"Are ultrasonic grease guns more effective or just a bunch of hype?"
Although ultrasonic grease guns might sound like a bunch of hype, the devices actually are undervalued. They can go a long way in providing you a simple means to achieve an optimal grease injection level.
In industry, ultrasonic monitoring technology listens to the vibrations produced from machine friction. These vibrations, which usually are at a frequency around 30 kilohertz, are measured and then adjusted to a new frequency that is audible to the human ear. This audible signal can then be analyzed by the operator to provide important feedback about the internal friction conditions of the machine.
With grease gun applications, this is used a step further. The grease gun can be physically attached to the ultrasonic monitoring device, which is then mounted onto the grease fitting on a bearing housing of a machine. After an initial amount of grease is injected into the bearing housing, a unique frequency will be registered. Note that the machine must be in operation in order to register any kind of internal friction-related vibrations.
During each "shot" of grease into the housing, a temporary increase in audible frequency will occur. As the grease has time to move around, the frequency will return to or near its previous frequency. Each injection will follow this pattern until finally there is no noticeable drop in frequency or the signal begins to rise. This indicates that the bearings are operating in optimal grease-lubricating conditions and that no more grease should be added to the housing.
At times, greasing a bearing can be tricky, and the importance of avoiding under- or over-greasing can be overlooked. Simply knowing the calculated maximum volume of the bearing housing may not be adequate to ensure that proper grease levels have been reached. Over-greasing can lead to increased heat generation, which then leads to higher oxidation rates and energy consumption. With bearings located in motors, the grease could damage the seals and leak into the motor windings, causing further complications. Under-greasing, on the other hand, could result in bearing starvation, which is a clear promoter of increased friction wear and contamination.
An ultrasonic grease gun can provide an optimal method to make sure the correct amount of lubricant goes into a machine. Without these devices, this critical lube work can become risky guesswork.
There are several variations of ultrasonic grease guns on the market that allow application for just about any type of grease gun. If used correctly, ultrasonic greasing can be simple and effective, which is why these devices have received so much hype.