A motor shaft for an oil-cooled motor, an oil-cooled motor and an electric vehicle

Abstract

The application discloses a motor shaft for an oil-cooled motor, a rotor core in the oil-cooled motor is provided with a cooling oil channel, the motor shaft comprises a shaft body, an axial shaft hole is formed in the shaft body, the shaft body has an oil inlet end, the shaft body is provided with a first oil throwing hole and a second oil throwing hole in the radial direction of the shaft body, the first oil throwing hole and the second oil throwing hole are distributed on the shaft body in the axial direction, and the first oil throwing hole is closer to the oil inlet end than the second oil throwing hole; the first oil throwing hole is in sealed communication with an oil blocking pipe, the oil blocking pipe protrudes from the inner wall of the shaft hole, the oil blocking pipe has an oil inlet, and the oil inlet has a set height from the inner wall of the shaft hole in the radial direction of the shaft body. The application also discloses an oil-cooled motor provided with the motor shaft and an electric automobile provided with the oil-cooled motor. When the application is applied, the oil blocking pipe can be used to distribute the cooling oil, so that the oil amount flowing into the first oil throwing hole and the second oil throwing hole is balanced.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and more particularly to a motor shaft for an oil-cooled motor, an oil-cooled motor, and an electric vehicle. Background Technology

[0002] With the continuous upgrading of electric vehicle technology, the speed requirements for drive motors are becoming increasingly higher. Currently, the highest speed of drive motors can reach 18,000 rpm, and correspondingly, the power density and torque density are also increasing. At the same time, there is a desire to keep the drive motor's size as compact as possible, leading to increasingly stringent requirements for its cooling performance. Currently, oil-cooled motors on the market generally use oil pipes to circulate cooling oil through the rotor core for cooling. However, this method has limitations. Firstly, the area through which the cooling oil flows is restricted, preventing direct cooling of the entire rotor core and resulting in uneven temperature distribution, thus failing to meet cooling requirements. Secondly, the complex structure of the oil pipes increases the difficulty of overall motor assembly. To solve these problems, related technologies propose a solution of arranging cooling oil circuits inside the rotor core. By guiding an appropriate amount of cooling oil into the interior of the rotor core, direct cooling can be achieved throughout the core, maintaining a uniform temperature and improving cooling efficiency. Furthermore, this solution eliminates the need for numerous oil pipes, reducing the difficulty of motor assembly. For example, the aforementioned technical concept is disclosed in published patents CN114567102A, CN115242010A, CN218335482U, CN214069749U, and CN218243259U. To guide the cooling oil into the rotor core, these patents all employ a scheme of setting oil channels inside the motor shaft and radially setting oil-throwing holes to connect the oil channels with the cooling oil passages of the rotor core. That is, the cooling oil first flows into the motor shaft, and then, under the high-speed rotation of the motor shaft, centrifugal force is used to throw the cooling oil through the oil-throwing holes into the cooling oil passages of the rotor core.

[0003] However, the above solution has the following problems in practical application: Two sets of oil slingers are arranged axially along the motor shaft, one set being close to the oil inlet end of the motor shaft where cooling oil enters. When the motor shaft rotates at high speed, the centrifugal force is very large, causing the cooling oil to be preferentially thrown out from the oil slinger near the oil inlet end, ultimately resulting in a large difference in the amount of oil entering the two sets of oil slingers. Consequently, due to the large difference in oil volume, the rotor core cannot be cooled evenly, ultimately leading to uneven rotor core temperature and insufficient cooling effect. Through experimental research, the inventors found that when the motor shaft speed is below 4000 rpm, the amount of oil thrown out through the two sets of oil slingers is roughly equal; when the motor shaft speed exceeds 4000 rpm, the difference in the amount of oil thrown out through the two sets of oil slingers gradually increases; when the motor shaft speed exceeds 10000 rpm, the cooling oil can almost only be thrown out from the oil slinger near the oil inlet end.

