The usage method of precision shaft sleeve for screw machine is as follows:
Preparation before installation:
Cleaning parts: Before installation, the surface of the shaft, bearing seat, and shaft sleeve should be thoroughly cleaned to remove impurities, oil stains, and burrs, to prevent dust or particles from entering during installation and affecting the fitting accuracy.
Check dimensions and tolerances: Confirm that the dimensions of the shaft, bearing seat, and shaft sleeve meet the design requirements, the tolerances are within the allowable range, and ensure that the fit clearance is appropriate.
.Choose the appropriate installation method: Depending on the size, material, and interference fit of the shaft sleeve, choose appropriate installation methods such as pressing, heating, or cooling.
.Installation method:
Pressing method:
Positioning and fixing: Fix the shaft vertically on the V-shaped block or special fixture, ensure that the axis of the shaft is consistent with the pressing direction, use a dial gauge to calibrate, and the coaxiality error should be ≤ 0.01mm.
Guiding alignment: Insert a guiding sleeve on the end face of the shaft sleeve to accurately align the inner hole of the shaft sleeve with the outer surface of the shaft and prevent tilting.
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Uniform pressing:
Manual pressing: Use a copper hammer to lightly tap the end face of the guide sleeve, evenly tapping along the circumference with consistent force each time, gradually pressing the shaft sleeve to the designated position.
. Mechanical pressing: Use a manual or hydraulic press to control the pressing speed at 5-10mm/min, and monitor the pressing force with a torque wrench to avoid sudden pressure changes.In place confirmation: After the shaft sleeve is pressed to the assembly reference surface, use a dial gauge to check the perpendicularity between the shaft sleeve end face and the reference surface, with an error of ≤ 0.01mm/m.
.Heating method (suitable for medium to heavy interference fit):
Heating shaft sleeve: Use a hot air gun, oil bath, or induction heating method to evenly heat the shaft sleeve, control the temperature to avoid overheating and material performance changes.
.Quick assembly: The heated shaft sleeve should be fitted onto the shaft within 30 seconds, quickly aligned with the axis with the help of the guide sleeve, and gently pushed to the designated position.
. Cooling and solidification: Allow the shaft sleeve to cool to room temperature in a natural environment. Do not use water cooling or forced air cooling to prevent deformation caused by thermal stress.Cooling method (suitable for heavy interference fit):
Cooling shaft: Use dry ice or liquid nitrogen to cool the shaft, reduce the outer diameter size, and facilitate the insertion of the shaft sleeve.
.Assembly operation: After cooling, the shaft should be quickly inserted into the shaft sleeve to ensure alignment of the axis. After restoring room temperature, check whether the mating surface is tightly fitted.
.After installation inspection:
Appearance inspection: Observe whether the end face of the shaft sleeve is flat, without deformation or scratches, the mating surface is free of scratches or burrs, and the shaft sleeve is free of cracks.
.Dimensional and positional tolerance inspection: Use a dial gauge to measure the radial runout and end face circular runout of the shaft sleeve, and the error should meet the design requirements.
.Coordination firmness check: Gently tap the end face of the shaft sleeve without looseness or abnormal noise;
; For rotating components, a no-load test run can be conducted to check if the temperature and vibration values are within the allowable range. Sealing and lubrication inspection: If the shaft sleeve has a sealing structure, check whether the sealing components are installed in place and there is no leakage; In situations where lubrication is required, add designated lubricating grease.Precautions for use:
Avoid violent assembly: Do not use a hammer to directly strike the shaft sleeve to prevent deformation or strain on the mating surface. Use a guide sleeve or copper hammer to transmit force.
.Control interference fit: The actual interference fit should not exceed 15% of the design value. Excessive interference fit can easily cause the shaft sleeve to crack, while insufficient interference fit can lead to loose fit.
.Prevent temperature damage: Avoid local overheating when heating the shaft sleeve, and prevent material brittleness caused by low temperature when cooling the shaft.
.Keep clean: During the assembly process, keep the mating surfaces clean. If impurities are found, stop assembly immediately and clean again before proceeding.
.Safety protection: Keep away from flammable and explosive materials when using heating tools, and wear insulated gloves;
; Wear antifreeze gloves and goggles when using liquid nitrogen and dry ice.