Patent Description:
With the rapid development of vehicle technology, related technical requirements for driving electric motors are becoming increasingly stringent, and the future development of electric motors will trend towards high speed, high power density, and high integration. For electric motors, this development trend puts forward higher cooling requirements and requires a more efficient cooling manner.

In existing electric motors for vehicles, a spray oil ring is usually used to spray on an end portion of a winding and an outer surface of an iron core so as to cool the electric motor. For example, published Chinese patent applications <CIT>, <CIT>, and <CIT> each disclose a motor including a stator and an oil cooling structure for the stator, wherein the oil cooling structure includes an oil-spraying member mounted to an axial end of the stator for cooling the end portion of a winding of the stator. In addition, <CIT> and <CIT> each disclose an arc-curved oil guide structure fixed to an axial end of a stator.

However, the existing electric motor for vehicles usually have the problems that during spraying and cooling of the outer surface of the iron core, a heat dissipation area of the outer surface of the iron core is small, a convective heat transfer coefficient of a heat dissipation surface is small and is greatly affected by a direction of gravity, and a cooling oil easily flows along an outer wall of a cooling oil ring at a low temperature and a low flow rate, so that the end portion of the winding cannot be cooled.

Accordingly, there is a need in the art for a novel electric motor for a vehicle and a vehicle to solve the foregoing problems.

To solve the foregoing problems in the prior art, the invention is set out in the appended set of claims <NUM>-<NUM>.

It can be understood by those skilled in the art that in the technical solution of the disclosure, the electric motor for a vehicle comprises a stator, cooling oil rings, and an oil intake pipeline, wherein the cooling oil rings are fixedly connected to the stator; each of the cooling oil rings is a hollow column with a circular ring-shaped cross-section, a side wall of the hollow column is provided with a cooling oil inlet and a plurality of oil spray holes, an inner side wall of the hollow column is further provided with an oil guide rib, and the oil guide rib is configured to be able to guide an oil sprayed from the oil spray holes to one side of the hollow column, so as to enable the cooling oil sprayed from the oil spray holes to fully cool an end portion of the electric motor; the stator comprises a plurality of first laminations, each of the first laminations is configured into the shape of a circular ring and is provided with oil passage holes, the plurality of first laminations are stacked in an axial direction of the first laminations, the plurality of stacked first laminations jointly enclose a cylindrical structure, the oil passage holes in the plurality of first laminations are in communication with each other to form cooling oil passages, and the oil intake pipeline is in communication with the cooling oil passages; and the cooling oil passages are arranged to enable the cooling oil to flow in an axial direction of the stator, and also enable the cooling oil to flow between a plurality of cooling oil passages in a radial direction of the stator; wherein the cooling oil rings are respectively arranged at two ends of the stator, and the oil intake pipeline, the cooling oil passages and the hollow columns are sequentially in communication with one another, so as to enable the cooling oil to flow between the oil intake pipeline, the cooling oil passages, and the hollow columns.

By means of the foregoing arrangement, in the electric motor for a vehicle according to the disclosure, the cooling oil passages in communication with each other are formed, and the oil intake pipeline is in communication with the cooling oil passages, so that the cooling oil can enter the cooling oil passages and flow inside the cooling oil passages in the axial direction of the stator, so as to cool the interior of the stator formed by stacking the plurality of first laminations in the axial direction of the first laminations. Further, in the electric motor for a vehicle according to the disclosure, the cooling oil passages are further arranged to enable the cooling oil to flow in the axial direction of the stator, and also enable the cooling oil to flow between a plurality of cooling oil passages in the radial direction of the stator, so as to increase a flow path of the cooling oil inside the stator. This, compared with a plurality of independent cooling oil passages, further enables the oil temperature to be more balanced, has a better cooling effect, and also provides a longer flow path and more routes, thereby further increasing a heat exchange area inside the stator, and improving the cooling effect on the interior of the stator.

