Introduction To Mechanical Drives

Front 1

What are the LOTO steps?

Back 1

P - Prepare to shut down the machine
S - Shut Down/off the machine
I - Isolate power supply from machine
A - Apply lockout device
C - Control stored energy
V - Verify de-energization

Front 2

Why are LOTO procedures used?

Back 2

Protects the worker who is working on the equipment. Requires a test to ensure the equipment has been de-energized. ALL sources of power must be isolated, controlled and tested before beginning work.

Front 3

What 2 things must be included on a tag that has been placed on a machine?

Back 3

"DO NOT OPERATE" and installer's name

Front 4

Who is authorized to remove a LOTO device?

Back 4

ONLY the person who installed it.

Front 5

Main shaft primary function and the general function of any shaft

Back 5

Transfers mechanical/rotary power in the for of torque to the gearbox. / Generally, a shaft transfers rotary power from one location to another.

Front 6

What is the function of the gearbox in a turbine and what can it NOT do?

Back 6

To convert low speed high torque of the main shaft to high speed low torque at the output shaft. It cannot increase overall power.

Front 7

What is the purpose of the clutch?

Back 7

Allows two shafts to be disconnected while in operation

Front 8

List the four methods of power tranmission

Back 8

Thermal, Fluid, Mechanical, Electrical

Front 9

Name three types of shaft-to-adjacent shaft power transmission.

Back 9

Belt, Chain drive, Gear Drive

Front 10

What is the function of the bedplate/baseplate? What procedure is necessary before mounting?

Back 10

Provides a rigid, level surface for mounting a motor, generator, gearbox etc. Bedplate must be leveled beforehand.

Front 11

What circumstances would an adjustable motor mount be used?

Back 11

When the tension on a belt needs to be adjusted routinely.

Front 12

What are accuracy and precision? How do they differ?

Back 12

Accuracy is how close the measured value is to the true or actual value. Precision is how close the measured values are to each other.

Front 13

List the parts needed to attach a motor to a bedplate

Back 13

hex head bolt, two flat washers, one lock washer, one nut

Front 14

What ensures the bolt will not slip through the bolt hole?

Back 14

the flat washer

Front 15

How do you determine the grade of a bolt?

Back 15

Reading/interpreting the markings on the head of the bolt.

Front 16

Revolutions per Second (RPS) convert to Revolutions per Minute (RPM)

Back 16

Multiply said number by 60 or divide if going from RPM to RPS

Front 17

What two things can a level determine?

Back 17

True horizontal and True vertical

Front 18

What do you do to a key after cutting it from keystock?

Back 18

Lightly chamfer the ends of the key

Front 19

How does the torque load on the shaft of an electric motor affect the amount of electric current?

Back 19

As torque increases, current increases. As torque decreases, current decreases

Front 20

Where does the key fit in a keyed shaft and how should it fit?

Back 20

Fits into the key seat of the shaft without being forced

Front 21

Convert 25 HP to Kilowatts using Pkw = Php x 0.746

Back 21

18.65kW

Front 22

What types of motor mounts are there?

Back 22

Foot mount, c-face/flange mount (attaches directly to the face of a component), adjustable mount.

Front 23

What is end float and its tolerance?

Back 23

The amount the shaft moves along its axis. Tolerance = .001"

Front 24

What is TIR? What is run out and its tolerance?

Back 24

Total Indicator Reading. Runout is the dynamic radial eccentricity (wobble that occurs when a shaft rotates) = 1/2 the TIR. Tolerance = .002"

Front 25

What is soft foot? How do you correct it? What is the tolerance?

Back 25

Condition of a machine where it rests on three feet instead of four. Corrected by shimming the affected foot. Tolerance = .002"

Front 26

What are the four types of misalignment?

Back 26

Vertical offset, Horizontal offset, Vertical angular, Horizontal angular. VO HO VA HA

Front 27

What are the eight steps of rough alignment (including pre-alignment)?

Back 27

Level the shaft(s) of all machines, Measure and correct soft foot, Measure shaft runout, Measure the shaft end float, Measure and correct vertical offset, Measure and correct horizontal offset, Measure and corrrect vertical angularity, Measure and correct horizontal angularity.

Front 28

What five precision instruments are required to perform the pre-alignment and rough alignment procedures?

Back 28

Dial caliper, dial indicator, straight edge, feeler guage, spirit level.

Front 29

What size bolt would you use for a 1" diameter hole? 3/4" hole? 1/2" hole?

Back 29

One size below the hole: 7/8" bolt, 5/8" bolt and 7/16" bolt.

Front 30

Describe the functions of a bearing

Back 30

Reduces friction, Guides and supports a load, replacebale wear surface.

Front 31

Describe the function of a coupling

Back 31

Conects two shafts and transfers rotary power

Front 32

List and describe three types of loads on bearings

Back 32

Radial - load is at a right angle to the shaft axis, eg: a shear load
Axial - load runs along or parallel to the axis of rotation
Combination - radial and axis loads combined, eg: moment loads

Front 33

What are two primary categories of bearings?

Back 33

Plain (friction) bearings and Rolling element (antifriction) bearings.

