Oil cooling motor with low oil stirring loss

Abstract

The utility model relates to an oil cooling motor with low oil stirring loss, which comprises a casing, a front end cover, a rear end cover, a stator assembly and a rotor assembly, the rotor assembly comprises a rotating shaft, a rotor core and an oil slinger, the rotor core is sleeved and fixed on the rotating shaft, the oil slinger comprises a ring body and an oil spraying pipe, the ring body is also sleeved and fixed on the rotating shaft, and the oil spraying pipe is sleeved and fixed on the ring body. The oil spraying pipe is arranged on the outer side wall of the ring body, one end of the oil spraying pipe extends to the winding, at least part of the interior of the rotating shaft is hollow, an oil through hole is formed in the inner wall of the rotating shaft, and a through hole used for connecting the oil through hole and the oil spraying pipe is formed in the ring body. According to the utility model, the oil slinger is arranged on the rotating shaft, so that cooling oil can be directionally sprayed to the winding of the stator assembly after passing through the rotating shaft and the oil slinger, the oil slinging path of the rotor is restrained to the greatest extent, the oil is prevented from being randomly and disorderly distributed in the motor cavity, the oil is prevented from adsorbing a rotating part, and the oil stirring loss is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of new energy vehicle drive motor technology, and in particular relates to an oil-cooled motor with low oil churning loss. Background Technology

[0002] New energy vehicle drive motors pursue high power and high torque density, leading to an increasing trend towards oil-cooled flat wire motors. Common rotor cooling oil circuits include: hollow rotor shaft + oil hole slinger, and hollow rotor shaft + radial oil circuit on rotor end plate + axial oil circuit on rotor core. These common rotor oil circuit solutions effectively cool the inner surface of the winding ends, as well as the rotor core and magnets, reducing temperatures at these locations and improving overall motor reliability. However, the rotor slinger design (regardless of whether the slinger holes are located on the shaft or baffle) inevitably results in oil distribution in the end space and air gap. When the oil contacts the rotating rotor components, it generates resistance torque, resulting in churning mechanical losses and reducing motor efficiency. This is particularly detrimental to the CLTC (critical cycle test) efficiency, which significantly worsens the CLTC efficiency. Experiments have shown that churning losses can reduce CLTC efficiency by 0.5-0.8%, significantly reducing the vehicle's driving range. This issue has become one of the key limitations restricting the application of rotor slinger solutions in high-efficiency drive motors, necessitating in-depth analysis and optimization of the relevant structure. Utility Model Content

[0003] In order to solve the above-mentioned technical problems, the purpose of this utility model is to provide an oil-cooled motor with low oil churning loss, which can ensure the overall cooling effect of the motor while reducing oil churning loss.

[0004] To achieve the above-mentioned objectives, this utility model adopts the following technical solution:

[0005] An oil-cooled motor with low churning loss includes a housing, a front cover, a rear cover, a stator assembly, and a rotor assembly. The stator assembly is fixed to the inner wall of the housing and includes a stator core and windings. The front cover and rear cover are fixed to both ends of the housing, and both ends of the rotor assembly are rotatably connected to the front cover and rear cover via bearings. The rotor assembly includes a shaft, a rotor core, and an oil slinger ring. The rotor core is sleeved and fixed on the shaft. The oil slinger ring includes a ring body and an oil injection pipe. The ring body is also sleeved and fixed on the shaft. The oil injection pipe is located on the outer wall of the ring body, and one end of the oil injection pipe extends to the windings. The shaft is at least partially hollow, and an oil passage hole is provided on the inner wall of the shaft. The ring body has a through hole for connecting the oil passage hole and the oil injection pipe.

[0006] As a preferred embodiment, there are multiple fuel injection pipes, and the fuel injection pipes are integrally formed with the ring body.

[0007] As a preferred embodiment, there are four fuel injection pipes, which are equidistantly spaced along the outer side of the ring body.

[0008] As a preferred embodiment: the stack thickness of the rotor core is greater than that of the stator core; rotor baffles are also provided at both ends of the rotor core, and the diameter of the rotor baffles is greater than that of the stator core.

[0009] As a preferred embodiment: the outer walls of the rotor core and rotor baffle are provided with an oleophobic coating; the inner surfaces of the front end cover and rear end cover are provided with an oleophilic coating.

[0010] As a preferred embodiment, the thickness of both the oleophobic coating and the oleophilic coating is 5-10 μm, and the oleophobic coating is a fluororesin; the oleophilic coating is a polyester coating.