In addition, in the electric motor for a vehicle according to the disclosure, further, the cooling oil rings are arranged at two ends of the stator, the cooling oil rings are each configured as a hollow column with a circular ring-shaped cross-section, the side wall of the hollow column is provided with the cooling oil inlet and the plurality of oil spray holes, and the oil intake pipeline, the cooling oil passages and the hollow columns are sequentially in communication with one another, so as to form a complete oil path in which the cooling oil enters the cooling oil passages from the oil intake pipeline, then flows out from the cooling oil passages and enters each hollow column through the cooling oil inlet, and is then sprayed from the oil spray holes in the side wall of the hollow column under the action of an internal pressure of the hollow column. Therefore, the cooling oil flows in the oil path to provide a spray effect on the end portion of the winding of the electric motor, and then meet requirements for cooling the end portion of the winding of the electric motor by the cooling oil rings. Further, the inner side wall of the hollow column is further provided with an oil guide rib, and the oil guide rib is configured to be able to guide an oil sprayed from the oil spray holes to one side of the hollow column, so as to enable the oil sprayed from the oil spray holes to fully cool the end portion of the electric motor, thereby preventing the cooling oil from flowing along the outer wall of the cooling oil ring, and then further improving the cooling effect of the cooling oil on the end portion of the winding of the electric motor. In addition, the arrangement of the oil guide rib on the inner side wall of the hollow column further enables the cooling oil sprayed from the oil spray holes to flow to the end portion of the winding of the electric motor under the oil guide function of the oil guide rib at a low flow rate or at a low temperature (that is, when the cooling oil is not enough for spraying on the end portion of the winding of the electric motor only under the spray effect of the oil spray holes).

An electric motor for a vehicle according to the disclosure is described below with reference to the accompanying drawings. In the accompanying drawings:.

Preferred implementations of the disclosure are described below with reference to the accompanying drawings. Those skilled in the art should understand that these implementations are only used to explain the technical principles of the disclosure, and are not intended to limit the scope of protection of the disclosure. Those skilled in the art can make adjustments according to requirements, so as to adapt to specific application scenarios.

It should be noted that, in the description of the disclosure, the terms that indicate the directions or positional relationships, such as "upper", "lower", "inner" and "outer", are based on the directions or positional relationships shown in the accompanying drawings, are merely for ease of description instead of indicating or implying that the device or element must have a particular orientation and be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the disclosure. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be construed as indicating or implying relative importance.

In addition, it should also be noted that, in the description of the disclosure, the terms "connect" should be interpreted in a broad sense unless explicitly defined and limited otherwise, which, for example, may be a fixed connection, a detachable connection or an integral connection; or may be a direct connection, or an indirect connection by means of an intermediate medium. For those skilled in the art, the specific meanings of the foregoing terms in the disclosure can be interpreted according to a specific situation.

Referring to <FIG> and <FIG> first, an electric motor for a vehicle according to the disclosure is described.

As shown in <FIG> and <FIG>, to solve the problems usually existing in an existing electric motor for a vehicle that during spraying and cooling of an outer surface of an iron core, a heat dissipation area of the outer surface of the iron core is small, a convective heat transfer coefficient of a heat dissipation surface is small and is greatly affected by a direction of gravity, and a cooling oil easily flows along an outer wall of a cooling oil ring at a low temperature and a low flow rate, so that an end portion of a winding cannot be cooled, an electric motor for a vehicle according to the disclosure comprises a stator <NUM>, cooling oil rings <NUM>, and an oil intake pipeline <NUM>. The cooling oil rings <NUM> are fixedly connected to the stator <NUM>. Each of the cooling oil rings <NUM> is a hollow column <NUM> with a circular ring-shaped cross-section, a side wall of the hollow column <NUM> is provided with a cooling oil inlet <NUM> and a plurality of oil spray holes <NUM>, an inner side wall of the hollow column <NUM> is further provided with an oil guide rib <NUM>, and the oil guide rib <NUM> is configured to be able to guide an oil sprayed from the oil spray holes <NUM> to one side of the hollow column <NUM>, so as to enable the cooling oil sprayed from the oil spray holes <NUM> to fully cool an end portion of the electric motor. The stator <NUM> comprises a plurality of first laminations <NUM>, each of the first laminations <NUM> is configured into the shape of a circular ring, the first laminations <NUM> are provided with oil passage holes <NUM>, the plurality of first laminations <NUM> are stacked in an axial direction of the first laminations <NUM>, the plurality of stacked first laminations <NUM> jointly enclose a cylindrical structure, the oil passage holes <NUM> in the plurality of first laminations <NUM> are in communication with each other to form cooling oil passages <NUM>, and the oil intake pipeline <NUM> is in communication with the cooling oil passages <NUM>. The cooling oil passages <NUM> are arranged to enable the cooling oil to flow in an axial direction of the stator <NUM>, and also enable the cooling oil to flow between a plurality of cooling oil passages <NUM> in a radial direction of the stator <NUM> (as shown in <FIG>, the cooling oil flows axially in an X direction, and a plurality of cooling oil passages <NUM> are in communication with each other in a Y direction, so the cooling oil also flows radially in the Y direction). The cooling oil rings <NUM> are respectively arranged at two ends of the stator <NUM>, and the oil intake pipeline <NUM>, the cooling oil passages <NUM> and the hollow columns <NUM> are sequentially in communication with one another, so as to enable the cooling oil to flow between the oil intake pipeline <NUM>, the cooling oil passages <NUM>, and the hollow columns <NUM>.

