MSSC QUESTIONS AND VERIFIED SOLUTIONS

MSSC QUESTIONS AND VERIFIED SOLUTIONS Chain sag can be changed by __________ the sprockets. - ANSWER Moving A chain drive system has a driver sprocket with 72 teeth and a driven sprocket with 24 teeth. If the driver shaft has 1899 ft-lbs torque, the torque on the driven shaft will be __________. - ANSWER - 633 ft-lbs Chain drive torque is the same as the gear ratio, meaning that when torque increases the sprocket ratio __________. - ANSWER - Increases Misaligned chain drives can be visually inspected to note vertical angular, horizontal angular, and __________ parallel misalignments. - ANSWER - Horizontal The ratio of the speeds of the sprockets is the __________ of the sprocket ratio. - ANSWER - Inverse Sprocket sizes are determined by the __________ instead of the diameter of the sprocket. - ANSWER - Number of teeth The chain climbing the sprocket is a symptom of which condition? - ANSWER - Excessive chain wear or sprocket wear What is a master link? - ANSWER - The preferred method of connecting a chain When a chain's length becomes 3% longer than its original length, __________. - ANSWER - It is time to replace it Chain drives deliver __________ mechanical power than belt drives. - ANSWER - More Timing belts are used in which of these drive belt drive applications: - ANSWER - Stepper motor applications and automobile engines What is the belt drive ratio? - ANSWER - Driven sheave pitch diameter divided by the driver sheave pitch diameter The shaft of a belt drive may be bent if the maintenance person performs an alignment check with a straight edge and finds what condition? - ANSWER - The straight edge initially contacts all four points, and after rotating the shaft, it only contacts two points. What is the diameter of the driven pulley that is turning 700 rpm, when the 6-inch driver is rotating 2,100 rpm? - ANSWER - 18 inches The belt drive ratio is also used to calculate the belt drive torque. The formula is __________ proportional to the drive ratio. - ANSWER - Directly Which drive alignment method is faster and more accurate than the straight edge method? - ANSWER - Laser alignment Prior to maintenance, a machine produced 100 parts per minute. The machine was designed to produce 200 parts per minute. The drive belt was replaced. The machine should now be monitored in order to verify that __________. - ANSWER - It will produce 200 parts per minute The following condition is an indicator of improper v-belt alignment. - ANSWER - Excessive bearing and belt wear Measuring a groove angle for wear is a maintenance check performed on what machine component? - ANSWER - Belt drive sheave In contrast to other types of belts, which of the following is determined to be properly adjusted when belt slap is eliminated? - ANSWER - Flat leather belts A gear drive has a minimum of two gears called __________. - ANSWER - Driver and driven Gears are pre-aligned at the factory; however, the shafts of the gear box must be attached using a __________ device to other shafts. - ANSWER - Coupling The gear drive torque is __________ the gear ratio. - ANSWER - Directly proportional to To calculate the speed of a gear, the speed ratio and the __________ will be needed. - ANSWER - Gear ratio Which of the following gear types is used in machine tools like lathes, drills, and planer machines? - ANSWER - Rack and pinion In a spur gearing system, the small gear is called the __________. - ANSWER - Pinion What is the name of the clearance that allows lubricant to reach the gear teeth? - ANSWER - Backlash What is the gear ratio? - ANSWER - Driven gear pitch diameter divided by driver gear pitch diameter If gear X turns clockwise at a constant speed of 10 rpm, how does gear Y turn? - ANSWER - Counterclockwise at 10 rpm The gear system shown is added to a motor rotating at 200 rpm. What is the speed of the driven gear? - ANSWER - 50 rpm Which of the following is NOT a type of shaft-to-adjacent shaft power transmission? - ANSWER - Clutch drive What causes soft foot? - ANSWER - Uneven mounting surfaces __________ all machine components before coupling them together will reduce the number of shims required for alignment. - AN