Motor with cooling system

Abstract

The present application relates to an electric motor. The electric motor includes a cooling system configured to cool a stator having an iron core wound with coils, wherein the cooling system includes an oil retainer installed on a side below the stator in an interior space of a motor housing and configured to allow oil to collect to a level that allows at least a portion of a lower end portion of the stator to be immersed for cooling.

Description

Technical Field

[0001] The invention relates to an electric motor provided with a cooling system. Background Art

[0002] As is known to all, environmentally friendly vehicles including pure electric vehicles (EV), hybrid electric vehicles (HEV / PHEV) and fuel cell electric vehicles (FCEV) are electric vehicles driven by motors.

[0003] The environmentally friendly vehicle is equipped with a motor as a driving source for driving the vehicle and an inverter that converts direct current (DC) current from a high-voltage power source into alternating current (AC) current and applies the AC current to the motor, thereby driving and controlling the motor.

[0004] As described above, in an environmentally friendly vehicle, a motor is used to generate driving force for driving the vehicle.

[0005] In the case of a motor that drives an environmentally friendly vehicle, that is, as a drive motor, high efficiency and high power density are required.

[0006] In recently developed eco-friendly cars, it is known that the efficiency of the drive motor is about 90%, and most of the remaining 10% is lost as heat.

[0007] This heat loss can cause the motor system, including the stator and rotor, to exceed the specified motor temperature. The motor temperature is a preset allowable temperature that prevents the motor system from exceeding this temperature to prevent demagnetization of the permanent magnet rotor and overheating damage to the stator coils.

[0008] When the temperature of the motor system exceeds the allowable temperature of the motor, it may cause damage due to overheating of the stator coil, demagnetization of the permanent magnet rotor, damage to the rotor molding, etc.

[0009] Therefore, to meet the ongoing demands for motor miniaturization, high output, and high efficiency, a stable thermal management system is essential.

[0010] Since a large amount of heat is generated from coils and other components when driving a motor, cooling of key components such as coils is essential. In this sense, cooling of the interior permanent magnet synchronous motor (IPSM), which is widely used as a vehicle drive motor, plays a major role in improving motor efficiency and protecting core components (permanent magnets, coils, etc.).

[0011] When the temperature of the permanent magnet becomes at least a certain level, demagnetization of the permanent magnet may occur and the intensity of magnetic force may become weak, thereby greatly affecting the efficiency of the motor.

[0012] Consequently, in order to prevent the motor system from reaching an overheating state exceeding the permissible temperature of the motor or demagnetization occurring in the permanent magnets of the motor, thermal management of the motor system is necessary.

[0013] According to the coolant, the thermal management system of the motor, especially the cooling system, can be divided into air cooling system, water cooling system and oil cooling system; according to the injection method, it can be divided into splash lubrication system using motor rotation and forced lubrication system using electric oil pump (EOP).

[0014] Furthermore, motor cooling systems can be further categorized into direct cooling and indirect cooling. In recent years, due to the demand for high cooling performance, direct cooling has become more widely used, with the use of EOP oil pressure for forced lubrication systems, including jet cooling, and shaft splash lubrication systems, also gaining popularity.

[0015] In addition, various studies on cooling optimization are being actively conducted to improve the shape of the motor and housing, improve the cooling spray structure, or develop a cooling support structure.

[0016] However, in vehicles using direct oil cooling for their drive motors, overheating due to uneven distribution of the cooling oil can burn certain parts of the motor. Furthermore, even with overheat protection logic, it's impossible to perform temperature sensing in all areas of the motor, so there's still a risk that certain overheated areas could burn out.

[0017] Damage caused by overheating of motor components occurs at a fragile cooling portion, and generally, a lower end portion of a stator, to which cooling oil does not sufficiently reach, becomes the fragile cooling portion.

[0018] Therefore, there is a need for an effective cooling technology that allows oil to be evenly distributed by zone along with real-time temperature modeling technology.

[0019] In conventional technology, some of the oil injected into motor components such as the stator through the holes of the injection pipe in the interior space of the motor housing collects on the lower side of the housing's interior space, causing the lower end portion of the stator to be immersed in the oil collected on the lower side of the housing's interior space. This allows the lower end portion of the stator, while immersed in the oil, to be cooled.

[0020] However, when the motor tilts during vehicle travel, the lower end of the stator may not be immersed in oil and cooling may not be achieved. As a result, problems may occur due to poor cooling.

[0021] The foregoing is only intended to help understanding the background of the present invention and is not intended to indicate that the present invention falls within the scope of the relevant technologies known to those skilled in the art. Summary of the Invention

[0022] The present invention relates to a motor, and more particularly, to a motor capable of more efficiently cooling components using oil.

[0023] Therefore, embodiments of the present invention solve problems in the art. Embodiments of the present invention provide a motor cooling system that can more effectively cool components using oil, and a motor provided with the motor cooling system.

[0024] One embodiment of the present invention provides a motor including a cooling system configured to cool a stator having an iron core around which a coil is wound, wherein the cooling system includes an oil retainer installed on one side below the stator in an interior space of a motor housing and configured to allow oil to be collected to a level at which at least a portion of a lower end portion of the stator can be immersed for cooling.

[0025] Therefore, according to the motor of the embodiment of the present invention, the oil retainer capable of collecting and storing oil is additionally installed at one side below the stator in the inner space of the case.

