Application of shaft seal device in gear oil pump

First, introduce the shaft seal device

The function is to prevent the liquid in the gear oil pump from leaking along the shaft or the outside air from leaking into the pump body.

The commonly used shaft seal device has two kinds of packing seal and mechanical seal

The packing is usually made of asbestos rope soaked in oil or coated with graphite.

The mechanical seal mainly depends on the movable ring installed on the shaft and the static ring fixed on the pump body between the end face of the relative movement to achieve the purpose of sealing

 

* The gear is installed in pump body 2..

And fastening on pump shaft 3...

The pump shaft is driven directly by the motor.

The center of the pump body has a liquid inhalation 4 connected with the inhalation pipe 5.

The liquid enters the pump through the bottom valve 6 and the suction pipe.

The liquid discharge outlet 8 on the pump body is connected with the discharge pipe 9.

Before the pump starts..

The pump body is filled with the liquid to be transported  after starting..

The gear is driven by the shaft to rotate at high speed..

The fluid between the blades must also rotate.

Under the action of centrifugal force..

Fluid is thrown from the center of the gear to the outer edge and gains energy..

Leave the outer edge of the gear at high speed and enter the cochlear pump body.

* In the volute case..

The fluid is slowed down by the gradual expansion of the flow channel..

It also transforms part of kinetic energy into static pressure energy..

Finally with a higher pressure into the discharge pipe......

Send it to the place where it is needed.

* When fluid flows from the center of the gear to the outer edge...

A certain vacuum is formed in the center of the gear...

Because the pressure above the tank level is greater than the pressure at the pump inlet...

The fluid is continuously pushed into the gears.

Visible..

As long as the gears keep turning...

The liquid is constantly sucked in and expelled.

2. Air binding phenomenon

When there is air in the pump...

Because the density of air is much lower than that of liquid, there is a smaller centrifugal force.

So..

The pressure difference between the tank surface and the suction inlet of the stainless steel oil pump is not sufficient to push the liquid in the tank into the pump..

That is, the gear oil pump has no self-priming capacity..

Make the gear pump unable to transfer liquid..

This phenomenon is called "the phenomenon of air tying".

In order to fill the pump with liquid...

Usually a bottom valve with a filter is installed at the bottom of the suction pipe..

The bottom valve to the reverse valve..

The role of the filter is to prevent solid material into the pump to damage the gear or prevent the normal operation of the pump

The main components of gear oil pump: the main components are gear, pump body and shaft seal device.

3. Gear of diesel oil pump:

The function of the gear is to transfer the mechanical energy of the prime mover directly to the liquid.

To increase the static pressure energy and kinetic energy of the liquid (mainly increase the static pressure energy).

Gears generally have 6 to 12 backward curved blades.

There are three kinds of gear: open type, semi-closed type and closed type..

As is shown in the figure.

The open gear has no cover plate on both sides of the blade..

Manufacture is simple, cleaning is convenient..

Suitable for conveying materials containing a large number of suspended solids..

Low efficiency..

The liquid pressure is not high

The semi-closed gear has no cover plate on one side of the suction inlet..

And on the other side there's a cover...

Suitable for conveying materials that are easy to precipitate or contain particles..

It's also less efficient

Closed gear has front and rear cover plates on both sides of the gear blade..

High efficiency..

Suitable for conveying clean liquid without impurities.

General gear pump gear for this kind.

Gear has single suction and double suction two suction methods

 

4. Explosion-proof pump body

The function of the pump body is to close the gear in a certain space..

So that the liquid can be sucked in and pressed out by the action of the gears.

Pump body made of volute shape more..

Therefore, it is also called volute case.

As the cross-sectional area of the flow passage gradually expands..

So the high speed liquid thrown around the gear gradually decreases the flow rate...

Part of the kinetic energy is effectively converted into static pressure energy.

The pump body not only collects the fluid thrown out by the gear...

It is also an energy conversion device.