Machine Design A.2

Grashof`s Law

" For a planar four-bar linkage, the sum of the shortest and longest lengths cannot be greater than the sum of the remaining two link lengths if there is to be a continuous relative rotation between two member." How do you call the preceeding statement?

upper deviation is zero

A basic shaft is one whose

root circle

A circle coinciding with a tangent to the bottom of the tooth space

collinear shaft

A flange coupling is used for

flywheel

A heacy rotating body which serves as reservoir for absorbing and redistributing kinetic energy

worm gear

A kind of gear used for heavy duty works where a large ratio of speed is required and are extensively used in speed reducers

bevel gear

A kind of gear used to transmit motion from one shaft to another shaft at angle to the first

Square Thread

A kind of thread in which the width of the thread is approximately equal to its depth and the space between the threads is uniform

impact load

A load that is applied at some initial velocity.

bearing stress

A localised compressive stress at the area of contact between two members is known a

quick-return mechanism

A mechanism that includes an oscillating link or a reciprocating slider that moves forward slowly and returns quickly, with constant speed input.

less than (done) 50%

A screw is said to be self -locking screw if its efficiency is

hydrostatic lubricated bearing

A sliding bearing which supports load without any relative motion between the journal and the bearing by forcing pressurized lubricant between the members, is called

equilibrium is maintained

A system of forces in space is in equilibrium.If two equal and opposite collinear forces are added, which of the following if any is true?

All of the above (Column, Pillar, Stanchion)

A vertical strut is known as ____.

epicycloid

Addendum of a cyclodial gear tooth is

maximum

At the neutral axis of a beam, the shear stress is

all of these (loose load, driving pulley too small, heavy belt)

Belt slip may take place because of

2130mm (max)

Clearance to a new boiler installation to the existing or old plant building should follow a minumum clearance of __ between top the boiler proper and the ceiling as stated in the PSME Code:

80

Considered a maximum safe center distance of sprockets should be____ pitches. Very long center distance cause catenary tension on the chain.

kinematics

Deals only with the motion of bodies without reference to the forces that causes them

none of the above (20%, 10%, 25%)

For a roller chain drive, the slack side tension is approximately ______ of the tight side tension.

neutral surface

For a simply supported beam subjected to a flexural stress, what do you call the surface at which the fibers are neither shortened or lengthened?

hunting tooth addition

For an evenly distributed and uniform wear on each meshing gear tooth, the ideal design practice is to consider a _________.

1.25 - 4

For moderatre speed of mating gears, the ideal ratio of contact is:

3/4

Half the maximum shear stress developed in a beam of rectangular section is ........ the average shear stress

addendum

Height of tooth above pitch circle or the radial distance between pitch circle and top land of the tooth.

rusting

How do you call the corrosion of iron-based alloys?

spring index

How do you call the ratio of mean diameter coil and the coil diameter of a spring?

bevel gear

Hypoid gear is a special type of gear like:

pitch plane

In a pair of gears,__ is the plane perpendicular to the axial plane and tangent to the pitch surface.

the shoe floats

In centrifugal clutch, when the centrifugal force is equal to the spring force,

both ends hinged

In designing a connecting rod, it is considered like .............. for buckling about X-axis.

Design = ultimate stress divided by factor of safety

In general, the design stress and factor of safety are related as follows:

axial load also increases

In helical gears, as the helix angle increases,

axial pitch

In helical gears, the ratio of the transverse circular pitch to the tangent of the helix angle is

high

In majority of machine members, the damping capacity of the material should be

50

In shear pin or breaking pin design, we may use the data experienced by link belt from 1/8 inch to 1inch pins and the breaking stress is ___ksi.

45 °

In the analysis of combined stresses, the planes of maximum shear stress lie at ____ to the principal planes

0.56

In the gear design, the total work must be equally shared by its arms. Rim must be rigid to support these arms and also the bead is recommended for its stiffening value. The assumption in the detailed design of rim thickness and depth of bead is _______ circular pitch (PC).

regular lay rope

In this popular wire rope, the direction of twist of wires in the strands is opposite to the direction of twist of the strands in the rope

all of these (flywheel, balance of wheel, flywheel pulley)

It equalizes the energy exerted and the work done thus preventing excessive or sudden changes of speed:

kinematics

It is a science of motion that can be solved in terms of scalar or vector algebra:

15 to 20

It is advised that in rubberr belts application?mounting, it should have an initial tension of ___inch/ply.

circular pitch

It is the circular pitch in the plane of rotation of a helical gear.

clearance

It is the difference between the addendum and dedendum which is equivalent to the whole depth less working depth.

average life or a bearing

It is the life which 50 per cent of a group of bearings will complete or exceed and is approximately 5 times the life which 90 per cent of the bearings will complete or exceed

