Electric oil pump

Abstract

An electric oil pump. The electric oil pump comprises a driving motor (10), a pump rotor assembly (20), a controller (30), a temperature sensor (40) and a housing (50); the driving motor (10) is controlled by the controller (30) to drive the pump rotor assembly (20); the housing (50) comprises a partition plate, a motor chamber (C1) in which the driving motor (10) is installed and a control chamber (C2) in which the controller (30) is installed, the motor chamber (C1) and the control chamber (C2) being adjacently arranged in the axial direction and partitioned by the partition plate. The temperature sensor (40) is fixed to the side surface of the controller (30) facing the motor chamber (C1); the partition plate comprises a main body part (51) and a heat conduction plate (52) made of a heat conduction material, and the main body part (51) comprises an axial through hole (51a) formed in an area corresponding to the temperature sensor (40); the heat conduction plate (52) is fixed to the main body part (51) at the axial through hole (51a) so as to seal the axial through hole (51a), allowing engine oil in the motor chamber (C1) to directly flow to the heat conduction plate (52) via the axial through hole (51a). The electric oil pump has an improved temperature sensing mode.

Description

Electric oil pump Technical Field

[0001] The present invention relates to the technical field of oil pumps, and in particular to an electric oil pump with a temperature sensor. Background Art

[0002] An electric oil pump is a device used to drive fluid flow and generate fluid pressure in a mechanical system. For example, electric oil pumps are commonly used in current motor vehicles to drive working fluid for cooling and lubrication. An electric oil pump generally includes components such as a drive motor, a pump rotor assembly, and a controller mounted in a housing. The drive motor and the controller are mounted in different chambers in the housing. In the motor cavity where the drive motor is mounted, there is engine oil for cooling and lubrication. A temperature sensor is required to measure the temperature of the engine oil in the motor cavity in order to monitor the operating status of the drive motor. The temperature sensor needs to be connected to the controller to provide the controller with a measured temperature signal.

[0003] In the prior art, temperature sensors can be installed at different locations in electric oil pumps. The installation location of the temperature sensor has a significant impact on the accuracy of temperature measurement. For example, in the electric oil pump disclosed in CN 218325063 U, the temperature sensor is installed in a groove on the side of the partition facing the controller. In this design, the temperature sensor is installed in an insert-type manner, which is easily damaged during installation, has high installation costs, and is difficult to implement through automated procedures. In addition, the leads of the temperature sensor are exposed in the installation groove and may accidentally contact the surrounding metal materials, causing the risk of leakage.

[0004] Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to provide an electric oil pump with an improved temperature sensing method.

[0006] The above technical problems are solved by an electric oil pump according to the present invention. The electric oil pump includes a drive motor, a pump rotor assembly, a controller, a temperature sensor and a housing. The drive motor is controlled by the controller to drive the pump rotor assembly. The housing includes a partition plate, a motor cavity for installing the drive motor and a control cavity for installing the controller. The motor cavity and the control cavity are arranged adjacent to each other along the axial direction and separated by the partition plate. The temperature sensor is fixed to the side surface of the controller facing the motor cavity. The partition plate includes a main body and a heat-conducting plate made of heat-conducting material. The main body includes an axial perforation formed in an area corresponding to the temperature sensor. The heat-conducting plate is fixed to the main body at the axial perforation to close the axial perforation, so that the oil in the motor cavity can flow directly to the heat-conducting plate through the axial perforation. By arranging the heat-conducting plate in the area of ​​the partition plate corresponding to the temperature sensor, the heat conduction effect between the motor cavity and the temperature sensor is improved, thereby improving the sensing effect of the oil temperature in the motor cavity. At the same time, the installation method of the temperature sensor is simpler.

[0007] According to a preferred embodiment of the present invention, the drive motor may include an axially extending motor shaft. The motor shaft may include an oil inlet hole extending axially therethrough for introducing oil into the motor cavity via the oil inlet hole in a direction toward the partition plate, with the axial through-hole aligned with the oil inlet hole. Because the oil inlet hole is aligned with the axial through-hole, oil introduced into the motor cavity via the oil inlet hole can flow directly into the axial through-hole and contact the heat conducting plate. This enhances oil fluidity in the area contacted by the heat conducting plate, thereby improving temperature sensing accuracy.

