Timken bearing and shaft diameter or bearing seat hole interference is small, and the press in method is often used for assembly. The method of striking the bearing and pressing the bearing into the seat ring symmetrically is to use the hand hammer to press the bearing into the seat ring symmetrically according to a certain order. In addition, soft metal casing can also be driven by hand hammer or press.
If the operation is improper, the seat ring will be deformed and cracked, or the hammer will hit the seat ring without interference fit, which will make the raceway and bearing body indentation or the bearing will be damaged indirectly.Common faults and necessary remedial measures of Timken thrust ball bearing
Common faults and necessary remedial measures of Timken thrust ball bearing
During assembly, if the interference between the bearing and the shaft diameter is large, the hot assembly method is generally adopted. Put the bearing into the oil barrel containing engine oil, and heat the outside of the oil barrel with hot water or flame.
The process requires that the heated oil temperature be controlled at 80 ℃ ~ 90 ℃, generally not more than 100 ℃, and mostly not more than 120 ℃. Timken bearing is quickly taken out after heating and sleeved on the journal.
If the heating temperature is too high due to improper temperature control, the bearing will be tempered and the hardness will be reduced, and the thrust ball bearing is easy to wear, peel off and even crack during operation.Common faults and necessary remedial measures of Timken thrust ball bearing
Damage state: when the bearing rotates under load again, the raceway surface or rolling surface of the inner ring and outer ring presents fish scale peeling phenomenon due to rolling fatigue.
Cause: excessive load. Poor installation (non-linear) moment load, foreign matter intrusion and water ingress. Poor lubrication, improper lubricant and improper clearance of thrust ball bearing.
Poor accuracy of bearing housing, uneven rigidity of bearing housing, large deflection of shaft, development caused by rust, erosion point, scratch and indentation (surface deformation phenomenon).Common faults and necessary remedial measures of Timken thrust ball bearing
Measures: check the load and re study the bearing used, improve the installation method, improve the sealing device and prevent rust during shutdown. Use lubricant with proper viscosity and improve lubrication method. Check the accuracy of the shaft and bearing housing. Check the play.Common faults and necessary remedial measures of Timken thrust ball bearing
PeelingCommon faults and necessary remedial measures of Timken thrust ball bearing
Damage state: it presents a dark surface with slight wear, on which there are several micro cracks with a depth of 5-10m from the surface to the inside, and micro peeling (micro peeling) occurs in a large range
Damage state: the so-called wear is the wear of raceway surface or rolling surface, roller end face, shaft ring surface and concave surface of cage caused by friction.
Cause: development caused by foreign matter intrusion, rust and electric corrosion. Poor lubrication. Slippage caused by irregular movement of rolling elements.Common faults and necessary remedial measures of Timken thrust ball bearing
Measures: improve the sealing device. Clean the bearing housing. Fully filter the lubricating oil. Check the lubricant and lubrication method. Prevent non-linearity.Common faults and necessary remedial measures of Timken thrust ball bearing
Micro vibration wear
Damage state: wear caused by relatively repeated small sliding between the two contact surfaces occurs on the contact part between the raceway surface and the rolling element. Due to the occurrence of reddish brown and black wear powder, it is also called micro vibration wear corrosion.
Cause: poor lubrication. Small amplitude rocking motion. Insufficient interference.
Action: use proper lubricant. Preload. Check the interference. Apply lubricant to the mating surface
Pseudo Brinell indentation
Damage state: during micro vibration, the wear of the contact part between the rolling element and the raceway wheel develops due to vibration and shaking, resulting in impressions accumulated like Brinell indentation.
Cause: during transportation, the vibration and swing of the bearing when it stops running. Oscillating motion with small amplitude. Poor lubrication.
Measures: fix the shaft and bearing housing during transportation. The inner ring and outer ring shall be packed separately during transportation. Add preloading to reduce vibration. Use appropriate lubricant.Common faults and necessary remedial measures of Timken thrust ball bearing
Damage state: the so-called creep refers to the relative sliding between the mating surfaces when there is a gap on the mating surface of Timken bearing. In terms of the mating surface with creep, the mating surface presents a bright or dark mirror surface, and sometimes the page is damaged and worn.
Cause: insufficient interference or clearance fit. The fixing sleeve is not tightened enough.
Measures: check the interference and implement anti rotation measures. Tighten the set sleeve properly. Study the accuracy of shaft and bearing housing. Axial preloading. The side of the raceway wheel is fastened. Bond the mating surface. Apply to the mating surface? Lubricant.
Damage state: the raceway wheel, rolling element and cage are heated sharply during rotation until they change color, soften, deposit and damage.
Cause: poor lubrication. Excessive load (excessive preloading). Excessive speed. The clearance is too small. Intrusion of water and foreign matters. The accuracy of shaft and bearing box is poor and the deflection of shaft is large.
Measures: study lubricants and lubrication methods. Correct the selection of bearings. Study fit, bearing clearance and preloading. Improve the sealing device. Check the accuracy of the shaft and bearing housing. Improve installation methods.
