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. For example, published <CIT>, <CIT> and <CIT> each disclose a motor with axial cooling passages provided in a stator and extending along an axial direction of the stator. Published Chinese patent applications <CIT> and <CIT> each disclose a similar motor for a vehicle integrated with axial cooling passages in a stator.

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, <CIT> and <CIT> disclose cooling channels formed between an outer surface of a stator core and a housing or a sleeve so that coolant can flow along the outer surface of the stator core.

However, the existing electric motor for a vehicle usually has 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, and a convective heat transfer coefficient of a heat dissipation surface is small, and is greatly affected by a direction of gravity.

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

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

It can be understood by those skilled in the art that in the technical solution of the disclosure, the electric motor comprises a stator and an oil intake pipeline, wherein 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 circumferential direction of the stator. The stator further comprises a second lamination provided with a pressure relief hole formed in the second lamination, the pressure relief hole has a cross-sectional area greater than that of the oil passage hole, and at least one second lamination is arranged between two first laminations, so that the cooling oil flowing from the oil passage holes located above the second lamination passes through the pressure relief hole, and then flows into the oil passage holes located below the second lamination.

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 circumferential 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. By means of the foregoing solution, the disclosure solves the problems usually existing in the existing electric motor for a vehicle 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, and a convective heat transfer coefficient of a heat dissipation surface is small, and is greatly affected by a direction of gravity.

An electric motor for a vehicle and 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.

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

As shown in <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, and a convective heat transfer coefficient of a heat dissipation surface is small, and is greatly affected by a direction of gravity, an electric motor for a vehicle according to the disclosure comprises a stator <NUM> and an oil intake pipeline <NUM>. 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 circumferential direction of the stator <NUM>. It should be noted that, in this embodiment, an oil path in the cooling oil passage <NUM> is a section of oil path that is marked A in <FIG>. The axial direction of the stator <NUM> refers to the X direction in <FIG>, and the circumferential direction of the stator <NUM> refers to the Y direction in <FIG>.

By means of the foregoing arrangement, 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 circumferential 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>. This solves the problems usually existing in the existing electric motor for a vehicle 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, and a convective heat transfer coefficient of a heat dissipation surface is small, and is greatly affected by a direction of gravity.

In addition, in this embodiment, the number of oil passage holes <NUM> formed in the first laminations <NUM> may be set according to different cooling requirements of the electric motor.

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, 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> and <FIG> can be presented.

By means of the foregoing arrangement, in the electric motor for a vehicle in this embodiment, 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, to form staggered cooling oil passages <NUM>. This increases the flow path of the cooling oil in the cooling oil passages <NUM> and increases the heat exchange area inside the stator <NUM>, so as to improve the cooling effect on the interior of the stator <NUM>. In addition, 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, to enable the cooling oil to flow in the axial direction of the stator <NUM>, and also enable the cooling oil to flow between the plurality of cooling oil passages <NUM> in the circumferential direction of the stator <NUM>, so as to further improve the cooling effect on the interior of the stator <NUM>.

As shown in <FIG>, 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 also 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>.

As shown in <FIG>, in a possible implementation, a cross-section of each oil passage hole <NUM> is a rectangular hole, and the cross-section in the disclosure is a cross-section taken along M-M.

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 order to improve the cooling effect inside the stator <NUM>, in this embodiment, an axis of each oil passage hole <NUM> is not parallel to a thickness direction of each first lamination <NUM>.

It should be noted that in this embodiment, the axis of each oil passage hole <NUM> being not parallel to the thickness direction of each first lamination <NUM> means that the axis of the oil passage hole <NUM> forms an angle a with respect to the thickness direction of the first lamination <NUM>, as shown in <FIG>. The thickness direction of the first lamination <NUM> is a direction J in <FIG>, and the axial direction of the oil passage hole <NUM> is a direction K in <FIG>.

Through the foregoing arrangement, in the stator <NUM> of this embodiment, each oil passage hole <NUM> is arranged in such a way that the axis of the oil passage hole <NUM> is not parallel to the thickness direction of the first lamination <NUM>, so that the flow path of the cooling oil is increased when the cooling oil flows through the oil passage hole <NUM>, thereby increasing the heat exchange area inside the stator <NUM> and improving the cooling effect inside the stator <NUM>.

As shown in <FIG>, in a possible implementation, a cross-section of each oil passage hole <NUM> is a trapezoidal hole.

