PLTW Robotics Test
What is the output movement of a rack and pinion
linear
what is a leadscrews output movement?
linear
What types of mechanisms change direction?
meshed gears and output shafts
Input movement of a crank and slider
rotary
What is the input movement of a rack and pinion
rotary
input movement of a Cam and Follower
rotary
what is a leadscrews input movement?
rotary
a rack and pinion are used to convert between ____ and _____ motion.
rotary and linear
Universal joints are used to transmit ______ movement at an angle that is not ___°.
rotary movement at an angle that is not 90°
a leadscrew Changes _____ movement into _____ movement
rotary to linear
As a cam rotates, the flat follower is raised and lowered, converting _______ motion to _______ (back and forth) motion.
rotary to reciprocating
The bevel gear is used to change_______ motion at an angle.
rotational
An Idler Gear allows the drive and driven gears to rotate in the ____ direction.
same
Shaft direction in a chain drive
same
input & output gears in a Simple Gear Train with idler goes in the _____ direction
same
universal joints in input and output shafts
same direction
what direction does the open belt go in the belt drive
same direction
Using gears with differing numbers of teeth will change the ____ and ____.
speed and torque
In the bevel gear, if input is < output what happens?
speed decreased torque increases
what is smaller in a chain drive
sprocket
Where do you find a pulley and belt?
Lawn mower, car engine
Follower moves up and down _ times for every revolution of the crank in the cam and follower
1
ratio of a chain drive
18:30 or 3:5
A Simple Gear Train ratio is ?:?
1:1
A Simple Gear Train with idler ratio is ?:?
1:1
Ratio of a universal joint
1:1
ration in the belt drive
1:1
In the bevel gear, what is the gear ratio?
1:2
slider moves of a crank and slider
2 inches
in the worm and wheel what is the gear ratio?
24:1
A Ratio in a Simple Gear Train is __Teeth:__ teeth or _:_
36 teeth:60 teeth or 3:5
how many revolutions does a leadscrew have?
4.75
what direction is the Worm and Wheel
90 degree angle
Angular range of a universal joint
>90 <270
What is a Mechanism?
A mechanism is the part of a machine which contains two or more pieces arranged so that the motion of one compels the motion of the others
Where do you find a chain and sprocket?
Bicycle and motorcycle
Where Do You Find a Cam and Follower?
Cam shaft
Speed in a Simple Gear Train with idler is
Constant
Where can you find a universal joint?
Drive shaft of vehicles, power take-off
Where can you find the bevel gear
Hand drill, car differential, shaft-driven bicycle
Where do you find a lead screw?
Jack, vice
The motion is _________ ; a gear cannot drive a worm.
NOT REVERSIBLE
Where Do You Find a Simple Gear Train with Idler?
Paper transport rollers
Input and output shafts in a Simple Gear Train with Idler are
Parallel
Why would you use belts instead of chains
Quieter and less expensive
What happens because the larger drive pulley in the belt drive
Speed - increased Torque - decreased
Where Do You Find a Crank and Slider?
Steam train, internal combustion engine.
______ is a push or pull in a circular direction
Torque
Advantage of Chain and Sprocket over spur gears
Transfer torque and speed over long distances
Where do you find worm and wheel
Tuning mechanisms on string instruments, electric motors, winch
Where do you find a rack and pinion?
Used in steering systems to convert the rotary movement of turning the steering wheel into linear motion in wheels
Where do you find a simple gear train?
Watches, sewing machine, motor
What direction is the bevel gear in
angled
Speed and torque in a universal joint
constant
Speed in a Simple Gear Train is
constant
Torque in a Simple Gear Train is
constant
speed in the belt drive
constant
torque in the belt drive
constant
Torque in a Simple Gear Train with idler is
constatnt
In the bevel gear, torque is
decreased
Torque is _____ in a Simple Gear Train
decreased
in the Worm and Wheel speed is
decreased
torque of a chain drive
decreased
Simple gear train without idler gear
different directions
A _____ is a push or pull in a straight line
force
in the leadscrew _____ is increased
force
In the bevel gear, speed is
increased
Speed is _______ in a Simple Gear Train
increased
in the worm and wheel torque is
increased
speed of a chain drive
increased
increased crank of a crank and slider
increased distance slider moves
a leadscrew Significantly ______ force
increases
Flow of power of a crank and slider
not reversible
direction of travel in the cam and follower
not reversible
flow of power in the cam and follower
not reversible
in the worm and wheel the flow of power is
not reversible
the flow of power in a leadscrew is _________
not reversible
Gear direction in a Simple Gear Train is _____
opposite
Two meshed gears will rotate in _______ directions
opposite
what direction does the crossed belt go in the belt drive
opposite
What are the types of movement
oscilating rotary linear and reciprocating
If the _____ Gear is larger than the _____ gear the speed will decrease but the torque will increase
output gear is larger than the input
If the ______ gear is smaller than the ______ gear the speed will increase but the torque will decrease
output gear is smaller than the input
Gear ratios compare the ________ to the ________
output to the input
Angle of a chain drive
parallel
Input and output shafts in a Simple Gear Train are
parallel
What is the shaft in the belt drive
parallel
output movement of a Cam and Follower
reciprocating
output movement of a crank and slider
reciprocating
A worm is used to ____ speed and _____ torque.
reduce and increase
Flow of power in a Simple Gear Train is _______
reversible
Flow of power in a Simple Gear Train with idler is _______
reversible
Flow of power in a universal joint
reversible
In the bevel gear, what is the flow of power?
reversible
What is the direction of power of a rack and pinion
reversible
What is the flow of power in a rack and pinion
reversible
in the leadscrew direction of travel is _______
reversible
in the worm and wheel what is the direction of travel?
reversivle
what will happen to a rack and pinion with a larger pinion gear
the rack will move a longer distance
How can gear ratios be determined?
using the number of teeth or the diameter of the gear