48V power supply platform direct current brush motor fuel pump

Abstract

The invention belongs to the field of automobile fuel, and provides a 48V power supply platform direct current brush motor fuel pump which comprises a machine shell, a permanent magnet and a rotor assembly located in an inner hole of the permanent magnet are arranged in the middle of the inner side of the machine shell, the rotor assembly comprises a rotor shaft, the rotor shaft is vertically located in the machine shell, and a carbon brush holder is in interference fit with an opening in the top of the machine shell. The outer circle of the bottom of the carbon brush holder axially limits the permanent magnet, an upper oil bearing located on the upper portion of the rotor shaft is in interference fit with the interior of the carbon brush holder, and a pump head is in interference fit with the top between the carbon brush holder and the machine shell. The fuel pump is matched with a 48V power supply platform, the current is only 1 / 4 of that of a 12V system under the same power load, the wire harness loss and heating are greatly reduced, the energy utilization efficiency is improved, the potential safety hazard caused by overheating is fundamentally reduced, compared with the 12V system, the 48V system has the advantages that the cable sectional area is greatly reduced, the overall weight is effectively reduced, the 48V system can be seamlessly connected into a whole vehicle domain control framework, and the whole vehicle domain control framework can be seamlessly connected. And the whole vehicle voltage platform upgrading requirement is met.

Description

Technical Field

[0001] The invention belongs to the field of automobile fuel, and in particular relates to a 48V power supply platform DC brushed motor fuel pump. Background Art

[0002] The fuel pump plays an indispensable and critical role in the fuel system of new energy vehicles. Although new energy vehicles are primarily powered by electricity, some hybrid models and vehicles using extended-range technology still retain fuel engines as auxiliary power sources or as a driving device under specific operating conditions. When the engine is operating, fuel must be continuously, stably, and at a certain pressure from the fuel tank to the engine's combustion chamber to ensure that the fuel and air are fully mixed and efficiently burned, thereby providing stable power output for the engine. The fuel pump is the component that undertakes this important task. It can precisely adjust the fuel delivery volume and pressure according to the requirements of different engine operating conditions, ensuring that the engine receives the appropriate proportion of fuel supply under various operating conditions, thereby maintaining normal engine operation, improving combustion efficiency, reducing exhaust emissions, and ensuring the reliability and performance of the new energy vehicle's overall power system.

[0003] Traditional fuel pumps mostly use brushed DC motors driven by a 12V power supply. Structurally, the motor portion of this motor is primarily composed of permanent magnets, carbon brushes, a commutator, and armature windings. Its working principle relies on the carbon brushes contacting the commutator segments to switch the current direction, thereby driving the motor. The pump body, on the other hand, is composed of an impeller, an oil inlet cover, and an oil outlet cover assembled to form the pump chamber. The motor shaft is connected to the impeller, which rotates when the motor is running, generating suction and pressure to achieve fuel medium output and provide power support for the fuel supply system. However, existing fuel pump technology, driven by traditional 12V systems, suffers from significant drawbacks. Firstly, due to the lower voltage of the 12V system, the current drawn by the same power load is higher. For example, a 120W load requires 10A, while a 48V system only requires 2.5A. This excessive current significantly increases wiring losses and heat generation, reducing energy efficiency and potentially posing safety risks. This makes it difficult to adapt to the vehicle's transition to a 48V voltage platform. Secondly, existing fuel pumps suffer from significant compatibility issues. Their designs are not adapted for the 48V power platform, preventing them from fully utilizing the advantages of the battery system in new energy vehicles. This limits the further application and development of fuel pumps in this sector.

[0004] To this end, those skilled in the art have proposed a 48V power supply platform DC brushed motor fuel pump to solve the problems raised in the background art. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a 48V power supply platform DC brushed motor fuel pump.

