It is not necessary to install gaskets. Many aircraft, cars, ships, wind turbines, and atomic energy equipment do not have gaskets installed on their connections. It can be seen that the bolts on the wheel hubs of heavy-duty cars and small cars do not have gaskets. piece. The scientific name of gaskets is washers, which include flat washers, special-shaped washers, spring washers, stop washers, and lock washers. Whether to install a gasket or not, and what kind of gasket to install, depends on the specific design requirements and must be chosen based on the basis. Generally speaking, the position of the bolt hole is very high, the diameter of the bolt hole is relatively small, and the fit is close to that of a reamed hole. It is redundant to install a flat washer, which does not increase the friction of the nut. For those bolted connections with very rough holes, such as holes with M12 bolts with a diameter of 16mm or 18mm, flat washers should be installed. These connections are often overlapping steel frames, hand-drilled in poorly positioned equipment. The holes on the automobile gearbox housing are usually produced on the assembly line. The position of the holes is relatively high, and the matching gap between the holes and the bolts is relatively small. Do not install washers, otherwise the contact area of the nuts will become smaller and the bolts will easily loosen.
What phenomena can go back and forth in life
1. As for the vibration caused by the dynamic and static imbalance of the rotor, in addition to the quality of manufacturing, installation and maintenance, It is also related to factors such as asymmetric corrosion and wear during operation, uneven dust accumulation on the blades, bending of the rotating shaft, movement or falling off of the original balance block of the rotor, and unbalanced air volume on both sides of the bilateral air inlet fan.
2. The fan and motor couplings are not centered accurately or the coupling pins are loose, causing the motor and fan shafts to be not on the same center line.
3. The fasteners of the rotor are loose or the clearance between the movable parts is too large, the clearance between the shaft and the bearing bush is too large, the fixing nut of the rolling bearing is loose, etc.
4. The foundation is not strong or the machine base is not rigid enough, such as poor foundation pouring quality, loose anchor bolts or pads, weak connection of the machine base or loose connecting nuts, and poor structural rigidity of the machine base, etc. . ?
Extended information:
The fan is a machine that relies on input mechanical energy to increase the gas pressure and discharge the gas. It is a driven fluid machine. Fan is the customary abbreviation for gas compression and gas transportation machinery in China. Fans commonly include ventilators, blowers, and wind turbines.
Fans are widely used in ventilation, dust removal and cooling of factories, mines, tunnels, cooling towers, vehicles, ships and buildings, ventilation and draft induction of boilers and industrial furnaces; air conditioning equipment and household Cooling and ventilation in electrical equipment; drying and sorting of grains, wind tunnel wind sources and inflation and propulsion of hovercrafts, etc.
References:
A 100-meter-high wind turbine collapsed and broke into several sections in Gaoyou, Yangzhou, causing heated discussion! What is the reason?
Linear motion on the highway, sliding windows or drawers, shooting bullets from the gun chamber quickly towards objects, and trains moving along the track. These are actually They are all typical translational movements.
The phenomenon of rotation, such as using a wrench to tighten a screw, a windmill rotating to draw water, the blades on a wind turbine rotating, the hands of a clock constantly rotating, these They are all typical rotation phenomena.
Translation means that all parts of an object move to another place in a certain direction, and the distance moved is the same. This is translation. Rotation is the continuous circular motion of an object around a certain point or axis.
Basic properties of translation
(1) The shape and size of the graphics before and after translation do not change, only the position changes.
(2) After the graph is translated, the line segments connecting the corresponding points are parallel (or on the same straight line) and equal.
(3) Multiple consecutive translations are equivalent to one translation.
(4) The figure after even-numbered symmetry is equal to the figure after translation.
(5) Translation is determined by direction and distance.
(6) After translation, the corresponding line segments are parallel (or collinear) and equal, the corresponding angles are equal, and the line segments connected to the corresponding points are parallel (or collinear) and equal.
Basic properties of rotation
(1) The distance from the corresponding point to the center of rotation is equal.
(2) The angle between the corresponding point and the line segment connected to the rotation center is equal to the rotation angle.
(3) The graphics before and after rotation are congruent, that is, the size and shape of the graphics before and after rotation have not changed.
(4) The center of rotation is the only point that does not move.
(5) The angle intersected by the straight line connecting a set of corresponding points is equal to the rotation angle.
There should be some problems during the installation of this wind turbine, resulting in some defects in the connection between the first stage and the second stage. It may be because of a certain The screws are not tightened, and then under the influence of other natural environments, this shortcoming is infinitely magnified. But as the saying goes, a slight difference can make a difference a thousand miles. It is this little problem that has led to such disastrous consequences. things happenIt is undoubtedly a very large economic loss. We have to be warned that we must check repeatedly and carefully during the next construction and installation. Don't let a similar situation happen again. The price paid for this kind of attempt is still very huge, and there is no room for any mistakes.
In other words, one day in Gaoyou City, Yangzhou, the temperature may have been affected, causing strong winds to blow in the city. There is nothing strange about the strong wind, but what happened next is surprising. The wind, which cannot even blow down a person, blew down a huge wind turbine hundreds of meters high.
When the wind blows, this wind turbine seems a little unstable, swaying left and right in the wind, and looks precarious. As expected, it didn't take long for this behemoth to collapse. . If such a big thing falls from a high altitude, it will naturally cause a very loud noise. Naturally, it also attracted people's attention. With the collapse of the wind turbine, the Jiujiang Highway was broken in half, causing great obstruction to local traffic. At the same time, it also knocked down several wires. After all, the wind turbine itself generates electricity, and there must be surrounding areas. There are wires connected to it to facilitate the transportation of electricity. Fortunately, there were no casualties, just some material losses.
But it is still a pity. After all, this wind turbine has not been installed for a long time, only more than half a year. You must know that when wind turbines were designed, their purpose was to bring more convenience to people’s lives and they could work for many years without being damaged.Wind turbines are expensive to build, but they bring The income is very large, but now it is good, the income has not started yet, and the money has not even been paid back. However, the accident occurred because of the temporary negligence of the construction team.