Spur Gear is a device that transfers force to another device via rotation mechanism. The spur gear with the aid of its teeth is joined with another gear and applies full force. According to its mechanism a gear has the capacity to enhance force at various torques towards diverse directions originating from the root source whence it attains power.
　　It is an acceptable fact; a gear is fitted well with another gear that has teeth. But the matter to be brooded is that a gear fits well with any device, not specifically with another gear, that owns its teeth to be fitted quite coherently.
　　Spur Gearmay be of different sizes, may be easily combined with another of a different size. The factor that predominates to a great extent is that though the second device with which the first gear is fitted with creates no problem to generate force and the rotational source of force is kept intact.
　　We can define a spur gear according to the teeth it has. Teeth and the diameter play the crucial part in the mechanism of a gear. Hence it can be easily told that the performance of a gear solely depends on the characteristic qualities that a gear originally is in possession of. The actual role that a gear plays is that it generates force to one shaft to another one irrespective of teeth and diameter.
　　The mechanism of the gear follows the rule of linear physics that determines its rotation per second or minute. The speed is generated vide an equation of the gear's circumference dived by the radius of it. Actually it must be taken care that the second gear is also given the tremendous importance too.
　　The teeth of a gear play the most crucial role in generating force. Again the radius of it also is of no less importance. Probably depending on the diameter the force is generated. The larger is the radius the slower is the speed.
　　It is to be noted that the teeth adjoining two spur gears are corresponded to one another to rotate. Thus when teeth related to the small gear press the other one, the large one is to make one rotation. As a matter of fact when the small gear moves in a fast pace the large gear moves faster generating more power. The points of the gears must have to pass a particular point to rotate following a comprehensive mechanism to generate actual force.
　　When we find an ordinary gear we notice that there are axes of the gear that is absolutely static when there is rotation in the gear. The axes can be much in number as in the case of epicyclic gear. Again the gear referred to as the sun - planet gear has a wonderful mechanism. In this gear the gear that is called planet rotates round the sun gear.
　　If we brood over the mechanism of Spur Gear we have to keep in mind the fact that the gear is based on particularly four items as the axis, the pitch point, pitch circle and the pitch diameter.