Monday, August 23, 2010

Spur Gears

Spur gears are the most common and also the oldest type of gear available. They are used in many different machines for a wide variety of functions. Although they are very simple in design, several different, discrete types of spur gears exist. Anyone who is interested in mechanical engineering or who is about to undertake a project that involves the use of gears of any type ought to familiarize themselves with spur gears and the ways in which they are used.

Spur gears are extremely important mechanical components and come in many varieties.

Spur Gears in General

In general, spur gears are round metal disks with teeth cut around the circumference. In order for the gear to qualify as a spur gear, the teeth must be cut so that they run perpendicular to the gear's face. Spur gears are the simplest design of gear produced. They are usually used for the transmission of rotary force. For instance, if two shafts are parallel to one another, and one is spinning, a spur gear can help to transfer that force onto the other shaft. Spur gears usually have an operating efficiency of 98% to 99%.


Spur Gear Blanks

Spur gear blanks are spur gears with no teeth cut into them. These types of spur gears can be useful if you do not yet know the precise number of teeth you will require for your spur gear's application.

Spur Gear Materials

Spur gears can be built from a wide variety of different materials. Different materials are often used for different types of applications. For instance, cast iron spur gears are strong and are used in many commercial applications. Aluminum alloy spur gears, conversely, are lighter but can also be built into more precise shapes, so they are used for low-impact applications requiring high precision, such as measuring instruments. Other materials from which spur gears are built include cast steels, carbon steels, stainless steels, brass, magnesium and titanium alloys, and sometimes even nylon.

Anti-Backlash Spur Gears

Antibacklash spur gears, as their name suggests, have little to no backlash, and so are used in high-precision applications. Often, these spur gears are built with springs for proper tensoring. They are usually built from brass, aluminum or stainless steel. In order for antibacklash spur gears to work together, they must have the same diametral pitch and pressure angle.

Cluster Spur Gears

Cluster spur gears come "clustered" together, usually on the same shaft, and have varying diameters.

Clamp Hub Spur Gears

Clamp hub spur gears are named for the manner in which they connect to their shaft, that is, with a clamp at the spur gear's center.

Pinion Shafts

Pinion shafts are basically stretched-out spur gears, cylinders with teeth running for their entire length.

Ratchets and Pawls

Ratchets and pawls are two spur gears that work together. Ratchets are gear wheels with teeth, while pawls are spring-loaded and pivot. Pawls are usually slanted. Together, these gears allow for unidirectional movement.

Hubless Spur Gears

Hubless spur gears have no hub and instead connect to their shafts through friction or with adhesive.

Pin Hub Spur Gears

Pin hub spur gears connect to their shaft through the use of a removable pin as opposed to a clamp.

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