What are the main differences in the basic concept information of ATOS gear pump
The most basic form of ATOS gear pump is two gears of the same size that fit tightly together in a housing
Mesh rotation, the interior of this housing resembles an '8' shape, with two gears installed inside. The outer diameter and sides of the gears are tightly matched with the housing. The material from the extruder enters the space between two gears at the suction port and fills it. It moves along the shell with the rotation of the teeth and is discharged when the two teeth mesh.
In terms of terminology, gear pumps are also known as positive displacement devices, which are like pistons in a cylinder. When one tooth enters the fluid space of another tooth, the liquid is mechanically squeezed out. Because liquids are incompressible, liquids and teeth cannot occupy the same space at the same time, thus eliminating liquids. Due to the continuous meshing of teeth, the phenomenon of ATOS gear pump occurs continuously, thus providing a continuous discharge volume at the pump outlet. The discharge volume is the same for each rotation of the pump. As the drive shaft rotates continuously, the pump also continuously discharges fluid. The flow rate of a pump is directly related to its rotational speed.
In fact, there is a very small amount of fluid loss inside the pump, which makes the operating efficiency of the pump unable to reach *, because these fluids are used to lubricate the bearings and gears on both sides, and the pump body cannot fit without clearance, so the fluid * cannot be discharged from the outlet, so a small amount of fluid loss is inevitable. However, the pump can still operate well and achieve an efficiency of 93% to 98% for most extruded materials.
For fluids with changes in viscosity or density during the process, this pump will not be greatly affected. If there is a damper, such as placing a filter or a limiter on the discharge side, the pump will push the fluid through them. If the damper changes during operation, that is, if the filter becomes dirty, clogged, or the back pressure of the limiter increases, the pump will still maintain a constant flow until it reaches the mechanical limit of the weakest component in the device (usually equipped with a torque limiter).
There is actually a limit to the speed of a pump, which mainly depends on the process fluid. If oil is being transported, the pump can rotate at a high speed. However, when the fluid is a high viscosity polymer melt, this limit is greatly reduced.
It is very important to push high viscosity fluid into the two tooth space on one side of the suction port. If this space is not fully filled, the pump cannot discharge accurate flow, so PV value (pressure x flow rate) is also another limiting factor and a process variable. Due to these limitations, gear pump manufacturers will offer a range of products in different specifications and displacements (the amount discharged per revolution). These pumps will be matched with specific application processes to enhance system capacity and achieve *.
The gears and shafts of the ATOS gear pump are integrated and use a whole body quenching process, which can achieve a longer working life. The 'D' type bearing combines a lubrication mechanism, allowing the polymer to pass through the bearing surface and return to the inlet side of the pump to ensure effective lubrication of the rotating shaft. This feature reduces the possibility of polymer retention and degradation. The processed pump body can match the 'D' type bearing with the gear shaft, ensuring that the gear shaft is not eccentric to prevent gear wear. The Parkool sealing structure and PTFE lip seal together form a water-cooled seal. This seal does not actually touch the surface of the shaft, and its sealing principle is to cool the polymer to a semi molten state to form a self seal. Rheoseal sealing can also be used, which has reverse spiral grooves machined on the inner surface of the shaft seal to allow the polymer to be back pressed back to the inlet. For ease of installation, the manufacturer has designed a circular bolt mounting surface to match the flange installation of other equipment, making the manufacturing of cylindrical flanges easier.
(1) Simple structure,;
(2) Low job requirements and wide application;
(3) The end caps and various inter tooth grooves of the gears form many fixed sealed working chambers, which can only be used as quantitative pumps.
The gear adopts a new technology with advanced technology in the 1990s - double arc sine curve tooth profile arc. Compared with involute gears, the most prominent point of it is that there is no relative sliding of the tooth profile during the gear meshing process, so there is no wear on the tooth surface, balanced operation, no trapped liquid phenomenon, low noise, long service life, and high efficiency. This pump breaks free from the constraints of traditional design, entering a new realm in the design and use of gear pumps.
The pump is equipped with a differential pressure safety valve as overload protection, and the full reflux pressure of the safety valve is 1.5 times the rated discharge pressure of the pump. It can also be adjusted according to actual needs within the allowable discharge pressure range. However, this safety valve cannot be used as a pressure reducing valve for long-term operation, and can be installed separately on the pipeline if necessary.
The pump shaft end seal is designed in two forms, one is mechanical seal and the other is packing seal, which can be determined according to specific usage and user requirements.
Classification of Folding Pumps
As for the core components of gears, they mainly consist of common normal line gear pumps and circular arc gear pumps. The common law gear pump is more durable in conveying media containing impurities than the circular arc gear pump, and the circular arc gear pump has a special structure, low noise, long service life, and various advantages in conveying clean media.
Folding and editing the characteristics of this paragraph's work
Points: Simple and compact structure, small size, light weight, processability, strong self suction force, insensitive to oil pollution, large speed range, able to withstand impact loads, easy maintenance, and work.
Disadvantages: Unbalanced radial force, large flow pulsation, high noise, low efficiency, poor interchangeability of parts, difficult to repair after wear, and cannot be used as a variable displacement pump.
Reason: During the operation of the involute gear pump, a portion of the hydraulic oil is often sealed between the teeth due to changes in the enclosed volume at the intersection of the gears over time, as shown in the figure, known as trapped oil phenomenon. The incompressibility of the hydraulic oil will cause large vibrations and noise in the external gears, affecting the normal operation of the system.
Measures: Open unloading slots on the front and rear cover plates or floating shaft sleeves. The principle of opening unloading slots is to minimize the distance between the two slots and close the dead volume, so that when the dead volume changes from large to small, it is connected to the oil pressure chamber, and when the dead volume changes from small to large, it is connected to the oil suction chamber.
The leakage of gear pumps is relatively large, and there are three leakage paths during the operation of external meshing gears: first, the gear backlash, second, the backlash measurement, and third, the meshing clearance.