[0006] A 48V power supply platform DC brushed motor fuel pump includes a casing, a permanent magnet and a rotor assembly located in the inner hole of the permanent magnet are arranged in the middle of the inner side of the casing, the rotor assembly includes a rotor shaft, the rotor shaft is vertically located inside the casing, a carbon brush holder is interference fit at the opening at the top of the casing, the outer circle of the bottom of the carbon brush holder forms an axial limit for the permanent magnet, the internal interference fit of the carbon brush holder is an upper oil-containing bearing located on the upper part of the rotor shaft, the top interference fit between the carbon brush holder and the casing is a pump head, the bottom interference fit of the inner side of the casing is an oil outlet end cover, the internal interference fit of the oil outlet end cover is a lower oil-containing bearing located at the lower part of the rotor shaft, the bottom end of the casing is interference fit with an oil inlet end cover located below the oil outlet end cover, a pump chamber is formed between the oil inlet end cover and the oil outlet end cover, an impeller is suspended in the pump chamber and is slidably connected to the rotor shaft, and the internal interference fit of the oil inlet end cover is a pump nail that contacts the rotor shaft.

[0007] Preferably, the rotor assembly also includes an iron core, an armature winding and a commutator. The outer side of the rotor shaft is interference fit with the iron core and the end face commutator located above the iron core. The armature winding is wound on the iron core, and filler is integrally injection-molded between the armature winding, the iron core, the rotor shaft and the end face commutator.

[0008] Preferably, a lug is installed through the pump head, the bottom of the lug is connected to a compression spring, the bottom of the compression spring is connected to a carbon brush located in the brush holder, and the bottom of the carbon brush abuts against the top of the commutator.

[0009] Preferably, an oil nozzle and a pressure relief hole are provided on the top of the pump head, a one-way valve is provided in the oil nozzle, and a safety pressure relief valve is provided in the pressure relief hole.

[0010] Preferably, an oil inlet hole is integrally formed on the bottom of the oil inlet end cover.

[0011] Preferably, the permanent magnet and the rotor assembly are both located on the same central axis, and the inner hole of the upper oil-containing bearing and the inner hole of the lower oil-containing bearing are both located on the same central axis.

[0012] Preferably, the connection between the housing, the carbon brush holder and the oil outlet cover is provided with a stop step for axial limiting.

[0013] Preferably, a semicircular flat square for sliding assembly with the central hole of the impeller is provided at the connection between the rotor shaft and the impeller.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The fuel pump of this invention is compatible with the 48V power platform. Under the same power load, the current is only 1 / 4 of that of the 12V system, which significantly reduces wiring loss and heat generation, improves energy efficiency, and fundamentally reduces safety hazards caused by overheating. In addition, the 48V system has a significantly smaller cable cross-sectional area than the 12V system, effectively reducing the overall weight. It can be seamlessly integrated into the vehicle's domain control architecture, meeting the requirements of the vehicle's voltage platform upgrade and expanding the application scenarios of fuel pumps in new energy vehicles. 2. In the present invention, multiple key components adopt an interference fit design, including the interference fit between the casing and the carbon brush holder, pump head, and oil outlet cover, the interference fit between the carbon brush holder and the upper oil-containing bearing, and the interference fit between the oil outlet cover and the lower oil-containing bearing. This effectively enhances the connection strength between components, reduces assembly clearance, improves overall sealing, and avoids fuel leakage. At the same time, the coaxiality design between the permanent magnet and the rotor assembly, the upper oil-containing bearing, and the lower oil-containing bearing can reduce eccentric vibration during rotor operation, reduce wear, and extend service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a main structural diagram of the present invention; Figure 2 This is a bottom-up split structure diagram of the present invention; Figure 3 It is a top view of the structure of the present invention; Figure 4 It is a side sectional structural diagram of the present invention.

[0016] In the picture: 1. Casing; 2. Permanent magnet; 3. Rotor assembly; 301. Rotor shaft; 302. Iron core; 303. Armature winding; 304. Commutator; 305. Filler; 4. Brush holder; 5. Upper oil-containing bearing; 6. Pump head; 7. Oil outlet cover; 8. Oil inlet cover; 9. Lower oil-containing bearing; 10. Impeller; 11. Pump nail; 12. Terminal block; 13. Compression spring; 14. Carbon brush; 15. Oil nozzle; 16. Pressure relief hole; 17. Oil inlet hole; 18. Semi-circular flat square. DETAILED DESCRIPTION