Front 34

List four different shaft materials and give an advantage of each

Back 34

Cold rolled steel: inexpensive
Hardened steel: heat treated to improve strength and durability
Chrome-plated steel: corrosion resistant
Stainless steel: resists rusting, stronger than cold rolled steel

Front 35

What is a lock collar's purpose?

Back 35

Secures the bearing to the shaft

Front 36

How do you calculate mechanical efficiency (formula)?

Back 36

Output Power/Input Power x 100

Front 37

Give five precision tool handling best practices

Back 37

Handle with care, never drop, ensure the tool is calibrated properly, clean before each use, store in its protective case when not in use.

Front 38

What tool is used to take precise outer, inner and depth measurements?

Back 38

Dial caliper

Front 39

What four things can a dial indicator be ued to measure?

Back 39

End float, run out, soft float, and gear backlash

Front 40

One inch is how many millimeters?

Back 40

25.4mm

Front 41

What is a photo tachometer's primary purpose?

Back 41

Determins the rotational shaft speed, in RPM

Front 42

What five categories are shafts specified by?

Back 42

Type of material, Nominal diameter, Diameter tolerance, Straightness, Length

Front 43

Main difference between a pillow block and flanged mount bearing?

Back 43

Pillow - shaft mounts to a horizontal or angled surface.
Flanged - Shaft orientation is perpendicualr to the mounting surface.

Front 44

Main purpose of the shrink disk?

Back 44

Couples the main shaft to the hollow gearbox input shaft.

Front 45

Function of the high speed coupling?

Back 45

Coupling that ues a rubber-like insert between two hubs to absorb any slight misalignment that may be present.

Front 46

How is vertical angular misalignment measured?

Back 46

Measuring the gap between the coupling halves at the top and bottom (90 degrees and 180 degrees)

Front 47

How is horizontal angular alignment measured?

Back 47

Measuring the gap between the coupling halves at the sides (90 degrees and 270 degrees)

Front 48

What are three benefits to proper shaft and coupling alignment?

Back 48

Reduces vibration, increases efficiency, extends the life of the coupling, bearings and seals

Front 49

Main function of the rotor in a wind turbine

Back 49

Used to capture the kinetic energy of the wind and convert it to high torque rotary motion.

Front 50

Mechanical Power =

Back 50

Work/Time

Front 51

The _____ of a mechanical power transmission system is _______ than the ______.

Back 51

Output power is always less than the input power.

Front 52

Two main causes of mechanical inefficiency

Back 52

Friction and Vibration

Front 53

Power (Horsepower formula)

Back 53

Torque(lb-ft) x Speed (rpm)/5252

Front 54

What is the most common prime mover for a Mechanical Power Transmission System (MPTS)?

Back 54

an electric motor

Front 55

A ______ is used to measure both the output power and the mechanical efficiency of a machine.

Back 55

dynomometer

Front 56

Torque is determined by multiplying the _____ applied by the _______ from the axis of rotation

Back 56

force, speed

Front 57

A ______ is used to measure the electric current drawn by the prime mover

Back 57

Amperes. Measured by inductive ammeters, digital multi-meters, built-in ammeters

Front 58

The purpose of a mecahnical power transmission system (mpts) is to ________ and _____ _____ _____

Back 58

transmit and convert mechanical power

Front 59

Three methods of axial power transmissions commonly used are __________________.

Back 59

Direct Coupled, Shaft extension, clutch coupled

Front 60

Two basic types of mechanical motion

Back 60

Linear and Rotary. Linear eg - solenoid Rotay eg - drill

Front 61

Rotary machanical power has what two components?

Back 61

Torque and speed

Front 62

Torque can be defined as......

Back 62

the tendency of a force to rotate an object about its axis. Braking force can be expressed as torque.

Front 63

What is the best instrument to use when measuring an inside width of a keyseat or the depth of the keyseat?

Back 63

Caliper

Front 64

What are three functions of a foundation?

Back 64

Support compressive and shear loads, Maintain alignment between connected components, Absorbs vibration.

Front 65

A foundation is typically made of _______ or _______.

Back 65

Solid/reinforced Concrete or Steel

Front 66

ISO bolt grade indentification

Back 66

Minimum tensile strength (stress that material can withstand before necking), second numer is yield strength. If a bolt says "8.8" on its head: 8 x 100 MPa = 800 MPa (tensile) .8 x 800 MPa = 640 MPa (yield)

Front 67

Shim Ratio and Shim Value

Back 67

Lb/Le = shim ratio (base length divided by effective length)
Lb/Le x feeler guage = shim value

Front 68

The device most often used to measure motor speed is a __________.

Back 68

tachometer

Front 69

Rotational speed of a motor is most often measured in ____.

Back 69

RPM

Front 70

Angular speed is measured in _____ units in the International System of measurement.

Back 70

RPS

Front 71

The ____ tachometer has attachments which enable it to take direct readings

Back 71

hand-held

Front 72

The ____ tachometer determines motor shaft speed by counting the number of times a piece of reflective tape passes through the light.

Back 72

Photo tachometer.

Front 73

Torque formula

Back 73

Multiply load (lbs) by radius (feet) ... answer is torque.

Front 74

LOTO procedures.. other than PSIACV

Back 74

Notify affected personnel
Evaluate hazards
Shut down, isolate, block + lock
Tagout
Flag the machine
Clear Area
De-energize, test it!