Experimental Investigations on Leakages in Positive Displacement Machines

Table 1

Leakages in positive displacement machines.

Type of machine	Applications	Parts (which creates clearance paths)	Type of leakages	Simplified clearance structure
Reciprocating machines [2, 3]	Compression, pumping, expansion	Piston and cylinder	Piston-cylinder clearance leakages; Valve and valve plate seat clearance leakage	Annular; Circular
Screw machines [4]	Compression, pumping, expansion	Rotors and housing	Interlobe leakages; Rotor-tip housing leakages; End plate leakages; Blowhole leakages	Rectangular; Triangular
Vane machines [5]	Compression, pumping, expansion	Rotor, rotor blades, and housing	Radial leakages; End plate leakages; Leakages from isolated volumes	Rectangular
Claw (rotary tooth) machines [6]	Compression and pumping	Rotors and housing	Leakages from isolated volumes; End plate leakages; Tip and housing leakages	Rectangular
Root blowers [7]	Compression, pumping, expansion	Roots lobe and housing	Interlobe leakages Lobe-tip housing leakages; End plate leakages	Rectangular
Scroll machines [8]	Compression, pumping, expansion	Fixed scroll and orbiting scroll	Tip seal leakages (tangential and radial leakage)	Rectangular
Rotary valves [9]	Multiple applications	Impeller and housing	Axial clearance leakages; Radial clearance leakages	Rectangular