Electric oil pump and oil cooling system for vehicle

Abstract

The utility model relates to an electric oil pump and an oil cooling system for a vehicle. The electric oil pump comprises a motor unit and an oil pump unit which are sequentially arranged in the axial direction, and the electric oil pump further comprises a first shell (5) which is a steel stamping shell and comprises a first section (5a) constructed on the radial outer side of the motor unit; the utility model relates to an oil pump unit comprising a first housing (5), a second housing (8), which is a stamped steel housing and comprises a sleeve section (8b) formed radially outside the oil pump unit, the first housing (5) and the second housing (8) being connected to each other by a stamped point connection. The oil cooling system is used for a vehicle, particularly an electric vehicle or a hybrid vehicle, and comprises the electric oil pump.

Description

Technical Field

[0001] The utility model relates to the technical field of oil cooling systems for vehicles, and more particularly to an electric oil pump. Background Art

[0002] To meet the energy conservation and emission reduction requirements of the global vehicle market, the current solution is to adopt a fully electric drive system using batteries and electric motors, or a hybrid drive system using internal combustion engines and electric motors. In these electric and hybrid vehicles, oil cooling technology will become a trend due to the increasing power density requirements of motors. At the same time, the traditional mechanical oil pump can no longer meet the new technical requirements, and electric oil pumps are gradually becoming the mainstream design.

[0003] Existing electric oil pump solutions mostly utilize aluminum housings. For example, Chinese patent application CN110541819A discloses an electric oil pump comprising a cast aluminum housing. However, due to the high oil pressure within the electric oil pump, the design requirements for preventing oil seepage and leakage can only be met if the aluminum housing has very thick walls. This increases the weight and size of the product. Utility Model Content

[0004] Therefore, an object of the present invention is to provide an electric oil pump or an oil cooling system having an electric oil pump, wherein the electric oil pump as a whole can have a smaller size and a lower production cost.

[0005] According to one aspect of the present invention, the above-mentioned object is achieved by an electric oil pump. The electric oil pump includes a motor unit and an oil pump unit arranged in sequence along the axial direction, wherein the electric oil pump further includes: a first housing, which is a steel stamped housing and includes a first section constructed radially outward of the motor unit; and a second housing, which is a steel stamped housing and includes a sleeve section constructed radially outward of the oil pump unit, wherein the first housing and the second housing are connected to each other via a stamped point connection.

[0006] Here, the motor for actuating the oil pump is preferably configured as an inner rotor motor. Here, the motor unit primarily comprises a stator assembly and a rotor assembly disposed radially inwardly of the stator assembly. The motor unit also includes a motor shaft for outputting the rotational motion of the rotor assembly.

[0007] Here, the oil pump unit preferably includes a pump shaft for introducing a rotational movement of the motor unit, a first rotating member connected to the pump shaft in a rotationally fixed manner, and a second rotating member meshing with the first rotating member.

[0008] Preferably, the motor unit and the oil pump unit are arranged substantially coaxially. Here, main components of the motor unit, such as the stator assembly, the rotor assembly and the motor shaft, are arranged coaxially with main components of the oil pump unit, such as the pump shaft and the first rotating member.

[0009] It should be noted that, within the scope of this document, unless otherwise specified, the terms "axial," "radial," and "circumferential" all refer to the common rotational axis of the motor unit and the oil pump unit, that is, the rotational axis of the motor shaft and the pump shaft. Specifically, "axial" refers to the direction of or parallel to the common rotational axis. "Radial" refers to a direction perpendicular to and intersecting the common rotational axis. "Circumferential" refers to a direction surrounding the common rotational axis.

[0010] Here, the housing of the electric oil pump is assembled from a plurality of parts. According to the present invention, the electric oil pump includes a first housing and a second housing, wherein the first housing and the second housing are both steel stamping parts. The first housing includes a first section that is constructed on the radial outside of the motor unit and preferably extends in the axial direction in a cylindrical shape. The second housing includes a sleeve section that is constructed on the radial outside of the oil pump unit and preferably extends in the axial direction in a cylindrical shape. Here, the first housing and the second housing, for example, the first section or other sections of the first housing and the sleeve section or other sections of the second housing are fixedly connected to each other through a stamping point connection. The stamping point connection is realized in particular by a cold forming process, and the stamping point connection is achieved by forming a structure that is embedded in each other's materials or interlocked with each other between two layers of metal sheets, here, between the steel sheets of the first housing and the second housing, due to material deformation / flow during the stamping process, thereby realizing an efficient and firm connection between the first housing and the second housing.

