circumferential direction so that the stator core 100 can exchange heat more fully with the cooling lubricating oil.

[0055] like Figure 1 and Figure 3 As shown, the branch oil passage 310 includes an inlet oil passage 311, an outlet oil passage 312, and a serpentine oil passage 313. Both the inlet oil passage 311 and the outlet oil passage 312 extend along a first direction. The first direction satisfies the condition of parallelism with the axial direction of the annular oil inlet groove 200, that is, the first direction can be parallel or approximately parallel to the axial direction of the annular oil inlet groove 200. The first end of the serpentine oil passage 313 is connected to the annular oil inlet groove 200 through the inlet oil passage 311. The second end of the serpentine oil passage 313 is connected to the outlet oil passage 312. The serpentine oil passage 313 can be composed of multiple intersecting and connected straight oil passages 31311, or it can be composed of multiple sequentially smoothly connected curved oil passages. The outlet oil passage 312 extends to the axial end of the stator core 100 and forms an outlet at the axial end of the stator core 100.

[0056] Compared with the prior art, the motor stator oil cooling structure provided in this embodiment of the utility model has a multi-reversal oil channel 300 composed of multiple circumferentially distributed branch oil channels 310 on both sides of the annular oil inlet groove 200. The branch oil channels 310 extend directly from the annular oil inlet groove 200 to the end of the stator core 100. The path is simple, and the flow rate and velocity in each branch oil channel 310 are easy to ensure. The serpentine oil channel 313 in the branch oil channel 310 can make the cooling lubricating oil flow fully through the stator core 100, which can increase the turbulence generated by the reversal during the flow, thereby improving the heat exchange capacity of the stator core and ensuring the high continuous performance of the drive motor of new energy commercial vehicles.

[0057] To increase the heat exchange area, please refer to Figure 3The serpentine oil channel 313 includes N serpentine units 3131 and N-1 connecting oil channels 3132, where N is a natural number greater than or equal to 2. The serpentine units 3131 are arranged at intervals along the first direction. The serpentine units 3131 are connected in series through the connecting oil channels 3132 to form the serpentine oil channel 313. The two serpentine units 3131 at both ends of the serpentine oil channel 313 are connected to the inlet oil channel 311 and the outlet oil channel 312, respectively.

[0058] The serpentine oil passage 313 can extend axially in various ways, such as... Figure 3 In the illustrated embodiment, the arrangement direction of each serpentine unit 3131 of the serpentine oil channel 313 is completely parallel to the axis of the stator core 100. That is, the projections of each serpentine unit 3131 of the serpentine oil channel 313 onto a plane perpendicular to the axis of the stator core 100 coincide. In other words, the bending directions of two adjacent serpentine units 3131 of a serpentine oil channel 313 are opposite. Of course, in other embodiments, the arrangement direction of each serpentine unit 3131 of the serpentine oil channel 313 can also be at an angle to the axis of the stator core 100. That is, the projections of each serpentine unit 3131 of the serpentine oil channel 313 onto a plane perpendicular to the axis of the stator core 100 do not coincide. In this case, the bending directions of each serpentine unit 3131 of a serpentine oil channel 313 can be completely the same. Figure 13 As shown.

[0059] exist Figure 3 In the illustrated embodiment, the serpentine oil passage 313 includes three serpentine units 3131 and two connecting oil passages 3132. Of course, in other embodiments, the serpentine oil passage 313 may include one, two, four or more serpentine units 3131. When the serpentine oil passage 313 includes only one serpentine unit 3131, the number of connecting oil passages 3132 is 0.

[0060] Those skilled in the art will understand that the serpentine units 3131 in a serpentine oil channel 313 can be exactly the same size or different sizes. In order to facilitate stamping and stacking, in the embodiments of this application, the serpentine units 3131 in each serpentine oil channel 313 are exactly the same size.

