Motion study to find torque requirement for tilting the headrest of a medical bed

Hi all !!

i'm a beginner to solid works motion and I 'm interested to find the torque and power requirement for tilting the headrest of a medical bed. Apparently i'm getting questionable results for the procedure i've followed. the power consumption i'm getting is about 3W for 20 rpm of motor speed and it keep getting decreses with the simulation time. I can't figure out whether the problem is in my model, mates or the motion study parameters i've set. Here i'm posting my model which include the motion study i've performed.

  • Screw is used as the lifting mechanism
  • Action forces are given( Weight and friction)
  • Solid contacts are given where ever significant contacts are precent(screw mechanism, track and pulley)

Though i've set the forces i dont have a thorough understanding of the difference between how and where to apply action force or action and reaction force parameters.

If any one familear with the motion study problem please be kind enough to reply. Cheers !!!

Link to the assembly file

https://app.box.com/s/0vyqgs1k47vt5jp9i5d6

SolidworksMotion Studies