[0017] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0018] As attached Figure 1 To the attached Figure 4 As shown: The present invention provides a 48V power supply platform DC brush motor fuel pump, comprising a casing 1, a permanent magnet 2 and a rotor assembly 3 located in an inner hole of the permanent magnet are arranged in the middle of the inner side of the casing 1, the rotor assembly 3 includes a rotor shaft 301, the rotor shaft 301 is vertically located inside the casing 1, a carbon brush holder 4 is interference-fitted at the opening at the top of the casing 1, the outer circle of the bottom of the carbon brush holder 4 forms an axial limit for the permanent magnet 2, an upper oil-containing bearing 5 located on the upper part of the rotor shaft 301 is interference-fitted inside the carbon brush holder 4, a pump head 6 is interference-fitted at the top between the carbon brush holder 4 and the casing 1, an oil outlet cover 7 is interference-fitted at the bottom inside the casing 1, a lower oil-containing bearing 9 located at the lower part of the rotor shaft 301 is interference-fitted inside the oil outlet cover 7, an oil inlet cover 8 located below the oil outlet cover 7 is interference-fitted at the bottom end of the casing 1, a pump chamber is formed between the oil inlet cover 8 and the oil outlet cover 7, and an impeller 10 slidingly connected to the rotor shaft 301 is suspended in the pump chamber.

[0019] It should be further explained that the upper and lower openings of the housing 1 are sealed by mold forming, which can effectively ensure the stability and tightness of the connection of the entire component.

[0020] It should be further explained that the upper oil-containing bearing 5 and the lower oil-containing bearing 9 jointly support the rotor shaft 301, forming a two-point support, thereby improving the rotation accuracy and vibration resistance. The upper oil-containing bearing 5 and the lower oil-containing bearing 9 contain lubricating oil inside, and the oil seeps to the mating surface through the centrifugal force during rotation.

[0021] refer to Figure 4 The oil inlet cover 8 has an internal interference fit with a pump pin 11 that contacts the rotor shaft 301 .

[0022] Among them, the pump nail 11 is usually cylindrical, with one end as the positioning end in contact with the rotor shaft 301, and the other end as the fixed end in cooperation with the oil inlet end cover 8, which is used for axial limit support. By contacting the end face or shoulder of the rotor shaft 301, the axial movement is limited to ensure that the center line of the rotor shaft 301 is consistent with the axial center line of the permanent magnet. When rotating at high speed, the pump nail 11 can share part of the radial load and reduce the load-bearing burden of the rotor shaft 301.

[0023] refer to Figure 4 The rotor assembly 3 also includes an iron core 302, an armature winding 303 and a commutator 304. The iron core 302 and the end face commutator 304 located above the iron core 302 are interference fit on the outer side of the rotor shaft 301. The armature winding 303 is wound on the iron core 302. Filler 305 is integrally injection-molded between the armature winding 303, the iron core 302, the rotor shaft 301 and the end face commutator 304.

[0024] In the rotor assembly 3, the armature winding 303, iron core 302, rotor shaft 301, and end commutator 304 are integrally formed by integrally injection-molding a filler 305. This strengthens the connection strength of the components and reduces loosening or wear caused by vibration. Furthermore, the filler 305 isolates the windings from corrosion by the fuel medium, improving the corrosion resistance and stability of the motor and indirectly extending the overall service life of the fuel pump.

[0025] refer to Figure 4 A terminal piece 12 is installed through the pump head 6, and the bottom of the terminal piece 12 is connected to a compression spring 13, and the bottom of the compression spring 13 is connected to a carbon brush 14 located in the carbon brush holder 4, and the bottom of the carbon brush 14 abuts against the top of the commutator 304.

[0026] Among them, the elastic force of the compression spring 13 can ensure that the carbon brush 14 always maintains stable contact with the commutator 304 during the wear process, avoiding sparks or resistance fluctuations due to poor contact, and ensuring the continuity of current conduction; at the same time, the elastic contact can buffer the tiny vibrations during the operation of the rotor, reduce the rigid friction between the carbon brush 14 and the commutator 304, reduce the wear rate of both, and extend the service life of the carbon brush 14 and the commutator 304. When the terminal 12 is energized with the external DC power supply, the armature winding 303 generates a rotating magnetic field that interacts with the magnetic field of the permanent magnet.

[0027] It should be further explained that a capacitor and a resistor are installed and connected between the positive and negative electrodes of the terminal piece 12 , and an inductor is connected in series between the terminal piece and the carbon brush 14 .

[0028] The capacitor and the resistor can absorb the voltage spike at the commutation moment, suppress sparks, reduce arc energy, and reduce the ablation of the carbon brush 14 and the commutator 3.

