From the day machines with reciprocating piston has come into existence efforts have been undertaken to improve the efficiency of the machines .The main drawbacks of reciprocating machines are the considerably large number of moving parts due to the presence of valves , greater inertial loads which reduces dynamic balance and leakage and friction due to the presence of piston rings . The invention urges has reached on Rotary machines .
One main advantage to be gained with a rotary           machine is reduction of inertial loads and better dynamic balance. The           Wankel rotary engine has been the most successful example to date ,           but sealing problems contributed to its decline . There , came the           ideas of ball piston machines . In the compressor and pump arena,           reduction of reciprocating mass in positive displacement machines has           always been an objective, and has been achieved most effectively by           lobe, gear, sliding vane, liquid ring, and screw compressors and pumps           , but at the cost of hardware complexity or higher losses. Lobe, gear,           and screw machines have relatively complex rotating element shapes and           friction losses. Sliding vane machines have sealing and friction           issues . Liquid ring compressors have fluid turbulence losses.
         The new design concept of the Ball Piston Engine uses a different           approach that has many advantages, including low part count and           simplicity of design , very low friction , low heat loss, high power           to weight ratio , perfect dynamic balance , and cycle thermodynamic           tailoring capability