Patent Analysis
This paper will take a look at U.S. Patent no. 6049146, “Electromagnetic Piston Engine,” invented by Muneaki Takara and filed in 1997. The invention describes an electromagnetic piston engine that produces enough force to propel a vehicle using the reciprocal motion of a piston cylinder, which is itself propelled by electromagnetic force. The problem that this patent solves is the ability to produce the driving force necessary without the numerous types of resistance that inherently occur in internal combustion engines.
In the electromagnetic piston engine, the inner wall of the cylinder is magnetizable to a single magnetic pole. To make the piston more able to engage with the cylinder, the piston magnetization unit magnetizes part of the piston to another single pole. The cylinder’s magnetization creates a force between the cylinder and piston that is magnetically attractive. This, in turn, causes the piston to move in one direction until it is repelled by the opposing magnetic force in the opposite direction.
Friction force arises from motion of one object with respect to another when the two objects are within contact distance. This is due to the surface molecules of one object forming atomic bonds with the surface molecules of the other object. These bonds apply a force that resists any motion of the objects (which break the bonds). Friction force depends on the relative speed of the objects with respect to one another, being smaller at higher speeds. For all practical applications, the friction force is constant at rest (called static friction) and a different constant as the objects move (called kinetic friction).
The friction force obviously depends also on the type of materials the objects are made of, the roughness of the surface etc. The friction force direction is always opposite the motion of the object it applies to.
Friction