[0008] According to another preferred embodiment of the present invention, the motor shaft can extend axially into the axial through-hole without contacting the axial through-hole or the heat conducting plate. This reduces the distance between the outlet of the oil inlet and the heat conducting plate, allowing the heat conducting plate to more fully contact the engine oil.

[0009] According to another preferred embodiment of the present invention, the heat conducting plate may have a thickness smaller than that of the main body at least in the portion coinciding with the axial projection of the axial perforation, thereby reducing the distance between the engine oil and the temperature sensor and improving the heat conduction effect of the heat conducting plate.

[0010] According to another preferred embodiment of the present invention, the portion of the heat conducting plate that coincides with the axial projection of the axial through hole can be arranged flush with the side surface of the main body facing the control cavity. This brings the heat conducting plate closer to the temperature sensor, thereby improving the temperature sensing effect.

[0011] According to another preferred embodiment of the present invention, the heat conducting plate may include a central portion extending in a plane perpendicular to the axial direction and an edge portion surrounding the central portion. The heat conducting plate may close the axial perforation via the central portion and be fixedly connected to the main body via the edge portion. The edge portion may be fixed to the main body, for example, by press-fitting or embedding.

[0012] According to another preferred embodiment of the present invention, the main body can be made of injection molded material, and the edge portion can be offset relative to the main body in a direction away from the control chamber and encapsulated in the material of the main body, thereby achieving a secure connection between the edge portion and the main body in a simple manner.

[0013] According to another preferred embodiment of the present invention, an axial gap may exist between the temperature sensor and the heat conducting plate, and the electric oil pump may further include a thermally conductive filling material to fill the axial gap. The thermally conductive filling material can further improve the heat conduction between the heat conducting plate and the temperature sensor. Preferably, the thermally conductive filling material may be a thermally conductive adhesive. This allows the thermally conductive filling material to be simply filled between the temperature sensor and the heat conducting plate.

[0014] According to another preferred embodiment of the present invention, the heat conducting plate can be made of steel material. The heat conducting plate made of steel material has sufficient strength and good thermal conductivity, and can be thinner, thereby further improving the thermal conductivity effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention is further described below with reference to the accompanying drawings. Elements with the same function are represented by the same reference numerals in the drawings. Among them:

[0016] FIG1 shows a cross-sectional view of an electric oil pump according to an exemplary embodiment of the present invention;

[0017] FIG2 shows a partial enlarged view of the electric oil pump shown in FIG1 ;

[0018] FIG3 shows a perspective view of the heat conducting plate of the electric oil pump shown in FIG1 ; and

[0019] FIG. 4 illustrates a cross-sectional view of an electric oil pump according to another exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0020] The following detailed description and accompanying drawings are used to illustrate the principles of the present invention. The present invention is not limited to the preferred embodiments described. The scope of protection of the present invention is defined by the claims.

[0021] According to an embodiment of the present invention, an electric oil pump for driving a working fluid and generating fluid pressure is provided. The accompanying drawings illustrate exemplary embodiments of the electric oil pump according to the present invention. The specific structure of the electric oil pump will be described below with reference to the accompanying drawings.

[0022] Figure 1 shows a longitudinal cross-sectional view of an electric oil pump according to an exemplary embodiment. As shown in Figure 1 , the electric oil pump primarily includes a drive motor 10, a pump rotor assembly 20, a controller 30, a temperature sensor 40, and a housing 50. The drive motor 10 includes a stator 11, a rotor 12, and a motor shaft 13. The stator 11 is secured within the housing 50. The rotor 12 is coaxially mounted radially inwardly of the stator 11 and is rotatable relative to the stator 11 about a central axis parallel to the axial direction. The motor shaft 13, which extends generally axially, is coaxially secured radially inwardly of the rotor 12 and is rotatable relative to the stator 11 and the housing 40 along the common central axis with the rotor 12. The motor shaft 13 protrudes axially beyond the drive motor 10 to provide a driving connection with the pump rotor assembly 20. The motor shaft 13 transmits the drive torque generated by the drive motor 10 to the pump rotor assembly 20, thereby driving the pump rotor assembly 20 to rotate and generate pump suction. The operation of the drive motor 10 is controlled by the controller 30. The controller 30 is also fixedly mounted in the housing 50 and is located axially outside the end of the drive motor 10 that is away from the pump rotor assembly 20 .

