helical gearbox Shaft in line, High efficiency, Low noise, Long life! Delivery in short time! ISO9001, CE, OEM service... We ... service offered. Product features of RC series helical gearbox 1. RC series helical gearmotor own rational design, compact construction ... , mine and power transmission machinery, metallurgy etc. RC series helical gearmotorEfficiency94%~96% (depends on the transmission stage) ...