Force Analysis of Double Pitch Point Cycloid Drive with Intermediate Rolling Elements and Free Retainer

2015 ◽  
Vol 756 ◽  
pp. 29-34
Author(s):  
E.A. Efremenkov ◽  
E.E. Kobza ◽  
S.K. Efremenkova
Keyword(s):  
Performance Improvement ◽  
Wedge Angle ◽  
Force Distribution ◽  
Force Analysis ◽  
Angle Variation ◽  
Rolling Elements ◽  
Further Development

This paper illustrates the analysis of wedge angle influence on force distribution in the meshing of double pitch point cycloid drive in comparison with single pitch point cycloid drive. Double pitch point cycloid drive may provide smoother performance of transmission at starting period in consequence of wedge angle variation capabilities. Matching initial parameters it is possible to modify the wedge angle and achieve its effective value. The influence of various combinations of initial parameters on the wedge angle and retainer force was studied and presented on diagrams. Some recommendations in designing related to performance improvement are given. The obtained results can be used for further development of better designs of cycloid drives.

Force Analysis of the Film in a COF Chip Mounter’s Loader

2004 ◽  
Author(s):  
Dein Shaw ◽  
H. C. Lin
Keyword(s):  
Friction Force ◽  
Relative Motion ◽  
Lower Layer ◽  
Axial Direction ◽  
Tension Force ◽  
Force Distribution ◽  
Force Analysis ◽  
Transportation Vehicle

In this study, the tension force distributions in the film of COF cartridge are studied. It is noted that if the tension force on the film is too high, the interface between chip and film cracked. If the force is too low, there is no enough friction force to keep the COF in fix position when the cartridge is on the transportation vehicle. The relative motion between the chips of lower layer and the film of upper layer will cause the fatigue of interface of chips and film. It is also important to note that due to the friction the tension force at any section of the film is different. To fine the force distribution, a method to determine the tension force is developed and only effect of axial direction is considered. The assumption makes the film behave like a string. The results show that the forces on the film are different whenever the film passes a chip underneath.

New Focus on Gearbox Condition Monitoring for Failure Prevention Technology

2013 ◽  
Vol 588 ◽  
pp. 184-191 ◽  
Author(s):  
Walter Bartelmus
Keyword(s):  
Condition Monitoring ◽  
Degradation Process ◽  
Dust Particles ◽  
Oil Contamination ◽  
Failure Prevention ◽  
Operation Conditions ◽  
Frictional Wear ◽  
Rolling Elements ◽  
Oil Purification ◽  
Further Development

Condition monitoring is a tool for detection of faults and failure prevention. Fault andfailure are regarded as inevitable during the machine operation as the process of wear and theprocess of degradation. The question is, if one can influence the wear and degradation process,using condition monitoring. The paper will present technology which demonstrates that the use ofthe proper method can influence the wear and machine degradation process, using proper conditionmonitoring techniques and knowing scenarios of wear and degradation process. In the discussionpresented in the paper as a prerequisite has been taken that machinery works in severe dustyenvironment and varying operation conditions. It has been pointed that degradation process is notjust simply development of one fault. Most research for developing technology for conditionmonitoring is concentrated on one fault development. If one considers condition monitoring for acrack and brakeage of a tooth in gearbox, one should take in consideration that tooth crack andbrakeage is the result of several events, like rolling elements bearing frictional wear, which causesecondary misalignment of shaft and gears. The frictional wear is caused by dust particles whichget into oil from the environment in which a gearbox is operating. To avoid an influence ofcontaminated oil, contamination proactive technology should be used for the assessment of thedegree of contamination and the decision on oil purification or change should be taken. The wholeprocess connected with a gearbox condition change (wear and degradation process) shall bedescribed in the paper. The oil purification or its replacement extends the live of gearboxes butlong live of a gearbox, even with very little contamination causes some frictional wear of bearingsand finally secondary misalignment. To avoid further development of degradation process propertechnology should be used. There is a need to measure the degree of misalignment and makedecision on bearings replacement, in order to avoid further gearbox degradation, like teeth scuffingwhich may leads to crack initiation.