[0011] It can be seen that with the help of the technical solution of the utility model, the first shell and the second shell are both steel stamping parts. On the one hand, compared with the design of the aluminum shell in the existing electric oil pump solution, the shell wall thickness can be greatly reduced, thereby reducing the overall size of the electric oil pump, meeting the boundary size requirements of a narrower installation environment, and at the same time reducing the weight of the shell, realizing the lightweight design requirements of the product. On the other hand, since the amount of shell material used is reduced, the material cost in product manufacturing can be reduced. In addition, since the first shell and the second shell in this solution are connected by a stamping point connection part, the use of additional fasteners, such as rivets, bolts, etc., can be avoided, and no auxiliary materials and heating are required. While ensuring sufficient connection strength, the process involving shell connection can be reduced and shortened, thereby reducing the manufacturing cost of the product.

[0012] In some preferred embodiments, the first shell also includes a second section connected to the first section, the second section extending radially inward from the first section in a disc shape, and the second shell also includes a disc-shaped section connected to the sleeve section, the disc-shaped section extending radially outward from the sleeve section in a disc shape, wherein the second section and the disc-shaped section are in abutment with each other, and the stamping point connection portion is formed in the area where the second section and the disc-shaped section are in abutment with each other.

[0013] Here, the punched point connections preferably form raised structures, which are located on the axial sides of the second section and the disk-shaped section facing the motor unit.

[0014] In some preferred embodiments, the first shell also includes a second section connected to the first section and a third section connected to the second section, wherein the second section extends radially inward from the first section in a disc shape, and the third section extends axially toward the motor unit from the second section in a cylindrical shape, wherein the electric oil pump includes a shaft member that serves as both a motor shaft and a pump shaft, and the shaft member is radially supported at the third section by means of a bearing so as to be relatively rotatable.

[0015] Here, preferably, the first housing further includes a fourth section connected to the third section, the fourth section extending radially inward from the third section in a disk shape, wherein the position of the bearing in the axial direction is defined by the fourth section.

[0016] Further preferably, the first housing further includes a fifth section connected to the fourth section, the fifth section extending cylindrically from the fourth section in the axial direction away from the second section, wherein the position of the shaft can be defined radially by the fifth section.

[0017] Further preferably, lubricating oil is filled between the shaft and the fifth section.

[0018] In some preferred embodiments, the first housing also includes a second section connected to the first section, the second section extending radially inward from the first section in a disc shape, wherein the axial surface of the second section facing the oil pump unit is configured with an oil groove, wherein the oil pump unit includes a first rotating member and a second rotating member that are meshed with each other, and the oil groove connects the meshing area of ​​the first rotating member and the second rotating member.

[0019] In some preferred embodiments, the first housing further includes a sixth section connected to the first section, the sixth section extending radially outward from the first section in a disc shape, and the electric oil pump further includes an end cover connected to the sixth section via a connecting member.

[0020] According to another aspect of the present invention, the aforementioned object is achieved by an oil cooling system for a vehicle, particularly an electric vehicle or a hybrid vehicle. The oil cooling system includes an electric oil pump constructed according to the aforementioned embodiment. The electric oil pump primarily provides flow power for the working medium in the vehicle's oil cooling system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The features, advantages and technical effects of the embodiments of the present invention will be described below with reference to the accompanying drawings.

[0022] Figure 1 is an axial cross-sectional view of an electric oil pump according to an embodiment of the present utility model, and

[0023] Figure 2 yes Figure 1 The electric oil pump in the Figure 1 A partial axial cross-sectional view at a radial plane. DETAILED DESCRIPTION

[0024] Figure 1 An axial cross-sectional view of an electric oil pump according to an embodiment of the present invention is shown. The electric oil pump according to this embodiment provides power for a working medium, in particular cooling oil, in an oil cooling system of a vehicle, in particular an electric vehicle or a hybrid vehicle.

[0025] The electric oil pump mainly includes a motor unit, an oil pump unit, and a housing that at least partially surrounds the motor unit and the oil pump unit.

