After long time of service, the rotation speed of the hydraulic pump will become low. Here are several reasons for low rotation speed of the hydraulic pump:
1. After the original motor of the hydraulic pump breaks down, it is replaced with a new motor at random, as a result, the flow becomes less, the head becomes low and even water cannot be pumped.
2. The fastening nut of the impeller and the hydraulic pump shaft is loose or the pump shaft is curve, then much displacement happens to the impeller and the impeller impacts the pump body; or the bearing breaks down, all of which will result in a lower rotation speed of the hydraulic pump.
3. Worn driving belt: After long service of the hydraulic pump, the driving belt will be worn and loose, then skid occurs and the rotation speed of the hydraulic pump lowers.
4. Improper motor repair: The motor loose excitation for burning of the winding. Alteration of the number of turns of winding, winding diameters and wiring method during repair or crucial problems unaddressed during repair will make the rotation speed of the hydraulic pump lower.
5. Improper installation: The distance of two belt pulley bases is too short or the two shafts are not parallel. The tight side of the driving belt is installed above, as a result, the cornerite is too small. Calculation of the diameter of two driving belt pulleys is wrong. The eccentricity of two shafts of the hydraulic pump featuring coupling transmission is too large. All the situations mentioned above may result in a change of the rotation speed of hydraulic pumps.