Heating method for hot installation of bearings

What is hot installation of bearings? How should we heat up the hot installation of bearings? According to our understanding, hot fitting of bearings generally refers to a heating process in which the inner ring of the bearing is fitted onto the bearing block of the shaft, and is divided into two processes: hot fitting (also known as hot fitting) and cold fitting. Generally speaking, the former has better results than the latter.

There are four common methods for heating bearings during hot installation:

(1) Oil boiling method

Place the bearings on the grid in the transformer oil. Heat the transformer oil, remove it after the scheduled time, wipe off the oil stains and attachments with a clean and lint free cloth, and quickly put it on the shaft.

(2) Power frequency eddy current heating method

After fitting the bearing onto the moving iron core of the power frequency heater, connect the AC power supply of the heater. Bearings will generate eddy currents (currents) in the inner and outer rings due to electromagnetic induction, which will generate heat and cause them to expand. This type of heater is produced by professional factories and comes in different capacity specifications, which can be selected according to the size of the bearings. The control of heating temperature can be achieved by using its built-in temperature measuring device. If not available, it can be directly measured by thermocouples or thermometers, or after actual measurement, the required time can be counted and controlled by time. This will be more convenient, but different heating times should be given according to different environmental temperatures.

(3) Oven heating method

Place the bearings in a dedicated oven, where the temperature should be constant and uniform. After the set time, take it out and put it on the shaft as soon as possible.

(4) Induction cooker heating method

Heating the bearings on an induction cooker is more suitable for smaller bearings, especially in the absence of the aforementioned equipment, such as when replacing bearings at the user's site, which is a good method. The induction cookers used include products produced by professional factories, as well as ordinary induction cookers used for home cooking. During operation, attention should be paid to adjusting the temperature switch, measuring and controlling the temperature.

Reminder: The so-called hot installation process is to heat the bearing, expand the inner diameter of its inner ring, and then insert it into the bearing stopper of the shaft. After cooling, the inner ring shrinks, forming a tight fit with the shaft. The heating temperature of the bearing should be controlled within 80-100 ℃, and the heating time depends on the size of the bearing, generally between 5-10 minutes.