Fuel filter assembly with electric oil self-absorption function

Abstract

The invention discloses a fuel filter assembly with an electric self-oil-absorption function, which relates to the technical field of vehicle fuel filter systems and comprises a filter seat, an electric self-oil-absorption component, a middle shell, a filter element component and a maintenance lower cover component. The filter seat is provided with a first oil cavity, a second oil cavity, an oil inlet and an oil outlet. The second oil cavity is divided into an oil suction cavity and an oil outlet cavity by the electric self-oil-suction assembly, and the oil outlet is communicated with the oil outlet cavity. And the inner cavity of the middle shell is divided into a pre-filtering cavity and a post-filtering cavity by the filter element assembly. The before-filtering cavity is communicated with the first oil cavity, and the after-filtering cavity is respectively communicated with the oil suction cavity and the oil outlet cavity. A one-way valve is arranged in a passage of the after-filtering cavity and the oil outlet cavity so as to allow fuel oil to flow to the oil outlet cavity from the after-filtering cavity in a one-way mode. The maintenance lower cover assembly is used for discharging water filtered out by the filter element assembly. According to the fuel filter assembly with the electric self-oil-absorption function, automatic oil pumping can be achieved, fatigue of manual oil pumping is relieved, and meanwhile the starting capacity and operation stability of an engine are improved in an auxiliary mode.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle fuel filter systems, and in particular to a fuel filter assembly with an electric self-priming oil function. Background Art

[0002] The fuel filter assembly with electric self-priming function is an important component to maintain efficient and stable operation of the engine. Its main function is to provide clean fuel for the engine's combustion system.

[0003] Filling the newly replaced fuel filter with oil is a routine operation before starting the engine. At present, most small and medium-sized power models of light trucks are manually self-priming, which requires repeatedly pressing the diaphragm manual pump of the fuel filter assembly with electric self-priming function to suck oil. There are characteristics such as small operating space, cumbersome operating procedures, many pumping times, and strong manual fatigue. Summary of the invention

[0004] The purpose of the present invention is to provide a fuel filter assembly with an electric self-priming function to solve the problems existing in the above-mentioned related technologies, relieve fatigue of manual oil pumping, and assist in improving the starting ability and running stability of the engine.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The invention discloses a fuel filter assembly with electric self-priming function, comprising:

[0007] A filter seat, the filter seat having a first oil chamber, a second oil chamber, an oil inlet, an oil outlet and a mounting port, the first oil chamber is separated from the second oil chamber, the oil inlet is connected to the first oil chamber, and the oil outlet is connected to the second oil chamber;

[0008] An electric self-priming oil component, the electric self-priming oil component is located in the second oil chamber, and the second oil chamber is divided into an oil suction chamber and an oil outlet chamber; the oil outlet is connected to the oil outlet chamber, the inlet of the electric self-priming oil component is located in the oil suction chamber, and the outlet of the electric self-priming oil component is located in the oil outlet chamber; the installation port is used to take and place the electric self-priming oil component;

[0009] A middle shell, a first end of which is connected to the filter seat;

[0010] A filter element assembly, wherein the filter element assembly is located in the middle housing and divides the inner cavity of the middle housing into a pre-filter cavity and a post-filter cavity; the pre-filter cavity is connected to the first oil cavity, and the post-filter cavity is connected to the oil suction cavity and the oil outlet cavity respectively; a one-way valve is provided in the passage between the post-filter cavity and the oil outlet cavity to allow the fuel to flow from the post-filter cavity to the oil outlet cavity in one direction;

[0011] A maintenance lower cover assembly is connected to the second end of the middle shell body and is used to discharge the water filtered by the filter element assembly.

[0012] Preferably, the filter seat further has a first heater connection port, and the first heater connection port is used to connect a first heater.

[0013] Preferably, the electric self-priming oil assembly includes a motor, a first sealing ring, a second sealing ring, an oil suction pump core, and a controller; the first sealing ring is sleeved on the outside of the motor and is sealed with the inner wall of the second oil chamber, so as to separate the second oil chamber into the oil suction chamber and the oil outlet chamber; the second sealing ring is located in the oil outlet chamber and is sleeved on the outside of the controller, so as to prevent fuel from leaking from the mounting port; the oil suction pump core is connected to one end of the motor located in the oil suction chamber, and the controller is connected to one end of the motor located in the oil outlet chamber.

