Category: Fluid Mechanics And Hydraulic Machines

In this case, torque on the driver and driven shafts are equal. The application is for direct drives of machines. But in some cases, the torque required at the driven shaft could be more than the torque on the driver shaft. In this case, speed will be in the reverse ratio. Such an application is…

This device is used to transmit the power from one shaft to another. The driver shaft carries a pump with radial vanes and the driven shaft carries runners (Figure 9.30). Both of these are enclosed in a casing filled with oil of required viscosity. The pump accelerates the oil by imparting energy to it. The…

The three-screw, high-pitch, screw pump has many of the same elements as the two-screw, low-pitch, screw pump, and their operations are similar as shown in Figure 9.29. Three screws, oppositely threaded on each end, are employed. They rotate in a triple cylinder, the two outer bores of which overlap the centre bore. The pitch of the…

The two-screw, low-pitch, screw pump consists of two screws of right-handed and left-handed threads mesh with close clearances, mounted on two parallel shafts. The driving shaft drives the other shaft through a set of herringbone timing gears. The gears maintain the clearances between the screws as they rotate and to promote quiet operation. The screws…

There are many variants of screw type positive displacement, rotary pump. The various designs depend on the number of intermeshing screws involved, the pitch of the screws and the direction of fluid flow. Two common designs are the two-screw, low-pitch, double-flow pump and the three-screw, high-pitch, double-flow pump.

This is also used to pump oils. The schematic diagram of a lobe pump is shown in Figure 9.27. This is a three-lobed pump. Two-lobed pump is also used. Two lobes are arranged in a casing. As the rotor rotates, oil is trapped in the space between the lobe and the casing and is carried to the…

In a vane pump, a rotor is coupled to the drive shaft and rotates inside a cam ring. Vanes are fitted to the rotor slots and follow the inner surface of the ring as the rotor turns (Figure 9.26). Centrifugal force and pressure under the vanes keep them pressed against the ring. Pumping chambers are…

A gear pump maintains the flow of fluid by carrying the fluid between the teeth of two meshed gears. One gear is connected to drive shaft and other is meshed with the first gear. The pumping chambers formed between the gear teeth are enclosed by the pump housing and the side plates. A low pressure…

Air vessel is a closed chamber containing compressed air in the top space and liquid at the bottom of the chamber. At the base of the chamber, there is an opening through which the liquid (water) may flow into or out from the vessel. When liquid enters the air vessel, air gets compressed and when…

In centrifugal pump, transformation of energy from mechanical to hydraulic form is done by rotating action of impeller, but in reciprocating pump this energy transformation is done by reciprocating action of piston. In reciprocating pump, the rotary motion of crank shaft is converted into reciprocating motion of pump by means of a connecting rod. Pressure…