What is the difference between spiral and hypoid gear?

Hypoid gearboxes are a type of spiral bevel gearbox, with the difference that hypoid gears have axes that are non-intersecting and not parallel. In a hypoid gearbox, the spiral angle of the pinion is larger than the spiral angle of the gear, so the pinion diameter can be larger than that of a bevel gear pinion.

What is helical spiral gear?

Helical gears connect two parallel shafts, while Spiral gears can connect two skew shafts (shafts that are neither parallel nor intersecting). Geometrically, Helical gears are a slice of a cylinder while Spiral gears are slices of a Hyperboloid (a surface you get by revolving a hyperbola).

What are hypoid gears and why are hypoid gears used?

Hypoid gears are typically used in rear-drive automobile drivetrains. A higher hypoid offset allows the gear to transmit higher torque. However increasing the hypoid offset results in reduction of mechanical efficiency and a consequent reduction in fuel economy.

What is the meaning of hypoid gear?

Definition of hypoid gear : one of a pair of bevel gears that are used especially in automotive transmissions, are designed so that the axis of the pinion does not intersect the axis of the gear, and have the teeth on the pinion cut spirally and the teeth on the gear cut nonradially.

What is a hypoid differential?

Commonly found in axle differentials, hypoid gears are used to transmit power from the driveline to the axle shafts. They are basically spiral bevel gears, where the pinion engages below the centerline of the ring gear. This lowers the driveshaft away from the bottom of the vehicle.

What are hypoid gears for?

How are hypoid gears made?

Most spiral bevel and hypoid gears are produced by either face-milling (single indexing) or face-hobbing (continuous indexing) [1,2]. To achieve a high level of geometric accuracy and surface finish, face-milled gears can be successfully ground. This finishing process has several advantages.

What is the difference between hypoid and spiral bevel gears?

The distance between a hypoid pinion axis and the axis of the hypoid gear is called the “ offset”. If the offset is zero, the hypoid gears become spiral bevel gears. Shaft angle is usually 90 degrees but other angles are also possible.

What is the basic geometry of a hypoid gearbox?

The basic geometry of the hypoid gear is hyperbolic, rather than having the conical geometry of a spiral bevel gear. In a hypoid gearbox, the spiral angle of the pinion is larger than the spiral angle of the gear, so the pinion diameter can be larger than that of a bevel gear pinion.

What is the difference between spur gears and helical gears?

Helical Gear : Helical gears have teeth inclined to the gear axis. For the same width, helical gear teeth are longer than spur gears. Therefore they can transfer more power between parallel shafts compared to spur gears. Hypoid Gear : A Hypoid Gear is a type of spiral bevel gear whose axis does not intersect with the axis of the meshing gear.

Why are hypoid gearboxes so quiet?

The difference in spiral angles between the pinion and the crown (larger gear) causes some sliding along the teeth, but the sliding is uniform, both in the direction of the tooth profile and longitudinally. This gives hypoid gearboxes very smooth running properties and quiet operation.