Theoretical assessment of the stress-strain state of the cylinder sleeve of a marine diesel engine from the effects of variable moving gas loads

Цилиндровые втулки относятся к наиболее нагруженным деталям судовых дизелей. Оценка их напряженно-деформированного состояния показывает, что последовательное форсирование дизелей по среднему эффективному давлению требует существенного пересмотра некоторых положений конструирования этих деталей. Это касается конструктивного оформления наружных поверхностей втулок, а также их закрепления в блоке цилиндров. В статье рассматривается влияние условий закрепления верхнего торца втулки и промежуточных опор-уплотнителей на деформирование цилиндровой втулки газовыми нагрузками. Показано, что для выбора оптимального места установки кольца-уплотнителя по длине втулки целесообразно исходить из минимизации воздействий на него со стороны подвижных газовых нагрузок. Предлагается расчётная методика, которая позволяет определить то место установки промежуточной опоры, где она практически не влияет на параметры напряженно-деформированного состояния цилиндровой втулки судового дизеля с учётом особенностей закрепления её верхнего торца в цилиндровом блоке. Применение данной методики позволяет с учётом особенностей конкретного двигателя обоснованно решить вопрос размещения дополнительных опор-уплотнителей. Cylinder bushings are among the most loaded parts of marine diesel engines. Evaluation of their stress-strain state shows that the sequential forcing of diesel engines according to the average effective pressure requires a significant revision of some provisions for the design of these parts. This applies to the design of the outer surfaces of the bushings, as well as their fastening in the cylinder block. The article examines the influence of the conditions for fixing the upper end of the sleeve and intermediate support-seals on the deformation of the cylinder sleeve by gas loads. It is shown that in order to select the optimal place for installing the seal ring along the length of the sleeve, it is advisable to proceed from the minimization of the effects on it from the movable gas loads. A calculation method is proposed that allows you to determine the place of installation of the intermediate support, where it practically does not affect the parameters of the stress-strain state of the cylinder liner of a marine diesel engine, taking into account the peculiarities of fixing its upper end in the cylinder block. The use of this technique allows, taking into account the characteristics of a particular engine, to reasonably solve the issue of placing additional support-seals.

Cylinder sleeve of the internal combustion engine. Mathematical model of the deformation process

During the operation of internal combustion engines, deformation of the cylinder sleeve is possible, which causes its premature wear during the operation of the “piston ring – sleeve” pair. Imagine the sleeve as a two-stage hollow cylinder with forces applied to it, which cause deflection in the section. It can be assumed that if the greatest deformation of the cylinder is in the section of the application of forces, then with distance from this place it will decrease. At some distance from the point of application of forces, the deflection of the sleeve will be equal to zero. It is required to simulate a mathematical formula that would make it possible to evaluate the possibility of estimating the value depending on the basic geometric dimensions of the cylinder sleeve. A mathematical model of the deformation process of a hollow two-stage sleeve of an internal combustion engine has been developed, an analytical dependence has been obtained for the value of the “neutral” section depending on the main geometrical dimensions of the cylinder sleeve of the engine, a rather extensive analysis of the influence of various parameters on the value of the “neutral” section has been carried out.

Developing technology of creating wear-resistant ceramic coating for internal combustion engine cylinder sleeve

This paper presents the results of testing a wear-resistant ceramic coating on the work surface of an internal combustion engine (ICE) cylinder’s sleeve. A combined coating formation technology is described that consists in applying an aluminum layer to the sleeve’s work face by gas dynamic spraying and then covering this face with a ceramic layer by microarc oxidation (MAO). A tenfold reduction in the reinforced sleeve has been determined by the accelerated comparative wear rig tests of reference (new) sleeve-piston ring coupling specimens and reinforced specimens with a combined coating. The supplementation of nanoparticle admixture to MAO coating reduces the friction factor between the cylinder sleeve face and the piston ring by 25-30%. The proposed technology can be used to reinforce work surfaces of new cylinder sleeves and recover worn out ones.

