Cleveland Gear Company
Manufactures broad range of power transmission equipment. Includes open gearing, helical and bevel gear units, speed reducers and variators, and custom drives. Site provides manufacturing process and product information.
http://www.clevelandgear.com/

Variators Ltd.
Variators designs and builds mechanical variable speed drives used to control speeds on industrial machinery.
http://www.variators.com

Rossi Motoriduttori
Rossi Motoriduttori is one of the biggest European industrial group for production and sales of  gear reducers, gearmotors, eletronic speed variation and electric motors. We 'thinking ahead' meaning the unremitting quest for excellence, putting the customer and his needs at the centre.
http://www.rossi-group.com