1. KOYO sliding bearing assembly
There are two common types of assembly of KOYO sliding bearings: one is the assembly of split sliding bearings, and the other is the assembly of integral sliding bearings.
(1) The assembly process of split sliding bearing includes:
a. Clean and inspect the bearing bush;
First check the KOYO bearing model, clean the bearing, check the surface of the bearing bush with a copper hammer and listen to the sound to check for cracks, holes and blisters.
b. Fixed bearing seat;
When fixing the KOYO bearing seat, ensure that the center line of the bearing seat on the same shaft should be on the same axis. Then check the drawing method and coloring.
c. Scrape the tile back;
There should be good contact between the back of the bush and the inner hole of the bearing seat and a close fit. (. Upper bush: 50% or more; Lower bush: 60% or more, upper); Scraping order: first down and then up, scraping and grinding based on the bearing inner hole, the split surface of the bearing bush should be higher than the split surface of the bearing seat.
d. Assemble the bearing
The main points to pay attention to when assembling the bearing bush are:
① The contact surface of the upper and lower bearing bushes should be tight;
②The fit between the bearing bush and the bearing seat-generally a small interference fit (0.01mm-0.05mm);
③The diameter of the bearing bush should not be too large or too small;
④The positioning pin must be installed firmly;
⑤ There should be no axial gap between the flange or spigot and the bearing seat;
⑥Check the contact angle and contact point by painting method. Contact angle: 60°-90°, contact point: 1-1.5 points/cm2 for low-speed and intermittent mechanisms; 2-3 points/cm2 for medium-load and continuous-running machines; 3-4 points/cm2 for heavy-duty and high-speed machines
(2) Assembly of integral KOYO sliding bearing (shaft sleeve)
The operating procedure of the shaft sleeve into the machine body is to press in and fix the shaft sleeve, inspect and trim after assembly. When assembling, according to the size of the sleeve and the matching interference and the position of the sleeve on the body, the sleeve can be installed by cold pressing, heating the body or cooling the sleeve.
①Methods and tools for pressing in the shaft sleeve.
According to the position of the shaft sleeve on the body and the size of the shaft sleeve, the shaft sleeve can be pressed in with a hand hammer or a press. Figure 6 shows one of the simplest press-in methods (injection with a pad and a hammer). When driving in the shaft sleeve, you must put it in the right position at the beginning, and check while pressing, and then increase the driving force after it is corrected. Otherwise, the mating surface will be scratched and the shaft sleeve will be deformed. KOYO 6203 2RSC3 bearings online , pls click here :
Guide sleeve and hammer driving method: Put a guide sleeve on the hole. When the shaft sleeve is pressed in, the guide sleeve ensures the direction of the shaft sleeve and prevents the shaft sleeve from tilting. To ensure that the shaft sleeve is aligned with the center of the hole, tools can be used. When assembling, put the shaft sleeve on the special mandrel first, then screw on the backing plate, transfer the pressure of the hammer or press through the backing plate, and press the shaft sleeve into the hole. In mass production, this tool is most suitable.
Before pressing in the shaft sleeve, you must carefully check the shaft sleeve and the holes on the body, trim the sharp corners on the end face, wipe the contact surface and apply lubricating oil, and align the shaft sleeve with the oil hole on the body when pressing in. Oil hole.
When the diameter is too large or the fit interference is greater than 0.1mm, if the shaft sleeve is press-fitted at room temperature, it will cause damage. Therefore, the method of heating the body or cooling the shaft sleeve is often used for assembly. The length of heating or cooling time depends on the shape, quality and material of the part.
② Method of fixing the shaft sleeve.
After the shaft sleeve is pressed in, in order to prevent rotation, it can be fixed by the method of set screw, pin, and seam screw.
③Inspection and trimming after assembly After the bushing is pressed in, deformation (such as ellipse, cone and deflection, etc.) or damage to the working surface will often occur. Therefore, inspection and trimming are required after assembly. Reaming and scraping are often used to trim, so that the gap and contact points between the shaft sleeve and the journal can reach the required quality.
2. Assembly of KOYO rolling bearings
The assembly quality of KOYO rolling bearings is the prerequisite to ensure the flexible and reliable movement of the machine tool, because the precision of the raceway bearing itself cannot directly explain the precision of its mechanical selection. There are many types of rolling bearings, and the assembly methods of different types of bearings are also different. Below, Eric Bearing Limited shares some common methods based on understanding.
Assembly method of rolling bearing:
(1) Push-in method
When the inner hole of the KOYO bearing is tightly matched with the journal, and the outer ring and the housing are loosely matched, the bearing should be installed on the shaft first; otherwise, the KOYO bearing should be pressed into the housing first. If the inner hole of the KOYO bearing is tightly matched with the journal, and the outer ring and the housing are also tightly matched, the bearing inner hole and outer ring should be installed on the shaft and the housing at the same time.
(2) Even knock-in method
When the matching interference is small and there is no special sleeve, the inner ring (or outer ring) of the bearing can be evenly knocked in through the round rods. It can also be knocked in with a hammer by assembling the sleeve. However, soft metals such as copper rods cannot be used, because it is easy to drop the soft metal scraps into the KOYO bearing, and you cannot directly hit the KOYO bearing with a hammer. When knocking, you should tap symmetrically and evenly around to avoid tilting the bearing due to excessive force or concentrated knocking.
(3) Machine pressing method
Press in with a lever rack or screw press.
(4) Hydraulic sleeve method
This method is suitable for situations where KOYO bearings are large in size and interference and require frequent disassembly. It can also be used for precision bearings that cannot be hammered. When assembling the tapered bore bearing, the high-pressure oil generated by the hand pump enters the shaft end and is introduced into the annular groove of the journal through the passage to expand the inner hole of the bearing. Then tighten the shaft end nut to install the KOYO bearing.
(5) Temperature difference method
KOYO bearings with interference fit are often assembled by the temperature difference method. The bearing can be heated in an oil bath at 80～100℃. When heating, it should be placed on a grid at a certain height from the bottom of the oil bath. For smaller KOYO bearings, a hook can be suspended in the oil bath to prevent overheating.
After taking out the KOYO bearing, use a measuring rod about 0.05mm larger than the journal size to measure the bearing bore diameter. If the size is appropriate, wipe off the oil and attachments with a clean cloth immediately, and pad the KOYO bearing with a cloth and flatten the end, and push the bearing quickly Insert the journal and assemble it with the shaft diameter while it is hot. Always push the bearing tightly by hand during the cooling process, and rotate the outer ring slightly to prevent tilting or jamming, and a firm fit will be produced after cooling. If you want to remove the KOYO bearing, you have to warm it in oil. It can also be placed in an industrial refrigerator to cool KOYO bearings or parts, or placed in a sealed box with a lid, poured into dry ice or liquid nitrogen, and after a period of heat preservation, take it out for assembly.
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