[0026] Therefore, even during slope driving or when the motor is tilted due to vehicle behavior, fragile cooling parts such as the lower end portion of the stator, particularly the lower end portion of the stator coil, can always be kept immersed in oil inside the oil retainer in the housing.

[0027] As a result, the conventional problems of a fragile cooling portion such as a lower end portion of a stator due to the tilt of the motor and a problem of a rotor being immersed in oil due to the tilt of the motor, thereby causing additional hindrance, can be solved.

[0028] Furthermore, by taking gear losses into account, it is possible to solve the problems of designing the motor reducer housing and limiting the amount of oil. Furthermore, regardless of the shape of the motor reducer housing, the cooling effect achieved by always being immersed in oil can be fully utilized.

[0029] In addition, compared with conventional technologies, the overall cooling performance and cooling effect on the motor can be greatly improved, more efficient and better motor cooling can be achieved, and the oil pump can be operated more efficiently. As a result, while providing advantages even in terms of electrical loads, the overall fuel economy of the vehicle can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and other objects, features and other advantages of various embodiments of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0031] Figures 1 to 3 A diagram showing a conventional motor and its cooling system;

[0032] Figure 4 A cross-sectional view showing a known motor structure;

[0033] Figure 5 A block diagram illustrating a cooling system and a motor of a vehicle according to an exemplary embodiment of the present invention;

[0034] Figure 6 A cross-sectional view showing a motor according to an embodiment of the present invention;

[0035] Figures 7 to 10 A diagram showing a state in which an oil retainer is installed in a motor according to an embodiment of the present invention;

[0036] Figures 11 to 13 A view showing an oil retainer in a motor according to an embodiment of the present invention;

[0037] Figure 14 and Figure 15 A view showing a state in which oil is collected to at least a predetermined level by an oil retainer in a state in which the motor according to an embodiment of the present invention is tilted; and

[0038] Figures 16 to 19 A review is provided to illustrate various modifications of the oil retainer in the motor according to the embodiment of the present invention. DETAILED DESCRIPTION

[0039] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. In all drawings, the same reference numerals will refer to the same or similar parts. However, the present invention is not limited to the embodiments described herein and may be implemented in other forms.

[0040] When any part of the specification will “include” any components, it means that it can further include other components rather than excluding other components unless specifically stated otherwise.

[0041] First, a conventional motor cooling system and its problems will be briefly described to help understand the embodiments of the present invention.

[0042] Figures 1 to 3 A diagram showing a conventional motor and its cooling system, wherein Figure 1 A perspective view of the motor and its cooling system. Figure 2 A front view of the motor and its cooling system, and Figure 3 This is a plan view of the motor and its cooling system.

[0043] In the following description, Figure 1 and 3As shown, the side of the rotor 20 where the shaft 24 protrudes from the motor 1 is referred to as the "front," and the opposite side is referred to as the "rear."

[0044] exist Figures 1 to 3 However, the motor housing is provided so that motor components such as a stator and a rotor can be accommodated in its inner space and is an outwardly positioned component to surround the stator 10 and the rotor 20 shown in the figure.

[0045] In addition, Figures 1 to 3 However, each of the injection pipes 101 and 102 shown is connected to the oil pump through a pipeline such as a hose or a pipe not shown.

[0046] In addition, holes are provided at predetermined intervals in the longitudinal direction of the injection pipes 101 and 102 to allow oil to be sprayed toward the stator 10 located below and to the sides thereof. Therefore, when oil pressurized by an oil pump is supplied to the injection pipes 101 and 102 through the pipelines, the oil can be sprayed onto motor components such as the stator 10 through the oil holes of the injection pipes 101 and 102.

[0047] at the same time, Figure 4 FIG1 is a cross-sectional view showing a known motor structure, and illustrates the structure of an interior permanent magnet synchronous motor (IPMSM) widely used as a drive motor for environmentally friendly vehicles.

[0048] As a driving motor serving as a driving source for an environmentally friendly vehicle, a permanent magnet synchronous motor, more specifically, an IPMSM having a permanent magnet embedded in a rotor, can be used.

[0049] like Figure 4 As shown, the permanent magnet synchronous motor includes a stator 10 and a rotor 20 .

[0050] Here, the stator 10 may include an iron core 11 and a coil 14 wound around a tooth portion 12 of the iron core 11 , and the rotor 20 may include an iron core 21 and a permanent magnet 23 embedded in or attached to the iron core 21 .

[0051] refer to Figure 4 As can be seen, teeth 12 are provided at predetermined intervals along the entire circumference of the inner side of the stator core 11. At the same time, slots 13 are provided and arranged between each adjacent tooth 12.

[0052] The teeth 12 are wound with coils 14. At this time, the coils 14 are wound around the teeth 12 through the slots 13, so that the coils 14 in the stator core 11 are accommodated in the slots 13 while being wound around the teeth 12.

[0053] Meanwhile, the rotor 20 is arranged inside the stator 10 to have a gap portion between the rotor 20 and the stator core 11. In addition, insertion holes 22 are provided in the rotor core 21 along the circumferential direction, and permanent magnets 23 are inserted and installed in each of the insertion holes 22 of the rotor core 21.

[0054] exist Figures 1 to 3 A cooling system of FIG. 1 is shown in which oil supplied from a pump not shown is sprayed through holes of spray pipes 101 and 102 for cooling motor components such as stator 10 and the like.

