2 Replies Latest reply on Aug 20, 2012 4:37 PM by Ameya Wadekar

    Shaft sizing calculations

    Umang Dighe

      Hello All,

       

      I am trying to determine what diameter of shaft I will need based on all the loads I know.  I have few bearings supporting the shaft,some sprockets and a drive sprocket ( provides torque) . I have to consider the weight of all the sprockets and I am using a force in Y direction to simulate the weight of the sprockets. any ideas how to proceed ??

       

      Thanks.

       

       

      Umang

        • Re: Shaft sizing calculations
          Jerry Steiger

          Umang,

           

          I would think that your drive shaft diameter is going to be determined more by the torque you are transmitting.

           

          Sprockets aren't usually that heavy. The force exerted on the sprockets to transmit the torque could also be a concern, as it is a cyclic load, so you could have a fatigue failure.

           

          Jerry Steiger

          • Re: Shaft sizing calculations
            Ameya Wadekar

            Umang,

             

            If you know the torque then Torsional Stress=(Torque/Polar Moment of Inertia)*radius

            equate this to shear stress of the material, then u can solve the RHS for radius.

             

            Also as Jerry said, the sprockets are usually not heavy, but if you really want take in account their weight then you have to solve this problem using Mohrs Circle Theory. Because now you have bending moment due to sprocket weight and the acting torque.

             

             

            Ameya Wadekar