thin section bearing surface roughness

 the surface roughness effects of corrosion resistance of bearing parts. The rough surface, easy to make the corrosive gas or liquid through the table

The micro valley into the metal inner layer, causing the surface

Corrosion.

 the surface roughness of the Thin section bearings‍ sealing performance of bearing. Joint cannot be closely between the rough surface, gas or liquid.

Through the gap leakage between the contact surfaces of the.

 the surface roughness of bearing parts of the contact stiffness. The contact stiffness is parts with surface under the action of external force, resistance

The ability to contact deformation. The machine stiffness in the very great degree

Depending on the components  Thrust Roller Bearings ‍ of the contact stiffness between.

Measurement accuracy of effects of cross roller. Parts of the measured surface and a tool for measuring surface roughness will directly

Affect the precision of measurement, especially in precision measurement.

In addition, the surface roughness reali slim bearings‍ of the parts of the coating, thermal conductivity and contact resistance, reflection and radiation performance, liquid

The surface current resistance, conductor and the gas flow distribution etc.

Will have different degrees of influence.  ‍

slewing ring bearings Surface roughness analysis

 effect of crossed roller bearing properties

Effect of surface roughness on the performance of cross roller bearings parts is mainly manifested in the following aspects:

1, the surface roughness affect the wear resistance of parts. The surface is rough, with the effective contact area between the surface pressure is smaller, faster, slewing ring bearings‍ and wear.

2, the surface roughness effects of cross roller bearing ring with the properties of stability. The clearance fit, the surface of the more

Rough, more easy to wear, so the work process of intermediate gap gradually

Increased; the interference fit, the assembly will micro convex peak crowded flat, reduces the effective interference, reduce the

The strength of the bond.

3, the surface roughness of fatigue strength crossed roller bearing slewing rings‍ of bearing parts. There is a big trough surface roughness of parts, they are like sharp

Angular notch and crack, the stress concentration is very sensitive,

Thus affecting the fatigue strength of parts.                                                                                                                            ‍

slim ball bearing According to the load direction

According to the load direction, acting on the cross roller bearing inner ring and the outer ring of the nature and which side of the ferrule is rotating, the load can be divided into the rotating load, static load or non directional load. Under the rotating load and non directional loads shall be slim ball bearing‍ taken with the (static ring interference fit), static load bearing ferrule, desirable transition fit or movable fit (clearance). The bearing load

Large or withstand the impact load, vibration, the interference must be increased. The hollow shaft, thin-wall bearing box or light alloy, plastic housings, also high precision bearings‍ need to increase the amount of interference. The requirement to maintain high rotation, should be used in high precision bearings, and improve the dimensional precision of shaft and bearing box, to avoid interference is too large. If the interference is too large, may make the geometry precision bearing shaft or bearing box

Geometry, to the detriment of the rotating precision bearings.‍

thin section bearing What is the angular contact ball bearing

Angular contact ball bearings, thrust ball bearings to the heart that is usually said, the allowable working speed and deep groove ball bearing is similar, but the support rigidity ratio of deep groove ball bearing is stronger, mainly because of the bearing steel ball is more, the radial load capacity than the ordinary ball bearing, but also bear large axial load or subject to pure axial load. The bearings are generally used in pairs, used thin section bearing‍ for Small Span Rigid double supporting shaft or precision spindle, can improve the rigidity of the bearing system.

Can bear radial load and axial load for angular contact ball bearing. Can work at a higher speed. The larger the contact angle, the higher the axial bearing capacity. High precision and high speed bearings usually take 15 degrees contact angle. Under the action of axial force, contact angle increases. crossed roller bearings‍ The axial load of single row angular contact ball bearings can bear a direction, in radial load, will cause additional axial force. The axial displacement of the bearing can limit shaft or shell in one direction. If quality.the installation, the outer ring of a bearing on the relative, the wide end of the wide face, narrow end face with narrow end. So to avoid the additional axial force, but also in the two direction of the shaft or shell limit in the axial clearance range.

Because of its inner and outer ring raceway can have relative displacement metallurgical bearing‍ on the horizontal axis angular contact ball bearing, can bear radial load and axial load -- combined load (single row angular contact ball bearings can only endure single direction axial load, mounting is often adopted to them).

