Because spiral bevel gears do not have the offset, they have less sliding between the teeth and are better than hypoids and generate 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 an ideal option for high quickness, high torque applications.
Spiral bevel gears, like additional hypoid gears, are made to be what’s called either correct or left handed. The right hand spiral bevel gear is defined as having the outer half of a tooth curved in the clockwise direction at the midpoint of the tooth when it’s viewed by searching at the facial skin of the apparatus. For a left hand spiral bevel gear, the tooth curvature would be in a counterclockwise path.
A equipment drive has three primary functions: to improve torque from the traveling equipment (engine) to the driven apparatus, to reduce the speed generated by the electric motor, and/or to change the direction of the rotating shafts. The bond of this equipment to the gear box can be achieved by the use of couplings, belts, chains, or through hollow shaft connections.
Acceleration and torque are inversely and proportionately related when power is held constant. Therefore, as rate decreases, torque improves at the same ratio.
The helical spiral bevel gear motor center of a gear drive is actually the gears within it. Gears function in pairs, engaging each other to transmit power.
Spur gears transmit power through shafts that are parallel. One’s 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 tend to end up being noisier than helical gears because they operate with a single type of contact between the teeth. While the teeth are rolling through mesh, they roll from contact with one tooth and accelerate to get hold of with another tooth. 
This is different than helical gears, which 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 communicate during procedure and helical gears can handle having more load than spur gears. Due to the load sharing between teeth, this set up also enables helical gears to operate smoother and quieter than spur gears. Helical gears create a thrust load during procedure which must be considered if they are used. Most enclosed gear drives make use of helical gears.
Double helical gears are a variation of helical gears where two helical faces are placed next to each other with a gap separating them. Each encounter has identical, but opposing, helix angles. Employing a double helical group of gears eliminates thrust loads and will be offering the possibility of even greater tooth overlap and smoother operation. Just like the helical gear, double helical gears are generally found in enclosed gear drives.
Herringbone gears are very similar to the double helical gear, but they do not have a gap separating the two helical faces. Herringbone gears are usually smaller than the comparable dual helical, and are ideally fitted to high shock and vibration applications. Herringbone gearing is not used very often because of their manufacturing troubles and high cost.
While the spiral bevel gear is actually a hypoid gear, it is not always viewed as one because it doesn’t have an offset between your shafts.
One’s teeth on spiral bevel gears are curved and have one concave and one convex side. They also have a spiral angle. The spiral angle of a spiral bevel gear is defined as the angle between your tooth trace and an component of the pitch cone, similar to the helix angle found in helical gear teeth. Generally, the spiral position of a spiral bevel gear is defined as the mean spiral angle.