Electric oil pump

Abstract

An electric oil pump includes a drive motor (10), a pump rotor assembly (20), an intermediate plate (41), a controller (30), and a temperature sensor (50). The drive motor (10) is controlled by the controller (30) to drive the pump rotor assembly (20). The drive motor (10) is installed in a motor cavity (C1) filled with liquid. The intermediate plate (41) is axially located between the drive motor (10) and the controller (30), thereby separating the controller (30) from the motor cavity (C1). The intermediate plate (41) includes an axially penetrating mounting hole (42). The temperature sensor (50) is fixedly installed in the mounting hole (42) and the mounting hole (42) is closed, allowing the end of the temperature sensor (50) facing the motor cavity (C1) to contact the liquid in the motor cavity (C1) to measure the liquid temperature. The end of the temperature sensor (50) facing the controller (30) is connected to the controller (30) via a connecting cable. This electric oil pump features an improved temperature sensor mounting method.

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 the electric oil pump. The installation position of the temperature sensor has a significant impact on the accuracy of temperature measurement. For example, in one existing solution, the temperature sensor is installed on the stator of the drive motor. In this design, since the stator windings will heat up when the motor is running, the temperature measurement results will be inaccurate; at the same time, the connecting cable between the temperature sensor and the controller needs to pass through the intermediate plate between the motor cavity and the controller, which requires an additional sealing structure to prevent the oil in the motor cavity from leaking into the space where the controller is located and to ensure the installation security of the cable and sensor. In another existing solution, the temperature sensor is installed in a blind hole on the side of the intermediate plate facing the controller. This design can solve the problem of installation security, but it is necessary to protect the temperature sensor from damage. The temperature sensor needs to be as small as possible to reduce the assembly space. At the same time, the temperature sensor cannot directly contact the oil in the motor cavity, and the temperature measurement results often deviate from the actual temperature.

[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 sensor installation 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, an intermediate plate, a controller and a temperature sensor. The drive motor is controlled by the controller to drive the pump rotor assembly. The drive motor is installed in a motor cavity filled with liquid (motor oil for cooling and / or lubrication). The intermediate plate is axially located between the drive motor and the controller to separate the controller from the motor cavity. The intermediate plate includes an axially extending mounting hole, and the temperature sensor is fixedly installed in the mounting hole and closes the mounting hole, so that the end of the temperature sensor facing the motor cavity can contact the liquid in the motor cavity to measure the liquid temperature, and the end of the temperature sensor facing the controller is connected to the controller via a connecting cable. The temperature sensor installed in this way can not only directly contact the motor oil in the motor cavity, but also be conveniently connected to the controller, and also has reliable installation firmness.

[0007] According to a preferred embodiment of the present invention, the end of the temperature sensor facing the motor cavity can protrude axially from the intermediate plate and extend into the motor cavity. This allows the temperature sensor to fully contact the oil in the motor cavity, thereby improving the accuracy of temperature measurement.

[0008] According to another preferred embodiment of the present invention, the temperature sensor may have a flange at the end facing the controller, the flange axially abutting the intermediate plate to position the temperature sensor. The temperature sensor may be installed in the mounting hole from the side facing the controller toward the motor cavity, and axially positioned by the flange abutting the intermediate plate.

[0009] According to another preferred embodiment of the present invention, the electric oil pump may further include a sealing ring that surrounds the temperature sensor and is clamped between the temperature sensor and the mounting hole to secure the temperature sensor and seal the mounting hole. This facilitates securing the temperature sensor and sealing the mounting hole.

[0010] According to another preferred embodiment of the present invention, the temperature sensor can be fixed to the mounting hole by screw thread engagement, thereby conveniently achieving the fixing of the temperature sensor and the sealing of the mounting hole.

[0011] According to another preferred embodiment of the present invention, the temperature sensor can be fixed to the mounting hole by interference fit, thereby conveniently achieving the fixing of the temperature sensor and the sealing of the mounting hole.

[0012] According to another preferred embodiment of the present invention, the temperature sensor can be fixed to the mounting hole by an adhesive, thereby conveniently achieving the fixing of the temperature sensor and the sealing of the mounting hole.

