The shaft is supported in the radial and axial with two bearings, the side of the bearing is called fixed end bearing, it bear radial and axial load from two, relative axial displacement between the fixed shaft and bearing box function. The other side is called the free end, only BEARINGS LIMITED bear radial load, axial movable relative to.
Bearing for the medium high viscosity, good lubrication, p0.8MPa, or low viscosity, low lubricating medium, p0.5MPa, usually choose non balanced structure. P value exceeds the range, should consider to choose a balance structure. When p > 15MPa, single end balance structure is difficult to achieve the requirements of sealing, the selection of series type seal.
Refers to the circumferential speed of sealing surface mean diameter, according to the value to determine whether the elastic element rotates along with the shaft, the rotary spring or spring type structure, the general < 20 ~ can use rotary spring 30m/s, higher speed conditions, the uneven quality of the rotating parts easily caused a strong vibration, the best use of BEARINGS LIMITED spring type structure. If P and values are high, can consider to choose a fluid dynamic pressure structure.

The fixed end bearing must be simultaneously with the shaft and bearing box are fixed, the bearing is suitable is the composite load bearing, bearing for example, deep groove ball bearings, spherical roller bearing and double row or matched angular contact ball bearing or tapered roller bearing. Radial bearing composite subjected to pure radial load, such as inner and outer ring without cylindrical roller bearing and deep groove ball bearing rib or BEARINGS LIMITED four point contact ball bearings or thrust bearing combination, can also be used as fixed end bearing. Then, second bearings provide two-way axial positioning, but must keep a certain radial distance of bearing box installation. Free end bearing in shaft due to thermal expansion, length changes, bearing inside won't produce extrusion. Axial displacement occurs in the inner part of BEARINGS LIMITED the bearing, also can produce the bearing ring and the bearing.
According to the working parameters and the dielectric properties of the selected is often only a preliminary proposal, bearing ultimately determine the host must also consider the characteristics and special requirements of certain sealed. For example, the rocket engine seal life just a few minutes, but require a short period of time does not leak. Sometimes the host vessels in order to obtain more effective space, the size of the seal and installation of BEARINGS LIMITED the proposed location is often very demanding, and as the drainage pump on the submarine, the submarine in the process of ups and downs, the magnitude of the pressure change. In these circumstances, will not be able to structure by conventional selection criteria, and must make a special design of the specific conditions, and take the necessary support measures.