[0004] Of the five publicly disclosed patents mentioned above, only patent CN115242010A addresses this issue. In paragraph 0053 of its specification, it states that "because the first oil hole is close to the oil inlet, the oil sprayed from the injection pipe reaches the first oil hole first. As a result, the centrifugal force generated by the rotation of the motor shaft continuously throws the oil that reaches the first oil hole out of it, leading to a reduction in the amount of oil inside the motor shaft. This reduces the amount of oil reaching the second oil hole, resulting in more oil cooling the inner side of the left winding and less oil cooling the inner side of the right winding. This may lead to a significant difference in cooling effect between the inner sides of the right and left windings." The proposed solution is to arrange the number of the first and second oil holes differently, that is, fewer oil-throwing holes closer to the oil inlet and more oil-throwing holes farther from the oil inlet. Understandably, given the uneven oil flow at both ends, those skilled in the art would readily conceive of different numbers of the two sets of oil slingers, or, although not mentioned in the patent, different orifice diameters. It is reasonable to infer that the inventors of the aforementioned patent believed that by making the total cross-sectional area of ​​the two sets of oil slingers different—specifically, by designing the cross-sectional area of ​​the oil slinger near the inlet to be relatively smaller—the amount of oil entering the oil slinger near the inlet could be reduced, thereby increasing the amount of oil entering the oil slinger far from the inlet, thus achieving a balance in oil flow. However, in practical applications, the inventors' experimental research revealed that when the motor shaft speed exceeds 4000 rpm, the difference in oil flow through the two sets of oil slingers continues to gradually increase; when the motor shaft speed exceeds 10000 rpm, the cooling oil is still almost entirely slinged out from the oil slinger near the inlet. In other words, the above solution does not substantially solve the problem of "uneven oil volume ejected through the two sets of oil slingers under high-speed rotation of the motor shaft". Therefore, the oil-cooled motor used in electric vehicles still has the problem of "uneven rotor core temperature and difficulty in meeting the cooling requirements". Summary of the Invention

[0005] The present invention aims to address, to a certain extent, one of the technical problems in related technologies. To this end, the present invention provides a motor shaft for an oil-cooled motor, an oil-cooled motor, and an electric vehicle.

[0006] The present invention adopts the following technical solution: a motor shaft for an oil-cooled motor, wherein the rotor core of the oil-cooled motor is provided with a cooling oil passage, the motor shaft includes a shaft body, a shaft hole is formed axially inside the shaft body, the shaft body has an oil inlet end, and the shaft body is provided radially with a first oil sling hole and a second oil sling hole for connecting the shaft hole and the cooling oil passage, the first oil sling hole and the second oil sling hole are distributed axially at intervals on the shaft body, and the first oil sling hole is closer to the oil inlet end than the second oil sling hole; the first oil sling hole is sealed and connected to an oil baffle pipe, and the oil baffle pipe protrudes from the inner wall of the shaft hole, the oil baffle pipe has an oil inlet, and the oil inlet is at a set height radially from the inner wall of the shaft hole.

[0007] The present invention has the following beneficial effects: By setting an oil baffle pipe at the first oil slinger hole, and sealing the oil baffle pipe with the first oil slinger hole, when the cooling oil flows to the oil baffle pipe, the cooling oil below the set height is blocked and difficult to flow into the first oil slinger hole. It can be understood that the oil baffle pipe acts as a diversion device; the cooling oil below the set height can only continue to flow towards the second oil slinger hole after passing through the oil baffle pipe, while the cooling oil above the set height can flow into the first oil slinger hole through the oil inlet of the oil baffle pipe. Therefore, by designing the set height, the amount of oil flowing into the first and second oil slingers hole can be controlled, achieving a balance in oil volume.

[0008] Preferably, the set height is a selected value between 0.1mm and 4mm. Experimental studies have found that a set height between 0.1mm and 4mm can effectively divert the amount of cooling oil, thus improving the cooling effect on the rotor core.

[0009] Preferably, the set height is a selected value between 0.3mm and 3.5mm. Experimental studies have found that a set height between 0.3mm and 3.5mm can achieve a better balanced distribution of coolant volume.

[0010] Preferably, the oil baffle tube is fixedly inserted into the first oil slinger hole. This fixed insertion assembly method facilitates the assembly of the oil baffle tube with the motor shaft; it only requires direct insertion after meeting dimensional requirements during manufacturing. Furthermore, it allows for accurate control of the set height.

[0011] Preferably, a mounting plate is provided at one end of the oil baffle tube opposite to the oil inlet. The mounting plate has an arc surface adapted to the inner wall of the shaft hole. The oil baffle tube is fixedly bonded to the inner wall of the shaft hole by the mounting plate, and the mounting plate has a through hole that seals and connects the oil baffle tube and the first oil slinger hole. By providing the mounting plate, the oil baffle tube and the first oil slinger hole are sealed and connected by the mounting plate being fixedly bonded to the inner wall of the shaft hole.

