The latest centralized automatic lubrication techn

2022-08-24
  • Detail

New technology of centralized automatic lubrication of vehicles

1 overview

since the foreign commercial vehicle chassis centralized lubrication products entered China in the 1990s, because it replaced the manual centralized lubrication to realize the automatic greasing of dozens of friction pairs on vehicles, it has set off a revolution in vehicle grease lubrication technology in China, and domestic manufacturers began to enter this field. The Ministry of construction and the Ministry of transportation issued standards to support it, Promote the application of this technology in passenger cars

most of the vehicle centralized lubrication products configured in batches on the market at present are imported German technology, which is similar to the structural performance and function of German products configured in a small amount by some domestic passenger car factories. There have been few substantial improvements in recent years, and some problems have also been exposed in use, mainly manifested in:

1) the controller program is backward, which is manifested in the long running time of system lubrication, It is easy to cause excessive oiling and early damage of motor and gear pump; The automatic fault detection function is not perfect, and it is not easy to be found in time when the product is working with a problem, and the expected lubrication effect cannot be achieved

2) the applicable grease is too thin. In the low temperature environment below 0 ℃, the viscosity of the extreme pressure lithium grease used is NL gi200 at most, and the lubrication effect is poor

3) the oil discharge pressure of the right angle pressure relief quantitative oil separator is low, The ar60a vehicle centralized lubrication system launched by Aote technology company has systematically solved the above problems. The product has applied for a number of patents and passed the testing of national legal institutions. After long-term use on many models such as wg6980 xmq6792c2 and zk6100h, Good effect

ar60a takes the grease lubrication friction pair of the oil nozzle of the whole bus as the research object. In addition to making 360 ° rotating friction pairs on the vehicle, they are all included in the centralized lubrication system for research, so as to meet the needs of vehicle lubrication to the greatest extent. The product is composed of a grease supply unit and a monitoring unit. The grease supply unit is composed of a grease supply pump station and an oil separator, which connect dozens of grease lubrication points distributed on the vehicle into a complete closed system through pipeline accessories; The monitoring unit is controlled by a K monitor with liquid crystal display. The oil pressure sensor and oil level sensor control the grease supply unit through the line, display various dynamic information and have the function of automatic fault detection. The system automatically and regularly supplies oil to each friction pair during vehicle operation, so as to ensure that each friction pair is well lubricated

2 AK monitor

ak monitor has advanced performance, Safe and reliable operation

2.1 the running state of the program is clear at a glance

a K monitor highlights the humanized design concept of people-oriented, and adopts a new Chinese LCD, which is the first of its kind. Its dynamic operation is very convenient for ordinary drivers, passengers and maintenance personnel to understand the rest state when the system is not running. The display shows the cumulative oil level of the fuel tank in the current working cycle and the countdown to rest; In the system operation state, the display screen shows the instantaneous pressure of the oil pressure, the oil level of the oil tank and the instantaneous running time; When the system breaks down, the display screen accurately displays the fault phenomenon and gives an audible and visual alarm, as shown in Figure 1.

the rest state information can be stored for a long time after parking, and its performance is better than the commonly used capacitor storage mode

2.2 the control program is advanced

at present, the operation time set by the controllers of similar products in the market is a fixed value, which is basically about 2.5min per cumulative operation. This value has too much surplus in the early stage of vehicle operation, It is a conservative value set in consideration of the reduced efficiency of the gear pump after late wear, which makes it easier for the gear pump to wear in the early stage. Looking for other materials to make plastics, especially on city buses, there are many disadvantages. Because of the restrictions of road conditions, traffic flow, intersection traffic lights and station distance, some city buses often shut down and slide during driving. Due to the characteristics of electric pressure relief gear pump positive displacement centralized lubrication system, During the operation time of about 2.5min, the friction pair will be refuelled repeatedly due to shutdown and taxiing due to flameout, so that the lubrication point receives too much oil, which is not conducive to lubrication, but also a waste of grease and loses the significance of accurate quantification.

the AK monitor of ar60a vehicle centralized lubrication system is designed according to the characteristics of vehicle operation and centralized lubrication system. When the oil pressure at the farthest end of the main oil passage reaches the set 2.6MPa, The oil pressure sensor connected here will send a signal to the monitor. At this time, the oil pressure display on the LCD screen will change from "off" to "on", and let the grease supply pump station continue to work. After maintaining the pressure for 40s, it will stop working. Generally, the time when the oil pressure at the farthest end of the main oil duct reaches the set 2.6MPa is related to the ambient temperature. From summer to winter, it generally changes between 15 ~ 30s, and maintaining the pressure for 40s is enough to make the metering of the oil separator accurate. In this way, The running time of each system is between 55 ~ 70s, less than half of the similar products at home and abroad on the market, which greatly reduces the possibility of excessive oiling caused by flameout during driving. In addition to the countdown prompt of the display and the backlight bright prompt during operation, the driver can avoid repeated oiling with a little attention. In particular, according to the characteristics that some city buses are easy to stall, stop and slide halfway, A also makes the sample slip in the process of the experiment. The K monitor is also specially designed in terms of the program according to the pressure of the main oil circuit, ensuring that the oil separator accurately supplies oil according to the oil demand of the friction pair

