Bearings are mounted correctly or not, have a direct impact on their life and precision of the host. In case of improper installation, bearing not only the vibration, noise, low precision, temperature increase, but also in danger of being stuck burning out, conversely, the well installed, not only guarantees the accuracy, will greatly extend the service life. Therefore, after installation of NSK bearings, must be examined.
Focus testing is as follows: after bearing installation test the installation location, first verify that the working parts and fixed parts collide, lubricating oil can flow into the bearings, seals and axial fastening device are properly installed.
Radial clearance of inspection in addition to install the bearing with interference, radial clearance should be tested. Deep groove ball bearings can be hand-turn test, in a smooth and flexible, vibration-free, no sway at all. Cylindrical roller and spherical roller bearings can be feeler gauge testing, feeler gauge inserted between roller and bearing, roller feeler gauge insertion depth should be greater than the length of one-second. When the radial internal clearance of the bearing cannot be used with feeler gauges to measure, can be measured in axial movement of the bearing, instead of a reduction of radial clearance. Under normal circumstances, such as for bearing inner ring tapered bore, cone is the approximate amount of axial movement on radial clearance contract by a factor of 15 times.
The radial internal clearance of the bearing, some unqualified can be adjusted after installation, angular contact ball bearings, tapered roller bearings, some standard tune, was at the time of manufacture, not qualified nor adjustment after installation, such as deep groove ball bearings, self-aligning ball bearings, cylindrical roller bearing, spherical roller bearing, etc. The bearings are tested after installation if it is not qualified, radial Assembly clearance is too small, then the bearings are combined with improper or incorrect Assembly parts processing. At this point, the FAG bearings must be removed, identified, avoided again after installation. Of course not bearing clearance is too large.
Inspection level of bearing and shaft close under normal circumstances, interference of bearing must be installed close tight fit shaft. Test method:
(1) lighting method. Lights at the bearing and the shaft, leakage of light circumstances. If the light tight, instructions to install properly if uniform light leakage around along the shaft, indicating no shoulders close to the axis of the bearing, bearing pressure making it close; if some light leakage, indicating bearing installation tilt, tapping available Bishop, copper rod or sleeve bearing inner ring, Yasumasa slowly.
(2) the gauge test. Gauge thickness from 0. 03mm start. Test Shi, in bearing within ring end surface and axis shoulder of whole circumference Shang try plug several Department, as found has gap and is uniform, description bearing is not loaded in place, should bearing within ring pressurized make its by tight axis shoulder; if increased pressure also by not tight, description axis neck round corner parts of round corner too large, put bearing card live has, should trimming axis neck round corner, make its variable small; if found bearing within ring end surface and bearing shoulder individual parts gauge can through, description not at this time must demolition down, be trimming, again installed.
If SKF bearings with an interference fit in the housing bore, when bearing abutment fixation by shell holes in the outer ring, loop end with hole abutment surface of the shell is close, are properly installed, can also be used gauge test.
After installation of thrust bearing test
When you install the thrust bearing, test of vertical shaft and shaft centerline. By moving the dial fixed on the tank shell surface, touch the top of the table in the bearing ring raceway top wheel bearing, observe the indicator pointer, pointer to swing, indicating shaft and shaft centerline is not normal. When a tank shell hole deeper, can also be used to lengthen the micrometer heads tested.
When the thrust bearing is installed correctly, the seat can automatically adapt to the rolling of the scroll, ensure the rolling body at the Raceway. If installed backwards, bearing not only does not work correctly, and the mating surfaces will be badly worn. Due to the shaft and seat and the difference is not very apparent, assembling be careful, do not get me wrong. In addition, the thrust bearing between the seat and the housing bore should be 0. 2-0. 5mm gap to compensate parts, installation errors caused by inaccurate, when Center deviation of bearing rings when running, this gap to ensure its automatic adjustment to avoid touching the friction so that its normal functioning. Otherwise, it will cause severe damage of the bearings.
Commissioning, testing bearing noise, temperature, vibration, whether it meets the requirements. General bearing operating temperature should be below 90 ° c, when the temperature is too high will result in burning of annealing or heating in the bearings, lower service life.