[0061] Please see Figure 3In one embodiment of this application, the serpentine unit 3131 includes M straight oil channels 31311 and M-1 rotary oil channels 31312, where M is an odd number greater than or equal to 3. The odd number of straight oil channels 31311 results in opposite extension directions at both ends of the serpentine unit 3131. The straight oil channels 31311 are arranged in parallel at intervals and extend along a first direction or a second direction. The second direction is perpendicular to the axial direction of the annular oil inlet groove 200, that is, the second direction is perpendicular or approximately perpendicular to the axial direction of the annular oil inlet groove 200. Figure 3 In the illustrated embodiment, the straight oil passage 31311 extends along a first direction, and each rotating oil passage 31312 is alternately connected to both ends of each straight oil passage 31311 along the arrangement direction of each straight oil passage 31311, so as to connect each straight oil passage 31311 in series to form a serpentine unit 3131. Each connecting oil passage 3132 is alternately connected between two adjacent serpentine units 3131 along the arrangement direction of each serpentine unit 3131.

[0062] like Figure 1 and Figure 3 As shown, in one embodiment of this application, the inlet oil passage 311, the outlet oil passage 312, the connecting oil passage 3132, and the straight oil passage 31311 all extend along the first direction, that is, the cooling lubricating oil basically flows back and forth along the first direction and gradually flows from the middle of the stator core 100 to the end of the stator core 100.

[0063] Please see Figure 4 and Figure 5 Based on the number of serpentine units 3131 included in a serpentine oil channel 313, the stator core 100 is composed of the same number of core stacked segments, so that the composition of each core stacked segment is the same or basically the same.

[0064] Specifically, such as Figure 10 and Figure 11 As shown, in one embodiment of this application, the stator core 100 is stacked in a predetermined order by an inlet / outlet and connecting oil passage 3132, a rotating oil passage 31312, a straight oil passage, and an annular oil inlet groove 200. Each core stacking segment is stacked in the same or different order according to the settings. The inlet / outlet and connecting oil passage 3132 is provided with a first oil passage groove structure in the circumferential direction to form an inlet oil passage 311, an outlet oil passage 312, and a connecting oil passage 3132. The rotating oil passage 31312 is provided with a second oil passage groove structure in the circumferential direction to form a rotating oil passage 31312. The straight oil passage is provided with a third oil passage groove structure in the circumferential direction to form a straight oil passage 31311. The diameter of the annular oil inlet groove 200 is less than or equal to the minimum distance between the first oil passage groove structure, the second oil passage groove structure, and the third oil passage groove structure and the axis of the stator core 100, so as to form the annular oil inlet groove 200.

[0065] like Figure 6 As shown, the inlet / outlet and connecting oil passage 3132 section is composed of multiple A-type laminations 130 stacked together. Multiple first holes 131 are evenly distributed around the circumference of the A-type laminations 130. The number of first holes 131 is X, that is, the number of first holes 131 is the same as the number of branch oil passages 310.

[0066] like Figure 7 As shown, the rotary oil passage 31312 is formed by stacking multiple B-type laminations 140. The B-type laminations 140 are circumferentially alternately provided with multiple second holes 141 and multiple slots 142. The shape and size of the second holes 141 are the same as those of the first holes 131, that is, the circumferential and radial dimensions of the second holes 141 are the same as those of the first holes 131, and the shapes are also the same, so as to facilitate the docking of the first holes 131. The second holes 141 are used to form the connecting oil passage 3132 or the straight oil passage 31311 on one side of the rotary oil passage 31312. The slots 142 are used to form the rotary oil passage 31312. The radial dimension of the slots 142 is the same as that of the second holes 141. The circumferential dimension of the slots 142 is more than twice the circumferential dimension of the second holes 141. At least one slot 142 is provided between two adjacent second holes 141.

[0067] like Figure 8 As shown, the straight oil passage section is formed by stacking multiple C-shaped punches 150. Multiple third punches 151 are evenly distributed around the circumference of the C-shaped punches 150. The shape and size of the third punches 151 are the same as those of the first punches 131. The third punches 151 are used to form straight oil passages 31311. Therefore, the number of third punches 151 is X×M, which is the product of the number of branch oil passages 310 and the number of straight oil passages 31311 in a serpentine unit 3131, that is, the number of straight oil passages 31311 around the circumference. The circumferential dimension of the above-mentioned groove 142 is more than twice the circumferential dimension of the second punch 141. Since the size of the second punch 141 and the size of the third punch 151 are the same, the groove 142 can connect two adjacent third punches 151 at the same time, that is, realize the connection between the rotary oil passage 31312 and the two straight oil passages.

