Bearing installation

A basic rule of rolling element bearing installation is that one ring must be mounted on its mating shaft or in its housing with an interference fit to prevent rotation. This is necessary because it is virtually impossible to prevent rotation by clamping the ring axially. 

Most pillow-block designs incorporate self-aligning bearing types and do not require the precision mountings utilized with other bearing installations. 

Grease lubrication / hybrid bearings + Installation in any orientation... 

Packed columns were used in the first Windscale plant (Sellafield, UK). Pulsed columns were used at Hanford (USA), in the old Eurochemic plant at Mol (Belgium), and are currently in use in the newer La Hague and THORP plants. Mixer-settlers have be used at Savannah River (USA), in the Magnox plant at Sellafield (UK), and at La Hague (France). Centrifugal extractors have bear installed at Savannah River and at La Hague. 

Lemon hore or elliptical. This bearing is bored with shims split line, which are removed before installation. The resulting shape approximates an ellipse with the major axis clearance approximately... 

Cause I has been covered in the preceding subsection. Causes 4 and 5 can be handled through careful design and installation. Causes 2 and 3 bear additional discussion at this point. 

The rolling elements are installed in a cage that performs the ei v important role of reducing the friction inside bearings. The conditions without a cage are shown in Fig, 29-70, It can be demonstrated that the rotational speed of a rolling element around its geometric center is ... 

Pump is operated Match pump capacity to the service at a fraction of, Install minimum flow recirculation line to heat capacity. Possihil- ensure adequate cooling of the pump ities of excessive internal interlock to shutdown pump on mini-recirculation, fre- indication quent seal and Implement procedural controls to avoid operat-bearing failure ing at too low a flow resulting in loss of, Provide deadhead protection containment. CCPS G-23 CCPS G-29... 

These motors have a lower efficiency as a result of running in liquid, causing more liquid drag and also axial thrust bearing loss, which is also a part of the motor. However, this lower efficiency of the motor is compensated by fewer mechanical and hydraulic losses in a submersible motor-pump installation, compared to a vertical turbine pump installation. 

Any of the above reasons tnay result in noise and an increase in temperature and must be corrected. Critical installations such as a refinery, a petrochemical plant, a chemical plant or a petroleum pipeline may require special precautions and control to avert any excessive heating of the bearings, which may become fire hazards. For these installations, bearing temperature detectors with a relay and alarm facility may also be installed in the control circuit of the switching device to give warning or trip the motor if the temperature of the bearing exceeds the preset safe value. 

Code of practice for installation and maintenance of rolling bearings... 

Installation of bearings and pulleys Important checks at the time of commissioning Maintenance of electric motors and their checks Maintenance of bearings General problems in electric motors and their remedy Winding temperature measurement at site Analysis of insulation failures of an HT motor at a thermal power station... 

In the third e.vample, the line terminates at 53%. This means DO NOT run this pump at less than 53% of the BEP. 53% of 4500 gpm is 2385 gpm. Because this is a firewater pump and because firemen need to throttle the nozzles on their fire hoses, then we need to install a pressure relief valve on this system with a discharge bypass line so that the pump dumps the restricted water (less than 2400 gpm) back into the suction tank or lake. If not, this firewater pump is likely to suffer bearing failure during an emergency. 

Improper procedure when mounting the bearing on the shaft is one of the most common causes of premature failure. Roller bearings and ball bearings are precision devices, and correct installation... 

You should strictly follow correct and acceptable practices w hen removing the old bearing and installing the new one. Cleanliness is the order of the day. You ll need a clean work area, clean hands, and cleaning cloths without fuzz, lint, or strings. So much of premature hearing failure is the direct result of not observing these basic concepts. 

Clean the internal bearing housing and shaft seat before installing the bearing. 

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