choice type of reducer

[danielinox]

I am making a concrete mixer for a didactic project.

this has a capacity of 0.6 cubic meters of cement.

I have a 1.5kw engine from 1400giri/min and I must have at the user about 16giri/min, then reduction ratio 87,5; quite high.
with so high reduction ratio and for reasons of cheapness are oriented to the choice of an endless screw reducer; in case of full beton stop I'm afraid that the countertops of the moving masses can prompt and damage the reducer.
the second option is a multistage reducer that, being reversible, would not have this problem.

what you recommend.

thanks in advance

 

[PierArg]

Hi.
First of all, I recommend that you present yourself in the appropriate section as a regulation.

As for your problem, I think you should focus not so much on the reducer but on the type of joint to be used.
Perhaps, the right throw so that I don't know how the car is made, you could put a unidirectional joint.

 

[radio]

Hi.
First of all, I recommend that you present yourself in the appropriate section as a regulation.

....

right, read here:http://www.cad3d.it/forum1/showthread.php/26548-piccolo-regolamento

e quihttp://www.cad3d.it/forum1/showthread.php/32804-se-cercate-risposte-leggete-quiBenvenut.

 

[cacciatorino]

with so high reduction ratio and for reasons of cheapness are oriented to the choice of an endless screw reducer; in case of full beton stop I'm afraid that the countertops of the moving masses can prompt and damage the reducer.

endless screw reducers almost always have the option to mount a couple limiter joint that can slip when necessary protecting the tasmissione.

 

[MBT]

1:87,5 (at which it exists, but there will be something next) is a rather pushed reduction ratio for an endless screw
most manufacturers, not wrongly, for such relationships are oriented on an endless screw with parallel axes pre-reduction
maybe you should use an epicycloidal, much more compact, although perhaps more expensive, and reversible in the motorcycle
for start-up, you can think of using soft-start devices or, since the powers in play are minimal, put the motor under inverter

 

[zeigs]

Most of the betoners I've seen on the street were taking the reduction of the laps to a rack mounted directly on the circumference of the same. the pinion is relatively normal, slightly conical, and the rack being extremely large compared to the pinion allows to have a strong reduction with a single jump. presumably the pinion will have a very correct toothing, but the sizing is as if it were a linear pinion-cremagliera. in this case you do not have the limits typical of circular gears. This method also puts you away from any brusche stops, since the motor in case is free to turn. to make sure that however at the stop do not continue to rotate for a long time you can predict a brake on the motor, they sell of already equipped ones that are unlocked at the moment when the motor is fed and they stop to shut down

 

[danielinox]

thank you all for the answers.
effectively with the endless screw, due to the very low yield for so pushed reductions, I lose a lot of power.
I can't install the shaft on the perimeter, so I think I'll opt for an endless screw + prepair.

 

[anpa]

the adoption of the precouple could lead the reducer as a whole to be reversible.... I would still make sure that the precouple made the reducer reversive.

 

[meccanicamg]

the first most widespread betoners have the following cinematism:
- three-phase or monophase asynchronous motor
- pulley and wheel driven with belt drive
- toothed sprocket and rack on rotating basket
- some betoners have the ignition star triangle

This mode has the disadvantage that cinematism gets dirty and is not the maximum safety since the moving mechanical organs are not covered.

the new betoners have the following cinematography:
- single-phase or three phase asynchronous motor
- gear or axial epicycloidal gear reducer (some even have the connected motor on the rotating axis of the basket)

is unthinkable to mount an endless screw even with couple limiter because it is a useless cost not justified. inverter idem....it's too much and you don't need to reduce or increase the number of turns....it's a yard beton.
with the inertia of concrete in the basket and the variable inclination of the mouth must not have any obstacle to reversible motion level, so the reducer must be able to work in direct motion and in reverse motion

 

[MBT]

the adoption of the precouple could lead the reducer as a whole to be reversible.... I would still make sure that the precouple made the reducer reversive.

? ? ?
the endless screw reducer is irreversible (with some exceptions. . . )
you can mount us on what you want, but always irreversible will be! the incoming precopies cannot change the situation.

 

[MBT]

the first most widespread betoners have the following cinematism:
- three-phase or monophase asynchronous motor
- pulley and wheel driven with belt drive
- toothed sprocket and rack on rotating basket
- some betoners have the ignition star triangle

This mode has the disadvantage that cinematism gets dirty and is not the maximum safety since the moving mechanical organs are not covered.

Very true!
quoti in toto

the new betoners have the following cinematography:
- single-phase or three phase asynchronous motor
- gear or axial epicycloidal gear reducer (some even have the connected motor on the rotating axis of the basket)

is unthinkable to mount an endless screw even with couple limiter because it is a useless cost not justified. inverter idem....it's too much and you don't need to reduce or increase the number of turns....it's a yard beton.
with the inertia of concrete in the basket and the variable inclination of the mouth must not have any obstacle to reversible motion level, so the reducer must be able to work in direct motion and in reverse motion

bhe, on the last part I can object.
an epicycloidal reducer costs much more than an endless screw!
the endless screw in this case is inapplicable because it is irreversible.
rather, I would use a parallel axle or a coaxial
on the drive with inverter, for small sizes like the one indicated, its cost is really minimal.
200 € stuff, even less. does not make sense to increase or reduce the number of turns, but it can be useful to start the engine gently.
I agree that it is a shipyard beton, not a Swiss watch! for me, a good parallel axle reducer directly connected to the motor and running away!

 

[anpa]

endless screw gearboxes are not all irreversible, so with a decent precouple (say 3) you can get the searched result

 

[MBT]

endless screw reducers are "more or less" reversible if with low reduction ratios, from 1:7, 1:10, maybe 1:20
from there on reversibility is not sure! (not even irreversible, actually... )
if you need 1:100 total reduction, and if you want to be safe, the reduction ratio of the screw module must be at max 1:10. the remaining with another reducer. If you use two series mounted screw gearboxes, in addition to having a bad performance, reversibility is again in doubt....