[0068] like Figure 9 As shown, the annular oil inlet groove 200 is composed of multiple D-shaped laminations 160 stacked together. The diameter of the D-shaped lamination 160 is less than or equal to the minimum distance between the first punch 131, the second punch 141, and the third punch 151 and the axis of the stator core 100. The minimum distance between the first punch 131, the second punch 141, and the third punch 151 and the axis of the stator core 100 is the distance between the side of the first punch 131, the second punch 141, and the third punch 151 that is radially close to the axis of the stator core 100 and the axis of the stator core 100.

[0069] In practical applications, a certain number of A-type laminations 130 are stacked to form inlet / outlet and connecting oil passages 3132 of a certain length, typically 0.5 mm to 10 mm. A certain number of B-type laminations 140 are stacked to form a rotary oil passage 31312 of a certain thickness, typically 0.5 mm to 5 mm. A certain number of C-type laminations 150 are stacked to form a straight oil passage segment of a certain length, typically 0.5 mm to 10 mm. It should be noted that the stacked inlet / outlet and connecting oil passages 3132 can serve as an inlet oil passage segment, an outlet oil passage segment, and a connecting oil passage 3132 segment. Different functional segments can be formed by adjusting the angles of the inlet / outlet and connecting oil passages 3132. Similarly, the stacked rotary oil passage 31312 segment can be either the front rotary segment near the inlet oil passage segment in the serpentine unit 3131, or the rear rotary segment near the outlet oil passage segment in the serpentine unit 3131.

[0070] like Figure 10 As shown, the inlet oil passage section 111a, the front rotating section 112a, the straight oil passage section 113, the rear rotating section 112b, and the outlet oil passage section 111b are stacked together in sequence to form a first iron core stacked section 110. A complete single serpentine unit 3131 can be formed on this first iron core stacked section 110, as shown in the diagram. Figure 4 and Figure 5 As shown, since the serpentine oil channel 313 in this embodiment is formed by three serpentine units 3131 connected in series, three iron core stacked sections are required to stack to form a complete serpentine oil channel 313.

[0071] The oil flows axially in the inlet oil passage section 111a, the straight oil passage section 113, and the outlet oil passage section 111b, and flows circumferentially in the front rotary section 112a and the rear rotary section 112b. Each time the oil passes through a rotary oil passage 31312 in the front rotary section 112a or the rear rotary section 112b, its flow direction changes once in the downstream straight oil passage section 113.

[0072] Because in Figures 1 to 3 In the illustrated embodiment, the bending directions of two adjacent serpentine units 3131 are different; therefore, two different stacking methods are required, except... Figure 10 In addition to the stacking method shown, Figure 11Another lamination method is provided, in which the outlet oil passage section 111b, the rear end rotating section 112b, the straight oil passage section 113, the front end rotating section 112a, and the inlet oil passage section 111a are stacked together in sequence to form a second iron core stack section 120. The bending direction of the serpentine unit 3131 of the second iron core stack section 120 is opposite to the bending direction of the serpentine unit 3131 of the first iron core stack section 110. Then, one second iron core stack section 120 and two first iron core stack sections 110 are arranged according to… Figure 4 and Figure 5 The two first iron core stacking sections 110 are respectively arranged on both sides of the circumference of the second iron core stacking section 120, thus forming a structure like... Figure 3 The serpentine oil channel 313 is shown.

[0073] This application also provides another serpentine oil channel structure, namely Figure 13 The serpentine oil channel 313 shown is as follows: Figure 12 As shown, this serpentine oil channel 313 does not require two stacking methods. It only requires that the three first iron core stacked sections 110 be offset relative to each other by a preset angle α along clockwise or counterclockwise, so that the outlet of the serpentine unit 3131 of one of the two adjacent first iron core stacked sections 110 is connected to the inlet of the other serpentine unit 3131.

