Universal three-screw pump with wide application
1.The screw units is rotating along with the external prime mover.
2.The spiral groove of the screw opens periodically,and the volume of suction cavity increases,resulting into a vacuum.
3.The medium is absorbed into the spiral groove and sealed in the spiral groove.
4.Along with the rotation of screw,the medium moves toward the outlet along the axial line of the screw.
5.The medium is pumped out.This is the operating principle of screw pump.
Oil pump is a kind of light and compact pump, which can be divided into three categories: in-line type, distribution type and single type. The oil pump needs power source to run, and its lower camshaft is driven by engine crankshaft gear.
The oil pump presents an oil pump with a shell made of aluminium-containing material and a movable die set in the shell, in which the movable die is at least partially made of a sinterable material containing at least one austenitic iron-based alloy, and in which the die made of a sinterable material has at least one heat for the shell. The coefficient of thermal expansion is 60%.
Performance Viscosity:3.0 ~ 1500 mm2/s
Flow:5 ~ 5300 L/min
Maximum Pressure:4.0 Mpa
Maximum Temperature:150 ℃
Causes of screw wear:
1. When the screw rotates in the barrel, the friction between the material and the barrel causes the working surface of the screw and the barrel to wear away gradually: the diameter of the screw decreases gradually, and the diameter of the inner hole of the barrel increases gradually. In this way, the matching diameter clearance between screw and barrel increases little by little with the gradual wear and tear of screw and barrel. However, as the resistance of the nose and diversion plate in front of the barrel remains unchanged, the leakage flow of the extruded material in advance is increased, that is, the flow of the material from the diameter gap to the feed direction is increased. As a result, the production of plastic machinery decreased. This phenomenon also increases the residence time of materials in the barrel, resulting in material decomposition. In the case of polyethylene, the decomposition of hydrogen chloride gas strengthens the corrosion of screw and barrel.
2. If there are fillers such as calcium carbonate and glass fibre in the material, the wear of screw and barrel can be accelerated.
3. Because the material is not plasticized uniformly or metal foreign matter is mixed into the material, the rotational torque of the screw increases suddenly, which exceeds the strength of the screw and causes the screw to break. This is an unconventional accident damage.