[0055] However, in conventional cooling methods, when oil is sprayed from the spray pipes 101 and 102 located on the upper side to cool the motor, the lower end portion of the stator 10 becomes a vulnerable cooling portion, and the oil sprayed from the spray pipes 101 and 102 does not sufficiently reach this vulnerable cooling portion. As a result, the lower end portion of the stator, particularly the lower end portion of the stator coil 14, may be damaged due to overheating.

[0056] Therefore, in order to improve the cooling performance of the lower end portion of the stator, which is a vulnerable cooling portion, a shaft splash lubrication system or a structure immersed in oil through a housing is used.

[0057] Among them, the structure allowing immersion in oil is a cooling method for allowing oil sprayed from the spray pipes 101 and 102 to be collected in the lower space of the case to a level at which the lower end portion of the stator 10 can be immersed.

[0058] Specifically, the oil sprayed from injection pipes 101 and 102, after cooling motor components such as stator 10, is collected in the lower portion of the housing's interior space and then discharged to the outside through the housing's outlet. During this process, the sprayed oil is preferably not immediately discharged through the outlet, but rather, at least a certain level of oil is forced into the lower space within the housing. This allows the lower end of the stator, a vulnerable part to cooling, to be immersed in the oil collected in the lower space of the housing, effectively cooling the stator.

[0059] However, according to the conventional structure allowing immersion in oil through the case, it is necessary to always collect oil and fill the oil with a required volume inside the lower end portion of the case so that the lower end portion of the stator is always immersed in the inner space of the housing.

[0060] However, when the motor is tilted in the pitch or roll direction due to the behavior of the vehicle during travel, the aspect of motor components such as the stator immersed in the oil varies greatly.

[0061] That is, when the vehicle is traveling in a straight line without the motor tilting, the lower end portion of the stator (the lower end portion of the stator coil) may be immersed in the oil of the case at the front and rear sides of the motor.

[0062] However, even if the oil level in which motor components such as the stator are immersed is properly set in the housing, the motor may tilt toward the front or rear side. In this case, the coil on the tilted side may be completely immersed in the oil, while the coil on the opposite side may not be immersed in the oil at all.

[0063] Furthermore, on the inclined side, not only the coil but also the rotor may be immersed in oil. When the rotating rotor is immersed in oil in the housing interior space during motor driving, the oil may act as resistance to the rotor and cause additional hindrance (loss), thereby reducing fuel economy.

[0064] In addition, when a speed reducer is applied, components of the motor and the speed reducer are accommodated in each corresponding housing, thereby constituting a structure in which the housing surrounds the components of the motor and the speed reducer.

[0065] When designing the motor-reducer housing, it is necessary to allow the oil to be filled to a certain level inside the housing to achieve sufficient cooling by immersion in the oil. However, in this case, the reducer becomes excessively immersed in oil, resulting in excessive gear losses due to the oil. Therefore, motor-reducer housings are actually designed to allow the oil to be filled below a certain level.

[0066] Since the motor-reducer housing must be designed within such a limited vehicle space, the oil volume must be limited to account for gear losses. This increases the number of cases where targeted oil immersion and cooling effects cannot be achieved.

[0067] Therefore, to address this issue, an embodiment of the present invention incorporates a separate structure that can store oil laterally below the stator within the housing's interior space. This allows vulnerable cooling elements (such as the lower end of the stator, particularly the lower end of the stator coils) to remain submerged in the oil within the housing, even when the motor tilts due to vehicle motion.

[0068] Thus, the problem of the rotor being immersed in oil due to the tilt of the motor can be solved, and a more efficient and better motor cooling system can be achieved. In addition, regardless of the shape of the motor-reducer housing, sufficient cooling effect can be provided by immersing it in oil.

[0069] Hereinafter, a configuration of a motor and a cooling system thereof according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0070] Figure 5A block diagram illustrating a cooling system and a motor of a vehicle according to an exemplary embodiment of the present invention, wherein an electric oil pump is represented by EOP 4. An electric water pump (EWP) is included in the water cooling system.

[0071] The figure shows an oil cooling system for a vehicle using oil, as well as a water cooling system for a vehicle using cooling water. The cooling water is designed to circulate between heating elements such as the radiator and inverter 6 and the heat exchanger 5 via an electric water pump, while the oil is designed to circulate through the EOP 4 through the heat exchanger 5, the motor 1, the speed reducer 2, and the oil filter 3.

[0072] In addition, in the embodiment of the present invention, in the inner space of the housing 30 of the motor 1, separate oil retainers 110a and 110b are installed, which temporarily store oil so that the lower end of the stator 10 can be cooled while being immersed in oil.

[0073] Finally, the oil transferred by pressurization in the EOP 4 is cooled by exchanging heat with cooling water in the heat exchanger 5. Subsequently, the oil cooled in the heat exchanger 5 moves to the motor 1, thereby being sprayed into motor components such as the stator 10 through the spray pipes 101 and 102 provided inside the housing 30 of the motor 1.

[0074] In addition, the oil that has cooled the motor 1 moves to the inside of the housing 40 of the reducer 2, thereby allowing the reducer to be cooled by gear agitation. Next, the oil discharged from the housing 40 of the reducer 2 is sucked into the EOP 4 after passing through the oil filter 3.

[0075] In this way, the oil is circulated along a preset path of the cooling system (oil cooling system) through the EOP 4 by suction and pressurized transmission, and the oil that has completed cooling in the motor 1 and the reducer 2 is sucked into the EOP 4 after impurities are removed therefrom in the process of passing through the oil filter 3.

