# Strength an of Electric motor?

Discussion in 'Sensors and Actuators' started by Moha99, Apr 3, 2012.

1. ### Moha99

261
0
Nov 18, 2011
Hey everyone...

I know this title is kinda weird but... Lately i've been thinking about the amount of mechanical power a motor can generate! I mean specifically the motor's shaft! If im supplying it with enough power... How much can the motor shaft handle? The shaft rotate or move etc... things that is more than its weight?

I don't really know how to describe this much... Just think of it this way: How strong is a motor?

Thanks.

Last edited: Apr 3, 2012
2. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,482
2,830
Jan 21, 2010
It all depends on the motor and how much power you're supplying to it.

A trivial solution is when its unpowered, it can supply no power -- indeed that's the only time the input power is = output power. All other solutions the output power < input power.

218
1
Nov 28, 2011
4. ### BobK

7,682
1,688
Jan 5, 2010
Are you really intersting in power (how much work it an do per second) or torque, which is how much force it can apply at a given radius? Motors are usually rated by horsepower or watts for power and foot pounts or newton meters for torque. Both parameters are needed for mechanical design.

Bob

5. ### john monks

693
2
Mar 9, 2012
Maybe this will help. An induction motor has low starting torque and good running torque. These are normally used in electric fans. A series wound motor typically has high starting torque and run very fast with no load. Therefore a load should always be attached or it might blow apart. These are normally used in street cars. A parallel wound motor has low starting torque and has a fixed running speed. These are normally used in blenders, sowing machines, and electric starters. A permanent magnet motor is like a parallel wound motor but is more efficient because there is no field winding. These are normally used in wheel chairs and toy cars.

6. ### Moha99

261
0
Nov 18, 2011
Thanks that give me a pretty good image of how strong theses kinds motors can be.

Im interested in how much weight can it carry and how fast can it carry it and is is powerful enough to move very heavy things more heavier than its own mass across a room in seconds?

Yea the input power would mostly be very high near to the motor's required input but I was kinda thinking of how much can it handle and carry and move around that's what i was interested in is the mechanical energy produced from the motor that strong? how can i calculate the resistance added to it like if for example this induction motor:

If i connected a rope pulley to the 1st motor to for example the second motor's shaft while its not connected to an input just rotating at the 1st motor's speed. How can i calculate that effect and rotation and so on...?

Well thats just HUDGE and 101MW I can never afford...

7. ### BobK

7,682
1,688
Jan 5, 2010
The horsepower rating of a motor tells you how much work it can go in a given time. One horsepower is 550 foot pounds per second. This means that it can lift 550 pounds 1 foot in 1 second, or 1 pound 550 feet in one second, or any combination of pounds and feet that multiply to 550 in 1 second. Give it 2 seconds and it can lift 1100 lbs one foot etc.

Have you thought about taking a class in physics?

Bob

8. ### Moha99

261
0
Nov 18, 2011
I've taken classes in physics back in high school and in my school that class was never taken seriously due to countless reasons, last time i went into a physics class and went out understanding everything was back in middle school where our teacher was amazing.

Now im collage and im not taking physics until next semester so Im studying things here and there.

But thanks for the information that helped a lot!