Shaft cantilever

Figure 6 Pilot-scale RPB illustrating the horizontal-shaft cantilever design with direct motor drive. (Photo courtesy of Higravitec Center of Beijing University of Chemical Technology.)... 

Options for connecting the motor drive to the shaft depend on the shaft orientation. A vertical-shaft cantilever design would prefer a belt drive to reduce the cost of manufacture of the support structure and to facilitate maintenance. A horizontal shaft has the additional option of direct coupling. Variable speed can be accomplished through a gearbox or preferably through variable frequency control on the motor. In addition to the power requirements discussed previously, the startup power to overcome the torque of the rotor must be considered. This startup power is related to the time required to reach the desired rotor speed. 

Figure 9 Commercial RPB for HOCI production using the vertical-shaft cantilever design with belt drive. (Photo courtesy of The Dow Chemical Company.)... 

In this group, the impeller or impellers are mounted on the extreme end of the shaft in a cantilevered condition hanging from the support bearings. This group of pumps is also subdivided into a class known as motor-pumps or close-coupled pumps where the impeller is directly mounted onto the motor shaft and supported by the motor s bearings. 

The pinion shafts are typically a cantilever-type design that has an enclosed impeller on one end and a tilting-pad bearing on the other. The pinion gear is between these two components. The number of impeller-pinions (i.e. stages) varies with the application and the original equipment vendor. However, all bullgear compressors contain multiple pinions that operate in series. 

SINGLE CASING VOLUTE LINE SHAFT (VS4) AND VOLUTE CANTILEVER (VS5) PUMPS... 

The rotor shall be cantilevered from its bearing assembly. Snbmerged bottom bearings and/or bushings are not nsed to gnide the shaft. 

For vertically suspended pumps with shafts exposed to liquid and running in bushings, the shaft shall be 12 percent chrome, except for Classes S-9, A7, A-8, and D- 1. Cantilever (Type VS5) pumps may utihze AlSl 4140 where the service liquid will allow. 

Single-casing line shaft (VS4) and cantilever (VS5) pumps... 

Proper mechanical design principles determine the option of cantilevered or centerhung rotor, the shaft diameter, the type and position of bearings, and seal design. The drive train, whether belt driven or direct coupled, is determined by the power requirements and the shaft orientation. The housing must be sufficient to contain the temperature and pressure of the operation and to provide adequate inlet and outlet nozzles for the process fluids. 

BENDING OF A BEAM. The complex dynamic Young s modulus can be determined from the forced, non-resonant oscillations of a single or double cantilever beam. The apparatus considered in this paper is the Dynamic Mechanical Thermal Analyzer (DMTA) (6), manufactured by Polymer Laboratories, Inc. Figure 3 shows the experimental setup for the single cantilever measurement. A thin sample is clamped at both ends. One end is attached to a calibrated shaker through a drive shaft. 

Fig. 16.5 SEM images of various types of metallic probes, (a) Ag-coated Si cantilever (b) Ag tip made by wire etching (Reprinted from [37], Copyright 2005, with permission from American Chemical Society) (c) metallic probe with a grating fabricated on the shaft (Reprinted from [48], Copyright 2005, with permission from American Chemical Society) (d) metallic probe with Otto coupler (Reprinted from [49], Copyright 2005, with permission from American Institute of Physics)...

Figure 256. Diagram of a roller press with cantilever-shaft design. (Courtesy of Bepex/Hutt, Leingarten, FRG)...

In cantilever-shaft designs the rollers are located outside the frame (Figure 256). This design is normally used for smaller machines. In many cases such machines are applied for laboratory or pilot work because the location of the rolls allows for easy and quick changeover to different roll surface configurations. 

In Figure 257 two typical cantilever-shaft designs are depicted. In Figure 257(a) (K. R. Komarek, Inc., Elk Grove Village, 111., USA) the rolls (1) are positioned one above the other. In this case, feeding must be accomplished horizontally from one side. The roll shafts (2) are supported in two lower (4) and two upper bearing blocks (4a) which are clamped in between two frame plates (3) held... 

So far, all machines that were presented used the mill shaft design in which the roller shafts are supported on both sides by bearings that are mounted in a frame. Another, relatively new design of roller presses uses cantilevered shafts and rolls. 

Since the equipment following the extrusion is associated with belts (Fig. 6.4-30b), the roller presses are often executed in a bridge type fashion (Fig. 6.4-32), called mill shaft design in high-pressure roller presses [B.48, B.97]. An actual combination of formers, one bridge type and the other cantilevered, and a cutter are depicted in Fig. 6.4-33. Other equipment is available that can be added to complete lines, including ... 

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