Projects

1Determination of the Usage, Development and Design Criteria of Precision Forging Process in the Manufacturing of Asymmetric Spur Gears
If asymmetric gears are used especially in helicopter gearboxes and gear pumps, it is anticipated that significant advantages can be obtained compared to standard gears. The engagement ratio and contact angle of asymmetric gears are obtained at higher levels compared to standard gears and they have very advantageous results in unidirectional rotating systems. However, due to the profile geometry of the asymmetrical gears, the production by the classical thread cutting method brings limitations in the design of the profile. Recent studies on this subject have shown that asymmetric profiles designed independently of cutting tool limitations will be more efficient. In the precision forging method, there is no limitation related to the profile in the production of the gear mold and therefore the flexibility of the gear profile to be produced shows that it will be advantageous to use precision forging in asymmetric gear manufacturing. However, die and process design needs to be developed in order to apply precision forging technology to asymmetric gears. The design and manufacture of the die with the desired precision will directly affect the quality of the gears to be produced. The success of precision gear forging technology depends on the predetermination of dimensional changes (caused by factors such as tight fit, temperature, forging load, and material flow) and the production of the workpiece at the desired tolerances (size and surface). In order to obtain the targeted asymmetric tooth profile, the changes to be made in the tooth profile of the mold must be modeled mathematically. In addition, due to the high forging load that occurs in precision forging, die strength and life are important parameters, so the design of material flow, die elements, and forging parameters (temperature, forming speed, lubrication, etc.) arise as problems to overcome. For asymmetric gears, there is no study on these issues yet reflected in the literature. The project coordinator has many international publications on the precision forging of standard spur gears, die design, performance analysis of forged gears. Experience in this field will enable the development of precision forging technology as a feasible method in the manufacture of asymmetric gears and will contribute to our country being one of the pioneers in this field. <br />
My position in this project is "Design and Manufacturing of Asymmetric Spur Gear Forging Die", this project supported by The Scientific and Technological Research Council of Turkey (TUBITAK) (Grand No: 217M063). The purpose of my study is to design and manufacture of asymmetric spur gear forging dies. For this purpose, the study focuses on the following:
1. Evaluation of the die stresses encountered by forging load, 
2. Evaluation of the shrink fitting and presenting shrink fit design criteria for asymmetric gear forging die,
3. Evaluation of the parameters that affects gear tooth accuracy,
4. Manufacturing gear forging die components,
5. Development of an image processing system for gear die measurements.

Supervisor : Prof. Dr. Omer Eyercioglu

Perios: M.Sc. Degree

Duration : 24 Months

Supporting Organization: The Scientific and Technological Research Council of Turkey (TUBITAK)

Situation: Completed

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2Design and Manufacturing of Asymmetric Spur Gear Forging Die
The gears, which are the basic elements in mechanical power transmission, have been in use for about 4000 years and have made great developments in the last century to suit the needs of modern technology. In recent years, the reductions of energy consumptions and environmental factors (reduction of carbon emissions) have gained importance, thus increasing the studies of reducing the weight of mechanical systems and increasing their efficiency. There are many important areas ranging from gearboxes for helicopters and motor vehicles to generators, lifting gears to gear pumps, work focusing on gear design and manufacturing with high precision and high efficiency. The use of asymmetric gears instead of standard gears is considered an innovative approach to this area. The production of the asymmetric gear profile by the conventional thread cutting method is dependent on the cutting tool design and the machining process, which limits the tooth profile. In the production of asymmetric gears, the use of precision forging technology will enable the production limitations stemming from the profile to be removed and the gears with high strength to be produced efficiently. For this purpose, the design of asymmetric gear forging dies, modeling of material flow and design of the forging process will be realized.<br />Prediction of the exact behavior of the enclosed die forging process is becoming increasingly essential and it also important to optimize the process design to reduce the required load and consumed energy [1]. Precision forging is a field in which decision support systems can be effectively and widely applied and depends on knowledge and rules derived from the past experience of forging die design engineers. Precise components are becoming quite important in attempts to reduce costs and improve reliability. There are thus many application areas in which the rules themselves become inherent to the parts or the processes. In forging die design, dimensional accuracy is one of the main goals [2]. But, there are many important parameters for designing forging die [3]. The process has been successfully applied to bevel, spur and helical gears in the near past. The process may be applied to the asymmetric gears with a proper die and process design. Precision forging technology facilitates the mass production of gears with many advantages in terms of cost and quality [4].<br />The purpose of this study is to design and manufacture of asymmetric spur gear forging dies. The load requirement and the resulting die stresses are determined by using finite element simulations and the die components will be designed accordingly. The die components will be manufactured using CNC machining, wire EDM cutting and/or laser cutting methods. A prototype asymmetric gear (made of a soft material like lead or plasticine) will be manufactured to validate the designed die.</p>

