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YRT turntable bearings have suitable axial and radial load bearing mechanisms. High tilt rigidity and high precision for rotary tables, chucks and iron cutter heads as well as bearing arrangements in measurement and experimentation. The requirements for YRT turntable bearings are also very strict during installation. Today we will talk about the installation of YRT turntable bearings.
YRT turntable bearing installation fit
The matching form of the turntable bearing with the shaft and the bearing seat is a transition fit. Improper fit selection will affect the running accuracy and dynamics of the bearing. For example, an overtight fit will increase the radial preload of the bearing, thereby causing friction, heat generation, raceway load and wear of the bearing, and reducing the limited speed of the bearing. and service life.
The machining accuracy of the shaft and the bearing seat and the fit between the bearing and the shaft and the bearing seat will affect the axial and radial runout accuracy of the bearing. In order to obtain very high running accuracy, the matching clearance should be as zero as possible.
In order to make it easier to match the actual size of the shaft and bearing seat with the bearing, please refer to the inspection record attached to each set of bearings when they leave the factory.
1. Matching with the shaft
The manufacturing tolerance of the shaft is h5. For high running accuracy requirements and inner ring rotation, the fit gap should be as close to zero as possible, otherwise the fit clearance will increase the runout of the bearing. For high-speed and longer operating conditions, the fitting clearance cannot exceed 0.01mm; for YRTS high-speed series, the fitting clearance cannot exceed 0.005mm.
For the ZKLDF series, since there are two inner rings, the fitting clearance should be determined according to the size of the inner ring with small inner diameter.
2. Matching with bearing seat
The manufacturing tolerance of the housing is J6. For high running accuracy requirements and the rotation of the outer ring, the fit clearance should be as close to zero as possible. If the outer ring is stationary, a clearance fit or a design without radial alignment should be selected;
In other cases, the outer ring of the bearing should have no radial centering and positioning design and should adopt a matching barrier of at least 0.02mm with the bearing seat, so as to reduce the increase in preload caused by the heating of the bearing.
3. Bearing selection
Since the rotary table bearing adopts the bolted connection method, if the bearing outer ring is bolted to the stationary part, you can choose not to need the radial positioning of the bearing seat, or you can choose a clearance fit, which usually makes the installation easier.
If the inner ring of the slewing bearing is screwed to the stationary part, functionally the entire height of the slewing bearing is still radially supported by the shaft and tends to be a clearance fit.
Due to its high-speed performance, the YRTS high-speed series has stricter requirements on the accuracy of the bearing housing. Please contact us for specific parameters.
Requirements for the installation size of YRT turntable bearings
If the height tolerance is to be as small as possible, the dimensional tolerance of H1 must be controlled according to the numerical value of the installation size, and H2 determines the position of the deep wheel in all the turbine and worm structures, as shown in the figure, the L-shaped inner ring of the constant support ring.
The entire large surface of the L-shaped inner ring of the L-shaped inner ring YRT bearing with and without support ring can be fully supported or not , as shown in the figure. If the L-shaped inner ring is supported, the overturning rigidity will be higher. Support ring (eg turbine not included in scope of delivery).
For the L-ring installed with the support ring, the bearing model has a rear VSP, such as YRT200VSP, etc.; and the height of the support ring should be at least twice the height of the bearing two and inner ring.
Note: When ordering, please indicate the installation method.
L-ring without support ring
L-ring with support ring
YRT turntable bearing installation guide
Compared with ordinary bearings, YRT series bearings have higher precision, so care must be taken when installing and using them, otherwise the accuracy and service life of the bearings will be seriously affected.
The bearing should be handled with care, and the connecting bolts ensure the safety of the bearing during transportation. In order to make bearing alignment easier, loosen the coupling bolts of the bearing itself before installation, and tighten or remove it after installation.
According to the given tightening torque MA, use a torque wrench to install, follow the “cross method”, tighten step by step, the process is tightened in three stages, and the bolt tightening torque MA is reached later, while tightening the trapped bolts.
Stage 1: MAX40%;
Stage 2: MAX70%;
Stage 3: MAX100%;
The fixing process of the outer ring is the same as that of the inner ring.
Precautions for YRT turntable bearing installation
1. The installation bolts are more than 10.9.
2. The installation force can only be applied to the bearing ring to be installed, and it is not allowed to be stressed by the rolling elements.
3. During installation and disassembly, the bearing components cannot be disassembled or interchanged.
4. If the bearing is extremely difficult to rotate, loosen the mounting bolts and re-tighten them in three steps in a crisscross sequence to eliminate the bearing deformation.
5. Do not knock the bearing during installation.
