Spur gears are the most easily visualized common gears that transmit movement between two parallel shafts. Because of the shape, they are categorized as a type of cylindrical gears. Since the tooth surfaces of the gears are parallel to the axes of the mounted shafts, there is absolutely no thrust force produced in the axial path. Also, because of the ease of production, these gears can be made to a high degree of precision. On the other hand, spur gears possess a disadvantage for the reason that they easily make noise. In most cases, when two spur gears are in mesh, the apparatus with more the teeth is called the “gear” and the one with the smaller number of the teeth is named the “pinion”.

The unit to point the sizes of spur gears is often stated, as specified by ISO, to be “module”. In recent years, it is usual to create the pressure angle to 20 degrees. In commercial machinery, it is most common to employ a portion of an involute curve as the tooth profile.

Even though not limited to spur gears, profile shifted gears are Rotary Air Compressor utilized when it is required to adjust the center distance slightly or even to strengthen the equipment teeth. They are produced by adjusting the range between the gear cutting device called the hobbing tool and the apparatus in the production stage. When the shift is usually positive, the bending power of the gear increases, while a poor shift slightly reduces the guts distance. The backlash may be the play between the tooth when two gears are meshed and is necessary for the easy rotation of gears. When the backlash is definitely too big, it leads to improved vibration and noise as the backlash that is too small leads to tooth failing because of the lack of lubrication.

All KHK spur gears possess an involute tooth form. Basically, they are involute gears using part of the involute curve as their tooth forms. Searching generally, the involute shape is the most wide-spread gear tooth form due to, among other reasons, the ability to absorb small center distance errors, very easily made production equipment simplify manufacturing, solid roots of the teeth make it solid, etc. Tooth shape is often described 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.