Reduced or no mechanical seal coolant flow

a. Reduced coolant flow

Question 1:The impurities in the coolant are adsorbed on the oil inlet filter by the electric oil pump, which makes it difficult to enter the oil and reduces the oil output.

Treatment:Open the cover above the engine base, lift the oil inlet pipe of the electric oil pump out of the oil tank, and remove the impurities on the filter net.

Question 2:When the mechanical seal spring compression or spring pressure is too large, the coolant temperature increases, and the electronic components in the electric oil pump have poor thermal stability. At this time, the working frequency of the electric oil pump decreases and the coolant flow decreases.

Treatment:Reduce the number of springs.

Note:The number of reduction springs must be a multiple of 2, 2 or 4 or 6 and the number of reduction springs must be symmetrical.

B. No coolant is sprayed out from the oil cover above the machine base

① The electric oil pump does not work (the oil pump does not shake).

Question 1:The plunger in the electric oil pump is stuck by impurities in the oil and cannot move (the electric oil pump can be felt by touching the electric oil pump at the moment when the pump is turned on, and then there is no movement or very slight jitter).

Treatment:Remove the end of the electric oil pump discharge cover, observe whether the plunger is stuck and clean it.

Question 2:The electronic components in the electric oil pump are damaged (the red power indicator of the electric oil pump is on at this time).

Treatment:Replace the pump with a new one or repair the electronic circuit in the pump.

Question 3:24V DC air switch protection in the electrical box (at this time, the solenoid valve does not operate without noise).

Treatment:Check solenoid valve and electric oil pump for short circuit.

Question 4:The 24V DC regulated switching power supply has no output, and the green indicator light on the regulated switching power supply is not on.

Treatment:Check whether the 220V AC air switch is protected and whether the overcurrent protection of the main motor thermal relay is activated. If it is started (at this time, the two normally-on terminals under the red button of the thermal relay have been connected to the line, one of which has no 220V, and both terminals are charged normally), it can be pressed, or it can be automatically restored after half an hour.

② The electric oil pump can move (the electric oil pump shakes) without circulating coolant.

Question 1:The electric oil pump can move (the electric oil pump shakes) and cannot circulate the coolant.

Treatment:The filter screen of the oil inlet is completely blocked or the one-way valve in the electric oil pump does not operate. Clean the filter screen or the one-way valve in the oil pump.

Coolant flows out from below the housing barrel

If there is oil flowing out from the bottom of the cylinder, don't worry about the oil running into the material.The reason is that when the sand mill is working, the pressure of the material in the cylinder is higher than the pressure of the coolant in the oil cover, so there is only the possibility of the material entering the coolant in the oil cover. When the sand mill is not in use, the oil cannot enter the cylinder due to the tension of the oil. At this time, the sealing surface of the dynamic and static ring of the mechanical seal is relied on to block the material from entering the oil.

Question 1:Oil leakage at the coolant connector connection on the oil cover. Eyes can be observed directly or with a napkin on the root of the joint to observe whether there is oil on the paper towel.

Treatment:Remove the connector and wind a small amount of fine twine or cotton yarn on the root of the joint thread, and then wind a small amount of PTFE tape on it.

Question 2:Leakage of skeleton oil seal.

After confirming that there is no oil leakage at the connection part of the coolant connector on the oil cover, wipe off the residual oil under the oil cover, put a piece of white paper about 25cm long and 4cm wide under the oil cover, and observe whether the white paper leaks oil 20~30 minutes after starting the main engine. If there are traces of oil, you should carefully observe whether it is oil or butter. According to the location of the oil traces on the white paper to determine whether the residual oil or skeleton oil seal leakage.

Treatment:The skeleton oil seal and the mechanical seal moving ring are dynamic seals, allowing a small amount of oil leakage. It is normal to leak a drop in 30 to 40 minutes. If there is too much leakage, the skeleton oil seal needs to be replaced. At this time, attention should be paid to observe the matching position of the mechanical seal moving ring and the skeleton oil seal, and whether there are deep wear marks on the outer ring of the moving ring. If so, the moving ring and the skeleton oil seal should be replaced together.

Question 3:When the coolant in the oil cover above the base returns to the oil tank, it splashes on the base cover. Due to the tension of the oil, the oil flows in all directions and flows down the discharge pipe.

Treatment:Add a plastic film under the oil cover to prevent oil from splashing around.