[0014] Preferably, the controller includes a bracket, a circuit board and a decorative cover; the bracket has a groove for accommodating the circuit board, and the decorative cover covers the groove; the bracket has a plug interface so that an external device can be electrically connected to the circuit board through the plug interface; the bracket has a wire outlet for the wire to pass through, and the two ends of the wire are electrically connected to the motor and the circuit board respectively.

[0015] Preferably, the electric self-priming oil assembly also includes a first sealing ring mounting bracket, which is a hollow cylindrical structure, and a second filter layer is provided in the hollow part; the first sealing ring is sleeved on the outside of the first sealing ring mounting bracket, and the first sealing ring mounting bracket is sleeved on the outside of the motor and axially limited; the second filter layer is located on the side of the first sealing ring close to the oil outlet cavity, and is located between the outlet of the electric self-priming oil assembly and the oil outlet.

[0016] Preferably, the middle housing has a connecting portion to achieve fixed connection with adjacent components.

[0017] Preferably, the middle shell is threadedly connected to the maintenance lower cover assembly, and sealing is achieved through a third sealing ring.

[0018] Preferably, the filter element assembly includes a support tube, a first filter layer, an upper cover, a lower cover, a fourth sealing ring and a fifth sealing ring; the first filter layer is attached to the support tube, and the two ends of the support tube are respectively connected to the upper cover and the lower cover, and the fourth sealing ring is sleeved on the outside of the upper cover for docking with the inner wall of the second oil chamber; the fifth sealing ring is sleeved on the outside of the lower cover for docking with the inner wall of the maintenance lower cover assembly.

[0019] Preferably, the first filter layer includes an impurity filter layer, a water droplet coalescing layer and a water droplet hydrophobic layer which are arranged in sequence from the outside to the inside.

[0020] Preferably, the maintenance lower cover assembly includes a sixth sealing ring, a maintenance lower cover, a drain valve, a water level sensor connection port and a second heater connection port; the maintenance lower cover has a water storage cavity, and the outer side of the maintenance lower cover is provided with a connecting thread, a sealing ring mounting groove, a drain port, a second heater connection port and a water level sensor connection port; the connecting thread is used to connect the middle shell body, and the sixth sealing ring is used to seal the gap between the maintenance lower cover and the middle shell body; the drain valve is installed on the maintenance lower cover, the second heater connection port is used to connect the second heater, and the water level sensor connection port is used to connect the water level sensor.

[0021] Compared with the related art, the present invention has achieved the following technical effects:

[0022] 1. Compared with traditional products on the market, the electric self-priming oil component has the characteristics of small size, light weight and low cost. The oil absorption characteristics presented in the fuel system are more in line with the operating requirements of light trucks and small and medium-power engines;

[0023] 2. The operation mode of the electric self-priming oil component is intelligent operation control, and its operating status can be differentially controlled in combination with the physical characteristics of different fuel systems.

[0024] 3. By setting up a bypass oil circuit inside the electric self-priming oil component, the motor and the oil suction pump core can achieve low-noise and stable operation under extreme working conditions, meeting higher auditory comfort requirements.

[0025] 4. The fuel flow channel inside the filter seat assembly adopts a dual-channel design. The fuel supply status of each working state does not affect each other. The above design can effectively reduce the fluid resistance of the fuel system, improve the smoothness of fuel flow, extend the service life of the filter element, and reduce fuel consumption.

[0026] 5. The fuel filter assembly with electric self-priming function is arranged on light trucks or small and medium-power engines, which can effectively improve the starting performance of the engine and increase the first-time starting success rate under harsh conditions such as high oil viscosity and poor oil fluidity in low-temperature conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1It is the front view of the fuel filter assembly with electric self-priming function.

[0029] Figure 2 A top view of the filter seat.

[0030] Figure 3 It is a left view showing the positional relationship between the filter seat and the electric self-priming oil assembly.

[0031] Figure 4 This is the left view of the electric self-priming oil component.

[0032] Figure 5 The front view of the filter element assembly.

[0033] Figure 6 Maintain the front view of the lower cover assembly.

[0034] Figure 7 Schematic diagram of the first sealing ring mounting bracket.

