Greasing of Pillow Blocks with or without relief ports

We do not have grease reliefs in any of our pillow blocks and we have been able to get 9 years out of the bearings on many of our large fans. We also see this temperature rise right after greasing and we use it along with our sonic attachment to the grease gun to determine if the correct amount of grease has been put in the bearing. Don't let this transitory temperature rise alarm you. What would be a larger concern is how your greasing guru is determining how much grease to pump into the bearings. Does he use sonic or ultrasonic or does he just pump in until he gets a temperature rise or 'feels' that the right amount of grease has been put in.

Hi Striker,
This post is from the analysis lab view point,
we will always insist if asked that the grease relief port be where you stated on the opposite side of the bearing, we ususlly install a grease relief port simular to what is used on Cummings engines water pumps as these let the grease escape @ 2-3 PSI,
the reason the port is installed is we can flush the loaded zone of the bearing and then inspect the grease under the microscope, we usually filter 1 gram of grease @ 11 µm,
this will tell if we are over greasing, under greasing, if contaminates present etc, also if a continuous auto greaser installed we can lower the amount of grease applied until we get black oxides and no adhesive wear giving best lubrication without damage or grease wastage,
check out www.rttech.com.au for more info
Regards Rob S

Bill;
Currently our greasing guru's go on feel and what they have experianced in the past (a problem), same people have been doing it for years.
In the future we are planning to purchase either sonic or ultrasonic listening devices for the greasing guru's.
If we go ultrasonic, then do we need to drill grease reliefs into our pillow blocks?

First, always buy a bearing with a groove in the middle of the outer race (W33 for SKF bearing). Drill the pillow block in the middle to be able to grease by that groove. For a new bearing, before closing the cover, fill between the balls (or rolls) and fill 25-30% of the free space with grease. If you have a vibration team, ask them to take a reading after two-three days and take the temperature. You will have the "signature" of that bearing. Your vibration team should verify that bearing each 1-2 weeks. When they have a high frequency plus an inner ring frequence it means that the bearing needs grease. you count the amount of grease you put in the bearing until the high frequency disappear. It's about the same with an ultrasonic adaptor on a grease gun. If you put to much grease, the bearing yill overheat. Remember that you have his "signature" in reference. Take note for the interval of regreasing and the amout of grease you put each time. After few times, you have the interval and the amout of grease to put in. And you will not need a relief port. But, if you want to a put a relief port, drill a hole each side of the bearing, opposite, and put a relief fitting no more than 5 psi, like the Alemite #47200. If you use an automatic greasing system, put a drain tubing about 4-5 inches long each side for the excess of grease. Always pregrease those tubes to avoid contamination. We use those two methods with success. You can,also suscribe to LubeSelect from SKF. It helps for a "start with" procedure for the choice of grease, the intervals and the amount.
Hope that it will help.
Alain B.