[0012] Preferably, the motor shaft further includes a mounting ring, which is tightly fitted into the shaft hole, and the mounting ring is provided with a connecting hole aligned with the first oil slinger hole. The oil baffle pipe is fixedly inserted into the connecting hole by the inner ring of the mounting ring. By providing the mounting ring, the oil baffle pipe and the first oil slinger hole are sealed and connected by the tight fit between the mounting ring and the shaft hole.

[0013] Preferably, the number of the first oil-throwing hole and the second oil-throwing hole is the same.

[0014] To solve the above technical problems, the present invention also adopts the following technical solution: an oil-cooled motor, including a rotor core, and a motor shaft for the oil-cooled motor as described in any of the above technical solutions, wherein the rotor core is provided with a cooling oil passage, the cooling oil passage including a first oil passage and a second oil passage, the first oil slinger hole being sealed and connected to the first oil passage, and the second oil slinger hole being sealed and connected to the second oil passage.

[0015] Preferably, both ends of the rotor core are provided with end plates, and the side of the end plate facing the rotor core is provided with a groove. The side of the rotor core facing the end plate cooperates with the groove to form a channel for the flow of cooling oil. The first oil slinger hole is sealed and connected to the first oil circuit through the channel, and the second oil slinger hole is sealed and connected to the second oil circuit through the channel.

[0016] To solve the above-mentioned technical problems, the present invention also adopts the following technical solution: an electric vehicle equipped with the oil-cooled motor described in the above technical solution.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a motor shaft for an oil-cooled motor provided in Embodiment 1 of the present invention;

[0019] Figure 2 This is an exploded view of a motor rotor assembly with the motor shaft provided in Embodiment 1 installed.

[0020] Figure 3 A schematic diagram of the structure of a motor rotor assembly equipped with the motor shaft provided in Embodiment 1;

[0021] Figure 4 yes Figure 3 A cross-sectional view of the rotor assembly of the electric motor along the AA direction;

[0022] Figure 5 yes Figure 4 Enlarged schematic diagram of part B;

[0023] Figure 6 This is a schematic diagram of a motor rotor assembly with the motor shaft provided in Embodiment 1 installed;

[0024] Figure 7 yes Figure 6 Exploded view of the rotor assembly of the electric motor along the CC direction;

[0025] Figure 8 yes Figure 7 An enlarged schematic diagram of section D in the middle;

[0026] Figure 9 This is a cross-sectional view of the oil baffle pipe with a mounting plate in Embodiment 2;

[0027] Figure 10 This is a cross-sectional view of the oil baffle pipe installed on the mounting ring in Embodiment 3.

[0028] Among them, 1. Shaft body, 10. Shaft hole, 11. First oil slinger hole, 12. Second oil slinger hole, 13. Oil inlet end, 2. Oil baffle pipe, 20. Oil inlet, 3. Mounting plate, 30. Through hole, 4. Mounting ring, 40. Connecting hole, 5. Rotor core, 50. End plate, 500. Groove, 51. First oil passage, 52. Second oil passage. Detailed Implementation

[0029] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0030] Embodiments of the present invention are described below with reference to the accompanying drawings.

