In the brake shown in Figure 10.7, the coefficient of friction between the brake shoe and the drum is 0.45. Find the smallest value of force F required to prevent rotation of the drum against an applied torque of 75 N.m.
In the brake shown in Figure 10.7, the coefficient of friction between the brake shoe and...
Figure 3: Double internal long shoe drum brake The double internal long shoe drum brake as shown in Figure 3 has a shoe outer diameter 420 mm and shoe width of 65 mm. Each shoe is actuated by a force of 4500N. The coefficient of friction for the brake lining is 0.30. Find the magnitude of the maximum pressure and the braking torque.
Question 4 Refer to the following diagram of a short-shoe brake assembly. Coefficient of friction is .35 • Is the brake self-energizing or deenergizing for the given direction of drum? What is the magnitude of the torque developed by the brake? How far below the drum center would the arm pivot need to be to make the brake self- locking? F = 1500 N 400 mm 500 mm 200 mm Rotation 340 mm
The arrangement EXERCISES 400 120 us 3 The arrangements of a transmission brake is shown in Fig. 19.40. The arms are pivoted at o, and O2 and when force is applied at the end of a hand lever, the screw AB rotates. The left and right hand 120 force on the hand lever is applied 400 mm from the axis of the screw The drum is 240 mm in diameter and the angle subtended by each is 90°. The screw...
The brake, shown in figure below, is 300 mm in diameter and is actuated by a mechanism that exerts the same force F on each shoe. The shoes are identical an have a face width of 30 mm. The lining is a of ceramic type having a coefficient friction of 0.35 and a pressure limitation of 1.1 MPa. Find the following: (a) Actuating force F. (b) Braking torque capacity
A double external long shoe drum brake is illustrated in Figure 10.37 . The face width of the shoes is 50 mm and the maximum permissible lining pressure is 1 MPa . If the coefficient of friction is 0.32 determine the limiting actuating force and the torque capacity .
6. Band Brake A differential band brake is used to control the speed of a drum which rotates at a constant speed. Knowing that the coefficient of kinetic friction between the belt and the drum is 0.30 and that a couple of magnitude 150 N.m is applied to the drum, determine the corresponding magnitude of the force P that is exerted on end D of the lever when the drum is rotating (a) clockwise, (b) counterclockwise. r 140 mm 30...
The figure shows a 400-mmidiameter brake drum with four internally expanding shoes. Vach of the hinge pins 4 and 8 sapports a pair of shoes. The sctuating mechanism is to be aranged to produce the same force F on each shoe. The face width of the shoes is 75 mm The material unel permits a coefficient of friction of 0.24 and a maximum pressure of 100o kPa.) (a) Determine the actuating force. (b) Estimate the brake capacity (c) Notingg that...
Question 1 [25 marks] Figure 1 shows a brake drum 325 mm internal diameter, acted on by two brake shoes which are mounted on a pin A, and pushed apart by two hydraulically operated pistons at B, each exerting a force of P on the shoe on which it makes contact. The blocks are centred on the horizontal centre line as shown in the figure. The coefficient of friction is 0.25. Find the value of P to produce a brake...
Consider the drum brake belaw Rotation 50 mm 110 Given y- 30° and a coefficient of friction of 0.3 between the shoe lining and the drum, calculate a) The mechanical advantage of the leading shoe b) The mechanical advantage of the trailing shoe If the coefficient of friction is increased to 0.5, calculate: c) Percentage change in the mechanical advantage of the leading shoe d) Percentage change in the mechanical advantage of the trailing shoe ANSWERS a) 0.86 b) 0.46...
The symmetric brake shown in the figure has a width of 30 mm with a mean friction coefficient of 0.25. Note that L 150 mm 1 = , L 200 mm 2 = , L 200 mm 3 = and radius of the drum is 150 mm. For an estimated actuating force of F=500 N for each brake, determine: a) The maximum pressure on each shoe b) The total brake torque capacity c) Comment on the self – energizing behavior...