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Project Planning for Gear Units Efficiency of gear units

Run-in phase The tooth flanks of new helical-worm and Spiroplan

®

gear units are not yet completelysmooth. That fact makes for a greater friction angle and less efficiency than during lateroperation. This effect intensifies with increasing gear unit ratio. Subtract the followingvalues from the listed efficiency during the run-in phase: The run-in phase usually lasts 48 hours. Helical-worm and Spiroplan

Worm i range η reduction1 start approx. 50 ... 280approx. 12 % 2 start approx. 20 ... 75approx. 6 % 3 start approx. 20 ... 90approx. 3 % 5 start approx. 6 ... 25approx. 3 % 6 start approx. 7 ... 25approx. 2 % Spiroplan
® W10 - W30 Spiroplan
® W37 i range η reduction i range η reduction approx. 35 ... 75approx. 15 %--approx. 20 ... 35approx. 10 %-- approx. 10 ... 20approx. 8 %approx. 30 ... 70approx. 8 %approx. 8approx. 5 %approx. 10 ... 30approx. 5 %approx. 6approx. 3 %approx. 3 ... 10approx. 3 % ®

gear unitsachieve their listed rated efficiency values when:•The gear unit has been completely run-in,•The gear unit has reached nominal operating temperature,•The recommended lubricant has been filled in and•The gear unit is operating in the rated load range. Churning losses In certain gear unit mounting positions ( → Sec. "Mounting positions and important orderinformation"), the first gearing stage is completely immersed in the lubricant. Consider-able churning losses occur in larger gear units and when the circumferential velocity ofthe input stage is high. Contact SEW-EURODRIVE if you wish to use gear units of thistype.If possible, use mounting position M1 for R, K and S gear units to keep the churning loss-es low.

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Catalog – DR Gearmotors 01/2008