[0035] In the figure: 1-filter seat; 2-electric self-priming oil assembly; 3-middle housing; 4-filter element assembly; 5-maintenance lower cover assembly; 10-second oil chamber; 11-first oil chamber; 12-oil suction chamber; 13-oil outlet chamber; 14-oil inlet; 15-oil outlet; 16-installation port; 17-first heater connection port; 18-screw; 19-check valve; 20-first sealing ring installation bracket; 21-motor; 22-first sealing ring; 23-second sealing ring; 24-oil suction Pump core; 25-controller; 26-bracket; 27-circuit board; 28-decorative cover; 29-plug interface; 41-support tube; 42-first filter layer; 43-upper cover; 44-lower cover; 45-fourth sealing ring; 46-fifth sealing ring; 47-impurity filter layer; 48-water droplet aggregation layer; 49-water droplet hydrophobic layer; 51-third sealing ring; 52-maintenance lower cover; 53-drain valve; 54-water level sensor connection port; 55-second heater connection port. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] The purpose of the present invention is to provide a fuel filter assembly with an electric self-priming function to solve the problems existing in the above-mentioned related technologies, relieve fatigue of manual oil pumping, and assist in improving the starting ability and running stability of the engine.

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] Reference Figure 1 to Figure 6 This embodiment provides a fuel filter assembly with an electric self-priming oil function, including a filter seat 1, an electric self-priming oil component 2, a middle shell 3, a filter element component 4 and a maintenance lower cover component 5.

[0040] The filter seat 1 has a first oil chamber 11, a second oil chamber 10, an oil inlet 14, an oil outlet 15 and a mounting port 16. The first oil chamber 11 is separated from the second oil chamber 10. The oil inlet 14 is connected to the first oil chamber 11, and the oil outlet 15 is connected to the second oil chamber 10. The oil inlet 14 is connected to the fuel tank through an oil inlet pipe, and the oil outlet 15 is connected to the engine through an oil outlet pipe. The connection method between the interface and the pipeline here can be rotary friction welding, reverse buckle clamping or other connection methods.

[0041] The electric self-priming oil assembly 2 is located in the second oil chamber 10, and the second oil chamber 10 is divided into an oil suction chamber 12 and an oil outlet chamber 13. Obviously, the oil suction chamber 12 and the oil outlet chamber 13 are both annular chambers. The oil outlet 15 is connected to the oil outlet chamber 13, the inlet of the electric self-priming oil assembly 2 is located in the oil suction chamber 12, and the outlet of the electric self-priming oil assembly 2 is located in the oil outlet chamber 13. The installation port 16 is used to take and place the electric self-priming oil assembly 2.

[0042] The first end of the middle shell 3 is connected to the filter seat 1. The filter element assembly 4 is located in the middle shell 3, and divides the inner cavity of the middle shell 3 into a pre-filter cavity and a post-filter cavity. The pre-filter cavity is connected to the first oil cavity 11, and the post-filter cavity is connected to the oil suction cavity 12 and the oil outlet cavity 13 respectively. A one-way valve 19 is arranged in the passage between the post-filter cavity and the oil outlet cavity 13 to allow the fuel to flow from the post-filter cavity to the oil outlet cavity 13 in one direction. The maintenance lower cover assembly 5 is connected to the second end of the middle shell 3, and is used to discharge the water filtered by the filter element assembly 4. In this embodiment, the lower part of the filter seat 1 has an inner pipeline and an outer pipeline, and the inner pipeline is concentrically arranged with the outer pipeline. The post-filter cavity is connected to the oil outlet cavity 13 through the inner pipeline, and the post-filter cavity is connected to the oil suction cavity 12 through the outer pipeline. The one-way valve 19 is located on the inner side of the inner pipeline.

[0043] The working principle of the fuel filter assembly with electric self-priming function in this embodiment is as follows:

[0044] The fuel provided by the fuel tank reaches the first oil chamber 11 through the oil inlet pipe and the oil inlet port 14, and then flows to the pre-filter chamber in the middle housing 3, and reaches the post-filter chamber after being filtered by the filter element assembly 4. If the electric self-priming oil assembly 2 is in working state, the fuel in the post-filter chamber enters the oil suction chamber 12, and is then pumped to the oil outlet chamber 13 by the electric self-priming oil assembly 2, and finally delivered to the engine through the oil outlet port 15 and the oil outlet pipe. If the electric self-priming oil assembly 2 is in the shutdown state and the engine is in working state, the fuel in the post-filter chamber enters the oil outlet chamber 13, and is then delivered to the engine through the oil outlet port 15 and the oil outlet pipe.

