BSG liquid cooling motor and motor housing and cooling structure thereof

Abstract

The invention relates to a BSG liquid cooling motor and a motor housing and a cooling structure thereof, the BSG liquid cooling motor comprises the motor housing, the motor housing comprises the cooling structure, and the cooling structure comprises an outer water jacket; the inner water jacket is sleeved in the outer water jacket; the first cooling water channel is arranged on the inner water jacket, and a water outlet and a water inlet of the first cooling water channel are formed in the outer water jacket; the second cooling water channel is arranged on the inverter; the first switching water channel and the second switching water channel are arranged on the outer water jacket and the rear end cover; a water inlet of the second cooling water channel is communicated with a water inlet of the first cooling water channel through the first switching water channel, and a water outlet of the second cooling water channel is communicated with a water outlet of the first cooling water channel through the second switching water channel; cooling water enters the first cooling water channel and the first switching water channel synchronously from the switching water inlet and enters the second cooling water channel through the first switching water channel, and cooling and heat dissipation of a stator, a rotor and an inverter of the BSG liquid-cooled motor are achieved at the same time.

Description

Technical Field

[0001] The invention relates to a BSG liquid-cooled motor, in particular to a BSG liquid-cooled motor and a motor housing and a cooling structure thereof. Background Art

[0002] BSG (Belt-driven Starter Generator) belongs to the mild hybrid technology in hybrid power. It is a motor system that integrates the inverter controller with the motor. It can realize the rapid start and stop of the motor when the car is idling, and recover energy when braking. At present, the 48V BSG system has been applied to some passenger cars. It is installed in the front wheel system of the engine, resulting in a small installation space and high temperature, which seriously affects the performance and efficiency of the motor. At present, the BSG motor generally uses a liquid cooling system for cooling, which mainly includes the motor water circuit for cooling the stator and rotor and the controller water circuit for cooling the controller. In order to reduce the size of the motor and save product costs, the existing technology integrates the whole machine and inverter water circuits in series into the motor housing. For example, the two parts of the motor and inverter water circuit are connected in series: the inverter water channel inlet is connected to the water inlet pipe, the whole machine water channel inlet is connected to the inverter water outlet, and the whole machine water channel outlet is connected to the drain pipe. The front cover or rear cover of the motor is integrated with the water channel. The inner and outer walls of the casing are thick, the casing is heavy, and the manufacturing is difficult. Only series water channels with large flow resistance and low heat dissipation efficiency can be manufactured. The water channel pressure of the whole vehicle is high, and it is not convenient to be used in low-pressure water channel conditions. Summary of the invention

[0003] The technical problem to be solved by the present invention is that the prior art is not convenient to be applied to external low-pressure water circuit conditions, the heat dissipation efficiency using series water circuits is low, the inner and outer walls of the casing are thick, the casing is heavy and difficult to manufacture, and the present invention provides a BSG liquid-cooled motor, its motor housing and cooling structure.

[0004] In order to achieve the above object, the present invention provides a cooling structure of a BSG liquid-cooled motor, which includes:

[0005] An outer water jacket is arranged between the front cover and the rear cover of the BSG liquid-cooled motor, and two ends of the outer water jacket are respectively connected to the front cover and the rear cover;

[0006] An inner water jacket, which is sleeved inside the outer water jacket, one end of the inner water jacket abuts against the front end cover, and the other end of the inner water jacket is connected to an end of the outer water jacket close to the rear end cover;

[0007] A first cooling water channel is arranged on the inner water jacket, a water outlet and a water inlet of the first cooling water channel are both arranged on the outer water jacket, and are respectively connected to the cooling water channel of the BSG liquid-cooled motor;

[0008] A second cooling water channel is provided on the inverter of the BSG liquid-cooled motor;

[0009] A first transfer water channel is provided on the outer water jacket and the rear end cover, the water inlets of the first cooling water channel and the second cooling water channel are both connected to the first transfer water channel, a transfer water inlet is provided on the first transfer water channel corresponding to the water inlet of the first cooling water channel, and the transfer water inlet is connected to the cooling water path of the BSG liquid-cooled motor; and