Supervisor : Prof. Dr. Omer Eyercioglu

Perios: M.Sc. Degree

Duration : 24 Months

Supporting Organization: The Scientific and Technological Research Council of Turkey (TUBITAK)

Situation: Completed

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3MA.Vision.Gauge: Gear Measurement Based on Image Processin Technique
In this study, a non-contact measurement method based on image processing to measure the asymmetric spur gear is presented. The digital image of the asymmetric spur gear is captured by the CMOS camera and the software is developed by using Python and as OpenCV image processing library. Some digital image processing techniques and algorithms are used, including distortion correction, frame resizing, color conversion, median filter, binarization, edge detection, and sub-pixel fitting arithmetic. According to the shape feature of the asymmetrical gear, some basic principles such as fit to least squares, Hough transformation and Bresenham drawing circle were applied and the algorithm for measurement of the number of teeth, tooth width and height, addendum, dedendum and pitch diameters, and tooth profile errors was developed. The theoretical gear dimensions and the 3D CMM measurements were compared with the image processing results. The results show that this method satisfies the requirements of real-time inspection of asymmetric gears.

Supervisor : Prof. Dr. Omer Eyercioglu

Duration : 24 Months

Supporting Organization: (Gaziantep University) BAPYB

Situation: Completed

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4MA.inDie v20: Asymmetric Spur Gear Forging Die Desing Software
In order to determine the shrink fit parameters and die geometry corrections of the asymmetric spur gear die, computer software was developed. The software was developed by using well known Python programming language [66]. Python is a very powerful programming language especially manipulating data [67]. The developed software has a shrink-fit design (MA.inDie.ShrinkFit) and a die geometry correction (MA.inDie.Shrinkage) modules. The details of the developed software are given in web address in below. It was integrated into the gear forging die design package which was prepared for the project [53]. The gear forging die design package has two more modules; gear measurement with image processing technique (MA.VisionGauge) and forging load calculation by upper limit method (MA.inDie.Forge), and a material database (MA.inDie.Material).

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5Large Scale Additive Manufacturing System Desing and Manufacturing
A direct extrusion system shown in Figure 1 is designed, manufactured and it was replaced with the spindle of the 3-axis CNC unit available in the department. The maximum displacements in X Y and Z directions are 1800, 2500, and 400 mm, respectively. The extruder is a single screw extruder and it is driven by a variable speed motor. The ABS granules are feeding through the extruder by an automatic feeder. The number of granules and the speed of the screw can be controlled to melt and deposit molten polymer at a rate consistent with the movement of the axes (building speed) and desired bead profile. The barrel has band heaters and a control unit to keep the chamber and nozzle temperatures in the required ranges. In the experimental study 6 mm diameter nozzle was used. A rolling unit is also integrated into the system to spreading the wall width and bead profile.

Supervisor : Prof. Dr. Omer Eyercioglu

Perios: Bachlelor's degree graduation project

Duration : 8 Months

Supporting Organization: Gaziantep University

Situation: Completed

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