Bearing Installation Method
Bearing Installation Method
2021年12月21日
Influence Of Ina Imported Bearing Installation On Bearing Performance And Service Life
Influence Of Ina Imported Bearing Installation On Bearing Performance And Service Life
2021年12月21日

Bearing Installation Knowledge

Bearing Installation Knowledge

Whether the bearing is installed or not will affect the accuracy, service life and performance of the bearing. Therefore, please fully study the bearing installation, that is, please install the bearing according to the operating standards including Bearing Installation Knowledge the following items.

1、 Clean bearings and related parts

For grease lubricated bearings and bearings with oil seals or dust covers on both sides, the sealing ring bearings do not need to be cleaned Bearing Installation Knowledge before installation.

2、 Check the size and finish machining of relevant parts

3、 Installation method

The installation of the bearing shall be determined according to the bearing structure, size and the matching nature of the bearing components. Bearing Installation Knowledge 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 bearing installation generally adopts the following methods:

a. Press fit

When the inner ring of the bearing is tightly matched with the shaft and the outer ring is loosely matched with the bearing seat hole, the bearing can be press installed on the shaft with a press, Bearing Installation Knowledge and then the shaft and the bearing are installed into the bearing seat hole together. During press installation, it is on the end face of the inner ring of the bearing,

Pad an assembly sleeve made of soft metal material (copper or mild steel), the inner diameter of the assembly sleeve should be slightly larger than the diameter of the journal, and the outer diameter should be  Bearing Installation Knowledge slightly smaller than the retaining edge of the bearing inner ring to avoid being pressed on the cage. The bearing outer ring fits tightly with the bearing seat hole, and when the inner ring fits loosely with the shaft, the bearing can be pressed into the bearing seat hole first.

In this case, the outer diameter of the supporting pipe should be slightly smaller than the diameter of the seat hole. If the bearing ferrule and the shaft and seat hole are Bearing Installation Knowledge During tight fitting, 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 compress the end faces of the bearing inner ring and outer ring at the same time.

Bearing Installation Knowledge

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 and labor-saving installation method. Bearing Installation Knowledge This method is suitable for the installation of bearings with large interference. Before hot installation, put the bearing or the ferrule of separable bearing into the oil tank and heat it evenly for 80-100 ℃, then take it out of the oil and install it on the shaft as soon as possible.

In order to prevent the end face of inner ring and shaft shoulder from not tight after cooling, the bearing can be tightened axially after cooling. Bearing Installation Knowledge When the bearing outer ring is tightly matched with the bearing seat made of light metal, the hot installation method of heating the bearing seat can avoid the scratch of 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 bearing shall not be placed on the box bottom to prevent sinking impurities from entering the bearing or uneven heating. Bearing Installation Knowledge 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 of the tightening sleeve and withdrawal sleeve. Bearing Installation Knowledge The tightness of its fit can be measured by the reduction of the radial clearance of the 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 the clearance. Generally, lock nuts are used for installation, Heating installation method can also be used.

d. Installation of thrust bearing

The fit between the shaft ring and the shaft of the thrust bearing is generally transition fit, Bearing Installation Knowledge and the fit between the seat ring and the bearing seat hole is generally clearance fit. Therefore, this kind of bearing is easy to install. The middle shaft ring of the two-way thrust bearing shall be fixed on the shaft to prevent rotation relative to the shaft. Generally, the installation method of bearing is mostly shaft rotation. Therefore, the fit between inner ring and shaft is interference fit, and the fit between bearing outer ring and bearing chamber is clearance fit.

4、 Inspection after bearing installation

5、 Addition of lubricant

Installation of high speed precision angular contact ball bearing:

High speed precision angular contact ball bearing is Bearing Installation Knowledge mainly used in high-speed rotation occasions with light load. It requires high precision, high speed, low temperature rise, low vibration and certain service life. It is often used as the support of high-speed motorized spindle. It is the key kit of high-speed motorized spindle of internal surface grinder.

