Frequently Asked Questions

Why don't you use ball bearings on your hinge assembly like the other manufacturers?

Ball bearings and metal spherical rod ends have problems in oscillatory applications. Specifically, the balls have small contact area and small radial load capability. Also, back and forth motion tends to squeeze out the lubrication, rather than maintaining a film, and the repetitive load tends to fatigue (spall) the balls and/or races. One way to help this is to get more bearing area so the contact stress is lower. This may be done by using roller bearings or angular taper roller bearings where side loads are present. But these get heavier and there is still the lubrication problem. The next option is to use a journal sleeve bearing like oilite bushings where the contact area is greater and self lubrication is supplied by oil, grease, babbit, lead or ptfe (teflon).

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