[0074] To further optimize the above technical solution and facilitate stacking, in one embodiment of this application, the inlet and outlet and connecting oil passage 3132, the rotary oil passage 31312, and the straight oil passage are respectively provided with positioning hole structures. The positioning holes may include one or more positioning holes. The inlet and outlet and connecting oil passage 3132, the rotary oil passage 31312, and the straight oil passage are arranged in a preset order and the positioning hole structures are aligned so that the first oil passage groove structure, the second oil passage groove structure, and the third oil passage groove structure are connected to form a multi-folding oil passage 300.

[0075] like Figure 4 , Figure 5 , Figure 10 and Figure 11 In the embodiment shown, only one positioning hole is needed on each lamination, while Figure 12 In the embodiment shown, each lamination should be provided with two positioning holes, and the angle between the two positioning holes and the axis of the stator core 100 is α.

[0076] like Figure 4 , Figure 5 and Figure 6 As shown, the A-type lamination 130 is provided with a first positioning hole 132. Multiple A-type laminations 130 are aligned through their respective first positioning holes 132, and are also aligned with the positioning holes on the iron core segment formed by stacking other laminations.

[0077] like Figure 4 , Figure 5 and Figure 7 As shown, the B-type punch 140 is provided with a second positioning hole 143, the C-type punch 150 is provided with a third positioning hole 152, and the D-type punch 160 is provided with a fourth positioning hole 161.

[0078] like Figure 14 As shown, in one embodiment of this application, the motor stator oil cooling structure further includes a housing 400, which is interference-fitted with the stator core 100. An oil inlet 410 is provided at a position corresponding to the annular oil inlet groove 200 of the stator core 100. The axial length of the housing 400 is greater than the axial length of the stator core 100.

[0079] Those skilled in the art will understand that in the stator oil cooling structure of the motor, a spray cooling of the winding ends needs to be formed downstream of the outlet oil passage 312 in order to improve the overall cooling capacity of the oil cooling system and make full use of the cooling capacity of the cooling lubricating oil.

[0080] Spray cooling of the winding ends can be achieved in several ways, such as... Figure 15 and Figure 16 As shown, in one specific embodiment, a radial nozzle 500 is provided at the end of the outlet oil passage 312 away from the serpentine oil passage 313. The radial nozzle 500 can be fixed to the stator core 100 by means of interference fit, adhesive bonding, flap clamping, etc. The radial nozzle 500 is provided with an oil spray hole 530 extending from one end of the radial nozzle 500 to the other end. The outlet of the radial nozzle 500 faces the axial direction of the stator core 100 so as to export the cooling lubricating oil in the outlet oil passage 312 and spray it towards the winding end.

[0081] like Figure 17 and Figure 18 As shown, the centripetal nozzle 500 includes an axial section 510 and a centripetal section 520 connected to the axial section 510. The end of the axial section 510 away from the centripetal section 520 is inserted into the outlet oil passage 312. The centripetal section 520 is inclined towards the axis of the stator core 100 from the end connected to the axial section 510. The angle β between the centripetal section 520 and the axial section 510 satisfies 120°≤β≤135°. The extension direction of the oil injection hole 530 in the centripetal section 520 is the same as the extension direction of the centripetal section 520. The extension direction of the oil injection hole 530 in the axial section 510 is the same as the extension direction of the axial section 510.

[0082] like Figure 17As shown, a limiting step surface 540 is formed at one end where the centripetal section 520 connects to the axial section 510. This limiting step surface 540 is used to limit contact with the end face of the stator core 100. At the same time, if the centripetal nozzle 500 is connected to the stator core 100 by adhesive bonding, the limiting step surface 540 can also increase the adhesive area and enhance the connection strength between the centripetal nozzle 500 and the stator core 100.

[0083] In another embodiment, such as Figure 19 As shown, an oil distribution ring 420 is provided on the inner side wall of the end of the housing 400. An oil collecting ring cavity 430 is formed between the oil distribution ring 420 and the inner side wall of the end of the housing 400. The oil collecting ring cavity 430 is connected to the end of the outlet oil passage 312 away from the serpentine oil passage 313. Multiple oil outlet holes 440 are provided on the oil distribution ring 420 along the circumference. One end of the oil outlet hole 440 is connected to the oil collecting ring cavity 430, and the other end is directed toward the axis of the stator core 100.

