Coatings for the thrust bearings of the oil pump hydraulic protection. MODENGY products have successfully passed tests at a large oil-servicing company

Coatings for the thrust bearings of the oil pump hydraulic protection. MODENGY products have successfully passed tests at a large oil-servicing company.

One of the most common technologies to pump tabular fluid containing oil, water, gas, and mechanical impurities out of the oil well is by using plants of electric centrifugal pumps (PECPs).

Hydraulic protection of the PECP is used to prevent tabular fluid from penetrating into the internal cavity of the oil-filled electric engines.

Ones of the most loaded elements of this equipment are thrust bearings.

A thrust bearing is set under the electric engine shaft abutment, and it takes the heavy axial loads through it.

Special attention in the thrust bearing structure is paid to its body and the segments onto which a special wear-resistant coating is applied. It is intended to reduce friction at the moment of starting and stopping, to extend service lifetime of these high-loaded elements.

For the purpose of selecting the most wear-resistant coating to be used at manufacturing the PECP’s hydraulic protection thrust bearings, one of the leading oil-servicing companies has held the tests on a certified computerized hydro protection test bench. 

The coatings from the Russian Modengy company, the products based on molybdenum disulfide and graphite, namely MODENGY 1006 and MODENGY 1066, as well as MODENGY experimental coating based on polyetheretherketone (PEEK) took part in this experiment.

Test Conditions and Stages

To detect operability of the thrust bearings treated with different anti-friction coatings, two stages of testing were held: one at high temperature without load changing, and the other one in the mode of cyclic loads of 400 to 2,000 kg.

As a part of the first stage of testing, the test chamber with a thrust bearing was getting filled with oil and heated up to +150 °С. The test bench was started without initial axial load at rotation frequency of 2,910 rpm. Next, load was gradually being increased up to 2,000 kg. Testing time at continuous heating and load increasing made 8 hours.

When the first stage was completed, the data of power consumption, rotation frequency, axial thrust, temperature inside the test chamber, and temperature of the segment of the thrust bearing were registered. Parameters logging was carried out every 5 minutes. After that the axial load was removed, and the test bench was stopped.

The second stage of testing was holding at +150 °С in the cyclic load mode. The test bench was started at initial axial load equal to 400 kg. Next, axial load was being gradually increased up to 2,000 kg at joint increasing in engine rate up to 2,910 rpm.

The axial load of 2,000 kg at engine rotations of 2,910 rpm was kept stable during 3 minutes, and next, it was decreased down to value of 400 kg. After that the test bench stayed idle for 0.5 to 1 minute.

The sequence of actions described above was repeated until 100 start-stop cycles were reached.

Benchmark tests results for the hydraulic protections thrust bearings treated with MODENGY coatings

The thrust bearings treated with MODENGY 1006, MODENGY 1066 coatings, and MODENGY experimental coating based on PEEK have successfully passed benchmark trails, no acceptable values of end beats between the thrusts bearing and the abutment were exceeded. Appropriateness of these materials to be used under conditions of higher temperature (up to +150 °С) and axial load of 2,000 kg has been proven in experimental way. The actual results of end beats after the tests are presented in Table 1.

Table 1

MODENGY coatings are successfully used in the bearings of the oil pumps hydraulic protections slide units. They have high load-carrying capacity, high wear-resistance at dynamic loads, low friction coefficient, long service lifetime.