[0076] In addition, in the motor 1 according to the embodiment of the present invention, oil retainers 110 a and 110 b are provided at the front and rear sides of the motor, respectively, which are independent structures for collecting oil to the side below the stator 10 in the housing 30 .

[0077] Even in the internal space of the housing 30, the oil retainers 110a and 110b are installed in the space between the lower end portion of the stator core and the lower end portion of the housing, wherein the oil retainers 110a and 110b can be coupled together and fixed on the coupling portion between the stator core and the housing.

[0078] The oil retainers 110a and 110b are provided to allow the oil moving downward after being injected through the holes of the injection pipes 101 and 102 to be temporarily collected in the inner space of the housing 30. More specifically, the oil retainers 110a and 110b are configured to be provided with an inner space capable of collecting oil, that is, an oil storage space.

[0079] In addition, each of the oil retainers 110a and 110b in the embodiment of the present invention functions as an oil dam that can capture a certain amount of oil that can cool the lower end portion of the stator at the lower side of the stator 10, and is provided with a side surface portion (at the bottom of the stator 10). Figure 11 111) and the bottom portion (indicated by reference numeral "111" in FIG. Figure 11 denoted by reference numeral "114" in the figure) to capture oil.

[0080] In addition, in an embodiment of the present invention, the oil retainers 110a and 110b can be provided with a structure with one side open, thereby allowing the oil discharged through the opening portion of the oil retainers 110a and 110b to move to the lower end portion of the internal space of the housing 30 of the motor 1, and then move to the internal space of the housing 40 of the reducer 2.

[0081] Thus, oil retainers 110a and 110b, located on the side below stator 10, are installed at the lower portion of the interior space of housing 30 of motor 1. Therefore, regardless of the behavior of the vehicle body or the inclination of the motor, the oil can be collected to a certain level so that the lower end portion of the stator is always immersed in the oil retainer located in the interior space of the motor housing, thereby fully utilizing the cooling performance effect of being immersed in oil.

[0082] In particular, since at least some of the lower end portion of the stator 10, more specifically, at least some of the lower end portion of the stator coil 14 can be cooled while immersed in the oil filled in the oil retainers 110a and 110b, damage due to overheating of the stator coil, etc. can be effectively prevented. In addition, regardless of the housing shape or oil level setting, the cooling performance of the existing fragile cooling portion can be greatly improved without worrying about additional rotor obstruction (loss).

[0083] Next, Figure 6 FIG. 1 is a cross-sectional view showing a motor according to an embodiment of the present invention.

[0084] exist Figure 6 , reference numeral 2 denotes a speed reducer, reference numeral 30 denotes a motor housing, and reference numeral 40 denotes a speed reducer housing.

[0085] in addition, Figures 7 to 10 A diagram showing a state in which an oil retainer is installed in a motor according to an embodiment of the present invention, wherein Figure 71 is a perspective view showing the stator 10, the rotor 20 and the oil retainers 110a, 110b, Figure 8 is a side view, Figure 9 is a front view, and Figure 10 This is the bottom view.

[0086] exist Figures 7 to 10 In the figure, the housing of the motor 1 is omitted (in Figure 6 30). Figure 6 As shown, since motor components such as the stator 10 , the rotor 20 , etc. are accommodated in the inner space of the housing, the housing 30 is located outside to surround the stator 10 and the rotor 20 .

[0087] In addition, Figures 7 to 10 The illustration of the injection pipe is also omitted, and the injection pipe (in Figures 1 to 3 101 and 102) can be referred to Figures 1 to 3 In an embodiment of the present invention, Figures 1 to 3 Different, additional injection pipes can be further installed.

[0088] For example, in Figures 1 to 3 In the embodiment, the injection pipes 101 and 102 are arranged longitudinally on the left and right sides above the stator 10, respectively, along the front-to-back direction of the motor. However, the injection pipes arranged longitudinally along the front-to-back direction of the motor can be further installed in the center between the left and right sides. In this case, the injection pipes on the left, right, and center sides are arranged side by side.

[0089] In addition, each of the injection pipes 101 and 102 is provided with holes capable of injecting oil at predetermined intervals in the front-rear longitudinal direction, and oil pressurized by an oil pump (not shown) can be injected toward the stator 10 through the holes in the injection pipe.

[0090] Reference numeral ' 15 ' denotes a bus bar for electrical connection of each coil by being connected to each coil 14 of the stator 10 , and the bus bar 15 may be located at the front of the motor 1 .

[0091] In addition, reference numeral 11a denotes a case connection portion of the stator core 11, and the case connection portion 11a is a portion where the stator core 11 is coupled to the case 30. In addition, as shown in the figure, the case connection portion 11a is protrudingly provided on the surface of the stator core 11.

[0092] In the illustrated embodiment, two shell connection parts 11a can be installed on the upper side of the stator core 11, and one shell connection part 11a can be installed on the lower side of the stator core 11, wherein the shell connection part 11a installed on the lower side can be protrudingly set to be longitudinally arranged in the front-to-back direction at the center of the lower end part of the stator core 11.

[0093] In an embodiment of the present invention, the oil retainers 110a and 110b may be coupled and fixed to the housing connection portion 11a provided on the lower side of the stator core 11. That is, the front oil retainer 110a and the rear oil retainer 110b are coupled to the front end portion and the rear end portion of the housing connection portion 11a, respectively.