[0084] The motor stator oil cooling structure provided in this application embodiment needs to be used in conjunction with an oil cooler with a certain heat exchange capacity and a circulating oil pump with a certain oil flow driving capacity to form a complete cooling and lubrication oil circuit.

[0085] In summary, the motor stator oil cooling structure provided in this application has a multi-branch, multi-reversal oil channel 300 structure. Each branch oil channel 310 extends directly from the annular oil inlet groove 200 to the end of the stator core 100, which can increase the flow rate of each branch and the turbulence generated by the reversal during the flow process, thereby improving the heat exchange capacity of the stator core and ensuring the high continuous performance of the drive motor of new energy commercial vehicles. The stator core 100 is formed by reasonably stacking four types of laminations. The processing and assembly process is simple and flexible, and it has good applicability to oil-cooled motors with various core outer diameters and stacking heights. The structure of the cooling lubricating oil entering and exiting the multi-reversal oil channel 300 is simple, compact and reliable, and can realize a simple and efficient centripetal spraying method, which can save end spraying space and cost, and ensure the ability of spraying to cool the ends of the windings.

[0086] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "a," and / or "the" are not specifically singular and may include the plural. Generally, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0087] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0088] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0089] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. An oil cooling structure of a stator of an electric machine, provided in a stator core (100) of the electric machine, characterized by, include: An annular oil inlet groove (200) is provided on the outer circumferential surface of the stator core (100); The stator core (100) has multiple return oil channels (300) of the same shape and size on both sides of the annular oil inlet groove (200) on its outer circumferential surface. The multiple return oil channels (300) include X branch oil channels (310) evenly distributed along the circumference of the stator core (100), where X is a natural number greater than or equal to 2. The branch oil channels (310) include an inlet oil channel (311), an outlet oil channel (312), and a serpentine oil channel (313). The inlet oil passage (311) and the outlet oil passage (312) both extend along a first direction, which is parallel to the axial direction of the annular oil inlet groove (200). The first end of the serpentine oil passage (313) is connected to the annular oil inlet groove (200) through the inlet oil passage (311), and the second end of the serpentine oil passage (313) is connected to the outlet oil passage (312). The outlet oil passage (312) extends to the axial end of the stator core (100).

2. The motor stator oil-cooling structure according to claim 1, characterized in that, The serpentine oil channel (313) includes N serpentine units (3131) and N-1 connecting oil channels (3132), where N is a natural number greater than or equal to 2. The serpentine units (3131) are arranged at intervals along the first direction. The serpentine units (3131) are connected in series through the connecting oil channels (3132) to form the serpentine oil channel (313). The two serpentine units (3131) at both ends of the serpentine oil channel (313) are respectively connected to the inlet oil channel (311) and the outlet oil channel (312).

3. The motor stator oil-cooling structure according to claim 2, characterized in that, The serpentine unit (3131) includes M straight oil channels (31311) and M-1 rotary oil channels (31312), where M is an odd number greater than or equal to 3. The straight oil channels (31311) are arranged in parallel at intervals. The straight oil channels (31311) extend along the first direction or the second direction. The second direction is perpendicular to the axial direction of the annular oil inlet groove (200). The rotary oil channels (31312) are alternately connected to both ends of the straight oil channels (31311) along the arrangement direction of the straight oil channels (31311) to connect the straight oil channels (31311) in series to form the serpentine unit (3131). The connecting oil channels (3132) are alternately connected between two adjacent serpentine units (3131) along the arrangement direction of the serpentine units (3131).

4. The motor stator oil-cooling structure according to claim 3, characterized in that, The inlet oil passage (311), the outlet oil passage (312), the connecting oil passage (3132), and the straight oil passage (31311) all extend along the first direction.

