Typical bearings are used for a specific operating temperature range. However, many production processes take place in non-standard conditions. Extreme temperatures, both low and high, require specific properties from the components. A conventional bearing is not designed for this operation: the physical characteristics of materials change, and as a result, the part can quickly become unusable.
Therefore, it becomes necessary to order special bearings that have increased thermal resistance. Let’s talk in more detail about their specifics.
What bearings can be used in non-standard temperature environments? There are 3 types of such products:
- High temperature.
- Low temperature.
They differ from each other in the materials used in the release of the part, as well as in the types of lubricants used during operation. Taking these characteristics into account will help you choose the right bearing.
What to consider when choosing?
Each product has its own characteristics in terms of the degree of cooling and heating. All bearings produced today are designed to operate at a precisely specified temperature: this is one of their main technical characteristics. In standard parts, with sharp heating or temperature changes, the rolling bodies expand, as a result, the product wedges.
This happens because the typical metal from which the rings are made is not heat-resistant, it deforms when heated. The same goes for regular grease – it cannot withstand extreme heat.
Therefore, if heat cannot be removed, the operation of heat-resistant bearings is a necessity.
The conditions of extreme temperatures are distinguished by the time of their flow for constant, periodic and short-term. Note that special bearings with improved thermal stability properties are required in the first case. That is, when the operating temperature is constantly high. Some leaded bronze bearings are designed to maintain performance in these conditions.
They have a specific field of application, most often it is the food industry, metallurgy and paint and varnish production.
What are the features of heat-resistant bearings?
Structurally, they differ from their standard “brothers” in that:
- The effect of expansion of bodies upon heating is taken into account.
- For this, an increased technological gap between the components is created.
- Also, to enhance the necessary properties, special materials are used: for load-bearing components – special grades of steel, with an increased concentration of nitrogen; for seals – polymers with low thermal conductivity; for rolling elements – silicon nitride, ceramics and bearing bronze.
When manufacturing products, specific processing methods are used, which ultimately gives the finished product strength and increased hardness, the ability to withstand heat up to 1,000 degrees.
The so-called “hybrid” parts have been developed and are actively being produced, where rolling elements made of ceramics and steel rings are combined. They can be operated at high rotation speeds, under conditions of increased mechanical stress.
Bearings designed for high temperature environments have special protection for friction zones. It is provided by:
- Oil-based grease;
- Lubricating formulations contain elements (usually calcium and lithium) designed to maintain high temperature stability. They also protect the part from oxidation.
- The addition of graphite gives the oil film stability in friction zones.
These properties make it possible to use bearings in conditions of high thermal values and pressures. You can easily order rubber goods, lubricants, loose parts, components and heat-resistant bearings and bearing bronze online from trusted suppliers.