Spur gears will be the most easily visualized common gears that transmit movement between two parallel shafts. Because of their shape, they are categorized as a type of cylindrical gears. Because the tooth surfaces of the gears are parallel to the axes of the installed shafts, there is absolutely no thrust force generated in the axial direction. Also, because of the simple production, these gears could be made to a higher Air Compressor degree of precision. However, spur gears possess a disadvantage in that they very easily make noise. Generally speaking, when two spur gears are in mesh, the gear with more tooth is called the “equipment” and the main one with small number of tooth is called the “pinion”.

The unit to point the sizes of spur gears is commonly stated, as specified by ISO, to be “module”. Recently, it is normal to create the pressure position to 20 degrees. In commercial machinery, it really is most common to employ a part of an involute curve as the tooth profile.

Even though not limited by spur gears, profile shifted gears are utilized when it is required to adjust the center distance slightly or even to strengthen the gear teeth. They are produced by adjusting the range between the gear cutting device called the hobbing tool and the gear in the creation stage. When the change can be positive, the bending power of the apparatus increases, while a poor shift slightly reduces the guts distance. The backlash is the play between the tooth when two gears are meshed and is needed for the clean rotation of gears. When the backlash is definitely too big, it leads to increased vibration and noise while the backlash that is too little leads to tooth failing due to the lack of lubrication.

All KHK spur gears possess an involute tooth form. In other words, they are involute gears using area of the involute curve as their tooth forms. Looking generally, the involute shape may be the most wide-spread gear tooth form due to, among other factors, the ability to absorb small middle distance errors, very easily made production equipment simplify manufacturing, solid roots of one’s teeth make it solid, etc. Tooth form is often referred to as a specification in drawing of a spur gear as indicated by the elevation of teeth. In addition to standard complete depth teeth, prolonged addendum and stub tooth profiles exist.