Please advise what type of damage. Bearing failure, shell wear, shaft breakage or what? Is this a new installation or old. Was the supplier recently changed?

The more information you can provide the better we can help you with an answer. ■

It is common, almost universal, for designers to ignore the transition between the flat profile of the snub drum and the first V return idler. Edge tension dictates that the outermost bearings undergo higher loading than inboard bearings. Possible remedies could be to reverse the idlers to balance load sharing and if you have space you can interpose a flat return idler which is superelevated to reduce the edge tension.

Several belt manufacturers publish handbooks which address the carrying side transition geometry admirably but few of them emphasise the application to the return strand: probably because of the lower tension involved. Most users accept the high failure of this particular roller locale. A special heavier duty roller would help but there is no guarantee that it would not be used elsewhere.

If the rollers are generally damaged along the line then there are belt slapping issues and transient vibrations to consider and, as Gary says, these will require more detailed input. ■

Originally Posted by bhaskarsnctr

Dear experts,

We have conveyors for V-type return idler frequently return rollers are getting damaged for frequently Inclined conveyor.

is their any specific guide lines for fixing first return idler or any other reasons for.

Thanks in advance & regards to all,

Dear Mr.Bhaskar,

Are you facing problems in all the conveyors or only in a particular location of a specific conveyor?

Regards, ■

Originally Posted by bhaskarsnctr

Dear experts,

We have conveyors for V-type return idler frequently return rollers are getting damaged for frequently Inclined conveyor.

is their any specific guide lines for fixing first return idler or any other reasons for.

Thanks in advance & regards to all,

Hello Bhaskar!

There are numerous reasons due to which "Vee" type return idlers are tend to get damage.

1. Most common reason is due to uneven/not full & one-fourth of belt weight contacting the roll of roll length from center line of idler.

2. type of Vee return Idler i.e. Suspended or Rigid.

3. Belt Training at that location can be possible cause. Because Vee type idlers has some training effect on the Belt.

4. Resonance/Vibration of conveyor belt in that location may also be leading to the failure.

Explore possibility to eliminate above reasons by installation of appropriate strength Idler in that location. ■

Hello,

You have not mentioned whether v-type idlers are of fixed frame type or garland type. I presume these are of fixed frame type.

V-type return idlers are extensively used for conveyors, because they also promote aligned running of return run belt. Their failure in your case implies that these are not of adequate strength. The bearing should be sized for life and spindle should be sized for its stress and particularly its angular deflection. The angular deflection at bearing should be less than 10 minute, for C3 clearance bearings.

The failure can also occur if idlers have objectionable up-down installation misalignment. In such case up idlers will be over-stressed and fail. V–type return idler failure in your case is specific to the installation and it has no relation to whether these are single roller type or 2 roller v-type.

Ishwar G. Mulani

Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis ISO (thereby book is helpful to design conveyors as per national standards of most of the countries across world). New print Nov., 2012.

Author of Book: ‘Belt Feeder Design And Hopper Bin Silo’

Advisor / Consultant for Bulk Material Handling System & Issues.

Pune, India. Tel.: 0091 (0)20 25871916

Email: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com ■