Pillow blocks

Figure 12-61 also illustrates three basic types of trunnion rollbearing assemblies. Antifriction pihow blocks are the most common on modern diyers however, when the dryer load requires larger than a 12.7- to 15.2-cm-diameter bearing on the trunnion shaft, the dead-shaft antifriction bearing is substituted. This represents a considerable cost saving compared with the larger pillow blocks. They are completely sealed and continuously bathed in lubricant. Pillow-block bushings are less often used. The thrust washers are difficult to seal against dust, and they draw more power. Thrust roll mountings are depicted also in Fig. 12-61. These are usually dead-shaft.

The motor carries and supports any axial thrust by the pump (hydraulic or mechanical). The motor on these pumps can be fitting with precision rolling element bearings, either angular contact, spherical rollers, or pillow blocks inclined depending on the thrust load and velocit of the shaft. 

Rather than evaluate each measurement point separately, plot the energy of each measurement point on a common shaft. First, the vertical measurements were plotted to determine the mode shape of the machine s shaft. This plot indicates that the outboard end of the motor shaft is displaced much more than the remaining shaft. This limits the machine problem to the rear of the motor. Based strictly on the overall value, the probable cause is loose motor mounts on the rear motor feet. The second step was plotting the horizontal mode shape. This plot indicates that the shaft is deflected between the pillow block bearings. Without additional information, the mode shaft suggests a bent shaft between the bearings. 

Even though we cannot identify the absolute failure mode, we can isolate the trouble to the section of the machine-train between the pillow block bearings. 

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

Ribbon blenders. Price includes standard floor-mounted support, baffled shell cover, antifriction pillow blocks mounted on outboard bearing shelves, stuffing box, flanged inlet opening, and lever-operated discharge gate. 

FIG. 29-63 Typical oil-film pillow-block bearing. Lubrication is provided both by an oil flow and by oil rings. 

After replacing 0 -rings or other clutch cylinder packings, the clutch assembly should be checked for air leaks while on the floor. Do not install the pillow block roller bearings until you are sure there are no air leaks in the clutch. 

Pillow block An assembly comprising a radial-type bearing and a bearing housing which has a base with bolt holes for mounting on a support parallel with the bearing shaft. 

FIGURE 5.46 Ball bearing housing units, (a) Pillow block (b) flange cartridge (c) cylindrical cartridge (d) take-up unit. 

FIGURE 5.54 Spherical roller bearing pillow block. 

Now let s try some inside measurements with the inside micrometer. Remember, this is similar to the outside micrometer, only you are measuring inside dimensions. You will need an assortment of pillow-block bearings to perform these exercises. 

Using the same pillow-block bearings, turn the end of the handle counterclockwise, squeeze together the snap gauge, and turn the handle back clockwise (this will lock the gauge). Then insert the snap gauges inside the... 

Using the same pillow-block bearings and drill bits that were used in the previous exercises, measure the objects and compare the measurement that you get with the dial caliper to that of the micrometers. If you did not write down your answers from the previous exercise, then repeat the other exercises along with this one. 

The front hub (the liquid discharge hub) bolts to one end of the bowl. It has an inner spindle to locate the conveyor, its bearing and seals, and an outer spindle for the fitting of the front main bearing and pillow block. Seals will also be fitted to the outer spindle as required. The discharging liquid is commonly known as the centrate. 

On smaller decanters, the frame has often been made from cast iron. More usually it is fabricated from steel channel or box sections. The frame needs to be a rigid support for the rotating assembly. The surfaces for the main bearing pillow blocks are accurately machined in the same plane, and in line, to ensure no end-to-end misalignment of the rotating assembly, which would cause premature bearing failure. Some manufacturers fill part of the main frames of their larger machines with concrete effectively to form an inertia... 

The main bearings with seals are mounted onto the main frame in pillow blocks. When oil lubricated, the pillow blocks will be piped to an oil system, which will include a circulating pump, an oil reservoir and cooler with associated pressure, flow, and temperature instrumentation (see Section 2.2.4.4). 

In order to increase the critical speed of the rotor a number of different modifications can be made to the rotor system. By supporting one or both main bearings in a flexible pillow block the first critical speed of the rotor can be turned into a low speed rigid-body motion for the rotor. It can then be operated supercritically with respect to this critical speed. Other modifications are the floating conveyor and the separately supported gearbox. 

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