Common five kinds of machine tool spindle bearings Features

1. Deep groove ball bearings

This class bearings generally only used to bear radial load, due to clearance is not adjustable, so commonly used in less precision, without pretension occasions, such as the common drilling spindles.

2. angular contact ball bearings

These bearings can support radial and axial loads, since the radial load will cause internal axial force, and hence, to install and use, and its configuration has "back to back", "face to face", "series" and " multi-joint ", and by tightening can increase the stiffness of the spindle. These double row ball slewing bearing have a contact angle of 15 °, 25 °, 40 ° three, including a contact angle of 15 ° B7000CY-precision angular contact ball bearings are designed for dedicated high-speed grinder spindle bearing designs, in addition to the internal structure of the bearing design changes, rings and rolling elements are made ​​of high-quality bearing steel slag. Cage material is phenolic cloth laminated tube, tolerance levels have 5,4 and 2. Therefore, these bearings have high rotational accuracy and speed limits, low friction, low temperature rise.

3. angular contact thrust ball bearings

Usually used 230,000 two-way thrust angular contact ball bearings, the contact angle of 60 °, by a seat belt lubrication holes, two shaft washer, a spacer and two ball and cage components. Select the appropriate height of the spacer can be assembled deck crane bearing having a desired pre-load.

Such bearings can withstand axial load, with good rigidity, the normal low temperature lubrication, high speed, and easy assembly and disassembly, as a new structure, currently used for grinding machines, lathes, boring, milling, drilling and other spindle on, often with the use of double row cylindrical roller bearings group with.

4. Double-row cylindrical roller bearings

These bearings can withstand greater radial load and allows a higher speed. Bearing in two rows of rollers arranged in a cross pattern, rotation fluctuation frequency than single row bearings double the amplitude decreased 70%. Such bearings are commonly used in two forms: NN30 / W33, NN30K / W33 two series bearing inner ring with ribs, outer separable; NNU49 / W33, NNU49K / W33 two series bearing outer ring with ribs, internal Circle separable, which NN30K / W33 and NNU49K / W33 series inner ring of tapered bore (taper 1:12), and a tapered shaft journal mate, axial movement of the inner ring, the inner ring can swell to reduce even small bearing clearance bearing preload. Cylindrical bore bearings usually thermal loading, using an interference fit reduced bearing clearance, or to achieve the purpose of pretension. Separable NNU49 series on the inner bearing inner ring mounted on the spindle generally made ​​after finishing the race in order to obtain high spindle rotation accuracy.

5. Tapered Roller Bearings

Both radial and axial loads, double row tapered roller bearings can withstand axial load. Tapered Roller sliding friction due to the large end and the inner wall between the child, the speed limit is often lower than the same-size cylindrical roller bearings. Hollow tapered roller bearings available oil cooling roller, so that temperature decreases, thereby increasing the allowable speed. But this thin wall bearings

 complex manufacturing process, machine tool lubrication system requirements are higher, generally used only for the special requirements of the horizontal spindle. 

How to choose the right bearing for the project?

