The use of bearings in the car is very extensive and has taken on a tense role. Bearings are used from the engine, the chassis, and the electrical assembly. Automotive bearings are divided into two categories: plain bearings and rotary bearings.
Sliding bearings are important for use on the engine. Sliding bearings are generally divided into two types, one is a lining type thin-walled bearing, which is similar to a tile commonly known as a bearing bush; the other is a bushing, also known as a copper sleeve, which is in the shape of a hollow cylinder. The lining type thin-walled bearings are important for supporting the crankshaft and connecting rods. Bushings are important for supporting camshaft journals and piston pins, but are also used in the rest of the car, such as the steering knuckle kingpin bushings, suspension steel pin bushings, gear bushings, and electromechanical bushings. Reduce the effects of the center body.
Crankshafts and connecting rod bearings look like tiled singles, but their performance requirements are high. Although there is a smooth system of smooth oil to separate the parts from the bearing surface, but compared with the year, the engine continues to grow at high speed and pressure, the oil film pressure of the bearing increases, the thickness of the oil film is reduced, and the environment of the bearing is improved. Requests for materials and fabrication of crankshaft and connecting rod bearings are also increasing. Generally, the bearing adopts the double-layer metal situation, and some of them are multi-layered. The first layer is the steel tile back to cover the machine strength, and the second layer is the bearing alloy to cover the general situation. It is often used as a kind of babbitt alloy. The third layer is further plated with an extremely thin alloy on the base of the above two layers to further improve the general function.
Compared with the bearing bush, the camshaft bushing has less stress than the force. Its material is usually plated with bronze or steel backing. The bushing of this material is also used in the kingpin, brake shoe, door hinge, Peaceful belts and other places. The bushing materials used in automobiles are more powerful, such as the oil-containing metal bushings for the idea head and the electric fan, the bushings made of the polymeric material on the shock-absorbing steel plate pin and the wiper, and the like.
Rotating bearings are used throughout the various machines and electrical assemblies used in automobiles. Important are transmissions, steering gears, pumps, fans, clutches, differentials, front and rear wheels and drive shafts.
The rotating bearing has two kinds of spherical and roller bearings. It is divided into radial bearing and thrust bearing according to the size of the load and the target. The radial bearing should be subjected to the radial (reccentric to the axial line) load, and the thrust bearing should be properly withstood. Axial (parallel to the axis) load, and a radial thrust bearing that is simultaneously subjected to radial and axial forces. In fact, almost all of the rotating bearings can now be subjected to both radial and lateral loads under certain conditions, but only on the one hand and the two. The rotary bearing is mainly divided into a ball bearing, a roller bearing and a needle bearing, and is divided into various parts of the automobile according to the influence difference.
The drive shaft of the transmission is usually supported at both ends. Because the transmission shaft has a longer specific force, it is planned to take the bearing on one side as the solid side bearing. It is subjected to both radial and axial loads, which plays a role in the relative axial displacement between the shaft and the gearbox. Adopt centripetal thrust ball bearings. The bearing on the other side is called a free-side bearing, and it is only subjected to radial load, and the axial direction can be relatively moved to handle the problem of the expansion and contraction of the shaft due to temperature change during the operation of the transmission gear and the deviation occurring during the installation. Column bearing.
The bearing ring and rotating element of the rotating bearing are generally made of high-purity special chrome alloy steel, and the hardness is quite high. However, if it is not smooth, improperly selected, or improperly placed, it may cause obstruction. However, even if the bearing is used under the premise of deformity, the rotating surface of the external component will cause embarrassment under the influence of the alternating compressive stress, so that the peeling is impossible to use, and the bearing has its life limit. The material supplied by NTN in Japan, even if it is a group of identical bearings operating under the same premise, its life span is also very different, which is because the material euphemism itself has "separability." Therefore, the nominal life of the so-called rotating bearing is a total number of revolutions or total torsion time when 90% (reliable 90%) does not produce a rotational euphemistic peeling when a set of identical bearings are fed in the same premise. The bearing seems to be a pivot point, and its quality is directly related to the running quality of the car. However, it is difficult to ensure that each bearing is completely above the uniform quality scale in the production of a large number of bearings. Some new vehicles will exhibit such types or obstacles early in the process of use. Timely lubrication is extremely important for the performance of the bearing. Because the lubricant or lubrication method is correct or not, it will greatly affect the life of the bearing.
