A significant characteristic of rolling bearing with steel ball indicators have?

A significant characteristic of rolling bearing with steel ball indicators have? 2021 - 02 - The precision of 20 goals of material ball rolling bearing ( The spherical error) Has reached the advanced rice field, materials, manufacturing process and requirements for the ball has been improved. High carbon chromium bearing steel (with the material of the ball Vacuum degassing) ； Stainless steel ( G95Cr18、G102Cr18Mo） ； Engineering ceramics ( Silicon nitride, silicon carbide, alumina) ； Of course, there are other kinds of material of the ball, such as carbide, glass, plastics, carbon steel ball and so on. More specific goals are porous, hollow ball, ball mill, polishing devices, etc. , with a ball of porous ball used in the push rod, ball valve, etc. ; The hollow ball is applied to aircraft engine; Ball mill used in paints, ferrite, food pieces; Polishing the ball used in the surface of the aluminum die casting polishing and deburring of castings, stamping parts. The characteristic parameters of steel ball (1, 1) geometric accuracy The ball diameter change quantity & Delta; Dws put a steel ball in plane and vertical plane phase between the measuring head, change the direction of steel ball is measured, the maximum and minimum values of steel ball diameter difference ( Two point contact method) 。 Measuring head adopts pointer micrometer or electronic measuring instrument, the precision of measuring instruments in accordance with the ball into 0. 1 to 0. 02 microns. 2) The spherical error & Delta; RSw using roundness instrument or contour meter measurement, the measurement section must be no fewer than three section. 3) Batch of diameter change quantity VDwL the diameter of the ball and not completely the same, put a ball in plane and vertical plane phase between the probe and measure to change the direction of the ball, the measure of the maximum and the minimum of arithmetic mean called average diameter of the ball. Will advance to determine the average diameter of the ball as a standard, using Pointers micrometer or electronic measuring instrument measuring after comparing with the standard ball. Batch diameter difference is within the average diameter of the big ball and minimum of the difference of the average diameter of the ball, it represents the change of average ball diameter within the batch quantity. 4) Surface roughness Ra with surface roughness measuring instrument or measuring binocular microscope, the qualified determination can be based on CSBTS TC98. 631999 'rolling bearing steel ball surface roughness technical conditions' relevant content or on the basis of internal control standards. 2, waviness are used in computer HDD spindle motor and VTR + drum of the rotation of the spindle bearing requirements to have high precision and small vibration. High-speed rotating bearing if it vibrate, HDD will generate read value error, may also affect the VTR + image and sound quality. For this type of bearing ball in addition to the GB/T 308. The size of the 12013 regulation precision ( Ball diameter changes, spherical error, batch of diameter change amount) Requirements, and the requirement of the waviness. If the ball with roundness measuring instrument magnified 200000 times to measure its shape, there are all kinds of waveform in circumferential direction. Waviness is the ball of each point on the surface of amplitude, in various types of high and low amplitude and from fine to long wave ( The ball of a circular band as shown) 。 Waviness waviness instrument measurement with a ball. Let the ball rotate at a certain speed, contact pin contact sphere, the movement of the stylus into electrical signal, measure the ball each circular band size and speed of change in volatility. Ball bump on each of the circumferential wave from a fine to the number of long study is divided into several regions. 3, the fatigue life of fatigue life test through the life of vibration testing machine test, and the purity of material life, the ball of the organization ( The strength of the matrix) The relevant. 4, the size of the size stability ball rolling bearings with high precision and long time didn't change, will cause the size of the retained austenite decomposition, along with the change of time must be strictly control its content. In order to prolong the service life of steel ball, the purity of materials with the development of the refining technology constantly improve, now has almost reached the limit, the future needs in the development of new steel grade and heat treatment process on the continuous exploration. In addition, more and more attention to the bearing the dynamic vibration performance of bearing vibration causes including the shape of the channel error and shape error of the ball, the ball most affected by the shape of the error, so using the ball most required roundness in 0. The following 5 microns. （ Source: shaft research website)