Design development of office copier gearbox

As we have already noted, this gearbox originally used steel ears. These were noisy and costly. They were made from case-hardened steel and there was chatter, especially when they became worn or damaged, resulting in wear on the back flanks of the teeth. They also required external lubrication, which can be a nuisance in an office environment. 

Material SG Tensile Strength psi Flexural Modulus psi Izod Impact Strength ft Ib/in Distortion Temperature Under Load G 264 psi Co-efficient of Linear Thermal Expansion 

Material Pair Wear Factor K Coeft of Friction Limiting PV  

Stationary Moving Stationary Moving Static Dynamic 10 100 1000 

The design of the gear at this stage included a continuous web, centrally located through the thickness, and radial ribs outside the central web. This was a fairly stiff design, in torsion or diametral compression. 

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