ported and found to be due to contaminants 

 between seal faces introduced at the assem- 

 bly stage. 



Hermetically Sealed Motors; 



In this design (Fig. 8.22) the electrical sys- 

 tem is completely isolated from seawater by 

 impregnating the stator windings in an 

 epoxy resin and sealing the component in- 

 side a welded, corrosion-resistant metal case. 

 The design may incorporate either oil or 

 water as a lubricant and a shaft seal and 

 pressure-compensation system can be em- 

 ployed. According to Thomas, hermetically 

 sealed motors have successfully performed 

 as deep as 11,500 feet and can, with minor 

 modifications, operate successfully to 20,000 

 feet. He further states that this design pro- 

 vides maximum reliability in seawater. 



The variety of commercially available elec- 

 tric motors is manifold and submersible 

 builders do not appear to favor any particu- 

 lar brand over the other (See individual list- 

 ings in Chap. 4). In a few instances they have 

 modified the design of an off-the-shelf item 

 to fit their own requirements, e.g., Perry 

 Submarine Builders. In other cases, such as 

 HYCO, they manufacture their own. The 

 shallow diving, smaller vehicles have a 

 greater range of options than their deep- 

 diving counterparts because of the small 

 power requirements and reduced pressures. 

 In the case of KUMUKAHI, a trolling motor 

 from Sears & Roebuck suited the task. 



A few vehicles employ electro-hydraulic 

 motors to provide propulsive power; an ex- 

 ample of this arrangement for MAKAKAI is 



STAINLESS 

 CONSTRUCTION 



PRESSURE AND TEMPERATURE 

 .COMPENSATING BELLOWS WITH 

 POSITIVE INTERNAL PRESSURE 



LABYRINTH SHAFT 

 SEAL 



OIL FILLED BORE 



ANTI-FRICTION 

 BALL BEARINGS 



WATER BLOCK 

 CONNECTOR 



HERMETICALLY SEALED - 

 ENCASULATED STATOR WINDINGS 



DYNAMICALLY 

 BALANCED ROTOR 



RUNNING FACE 

 SEAL 



Fig. 8 22 Cutaway ot Franklin Electrics hermetically sealed motor with pressure compensaton (Franklin Eiec Co ) 



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