[0013] According to another preferred embodiment of the present invention, the temperature sensor and the mounting hole may have corresponding cross-sectional shapes, thereby facilitating the installation and positioning of the temperature sensor in the mounting hole.

[0014] According to another preferred embodiment of the present invention, the middle plate may include a thickened region, wherein the axial thickness of the thickened region is greater than the axial thickness of the surrounding region, and the mounting hole is formed in the thickened region. The thickened region provides more sufficient space for the temperature sensor to fit into the mounting hole.

[0015] According to another preferred embodiment of the present invention, the drive motor may include an axially extending motor shaft, and the electric oil pump may further include a cylindrical support portion extending axially from the intermediate plate toward the motor cavity, the motor shaft is supported on the support portion, the thickened area may be located radially outside the support portion, and the support portion may include a guide hole extending through its side wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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.

[0017] FIG1 shows a cross-sectional view of an electric oil pump according to an exemplary embodiment of the present invention; and

[0018] 2a to 2c are schematic diagrams showing temperature sensors applied to electric oil pumps according to different embodiments of the present invention. DETAILED DESCRIPTION

[0019] 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.

[0020] 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.

[0021] Figure 1 shows a longitudinal cross-sectional view of an electric oil pump according to an exemplary embodiment. As shown in Figure 1 , this electric oil pump primarily includes a drive motor 10, a pump rotor assembly 20, a controller 30, and a housing 40. The drive motor 10 includes a stator 11, a rotor 12, and a motor shaft 13. The stator 11 is fixed within the housing 40, while 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 is coaxially mounted radially inwardly of the rotor 12, allowing it to rotate 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 driving 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 a controller 30, which can be, for example, a control device such as a printed circuit board. The controller 30 is also mounted to the housing 40.

[0022] 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 installed needs to be filled with a certain amount of liquid (usually engine oil) to cool and lubricate the drive motor 10. To prevent engine oil from intruding into the controller 30, the housing 40 is formed with two different chambers for installing the drive motor 10 and the controller 30, respectively. The chamber where the drive motor 10 is installed is called the motor chamber C1, while the chamber where the controller 30 is installed is called the control chamber C2. A portion of the housing 40 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 40 can be referred to as the intermediate plate 41. As shown in Figure 1, the intermediate plate 41 can extend generally in a direction perpendicular to the axial direction, with the drive motor 10 and the controller 30 located axially on either side of the intermediate plate 41. The engine oil filled in the motor chamber C1 cannot pass through the intermediate plate 41 and enter the control chamber C2 where the controller 30 is installed.

[0023] In addition, the electric oil pump further includes a temperature sensor 50 for detecting the temperature of the oil in the motor cavity C1. The temperature sensor 50 is connected to the controller 30 via a connection cable to transmit the measured temperature information to the controller 30. The controller 30 can control the drive motor 10 based on the oil temperature information.

[0024] As shown in Figure 1, the middle plate 41 is formed with a mounting hole 42. The mounting hole 42 extends axially through the middle plate 41. The temperature sensor 50 is fixedly mounted in the mounting hole 42 so that, on the one hand, the end of the temperature sensor 50 facing the motor cavity C1 can contact the oil in the motor cavity C1 to measure the temperature of the oil, while on the other hand, the other end of the temperature sensor 50 facing the controller 30 can also be exposed to the control cavity C2, thereby facilitating connection with the controller 30 via a connecting cable. At the same time, the temperature sensor 50 closes the mounting hole 42 so that the oil in the motor cavity C1 cannot penetrate the control cavity C2 through the mounting hole 42. This installation method ensures the secure installation of the temperature sensor 50, accurately measures the temperature of the oil, and facilitates connection to the controller 30.

[0025] As shown in FIG1 , when installed, the end of the temperature sensor 50 facing the motor cavity C1 preferably protrudes axially beyond the intermediate plate 41 and extends into the interior of the motor cavity C1. This means that a portion of the temperature sensor 50 is located directly within the motor cavity C1, thereby enabling sufficient contact with the engine oil in the motor cavity C1. The sensing component of the temperature sensor 50 for measuring temperature is preferably located at this end, so as to directly contact the engine oil.

