Other equipment that uses vacuum motors

[mathewhebailey0]

The belts on some platters fit around a capstan.
Others use a rubber capstan which fit onto the motor shaft.
The rubber capstans are of the kind you would see on some printing,office & copying equipment.

 

[johnb300m]

hmm, interesting. thanks!

 

[tolivac]

Interesting on the platters-I was thinking of a capstan on the motor to turn the platter disc.The size of the platter versus the motor capstan would give a good speed reduction-and simple-would explain as the belt wears-the disc will slip-I would then suppose preventing payout of film and improper takeup after the film goes thru the projector.The platter is reminding me of the supply and take-up reel systems on a tape deck.

 

[sudsmaster]

Loud floor vacuums

I believe part of the loudness problem is that vacuum cleaner manufacturers discovered that a lot of customers didn't think the vacuum was any good unless it made a lot of noise. So for better sales they started designing noise into the systems, to the detriment of our peace of mind.

I think also there might be something to do with the sound characteristics of trying to pull a large column of air through a relatively small opening. That is sure to cause turbulence and noise, all by itself.

 

[compactc9]

Loud vacuums bother me. When I use a vacuum that shrieks, i notice 2 other things; heat and vibration. The motors in these vacuums are usually small, high speed motors that run pretty hot. I usually like larger, slower cooler motors. There are many quiet vacuums, but probably not at a big box store. I notice this not only in vacuums, but other appliance too. If it has a small high amp motor, it runs hot ans is louder than a similarly built model with a larger motor.

 

[tolivac]

Aeros-Lux new "Guardian" canister vacuum is an example of a noisey vacuum that-remember older 'Lux's how quiet they were-this new Guardian sounds like you have a B52 engine in your living room.
On cheaper vacuums-they use lower quality motors and fans-another thing effecting the noise-how well balanced the motor and fans are-poorly balanced ones will generate more vibration-then more noise esp if the motor is directly mounted in the plastic vac housing with a sound mount cushion-then the plastic vac body makes a great sounding board to further amplify the motor noise.And yes the small "hi amp" motors do run hotter-and sometimes go up in flames-These motors amy also have aluminum windings instead of copper-and when the aluminum windings overheat-they catch fire more easily than copper-Royal Dirt devil "Featherlight" uprights were an example.This model had several motor "flamouts"-and they were VERY noisey.Yes the vacs with larger lower amp motors run quieter and cooler.The motor is equipped with a larger fan and runs at a lower speed.NSS Model "M1" vacs are an example-the motors in those can be run for DECADES.

 

[gizmo]

SR motor

VFD motor

What do these terms mean please?

Chris

 

[tolivac]

SR-Switched Reluctance
VFD-Variable Frequency Drive-Used on induction,wound rotor motors to vary speed electronically by changing the input frequency to the motor-instead of 60Hz-the drive may run the motor at a lower or higher frequency-to change the speed-but within limits.Uusually + or -10%.Outside this the motor becomes less efficient or loses power and torque-and will overheat.
Switch reluctance is a type of AC motor that can also use a varible frequency inverter device that converts a an AC or DC power source to a variable frequency pulse or square wave to operate the motor.Like an induction motor SR motors have a stator-with the windings the power is fed into-and a rotor that turns the load.It is a cog shaped peice of iron.As the pulses flow thru the stator windings-the rotor turns.SR motores can speed can be varied over a wider range than induction motors.
The VFD device driving the motor is a form of inverter-recifies the incoming power line voltage-converts it to DC-and a digital frequency source3 in the drive converts the DC to a variable frequency AC power to drive the motor.In some cases the VFD drive can convert single phase to three pahse to run a three pahse motor from a single phase source.Most of the time the VFD is three phase in to three phase out at the same power line input voltage.Pulse width modulation is used a lot in these-A high frequency voltage is modulated by a lower frequency-controlling the widith of the pulses-than filtered and run to the motor.The filter removes the high frequency carrier pulses.These would damage the motor if they went into it.For motors that are older or non VFD rated-an addiational filter is used-then only the variable AC goes to the motor.