Common contact ratio of a pair of spur pinion and gear is

Common contact ratio of a pair of spur pinion and gear is Correct Answer Between 2 and 3

The ratio of the length of arc of contact to the circular pitch is known as contact ratio i.e. number of pairs of teeth in contact. The contact ratio for gears is greater than one. Contact ratio should be at least 1.25. For maximum smoothness and quietness, the contact ratio should be between 1.50 and 2.00. High-speed applications should be designed with a face-contact ratio of 2.00 or higher for best results.

Related Questions

Statement (I): In an epicyclic gear train, the size of the gearbox is smaller than that of the spur gearbox for the same horsepower and the same velocity ratio. Statement (II): In an epicyclic gearbox, more than one pair of gear pinion contacts always exist, whereas it is not so in spur gearbox.