what's going on?

[ansyolitico]

Hi.
I have a little problem that I can't understand why

I have a vertically mounted ball recirculation screw that moves a weight of about 1800 kg , the weight is supported by a plate bound by 4 linear skates on two parallel linear guides between them... the snail makes strength on a frame bound on the plate but moved by tot cm from its half-work (in the center you can not put). the screw is inserted in a gearbox located at its extreme high.
between the reducer and the bolt there is the support structure of the screw so configured (from the top down):
wreath with grain
2500 kg axial bearing
support
Conical roller bearing inserted in the cast made in the support
screw shouldering that goes in line with the inner ring of the conical roller bearing

the surface of the support that goes in support with the axial bearing is not worked, but simple left raw, being the crude a drawn.(I think here is the first big mistake)

now with a operation of 200 cycles per day on a time of about 3 months that wreath tends to unscrew.

I assume that the axial bearing blocks (grip) and avoid the wreath just at a time... .

What do you think?

 

[Stan9411]

Don't you have a design of an axieme section? you have also been clear in the description, but to imagine everything is a useless effort. .

 

[meccanicamg]

trying to understand the description....what a technician should put a design.
normally the use of an axial bearing, perhaps without a cage already is a quite frequent error for repetitive movements at medium speed because it has to be ultra centered otherwise it does oscillate the assembly. the front bearing made with conical rollers (1 row? two files? orientable?) also this is not indicated.

the correct configuration is that of two more oblique contact bearings to a crown of balls.then normally we use already combined units and ready, like the zklf units of the ina that already have everything mounted in a cylinder with fixing holes.you can use two bearings arranged to or with conical rollers even if you need to pack well with shaved rings to the assembly and the greater the rigidity is maintained over time.your problem arises normally because:

- the ball screw is precise and has no radial games
- screw/kid alignment with guides is perhaps not accurate or along the stroke presents variation of alignment
- unsuitable choice of bearings (more conical pure assemblies)
- at the moment of the reversal of motion, being decentralized the load compared to the guides creates a horizontal thrust on the axial bearing that disalline the slopes and creates premature wear.

you could improve the choice of the wreaths using something stronger to block instead of the wreath you have now.

 

[stevie]

Hi.
I have a little problem that I can't understand why

I have a vertically mounted ball recirculation screw that moves a weight of about 1800 kg , the weight is supported by a plate bound by 4 linear skates on two parallel linear guides between them... the snail makes strength on a frame bound on the plate but moved by tot cm from its half-work (in the center you can not put). the screw is inserted in a gearbox located at its extreme high.
between the reducer and the bolt there is the support structure of the screw so configured (from the top down):
wreath with grain
2500 kg axial bearing
support
Conical roller bearing inserted in the cast made in the support
screw shouldering that goes in line with the inner ring of the conical roller bearing

the surface of the support that goes in support with the axial bearing is not worked, but simple left raw, being the crude a drawn.(I think here is the first big mistake)

now with a operation of 200 cycles per day on a time of about 3 months that wreath tends to unscrew.

I assume that the axial bearing blocks (grip) and avoid the wreath just at a time... .

What do you think?

Why, instead of the radial grain wreath, do not use the safety wreaths like km ?