[0031] Example 1: This example provides a motor shaft for an oil-cooled motor, such as... Figure 1As shown, the motor shaft includes a shaft body 1, with an axially formed shaft hole 10 inside the shaft body 1. The shaft body 1 has an oil inlet end 13, from which cooling oil flows into the shaft hole 10 and flows towards the other end of the motor shaft. The shaft body 1 has a first oil slinger hole 11 and a second oil slinger hole 12 arranged radially thereon. The first oil slinger hole 11 and the second oil slinger hole 12 are axially spaced on the shaft body 1, with the first oil slinger hole 11 closer to the oil inlet end 13 than the second oil slinger hole 12. Specifically, in this embodiment, three of each type of oil slinger hole 11 and second oil slinger hole 12 are provided, and the three first oil slinger holes 11 and three second oil slinger holes 12 are evenly arranged circumferentially along the shaft body 1. It is understood that the number of first oil slinger holes 11 and second oil slinger holes 12 and their arrangement along the circumferential direction of the motor shaft can be adjusted as needed. The rotor core 5 of the oil-cooled motor, on which the motor shaft is mounted, is equipped with a cooling oil passage. The first oil-throwing hole 11 and the second oil-throwing hole 12 of the motor shaft are connected to the cooling oil passage to deliver cooling oil, thereby directly cooling the rotor core 5 and improving the cooling effect. The oil-cooled motor mainly includes a motor rotor assembly, a motor stator assembly, and a motor housing, such as... Figure 2 As shown, the aforementioned motor rotor assembly includes a motor shaft and a rotor core 5. The rotor core 5 is formed by stacking multiple rotor laminations on the motor shaft. End plates 50 are provided at both ends of the rotor core 5 to reinforce the rotor laminations. (Combined with...) Figure 3 and Figure 4 As shown, the rotor core 5 has a cooling oil passage inside, including a first oil passage 51 and a second oil passage 52. A groove 500 is provided on the side of the end plate 50 facing the rotor core 5. The side of the rotor core 5 facing the end plate 50 mates with the groove 500 to form a channel for the cooling oil to flow. The first oil-throwing hole 11 on the motor shaft is sealed and connected to the first oil passage 51 through the channel, and the second oil-throwing hole 12 is sealed and connected to the second oil passage 52 through the channel. With the above arrangement, a complete cooling oil circulation circuit can be formed. External cooling oil, powered by the oil pump, enters the shaft hole 10 through the oil inlet 13, and is then thrown into the first oil-throwing hole 11 and the second oil-throwing hole 12 under the high-speed rotation of the motor shaft. It then enters the first oil passage 51 and the second oil passage 52 through the channel, thereby directly cooling the rotor core 5.

[0032] Because the cooling oil preferentially flows through the first oil slinger hole 11, under the high-speed rotation of the motor shaft, the centrifugal force causes most of the cooling oil to preferentially enter the first oil slinger hole 11, resulting in a significant difference in the amount of cooling oil slinged out by the first oil slinger hole 11 and the second oil slinger hole 12. To solve the above technical problem, combined with... Figures 4 to 8As shown in the diagram, in this embodiment, the first oil slinger hole 11 is sealed and connected to an oil baffle pipe 2, and the oil baffle pipe 2 protrudes from the inner wall of the shaft hole 10. The oil baffle pipe 2 has an oil inlet 20, and the oil inlet 20 is at a set height along the radial direction of the shaft body 1 from the inner wall of the shaft hole 10. In this embodiment, by setting an oil baffle pipe 2 at the first oil slinger hole 11, and sealing and connecting the oil baffle pipe 2 with the first oil slinger hole 11, when the cooling oil flows to the oil baffle pipe 2, the cooling oil below the set height is blocked and restricted from flowing into the first oil slinger hole 11. It can be understood that the oil baffle pipe 2 plays a diversion role. The cooling oil below the set height can only continue to flow to the second oil slinger hole 12 after flowing through the oil baffle pipe 2, while the cooling oil above the set height can flow into the first oil slinger hole 11 through the oil inlet 20 of the oil baffle pipe 2. Therefore, by designing the set height, the amount of oil flowing into the first oil slinger hole 11 and the second oil slinger hole 12 can be controlled, thereby achieving the effect of balancing the amount of oil.

[0033] The differences and advantages of the solution for balancing the cooling oil volume provided in this embodiment compared to the solution in patent CN115242010A are detailed below: After in-depth research and experimental verification, the inventors found that if only the flow cross-sectional areas of the first oil-throwing hole 11 and the second oil-throwing hole 12 are designed to be different (e.g., by designing different numbers of the two orifices or different orifice diameters), it is difficult to achieve a balanced flow of cooling oil into the first oil-throwing hole 11 and the second oil-throwing hole 12. This is mainly due to two limitations in the manufacturing process: Firstly, as disclosed in paragraph 0057 of patent CN115242010A, due to the size limitation of the motor shaft, the number of both the first oil-throwing hole 11 and the second oil-throwing hole 12 cannot be unlimited and is difficult to exceed eight. Secondly, the size of the first oil-throwing hole 11 and the second oil-throwing hole 12 is difficult to process to less than 1.3mm (not that it cannot be processed to less than 1.3mm, but it is difficult to achieve in mass production). Experiments have shown that when the diameter of the first oil-throwing hole 11 is 1.3mm, at a motor shaft speed of 8000rpm, most of the cooling oil is thrown out from the first oil-throwing hole 11, and a small amount is thrown out from the second oil-throwing hole 12. When the motor shaft speed reaches 10000rpm, it is almost impossible to observe any oil being thrown out from the second oil-throwing hole 12. Therefore, the solution disclosed in patent CN115242010A is unlikely to achieve a good balance of oil volume in mass industrial production. Furthermore, even if the flow cross-sectional area of ​​the first oil-throwing hole 11 can be reduced after process improvements, the balance of oil volume can only be achieved within a certain speed range of the motor shaft. This is because the solution disclosed in patent CN115242010A does not have a forced diversion effect on the cooling oil; as the motor shaft speed increases, the centrifugal force continues to rise, and the amount of cooling oil flowing into the first oil-throwing hole 11 increases. That is, after the ratio of the flow cross-sectional area of ​​the first oil slinger 11 to the flow cross-sectional area of ​​the second oil slinger 12 is determined, it may be possible to achieve a rough balance of the amount of cooling oil within a certain speed range of the motor shaft. However, when the speed of the motor shaft exceeds this range, the amount of oil entering the first oil slinger 11 will increase.