[0094] like Figure 6 As shown, the coupling member 109 inserted into the inner side of the case connecting portion 11a of the stator core 11 is coupled to the case 30 of the motor 1, whereby the stator core 11 and the oil retainers 110a and 110b can be integrally fixed and mounted to the case 30. Here, the coupling member 109 may be a long bolt or a rod-type coupling member that can be inserted into the inner side of the case connecting portion 11a in the longitudinal direction.

[0095] In this way, when the case connecting portion 11 a of the stator core 11 and the case 30 are coupled to each other through the coupling member 109 , the oil retainers 110 a and 110 b can also be coupled to the stator core 11 and the case connecting portion 11 a together through the coupling member 109 .

[0096] As described above, the oil retainers 110a and 110b are installed on the side below the stator 10 and are used to temporarily collect oil. As a result, at least some of the lower portion of the stator 10, and more specifically, at least some of the lower end portion of the stator (i.e., the lower portion of the stator coil), which has conventionally been a vulnerable portion to cooling, can be cooled while always immersed in oil.

[0097] That is, in order to obtain a more excellent cooling performance by using the oil sprayed from the holes of the spray pipe provided on the upper side of the stator 10, oil retainers 110a, 110b having a preset height are provided on the lower side of the stator 10. Therefore, the oil is collected inside the oil retainers 110a and 110b to a level where the lower end portion of the stator can be immersed therein.

[0098] At this time, as described above, the oil retainers 110 a and 110 b are coupled to the lower end portion of the stator core 11 , more specifically, to the case connection portion 11 a of the stator core 11 , through the coupling member 109 , thereby being fixedly mounted thereto.

[0099] As a result, inside the housing 30 of the motor 1, when the oil sprayed from the injection pipe on the upper side of the stator 10 flows downward by gravity and is collected in another structure, namely the oil retainers 110a and 110b installed on the lower side of the stator 10, the lower end portion of the stator can be immersed in the oil inside the oil retainer.

[0100] Thus, the oil retainers 110a and 110b are structures that allow oil falling downward from the stator 10 to temporarily remain therein, thereby cooling the core and coil portions at the lower end portion of the stator 10 while immersed in the oil collected in the structures. Here, a coupling portion 115 having a through-hole 116 is protrudingly provided at the lower end portions of the oil retainers 110a and 110b.

[0101] As a result, the coupling portion 115 is coupled to the housing 30 of the motor 1 through the coupling member 109 while being connected to the housing connecting portion 11a provided at the lower end portion of the stator core 11, whereby the oil retainers 110a and 110b can be fixed to the stator 10 and the housing 30.

[0102] In an embodiment of the present invention, the oil retainers 110a and 110b may be configured to include the front oil retainer 110a and the rear oil retainer 110b as described above, and each of the oil retainers 110a and 110b is coupled to the housing 30 together with the stator core 11 through a coupling member 109 .

[0103] The front oil retainer 110 a is installed at the lower end portion of the stator core 11 at the front side of the motor, and the rear oil retainer 110 b is installed at the lower end portion of the stator core 11 at the rear side of the motor.

[0104] Although an example in which the front-side oil retainer 110 a and the rear-side oil retainer 110 b are installed has been described, the oil retainer may be preemptively installed only at any one of the front side and the rear side of the motor that is relatively fragile and not cooled.

[0105] In other words, only the front-side oil retainer 110 a may be installed, or only the rear-side oil retainer 110 b may be installed.

[0106] Figure 11 A perspective view showing an oil retainer in a motor according to an embodiment of the present invention, Figure 12 is a front view showing an oil retainer in a motor according to an embodiment of the present invention, and Figure 13 FIG. 1 is a side view showing an oil retainer in a motor according to an embodiment of the present invention.

[0107] As shown in the figure, at least some of each of the left side surface portion 111 and the right side surface portion 111 of the oil retainers 110a and 110b is set in a curved surface that can be connected to the outer peripheral surface of the stator core 11, and the opening portion 112 can be set in at least some of the bottom surface portions of the oil retainers 110a and 110b to expose the lower end portion of the outer peripheral surface of the stator core 11.

[0108] In this case, the opening portion 112 of each of the oil retainers 110 a and 110 b is provided between the curved surface portions of the left and right surface portions 111 joined to the outer peripheral surface of the stator core 11 .

[0109] As described above, each of the oil retainers 110a and 110b can be installed in a state where at least some of each side portion 111 is provided in a curved surface, and each side portion 111 provided with a curved surface is connected to the outer peripheral surface of the stator core 11, more specifically, to the lower end portion of the outer peripheral surface of the stator core 11.

[0110] In addition, since the opening portions 112 are provided in the bottom surface portions of the oil retainers 110 a and 110 b , respectively, it is possible to prevent the oil retainers from being deformed due to the load of the oil filled inside the oil retainers 110 a and 110 b .

[0111] In addition, at the front surface portion of the front oil retainer 110a and the rear surface portion of the rear oil retainer 110b, walls 113 are provided in a form that blocks the lower end portion of the stator core 11 and the lower end portion of the coil 14 from the front and rear.

[0112] In each of the oil retainers 110 a and 110 b , a wall 113 is provided to be spaced apart from the lower end portion of the stator 10 in the front-rear direction and is provided to connect a space between the left side surface portion 111 and the right side surface portion 111 .