[0026] As shown in FIG1 , the temperature sensor 50 may preferably have a flange 51 at the end facing the controller 30. The flange 51 protrudes radially outward relative to the main body of the temperature sensor 50. In the installed state, the flange 51 axially abuts against the side surface of the intermediate plate 41 facing the controller 30, thereby axially positioning the temperature sensor 50 relative to the intermediate plate 41.

[0027] The fit between the temperature sensor 50 and the mounting hole 42 must meet both fixation and sealing requirements. This can be achieved through a variety of different fixation methods. Figures 2a to 2c illustrate several different fixation methods for the temperature sensor 50.

[0028] In the first embodiment shown in Figure 2a, a sealing ring can be used to secure and seal the temperature sensor 50 against the mounting hole 42. Specifically, in this embodiment, the electric oil pump further includes a sealing ring 60. The sealing ring 60 is an annular component made of an elastic material. When installed, the sealing ring 60 surrounds the temperature sensor 50 and is clamped between the temperature sensor 50 and the mounting hole 42. Preferably, to facilitate positioning of the sealing ring 60, an annular groove 52 extending around the temperature sensor 50 can be formed in the axially central region of the temperature sensor 50. The sealing ring 60 is mounted in the annular groove 52, with a portion of the sealing ring 60 radially protruding beyond the annular groove 52 to abut the inner wall of the mounting hole 42. In this case, a radially inwardly protruding engaging portion can be formed in the mounting hole 42, and a corresponding radially inwardly recessed annular groove can be formed on the temperature sensor 50. When installed, the engaging portion can be radially inserted into the annular groove to achieve axial positioning of the temperature sensor 50 relative to the mounting hole 42.

[0029] In the second embodiment shown in FIG2 b , the temperature sensor 50 can be secured to the mounting hole 42 via a threaded fit. Specifically, the temperature sensor 50 can have external threads 53 formed on its outer sidewall, and the mounting hole 42 can have internal threads (not shown) formed on its inner sidewall that correspond to the external threads of the temperature sensor 50. When the temperature sensor 50 is installed in the mounting hole 42, the external threads 53 of the temperature sensor 50 engage with the internal threads of the mounting hole 42, thereby forming a threaded fit. This threaded fit allows the temperature sensor 50 to be secured and sealed to the mounting hole 42.

[0030] 2c, the temperature sensor 50 may be fixed to the mounting hole 42 by interference fit. In this case, the outer side surface of the temperature sensor 50 and the inner side surface of the mounting hole 42 may be formed as smooth surfaces.

[0031] Alternatively, the temperature sensor 50 can be secured to the mounting hole 42 using an adhesive. The adhesive can be used in conjunction with any of the aforementioned mounting methods. That is, when using any of the aforementioned mounting methods, an additional adhesive can be applied between the temperature sensor 50 and the mounting hole 42. Alternatively, the adhesive can be used alone, achieving both securement and sealing by applying only the adhesive between the temperature sensor 50 and the mounting hole 42. In this case, the temperature sensor 50 and the mounting hole 42 can be loosely fitted.

[0032] Preferably, the temperature sensor 50 and the mounting hole 42 can have corresponding cross-sectional shapes. This facilitates installation of the temperature sensor 50 and ensures that the temperature sensor 50 and the mounting hole 42 are in proper alignment. For example, in the embodiment shown in Figures 2a to 2c, the temperature sensor 50 and the mounting hole 42 both have corresponding circular cross-sectional shapes, which facilitates processing and assembly. However, for example, in the embodiment shown in Figures 2a and 2c, the temperature sensor 50 and the mounting hole 42 can also have other cross-sectional shapes, such as polygonal cross-sectional shapes.

[0033] As shown in Figure 1 , the mounting hole 42 can preferably be formed in a thickened area of ​​the intermediate plate 41. This thickened area has a greater axial thickness than the surrounding areas. This allows the mounting hole 42 to have a larger axial dimension, thereby providing more space for the temperature sensor 50 to be installed. However, in some cases, to support the motor shaft 13, the housing 40 may also be formed with a cylindrical support portion 43 extending axially from the intermediate plate 41 toward the motor cavity C1, with the motor shaft 13 supported radially inward of the support portion 43. This results in less space between the area of ​​the intermediate plate 41 facing the motor shaft 13, radially inward of the support portion 43. To provide sufficient axial space for the thickened area, the thickened area is typically located radially outward of the support portion 43. However, since the engine oil in the motor cavity C1 is typically introduced through an axial through-hole in the motor shaft 13, the support portion 43 may obstruct the temperature sensor 50 in the thickened area from contacting the engine oil. To this end, a guide hole 44 may preferably be formed in the support portion 43, extending through its sidewall. The guide hole 44 penetrates from the radially inner wall to the radially outer wall of the support portion 43 , thereby guiding the oil radially inside the support portion 43 to flow radially outward to contact the temperature sensor 50 in the thickened region.

