Crankshaft Deflections Measurement

  • Crankshaft deflections are measured by using deflection gauge.

  • The deflection gauge is a dial gauge, which measures the distance between the adjacent webs spread at different angular positions of the shaft.
  • The dial gauge shows the distance up to which the stylus move when it is pressed.

  • Fit the dial gauge between the punch marks of adjacent webs, opposite to crankpin. Ensure that it is at half of the diameter from shaft centre to press the stylus 3 mm.
  • The clockwise rotation of the needle indicates closing of the webs.

  • The Corresponding gauge reading is taken as negative value.
  • Anticlockwise rotation indicates opening of the webs. The corresponding gates reading is taken as positive value.

  • Take the first measurement when the engine is at 30 degree after the bottom dead centre position.
  • Keep the gauge close to the side of the connecting rod.
  • Set the gauge to zero at this position.
  • Rotate the engine by turning gear.
  • Stop at each quarter and take the gauge reading using a mirror with flexible handle.
  • Take the final reading near bottom dead centre. The connection rod he is now at a position opposite to the first reading.
  • Take the average of the first and last reading to get the approximate bottom position.

  • Repeat the procedure for each unit.

No comments

Powered by Blogger.