A car usually has about 30 kinds of 50 sets of bearings installed in different rotating parts. In practice, automobile bearings are generally classified according to the installation or use position. Corresponding to the division of automobile into engine, transmission, steering system and air conditioning system, automobile bearings can be divided into engine bearings, transmission bearings, steering system bearings, air conditioner bearings and other bearings according to the installation position, and then can be further subdivided into each component of the above system and the specific installation position of bearings. Due to the diversification of automobile and bearing design, similar components of different automobiles often adopt different component structures and bearing structures. The installation position of the bearing can be expressed in more detail and directly by using the bearing installation position map and the corresponding bearing type spectrum, and the internal relationship between the components and the bearing can be revealed by giving the bearing model, overall dimension and installation position at the same time.
Development overview
With the development of automobile technology, the design, manufacture, test and application technology of automobile bearings have made great progress. However, from the perspective of application, the development of automobile bearings can be summarized as the expansion of the application of general bearings, the development of special bearings, and the improvement of bearing performance and life.
(1) Extended Application of Universal Bearings
The improvement of automobile structure, the development of varieties and specifications, the improvement of performance and service life, and the diversification of automobile design and bearing design have led to the expansion of the application range of universal bearings.
Up to now, universal bearings directly used in automobiles have covered almost all basic structural types, more and more series and more and more specifications of universal bearings, while the improvement and development of universal bearings directly used have led to some new universal bearing series and special bearings.
(2) Development of special bearings
On the basis of general bearings, some special bearings for automobiles have structure and function features that traditional rolling bearings do not have and are closely related to automobile applications. Among these special automotive bearings, the expansion of the structure and function of hub bearing and clutch release bearing is the most noticeable.
Hub bearing
1. The earliest hub bearing
The earliest used hub bearing is composed of two sets of single row radial ball bearings or tapered roller bearings. Its disadvantage is that the installation and maintenance need to be filled with grease and the clearance should be adjusted. However, improper type and amount of grease or insufficient cleanliness and improper clearance adjustment often lead to serious consequences of greatly reduced bearing life.
The improvement of the hub bearing composed of two sets of single row bearings led to the use of a sealed double row bearing with preset clearance. The clearance of this bearing has been adjusted correctly when it was manufactured, and the sealing and lubrication provided by the bearing itself can avoid the risk of dirt entering during installation and the wrong type and amount of lubricating grease. This kind of hub bearing, which extends the functions of lubrication, sealing and clearance adjustment, is called the first generation hub bearing.
The outer ring of the first generation hub bearing is flanged to form the second generation hub bearing. The expansion of the structure and function of the wheel hub bearing greatly simplifies the supporting structure of the wheel hub, reduces the demand for wheel hub parts, and makes the installation easier. The third generation wheel hub bearing produced by the further expansion of the structure and function of the wheel hub bearing has the functions of the bearing itself, the short shaft and the ordinary wheel hub. Its inner ring flange is used to support the wheel and the brake disc, and the outer ring flange is used to connect the suspension device. In addition to many technical advantages, such as simplifying the design of automobile wheels and suspension devices, reducing the volume, simplifying the assembly, easy to move, and having little possibility of wrong installation, this bearing assembly also effectively reduces the cost of automobile parts.
At present, the expansion of structure and function has made the hub bearing develop into the fourth generation integrated with the constant velocity universal joint, so that the technical performance and economic effect of the hub bearing have reached a new level.
The main function of the hub bearing is to bear weight and provide accurate guidance for the rotation of the hub. It bears both axial and radial loads and is a very important component.
The traditional bearings for automobile wheels are composed of two sets of tapered roller bearings or ball bearings. The installation, oiling, sealing and clearance adjustment of the bearings are all carried out on the automobile production line. This structure makes it difficult to assemble in the automobile factory, with high cost and poor reliability. In addition, when the automobile is maintained at the maintenance point, the bearing also needs to be cleaned, oiled and adjusted. Hub bearing unit is developed on the basis of standard angular contact ball bearing and tapered roller bearing. It integrates two sets of bearings and has the advantages of good assembly performance, omission of clearance adjustment, light weight, compact structure, large load capacity, pre loading of lubricating grease for sealed bearing, omission of external hub seal and maintenance free. It has been widely used in cars, and also has the trend of gradually expanding application in trucks.
