• Title/Summary/Keyword: Spherical Bearing

Search Result 64, Processing Time 0.033 seconds

The study on the friction characteristics of spherical hydrostatic bearing for hydraulic piston motor (유압모터 구면 정압베어링의 마찰특성에 관한 연구)

  • 함영복;최영호;김성동
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2001.04a
    • /
    • pp.647-650
    • /
    • 2001
  • In case of bent axis type axial piston hydraulic pump or motor, hydrostatic bearing used to achieve the lubrication effect on the mechanical sliding contact areas between the following pairs ; piston shoe and swash plate, valve plate and cylinder block, piston and cylinder block, etc. In this research, we designed two pairs of spherical ball joint in witch connecting rod piston end. The one is not hydrostatic bearing, the other is designed with spherical hydrostatic bearing in point of view minimum pumping power loss. By varying supply pressure on the piston, we can know that it is possible to reduce the friction torque by using hydrostatic bearing designed one. Finally, by comparing the results of driving torque between the two models, it was verified that the spherical hydrostatic bearing is well designed.

  • PDF

Characteristics and Replacement of Separated Spherical Bridge Bearings (분리형 스페리칼 교량받침의 특징 및 교체실험)

  • Park, Sung-Woo;Liu, Syung-Kyu;Choi, Eun-Soo
    • Proceedings of the KSR Conference
    • /
    • 2008.06a
    • /
    • pp.1729-1734
    • /
    • 2008
  • This study developed a new separated shperical bridge bearing that can be used for replacement of existing bridge bearings without crushing bearing-concrete. The separated spherical bearing have the upper and lower sole plate connected by bolts to the upper plate under bridge-girders and the lower plate on bearing-concrete. The targets of the separated spherical bearing are the maximum 3 mm of up-lifting height during replacement and the maximum required time of 30 minutes. Four separated spherical bearings are manufactured and replaced the existing bearings of a railway bridge in service and the replacing tests was performed. The number of the tests is two and the target of maximum 3 mm and 30 minutes was satisfied.

  • PDF

Behavior of Bridge Bearings for Railway Bridges under Running Vehicle

  • Choi, Eun-Soo;Yu, Wan-Dong;Kim, Jin-Ho;Park, Sun-Hee
    • International Journal of Railway
    • /
    • v.5 no.1
    • /
    • pp.10-21
    • /
    • 2012
  • Open steel plate girder (OPSG) bridges are the most prevalent railroad bridge type in Korea, constituting about 40% of all railroad bridges. Solid steel bearings, known as line type bearings, are placed in most OSPG railway bridges. However, the line type rigid bearings generate several problems with the bridge's dynamic behavior and maintenance in service. To compare and investigate the dynamic behaviors of line type, spherical and disk bearings, the vertical displacements of each bearing, including fixed and expansion type, under running vehicles are measured and analyzed. The displacements of disk and spherical bearings are measured after replacing the line type bearings with spherical and disk bearings. This study also analyzed dynamic behaviors of bridges. Furthermore, the deformation of the PTFE (Polytetrafluoroethylene) plate that is placed inside of expansion type spherical and disk bearings is measured and its effect on the dynamic behavior of the bridges is discussed. The up-lift phenomenon at the bearings installed for the steel bridges is estimated. The vertical displacements at mid-span of the bridges are compared according to the bearing types. Finally, the 1st mode natural frequencies are estimated, and the relationship to the vertical displacement is discussed.

Development of Friction Torque Measurement Device for Spherical Hydrostatic Bearing (구면 정압베어링의 마찰토크 측정장치 개발)

  • 함영복;최영호;박경민;윤소남;김광영
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2002.05a
    • /
    • pp.181-186
    • /
    • 2002
  • Lately, as going on increasing in the demand of high power density(power/weight), it is necessary for hydraulic axial piston pump/motor to operate more high pressure and speed. But in these condition, there are some trouble like as friction loss. To reduce this friction loss, hydrostatic bearing is used far axial piston pump/motor frequently. In general, it is difficult to measure accurate friction torque of spherical hydrostatic bearing in the use of the existing devices. So, we have developed the measurement device using the reaction torque sensor to obtain the pure friction torque, fitted in the casing. In this report, we intend to make an introduction about this measurement device for friction torque of the spherical wear part and clarify the effect of friction characteristics on supply pressure and rotational speed with three types of pocket size by using this measurement device.

  • PDF

Application of Fe-Mn Damping Alloy for Divided Spherical Bearing in Bridge (Fe-Mn 제진금속을 적용한 교량용 교좌장치)

  • Han, Dong-Woon;Kim, Tai-Hoon;Back, Jin-Hyun;Kim, Jung-Chul;Baik, Seung-Han;Yoo, Mun-Sik
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2006.05a
    • /
    • pp.1024-1028
    • /
    • 2006
  • The Fe-Mn damping Alloys which combine a high damping capacity with good mechanical properties can provide attractive technical and economic solutions to problems involving fatigue, noise and vibration. This study is aimed at finding its applicability to divided spherical bearing in bridge. The results obtained are summarized as follows : 1) The specific damping capacity of the Fe-Mn damping alloy is superior to that of SM490B. 2) The divided spherical bearing manufactured Fe-Mn damping alloy passes the load test to confirm applicability of that in bridge.

