The machine can meet the life and reliability strengthening test of insert bearing with housing and it can also do limit speed and grease leakage temperature rise test.

1650288803701245.png 

 

Abstract: the main structure of ABLT-7 bearing life and reliability strengthening testing machine, the main functions and components of loading system and monitoring system are introduced. The test shows that it can meet the life and reliability enhancement test of the insert bearing with housing, and can also be used as the limit speed and grease leakage temperature rise test.

 

Key words: insert bearing ; life; testing machine; reliability

 

In the “Eleventh Five Year Plan” development plan of China’s bearing industry, one of the key points is to carry out technical research on improving the service life and reliability of rolling bearings. Therefore, ABLT series bearing service life and reliability strengthening testing machine has been developed, and two Chinese invention patents have been authorized. This paper introduces in detail the ABLT-7 life and reliability strengthening testing machine for insert bearing with housing.

 

1. Main technical parameters

According to the actual working conditions of the insert bearing with housing, the testing machine is designed according to the following parameters.

The inner diameter of the test bearing is 20 ~ 60mm; The number of test bearings is 4 sets; The test bearing speed is 500 ~ 5000r / min (variable frequency speed regulation); The maximum radial load of the test bearing is 25kN; The measurement and control mode is computer automatic monitoring, automatic alarm, shutdown and automatic recording; The measured parameters are bearing speed, temperature and vibration.

 

图片2.png  

Fig.1 Main structure of ABLT - 7 testing machine

 

1. Test shaft   2.Nut; 3.Test bearing   4.Middle base plate   5.Vibration sensor

6. End pad   7.Temperature sensor   8.Coupling   9.Transmission device  

10. Motor   11.Hydraulic cylinder

 

2. Main structure and characteristics

ABLT-7 testing machine can test 4 sets of bearings at the same time (2 sets in the middle and 2 sets at both ends). The bearing seat is equipped with vibration sensor and temperature sensor. During the test, the vibration and temperature changes of 4 sets of bearings can be measured respectively. The main structure of the testing machine is shown in Figure 1. A radial loading oil cylinder is respectively arranged under the two middle base plates to apply radial load to the test bearing. The speed of test bearing is realized by frequency converter, motor, multi wedge belt, transmission shaft, coupling, connecting shaft (small square shaft) and test shaft.

 

The bearing seat with outer spherical bearing seat is generally formed by casting or stamping, with large size dispersion. The traditional single oil cylinder loading method is easy to cause eccentric load; Therefore, the machine adopts double oil cylinder loading, which can effectively make up for the eccentric load caused by dimensional error and ensure that each set of bearings is loaded evenly.

 

2.1 Transmission system

The motor and the drive shaft are driven by a V-belt. The frequency converter is used for speed regulation. The speed sensor is next to the drive shaft pulley. The synchronous speed of the motor is 1500r / min. There are two transmission ratios between motor and transmission shaft (i = 2 or i = 1 / 2). When the required speed n ≤ 1500r / min, install the large pulley on the transmission shaft and the small pulley on the motor shaft. At this time, the transmission ratio is i = 1 / 2. When n ≥ 1500r / min, the small pulley is installed on the transmission shaft and the large pulley is installed on the motor shaft. At this time, the transmission ratio is i = 2.

 

2.2 Loading system

The principle of the loading system of ABLT-7 testing machine is shown in Figure 2. The pressure oil is provided by the hydraulic pump station. The pressure regulating valve depends on the weight of the weight to set the secondary pressure oil pressure of the valve. The maximum allowable pressure of the secondary pressure oil is 13Mpa. The accumulator can stabilize the pressure and reduce the pressure fluctuation caused by leakage. CT1 is a two position four-way directional valve, which is in position during oil inlet and position B during oil outlet. The diameter of the rubber film in the radial loading cylinder (2) is 50mm and the area is 19.63cm2. When the oil pressure is 12.74 Mpa, the total thrust can be 25kN. The ratio of the thrust of the radial loading oil cylinder to the weight of the weight and the weight of the hook used for placing the weight on the pressure regulating valve is 20.25  1.