2. Installation and Use of Automobile Hub Bearing
In the past, single row tapered roller or ball bearings were mostly used in pairs for wheel hub bearings of cars. With the development of technology, car hub units have been widely used in cars. The use range and amount of hub bearing units are growing, and now they have developed to the third generation: the first generation is composed of double row angular contact bearings. The second generation has a flange on the outer raceway to fix the bearing, which can simply cover the bearing on the axle and fix it with a nut. Make car maintenance easier. The third generation wheel hub bearing unit adopts the bearing unit and anti lock brake system ABS. The hub unit is designed with inner flange and outer flange? It is bolted to the drive shaft and the outer flange holds the entire bearing together. Worn or damaged wheel hub bearings or wheel hub units may cause inappropriate and costly failures of your vehicle on the road, or even harm your safety.
3. Please pay attention to the following items during the use and installation of the hub bearing
1) In order to ensure the maximum? Completeness and reliability. It is recommended that you always check the wheel hub bearing no matter how old your car is - pay attention to whether there is an early warning signal of bearing wear: including any friction noise during rotation or abnormal deceleration of the suspension combination wheel when turning. For rear wheel drive vehicles, it is recommended to lubricate the front wheel hub bearing when the vehicle has driven 38000km. When replacing the brake system, check the bearing and replace the oil seal.
2) If you hear the noise from the hub bearing, first of all, it is important to find the location where the noise occurs. There are many moving parts that may produce noise, or some rotating parts may contact with non rotating parts. If it is confirmed that the noise is from the bearing, the bearing may be damaged and needs to be replaced.
3) Because the working conditions of the front hub causing the failure of bearings on both sides are similar, even if only one bearing is damaged, it is recommended to replace it in pairs.
4) The wheel hub bearing is sensitive, and the correct method and proper tools should be used in any case. During storage, transportation and installation, the components of the bearing shall not be damaged. Some bearings require higher pressure to press in, so special tools are required. Be sure to refer to the automobile manufacturer's manual.
5) The bearing should be installed in a clean and tidy environment. The service life of the bearing will also be shortened if small particles enter the bearing. It is very important to maintain a clean environment when replacing bearings. It is not allowed to strike the bearing with a hammer. Pay attention not to drop the bearing on the ground (or the similar treatment is improper). Before installation, check the condition of the shaft and bearing seat. Even minor wear will lead to poor fit, which will lead to early failure of the bearing.
6) For the hub bearing unit, do not attempt to disassemble the hub bearing or adjust the seal ring of the hub unit, otherwise the seal ring will be damaged and water or dust will enter. Even the raceway of the seal ring and inner ring is damaged, resulting in permanent failure of the bearing.
7) There is a magnetic thrust ring in the seal ring equipped with ABS device bearing, and this thrust ring cannot be impacted, impacted or collided with other magnetic fields. Take them out of the packing box before installation, and keep them away from the magnetic field, such as the motor or electric tool used. When installing these bearings, observe the ABS alarm pin on the instrument panel through the road test to change the operation of the bearings.
8) For the wheel hub bearing equipped with ABS magnetic thrust ring, in order to determine which side the thrust ring is installed on, a small light object can be used to close to the edge of the bearing, and the magnetic force generated by the bearing will attract it. During installation, point one side of the magnetic thrust ring inward, facing the sensitive element of ABS.
Note: Incorrect installation may lead to failure of the brake system.
9) Many bearings are sealed, and this type of bearing does not need to be greased throughout its life. Other unsealed bearings such as double row tapered roller bearings must be lubricated with grease during installation. It is difficult to determine the amount of grease to be added due to the different sizes of the inner cavities of the bearings. The most important thing is to ensure that there is grease in the bearings. If there is too much grease, the excess grease will leak out when the bearings rotate. General experience: during installation, the total amount of grease should account for 50% of the bearing clearance.
10) When installing the lock nut, the torque varies greatly due to different bearing types and bearing seats.
4. Maintenance attention
In the maintenance process, it is often found that some vehicles make loud driving noise. Check the tires for abnormal wear, and turn the wheels on the lift without obvious abnormal noise. This phenomenon is often caused by abnormal damage of the hub bearing, which refers to the bearing damage caused by installation. The front wheel bearing of an automobile is usually a double row ball bearing. If a hammer is used to knock the bearing when installing it, or if the bearing is installed by pressing the inner ring of the bearing when installing it into the bearing seat, the bearing raceway on one side will be damaged. Noise is generated when the vehicle is running, and no obvious noise can be heard when the wheel is off the ground because there is a good side of the raceway. The correct installation operation is the key to the long service life of the bearing.
