Complete Balancing of Space Mechanisms—Shaking Force Balancing

1983 ◽  
Vol 105 (4) ◽  
pp. 609-616 ◽  
Author(s):  
C. Bagci
Keyword(s):  
Mechanism Design ◽  
Total Mass ◽  
Force Transmission ◽  
The Subject ◽  
Gear Rack ◽  
Space Mechanisms

Complete balancing of shaking forces and shaking moments in space mechanisms is the subject of this article. Using real vectors, it presents methods of balancing shaking forces completely in space mechanisms. Force balancing of a mechanism is achieved by attaining a stationary center of the total mass of the mechanism. Design equations for force balancing of the RSSR, RSSP slider-crank and RSRC, CSC, and RCRC screw generators are developed. These mechanisms, their pair inversion mechanisms are force balanced thus establishing general guidelines for force balancing of space mechanisms. It is shown that SC and SRC dyads in space mechanisms also introduce force transmission irregularity in addition to the CRC, CCC, CRP, PRP, PSP, PSC dyads that introduce force transmission irregularity. Space mechanisms with force transmission irregularities are balanced by attaching a force balancing RRR dyad or a linearly moving conterbalancer driven by gear-rack drive, a belt, chain, or rolomite mechanism.

An Improved Alternative to the Three-Dimensional, Swash Plate Mechanism

1983 ◽  
Vol 105 (3) ◽  
pp. 468-470 ◽  
Author(s):  
T. E. Shoup ◽  
D. Chi
Keyword(s):  
Theoretical Analysis ◽  
Mechanism Design ◽  
Research Effort ◽  
Three Dimensional ◽  
Design Technique ◽  
Force Transmission ◽  
Swash Plate ◽  
Displacement Pump ◽  
Variable Displacement ◽  
Crank Mechanism

This paper presents a theoretical analysis and a design technique for the use of a special type of adjustable spatial slider crank mechanism to replace the swash plate device commonly used as a variable displacement pump or compressor. This paper is an extension of a previous research effort utilizing the RSSP mechanism [7] and considers the influence of geometric proportions of a device on stroke size, velocity fluctuation, and force transmission effectiveness. The device is shown to have significant kinematic advantages over the traditional form of the swash plate mechanism. Design curves are presented and an example application is provided.

scholarly journals Design and Development of a Compact High-Torque Robotic Actuator for Space Mechanisms

2017 ◽  
Vol 9 (6) ◽  
Author(s):  
Elias Brassitos ◽  
Nader Jalili
Keyword(s):  
Gear Ratio ◽  
System Level ◽  
Force Transmission ◽  
Torque Density ◽  
Output Force ◽  
Short Development Time ◽  
Transmission Structure ◽  
Drive Systems ◽  
Two Stages ◽  
Space Mechanisms

Space robots require compact joint drive systems (JDSs), typically comprising of actuator, transmission, joint elements that can deliver high torques through stiff mechanical ports. Today's conventional space drive systems are made from off-the-shelf actuators and multistage transmissions that generally involve three to six stages. This current practice has certain benefits such as short development time due to the availability of mechanical components. However, it lacks a system-level integration that accounts for the actuator structure, size and output force, transmission structure, gear-ratio, and strength, and often leads to long and bulky assemblies with large number of parts. This paper presents a new robotic hardware that integrates the robot's JDS into one compact device that is optimized for its size and maximum torque density. This is done by designing the robotic joint using a special transmission which, when numerically optimized, can produce unlimited gear-ratios using only two stages. The design is computerized to obtain all the solutions that satisfy its kinematic relationships within a given actuator diameter. Compared to existing robotic actuators, the proposed design could lead to shorter assemblies with significantly lower number of parts for the same output torque. The theoretical results demonstrates the potential of an example device, for which a proof-of-concept plastic mockup was fabricated, that could deliver more than 200 N·m of torque in a package as small as a human elbow joint. The proposed technology could have strong technological implications in other industries such as powered prosthetics and rehabilitation equipment.

