Definition of number of chain links (Adjustment of the number of links)

Ribbon: Top Mechanical Draw > Transmissions > Define Number of Links

  • What
  • This command allows the user to recalculate the position of a Sprocket so that the chain will always be under tension.
  • Why
  • After defining chain and sprockets correctly, it may be necessary to adjust the position of a sprocket. This is because with the chain under tension the number of links cannot be correct. The program will automatically reposition a sprocket in order to obtain a correct number of links. The command will show you the current number of links and the two values rounded up or down. This will allow you to define the correct number of links of your chain.
  • How
  • The command asks for the selection of the sprocket to be repositioned in order to tension the chain. Once done, the command will display the current number of links and the two values rounded up or down. This will allow you to define the correct number of links of your chain.

The command also verifies that the number of chain links is not a multiple of the number of teeth of a sprocket. If this occurs the program alerts the user with a message. This operating condition, for chains with a high number of revolutions causes a greater wear and the premature end of chain life-cycle.

The program allows you to choose between two relocation methods of sprockets Curve/<Auto>. The method Curve allows you to force the movement of a sprocket along any curve of Autocad. This allows you to simulate the movement of chain tension along shaped slots. The Auto method -command default- defines one movement according to the angle of the sprocket with respect to the transmission (Bisector) in order to balance the load of tension between the two branches of the chain involving it. User will later be asked whether he or she wants to move the whole part, that if the drawing has been properly structured should represent only one entire sprocket or only the entity considered as a sprocket, which consists in the circle or arc being touched when selecting the round chain.

Example 66. Adjustement of the number of chain links

Comand: ADJCHAIN
                  <ENTER> Select sprocket to
                  reposition...<ENTER> Select link
                  number (min:82, max:84, is:83.036274): 82
                  <ENTER> Tension. Select option
                  [Entity/<Auto>]: C <ENTER>