12V 24V Tractor Electric Fuel Pump HEP-02A

Automobile Diesel Engine Excavator Tractor Eletric Fuel Pump HEP-02A

Products detail

working principle

The electric fuel pump is composed of a pump body, a DC motor and a shell. Its basic working principle is that after the DC motor is energized, the rotor in the pump housing is driven to rotate at a high speed. The cut surface at the lower end of the rotor shaft is combined with the cut surface of the inner hole of the impeller, so that when the rotor rotates, the impeller is driven to rotate in the same direction through the rotor shaft. During the high-speed rotation of the impeller, vacuum low pressure is created at the oil inlet, and the filtered fuel is sucked from the oil inlet of the pump cover. The sucked fuel is pressurized by the fuel pump impeller and enters the pump housing and then passes through the oil outlet pressure. To provide fuel with a certain pressure for the fuel system. The structure of the DC motor includes a permanent magnet fixed on the inner wall of the pump casing, a rotor capable of generating a magnetic torque after being energized, and a graphite carbon brush assembly installed on the upper end of the pump casing. The carbon brush is in elastic contact with the commutator on the armature rotor, and its lead is connected to the plug-in wiring electrode of the shell. The outer ends of the electric fuel pump casing are crimped and riveted to become a non-detachable assembly.

Fuel pump type

In the fuel system, the electric fuel pump is responsible for supplying fuel with a certain pressure, and its fuel delivery per unit time is more than 8 times more than the fuel consumption per unit time of the engine's rated power condition. A large amount of fuel is continuously returned to the fuel storage tank through the oil pressure regulator, which not only controls the oil pressure, but also cools the fuel pipeline to avoid air lock.
Although the specific structures of electric fuel pumps are diverse, they are all composed of pump oil components, permanent magnet motors, end caps and shells. The shell crimping rivets the other parts into a whole. The rotor (or pump wheel) of the oil pump assembly is coaxial with the rotor of the electric motor. The fuel is output from the pump oil assembly through the motor and the end cover. The terminal of the motor is arranged on the end cover. A one-way valve is installed in the oil outlet of the end cover. When the engine is stopped, the one-way valve is closed, and the fuel in the fuel pipeline will not return to the fuel transfer pump and maintain a certain residual oil pressure, which is beneficial to the next quick start. In addition, there is an overpressure relief valve (safety valve) installed on the support or end cover of the pump oil assembly. When the fuel line is blocked and the oil pressure in the system exceeds the allowable value, it opens to overflow and relieve the pressure. In this way, damage to the oil pipe or the oil transfer pump can be avoided.
Different types of electric fuel pumps are mainly different in pump oil components. According to the working principle, the pump oil components can be divided into two categories: positive displacement pump and fluid power pump. Positive displacement pumps rely on changes in the volume of the pump cavity to suck and press oil, so they are intermittent oil delivery, with greater oil pressure fluctuations and vibration and noise, but the working pressure is higher. Roller pumps, gear pumps and vane pumps are all positive displacement pumps. The working pressure of roller pump is about 200kPa, gear pump can reach 400kPa, and the working pressure of vane pump can be higher. The first two pumps are used more.
The fluid power pump relies on the pump wheel to drive the fuel flow. The fuel in the flow generates oil pressure due to the change of momentum. It is a continuous oil pump with small pressure fluctuations but low working pressure. It is suitable for large oil volume and low oil pressure. Occasions. Axial pumps, centrifugal pumps, turbo pumps and side channel pumps are all hydrodynamic pumps. The working pressure of the axial flow pump and the side tank pump is about 100kPa, and the other two pumps are about 300kPa. Turbo pumps and side channel pumps are used more.

Products picture