INCREASING THE CURRENCY RESISTANCE OF CYLINDER-PLASTING OF PYSTON PUMPS BY PLASMA METHOD

The article examines the study of increasing the wear resistance of the cylinder-sleeve of a piston pump using the developed technology of plasma spraying. Wear-resistant and durable coatings of nickel, chromium, molybdenum and tungsten were obtained on the surface of the piston pump cylinder-sleeve. A graph of the dependence of the coating thickness depending on the surface hardness of the cylinder-sleeve is presented. According to the graph, depending on the hardness, you can determine the wear resistance of the coating surface of the cylinder-sleeve. Keywords: piston pump, cylinder liners, plasma method, nickel, chromium, molybdenum, tungsten, wear resistance, coating thickness, hardness, graphical dependence

Optimasi Penjadwalan Produksi Menggunakan Metode Simulated Annealing di Industri XYZ

Perusahaan XYZ pada bulan Januari 2020 mendapatkan complain dari salah satu konsumennya karena pesanan datang terlambat. Peristiwa ini bisa terjadi karena beberapa hal yang mempengaruhinya, seperti kecelakaan kerja, perbaikan mesin dan penjadwalan yang tidak tepat. Namun pada saat konsumen complain tentang pesanan terlambat, ternyata jadwal produksi kurang baik yang menjadi penyebabnya. Perusahaan XYZ menerapkan metode FCFS (First Come First Serve) dalam menentukan jadwal produksinya. Jadwal produksi periode Januari 2020 kembali terjadi keterlambatan dimana untuk pada periode ini line satu cylinder sleeve mendapat jobs untuk mengerjakan lima jenis produk, diantaranya cylinder sleeve 73 mm, 78 mm, 92 mm, 86 mm, dan 95 mm dengan jumlah total sebanyak 940 pcs produk. Waktu untuk mengerjakan produk ini tersedia sebanyak 24 hari kerja. Jadwal produksi menggunakan FCFS dengan susunan formasi jobs 4-2-5-1-3 serta memiliki nilai makespan 30175 detik. Setelah itu menggunakan metode Simulated Annealing (SA) untuk menganalisis production schedule. Penelitian ini menghasilkan usulan production schedule dengan susunan jobs 1-3-5-2-4 dan memiliki nilai makespan 29165 detik. Setelah dilakukan analisa, ternyata usulan jadwal produksi baru dapat mengurangi waktu produksi. Jadwal produksi awal menghasilkan 940 pcs produk dengan 25,01 hari, sedangkan jadwal produksi dengan penjadwalan yang diusulkan dapat menghasilkan 940 pcs produk dalam 24,17 hari kerja. Waktu produksi yang berhasil diturunkan mampu mencapai 20,16 jam. Waktu yang tersedia untuk mengerjakan adalah 24 hari kerja. Dengan penjadwalan perusahaan (FCFS) diketahui susunan jobs adalah 4-2-5-1-3 dan memiliki nilai Makespan 30175 detik. setelah dilakukan perhitungan Simulated Annealing (SA) didapat penjadwalan usulan dengan susunan jobs 1-3-5-2-4 dan memiliki nilai Makespan 29165 detik. setelah melalui perhitungan, dikethaui bahwa dengan penjadalan awal waktu yang dibutuhkan untuk mengerjakan 940 pcs produk adalah 25,01 hari kerja sedangkan dengan penjadwalan usulan selesai dalam waktu 24,17 hari kerja. Dari hal tersebut dapat disimpulkan bahwa penjadwalan usulan dapat mengatasi permasalahan tentang keterlambatan.

Design features of engines of generation of A-41SI family

Design documentation on diesel engines of the A-41SI model is analysed. By results of the analysis it is revealed that on diesels of this type individual heads of cylinders, an electric starter with a pro-rate for start of engines are introduced, assembly units and details are improved: cranked shaft, sets of radical and shatunny inserts, cylinder sleeve, the piston, set of piston rings, casing with disks of the coupling of coupling, etc. Introduction of new constructive changes on A-41SI diesels allowed to raise their rabotosposbnost and durability.

Friction and wear performance of bionic stripped piston of BW-160 slime pump

Bionic strips were designed and processed on the piston of BW-160 slime pump to improve its friction performance, decrease wear mass losses, and prolong service life. Nine stripped pistons were processed and manifested by different strip depths and included angles between stripes and piston surface. A workbench of slime pump piston was created to test the frictional force, oil film width, and wear mass losses. Test results demonstrated that the stripped structure can significantly decrease the frictional force on the piston. Optimal strip depth, included angle, and resistance reduction rates for stripped piston reached 2 mm, 90°, and 53.89%, respectively. The oil film on stripped piston was significantly wider compared with that of the standard piston, thus reducing frictional force between the piston and cylinder sleeve. The wear mass losses and the wear rate of the bionic piston are lower than that of the standard piston. Finally, the friction and stress of the piston are analyzed by finite element method, and the influencing mechanism on performance of pistons was discussed. The test results provide parameters for piston design of BW-160 slime pump for engineering.