An engine or motor is a machine designed to convert one form of energy into mechanical energy. Heat engines convert heat into work via various thermodynamic processes. The internal combustion engine is perhaps the most common example of a heat engine, in which heat from the combustion of a fuel causes rapid pressurisation of the gaseous combustion products in the combustion chamber, causing them to expand and drive a piston, which turns a crankshaft. Electric motors convert electrical energy into mechanical motion, pneumatic motors use compressed air, and clockwork motors in wind-up toys use elastic energy. In biological systems, molecular motors, like myosins in muscles, use chemical energy to create forces and ultimately motion.
I need a better understanding of limit swtiches and servo motors than I'm getting from Wikipedia :)
Any website/textbook recommendations? (My background is physics.)
TIA!
Hello all!
I was curious how to figure out which motor to use to help pull a sled up an inclined surface of about 55 degrees. It would be pulled on snow and has a weight of about 300lbs. Would it make a difference if the motor was on the sled vs pulling from the top of the hill? How do you...
Given an unconstrained (suspended without contact to anything) electric motor with its own power in total has mass m1
Given the motor shaft is connected to a payload of mass m2
If m1>m2 then: m1 no-spin + m2 spin
If m2>m1 then: m1 spin + m2 no-spin
What happens at the unit ratio (m1/m2 = 1...
Hello, I'm trying to use this gearbox motor as a winch to lift up a small box (5kg), however it needs to have some sort of drum that's mounted to the motor shaft to wrap the string around. Although I'm unable to find anything suitable that I could use. Is there already something that exists that...
Hello everyone!
I'm doing a school project where we are responsible for designing a dragster race car powered by a small electric motor (1.5 to 4.5 V) h it seems to be called MOT12 (which I don't know the meaning of, it would be helpful if someone helped me understand).
We are allowed to power...
Homework Statement
Good day, i am currently working on a design project. the device is part of a cricket bat knocking machine. i need advice on how i would go about calculating the motor torque required
Homework Equations
Tq = Inertia x angular acceleration
The Attempt at a Solution
attached...
I am running into a minor snag and would like to know if I am going in the right direction or not. Most gearbox catalogs rate everything for input HP rather than input torque. Would I be able to calculate the motor HP by rearranging the Torque(in-lb) = HP*63025 / rpm, or in this case...
I have acquired an old 1.5kW/2HP VFD [1] with aim to power a drill (which I don't have yet) with a three-phase motor from the single-phase outlet in my garage. It was supposed to be in working order, but alas it was not as the LCD display, for one, is only displaying gibberish (yes, I have...
Dear Forum,
I would like to get familiar with motors. I "think" I understand the basic principles of DC motor:
1) Fix magnetic field (stator), Bf
2) Rotating magnetic field( rotor), Br
3) Force (Torque) proportional to intensities of Bf, Br, angle
4) Commutation of loops to keep Br at constant...
I’ve been given a food mixer to repair - more sentimental value than monetary. It’s barely been used, if at all - the brushes still have their bedding-in ribs. It would only run if I gave it a spin, but this was just bad contact between brushes and commutator. Solved with switch cleaner. When...
Hi all
I would like to ask your professional guide in designing a hydraulic system. I attached a file, showing sketch of the RTG crane wheel structure.
Here are the conditions:
1. The red-line is the hydraulic cylinder with "X" as the fix point.
2. The hydraulic cylinder will stroke out from...
In a DC motor as I understand it, a current is passed through a coil of wire within a magnetic field. The magnetic field exerts a force on the current perpendicular to the direction of the current. This force causes the coil to spin. Is the coil is between the north and south poles of 2 magnets...
Hi
Would someone please be able to help?
I am based in the UK
We need a large hydraulic motor... 6000 metres of torque with a speed of 1800 or 1500 RPM
If two motors were in-line would this achieve our goal?
Many thanks for your interest.
Chris
Hello,
I have decided that no matter how many times I ask, people will always leave my bedroom door open. Therefore, I have decided to try my hand at a DYI project to create an automatic door closer. I'm aware these already exist but I'm also doing this because I've always been interested in...
