Transcript Jig Saw Dissection

Jig Saw Dissection
By: Shayne Welsh
Jig Saw
• Objective
– How the saw operates from battery to motor
• This type is also known as a reciprocating saw
Parts
•
•
•
•
Power Source
Trigger/Throttle
Safety Switch
Motor
Power Source
• Power source can be either a battery or plug
• Batteries range in voltage, depending on model
– 8V
– 14.4V
• Using a plug allows a larger motor, so more
powerful saw
• Batteries are portable and are able to be used at
any worksite
Trigger/Throttle
• The trigger acts as both an ‘On’ switch and
a voltage regulator
• As the trigger is squeezed, the connection
inside is completed, allowing energy to
move from the battery into the motor
• The further the trigger is squeezed the
more energy that passes at a given instant
• Causes the motor to accelerate by
squeezing harder
Safety Switch
• Safety switches prevents saw from
running when unintended
• Plastic object that prevents trigger from
being pulled back unless it is moved to the
side
• Spring loaded so it reset itself into the
‘safe’ position immediately after being let
go
Motor
• Converts electrical energy to mechanical
energy, electromagnetism
• Mechanical force on an wire when it is
conducting electricity while contained
within magnetic field
– Perpendicular to both wire and magnetic field
– In rotary motor
• Wires and magnetic field are arranged so torque is
developed on rotary axis
Motor
•
•
•
•
Rotating part is called the rotor
Stationary part is stator
Electromagnets are wound on a frame
Armature
– Part of motor which input voltage is supplied
across
– Can be either stator or rotor, depending on
model
Motor
Step 1
Magnetic field
generated around
armature, left side is
pushed away form left
magnet and drawn
toward right
Step 2
Armature
continues to
rotate
Step 3
When armature is horizontally
aligned, commutator reverses
direction of current through coil,
reversing magnetic field and
process repeats
Conclusion
• Reciprocating saw operated by motor
converting electric energy to mechanical
energy
References
• http://www.defusco.com/Images/RS5.jpg
• http://en.wikipedia.org/wiki/Electric_motor#
Operation
• http://cgi.ebay.com/ws/eBayISAPI.dll?View
Item&item=6013540126