[0113] The bottom portion 114 contacting the lower end portion of the wall 113 in each of the oil retainers 110a and 110b may be provided as a flat surface instead of a curved surface, and may be provided to connect spaces between the left and right side surface portions 111 and the wall.

[0114] The bottom portion 114 is the bottom of the storage space of the oil stored in each of the oil retainers 110 a and 110 b , and is the bottom located between the wall 113 and the lower end portion of the stator core 11 of each of the oil retainers 110 a and 110 b .

[0115] In addition, the bottom portion 114 of the front oil retainer 110a is the bottom exposed to the front of the lower end of the stator core 11, and the bottom portion 114 of the rear oil retainer 110b is the bottom exposed to the rear of the lower end of the stator core 11.

[0116] As a result, the storage space for storing oil in the front oil retainer 110a becomes a space that is set by some of each of the left surface portion 111 and the right surface portion 111 and is not connected to the outer peripheral surface of the stator core 11, the wall 113, the bottom portion 114 and the lower end portion (front surface portion) of the stator core 11.

[0117] In addition, the storage space for storing oil in the rear oil retainer 110b also becomes a space set by some of each of the left surface portion 111 and the right surface portion 111, which is not connected to the outer peripheral surface of the stator core 11, the wall 113, the bottom portion 114 and the lower end portion (rear surface portion) of the stator core 11.

[0118] In addition, in each of the oil retainers 110 a and 110 b , at least some of the lower end portion of the stator, particularly, at least some of the lower end portion of the stator coil 14 , remains immersed in the oil storage space.

[0119] refer to Figure 7 、 Figure 8 and Figure 10 , it can be seen that the stator coil 14 is wound at the rear side of the stator 10 to protrude rearward from the rear end of the stator core 11 by a predetermined width.

[0120] Similarly, it can be seen that the stator coil 14 is wound at the front side of the stator 10 so as to protrude forward from the front end of the stator core 11 by a predetermined width.

[0121] At this time, when stator coil 14 is wound to protrude forward and backward of stator core 11, the shape of the coil portion protruding forward from stator core 11 and the shape of the coil portion protruding backward from stator core 11 may both be cylindrical.

[0122] In addition, the oil filled in the storage space of the front oil retainer 110 a is arranged to contact the lower end portion of the stator core 11 and simultaneously allows the lower end portion of the portion of the stator coil 14 protruding forward from the core 11 to be immersed.

[0123] Similarly, the oil filled in the storage space of the rear oil retainer 110 b is arranged to contact the lower end portion of the stator core 11 while allowing the lower end portion of the portion of the stator coil 14 protruding rearward from the core 11 to be immersed.

[0124] In this manner, the lower end portion of the stator core 11 and the lower end portion of the stator coil 14 can be cooled while being immersed in the oil in the storage space.

[0125] In the case where the front wall 113 of the front-side oil retainer 110a and the rear wall 113 of the rear-side oil retainer 110b are too high, the rotor 20 may also be immersed in the oil inside the oil retainers 110a and 110b, and additional obstruction may also occur.

[0126] Therefore, it is necessary to set the height of the wall 113 of each of the oil retainers 110 a and 110 b so as to restrict the height of the oil collected in each of the oil retainers 110 a and 110 b from becoming too high.

[0127] Therefore, in order to not allow additional obstruction due to the immersion of the rotor 20 in the oil, the height of the wall of each of the oil retainers 110a and 110b may be set to be at least 2 mm lower than the height of the lower end portion of the rotor 20 in consideration of the viscosity and sloshing of the oil (i.e., Figure 9 "d ≥ 2 mm" in the figure).

[0128] Furthermore, in the internal space of the housing 30 , the bottom portion 114 of each of the oil retainers 110 a and 110 b may be positioned higher than the height of the lowermost end of the lower end portion of the stator 10 .

[0129] Here, the lowermost portion of the lower end portion of the stator may be the housing connection portion 11 a .

[0130] In addition, in the embodiment of the present invention, the oil retainers 110a and 110b can be made of a material having oil resistance and heat resistance, so that corrosion caused by oil and thermal deformation caused by the temperature of the oil and the temperature of the stator core 11 do not occur.

[0131] In addition, the oil retainers 110a and 110b are to be made of a material having sufficient rigidity so that sagging due to the weight of the oil does not occur, and the oil retainers 110a and 110b may be manufactured to have at least a predetermined level of thickness to ensure rigidity.

[0132] In addition, the sizes of the oil retainers 110 a and 110 b should be set in consideration of the clearance inside the housing 30 .

[0133] at the same time, Figure 14 and Figure 15 It is a view showing a state in which oil is collected to at least a predetermined level by the oil retainers 110 a and 110 b in a state in which the motor 1 is tilted during running of a vehicle.

[0134] Referring to the accompanying drawings, it can be seen that in a state where each coupling portion 115 of the front oil retainer 110a and the rear oil retainer 110b is connected to the front and rear end surfaces of the housing connecting portion 11a of the stator core 11, each of the oil retainers 110a and 110b, the stator core 11 and the housing 30 are integrally coupled by a coupling member 109 such as a long bolt, which passes through them.

[0135] The oil flowing downward after being injected from the injection pipe toward the stator core 11 and the coil 14 is collected in the storage space (internal space) of each of the oil retainers 110a and 110b, wherein the storage space is provided by the left and right side surface portions 111, the wall 113, and the bottom portion 114. Therefore, even when the vehicle body and the motor are tilted, some lower end portions of the front and rear sides of the stator 10 can always be immersed in the oil stored in each of the oil retainers 110a and 110b.

