Performance spectrum of CYZ-A self-priming oil pump

Structural diagram of CYZ-A self-priming oil pump

Working principle of CYZ-A self-priming oil pump

The CYZ-A self-priming oil pump adopts an axial return pump body structure. The pump body is composed of a suction chamber, a liquid storage chamber, a scroll chamber, a liquid return hole, a gas-liquid separation chamber, etc. After the pump starts normally, the impeller sucks the liquid stored in the suction chamber and the air in the suction pipeline together, and is mixed in the impeller. Under the effect of centrifugal force, the liquid carries the gas to the outer edge of the scroll chamber, forming a white foam belt with a certain thickness and a high-speed rotating liquid ring on the outer edge of the impeller. The gas-liquid mixture enters the gas-liquid separation chamber through a diffusion tube. At this point, due to the sudden decrease in flow rate, lighter gases are separated from the mixed gas-liquid mixture, and the gases continue to rise and be discharged through the pump outlet. The degassed liquid returns to the storage chamber and enters the impeller again through the reflux hole, where it mixes with the gas sucked in from the suction pipeline inside the impeller. Under the action of the high-speed rotating impeller, it flows towards the outer edge of the impeller. As this process repeats itself, the amount of air in each suction tube decreases continuously until all gas is sucked out, completing the self-priming process, and the pump is put into normal operation. Because the pump has this exhaust capability, it can transport liquids containing gases without the need for bottom valves, and has good cleaning function when used on oil tankers.
Some pumps also have cooling chambers at the bottom of their bearing bodies. When the bearing heats up and causes the temperature of the bearing to rise by more than 70 degrees, coolant can be injected into the cooling chamber through any coolant pipe joint for circulating cooling. The sealing mechanism inside the pump to prevent liquid leakage from the high-pressure area to the low-pressure area is the front and rear sealing rings. The front sealing ring is installed on the pump body, and the rear sealing ring is installed on the bearing body. When the sealing ring wears out to a certain extent after long-term operation of the pump and affects the efficiency and self-priming performance of the water pump, it should be replaced

Installation instructions for CYZ-A self-priming oil pump

1. When the oil pump is directly connected to the electric motor for transmission, attention should be paid to the coaxiality of the pump shaft and the output of the electric motor; The accuracy of pump installation has a significant impact on the smooth operation and service life of the pump, so it must be carefully installed and calibrated.
2. The pump coupling must be securely fastened with nuts and locked to prevent loosening, otherwise it may cause impeller movement and mechanical failure.
3. In order to maintain a certain amount of stored liquid in the pump body, achieve good self-priming capacity, and prevent dry friction of the mechanical seal, it is necessary to make the inlet of the pump higher than the centerline of the pump shaft.
4. Attention should be paid to the installation of suction pipes:
A. The installation height of the suction pipe should not exceed 5 meters as much as possible. When conditions permit, the installation height of the suction pipe should be as low as possible below the oil storage surface of the oil depot, and the length of the suction pipe should be shortened as much as possible, with fewer bends installed. This is beneficial for shortening the self-priming time and improving the cleaning function.
B. Valves, flanges, etc. in the suction pipeline should be strictly guarded against air leakage or liquid leakage, that is, there should be no air leakage in the suction pipeline.
C. To prevent the suction of solids and other debris into the pump body, a filter should be installed on the suction pipeline. The effective flow area of the filter should be 2-3 times the cross-sectional area of the suction pipe, and the filter should be checked regularly.
D. The suction and discharge pipelines should have their own supports, and the pump body itself is not allowed to bear the load of the pipelines.
5. When installing the oil pump, the static grounding resistance of the pump and pipeline should meet its specified requirements.
6. During installation, it is necessary to strictly inspect the pump casing and pipelines for any stones, iron sand, or other debris.
7. Correct the installation clearance and coaxiality of the pump coupling and motor coupling, with a permissible deviation of 0.1 millimeters for different axial degrees. The height difference between the pump shaft and the motor shaft can be adjusted by placing copper or iron pads on the feet.
8. After 3-4 hours of actual operation of the unit, a final inspection should be conducted. If there are no adverse phenomena, it is considered that the installation is done properly. During the trial operation, the temperature of the bearings should be checked, and the temperature of the bearing body should not exceed 70 degrees.
9. The bearing body of the pump is equipped with a cooling chamber device and a cooling water joint for fitting rubber or plastic pipes with inner holes of 1 or 2. The thread size is M1 2 × 175.
If a one-way valve is installed on the outlet pipeline of the pump and the pump cannot smoothly discharge gas during the self-priming process, an exhaust pipe and valve should be added at the outlet of the pump.

Disassembly and maintenance of CYZ-A self-priming oil pump

The characteristic of this pump is its simple and reliable structure, as well as its durability. Under normal circumstances, the pump generally does not require frequent disassembly and maintenance. Once a malfunction is detected, it can be resolved at any time.
When maintaining the pump, attention should be paid to several main parts.
A. Rolling bearings: When the oil pump runs for a long time and the bearings wear out to a certain extent, they need to be replaced.
B. Front sealing ring and rear sealing ring: When the sealing ring is worn to a certain extent, it needs to be replaced.
C. Mechanical seal: Mechanical seals should generally not be disassembled for inspection without oil leakage. If there is a serious leakage at the leakage port at the lower end of the bearing body, the mechanical seal should be disassembled and inspected. When installing and dismantling mechanical seals, they must be handled with care, paying attention to the cleanliness of the mating surfaces, protecting the mirror surfaces of the stationary and moving rings, and strictly prohibiting knocking and collision. The main reason for leakage caused by mechanical sealing is due to the rubbing of the mirror surface. The repair method can be to grind the friction surface to restore the mirror finish. Another reason for leakage in mechanical seals is improper installation or deformation and aging of the "o" - shaped rubber seal ring (or buffer pad). At this point, it is necessary to adjust or replace the "O" ring seal for reassembly.
2. Disassembly and assembly sequence of oil pump:
A. Remove the motor or disconnect the coupling.
B. Remove the bearing assembly, check the radial clearance between the impeller and the front ring, and check if the impeller nut is loose.
C. Remove the impeller nut, pull out the impeller, and check the radial clearance between the impeller and the rear sealing ring.
D. Loosen the set screw of the mechanical seal, pull out the dynamic ring part of the mechanical seal, check the fit of the dynamic and static ring end faces, and inspect the "o" - shaped sealing ring (or slow seal)
The sealing condition of the gasket.
E. Unscrew the fastening nut of the coupling and pull out the coupling.
F. Remove the bearing end cover and disassemble the pump shaft and bearing.
G. Assemble in reverse order during installation.

Reasons and troubleshooting methods for CYZ-A self-priming oil pump faults