Deep groove ball bearing installation
Specification of deep groove ball bearings, the large number of applications. Installation method is relatively simple, consider choices should be focused on. Its inner ring and shaft neck tie interference according to the following formula:
D-and interference between the inner diameter of the bearing and axle (μ m)
D-bearing diameter (mm)
B-width of the bearing (mm)
R-bearing radial load (n)
Δ T-bearing temperature difference between the inside and around the shell-hole, usually take 5-10 ℃
After the calculation, based on the interference calculation, determine the nature of the cooperation with the axis, and then the shaft to the required dimensions for installation.
1. installation of full complement needle roller bearings
Install the full complement needle roller bearings, usually using auxiliary socket. Supplementary roll, supporting sleeve outside diameter should be smaller than the shaft diameter 0. 1-0. 3mm。 Installed Shi, first will bearing outside circle surface James to grease, by tight within surface posted placed roll needle (into finally a root roll needle Shi should left has gap), then to instead of axis neck or bearing within ring of secondary roller or secondary sleeve push into outer ring hole within, and makes its end face associate installed axis end surface or has installed in axis Shang of FAG bearing within ring end surface, then with pressure machine or every passenger steamship beat pressure. At this point, secondary roller or secondary sleeves hold the needle does not make the needle out, chamfer of the journal in its own needle set off, with needle roller bearings on the shaft to move slowly, auxiliary roller or auxiliary socket then started quits up into working position.
Needle roller bearings can also be installed, supporting sleeve outside diameter coated with a thin layer of lubricant, set into the bearing outer ring, sleeve and bearing secondary forms a circular hole in the outer ring, and then stuff in the circular hole needle. Once the needle is loaded, axis launched will complement the sleeve.
For needle roller bearings without inner or outer ring, at the time of installation, you can scroll the axis hole or shell coated with a thin layer of grease, and in turn close to the installation part of the needle on the grease. Sticker is put a needle on the end should have a gap, gap at perimeter of needle roller bearings to 0. 5mm suitable. Must not hard squeeze into the final a needle, or less with a needle because hustle when, bearing jam cannot be rotated; less when loaded, clearance is too large, prone to bearing operation torsion pendulum and needle occurs when broken.
Here in particular that the only drawn cup needle roller bearings, because of the thin-walled outer ring, preferably not every passenger steamship hit install, press push should be used. Because when every passenger steamship hit, uneven pressure, easy to make the needle roller bearing outer ring of local deformation.
2. installation of tapered roller bearing
Tapered roller bearings are separable bearings, the inner and outer rings can be separated. When installed, respectively inner ring cage roller Assembly and mounting on the shaft, separately mounted in the outer ring in the housing bore using sleeve when mounting, you should be aware, you must make one end of the sleeve on the outer ring side face shall not be placed on the incline of Raceway surface.
Tapered roller bearings for paired mounting, installations should focus on three areas: select install support adjust axial clearance; for commissioning and testing temperature.
• Choose to install tie
Tapered roller bearing outer ring and housing shell holes should not be an interference fit, the inner ring and shaft neck tie should not be too tight, requiring adjustment nuts should be used in the installation of axial displacement can be more flexible. Tapered roller bearings if the interference fit, easy to make bearings contact angle changes, resulting in uneven bearing load distribution, caused by high temperature. Therefore, inner and outer rings of these bearings and axle and bearing housing installation combined with shell holes, thumb should generally both hands just push in the axle journal and the bearing shell holes as the best.
• Adjust axial clearance
For tapered roller bearings installed axial clearance, adjusting nut, adjust the spacer on the axle and bearing bore in the thread, or with methods such as tightening spring to adjust. Axial clearance of the size, and distance between bearing installation arrangement, bearing, shaft and FAG bearings material, can be determined according to working conditions. Tapered roller bearings for high loads and high speeds, adjust the clearance time, you must consider the impact of temperature on axial clearance, estimation of the temperature rise caused by the reduction of clearance, and that is, to appropriately adjust the axial clearance. For low speeds and withstand the vibration of the bearing should be installed without clearance, or applying preload is installed. The aim is to keep rollers and raceways of tapered roller bearings have a good contact, load evenly to prevent destruction of the roller and the Raceway vibration shocks. After adjustment, axial clearance size indicator test. Method is to first set the dial fixed on the fuselage or housing, make the micrometer contacts against the smooth surface of the shaft, along the shaft to the left and push shaft, hands a maximum swing of axial clearance values.
• To commissioning and testing temperature
For tapered roller bearings roller Raceway contact, and obtain a suitable axial clearance, Taper roller bearings are mounted and after each adjustment clearance shall carry out commissioning and testing temperature. Low-speed operation by first 2-8 minutes, and turn speed test in 2 hours, and then progressively raised to high speed. Speed test run shall be not less than 30 minutes per level, rate of temperature rise cannot be more than 5 degrees centigrade per hour, last stable temperature must not exceed 70 ° c.
In addition, installation and adjustment of tapered roller bearing clearance, it should also be noted, you must make the inner ring of tapered roller and flanges contact.
1. installation of angular contact ball bearings
Angular contact ball bearing installation more complicated than deep groove ball bearings, are installed in pairs, and use the preload. Install good hosts working precision and service life of the bearing can be greatly improved, otherwise, not only the accuracy does not meet the requirements, life will also be affected.
1. installation type
Angular contact ball bearings installed, there are back to back, face to face and arranged in series three. Back to back (two wide end of FAG bearings) installed, the proliferation of bearing contact angle along the rotation axis, can increase the supporting point of the radial and axial rigidity, resistance to deformation maximum; face (two narrow face bearing) installed, the bearing contact angle line convergence toward the rotary axes, angles less rigid. Due to the inner ring of the bearing out of the outer ring, when both bearing outer ring tightly together, the original gap in the outer ring to eliminate, you can increase the bearing preload; arranged in series (two bearings of the wide end in one direction) when installed, bearing the line with the contact angle and parallel, can share the same direction of the two bearing working loads. But when you use this form, in order to ensure the stability of installed axial, two pairs of in-line arrangement of bearing must be installed at both ends of the shaft to reset.