[0010] a second transfer water channel, arranged on the outer water jacket and the rear end cover, wherein the water inlet of the second cooling water channel is connected with the water inlet of the first cooling water channel through the first transfer water channel, and the water outlet of the second cooling water channel is connected with the water outlet of the first cooling water channel through the second transfer water channel;

[0011] Among them, the cooling water enters the first cooling water channel and the first transfer water channel synchronously from the transfer water inlet, and enters the second cooling water channel through the first transfer water channel, thereby realizing simultaneous cooling and heat dissipation of the stator, rotor and inverter of the BSG liquid-cooled motor.

[0012] The cooling structure of the above-mentioned BSG liquid-cooled motor, wherein the upper end surface of the outer water jacket abuts against the rear end cover, an outer stop is provided on the inner side of the upper end surface of the outer water jacket, the outer stop abuts against the end surface of the stator of the BSG liquid-cooled motor, and a first gap is provided at the connection between the lower end surface of the outer water jacket and the front end cover.

[0013] The cooling structure of the above-mentioned BSG liquid-cooled motor, wherein an inner stop is provided on the inner side of the lower end surface of the inner water jacket, the inner stop abuts against the end surface of the stator, and the outer circumferential surface of the stator is interference-connected with the inner wall of the inner water jacket; the lower end surface of the inner water jacket abuts against the front end cover, and a second gap is provided at the connection between the upper end surface of the inner water jacket and the outer water jacket.

[0014] In the cooling structure of the above-mentioned BSG liquid-cooled motor, the first gap and the second gap are both 0.1-1 mm.

[0015] In the cooling structure of the above-mentioned BSG liquid-cooled motor, the first cooling water channel is spirally arranged along the outer wall of the inner water jacket, and a water outlet is arranged at the end of the first cooling water channel.

[0016] The cooling structure of the above-mentioned BSG liquid-cooled motor, wherein the second cooling water channel is a U-shaped water channel, is arranged on the water plate of the inverter, and the cooling water flows into the second transfer water channel from the outlet of the second cooling water channel, and then flows out from the outlet of the first cooling water channel after merging with the cooling water of the first cooling water channel from the outlet of the second transfer water channel.

[0017] The cooling structure of the above-mentioned BSG liquid-cooled motor, wherein a plurality of spoiler heat dissipation columns are arranged in the U-shaped water channel.

[0018] The cooling structure of the above-mentioned BSG liquid-cooled motor, wherein a drain port is also provided on the first adapter water channel, and the drain port is provided directly below the adapter water inlet, and the drain port is connected to the cooling water channel of the BSG liquid-cooled motor; when the drain port is opened, the cooling water directly enters the drain port from the adapter water inlet to avoid entering the BSG liquid-cooled motor for cooling.

[0019] The cooling structure of the above-mentioned BSG liquid-cooled motor, wherein the first transfer water channel is arranged on the outer water jacket and the rear end cover and is staggered to avoid the corner hanging hole; the second transfer water channel is arranged on the outer water jacket and the rear end cover and is staggered to avoid the corner hanging hole.

[0020] In order to better achieve the above-mentioned purpose, the present invention also provides a motor housing of a BSG liquid-cooled motor, which includes a front end cover, a rear end cover and a cooling structure, and the cooling structure is the above-mentioned cooling structure.

[0021] In order to better achieve the above-mentioned objectives, the present invention also provides a BSG liquid-cooled motor, including a motor housing, a stator, a rotor and an inverter, wherein the stator is installed in the motor housing, the rotor is installed and supported on the motor housing corresponding to the stator, and the inverter is connected to the motor housing, wherein the motor housing is the above-mentioned motor housing.

[0022] The technical effects of the present invention are:

[0023] The present invention adopts parallel water channels suitable for low-pressure working conditions, and the water flow of the first cooling water channel and the second cooling water channel is balanced and has higher heat dissipation efficiency; the split shell is adopted, which is convenient for processing part of the motor water channels to set up water channels with high heat dissipation efficiency.