The main effects of lubrication on the performance of the bearing are as follows:
1. Lubricate the various parts of the bearing to reduce the friction and wear of the bearing;
2. The heat generated by friction or other reasons inside the bearing is removed by lubrication;
3. The rolling contact surface of the bearing often forms an appropriate oil film to prolong the fatigue life of the bearing;
4, through the lubrication can achieve the role of anti-rust and dustproof bearings.
The lubrication method of the bearing is mainly divided into two ways: grease lubrication and oil lubrication.
Grease lubrication can be used after filling the grease for a long time without replenishing, and the structure of the sealing device is relatively simple, so it is widely used. Grease lubrication has a sealing method in which the sealed bearing is filled with grease in advance, and a filling and fat filling method in which the inside of the outer casing is filled with an appropriate amount of grease and replenished or replaced at intervals. In addition, for machines with multiple bearings that require lubrication, a centralized grease supply method that connects the pipes to each lubrication location is also used.
In short, it is necessary to lubricate the bearings in time, which will increase their service life.
2018年9月29日星期六
State detection and fault diagnosis of rolling bearings
Rolling bearings are important parts of rotating machinery. Statistics show that in rotating machinery using rolling bearings, about 30% of mechanical failures are caused by rolling bearings. With state detection and fault diagnosis technology, the accident rate can be reduced by 75% and maintenance costs can be reduced by 25% to 50%.
First, the failure form of rolling bearings
(1) Fatigue spalling
The inner and outer raceways and rolling elements of the rolling bearing alternately enter and exit the bearing area. These components are subjected to the alternating load for a long time, firstly generating fatigue cracks from the maximum alternating shear stress below the contact surface, and then expanding to the contact surface to produce on the surface layer. Peeling off, gradually develop into large pieces of peeling, called fatigue spalling.
(two) wear
Due to the relative motion of the raceway and the rolling elements and the surface wear caused by dust foreign matter, poor lubrication will aggravate the wear, resulting in increased bearing clearance, increased surface roughness, reduced bearing running accuracy, and thus reduced machine motion accuracy. It is manifested by an increase in vibration level and noise.
(three) bruises
Due to the microscopic bumps or hard particles on the contact surfaces of the inner and outer races of the bearing and the rolling elements, the contact surface is unevenly stressed. Under the poor lubrication and high-speed heavy-load conditions, the contact surface is locally deformed due to the heat generated by the local friction. Friction welding, the surface metal may be partially melted in severe cases, and the force on the contact surface tears the local friction welding point from the substrate.
(4) Breaking
When the load and vibration of the bearing are too large, the defect position of the inner and outer rings is gradually expanded and fractured under the repeated impact of the rolling elements.
(5) Corrosion
Moisture or direct intrusion of acid or alkaline substances can cause bearing corrosion. When a shaft current passes inside the bearing, an electric spark is generated at the contact point of the raceway and the rolling element to cause electric corrosion, and a seesaw-like unevenness is formed on the surface.
Second, the failure process of rolling bearings
Bearing failure is usually divided into four phases:
(1) The first stage: the ultrasonic frequency vibration phase of the bearing
The earliest fault of the bearing is the vibration anomaly of the ultrasonic frequency in the range of 250 kHz to 350 kHz. As the fault develops, the abnormal frequency gradually decreases to 20 kHz to 60 kHz. At this time, the minor fault of the bearing can be impacted by the envelope and the acoustic emission. The method detects that the impact envelope value can be up to 0.5gE (acceleration envelope, an acceleration index indicating the amplitude in the vibration analysis).
(2) The second stage: the natural frequency vibration phase of the bearing
As the bearing operates, the bearing rolling surface will produce slight defects. The vibration caused by these slight defects will arouse the natural frequency (fn) vibration of the bearing component or the resonance of the bearing support structure. The vibration frequency is generally 500 Hz to 2 kHz. At the same time, the frequency is also used as the carrier frequency to modulate the fault frequency of the bearing. At first, this frequency can only be observed, and the latter appears as a side frequency near the natural frequency. If the acceleration envelope method is used, it will find that the envelope value will rise to about 0.5 to 1.OgE. At this point, the bearings are still safe to operate.
