Unformatted text preview: MECH 325 Machine Elements
Tutorial 5 – Flexible Drives 1. Adapted from Shigley, Problem 17‐1 (8 and 9th Eds.) th A 6‐in‐wide polyamide F‐1 flat belt is used to connect a 2‐in‐diameter pulley to drive a larger pulley with an angular velocity ratio of 0.5. The centre‐to‐centre distance is 9 ft. The angular speed of the small pulley is 1750 rev/min as it delivers 2 hp. The application is such that a service factor Ks of 1.25 is appropriate. Part 1: To be demonstrated by the TA a. Find Fc, Fi, F1a, and F2 Part 2: To be done by the class b. Find the allowable power Ha c. Find the safety factor for the belt nfs (in terms of allowable and transmitted power) d. Find the belt length e. Find the dip 2. Adapted from Shigley, Problem 17‐18 (8th and 9th Eds.) Two B85 V‐belts are used in a drive composed of a 5.4‐in driving sheave, rotating at 1200 rev/min, and a 16‐in driven sheave. Part 1: To be done by the class a. Find the centre‐to‐centre distance b. Find the power capacity of the drive based on a service factor of 1.25 3. Adapted from Shigley, Problem 17‐25 (8th and 9th Eds.) A double‐strand no. 60 roller chain is used to transmit power between a 13‐tooth driving sprocket rotating at 300 rev/min and a 52‐tooth driving sprocket. Part 1: Extra Practice (to be done at home) a. Show the allowable horsepower of this drive is 7.91 hp. b. Show the centre‐to‐centre distance is approximately 18 in if the chain length is 82 pitches. c. Show the torque and bending force on the driving shaft by the chain are 1164 lb∙in and 744 lb, respectively, if the actual horsepower transmitted is 30 percent less than the corrected (allowable) power. MECH 325 Tutorial Additional Information
Tutorial 5: Flexible Drives ...
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This note was uploaded on 02/01/2011 for the course MECH 325 taught by Professor Peteostafichuk during the Fall '10 term at UBC.
- Fall '10