By means of the foregoing arrangement, in the electric motor for a vehicle according to the disclosure, the cooling oil passages <NUM> in communication with each other are formed, and the oil intake pipeline <NUM> is in communication with the cooling oil passages <NUM>, so that the cooling oil can enter the cooling oil passages <NUM> and flow inside the cooling oil passages <NUM> in the axial direction of the stator <NUM>, so as to cool the interior of the stator <NUM> formed by stacking the plurality of first laminations <NUM> in the axial direction of the first laminations <NUM>. Further, in the electric motor for a vehicle according to the disclosure, the cooling oil passages <NUM> are further arranged to enable the cooling oil to flow in the axial direction of the stator <NUM>, and also enable the cooling oil to flow between a plurality of cooling oil passages <NUM> in the radial direction of the stator <NUM>, so as to increase a flow path of the cooling oil inside the stator <NUM>. This, compared with a plurality of independent cooling oil passages, further enables the oil temperature to be more balanced, has a better cooling effect, and also provides a longer flow path and more routes, thereby further increasing a heat exchange area inside the stator <NUM>, and improving the cooling effect on the interior of the stator <NUM>.

In addition, still referring to <FIG> and <FIG>, in the electric motor for a vehicle according to the disclosure, further, the cooling oil rings <NUM> are arranged at two ends of the stator <NUM>, the cooling oil rings <NUM> are each configured as a hollow column <NUM> with a circular ring-shaped cross-section, the side wall of the hollow column <NUM> is provided with the cooling oil inlet <NUM> and the plurality of oil spray holes <NUM>, and the oil intake pipeline <NUM>, the cooling oil passages <NUM> and the hollow columns <NUM> are sequentially in communication with one another, so as to form a complete oil path in which the cooling oil enters the cooling oil passages <NUM> from the oil intake pipeline <NUM>, then flows out from the cooling oil passages <NUM> and enters each hollow column <NUM> through the cooling oil inlet <NUM>, and is then sprayed from the oil spray holes <NUM> in the side wall of the hollow column <NUM> under the action of an internal pressure of the hollow column <NUM>, in a direction shown by the arrows in <FIG>. Therefore, the cooling oil flows in the oil path to provide a spray effect on the end portion of the winding of the electric motor, and then meet requirements for cooling the end portion of the winding of the electric motor by the cooling oil rings <NUM>. Further, the inner side wall of the hollow column <NUM> is further provided with an oil guide rib <NUM>, and the oil guide rib <NUM> is configured to be able to guide an oil sprayed from the oil spray holes <NUM> to one side of the hollow column <NUM>, so as to enable the oil sprayed from the oil spray holes <NUM> to fully cool the end portion of the electric motor, thereby preventing the cooling oil from flowing along the outer wall of the cooling oil ring <NUM>, and then further improving the cooling effect of the cooling oil on the end portion of the winding of the electric motor. In addition, the arrangement of the oil guide rib <NUM> on the inner side wall of the hollow column <NUM> further enables the cooling oil sprayed from the oil spray holes <NUM> to flow to the end portion of the winding of the electric motor under the oil guide function of the oil guide rib <NUM> at a low flow rate or at a low temperature (that is, when the cooling oil is not enough for spraying on the end portion of the winding of the electric motor only under the spray effect of the oil spray holes <NUM>).