(III) The third stage: bearing defect frequency and its frequency doubling vibration stage
With the further expansion of the bearing minor defects, the bearing defect frequency and its frequency multiplication begin to appear. As the bearing wear progresses further, the frequency multiplication of more defect frequencies begins to appear, and the number of sidebands surrounding these frequency doublings and the natural frequency of the bearing components It is also gradually rising. At this time, the vibration of the bearing is already obvious, and it should be considered to replace the bearing as soon as possible.
(four) the fourth stage: the random broadband vibration phase of the bearing
The bearing is almost completely ineffective, the life of the bearing is nearing the end, and even the power frequency is affected by it and rises and produces many power frequency multiples. The original discrete bearing defect frequency and natural frequency begin to "disappear" and are replaced by random Broadband high-frequency "noise vibration", high-frequency noise vibration and envelope value have decreased, but the envelope impact value will increase significantly before the final failure of the bearing.
First, the failure form of rolling bearings
(1) Fatigue spalling
The inner and outer raceways and rolling elements of the rolling bearing alternately enter and exit the bearing area. These components are subjected to the alternating load for a long time, firstly generating fatigue cracks from the maximum alternating shear stress below the contact surface, and then expanding to the contact surface to produce on the surface layer. Peeling off, gradually develop into large pieces of peeling, called fatigue spalling.
(two) wear
Due to the relative motion of the raceway and the rolling elements and the surface wear caused by dust foreign matter, poor lubrication will aggravate the wear, resulting in increased bearing clearance, increased surface roughness, reduced bearing running accuracy, and thus reduced machine motion accuracy. It is manifested by an increase in vibration level and noise.
(three) bruises
Due to the microscopic bumps or hard particles on the contact surfaces of the inner and outer races of the bearing and the rolling elements, the contact surface is unevenly stressed. Under the poor lubrication and high-speed heavy-load conditions, the contact surface is locally deformed due to the heat generated by the local friction. Friction welding, the surface metal may be partially melted in severe cases, and the force on the contact surface tears the local friction welding point from the substrate.
(4) Breaking
When the load and vibration of the bearing are too large, the defect position of the inner and outer rings is gradually expanded and fractured under the repeated impact of the rolling elements.
(5) Corrosion
Moisture or direct intrusion of acid or alkaline substances can cause bearing corrosion. When a shaft current passes inside the bearing, an electric spark is generated at the contact point of the raceway and the rolling element to cause electric corrosion, and a seesaw-like unevenness is formed on the surface.
Second, the failure process of rolling bearings
Bearing failure is usually divided into four phases:
(1) The first stage: the ultrasonic frequency vibration phase of the bearing
The earliest fault of the bearing is the vibration anomaly of the ultrasonic frequency in the range of 250 kHz to 350 kHz. As the fault develops, the abnormal frequency gradually decreases to 20 kHz to 60 kHz. At this time, the minor fault of the bearing can be impacted by the envelope and the acoustic emission. The method detects that the impact envelope value can be up to 0.5gE (acceleration envelope, an acceleration index indicating the amplitude in the vibration analysis).
(2) The second stage: the natural frequency vibration phase of the bearing
As the bearing operates, the bearing rolling surface will produce slight defects. The vibration caused by these slight defects will arouse the natural frequency (fn) vibration of the bearing component or the resonance of the bearing support structure. The vibration frequency is generally 500 Hz to 2 kHz. At the same time, the frequency is also used as the carrier frequency to modulate the fault frequency of the bearing. At first, this frequency can only be observed, and the latter appears as a side frequency near the natural frequency. If the acceleration envelope method is used, it will find that the envelope value will rise to about 0.5 to 1.OgE. At this point, the bearings are still safe to operate.
(III) The third stage: bearing defect frequency and its frequency doubling vibration stage
With the further expansion of the bearing minor defects, the bearing defect frequency and its frequency multiplication begin to appear. As the bearing wear progresses further, the frequency multiplication of more defect frequencies begins to appear, and the number of sidebands surrounding these frequency doublings and the natural frequency of the bearing components It is also gradually rising. At this time, the vibration of the bearing is already obvious, and it should be considered to replace the bearing as soon as possible.
