• Journal of Advanced Marine Engineering and Technology
• /
• v.35 no.6
• /
• pp.786-795
• /
• 2011

This paper described the characteristic of vibration in wind turbine system including gearbox housing, gear drive, blade, generator. Especially, in planetary gear set, planet gears are supported by flexible pin. So, in planet gear, to consider not only torsional movement but also lateral movement. And include housing movement, because wind turbine system is supported by mount. To find out the characteristic of vibration, take the excitation source and study campbell diagram in operating range. Results of campbell diagram, resonances are occurred at 81.2HZ, 104.7Hz by 2nd tooth passing frequency. And resonance are also occurred at 264.5HZ, 377Hz, 424.6Hz by 3th tooth passing frequency. From the result, take vibration reduced measures.

• International Journal of Automotive Technology
• /
• v.8 no.6
• /
• pp.799-806
• /
• 2007

One method for improving the torque capacity of the CVT is to use a split-powered CVT(SPCVT) to reduce the power transmitted into a continuously variable unit(CVU). A variable bridge SPCVT with two planetary gear units(PGUs), which are composed of a sun gear, a ring gear, and carrier and planetary gears, can minimize the power to the CVU. However, a SPCVT with a conventional CVT should possess a dual mode, which would allow the conventional CVT to be used at high speeds and an additional gear train to be used at low speeds. The inner-spherical CVU(ISCVU) with an inner and outer spherical contact mechanism developed in this study can cover the range from low to high speeds. The rated power and the overall speed ratios were 100 kW and $0.09{\sim}0.36$, respectively. Power efficiency was numerically calculated to be over 90% over the speed ratio range of $0.1{\sim}0.29$. The maximum shear stress at the two contact areas of the rotor pairs, the minimum life and the overall size were estimated to be 700 MPa, 276 kh and $350{\times}350{\times}400mm^3$, respectively. This study shows that an ISCVU and a variable bridge type PGU can realize the SPCVT with a single mode for a vehicle.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.5
• /
• pp.537-543
• /
• 2012

In this study, we experimentally investigate a noise mechanism related to the machining accuracy of the reducer in the driving state. We fabricate a planetary reducer and four types of gears for use in the planetary reducer. We use signal analysis to determine the noise and vibration of the reducer at different motor speeds; the motor speed is increased from 0 rpm to the maximum speed in a stepwise manner. In addition, we obtain the sound level by using a sound level meter. The machining accuracy of gears is evaluated by public organizations, Korea Testing Laboratory (KTL), on the basis of the Japanese Industrial Standard (JIS). We analyze and compare the results with the noise and vibration of the reducer.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.839-840
• /
• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.04a
• /
• pp.302-303
• /
• 2014

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.561-562
• /
• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.10a
• /
• pp.323-324
• /
• 2009

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.1195-1200
• /
• 2007

It is desirable that the guard robot should be small-sized and light-weighted to increase its portability. In addition, it should be able to overcome a relatively high obstacle to cope with different situations. The jumping robot can reach a higher place more rapidly than other locomotion methods. This research proposes the jumping mechanism based on the conical spring for a small robot. Both the clutch mechanism and conical spring are incorporated into the jumping mechanism. In the clutch mechanism, the spring can be immediately compressed and released by one actuator with the planetary gear train and one-way clutch. The robot equipped with the jumping mechanism can overcome the obstacles which are higher than its height. In this paper, the characteristic of the conical spring for the jumping robot is determined and the small-sized, lightweight jumping mechanism is developed. The validity of the jumping mechanism was verified by various experiments. It is shown that the robot using this mechanism can provide good mobility in the rough terrain.

• Journal of Advanced Marine Engineering and Technology
• /
• v.31 no.1
• /
• pp.34-43
• /
• 2007

As a method to improve the poor torque capacity on the continuously variable transmission(CVT), power splitted devices(PSD) reducing the power entering into the transmission has been considered. But this kind of PSD requires for the variator to be a large coverage of the speed ratio (CSR) Since the CSRs of the well-known push belt or the toroidal ones are not enough large, the power splitted CVTs (PSCVTs) using them should be made with multiple modes. inevitably adding the do9 clutches and the associated accessories. In this paper a PSCVT with single mode is conceptually designed A new continuously variable unit (CVU) consisting of the paired inner and outer spherical rotors is used. The CVU has large CSR and excellent compactness. As a PSD. a variable bridge (VB) using the Planetary gear units (PGUs) is considered because it has an upper bound on the power ratio. An optimal design to minimize the effective efficiency of the PSCVT is carried out. Through the performance analysis on the designed model, good expectation on the practicability in the heavy vehicle system is shown.

• Journal of the Korean Society for Precision Engineering
• /
• v.29 no.7
• /
• pp.770-777
• /
• 2012

This paper deals with the design and modal characteristics analysis of a drive-train for a paralleltype hybrid electric vehicle (HEV). The function of the drive-train system (DTS) in the HEV combines or divides the torque and velocity from the internal combustion engine along with the induction motor. The system consists of a compound planetary gear and unit's electromagnetic clutch to provide the operation modes such as Engine Only (EO), Electric Vehicle (EV), and Hybrid Electric Vehicle (HEV) modes. In order to investigate the characteristics of the velocity and torque flow for the system, dynamic models of the HEV with DTS are derived from the prototype DTS. The performance of the derived dynamic models is evaluated by both computer simulations and experiments according to each mode.