Shield pump repair technology

Shanghai People's Shield Pump Regular Maintenance In order to avoid and reduce the sudden damage to the shield pump, the shield pump needs regular maintenance. In case of bearing monitor "alarm", must be immediately overhaul. Chemical plant is generally continuous operation, shielding pump regular maintenance only when the device is scheduled to stop. Most shield pumps can be serviced once a year. Shielding pump repair method is: Disassemble the shield pump: first clean up the parts, and then make an apparent inspection of them, whether there is any exception. Then measure the size of the key parts, electrical inspection of the motor windings. (1) mechanical inspection, u-; q 'u0} & v measurement of graphite bore diameter and sleeve shaft diameter, and look at their mating surface finish. Such as graphite bearings and bushings with clearance over the provisions of maintenance standards (0.55-11kw with the gap, the diameter difference of 0.4 mm, 15-45kw with the gap, the diameter difference of 0.5 mm) or with poor surface finish, the need to be replaced according to circumstances Bearings, bushings or thrust plates. Measure the size of the impeller upper and lower outer stop and their matching buckle and pump seat inner diameter of the size of the two with the gap is overhaul standards Of the range, the need to replace the parts or take other measures when overweight (such as: surfacing, set) to meet the requirements of the gap. Otherwise it will affect the pump performance, flow, lift, axial balance and so on. Observe the inspection set, the appearance of the rotor shield sleeve, with particular attention to whether there is any abnormal weld, if necessary, should be for testing, leak detection. 'S, D, x0 A3 M After long-term operation, the balance of the rotating parts may change. Therefore, it is necessary to rotate the rotor together with the impeller and other rotating parts assembled to do dynamic balancing test. (2) Electrical Check 8 A / S # A2 X2 z, o. I DC Resistance Check: The unbalance of three-phase resistor should not exceed 2%. 4 n! H3 r: b0 G6 c 'S) S Insulation resistance check: Shielding pump motor winding insulation resistance can generally reach more than 100MΩ. Such as less than 5MΩ need to analyze the reasons for insulation is damp, or shielding the leak if there is no problem, such as leakage through the stator shield no problem, then purely moisture insulation, the need for drying treatment, such as stator shield has a problem, You need to change the shielding sleeve. Rehabilitative overhaul of shielded pump * I0 D2 d6 B i9 G. h 'o / In case of shielded pump damaged by winding or shield, recovery overhaul is required. Damage is generally divided into two types: one is the stator shield is good, and the stator winding occurs on the ground, phase breakdown, winding inter-turn short circuit, overload caused by the winding burn. The other is due to damage to the stator shield to make the medium invade the stator winding stator winding damage. In either case, replace the stator coil and shield sleeve. Since the shield pump structure is special, the stator winding replacement becomes more complicated, the stator shield and the both ends of the shield must be removed to remove the stator winding. After the winding is repaired, The new shielding sleeve and sealing plate must be reworked, the material requirements are special, and the manufacturing precision is also required to be higher. (1) The stator winding is replaced and the stator winding is replaced The motors are similar except for the higher insulation, which is mostly H-grade Insulation. Class H insulation materials are required for QY polyimide enameled wire, slot insulation, slot wedge, insulation sleeve, lead wire and varnish. Winding principle is: as is, repair, especially the number of turns of the coil can not be arbitrarily changed, changes in the number of turns will significantly affect the main performance of the motor, the wire diameter as long as the original total area can be close to the winding form, the coil span do not change. (2) The replacement of the shield sleeve Shield shield is to repair the pump pump difficult and special, is to ensure the quality of repair shield pump key To achieve the original level, we must pay attention In the following aspects: (a) Selection of Shielding Sleeves In the losses of shielded pump motors, the stator shields wear out to a large extent and sometimes achieve iron loss Of the 2 to 3 times, after repair shield sleeve loss should be maintained at the original level. 3 C * \ 9] (f% f stator shield loss PB is proportional to the thickness of the shield sleeve, inversely proportional to the resistivity of the shield sleeve material ρ. Shielding sleeve material must be non-magnetic material with good mechanical properties and corrosion resistance , In order to reduce the eddy current loss to choose a large coefficient of resistance of the material thickness should not be too thin, to affect the mechanical strength, should not be too thick, too thick will increase the loss of shielding sleeve shield mask imported most of a shield with a containing Nickel content of more than 50% called Hastelloy-c special stainless steel material, the performance of this material can fully meet the above requirements, and its resistivity than the general stainless steel 1Cri8Nig9Ti double, that is, the shield sleeve loss is normal stainless steel The material of 1/2. (B) the production of shielding sleeve! O% E! O% Y 'M9 F shielding sleeve production process should be shielded pump recovery overhaul the crux of the difficulty and the key. Shielding sleeve dimensional accuracy and shape tolerance Higher requirements, welding quality requirements of the weld is also very strict.From the unwinding of the size of the calculation, cutting, straight seam welding, full circle, pressfit, girth welding, leak detection and so have a certain degree of technical difficulty The effective gap between the stator and stator of the shielded motor is generally only 0.5-1.0 mm, so the shielded sleeve must not only be pressed into the stator core and the rotor core smoothly, but also be shielded against the iron core. Only in this way can the stator and rotor be ensured Enough effective clearance. (C) Overall stator leak detection; After completion of the stator seal plate and the shell of the welding, press into the shielding sleeve and the shielding sleeve after both ends of the girth welding , The overall inspection of the stator leak check method is: the base and the stator shield between the cavity filled with 0.5㎏ / c ㎡ of pressure, and then the overall immersion in the water stator, if there is a leak, the water It will be a bubble, which is a simple and effective method of leak detection (3) Final assembly and inspection test After the completion of the stator and rotor repair, ready Qualified graphite bearings, bushings, thrust plates, seals, etc. can be carried out assembly.After assembly is completed by hand rotation of the rotor, the rotation should be uniform and flexible, the rotor should have a certain amount of axial movement, the amount of its movement should be overhaul standards Within the specified range: Shielded pump power k w 0.55 ~ 3.7 5.5 ~ 11 15 ~ 45 Axial movement mm 0.9 ~ 1.5 1.4 ~ 2.0 1.8 ~ 2.5 'k4 Q + e0 _' u 'n After the completion of the assembly, check the DC resistance and insulation resistance, etc., that the electrical properties of normal After the shield pump immersed in the water tank (the junction box to be on the water, water can not enter the junction box) to do electric test (at this time the pump outlet can be covered) to observe its current, running sound, vibration and other anomalies If the test conditions can do the performance test of the pump is better. (Shanghai People's Motor Co., Ltd. provides)