[0011] As a preferred embodiment, the front or rear cover is further provided with a conductive brush for preventing bearing corrosion.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0013] This invention, by setting an oil-slinging ring on the rotating shaft, allows the cooling oil to be sprayed directionally onto the windings of the stator assembly after passing through the rotating shaft and the oil-slinging ring. This maximizes the constraint on the path of the rotor oil slinging, avoids the random and disordered distribution of oil in the motor cavity, and thus prevents the oil from adsorbing onto the rotating parts, reducing oil churning losses. Attached Figure Description

[0014] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute a limitation thereof.

[0015] Figure 1 This is a structural schematic diagram of the present invention from one angle;

[0016] Figure 2 This is a cross-sectional structural schematic diagram of the present invention;

[0017] Figure 3 This is a schematic diagram of the disassembly structure of the front cover, bearing, conductive brush, housing, stator assembly, and rotor assembly of this utility model.

[0018] Figure 4 This is an exploded structural diagram of the present invention (the housing and stator assembly are not shown).

[0019] Figure 5 This is a schematic diagram of the assembly structure of the rotor assembly and the oil slinger ring of this utility model.

[0020] Figure 6 This is a schematic diagram of the oil-slinging ring of this utility model.

[0021] The attached diagram is labeled as follows: 1. Housing; 11. Front cover; 12. Rear cover; 2. Stator assembly; 31. Shaft; 32. Rotor baffle; 33. Rotor core; 4. Oil slinger ring; 41. Ring body; 42. Through hole; 43. Oil injection pipe; 5. Bearing; 6. Conductive brush. Detailed Implementation

[0022] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] Furthermore, in the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more, unless otherwise expressly defined.

[0026] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0029] like Figures 1 to 6 As shown, an oil-cooled motor with low churning loss includes a housing 1, a front cover 11, a rear cover 12, a stator assembly 2, and a rotor assembly. The stator assembly 2 is fixed to the inner wall of the housing 1. The stator assembly includes a stator core and windings. The front cover 11 and the rear cover 12 are respectively fixed to both ends of the housing 1. The two ends of the rotor assembly are rotatably connected to the front cover 11 and the rear cover 12 respectively through bearings 5. The front cover 11 or the rear cover 12 is also provided with conductive brushes 6 to prevent corrosion of the bearings 5.

[0030] The rotor assembly includes a rotating shaft 31, a rotor core 33, and an oil slinger ring 4. The rotor core 33 is sleeved and fixed on the rotating shaft 31. The oil slinger ring 4 includes a ring body 41 and an oil injection pipe 43. The ring body 41 is also sleeved and fixed on the rotating shaft 31. The oil injection pipe 43 is disposed on the outer wall of the ring body 41, and one end of the oil injection pipe 43 extends to the winding. The rotating shaft 31 is at least partially hollow, and an oil passage hole is provided on the inner wall of the rotating shaft 31. The ring body 41 is provided with a through hole 42 for connecting the oil passage hole and the oil injection pipe 43. There are multiple oil injection pipes 43, and the oil injection pipes 43 are integrally formed with the ring body 41. In this embodiment, there are four oil injection pipes 43, which are equidistantly spaced along the outer side of the ring body 41.

[0031] The rotor oil-throwing structure of this utility model has the following characteristics: 1. It constrains the oil-throwing path and throws oil at fixed points; it minimizes and avoids irregular filling of the end space by the thrown oil, thereby reducing contact with the rotating parts and reducing oil stirring loss! 2. This structure has strong design flexibility and can be flexibly adjusted according to the oil volume distribution at the front and rear ends, the speed conditions, and the heat distribution of the whole machine, as well as the number, diameter, and spatial distribution of the oil outlet holes.

[0032] The thickness of the rotor core 33 is greater than that of the stator core; rotor baffles 32 are also provided at both ends of the rotor core 33, and the diameter of the rotor baffles 32 is greater than that of the stator core 33. The rotor baffles extend axially towards the end face of the stator core, forming a semi-enclosed shield, which further reduces the probability of oil entering the motor air gap, thereby reducing oil churning losses.

[0033] The above-mentioned air gap oil prevention structure features: rotor core stack thickness > stator core stack thickness (rotor overhang); fully utilizes the existing structure of the rotor baffle without increasing costs; rotor baffle diameter > rotor core, and based on CFD verification results: when the difference in radial outer diameter between the two is Δd = (1.5~2)*δ (δ is the air gap length), the blocking effect on oil entering the air gap is the best.