Select the bearing type when fully grasp the conditions of use of the bearing is essential.
The following table lists the main analysis items:
Analysis Project Selection Method
1) The installation space can be accommodated in the bearing stiffness and strength of the bearing type shaft bearings installation space due to the focus on the design of the shaft axis, it is generally first determine the shaft, ie bearing diameter. But Rolling a variety of sizes and types of series, should choose the most suitable bearing type.
2) Load bearing load size, direction and nature of the [load bearing capacity with a basic load rating, said its value is contained in the bearing size table] bearing loads varied, such as the size of the load, if only radial load, axial load one-way or two-way, and so the degree of vibration or shock.
3) Speed ​​can adapt the mechanical speed of the bearing type [bearing speed limit speed limit value represented by the benchmark, its value is contained in the bearing size table] bearing speed limit not only take on the bearing type has limited bearing size, cage type, accuracy class load condition and lubrication methods, therefore, must consider these factors while selecting. Most of these bearings for high-speed rotation: deep groove ball bearings, angular contact ball bearings, cylindrical roller bearings.
4) having a truck mounted crane bearing type rotary precision desired rotational accuracy [dimensional accuracy and precision of the bearing rotation by bearing type has been standardized GB] spindle, gas turbines, and control of the machine requires high rotational accuracy, respectively, high speed and low friction, which should be used when more than five precision bearings. Generally use the following bearings: deep groove ball bearings, contact ball bearings, cylindrical roller bearings.
5) Just performance required to meet the mechanical rigidity of the bearing shaft type [when the bearing load, the contact portion of the rolling element and raceway will produce elastic deformation. "High rigidity" refers to the smaller amount of deformation of this elastic deformation] at the site of the machine spindle and the final stage of the deceleration devices, automobiles, to improve the rigidity of the shaft, it is also necessary to increase the rigidity of the bearing. Roller bearings under load deformation born smaller than ball bearings. Bearing preload (negative clearance) can improve rigidity.
This method is suitable for angular contact ball bearings and tapered roller bearings.
6) is inclined relative to the inner ring and outer ring of the bearing inner ring and the outer ring analysis produce relatively tilted factors (such as poor accuracy or the mounting error of the deflection, caused by the load of the shaft and the housing axis) and can adapt to this selection Conditions of bearing types. If the inner and outer rings relative inclination is too large, the bearing load due to internal damage produced.
Therefore, the bearings should be selected to withstand this type of tilt. In general, allows the tilt angle (or aligning angle) increments in the following order: plane bearing cylindrical roller bearings, needle roller bearings, deep groove ball bearings (angular contact ball bearings), self-aligning roller (ball) bearings.
7) The installation and removal of detachable regular inspection frequency and frequent assembly and disassembly disassembly methods using separable inner and outer rings of cylindrical roller bearings, needle roller bearings and tapered roller bearings is more convenient. Tapered bore spherical ball bearings and tapered bore spherical roller bearings through the use of fasteners or withdrawal sleeves can be easy assembly and disassembly.
After considering these factors, again select the most suitable bearing type. In general, the radial load crossed roller bearings capacity of the same inner diameter increments in the following order: deep groove ball bearings <angular contact ball bearings <cylindrical roller

bearings <tapered roller bearings <aligning roller bearings.

Selection Method precision machine tool spindle bearings

Rolling use on the machine is mainly used for the following three parts: the spindle, ball screws and general drive shaft. First, the rotation accuracy of precision rolling bearings for machine tool spindle system accuracy precision machine tool spindle bearings on the P5 and above level should be, and for machine tools, machining centers, high-speed, high-precision machine tool spindle bearings, P4 and above should be used Ultra precision bearings.
Rolling use on the machine is mainly used for the following three parts: the spindle, ball screws and general drive shaft.
First, the accuracy of precision machine tool spindle rotation system Machining centers, high-speed, high-precision machine tool spindle rolling mill bearing should be used in P4 and above-grade super-precision bearings. Machine tool spindle bearings as the basis for matching pieces, and its performance directly affects the speed of the machine, rotary precision, rigidity, resistance to cutting chatter vibration, noise, temperature and thermal deformation, thereby affecting the accuracy, surface quality of machined parts and the like. Therefore, high-performance machine must be equipped with high-performance bearings.
Precision spindle rotation system means that the machine is idling at a low speed manual or motorized rotating case, the measurement reference plane radial front spindle runout, section runout and axial movement of accuracy.Precision spindle system is mainly affected by the following factors Radial runout channel bearing rings, corresponding to the precision spindle bearings axis of the spindle system is radial runout, so that the complex part of the errors of these enantiomers on the surface being processed.
Diameter rolling element bearings inconsistencies and shape error will cause the spindle to produce a regular errors.
The axial end surface of the channel on the side of the pendulum will cause the spindle runout, axial play of the spindle for precision grinding machines, especially spindle bearing