2.3 the automatic fault detection function is perfect

during the operation of the motor, the monitoring system does not detect the oil pressure to pressure signal, and the motor will stop after 120s of operation. At this time, the display displays "off" and "EE21" at the same time, and sends out an alarm sound, At this time, the oil level sensor of the oil tank developed according to the characteristics of viscous grease should be overhauled in time to detect whether the oil tank is short of oil in real time. When the oil tank is not short of oil, the LCD display shows three full grids, and the oil level drops to the set minimum oil level line. If the oil burst resistance measurement range is 250 ~ 5600kpa, the tank is not refueled in time, and the grease supply pump station is allowed to work for the specified number of times, The oil level display on the LCD screen will gradually change to two grids and one grid until the blank alarm and "ee22" are displayed. At this time, the program will no longer support the operation of the grease supply pump station to avoid the damage of the gear pump oil tank due to lack of oil idling in the grease supply pump station. After refueling, the oil level will display three full grids in time. The program will restore the support for the operation of the grease supply pump station

ak monitor also sets a 15 gear adjustable rest interval from 6 to 20h, In order to facilitate users to adjust according to the actual situation,

the loading and use situation on many models shows that the a K monitor is durable and reliable, has strong anti-interference ability, operates normally, and has good customer response

3 ar60a grease supply pump station

ar60a grease supply pump station has reasonable structure and advanced performance

the centralized lubrication system currently used on vehicles is mostly gear pump positive displacement structure, whether domestic or foreign products, In the low temperature environment below 0 ℃, NL gi200 extreme pressure lithium grease, which is close to liquid, can only be used as the lubricating medium at most. Because the grease is too thin, the leakage and waste are serious, which is gradually implemented. In particular, some high-temperature and high-speed vehicle friction pairs cannot form a good lubricating oil film, and the grease is very easy to leak, so it is inconvenient to be included in the lubrication points of the centralized lubrication system, As a result, these lubrication points also need to be oiled with an artificial grease gun

Aote technology company systematically studied the structure of the gear pump positive displacement centralized lubrication system, organically integrated some new inventions, and developed a new ar60a pump station, which improves the viscosity of the pumped grease, can meet the lubrication requirements of the friction pairs at higher speeds, and greatly improves the economy. Under the simulated conditions of the low temperature laboratory, The ar60a vehicle centralized lubrication system can smoothly inject nlgi grade 20 extreme pressure lithium grease close to the software into the friction pairs at the ambient temperature of -11 ~ -13 ℃. The loading test of several models with a length of 100000 km shows that the ar60a vehicle centralized lubrication system can meet the lubrication requirements of higher speed friction pairs such as transmission shaft support bearings

because nlgi grade 0 extreme pressure lithium grease has good lubrication performance and is not easy to leak, Therefore, it is recommended to set the interval between two lubrication times as 13 ~ 15h (the basic factory setting value of current market products is 10h). Since the vehicle is loaded and operated under the ambient temperature of -8 ~ 40 ℃ in four seasons in the Central Plains, the lubrication effect is good, the fuel saving effect is obvious, and the driver can operate the vehicle with less effort

similar products on the market at present, even if NL gi-0 extreme pressure lithium grease can be used as the medium under the environmental conditions above 0 ℃, There is also the problem that the grease at the bottom of the oil tank cannot be pumped for a long time and deteriorates. Ar60a solves this problem better.

the rated speed of the low-speed motor developed for ar60a matching is only about half of the rated speed of the motor of similar products on the market. Reducing the speed is conducive to the smooth pumping of viscous grease by the gear pump, avoiding air inhalation, reducing noise, and improving the reliability of the gear pump, In addition, the service life of the key parts of the grease supply pump station can be doubled by shortening the operation time during lubrication, prolonging the interval between two lubrication times and protecting the oil tank from oil shortage and power failure.

4 new pressurized oil separator

the quantitative pressurized oil separator specially developed for the ar60a vehicle centralized lubrication system has accurate measurement and high oil discharge pressure. Its working principle is: when the grease supply pump station pressurizes and supplies oil through the main oil circuit, The oil pressure of the main oil circuit compresses the return spring of the oil separator and directly presses the grease measured in the previous cycle of the oil separator to the lubrication point through the oil distribution pipe; After the motor stops and the main oil circuit is depressurized, the oil separator measures the oil storage. The oil inlet pressure of the oil separator at the end of the main oil circuit minus the return spring force and the friction resistance of the seals (the sum of the two is not more than 0.8MPa) is the oil outlet pressure of the oil separator. When the safety valve at the oil outlet of the grease supply pump station sets the pressure to 3.8mpa, the oil pressure at the farthest end of the main oil circuit will rise to 3.3Mpa at most and remain until the motor stops. Therefore, when the resistance from the oil distribution pipe to the lubrication point is large, The pressure at the oil outlet of the oil separator can be increased to nearly 2.5MPa at the same time. The right angle relief oil separator used in the centralized lubrication system on the market at present, on the premise that the oil pressure of the main oil circuit ensures its accuracy of measurement, the continuously increased oil pressure of the main oil circuit does not affect the pressure at the oil outlet. The pressure at the oil outlet is only related to the compression of the spring in the metering chamber. The maximum pressure at the initial instant of oil drainage is 2.0MPa, and with the weakening of the spring force, the pressure at the end of oil drainage is only 1.4mpa, Overcoming the resistance of 2 ~ 3M long oil distribution pipe, there is little pressure left after reaching the lubrication point, especially in the low temperature environment, which affects the lubrication effect

the loading and use of several models shows that the quantitative pressurized oil separator can ensure the accurate grease filling at the lubrication points with high sealing requirements such as the automatic adjusting arm when using viscous NL gi-0 extreme pressure lithium base grease

if necessary, It can also increase the set pressure of the safety valve at the oil outlet of the grease supply pump station, and the oil discharge pressure of the pressurized oil separator will also increase, while the oil discharge pressure of the right angle pressure relief oil separator will remain unchanged

5 Conclusion

ar60a vehicle automatic centralized lubrication system is advanced in design and reliable in operation, which widens the scope of applicable friction pairs, improves the lubrication effect and reliability of vehicles, and its monitoring system is also more humanized and convenient for use and maintenance (end)

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