Clutch release bearing
1. Function of clutch release bearing
The clutch release bearing is installed between the clutch and the transmission. The release bearing seat is loosely sleeved on the tubular extension of the first shaft bearing cover of the transmission. The shoulder of the release bearing is always against the release fork through the return spring, and the release bearing is retracted to the last position to maintain a clearance of about 3~4mm with the end of the release lever (release finger).
Since the clutch pressure plate and release lever operate synchronously with the engine crankshaft, while the release fork can only move axially along the clutch output shaft, it is obviously not possible to directly use the release fork to shift the release lever. The release bearing allows the release lever to rotate while moving axially along the clutch output shaft, thus ensuring smooth clutch engagement, soft separation, reducing wear, and extending the service life of the clutch and the entire transmission system.
2. Working condition of clutch release bearing
In the process of use, it is subject to axial load, impact load and radial centrifugal force during high-speed rotation. In addition, because the counter force of the fork thrust release lever is not in the same straight line, it also forms a torsional moment. The working conditions of the clutch release bearing are poor. It rotates at high speed intermittently and bears high speed friction. The temperature is high, the lubrication condition is poor, and there is no cooling condition.
3. Clutch release bearing unit tolerance
1) The single inner diameter deviation of bearing unit shall comply with the provisions in Table 3-2. 2) The single straight diameter deviation △ D1S of the contact circle is ± 0.5mm. 3) The single diameter deviation △ D2S of the connecting groove is: upper limit: 0 mm, lower limit: -0.30 mm. 4) The actual fitting deviation △ HS with the sorting fork is: upper limit: 0 mm, lower limit: -0.30 mm. 5) In case of no axial load, the actual fitting width deviation △ TOS of bearing unit: ± 0.5 mm for push bearing unit and ± 0.8 mm for pull bearing unit.
4. Failure mode of clutch release bearing
The failure forms of clutch release bearing mainly include: loose sleeve of release bearing, scattered release steel balls of bearing inner and outer rings, wavy (concave and convex) wear of release bearing ball head surface, abnormal noise of release bearing, and stuck release bearing.
3. Other special bearings
Other special bearings for automobiles mainly include tensioner bearings, water pump shaft bearings, steering shaft bearings and steering gear bearings in some steering systems, and some bearings in manual transmissions and final reducers.
Improvement of performance and service life
Generally speaking, the improvement of the performance and service life of automobile bearings includes the reasonable selection and modification of general bearings? And the expansion of structure and function.
Rational Selection of Universal Bearings
The diversification of universal bearing design provides a wide space for the selection of automobile bearings. It is often the key to improve the performance and life of automobile bearings to select the most appropriate bearing from a large number of universal bearings in terms of structure, clearance, accuracy, size and performance.
1. Improvement of Universal Bearing
In order to adapt to the special environment and special requirements of automotive applications, the internal structure and materials of general bearings have been improved to improve the performance and life of automotive bearings. These improvements include the improvement of bearing structure parameters, raceway and rolling body profiles, cage structure and materials, sealing structure and materials, and lubricating grease, etc. in order to improve the bearing capacity, eliminate or reduce stress concentration, reduce volume, reduce friction and wear, and improve high-speed and high-temperature performance.
2. Expansion of structure and function of universal bearing
The bearing and its adjacent parts in the automobile are considered as a whole or system, and the optimization of the overall structure performance and life is realized through the expansion of the structure and function of the general bearing. The automobile special bearing developed from this not only improves the performance and life of the bearing itself, but also improves the performance and life of the automobile parts or assemblies including the bearing. At the same time, it can simplify automobile design, assembly, maintenance and reduce the cost of automobile parts. In the future, automobile bearings will continue to develop along the above main directions, so as to meet the development requirements of automobile design diversification and performance and life improvement.
Automobile engine bearing
Automobile engine bearings generally refer to the bearings used on the automobile engine itself and its accessories: namely, the bearings used in the crank linkage, valve train, fuel system, lubrication system, cooling system and ignition system. This section introduces generator bearings, water pump bearings, ventilator bearings, drive belt tensioner bearings and supercharger bearings that are commonly used in the above mechanisms or systems.
Generator bearing
（1） Classification
There are two kinds of generators in automobile ignition system: parallel excited DC generator and semiconductor rectifier generator.
Among them, the alternator is developing rapidly due to its strong generating capacity, large speed range, compact structure, reliable operation and long service life. For generator bearings, adapting to this development means that it is necessary to improve the bearing capacity, limit speed, rotation accuracy, lubrication and sealing performance and noise performance.
