Time：2020.03.05 Source：Roller Bearings Suppliers
Although there are thousands of types of bearings, they all follow the same
mechanical principles and mechanical laws. According to the different force
transmission methods, bearings can be divided into two categories: sliding
bearings and rolling bearings. The former depends on pushing conduction forces,
and the latter depends on rolling conduction forces.
Even if one's middle school physics is taught by a physical education teacher, with life intuition, you can know that rolling friction is much smaller than sliding friction. If you need to save effort, there should be no doubt that rolling bearings are the first choice. Therefore, rolling bearings are used in more applications than plain bearings. Therefore, only rolling bearings are discussed below.
Rolling bearings are generally composed of an inner ring, an outer ring, a rolling element, and a cage. What is a rolling part?
As you may have guessed, the reason why bearings can roll depends on these rolling elements: silver balls, very round steel balls! These steel balls are the basis on which the bearings roll, and are wrapped in cages, which are tightly protected.
Among them, the steel balls in the bearings must be the same size, and the surface is exceptionally smooth (it can shine a bright shadow like a mirror). It also needs to maintain stable work under an absolute pressure, and the surface must not have visible wear. The requirements for materials and processing accuracy are very high.
First, the steel used to make the balls is exceptional: it is not ordinary steel, but high chromium steel containing Chromium.
After adding Chromium, the steel has changed its shortcomings of rusting and breaking easily, and has become more robust: it is only not easy to deform, high wear resistance, but also corrosion resistance. Bearing balls are undoubtedly the best choice; it can be said to be tailor-made!
But it is not enough to have the right materials. To change from steel to bearing balls, we still have to go through a difficult journey. Let's take a look together, what kind of suffering has gone through from steel to bearing balls!
The raw material of bearing balls is, of course, linear steel. Different bearing balls require different wire widths. These have industry standards, and the standards are universal. So don't worry about bearing balls made in China that cannot be used on Canadian bearings.
The first step in ball production is to make the embryo: the wire is cut to a particular length and then compressed into a rough ball shape on a forging machine.
Coarse grinding (deburring)
This procedure is to process the compression-formed embryo on a rough grinder. The nucleus is sandwiched between two grooved grinding discs, one of which rotates and applies pressure. Both plates are grooved to guide the balls. Scroll along a circular path. One part of one of the dishes was cut off; this is the entrance of the ball into and out of the groove. When the machine is running, the slots are full of nuts. When a ball rolls out of one slot, it will fall into the opening of the board, where the ball goes for a moment, and then enters another slot. Make sure that each ball passes through many different slots, so that even if the size of the slots is different, the size of the shots coming out is the same, and the surface burrs are removed and polished into round balls. It should also be pointed out that the process of squeezing the balls compresses the metal and generates a lot of heat, so the nuts and plates must be watered to cool them to avoid overheating and accidents. But the steel balls coming out at this time are still not enough "balls", what should I do? According to the needs, there can be multiple rough grindings until rounding!
Heat treatment (make your heart stronger)
After two stages of torture, can the steel balls produced be called bearing balls? Sorry, the current product is still in a weak state. It only has a round appearance and no gritty heart. If you install such nuts on aero engines, I am afraid that people who fly by plane will be panic. Only after undergoing the most severe test can we forge a solid heart. The balls in the bearing must be able to withstand a certain weight and must be wear-resistant. This requires further processing of the steel balls, that is, heat treatment.
Put the steel ball into the oil; after quenching, tempering, and other processes, the strength and wear resistance of the steel ball can be improved.
Refined (back to old age)
The heat-treated ball is refined with a unique precision grinder to improve shape accuracy and smoothness. Fine grinding is roughly the same as rough grinding, except this time, an abrasive is added to the coolant. After the ball passes through the groove again, the surface is polished and smooth, and the size is compressed to the final size. As for how fine it can be, it depends on the level of craftsmanship in each country. Similarly, fine polishing can be performed multiple times. The surface of the steel balls obtained after fine grinding and polishing is exceptionally smooth.
Clean and inspect (pretty face also needs maintenance)
Like no beauty does not pay attention to maintaining the skin, the polished steel balls also need to use ultrasonic waves to remove the debris on the ball surface to keep the appearance clean. The last step is to use an optical automatic appearance sorter to check the surface of the balls, detect and remove the nuts with scratches on the surface. Of course, visual inspection is also essential, although I don't know exactly how it is done with the naked eye.
In this way, after going through these ordeals, the wire has become bearing balls. But don't underestimate their strength. She is a goddess with both beauty and soul: a ball with a diameter of 10 mm is usually less than 0.1 micron but can bear a weight of more than 30 tons.