Automobile bearing manufacturers will welcome the speed and thoroughness of an ultrasonic bearing cleaner as a replacement for brushing and scrubbing in a solvent wash tank to remove contaminants introduced during the manufacturing process. Similarly, ultrasonic cleaning can be used by fleet owners, and auto and truck repair shops to completely remove grease and grit that accumulate during use.
Cleaning Newly Manufactured Bearings
Ultrasonic cleaners available from Tovatech come in a wide range of sizes ranging from benchtop units to industrial-scale floor models suitable for automated cleaning lines.
The cleaner consists of a tank to hold the biodegradable water-based cleaning solution. Generator-powered ultrasonic transducers bonded to the tank provide powerful 35 to 45 kHz cavitation action that does the cleaning. This is described as violent but safe implosion of billions of minute bubbles that blast away contaminants from all wetted surfaces. Cleaning is aided by the “sweep” function to evenly distribute the energy throughout the bath. Cleaning time and solution temperature are set on control panel dials.
Ultrasonic cleaning solutions should be prepared in advance by adding water to the tank fill line (allowing for displacement by parts being cleaned) and the correct amount of cleaning solution concentrate. A good selection for cleaning newly manufactured bearings is elma tec clean A4 to remove contamination from metal surfaces. Available from Tovatech it can be diluted to 2 to 5 percent. If rust is a concern add 0.1% of elma KS inhibitor to the solution.
Turn the ultrasonic cleaner on and set the temperature to 80⁰C. Allow it to operate without a load to both mix the solution and to drive off cavitation-inhibiting trapped air (degassing). The amount of time required depends on the volume of solution in the tank, and degassing must be done when fresh solutions are prepared. Some cleaners come with a degas mode to speed the process.
Bearing Cleaning Sequence
- Turn on the ultrasonic cleaner and set the temperature dial to 80⁰C. Some models will start the cavitation process when the set temperature is reached. In the meantime arrange bearings in the mesh basket so they do not contact each other.
- Place bearings in the mesh basket in such a way that they do not contact each other. When cavitation starts, lower the basket into the solution and set the timer for 10 minutes. Experience will enable you to judge the cleaning time based on the condition of the bearings. The unit shuts down when the cleaning cycle is completed.
- Remove and inspect the bearings. If cleaning is satisfactory allow them to flash dry, otherwise clean them longer.
Automobile Bearing Maintenance
A different procedure may be called for in fleet owner, auto and truck repair shops and service bays to completely remove grease and grit that accumulate in bearings during use. This is because high melting point lubricating greases in the bearings are not readily removed by aqueous-based ultrasonic cleaning solutions.
Two procedures can be employed. In one an industrial steam jet cleaner such as the 3- and 5-liter Elmasteam 3000 and 5000 models available from Tovatech are used to remove the heavy grease deposits by allowing mechanics to direct the steam precisely where needed. If further cleaning is required the bearings can be cleaned ultrasonically following the above procedures.
As an alternative high alkaline cleaning formulations can be used in the ultrasonic cleaner. The tenacity of these grease deposits calls for an ultrasonic cleaner operating at a much stronger 25 kHz frequency and a solution temperature of 75-80°C. Because of their composition high alkaline solutions may require special handing as described on the containers. Otherwise the process is much the same but should be followed by rinsing to remove traces of the cleaning solution. The elma KS rust inhibitor should be added to the rinse water.
Maintaining the Ultrasonic Bearing Cleaner
Oily residues that rise to the surface of the cleaning bath should be skimmed off for proper disposal. Large industrial units can be fitted with oil skimmers and with filters that remove tank damaging metallic particles.
The cleaning solution should be replaced when cleaning efficiency drops. Drain the tank and dispose of the spent solution along with skimmed contaminants in an approved fashion. Use this time to remove solid wastes that have accumulated at the bottom of the tank following the manufacturer’s instructions.
Regardless of how you approach the cleaning of automobile bearings you should contact the ultrasonic cleaning experts at Tovatech for more detailed information on selecting the correct cleaning system.