Definition of a Motor
Definition of a Motor
(OP)
Hi everyone, just looking for some categorical clarification as I am writing a report on rotating equipment and giving brief overviews of the main types of rotating equipment. In my report I have basically categorized all rotating equipment into two classes: drivers and driven equipment.
My understanding of the hierarchical definition of a motor is that it is the most broad term. In essence, electic motors, engines (heat powered motors), hydraulics motors, pneumatic motors, etc. are all "motors". For instance I have always been of the understanding that an engine is a type of motor (a heat motor), but a motor is not necessarily an engine (e.g. an electric motor is not an engine). Does this seem to make sense?
My real question is related to turbines and motors. A turbine, like a motor, is a "driver". It converts heat and pressure energy into mechanical shaft rotation. Is a turbine a type of motor...? I mean, as per my logic above (an "engine" is a type of heat powered motor) wouldn't a typical gas turbine "engine" then be a type of motor?
I know nobody expresses things this way in a colloquial sense, but I am looking for a fundamental, hierarchical definition.
Thanks for the input!
My understanding of the hierarchical definition of a motor is that it is the most broad term. In essence, electic motors, engines (heat powered motors), hydraulics motors, pneumatic motors, etc. are all "motors". For instance I have always been of the understanding that an engine is a type of motor (a heat motor), but a motor is not necessarily an engine (e.g. an electric motor is not an engine). Does this seem to make sense?
My real question is related to turbines and motors. A turbine, like a motor, is a "driver". It converts heat and pressure energy into mechanical shaft rotation. Is a turbine a type of motor...? I mean, as per my logic above (an "engine" is a type of heat powered motor) wouldn't a typical gas turbine "engine" then be a type of motor?
I know nobody expresses things this way in a colloquial sense, but I am looking for a fundamental, hierarchical definition.
Thanks for the input!





RE: Definition of a Motor
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Definition of a Motor
maybe fluid-powered motors ... although I can't think of any heat-powered ones which aren't fluid-powered offhand, nor vice-versa.
take that back ... hydraulic motors are not heat powered but are fluid powered. stick with heat.
RE: Definition of a Motor
However, I think today in the modern day context, "Motors" are meant (or should be meant) to refer to machines that convert a certain potential energy (chemical, electric, pneumatic, hydraulic, etc.) into rotational mechanical energy. I have read a lot of opinions that a motor is something that simply converts a potential energy into a rotational OR linear force, but I don't think this makes much sense... We have a more generic term that nicely captures both: an Actuator. Actuators can be classified as both rotational and linear, with the latter encompassing everything a Motor would not. Also, when I think of a Motor I think of a rotating shaft.
Still open to any thoughts on this!
RE: Definition of a Motor
Why don't you throw this up into forum1010: Engineering Language/Grammar Skills and let those guys bash it around. This Motor ,Engine, Rotary actuator, Rotary expander. semantics thing varies from country to country. See what the language guys say.
B.E.
You are judged not by what you know, but by what you can do.
RE: Definition of a Motor
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Definition of a Motor
GL - your original 4am statement seems valid enough to me - what do you think it should say?
RE: Definition of a Motor
But, if we accept that an electric motor and a water wheel (or water turbine) are not engines, but are motors, then... I was taught that an "engine" converts heat energy into motion. So, a steam engine consists essentially of two major components, a fire box and boiler that converts heat energy into pressure and then a motor that converts pressure into motion. So, a gas turbine consists of a burner that converts heat energy into pressure and kinetic gas flow and a turbine the converts kinetic gas flow into rotational motion. Without tapping the rotational motion of the shaft, the kinetic gas flow creates motion as a reaction to its momentum. So these are engines.
By the corresponding logic, a turbocharger could be a motor if it only converts gas momentum into rotational motion and it could be an engine if it converts exhaust heat into motion (there is a temperature drop across the turbo). So, because of adiabatic effects, the turbine of a turbocharger (and a steam motor) are not "pure" motors whereas a water wheel or water turbine would be "pure" motors.
I was not completely de-confused by what I was taught.
RE: Definition of a Motor
Let us not forget that outboard motors have engines inside them.
RE: Definition of a Motor
"I was taught that an "engine" converts heat energy into motion" - by that definition, guns and bombs are engines, and so is our atmosphere.
I really think it's like defining a screw vs. a bolt.
RE: Definition of a Motor
BTW a screw is not necessarily a bolt (jack screw, ships propeller), but AFAIK, a bolt has a screw as a part. Again, historical use.
RE: Definition of a Motor
Also, adressing the topic as a whole: there are always exceptions.
RE: Definition of a Motor
Further, we might include in the definition of heat engines things that convert heat energy into forms of potential energy or stored potential energy (like the steam boiler or electrical generator, battery, etc), but then the motor function may not exist and there is no discussion about what's a motor and what's an engine.
I think the above is sufficient for the restricted discussion of heat engines.
Then we can talk about motors that convert a form of potential energy into kinetic energy in apparent isolation from any heat engine like an electric motor or a wound rubber band, but when you look closely, inevitably there will be an attached heat engine at some time somewhere be it a nuclear plant or hydro system powered by the Sun, a human or a team of mules, etc.
RE: Definition of a Motor
RE: Definition of a Motor
RE: Definition of a Motor
Did you make them go, by yelling out " hooptie do!"
B.E.
You are judged not by what you know, but by what you can do.
RE: Definition of a Motor
I also discovered that a big proportion of new car makers call themselves "motor" or "motors" - such Toyota Motor Company and Nissan Motor Company etc. and even General Motors. The use of the word "motor" meaning "car" seems to have been more common than I thought.
RE: Definition of a Motor
No, we never yelled out "hooptie do". That would have been uncool. Most of what we yelled out started with "Hey baby..." and might continue with some borderline morally objectionable message. Anyway, a hooptie might not even be a running car or even a complete assembly of car parts, but the essential thing is that there was always a hope and a promise of a car.
RE: Definition of a Motor