how to solve 5

Question

3.1. the belt drive from electric motor transmits an effective driving force of 800N to the 250mm diameter driving pulley on a milling machine. The torque to overcome friction on the driving parts of a machine can be assumed as 8Nm. Calculate the following: 3.1.1. Torque transmitted to the machine pulley The effective driving force = 800 N. Diameter of the driving machine = 250 mm radius of the driving machine is (250/2) = 125mm. Total torque transmitted by the driving pulley Torque = force * radius. Therefore torque transmitted by machine pulley = 100 Nm. 3.1.2. torque that is available at the milling cutter 3.1.3. the effective cutting force that can be executed by the 115mm diameter milling cutter

Answer 1

(3.1.1)

The effective driving force = 800 N.

Diameter of the driving machine = 250 mm

Radius of the driving machine is (250/2) = 125mm = 125 * 10^-3 m

Total torque transmitted by the driving pulley Torque = force * radius.

The torque transmitted by machine pulley is 100 Nm.

Answer 2

3.1.2 )

Force F= 800 N , r = 125 * 10^-3 m

T = 100 N-m ( from the result problem 3.1.1 )

T_f = 8 N-m

The torque that is available at the milling cutter T_m = T + T_f

T_m = 100 + 8 = 108 N-m

The torque that is available at the milling cutter is 108 N-m.

Answer 3

3.1.3 )

Force F= 800 N , r = 125 mm.

T_m = 108 N-m ( from the result of the problem 3.1.2 )

Effective cutting force at machine pulley for 250 mm diameter is F_e1 = 108/ (125 * 10^-3) = 864 N

Effective cutting diameter D = 115 mm

Effective cutting diameter R = 115/2 = 57.5 mm

Effective cutting force at machine pulley for diameter of 115 mm is F_e2

Torque T = RF_e2 = rF_e1

(57.5)F_e2 = (125)(864)

F_e2 = (125)(864)/57.5 = 1878.26 N

Effective cutting force at machine pulley for diameter of 115 mm is 1878.26 N