Bearing clearance

Bearing clearance - 2021 01 - 29 Wang Jiahe one, bearing clearance definition and classification of bearing clearance is also known as the bearing clearance. Bearing clearance points three states, namely the original clearance, installation clearance and work clearance. According to the direction of movement, and can be divided into radial clearance and axial clearance. Clearance (in the operation of As the work clearance) About the size of the bearing fatigue life of rolling, temperature, noise, vibration etc. In general, the larger the radial clearance, axial clearance is bigger, and vice versa. The following is according to the bearing of the state, the clearance can be divided into three states description: 1, the original clearance bearing clearance of free state before installation. The original clearance is processing, assembling the identified by the manufacturer. 2, installation clearance is also called cooperate clearance, bearing and shaft and bearing seat installed but not yet work clearance. Due to the interference installation, or make inner ring increases, or the outer shrink, or both, make installation clearance is smaller than the original clearance. 3, work clearance of bearing in the working state of clearance, the largest circle temperature rise at work, thermal expansion, reduce bearing clearance, bearing clearance; At the same time, as a result of the action of load, rolling element and raceway contact produce elastic deformation, the bearing clearance increases. Bearing clearance than installation clearance big or small, depends on the synthesis of these two factors. Second, the introduction of clearance group clearance value according to the size of the three groups, the basic group ( C0 or ordinary group) And small clearance group ( C2) , large clearance group ( C3、C4、C5) 。 NSK, SKF, ZWZ brand and special clearance group, such as C9, CM, etc. , for high speed, low temperature rise, low vibration and low noise of product clearance are special said, so the choice is especially important for bearing applications. Three, clearance check 1, the radial clearance of the check method of feeling method this method mainly has experienced engineers without measurement tools, editors don't build everyone chooses, the method is as follows. （ 1) , have hands rotating bearing, bearing should be smooth and flexible no jamming phenomenon. （ 2) , with the hand shake bearing outer ring, even if the radial clearance is only 0. 01 mm, axial travelmotion of the top bearing point, also has a 0. 11 ~ 0. 14 mm, this method is dedicated to the single-row radial ball bearings. Measurement method ( 1) , with a feeler check, confirm the rolling bearing parts, maximum load with into 180 & deg; The rolling element and outside ( ) Between circle into feeler, elastic fitting for feeler thickness is the radial clearance of the bearing. This method is widely used in self-aligning bearings and cylindrical roller bearings. （ 2) ,, with a dial gauge to check the dial indicator to zero, then the top roller bearing outer ring, the reading of the dial gauge is bearing radial clearance. 2, axial clearance inspection party feeling method this method mainly has experienced engineers without measurement tools, editors don't build everyone chooses, the method is as follows. Check the axial clearance of rolling bearings with finger, this method is applied to the shaft end exposed. When the shaft end sealing or for other reasons and can't check with your fingers, can check flexible rotation axis. Measurement method ( 1) With a feeler check, operation method and check out the radial clearance with a feeler is the same, but the axial clearance should be c = & lambda; / ( 2 sinβ ） Type c in axial clearance & lambda; Feeler thickness & beta; Bearing cone Angle ( 2) Use dial gauge inspection, use tools with dynamic bearing axial two extreme position, the difference of the dial gauge readings for bearing axial clearance. But the force imposed on tool cannot too much, otherwise shell to produce elastic deformation even if small, also affect the accuracy of the measured axial clearance. Editor's essay: 1, double four row circular cone roller bearings should be considered when measuring the bearing axial prolapse. 2, spherical roller bearing clearance should be the most effective way of measuring for NSK measurement method.