In one embodiment, a bearing comprises a cylindrical bearing surface
supporting a spherical journal surface. In another embodiment, a device
comprises a shaft having a spherical journal surface supported inside and
rotatable against a cylindrical bearing surface. In another embodiment, a
sheet media feed mechanism comprises: a chassis; a motor mounted to the
chassis; a rotatable shaft operatively coupled to the motor; a roller
affixed to the shaft; an idler disposed opposite the roller; the idler
and the roller engagable with one another to form a nip therebetween;
bearings mounted to the chassis and supporting the shaft, each bearing
having a cylindrical inner bearing surface; and the shaft having a
spherical journal surface inside and rotatable against each bearing
surface.