(four) the fourth stage: the random broadband vibration phase of the bearing
The bearing is almost completely ineffective, the life of the bearing is nearing the end, and even the power frequency is affected by it and rises and produces many power frequency multiples. The original discrete bearing defect frequency and natural frequency begin to "disappear" and are replaced by random Broadband high-frequency "noise vibration", high-frequency noise vibration and envelope value have decreased, but the envelope impact value will increase significantly before the final failure of the bearing.
2018年9月27日星期四
Microcomputer bearing heater installation precautions
First, before ordering such a device, remember to pay more attention to whether it is a water-fired heater or a dry-burning heater, so as to better avoid the unit area because of the high heat load, and thus the electric heating tube is damaged. The phenomenon.
Second, the part of the heater wiring must be exposed outside the insulation layer so that the line will not be damaged during the heating process.
Third, after the installation is completed, remember that during the operation process, the power supply voltage of the working environment and other issues cannot exceed 10% of the rated voltage of the microcomputer bearing heater device, otherwise it is prone to problems such as safety accidents. The problem of the power supply voltage and the like cannot be lower than the rated voltage, otherwise the heat generated by the electric heating tube may gradually decrease.
Fourth, to install such a device, it is necessary to pay attention to the regular cleaning and maintenance of the terminal of the electric heating pipe to ensure that the terminal is dry and clean, otherwise the heating device may have a problem of failure or short circuit or breakdown.
Fifth, the micro-computer bearing heater products provided by professional and regular manufacturers are generally equipped with special parts, etc. At this time, we must check whether the parts are sufficient or whether there is serious wear and so on.
Sixth, if the components of such devices are not installed or replaced for a long time, they must be placed in a dry and ventilated environment. In addition, such components must be taken in a professional oven if the insulation resistance is lower than the specified range. Effective drying measures ensure that the insulation resistance can be restored to the specified standards.
Nowadays, more and more business users have started to use the microcomputer bearing heater device. I hope that through the above brief introduction, we can help you understand the correct installation method of the microcomputer bearing heater, so as to make correct operation during the later use and installation process. To make the device perform at its best. Choosing a product from a professional and regular manufacturer can bring about a safe heating process. I hope that through the above brief introduction, we can help you better understand the correct installation method for the microcomputer bearing heater.
Second, the part of the heater wiring must be exposed outside the insulation layer so that the line will not be damaged during the heating process.
Third, after the installation is completed, remember that during the operation process, the power supply voltage of the working environment and other issues cannot exceed 10% of the rated voltage of the microcomputer bearing heater device, otherwise it is prone to problems such as safety accidents. The problem of the power supply voltage and the like cannot be lower than the rated voltage, otherwise the heat generated by the electric heating tube may gradually decrease.
Fourth, to install such a device, it is necessary to pay attention to the regular cleaning and maintenance of the terminal of the electric heating pipe to ensure that the terminal is dry and clean, otherwise the heating device may have a problem of failure or short circuit or breakdown.
Fifth, the micro-computer bearing heater products provided by professional and regular manufacturers are generally equipped with special parts, etc. At this time, we must check whether the parts are sufficient or whether there is serious wear and so on.
Sixth, if the components of such devices are not installed or replaced for a long time, they must be placed in a dry and ventilated environment. In addition, such components must be taken in a professional oven if the insulation resistance is lower than the specified range. Effective drying measures ensure that the insulation resistance can be restored to the specified standards.
Nowadays, more and more business users have started to use the microcomputer bearing heater device. I hope that through the above brief introduction, we can help you understand the correct installation method of the microcomputer bearing heater, so as to make correct operation during the later use and installation process. To make the device perform at its best. Choosing a product from a professional and regular manufacturer can bring about a safe heating process. I hope that through the above brief introduction, we can help you better understand the correct installation method for the microcomputer bearing heater.