[0034] The solution for balancing the amount of cooling oil provided in this embodiment solves the above-mentioned problems. On the one hand, this solution only requires adding an oil baffle pipe 2 to the motor shaft, without affecting the processing difficulty of the first oil slinger hole 11 and the second oil slinger hole 12, making it easy for mass industrial production. On the other hand, since the oil baffle pipe 2 plays a role in forced diversion, cooling oil below the set height cannot enter the first oil slinger hole 11 through the oil inlet 20 of the oil baffle pipe 2, but can only continue to flow to the second oil slinger hole 12. Therefore, when the set height is determined, no matter how the speed of the motor shaft changes, the diversion effect of the oil baffle pipe 2 will not be significantly affected. In summary, when using an oil-cooled motor with the motor shaft provided in this embodiment, the flow rate of cooling oil flowing into the first oil slinger hole 11 and the second oil slinger hole 12 can be stably controlled, so that the amount of oil entering the two is roughly balanced, ultimately making the cooling effect of the rotor core 5 roughly the same and the temperature consistent, thus improving the cooling effect of the rotor core 5. In this embodiment, the oil baffle tube 2 is fixedly inserted into the first oil slinger hole 11. This fixed insertion assembly method facilitates the assembly of the oil baffle tube 2 with the motor shaft. Accordingly, the set height H in this embodiment is determined by three factors: the wall thickness of the motor shaft (the depth of the first oil slinger hole 11), the length of the oil baffle tube 2, and the depth to which the oil baffle tube 2 is fixedly inserted into the first oil slinger hole 11. These factors are easily controlled during manufacturing and assembly. Figure 5 As shown in the figure, in this embodiment, the oil inlet 20 is designed at the end of the oil baffle tube 2, and the oil baffle tube 2 is assembled into the first oil sling hole 11 by a fixed plug-in method. Therefore, the set height H in this embodiment refers to the height value of the part of the oil baffle tube 2 that extends out of the first oil sling hole 11 and is higher than the inner wall of the shaft hole.

[0035] In this embodiment, the following experimental method is used to observe the amount of oil thrown into the first oil-throwing hole 11 and the second oil-throwing hole 12, thereby verifying the proportion of oil distributed to the first oil-throwing hole 11 and the second oil-throwing hole 12 under different set heights. Specifically, the experimental method is described as follows: A transparent cover is placed around the outside of the motor shaft (the oil baffle 2 on which has a defined set height H); the motor shaft is then tightly fitted onto the output shaft of the motor to facilitate the rotation of the motor shaft by the motor; an oil pipe is connected to the oil inlet end 13 of the motor shaft, and an oil pump is installed at the other end of the oil pipe (the oil pump can be mounted on the motor shaft so that the oil pump can also rotate with the motor shaft), and the cooling oil can be pumped into the shaft hole 10 of the motor shaft by the oil pump. After the experiment starts, the cooling oil is pumped into the shaft hole 10 of the motor shaft by the oil pump, and at the same time, the motor shaft is driven to rotate by the motor. The rotating motor shaft throws the cooling oil in the shaft hole 10 into the cover through the first oil-throwing hole 11 and the second oil-throwing hole 12. Because the cooling oil has a certain viscosity, the splashed cooling oil can adhere to the casing, thus forming a ring-shaped oil stain with a certain width on the casing. The oil stain formed on the casing by the cooling oil splashed from the first oil splash hole 11 is named the first oil stain, and correspondingly, the oil stain formed on the casing by the cooling oil splashed from the second oil splash hole 12 is named the second oil stain.

