How do you know if ball bearings are right for you?
Navigating your bearing choice can be challenging, there are many opinions online about various types and promise of life hours. In my last article, I looked at 3 of the most common types used in commercial fan designs. In this conversation, we will look at the ball bearing option and talk about positive and negative attributes.
I like to advise my customers that the first criteria for deciding on the type of bearing used is the reliability needed for the application. You do not want to pay for something that is not bringing benefit to your systems goals for cost and performance. We are going to proceed under the assumption that we need 80k hours of fan life for our new box we are designing. A Dual Ball bearing is going to offer you that range of life in a 40 degrees C environment on most YS TECH fans in the 60-172mm frame size.
Now we must look at all the factors that affect fan life and make sure that the ball bearing is still going to meet all our design criteria:
Can your ball bearing handle the heat?
What are your operating temperatures looking like? Storage temp is important to consider too. Ball bearings function well in -10 to 70C applications, this is a commercial temp rating for many fans on the market today. The temperature range is not only defined by the bearing but more importantly the board level configuration and materials used in construction. When venturing into temperatures above 80C you must be aware that grease/lubricant should be paid attention to. This is something engineering at YS TECH can provide advice on and assist in getting the write combination for optimal results in your design.
Stationary vs. mobile fan designs
Is this a stationary or mobile device? How much vibration is there? Ball bearings do very well in stationary designs, that is the easy part. You will however want to watch if your device is subjected to a lot of vibration, ball bearings can be damaged in this condition. The balls inside the bearing are very small and any external force can impact the ball into the race of the bearing which leaves a dent. It will be your source of noise in time. Also, I must note that small fans are sensitive to dropping them! A fan falling off a work bench can create the same damage on the internal race of the bearing. It will sound ok if you test it now, but the ticking noise will surface soon.
Taking sound into account
What are your acoustic requirements? Technically ball bearing fans have the loudest acoustic profile out of all the bearing types because they have moving parts inside. They do produce their own frequency within the total sound quality of the part. Designs like YS TECH Sintetico bearing can have a lower frequency footprint improving the overall sound quality.
Orientation and fresh air in your system
What orientation is the fan mounted? Ball bearing is solid for any mounting orientation. From a design standpoint if you asked me if there is a less than desirable position? Yes, it would be the fan mounted so it is blowing up (perpendicular to the ground). Ideally you would not want the rotor “hanging” on the motor. Standard flow fans would be blowing you in the face if you are reading the label on the fan.
Is the fan exhausting or in taking air into the system? From a reliability standpoint you always want the fan blowing fresh air into your system. This prevents the motor from being preheated in the exhaust position. Heat and dust are the most common killers of fans, if we can keep the motor temp down the life of the fan is much longer.
These are just a few of the key items to keep in mind when considering what bearing system to integrate into your next design. YS TECH can support you with various data to help with the process and make good decisions that will enhance your fan using experience. Feel free to contact us any time!