Other regularity vibration
Reason one, the torsional vibration of the pump (especially the long axis of the diesel engine or pump). A, check method, the conditions and characteristics: 1, the determination of shafting torsional vibration frequency, when the torsional vibration frequency and prime mover torque change frequency, speed or speed x R (R is 2 and 4 integers) consistent; 2, the gear coupling under a certain speed, abnormal sound, sound disappears accelerated speed slightly; B, measures: 1, change the thickness or length of axis; 2, insert torsional vibration in shaft system of the buffer.
Reason two, thrust bearing thrust. A, check method, the conditions and characteristics: 1, horizontal double-suction centrifugal pump are visible; 2, usually noisy, but noise is stronger than vibration; 3, no additive load bearing structure become structure; 4, when low speed hitched hitched a voice of rules; 5, big thrust bearing clearance. B, measures: 1, improve the thrust bearing, so it can bear pre loading; 2, improve the pump structure, make its must produce axial thrust; 3, the elimination of thrust bearing clearance.
Three reasons, the vibration generated by the karman vortex is consistent with the natural frequency of the pipeline when the resonance. A, inspection method, the conditions and characteristics: 1, the pump suction tube surrounded by water flow; 2, the pump suction pipe is longer; 3, the shape of the suction tank, the position of the suction pipe is not appropriate; 4, caused by karman vortex frequency (Hz) approximate scope is as follows: f = K * V/D type coefficient K = 0.15 to 0.2; D = positive flow width; V = velocity.
Reason four, impulse noise caused by vibration. A, inspection method, the conditions and characteristics: 1, produce like surge pat has A rule type noise; 2, the discharge side of the pressure gauge pointer movements; 3, the peak of the performance of the pump are protuberant feature, if there is air in the discharge side send water retention, this kind of situation will often appear with the pump performance curve comparison (necessary). B, measures: use does not produce the pulse of the pump.
Five, the oil film rotary self-excited vibration. A, check method, the conditions and characteristics: 1, under normal circumstances, the speed for more than 3000 r/min; 2, the frequency is equal to or close to 1/2 speed; 3, the vibration of the bearing is more competitive than other parts. B, measures: adopt measures of changing bearing structure. |