- 汽机资料下载 - 热电技术联盟 电厂锅炉、汽轮机、电气、水处理（）

- 汽机资料下载 - 热电技术联盟 电厂锅炉、汽轮机、电气、水处理（） - 汽机资料下载 - 热电技术联盟 电厂锅炉、汽轮机、电气、水处理 () The temperature is 90 degrees --100 degrees of engine oil and pour hot oil, the old melt, with hook or a small spoon in the old oil bearing digging net, and then the remnants of the old kerosene oil oil, bearing internal rinse, finally rinse again can use gasoline. The cleaning quality of bearing is checked by hand feeling. After cleaning the bearings, observe carefully that there will always be some residual oil in the raceway of the inner and outer raceway, the rolling body and the gap of the cage. When the first test, the remaining oil scraped with a clean feeler, apply the thumb, index finger back and forth slowly rubbing fingers if there is research, the rustling sound, it indicates that the bearing is not clean, should wash again. The bearing in hand, pinch the inner ring, the outer ring (toggle horizontal rotating large bearings can be placed in the assembly stage, the inner pad, the outer ring is suspended, pressing within the circle, rotating outer ring), with flexible rotation, no block, no beating for qualified. For clean bearings, after filling with lubricant, it should be placed on the assembly table. The bottom is covered with net cloth or paper pad, and the top is covered with plastic cloth for assembly. It is not allowed to be placed on the ground or on the box. When moving bearings, it is not allowed to use the hand directly, Dafanb gloves or net cloth will be used to wrap up the bearing, otherwise, because of sweat and moisture on the hand, it is easy to cause the bearing to produce fingerprint rust after contact. Installation method The use of copper hammer and manual installation This is a simple way to install small and medium-sized bearings. When the bearing inner ring is tightly matched, the outer ring is a loose fit, the copper rod close to the end surface of the inner ring, copper with direct percussion and hammer, the copper dowel, will slowly fitted to the shaft bearing. The inner ring of the bearing is large, available copper along the bearing inner ring face evenly around the hard hit, not only on the side, also not overexert, symmetrical beat, tapping slowly loaded, to avoid loading the inclined crack of bearing. When the bearing outer ring is tightly matched with the inner ring is a loose fit, and the method can be used instead, use the hammer to knock the bar close to the end surface of the bearing outer ring, the bearing is pressed into the bearing seat, finally fitted to the shaft, it is not easy to damage parts. Sleeve installation The method and installation of bearing the same reason by copper. It is the direct pressure on the surface of sleeve bearing (bearing mounted on the shaft when pressing the end face of the inner ring; installed in the shell hole pressure gauge 6, the outer end face) with hammer percussion force can be evenly distributed in the whole installation of the bearing ring face, and can be used in conjunction with the press, installation of labor-saving and time-saving, reliable quality. The sleeves used for the installation shall be made of soft metal (either copper or low carbon steel tubes). If the bearing is mounted on the shaft, the inner diameter of the sleeve should be slightly larger than the shaft neck 1 4mm, diameter is slightly smaller than the diameter of bearing inner ring rib, or sleeve thickness, the thickness should be equal to the thickness of the bearing inner ring made of 2/3 - 4/5, and the two ends of the sleeve should be flat and vertical tube body. If the bearings are installed inside the hole, the outer diameter of the sleeve should be slightly smaller than the outer diameter of the bearing. The installation of the bearing sleeve when using, if the product is small, can be placed in the installation. The jaw pad is made of copper or aluminum to prevent the shaft from being clamped. If the product is large in size, should be installed on the gallows. The first bearing is mounted on the shaft, then install the sleeve, use the hammer to tap evenly arranged sleeve slowly. When the sleeve cover is flat, hammer should tap evenly along the circumference in turn set. Heating installation To install a large amount of surplus bearing or large size bearings, in order to facilitate the installation, the expansion and contraction principle, the bearing heating with copper, and hammer sleeve installation. Heating temperature is generally below 100, and 80 - 90 is appropriate. When the temperature is too high, the bearing ring raceway and rolling body are easy to be annealed, which affects the hardness and wear resistance, and leads to the decrease of bearing life and premature scrap. When the bearing is heated by heating method, the oil temperature should reach 10 minutes after the oil temperature reaches the specified temperature. The bearing should be removed from the oil quickly and installed on the shaft when it is hot. If necessary, a little bit of pressure on the inner ring end of the bearing can be installed with the installation tool, so that it is easier to install. Bearing installed on the shaft, must immediately press the inner ring until cooling. At present, some foreign bearing companies have developed a variety of devices for heating bearings in the installation of bearings, such as induction heaters. Test run and test temperature The temperature rise rate can not exceed 5 degrees per hour, and the final stable temperature should not exceed 70 degrees