Time：2021.02.18 Source：Roller Bearings Suppliers
Overview of motor fixed end bearings and non-locating bearings
The radial bearing used in the fixed end bearing can withstand combined (radial and axial) loads. In contrast to the fixed end, the floating end of the motor is also called the free end. Usually, the floating end is selected at the non-drive end, but the motor load requirements are higher, and the axial matching size of the load equipment is not very demanding. In this case, the floating end will be selected as the drive end.
Motor fixed end bearing
Fixed end bearing is used to withstand joint (radial and axial load of the radial bearing. These bearings include deep groove ball bearing, double row or matching single row angular contact ball bearings, self-aligning ball bearing, spherical roller bearings, with groups of tapered roller bearings, NUP type cylindrical roller bearings or circle with HJ Angle of NJ type cylindrical roller bearing.
For motor bearing support fixed end (hereinafter referred to as motor fixed end) choice, should consider the following factors:
(1) being dragged equipment accuracy control requirements;
(2) the motor load properties;
(3) combination of bearing or bearing must be able to absorb a certain amount of axial force. Need WSBC 22219-E1, click here to learn more.
Integrated the design elements of the three aspects above, in the small and medium-sized motor, the deep groove ball bearing is more as a motor of choice for fixed end bearing.
The advantages of deep groove ball bearings as motor fixed end bearings
The deep groove ball bearing is the most commonly used rolling bearing. Application of deep groove ball bearings, motor bearing support system structure is simple, maintenance is convenient. Deep groove ball bearing is mainly used to bear radial load, but when increasing the bearing radial clearance, having the features of angular contact ball bearing, can bear radial and axial load; High speed and should not be using thrust ball bearing, could also be used to carry pure axial load. With deep groove ball bearing size is the same as the other types of bearings, such bearing advantages of small friction coefficient, high limit speed and the disadvantage for impact resistance, suitable for carrying a heavy load.
Deep groove ball bearings mounted on a shaft, within the scope of the bearing axial clearance, can limit the direction of the shaft or housing two radial coordinates. In radial bearing and the shaft by interference fit, the bearing and the bearing chamber or the outer transgressions surplus to cooperate, the ultimate goal of this coordination is selected to ensure that in the process of the motor running, the bearing work clearance is zero or negative, such bearing has the good running performance. Located in axial, bearing and associated parts of the axial coordination, should be determined under the condition of the floating end bearing system. Bearing inner ring by shaft bearing limit the steps (shoulder) and to limit bearing retainer, bearing outer ring, which is then fit tolerance of bearing and the bearing chamber, bearing inner and outer cover check mouth to control the height and length of bearing chamber.
Motor floating end bearing
The motor floating end also called the free end, which is relative to the fixed end; In general, the floating end choice in the drive end, but in the motor load demand is higher, and connecting with the axial load equipment size requirement is not high, will be floating end choice in the drive end. Click here to learn more about WSBC 22226 E.
Motor bearing support system for the protection, the structure of the double bearing, when the radial load demand is bigger, also will drive end as a floating end, especially for low voltage high power and high voltage motor, floating on the cylindrical roller bearing can meet the requirements of radial load is bigger.
Selection requirements for the floating end bearing of the motor
Cylindrical roller bearing roller and raceway for the line contactor offline contact, radial load capacity is big, is applicable to under heavy load and shock load, an inner ring or outer ring separable, easy to install and disassemble. This series of bearing small friction coefficients, suitable for high speed and limit rotational speed is close to the working status of deep groove ball bearings. N which are frequently used in the motor type and NU type cylindrical roller bearings, bearing between the inner and outer circle can axial movement, can adapt to shaft caused by thermal expansion or installation error and shell the change of relative position, can be used for free end bearing. But, the bearings on the shaft or the bearing chamber hole processing the demand is higher, relatively deflection axis bearing installed inside and outside the circle should be kept under strict control, so as not to cause contact stress concentration.
Relative to the fixed end bearing, to meet in the process of the motor running part of rotor axial displacement demands, according to the bearing selection, axial clearance of bearing outer ring and bearing inner and outer cover different requirements.
(1) when the floating end using separable bearing on inner and outer, the two motor bearing structure, the fixed end choice in the drive end; Fixed end and the floating end bearing outer ring and bearing between the inner and outer cover adopt axial clearance fit.
(2) when the integral bearing of floating end-use, also is the more common on both ends of small and medium-sized motor are ball bearing structure, in view of the drag effect of equipment installation accuracy, the driven end is the fixed end, floating end bearing inner ring should limit, outer ring and bearing axial gaps between inner and outer cover seam allowance; At the same time, in order to keep the motor running the axial coordinate displacement of the requirements of the bearing outer ring with the radial bearing chamber not overtighten.
The actual bearing configuration should match the operation condition of the motor, including the choice of motor bearing for clearance, heat-resisting performance, specific parameters, such as precision and radial bearing and the bearing chamber cooperate relationship.