2. access to the preload
Preload by a grinding of bearing ring face, or with two different thickness of the spacer is placed between a pair of FAG bearings, inner and outer ring, clamp bearings, steel balls and raceways close contacts are.
FAG preload size effect on bearing service life is very large, according to the information on, when bearings are fitted with a 0. When the 012mm interference, loss of life 38%, 0. When the 016mm interference, loss of life 50%; when bearings are fitted with a 0. 004mm gap, using a marked reduction in life expectancy, 0. 008mm gap, life 70%. Therefore, the rational selection of the size of the preload is important. Use a small preload of high speed, low speed use a preload. At the same time, preload should be slightly greater than or equal to the axial load.
Preload adjustment
No-load operation test. Angular contact ball bearing Assembly after passing inspection, to no-load operation test speed, time of not less than 2H, the temperature rise shall not exceed 15 ° c.
1. installation of thrust ball bearings
Transition fit shaft and shaft, seat ring and shaft meet and often installed in pairs. Installed at the same time, should also be noted that tests their axial clearance, and with shafts rotating shaft and shaft centerline of verticality.
2. installation of the bearings with a tapered bore
Bearings with a tapered bore diameter of self-aligning ball bearings with a tapered bore cylindrical roller bearings and spherical roller bearings. This type of FAG bearings can be mounted directly on tapered journal, or you can use a cone adapter or withdrawal sleeves, mounted on cylindrical neck.
Bearings with a tapered bore combined with requirements are generally more closely. After installing clothes are required to measure radial clearance of bearings. Because it of tie elastic degree not by axis neck tolerances decided, but according to bearing installed Shi pressure into tapered tie surface Shang of distance by caused of bearing radial tour gap reduces volume to decided of, pressure into distance more large, radial tour gap reduces volume more and more, FAG bearing tie increasingly close; instead, pressure into distance more small, radial tour gap reduces volume more less, bearing tie also on comparison pine. It can be seen, bearings with a tapered bore combined with tension, completely depends on bearing radial clearance reduction guarantee before or after installation.
To guarantee tapered hole bearing of installed quality, here excerpts has part original Soviet adjusting heart ball bearing original radial tour gap of allows reduces volume (table 2-5), and Germany of FAG company provides of has tapered hole of cylindrical roll child bearing radial tour gap reduces volume (table 2-6), and the has tapered hole of adjusting heart roll child bearing radial tour gap reduces volume (table 2-7), can for measurement tapered hole bearing installed before and after of radial tour gap Shi reference. While in use, generally should not exceed the values in the table.
Method of measurement of the radial clearance. Inseparable-roller, spherical roller bearing is located, measure, when using a feeler gauge to measure spherical roller bearings, to ensure two inner ring raceways have a tilted relative to the outer ring is without speech, should measure at the two rows of rollers. For small spherical roller bearings, when radial internal clearance is small and could not have a feeler gauge measuring, measurement of axial displacement of the bearing on the Cone in place (axial displacement values as shown in table 2-6, table 2-7). If axial displacement cannot be measured, the bearing should be installed outside the housing shell, and then pressed into the bearing bore. After press, hand-pick, should enable the smooth rotation of the outer ring. Separable in cylindrical roller bearings radial clearance, measured by outside micrometers, measuring the inner ring expansion after mounted on the axle in place.
Here it should be noted that for noncompliance or after removal of bearings installed when you reinstall, its small radial clearance, ring expansion in the axial displacement quantity or volume, you must re-determination.
K values with the diameter d and bearing, as well as the axis and spindle tie neck average diameter d. Related. K-values see table 2-8,eH as shown in table 2-9,en table 2-10. Installation, axial displacement of the bearing capacity determination available micrometer contacts the bearing inner ring side face.
Two, outer ring in the FAG bearing thickness adjustment. Sure both poor bearing, inner and outer ring thickness there are three:
First is measuring method
First place the bearing on the circle, pressing a weight equal to a (preload) iron block, bearings eliminate the gap, have some elastic deformation of steel ball and roller, and then using a dial gauge to measure dimensions of the bearing inner and outer ring side face worse. Dang bearing for on the sly back installed Shi, should two a bearing are measurement wide end surface side of within, and outer ring size poor K1; Dang bearing for face-to-face (narrow end surface relative) installed Shi, should two a bearing are measurement narrow end surface side of both within and outside the ring size poor K2; Dang bearing for series arranged Shi, is on a bearing measurement its wide end surface side of both within and outside the ring size poor, on another bearing measurement its narrow end surface side both within and outside the ring size poor.
A pair of bearings for back to back installation. Within this measure a bearing at the wide end, the outer dimensions torque +0. 07mm, another bearing wide-end surface size difference inside and outside circles as +0. 08mm, inner ring thickness is 6. 25mm, and outer thickness across the circle.
Outer ring thickness = 6. 25+ (0. 07+0. 08) = 6. 40（mm）
When measuring size, each bearing measurements three times, intervals of 120 ° test, final averages them.
Figure 2-7 a pair of bearings arranged in-line installation. This measure a bearing ring size difference inside and outside at the wide end to +0. 16mm and the other at the narrow end of FAG bearings inner and outer rings size difference is-0. 12mm, inner ring thickness is 6. 25mm, and thickness of the outer ring.
Outer ring thickness = 6. 25+ (0. 16-0. 12) = 6. 29（mm）