Considerable power and speed can be developed under ordinary water-supply pressure by the turbine, or water motor, shown in the [sketch] and detailed in the [working drawings]. The parts are of simple construction, and the machine may be assembled or taken down easily. It is useful for either belt or direct connection to electrical generators, small machines, etc., the direct connection being preferable for a generator. The wheel is built up of sheet metal and provided with curved buckets set in the saw-tooth edge. The water is admitted through an opening in the lower part of the housing and passes out at the opposite end into a suitable drain pipe. The housing is made of two sections, the main casting and a cover plate. Bearings for the shaft are cast into the housing, which is reinforced on the back by ribs radiating from the center.
View of the Water Turbine with the Cover Plate Removed, Showing Inlet and Drain
Wooden patterns are made for the housing, the main casting and the cover plate being cast separately. The pattern for the cover plate should provide for the bearing lug, as shown in the sectional [detail], and for the angle forming a support at the bottom. Special attention should be given to allowance for proper draft in making the pattern for the main casting; that is, the edges of the reinforcing ribs, and the sides of the shell should be tapered slightly to make removal from the sand convenient. The advice of a patternmaker will be helpful to one inexperienced in this work, although many machine metalworkers are familiar with the process.
Details of a Water Turbine That will Give Considerable Power and Speed for Driving a Generator or Small Machine
The finishing and machining of the parts and their assembling should be undertaken as follows: Clean the castings and file off rough parts. Smooth the cover plate and the shell to a close fit, and drill and tap the fastening holes for 8-32 machine screws. Drill ¹⁄₄-in. holes for the bearings, through the bearing arm and ¹⁄₄ in. into the lug on the cover plate. Drill and tap the two grease-cup holes for ¹⁄₈-in. pipe thread, Drill the nozzle hole ¹⁄₄ in., and drill and tap it for a ¹⁄₂-in. pipe nipple.
Lay out the wheel of ¹⁄₁₆-in. brass, making 24 notches in its edge. Fasten the wheel to the ¹⁄₄-in. shaft with a flanged coupling, fixing it with a setscrew. Bolt the flange to the wheel with 8-32 steel bolts. Make the buckets of ¹⁄₃₂-in. sheet brass, curved as detailed, and round off the edges. Solder them into place, using plenty of solder and making certain that the curve is set properly. Place drops of solder on the flange nuts to secure them. Place the ends of the shaft on two knife-edges, and balance the wheel by adding drops of solder to the lighter side. This is very important, as undue vibration from lack of balance will wear the bearings quickly.
Assemble the machine, using shellac between the cover plate and shell. Make connection to the water supply with a ¹⁄₂-in. pipe. Bolt the machine down, and do not let it run at full speed without load.