（2） Design analysis
The use of generator bearing in semiconductor rectifier alternator is shown in the figure below:
Generator bearings are generally deep groove ball bearings and deep groove ball bearings with dust-proof or sealing structure. Double row ball bearings, cylindrical roller bearings or bearings of other structural types are sometimes used at the pulley side with large stress. The selection of generator bearing shall first consider that the calculated life meets the requirements, and then consider the problems of limiting speed, sealing, lubrication, noise and clearance.
1. Limiting speed
The limit speed listed in the bearing sample is the limit speed under standard conditions. When selecting bearings, they should be corrected according to the actual use conditions. When the correction value is lower than the operating speed, another bearing shall be selected or high-speed design shall be carried out.
2. Sealing
High speed and sealing are two contradictory characteristics of generator bearing seal design. The light contact high-speed rotating seal ring has good torque, temperature rise, dust prevention and grease sealing performance, but its mud and water prevention performance is poor; However, the contact type seal ring with sealing property as the main part will generate excessive temperature rise. Therefore, the sealing design of generator bearing must take into account the two contradictory characteristics of high speed and sealing. In order to give consideration to the sealing performance and high-speed performance, a good sealing design is to add an oil slinger outside the light contact seal ring, and form a labyrinth seal by the light contact seal ring and the oil slinger, so as to effectively prevent muddy water from entering the dual sealing structure. The basic structure of this design is shown in the figure below:
The outer sealing ring is composed of oil slinger and light contact sealing lip, and forms a labyrinth seal with the outer ring and inner sealing ring. At high speed and low speed, the labyrinth seal and light contact sealing lip respectively prevent mud and water from entering, thus achieving excellent sealing performance in the whole speed range from low speed to high speed.
3. Lubrication
The selection of engine bearing grease is generally considered from the aspects of adapting to high speed, high temperature resistance, good low temperature starting performance and low noise.
The high-speed adaptability of the lubricating grease can be determined from the table by calculating the Ka Dm N value of the bearing.
Due to the need of low noise, the lubricating grease of generator bearing shall not be too thick to improve the damping effect of lubricating grease on rolling body vibration, and prevent noise and starting torque from increasing due to dry friction at low temperature.
Based on the above reasons and considering the high temperature resistance and waterproof performance, the compound calcium base grease is generally used for the lubrication of generator bearings.
The filling amount of bearing lubricating grease can be determined according to the ratio between the limit speed of grease lubrication and the actual working speed.
Breather bearing
（1） Role
In order to keep the engine at the optimal working temperature and reduce power consumption as much as possible, modern engines generally use adjustable ventilators. When the driving airflow and radiation heat dissipation are sufficient to ensure that the optimal working temperature is not exceeded, the ventilators are in the stop state, and when the optimal working temperature is exceeded, the ventilators enter the working state.
This intermittent working ventilator has a variety of transmission structures, and different structures of ventilators have different requirements for bearings. But when directly installed in the ventilator impeller, the biggest problem faced by the bearing is to bear a large load and may be 150-230 ℃ high temperature.
Therefore, in the automobile ventilator, the lubrication and sealing of the bearing must be considered first, and then the proper fit between the bearing outer ring and the light metal shell should be ensured even at a high working temperature. In addition, the bearing shall be able to support? High torque load caused by imbalance of ventilator and accurate guidance shall be conducted, and friction torque shall be reduced as far as possible to save energy and reduce noise.
（2） Design analysis
Common ventilators use silicon oil clutch or electromagnetic clutch to control the cooling fan, so as to use silicon oil clutch to control the cooling fan? The ventilator bearing is analyzed as an example. In the ventilator with silicone oil clutch, the pump wheel of the clutch is driven by the engine, the turbine is fixedly connected with the fan, and the bearing is installed between the pump wheel shaft and the turbine housing. The pump wheel transmits torque to the turbine through silicon oil. The bimetallic temperature sensing element directly installed at the back of the radiator controls the flow of silicon oil into and out of the pump wheel and turbine working chamber. The fan speed is automatically adjusted according to the engine temperature to control the engine temperature.
1. Deep groove ball bearing
Deep groove ball bearing is the most common type of rolling bearing. This type of deep groove ball bearing is composed of an outer ring, an inner ring, a group of steel balls and a group of retainers. There are two types of deep groove ball bearings: single row and double row. The deep groove ball structure is also divided into sealed and open structures. The open type means that the bearing does not have a seal structure. The sealed deep groove ball is divided into dust seal and oil seal. The dust seal cover is made of steel plate, which can simply prevent dust from entering the bearing raceway. The oil proof type is contact oil seal, which can effectively prevent the overflow of lubricating grease in the bearing.