The advantages of micro-lubrication technology for machining crankshaft oil holes
The micro-lubrication technology is a lubrication method that uses compressed air as a power to atomize a small amount of lubricating oil into micron-sized suspended oil particles and transport the suspended oil particles to the cutting area. Contrary to the traditional spray lubrication method that uses a large amount of cutting fluid or cutting oil, it only provides spray lubrication cooling during cutting, so there is less lubricant left on the chips and the workpiece, and lubrication remaining in the splash mode. The oil is very small compared to the oil. The production plant uses the micro-lubrication technology to process the crankshaft oil hole, which can improve the production efficiency and lead the development of the micro-lubrication technology to adapt to changes in market demand.
The micro-lubrication technology can bring good economic and environmental benefits, because in the crankshaft oil hole processing, only a small amount of lubricating oil is needed to achieve a good lubrication effect, so that the factory can obtain considerable after using the micro-lubrication technology. Economic benefits. The crankshaft machining center efficiently transports the oil mist to the cutting area through the main shaft and the inner cooling drill. The control system of the machine tool is connected with the micro-lubrication device, and the lubrication is automatically adjusted according to the requirements of the processing technology by changing the opening frequency of the ball valve and the size of the inner hole passage of the drill bit. The amount of oil mist delivered.
The advantages of micro-lubrication technology for machining crankshaft oil holes are as follows:
(1) Oil mist can penetrate into the friction point to achieve good lubrication;
(2) In deep hole machining, the compressed air flow rate can take away the cutting heat, and a large amount of cutting heat is carried away with the chips.
(3) The fuel consumption is low, and the cutting friction point always maintains an appropriate amount of reliable lubrication;
(4) The product is small in size, low in gas source consumption, and easy to operate;
(5) Reduce the maintenance cost and operating cost of the machine tool.
The micro-lubrication technology can bring good economic and environmental benefits, because in the crankshaft oil hole processing, only a small amount of lubricating oil is needed to achieve a good lubrication effect, so that the factory can obtain considerable after using the micro-lubrication technology. Economic benefits. The crankshaft machining center efficiently transports the oil mist to the cutting area through the main shaft and the inner cooling drill. The control system of the machine tool is connected with the micro-lubrication device, and the lubrication is automatically adjusted according to the requirements of the processing technology by changing the opening frequency of the ball valve and the size of the inner hole passage of the drill bit. The amount of oil mist delivered.
The advantages of micro-lubrication technology for machining crankshaft oil holes are as follows:
(1) Oil mist can penetrate into the friction point to achieve good lubrication;
(2) In deep hole machining, the compressed air flow rate can take away the cutting heat, and a large amount of cutting heat is carried away with the chips.
(3) The fuel consumption is low, and the cutting friction point always maintains an appropriate amount of reliable lubrication;
(4) The product is small in size, low in gas source consumption, and easy to operate;
(5) Reduce the maintenance cost and operating cost of the machine tool.
2018年9月26日星期三
ZRB75X125 Cylindrical rollers
| Diameter | ||
| Length | ||
| Chamfer dimension |
| Mass, 1000 pieces |
ZRB75X155 Cylindrical rollers
| Diameter | ||
| Length | ||
| Chamfer dimension |
| Mass, 1000 pieces |
ZRB75X80 Cylindrical rollers
| Diameter | ||
| Length | ||
| Chamfer dimension |
| Mass, 1000 pieces |
ZRB7X10 Cylindrical rollers
| Diameter | ||
| Length | ||
| Chamfer dimension |
| Mass, 1000 pieces |
2018年9月25日星期二
ZRB80X90 Cylindrical rollers
| Diameter | ||
| Length | ||
| Chamfer dimension |
| Mass, 1000 pieces |
ZRB8X9 Cylindrical rollers
| Diameter | ||
| Length | ||
| Chamfer dimension |
| Mass, 1000 pieces |
ZSL192320-TB-XL Cylindrical roller bearings
| Axial displacement |
ZSL192320-TB-XL Cylindrical roller bearings
| Axial displacement |
2018年9月18日星期二
QJ205-XL-MPA Four point contact bearings
QJ205-XL-MPA
Four point contact bearings
main dimensions to DIN 628-4, separable, with split inner ring
Four point contact bearings
main dimensions to DIN 628-4, separable, with split inner ring
| Contact angle |
| Mass | ||
| Basic dynamic load rating, radial | ||
| Basic static load rating, radial | ||
| Fatigue limit load, radial | ||
| Limiting speed | ||
| Reference speed |
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