design of an electric shocker

[Sisina]

Hello everyone, I just signed up.
I'm a student at the master of mechanical engineering. I'm designing an electric shocker and I have to do the maximum calculations but I don't know where to start. I chose a brushless motor and a transmission with endless screw and wheel. the only since I have is the speed of the whips then of the wheel that reaches up to 2000 rpm. I have assumed a number of teeth of the wheel of 40 and the number of principles of the screw pairs to 1, through the transmission ratio I found speed of the screw and therefore of the motor of 750o s^-1 = 72000 turns/min. I think it's very big as value because the power of this kind of appliances is about 400w, you think it's okay or I'm wrong somewhere?

while for the design of the endless screw can I proceed as for normal rotisms? that is through a iterative calculation then calculation mt, sigma adm, transversal module with formula of the helical wheels, ray of the screw, peripheral speed of the screw and remake everything until I find values of the module close to the unified one.

I don't know if I've asked too much or different topics? I hope it's okay

 

[wert]

There's no 72k RPM engine. Why did you throw yourself on an endless screw reduction? Usually alternating motors are used that make little less than 3000 turns. you just need a 1:1.5 reduction to ordinary gears.

 

[Sisina]

in the state of the art all the beaters have endless screw coupling to reduce the spaces. for ordinary gears would serve a lot of space and the goal in the design of a beater and to minimize the bulk. Universal engines are usually used, which also reach 32k rpm. for me it would also be easier to design a normal rotism as I have already done it but it is not the best solution in my case.

 

[wert]

There's no 72k RPM engine. Why did you throw yourself on an endless screw reduction? Usually alternating motors are used that make little less than 3000 turns. you just need a 1:1.5 reduction to ordinary gears.

Excuse me... I have seen that there are 230 v engines that also arrive at higher speeds but no one arrives at 72k rpm.

 

[wert]

in the state of the art all the beaters have endless screw coupling to reduce the spaces. for ordinary gears would serve a lot of space and the goal in the design of a beater and to minimize the bulk. Universal engines are usually used, which also reach 32k rpm. for me it would also be easier to design a normal rotism as I have already done it but it is not the best solution in my case.

then, if you have to forcefully use an endless screw reduction, to keep low the number of engine turns at equal number of crown teeth, you can use screws at 2 or even at 3 principles.

 

[Sisina]

I was going to write it right now. Thank you very much for the answer

 

[stevie]

2000 turns out from an endless screw reducer?
and then why use a brushless motor (I imagine you mean brushless with permanent magnets) and not a common asynchronous monophase?

 

[Cadinpiedi]

Good morning, maybe it'll help you look at what your Swedish colleague did. .

Free CAD Designs, Files & 3D Models | The GrabCAD Community Library

The GrabCAD Library offers millions of free CAD designs, CAD files, and 3D models. Join the GrabCAD Community today to gain access and download!

grabcad.com

 

[Sisina]

2000 turns out from an endless screw reducer?
and then why use a brushless motor (I imagine you mean brushless with permanent magnets) and not a common asynchronous monophase?

Yes, in the technical details of the beaters I found speed of the blade groups ranging from 100 to 2300 rpm. I also feel very high because from the photos you can see how the wheels have a number of teeth ranging from 34 to 40 and therefore a high transmission ratio
I mean a brushless motor with permanent magnets but I don't know at what speed it can get, it's not yet definitive as a choice but having studied only the theory in practice I don't know well what type of engine to choose

 

[wert]

Yes, in the technical details of the beaters I found speed of the blade groups ranging from 100 to 2300 rpm. I also feel very high because from the photos you can see how the wheels have a number of teeth ranging from 34 to 40 and therefore a high transmission ratio
I mean a brushless motor with permanent magnets but I don't know at what speed it can get, it's not yet definitive as a choice but having studied only the theory in practice I don't know well what type of engine to choose

in household appliances, for reasons of cost (and also of space I think) use 230V brush engines, so they save the transformer. dyson, I think he can afford the brushless dc, but I don't think he's in the slashers yet. So I think that the exercise should include a 230 v alternating brushes.

 

[Sisina]

I think so, but I don't want to get the road to another type of engine that might improve the performance of the product even if at a slightly higher price. I have to collect more information about engines

 

[wert]

I think so, but I don't want to get the road to another type of engine that might improve the performance of the product even if at a slightly higher price. I have to collect more information about engines

for the brushless, in addition to the transformer there is also to consider all the control electronics, which is not a banality. while in 230 v alternating should all be simplified.

 

[Sisina]

in fact looking on the internet I found this chart, so only universal motors can reach very high speeds that allow me to use an endless screw reducer to reduce the spaces.

