Brakes and Clutches

4.24

A band brake is installed on a drum rotating at a 250 rpm, and a diameter of 900 mm. The angle of contact is 1.5 pi radians and one end of the brake band is fastened to a fixed pin while the other end to the brake arm 150 mm from the fixed pin. The coefficient of friction is 0.25 and the straight brake arm is 1000 mm long and is placed perpendicular to the diameter bisecting the angle of contact. Determine the net belt pull in kN applied at the kilowatts is being absorbed.

2413.26 N-m

A simple band brake has a 76 cm and fitted with a steel band 2/5 cm thick lined with a brake lining having a coefficient of friction of 0.25. The arc of contact is 245 deg. tThe drum is attached to a 60 cm hoisting drum that sustain a rope load of 820 kg. The operating force has a moment arm of 1.50 m and the band is attached 12 cm from the pivot point. Find a torque just required to support the load (clockwise).

388.2 W

A brake shoe is pressed against the surface of a 25.4 cm diameter drum rotating at 1250 rpm with a force of 111.20 N. If the coefficient of friction between drum and cylinder is 0.21, what power is dissipated in the form of heat by the drag of the brake shoe?

0.3928 kN

A cone clutch has an angle of 10 degrees and a coefficient of friction of 0.42. find the axial force required if the capacity is 7.46 KW at 500 rpm. The mean diameter of the active conical section is 300mm.

5.305 kN

An engine 40 kW at 1200 rpm, with a single plate clutch with two pairs of friction surfaces transmitting the power. Consider the coefficient of friction to be a 0.30 and mean diameter of disc to be 200 mm, determine the axial force required to engine the clutch and transmit the power.

2.28 hp

A disc clutch has a 6 pairs of containing friction surfaces. The frictional radius is 2-in and the coefficient of friction is 0.3. An axial force of 100 lb acts on the clutch. The shaft speed is 400 rpm. How much horsepower can be the clutch transmit?

39.566 hp

A multiple disc clutch of 10 steel disc and 9 bronze disc. the effective outside and inside diameter are 20.32 cm and 15.24 cm, respectively if the axial force of 450 Newton is applied and the shaft turns at 1200 rpm, find the horsepower capacity, assume a coefficient of friction of 0.27.

239 N-m

An engine of a motor vehicle with a wheel diameter of 712 mm develops 50 kW at 2,000 rpm combined efficiency of the differential and transmission is 75% with an over-all speed reduction to. Determine the torque to be delivered by the clutch N-m.

200 psi

A sleeve bearing has an outside diameter of 1.5 in and a length of 2 in, the wall thickness is 3/16 in. The bearing is subjected to a radial load of 450 lb. Find the bearing pressure.

19.5 s

Determine the machining time to drill a hole of 20 mm diameter in a workpiece 25 mm thick by a drill at a cutting speed of 30 m/min with a feed of 0.2 mm/rev.

10.45 min

A carbide milling cutter 250 mm in diameter is used to cut a block mild steel with a plain cutter. The block is 500 mm long. If the feed is 0.50 mm/rev and depth of cut is 1.2 mm, determine the time required to take one cut. The over travel is 16 mm. The cutting speed is 80 m/min.

1.2 min

Determine the time required to turn a brass component 50 mm diameter and 100 mm long at a cutting speed of 36 m/min. The feed is 0.4 and only one cut is taken.

82 m/min

A tool will cut for 4 hrs before it needs sharpening. Determine the time charged to one cycle if it takes 12 minutes to change the tool can be sharpened 10 times before it is discarded.

0.83 hp

Calculate the power consumed during cutting of a low carbon steel bar 40 mm diameter if cutting force is 150 kg at 200 rpm.

2 x 10⁶ kJ

A 10 m³ vessel contains 5 m³ of liquid water and 5 m³ of saturated water vapor at 100kpa. Calculate the internal energy of the system using the steam tables.

24.9 ft³

3.0 lbm of air are contained at 25 psia and 100 °F. Given that R_air = 53.35 ft-lbf / lbm-°F, what is the volume of the container?

1124 cal

Twenty grams of oxygen (O₂) are compressed at a constant temperature of 30°C to 5 % of their original volume. What work is done on the system?

3.16 kg

A vessel with a volume of 1 cubic meter contains liquid water and water vapor equilibrium at 600 kPa. The liquid water has a mass of 1 kg. Using the steam tables, calculate the mass of the vapor.

-432 kJ/kg

A cylinder and a piston arrangement contains saturated water vapor at 110 °C. The vapor is compressed in a reversible adiabatic process until the pressure is 1.6 MPa. Determine the work done by the system per kilogram of water.

0

Ideal Oxygen is throttled at 140degF from 10 atm to 5 atm. What is the temperature change?