One approach to building an efficient conveyor system is to use drum motors, also knows as motorized pulleys.
Drum motors from BDL America, Wilmington, N.C. (bdlamerica.com), transmit power through a gearbox coupled to a geared rim connected to the drum and motor housing. This totally encloses the motor, transmission, and bearings. The sealed motors should never need maintenance and mount with just two brackets. Steel teeth reduce noise to 50 dB or less to meet run at 96% efficiencies, saving 32% (unloaded) and 47% (loaded) on power consumption compared to exposed drives. The "sealed-for-life" drum protects against dirt, dust, chemicals, and other potential contaminants. Diameters range from 3.18 to 12.6 in., and they are rated from 0.11 to 7.5 hp. Belt speeds go from 23 to 1,369 fpm.