Main technical indicators:

1. Bearing accuracy index: exceeding grade P4 accuracy in GB / 307.1-94

2. High speed performance index: DMN value 1.3 ~ 1.8x 106 / min

3. Service life (average): > 1500 h. The service life of high-speed precision Bearing Installation Knowledge angular contact ball bearing is closely related to installation. The following matters should be paid attention to:

1. The bearing shall be installed in a dust-free and clean room. The bearing shall be carefully selected and matched. The spacer for the bearing shall be ground. Bearing Installation Knowledge On the premise of maintaining the equal height of the inner and outer spacer, the parallelism of the spacer shall be controlled below 1um;

2. The bearing shall be cleaned before installation. During cleaning, the inner ring slope shall be upward, and the hand shall be flexible without stagnation. After drying, put the specified amount of grease.Bearing Installation Knowledge  If it is oil mist lubrication, put a small amount of oil mist oil;

3. Special tools shall be used for bearing installation, with uniform stress and no knocking;

4. The bearing shall be stored in a clean and ventilated manner without corrosive gas, and the relative humidity shall not exceed 65%. For long-term storage, it shall be regularly rustproof.

Installation of tapered roller bearing and water pump shaft bearing:

1、 Bearing installation: the bearing must be installed under dry and clean environmental conditions. Before installation, carefully check the machining quality of the mating surface of the shaft and housing, the end face of the shoulder, the groove and the connecting surface. All mating connection surfaces must be carefully cleaned and deburred, and the unprocessed surface of the casting must be cleaned of molding sand.

The bearing shall be cleaned with gasoline or kerosene before installation, and used after drying, and good lubrication shall be ensured. The bearing is generally lubricated with grease or oil. When grease lubrication is used, grease with excellent properties such as no impurities, oxidation resistance, rust prevention and extreme pressure shall be selected.

The filling amount of lubricating grease shall be 30% – 60% of the volume of bearing and bearing box, and shall not be too much. Double row tapered roller bearing with sealing structure and water pump shaft connecting bearing have been filled with grease, which can be used directly by users and can not be cleaned.

During bearing installation, equal pressure must be applied on the circumference of the ferrule end face to press the ferrule in. It is not allowed to directly knock the bearing end face with hammer and other tools to avoid damaging the bearing. When the interference is small, press the end face of the bearing ring with the sleeve at room temperature, knock the sleeve with a hammer, and press the ring evenly through the sleeve.

In case of mass installation,

hydraulic press can be used. When pressing in, ensure that the end face of the outer ring and the end face of the housing shoulder, and the end face of the inner ring and the end face of the shaft shoulder are pressed tightly without clearance.

When the interference is large, the bearing can be installed by oil bath heating or inductor heating. The heating temperature range is 80 ℃ – 100 ℃, and the high temperature cannot exceed 120 ℃. At the same time, tighten the bearing with nuts or other appropriate methods to prevent the gap between the ferrule and the shaft shoulder due to the shrinkage in the width direction after the bearing is cooled.

The clearance of single row tapered roller bearing shall be adjusted after installation. The clearance value shall be determined according to different service conditions and the interference of the fit. If necessary, tests shall be carried out to determine. The clearance of double row tapered roller bearing and water pump shaft bearing has been adjusted at the factory, so it is not necessary to adjust it during installation.

After the bearing is installed, the rotation test shall be carried out. First, it shall be used for the rotating shaft or bearing box. If there is no abnormality, it shall run at no-load and low speed with power, and then gradually increase the rotation speed and load according to the operation, and detect the noise, vibration and temperature rise. If any abnormality is found, the operation shall be stopped and checked.

It can be delivered for use only after the operation test is normal.

2、 Disassembly of bearing: appropriate disassembly tools shall be selected when the bearing is to be used after disassembly. When removing the interference fit ferrule, only the tension can be added to the ferrule, and it is not allowed to transfer the disassembly force through the rolling element, otherwise the rolling element and raceway will be crushed.

3、 Service environment of bearing: select the specification, size and accuracy according to the service position, service conditions and environmental conditions, and cooperate with appropriate bearing is the premise to ensure the service life and feasibility of bearing.

1. Application position: tapered roller bearing is suitable for bearing the combined radial and axial load dominated by radial load. It is usually used in pairs with two sets of bearings. It is mainly used in the transmission parts of automobile, such as front and rear hubs, driving bevel gears, differential, reducer and so on.

2. Allowable speed: under the condition of correct installation and good lubrication, the allowable speed is 0.3-0.5 times of the bearing limit speed. Under normal conditions, it is appropriate to use 0.2 times of the limit speed.

3. Allowable inclination angle: generally, tapered roller bearings do not allow the shaft to tilt relative to the housing hole. If there is any inclination, the maximum inclination shall not exceed 2 ‘.

4. Allowable temperature: under the condition of bearing normal load, high temperature resistance of lubricant and sufficient lubrication, the general bearing is allowed to work at the ambient temperature of – 30 ℃ – 150 ℃.