It should be noted that in this embodiment, a section A of the oil path in <FIG> is a flow oil path of the cooling oil in the cooling oil passage <NUM>, a section B of the oil path in <FIG> is a flow oil path of the cooling oil in the cooling oil ring <NUM>, and a section C of the oil path in <FIG> is a flow oil path of the cooling oil sprayed from the oil spray holes <NUM>. The axial direction of the stator <NUM> refers to the X direction in <FIG>, and the radial direction of the stator <NUM> refers to the Y direction in <FIG>.

Further referring to <FIG>, the electric motor for a vehicle according to the disclosure is described in detail below.

As shown in <FIG>, in a possible implementation, each of the cooling oil rings <NUM> comprises an inner ring <NUM> and an outer ring <NUM>, the outer ring <NUM> is sleeved outside the inner ring <NUM>, the inner ring <NUM> and the outer ring <NUM> are each provided with limiting teeth <NUM> for mounting with the stator <NUM> to prevent the cooling oil ring <NUM> from rotating circumferentially with the stator <NUM>, and the inner ring <NUM> and the outer ring <NUM> are each further provided with an oil ring fastener <NUM> for axially fixedly connecting the cooling oil ring <NUM> to the stator <NUM>.

In this embodiment, the limiting teeth <NUM> are provided on both the inner ring <NUM> and the outer ring <NUM>, so that the circumferential movement between the cooling oil ring <NUM> and the stator <NUM> can be prevented after the cooling oil ring <NUM> is assembled with the stator <NUM>. In addition, the inner ring <NUM> and the outer ring <NUM> are each further provided with an oil ring fastener <NUM>, so that the cooling oil ring <NUM> is axially fixedly connected to the stator <NUM>.

It should be noted that in this embodiment, the outer ring <NUM> is sleeved outside the inner ring <NUM> to form the hollow column <NUM> in this embodiment.

As shown in <FIG>, in a possible implementation, a plurality of oil guide ribs <NUM> are provided, each of the oil guide ribs <NUM> is arranged on the inner side wall of the hollow column <NUM> in an axial direction of the hollow column <NUM>, the oil guide ribs <NUM> divide the inner side wall of the hollow column <NUM> into a plurality of regions <NUM>, and oil spray holes <NUM> in two adjacent regions <NUM> are the same in number.

In this embodiment, by providing the plurality of oil guide ribs <NUM> on the inner side wall of the hollow column <NUM> in the axial direction of the hollow column <NUM>, the cooling oil sprayed from the oil spray holes <NUM> can be guided to one side of the hollow column <NUM> under the action of the oil guide ribs <NUM>, and the oil guide effect on the cooling oil can be further enhanced by providing the plurality of oil guide ribs <NUM>, to further prevent the cooling oil from flowing along the outer wall of the cooling oil ring <NUM>, thereby further improving the spray effect of the cooling oil on the end portion of the electric motor, and then further enhancing the cooling effect on the end portion of the electric motor.

In addition, the cooling oil ring <NUM> in this embodiment divides the inner side wall of the hollow column <NUM> into the plurality of regions <NUM> by means of the oil guide ribs <NUM>, and oil spray holes <NUM> in two adjacent regions <NUM> are the same in number, so that the flow rates of the cooling oil flowing through the oil guide ribs <NUM> in unit time are similar. Therefore, the oil guide efficiency of the oil guide ribs <NUM> is improved, so that the oil guide ribs <NUM> can guide the cooling oil to one side of the hollow column <NUM> more evenly, and then the spray effect on the end portion of the electric motor is improved to enhance the cooling effect on the end portion of the electric motor.