[0045] This embodiment arranges two branches so that the filtered fuel can be delivered to the engine through the two branches, which can realize the low-noise and stable operation of the electric self-priming oil assembly 2 under extreme working conditions and meet higher auditory comfort requirements. At the same time, the oil supply status of the two branches does not affect each other, which can effectively reduce the fluid resistance of the fuel system, improve the smoothness of fuel flow, extend the service life of the filter element, and reduce fuel consumption. Therefore, the fuel filter assembly with electric self-priming oil function is suitable for light trucks or small and medium-power engines, which can effectively improve the starting performance of the engine and improve the one-time starting success rate under harsh conditions such as high oil viscosity and poor oil fluidity in low-temperature conditions.

[0046] As a possible example, in this embodiment, the filter seat 1 further has a first heater connection port 17, and the first heater connection port 17 is used to connect a first heater. The first heater is used to heat the fuel in the first oil chamber 11 in the filter seat 1 to improve the fluidity of the fuel in the filter seat 1 and prevent the fuel from solidifying and clogging the filter seat 1.

[0047] As a possible example, in this embodiment, the electric self-priming oil assembly 2 includes a motor 21, a first sealing ring 22, a second sealing ring 23, an oil suction pump core 24, and a controller 25. The first sealing ring 22 is sleeved on the outside of the motor 21 and is sealed and connected to the inner wall of the second oil chamber, and is used to separate the second oil chamber into an oil suction chamber 12 and an oil outlet chamber 13. The second sealing ring 23 is located in the oil outlet chamber 13 and is sleeved on the outside of the controller 25 to prevent fuel from leaking from the mounting port 16. The oil suction pump core 24 is connected to one end of the motor 21 located in the oil suction chamber 12, and the controller 25 is connected to one end of the motor 21 located in the oil outlet chamber 13. The interior of the oil suction pump core 24 is eccentrically arranged, and the oil suction pump core 24 realizes the same rotation as the motor 21 under the action of the central transmission shaft, and realizes the two functions of external oil suction and internal oil pressure when the oil suction pump core 24 rotates. The inlet of the electric self-priming oil assembly 2 is located on the oil suction pump core 24, and the outlet of the electric self-priming oil assembly 2 is located on the outer shell of the motor 21.

[0048] As a possible example, in this embodiment, the controller 25 includes a bracket 26, a circuit board 27 and a decorative cover 28. The bracket 26 has a groove for accommodating the circuit board 27, and the decorative cover 28 covers the groove. The bracket 26 is provided with a plug interface 29 so that an external device can be electrically connected to the circuit board 27 through the plug interface 29. The bracket 26 is provided with a wire outlet for the wire to pass through, and the two ends of the wire are electrically connected to the motor 21 and the circuit board 27 respectively. The groove and the decorative cover 28 form a relatively closed inner cavity to protect the circuit board 27. The bracket 26 is welded to the decorative cover 28. A groove for installing the second sealing ring 23 is provided on the outer side of the bracket 26, and the second sealing ring 23 is used to be sealed and connected to the inner wall of the second oil chamber to prevent the fuel from leaking outward from the gap between the filter seat 1 and the controller 25.

[0049] The operation mode of the motor 21 can be preset in the circuit board 27, and the operation of the motor 21 can also be controlled by an external control signal transmitted through the plug interface 29. After the electric self-priming oil component 2 is placed in the filter seat 1 through the installation port 16, the bracket 26 is fixed to the end surface of the filter seat 1 by the screw 18 to realize the positioning of the electric self-priming oil component 2.

[0050] As a possible example, in the present embodiment, the electric self-priming oil assembly 2 also includes a first sealing ring mounting bracket 20, the first sealing ring mounting bracket 20 is a hollow cylindrical structure, and the hollow part is provided with a second filter layer. The first sealing ring sleeve 22 is arranged on the outside of the first sealing ring mounting bracket 20, and the first sealing ring mounting bracket 20 is sleeved on the outside of the motor 21 and axially limited. The second filter layer is located on the side of the first sealing ring close to the oil outlet cavity, and is located between the outlet and the oil outlet of the electric self-priming oil assembly. The second filter layer is used for secondary filtration of the fuel delivered by the electric self-priming oil assembly 2 to avoid pollutants generated by mechanical wear of the electric self-priming oil assembly 2 from entering the engine through the oil outlet 15, thereby ensuring the performance of the engine. The second filter layer is evenly distributed along the circumferential direction of the first sealing ring mounting bracket 20 to avoid blocking the oil.

