Motor effect

[aadharmg]

A simple question. I have an assignment where I have to analyse a device that is also an application of the motor effect. The device I chose uses a Brushless hub motor rather than a DC/AC motor. I haven't been able to find any information about motor effect in a Brushless hub motor so far, which leads me to a possibly stupid question but do only DC motors use the motor effect, or is the effect applicable to ALL electric motors?

[The Special One]

All you need is a motor and a magnetic field for the motor effect, the opposite is called a generator effect.

Tbh you should probably make your life easier and change to a DC/AC motor as you will find more information and don't need to second guess yourself

[jamonwindeyer]

A simple question. I have an assignment where I have to analyse a device that is also an application of the motor effect. The device I chose uses a Brushless hub motor rather than a DC/AC motor. I haven't been able to find any information about motor effect in a Brushless hub motor so far, which leads me to a possibly stupid question but do only DC motors use the motor effect, or is the effect applicable to ALL electric motors?

Howdy! So firstly, most practical motors rely on more than the motor effect for their operation. Induction motors rely on electromagnetic induction to generate the current required for the motor effect, for example. But the motor effect is the basis of all motors, since the motor effect encompasses any force on a current carrying conductor due to a magnetic field - The way any motor works

A brushless hub motor, let's break that down:

- It is brushless, which without getting too complicated, means that instead of mechanical commutator contacts, you've got some solid state electronics that detect the angle of the rotor and adjust the current accordingly to maintain constant torque. In these motors, usually it is actually the magnets that are rotating rather than the armature that is carrying the current.

- A hub motor, which is basically where instead of using a motor to turn a wheel using some system of gears or similar, the motor is the wheel.

You probably don't need to analyse the operation of one of these things in too much depth, it is quite a complicated device, but this article looks like it does a good job explaining it. What device are you looking at?

[aadharmg]

Howdy! So firstly, most practical motors rely on more than the motor effect for their operation. Induction motors rely on electromagnetic induction to generate the current required for the motor effect, for example. But the motor effect is the basis of all motors, since the motor effect encompasses any force on a current carrying conductor due to a magnetic field - The way any motor works

A brushless hub motor, let's break that down:

- It is brushless, which without getting too complicated, means that instead of mechanical commutator contacts, you've got some solid state electronics that detect the angle of the rotor and adjust the current accordingly to maintain constant torque. In these motors, usually it is actually the magnets that are rotating rather than the armature that is carrying the current.

- A hub motor, which is basically where instead of using a motor to turn a wheel using some system of gears or similar, the motor is the wheel.

You probably don't need to analyse the operation of one of these things in too much depth, it is quite a complicated device, but this article looks like it does a good job explaining it. What device are you looking at?

Wow, this explanation sums up everything I was wondering about this type of motor. Thank you so much, greatly appreciated!

[jamonwindeyer]

Wow, this explanation sums up everything I was wondering about this type of motor. Thank you so much, greatly appreciated!

Awesome!! Glad my degree is actually being useful for a change happy to help!

[ninamatani]

So I have a Motors and Generators Assignment where i have to describe the the application of the motor effect in a device. The motor I've chosen to study is the stepper motor. My 2 problems,
1. I can't explicitly find what kind of devices use stepper motors. I think hard drives and printers do but I'm not clear on what kind of stepper motor (permanent magnet, variable reluctant or hybrid synchronous)
2. How is the motor effect actually applied in stepper motors?

[jamonwindeyer]

So I have a Motors and Generators Assignment where i have to describe the the application of the motor effect in a device. The motor I've chosen to study is the stepper motor. My 2 problems,
1. I can't explicitly find what kind of devices use stepper motors. I think hard drives and printers do but I'm not clear on what kind of stepper motor (permanent magnet, variable reluctant or hybrid synchronous)
2. How is the motor effect actually applied in stepper motors?

Hey! Welcome to the forums!

1. I know printers use them (3D printers too!), fairly sure you also find them in scanners, motorised camera lenses, that sort of stuff!! Totally clueless as to what sort of motor they each use though - That would be a tough bit of info to find I'd imagine! Could be worth googling technical datasheets for specific products as a start (take something you know has a stepper motor and research it in depth to find exactly what sort it is?)

2. Tough question! So essentially it's this - In the DC motors you learn about in the HSC, the magnets are stationary (the stator) and the current carrying coil rotates (the rotor). In a stepper motor, it swaps - The permanent magnet (in a very specific shape and construction) is what spins, now becoming the rotor, and a series of current carrying coils stay stationary around the outside. We feed those coils a series of pulses, switched by some solid state circuitry or a controller or whatever, and it turns them on and off in sequence. Each time the next one turns on, the magnet in the middle moves ever so slightly to align with it. Thus, by controlling the pulses, we can control the angle the motor sweeps through.

That was way too quick to explain a fairly complex bit of Physics, there's some good videos on YouTube about this! There's lots of intricacies like where the poles are on the permanent magnet and how the coils are switched on and off that might take some time to wrap your head around.

Where does the motor effect come in? It's sort of hidden in the operation. When those coils switch on and attract the permanent magnet in the middle, you've got an action/reaction pair of forces - The coil pulling on the gear, and the gear pulling on the coil. That's the motor effect, because it's a current carrying conductor experiencing a force. It's just that in this case, the conductor is also fixed, so it's the permanent magnet that is rotating

Feel free to ask follow up questions! You guys are studying some tricky little devices

[ninamatani]

Hey! Welcome to the forums!

1. I know printers use them (3D printers too!), fairly sure you also find them in scanners, motorised camera lenses, that sort of stuff!! Totally clueless as to what sort of motor they each use though - That would be a tough bit of info to find I'd imagine! Could be worth googling technical datasheets for specific products as a start (take something you know has a stepper motor and research it in depth to find exactly what sort it is?)

2. Tough question! So essentially it's this - In the DC motors you learn about in the HSC, the magnets are stationary (the stator) and the current carrying coil rotates (the rotor). In a stepper motor, it swaps - The permanent magnet (in a very specific shape and construction) is what spins, now becoming the rotor, and a series of current carrying coils stay stationary around the outside. We feed those coils a series of pulses, switched by some solid state circuitry or a controller or whatever, and it turns them on and off in sequence. Each time the next one turns on, the magnet in the middle moves ever so slightly to align with it. Thus, by controlling the pulses, we can control the angle the motor sweeps through.

That was way too quick to explain a fairly complex bit of Physics, there's some good videos on YouTube about this! There's lots of intricacies like where the poles are on the permanent magnet and how the coils are switched on and off that might take some time to wrap your head around.

Where does the motor effect come in? It's sort of hidden in the operation. When those coils switch on and attract the permanent magnet in the middle, you've got an action/reaction pair of forces - The coil pulling on the gear, and the gear pulling on the coil. That's the motor effect, because it's a current carrying conductor experiencing a force. It's just that in this case, the conductor is also fixed, so it's the permanent magnet that is rotating

Feel free to ask follow up questions! You guys are studying some tricky little devices

Thank you so much! This was very helpful.