Extra Edition / Technical

Explaining V-Belt Drive Misalignment

June 7, 2010
/ Print / Reprints /
ShareMore
/ Text Size+
Figure 1. Angular misalignment.

V-belt drive misalignment exists when the driver and driven sheaves are not properly aligned. Misalignment can take either the form of angular or parallel (offset) misalignment, or a combination of both.

Figure 2. Parallel misalignment.

Angular misalignment occurs when the faces of the sheaves do not form a straight line. (See Figure 1.)

With parallel misalignment, the sheaves may be in angular alignment, but their position on the shaft creates a parallel offset. (See Figure 2.) Ideally, you want to have both parallel and angular harmony. The objective is to have the shafts parallel and the center lines of the two sheaves in line with each other. (See Figure 3.)

Figure 3. Desired alignment.

IMPACTS OF V-BELT MISALIGNMENT

Excessive V-belt drive misalignment causes one or more of the following drive conditions:

1. Premature V-belt failure.

2. Uneven and premature sheave wear.

3. Higher V-belt operating temperature and energy consumption.

4. Uneven wear on belt sidewall.

5. V-belts rolling over in the sheave groove.

6. Transfer of load to one side of the V-belt, which can destroy the belt cords on that side.

7. Increased probability of vibration.

8. Drive instability.

Click on the image for an enlarged view.

BEST PRACTICES FOR V-BELT DRIVE ALIGNMENT

Acceptable V-belt misalignment for raw edge cogged V-belts is 1/2° or 1/10 inch per foot of center distance. Non-cogged V-belts can tolerate sheave misalignment of about 2° maximum.

The easiest way to quickly ensure sheave alignment is to use a straight edge or multi point contact string method.

Special Note: Sheave alignment should be checked before and after belt tensioning. Always adhere to strict safety and lock out and tag out procedures when performing maintenance on a V-belt drive.

Sidebar: V-Belt Drive Video

An informative V-belt drive sheave installation and tensioning instructional video is available at www.emerson-ept.com which details steps for correctly inspecting and installing V-belt drives. The download video path appears below.

1. Click on Product Literature tab.

2. Click on Download.

3. Click on Media Type dropdown.

4. Click on Video’s.

5. Click Submit – Available video titles will appear.

6. Click on V-Belt video.

Reprinted with permission from the Browning Belt Drive Monthly published by Emerson Industrial Automation. For more information, visit www.emerson-ept.com.

Publication date: 06/07/2010

Did you enjoy this article? Click here to subscribe to The NEWS Magazine

Recent Articles by Don Sullivan

You must login or register in order to post a comment.

Multimedia

Videos

Image Galleries

2014 MCAA Annual Convention

Scenes from the 2014 MCAA Annual Convention in Scottsdale, Ariz.

Podcasts

NEWSmakers: Julian Scadden

Training is an ongoing process. Julian will discuss how you can generate maximum return on time and energy invested training by following a three part process. Listen to this podcast to get expert tips on training, tracking and follow up. 

More Podcasts

THE MAGAZINE

ACHRNEWS

NEWS 04-14-14 cover

2014 April 14

Check out the weekly edition of The NEWS today!

Table Of Contents Subscribe

SERVICE CALLS POLL

Which statement on service calls best applies to your business?
View Results Poll Archive

HVACR INDUSTRY STORE

plumbing-hvac.gif
2014 National Plumbing & HVAC Estimator

Every plumbing and HVAC estimator can use the cost estimates in this practical manual!

More Products

Clear Seas Research

 

Clear Seas ResearchWith access to over one million professionals and more than 60 industry-specific publications, Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.

DON'T MISS A THING

Magazine image
 
Register today for complete access to ACHRNews.com. Get full access to the latest features, Extra Edition, and more.

STAY CONNECTED

facebook icontwitter iconyoutube iconLinkedIn i con