Because spiral bevel gears don’t have the offset, they have less sliding between the teeth and are more efficient than hypoids and create less heat during operation. Also, one of the main advantages of spiral bevel gears may be the relatively large amount of tooth surface that is in mesh throughout their rotation. For this reason, spiral bevel gears are a perfect option for high swiftness, high torque applications.
Spiral bevel gears, like various other hypoid gears, are designed to be what’s called either right or left handed. The right hand spiral bevel gear is defined as having the outer half of a tooth curved in the helical spiral bevel gear motor clockwise direction at the midpoint of the tooth when it is viewed by searching at the facial skin of the apparatus. For a left hands spiral bevel equipment, the tooth curvature will be in a counterclockwise direction.
A gear drive has three primary functions: to improve torque from the generating equipment (engine) to the driven equipment, to lessen the speed produced by the engine, and/or to improve the direction of the rotating shafts. The connection of the equipment to the apparatus box can be accomplished by the utilization of couplings, belts, chains, or through hollow shaft connections.
Rate and torque are inversely and proportionately related when power is held continuous. Therefore, as velocity decreases, torque increases at the same ratio.
The heart of a gear drive is actually the gears within it. Gears run in pairs, engaging one another to transmit power.
Spur gears transmit power through shafts that are parallel. The teeth of the spur gears are parallel to the shaft axis. This causes the gears to produce radial response loads on the shaft, but not axial loads. Spur gears have a tendency to become noisier than helical gears because they operate with a single type of contact between tooth. While the tooth are rolling through mesh, they roll from connection with one tooth and accelerate to contact with another tooth. This is unique of helical gears, that have several tooth in contact and transmit torque more smoothly.
Helical gears have teeth that are oriented at an angle to the shaft, in contrast to spur gears which are parallel. This causes more than one tooth to be in contact during procedure and helical gears are capable of holding more load than spur gears. Due to the load sharing between teeth, this set up also enables helical gears to use smoother and quieter than spur gears. Helical gears produce a thrust load during procedure which must be considered when they are used. The majority of enclosed gear drives use helical gears.
Double helical gears are a variation of helical gears in which two helical faces are placed next to each other with a gap separating them. Each encounter has identical, but opposite, helix angles. Employing a double helical set of gears eliminates thrust loads and offers the possibility of even greater tooth overlap and smoother procedure. Like the helical gear, dual helical gears are generally used in enclosed gear drives.
Herringbone gears are very similar to the double helical equipment, but they don’t have a gap separating both helical faces. Herringbone gears are usually smaller compared to the 
comparable dual helical, and are ideally fitted to high shock and vibration applications. Herringbone gearing is not used very often due to their manufacturing problems and high cost.
While the spiral bevel gear is truly a hypoid gear, it isn’t always considered one because it does not have an offset between your shafts.
The teeth on spiral bevel gears are curved and have one concave and one convex side. There is also a spiral angle. The spiral angle of a spiral bevel equipment is thought as the angle between your tooth trace and an element of the pitch cone, like the helix angle within helical gear teeth. Generally, the spiral angle of a spiral bevel gear is defined as the indicate spiral angle.