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Guide to Installing Angular Contact Ball Bearings in Process Pumps

Question:

I have been researching online for detailed instructions on how to install back to back angular contact ball bearings in our process pumps. While I found a helpful PDF manual from FAG Bearings, it is missing some crucial information. Is there a resource available from another bearing manufacturer that could provide the missing details? Specifically, I need guidance on properly installing the lock washer and nut on the shaft after the bearings have been mounted. Should the nut be tightened before or after the bearings have cooled down? And how tight should the nut be secured - until the outer races begin to drag or until they lock up completely?

Top Replies

Achieve consistent results by utilizing a torque wrench. When tightening a nut, make sure to use a cool bearing or apply a reasonable amount of force. Avoid using a drive rod and hammer, as it can introduce metal into the bearing. Instead, use a 'cold-roll' steel rod and never use brass. Ensure the pull is tight, fully tightened, not just lightly touching. Always inspect and record axial clearance. When working on older equipment, check the journal diameters in four locations (front and back) as well as the housing bore to confirm accurate diameters and the absence of taper.

When I need guidance on installation and removal, my go-to website is http://www.skf.com/mount/. Signing up is required, but it provides in-depth details on every step of the process.

It's time to revolutionize our approach to maintenance: Remove all hammers from tool chests and securely weld them to the nearest steel pillar to prevent any accidental hammering on bearings. Instead of using a hammer, opt for a lever with a properly fitting key to tighten nuts. For precision, consider using a long lever and a spring scale to apply specific torque. There are high-quality torque wrenches available for modified tools as well. Hammering can leave undesirable glide marks on bearings, causing premature wear and fatigue. By avoiding hammering, properly-sized and lubricated bearings can last for over two decades. While this may result in less work for the workshop, it will increase professionalism and provide more time to address other machine issues.

Discover a wide range of tools for bearing installation and removal, as well as lubrication and fluid handling at MaintenanceProductsDirect.com. Stay informed and equipped to properly maintain your equipment for optimal performance.

I have come across discussions regarding the importance of properly tightening back-to-back angle-contact bearings on overhung pumps. It is recommended to tighten them just enough so that the outer races can be moved against each other with some resistance, but not to the point of being bound up. This method serves as an alternative to using a torque wrench, as the effectiveness of the wrench check largely depends on the friction between the inner ring and the shaft. Your question about whether to adjust the bearings before or after they cool down raises some interesting points. It is worth considering that once the bearing cools, it may be challenging to move the inner ring on the shaft. By adjusting the bearings before they cool, you are establishing a preload that may shift as the bearing returns to ambient temperature (and possibly tightens again if it warms up during operation). Adjusting the bearings before they cool down may be more practical for a couple of reasons. Firstly, the operating temperature of the bearing falls somewhere between ambient and the temperature at which it was installed, so it is challenging to recreate the exact operating temperature with either approach. Additionally, adjusting before cooling allows for the opportunity to double-check the tightness of the outer races against each other after the bearing has cooled. If they feel too loose, adjustments can be made accordingly. It is important to note that these are just my observations and thoughts on the matter. For the most accurate guidance, it is advisable to consult the manufacturer's specific instructions for this application. It is interesting to point out that this post seems to be appearing before older messages on April 15 - the reason for this is unclear.

More Replies

It is imperative to allow the bearings to cool before tightening to prevent them from shrinking, causing the nut and bearings to become loose. This lesson was learned through firsthand experience.

Frequently Asked Questions (FAQ)

FAQ: 1. Where can I find detailed instructions on installing back to back angular contact ball bearings in process pumps?

Answer: - You can refer to resources provided by bearing manufacturers such as FAG Bearings or other manufacturers for comprehensive guidance.

FAQ: 2. How should I properly install the lock washer and nut on the shaft after mounting the bearings?

Answer: - It is essential to follow manufacturer-specific guidelines for installing the lock washer and nut to ensure proper assembly.

FAQ: 3. Should the nut be tightened before or after the bearings have cooled down?

Answer: - It is advisable to follow the recommended procedure provided by the bearing manufacturer for tightening the nut, whether before or after the bearings have cooled down.

FAQ: 4. How tight should the nut be secured when installing angular contact ball bearings?

Answer: - The tightening torque for securing the nut should be as per the manufacturer's specifications, typically until the outer races begin to drag or based on the specific locking mechanism provided.

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