1. Field of Invention
This present invention relates to piston structure and more particularly to a piston for internal combustion engine, compressor or the like which is capable of reducing the friction between the piston and the cylinder wall and the method thereof.
2. Description of Related Arts
Piston is the “heart” of an internal combustion engine. It needs to withstand the alternating mechanical and thermal loads. As one of the key components of internal combustion engine it works in the toughest condition. A piston has to keep air pressure and transmit the force to a connecting rod through a pin to rotate a crankshaft. Since the piston works under high temperature, high pressure and high speed condition, it is badly heated but its heat removal effect is relatively low due to its inherent structure. Working under such severe circumstance will cause deformation and more friction, resulting in additional load and stress. It is essential to reserve the performance of bear-resisting, heat balance, alignment, and sealability in order to reduce the friction loss, fuel consumption, noise, and exhaust.
Although piston is always considered to be important during the development of internal combustion engine technique, the column friction loss between piston skirt and cylinder wall can't be sufficiently reduced due to the inherent structure. If the column area between piston skirt and cylinder wall is too small, it can't align the movement steadily; if the column area between piston skirt and cylinder wall is too big, it will increase friction loss. Currently the design of the column area has already been optimized. Since the space between piston skirt and cylinder wall is very small, the failure of forming a lubricant film during high speed movement is the major reason of deformation and heavy wear. As a result, the output power of the internal combustion engine is seriously affected.