Sleeve or Ball, That Is the Question

July 11, 2022

Motor Minute™ Technical Tip – Sleeve or Ball, That Is the Question

Hi, Chris from Regal Rexnord here with your Motor Minute technical tip. Helping you become an HVAC motor pro one minute at a time.

Today’s motor minute topic is Sleeve or Ball, That Is the Question.

There are two types of bearings used in Fractional Horsepower (FHP), direct drive motors for HVAC applications:

• Sleeve
• Ball

Permanent Split Capacitor (PSC) motors are built with either of these types of bearings. Genteq® branded Electronically Commutated Motors (ECM) are only built with ball bearings, both for OEM and retrofit applications.

Most HVAC manufacturers choose PSC motors built with sleeve bearings for both indoor blower motor and outdoor fan motor applications due to cost.

When selecting a replacement for a PSC motor, however, you have the option of purchasing a sleeve or ball bearing motor. So, the question is, which one should you choose?

Some technicians may believe that sleeve bearings:

• are quieter than ball bearings
• cost less than ball bearings
• are less durable than ball bearings

Some technicians may believe that ball bearings:

• are noisier than sleeve bearings
• cost more than sleeve bearings
• are more durable than sleeve bearings

The truth is, due to improvements in materials and manufacturing processes, today there is a negligible difference in noise and cost between the two bearings.

I can already hear someone out there yelling at their phone saying they disagree that there is a negligible difference in noise between the two bearings.

Consider that ECM motors have been applied to OEM HVAC applications for over 30 years with few complaints about bearing noise when compared to the overall volume of these motors in the industry.

In today’s fractional horsepower direct drive HVAC motor applications, ball bearings provide an advantage over sleeve bearings in reliability. In fact, it is becoming common for motor manufacturers to produce motors built solely with ball bearings. Which helps solve the question “Sleeve or Ball".

And that’s a wrap on this segment of Motor Minute technical tips. Remember that we provide motor training and product information in multiple formats including videos, literature, podcasts, articles, of course, Motor Minute technical tips and classroom education both online and face-to-face. All of this industry-leading training is available at no charge to HVAC professionals at regalmmu.com. Thank you for taking the time to build your motor knowledge.