[0024] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of a BSG liquid-cooled motor according to an embodiment of the present invention;

[0026] Figure 2 A schematic diagram of the structure of a motor housing according to an embodiment of the present invention;

[0027] Figure 3 A schematic diagram of a cooling structure according to an embodiment of the present invention;

[0028] Figure 4 An exploded view of a motor housing according to an embodiment of the present invention;

[0029] Figure 5 It is a schematic diagram of the assembly of a motor housing according to an embodiment of the present invention;

[0030] Figure 6 for Figure 2 AA section view;

[0031] Figure 7 for Figure 2 BB cross-sectional view;

[0032] Figure 8 1 is a contour diagram of inlet pressure, whole machine temperature and inverter temperature according to an embodiment of the present invention.

[0033] Among them, the reference numerals

[0034] 1 Motor housing

[0035] 11Front end cover

[0036] 12 rear end cover

[0037] 121 hanging corner hole

[0038] 13Cooling structure

[0039] 131 outer water jacket

[0040] 1311 outer stop

[0041] 132 inner water jacket

[0042] 1321 internal stop

[0043] 133 First cooling water channel

[0044] 1331 Water outlet

[0045] 134 Second cooling water channel

[0046] 135 First Transfer Waterway

[0047] 1351 adapter water inlet

[0048] 1352 Drainage port

[0049] 136 Second Transfer Waterway

[0050] 137 water plate bottom plate

[0051] 138 water board cover

[0052] 139 spoiler cooling column

[0053] 2 Stator

[0054] 3 rotors

[0055] 4 Inverter

[0056] 5 Bearings

[0057] 6. Piercing nails

[0058] 7 Sealing ring DETAILED DESCRIPTION

[0059] The structural principle and working principle of the present invention are described in detail below in conjunction with the accompanying drawings:

[0060] See also Figure 1 , Figure 1 The BSG liquid-cooled motor structure schematic diagram of an embodiment of the present invention. The BSG liquid-cooled motor of the present invention comprises a motor housing 1, a stator 2, a rotor 3 and an inverter 4, wherein the stator 2 is installed in the motor housing 1, the rotor 3 is supported and installed on the motor housing 1 corresponding to the stator 2, and the inverter 4 is connected to the motor housing 1. Since the composition, structure, relative position relationship, connection relationship and function of other components of the motor are relatively mature prior art, they will not be described here in detail, and only the motor housing 1 and cooling structure 13 of the present invention will be described in detail below.

[0061] See also Figure 2 , Figure 2 The motor housing 1 of one embodiment of the present invention is a schematic diagram of the structure. The motor housing 1 of the present invention includes a front cover 11, a rear cover 12 and a cooling structure 13, and the rotor 3 is mounted on the front cover 11 and the rear cover 12 through a bearing 5. The through nail 6 passes through the rear cover 12, the outer water jacket 131, and the front cover 11 to fix the inner water jacket 132, the outer water jacket 131 and the stator 2 between the front cover 11 and the rear cover 12.