[0136] Therefore, even if a small amount of oil is used, immersion in the oil can be achieved, and improvement in cooling performance can be effectively achieved.

[0137] Conventionally, when the motor is tilted to the front or rear side, the stator coil located on the side opposite to the tilt direction is not immersed in the oil in the casing, while on the tilted side, part of the rotor becomes immersed in the oil in the casing, thereby reducing the motor efficiency due to additional obstruction.

[0138] However, in the embodiment of the present invention, even if Figure 14 and Figure 15 Even if the motor 1 is tilted, the oil is not completely discharged from the front oil retainer 110 a and the rear oil retainer 110 b , and the oil is maintained at at least a predetermined level to some extent.

[0139] Therefore, the stator 10 can be cooled by being immersed in oil on opposite sides, and even when the motor 1 is tilted, the height of the oil inside the oil retainers 110a and 110b does not become too high, thereby preventing additional obstruction caused by a portion of the rotor 20 being immersed in oil.

[0140] Regardless of the height of the oil used for immersion inside the housing, the embodiments of the present invention are not affected by the design limitation of the oil height inside the housing due to the height of the speed reducer (ie, the oil height limitation for preventing gear loss).

[0141] Therefore, in the embodiment of the present invention, the immersion effect can be achieved even with a small amount of oil, compared with a structure for immersion using an existing housing.

[0142] at the same time, Figures 16 to 19 are views showing various modifications of the oil retainer in the motor according to the embodiment of the present invention, and Figure 16 and Figure 17 An example is shown having a shape in which at least some upper ends of each of the left and right side surface portions 111 of each of the oil retainers 110 a and 110 b are inclined downward.

[0143] in addition, Figure 17 and Figure 191 is a view showing the installation state of the oil retainers 110a and 110b, wherein Figure 17 For installation Figure 16 A side view of the motor with the oil retainer shown in FIG, and Figure 19 For installation Figure 18 Bottom view of the motor with the oil retainer shown.

[0144] When the vehicle body and the motor 1 are tilted during ascent or descent of the vehicle, the oil collected in the oil retainers 110a and 110b may flow to the rotor side, and the oil flowing to the rotor side may cause the rotor to be immersed in oil, and may thereby cause additional obstruction (loss).

[0145] In order to improve this problem, Figure 16 and Figure 17 As shown, by inclining the upper end of each of the side portions 111 of each of the oil retainers 110a and 110b, even when the motor is tilted, oil that may cause obstruction is discharged more quickly in the inclined structure, thereby eliminating obstruction that may occur on the rotor.

[0146] exist Figure 18 and Figure 19 In FIG. 1 , an example is shown, that is, each of the oil retainers 110a and 110b is not provided with an opening (in Figure 16 and Figure 17 denoted by reference numeral “112” in the figure). Instead, it is shown that each of the oil retainers 110a and 110b has a bottom surface portion 117 in which the left and right side surface portions 111 extend so as to be joined together.

[0147] As shown in the figure, the bottom surface portion 117 extending from the left and right side surface portions 111 may be set to a shape corresponding to the shape of the lower end portion of the stator core 11 , more specifically, the shape of the case connection portion 11 a of the stator core 11 .

[0148] Therefore, when the oil retainers 110a and 110b are assembled on the side below the stator 10, the case connection portion 11a of the stator core 11 can be accommodated inside each bottom surface portion 117 of the oil retainers 110a and 110b. In this case, the surface of the case connection portion 11a of the stator core 11 can be assembled to be coupled to the inner side surface of each bottom surface portion 117 of the oil retainers 110a and 110b.

[0149] In this way, the presence of the bottom surface portion 117 connected between the left and right side surface portions 111 and 111 can provide an advantage of preventing each of the oil retainers 110 a and 110 b from sagging.

[0150] That is, in Figures 11 to 13 、 Figure 16 and Figure 17 In the example, when the oil retainers 110a and 110b rotate around the long bolt (coupling member) 109 and the housing connection portion 11a of the stator core 11 coupled to pass through the coupling portion 115, the left side portion or the right side portion of the oil retainer may droop relative to the opposite side surface portion.

[0151] On the other hand, Figure 18 and Figure 19 In the example shown, the bottom surface portion 117 connecting the left and right surface portions 111 and 111 is formed into a concave shape that allows the housing connection portion 11a, which is shaped to protrude downward and is provided to protrude downward at the lower end of the stator core 11, to be inserted inward and accommodated. Therefore, the oil inside the oil retainers 110a and 110b prevents the oil retainers from rotating around the long bolts 109 and preventing the housing connection portion 11a of the stator core 11 from drooping to the left or right.

[0152] Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto. In addition, various modifications and improvements by those skilled in the art using the basic concept of the present invention defined in the appended claims are also included in the scope of the present invention.

