Installation method of Koyo bearing
Whether the bearing is installed or not will affect the accuracy, service life and performance of the bearing. Therefore, please fully study the Installation Method bearing installation, that is, please install the Koyo bearing according to the operating standards including the following items.
1、 Clean Koyo bearings and related parts
For grease lubricated bearings and bearings with oil seals or dust covers on both sides, the sealing ring Installation Method bearings do not need to be cleaned before installation.
2、 Check the size and finish machining of relevant parts
3、 Installation method
The installation of Koyo bearing shall be determined according to the bearing structure, size and matching properties of bearing components. The pressure shall be directly added to the end face of the tightly matched ferrule, and the pressure shall not be transmitted through the rolling element. The installation of Koyo bearing generally adopts the following methods:
a. Press fit
The inner ring of the Koyo bearing is tightly matched with the shaft. When the outer ring is loosely matched with the bearing seat hole, the bearing can be press installed on the shaft, and then the shaft and the Koyo bearing can be installed into the bearing seat hole. During press installation, an assembly sleeve (copper or mild steel) made of soft metal material shall be padded on the end face of the inner ring of the Koyo bearing.
The inner diameter of the assembly sleeve shall be slightly larger than the diameter of the journal, The outer diameter shall be slightly smaller than the retaining edge of the bearing inner ring to avoid pressing on the cage. The outer ring of the bearing fits tightly with the bearing seat hole. When the inner ring fits loosely with the shaft, the bearing can be pressed into the bearing seat hole first.
At this time, the outer diameter of the assembly sleeve should be slightly smaller than the diameter of the seat hole. If the Koyo bearing ring is tightly matched with the shaft and seat hole, the inner ring and outer ring in the installation chamber shall be pressed into the shaft and seat hole at the same time, and the structure of the assembly sleeve shall be able to press the end faces of the bearing inner ring and outer ring at the same time.
b. Heating fit
The installation method of changing tight fit into loose fit by heating bearing or bearing seat and using thermal expansion. It is a common Installation Method and labor-saving installation method. This method is suitable for the installation of bearings with large interference. Before hot installation, the ferrule of bearings or separable bearings
shall be put into the oil tank and heated evenly at 80-100 ℃, and then taken out of the oil and installed on the shaft as soon as possible. In order to prevent the end face of inner ring Installation Method and shaft shoulder from not fitting tightly after cooling, the bearing can be tightened axially after cooling.
When the outer ring of the bearing is tightly matched with the bearing seat made of light metal, the hot installation method of heating the Koyo bearing seat can avoid scratches on the mating surface. When heating the bearing with the oil tank, there shall be a mesh grid at a certain distance from the box bottom, or the bearing shall be hung with a hook.
The Koyo bearing cannot be placed on the box bottom to prevent sinking impurities from entering the bearing or uneven heating. There must be a thermometer in the oil tank, and the oil temperature shall be strictly controlled not to exceed 100 ℃ to prevent tempering effect and reduce the hardness of the ferrule.
c. Installation of tapered bore bearing
The tapered hole bearing can be directly installed on the journal with taper, or on the conical surface loaded with fixed sleeve and withdrawal sleeve. The tightness of its fit can be measured by the reduction of radial clearance of Koyo bearing. Therefore, the radial clearance of the bearing should be measured before installation.
During installation, the clearance should be measured frequently to achieve the required reduction of clearance. Generally, lock nut is used for installation, Heating installation method can also be used.
d. Installation of thrust bearing
The fit between the circumference of the thrust bearing and the shaft is generally transition fit, and the fit between the race and the bearing seat hole is generally clearance fit. Therefore, this Koyo bearing is easy to install. The middle shaft spring of the two-way thrust bearing should be fixed on the shaft to prevent rotation relative to the shaft.
Generally, the installation method of Koyo bearing is mostly shaft rotation, so the fit between inner ring and shaft is win-win fit, and the fit between bearing outer ring and bearing chamber is clearance fit.
4、 Inspection after bearing installation
The disassembly of the bearing shall be carried out with the same care as the installation. Pay attention not to damage the bearing and parts, especially the disassembly of interference fit bearing, which is difficult to operate. Therefore, in the design stage, it is necessary to consider the convenience of disassembly in advance,
and it is also very important to design and manufacture disassembly tools according to needs. During disassembly, the disassembly method and sequence shall be studied according to the drawings, and the matching conditions of the bearing shall be investigated to ensure the safety of the disassembly operation.
1. Removal of outer ring
Remove the outer ring of the interference fit. Set several outer ring extrusion screws on the circumference of the shell in advance. Tighten the screws equally while removing. These screw holes are usually covered with blind plugs, tapered roller bearings and other separate bearings. Several cuts are set on the housing shoulder. Use cushion blocks, disassemble with a press, or knock gently.
2. Disassembly of cylindrical bore bearing
The inner ring can be easily removed by pressure machinery. At this time, pay attention to make the inner ring bear its pulling force.
The inner ring of large bearing is disassembled by oil pressure method. Oil pressure is applied through the oil hole arranged on the shaft to make it easy to pull out. For the bearing with large width, the oil pressure method is used together with the drawing fixture for disassembly.
The inner ring of Nu and NJ cylindrical roller bearings can be disassembled by induction heating. It is a method of drawing after heating part in a short time to expand the inner ring.
3. Disassembly of tapered bore bearing
Disassemble the smaller Koyo bearing with fixed sleeve, support the inner ring with the stop fastened on the shaft, turn the nut back several times, and knock it with a hammer with a cushion block.
For large bearings, it is easier to disassemble by oil pressure. Pressurize and send oil in the oil hole on the taper hole shaft to expand the inner ring. It is a method to disassemble Koyo bearings. During operation, the bearing may suddenly come out. It is better to use the nut as a stop.