[0029] refer to Figure 3 The top of the pump head 6 is provided with an oil nozzle 15 and a pressure relief hole 16. A one-way valve is provided in the oil nozzle 15, and a safety pressure relief valve is provided in the pressure relief hole 16.

[0030] Among them, the one-way valve can effectively prevent backflow during the fuel delivery process, ensure the pressure stability of the fuel supply system, and avoid fuel supply interruption or pressure fluctuation caused by backflow. The safety pressure relief valve can automatically open the discharge when the fuel pressure exceeds the set threshold, quickly reduce the oil circuit pressure, and prevent safety hazards such as the nozzle 15 and pipeline bursting due to excessive pressure, thereby protecting the safety of the fuel pump and the entire fuel supply system.

[0031] refer to Figure 2 The bottom of the oil inlet cover 8 is integrally formed with an oil inlet hole 17 .

[0032] The fuel medium is sucked into the oil inlet cover 8 from the oil inlet hole 17 , and is discharged through the oil outlet cover 7 into the air gap between the outer circle of the rotor assembly 3 and the permanent magnet under the action of the impeller 10 , and is finally output through the oil nozzle 15 of the pump head 6 .

[0033] refer to Figure 4 The permanent magnet 2 and the rotor assembly 3 are both located on the same central axis, and the inner hole of the upper oil-containing bearing 5 and the inner hole of the lower oil-containing bearing 9 are both located on the same central axis.

[0034] Among them, high coaxiality can ensure that the rotation trajectory of the rotor shaft 301 in the upper oil-containing bearing 5 and the lower oil-containing bearing 9 is centered, reducing radial runout caused by eccentricity, while reducing friction interference between the rotor and the permanent magnet 2, and wear between the bearings and the rotor shaft 301, thereby improving the running smoothness and energy conversion efficiency of the fuel pump and extending the service life of each component.

[0035] refer to Figure 4 The connection between the housing 1, the carbon brush holder 4 and the oil outlet cover 7 is provided with a stop step for axial limiting.

[0036] Among them, the stop step can quickly locate the axial position of each component during assembly, ensure the consistency of assembly dimensions, and avoid component misalignment or excessive gaps due to assembly deviations.

[0037] refer to Figure 2 A semicircular flat square 18 is provided at the connection between the rotor shaft 301 and the impeller 10 for sliding assembly with the center hole of the impeller 10.

[0038] Among them, the semi-circular flat square 18 realizes torque transmission between the rotor shaft 301 and the impeller 10 through a non-circular cross-section to avoid relative rotation. Compared with the full flat square or spline, the semi-circular flat square 18 retains part of the cylindrical surface while transmitting torque, reduces stress concentration, and improves fatigue life. During assembly, the impeller 10 can slide freely along the rotor shaft 301 without the need to align the keyway or spline, thereby improving production efficiency.

[0039] Working principle: When the fuel pump is working, the fuel medium is sucked into the oil inlet cover 8 from the oil inlet hole 17 at the bottom of the oil inlet cover 8. When the terminal piece 12 is energized with the external DC power supply, the current is transmitted to the compression spring 13 through the terminal piece 12. The compression spring 13 uses its elastic force to ensure that the carbon brush 14 is always in stable contact with the top of the commutator 304 of the rotor assembly 3, and the current is transmitted to the rotor assembly 3. The outer side of the rotor shaft 301 in the rotor assembly 3 has an interference fit with the iron core 302 and the end face commutator 304. When the armature winding 303 wound on the iron core 302 is energized, a rotating magnetic field is generated. The rotating magnetic field interacts with the magnetic field of the permanent magnet set in the middle of the inner side of the casing 1, so that the rotor shaft 301 drives the iron core 302, the end face commutator 304 and the overall structure with the filler 305 integrally injected to rotate. When the rotor shaft 301 rotates, the semicircular flat square 1 set at the connection 8 drives the impeller 10 to rotate, and the fuel medium is discharged through the oil outlet cover 7 into the air gap between the outer circle of the rotor assembly 3 and the permanent magnet under the action of the impeller 10, and finally output through the oil nozzle 15 on the top of the pump head 6. At the same time, when the fuel pressure exceeds the set threshold, the safety pressure relief valve in the pressure relief hole 16 on the top of the pump head 6 automatically opens to discharge, quickly reducing the oil circuit pressure and preventing safety hazards. The fuel pump is adapted to the 48V power supply platform as a whole. Under the same power load, the current is only 1 / 4 of the 12V system, which greatly reduces wiring harness loss and heat, improves energy utilization efficiency, and reduces safety hazards caused by overheating from the root. Compared with the 12V system, the cable cross-sectional area of the 48V system is greatly reduced, and the overall weight is effectively reduced. It can be seamlessly connected to the vehicle domain control architecture, meeting the vehicle voltage platform upgrade requirements, and expanding the application scenarios of fuel pumps in new energy vehicles.

