Best Way to Install Your Coupling

In this particular case, the picture really is worth a thousand words. Obviously what is depicted in the picture on the left would be something extreme that most reputable business will not do -  at least we hope is not the case in your own situation.

For proper coupling installation procedures that will look more like the picture on the right, Lovejoy recommends you follow your manufacturer's installation instructions. The installation procedure usually comes in a detailed step-by-step guideline (generally in PDF or print form). For warranty related aspects and to avoid any major problems related to improper coupling installation, you must follow your manufacturer's guidelines.

However, if you need some further knowledge or additional tips on coupling installation, you may consider watching Lovejoy's installation videos on couplings.com. Lovejoy has an excellent library of over 20 installation videos, where you can see the step-by-step details of proper ways to install your coupling. Our coupling videos will visually show you all the needed parts and tools for a successful installation. Additionally, all the coupling installation steps are clearly explained, in an easy to follow format, with visual aids and voice narration.

While these videos are specific to Lovejoy products (jaw, curved jaw, grid, disc, etc.), many of the concepts and principles pictured are broadly applicable to coupling installations in general, and could prove as a worthwhile reference relative to the coupling you are looking to install.

Again, our videos are a great aid to help you get some additional pointers on installing your flexible coupling (be it a jaw, gear, grid, disc... whatever). But Lovejoy certainly does not warranty or formally endorse using Lovejoy installation videos for non-Lovejoy couplings as the basis of your installation... use the manufacturer's provided guidelines.

Our videos are widely watched by people in different job functions such as engineering, maintenance, etc., servicing a variety of equipment like steam turbines, gensets, pumps, crushers, fans, blowers, exhausters, conveyors, injection molding, shredder, bailers, etc. Also, our users come from a variety of industries including power generation, fluid power, food and beverage, aggregates, pulp and paper, steel, mining, etc.

Shaft Inspection Prior to Coupling Installation

Prior to installing a coupling (new installation or replacing an existing unit) it is important to inspect the condition of the shaft.  If the shaft is sufficiently gouged, marred or otherwise distorted it may need to be dressed (reworked) prior to installing the coupling.  During laboratory testing of the coupling to shaft interface we found that a deformed shaft can reduce the torque capacity of the joint.  It is important to understand that the joint will only be as strong as the weakest link in the system.

An example of a shaft that needs to be dressed prior to coupling installation is shown above.

Recommended Follow On Reading: In addition to inspecting the shaft for damage prior to coupling installation, it is also important to inspect the shaft keyway and key for damage as well. The following is an article on shaft keyway damage: Shaft Keyway Damage

Should I rotate shaft keyways 180° apart when installing a coupling?

A common question that I am asked is if the keyway on the drive and the keyway on the driver shafts should be oriented 180° apart.

My response is twofold. If the unit is designed and manufactured as a single system, the orientation of the keyways should not matter as the key length will correspond to the bore length of the coupling (and the keyway cut into the shaft should also be only just long enough to properly fit the coupling). 

However, some applications have a longer key & keyway than what is needed for the coupling.  The longer key may cause an imbalance in the system if both keyways in the shafts are aligned. It is with this potential imbalance in mind that the “rule of thumb” to orient the keyways 180° apart was created.

Big picture, if you want to minimize imbalance in a system when installing a coupling the 180° keyway "rule of thumb" is certainly a worthwhile. While it may not always be required, it is a good "best practice" to follow.  

How to Install a Coupling

So you've got your flexible coupling in hand (be it a jaw, gear, grid, disc... whatever) and are ready to install it.... but are looking for some additional pointers. Perfect.

The first place you should go and reference/use is your manufacturer's installation instructions. Your manufacturer should be able to provide you a detailed step-by-step installation guideline (generally in PDF or print form), and you are best served to follow up with the manufacturer regarding any questions you have with their guidelines.

As a knowledge supplement to your specific manufacturer's installation instructions, you may also consider watching Lovejoy's installation videos either on YouTube or couplings.com. While these 20+ videos are specific to Lovejoy products (jaw, curved jaw, grid, disc, etc), many of the concepts and principles pictured are broadly applicable to coupling installations in general, and could prove as a worthwhile reference relative to the coupling you are looking to install. (We, of course, certainly don't warranty or formally endorse using Lovejoy installation videos for non-Lovejoy couplings as the basis of your installation... use the manufacturer's provided guidelines... but if you want to use our videos as a reference only/educational tool... please, be our guest.)

And for those of you who hate clicking on links, we've embedded a playlist of over 20 installation videos above. We defaulted to a pretty interesting one (a full spacer grid coupling video), but you can quickly change to another coupling type by clicking the "PLAYLIST" button on the top left hand corner of the screen.