Characteristics of slim ball bearing

(1) the friction coefficient is small and steady, easy to start. In general, f=0.001-0.002 slim ball bearing, roller bearing needle f=0.001-0.003, f=0.002, f=0.003 thrust ball bearings, thrust roller bearings f=0.004.
(2) the small axial dimension. Guide roller, guide, slider, linear bearings, miniature ball bearings series of deep groove ball bearing series needle roller (roller) bearings, thrust ball bearings
(3) the radial clearance is small, can be preloaded.
(4) lubrication, easy maintenance.
(5) some bearings can bear both circumferential and radial force, simple structure.
 (6)Excavator Slewing Bearing impact bearing ability is poor, the radial size, high speed when there is noise, short service life.

Grease of thin section bearing

At present, more and more refined using miniature bearing equipment, the grease the bearings must have no the following function:
(1) the operation life with no and thin section bearing the same, try to delay the maintenance cycle, reduce downtime, advance in labor productivity.
(2) in the high speed to low motor temperature rise, not oil, thereby reducing power consumption, to protect the motor.
(3) the net content control is the inevitable standard, the maximum reduction of equipment noise pollution.
(4) is the ultra low temperature work starting and operating conditions to ensure the bearing spiritual, common problems of bearing. The minimum guarantee the output power.
Needle Roller Bearing cleaning, cleaning rough and fine cleaning, placed in a container, metal mesh on the bottom first, make the bearing does not directly contact the container dirt. Rough cleaning, if you rotate the bearings with dirt, can damage the bearings of rolling surface, should be noticed. In the crude oil washing, use brush put to grease, adhesive material, generally clean, to wash.

The important role of the slewing ring bearings noise and maintenance using grease

Used in  slewing ring bearings  grease must have antirust effect, anti rust agent preferably insoluble in water. Grease has good adhesion, and can form a layer of oil film on the steel surface, the oil will become soft in the mechanical machining, resulting in leakage. During normal operation, the fat by Deep groove ball bearing seat to swing block ball bearings. If the grease is not enough mechanical stability, operation process, will make the oil soap structure produces mechanical disintegration, resulting in destruction of fat, resulting in loss of lubrication, if the wrong choice grease all prevention bearing measures in vain, select a grease base oil viscosity, it is able to provide sufficient lubrication effect at the working temperature is very important, viscosity is mainly affected by temperature, it decreased with the increase of temperature, when the temperature drop is that it increased. Therefore, must know the base oil viscosity at operating temperature. Machinery manufacturers are typically specified using some kind of grease, but the scope of most of the standard grease is very wide.
In the process of using spherical ball bearing, grease is the key. If, the use of grease deterioration, can not play a role, and will damage the bearing.
Bearing vibration of bearing failure effect is very significant. For example: peeling, indentation, rust, crack, wear will be reflected so the bearing vibration measuring device special in the bearing vibration detection (frequency analyzer and vibration meter) measure the magnitude of vibration can be inferred from the numerical details of abnormal vibration the measured by bearing the premise or sensor installation location and different therefore require prior to each machine measurements were compared to determine the scale by frequency distribution.

Thin wall bearings with clearance adjustment

1 adjusting shim method:

Between the bearing end cover and the   thin wall bearings end face filled a group of soft materials (mild steel plates or elastic gasket paper); adjustment, not to put the gasket is arranged on the bearing cover, a bearing end cover uniformly tighten the screws on the side of the axis of rotation, by hand, until the bearing rolling body and the outer ring contact and axes so far no clearance measurement; when the bearing cover with the clearance between the bearing surface, axial clearance of bearing needed in the normal work of the total thickness; this is the desired filled gasket, then between the gasket ready to fill on the bearing cover and the bearing surface, then tighten the screws.

2 adjusting bolt:

The pressure ring pressure in the Radial Bearing  outer ring, by adjusting bolts pressure; pressure before adjusting, first measure the pitch adjustment bolt, and then slowly tighten the adjustment bolt, until such time as bearing no gap, and then calculate the adjustment bolt corresponding rotation angle. For example, 1.5 mm pitch, the normal operation of the bearing clearance is needed, then the required rotation angle adjustment bolt is 3600 × 0.15 / l.5=360; then the adjusting bolt reverse 360, bearing for axial clearance of 0.5 mm, and then stop the gasket to be fixed.