It should be noted that, as shown in <FIG>, in this embodiment, the oil guide ribs <NUM> are each a rectangular rib <NUM> or a spiral rib (not shown in the figure). The rectangular rib <NUM> in the disclosure means an elongated rectangular strip-shaped rib in <FIG>, and accordingly, the spiral rib is that which reaches one side of the hollow column <NUM> in the form of a spiral coil on the inner side of the hollow column <NUM>, provided that the cooling oil can be led to the side of the hollow column <NUM> close to the interior of the electric motor.

As shown in <FIG>, in order to enhance the spray effect of the cooling oil ring <NUM> on the end portion of the electric motor, in this embodiment, an arrangement density of oil spray holes <NUM> in a first region <NUM> of the inner side wall of the hollow column <NUM> is greater than those in other regions.

Through the foregoing arrangement, the distribution positions of the oil spray holes <NUM> are arranged in such a way that the arrangement density in the first region <NUM> of the inner side wall of the hollow column <NUM> is greater than those in other regions, so that when the cooling oil rings <NUM> are assembled with the stator <NUM>, the oil spray holes <NUM> in the cooling oil rings <NUM> are distributed in the inner side wall of the hollow column <NUM> in the form of dense distribution at the top and sparse distribution at the bottom. Therefore, the cooling oil sprayed from the oil spray holes <NUM> in the first region <NUM> of the inner side wall of the hollow column <NUM> can be better sprayed to the end portion of the electric motor under the action of its own gravity, so that more cooling oil can be sprayed to the end portion of the electric motor during the spraying of the cooling oil, thus improving the spray effect of the cooling oil on the end portion of the electric motor, so as to strengthen the cooling effect of the end portion of the electric motor.

As shown in <FIG> and <FIG>, in a possible implementation, a first end <NUM> of the hollow column <NUM> is further sleeved with an oil blocking end ring <NUM>.

In this embodiment, the first end <NUM> of the hollow column <NUM> is sleeved with the oil blocking end ring <NUM>, so that when the cooling oil rings <NUM> are assembled with the stator <NUM> and the cooling oil rings <NUM> are in communication with the stator <NUM> via an oil path, the oil blocking end ring <NUM> can reverse the cooling oil during the flow of the cooling oil in the oil path formed by the stator <NUM> and the cooling oil rings <NUM>. That is, when the cooling oil flows from the stator <NUM> into the cooling oil rings <NUM>, the oil blocking end ring <NUM> sleeved on the cooling oil ring <NUM> can block the cooling oil to return the cooling oil to change the flow direction of the cooling oil, so that the cooling oil can circulate in the oil path formed by the stator <NUM> and the cooling oil rings <NUM>, so as to improve the cooling effect on the electric motor stator <NUM>.

As shown in <FIG>, <FIG>, in a possible implementation, the plurality of first laminations <NUM> are stacked in such a way that oil passage holes <NUM> in two adjacent first laminations <NUM> are in a staggered alignment. By way of example, for a plurality of same first laminations <NUM>, it is possible that one lamination at an angle of <NUM>° and one lamination at an angle of rotation of <NUM>° are stacked alternately, or that ten laminations at an angle of <NUM>° and ten laminations at an angle of rotation of <NUM>° are stacked alternately, provided that the cooling oil passages <NUM> according to any implementation shown in <FIG> can be finally presented.

It should be noted that in this embodiment, the arrangement positions and the number of oil passage holes <NUM> in the first laminations <NUM> may be set according to actual requirements, to meet the design requirements that the cooling oil passages <NUM> according to any implementation shown in <FIG> can be presented.

As shown in <FIG>, in a possible implementation, the stator <NUM> further comprises a second lamination <NUM>, the second lamination <NUM> is provided with a pressure relief hole <NUM>, the pressure relief hole <NUM> has a diameter greater than that of the oil passage hole <NUM>, and at least one second lamination <NUM> is arranged between two first laminations <NUM>, so that the cooling oil flowing from the oil passage holes <NUM> located above the second lamination <NUM> passes through the pressure relief hole <NUM>, and then flows into the oil passage holes <NUM> located below the second lamination <NUM>.

