Large vertical mill classifier with vibration problem of processing and analysis

With processing and analysis of the vertical mill classifier vibration - 2019 05 - Hubei just 13 ( Tangshan Jidong Equipment Engineering Co. , Ltd. ) Chongyang county, hubei province chicken blood industrial co. , LTD. The JLM - of raw material grinding 40A. 4 vertical mill, roller mill classifier adopted fixed ventilation blade groups and the structure of the cage rotor combinations, choose powder motor adopts frequency conversion motor, frequency modulation of 0 ~ 50 hz. Vertical mill in October 2014 when debugging single classifier of the following symptoms: at 10 hz frequency conversion motor, the overall vibration is small; 20 hz, the classifier speed reducer vibration significantly increased; When 30 hz, reducer significant jitter; 40 hz, reducer up dramatically jitter, reducer and spindle part of the coupling in the rotation of the oval track. During the rotor does not appear obvious cut ceng, voice is not obviously different. Classifier can't continue to trial run, run at the scene of the recorded a video later, to stop the test. 1 problem analysis on the reasons of vibration may cause classifier after screening analysis, preliminary think the problem should be the main shaft bearing ( Thrust self-aligning roller bearing) Clearance is too large, or bearing end is not installed, dangling the elliptic rotating track. Remove the related components, measurement on the bearing seat on the surface to the bearing inner ring ( Activities) On the surface distance dimensions a ( See figure 1) Measurements are 34 mm, at four o 'clock, and show that the number of drawings should be 37 mm. Which can be concluded that the bearing inner ring may be in a suspended state, not installed in place. Figure 1 vertical mill classifier supporting structure 2 problem due to the main shaft parts have been installed, plan feeding time is near, to make the scene emergency processing equipment. Next bearing outer convex add 5 mm asbestos rubber mat, together with the bearing and the bearing spindle under 4 mm, enable the bearing inner ring is in place. Actual process: the lower bearing seat and main shaft bracket connecting bolts and gaskets loose 6 mm, the spindle part of the coupling side does not appear to be markedly reduced. With a small bearing and spindle under the hammer bracket joint surface, spindle part of coupling the slight decline; Flat shovel along the joint surface, and the main shaft parts coupling obvious decline. Measurements for a 37 mm. Make 5 mm heat-resistant asbestos rubber mat, up and down the smear layer of heat-resistant surface sealant, insert the bearing outer convex and main shaft bracket joint surface, and tighten the bolt. Review on the bearing surface distance from on the bearing inner ring on the surface is still the 37 mm. Test again, classifier in 0 ~ 50 hz, steady running, the overall vibration small, measuring vibration reducer shell were 0. About 5 mm/s, pass the stand-alone commissioning acceptance. After feeding, in the operation of the classifier is running normally. 3 the depth of the problem analysis and treatment on the depth of the problem analysis, believe on the bearing inner ring is in a state of suspension of the specific reasons are the following: (1) the main shaft parts design flaws, bearing inner ring on the active reserve size is too small, spindle, spindle support integrated manufacturing error is too large; (2) the installation process of upper bearing not installed in place, not in accordance with the drawings to check a place size; (3) transportation and installation process, the main part of the rotor side affected by large external force, main shaft and the bearing inner ring move up together, no place after installation. To put an end to such incidents from happening again, from the design, assembly and installation instruction, made the following corresponding processing: (1) the original design considerations in the workshop assembly, bearing inner ring on the shaft sleeve, the spindle assembly after wear into the spindle axis frame, axle sleeve by the spindle shaft shoulder positioning, bearing in lower part of inner ring small round face with collar end face positioning. But as a result of thrust self-aligning roller bearing inner ring axial size was designed to determine the bearing manufacturer, is not the size of the domestic and foreign manufacturers, lead to each the size of the collar needs to be checked. When more than one vertical mill assembly at the same time, according to user requirements when using different bearing manufacturer, shaft sleeve error-prone. When partial long sleeve size, in order to ensure the size of a, the size of the end face to the bearing face under the lower bearing b is less, such as size b completely exhausted, the bearing inner ring will be in a state of suspension. To avoid the above phenomenon, axial size is reduced, the sleeves on collar face don't contact with the bearing inner ring ( See the optimized I) 。 Due to the thrust self-aligning roller bearing inner ring on the end face and the outer ring ( Fixed end) The end there is explicitly specified in national standard size, so choose different manufacturer test bearing, thrust self-aligning roller bearing inner ring on the end face to the main shaft shoulder dimension c can be as a fixed reference, according to the size of c assembly workshop assembly. At the same time will increase to 10 mm size b, eliminate the influence of the accumulated error. Spindle parts before assembly to cover gasket, measuring a size 37 mm. Less than 37 mm on bearing assembly in place, need to check the reason, and reassembled. Such as more than 37 mm is small ( 0~3mm) , can advance notice personnel by adjusting the speed reducer assembly at the scene, the base gasket between the part and spindle and discharging shell gasket adjustment, ensure the rotor at the top of the clearance between housing and, guarantee the speed reducer and cross coupling piece of clearance between spindle part; For the larger than 37 mm ( More than 3 mm) , judged to be unqualified, should find the reason, reassembled. (2) the main part of the workshop assembly after passing mark size, a size d ( On the spindle end face to the spindle shaft frame transverse distance) 。 Before the assembly at the scene, can measure size d first, such as size d is equal to or slightly less than 502 mm, can continue to install; Such as size d is greater than 502 mm, remove the plug, measuring dimension a, the above treatment method. After vertical mill using manufacturer after overhaul of main shaft, also can check check through such steps. Source: 'cement' 06, 2015