For the actuation of clutches and brakes the highest torque

For the actuation of clutches and brakes, the highest torque per unit volume is delivered by the following method:

(A)Mechanical (B)Hydraulic (C)Electric   (D)Pneumatic

The mechanical-lockup clutch that can engage at speeds up to 400 rpm is the?

(A)Square-jaw clutch   (B)Multiple tooth clutch   (C)Spiral-jaw clutch   (D)None of the above

Which of the following features best describes a magnetic particle clutch?

(A)Go between motor & reducer (B)Cannot perform zero slip

(C)perform at heavy duty applications   (D)Only works for non-ferrous output rotor

1-Describe the differences between the Eddy Current brake and the Hysteresis Brake?

2-List three different types of mechanical clutches, and describe their operation principles?

Please do it all of them hear ((DO NOT WRITE IN A PAPER))

Solution

B) Hydraullic

Hydraulically operated method deliver more torque per unit volume because, high oil pressure has more power density than pneumatic or electrically powered units.

B) multiple tooth

Multitooth clutches can have a running engagement speeds up to 400 rpm

C) perform at heavy duty applications.

Due to its fast response and accuracy in torque control.

1) The difference between eddy current brake and hysteresis brake is the design of the brake itself. Eddy current brakes have a splined rotor. The splined part of the rotor in the magnetic field produces the braking effect. Eddy current dynamometers apply braking power relative to the speed (up to 50,000 rpm or even 100,000 rpm).

Hysteresis brakes have a stator in two parts with a rotor in the form of a cup rotating in the magnetic field, between two stator parts. Hysteresis brakes provide braking factor from 0 rpm to middle range speed. (up 10,000 to 20,000 rpm, depending on size).

2) Positive contact clutches:

This type of clutches include jaw clutches, spiral jaw clutches and toothed clutches. In these clutches, power transmission is achieved by means of interlocking of jaws of teeth. There main advantage is positive engagement and once coupled, they can transmit large torque with no slip.

Frction clutches:

This include include single and multi plate clutces, cne clutches,and centrifugal clutches. In these clutches, power transmission is achieved by means of friction between contacting surfaces.

Electomagnetic clutches:

This incude magetic particle clutches, magnetic hysteresis clutches and eddy current clutches. In these clutches, power transmission is achieved by means of magnetic field. These clutches have rapid response time, ease of control and smooth starts and stops.

Fluid clutches:

In this type, power transmission is achieved by means of hydraullic pressure. A fluid coupling provides extremely smooth starts and absorbs shock.