scholarly journals Mechanism design and parameter optimization of a new asymmetric translational parallel manipulator

2019 ◽  
Vol 10 (1) ◽  
pp. 255-272
Author(s):  
Yi Yang ◽  
Yaqi Tang ◽  
Haijun Chen ◽  
Yan Peng ◽  
Huayan Pu
Keyword(s):  
Mechanism Design ◽  
Parallel Manipulator ◽  
Transmission Efficiency ◽  
Condition Numbers ◽  
Design Parameters ◽  
Evaluation Function ◽  
Force Transmission ◽  
Heavy Load ◽  
Pick And Place ◽  
Pick And Place Operation

Abstract. With the requirement of heavy load for pick-and-place operation, a new 3-DoF asymmetric translational parallel manipulator is invented in this paper. This manipulator is assembled by a kinematic limb with the parallel linear motion elements(PLMEs), and a single loop 2-UPR. Owning to the linear actuators directly connecting the moving and the fixed platforms, this parallel manipulator has high force transmission efficiency, and adapts to pick-and-place operation under heavy load. In this paper, the mobility and singularity are firstly analyzed by screw theory. And the simplified kinematic and dynamic model is established and solved. Secondly, the reaction forces of the prismatic joints in the PLMEs limb are investigated for the mechanism design. Also, the overall performance of the whole manipulator, such as the workspace, condition numbers of Jacobian matrices and motion transmission, etc, are discussed. Thirdly, a compound evaluation function, which involves the factors of workspace volume, transmission efficiency and reaction force, is proposed. In order to obtain a set of better design parameters, the optimization of the 3-DoF translational manipulator is conducted, for the object of maximum of the evaluation function. At last, the prototype is manufactured and experimented to validate the mobility and motion feasibility of this mechanism design.

scholarly journals SAFETY MEASURE OF MANDATORY TREATMENT FREEDOM OF ALCOHOLICS (STANDARD AND PRACTICE)

2021 ◽  
Vol 59 (2) ◽  
pp. 143-160
Author(s):  
Slađana Mi ◽  
◽  
Dragana Mitrović ◽  
Keyword(s):  
Total Mass ◽  
Criminal Code ◽  
Safety Measure ◽  
Security Measures ◽  
Safety Measures ◽  
Criminal Sanctions ◽  
Security Measure ◽  
The Subject ◽  
The Republic ◽  
Criminal Legislation

In accordance with modern understandings of criminal law science and solutions present in the comparative criminal legislation, the Criminal Code of the Republic of Serbia pays special attention to security measures as special and above all specific criminal sanctions. They are one of the four types of criminal sanctions provided for in this legal text. Among the eleven security measures, four are of a medical nature and they differ in a number of features, not only in relation to other criminal sanctions, but also other security measures. One of the medical safety measures is the obligatory treatment of alcoholics. There are a number of specifics of this security measure, and one of them is its manner of execution. Given this, the subject of analysis in the paper are two aspects of the safety measure of compulsory treatment of alcoholics. These are: normative and practical. The justification of this approach in the analysis of the subject matter is contained in the fact that only adequately performed and this security measure is in the function of its standardization - the function of eliminating conditions or conditions that may affect the perpetrator in the future does not commit crimes due to alcohol dependence. to the expression of criminal acts of violence that are increasingly present in the total mass of crime.

scholarly journals A Review of Dynamical Studies of Multiple Stars

1992 ◽  
Vol 135 ◽  
pp. 212-216
Author(s):  
Robert S. Harrington
Keyword(s):  
Total Mass ◽  
Body Problem ◽  
Dynamical Problem ◽  
Point Of View ◽  
Mass Ratio ◽  
Multiple Star ◽  
Multiple Stars ◽  
N Body Problem ◽  
The Subject ◽  
The Physical Realization