[0036] Using the above experimental method, the inventors manufactured motor shafts with different set height values ​​(referred to as motor shaft No. 3) by replacing oil baffles 2 with oil baffles of different lengths. Based on existing technology, they also manufactured motor shaft No. 1 (with three corresponding first and two oil slingers) and motor shaft No. 2 (with three corresponding first oil slingers and six corresponding second oil slingers). All other structural parameters of motor shafts No. 1, No. 2, and No. 3 were identical. Then, the width ratio of the first oil slick and the second oil slick produced by motor shafts No. 1, No. 2, and No. 3 were observed at different speeds. The experimental results at a motor shaft speed of 6000 rpm are detailed in the table below:

[0037]

[0038] The experimental results at a motor shaft speed of 8000 rpm are detailed in the table below:

[0039]

[0040]

[0041] The experimental results at a motor shaft speed of 10,000 rpm are detailed in the table below:

[0042] The experimental results at a motor shaft speed of 12000 rpm are detailed in the table below:

[0043]

[0044]

[0045] The above experiments revealed that the oil baffle 2 effectively distributes the cooling oil. A higher set height H of the oil baffle 2 allows the cooling oil to flow more towards the second oil slinger 12. When H ≥ 1.5 mm, the amount of cooling oil flowing to the second oil slinger 12 can even exceed the amount flowing to the first oil guide hole. Compared to the unevenness in existing technologies, the experiments showed that a set height H between 0.1 mm and 4 mm can achieve a balanced oil volume. Furthermore, a set height H between 0.3 mm and 3.5 mm produces an even better balanced oil volume. In this embodiment, H is 1.5 mm.

[0046] The motor shaft provided in this embodiment is for an oil-cooled motor, and the rotor core of the oil-cooled motor is provided with corresponding cooling oil circuits. This oil-cooled motor has a good cooling effect, and the temperature of the rotor core inside is roughly uniform. This oil-cooled motor can be used in common motor application scenarios, and is especially suitable for use in electric vehicles. While meeting the speed requirements of electric vehicles for drive motors, it effectively ensures the cooling effect of the oil-cooled motor itself.

[0047] Example 2: This example also provides a motor shaft for an oil-cooled motor, such as... Figure 9 As shown, the difference between this embodiment and the above embodiment lies in the assembly method of the oil baffle tube 2 and the motor shaft. Specifically, in this embodiment, a mounting plate 3 is provided at one end of the oil baffle tube 2 opposite to the oil inlet 20. The mounting plate 3 has an arc surface adapted to the inner wall of the shaft hole 10. The oil baffle tube 2 is fixedly bonded to the inner wall of the shaft hole 10 through the mounting plate 3, and the mounting plate 3 has a through hole 30 that seals and connects the oil baffle tube 2 and the first oil slinger hole 11. Specifically, one end of the oil baffle tube 2 is fixedly inserted into the through hole 30. By providing the mounting plate 3, the oil baffle tube 2 and the first oil slinger hole 11 are sealed and connected by the mounting plate 3 fixedly bonded to the inner wall of the shaft hole 10.

[0048] Accordingly, the set height H in this embodiment is determined by three factors: the radial thickness d of the mounting plate 3 along the motor shaft, the length L of the oil baffle tube 2, and the depth P of the oil baffle tube 2 fixedly inserted into the through hole 30. For example... Figure 9 As shown in the figure, in this embodiment, the oil inlet 20 is designed at the end of the oil baffle pipe 2, and the oil baffle pipe 2 is assembled into the through hole 30 of the mounting plate 3 by a fixed plug-in method. Therefore, the set height H in this embodiment is d + LP.

[0049] Example 3: This example also provides a motor shaft for an oil-cooled motor, such as... Figure 10 As shown, the difference between this embodiment and the above embodiment lies in the assembly method of the oil baffle pipe 2 and the motor shaft. Specifically, the motor shaft in this embodiment also includes a mounting ring 4, which is tightly fitted into the shaft hole 10. The mounting ring 4 is provided with a connecting hole 40 aligned with the first oil slinger hole 11. The oil baffle pipe 2 is fixedly inserted into the connecting hole 40 by the inner ring of the mounting ring 4. By setting the mounting ring 4, the oil baffle pipe 2 and the first oil slinger hole 11 are sealed and connected by the tight fit between the mounting ring 4 and the shaft hole 10.