[0023] When the drive motor 10 is running, the rotor 12 rotates at high speed, and the coil windings in the stator 11 generate a large amount of heat. Therefore, the space where the drive motor 10 is mounted needs to be filled with a certain amount of liquid (typically engine oil) to cool and lubricate the drive motor 10. To prevent engine oil from intruding into the controller 30, the housing 50 is formed with two different chambers for mounting the drive motor 10 and the controller 30, respectively. The chamber where the drive motor 10 is mounted is called the motor chamber C1, while the chamber where the controller 30 is mounted is called the control chamber C2. The motor chamber C1 and the control chamber C2 are arranged adjacent to each other in the axial direction. A portion of the housing 50 is axially located between the drive motor 10 and the controller 30, thereby separating the motor chamber C1 from the control chamber C2. This portion of the housing 50 can be referred to as a partition plate. As shown in Figure 1, the partition plate can extend generally perpendicular to the axial direction, with the drive motor 10 and the controller 30 located axially on either side of the partition plate. Engine oil filled in the motor chamber C1 cannot pass through the partition plate and enter the control chamber C2 where the controller 30 is mounted.

[0024] Figure 2 shows a partial enlarged view of the electric oil pump shown in Figure 1 at the partition plate. As shown in Figure 2, the controller 30 can be a plate-like component extending substantially perpendicular to the axial direction of the drive motor, such as a printed circuit board. The controller 30 has two axially opposite side surfaces, one of which is axially facing the motor cavity C1 and the partition plate. The temperature sensor 40 for measuring the oil temperature in the motor cavity C1 is directly fixedly mounted to the side surface of the controller 30 facing the motor cavity C1. For example, the temperature sensor 40 can be fixed to the controller 30 by surface mounting technology (SMT). The temperature sensor 40 is communicatively connected to the controller 30 so as to be able to provide a measured temperature signal to the controller 30.

[0025] As shown in FIG2 , the partition plate of the housing 50 is not an integrally formed component, but includes a main body 51 and a heat conducting plate 52 mounted together. The main body 51 includes an axial through-hole 51a formed in an area corresponding to the temperature sensor 40. The area corresponding to the temperature sensor 40 means that the orthographic projections of the temperature sensor 40 and the axial through-hole 51a in the axial direction at least partially overlap, and in particular, the orthographic projection of the temperature sensor 40 in the axial direction preferably completely falls within the range of the cross-section of the axial through-hole 51a. Preferably, the axial through-hole 51a can be a straight through hole extending in the axial direction, that is, the orthographic projections of the cross-sections at different positions in the axial direction in the axial direction completely overlap, and the shape of its cross-section can be, for example, circular or polygonal.

[0026] The heat conducting plate 52 is made of a heat conducting material, in particular a metal material, preferably a steel material. The materials of the heat conducting plate 52 and the main body 51 are usually different. The main body 51 can usually be made of an injection molding material (such as various plastic materials) or a lightweight metal material such as an aluminum alloy. The thermal conductivity of the injection molding material is not as good as that of the metal material, and the aluminum alloy cannot be made into a partition plate with a smaller thickness due to its porosity. Therefore, the heat conducting plate 52 made of a heat conducting material has a better heat conducting effect than the main body 51 due to its higher thermal conductivity and / or ability to be processed into a thinner plate.

[0027] The heat conducting plate 52 is secured to the main body 51 at the axial through-hole 51a, thereby sealing the axial through-hole 51a. Therefore, the main body 51 and the heat conducting plate 52 together separate the motor chamber C1 from the control chamber C2, preventing the oil in the motor chamber C1 from passing over the separator and entering the control chamber C2. Simultaneously, the oil in the motor chamber C1 can flow directly to the heat conducting plate 52 through the axial through-hole 51a. This allows the oil in the motor chamber C1 to contact the heat conducting plate 52 and transfer heat to it. Because the portion of the heat conducting plate 52 corresponding to the axial through-hole 51a also corresponds to the temperature sensor 40, heat from the oil in the motor chamber C1 can be transferred to the temperature sensor 40, enabling the temperature sensor 40 to accurately sense the oil temperature.