Claims

1. A motor comprising: A cooling system configured to cool a stator having a stator core wound with coils, wherein The cooling system includes an oil retainer installed on one side below the stator in the inner space of the motor housing and configured to allow oil to be collected to a level that enables at least a portion of a lower end portion of the stator to be immersed for cooling. Wherein, the oil retainer comprises: a front oil retainer mounted on a lower end portion of the stator core at the front side of the motor; and a rear oil retainer mounted on the lower end portion of the stator core at the rear side of the motor, the front oil retainer and the rear oil retainer being formed independently of each other, Wherein, each of the oil retainers comprises: opposite side surface portions; a wall provided to connect between the opposing side surface portions, the wall being positioned to be spaced apart from a lower end portion of the stator; and a bottom portion provided to connect between the opposite side surface portions and the wall and positioned between a lower end portion of the stator and the wall to provide a bottom of a space configured to store oil, wherein the wall has a shape configured to radially block the lower end portion of the stator core as viewed in the axial direction and the lower end portion of the stator coil at the front or rear portion of the stator coil, and a radial height of the wall is lower than a radial height of the lower end portion of the rotor by a predetermined dimension, wherein at least a portion of each of the opposing side surface portions is provided in a curved surface capable of being coupled to the outer peripheral surface of the stator core, and in: A housing connection portion of the stator core coupled to the motor housing is provided in a protruding shape on a lower end portion of the stator core; and A lower surface portion of at least one of the oil retainers has a concave shape that enables the housing connection portion to be inserted into and coupled with the concave shape.

2. The motor according to claim 1, wherein The cooling system is provided with holes, and the motor further includes a plurality of injection pipes configured to inject oil to the stator through the holes.

3. The electric machine according to claim 1, wherein: The front oil retainer is installed to allow a coil portion protruding forward from a stator core at a lower end portion of the stator to be immersed in oil stored inside the front oil retainer for cooling; as well as The rear oil retainer is installed to allow a coil portion protruding rearward from a stator core at a lower end portion of the stator to be immersed in oil stored inside the rear oil retainer for cooling.

4. The motor according to claim 1, wherein At least one of the oil retainers is mounted on the lower end portion of the stator core at one of the front side and the rear side of the motor, and is mounted to allow corresponding portions of the coil portions protruding forward and backward from the stator core at the lower end portion of the stator to be immersed in the oil stored inside the oil retainer for cooling.

5. The motor according to claim 1, wherein An opening portion is provided in a lower surface portion of each of the oil retainers to allow a lower end portion of the outer peripheral surface of the stator core to be exposed.

6. The motor according to claim 5, wherein The opening portion is provided between curved surface portions of the opposing side surface portions, the curved surface portions being coupled to an outer peripheral surface of the stator core.

7. The motor according to claim 1, wherein The oil retainer is installed so that a surface of the case connecting portion of the stator core is joined to an inner surface of a lower portion of the concave shape.

8. The motor according to claim 1, wherein The concave-shaped lower portion of the oil retainer and the case connecting portion of the stator core are arranged in a longitudinal direction in a front-rear direction of the motor.

9. The motor according to claim 1, wherein The concave-shaped lower surface portion in the oil retainer is provided between the curved surface portions of the opposing side surface portions, and the curved surface portions are adhered to the outer peripheral surface of the stator core.

10. The motor according to claim 1, wherein A bottom portion of at least one of the oil retainers in the inner space of the motor case is positioned higher than a height of a lowermost end of a lower end portion of the stator.

11. The motor according to claim 1, wherein At least a portion of each of the opposing side surface portions of the oil retainer has a downwardly inclined shape.

12. The electric machine according to claim 1, wherein: a housing connection portion having a protruding shape on a lower end portion of the stator core coupled to the motor housing; a coupling portion provided in at least one of the oil retainers; as well as In a state in which the coupling portion of at least one of the oil retainers is connected to the housing connecting portion of the stator core, a coupling member passing through a through hole provided in the coupling portion and the housing connecting portion is coupled to the motor housing, whereby the stator core, at least one of the oil retainers and the motor housing are fixed to each other.

13. A cooling system for cooling a stator, the stator having a coil wound around a stator core, the cooling system comprising: Motor housing; as well as at least one oil retainer mounted on one side of the interior space of the motor housing below the stator, the at least one oil retainer being configured to allow oil to be collected to a level that allows at least a portion of the lower end portion of the stator to be immersed for cooling, Wherein, the at least one oil retainer comprises: opposite side surface portions; a wall provided to connect between the opposing side surface portions, the wall being positioned to be spaced apart from a lower end portion of the stator; and a bottom portion provided to connect between the opposed side surface portions and the wall and positioned between the lower end portion of the stator and the wall to provide a bottom of a space configured to store oil, the bottom portion being positioned higher than a height of a lowermost end of the lower end portion of the stator, wherein the wall has a shape configured to radially block the lower end portion of the stator core as viewed in the axial direction and the lower end portion of the stator coil at the front or rear portion of the stator coil, and a radial height of the wall is lower than a radial height of the lower end portion of the rotor by a predetermined dimension, wherein at least a portion of each of the opposing side surface portions is provided in a curved surface capable of being coupled to the outer peripheral surface of the stator core, and in: A housing connection portion of the stator core coupled to the motor housing is provided in a protruding shape on a lower end portion of the stator core; and A lower surface portion of at least one of the oil retainers has a concave shape that enables the housing connection portion to be inserted into and coupled with the concave shape.

14. The cooling system according to claim 13, wherein: The at least one oil retainer comprises: a front oil retainer mounted on a lower end portion of the stator core of the stator at the front side of the motor, the front oil retainer being configured to immerse a coil portion protruding forward from the stator core of the stator in oil stored inside the front oil retainer for cooling; and A rear oil retainer is installed on the lower end portion of the stator core of the stator at the rear side of the motor, and is configured to immerse the coil portion protruding rearward from the stator core of the stator in oil stored inside the rear oil retainer for cooling.

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