[0026] The motor unit is used to actuate the oil pump, and the motor is constructed as an inner rotor type motor. Figure 1 As shown, the motor unit primarily comprises a stator assembly 2 and a rotor assembly 3 arranged radially inwardly of the stator assembly. The motor unit also includes a shaft 4 for transmitting the rotational motion of the rotor assembly 3. Here, the shaft 4, serving as the motor shaft, is non-rotationally connected to the rotor assembly 3. The motor unit also includes an electronic control board 11 for implementing ECU functions. The electronic control board 11 can be electrically connected to the rotor assembly 3 and the stator assembly 2 to control the motor.

[0027] like Figure 1 As shown, the oil pump unit includes a pump shaft that introduces the rotational motion of the motor unit. In this embodiment, the motor shaft of the motor unit and the pump shaft of the oil pump unit are constructed as a single component, namely, shaft 4. The oil pump unit also includes a first rotating member 6, which is non-rotatably connected to shaft 4, and a second rotating member 7 that meshes with the first rotating member 6. In this embodiment, the first rotating member 6 is constructed as a gear with an external toothing on the radial outside, and the second rotating member 7 is constructed as a ring gear with an internal toothing on the radial inside. The external toothing of the first rotating member 6 and the internal toothing of the second rotating member 7 mesh with each other.

[0028] like Figure 1 As shown, the motor unit and the oil pump unit are arranged adjacent to each other substantially coaxially. Here, the stator assembly 2 and the rotor assembly 3 of the motor unit, the first rotating member 6 and the second rotating member 7 of the oil pump unit, and the shaft 4 shared by the motor unit and the oil pump unit are arranged coaxially.

[0029] The housing of the electric oil pump is assembled from a plurality of components. In this embodiment, the housing of the electric oil pump includes a first housing 5 , a second housing 8 and an end cover 1 .

[0030] Figure 2 Shown Figure 1 The electric oil pump is different from Figure 1 The radial plane, that is, relative Figure 1 The radial plane shown is a partial axial cross-sectional view after the central axis of the shaft 4 is rotated by a certain angle. Figure 1 and Figure 2 The housing constructed according to this embodiment will be described.

[0031] The first housing 5 is a steel stamping housing made by stamping in one piece. Figure 1 and Figure 2 As shown, the first housing 5 structurally comprises a first section 5a, a second section 5b, a third section 5c, a fourth section 5d, a fifth section 5e, and a sixth section 5f. The first section 5a is generally cylindrical, extends axially, and is located radially outward of the motor unit. The second section 5b is connected to the first section 5a, extending radially inward in a disc-like manner from the first section 5a, particularly the axial end of the first section 5a that is adjacent to the oil pump unit. The third section 5c is connected to the second section 5b, extending radially inward in a disc-like manner from the second section 5b, particularly the radial end of the second section 5b that is adjacent to the shaft 4, toward the motor unit. The fourth section 5d is connected to the third section 5c, extending radially inward in a disc-like manner from the third section 5c, particularly the axial end of the third section 5c that is adjacent to the motor unit. The fifth section 5e is connected to the fourth section 5d, wherein the fifth section 5e is cylindrical and extends axially away from the second section 5b or the oil pump unit, starting from the fourth section 5d, in particular, the radial end of the fourth section 5d close to the shaft 4. The sixth section 5f is connected to the first section 5a, wherein the sixth section 5f is disc-shaped and extends radially outward from the first section 5a, in particular, the axial end of the first section 5a away from the oil pump unit.

[0032] According to this embodiment, see in particular Figure 2The shaft 4, which serves as both the motor shaft and the pump shaft, is supported in a relatively rotatable manner on the first housing 5 by means of bearings 9, particularly rolling bearings. Specifically, the outer ring of the bearing 9 is supported on the third section 5c of the first housing 5, while the position of the bearing 9 in the axial direction is defined by the fourth section 5d. In this way, a bearing seat for the bearing 9 can be formed by a partial section of the integrally formed first housing 5.

[0033] According to this embodiment, see in particular Figure 2 The fifth section 5e can define the radial position of the shaft 4. This prevents tilting of the shaft 4 during operation of the electric oil pump. In some embodiments, lubricating oil can be optionally filled between the shaft 4 and the fifth section 5e to reduce friction between the shaft 4 and the first housing 5, particularly the fifth section 5e, thereby minimizing impact on the operation of the electric oil pump and reducing wear on components.