[0050] Accordingly, the set height H in this embodiment is determined by three factors: the radial thickness D of the mounting ring 4 along the motor shaft, the length M of the oil baffle tube 2, and the depth N of the oil baffle tube 2 fixedly inserted into the connecting hole 40 of the mounting ring 4. Figure 10 As shown in the figure, in this embodiment, the oil inlet 20 is designed at the end of the oil baffle pipe 2, and the oil baffle pipe 2 is assembled into the connection hole 40 of the mounting ring 4 by a fixed plug-in method. Therefore, the set height H in this embodiment is D+MN.

[0051] In this invention, unless otherwise explicitly specified or limited in the embodiments, the terms "installation," "connection," "joining," and "fixing" appearing in the embodiments should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral part; it can also be a mechanical connection, an electrical connection, etc. Of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components, or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific implementation.

[0052] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A motor shaft for an oil-cooled motor, wherein the rotor core (5) of the oil-cooled motor is provided with a cooling oil passage, the motor shaft includes a shaft body (1), the shaft body (1) having an axially formed shaft hole (10) inside, the shaft body (1) having an oil inlet end (13), the shaft body (1) having a first oil-throwing hole (11) and a second oil-throwing hole (12) for connecting the shaft hole (10) with the cooling oil passage along its radial direction, the first oil-throwing hole (11) and the second oil-throwing hole (12) being axially spaced on the shaft body (1), and the first oil-throwing hole (11) being closer to the oil inlet end (13) than the second oil-throwing hole (12); Its features are, The first oil-throwing hole (11) is sealed and connected to an oil-blocking pipe (2), and the oil-blocking pipe (2) protrudes from the inner wall of the shaft hole (10). The oil-blocking pipe (2) has an oil inlet (20), and the oil inlet (20) has a set height along the radial distance of the shaft body (1) from the inner wall of the shaft hole (10). The motor shaft also includes a mounting ring (4), which is tightly fitted into the shaft hole (10). The mounting ring (4) is provided with a connecting hole (40) aligned with the first oil slinger hole (11). The oil baffle tube (2) is fixedly inserted into the connecting hole (40) by the inner ring of the mounting ring (4). Alternatively, the oil baffle tube (2) is provided with a mounting plate (3) at one end opposite to the oil inlet (20). The mounting plate (3) has an arc surface adapted to the inner wall of the shaft hole (10). The oil baffle tube (2) is fixedly bonded to the inner wall of the shaft hole (10) by the mounting plate (3). The mounting plate (3) has a through hole (30) that seals and connects the oil baffle tube (2) and the first oil slinger hole (11).

2. The motor shaft for an oil-cooled motor as described in claim 1, characterized in that, The set height is a selected value between 0.1 mm and 4 mm.

3. The motor shaft for an oil-cooled motor as described in claim 1 or 2, characterized in that, The set height is a selected value between 0.3mm and 3.5mm.

4. The motor shaft for an oil-cooled motor as described in claim 1, characterized in that, The oil baffle (2) is fixedly inserted into the first oil throwing hole (11).

5. The motor shaft for an oil-cooled motor as described in claim 1, characterized in that, The number of the first oil-throwing hole (11) and the second oil-throwing hole (12) is the same.

6. An oil-cooled motor, comprising a rotor core (5), characterized in that, It also includes a motor shaft for an oil-cooled motor as described in any one of claims 1 to 5, wherein the rotor core (5) is provided with a cooling oil passage, the cooling oil passage including a first oil passage (51) and a second oil passage (52), the first oil slinger hole (11) is sealed and connected to the first oil passage (51), and the second oil slinger hole (12) is sealed and connected to the second oil passage (52).

7. The oil-cooled motor as described in claim 6, characterized in that, Both ends of the rotor core (5) are provided with end plates (50). The side of the end plate (50) facing the rotor core (5) is provided with a groove (500). The side of the rotor core (5) facing the end plate (50) cooperates with the groove (500) to form a channel for the flow of cooling oil. The first oil slinger hole (11) is sealed and connected to the first oil passage (51) through the channel. The second oil slinger hole (12) is sealed and connected to the second oil passage (52) through the channel.

8. An electric vehicle, characterized in that, It is equipped with an oil-cooled motor as described in claim 6 or 7.

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