
Concept explainers
The three methods of breaking a motor.

Explanation of Solution
The electrical motor uses three types of braking the
Mechanical braking
In mechanical braking there are two type breaks drum and disc. In drum the pressure is applied to the metal cylinder called the drum by the help of break shoe. The drum is connected to the motor shaft. The pressure on the drum stops the motor from rotating. The disc rakes is most common braking, its working is similar to drum brake with difference that the brake pads exert the pressure on the spinning disc.
Dynamic braking
The dynamic braking is used to limit the dc motor and ac motor speed, in this method the motor supply is cut and rotating motor is connected across a load the power so produced is dissipated in the load thus stopping the motor.
Plugging
The plugging is the method used by the dc motor with the squirrel cage motor in this method. This is done by reversing the magnetic field in which the motor is operating. The reversing of the field reduces the speed and hence the motor.
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Chapter 43 Solutions
Industrial Motor Control
- Calculate the bending moment at the point D on the beam below. Take F=79 and remember that this quantity is to be used to calculate both forces and lengths. 15F 30F A сarrow_forwardShow work on how to obtain P2 and T2. If using any table, please refer to it. If applying interpolation method, please show the work.arrow_forwardcast-iron roller FIGURE P11-3 Shaft Design for Problems 11-17 Chapter 11 BEARINGS AND LUBRICATION 677 gear key P assume bearings act as simple supports 11-18 Problem 7-18 determined the half-width of the contact patch for a 1.575-in-dia steel cylinder, 9.843 in long, rolled against a flat aluminum plate with 900 lb of force to be 0.0064 in. If the cylinder rolls at 800 rpm, determine its lubrication condition with ISO VG 1000 oil at 200°F. R₁ = 64 μin (cylinder); R₁ = 32 μin (plate). 11-19 The shaft shown in Figure P11-4 was designed in Problem 10-19. For the data in the row(s) assigned from Table P11-1, and the corresponding diameter of shaft found in Problem 10-19, design suitable bearings to support the load for at least 5E8 cycles at 1200 rpm. State all assumptions. (a) (b) Using hydrodynamically lubricated bronze sleeve bearings with ON = 40, 1/ d=0.80, and a clearance ratio of 0.002 5. Using deep-groove ball bearings for a 10% failure rate. *11-20 Problem 7-20 determined the…arrow_forwardCalculate the shear force at the point D on the beam below. Take F=19 and remember that this quantity is to be used to calculate both forces and lengths. 15F A сarrow_forward"II-1 The shaft shown in Figure P11-I was designed in Problem 10-1. For the data in the row(s) assigned from Table P11-1, and the corresponding diameter of shaft found in Problem 10-1, design suitable bearings to support the load for at least 7E7 cycles at 1500 rpm. State all assumptions. (a) Using hydrodynamically lubricated bronze sleeve bearings with Ox = 20, 1/d=1.25, and a clearance ratio of 0.001 5. assume bearings act as simple supports FIGURE P11-1 Shaft Design for Problem 11-1 11-2 The shaft shown in Figure P11-2 was designed in Problem 10-2. For the data in the row(s) assigned from Table P11-1, and the corresponding diameter of shaft found in Problem 10-2, design suitable bearings to support the load for at least 3E8 cycles at 2.500 rpm. State all assumptions. (a) Using hydrodynamically lubricated bronze sleeve bearings with ON=30, 1/d=1.0, and a clearance ratio of 0.002. FIGURE P11-2 Shaft Design for Problem 11-2 Table P11-1 Data for Problems assume bearings act as simple…arrow_forwardFor the frame below, calculate the shear force at point Q. Take P=13 and note that this value is used for both the loads and the lengths of the members of the frame. 1 A Q ✗ 19 KBP 2.5P- B R C 45 degrees ✗ 1 .2P- 4PhN -P→arrow_forwardCalculate the Bending Moment at point D in the frame below. Leave your answer in Nm (newton-metres) J J A 2m 2m <2m х D 不 1m X E 5m 325 Nm 4x 400N/marrow_forwardIn the beam below, calculate the shear force at point A. Take L=78 and remember that both the loads and the dimensions are expressed in terms of L. 143 1 DX A - Li 4 LhN 14LRN/m Х B 22 3 L.arrow_forwardCalculate the Shear Force at Point F on the beam below. Keep your answer in Newtons and make shear force positive to the right. A х 2m <2m E D 5m 1m Хт 325N1m 400N/m 8arrow_forwardThe normal force at C on the beam below is equal to: A ShN C X 15h N 8 ○ OkN 2.5kN 10kN ○ 12.5kN 1m Im 1m 1m;arrow_forwardCalculate the y coordinate of the of the centroid of the shape below. Take A= 18.5 8 6A 4A X 6Aarrow_forwardIn MATLAB write out a program to integrate the equations of motion of a rigid body. The inertia matrix is given by I = [125 0 0; 0 100 0; 0 0 75] which is a diagonal, where diag operator provides a matrix with given elements placed on its diagonal. Consider three cases where the body rotates 1 rad/sec about each principal axis. Integrate the resulting motion and study the angular rates and the resulting attitude (use any attitude coordinates). For each principal axis case, assume first that a pure spin about the principal axis is performed, and then repeat the simulation where a small 0.1 rad/sec motion is present about another principal axis. Discuss the stability of each motion. The code should produce a total of 6 simulations results when it is ran.arrow_forwardarrow_back_iosSEE MORE QUESTIONSarrow_forward_iosRecommended textbooks for you
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