Through the foregoing arrangement, in the electric motor for a vehicle in this embodiment, further, the second lamination <NUM> is arranged in the stator <NUM>, the second lamination <NUM> is provided with a pressure relief hole <NUM>, the pressure relief hole <NUM> has a diameter greater than that of the oil passage hole <NUM>, and at least one second lamination <NUM> is arranged between two first laminations <NUM>. Since the pressure relief hole <NUM> formed in the second lamination <NUM> has a diameter greater than that of each oil passage hole <NUM> formed in the first laminations <NUM>, after flowing out of the oil passage holes <NUM> above the second lamination <NUM>, the cooling oil flows into the pressure relief hole <NUM> formed in the second lamination <NUM>, so that the pressure is reduced, and then during the flowing of the cooling oil from the pressure relief hole <NUM> into the oil passage holes <NUM> below the second lamination <NUM>, the pressure relief hole <NUM> can relieve the pressure of the cooling oil to enable the cooling oil to flow more smoothly in the cooling oil passages <NUM>. By means of the flow guide function of the pressure relief hole <NUM>, the pressure drop of the cooling oil during the flow is reduced, so as to further improve the cooling effect on the interior of the stator <NUM> through the flow of the cooling oil in the cooling oil passages <NUM>.

As shown in <FIG>, in order to further improve the cooling effect on the stator <NUM>, in this embodiment, side walls of the oil passage holes <NUM> are further provided with disturbance protrusions <NUM>.

In this embodiment, the side walls of the oil passage holes <NUM> are provided with the disturbance protrusions <NUM>, so that during the flow of the cooling oil in the cooling oil passages <NUM>, a heat dissipation area inside the stator <NUM> is increased, and the flow disturbance effect of the cooling oil is enhanced, thereby further improving the heat dissipation capability inside the stator <NUM>.

Further, as shown in <FIG>, in order to further improve the cooling effect on the stator <NUM>, in this embodiment, a side wall of the pressure relief hole <NUM> is further provided with a disturbance protrusion <NUM>.

Through the foregoing arrangement, in this embodiment, the side wall of the pressure relief hole <NUM> is provided with the disturbance protrusion <NUM>, so that during the flow of the cooling oil through the pressure relief hole <NUM>, a heat exchange area inside the stator <NUM> can be further increased under the effect of the disturbance protrusion <NUM> on the side wall of the pressure relief hole <NUM>, and the disturbance effect of the cooling oil is enhanced, thereby further improving the cooling effect inside the stator <NUM>.

It should be noted that, as shown in <FIG>, in this embodiment, a cross-section of each oil passage hole <NUM> is a rectangular hole.

In this embodiment, on the one hand, by configuring the cross-section of the oil passage hole <NUM> as a rectangular hole, necessary structural features are provided to enable the cooling oil to flow in the cooling oil passages <NUM>, and on the other hand, by configuring the cross-section of the oil passage hole <NUM> as a rectangular hole, the machining of the oil passage hole <NUM> is easy to operate, and machining costs are reduced.

As shown in <FIG>, in a possible implementation, the electric motor further comprises a housing <NUM>, and the housing <NUM> is sleeved outside the stator <NUM> and the cooling oil rings <NUM> such that the stator <NUM> is fixedly connected to the cooling oil rings <NUM>.

Through the foregoing arrangement, in this embodiment, the housing <NUM> is sleeved outside the stator <NUM> and the cooling oil rings <NUM>, so as to meet the requirement of fixedly connecting the stator <NUM> to the cooling oil rings <NUM>.

As shown in <FIG> and <FIG>, in order to enhance the sealing between each cooling oil ring <NUM> and the housing <NUM> of the electric motor, in this embodiment, further, a second end <NUM> of the cooling oil ring <NUM> is sleeved with a radial sealing ring <NUM> for hermetical connection to the housing <NUM> of the electric motor to achieve a radial sealing effect.

In addition, as shown in <FIG> and <FIG>, in order to enhance the sealing between each cooling oil ring <NUM> and the stator <NUM>, in this embodiment, further, an axial sealing ring <NUM> for hermetical connection to the stator <NUM> axially abuts against the first end <NUM> of the cooling oil ring <NUM>, and the cooling oil ring <NUM> is axially pressed against the stator <NUM> by means of the axial sealing ring <NUM> to achieve an axial sealing effect.