I want to build a trolley with four wheels and towed to a rope having pulley on both ends connected to a electric motor. one of the pulley will be drive and other will be idle. what will be the proper procedure to calculate the motor size for this type of problem. thanks in advance
Hi all,
Not a question about completing homework here, but I'm a teacher looking to create a realistic engineering question for an assignment.
I have an engineering scenario I've set for the assignment which is a junior engineer working for a marine engineering company so all of the questions...
Hello,
I'm boy who suddenly been strucked by curiosity on how hand crank generator works and i watch and read some of how to create one, specially this one on youtube:
and i want to create one but i don't have a 3D printer, but i saw some alternative but as i do/design my own coil based on...
greetings.
I designed a system on simulink.
it is missing a pmsm.
I found a block on simpowersystems in simulink nde matlab.
I hope that this engine provides a nominal power of 96kw and maximum of 100kw.
so how to test it? to verify that this engine can deliver these two powers?
cordially. said.
Hi forum,
I've been thinking about efficiency factors, I've read that they are more efficient at higher loads? I was wondering why this is...
On the one hand at higher loads (maybe lifting a heavier mass) the rotation rate is reduced so this reduces energy losses due to friction? (so goes with...
Is the pressure due to the hot gas exhaust stream on the inside walls of a rocket motor bell nozzle positive or negative?
Does the rocket exhaust exert a outward pressure on the nozzle walls due to the sheer volume of the exhaust gases or is the pressure a negative one due to the exhaust stream...
Hi fellas,
Really how to select the wattage of the motor as I'm stuck with that. I came across several formulae, yet still unable to do it so.
Vehicle Mass = 120Kg
Load Mass = 100Kg (max)
Front tyre = 8" x 2
Back Tyre = 12" x 2
Tyre material = Polyurethane
Dimension = 25" x 35"
Speed = 9.3km/hr...
Hello,
I'm a engineering student currently taking Thermodynamics and we have this project for our finals which is a sort of reeling /towing device, the assignment consists in a reeling motor that has to tow a small car up along a slope, loaded with a certain weight, the team that is able to...
Hello all,
I am trying to build a simulation to understand what power is required by an electric car in order to accelerate from 0-50kmh. As per my understanding the total power required by engine is calculated using Total Power required at given velocity formula as stated below. I am...
Homework Statement
(i) A star-connected, three-phase synchronous induction motor takes a current of 10 amps from a 415 volt supply at unity power factor when supplying a steady load. If the synchronous reactance is 5 ohms/phase and the resistance is negligible, draw the phasor diagram and...
Hi! I'm trying to figure out what kind of specs a small electric motor would need to power some small "positive displacement" blower.
According to my design, the total amount of space in the chambers would be approx 50 cubic inches (0,0861 cu feet). Then to reach a required 400 cfm it would...
Homework Statement
Motor runs at a rate of four revolutions/sec has a torque of 20. What is it's power.
Homework Equations
T = (2π) / w
f = w / (2π)
w = 2πf
P = T * w
Power = Torque * angular velocity
The Attempt at a Solution
[/B]
T = 20 Nm
f = 4 * 2π = 8π
w = 2π * (8π) = 16π^2
P = 20 *...
Homework Statement
A motor as an internal resistance of 0.5 ohms. It draws 20 amperes at full load from a 120-V supply.
a) What is the emf of the motor?
b) What is the load resistance?
Homework Equations
Potential difference between the terminals = emf - Ir (r = internal resistance)
(P.D...
Homework Statement
A car is traveling up a slope. Given that a(t) is constant at 1m/s^2, find the expression of motor power in time. Assuming that the maximum power of the car is 215kW, for how long can the car maintain such an acceleration?
Mass of car (m) = 2000 kg
The hill has a constant...
does the magnetic field created by AC alternate? reverse poles? if so why does a motor rotate the same way every time? does it alternate in three phase as well?
thanks, if you want to direct me to literature i would appreciate that, what i have in my motors book talks about the hand rule for...
