欢乐斗地主免费版安装 www.rymg.net First, the size of the limit.
Usually NTN bearings can be installed in the space is limited. In most cases, the diameter of the shaft (or the diameter of the bearing) is limited by the mechanical design or other design. So the choice of bearing type and size is determined according to the diameter of the bearing. As a result, the main dimensions of the standard NTN bearings are made according to the diameter of the international standard.
Standard NTN bearing type, size and different, in the design of mechanical device is best use of standard bearings (the design to the bearing is easy to purchase, here said the sentence digression, some bearing catalog model does have, but some non standard bearing NTN in mainland China there is no cash, sometimes futures will for a long time, so in the bearing selection to consider the time cost and a late replacement cost) bearing load, applied on the bearing load and the nature, size, direction is changeable. Generally, the basic load rating is displayed on the size table. But the axial load and radial load, etc., is also an important factor to select the appropriate NTN bearing. When the ball and needle bearing size quite, needle roller bearings typically have a higher load capacity and bear a larger vibration and shock loads.
Followed by speed.
Allowable speed is determined according to NTN bearing type, size, precision, holder type, load, lubrication, and cooling mode. Bearing table lists the standard precision bearings in oil lubrication and grease lubrication under the allowable speed. Usually, deep groove ball bearings, self-aligning ball bearings and cylindrical roller bearings are suitable for high speed operation.
Again, NTN bearing tolerance.
NTN bearing size accuracy and rotation accuracy is based on the ISO and JIS standards. Requirements for high precision and high-speed operation of the machinery, it is recommended grade 5 or above precision bearing, deep groove ball bearing, a centripetal thrust ball bearings or cylindrical roller bearing is applicable to high running accuracy of mechanical. The elastic deformation can be generated when the rolling element of the bearing and the contact surface of the rolling track are pressed. Some machines need to minimize elastic deformation. The roller bearing is smaller than the elastic shape of the ball bearing.
In addition, in some cases, NTN bearings have to be pre pressed to increase the stiffness. This procedure is usually used for deep groove ball bearing, a centripetal thrust ball bearings and tapered roller bearing inner ring and the outer ring of bias, bent shaft, shaft or bearing box tolerance variations, combined with errors will lead to the eccentricity of the inner and outer rings. In order to prevent the eccentric angle is too large, the automatic ball bearing, self-aligning roller bearing adjustable bearing seat is better choice. Voice frequency and torque, rolling bearings are based on a high standard of precision manufacturing, so the noise and small torque. Deep groove ball bearings and cylindrical roller bearings used for low voice, low torque occasions with special requirements.
Installation and removal, some applications require frequent removal and installation, in order to ensure that regular inspection and maintenance can be carried out. The inner and outer rings can be installed separately as: NTN bearing cylindrical bearings, needle roller bearings and tapered roller bearing is very suitable for the occasion. Self aligning ball bearing cone hole and self-aligning roller bearings on the shaft's help, but also simplify the installation procedure.
(1) the NTN bearings prior to installation, should use suitable measurement tools according to the design drawings, technical requirements, check the shaft and housing bore and the relevant parts of the processing quality (such as dimensional accuracy, shape accuracy and surface roughness).
(2), a shaft and a bearing seat hole assembly on the surface if there are bumps, burrs, rust or solid particles (such as grinding dust, grit, dirt) etc., not only will the bearing installation difficulties and the installation position is not correct, and solid particles such as falling into the NTN bearing will grind, when the working surface of the NTN bearing rotation will rubs or scratches NTN bearing, so before installation must carefully check, such as the discovery of the defect, should be modified. Using, for example, oil file to remove burrs, raised touch marks, rust, and with fine emery cloth polishing, such as cleaning solid particles, dirt.
(3) the assembly surface should be cleaned with a clean gasoline, kerosene, toluene or xylene solution, and with a clean cloth to dry, and then coated with a thin layer of lubricating oil, so that the installation and operation is more convenient.
(4) temporary installation open bearing package, will it immersed in the liquids such as gasoline with handle gently and slowly rotate, to ensure that cage, rolling body and rolling on the surface of the encapsulated oil is thoroughly clean.
(5) a large number of cleaning NTN bearing, first with temperature for 90 to 100 DEG C of engine oil, and pour hot to make packaging oil is melted, and seamless mouth and does not fall chip tool dig net all the old oil, and then poured hot for a few minutes and kerosene flushing oil, gasoline and then clean again. After cleaning, the bearing should be put on the clean cloth or paper to dry on the working table.
(6) pay attention to the use of this method can not be used to clean the seal, the internal should be kept as the original can not be cleaned.