Rolling bearing technology

Rolling bearing technology Rolling bearing temperature  

  The main factors of bearing operating temperature:

1.Bearing load,

2.Bearing speed,

3.Bearing friction torque,

4.Lubricant type and viscosity and amount of lubricant,

5.Bearing assembly/bearing seat design,

6. Working environment system Temperature: heat dissipation rate heat rate? In most bearing applications, the temperature level is relatively low, due to: 1. Lighter load/lower speed-------low heat rate 2. Air flow around the bearing is good, and there is sufficient space between the adjacent metals Heat conduction-------Strong conduction capacity Heat generation: frictional power consumption: Hf=1.047X10-4nM (M friction torque) For high-speed bearings, the local heat generation rate generated by the sliding of each contact zone: Hfj=( ∫vkdFkj)/J (J unit conversion coefficient (Nm/s→W) vk is the sliding velocity component along the direction of the frictional torque increment dFk. The heat generation rate of each rolling element and the spin of the inner and outer tracks: Hfj=(∫ωsjdMsj) /J  

Friction of rolling bearings

The causes of friction in rolling bearings:

1.Elastic hysteresis in rolling

2.Rolling element-raceway contact sliding caused by the geometry of the contact surface

3.Slip caused by contact deformation

4.Slip between cage and rolling element, and For cages guided by ribs, there is also sliding between the cage and the ring

5.The rolling element and the lubricant on the cage are viscous drag friction

6.The sliding between the roller end surface and the inner and outer ring ribs

7.Seal Friction description:

1.The elasticity lags behind the force-bearing material and the unit load on the contact surface. 2. Rolling and deformation---the front part of the contact area is raised and the rear part is recessed. Additional tangential force is required to overcome the resistance of the raised material 3. Cage Guide mode: inner ring rib guide IRLR, ball guide BR, outer ring rib guide ORLR 4. The friction force generated by the bearing seal is usually significantly greater than the sum of other types of friction force and the dynamic conditions of the cage: at high speed or large acceleration conditions Under the following conditions, the magnitude of the transient effect of the cage will be very large, which needs to be calculated: 1. The impact force and friction force on the interaction surface of the cage and the rolling element 2. The contact surface of the cage and the ring guide rib Normal force and friction force (rib guide) 3. Force caused by unbalanced cage center of mass 4. Gravity 5. Cage inertia force 6. Other forces (viscous friction force of lubricant on cage and stirring force of grease)  

  The friction moment of the bearing is the moment caused by the applied load M1=f 1 F β dm where f1 = z(C0/Cs)|y where x, y are related to the bearing type, and the nominal contact angle is related to the viscous friction moment Mv=10|- 7f 0(v0n)|1.5dm|3 v0n=2000Mv=160*10|- 7f 0dm|3 v0n= 2000f 0 Bearing type, the lubrication method is related to the kinematic viscosity of the base oil of the v0 grease. Roller bearing roller and rib friction Moment Mf=ff Fa dm 

  Therefore: Total friction torque M=M1 Mv Mf