The dynamic stability of the bearing system

In many engineering applications, in order to ensure the dynamic stability of rotor system, must know the bearing of the displacement, the problem in high speed bearing system, such as an aircraft gas turbine engine is important, in this case the bearing system of radial eccentric shift can be regarded as a system. In other applications, such as inertia screw, radio telescopes, and machine tool, in order to maintain the precision of the system or manufacturing precision, requires minimal displacement under the action of load bearing. The previous chapters have shown that the bearing displacement is designed, the size of the bearing, axis bearing internal clearance, speed and load distribution function. However does not need high accuracy in low speed applications, as this chapter introduces the simplified equation for estimating the bearing displacement with sufficient accuracy. In order to make the minimum displacement, axial or radial preload can be used, but must be careful not to make the pre-tightening load is too large, because it can cause friction torque increase, resulting in bearing temperature, lower bearing life. Sample cases of 8. 1 radial load under the action of radial displacement of cylindrical liquid child bearing problem: computing example of the 74 209 CRB bearing radial displacement, and the value and case 7. Line 4 in a build. Assume that the radial clearance of 0. 7:0406 mmo solution by example. 4Q。 2 = 1589 n by example. 7 l = 9。 6 m by type ( 8. 4) ( 1589097. 68x100. 00953m8. = 7. 68X10( 9. 6) 0. 8 p0。 04066. = 6 = 0. 00953 + = 0. 02983 was the case 7. 38 = 0. 03251mm＞0. 02983 cases of 8 mm. 2 under axial loading of angular contact ball bearing axial displacement problem: 7 cases. 5 in 218 acb bearing thrust load is 17800 n, calculate its axial displacement, and 7 cases. Five, six of the comparison. Solution: by case 7. 5 z = 16 by case 2. 3°= 40 d = 22。 By type (23 mm 7. 26) Have to F17800Q = zina = 16 x si40 ° = 1731 n by type ( 8. 5) 8, 436 x10q = = 4. 36x10( 1731). Dsina( 22. 23) 5 in40o0。 7 0348 mm by example. 5 or 6, = 0. 0386m。 This value is slightly larger than the calculated value of this case. This is due to the case. Considering the Angle of welding can change. Example 8. Three axial load under the action of axial displacement of angular contact ball bearings. Question: as shown in figure 8. 3 218 acbb bearing installed back to back in pairs, known axial pre-load is 440 in the 890 n thrust load calculation under the action of bearing axial displacement. Solution: by case 2. 3°= 40°D = 22。 23mmB=0. 0464 by 7. 5 z = 16 k = 896。 By type (7 n/mm 8. 16) 得FcosarsinaZDKcoso