[0051] As a possible example, in this embodiment, the middle housing 3 has a connection portion to achieve fixed connection with adjacent components. Exemplarily, the connection portion can be a hanging ear or a transition bracket, as long as it can achieve fixed connection.

[0052] As a possible example, in this embodiment, the middle shell 3 is threadedly connected to the maintenance lower cover assembly 5 , and sealing is achieved through a third sealing ring 51 .

[0053] As a possible example, in this embodiment, the filter element assembly 4 includes a support tube 41, a first filter layer 42, an upper cover 43, a lower cover 44, a fourth sealing ring 45 and a fifth sealing ring 46. The first filter layer 42 is attached to the support tube 41, and the two ends of the support tube 41 are respectively connected to the upper cover 43 and the lower cover 44. The fourth sealing ring 45 is sleeved on the outer side of the upper cover 43 to connect with the inner wall of the second oil chamber 10. The fifth sealing ring 46 is sleeved on the outer side of the lower cover 44 to connect with the inner wall of the maintenance lower cover assembly 5. Exemplarily, the support tube 41 and the first filter layer 42, the support tube 41 and the upper cover 43, and the support tube 41 and the lower cover 44 are all bonded to improve the integrity of the filter element assembly 4.

[0054] As a possible example, in this embodiment, the first filter layer 42 includes an impurity filter layer 4742, a water droplet coalescing layer 48, and a water droplet hydrophobic layer 49, which are arranged in sequence from the outside to the inside. The impurity filter layer 4742 can filter particulate matter in the fuel, the water droplet coalescing layer 48 can coalesce small-sized water molecules in the fuel, and the water droplet hydrophobic layer 49 is made of an oleophilic and hydrophobic material. The separated clean fuel enters the oil suction chamber 12 or the oil outlet chamber 13, and the water enters the maintenance lower cover assembly 5 after being separated, and is discharged by the maintenance lower cover assembly 5. According to different actual needs, those skilled in the art can also choose other types of first filter layers 42.

[0055] As a possible example, in this embodiment, the maintenance lower cover assembly 5 includes a maintenance lower cover 52, a drain valve 53, a water level sensor connection port 54 and a second heater connection port 55. The maintenance lower cover 52 has a water storage chamber, and the outer side of the maintenance lower cover 52 is provided with a connecting thread, a sealing ring installation groove, a drain port, a second heater connection port 55 and a water level sensor connection port 54. The connecting thread is used to connect the middle shell 3, and the third sealing ring 51 is used to seal the gap between the maintenance lower cover 52 and the middle shell 3. The drain valve 53 is installed on the maintenance lower cover 52, the second heater connection port 55 is used to connect the second heater, and the water level sensor connection port 54 is used to connect the water level sensor. The drain valve 53 can be a manual drain valve or an electromagnetic automatic drain valve. The water level sensor can convert the water level height in the maintenance lower cover 52 into an electrical signal and transmit it to the vehicle instrument, or it can transmit the water level signal to the integrated controller 25 while displaying the water level, and send a control instruction through the integrated controller 25 to control the opening and closing of the electromagnetic automatic drain valve. The maintenance lower cover 52 contains a small amount of fuel while containing water. The maintenance lower cover 52 is heated by the second heater to improve the fluidity of the liquid and prevent the liquid from solidifying and clogging the electromagnetic automatic drain valve. In order to improve the sealing performance, a sealing ring should be set at the installation position of the drain valve 53 and the water level sensor connection port 54.

[0056] In this embodiment, the maintenance lower cover 52 and the middle housing 3 are of a split structure, and the two are threadedly connected. However, the actual implementation is not limited to this. For example, the two can also be of an integrated structure.