Damage state: the so-called electric erosion refers to the phenomenon that when the current flows in the contact part between the bearing raceway wheel and the rolling body, sparks are sent out through the thin lubricating oil film, and local melting and concave convex appear on its surface.
Cause: ground potential difference between outer ring and inner ring.
Measures: when setting the circuit, the current should not flow through the bearing part. Insulate the bearings.
Rust and corrosion
Damage state: the rust and corrosion of bearings include pit rust, overall rust and corrosion on the surface of raceway wheel and rolling element.
Cause: invasion of water and corrosive substances (paint, gas, etc.). Improper lubricant. Water droplets are attached due to the condensation of water vapor. Stop when it is hot and wet. Poor rust prevention during transportation. Improper storage status. Improper use.
Measures: improve the sealing device. Study lubrication methods. Rust prevention measures during shutdown. Improve storage methods. Pay attention when using.
Damage state: axial linear scars on the raceway surface and rolling surface during installation and disassembly
Cause: the inner ring and outer ring during installation and disassembly are inclined, and the impact load during disassembly.
Measures: use appropriate tools and press to prevent impact load. Centering between each other during installation.
Temperature change and roller cage damage due to lubricant and reaction.
Cause: poor lubrication. Reaction with lubricant causes hot oil immersion. The temperature rises greatly.
Measures: improve lubrication methods.
It can be seen from the above that the axial clearance of Timken bearings with adjustable or non adjustable clearance shall be adjusted during assembly (but some bearings with non adjustable clearance do not need to leave axial clearance) to compensate for the thermal elongation of the shaft when the temperature rises, so as to ensure the normal operation of the thrust ball bearing body.
If the axial clearance is too small, it will make the bearing difficult to rotate, heat, and even make the bearing body stuck or damaged; If the axial clearance is too large, it will cause abnormal sound during operation, and even cause serious vibration or damage to the cage.
Cause: improper lubricant. Foreign matter has entered the lubricant. Poor lubricant causes rough surface. The surface finish of paired rolling parts is not good.Common faults and necessary remedial measures of Timken thrust ball bearing
Measures: select lubricant to improve the sealing device and improve the surface finish of paired rolling parts.
Damage state: the so-called stuck injury is the surface damage caused by the collection of minor burns in the part of the sliding surface injury. Linear scars in the circumferential direction of slide surface and rolling surface. The cycloidal scar on the end face of the roller is close to the clamping wound on the shaft ring surface of the end face of the roller.
Cause: excessive load and preloading. Poor lubrication. Foreign body bite. Deflection of the outer ring and the inclined shaft of the inner ring. The accuracy of shaft and bearing housing is poor.Common faults and necessary remedial measures of Timken thrust ball bearing
Action: check the size of the load. The preloading shall be appropriate. Improve lubricants and lubrication methods. Check the accuracy of shaft and bearing housing.Common faults and necessary remedial measures of Timken thrust ball bearing
Damage state: the so-called fracture refers to a small part of the fracture due to the impact or excessive load on the retaining edge of the raceway wheel or the local part of the roller angle.
Cause: hit during installation. Excessive load. Poor use such as falling.
Measures: improve the installation method (use hot installation and appropriate tool clamp). Correct load conditions. The bearing is installed in place so that the retaining edge is supported.Common faults and necessary remedial measures of Timken thrust ball bearing
Damage state: the so-called crack refers to the crack damage of the raceway wheel or rolling element. If it continues to be used, it will also include cracks with crack development.Common faults and necessary remedial measures of Timken thrust ball bearing
Cause: excessive interference. Excessive load, impact load. Stripping has developed. Heating and micro vibration wear caused by the contact between the raceway wheel and the mounting member. Heating caused by creep. The cone angle of the cone shaft is poor.
The cylindricity of the shaft is poor. The fillet radius of the shaft step is larger than the Timken bearing chamfer, resulting in interference with the bearing chamfer.Common faults and necessary remedial measures of Timken thrust ball bearing
Measures: proper interference. Check the load conditions. Improve installation methods. The shape of the shaft should be appropriate.
Damage state: dents on the raceway surface or rotating surface when biting into small metal powder, foreign matters, etc. Due to the impact during installation, a concave surface (Brinell hardness indentation) is formed on the spacing of the rolling elements.
Cause: foreign matters such as metal powder bite in. Excessive impact load during assembly or transportation.
Measure: impact the shaft sleeve. Improve the sealing device. Filter the lubricating oil. Improve assembly and use methods.Common faults and necessary remedial measures of Timken thrust ball bearing
Pear peel pitting
Damage state: weak gloss dark pear skin pitting on the raceway surface.Common faults and necessary remedial measures of Timken thrust ball bearing
Cause: foreign matters bite in during lubrication. Condensation due to moisture in the air. Poor lubrication.
Measures: improve the sealing device. Fully filter the lubricating oil. Use a suitable lubricant.