Brief Introduction of Hydraulic Top Rotor System of Large Vertical Water Pump Unit

The question raised Shenzhen City Flood Control Facilities Luo Yu pumping station is equipped with 630kW vertical pump unit 6, supporting the motor YL630-20. Unit running in flood season, non-flood season outage. Before starting, the rotor of the unit must be jacked up to fill the surface of the long-term stationary motor thrust bearing bush to avoid burning when starting. Previous artificial top rotor, 6 units need 4 individuals took 1 hour, and a lot of manual labor; now using hydraulic top rotor system, only one person needs 10 minutes to complete, to meet the requirements of the flood control and drainage work faster. Device introduction and main technical parameters System consists of the top ring, jack, tubing system, hydraulic valve, fuel pump, control cabinet and other components. Control cabinet with pump start and stop, hydraulic valve position, over pressure protection, jacking stroke indication and other functions. The oil pump is composed of 20l oil tank and plunger pump , the maximum pressure is 32MPa (working pressure 16MPa, flow rate 1L / min, motor power 1.5kW, etc. The hydraulic valve adopts M type hydraulic valve, model HD-3C6-G02-LW, Grade 60MPa. The tubing system adopts DN10 × 2 seamless steel pipe, the pressure rating is 70MPa. The jack adopts 4 sets of 60 plungers with stroke of 50mm and pressure rating of 60MPa, single overhead load≥8t. Rotor lifting height of 5 ~ 8mm According to the motor structure , The device is set to 7 ± 0.5mm. The top ring is a dedicated design of parts. The lifting rate of the device is 15mm / min, holding time 5min, falling speed 20 ~ 30mm / min, , But also can be adjusted according to the needs of a single unit from the top.Key technical measures 1, the top ring due to the outer rotor flange surface of the counterweight, coupled with the actual situation of space layout, jack can not directly lift the rotor, and therefore set A top ring lifting jack ring from the jack, the top ring and then lift the rotor Top ring must ensure that the parallel lifting requirements to prevent the top of the top flange of the lower flange welding 4 Pad, set in the jack plunger, so that the top ring positioning. 2, to prevent the top of each unit set 4 jack, through the top ring, jack stroke control, and the use of isobaric oil, to ensure that the jack Hydraulic balance to avoid the difference between jacking force and ascending speed caused by the top 3. To prevent the rotor down too fast When the rotor is down, in order to prevent the speed too fast, causing damage and impact thrust bearing tile surface, the unit into the valve Using throttle type, easy to adjust the rotor down speed, control in 1 ~ 2min. 4, Jack jack limit by the full stroke design to prevent the rotor from rising too much. 5, To prevent the tubing into the gas, the fuel tank, fuel pump placed The highest point of the system  on the ground floor of the motor, thus effectively preventing the tubing system due to long-term deactivation of the intake problem. 6, the hydraulic valve forward fuel supply, jack jacking. Reverse fuel supply, jack reset In the middle position, the tubing system holding pressure, jack to maintain the position of these functions to meet the rotor jacking up, the need to maintain a certain time is generally 5min and Need to be forced to reset after jacking 7. Electrical control 1 jack stroke indication Each jack has a lift and reset travel switch and indicator lights in place, and a pilot light test button to check whether the light is normal. 2 system over-voltage protection with relief valve and pressure relay double protection. When the system pressure reaches the set value, overflow valve overflow. If the system pressure exceeds the set value of a certain range, the pressure relay action, hydraulic valve response To the middle position, the pump stops running, at the same time, over-pressure indicator light 3 System working pressure calculation Jack jack pressure: P0 = W / nxs Where: P0 jack jack lift kg / cm2 W rotor weight kg n - The number of jacks S - The jack area of ​​piston cm2 P0 = W / nxs = 15 × 1000 / [4 × (3.1415926 / 4)] = 132.6kg / cm2 Relief valve working pressure: PV = 1.2 ~ 1.3P0 PV Set should meet more than three jack normal work before jacking up the rotor requirements, to avoid two top-off. Overpressure protection relay working pressure: PK = 1.1PV 4 power supply. Working power 220V, travel switch with 24V, in order to ensure safety. Application prospect The device has been successfully applied to Luo Yu pumping station 6 630KW pump rotor top rotor project, received a convenient and reliable use of the results. The device focuses on solving the actual situation that the rotor structure of the motor is irregular, the space layout is complicated and the simple lifting structure can not be used. The device can be widely applied to the more complicated top rotor projects in the fields of water supply and drainage, electric power, chemical industry and so on, and provides references for the design and calculation of other types of top rotor devices.