Question 24 of 50

In the static analysis of clutches and brakes, what defines a self-energizing brake shoe?

For the doorstop in Example 16-1, with a leftward floor movement, an actuating force F of 10 lbf, a coefficient of friction of 0.4, and a uniform pressure distribution, what is the calculated upward normal force N on the pad?

What is a key feature of a centrifugal clutch used for automatic operation, assuming no spring is used?

In the analysis of an internal-shoe device, how is the pressure p at any angle theta related to the maximum pressure pa at angle theta_a?

To avoid self-locking in an internal-shoe brake, what must be the relationship between the moment of the normal forces (MN) and the moment of the frictional forces (Mf)?

In Example 16-2, a 300 mm diameter brake is analyzed. What is the calculated actuating force F required for the self-energizing right-hand shoe?

What is the total braking capacity (torque) for the brake in Example 16-2, considering both the right-hand (self-energizing) and left-hand shoes?

What is a major advantage of disk brakes over self-energizing drum brakes, as discussed in the text?

In a frictional-contact axial clutch operating under the uniform-wear model, what is the fundamental relationship between pressure (p) and radius (r)?

For a single-surface disk clutch operating under the uniform-wear model, what is the formula for the torque (T) in terms of the actuating force (F), coefficient of friction (f), and diameters (D and d)?

What is the primary function of a flywheel in a mechanical system?

For the two annular pads in Example 16-3, with a total torque requirement of 13,000 lbf-in, what is the calculated largest normal pressure (pa) for uniform wear?

In the analysis of cone clutches under uniform wear, the operating force F is found to be identical to which equation for axial clutches?

What is the formula for the total energy E dissipated during a clutching operation, where I1 and I2 are the inertias and omega1 and omega2 are the initial angular velocities?

In Example 16-5, a caliper brake is used 24 times per hour. What is the calculated temperature rise (deltaT) for a single stop?

For a band brake, what is the relationship between the tight-side tension P1, the slack-side tension P2, the coefficient of friction f, and the angle of wrap phi?

According to the table for friction materials for clutches (Table 16-5), what is the typical dry coefficient of friction for cast iron on cast iron?

What is the coefficient of speed fluctuation (Cs) for a flywheel, as defined in the text?

In Example 16-6, a flywheel is analyzed for an engine with a nominal speed of 250 rad/s. What value of flywheel inertia (I) is calculated for a coefficient of speed fluctuation of 0.1?

What is a key characteristic of positive-contact clutches, such as the square-jaw clutch?

For the brake in Figure 16-8, which has a diameter of 300 mm and dimensions given in millimeters, what is the calculated distance 'a' from the center of the drum to the hinge pin?

In an external contracting shoe brake, how does the actuating force F relate to the normal moment MN and the friction moment Mf for clockwise rotation as shown in Figure 16-11?

For a symmetrical pivoted external brake shoe designed for symmetrical wear, what is the assumed pressure distribution p(theta)?

For a button-pad disk brake with a pad radius R = 0.5 in and an eccentricity e = 2 in, what is the value of the parameter delta used to find the effective radius?

What is the recommended range for the cone angle alpha in a cone clutch to provide a good compromise and avoid excessive disengagement force?

For the button-pad disk brake in Example 16-4, with a p_max = 350 psi, what is the calculated average pressure, p_av?

According to the analysis in Section 16-9, how is the temperature rise (deltaT) of a brake assembly approximated?

What does the dimensionless plot in Figure 16-17, comparing torque for uniform pressure vs. uniform wear in axial clutches, conclude?

From Table 16-4, what is the mean frictional coefficient for a woven lining material in a brake?

For the doorstop in Example 16-1, but for a rightward relative movement of the floor, what is the calculated average pressure (pav)?

What is the primary purpose of an overrunning clutch?

In the analysis of the engine in Example 16-6, what are the calculated maximum (omega2) and minimum (omega1) speeds for a nominal speed of 250 rad/s and Cs = 0.1?

When analyzing a band brake, what is the formula for the torque T it can sustain?

When considering an external contracting shoe brake, under what condition does self-energization exist?

In the analysis of the brake in Example 16-2, what is the resultant reaction force R on the hinge pin of the self-energizing right-hand shoe?

How is the change in kinetic energy (E2 - E1) related to flywheel inertia (I), nominal speed (omega), and coefficient of speed fluctuation (Cs)?

What is the primary reason that a new axial clutch (uniform pressure model) transmits more torque than a worn-in clutch (uniform wear model) for the same actuating force?

For the doorstop analysis in Example 16-1, part (d), what is the critical coefficient of friction (f_cr) required for the doorstop to become self-acting?

According to Table 16-3, which friction material has the highest instantaneous temperature limit?

In the steady-state thermal analysis of the caliper brake in Example 16-5, what is the final iterated value for the maximum temperature (Tmax)?

For a cone clutch with a given actuating force F, how does the torque capacity T change as the cone angle alpha decreases?

What are the four main elements of interest in analyzing the performance of clutches and brakes as listed in Section 16-1?

In Example 16-1 part (c), where pressure is modeled as proportional to the distance from the pivot, what is the calculated maximum pressure (pa)?

For the brake in Example 16-2, what is the maximum operating pressure (pa) on the left-hand (non-self-energizing) shoe?

What is the primary trade-off when selecting a material for a brake or clutch lining regarding coefficient of friction and temperature resistance?

How much energy (in Btu) is absorbed by the caliper brake in Example 16-5 during a single stop from 250 rev/min?

For a symmetrical pivoted external brake (Figure 16-12), how is the pivot location 'a' determined to ensure the moment of the frictional forces (Mf) is zero?

For an induction motor with a linear torque characteristic TM = a*omega + b, how is the constant 'a' determined from rated torque (Tr), synchronous speed (omega_s), and rated speed (omega_r)?

For the annular pads in Example 16-3, what is the calculated equivalent radius (re) for uniform wear?