[0057] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A fuel filter assembly with electric self-priming function, characterized in that: include: A filter seat, the filter seat having a first oil chamber, a second oil chamber, an oil inlet, an oil outlet and a mounting port, the first oil chamber is separated from the second oil chamber, the oil inlet is connected to the first oil chamber, and the oil outlet is connected to the second oil chamber; An electric self-priming oil component, the electric self-priming oil component is located in the second oil chamber, and the second oil chamber is divided into an oil suction chamber and an oil outlet chamber; the oil outlet is connected to the oil outlet chamber, the inlet of the electric self-priming oil component is located in the oil suction chamber, and the outlet of the electric self-priming oil component is located in the oil outlet chamber; the installation port is used to take and place the electric self-priming oil component; A middle shell, a first end of which is connected to the filter seat; A filter element assembly, wherein the filter element assembly is located in the middle housing and divides the inner cavity of the middle housing into a pre-filter cavity and a post-filter cavity; the pre-filter cavity is connected to the first oil cavity, and the post-filter cavity is connected to the oil suction cavity and the oil outlet cavity respectively; a one-way valve is provided in the passage between the post-filter cavity and the oil outlet cavity to allow the fuel to flow from the post-filter cavity to the oil outlet cavity in one direction; A maintenance lower cover assembly is connected to the second end of the middle shell body and is used to discharge the water filtered by the filter element assembly.

2. The fuel filter assembly with electric self-priming function according to claim 1 is characterized in that: The filter seat also has a first heater connection port, and the first heater connection port is used to connect a first heater.

3. The fuel filter assembly with electric self-priming function according to claim 1 is characterized in that: The electric self-priming oil assembly includes a motor, a first sealing ring, a second sealing ring, an oil suction pump core, and a controller; the first sealing ring is sleeved on the outside of the motor and is sealed with the inner wall of the second oil chamber, and is used to separate the second oil chamber into the oil suction chamber and the oil outlet chamber; the second sealing ring is located in the oil outlet chamber and is sleeved on the outside of the controller, and is used to prevent fuel from leaking from the mounting port; the oil suction pump core is connected to one end of the motor located in the oil suction chamber, and the controller is connected to one end of the motor located in the oil outlet chamber.

4. The fuel filter assembly with electric self-priming function according to claim 3 is characterized in that: The controller includes a bracket, a circuit board and a decorative cover; the bracket has a groove for accommodating the circuit board, and the decorative cover covers the groove; the bracket has a plug interface so that an external device can be electrically connected to the circuit board through the plug interface; the bracket has a wire outlet, and the wire outlet is for the wire to pass through, and the two ends of the wire are electrically connected to the motor and the circuit board respectively.

5. The fuel filter assembly with electric self-priming function according to claim 3 is characterized in that: The electric self-priming oil assembly also includes a first sealing ring mounting bracket, which is a hollow cylindrical structure, and a second filter layer is provided on the hollow part; the first sealing ring is sleeved on the outside of the first sealing ring mounting bracket, and the first sealing ring mounting bracket is sleeved on the outside of the motor and axially limited; the second filter layer is located on a side of the first sealing ring close to the oil outlet cavity, and is located between the outlet of the electric self-priming oil assembly and the oil outlet.

6. The fuel filter assembly with electric self-priming function according to claim 1 is characterized in that: The middle housing has a connecting portion to achieve fixed connection with adjacent components.

7. The fuel filter assembly with electric self-priming function according to claim 1, characterized in that: The middle shell is threadedly connected to the maintenance lower cover assembly and is sealed by a third sealing ring.

8. The fuel filter assembly with electric self-priming function according to claim 1, characterized in that: The filter element assembly includes a support tube, a first filter layer, an upper cover, a lower cover, a fourth sealing ring and a fifth sealing ring; the first filter layer is attached to the support tube, and the two ends of the support tube are respectively connected to the upper cover and the lower cover, and the fourth sealing ring is sleeved on the outside of the upper cover for docking with the inner wall of the second oil chamber; the fifth sealing ring is sleeved on the outside of the lower cover for docking with the inner wall of the maintenance lower cover assembly.

9. The fuel filter assembly with electric self-priming function according to claim 8, characterized in that: The first filter layer comprises an impurity filter layer, a water droplet coalescing layer and a water droplet hydrophobic layer which are arranged in sequence from the outside to the inside.

10. The fuel filter assembly with electric self-priming function according to claim 1, characterized in that: The maintenance lower cover assembly includes a sixth sealing ring, a maintenance lower cover, a drain valve, a water level sensor connection port and a second heater connection port; the maintenance lower cover has a water storage cavity, and the outer side of the maintenance lower cover is provided with a connecting thread, a sealing ring mounting groove, a drain port, a second heater connection port and a water level sensor connection port; the connecting thread is used to connect the middle shell body, and the sixth sealing ring is used to seal the gap between the maintenance lower cover and the middle shell body; the drain valve is installed on the maintenance lower cover, the second heater connection port is used to connect the second heater, and the water level sensor connection port is used to connect the water level sensor.

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