The type code of single row deep groove ball bearing is 6, and the code of double row deep groove ball bearing is 4. Its structure is simple, easy to use, is the most common production, the most widely used type of bearing.
2. Duplex bearing
Heavier ventilators require wider support seats and corresponding double row angular contact ball bearings or deep groove ball bearings installed in pairs. The utility model relates to a supporting structure of a car ventilator with two sets of deep groove ball bearings.
3. Needle bearing
If there is enough space, two sets of deep groove ball bearings can also be used to support the whole ventilator assembly, while a set of pressed outer ring needle roller bearings can be used to support the turbine and fan on the pump wheel shaft. Two sets of grease lubricated and sealed deep groove ball bearings are used to position the ventilator assembly - floating support. Only one set of needle bearing with stamped outer ring directly installed in the ventilator is under high temperature, so the lubrication, sealing and matching of needle bearing must be designed accordingly.
Tensioner wheel bearing
（1） Concept
With the popularization and application of high camshaft and overhead camshaft in modern automobile engines, synchronous chain drive and gear drive of camshaft have gradually been replaced by tooth belt drive. At the same time, the transmission of the fuel injection pump of the automobile diesel engine also adopts the synchronous toothed belt. In order to facilitate the installation and adjustment of the synchronous toothed belt, the tensioning pulley is generally used at the loose edge of the toothed belt. In the more complex toothed belt drive, the fixed idler gear is often used at the tight edge of the toothed belt to increase the wrap angle of the drive gear or change the position of the toothed belt.
（2） Design analysis
1. Tensioner wheel installed on base plate
The tensioning wheel with seat plate has two typical designs. The seat plate is fixed by a bolt through the swing tensioning belt of the seat plate; It is fixed by the swing tension belt of the base plate, but by the bolt passing through the bearing inner hole. The rolling bearings used in the above two designs are double row radial sealed ball bearings. Single row radial sealed ball bearings are often used in the tensioning wheels installed on the base plate.
2. Eccentric tensioner
The eccentric tensioner is used to tension the belt by swinging around the eccentric hole in the support pin, and the support pin is fixed by a double headed stud and a nut passing through the eccentric hole.
3. Lightweight design
The most noticeable development of the above tensioning wheels is the so-called lightweight design. The development of lightweight design has greatly reduced the quality of the tensioning wheel, and also effectively reduced the manufacturing cost of the tensioning wheel.
4. Tensioner action
The tensioning pulley is used to adjust the tightness of the timing belt, maintain the belt tension, avoid belt slipping, and compensate for the elongation caused by belt wear and aging. Adjust and compensate the deviation of the center distance of the engine system caused by the machining error of the shaft and the positioning hole. To a certain extent, it can eliminate the abnormal noise caused by the elongation or swing of the belt during the operation of the engine set. Restrain the vibration of the transmission system.
5. Working principle of tensioning wheel
When the engine system is unloaded, the belt against which the tensioning pulley is fastened will become loose under the condition of poor tension, that is, the tensioning pulley needs to swing rapidly counterclockwise along its own central axis under the effect of the torsion of the torsion spring to make up for the decrease of the tension on the belt; On the contrary, when the crankshaft is in loading motion, the belt against which the tensioning pulley is fastened will be further tightened. At this time, the pulley needs to rotate and swing along its own central axis. At the same time, the kinetic energy of the belt system will be converted into the elastic energy of the torsion spring and stored in the torsion spring for use during unloading. In order to maintain proper belt tension, avoid belt slipping, compensate for belt wear and elongation caused by aging, a certain torque is required for the tensioning pulley during actual use. When the belt tensioner pulley is running, the moving belt may cause vibration in the tensioner pulley, which will cause premature wear of the belt and tensioner pulley. To this end, add a resistance mechanism to the tensioner. However, because there are many parameters that affect the torque and resistance of the tensioning wheel, and the influence of each parameter is different, the relationship between the components of the tensioning wheel and the torque and resistance is very complex. The change of torque directly affects the change of resistance, and is the main influencing factor of resistance. The main factor affecting torque is the parameters of torsion spring. The resistance value of the tension pulley can be increased by appropriately reducing the pitch diameter of the torsion spring.
