The principle of the wobbling piston (WOB-L) or rocking piston (ROC-R) is a very known and amazing concept utilized since the early days of the industrial revolution. The Wobbling piston is a simple design. The main components consist of a cylinder, a piston, and a crankshaft. This crankshaft is connected to a power source, which in majority of the cases, is an electric motor. The Piston is connected eccentrically to the crankshaft which converts rotation to liner motion. This enables the upwards and downwards movement of the piston.
However, unlike the more conventional cylinder-and-piston designs, the ones that we see in standard car engines, the wobbling piston does not have a wrist pin – this means that the piston rod and the piston are a single part. As a result, the piston does not move in a straight, concentric motion up and down the cylinder, but rather in a rocking motion. Due to this wobbling motion, the design does not permit the sealing to occur along the perimeter of the piston.
The Piston is sealed through a specifically designed Flanged Disk Cup. This Flanged Disk Cup is made from a certain polymer or polymer composite which is a trade secret of the vacuum pump manufacturer. The function of this flanged cup is to act as a guide for the piston and to create a seal between the piston and the inside of the cylinder hence enabling compression and suction. How well the wobbling Piston Vacuum or Pressure Pump will perform depends on the ingenuity of this flanged seal design. The Piston and the cylinder are made from lightweight die-cast aluminum that are treated for corrosion resistance from moisture – some cylinder designs feature highly durable polymers.