5. The motor stator oil-cooling structure according to claim 4, characterized in that, The stator core (100) is composed of an inlet / outlet and connecting oil passage (3132) section, a rotary oil passage (31312) section, a straight oil passage (31311) section, and an annular oil inlet groove (200) section stacked in a predetermined order. The inlet / outlet and connecting oil passage (3132) section is provided with a first oil passage groove structure in the circumferential direction to form the inlet oil passage (311), the outlet oil passage (312), and the connecting oil passage (3132). The rotary oil passage (31311) section is composed of an inlet / outlet and connecting oil passage (31312) section, a rotary oil passage (31311) section, and an annular oil inlet groove (200) section. The 1312 segment is provided with a second oil passage groove structure in the circumferential direction to form the rotary oil passage (31312), and the straight oil passage (31311) segment is provided with a third oil passage groove structure in the circumferential direction to form the straight oil passage (31311). The diameter of the annular oil inlet groove (200) segment is less than or equal to the minimum distance between the first oil passage groove structure, the second oil passage groove structure and the third oil passage groove structure and the axis of the stator core (100).

6. The motor stator oil-cooling structure according to claim 5, characterized in that, The inlet / outlet and connecting oil passage (3132) section is formed by stacking multiple A-type laminations (130), and the A-type laminations (130) are evenly distributed with multiple first punches (131) at circumferential intervals, and the number of first punches (131) is X; The rotary oil passage (31312) section is formed by stacking multiple B-type punches (140). The B-type punches (140) are provided with multiple second punches (141) and multiple slots (142) in alternating circumferential intervals. The shape and size of the second punches (141) are the same as the first punches (131). The radial dimension of the slots (142) is the same as the radial dimension of the second punches (141). The circumferential dimension of the slots (142) is more than twice the circumferential dimension of the second punches (141). At least one slot (142) is provided between two adjacent second punches (141). The straight oil passage (31311) section is formed by stacking multiple C-shaped punches (150). The C-shaped punches (150) are evenly distributed with multiple third punches (151) at circumferential intervals. The shape and size of the third punches (151) are the same as the first punches (131). The number of third punches (151) is X×M. The annular oil inlet groove (200) is formed by stacking multiple D-shaped laminations (160). The diameter of the D-shaped laminations (160) is less than or equal to the minimum distance between the first punch (131), the second punch (141), and the third punch (151) and the axis of the stator core (100).

7. The motor stator oil-cooling structure according to claim 5, characterized in that, The inlet / outlet and connecting oil passage (3132) section, the rotary oil passage (31312) section, and the straight oil passage (31311) section are each provided with positioning hole structures. The inlet / outlet and connecting oil passage (3132) section, the rotary oil passage (31312) section, and the straight oil passage (31311) section are arranged in a preset order and the positioning hole structures are aligned so that the first oil passage groove structure, the second oil passage groove structure, and the third oil passage groove structure are connected to form the multi-return oil passage (300).

8. The motor stator oil-cooling structure according to any one of claims 1-7, characterized in that, A centripetal nozzle (500) is provided at one end of the outlet oil passage (312) away from the serpentine oil passage (313). An oil injection hole (530) is provided inside the centripetal nozzle (500) extending from one end of the centripetal nozzle (500) to the other end. The centripetal nozzle (500) includes an axial section (510) and a centripetal section (520) connected to the axial section (510). The axial section (510) is inserted into the outlet oil passage (312). The centripetal section (520) is inclined towards the axis of the stator core (100) from the end connected to the axial section (510). The included angle β between the centripetal section (520) and the axial section (510) satisfies 120°≤β≤135°.

9. The motor stator oil-cooling structure according to any one of claims 1-7, characterized in that, It also includes a housing (400), which is interference-fitted with the stator core (100), and the housing (400) is provided with an oil inlet (410) at a position corresponding to the annular oil inlet groove (200) of the stator core (100).

10. The motor stator oil-cooling structure according to claim 9, characterized in that, An oil distribution ring (420) is provided on the inner wall of the end of the housing (400). An oil collecting ring cavity (430) is formed between the oil distribution ring (420) and the inner wall of the end of the housing (400). The oil collecting ring cavity (430) is connected to the end of the outlet oil passage (312) away from the serpentine oil passage (313). A plurality of oil outlet holes (440) are provided on the oil distribution ring (420) along the circumferential direction. One end of the oil outlet hole (440) is connected to the oil collecting ring cavity (430), and the other end is directed toward the axis of the stator core (100).

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