centigrade. The axial clearance in the bearing can be realized by means of the axial position of the moving outer ring. Four. Adjustment method of bearing working clearance 1, The adjusting shim method: between the bearing end cover and housing filled with a group of soft materials (steel plates or elastic gasket paper); adjustment, first spacer installed on the bearing cover, a bearing end cover evenly tightened the screws on the side of the hand, the rotating shaft, until the bearing rolling body and the outer ring contact shaft no gap so far; when measuring the bearing end cover and bearing clearance between the end face of the axial clearance plus bearing required in normal working hours; the total thickness of which is required to fill the spacer, then put between the gasket ready to fill in the bearing end cover and housing. Finally, tighten the screws. Two Method: adjusting bolt circle pressure pressure on the bearing outer ring, by adjusting bolts pressure; pressure before adjusting, the first step is to measure the pitch adjustment bolt, and then slowly tighten the adjustment bolt, bearing no gap until now, and then calculate the corresponding rotation angle adjusting bolt. For example, pitch 1.5mm, the normal operation of the bearing clearance required, then the required rotation angle adjustment bolt is 3600 x 0.15 / l.5=360; when the adjustment bolt 360 inversion, axial clearance of the bearing on access to 0.5mm, and then use the stopper gasket can be fixed. Three The magnitude of preload has a great influence on the service life of bearings. According to the relevant information, when the bearing assembly is 0. When the interference amount is 012mm, the service life is reduced by 38%, with 0. When the 016mm interference amount is used, the service life is reduced by 50%; when the bearing assembly is 0. The service life of 004mm gap decreased significantly, with 0. When 008mm gap, service life decreased by 70%. Therefore, it is very important to choose the size of preload. Small preload should be used for high speed, and large preload should be used for low rotation speed. At the same time, the preload should be slightly greater than or equal to the axial load. Four According to the experience of use, the most suitable working clearance of ball bearing is close to zero; roller bearing should have a small amount of work clearance. In the parts requiring good supporting rigidity, the bearing allows a certain preload. It is specially pointed out that the so-called "work clearance" refers to the clearance of the bearing under the actual operating conditions. There is a clearance called the original clearance, refers to the clearance before the bearing is not installed. The original clearance is greater than the installation clearance. Our choice of clearance is mainly to choose the proper work clearance. 5 clearance selection Clearance is an important factor in the normal operation of rolling bearings, which can be divided into axial clearance and radial clearance. Select the appropriate clearance, can make the load bearing between the reasonable distribution; it can limit shaft (or shell) of the axial and radial displacement, ensure the precision of rotation shaft; bearings can make normal work at a prescribed temperature; reduce vibration and noise, improve the bearing life. Therefore. When selecting bearings, proper bearing clearance must be selected. When choosing bearing clearance, the following aspects should be considered: 1, the working conditions of bearings, such as load, temperature, speed and so on; 2. Requirements for bearing performance (rotation accuracy, friction torque, vibration, noise); 3, bearing and shaft and shell hole for interference fit, resulting in reducing bearing clearance; 4. When bearing is working, the temperature difference between inner and outer rings leads to the decrease of bearing clearance; 5, because of the expansion coefficient of shaft and shell material is different, resulting in the bearing clearance decreased or increased. Five, the power plant cooling pump Cisse in some problems before running in: 1.. Pump bottom of the oil drain plug using "O" ring sealed use, improper installation, oil leakage. 2.. Bearing clearance is too large or too small. Bearing temperature should be considered to reserve clearance. When the 3.. Is larger than the center, the influence of the tension of the inlet and outlet flanges on the center should be taken into account. If the inlet and outlet flange between the gap is too large, should eliminate the gap to flange, flange force may cause the pump shell deformation, resulting in the impeller and the sealing ring. Six. Some problems summed up in the overhaul of Ezhou: Mechanical seal leakage "O" ring seal is not tight The sealing surface shall be carefully checked for scratches, cracks and damages Spring force of mechanical seal There is no damage to the sealing ring "O" ring in the shaft sleeve leaking water sleeve. The cushion between the shaft sleeve and the impeller should be free from damage The cushion between the cap and the shaft sleeve should be intact and undamaged Clearance table of impeller and sealing ring Sealing ring inner diameter total clearance seal clearance limit value Min Max 80-120 0.30 0.45 0.60 120-180 0.35 0.55 0.80 180-260 0.45 0.70 1 260-320 0.50 0.75 1.10 320-360 0.60 0.80 1.20 360-470 0.65 0.95 1.30 470-500 0.70 1 1.50 500-630 0.80 1.10 1.70 630-710 0.90 1.20 1.90 710-800 1 1.30 2.10 800-900 1 1.35 2.50 2006-7-12 20:25#1 One