[0034] In this embodiment, especially referring to Figure 1 An oil groove 5h is formed on the axial surface of the second section 5b of the first housing 5, facing the oil pump unit. The oil groove 5h connects to the meshing area of ​​the first rotating member 6 and the second rotating member 7. This creates a flow channel for lubricating / cooling oil, promoting smooth operation of the electric oil pump.

[0035] The second housing 8 is a steel stamping housing. Figure 1 and Figure 2 As shown, second housing 8 comprises a disk-shaped section 8a and a sleeve section 8b connected to each other. Sleeve section 8b is generally cylindrical and extends axially and is arranged radially outward of the oil pump unit. Disk-shaped section 8a is connected to sleeve section 8b, wherein disk-shaped section 8a extends radially outward in a disk-like manner from the axial end of sleeve section 8b, particularly near the motor unit.

[0036] like Figure 2 As shown, the second section 5b of the first shell 5 and the disc-shaped section 8a of the second shell 8 are in contact with each other. In the area where the second section 5b of the first shell 5 and the disc-shaped section 8a of the second shell 8 are in contact with each other, stamping point connection parts 5g, 8c are formed by a stamping point connection process. The stamping point connection parts 5g, 8c are realized in particular by a cold forming process. The stamping point connection is achieved by forming a structure that is embedded in each other's materials or interlocked with each other between the second section 5b of the first shell 5 and the disc-shaped section 8a of the second shell 8 due to material deformation / flow during the stamping process, thereby realizing the connection between the first shell 5 and the second shell 8. Here, those skilled in the art can understand that it is possible to stamp out, preferably at one time, a plurality of stamping point connection parts 5g, 8c distributed in the circumferential direction, preferably evenly distributed, in the roughly annular area where the second section 5b and the disc-shaped section 8a are in contact with each other by means of a stamping die, thereby realizing an efficient and firm connection between the first shell 5 and the second shell 8. The present disclosure is disclosed in Figure 2 Only one set of the stamping point connections 5g, 8c is shown as an example. According to this embodiment, the stamping point connections 5g, 8c form a raised structure, which is located on the axial side of the second section 5b and the disc-shaped section 8a facing the motor unit, that is, it can face the inner side of the housing relative to the motor unit and / or the oil pump unit. In this embodiment, the stamping point connections 5g, 8c form a raised structure located in the axial space 10 between the first housing 5 and the motor unit. In some other embodiments, the stamping point connections formed during the stamping process can also be formed at other sections where the first housing 5 and the second housing 8 are in contact with each other. In some other embodiments, the raised structure formed by the stamping point connections can also face the outer side of the housing relative to the motor unit and / or the oil pump unit. In addition, in some alternative embodiments, the stamping point connections can also be implemented inside the steel plates of the first housing 5 and the second housing 8, that is, to achieve a material interlocking structure inside the two layers of steel plates, without forming a raised structure on any surface, thereby avoiding possible interference caused by the raised structure.

[0037] According to this embodiment, the end cover 1 can be constructed as an aluminum cover. Figure 1 As shown, the end cover 1 is connected to the sixth section 5f of the first housing 5 via connecting members, here bolts 13 and nuts 14. Thus, a space for accommodating the motor unit is formed by the first housing 5 and the end cover 1.

[0038] Alternatively, see Figure 1 An isolation plate 12 can also be arranged in the space for accommodating the motor unit, thereby isolating the space accommodating electronic components such as the electric control board 11 and the wet space accommodating cooling / lubricating oil.

[0039] With the solution of this embodiment, the first shell 5 and the second shell 8 are both steel stamping parts. On the one hand, compared with the design of the aluminum shell in the existing electric oil pump solution, the shell wall thickness can be greatly reduced, thereby reducing the overall size of the electric oil pump, meeting the boundary size requirements of a narrower installation environment, and at the same time reducing the weight of the shell, realizing the lightweight design requirements of the product. On the other hand, since the amount of shell material used is reduced, the material cost in product manufacturing can be reduced. In addition, since the first shell 5 and the second shell 8 in this solution are connected by a stamping point connection part, the use of additional fasteners, such as rivets, bolts, etc., can be avoided, and no auxiliary materials or heating are required. While ensuring sufficient connection strength, the process involving shell connection can be reduced and shortened, thereby reducing the manufacturing cost of the product.

