Points to note regarding deep-groove ball bearings
The preload of deep groove ball bearings is set at room temperature; however, during operation, the rise in system temperature causes slight elongation of the drive shaft, resulting in a change in bearing preload. Therefore, this factor must be taken into account when setting the preload.
The preload of deep groove ball bearings must be set appropriately based on load size, rotational speed and other operating conditions to ensure service life. If the preload is too high, it will increase power consumption and may even cause the bearing to overheat. If the preload is too low, under load, play and slippage will occur between the shaft, rolling elements and inner and outer rings, reducing transmission accuracy, increasing noise and affecting normal equipment operation; in severe cases, this may result in premature bearing failure.
Depending on the specific mounting requirements of deep groove ball bearings, clearance can be eliminated and preload achieved by axially compressing the inner ring or rotating the preload nut. A common installation method involves tightening the nut fully and then turning it back by a quarter turn. This method is simple, practical and cost-effective, and can be widely used provided bearing quality is ensured
1. Electric Heating Plate Method
Place the bearing on an electric heating plate set to 100°C for a few minutes. This is the simplest method; turning the bearing over a few times ensures even heating. It is highly efficient and suitable for deep groove ball bearings of all sizes.
2. Electric Furnace Heating Method
Place the bearing in a sealed, automatically temperature-controlled electric furnace for heating. This method ensures uniform heating, precise temperature control and rapid heating rates, making it suitable for batch heating of bearings.
3. Induction Heating Method
Using an induction heater allows deep groove ball bearings to be heated to the required temperature quickly, reliably and cleanly. This method is particularly suitable for tight-fit installations of the inner ring; as only the inner ring is heated and the outer ring receives minimal heat, it facilitates installation onto the shaft and into the housing bore.
4. Light Bulb Heating Method
Heating deep groove ball bearings using a 50W light bulb ensures a temperature of around 100°C. Small bearings can be placed directly above the bulb, whilst larger bearings can be placed inside a conical cover to ensure even heating. This method is suitable for scenarios involving small quantities of bearings and infrequent heating; it is both energy-efficient and practical.
5. Oil Bath Heating Method
This is a widely used traditional heating method. A metal mesh is placed 50–70 mm above the bottom of the oil bath, with the bearings positioned on the mesh; large bearings must be suspended using hooks. Bearings should not be placed directly on the bottom of the bath to prevent localised overheating or the ingress of contaminants. Non-corrosive mineral oil with good thermal stability (such as transformer oil) should be used, and both the oil and the container must be kept clean. The size of the oil bath must match the bearing dimensions to ensure effective continuous heating.
