General information about rolling bearings
Classification of rolling bearings
Rolling bearings are separated into radial bearings and persistent bearings.
Further depending on swing elements bearings are separated into the ball-bearings and roller bearings in more detail classified depending on the difference in their design or the specific purpose.
- Radial ball-bearings.
- Radial-stop ball-bearings.
- Bearings from three - and the four-point contact.
- The self-installed ball-bearings.
- Ball-bearings for bearing nodes.
- Magnetic bearings.
- Roller bearings.
Cylindrical roller bearings:
- Needle roller bearings.
- Bearings with long rollers.
- Conic roller bearings.
- Spherical roller bearings.
- Persistent ball-bearings.
- Persistent and radial ball-bearings.
- Cylindrical upornyerolikopodshipnik.
- Needle persistent roller bearings.
- Conic persistent roller bearings.
- Spherical persistent roller bearings.
- Automobile bearings for couplings.
- Automobile bearings for water pumps.
- Railway axle-box bearings.
- Bearings of rope sheaves of cranes.
- Basic and rotary devices.
- Bearings for chain conveyors.
Mekhatronny bearings — the kind of bearings with the built-in electronic part (special sensors and the enkoder). It is applied since the beginning of the 90th of the 20th century.
Depending on combinations of different sensors distinguish three generations of mekhatronny bearings:
- the rotations containing the speed sensor;
- containing the positioning sensor allowing to measure: angular provision, speed, rotation sense, quantity of turns;
- containing the sensor of the moments.
Such bearings find the application in automotive industry and the industry.
The first mekhatronny development which was widely adopted became the ASB® bearing (Active Sensor Bearing) of SNR which represents the automobile felloe bearing with the integrated speed sensor.
The main advantages of the ASB® bearing are:
- possibility of measurement of rotational speed of the wheel at speeds close or equal to zero;
- reduction of dimensions and weight of the felloe node;
- simplification of mounting and installation of the bearing;
- unification of components.
Service of bearings
For the purpose of the maximum increase in service life, prevention of mechanical damages, ensuring no-failure operation it is necessary to examine periodically bearings and to control operating conditions.
Service of bearings needs to be carried out regularly, considering operating conditions of bearings in the equipment. It is necessary to sort and examine periodically the equipment, to fill up or replace lubricant and to control operating conditions of bearings. Considering properties of lubricant, it is necessary to check compliance of characteristics of lubricant to working temperatures. During determination of terms of replacement of bearings and intervals of replenishment of lubricant it is necessary to consider vibrations and noise in bearings. At survey of bearings during scheduled works it is required to check racetracks regarding damages.
Some reasons of malfunctions of bearings are included below and measures for their elimination are proposed.
Noise during the operation of the bearing
Loud metal sound. Probable causes:
- abnormal loading. It is necessary: to specify landing, the internal gap, preliminary loading or provision of shoulders of the body;
- improper assembly. It is necessary: to increase the processing accuracy, accuracy of adjustment of coaxiality or accuracy of mounting of the shaft and the body, to use the appropriate technique of installation of the bearing;
- insufficient amount or unfitness of lubricant. It is necessary: to fill up lubricant or to pick up other lubricant for the bearing;
- contact of the rotating parts. It is necessary: to correct labyrinth consolidation.
Constant loud sound. Probable causes:
- cracks, corrosion or scratches on paths caused by presence of foreign debris. It is necessary: to replace or clean the bearing, to correct the condition of consolidation or to use pure lubricant;
- brinellirovaniye, i.e. emergence on the surface of rings of the dredging following one after another. It is necessary: to replace the bearing, pryavly care at installation;
- flaking in paths. It is necessary: to replace the bearing.
Discontinuous sound. Probable causes:
- excessive gap. It is necessary: to check landing, the gap and preliminary loading;
- pollution by foreign particles. It is necessary: to replace or clean the bearing, to correct consolidations and to use pure lubricant;
- cracks or flaking in balls. It is necessary: to replace the bearing.
Abnormal temperature increase
- excessively small gap. It is necessary: to check landing, the gap and preliminary loading;
- excessive amount of lubricant. To reduce amount of lubricant and to pick up more dense lubricant;
- insufficient amount or unfitness of lubricant. It is necessary: to fill up lubricant or to pick up the corresponding type;
- abnormal loading. It is necessary: to specify landing, the internal gap and preliminary loading or provision of shoulders of the body;
- improper assembly. It is necessary: to increase the processing accuracy, accuracy of adjustment of coaxiality or accuracy of mounting of the shaft and the body, to use the appropriate technique of installation;
- deformation of the corresponding surface or excessive friction of consolidation of the bearing. It is necessary: to isporavit consolidation or to replace the bearing, to correct landing or installation.
Vibrations (axial beating)
- brinellirovaniye. It is necessary: to replace the bearing, showing care at installation;
- flaking. It is necessary: to replace the bearing;
- improper assembly. It is necessary: to provide perpendicularity of the shaft in relation to zplechik of the body or the end face of the pro-rate;
- penetration of foreign particles. It is necessary: to zemnit or clean parts of the bearing and to correct consolidation.
Leak or decolouration of lubricant
- excessive amount of lubricant or pollution by foreign particles or products of wear. It is necessary: to reduce amount of lubricant, to pick up more dense lubricant, to replace the bearing or lubricant, to clean the body and adjacent parts.
Bearings – general information to Look or download in the PDF format
History of emergence of bearings
Primitive prototypes of the modern bearing simplified human life already many thousands years ago. Knew about existence of friction of people since the most ancient times.
The fact that the primitive person extracted fire quickly demonstrates to it rotating the stick, that is already then used the friction method, and began to cut fire by means of blows of one stone about another later (used transition of kinetic energy of friction to thermal). It also played the major role in the history of emergence of the bearing and its further improvement.
The very first primitive bearings of sliding were for the first time found in excavation, belonging to the Neolithic era. During this period people began to master friction action, seized ability to drill openings in the stone. So-called "bearings" were manufactured of the stone and used in different spinning spindles and drilling devices. Began to be used in different elementary simplest designs later - mill stones, the potter's wheel, the chariot, the bullock cart. To the invention of the wheel people moved the load on sledge in which harnessed people or animals.
Before the rolling bearing reached the form similar on modern, it passed the set of different stages of improvement. Till 2nd century BC for transportation of loads used ordinary logs (so-called rollers) which, by the way, still use for transportation of very heavy objects today.Top