Driving device of gear pump

Drive device

The gear pump is driven by an independent motor, which can effectively block the upstream pressure pulsation and flow fluctuation. The pressure pulsation at the gear pump outlet can be controlled within 1%. The use of a gear pump in the extrusion line can increase the flow output speed and reduce the shear and residence time of the material in the extruder.

External gear pump is the most widely used a gear pump, the general gear pump usually refers to the external gear pump. Its structure is shown in Figure 1, mainly composed of driving gear, driven gear, pump body, pump cover and safety valve. The sealed space formed by the pump body, pump cover and gear is the working room of the gear pump. The axles of the two gears are respectively installed in the bearing holes on the two pump covers, and the driving gear shaft extends out of the pump body and is driven by the motor to rotate. The external gear pump has simple structure, light weight, low cost, reliable work and wide application range.

When the gear pump works, the driving wheel rotates with the motor and drives the driven wheel to rotate with it. When the meshing teeth on one side of the suction chamber are gradually separated, the volume of the suction chamber increases and the pressure decreases, and the liquid in the suction pipe is sucked into the pump; the suction liquid is pushed to the discharge chamber by the gear in two ways in the tooth groove. After the liquid enters the discharge chamber, the liquid is squeezed from the discharge chamber into the discharge pipe due to the continuous engagement of the teeth of the two gears. Driving gear and driven gear rotation, the pump can continuously suction and discharge liquid.

The pump body is equipped with a safety valve. When the discharge pressure exceeds the specified pressure, the conveying liquid can automatically open the safety valve to return the high-pressure liquid to the suction pipe.

Internal gear pump, which consists of a pair of meshing internal gears and their intermediate crescent-shaped parts, pump casing and so on. The crescent serves to separate the suction chamber from the discharge chamber. When the driving gear rotates, a partial vacuum is formed at the place where the gear is disengaged, and the liquid is sucked into the pump to fill each tooth in the suction chamber, and then enters the discharge chamber in two ways along the inner and outer sides of the crescent-shaped piece. Where the teeth enter into engagement, the liquid present between the teeth is squeezed into the discharge tube.

In addition to the characteristics of self-priming ability and independent flow and discharge pressure, the gear pump has no suction valve and discharge valve on the pump casing. It has the characteristics of simple structure, uniform flow, and reliable operation, but it has low efficiency, high noise and vibration, and easy Wear, mainly used to transport various oils that are non-corrosive, non-solid particles and have lubricating ability. The temperature generally does not exceed 70 ℃, such as lubricating oil, edible vegetable oil, etc. The general flow range is 0.045~30 ms/h, the pressure range is 0.7-20MPa, and the working speed is 1200-4000r/min.

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