[0034] The above-mentioned rotor oil slinging channel combined with the air gap oil prevention structure, according to the preliminary CFD verification results, when applied to the rotor oil circuit design of a certain motor, compared with the traditional rotor oil circuit design, the amount of oil entering the air gap is reduced by about 46.5%, and the oil churning loss is reduced by about 51.3%.

[0035] The outer walls of the rotor core 33 and rotor baffle 32 are provided with an oleophobic coating; the inner surfaces of the front end cover 11 and rear end cover 12 are provided with an oleophilic coating. The thickness of both the oleophobic and oleophilic coatings is 5-10 μm, and the oleophobic coating is a fluoropolymer resin; the oleophilic coating is a polyester coating.

[0036] This invention involves coating the outer surface of the rotor baffle and the outer circumference of the rotor core (inner surface of the air gap) with an oleophobic coating (fluororesin), which greatly reduces the adsorption and adhesion of oil to the rotating parts; and coating the inner surface of the end cover and the inner surface of the housing with an oleophilic material (polyester coating), which increases the adsorption capacity of the oil on the corresponding surfaces, so that it flows downward along the surface only under the action of gravity, effectively avoiding the oil that has collided with the surface from impacting the rotating parts again, thereby reducing oil churning loss.

[0037] The two coating materials mentioned above are mature in the market, have low cost, and are simple to implement, with minimal impact on existing stator, rotor, and overall machine production. Depending on the specific motor design, the coating thickness ranges from 5-10 μm, resulting in a multi-layer coating film with high reliability. In a test involving reciprocating friction at a distance of 10 cm and a pressure of 3.2 kPa on 240-grit sandpaper, the 6-layer coating maintained its oleophobic properties after 650 cycles of friction.

[0038] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0039] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. An oil-cooled motor with low churning loss, comprising a housing (1), a front end cover (11), a rear end cover (12), a stator assembly (2), and a rotor assembly, wherein the stator assembly (2) is fixed to the inner wall of the housing (1), the stator assembly includes a stator core and windings, the front end cover (11) and the rear end cover (12) are respectively fixed to both ends of the housing (1), and both ends of the rotor assembly are rotatably connected to the front end cover (11) and the rear end cover (12) respectively via bearings (5), characterized in that: The rotor assembly includes a rotating shaft (31), a rotor core (33), and an oil slinger ring (4). The rotor core (33) is sleeved and fixed on the rotating shaft (31). The oil slinger ring (4) includes a ring body (41) and an oil injection pipe (43). The ring body (41) is also sleeved and fixed on the rotating shaft (31). The oil injection pipe (43) is located on the outer side wall of the ring body (41), and one end of the oil injection pipe (43) extends to the winding. The rotating shaft (31) is at least partially hollow, and an oil passage hole is provided on the inner wall of the rotating shaft (31). The ring body (41) is provided with a through hole (42) for connecting the oil passage hole and the oil injection pipe (43).

2. The oil-cooled motor with low oil churning loss according to claim 1, characterized in that: There are multiple fuel injection pipes (43), and the fuel injection pipes (43) are integrally formed with the ring body (41).

3. The oil-cooled motor with low oil churning loss according to claim 1, characterized in that: There are four fuel injection pipes (43), which are equidistantly spaced along the outer side of the ring body (41).

4. The oil-cooled motor with low oil churning loss according to claim 1, characterized in that: The thickness of the rotor core (33) is greater than that of the stator core; the rotor core (33) is also provided with rotor baffles (32) at both ends, and the diameter of the rotor baffles (32) is greater than that of the stator core (33).

5. The oil-cooled motor with low oil churning loss according to claim 1, characterized in that: The outer walls of the rotor core (33) and rotor baffle (32) are provided with an oleophobic coating; the inner surfaces of the front end cover (11) and rear end cover (12) are provided with an oleophilic coating.

6. The oil-cooled motor with low oil churning loss according to claim 1, characterized in that: The thickness of both the oleophobic coating and the oleophilic coating is 5-10 μm, and the oleophobic coating is a fluororesin; the oleophilic coating is a polyester coating.

7. The oil-cooled motor with low oil churning loss according to claim 1, characterized in that: The front cover (11) or the rear cover (12) is also provided with a conductive brush (6) for preventing corrosion of the bearing (5).

Images