The flow of grease lubricated bearings grease should be replaced after 1500 hours of operation, filling quantity of oil should be moderate, because too much or too little grease will cause bearing heating, fuel generally lies in the bearing chamber volume of 1/2 ~ 2/3.

However, for the use of NSK bearing lubricating oil, oil should be added to the position of the corresponding provisions;‍

Selection of slewing ring bearing fit should focus on the following four points:

(1) the circumferential surface of bearing rings should have good support and force uniform, in order to reduce the distortion, and give full play to the carrying capacity of the bearing.

(2) rings in their mating surfaces cannot slide along tangential direction, slewing ring bearing otherwise it will damage the mating surfaces.

(3) the free end bearing must adapt to changes in the length and the shaft and the bearing seat hole phase, which must have the ability to adapt to the axial position within a certain range of swimming.

(4) must pay attention to the  reali slim bearings installation and removal easy, spending is labor-saving and time-saving province. The operation of bearings, hand Khan will become the cause of rust. To note that the clean hands operation, the best to wear gloves.

The life of the bearing is with the care and maintenance is very important, because it is related to the bearing life, work efficiency. Maintenance of sealed bearing maintenance use, will bring a lot of benefits, for example can bring about high production efficiency, producing more high quality precision products, maintenance can extend the life of several times to save you a re purchasing cost.‍

Thin section bearing maintenance four big characteristics

1 suitable viscosity and good viscosity temperature characteristics

In order to make the machine tool spindle temperature is not too high and the machine tool thermal deformation, affect the machining precision or the lubrication of slewing ring bearing, should according to the lubricating oil bearing structure, rotational speed and bearing clearance with suitable temperature and asking them to have good viscosity temperature characteristic, prevents the spindle operating temperature and the ambient temperature change, viscosity the change is too large and the impact of its lubrication performance.

2 good lubricity

In order to make the spindle and the slim ball bearing contact surfaces are maintained between oil film uniform, but also in the spindle start or stop moving when the impact load of oil film is not damaged, keep good lubrication properties play a reduced friction and frictional heat, reducing the temperature rise, ensuring the processing precision, has good lubricating performance.

Antioxidant activity of 3 good

Machine tool spindle in the circulating lubrication mode, requires long-term use without deterioration so has excellent oxidation resistance of spindle bearing oil.

4 good rust resistance

The oil in the lubrication system work process will inevitably mixed condensed water or machine tool coolant in the air, so the requirements of oil has good corrosion.‍

Influence of bearing structure on the vibration and noise(one).

The 1 raceway acoustic

Rolling road sound is due to rotation of the single direction thrust ball bearing body raceway rolling in and create a smooth and continuous noise, only when the sound pressure level or tone greatly when attention. In fact, the rolling sound excited acoustic energy is limited, such as in the normal condition, the quality of the 6203 bearing raceway acoustic ranged from 25 to 27dB. Single row deep groove ball bearing this noise to bear radial load as the most typical, it has the following characteristics:

A. noise, vibration is random;

B. vibration frequencies above 1kHz;

C. No matter how changes in speed, noise frequency and sound pressure level is almost the same with the speed increase;

D. when the radial clearance increases, the sound pressure level increases sharply;

Rigid E. bearing increases, the lower the total sound pressure level, even if the speed increased, the overall sound pressure level increases slightly;

F. lubricant viscosity is high, the sound pressure level is low, but for grease lubrication, the shape and size of the viscosity, the soap fiber can affect the value of the noise.

Rolling road sound source is the inherent vibration caused by load ring after. Due to the elastic contact rings and rolling elements of nonlinear vibration system. When the lubrication or machining precision is not high it will inspire the vibration associated with the elastic characteristics, transfer into the air into a noise. As everyone knows, even using the modern technology of manufacturing the highest machining bearing parts, its work surface there are tiny geometric error is not a degree, so that the raceway and rolling body produce tiny wave excitation vibration vibration system. Although it is inevitable, however, can adopt high precision machining parts work surface, the correct selection of denoising bearing and precise use of the bearing so that the damping.