[0028] Preferably, as shown in Figures 1 and 2, the motor shaft 13 may include an axially extending oil inlet hole 13a. The oil inlet hole 13a directs oil from one end of the pump rotor assembly 20 into the motor cavity C1 in a direction toward the partition plate. Therefore, oil entering the motor cavity C1 through the oil inlet hole 13a will first reach the space between the end of the motor shaft 13 facing the partition plate and the partition plate. The axial through-hole 51a is preferably aligned with the oil inlet hole 13a, meaning that the orthographic projections of the axial through-hole 51a and the oil inlet hole 13a in the axial direction at least partially overlap. In particular, the orthographic projection of the oil inlet hole 13a in the axial direction preferably falls completely within the cross-sectional area of ​​the axial through-hole 51a. This ensures that the oil in contact with the axial through-hole 51a and the heat conducting plate 52 has high fluidity, thereby improving temperature sensing accuracy. In this case, the motor shaft 13 preferably extends axially into the axial through-hole 51a without contacting the axial through-hole 51a and the heat conducting plate 52. This can reduce the distance between the outlet of the oil inlet hole 13 a and the heat conducting plate 52 , and prevent the partition plate from interfering with the rotation of the motor shaft 13 .

[0029] As previously mentioned, to improve the thermal conductivity of the heat conducting plate 52, the heat conducting plate 52 may preferably have a thickness less than that of the main body 51, at least in the portion coinciding with the axial projection of the axial through-hole 51a. In particular, the heat conducting plate 52 may be formed from a plate having a substantially uniform thickness, with the plate having an overall relatively small thickness, particularly substantially less than that of the main body 51. To bring the heat conducting plate 52 closer to the temperature sensor 40, the portion of the heat conducting plate 52 coinciding with the axial projection of the axial through-hole 51a may preferably be arranged flush with the side surface of the main body 51 facing the control chamber C2. This arrangement not only brings the heat conducting plate 52 closer to the temperature sensor 40, but also allows the engine oil flowing into the axial through-hole 51a to be closer to the temperature sensor 40.

[0030] FIG3 shows a perspective view of the heat conducting plate 52. As shown in FIG3, in a preferred embodiment, the heat conducting plate 52 may include a central portion 52a extending in a plane perpendicular to the axial direction and an edge portion 52b surrounding the central portion 52a. The edge portion 52b may be an annular folded portion formed integrally with the central portion 52a. As shown in FIG2, when the heat conducting plate 52 is mounted to the main body 51, on the one hand, the central portion 52a covers the cross section of the axial through-hole 51a, thereby closing the axial through-hole 51a, and on the other hand, the edge portion 52b is fixedly connected to the main body 51, thereby mounting the heat conducting plate 52 to the main body 51.

[0031] The fixed connection between the edge portion 52b and the main body 51 can be achieved in different ways. The embodiment shown in Figure 2 adopts a preferred connection method. Specifically, in the embodiment shown in Figure 2, the main body 51 is made of injection molding material (for example, various plastic materials), the edge portion 52b is offset relative to the main body 51 in a direction away from the control chamber C2 and is coated into the material of the main body 51 during the injection molding process, thereby achieving the fixed connection between the edge portion 52b and the main body 51. This enables the edge portion 52b to be firmly fixed to the main body 51 and has a good sealing effect. As mentioned above, in this case, the center portion 52a can preferably be arranged flush with the side surface of the main body 51 facing the control chamber C2.

[0032] Alternatively, the edge portion 52b also can be fixed to the inner surface of the axial perforation 51a by the mode of tight fit or press fit. In this case, the edge portion 52b can be formed as a roughly cylindrical shape. In addition, in this case, a sealing ring can also be additionally provided to improve the sealing effect.

[0033] As shown in FIG2 , for ease of assembly, an axial gap may generally exist between the temperature sensor 40 and the heat conducting plate 52 when installed, so that the temperature sensor 40 does not directly contact the partition plate. This gap may affect the heat conduction effect. To this end, FIG4 shows an improved embodiment. As shown in FIG4 , the electric oil pump may also additionally include a heat conducting filling material 60 that fills this axial gap. For example, the heat conducting filling material 60 may be a heat conducting adhesive. The heat conducting filling material 60 connects the heat conducting plate 52 to the temperature sensor 40, and can transfer heat directly from the heat conducting plate 52 to the temperature sensor 40, thereby further improving the measurement accuracy.

