I have an electric drill with two side by side motors. It has an aluminum body casing that has no distinguishing marks. The cord was old and frayed and when replaced the motors just sparked. Were the two motors for two speed, or maybe for forward and reverse. There is no name plate on the drill. Has anyone ever seen this type of drill?
2007-04-05 16:40:01 · 5 answers · asked by Anne D 1 in Science & Mathematics ➔ Engineering
My guess is that it was to reverse directions. Old electric drills with one motor generally turned only one way, since they used series-wound motors and alternating current, and this type of motor only spins in one direction, even if you give it DC and reverse the polarity. Modern cordless drills do reverse direction by changing the DC polarity to the motor, but the motors are permanent magnet type, which require DC would not be found in an antique AC drill.
To get two speeds, a change of gearing would have been used rather than 2 motors, in order for the motor to always run at full speed so that at the lower drill speed you would have more torque (just as with a transmission in a car). You would not need 2 motors for two speeds.
2007-04-05 16:52:02 · answer #1 · answered by Adam S 4 · 1⤊ 0⤋
it is almost surely two speeds. it wouldn't be separate directions as they would have just reversed the flow of current to make the motor turn the opposite direction. i'm no expert on tools, but i can't think of any other reason to have two motors in it. are you positive it's a motor and not a transformer? they could look the same, and most motors need to run off of DC rather than AC. it could be a transformer/diode.
2007-04-05 16:45:43 · answer #2 · answered by metalluka 3 · 0⤊ 1⤋
to just drill holes, a drill does not need to reverse.
sometime kludges like this were made by companies that needed to avoid patent claims of existing products. they reversed engineered the function and found a slightly different way to perform it. not better, just enough different to prevent infringement.
2007-04-07 10:47:33 · answer #3 · answered by lare 7 · 0⤊ 0⤋
I wouldn't think it was for speed, or direction. My guess is that it was to increase the torque applied to the chuck.
2007-04-05 20:07:59 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Very unlikely
2016-05-18 02:22:54 · answer #5 · answered by ? 3 · 0⤊ 0⤋