2 fall rolling sound

The noise in general, mostly large bearings at low speeds and bear radial load. When the operation of the bearing in the radial load, load and non load bearing, if the bearing has a radial clearance, the non load area of the rolling body and the inner raceway no contact, but because of the action of centrifugal force may be associated with the outer ring contact, therefore, at low speeds, the centrifugal force is less than when rolling body weight when the natural vibration and noise, the rolling of the fall and and inner raceway or cage collision and motivate the thrust roller bearing, and has the following characteristics:

Easy to produce A. grease lubrication, oil lubrication is not easy to produce. When use inferior lubricating grease are more susceptible to.

B. often occurred in winter.

C. for only the radial load and the radial clearance is large but also easy to produce.

D. also can be in a certain range and different size bearing its speed range are also different.

E. may be a continuous sound may be intermittent sound.

F. the forced vibration often excited outer two order, three order bending vibration, thus make the noise. Through the use of pre load equation method can effectively reduce the noise, reduce the installed bearing radial clearance, choose good lubricants can also improve, some foreign enterprises adopt light rolling body, such as ceramic roller or hollow roller and other technical measures to prevent the occurrence of such noise.

The 3 tip.

It is a metal sliding friction produced quite sharp scream, though bearing temperature rise is not high, it will not have much impact on the service life of the bearing and grease life, does not affect the rotation, but not melodious sound disturbing, especially bear radial load of large cylindrical roller bearings often have this noise, the characteristics of:

A. bearing radial clearance large easy to produce.

B. usually occurs in grease lubrication, oil lubrication is rare.

C. decreases with the bearing size increases, and often appears in a certain speed range.

D. winter often.

E. its appearance is irregular, and unpredictable, and associated with the installation of operating conditions and performance, filling grease amount. This noise can be used to reduce the bearing radial clearance and the shallow outer ring raceway structure to prevent.‍

Abnormal phenomenon of bearing

Metal noise

Reason 1: abnormal load, countermeasures: modified with research, linear ball bearing clearance, adjustment and load, correction shell shoulder position.

Reason 2: poor installation, countermeasure: the processing precision of the shaft,housing, improve the installation accuracy, installation method.

3 reasons: lack of lubricant or not suitable, countermeasures: add lubricant, select the appropriate lubricant.

Reason 4: the rotating parts in contact, countermeasures: modify curve sealingcontact part.

Regular noise

Reason 1: the foreign bodies caused by rolling surface indentation, rust or scars,countermeasure: the replacement of bearings, wash the parts, improve sealingdevice, the use of clean lubricant.

Reasons: (2 Steel Carburized) surface deformation, countermeasure: the replacement of bearings, pay attention to the use of.

Reason 3: the raceway surface peeling, countermeasures: replacement of bearings.

Irregular noise

Reason 1: the clearance is too large, countermeasures: research cooperation andbearing clearance, modify the pre load.

Reason 2: foreign intrusion, countermeasures: a study of replacement of bearings,wash the parts, improve sealing device, the use of clean lubricant.

Reason 3: spherical injury, peeling, countermeasures: replacement of bearings.

Abnormal temperature rise

Reason 1: excessive lubricant, countermeasures: reducing lubricant grease, proper use, select the hard.

2 reasons: lack of lubricant or not suitable, countermeasures: add lubricant, select the appropriate lubricant.

Reason 3: abnormal load, countermeasures: modify the coordination, clearance of double direction thrust ball bearing‍ pre load, adjust, modify the shoulder position of the shell.

Reason 4: poor installation, countermeasures: improve machining precision, and shell axis installation accuracy, installation method.

Reason 5: surface creep, seal friction is too large, countermeasures: replacement of bearings, study, modify the shaft and housing, changes the sealing form.

Vibration (axial runout)

Reasons: (1 Steel Carburized) surface deformation, countermeasures: Note bearing replacement operation.

Reason 2: peel, countermeasures: replacement of bearings.

Reason 3: poor installation, countermeasures: axis, shell shoulder pad angle, sideangle.

Reason 4: foreign intrusion, countermeasures: replacement of bearings, cleaningparts, improved sealing device.

Lubricant leakage is overmuch, discoloration

Cause: excessive lubricant, foreign intrusion, wear powder foreign body,countermeasures: proper use of lubricant, change the selection of lubricant, the replacement of bearings, cleaning shell.‍