[0062] See also Figure 3-Figure 5 , Figure 3 Schematic diagram of a cooling structure 13 according to an embodiment of the present invention. Figure 4The figure is an exploded view of the motor housing 1 of an embodiment of the present invention. The cooling structure 13 of the present invention comprises: an outer water jacket 131, which is arranged between the front cover 11 and the rear cover 12 of the BSG liquid-cooled motor, one end of the outer water jacket 131 is connected to the front cover 11, and the other end of the outer water jacket 131 is abutted against the rear cover; an inner water jacket 132, which is sleeved in the outer water jacket 131, one end of the inner water jacket 132 is abutted against the front cover 11, and the other end of the inner water jacket 132 is connected to the outer water jacket 131. The first cooling water channel 133 is arranged on the inner water jacket 132. The water outlet 1331 and the water inlet of the first cooling water channel 133 are both arranged on the outer water jacket 131. The water outlet 1331 is connected with the cooling water path of the BSG liquid-cooled motor. The first cooling water channel 133 is formed by the inner water jacket 132 and the outer water jacket 131, and grooves are arranged at both ends of the first cooling water channel 133 to place O-rings 7. The second cooling water channel 134 is arranged at the inverter of the BSG liquid-cooled motor. 4; a first transfer water channel 135, which is arranged on the outer water jacket 131 and the rear end cover 12, and is preferably staggered to avoid the corner hole 121, the water inlets of the first cooling water channel 133 and the second cooling water channel 134 are both connected to the first transfer water channel 135, and a transfer water inlet 1351 is arranged on the first transfer water channel 135 corresponding to the water inlet of the first cooling water channel 133, and the transfer water inlet 1351 is connected to the cooling water path of the BSG liquid-cooled motor; and a second transfer water The second transfer water channel 136 is arranged on the outer water jacket 131 and the rear end cover 12, and is preferably staggered to avoid the corner hole 121. One end of the second transfer water channel 136 is connected to the first cooling water channel 133, and the other end of the second transfer water channel 136 is connected to the water outlet of the second cooling water channel 134, that is, the water inlet of the second cooling water channel 134 is connected to the water inlet of the first cooling water channel 133 through the first transfer water channel 135, and the water outlet of the second cooling water channel 134 is connected to the water outlet of the second cooling water channel 134 through the first transfer water channel 135. The second transfer water channel 136 is connected to the water outlet 1331 of the first cooling water channel 133 to realize the parallel connection between the first cooling water channel 133 and the second cooling water channel 134; wherein, the cooling water enters the first cooling water channel 133 and the first transfer water channel 135 synchronously from the transfer water inlet 1351, and enters the second cooling water channel 134 through the first transfer water channel 135, thereby realizing the simultaneous cooling and heat dissipation of the stator 2, rotor 3 and inverter 4 of the BSG liquid-cooled motor.

[0063] See also Figure 5-Figure 7 , Figure 5 This is a schematic diagram of the assembly of a motor housing 1 according to an embodiment of the present invention. Figure 6 for Figure 2 AA section view, Figure 7 for Figure 2BB cross-sectional view. In this embodiment, the upper end face of the outer water jacket 131 abuts against the rear end cover 12, and an outer stop 1311 is provided on the inner side of the upper end face, and the outer stop 1311 abuts against the axial end face of the stator 2 of the BSG liquid-cooled motor, and a first gap is provided at the connection between the lower end face of the outer water jacket 131 and the front end cover 11. An inner stop 1321 is provided on the inner side of the lower end face of the inner water jacket 132, and the inner stop 1321 abuts against the axial end face of the stator 2, and the outer circumferential surface of the stator 2 is interference-connected with the inner wall of the inner water jacket 132, and the lower end face of the inner water jacket 132 abuts against the front end cover 11, and a second gap is provided at the connection between the upper end face of the inner water jacket 132 and the outer water jacket 131. The first gap and the second gap are both 0.1-1mm.

[0064] See also Figure 3 In this embodiment, the first cooling water channel 133 is spirally arranged along the outer wall of the inner water jacket 132. The cross section of the first cooling water channel 133 is preferably rectangular, preferably spirally arranged for 3 turns, and a water outlet 1331 is arranged at the end of the first cooling water channel 133. The second cooling water channel 134 is a U-shaped water channel, which is arranged on the water plate of the inverter 4. The water plate of the inverter 4 includes a water plate bottom plate 137 and a water plate cover plate 138. The water plate bottom plate 137 is provided with a U-shaped flow channel groove, and a cylindrical spoiler heat sink can be arranged in the U-shaped flow channel groove; the cooling water flows into the second transfer water channel 136 from the water outlet of the second transfer water channel 136, and flows out from the water outlet 1331 of the first cooling water channel 133 after merging with the cooling water of the first cooling water channel 133. The first cooling water channel 133 and the second cooling water channel 134 are parallel, and the structure is compact. Among them, a plurality of spoiler heat dissipation columns 139 are arranged in the U-shaped water channel according to the heat dissipation element. The spoiler heat dissipation columns 139 are preferably spoiler heat dissipation cylinders with a diameter of 2.5-4mm, preferably a diameter of 2.5mm, which can make the heat dissipation of the two cooling water channels balanced, with high heat dissipation efficiency, and can be applied to low-pressure working conditions. The rear end cover 12 and the outer water jacket 131 and the inverter 4 water plate water channel transition end surface are all provided with grooves for placing O-rings.