Hencky and Von Mises theory

Maximum Distortion Energy Theory is also known as

babbit

Metal that assist lubrication or lubricant in itslef:

interference of metal

Negative allowance is also called

2.5Pc < b < 4Pc

One of the causes of spur gear tooth breakage is the unbalanced load on one end of the tooth that results in higher stresses than whe n the load is evenly distrubuted. To minimize this problem, the face width "b" should not be greater than the thickness ( or pitch) of the tooth. In the absence of test values, the following can be a guide

module

Ratio of pitch diameter to the number of teeth

bottom land

Refers to the surface of the gear between the fillets of adjacent teeth.

component forces

Separate forces which can be so combined are called

have any type of motion

Statement that a given body is in static equilibrium means that the body cannot:

girth

Th size of fiber rope is usually designated by its

inertia

That property of matter which causes it to resist any change in its motion or state of rest:

ductility

The ability of metal to stretch, bend or twist without breaking or cracking

all of these (HP= D^3N/80, HP=D^3N/53.5, HP=D^3/38)

The allowabe stresses that are generally used in practice are 4 ksi for main power transmitting shaft, 6 ksi for lineshaft carrying pulleys, and 8.5 ksi for small, short shaft/countershaft, etc. With these available stresses what will be simplified formula to determine transmitted horsepower, diameter of the shaft or even the rpm (N)?

equal to

The axial force on the worm gear is ____ the tangential force on the worm.

strains

The changes in shape or geometry of the body due to action of force on it is called deformation or ________.

backlash

The clearance between the tooth profiles of a gear tooth

law of gearing

The common normal at the point of contact between a pair of teeth must always pass through the pitch point. This statement summarizes the

fillet curve

The concave portion of the tooth profile where it joins the bottom of the tooth space

pitch

The distance between similar, equally spaced tooth surfaces in a given direction and along a given line.

completely reversed load

The endurance or fatigue limit is defined as the maximum value of the stress which a polished standard specimen can withstand without failure, for infinite number of cycles, when subjected to

long belt length

The following are the advantages in using a cross belt drive except:

to disconnect or connect at will the drive

The function of the clutch in ther machine tools is?

dead center

The kind of center which is being attached and meshed to the tailstock spindle which is also static while the work is rotating

ulitmate stress

The maximum stress to which a material may be subjected before failure occurs:

injection molding

The process commonly used for thermo-plastic material is

linear impulse

The product of the resultant of all forces acting on a body and the time that the resultant acts:

spring gradient

The ratio of the load on a spring to its corresponding axial deflection.

allowable stress

The ratio of the ultimate strength or yield strength of a material to a factor of safety is known as

module

The reciprocal of diametral pitch. It is equivqlent to the ratio of pitch diameter to the number of teeth

25%

The strength of a shaft with a keyway is almost reduced by as much as

double

The stress in the bar when load is applied suddenly is ............. as compared to the stress induced due to gradually applied load.

whole depth

The sum of addendums and dedendums.

continuous beam

The three moment of equation may be used to analyze:

screw

This is an externally threaded fastener capable of being inserted into holes in assembled parts, or mating with a preformed internal thread or forming its own thread and of being tightened or released by torquing the head.

tolerance

This refers to the permissible deviation of a dimension from a specified basic size

double block brake

This type of brake is often used in electric cranes.

smaller than friction angle

To ensure self -locking in a screw jack, it is essential that the helix angle is

saws and chisels

Tools usually used in wood pattern making in foundry shop

chordal thickness

Tooth width measured along the chord at the pitch circle:

4500

V-belts operate efficiently at speed of about (fpm)

bolt

What is a screw fastener with a nut on it?

59 deg

What is the recommended best cutting angle of drill for work on steel or cast iron?

clearance fit

What type of fit do journal bearings have?

helical

What type of gear is used for high speed operation?:

driving tension in tight side is twice the centrifugal tensopm

When a belt drive is transmitting maximum power,

double

When helical compression spring is cut into halves, the stiffness of the resulting spring will be

gear rack

When meshed with a gear, it is used to change rotary motion to reciprocating motion

interference of metal

When the hole is smaller than the shaft, it will take pressure to put the parts together. The allowance is said to be negative and is determined:

20 percent

When the outer race of a rolling contact bearing is rotating while the inner race is stationary, the radial load on the bearing is increased approximately by

conservation of momentum and conservation of energy

When two elastice bodies collide, which of the following laws can be used to solve for the resulting velocity?

Extra-course thread, UNEC

Which is not a standard thread?

needle bearing

Which of the following is antifriction bearing?

Rankine`s Column Formula

Which theory is applicable for both short and long columns?