Swimming clearance problems lead to crusher bearing heat processing

Swimming clearance problems lead to crusher bearing heat processing 2020 - 04 - 25 jin-long sun jian-zhong zhou Liu Xiaoye ( Dichroa southern cement co. , LTD. , zhejiang's 324209) Some cement company 5000 t/d production line, the limestone crusher bearing long-term fever problems, through the site to view and analysis, find out the reason of the bearing heating, and take measures to solve the problem, summarized as follows. The basic situation, the production line in April 2009 to start producing, supporting PCF2022 limestone single-section hammer crusher, the largest partical 1000 mm & times; 1000毫米× 1500 mm, discharging granularity & le; 70mm（ 90%) , the output capacity of 800 t/h. Production process, the two sets of crusher rotor bearing temperature all the year round in about 85 ℃, especially to the summer, the bearing should be carried out with compressed air cooling, even need to be done on the pulley end bearing with cooling water cooling, to maintain the normal production. The free end ( The drive end) Bearing damage, with fever each year to replace two sets. Second, the analysis of bearing heating ( 1) Lubricating oil selection problem: rotor bearing using mobil EP2 grease lubrication, grease stable operation of each index can meet the bearing, grease choose no problem, can be ruled out. （ 2) Oil pollution problem: open the bearing end cover inspection, oil clean and no impurities such as dust, eliminate this problem cause bearing heating. （ 3) Bearing grease in excessive add: in general, excess grease will cause bearing heat dissipation is not good, cause bearing heating. In each crusher rotor bearing end cover bottom sets of drainage holes, grease add too much, a short period of time will cause temperature rise, after running for a period of time the old oil discharge, bearing temperature back to normal. The crusher bearing temperature about 85 ℃ high temperature all the year round operation, should not be the cause. （ 4) Bearing assembly: open the free end bearing outer end cover inspection, measurement of bearing outer ring bearing lateral distance is 26. 3 mm, measuring the length of the bearing end cover 30 mm. The two data are compared, the problem of bearing heating has been identified, is a free end bearing end cover outside pressure is too tight, the end cover check closemouthed pressure on the bearing outer ring, rotor shaft without thermal capacity, bearing heating. （ 5) On both ends of the rotor shaft of thermal calculation: the bearing center distance 3400 mm, working temperature 100 ℃, the linear expansion coefficient of plain carbon steel 1. 2× 10 - 5/℃； The expansion volume 4. 08mm（ 3400毫米× 100℃报; 1. 2× 10 - 5/℃） 。 The limestone crusher in normal work, the rotor shaft thermal quantity is 4. 08mm。 Rotor at run time, the bearing temperature rise gradually, the rotor axis will be extended, the free end bearing can produce axial displacement with temperature changes. Considering the assembly dimension error, in the process of the installation of the rotor, the free end bearing outer seam allowance to the bearing outer ring spacing should be set aside more than 10 mm, to guarantee the rotor shaft in the normal production in the process of thermal expansion, or bearing will produce because of axial force, and high temperature, long running, bearing damage. So moving clearance problem is the primary cause of bearing run high temperature for a long time. Three measures to resolve, through the above analysis, the free end bearing no axial thermal volume is a major cause of lead to bearing heating, can be adjusted through the bearing outer ring and bearing end cover mouth clearance solution. Solution has two, one is to put the car bearing end cover check mouth off 10 mm; The second is to add gasket to offshoring bearing end cover. According to site condition, adopt the second method, local materials, with the old rubber gasket made a 10 mm, outside in a free end bearing end cover and bearing seat, ensure that the expansion of the rotor in the work have enough quantity. Equipment abnormal situation happened mostly in accordance with the technical specifications not installed correctly. As long as you find out why, targeted technical measures are taken, the problem will be solved. Source: 'cement' in 2018, no. 4