Any transmission design requires meticulous attention to detail including gear engineering, required
performance, and manufacturing methodology. Plastic geared transmissions are no different in many ways
than metal; however they do require a unique knowledge of the materials, the molding process, and special
attributes that affect manufacture, performance, and life of the resulting transmission. In this paper we will
discuss the design and manufacture of a particular plastic molded transmission with the purpose of describing
design intent, manufacturing reality, inspection and testing results, and lessons learned. The selected
transmission is a molded plastic gear pump.