 grinder influence was particularly notable, if tributary Mogou way using the process, will make the rejection rate improved significantly, the noise will be greatly improved.
Size and shape make errors bearing mounting face bearing raceway produce the corresponding deformation, so that the bearing inner and outer rings tilted so that the stiffness of the bearing in each direction is inconsistent, which will reduce the rotational accuracy spindle system. Gap adjustment nut, the spacer, the washer is required for grinding the end face and perpendicular to the axis of rotation of the shaft and the bearing installation accuracy corresponding, otherwise it will decrease the working accuracy of the bearing.
Second, the precision machine tool spindle lubrication and seal Earlier we mentioned the lubricant is an important part of the bearing arrangement, different lubrication, speed limit data bearing is different. In accordance with the design requirements lubricant replenish (High Speed ​​Precision Spindle grease filling amount is generally 10% to 20% of the bearing space), reasonable lubricant can reduce friction and wear shafting, extend the fatigue life of the bearing, frictional heat can be discharged simultaneously bearing system and play a role in cooling the bearing system; in addition to the grease, as well as liquid lubricating oil lubrication, oil mist lubrication and oil lubrication, etc. bearing system, oil lubrication system in which high-speed spindle abroad has been widely used, fuel oil lubrication, no pollution, and can significantly increase the DN value of the spindle system, and is able to intelligently control shaft lubricant requirements recharge.
Spindle structure design, lubrication and sealing must take different forms depending on the situation. Timely replacement of worn seals, seal lip contact with the rotating body at more than 15m / s is necessary to use non-contact sealing structure, high-speed precision machine tools they use a labyrinth, and the need to dump oil in place designed grooves, because contact Not only will seal sealing contact friction loss and overheating at, but will impact on the bearing system rotation accuracy.
Third, as a precision ball screw, efficient and sensitive transmission components, should be used in addition to high-precision screw, nut and ball, we must also pay attention to the choice of the axial stiffness, low friction torque, high operating precision bearings. Ball bearing used in the past two-way thrust angular contact ball bearings, tapered roller bearings, needle roller and thrust roller bearings, deep groove ball bearings and thrust ball bearings. Currently, ball bearing using the most is the contact angle of 60 ° single row angular contact ball bearings, and precision grade is mainly to P4 level and above.

How to buy Agricultural Bearings

Bearing is rotating shaft of various mechanical or moving parts support, widely used in farm vehicles, tractors, diesel engines, electric motors, threshers and other agricultural machinery. Choose Common bearing code, but bearing code more complicated, if agricultural hand grasp identification bearing code of law, the purchase is easy.
Bearings are some of the commonly used standard model, codenamed "0" tolerance class "G" (ordinary level), the general agricultural bearings of the first paragraph can not write, so its more than seven-digit code representing the basic code.
To illustrate the meaning of bearing code: Example 7002136 (135 series diesel engine shaft main bearings), the basic code from right to left to identify. "36" within a two-digit representation of light, which is calculated as 36 × 5 = 180 mm; "1" represents the diameter of the series special light; "2" indicates the type of cylindrical roller bearings; "00" indicates the form of the outer bearing structure without ribs; "7" represents the width of the narrow series. If the machine hand to buy other standard models bearing seven-digit code can and so on.
Optional multi-reference bearing diameter bearings, tower crane bearing diameter in the basic code using the right end of the first, second digit indicates. Sub-standard and non-standard bearing bore diameter, the difference is not an integer or a non-standard inner diameter of the whole multiple of 5.
To facilitate machine hand purchase.
To illustrate:
① bearing diameter in 9 mm below the right end of the first digit is represented by the actual size. For example, the bearing 18, an inner diameter of 8 mm.
② bearing diameter of 10 - 17 mm is represented by a set number. Such as bearings 100, 201, 302, 403, an inner diameter of the right end of the two-digit code is respectively 00, 01, 02, 03, respectively, an inner diameter of 10, 12, 15, 17 mm fixed numbers.
③ bearing diameter in 20--480 mm (22, 28, except 32), in addition to the inner diameter of 5 resulting numbers.
④ bearing diameter of more than 500 mm (22, 28, 32), expressed as a fraction, the denominator represents the inner diameter, the numerator represents the size of the series, the type and structure of the deck crane bearing

. Example No. 30031/560 bearings, an inner diameter of 560 mm, the other and so on.