Analysis and Synthesis of Multi-Rotor Aerial Vehicles

2011 ◽  
Author(s):  
Qimi Jiang ◽  
Daniel Mellinger ◽  
Christine Kappeyne ◽  
Vijay Kumar
Keyword(s):  
Experimental Studies ◽  
Force Distribution ◽  
Force Analysis ◽  
Analysis And Synthesis ◽  
Angular Velocities ◽  
Aerial Vehicle ◽  
Position And Orientation ◽  
Configuration Synthesis ◽  
Save Energy ◽  
Optimal Set

This work addresses two basic problems of the multi-rotor aerial vehicle (MRAV). The first problem is the force analysis of the rotors. In order to save energy and maximize the lifetime of a given MRAV, the force distribution of the rotors is analyzed. As a result, an optimal set of angular velocities is obtained. The second problem is the configuration synthesis of the MRAV. In order to maximize the acceleration and improve the maneuverability of the MRAV, the geometric configuration (position and orientation) of the rotors is synthesized. The approaches for analysis and synthesis are presented and demonstrated by several case studies. The obtained results can be applied in the design of the MRAV and used as a guide for experimental studies.

scholarly journals Characteristics analysis of segmental and regional lumbar spontaneous compensation post thoracic fusion in Lenke 1 and 2 adolescent idiopathic scoliosis

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Kai Chen ◽  
Xiao Zhai ◽  
Tianjunke Zhou ◽  
Yu Deng ◽  
Beichen Zhang ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Demographic Data ◽  
Wedge Angle ◽  
Lumbar Region ◽  
Lumbar Curve ◽  
Angle Variation ◽  
Spontaneous Correction

Abstract Objective To explore the characteristics of compensation of unfused lumbar region post thoracic fusion in Lenke 1 and 2 adolescent idiopathic scoliosis. Background Preserving lumbar mobility in the compensation is significant in controlling pain and maintaining its functions. The spontaneous correction of the distal unfused lumbar curve after STF has been widely reported, but previous study has not concentrated on the characteristics of compensation of unfused lumbar region post thoracic fusion. Method A total of 51 Lenke 1 and2 AIS patients were included, whose lowest instrumented vertebrae was L1 from January 2013 to December 2019. For further analysis, demographic data and coronal radiographic films were collected before surgery, at immediate erect postoperatively and final follow-up. The wedge angles of each unfused distal lumbar segments were measured, and the variations in each disc segment were calculated at the immediate postoperative review and final follow-up. Meanwhile, the unfused lumbar curve was divided into upper and lower parts, and we calculated their curve angles and compensations. Results The current study enrolled 41 females (80.4%) and 10 males (19.6%). Thirty-six patients were Lenke type 1, while 15 patients were Lenke type 2. The average main thoracic Cobb angle and thoracolumbar/lumbar Cobb angle were 44.1 ± 7.7°and 24.1 ± 9.3°, preoperatively. At the final follow-up, the disc wedge angle variation of L1/2, L2/3, L3/4, L4/5 and L5/S1 was 3.84 ± 5.96°, 3.09 ± 4.54°, 2.30 ± 4.53°, − 0.12 ± 3.89° and − 1.36 ± 2.80°, respectively. The compensation of upper and lower coronal lumbar curves at final follow-up were 9.22 ± 10.39° and − 1.49 ± 5.14°, respectively. Conclusion When choosing L1 as the lowest instrumented vertebrae, the distal unfused lumbar segments’ compensation showed a decreasing trend from the proximal end to the distal end. The adjacent L1/2 and L2/3 discs significantly contributed to this compensation.

scholarly journals Characteristics Analysis of Segmental and Regional Lumbar Spontaneous Compensation Post Selective Thoracic Fusion in Lenke 1 and 2 Adolescent Idiopathic Scoliosis

2021 ◽  
Author(s):  
Kai Chen ◽  
Xiao Zhai ◽  
Tianjunke Zhou ◽  
Yu Deng ◽  
Shaofeng Chen ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Demographic Data ◽  
Wedge Angle ◽  
Lumbar Region ◽  
Angle Variation ◽  
Selective Thoracic Fusion ◽  
Characteristics Analysis

Abstract Objective To explore the characteristics of compensation of unfused lumbar region post selective thoracic fusion in Lenke 1 and 2 adolescent idiopathic scoliosis Method A total of 51 Lenke 1 and2 AIS patients were included, whose lowest instrumented vertebrae was L1 from January 2013 to December 2019. For further analysis, demographic data and coronal radiographic films were collected before surgery, at immediate erect postoperatively and final follow-up. The wedge angles of each unfused distal lumbar segments were measured, and the variations in each disc segment were calculated at the immediate postoperative review and final follow-up. Meanwhile, the unfused lumbar curve was divided into upper and lower parts, and calculated their curve angles and compensations.Results The current study enrolled 41 females (80.4%) and 10 males (19.6%). 36 patients were Lenke type 1, while 15 patients were Lenke type 2. The average main thoracic Cobb angle and thoracolumbar/lumbar Cobb angle were 44.1±7.7°and 24.1±9.3°, preoperatively. At the final follow-up, the disc wedge angle variation of L1/2, L2/3, L3/4, L4/5 and L5/S1 was 3.84±5.96°, 3.09±4.54°, 2.30±4.53°, -0.12±3.89° and -1.36±2.80°, respectively. The compensation of upper and lower coronal lumbar curves at final follow-up were 9.22±10.39° and -1.49±5.14°, respectively.Conclusion When choosing L1 as the lowest instrumented vertebrae, the distal unfused lumbar segments' compensation showed a decreasing trend from the proximal end to the distal end. The adjacent L1/2 and L2/3 discs significantly contributed to this compensation.