This is not going to be an exhaustive review of all of the literature on the subject of multiple star dynamics, although I will call your attention to the very recent review by Valtonen & Mikkola (1991) entitled “The Few-Body Problem in Astrophysics”. After all, from a dynamical point of view a multiple-star system is the physical realization of the n-body problem of celestial mechanics, and an enormous literature exists for that subject. Rather, this will be some personal thoughts on aspects of the few-body problem that are particularly relevant to the multiple-star astronomer.One should not forget the case of n=2. Although the problem is completely solvable and contains no surprises, it is one of our reasons to exist. Especially if a binary is on a photographic program, which can yield a parallax, a total mass, and a mass-ratio, and if photometry exists, as is usually the case now for parallax stars, a real contribution is possible. Do an orbit, which is the dynamical problem, and you have two more good points for the empirical mass/luminosity relationship, which is not a bad day’s work for the astrophysicist.

The Focusing Mechanism Design for Laser Anti-Counterfeit Platform in Production Manufacturing Engineering

2013 ◽  
Vol 345 ◽  
pp. 425-428
Author(s):  
Rui Tian
Keyword(s):  
Mechanism Design ◽  
Ball Screw ◽  
Zoom Lens ◽  
Guide Rail ◽  
Driving Mode ◽  
Design Requirements ◽  
Authentication System ◽  
Manufacturing Engineering ◽  
Gear Rack ◽  
Dsp Controller

Focusing mechanism is an important part of zoom lens in production manufacturing engineering, in order to meet the reading and detection of anti-counterfeiting label laser anti-counterfeit platform, this paper presents the principle and method of using linear driving mode focusing and introduces the focusing mechanism which consists of a stepping motor, linear guide rail, rail screw or gear rack, the DSP controller. By contrast test, it verifies the location precision ball screw type focusing mechanism for 0.061 ~ 0.067 mm which higher than the design requirements and it is suitable for use in laser anti-counterfeit authentication system in production manufacturing engineering.

Words

PMLA ◽  
1935 ◽  
Vol 50 (4) ◽  
pp. 1320-1327
Author(s):  
Colbert Searles
Keyword(s):  
Subject Matter ◽  
Assistant Professor ◽  
The Subject

THE germ of that which follows came into being many years ago in the days of my youth as a university instructor and assistant professor. It was generated by the then quite outspoken attitude of colleagues in the “exact sciences”; the sciences of which the subject-matter can be exactly weighed and measured and the force of its movements mathematically demonstrated. They assured us that the study of languages and literature had little or nothing scientific about it because: “It had no domain of concrete fact in which to work.” Ergo, the scientific spirit was theirs by a stroke of “efficacious grace” as it were. Ours was at best only a kind of “sufficient grace,” pleasant and even necessary to have, but which could, by no means ensure a reception among the elected.

Artificial satellite orbit computations

1966 ◽  
Vol 25 ◽  
pp. 363-371
Author(s):  
P. Sconzo
Keyword(s):  
Artificial Satellite ◽  
Satellite Orbit ◽  
Artificial Satellites ◽  
Orbital Elements ◽  
Differential Correction ◽  
Gravitational Effects ◽  
Short Intervals ◽  
The Subject ◽  
Introductory Discussion ◽  
Orbit Computation

In this paper an orbit computation program for artificial satellites is presented. This program is operational and it has already been used to compute the orbits of several satellites.After an introductory discussion on the subject of artificial satellite orbit computations, the features of this program are thoroughly explained. In order to achieve the representation of the orbital elements over short intervals of time a drag-free perturbation theory coupled with a differential correction procedure is used, while the long range behavior is obtained empirically. The empirical treatment of the non-gravitational effects upon the satellite motion seems to be very satisfactory. Numerical analysis procedures supporting this treatment and experience gained in using our program are also objects of discussion.

C. Wire Cabling for Telescope Systems

1966 ◽  
Vol 27 ◽  
pp. 159-161
Keyword(s):  
The Subject ◽  
Data Multiplexing

Rule: I'd like at this point to bring up the subject of cables and wireways around the telescope. We've touched upon this twice during previous sessions: the cable wrap up problem, the communications problem, and data multiplexing problem. I think we'll ask Bill Baustian if he will give us a brief run down on what the electrical run problems are, besides doubling the system every year.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

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