[0065] In this embodiment, a drain port 1352 is further provided on the first adapter water channel 135. The drain port 1352 is arranged directly below the adapter water inlet 1351, and the drain port 1352 is connected to the cooling water path of the BSG liquid-cooled motor. When the drain port 1352 is opened, the cooling water directly enters the drain port 1352 from the adapter water inlet 1351 to avoid entering the BSG liquid-cooled motor for cooling.

[0066] During operation, the drain port 1352 is blocked, and the cooling water channel supplies water to the transfer water inlet 1351. The cooling water simultaneously enters the first cooling water channel 133 and the first transfer water channel 135, and then enters the second cooling water channel 134, realizing the cooling and heat dissipation of the stator 2, the rotor 3 and the inverter 4 respectively. The cooling water entering the first cooling water channel 133 flows downward along the inner water jacket 132 into the water outlet 1331, and the cooling water entering the second cooling water channel 134 flows into the second transfer water channel 136 along the U-shaped water channel, and flows out from the water outlet 1331 of the first cooling water channel 133 after merging with the cooling water at the end of the first cooling water channel 133 from the water outlet of the second transfer water channel 136. Alternatively, the drain port 1352 is connected to the cooling water circuit and opened, and the cooling water circuit supplies water to the transfer water inlet 1351. The cooling water directly enters the water pipe connected to the drain port 1352 to avoid entering the whole machine cooling. When the BSG liquid-cooled motor is shut down, the cooling water circuit of the BSG liquid-cooled motor can be cut off without closing the water circuit of the entire vehicle, and the circulation of other water circuits of the system will not be affected.

[0067] See also Figure 8 , Figure 8 The following is a contour diagram of the inlet pressure, whole machine temperature and inverter temperature of an embodiment of the present invention. The simulation settings of this embodiment are as follows: the inlet flow rate is 0.2kg / s, the inlet water temperature is 80°C, the stator 2 winding loss is 1024W, the iron loss is 283W, the inverter 4 chip loss is 40W, and the capacitor and busbar are 70W in total. Check the inlet pressure under different water channel turns and heat dissipation column diameter conditions, the temperature of the whole machine and inverter 4 to evaluate the parallel water channel flow balance and water channel flow resistance. The data results are as follows:

[0068]

[0069] The cooling effect of the first cooling water channel 133 is evaluated by the temperature of the stator part of the whole machine, and the cooling effect of the second cooling water channel 134 is evaluated by the temperature of the inverter 4 part. The scheme is optimized based on the principle of selecting low-pressure and high-heat dissipation efficiency water channels. The first 30% (30% low pressure, 30% low temperature) data is selected and a contour map is drawn. From the contour map, it can be seen that the low-pressure and high-heat dissipation efficiency selection range is: 3 circles of water channels and the diameter of the turbulent heat dissipation cylinder is 2.5-4mm. Combined with the data table, it can be seen that when the diameter of the turbulent heat dissipation cylinder is 2.5mm for 3 circles of water channels, the water channel flow resistance is the smallest and the heat dissipation efficiency is the highest.