scholarly journals Isotropic Design of Tendon-Driven Manipulators

1996 ◽  
Vol 118 (3) ◽  
pp. 360-366 ◽  
Author(s):  
Yeong-Jeong Ou ◽  
Lung-Wen Tsai
Keyword(s):  
Necessary Conditions ◽  
Degree Of Freedom ◽  
Mechanical Transmission ◽  
Force Distribution ◽  
Static Force ◽  
Design Equation ◽  
Force Analysis ◽  
Transmission Characteristics ◽  
Transmission Structure ◽  
Tendon Force

This paper deals with the synthesis of mechanical transmission structures for tendon-driven manipulators. Based on static force analysis, necessary conditions are developed for the synthesis of tendon-driven manipulators with isotropic transmission characteristics. It is shown that an n degree-of-freedom (dof) manipulator will possess the isotropic transmission characteristics, if it satisfies two isotropic conditions. Furthermore, a design equation is derived for the construction of isotropic transmission structure matrices and a three-dof spatial manipulator is synthesized to demonstrate the methodology. It is shown that the isotropic design leads to a more uniform tendon force distribution.

scholarly journals The Functional Interdependence of Wind Instrumentalists’ Embouchure and Their Craniofacial Features

2019 ◽  
Vol 15 (13) ◽  
pp. 17
Author(s):  
Miguel Pais Clemente ◽  
José Manuel Amarante ◽  
André Moreira ◽  
Afonso Pinhão Ferreira ◽  
Ricardo Vardasca ◽  
...  
Keyword(s):  
Infrared Thermography ◽  
Oral Exam ◽  
Force Distribution ◽  
Force Analysis ◽  
Teaching Techniques ◽  
Wind Instrumentalists ◽  
Lateral Cephalograms ◽  
Orofacial Region ◽  
Craniofacial Features ◽  
Dental Appointment

<p class="xp2">The criteria of performing a correct embouchure can differ according to particular craniofacial features. Different teaching techniques can also lead to specific patterns of a musician embouchure, where playing in a relaxed position is one of the major indications. In order to understand if there is a “perfect embouchure”, several techniques were used on the analysis of the embouchure of three different wind instrumentalists. Force sensing resistors were applied to the mouthpiece of a clarinet, infrared thermography was performed to a brass player, while a bassoon player underwent two lateral cephalograms. The examinations techniques were chosen to take advantage of the possible information that could be taken from each musician, on addition to the evidence of the intra-oral exam. The force analysis showed that the clarinetist had an asymmetrical force distribution among the two central incisors. The infrared thermography showed that the tuba player had thermal asymmetry at the region correspondent to the masseters muscles possibly related to the teeth position. The lateral cephalograms showed a 10° posterior rotation of the mandible during the embouchure of the bassoon player. Therefore, understanding the anatomical limitations of the orofacial region, which may lead to an asymmetrical embouchure, is fundamental to analyze and treat a wind instrumentalist within a dental appointment.</p>

A Generalized Stiffness Matrix Method for Force Distribution of Robotic Systems with Indeterminancy

1993 ◽  
Vol 115 (3) ◽  
pp. 585-591 ◽  
Author(s):  
Xiaochun Gao ◽  
Shin-Min Song ◽  
Chun Qi Zheng
Keyword(s):  
Stiffness Matrix ◽  
Matrix Method ◽  
Robotic Systems ◽  
Force Distribution ◽  
Force Analysis ◽  
Chain Geometry ◽  
Walking Machines ◽  
Foot Force ◽  
Closed Chain ◽  
Finger Forces

Foot forces in walking machines and finger forces in multi-fingered grippers are usually indeterminate due to the multi-closed-chain geometry of the systems. While many methods were proposed to solve the force distribution of such systems, a method called stiffness matrix method [2] was developed based on the concept that the force must satisfy the equations of material deformations. However, only leg compliances were considered in the stiffness matrix method. In this paper, the stiffness matrix method is generalized to include all the major system compliances, i.e., those of legs (fingers), actuators and terrain (object to be grasped). Based on the developed generalized stiffness matrix method, an example of foot force analysis of a quadruped is presented to demonstrate the effects of different system compliances on the foot forces.

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