Hardened steel bearing rings die after quenching, mostly contraction phenomenon. Continue to shrink after the release of the workpiece, we call this contraction as "recoil." Recoil amount can not be ignored, it is determined after turning disc the size of the balance and the key to determine a reasonable allowance essential products. This paper focuses on: tapered bearing outer ring of the workpiece recoil Calculation hardened steel double row outer raceway margin determined after turning, grinding after quenching actual amount of prediction calculations and examples.
1 recoil Calculation
That practice by the manufacturer, carburizing steel bearing rings elastic recoil of the size and the thickness of the workpiece, about the size of the diameter. We summarize the empirical formula amount of elastic recoil is d = 26B4 / D3 (1)
Where: B-- maximum wall thickness of the workpiece
D-- outer diameter of the ferrule
Factor in the lower die 26 is rotating quenching conditions, after repeated practice data and push.
Formula (1) the outer diameter of the workpiece in the scope of application of 200 ~ 300mm.
Margin raceway 2 after turning outer OK
After turning margin determined, influenced by elastic recoil basin size, the greater the amount elastic recoil, smaller margin, and vice versa. Through the production of practical and theoretical analysis showed that, after turning outer raceway margin (HΔD) 1 and the workpiece thickness to diameter ratio of about, namely HΔD1αD / B.
Quantitative expressions are HΔD1 = 0.042D / B (2)

Coefficient of 0.042 is based on the repeated practice data and push.
The actual amount of 3 grinding after quenching determination
Learned by the practice. Not because of trace amount of elastic recoil margin decrease after turning change, so the actual amount of wear after quenching should HΔD2 = HΔD1 + d (3)

4 An example
Known 197726 bearing outer ring of the maximum wall thickness B = 18.85mm, the outer diameter D = 230.9mm, the original margin to take the outer race track after turning ΔD1 = 0.65, try and find the balance after quenching reasonable after turning grinding amount and verify the suitability of the original value.
Solution: From (1) to obtain the amount of recoil
d = 26B4 / D3 = 26 × 18.854 / 230.93 = 0.266
After turning the balance was represented by formula (2)
HΔD1 = 0.042D / B = 0.042 × 230.9 / 18.85 = 0.514
The actual amount obtained by the formula grinding after quenching (3)
HΔD2 = HΔD1 + d = 0.266 + 0.514 = 0.78
And this specification original outer bearing outer ring raceway after turning over pots ranging ΔD1 = 0.65, measured the amount of wear after quenching is 0.9, 0.78 and calculated results quite different, so the original value is not appropriate. After taking the balance ΔD1 = 0.5, the measured amount of wear was 0.76 after quenching, the calculation results with the experimental situation is very close to the description of the latter argument is reasonable.
It is worth noting that the quenching die size should be the same as the size of the turner figure proved to hardened steel bearing rings quenching shrinkage as plastic in an amount sufficient to achieve the shaping effect.