No maintenance gear unit for hydronic valve

grabcad

Two goals have been set for this proposed solution:MAIN GOAL: Create a maintenance-free gear system which operates within the parameter ranges specified in the challenge;SECONDARY GOAL: Keep the costs of the unit as low as possible while fulfilling the main goal. A novel solution is thus proposed: use a self-lubricating chain drive for the final reduction stages and small module polymer gears for the initial reduction stages.The gear unit has 5 stages and input torque is 0.042 Nm at 600 rpm.- 1st stage: 6.67:1 reduction, 15t m0.5 spur gear (steel) mated with 100t m0.5 spur gear (polyacetal). Outputs 0.27 Nm at 90 rpm;- 2nd stage: 5.56:1 reduction, 18t m0.5 spur gear (steel) -> 100t m0.5 spur gear (polyacetal). Outputs 1.46 Nm at 16.2 rpm;- 3rd stage: 3.53:1 reduction, 17t m1.0 spur gear (steel) -> 60t m1.0 spur gear (polyacetal). Outputs 4.95 Nm at 4.6 rpm;- 4th stage: 2.13:1 reduction, chain drive with 9.525mm pitch chain 8t sprocket -> 17 t sprocket. Outputs 9.91 Nm at 2.16 rpm;- 5th stage: same as 4th, outputs 19.79 Nm at 1.02 rpm.Overall efficiency: 77%