The clearance standard of a single row tapered roller bearing needs to be determined comprehensively based on the bearing inner diameter, series type, and contact angle. The axial clearance range is usually 0.02mm to 0.35mm, and the radial clearance can be calculated using the formula C=2Ca · tg β (Ca is the axial clearance, β is the contact angle). The following is a specific analysis:
1. Classification and definition of clearance
Radial clearance: the maximum distance that one ring is fixed and the other ring moves radially when there is no load.
Axial clearance: The maximum distance that one ring is fixed and the other ring can move along the axial direction when there is no load.
.Working clearance: The actual clearance of a bearing during operation due to factors such as temperature and load.
.II. Clearance Standards for Single Row Conical Roller Bearings
Axial Clearance Range
According to the bearing inner diameter and series type, axial clearance is usually divided into the following ranges:
Light series:
Inner diameter<30mm：0.03~0.10mm
30~50mm：0.04~0.11mm
50~80mm：0.05~0.13mm
Light and Medium Width Series:
Inner Diameter<30mm：0.04~0.11mm
30~50mm：0.05~0.13mm
50~80mm：0.06~0.15mm
Other inner diameter ranges:
80~120mm：0.06~0.15mm
120~150mm：0.07~0.18mm
150~180mm：0.09~0.20mm
180~200mm：0.12~0.22mm
200~250mm：0.18~0.30mm
The relationship between radial clearance (C) and axial clearance (Ca) is:
C=2Ca · tg β
where β is the contact angle (common values are 15 ° or 25 °~29 °). For example:
If the axial clearance is 0.12~0.2mm and the contact angle is 15 °, the radial clearance is:
C=2 × (0.12~0.2) × 0.2679 ≈ 0.064~0.107mm
III. Clearance Adjustment Method
Gasket Adjustment Method
Remove the original gasket, tighten the bearing pressure cover bolt until the shaft cannot rotate, and measure the clearance (K) between the cover and the box end face with a feeler gauge.
.Gasket thickness=K+required axial clearance (C).
Screw Adjustment Method
Loosen the locking nut, tighten the adjustment screw until the shaft cannot rotate, and then reverse the screw by a certain angle based on the axial clearance value (angle calculation formula: α=(specified clearance/pitch) × 360 °).
.Adjustment method for thrust ring
Tighten the thrust ring until the shaft cannot rotate, then reverse it by a certain angle according to the axial clearance value, and finally fix it with a stopper.
.Inner and outer sleeve adjustment method
Suitable for situations where two tapered roller bearings are installed on the same shaft, axial clearance control is achieved by adjusting the length of the inner and outer sleeves.
.IV. Key precautions
Contact angle influence
The larger the contact angle, the more significant the effect of axial clearance on radial clearance, and the clearance value needs to be converted based on the actual contact angle.
.Pre tightening requirements
Some applications require pre tightening to eliminate clearance (such as high-precision machine tool spindles), but excessive pre tightening should be avoided to reduce lifespan.
.Temperature Effect
In high temperature environments, the expansion of the bearing inner ring may cause a decrease in clearance, and compensation clearance needs to be reserved.
.Paired bearing clearance
The tapered roller bearings used in pairing (such as face-to-face or back-to-back configurations) need to be uniformly adjusted for clearance to ensure good contact between the rollers and the retaining edge.
.