  

 图片3.png

Fig. 2 Schematic diagram of loading system of ABLT - 7 testing machine

 

1. Hydraulic pump station   2. One way throttle valve   3. Accumulator  

4. Electric contact pressure gauge   5. Stop valve   6. Pressure regulating valve  

7. Electromagnetic directional valve   8. Pressure gauge   9. Radial cylinder

 

2.3 Monitoring system

ABLT-7 testing machine monitoring system can monitor the vibration and temperature of the test bearing and realize cross-border shutdown. The sensor transmits the measured bearing vibration and temperature signals to the signal amplifier and displays them on the display after being processed by the industrial computer. When the bearing fails or the testing machine is abnormal, the monitor transmits the failure information to the computer, and the computer automatically shuts down the running testing machine and saves the previous monitoring data. Figure 4 is the interface of the monitoring system.


图片4.png 

Fig. 4 Monitoring interface diagram of ABLT – 7 testing machine

 

3. Test application

In order to verify the validity of test data, ABLT-7 testing machine shall be identified according to the standard, and then the qualified testing machine shall be used for test verification. Since there are no relevant national and industrial standards at present, the self-calibration procedures of rolling bearing life testing machine of National Testing Laboratory of Hangzhou bearing test and Research Center (CNASNO. L0309) are used to identify ABLT-7 testing machine.

 

The qualified ABLT-7 testing machine is used to test the outer spherical ball bearing UCP207 with seat (8 sets each) produced by 3 different manufacturers provided by a company. The test conditions are as follows: the rotating speed is 2000r / min, the radial load Fr = 6.533kN, the axial load Fa = 0, Cr = 19.8kN, the rated life L10 = 232h, the lubrication method is the original grease lubrication of manufacturer B, and the continuous grease lubrication of manufacturers A and C. the test data are shown in Table 1.

 

The test results show that all inner rings of bearing of manufacturer have fatigue spalling, two inner rings of bearing C of manufacturer have fatigue spalling, and the test is stopped without failure of other bearings. Different from the bearings of manufacturers a and C, the bearings of manufacturer B are not greased in the test because of the original grease lubrication of the bearings of manufacturer B. among them, the grease failure of 6 sets of bearings increases the bearing temperature, burns and discoloration of the steel ball surface and inner and outer ring channels, and the cage is damaged; The other two sets of bearings have inner ring failure. The test results show that the test data of ABLT-7 bearing life and reliability strengthening testing machine are effective, consistent with the reality, and can be applied. However, the test results can only reflect whether the test equipment can simulate the real use of the bearing.

 

Table1. Life strengthening test results of ABLT - 7 testing machine

1650288872116904.png 

 

4. Conclusion

ABLT-7 bearing life and reliability strengthening testing machine can meet the life and reliability strengthening test of insert bearing with housing. At the same time, it can also do limit speed and grease leakage temperature rise test, which enriches and improves the product series of ABLT strengthening testing machine. Heating or cooling devices can also be added, and the building block extended ABLT-7 testing machine can simulate the test environment, improve the real feasibility of the enhanced simulation test of the outer spherical bearing, and ensure the realistic reliability of the test data.

 

More about FK Insert bearing:

As one of the leading insert bearings manufacturers and suppliers in China for more than 50 years, we warmly welcome you to buy top quality insert bearings from FK Group. For dimensions and specifications, contact us now.


图片6.png 

 

Founded in 1969, FK has always focused on bearing part industry, after 50 years development and accumulation, FK is accelerating the transformation and upgrading to be “Bearing Parts Expert and Leading Supplier”. FK has complete industrial chain automatic factory of its own, now FK is one of the biggest bearing parts factories in China with production and sales up to 18 million pieces.

Bearing units provide simple and effective bearing arrangements capable of accommodating moderate initial misalignment from mounting errors, they are easily mounted onto commercial shafting. The reliability, simplicity and ease of assembly of FK bearing units has resulted in their popularity in sectors.


FK, a bearing products expert and leading supplier will continue to be one of most professional bearing manufacturer in the world!