Thrust collar

Overhaul pump reposition individual impellers as needed. Reposition whole rotor by changing thrust collar locator spacer. 

The maximum outer diameter of thrust bearing (based on thrust collar design and allowable stresses)... 

If an intermediate gear is necessary, some manufacturers use single helical gears provided with thrust collars on the pinion shaft, as shown in Figures 4-32 and 4-33. The thrust collars not only neutralize the... 

Figure 4-32. Method of axial thrust transfer in a single helical gear with thrust collar.

A number of coupling options exist with motor drivers. The main gear is often equipped with a simple shoulder bearing, does not have thrust collars, and is connected to the compressor train with a solid coupling. Other manufacturers opt to use flexible couplings and conventional thrust bearings. 

Fig ure 5-18. Finish-machined shaft showing integral thrust collar. The rotor is a stiff-shaft design. 

The axial transducers should have one probe sensing the shaft itself within 12 inches (305 mm) of the active surface of the thrust collar with the other probe sensing the machined surface of the thrust collar. The probes should be mounted facing in opposite directions. Temperature probes embedded in the bearings are often more useful in preventing thrust-bearing failures than... 

Axial proximity probes are another means of monitoring rotor position and the integrity of the thrust bearing. A typical installation is shown in Figure 21-11. In this case two positions are being monitored one at the thrust runner, and one at the end of the shaft near the centerline. This method detects thrust-collar runout and also rotor movement. In most cases this ideal positioning of the probes is not possible. Many times the probes are indexed to the rotor or other convenient locations and thus do not truly show the movement of the rotor with respect to the thrust bearing. 

Speed is not limited by a surface speed as in the hydrodynamic bearing. Unfortunately, however, the stresses in the thrust collar pose one limit and the other is caused by need for an auxiliary bearing, which does have a limitation based on the type of bearing being used. 

Thrust collars shall be positively locked to the shaft to prevent fretting. 

Both faces of thrust collars shall have a surface finish of not more than 0.4 pm (16 pin.) R, and, after mounting, the axial total indicated runout of either face shall not exceed 13 pm (0.0005 in.). 

Fig. 4.30. Rod seal of slush pump U8-6M (1) bushing (2) mantle ring (3) bearing collar (4) rubber gland (5) thrust collar (parts 1, 2, 3, 5 are made of INHAM)...

THRUST COLLAR POSITION INDICATOR - The axial position of the rotor is very important and an axial position indicator is often applied to the thrust bearing. 

It may be a large dial micrometer with alarm setting for an axial movement of 0.4 millimeter and shutdown at 0.8 millimeter, or An oil pressure gauge connected to an oil leak-off device may also be used as an axial position indicator. The oil is supplied at say 500 kPa, flows through an orifice and leaks off through a nozzle. The pressure between the orifice and nozzle depends on the distance between the nozzle and shaft thrust collar the larger the distance the lower the... 

Figure 16. High-pressure optical cell for static solubility measurements (1 = soft-iron wire, 2 = Bridgman piston, 3 = screw cap, 4 = thrust collar, 5 = teflon packing, 6 = inner Bridgman piston, 7 = cap of autoclave, 8 = sliding piston, 9 = body of autoclave, 10 = window fitting, 11 = sapphire window, 12 = sample container, 13 = sealing screw, 14 = stirring rod for details see [45,76]).

Heat loss by conduction through thrust collar and tilting pads... 

---