Bearing with seat
The rolling bearing with seat is a high-precision component product composed of grease sealed rolling bearing and bearing seat of various shapes. The rolling bearing with seat can be directly installed on the main body of the mechanical device through several bolts. It has automatic centering performance and can supplement lubricating grease. It is a very simple product for installation and use.
The pedestal rolling bearing is composed of a ball bearing with a spherical outer diameter surface assembly and a bearing pedestal with a spherical inner hole.
Features of bearing with seat:
1) With automatic heart adjustment function
The outer diameter of the outer spherical bearing and the inner diameter of the bearing seat are spherical, and the two have the automatic centering function, which can compensate for the misalignment of the axis and the deformation of the installation bottom caused by the installation error.
2) Large load capacity
As the internal structure of the outer spherical ball bearing is the same as that of the 6200 and 6300 series deep groove ball bearings, the IB seated outer spherical ball bearing can not only withstand the radial load, but also? Capable of withstanding large axial load. At the same time, the working noise of the bearing is low.
3) Long service life
The spherical ball bearing with seat is usually used in harsh working environment such as soil, dust, humidity and high temperature. The lubricating grease inside the bearing will deteriorate in a short time. Therefore, it is necessary to regrease the spherical ball bearing with seat within an appropriate time interval, and replace the deteriorated grease with fresh grease. IB cast iron spherical ball bearings are equipped with grease fittings, which can be re lubricated to ensure perfect performance and long service life in any working environment.
4) Excellent sealing performance
Both sides of the outer spherical ball bearing are equipped with heat resistant and oil proof rubber seals and steel dust cover combined seals. The dust cover is assembled on the outer diameter of the bearing inner ring and rotates with the inner ring, which can effectively prevent external foreign matters from entering the bearing and protect the bearing against external pressure. This combined seal consisting of the seal ring and dust cover can prevent dirt, dust and moisture from entering the bearing and prevent the leakage of lubricating grease inside the bearing. The bearing can also maintain perfect working performance under harsh working conditions.
5) Robust bearing pedestal
The cast iron seat is an integral seat structure, and the bearing seat is extremely rigid to prevent deformation of the bearing during assembly. The bearing seat is durable under any working conditions.
6) The bearing can be locked on the shaft easily
There are three ways to lock the bearing on the shaft. The common way is to lock two set screws on the extended end of the inner ring, or use a set sleeve or eccentric sleeve to lock. These three methods can easily lock the bearing on the shaft.
7) Special heat treatment for bearing inner race
The inner ring groove and its surrounding parts that need to be hardened are subject to normal quenching. The elongation end of the inner ring for assembling the set screw is subject to high temperature local tempering to maintain toughness and impact resistance. After local high temperature tempering around the screw hole of the inner ring, the bearing can obtain better performance, which can prevent the screw from loosening during the operation of the bearing. At the same time, if the screw is tightened tightly, the inner ring will not burst.
8) Unique design to prevent the outer ring from rotating
The outer ring of the bearing is equipped with a unique stop pin (ball), which allows the bearing to adjust its center automatically, and prevents the outer ring from rotating, so that the service life of the bearing is longer.
9) The bearing and bearing seat can be completely interchanged
The bearing and bearing seat are precision machined, and the bearing and bearing seat can be completely interchanged, so that the bearing can be easily replaced at any time.
10) Easy to install
Enough high-quality lubricating grease has been injected into the spherical ball bearing in advance, and the spherical ball bearing with seat can be directly installed on the shaft. Thus, harmful substances can be prevented from entering the bearing interior during the installation of the bearing unit.
More about UNIM Gearbox Bearing:
Transmission or gearbox are widely applied in Mechanical Transmission, wind turbines, and also used in agricultural, industrial, construction, mining and automotive equipments. WD high precision deep groove ball bearings, angular contact ball bearings, cylindrical roller bearings and some customized bearings for gearboxes are high speed, low noise and long life.
UNIM has over ten-year experience in making conventional bearings, precise bearings and non-standard bearings. UNIM also produces and exports bearing parts (roller, ball, seal, ring and so on), chain, sprocket, pulley and such other machinery parts.
Following strict quality control system, all the members of UNIM are strictly implementing ISO 9001, 14001, and relevant industry quality standard system and environment protection. We distinguish ourselves by: Abundant experience; special facilities and instruments as well as the inspection methods; strict procedure of purchasing the raw material.
In order to make the better support for our customers to produce and develop their products and to expand their market, we try best to improve ourselves on the company management, product design and staff training.
2022-12-18