  • PDF

Application of Elastomeric Bearing for Railway Bridge (철도교량의 탄성받침 적용방안)

  • Kang, T.W.;Oa, S.W.;Kim, D.S.;Kang, Y.S
    • Proceedings of the KSR Conference
    • /
    • 2010.06a
    • /
    • pp.1697-1702
    • /
    • 2010
  • It has been recognized for decades that the spherical bearing which is sliding on curved surface in the intrinsic behavior is optimized for the railway bridge requiring a large slope deflection. However, the spherical bearing is easily corrosived at the PSC girder bridge which is exposed to the outside so the normal function of bridge bearing is not fulfilled fully. It is common that the corrosion is happened at the operating plate of steel bridge bearing and generally it is necessary to replace the bridge bearing after 20~25 years. Accordingly, It costs multi billion dollars for maintenance each year and the necessity of improvement become a issue. Korea Rail Network Authority(KR) suggested to apply the Elastomeric bearing instead of Spherical bearing through the task of construction site of 2006. But the normal Elastomeric bearing is optimized for the Highway bridge so it needs the special consideration to satisfy each design condition required by railway bridge. As the result of examination of Elastomeric bearing at the railway bridge construction site, the stress is decreased by effective dispersion of earthquakes and the maintenance fee is also decreased.

  • PDF

A Study on the Shape Design and Nonlinear Analysis of Elastomeric Spherical Bearings for Railway Bridge Systems (철도교용 반구면 탄성체 베어링의 형상설계 및 해석에 관한 연구)

  • Oh, Ju;Cho, Hyun-Jin;Lee, Wan-Ha;Park, Jin-Young;Park, Kun-Nock
    • Proceedings of the KSR Conference
    • /
    • 2009.05a
    • /
    • pp.589-592
    • /
    • 2009
  • In this paper is presenting the shape design and elastomer bearings, which functioned as a joint connecting sub-structures and upper-structures with a railway bridge bearing systems. The elastomeric spherical bearing shaped and composed of alternated 17-layered metal shim plates and 18-layered elastomer plates, respectively. The elastomeric spherical bearing a high compressive load for perpendicular axis to layered plates and flexible motions are provided coincidently for other axes. The three types of elastomers, which were developed due to a designed shear modules were applied. Nonlinear analysis based on the material properties of designed bearing were accomplished. Therefore, the Nonlinear Analysis results were compared with the calculation results and the optimized shapes were designed.

  • PDF

Maintenance and Dynamic Behavior of Advanced Spherical Bearings under Railway Open-Steel-Plate-Girder Bridges (판형교에서 개량된 스페리칼받침의 유지보수 및 동적 거동)

  • Choi, Eun-Soo;Lee, Hee-Up;Lee, Seung-Yong
    • Journal of the Korean Society for Railway
    • /
    • v.11 no.2
    • /
    • pp.165-175
    • /
    • 2008
  • Line type rigid bearings for Open-Steel-Plate-Girder railway bridges have several problems in service, and they are unstable structurally. A series of lateral resistance tests were performed for a retrieved line type bearing. A spherical bearing with advanced maintenance-capability and a device to resist the up-lift was developed and replaced the existing ones. An experiment of maintenance for a new spherical bearing under real Open-Steel-Plate-Girder bridge was conducted and their good maintenance performance was proved. Also, a test against up-lift was performed for the bearing. The dynamic behavior of the bridge was measured and analyzed for the two cases of the existing and replaced bearings. Therefore, the suitability of the new spherical bearings on the railway bridge was improved.

A Study on Air-Lubricated Spherical Tilting Pad Bearings (공기윤활 구면틸팅패드베어링에 대한 연구)

  • 김성국;김경웅
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
    • /
    • 1998.10a
    • /
    • pp.160-165
    • /
    • 1998
  • A theoretical analysis has been undertaken to show the influence of bearing geometry on the steady state characteristics of air lubricated spherical tilting pad bearings. The geometry variations considered are the number of pads, the eccentricity ratio, the direction of load, and the preloading.

  • PDF

Seismic control of high-speed railway bridge using S-shaped steel damping friction bearing

  • Guo, Wei;Wang, Yang;Zhai, Zhipeng;Du, Qiaodan
    • Smart Structures and Systems
    • /
    • v.30 no.5
    • /
    • pp.479-500
    • /
    • 2022
  • In this study, a new type of isolation bearing is proposed by combining S-shaped steel plate dampers (SSDs) with a spherical steel bearing, and the seismic control effect of a five-span standard high-speed railway bridge is investigated. The advantages of the proposed S-shaped steel damping friction bearing (SSDFB) are that it cannot only lengthen the structural periods, dissipate the seismic energy, but also prevent bridge unseating due to the restraint effectiveness of SSDs in the large relative displacements between the girders and piers. This study first presents a detailed description and working principle of the SSDFB. Then, mechanical modeling of the SSDFB was derived to fundamentally define its cyclic behavior and obtain key mechanical parameters. The numerical model of the SSDFB's critical component SSD was verified by comparing it with the experimental results. After that, parameter studies of the dimensions and number of SSDs, the friction coefficient, and the gap length of the SSDFBs were conducted. Finally, the longitudinal seismic responses of the bridge with SSDFBs were compared with the bridge with spherical bearing and spherical bearing with strengthened shear keys. The results showed that the SSDFB can not only significantly mitigate the shear force responses and residual displacement in bridge substructures but also can effectively reduce girder displacement and prevent bridge unseating, at a cost of inelastic deformation of the SSDs, which is easy to replace. In conclusion, the SSDFB is expected to be a cost-effective option with both multi-stage energy dissipation and restraint capacity, making it particularly suitable for seismic isolation application to high-speed railway bridges.