Hello.

Maybe someone can suggest me , how often it is necesary to change seal's and oil in bearings. which are situated in transporter's, loading bulk feltilizers in heavy and medium working conditions.

After how many working hours is it necessary to make an inspection of bearings. Now transporters have worked about 7,500 hours and bearings haven't been changed.

Thanks.

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Greeetings and salutations,

bearings have a very high B10 generally and 7500 hours is not that much in time for them. This begs the question about operating hours, are you assuming the hour meter on the truck indicates the fertilizer delivery system?

Any operating hours on a power take off are much lower than the operating hours of the truck.

As a rule you do not change seals unless they are leaking and bearings only when they fail as the repair and replacement of them is very time consuming.

Inspecting a bearing requires complete removal and extraction of a bearing from the bearing housing.

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Are you sure the bearings are oil lubricated?, is there a fresh oil reservoir, oil pump, and a waste oil reservoir?, or are they roller bearing with an oil sump rather than using grease.

When you speak of a transporter are you referring to:

A 10 wheel lorry;

with a fertilizer hauling body that is slanted sides with a bed chain to feed a delivery auger that fills fertilizer hoppers on a corn or cotton planter or grain drill?

Or are you using a semi trailer with a conveyor belt ior auger n the bottom of the truck body that removes the load to the rear of the trailer?

typically any bearing in corrossive environments and low speed applications are sealed grease lubricated bearings.

A fertilizer truck operates only for a few minutes at a time to discharge and deliver the fertilzer and is then shut off by the operator.

This is no different than a lorry that spreads lime, gypsum, or manure on a farm field.

I think you may have the trucks operating hours confused with the power take off for the fertilizer unloading system.

This also begs the question if you have a separate engine to operate the fertilizer delivery system. Even with 7500 hours the number of hours is not that high.

Quite often the attachment on the lorry outlives the truck itself and is moved from that truck to another one.

If you could post a picture of the transporter it would be helpful.

lzaharis ■

Originally Posted by Montana

Housing SNL 520 SNL 524 SNL 526.

Which seals are fitted to these housings?? ■

Typically a labrinth seal is used for oil lubrication on a pressurised system but it is apparent that you are using splash lubrication.

As long as the oil levels are maintained you will have no problems as the bearing is constantly splashing oil while revolving.

As long as the oil levels are maintained I see no problems, bearings fail gradually at a very slow rate simply from wear.

first be sure to lock out the power switch for the belt!

if you decide to dismantle the bearings it will take time, parts, and more time as:

The belt must be positioned at a convenient place to separate the splice, it should be done at the mid point of the belt to allow for room to adequately allow the belt to go slack (after releasing the take up and with a pair of chain come alongs and belt clamps taking care that a second set of clamps secures the other splice and holds it in place to keep it from rolling away.

you will be able to remove the entire head pulley then take it to a clean work area for dismantling.

If you have a mid-drive unit that requires more belt work

First lock out the power switch for the belt!

If a gravity take up is used you must raise the take up to release tension on the belt befor anything else is done.

The belt must be completely removed from the drive unit with belt clamps and chain falls from the upper strand by clamping the belt at two locations one point being chained and held in place and the other clamp and a pair of chain falls used to pull the belt back through the drive unit.

You will have to sacrifice the old splice and replace it with a new one.

As long as the bearings are not leaking through the seals and the housing is not overfilled with oil you will have a long bearing life-otherwise I would not touch the bearing sets as both of them will have to be changed.

lzaharis ■

greetings and salutations,

If the oil has never been changed I would change it at the next plant shut down period and replace the old oil with new oil rated for the bearing operating speed per the manufacturers recommendations once each year.

lzaharis ■

Originally Posted by Montana

Greatings Izaharis.

Sorry for mistaken you, i had in minde that transporter is belt conveyor . We are using 1400 mm belt width conveyor system to transport bulk feltilizers to warehouses or to ships by ship loader . I was talking about the bearings wich are mounted on drums shaft. Most of the bearing are SKF 22224 SKF 22222 and so on. Housing SNL 520 SNL 524 SNL 526.

Thanks for your replie.

Dear Mr.Montana,

Are your drum shaft bearings are oil lubricated? Time based maintenance strategy is being replaced by condition based, predictive maintenance. Why do you need to change oil or seal as long as there is no problem?

Regards, ■

Originally Posted by Montana

I choose seals by recomendation and usualy we use lip seals . http://www.skf.com/skf/productcatalo...e=3&startnum=6

For a belt conveyor and similar I'd be using grease not oil with labyrinth or taconite seals, the housing fitted with one of those screw-in continuous greasing units. The continuous purge of grease from inside to outside prevents the ingress of contaminant and promotes bearing life. (NB based on actual experience not manufacturers advertisements ) ■

Dear Montana

I guess the oil lubrication for belt conveyor bearing system that deals with speed less than 3 m/s is not good choice !! for same appliation exactuly grease lubrication is more saftey . And if the topics talk about seals life for SNL housing unite ( not for belt drum application ) , i hae to past what SKF recommend :- ((( The SNL housings can be used for oil bath lubrication at relatively high speeds. When using oil, however, the specially developed U-design seals have to be incorporated to avoid oil loss from the housing . In order for these seals to be used the housing must be modified so that SNL housings for oil lubrication are only supplied complete with seals. It is important not to exceed the recommended oil level if leakage is to be avoided .)))

Thanks

A. Awad ■