Along withImport Bearing，the design specification and application range are expanded. To select the right bearing for the application, when selecting a bearing, since the shaft diameter is usually predetermined, it is necessary to conduct a comprehensive study of the bearing and the equipment on which the bearing is mounted, including the installation space, operating conditions, required performance of the bearing, expected arrangement and the required bore diameter to select the expected bearing type and the specifications of other components to be mounted with the bearing etc.
The required service life is then determined based on the bearing specification compared to the service life of the equipment using it, and the actual service life is calculated based on the operating load. Internal specifications are also selected based on the application, including bearing accuracy, internal clearance, cage and lubricant.
Bearing Selection Procedure
1. Bearing Type, Arrangement
Installation Space The bearing can be installed in the target equipment
When designing a shaft, its stiffness and strength must be considered; therefore, the shaft diameter, which is the bore diameter, It was determined at the beginning. For rolling bearings, since there are many different sizes of bearings to choose from, the appropriate bearing type should be selected.
·Load load magnitude, type and application direction
(The load resistance of the bearing is specified according to the basic load rating, and its value is specified in the bearing specification table.) Since the bearing is subjected to various types of loads, it must be considered Load magnitude, type (radial or axial) and direction of application (two-way or one-way in the case of axial loads), as well as vibration and shock, in order to select the appropriate bearing.
The following is the general order of radial resistance;
(Deep groove ball bearing < Angular contact ball bearing < Cylindrical roller bearing < Tapered roller bearing < Spherical roller bearing)
· The response of the rotational speed to the rotational speed of the equipment on which the bearing will be mounted
(The limit rotational speed of a bearing is expressed as the allowable rotational speed, which is specified in the bearing specification table.) Since the allowable rotational speed depends not only on the bearing type, but also on the bearing size, holding frame, accuracy, load and lubrication, so all factors must be considered when selecting a bearing. Generally speaking, the following bearings are widely used for high-speed running bearings. (Deep Groove Ball Bearings, Angular Contact Ball Bearings, Cylindrical Roller Bearings)
· Running Accuracy Accurate Rotation to Achieve the Required Performance
(The dimensional accuracy and running accuracy of the bearings are provided by JIS, etc.) The required performance depends on the The equipment on which the bearings are installed varies: for example, machine tool spindles require high running accuracy, gas turbines require high-speed rotation, and control equipment requires low friction. In this case, a bearing of tolerance class 5 or higher is required.
The following are widely used bearings.
(Deep Groove Ball Bearings, Angular Contact Ball Bearings, Cylindrical Roller Bearings)
Rigidity to provide the required bearing performance
(When a load is applied to the bearing, its rolling elements contact the raceway surface elastic deformation occurs at the point where the bearing has a higher stiffness, the better they control elastic deformation.) In machine tool spindles and automotive final drives, it is necessary to increase the stiffness of the bearings as well as the stiffness of the equipment itself. Roller bearings have less elastic deformation than ball bearings. Rigidity can be enhanced by providing a preload. This method is suitable for angular contact ball bearings and tapered roller bearings.
Operating conditions that cause misalignment (shaft deflection due to load, inaccuracy of shaft and housing, mounting errors) can affect bearing performance (described in part before bearing specification sheets) The allowable misalignment (angle) for each bearing type is listed to facilitate determination of the bearing's self-aligning capability.) Internal loads caused by excessive misalignment can damage the bearing. Bearings designed to absorb this misalignment should be selected. The more self-aligning the bearing has, the more angular misalignment it can absorb. The following is the general order of the allowable angular deviation of the bearing: (cylindrical roller bearing < tapered roller bearing < deep groove ball bearing, angular contact ball bearing < spherical roller bearing, self-aligning ball bearing) installation Convenient periodic inspection of the required mounting and dismounting method and frequency Cylindrical roller bearings, needle roller bearings and tapered roller bearings, with separable inner and outer rings, are recommended for applications where mounting and dismounting are frequent. The use of sleeves simplifies the installation of self-aligning ball bearings and spherical roller bearings with tapered bores.
· Bearing arrangement
· Noise characteristics, friction torque
· Marketability, price/performance ratio
For reference, general selection procedures and operating conditions are described. No need to follow a specific order.
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