Precision Bearings configuration issues

   For some high-precision bearings, its configuration requirements are very high, today we have to introduce a configuration problem on precision bearings.
Traditional applications of precision machine tool precision spindle bearings are, depending on the machine spindle processes have different requirements. In general, the lathe spindle is used at lower speeds and larger cutting metal cutting load. This type of transmission of the driving torque of the spindle usually through the pulley or gear. This means that the load on the drive end of the spindle is also quite large.Such applications of the speed is not too high, and more important parameter is the stiffness and load-carrying capacity. A very common method is to install a working end of the spindle-row cylindrical roller bearings and a double row angular contact thrust ball bearings, while at the driving end of the spindle using a double row cylindrical roller bearings. This configuration ensures a long working life and excellent rigidity, to produce high quality parts. Moreover, the agricultural bearings

 can be operated stably in terms of kinematics is concerned, because the two types of bearings (radial and axial) were carrying the load applied to the spindle (in fact, in order to prevent angular contact thrust ball bearing bearer path to the load, the outer diameter with special tolerances foreign ensure it will never be able to contact bearing).
  In the design of these types of spindles (which is usually applied to the load is heavy), a rule of thumb about the axis of the bearing is located where the distance between the centers of the front and rear support bearings for the 3-3.5 times the inner diameter.In need higher speeds (ie, high-speed machining centers or internal grinding), you need to find a different bearing solutions. Obviously, you need to make some sacrifices in terms of stiffness and load capacity in these cases. High-speed applications usually by direct-motor and / or direct drive spindle coupling (the so-called motor spindle).

Imperative to build brand value in the bearing industry

     Ball and roller combined bearing industry growing at an average annual size of China's double-digit growth rate rapidly growing . However , in this era of brand fighting to survive in the industry , many enterprises of China's bearing industry is also ready to welcome the "brand era" come ready ? Let's listen to the China Bearing Industry Association executive vice president Wang Quanqing views.
    What is a brand?
    Good product allows you to value for money and good brand but allows you to value for money!
    This is a " brand era," said the first decade if we are laying the foundation for product quality , time after then , we should do the brand on the basis of the product , otherwise companies do not have a competitive advantage , profit margins than others , but You know, the average profit margin of China's bearing industry is only about 5% .Recalling the development course of China's thin section angular contact bearings industry , "15 " , "Eleventh Five-Year" , the whole industry is very significant technological advances , coupled with Bearing Industry Association, the industry engaged in a technical research, the life of the product, reliability, noise and materials technology gained tremendous progress, especially small , miniature bearings , Jiangsu and Zhejiang Provinces production of small Full complement cylindrical roller bearing and product quality comparable to Japan . But later , due to increasing competition among enterprises , some companies do not want to come up with a special technique to share with their peers , some slow progress .Products based on the brand building has a good supporting force , then move forward step can become a world-renowned brands. Brand well, pricing naturally went to their own hands.

agricultural bearings needle roller bearings

Why do so many industries need to needle roller bearings?

Needle roller bearings are widely used at present market is very hot, and in this process, the field of machine tools use some relatively wide.

Scope of application: this agricultural bearings‍ bearing needle roller bearings are used for gearbox, motorcycle, automobile, the small end of connecting rod. Gear. Because the cylinder temperature reducer, increase, so the bearing high temperature. With thin and long needle bearing roller (roller length is 3~10 times the diameter, the diameter is generally not more than 5mm), so the radial structure is compact, its diameter size and load capacity compared with other types of bearings at the same time, minimum diameter, especially for radial installation support results in limited size. According to the use of different occasions, can be used without inner ring bearings or needle roller and cage assemblies, the Double Row Ball Slewing Bearing‍ shaft neck surface and the surface of shell holes matched with a bearing directly as bearing inner and outer rolling surface, to guarantee load capacity and operating performance and have the same ring bearing, shaft or housing holes raceway surface hardness, the machining precision and the surface quality of bearing ring raceway and similar.                                                                 

LYHY precision spindle bearings Wheel Hub Bearing

In standard angular contact ball bearings and tapered slewing ring bearings‍ roller bearings developed on the basis precision spindle bearing, it sets bearing as a whole, with good assembly performance can be omitted clearance adjustment, light weight, compact structure, large load capacity, for can advance into the grease sealed bearings, seals and hub maintenance omitted from the outside wheel, etc., have been widely used in cars, Spherical roller bearings‍ and in the truck also has a tendency to gradually expand the application.