The adapter sleeve is an accessory of an inner tapered bore bearing, which can ensure stable running of the matched bearing. The longest life is the basic requirement, so the adapter sleeve product must achieve high accuracy to achieve this goal. The accuracy is the most important to the following four technologies:
1. The outer tapered surface of the adapter sleeve has a high accuracy requirement on the radial run-out (generally called wall thickness difference KD0) of an inner bore, otherwise, a rotating shaft generates centrifugal force due to eccentricity, cannot stably run and causes large vibration and high noise. The ideal state is the wall thickness difference of “0”. According to the maximum KD0 value stipulated by the national standard, the size of less than 65 (the inner diameter of the bearing) is about 1/2 of the maximum play value of the standard group, which is equivalent to the maximum play value at C2 grade accuracy, so the adapter sleeve product qualified according to the national standard cannot be matched with a precision high-load bearing.
The actual measurement of the imported high-accuracy high-price adapter sleeve product and the application effect in domestic compressor industry draw a conclusion that KD0≤0.005 can be called high accuracy and can meet the performance requirement of the high-accuracy high-load matched bearing. This value is 5 to 12 times higher than the average of sizes of the maximum value of national standard allowance.
2. The taper difference of the adapter sleeve must be appropriate.
The taper difference is represented by delta D1mp-delta d3mp according to the national standard, the allowance of different sizes is upper deviation from +0.018 to -0.09, which requires that the taper difference of the adapter sleeve can only be large and cannot be small, namely the large end must be matched for contact, the end with small taper can have a little gap, the tapered bore is poorly matched, the condition that the single row of rollers of the matched self-aligning roller bearing are stressed can be caused, the bearing unstably runs, causes large vibration and high noise, is easily loosened and has short life, and the taper difference of the high-accuracy adapter sleeve should be less than or equal to 0.005 to ensure that the matched contact area is not less than 90%.
3. The linearity of the outer tapered surface and inner bore surface of the adapter sleeve must be appropriate, namely geometric tolerance and cylindricity accuracy must be appropriate. This point is not stipulated by the national standard, any single section size is qualified in the allowance range, as a result, the linearity of the outer tapered surface is not strictly controlled, particularly the outer tapered surface undergoes plunge-cut grinding. The linearity of the blank is inappropriate, the grinding wheel is poorly dressed, the surface linearity is very poor, and the general enterprise does not provide contourgraph inspection, so this project has a big problem in the product of Chinese adapter sleeve industry, matching accuracy and matching stability are severely influenced, and poor bearing performance is also caused.
4. The thread locking performance of the adapter sleeve
The matched bearing rotates and axially moves to extrude the end face of an inner sleeve of the bearing through the locking nut, so the internal taper of the adapter sleeve and the inner bore of the bearing are reduced, and the aim of fixing the bearing on the rotating shaft is fulfilled. The threads of the bearing nut and the adapter sleeve must be well matched and meet the national standard requirement of the common thread.
In conclusion, the adapter sleeve which accords with the above-mentioned four conditions and of which other technical conditions must meet the national standard requirement is a high-accuracy product, and only high-accuracy adapter sleeve and withdrawal sleeve products can exert the performance and life of the bearing to the greatest extent.
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