[0034] In the electric oil pump according to the present invention, the heat conduction plate improves heat conduction between the motor cavity and the temperature sensor, reducing the direct distance between the temperature sensor and the oil in the motor cavity, thereby improving temperature measurement accuracy. Furthermore, the temperature sensor can be directly mounted to the controller, facilitating assembly, which helps reduce production costs and adapts to mass production.

[0035] While the foregoing descriptions illustrate possible embodiments, it should be understood that numerous variations exist through combinations of all known and other technical features and implementations readily conceivable to a skilled artisan. Furthermore, it should be understood that the exemplary embodiments serve merely as examples and in no way limit the scope, application, or configuration of the present invention. The foregoing descriptions are intended primarily to provide a skilled artisan with technical guidance for implementing at least one exemplary embodiment. Various modifications, particularly regarding the functionality and structure of the components described, may be made without departing from the scope of the claims.

[0036] Reference Signs List 10 driving motor 11 stator 12 rotor 13 motor shaft 13a oil inlet hole 20 pump rotor assembly 30 controller 40 temperature sensor 50 housing 51 main body 51a axial through hole 52 heat conducting plate 52a center portion 52b edge portion 60 heat conducting filling material C1 motor cavity C2 control cavity

Claims

1. An electric oil pump, comprising a drive motor (10), a pump rotor assembly (20), a controller (30), a temperature sensor (40), and a housing (50), wherein the drive motor (10) is controlled by the controller (30) to drive the pump rotor assembly (20), and the housing (50) comprises a partition plate, a motor cavity (C1) for mounting the drive motor (10), and a control cavity (C2) for mounting the controller (30), wherein the motor cavity (C1) and the control cavity (C2) are arranged adjacent to each other in the axial direction and are separated by the partition plate. It is characterized by: The temperature sensor (40) is fixed to the side surface of the controller (30) facing the motor cavity (C1), the partition plate includes a main body (51) and a heat conducting plate (52) made of a heat conducting material, the main body (51) includes an axial through hole (51a) formed in a region corresponding to the temperature sensor (40), and the heat conducting plate (52) is fixed to the main body (51) at the axial through hole (51a) to close the axial through hole (51a), so that the oil in the motor cavity (C1) can flow directly to the heat conducting plate (52) via the axial through hole (51a).

2. The electric oil pump according to claim 1, characterized in that The drive motor (10) includes an axially extending motor shaft (13), the motor shaft (13) including an axially penetrating oil inlet hole (13a) for introducing engine oil into the motor cavity (C1) via the oil inlet hole (13a) in a direction toward the partition plate, and the axial through hole (51a) is aligned with the oil inlet hole (13a).

3. The electric oil pump according to claim 2, characterized in that: The motor shaft (13) extends axially into the axial through hole (51a) and does not contact the axial through hole (51a) and the heat conducting plate (52).

4. The electric oil pump according to claim 1, characterized in that The heat conducting plate (52) has a thickness smaller than that of the main body (51) at least in a portion that coincides with an axial projection of the axial through hole (51a).

5. The electric oil pump according to claim 4, characterized in that: The portion of the heat conducting plate (52) that coincides with the axial projection of the axial through hole (51a) is arranged flush with the side surface of the main body (51) facing the control chamber (C2).

6. The electric oil pump according to claim 4, characterized in that The heat conducting plate (52) includes a central portion (52a) extending in a plane perpendicular to the axial direction and an edge portion (52b) surrounding the central portion (52a). The heat conducting plate (52) closes the axial through hole (51a) through the central portion (52a) and is fixedly connected to the main body (51) through the edge portion (52b).

7. The electric oil pump according to claim 6, characterized in that: The main body (51) is made of injection molding material, and the edge portion (52b) is offset relative to the main body (51) in a direction away from the control chamber (C2) and is coated in the material of the main body (51).

8. The electric oil pump according to claim 1, characterized in that An axial gap exists between the temperature sensor (40) and the heat conducting plate (52), and the electric oil pump further comprises a heat conducting filling material (60) filling the axial gap.

9. The electric oil pump according to claim 8, characterized in that The thermally conductive filling material (60) is a thermally conductive adhesive.

10. The electric oil pump according to any one of claims 1 to 9, characterized in that: The heat conducting plate (52) is made of steel.

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