Originally Posted by tshidzumbam

Gentlemen, would kindly help me with answers to the following questions, i have also added some information about the application:

Questions:

•At what intervals should the bearings be refilled/ topped up with grease for the operating conditions stated below in order to reach the minimum life requirement?

•What quantity should be filled in at each interval?

•Is there normaly a need to implement an automatic lubrication system?

General information:

Bearing shaft Sizes : 115 mm to 300 mm

Application: Bearings for machine and yard conveyor pulleys

Pulley sizes: 500 mm to 1000 mm

Belt speeds: 2.86 m/s to 4.5 m/s

Capacities: 3400 tph to 4000 tph operation capacity

Duty: 24hours, 7 days a week

Climatic factors:

•Site Altitude : 896 – 916 m (ASL)

•Relative humidity – Maximum : 80 %

•Temperature – Max / Average : +40 °C / +22.5 °C

•Minimum Temperature : -6 °C

•Rainfall – Mean : 500 mm / annum

•Rainfall – Average (Nov-March) : 380 - 700 mm

Bearing requirements:

Minimum required L10 life: 100 000 hours

Lubrication type: SKF LGEP2

Thanks

Mpho Tshidzumba

Speaking from my 22 years experience with daily maintenance

of belt conveyors transporting Halite.

The issues of bearing size,belt speed, tonnage, ambient temperature,

duty cycle are a small part of the puzzle.

The issues are simply of maintenance and more maintenance.

Centralised lubrication is fine, and the concept is fine, but itis more costly

in implementation and subject to cleanliness requirements and in very dirty

environments the potential for contamination is mind numbing if the reservoirs

and manifolds are exposed to dust.

The simple approach is to use spring pressuried grease cups.

I used them for the head pulley, tail pulley, drive pulleys, take up pulleys for years and used much less grease and much lower rate of bearing failure (only after they -the grease cups were removed by others).

Please look at www.mcmastercarr.com/greasecups/

You would spend much less money installing the grease cups on the bearings and they will perform the job flawlessly as long as the bearings are full and the seals are intact prior to installation as the grease in the pillow block is the resistance to the metered grease exiting the grease cup.

The metal grease cups will have the benefit of larger reservoirs and no chance of dirt entering the grease cups where the clear plastic polycarbonate cups have air vents that will allow dust to enter.



The grease cup is one of the great maintenance helpers for conveyors or bearings of any size or speed and they will fit bearings housings up to 1/2 inch thread diameter and replace the grease fitting in the bearing housing with no difficulty as long as they are the same thread size and or permissable adapter bushing.

About grease cups and dirt; If you have a high dust environment as you apparently have with your operating conditions you should think about covering the grease cups with a heavy canvas bag and using reusable black zip ties which are sun resistant and easy to remove and use to seal the bag around the grease cup.

I suggest that you look in the McmasterCarr catalog for good sand bags as these will last in the heat and sunlight but they will have to be replaced occasionally.

You would have to cut the bag to make it shorter of course but as long as the reuseable zip tie is tight the bag is not going anywhere. You should have no issue getting reusable zip ties from McmasterCarr either or an electrical supply house. Be sure to buy the zip ties with the wide belts as they are easy to grip and less likely to break from reuse as long as they are handled and installed properly.

about greasing:

You have to be sure that the drive units and belt take ups are shut down so that they will not move when you are opening the bags to examine the grease level other wise someone could be maimed or killed if the sled jumps.

And be sure that the zip ties have no grease on them otherwise they become useless until they are cleaned of grease using rubbing alcohol. ■

Leons link will not work so please try this one.

http://www.mcmaster.com/#additional-cups/=aqx9ip ■

Try again:

http://www.mcmaster.com/#grease-cups/=aqzs9k ■

Thanks much for fixing my mistake for the link

to the grease cups at McmasterCarr

Gary and Mr. Nordell.

Tired etc., ■