MECHANICAL

Spiral Bevel Gears: Review on Dynamics.

Farhad S. Samani — 2025-04-23

Bevel gears are a type of gears commonly used in various applications, especially where a change in the direction of power transmission is needed. The teeth on bevel gears are vulnerable to various defects that can affect their performance, such as pitting, wear, and chipping. These defects can lead to increased vibrations, noise, and decreased efficiency of the gear system. In order to ensure optimal performance and longevity of bevel gears, it is essential to properly diagnose and address any defects on their teeth. The paper investigates the dynamics of bevel gears under varied operational conditions and analyzes the impact of factors, such as crowning modification, on system transmission error. This research explores load-sharing concepts, detailing operational conditions and mathematical models for calculating load-sharing among planets. Moreover, it evaluates factors influencing load distribution among planets, emphasizing parameters like bearing, backlash, run-out errors, position errors, and manufacturing errors while assessing PGS effectiveness in load-sharing. To enhance load-sharing, including floating systems and flexible pins, methods and solutions are discussed. PGS is examined from a phasing perspective. Additionally, this paper summarizes studies on the impact of faults on the planet phase.

Analisa keausan dan evaluasi produktivitas serta efisiensi operasional hammer crusher pada area crusher & raw mill di Pabrik Semen Baturaja II.

Abert Anugerah Lumban Tobing — 2025-04-23

PT Semen Baturaja is one of the largest cement producers in Indonesia, located in South Sumatra. This company produces various types of cement to meet market needs in the Sumatra region and surrounding areas. In the production process, PT Semen Baturaja Tbk uses a crushing tool to reduce the scale of the materials to be used, one of which is limestone or limestone found in the crusher and raw mill areas. A hammer crusher is an important tool in the cement production process, which functions to hit the material so that it is crushed into smaller sizes. Hammer wear and productivity greatly determines the results of the cement production process. The wear that occurs in this hammer crusher is abrasion wear. In terms of hammer crusher productivity from January to July, the highest value was obtained in March, namely 680.05 tons/hour and the lowest productivity value was in February, namely 547.16 tons/hour. Regarding the efficiency of the hammer crusher, it can be seen that the hammer crusher has a very good efficiency value of 81.48%.

Investigating Environmental Degradation of Banana-Sisal Epoxy Composites: Physical and Thermal Properties

Hyginus Chidiebere Onyekachi Unegbu — 2025-04-23

This study evaluates the environmental degradation of banana-sisal epoxy composites, focusing on their physical and thermal properties after exposure to moisture, ultraviolet (UV) radiation, and thermal aging. Alkali-treated and untreated composites were fabricated and tested for moisture absorption, tensile strength, flexural strength, thermogravimetric stability, and UV resistance. Results indicate that alkali-treated composites absorbed significantly less moisture (1.26%) than untreated composites (2.62%) after 120 hours of water immersion. Treated composites retained 87.6% of their initial tensile strength and 92% of their flexural strength, demonstrating superior mechanical performance compared to untreated composites. Thermogravimetric analysis (TGA) showed higher onset degradation temperatures (T_onset = 275°C) for treated composites compared to untreated composites (T_onset = 255°C) and better residual mass retention at 600°C. Differential scanning calorimetry (DSC) revealed a higher glass transition temperature (Tg = 93°C) for treated composites, indicating improved thermal stability. After 100 hours of UV exposure, treated composites retained 82% of their tensile strength, compared to 68% for untreated composites. These findings demonstrate that alkali-treated banana-sisal epoxy composites possess enhanced resistance to environmental degradation, making them viable for use in construction, automotive, and marine industries. Future research should aim to optimize fiber treatments, develop hybrid and nanocomposites, and conduct long-term durability and sustainability assessments.

Analisa Getaran Mesin Milling 1217 Horizontal Terhadap Pengaruh Variasi Kedalaman Potong Pada Proses Pembuatan Roda Gigi

Jupri Yanda Zaira — 2025-04-23

Seiring perkembangan teknologi, mesin frais (milling) semakin dibutuhkan dalam produksi dan pendidikan. Penelitian ini menganalisis pengaruh variasi ketebalan pemakanan dan diameter cutter terhadap getaran yang terjadi selama proses pemakanan muka. Variasi ketebalan pemakanan yang digunakan adalah 0,5 mm, 1 mm, dan 1,5 mm, dengan diameter cutter 55 mm. Pengukuran getaran dilakukan menggunakan vibration tester VM-6380 pada tiga arah (vertikal, horizontal, dan aksial), menghasilkan data berupa displacement, velocity, dan acceleration yang diolah menjadi amplitudo. Hasil penelitian menunjukkan amplitudo terbesar terjadi pada arah horizontal dengan kedalaman pemakanan 0,5 mm menggunakan cutter diameter 55 mm pada kecepatan 125 rpm sebesar 0,1153 mm. Pada arah aksial, amplitudo tertinggi tercatat sebesar 0,0453 mm pada kedalaman 1 mm, dan pada arah vertikal amplitudo terbesar adalah 0,0492 mm pada kedalaman 1,5 mm. Kesimpulan menunjukkan bahwa amplitudo terbesar secara umum terjadi pada arah horizontal dengan ketebalan pemakanan 0,5 mm. Penelitian ini memberikan wawasan penting mengenai pengaruh parameter pemakanan terhadap getaran, yang dapat membantu optimalisasi proses milling.

STUDY OF DIFFERENT WINGLET CONFIGURATION IN CEILING FAN TO IMPROVE THE AIR FLOW IN CUBIC ROOM

ARTHANARI KARTHIKEYAN — 2025-04-23

Winglet attachment is reducing the induced drag in aircraft; similar concept is tried in ceiling fan, in order to reduce the tip vortices which increase the fan speed and airflow and reduce the electricity consumption. Various shape of winglet attachment such as blend edge, sharp edge, wedge shape, triangle. The air flow was experimentally measured at various locations in various speeds and results were finally discussed. There is a considerable improvement in airflow as compared to without attachment of winglet