The ball bearing is a very round and smooth ball ball, most commonly used in ball bearings, but is also used as a component in things like the freewheel mechanism. The balls come in many different levels . These values ​​are defined by bodies such as the American Bearing Manufacturers Association (ABMA), an agency that sets standards for precision ball bearings. They are manufactured in machines designed specifically for the job.
In 2008, the United States produced 5,778 billion ball bearing.
Video Ball (bearing)
Class
Ball bearings are produced to a certain level, which defines their geometric tolerance. Values ​​range from 2000 to 3, where the smaller the number the higher the accuracy. Value written "GXXXX", ie class 100 will be "G100". Lower values ​​also have fewer defects, such as flats, pits, soft spots, and chunks. Surface fineness is measured in two ways: surface roughness and waviness.
Size refers to how tight the tolerances are to the size, as measured by two parallel plates that are in contact with the surface of the sphere. The initial size is the nominal sphere diameter , which is the nominal, or theoretical ball diameter. The ball size is then determined by measuring the spherical diameter variation , which is the difference between the largest and smallest diameter measurements. For the given lot there are many diameter variations , which is the difference between the average diameter of the largest bulb and the smallest bulb of the lot.
Sphericity, or deviation from spherical shape , refers to how many balls deviate from a true round shape (outside of roundness). This is measured by turning the ball against a linear transducer with a measuring power of less than 4 grams (0.14 oz). The resulting polar graph is then limited to the smallest possible circle and the difference between this finite circle and the nominal ball diameter is the variation.
Maps Ball (bearing)
Producing
The manufacture of ball bearings depends on the type of ball material being made.
Metal
The metal ball begins as a wire. Wire is shaved to provide a pellet with a volume of approximately the desired outer diameter of the ball (OD). This pellet then leads to a rough round shape. Furthermore, the balls are then inserted into the machine that flash it. The machine does this by feeding the ball between two heavy cast iron or hardened steel plates, called a "rill plate". One of the plates was silent while the others were spinning. The top plate has openings to allow the ball in and out of the rill plates. This plate has a fine circular groove tracked by the ball. The ball is run through a machine long enough so that each ball goes through many of these grooves, which ensures each ball has the same size, even if a particular groove does not meet the specifications.. Controlled machine variables are the amount of pressure applied, the speed of the plate, and how long the ball remains in the machine.
During refrigeration the operation is pumped between the rill plates because the high pressure between the plates and the friction creates a considerable heat. The high pressure applied to the ball also induces cold work, which strengthens the ball.
Sometimes the balls are then run through a soft grinding process afterward to improve the precision. This is done in the same type of machine, but the rill plate is replaced with a grinding wheel.
If the balls are steel, then they are given heat treatment. After heat treatment, they are urged to remove residues or by-products.
The balls are hard ground . They are milled in the same type of machine as used before, but either the abrasive is inserted into the cooler or the rotating plate is replaced with a very hard grain fine grinding wheel. This step can get the ball in Ã, Â ± 0.0001 in (0.0025 mm). If the ball requires higher precision then they will be arranged, again in the same type of machine. However, this time the rill plate is made of a softer material, usually cast iron, less pressure is applied, the plates are rotated slowly. This step is what gives the ball bearing their glossy looks and can carry the ball between classes 10 and 48.
If higher precision is required then proprietary chemical and mechanical processes are usually employed.
The ball bearing examination is one of the classic case studies in Frederick Winslow Taylor's Principles of Scientific Management.
Plastic
Plastic bearing balls are made in the same way as described above.
Ceramics
Ceramic bearing balls are made of sintered material which is then milled into the size and shape as above. Common materials include: silicon nitride ( Si
3 N
4 ) and zirconium dioxide ( ZrO
2 ).
Materials
Common materials include carbon steel, stainless steel, chrome steel, brass, aluminum, tungsten carbide, platinum, gold, titanium, plastic. Other less common ingredients include copper, monel, k-monel, lead, silver, glass, and niobium.
Atypical uses
One of the attractive atypical used for ball bearings is at San Francisco International Airport. The building is supported by 267 columns, each resting on a steel ball with a diameter of 5 feet (1.5 m). The ball sits on a sunken concave. If an earthquake occurs, the soil can move up to 20 inches (0.51 m) in any direction, since the columns roll over at their base. This is an effective way to separate buildings from ground motion. After the earthquake has ended, the columns are re-centered on their base by the force of gravity.
See also
- Steel shot
References
Source of the article : Wikipedia
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