In conclusion, in the electric motor for a vehicle according to the disclosure, the cooling oil passages <NUM> are arranged to enable the cooling oil to flow in the axial direction of the stator <NUM>, and also enable the cooling oil to flow between a plurality of cooling oil passages <NUM> in the radial direction of the stator <NUM>, so as to increase a flow path of the cooling oil inside the stator <NUM>. This, compared with a plurality of independent cooling oil passages, further enables the oil temperature to be more balanced, has a better cooling effect, and also provides a longer flow path and more routes, thereby further increasing a heat exchange area inside the stator <NUM>, and improving the cooling effect on the interior of the stator <NUM>.

In addition, in the electric motor for a vehicle according to the disclosure, further, the cooling oil rings <NUM> are arranged at two ends of the stator <NUM>, so as to form a complete oil path in which the cooling oil enters the cooling oil passages <NUM> from the oil intake pipeline <NUM>, then flows out from the cooling oil passages <NUM> and enters each hollow column <NUM> through the cooling oil inlet <NUM>, and is then sprayed from the oil spray holes <NUM> in the side wall of the hollow column <NUM> under the action of an internal pressure of the hollow column <NUM>. Therefore, the cooling oil flows in the oil path to provide a spray effect on the end portion of the winding of the electric motor, and then meet requirements for cooling the end portion of the winding of the electric motor by the cooling oil rings <NUM>.

It should be noted that the foregoing implementations are only used to explain the principles of the inventions claimed by the appended claims, and are not intended to limit the scope of protection of the claimed inventions. Those skilled in the art can adjust the foregoing structures without departing from the claimed inventions, so that the claimed inventions are applicable to more specific application scenarios.

Claim 1:
An electric motor for a vehicle, wherein the electric motor comprises a stator (<NUM>), cooling oil rings (<NUM>), and an oil intake pipeline (<NUM>), wherein the cooling oil rings (<NUM>) are fixedly connected to the stator (<NUM>);
wherein each of the cooling oil rings (<NUM>) is a hollow column (<NUM>) with a circular ring-shaped cross-section taken perpendicular to an axial direction of the stator (<NUM>);
wherein the stator (<NUM>) comprises a plurality of first laminations (<NUM>), each of the first laminations (<NUM>) is configured into the shape of a circular ring and is provided with oil passage holes (<NUM>), the plurality of first laminations (<NUM>) are stacked in an axial direction of the stator (<NUM>), the plurality of stacked first laminations (<NUM>) jointly enclose a cylindrical structure, the oil passage holes (<NUM>) in the plurality of first laminations (<NUM>) are in communication with each other to form cooling oil passages (<NUM>), and the oil intake pipeline (<NUM>) is in communication with the cooling oil passages (<NUM>);
wherein the cooling oil passages (<NUM>) are arranged to enable the cooling oil to flow in an axial direction of the stator (<NUM>), and also enable the cooling oil to flow between a plurality of cooling oil passages (<NUM>) in a circumferential direction of the stator (<NUM>);
wherein the cooling oil rings (<NUM>) are respectively arranged at two ends of the stator (<NUM>), and the oil intake pipeline (<NUM>), the cooling oil passages (<NUM>) and the hollow columns (<NUM>) are sequentially in communication with one another, so as to enable the cooling oil to flow between the oil intake pipeline (<NUM>), the cooling oil passages (<NUM>), and the hollow columns (<NUM>); and wherein
a side wall of the hollow column (<NUM>) in the axial direction of the hollow column (<NUM>) is provided with a cooling oil inlet (<NUM>),
an inner side wall of the hollow column (<NUM>) in the radial direction of the stator (<NUM>) is further provided with a plurality of oil spray holes (<NUM>) and an oil guide rib (<NUM>), and the oil guide rib (<NUM>) is configured to be able to guide an oil sprayed from the oil spray holes (<NUM>) to one side of the hollow column (<NUM>), so as to enable the cooling oil sprayed from the oil spray holes (<NUM>) to fully cool an end portion of the electric motor.