[0070] The first cooling water channel 133 (the whole machine water channel) and the second cooling water channel 134 (the inverter water channel) of the present invention are connected in parallel. The water outlet 1331 and the water inlet of the first cooling water channel 133 are both arranged on the outer water jacket 131. The water inlet of the first cooling water channel 133 is connected to the switching water inlet 1351. The water outlet 1331 is connected to the external drain pipe, and the switching water inlet 1351 is connected to the water pipe. The water inlet of the second cooling water channel 134 is connected to the first switching water channel 1331 through the first switching water channel 1331. The first cooling water channel 133 is connected to the water inlet 135 of the first cooling water channel 133, and the water outlet 1331 of the second cooling water channel 134 is connected to the water outlet 1331 of the first cooling water channel 133 through the second transfer water channel 136, so as to realize the parallel connection between the first cooling water channel 133 and the second cooling water channel 134; the first transfer water channel 135 and the second transfer water channel 136 are both arranged on the rear end cover 12 and the outer water jacket 131, and are staggered to avoid the corner hole 121; the transfer water inlet 1351 A drain port 1352 is provided directly below the inner end surface of the inner water jacket 132 and is connected thereto; a raised inner stopper 1321 is provided at the lower part of the inner end surface of the inner water jacket 132, the end surface of the inner stopper 1321 is in close contact with the stator 2, the lower end surface of the inner water jacket 132 is in close contact with the stopper of the front end cover 11, and a first gap is provided between the upper end surface of the inner water jacket 132 and the outer water jacket 131, and the first gap is preferably 0.1-1 mm; a raised outer stopper 1311 is provided at the upper part of the inner end surface of the outer water jacket 131, and the outer water jacket 131 is in close contact with the stator 2; ... inner water jacket 132 is in close contact with the stator 2; the inner water jacket 132 is in close contact with the stopper of the front end cover 11; the inner water jacket 132 is in close contact with the stator 2; the inner water jacket 132 is in close contact with the stopper of the front end cover 11; the inner water jacket 132 is in close contact with the stator 2; the inner water jacket 132 is in close contact with the stopper of the front end cover 11; the inner water jacket 132 is in close contact with the stator 2; the inner water jacket 132 is in close contact with the stopper of the front end cover 11 The upper end face of the sleeve 131 is in close contact with the rear end cover 12, the outer stop 1311 is in close contact with the stator 2, and the lower end face of the outer water jacket 131 is provided with a second gap with the front end cover 11, and the second gap is preferably 0.1-1mm; the axial end face of the stator 2 is in close contact with the inner stop 1321 of the inner water jacket 132 and the outer stop 1311 of the outer water jacket 131, and the stator 2 is radially fitted with the inner wall of the inner water jacket 132 by interference, and the interference is preferably 0-0.2mm. The split housing of the motor can realize the production of the switching water channel, so that the switching water channel connects the first and second cooling water channels, and then realizes the parallel connection of the first and second cooling water channels.

[0071] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A cooling structure (13) of a BSG liquid-cooled motor, characterized in that: include: An outer water jacket (131) is arranged between a front end cover (11) and a rear end cover (12) of the BSG liquid-cooled motor, and two ends of the outer water jacket (131) are respectively connected to the front end cover (11) and the rear end cover (12); An inner water jacket (132) is sleeved inside the outer water jacket (131), one end of the inner water jacket (132) abuts against the front end cover (11), and the other end of the inner water jacket (132) is connected to an end of the outer water jacket (131) close to the rear end cover (12); A first cooling water channel (133) is arranged on the inner water jacket (132); a water outlet and a water inlet of the first cooling water channel (133) are both arranged on the outer water jacket (131) and are respectively connected to the cooling water circuit of the BSG liquid-cooled motor; A second cooling water channel (134) is provided on the inverter (4) of the BSG liquid-cooled motor; A first transfer water channel (135) is arranged on the outer water jacket (131) and the rear end cover (12); the water inlets of the first cooling water channel (133) and the second cooling water channel (134) are both connected to the first transfer water channel (135); a transfer water inlet (1351) is arranged on the first transfer water channel (135) corresponding to the water inlet of the first cooling water channel (133); the transfer water inlet (1351) is connected to the cooling water path of the BSG liquid-cooled motor; as well as a second transfer water channel (136) disposed on the outer water jacket (131) and the rear end cover (12); a water inlet of the second cooling water channel (134) being connected to a water inlet of the first cooling water channel (133) through the first transfer water channel (135); and a water outlet of the second cooling water channel (134) being connected to a water outlet of the first cooling water channel (133) through the second transfer water channel (136); The cooling water enters the first cooling water channel (133) and the first transfer water channel (135) synchronously from the transfer water inlet (1351), and enters the second cooling water channel (134) through the first transfer water channel (135), thereby realizing cooling and heat dissipation of the stator (2), rotor (3) and inverter (4) of the BSG liquid-cooled motor respectively and simultaneously.

