• Journal of Power System Engineering
• /
• v.11 no.4
• /
• pp.65-71
• /
• 2007

According to the survey, abnormal condition of the system is the main source for interrupting an elevator service, especially faults in worm gears used for the traction machine. Worm gear is popularly used in traction machine for middle and low speed elevators. Elevators need high reliability and stability, because they are closely related to human life. Usually, traction machine is applied to drive the elevators that have height about 35 m and it is an important mechanical unit for riding quality in elevators. There are some research results about types of vibration fault for worm gear in International Association Elevator Engineers (IAEE). But this study concerns with diagnosis of various faults in elevator worm gear using vibration signal. The analysis of fault characteristics is compared with previous researches in traction machine.

• Tribology and Lubricants
• /
• v.30 no.2
• /
• pp.86-91
• /
• 2014

This paper presents a design procedure for a face gear and pinion used in a handpiece with a $160^{\circ}\acute{y}$ contra angle and 1:2 gear ratio. Based on the geometric theory of gearing, the tooth profile of the face gear and pinion is developed. To analyze the contact pressure, the gear profile should be determined before calculating the stress between the two gears. The concept of calculating the face gear profile is that it can be generated by the coordinate transformation of the shaper profiles, which have involute curves, using a simulation method from the gear manufacturing process.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1996.03b
• /
• pp.156-164
• /
• 1996

As high capacity and precision forging presses have become available, it is possible to manufacture gears by forging technology. In gear manufacturing by forging, however, there are problems of designs of ides and preforms. In the present paper, two exampels are presented to show how the rigid plastic finite element method can be utilized to overcome the problems. The examples are spur gear forging and interanl-apline gear forging. Both analyses are three dimensional using eight node linear block elements with approximation that the involute curve can be represented by lines and arcs. Results of the analyses include metal flow in dies and required load during forging which aid to decide proper designs.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.04b
• /
• pp.39-44
• /
• 1995

The gas nitro-carburizing treatment with the merits of carburizing and nitriding treatment is recently applied to transmission gears. the shafls of an engine oil pump and steering shafls. For all that, the researches of the gas nitro-carburizing treatment are short of the fatigue behavior and the evaluation of fatigue life. In this paer, it is examined for the effect of inclusions and hole defects with fatigue limit and the evaluation of the fatigue strengthaccording tothe hardness and resifualstress with the specimen of a notro-carburizing treatment.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.959-963
• /
• 1996

Hardened layer and compressive residual stress created by carburized treatment effect on bending fatigue strength of gear massively. Also, shot peening treatment improves the strength of carburized gear as it does the hardness and residual stress of surface layer. In these days shot peening techniques are welcomed as one of physical improvement ways around the surface of materials. It is used widely because qualitative analysis of shot peening has become possible and surface treatment can be done with very little costs compared to other surface improvement methods. Therefore this study investigates the effect of shot peening in surface shape and bending fatigue strength after doing many kinds of shot peening treatments, then doing fatigue test and also explained characteristics of shot peening gear.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.2
• /
• pp.139-147
• /
• 2005

The lubricant impregnated MC nylon has good frictional properties, but its mechanical strength is inferior to steel for the mechanical elements. For the tribological application Nylon as gears, sliding bearings, cam and etc, the steel shafts are fitted in pre-heated nylon cylinder by a process of interference expansion fit and bonded by induction heating method. The joint shear strength of the two materials was measured by a universal test machine. From the study, the adhesive shear strength between these two materials was affected by the factors of the interference between nylon and steel, the size of nylon cylinder, knurl of steel shaft and inducting heating conditions. The most effective jointing conditions were analyzed and decided for the practical application in the industry.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1994.10a
• /
• pp.543-548
• /
• 1994

This is the paper on the development of assemnly automation and visual inspection system for smart card reader connector. The automation consists of 3 main process injection, assembly and inspection. During the injection, the main pin of a reel. transferred under uniform tension, is cut with an injection interval and positioned precisely to an injection mold by roll feeder after injection. The main base is stacked to a magazine for main pin's exact positionning to a mold . For last effective production, The turn table and pick & place are driver with gears and came by a single monter. We developed the small parts handling technigue for stable supply of micro ist pin and 2nd pin and could determine the orientation and position of those pins. For reliable inspection, We used the vision system which examins the guality of arranged pins with a CCD camera. The connector models which can be manufactured with this system are 8 pin and 10 pin type. The user can select the connector model for production and adjust the torerable error range during the inspection of arranged pins.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.857-860
• /
• 1996

The area of gear dynamics has recently been the focus of many studies. A new tooth profile modification was proposed by author for reducing vibration and noise of involute gears. A comparative dynamic analysis of the gear drive with the involute tooth and the modified tooth profile(using cubic splines) is performed to the unuformal transmission error reduces the gear vibration and noise due to less dynamic tooth load variation during the meshing cycle. This work also include a gear design process by the meaning of a practical approach, such as Win95 based simulation program with all using basic geardesign variables. Especially this program enables gear designers to dynamic analysis based on G.U.I.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.97-98
• /
• 2006

This study deals with the Transmission Error of gear tooth profile by modifying a Profile and lead of a surface of Tooth. First, we experimentally confirmed that the Transmission Error is a synthesis of the sliding Velocity between both gears. Since various types of Transmission errors appear in the experiments, we introduced definition of Transmission Error and The Optimism Design by modifying a surface parameters The test stand's performance is then evaluated through a series of multiple torque transmission error tests. Comparisons are made between data recorded before and after the test stand's redesign, and subsequently repeatability studies are performed to verify the veracity of the measured data. Finally, the experimental results are compared to the analytical predictions of two different gear analysis programs.

• International Journal of Precision Engineering and Manufacturing
• /
• v.8 no.3
• /
• pp.45-49
• /
• 2007

A gearing system emits inconsistent noises from the impact of gear teeth when defects are present, but it is not easy for a noise inspector on a production line to distinguish defective products objectively. Since customers constantly complain about various noises from geared motors, it is desirable to devise an analytical technique to classify motors. However, it is difficult to separate inconsistent noises due to defective gears from the overall noise produced by a geared motor using a general signal processing method such as a FFT because low frequency impulse signals have a tendency not to appear in the frequency domain. In this paper, we propose a method that can be used to obtain more objective estimates and measurements of inconsistent noises from a gearing system. The proposed method makes use of the cepstrum domain with an applied autocorrelation and comb lifter, followed by a domain inversion.