Pengaruh beban-kecepatan putar terhadap kenaikan temperatur dan keausan bantalan bola

WINDARTA, Ir. Mudjijana, M.Eng

2007 | Tesis | S2 Teknik Mesin

Bantalan bola telah digunakan secara luas untuk sistem yang berputar. Penggunaan beban dan kecepatan putar pada kondisi operasional sering menimbulkan kerusakan pada bantalan bola. Penelitian ini bertujuan untuk mengetahui pengaruh variasi pembebanan dan kecepatan putar terhadap kenaikan temperatur dan laju aus dari benda uji single row angular contact ball bearing. Metode pengujian yang digunakan pada penelitian ini dibuat mendekati kondisi operasional bantalan bola. Pelumasan dilakukan dengan metode oliudara. Pelumas ditembakkan dengan nozel pada ring bantalan bola baja dengan laju udara 46 liter/menit dan laju oli 0,1 liter/jam. Variasi beban awal 50 N aksial dan 50 N radial, 50 N aksial dan 100 N radial, serta 100 N aksial dan 100 N radial, variasi putaran 3000, 4000, dan 5000 RPM, pengujian dilakukan sampai 1,5 juta siklus. Data pengujian kenaikan temperatur dengan sistem pelumasan udara-oli dan pelumasan grease dibandingkan dengan data kenaikan temperatur tanpa pelumasan. Hasil penelitian menunjukkan bahwa kekerasan ring luar, ring dalam, dan bola menurun seiring penambahan jarak dari race. Bola mempunyai kekerasan paling tinggi (900 VHN) dan ring luar mempunyai kekerasan terendah (681 VHN). Penambahan beban awal sampai 100 N aksial dan 100 N radial meningkatkan temperatur permukaan bola sampai 12 %. Variasi pembebanan tersebut juga mengakibatkan laju aus masing-masing 5,2E-10 mm3/N.m, 5,1E-10 mm3/N.m, dan 1,0E-9 mm3/N.m. Penambahan putaran sampai 5000 RPM meningkatkan temperatur permukaan sampai 35 %. Variasi kecepatan putar tersebut juga mengakibatkan laju aus masing-masing 1,0E-12 mm3/N.m, 1,6E-12 mm3/N.m, 2,2E-12 mm3/N.m. Penggunaan pelumas pada beban aksial 100 N dan radial 100 N menurunkan temperatur sebesar 16 %. Penggunaan pelumas grease tidak menunjukkan perubahan temperatur yang signifikan tetapi menurunkan laju aus menjadi 1,1E-10 mm3/N.m.

The ball bearings are widely used for rotating systems. The use of the load and the rotational speed on the operational condition often causes the the damages on the ball bearings. The objectives of this research are to evaluate the influence on the variations of the loading and the rotational speed toward the temperature rise and wear rate from the speciments so-called single row angular contact ball bearing. The testing method used on this research was designed closely approximate with the operational condition of the ball bearings. The lubrication was conducted associated with the oil-air method. The lubricant was spread with the nozzles on the rings of steel ball bearings with air speed of 46 litre/minute and the oil rate of 0.1 litre/hour. The variation of the preload were 50 N axial and 50 N radial, 50 N axial and 100 N radial, and 100 N axial and 100 N radial; variation of rotation was 3000, 4000, and 5000 RPM; the testing was undergone up to 1.5 millions of cycles. Result of temperature test with oil-air lubrication systems and grease lubrication were compared to the result with non-lubricated temperature rise. The result of the research shows that the hardness of the outer ring, inner ring, and ball decreases along with the addition of the distance of the race. The ball has the highest hardness (900 VHN) and the outer ring has the lowest hardness (681 VHN). The addition of the preload up to 100 N axial and 100 N radial increases the surface temperature of the ball up to 12 %. The variation of the loading also causes each wear rate into 5.2 E-10 mm3/N.m, 5.1 E-10 mm3/ N m, and 1.0 E-9 mm3/N m. The addition of the rotation up to 5000 RPM increases the surface temperature until 35 %. The variation of the rorational speed also brings about each wear rate into 1.0 E-12 mm3/ N m, 1.6 E-12 mm3/ N m, 2.2 E- 12 mm3/ N m. The use of the lubricants on the axial load of 100 N and radial load of 100 N decreases the temperature of 16 %. The use of the grease lubrication does not show the significant change of the temperature but decreases the wear rate into 1.1 E-10 mm3/N m.

Kata Kunci : Bantalan Bola,Beban dan Kecepatan Putar,Temperatur dan Keausan, load, rotational speed, temperature, ball bearings.