[0034] In the electric oil pump according to the present invention, a temperature sensor is mounted in a mounting hole on the intermediate plate separating the controller and the drive motor. One end of the temperature sensor can directly contact the oil in the motor cavity, while the other end can be connected to the controller via a connecting cable. This allows the temperature sensor to accurately measure the oil temperature while conveniently connecting to the controller. Furthermore, the temperature sensor can seal the mounting hole, preventing oil from the motor cavity from leaking into the control cavity. Furthermore, the temperature sensor is easy to install and secure in the mounting hole, and its installation is highly secure.

[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 20 pump rotor assembly 30 controller 40 housing 41 intermediate plate 42 mounting hole 43 support portion 44 guide hole 50 temperature sensor 51 flange 52 annular groove 53 external thread 60 sealing ring C1 motor chamber C2 control chamber

Claims

1. An electric oil pump, comprising a drive motor (10), a pump rotor assembly (20), an intermediate plate (41), a controller (30), and a temperature sensor (50), wherein the drive motor (10) is controlled by the controller (30) to drive the pump rotor assembly (20), the drive motor (10) is installed in a motor cavity (C1) filled with liquid (engine oil for cooling and / or lubrication), and the intermediate plate (41) is axially located between the drive motor (10) and the controller (30) to separate the controller (30) from the motor cavity (C1). It is characterized by: The intermediate plate (41) includes an axially penetrating mounting hole (42), and the temperature sensor (50) is fixedly mounted in the mounting hole (42) and closes the mounting hole (42), so that the end of the temperature sensor (50) facing the motor cavity (C1) can contact the liquid in the motor cavity (C1) to measure the liquid temperature, and the end of the temperature sensor (50) facing the controller (30) is connected to the controller (30) via a connecting cable.

2. The electric oil pump according to claim 1, characterized in that The end portion of the temperature sensor (50) facing the motor cavity (C1) protrudes from the intermediate plate (41) in the axial direction and extends into the interior of the motor cavity (C1).

3. The electric oil pump according to claim 1, characterized in that The temperature sensor (50) has a flange (51) at the end facing the controller (30), and the flange (51) abuts against the intermediate plate (41) in the axial direction to position the temperature sensor (50).

4. The electric oil pump according to claim 1, characterized in that The electric oil pump further includes a sealing ring (60) which surrounds the temperature sensor (50) and is clamped between the temperature sensor (50) and the mounting hole (42) to fix the temperature sensor (50) and to seal between the mounting hole (42) and the temperature sensor (50).

5. The electric oil pump according to claim 1, characterized in that The temperature sensor (50) is fixed to the mounting hole (42) by threaded engagement.

6. The electric oil pump according to claim 1, characterized in that The temperature sensor (50) is fixed to the mounting hole (42) by interference fit.

7. The electric oil pump according to claim 1, characterized in that The temperature sensor (50) is fixed to the mounting hole (42) by adhesive.

8. The electric oil pump according to claim 1, characterized in that The temperature sensor (50) and the mounting hole (42) have cross-sectional shapes corresponding to each other.

9. The electric oil pump according to any one of claims 1 to 8, characterized in that: The intermediate plate (41) includes a thickened area, the axial thickness of the thickened area is greater than the axial thickness of the surrounding area, and the mounting hole (42) is formed in the thickened area.

10. The electric oil pump according to claim 9, characterized in that: The drive motor (10) includes an axially extending motor shaft (13), and the electric oil pump also includes a cylindrical support portion (43) extending axially from the intermediate plate (41) toward the motor cavity (C1). The motor shaft (13) is supported on the support portion (43), the thickened area is located radially outside the support portion (43), and the support portion (43) includes a guide hole (44) penetrating a side wall thereof.

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