 

[TETRASTORE]

in shocks, single-phase electric motors (230 v) are used for these applications.
speeds can exceed 50000 rpm. in the specific case of the beaters, the motors can be with powers from 90 w up to over 1000 w (the most performing have over 500 w).
an endless screw is connected to the engine output shaft that integrates with two toothed crowns in counterrotating plastic material that normally rotate at a maximum speed of 1000-2300 rpm (the speed of the whips). electric shocks are generally proposed with various speeds of the whips to make them usable for the processing of various products.
the high rotation speed on the unfinished screw inevitably determines a relatively short duration but, unlike the gearboxes used in the industrial field for which the durations required for a normal service (sf=1) are on average 10000 - 15000 hours (up to 5 years), it is necessary to consider that these appliances are used in the domestic field for a few hours a year, so also a duration of a few hundred hours can be considered sufficient.
considering a 17000 - 30000 rpm engine, you can calculate the reduction according to the output speed you need, however, considering at least two - three principles of the screw (the end ratio normally used is about 8-15).

on directindustry you can find various electric motor manufacturers for household appliances in the route:
mechanical power transmission > motor and motor control > motor for electrodomestic apparatus,
Who brings you in page of the various manufacturers.

su 8 bottom find also the engines with the endless screw reducer already coupled and its dimensional design

 

[Sisina]

in shocks, single-phase electric motors (230 v) are used for these applications.
speeds can exceed 50000 rpm. in the specific case of the beaters, the motors can be with powers from 90 w up to over 1000 w (the most performing have over 500 w).
an endless screw is connected to the engine output shaft that integrates with two toothed crowns in counterrotating plastic material that normally rotate at a maximum speed of 1000-2300 rpm (the speed of the whips). electric shocks are generally proposed with various speeds of the whips to make them usable for the processing of various products.
the high rotation speed on the unfinished screw inevitably determines a relatively short duration but, unlike the gearboxes used in the industrial field for which the durations required for a normal service (sf=1) are on average 10000 - 15000 hours (up to 5 years), it is necessary to consider that these appliances are used in the domestic field for a few hours a year, so also a duration of a few hundred hours can be considered sufficient.
considering a 17000 - 30000 rpm engine, you can calculate the reduction according to the output speed you need, however, considering at least two - three principles of the screw (the end ratio normally used is about 8-15).

on directindustry you can find various electric motor manufacturers for household appliances in the route:
mechanical power transmission > motor and motor control > motor for electrodomestic apparatus,
Who brings you in page of the various manufacturers.

su 8 bottom find also the engines with the endless screw reducer already coupled and its dimensional design

Thank you very much for your answer

 

[meccanicamg]

I see they've already told you everything.
I started with a reflection: normally in every house, if someone cooks, an electric beater has it. so it would be good to take it from the drawer and see what is written on the tag and maybe if in the instructions (also available on san google) there is some data.
After that, once we have decided to make a mid-level electrodomestic, that is 200-300w we try to look at the next characteristics of the product.
When you don't know the matter, you can take those crabs and you won't even notice.
Perhaps it would be worth buying a beater a few euros on amazon and disassembly it to analyze it.
definitely an endless screw is a reducer with the worst possible performance on the market and the epicycloidal would be the most expensive ever.
the intermittent service is very low, in fact if you take a manual and read it you can get the aforementioned intermittent service that you will need for the evaluation of wear and heat on the gears.

one random...mulinex quick mix safety instructions use mode ...for intermittent service maximum working time just to start.. . .
We must have a goal in mind. then maybe if you are lucky you can find an explosion and swallow the drivers of spare engines....or as we were doing in our time, we asked the companies to give us information because we were doing thesis, year project, etc.
for the electric part I would say 230vac 50hz at high turns.

 

[meccanicamg]

As for the dimensioning of the endless screw, you should start from low module and check. This interactively.
Keep in mind that you can make an excel sheet with the calculation.
sources from which to draw are khk gear, where you find an online manual and a free computer after registration; niemann organs of machines all three volumes; manual of the bonfiglioli reducer (free).
If you're looking for fir we've dimensioned some endless screw reducer and you can realize what checks to do.
a calculation program that you can ask in test is kisssoft, the best on the square to do anything that anticipates gears.
However you will have to deal with two substantial problems:
- verification of endless screw reducer
- test with gears of unconventional material because they are polymers and not metals
We certainly need good technological support to address the issue.
but is it a year project or are we talking about thesis?

 

[meccanicamg]

just to have an idea of greatness put you what happens with conventional materials:Surely we are very out of classical computing standards and we should understand if there are specific regulations that can help us with plastics.

 

[Sisina]

It's a year project and it's organized like this: technical specification, morphological matrix for the choice of mechanisms and components, maximum calculations and choice of materials on the basis of maximum calculations.
therefore the materials must decide after the calculations of maximum according to the required performance.
I thought I would assume a value of sigma adm, calculate the module and repeat and then use that value of sigma adm found to choose the suitable material. I was thus organizing a sheet of excels. Maybe I can take values for verification and then after the choice of the material checks permanently.
The aim of our professor is to make us think and try not to block us from what has already been done and I must admit that a slasher is not the best choice in this sense but I have only realized it in the full of the project? I will try to do my best for calculations, thanks for the advice.
Can I ask you the pictures you showed me are from a program?

 

[volaff]

pictures you see are from an excel sheet.