>> P.54
Oil lubrication1 Oil bath lubricationThis is the most commonly used oil oil ows along the grooves in the case and accumu-lates in the oil pockets, keeping the oil level constant. So the oil is steadily supplied to the bearing.lubrication method, and is used for medium and low speeds. If the amount of oil is too large, heat will be generated by churning, and if the amount is too small, seizure will occur. Therefore, the correct amount of oil must be maintained. When the machine is stationary, the correct oil level in the case of a bearing mounted on a horizontal shaft, is near the center of the lowest rolling element. In the case of a vertical shaft, about 50% of the surfaces of the rolling elements should be sub-merged in oil.It is desirable to provide an oil gauge so that the oil level can be easily checked while the machine is sta-tionary or running.2 Oil drip lubricationOil drips, which are fed down from a sight-feed oiler or along a ber string, become an oil spray due to wind pressure generated by the rotating cage, shaft, nut, etc., or they strike the rotating parts and form an oil spray, which fills up the housing and every required part. Because oil spray removes frictional heat, this method has a more effective cooling effect than the oil bath method, and is widely used for high-speed rota-tion and medium load conditions.In the case of the sight-feed oiler (See Fig. 21), the number of drips can be adjusted. However, this is dif-ficult using the string-feed method. The number of drips depends on the bearing type, rotational speed, etc., but 5 〜 6 drips per minute is generally used.Fig. 22 Oil splash lubrication4 Oil circulating lubricationWhen automatic lubrication is more economical because lubrication is required at many points, or when cooling is required for high rotational speed, this method is used. The oil is supplied with a pump, which can control the oil pressure, and a lter or cool-er, etc. can be set up in the circulation system, mak-ing this an ideal method of lubrication. As shown in Fig. 23, the oil supply and discharge ports are located opposite to each other, and the discharge port is made large to prevent the accumulation of oil.Fig. 21 Oil drip lubrication3 Oil splash lubricationIn this method, oil is splashed in all directions by the Fig. 23 Oil circulating lubrication5 Oil mist lubricationAfter dirt and dust are removed by a filter, the oil is turned into a spray by dry compressed air, and this lubricates the bearing. When the air and oil pass through the bearing, the air cools the bearing and the oil lubricates it. In addition, because the air inside the housing is at a higher pressure than the outside air, the entry of water and foreign particles is prevented. rotation of the gear or disk. This can be used for con-There are many other advantages of this method, and siderably high-speed rotations without soaking the it is suitable for high rotational speed applications bearing directly in oil.such as high speed internal grinding spindles.In the gear case where shafts and bearings are lubri-cated with the same oil, wear particles may be intro-duced into the bearing as they might get mixed with 6 Oil jet lubricationThis is a highly reliable lubrication method and is used the oil. In this case, a permanent magnet is provided under severe conditions such as ultra-high rotational at the bottom of the gear case to collect metal parti-speeds and high temperatures. The speed of the oil cles, or a shield plate is installed next to the bearing.jet should be more than 20% of the peripheral speed Fig. 22 shows another method in which the splashed of the inner ring raceway surface, since the air around A51
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