WSW Technology Knowledge: Control of Clearance of Deep Groove Ball Bearing
The clearance of deep groove ball bearing is controlled by strictly controlling the accuracy of inner and outer ring and steel ball
Abstract: in view of the problem that the axial clearance is commonly used to control the radial clearance in the production of deep groove ball bearings, and the radial clearance is out of tolerance after sleeve fitting, by strictly controlling the accuracy of inner and outer ring and steel balls, and compressing the radial clearance range when calculating the axial clearance, the lower limit value remains unchanged and the upper limit value is compressed by 15%. The axial clearance obtained by this method is used as the benchmark to control the actual radial clearance after casing. The example shows that this method can meet the process requirements.
Key words: deep groove ball bearing; Radial clearance; Axial clearance; ball bearing quality
The radial clearance of deep groove ball bearing is an inspection item specified in the standard, and it is also one of the basis for users to select bearings. Radial clearance is generally measured by radial clearance instrument, and the measured value is relatively accurate, but the instrument has long adjustment time and low efficiency, so it is not suitable for mass production. Relatively speaking, the axial clearance measurement is convenient and efficient; Therefore, at present, most manufacturers use empirical formula to convert radial clearance into axial clearance in actual production, so as to measure and control axial clearance for sleeve fitting. However, in the actual production, it is found that the measured radial clearance of some bearings is out of tolerance after controlling the axial clearance. Aiming at this problem, an improved method of clearance control of deep groove ball bearing is given.
1. Existing Problems
In actual production, the empirical formula for the conversion of radial clearance and axial clearance of deep groove ball bearing is
Ga is axial clearance; Gr is radial clearance; R is the radius of curvature of the trench; Dw is the diameter of steel ball. It can be seen from formula (1) that the radial and axial clearance of deep groove ball bearing is related to R and Dw. When calculating the axial clearance, when the curvature radius R of the inner and outer ring grooves is different, it shall be calculated according to the geometric arithmetic mean value. Taking 6030EM bearing as an example, the inner groove radius of curvature Ri = 12.26 + 0.10 mm, the outer groove radius of curvature Re = 12.5 + 0.10 mm, the steel ball diameter DW = 23.8125 mm, and the basic group radial clearance Gr = 0.018 ~ 0.053 mm. The corresponding axial clearance Ga calculated from formula (1) is 0.26 ~ 0.41 mm. Control Ga to close the sleeve and detect the actual radial clearance Grs of the bearing after closing the sleeve, as shown in Table 1.
It can be seen from table 1 that the actual radial clearance of bearings 9 and 10 is out of tolerance by using axial clearance to control radial clearance, which can not meet the technical requirements.
2. Improvement of Control Method
2.1 Control of Inner and Outer Groove Curvature Radius R and Steel Ball Size
The precise control of channel shape is realized by using NC grinding equipment and profilometer. Strictly control the steel ball production process to make its accuracy meet the application requirements. By strictly controlling the processing technology of inner and outer ring channels and steel balls, the influence of channel and steel ball errors on axial clearance error is minimized.
2.2 Improvement Methods
When converting the radial clearance of deep groove ball bearing into axial clearance, adjust Gr and compress its upper limit value by 15% (i.e. G′r = 0.018 ~ 0.045 mm). At this time, the axial clearance is G′a = 0.26 ~ 0.38 mm. The bearing shall be sleeved based on G′a, and the actual radial clearance Grs after sleeved is shown in Table 2. It can be seen from Table 2 that the adjusted axial clearance is used to control the radial clearance, which meets the requirements.
3. Example Verification
Using the adjusted method, select any type of bearing (6232E) to verify the method. It is known that the radius of curvature of the inner groove Ri = 18.8+0.150 mm, the radius of curvature of the outer groove Re = 19.17+0.150 mm, the diameter of the steel ball Dw = 36.512 5 mm, and the radial clearance Gr of the basic group Gr = 0.018 ~ 0.053 mm. Adjust the radial clearance Gr and compress its upper limit value by 15%, that is, G ′ r = 0.018 ~ 0.045 mm. At this time, the axial clearance is G ′ a = 0.41 ~ 0.51 mm. Take G ′ a as the benchmark to close the sleeve. The actual radial clearance Grs measured after closing the sleeve is shown in Table 3.
Then, 10 types of bearings were continuously tracked and tested, and the corresponding adjustments were made. Finally, the radial clearance after sleeve fitting met the process requirements.
4.Conclusion
The production practice shows that the lower limit of radial clearance is kept unchanged, the upper limit is compressed by 15%, and the axial clearance is calculated according to the geometric arithmetic average of the curvature radius of the inner and outer ring grooves. Taking the axial clearance as the benchmark, the sleeve is closed, and the radial clearance after sleeve closing meets the process requirements.
More about WSW Deep Groove Ball Bearing:
Deep groove ball bearings are the most widely used bearing type and are particularly versatile. In structure, each ring of deep groove ball bearing has a continuous groove raceway with a cross section of about one third of the circumference of the ball. It can bear certain axial load and radial load. When the radial clearance of the bearing increases, it has the property of angular contact ball bearing and can bear the alternating axial load in two directions. Low friction and high speed. Simple structure, low manufacturing cost and easy to achieve high manufacturing accuracy. Generally, stamping wave cage is adopted. For bearings with inner diameter greater than 200mm or high-speed operation, turning solid cage is adopted.
WBM are professional taper roller manufacturers and suppliers in China, with bulk high-quality products in stock. If you are going to buy a customized taper roller at a competitive price, welcome to get a quotation from the WBM factory. In line with the business philosophy of pursuing excellence, continuous improvement and common prosperity, the ball header, solid steel balls, roller header produced from WBM is absolutely high-quality and inexpensive.
