Question

An electric drive consumes 1 KW electric power and generates 850 W of turning shaft power. Determine a)the drive efficiency and b) the dissipated (lost) power. A. B. Determine the tangential ( , radial ()and axial( ) forces on a spur gear tooth provided that the pressure angle is 20" and the normal force is 1 N. C. A pinion of 20 teeth turns a gear of 40 teeth at 100 rpm. What is the turning speed of the pinion. D. The load torque at a gear of 50 teeth is 1 Nm. What is the torque at the pinion provided that this has 10 teeth?

please solve all the questions.

Answer 1

Answer 2

SOLUTION :

A.

Input power = 1 KW = 1000 W

Output power = 850 W

a.

Drive efficiency 

= output power / Input power 

= 850/1000 

= 0.85 

= 85% (ANSWER).

b.

Dissipated (loss) power 

= Input power - output power

= 1000 - 850

= 150 W (ANSWER).

B.

                 Fr

           Fn I

      Ft   \   V

  ——> V __

               /    \

Fn = 1 N. Pressure angle = 20º (Fn makes angle (20º) with the horizontal)

So.

Ft = Fn cos(20) = 1 * 0.9397 = 0.9397 N (ANSWER)

Fr = Fn sin(20) = 1 * 0.3420 = 0.3420 N (ANSWER).

C.

T pinion / T gear = N gear / N pinion

=> 20/40 = 100 / N pinion

=> N pinion = 100 / (20/40)  = 200 rpm (ANSWER).

D.

Torque gear / Torque pinion = Teeth gear / Teeth pinion 

=> 1 N-m / Torque pinion = 50/10 = 5

=> Torque pinion = 1/5 N-m (ANSWER).