[0040] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the claims of the present invention. In the description of the present invention, the terms "first", "second" and other ordinal numbers are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

[0041] Reference Signs List

[0042] 1 end cap

[0043] 2 stator assembly

[0044] 3 Rotor assembly

[0045] 4 shaft parts, motor shaft, pump shaft

[0046] 5. First shell

[0047] 5a Section 1

[0048] 5b Second section

[0049] 5c Section 3

[0050] 5d Section 4

[0051] 5e Section 5

[0052] 5f Section 6

[0053] 5g stamping point connection

[0054] 5h groove

[0055] 6 First rotating member

[0056] 7 Second rotating member

[0057] 8 Second shell

[0058] 8a Discoid segment

[0059] 8b Cylindrical section

[0060] 8c Stamping point connection

[0061] 9 bearings

[0062] 10 Axial Space

[0063] 11 Electric control board

[0064] 12 Isolation Board

[0065] 13 bolts

[0066] 14 Nut

Claims

1. An electric oil pump, comprising a motor unit and an oil pump unit arranged in sequence along the axial direction, It is characterized in that The electric oil pump further comprises: a first housing (5) which is a steel stamped housing and includes a first section (5a) configured radially outside the motor unit; a second housing (8), which is a steel stamped housing and includes a sleeve section (8b) formed radially outside the oil pump unit, The first shell (5) and the second shell (8) are connected to each other via a stamping point connection portion (5g, 8c).

2. The electric oil pump according to claim 1, wherein: The first shell (5) further includes a second section (5b) connected to the first section (5a), wherein the second section (5b) is disc-shaped and extends radially inward from the first section (5a). The second housing (8) further comprises a disc-shaped section (8a) connected to the sleeve section (8b), wherein the disc-shaped section (8a) extends radially outward from the sleeve section (8b) in a disc shape. The second section (5b) and the disk-shaped section (8a) are in contact with each other, and the punching point connection (5g, 8c) is formed in the area where the second section (5b) and the disk-shaped section (8a) are in contact with each other.

3. The electric oil pump according to claim 2, wherein: The punching point connection portion (5g, 8c) forms a raised structure, which is located on the axial side of the second section (5b) and the disk-shaped section (8a) facing the motor unit.

4. The electric oil pump according to claim 1, wherein: The first housing (5) further comprises a second section (5b) connected to the first section (5a) and a third section (5c) connected to the second section (5b), wherein the second section (5b) is disc-shaped and extends radially inward from the first section (5a), and the third section (5c) is cylindrical and extends axially from the second section (5b) toward the motor unit. The electric oil pump comprises a shaft (4) serving as both a motor shaft and a pump shaft. The shaft (4) is supported in a radial direction on the third section (5c) by means of a bearing (9) so as to be rotatable relative to the shaft.

5. The electric oil pump according to claim 4, wherein: The first housing (5) further includes a fourth section (5d) connected to the third section (5c), wherein the fourth section (5d) extends radially inward from the third section (5c) in a disc shape, wherein the position of the bearing (9) is axially limited by the fourth section (5d).

6. The electric oil pump according to claim 5, wherein: The first housing (5) further comprises a fifth section (5e) connected to the fourth section (5d), wherein the fifth section (5e) extends cylindrically from the fourth section (5d) in an axial direction away from the second section (5b), wherein the shaft (4) can be radially limited in position by the fifth section (5e).

7. The electric oil pump according to claim 6, wherein: Lubricating oil is filled between the shaft (4) and the fifth section (5e).

8. The electric oil pump according to claim 1, wherein The first shell (5) further includes a second section (5b) connected to the first section (5a), wherein the second section (5b) is disc-shaped and extends radially inward from the first section (5a). The axial surface of the second section (5b) facing the oil pump unit is formed with an oil groove (5h). The oil pump unit includes a first rotating member (6) and a second rotating member (7) meshed with each other, and the oil groove (5h) communicates with the meshing area of ​​the first rotating member (6) and the second rotating member (7).

9. The electric oil pump according to claim 1, wherein: The first shell (5) further includes a sixth section (5f) connected to the first section (5a), wherein the sixth section (5f) is disc-shaped and extends radially outward from the first section (5a). The electric oil pump further comprises an end cover (1), and the end cover (1) is connected to the sixth section (5f) via connecting components (13, 14).

10. An oil cooling system for a vehicle, characterized in that: The oil cooling system includes the electric oil pump according to any one of claims 1 to 9.

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