[0040] The embodiments of the present invention are provided for the purpose of illustration and description. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A 48V power platform DC brushed motor fuel pump, comprising a housing (1), characterized in that: A permanent magnet (2) and a rotor assembly (3) located in the inner hole of the permanent magnet are provided in the middle of the inner side of the housing (1). The rotor assembly (3) includes a rotor shaft (301). The rotor shaft (301) is vertically located in the inner side of the housing (1). A carbon brush holder (4) is interference-fitted at the opening at the top of the housing (1). The outer circle at the bottom of the carbon brush holder (4) forms an axial limit for the permanent magnet (2). The inner side of the carbon brush holder (4) is interference-fitted with an upper oil-containing bearing (5) located on the upper part of the rotor shaft (301). A pump head is interference-fitted at the top between the carbon brush holder (4) and the housing (1). (6), the bottom of the inner side of the casing (1) is interference-fitted with an oil outlet cover (7), the inner part of the oil outlet cover (7) is interference-fitted with a lower oil-containing bearing (9) located at the lower part of the rotor shaft (301), the bottom end of the casing (1) is interference-fitted with an oil inlet cover (8) located below the oil outlet cover (7), a pump chamber is formed between the oil inlet cover (8) and the oil outlet cover (7), an impeller (10) slidably connected to the rotor shaft (301) is suspended in the pump chamber, and the inner part of the oil inlet cover (8) is interference-fitted with a pump pin (11) in contact with the rotor shaft (301).

2. A 48V power platform DC brushed motor fuel pump as claimed in claim 1, characterized in that: The rotor assembly (3) further comprises an iron core (302), an armature winding (303) and a commutator (304); the iron core (302) and the end face commutator (304) located above the iron core (302) are interference-fitted on the outer side of the rotor shaft (301); the armature winding (303) is wound around the iron core (302); and a filler (305) is integrally injection-molded between the armature winding (303), the iron core (302), the rotor shaft (301) and the end face commutator (304).

3. A 48V power platform DC brushed motor fuel pump as claimed in claim 2, characterized in that: A terminal piece (12) is installed through the pump head (6), the bottom of the terminal piece (12) is connected to a compression spring (13), the bottom of the compression spring (13) is connected to a carbon brush (14) located in the carbon brush holder (4), and the bottom of the carbon brush (14) is in contact with the top of the commutator (304).

4. A 48V power platform DC brushed motor fuel pump as claimed in claim 1, characterized in that: An oil nozzle (15) and a pressure relief hole (16) are provided on the top of the pump head (6). A one-way valve is provided in the oil nozzle (15), and a safety pressure relief valve is provided in the pressure relief hole (16).

5. The 48V power platform DC brushed motor fuel pump according to claim 1, characterized in that: An oil inlet hole (17) is integrally formed at the bottom of the oil inlet end cover (8).

6. A 48V power platform DC brushed motor fuel pump as claimed in claim 1, characterized in that: The permanent magnet (2) and the rotor assembly (3) are both located on the same central axis, and the inner hole of the upper oil-containing bearing (5) and the inner hole of the lower oil-containing bearing (9) are both located on the same central axis.

7. The 48V power platform DC brushed motor fuel pump according to claim 1, characterized in that: The connection between the housing (1), the carbon brush holder (4) and the oil outlet cover (7) is provided with a stop step for axial limiting.

8. The 48V power platform DC brushed motor fuel pump according to claim 1, characterized in that: A semicircular flat square (18) for sliding assembly with the center hole of the impeller (10) is provided at the connection between the rotor shaft (301) and the impeller (10).

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