Through the foregoing arrangement, the cross-section of each oil passage hole <NUM> is configured as a trapezoidal hole, so that when the cooling oil flows through the oil passage hole <NUM>, the flow path of the cooling oil is increased, thereby increasing the heat exchange area inside the stator <NUM> to improve the heat dissipation effect inside the stator <NUM>. In addition, with the cross-section of the oil passage hole <NUM> being configured as a trapezoidal hole, the aperture sizes of the oil passage hole <NUM> in the axial direction of the oil passage hole <NUM> are different, and thus the flow rate of the cooling oil is constantly changed during flowing in the oil passage hole <NUM>, so as to further improve the cooling effect inside the stator <NUM>.

It should be noted that in this embodiment, when the cross-section of each oil passage hole <NUM> is set to be trapezoidal, the stacking form of two adjacent first laminations <NUM> is as shown in <FIG>. As shown in <FIG>, in order to further increase the heat exchange area inside the stator <NUM> and improve the cooling effect inside the stator <NUM>, in this embodiment, a cross-section of each oil passage hole <NUM> is a stepped hole.

In this embodiment, the cross-section of each oil passage hole <NUM> is configured as a stepped hole, so that when the cooling oil flows through the stepped hole as the cross-section, the cooling oil flows down along a side wall of the stepped hole as the cross-section, and under the action of the step-shaped side wall, the flow path of the cooling oil in the oil passage hole <NUM> is increased, so as to increase the heat exchange area inside the stator <NUM>, so that the cooling effect on the stator <NUM> can be further improved.

It should be noted that in this embodiment, the number of steps in the stepped hole as the cross-section may be set according to actual cooling requirements for the electric motor, to meet requirements for vehicle performance. The more steps there are, the longer the flow path of the cooling oil in the oil passage hole <NUM>, the larger the heat exchange area inside the stator <NUM>, the better the heat dissipation effect inside the stator <NUM>, and the better the cooling effect on the stator <NUM>. However, as the number of steps increases, the machining difficulty of the oil passage hole <NUM> is greater, and the machining cost is higher.

It should be noted that, as shown in <FIG>, in this embodiment, the axial direction of the stator <NUM> refers to the X direction in <FIG>, and the circumferential direction of the stator <NUM> refers to the Y direction in <FIG>.

As shown in <FIG>, in a possible implementation, the electric motor for a vehicle is further provided with two cooling oil rings <NUM>, 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.

In this embodiment, each cooling oil ring <NUM> is provided with an oil spray hole <NUM> for spraying on an end portion of a winding of the electric motor, and a cooling oil inlet <NUM>.

Through the foregoing arrangement, in the electric motor for a vehicle in this embodiment, the cooling oil rings <NUM> are respectively arranged at the two ends of the stator <NUM>, and the oil intake pipeline <NUM>, the cooling oil passages <NUM> and the cooling oil rings <NUM> are sequentially in communication with one another, so that the cooling oil can enter the cooling oil passages <NUM> inside the iron core of the stator <NUM> through the oil intake pipeline <NUM>. Therefore, an oil path is formed 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 the cooling oil ring <NUM> through the cooling oil inlet <NUM>, and is finally sprayed from the oil spray holes <NUM>, in directions shown by the arrows in <FIG>. 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>.

In the electric motor for a vehicle in this embodiment, under the action of an internal pressure of each cooling oil ring <NUM>, the cooling oil is sprayed from the oil spray holes <NUM> formed in the side wall of the cooling oil ring <NUM>, so that 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>.

In addition, as shown in <FIG> and <FIG>, the inner side wall of each cooling oil ring <NUM> is further provided with an oil guide rib <NUM>, and the oil guide rib <NUM> is configured to be able to guide the cooling oil sprayed from the oil spray holes <NUM> to one side of the cooling oil ring <NUM>, so as to enable the cooling oil sprayed from the oil spray holes <NUM> to fully cool the interior 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. The arrangement of the oil guide rib <NUM> on the inner side wall of the cooling oil ring <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 flow 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>), so as to improve the cooling effect on the end portion of the winding of the electric motor.

As shown in <FIG>, in a possible implementation, the electric motor for a vehicle 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> 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 circumferential direction of the stator <NUM>, so as to increase the flow path of the cooling oil inside the stator <NUM>, thereby further increasing the heat exchange area inside the stator <NUM>, and then further improving the cooling effect on the interior of the stator <NUM>.

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

Claim 1:
An electric motor for a vehicle, wherein the electric motor comprises a stator (<NUM>) and an oil intake pipeline (<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 first laminations (<NUM>), the plurality of stacked first laminations (<NUM>) jointly enclose a cylindrical structure,
wherein 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>); and
wherein the stator further comprises a second lamination (<NUM>) provided with a pressure relief hole (<NUM>) formed in the second lamination (<NUM>), the pressure relief hole (<NUM>) has a cross-sectional area 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 axially upstream the second lamination (<NUM>) passes through the pressure relief hole (<NUM>), and then flows into the oil passage holes (<NUM>) located axially downstream the second lamination (<NUM>).