Water sprinkler truck pumps typically use centrifugal pumps. The common issues that arise during operation can be categorized into two types:
- Normal wear and tear from prolonged use, such as damage to the bakelite gasket and gasket seat, aging or deformation of the rubber water seal, and wear of the seal seat cavity.
- Lack of maintenance and improper use, which can lead to more severe problems such as pump casing cracks, pump shaft wear and bending, impeller damage, and loose fit between the pulley hub and pump shaft, or between the key and keyway.
These problems can lead to poor water suction, insufficient pressure, air leaks, and even cause the engine to overheat, potentially damaging it.
Solutions Based on Different Failures:
- Cracks in the pump housing: Cracks in the pump casing can usually be repaired by welding (electric or oxygen welding) or bonding with epoxy resin. If the bearing seat hole is excessively worn, it may need to be sleeved for repair. If the end face of the pump casing’s intake chamber has pits, grooves, or is uneven, it can be re-machined on a lathe to restore smoothness.
- Pump shaft damage and corrosion: The damaged or corroded parts can be filled with solder, and then machined back to a smooth, round shape. If the pump shaft is excessively worn, it can be repaired by electroplating to ensure the bearings operate smoothly and without noise.
- Aging or damaged water seals: The rubber water seals are prone to aging or deformation after long-term use. These seals should be replaced promptly to avoid leakage and other issues.
Water Pump Reassembly and Testing:
- Assembling the pump shaft and impeller: The end face of the impeller hole should protrude by 0.10-0.50 mm beyond the pump shaft end face (for pumps where the impeller is secured by bolts). This ensures a tight fit. Afterward, install the sealing gasket, tighten the fixing bolts, install the water seal assembly, and lock it in place with a round pin.
- Inserting the impeller into the pump casing: Slide the rear bearing locking ring onto one end of the shaft, followed by the rear bearing, spacer, and front bearing (if the bearings are one-piece, install the one-piece bearing into the pump casing). Check the fit, then install the locking ring.
- Installing the pulley hub: Secure the pulley hub to the front of the pump shaft with bolts, then install the V-belt and fan blade, tightening with a nut, and lock with a cotter pin or lock plate.
- Attaching the pump cover and gasket: Ensure that the gap between the impeller and cover plate (or the cylinder block front wall if no cover plate is present) is between 0.17-0.75 mm.
- Checking pulley wobble: After installing the V-belt pulley, measure the wobble within the groove, which should not exceed 1.0 mm. A practical method is to turn the impeller by hand, feeling for any play, to ensure a proper fit.
- Testing the pump before installation: Turn the V-belt pulley by hand to check for any obstruction. Block the water inlet of the pump casing, add water to the impeller chamber, and turn the pump shaft. If no water leaks through the inspection hole and there is no obstruction, the pump is ready for use. If issues like leaks or obstructions arise, troubleshoot and fix them before use.
If possible, perform a bench test to check the pump’s water output and any potential leakage. If no test bench is available, compare the performance with a new pump. After the test, apply grease to the pump for proper lubrication.
Conclusion:
Regular maintenance of the sprinkler truck is essential. It’s important to avoid allowing sand or other impurities into the water pump. Using a simple filtration system when drawing water can help reduce damage caused by sand and other contaminants. Proper maintenance and water quality control will significantly extend the pump’s life and ensure the vehicle operates efficiently.