2. The cooling structure (13) of the BSG liquid-cooled motor according to claim 1, characterized in that: The upper end surface of the outer water jacket (131) is in contact with the rear end cover (12); an outer stopper (1311) is provided on the inner side of the upper end surface of the outer water jacket (131); the outer stopper (1311) is in contact with the end surface of the stator (2) of the BSG liquid-cooled motor; and a first gap is provided at the connection between the lower end surface of the outer water jacket (131) and the front end cover (11).

3. The cooling structure (13) of the BSG liquid-cooled motor according to claim 2, characterized in that: An inner stop (1321) is provided on the inner side of the lower end surface of the inner water jacket (132), the inner stop (1321) abuts against the end surface of the stator (2), and the outer circumferential surface of the stator (2) is interference-connected with the inner wall of the inner water jacket (132); the lower end surface of the inner water jacket (132) abuts against the front end cover (11), and a second gap is provided at the connection between the upper end surface of the inner water jacket (132) and the outer water jacket (131).

4. The cooling structure (13) of the BSG liquid-cooled motor according to claim 3, characterized in that: The first gap and the second gap are both 0.1-1 mm.

5. The cooling structure (13) of the BSG liquid-cooled motor according to claim 1, characterized in that: The first cooling water channel (133) is arranged in a spiral shape along the outer wall of the inner water jacket (132), and a water outlet is arranged at the end of the first cooling water channel (133).

6. The cooling structure (13) of the BSG liquid-cooled motor according to claim 5, characterized in that: The second cooling water channel (134) is a U-shaped water channel, which is arranged on the water plate of the inverter (4). Cooling water flows from the outlet of the second cooling water channel (134) into the second transfer water channel (136), and then flows out from the outlet of the first cooling water channel (133) after merging with the cooling water of the first cooling water channel (133) from the outlet of the second transfer water channel (136).

7. The cooling structure (13) of the BSG liquid-cooled motor according to claim 6, characterized in that: A plurality of flow-disturbing and heat-dissipating columns (139) are arranged in the U-shaped water channel.

8. The cooling structure (13) of the BSG liquid-cooled motor according to claim 1, characterized in that: The first transfer water channel (135) is also provided with a drain port (1352), and the drain port (1352) is arranged directly below the transfer water inlet (1351), and the drain port (1352) is connected to the cooling water path of the BSG liquid-cooled motor; when the drain port (1352) is opened, the cooling water directly enters the drain port (1352) from the transfer water inlet (1351) to avoid entering the BSG liquid-cooled motor for cooling.

9. The cooling structure (13) of the BSG liquid-cooled motor according to claim 1, characterized in that: The first transfer water channel (135) is arranged on the outer water jacket (131) and the rear end cover (12) and is staggered to avoid the corner hanging hole (121); the second transfer water channel (136) is arranged on the outer water jacket (131) and the rear end cover (12) and is staggered to avoid the corner hanging hole (121).

10. A motor housing (1) of a BSG liquid-cooled motor, characterized in that: It comprises a front end cover (11), a rear end cover (12) and a cooling structure (13), wherein the cooling structure (13) is the cooling structure (13) according to any one of claims 1 to 9.

11. A BSG liquid-cooled motor, comprising a motor housing (1), a stator (2), a rotor (3) and an inverter (4), wherein the stator (2) is mounted in the motor housing (1), the rotor (3) is mounted and supported on the motor housing (1) corresponding to the stator (2), and the inverter (4) is connected to the motor housing (1), characterized in that: The motor housing (1) is the motor housing (1) according to claim 10.

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