I recall reading that in the context of special relativity, one will notice differences in the acceleration of an idealized born-rigid spaceship when one compares two identical spaceships, one with the rocket motor mounted in front, the other with the rocket motor mounted in the rear.
I'm...
Hi guys I was wondering if anyone had a good recommendation on a textbook to pick up on field oriented control, motor control, 3 phase control or modern motor control in general. Looking for a professional level text. I already have Electric Machinery Fundamentals by Chapman but looking for...
Hey,
I need a little help
I know in a DC motor there are permanent magnet and also coil
So my question is, what is the equation to calculate the magnetic field strength in a stator dc motor compound?
What is the perfect ratio of
rotor pm magnetic strength:stator em magnetic strength ?
What will happen if we have N52 rotor magnet surrounded by stator 187amp/turn electromagnet ?
Will stator magnetic field will be sufficient for revolution of rotor??
I run a small food manufacturing operation. We process nuts and seeds. We have several grinders/food processors that run at variable speeds. The speed of the motor is varied using an Emmerson VFD. The turning speed of the grinder is very low ( 50-100 RPM) arrived at using a sprocket and chain...
Dear community,
For one of the projects which I am currently working on, I want to quantify my three phase AC induction motor in the following ways:
1. Find Torque vs RPM Curve
2.Find Efficiency vs RPM Curve
Now since I don't have the industrial "Torque Sensor" to plot Torque vs RPM curves, I...
A 4160v chiller motor is drawing too much power at start-up. Utility company only let's them run it once or twice a year because of it. It dims all the lights etc.. It was originally a primary reactor starter (2 contactors). The PR was replaced with an auto-xfmr and wired the same. So now it’s a...
I need to perform stress analysis for the stand for an industrial sized electric motor like pic related. The motor stands on four legs. I need to know the force that the legs of the motor exert on the stand due to its torque. I have all the dimensions of the motor including weight and torque...
Hi All,
My daughter did a science experiment on homopolar motors. The only variable was the number of magnets on each motor. We found out through the experiment that the more magnets we attached to the motor, the longer it spun before the battery died. I'm assuming it has to do with the...
Hey I'm trying to work out a physics calculation,
if I have a drawer (any type of drawer regardless of size), that sits on wheels so friction = negligible, and it is as an example 14 inch deep, 6 inches high, and 20 inches wide, it has an empty weight of 4 pounds, and a loaded weight of 10lbs...
I am referring to the output torque of an electric motor when the rotational speed of the rotor is 0 RPM. Some sources say that having a stalled torque damages some motors, and I know that some motors have a constant torque regardless of their speed while others have a max torque at 0 RPM. So If...
Greetings Sir, I have a motorized RTS roller shutter (which can be controlled by both hand held remote controller Or wall switch) . The thing is when the motor detects an object, it will put its entire weight on the object and then stop (which means it will suffocate that "object"). Hence we can...
This is related to steel wire pulling machine. I have 2 cases.
In CASE-1: ONE MOTOR 160 kW
AND
CASE-2: TWO MOTORS 129 kW Each. i.e 2x129 kW
Which case would have an efficient pulling force and efficiency Case 1 or Case 2.
If I need 50,000 Nm of torque to rotate a wheel, and I am rotating it about its rim (like the London eye), would 5 10,000 Nm motors each connected to a set of tyres to rotate it (the motors are not connected to each other), or would these motors first need to be connected to each other and then...
Hi, I was looking for some information on how to safely handle a shaded-pole motor of the sort found inside electric can openers and plugged into the mains. I was not sure of the voltages present on the shaded pole coils in particular.
If I have a 7.5HP motor running at 1750rpm with a pulley and v-belt and connect it to a gearbox, where the right angle worm gearbox sees an input speed of 580rpm, how would I go about sizing the gearbox?
Am I correct to say that I would size the gearbox for the lower input speed and more...