Created on:2021-10-19 10:25

Locomotive equipment_ Fault detection and treatment of locomotive hydrostatic system

Locomotive equipment_ Fault detection and treatment of locomotive hydrostatic system

(1) Fault detection and handling

① Fault detection the vibration detection of the pipeline of the hydrostatic system shall be carried out after the high and low temperature fans are fully put into operation under the full load of the diesel engine at 1000 R / min. Since there is no data on the vibration amplitude and size of hydrostatic pipeline system for reference, lx-100 locomotive equipment diagnostic instrument is used to detect the vibration of more than 40 locomotive hydrostatic system accessories, pipelines and joints, and then conduct mathematical statistical analysis to obtain the empirical limit value of vibration detection shown in the table below, which can be used as the vibration detection threshold value. Through analysis, it is found that the pipeline vibration is mainly related to the maximum and effective value of vibration (kurtosis value can be used as a reference). The more serious the pipeline hand vibration is, the greater the maximum and effective value detected, and vice versa. According to the analysis of the detection and tracking situation, it is found that if the locomotive exceeds this threshold, the pipeline will be cracked in a short distance. For example, 1784 locomotive repaired in a locomotive factory was inspected after arriving at the depot. It was found that there was serious vibration in the pipeline of the low-temperature hydrostatic system. After detection, the maximum vibration of the oil inlet pipe of the temperature control valve was 107.68g and the effective value was 45.4g. The vehicle is required to return to the factory for treatment. After the manufacturer cleaned the hydraulic cylinder and replaced the static and other accessories, the vibration was relatively weakened. The measured maximum vibration value of the pipe was 85.31g and the effective value was 35.2G. After the vehicle was delivered and operated for 2158km, the root of the pipe joint was cracked and detained for temporary repair, which insured that there was no machine failure.

Vibration detection limit value of hydrostatic system

Pipeline and connector

名称

编号

最大值/g

有效值/g

峭度/(ds/dt)

 

管路、接头

名称

编号

最大值/g

有效值/g

峭度/(ds/dt)

低温液压缸出油管接头

D1

50

15

4

 

高温液压缸出油管接头

G1

20

6

3

低温泵体

D2

45

14

3

 

高温泵体

G2

45

11

3.8

低温温控阀进油管接头上

D3

32

12

2.6

 

高温温控阀进油管接头上

G3

30

10

2.0

低温温控阀进油管管身

D4

70

25

2.5

 

高温温控阀进油管管身

G4

60

30

2.3

低温温控阀进油管接头下

D5

30

8

3.3

 

高温温控阀进油管接头下

G5

30

9

3

低温温控阀出油管接头上

D6

40

15

10

 

高温温控阀出油管接头上

G6

35

12

4.5

低温温控阀出油管中部

D7

45

12

4

 

高温温控阀出油管中部

G7

40

11

3.5

低温温控阀出油管接头下

D8

40

12

5

 

高温温控阀出油管接头下

G8

35

10

4.0

低温安全阀进油管接头上

D9

35

10

3.5

 

高温安全阀进油管接头上

G9

18

5

3

低温安全阀进油管接头下

D10

30

15

6.5

 

高温安全阀进油管接头下

G10

18

5

3

低温安全阀出油管接头上

D11

30

15

6.5

 

高温安全阀出油管接头上

G11

20

6

4

低温安全阀出油管接头下

D12

30

15

6.5

 

高温安全阀出油管接头下

G12

20

6

4

 

 

② Fault treatment for the locomotive with pipeline crack of hydrostatic system, the cracked pipeline must be removed, beveled and welded (pay attention to thermal insulation) before assembly. At the same time, the crack cause shall be found out and the potential fault shall be eliminated before it can be put into use. For locomotives that exceed the limit or touch the pipeline with serious vibration, the hydrostatic pump and hydraulic cylinder shall be tested to find out the causes of vibration and eliminate potential faults before they can be put into use.

(2) Preventive measures

① In the process of locomotive maintenance, receiving and delivery, self load test shall be carried out, focusing on the inspection of pipeline vibration of hydrostatic system. It can be judged by touching the pipeline by hand. The defective vehicle must be repaired before delivery. If possible, lx-100 locomotive equipment diagnostic instrument can be used to detect the vibration of hydrostatic system, find out the vibration source of pipeline and completely repair.

② For locomotives under intermediate repair in the factory, the hydrostatic system oil shall be replaced in time after the running in test. During the first scheduled repair, the hydrostatic system oil shall be replaced to eliminate the impurities brought in during the assembly process and the copper powder and iron filings generated during the running in period. At the same time, the cleanliness of the oil tank shall be checked. The defective ones must be pressure cleaned and can be used only after being checked. During each periodical repair, the hydrostatic oil of the locomotive shall be tested, and the hydrostatic magnetic filter shall be inspected and cleaned. During refueling, it shall be carried out through the filter screen (for those equipped with oil filler filter, the filter shall be removed for inspection and cleaning, and those damaged shall be replaced).

③ Carefully implement the maintenance and assembly process and improve the maintenance quality of accessories. When assembling the pipeline, ensure that it is in a free state; During the maintenance of accessories, the maintenance process shall be strictly implemented to ensure that the matching clearance of each part meets the requirements. Focus on checking the welding status of the fixed seat of the hydrostatic oil tank, and measure the coaxiality and spacing of the upper and lower nozzles to meet the specified technical requirements.

④ Improve the cleanliness of accessories and eliminate pollution sources. Thoroughly wash the pipeline fittings disassembled by the locomotive under intermediate repair in the plant, remove the impurities inside the pipeline, phosphatize the hydrostatic pipeline, and effectively protect the joints and nozzles of hydrostatic pump, motor, oil tank and other important parts to ensure the assembly cleanliness of all spare parts. Secondly, pay attention to the cleanliness of all accessories in the assembly process, require the site to be clean and eliminate secondary pollution.

⑤ For hydrostatic system during factory repair φ 38、 φ 48. If the oil tank has serious damage or hard injury (the depth exceeds 0.5mm), it must be replaced or treated before it can be assembled on the vehicle. It is suggested that when replacing the hydrostatic system pipeline in the factory, select the pipeline with a wall thickness not less than the specified thickness, and try to increase the curvature radius of the hydrostatic pipeline, so as to reduce the oil pressure impact of the pipeline and reduce the vibration of the pipeline system. On the other hand, ensure that the inner diameter of the pipeline tends to be the same as far as possible, and eliminate the bulge during joint welding, so as to reduce the oil pressure fluctuation of the pipeline and reduce the vibration of the pipeline.

⑥ During operation, the locomotive crew shall focus on the hydrostatic system. If obvious vibration or leakage fault is found in the pipeline, it must be reported for repair.

 

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