Design of Constant-Velocity Transmission Devices Using Parallel Kinematics Principle

2014 ◽  
Author(s):  
Jingjun Yu ◽  
Jiazhu Yu ◽  
Kang Wu ◽  
Xianwen Kong
Keyword(s):  
Constant Velocity ◽  
Parallel Mechanisms ◽  
Parallel Kinematics ◽  
Pure Rolling ◽  
Motion Range ◽  
New Type ◽  
Moving Coordinate ◽  
Instant Screw Axis ◽  
Velocity Transmission ◽  
Spherical Gear

This paper presents a new type of constant-velocity transmission devices based on parallel mechanisms with properties of equal-diameter spherical pure rolling. The method we used is essentially an extension of the planar ellipse gear to the spherical one. Both the fixed and moving axodes of a specified parallel mechanism are obtained, as traced by the spatial instant screw axis (ISA) with respect to the fixed and moving coordinate systems. Based on Poinsot’s theorem and achievements, a series of these parallel mechanisms which satisfy constant-velocity condition have been disclosed correspondingly. Their motion range and transmission performances are also explored by taking the 3-4R mechanism as an instance. As the main part of this paper, two important applications for this type of constant-velocity transmission devices are also explored. One is used as a gearless spherical gear, and the other is used as a constant-velocity universal joint (CVJ). Simulations were fulfilled on ADAMS to verify the transmission performance in terms of different applications.

scholarly journals The Design of a Novel Prismatic Drive for a Three-DOF Parallel-Kinematics Machine

2005 ◽  
Vol 128 (4) ◽  
pp. 710-718 ◽  
Author(s):  
D. Chablat ◽  
J. Angeles
Keyword(s):  
Parallel Robot ◽  
Rolling Motion ◽  
Parallel Kinematics ◽  
Cam Mechanism ◽  
Pure Rolling ◽  
Parallel Kinematics Machines

The design of a novel prismatic drive is reported in this paper. This transmission is based on Slide-o-Cam, a cam mechanism with multiple rollers mounted on a common translating follower. The design of Slide-o-Cam was reported elsewhere. This drive thus provides pure-rolling motion, thereby reducing the friction of rack-and-pinions and linear drives. Such properties can be used to design new transmissions for parallel-kinematics machines. In this paper, this transmission is intended to replace the ball-screws in Orthoglide, a three-dof parallel robot intended for machining applications.

Development of the Variable-Rate Transymmetric Motion With Discretely Vanishing Shock

1984 ◽  
Vol 106 (1) ◽  
pp. 109-113 ◽  
Author(s):  
S. N. Kramer
Keyword(s):  
Constant Velocity ◽  
Angular Displacement ◽  
Operating Cost ◽  
Dynamic Responses ◽  
Variable Rate ◽  
Constant Acceleration ◽  
Functional Relationships ◽  
Rest Position ◽  
New Type ◽  
Velocity Motion

In industry when a link, crank, or other mechanical component is to be rotated from one rest position to another, it is necessary to establish appropriate functional relationships for angular displacement, velocity, and acceleration versus time such that the output motion satisfies certain kinematic and dynamic requirements. In the work presented here, a new type of motion is developed which has distinct advantages over constant velocity motion, constant acceleration motion, simple harmonic motion, cycloidal motion, and polynomial motions. The “variable-rate transymmetric” motion allows a designer to assign specific portions of the motion to be described by a linearly varying acceleration and other portions by a constant acceleration. As a result, the designer can decrease the power required, decrease the operating cost, and decrease dynamic responses such as shock, vibration, and shaking force.

Uncoupled actuation of overconstrained 3T-1R hybrid parallel manipulators

Robotica ◽  
2009 ◽  
Vol 27 (1) ◽  
pp. 103-117 ◽  
Author(s):  
Chung-Ching Lee ◽  
Jacques M. Hervé
Keyword(s):  
Lie Group ◽  
Constant Velocity ◽  
Algebraic Approach ◽  
Parallel Manipulators ◽  
Parallel Mechanisms ◽  
Algebraic Properties ◽  
Lie Subgroup

SUMMARYBased on the Lie-group-algebraic properties of the displacement set and intrinsic coordinate-free geometry, several novel 4-dof overconstrained hybrid parallel manipulators (HPMs) with uncoupled actuation of three spatial translations and one rotation (3T-1R) are proposed. In these HPMs, three limbs are those of Cartesian translational parallel mechanisms (CTPMs) and the fourth limb includes an Oldham-type constant velocity shaft coupling (CVSC). The Lie subgroup of Schoenflies (X) displacements of the displacement Lie group and its mechanical generators with nine categories of their general architectures are recalled. A comprehensive enumeration of all possible Oldham-type CVSC limbs is derived fromX-motion generators. Their constant velocity (CV) transmissions are verified by group-algebraic approach. Then, combining one CTPM and one CVSC, we synthesize a lot of uncoupled 3T-1R overconstrained HPMs, which are classified into nine distinct classes of general architectures. In addition, all possible architectures with at least one hinged parallelogram or with one cylindrical pair are disclosed too. At last, related non-overconstrained HPMs are attained by the addition of one idle pair in each limb of the previous HPMs.

The Generation Principle and Mathematical Models of a Novel Spherical Gear Drive

2012 ◽  
Vol 479-481 ◽  
pp. 1421-1428 ◽  
Author(s):  
Jian Wang ◽  
Liang Hou ◽  
Shan Ming Luo
Keyword(s):  
Mathematical Models ◽  
Load Capacity ◽  
Tooth Profile ◽  
Gear Transmission ◽  
Gear Drive ◽  
New Type ◽  
Spherical Gear

A new type of spherical gear drive, which takes micro-segment involute profile as tooth profile, is presented in this paper. The generation principle of the spherical gear is described. The mathematical models including the equation of micro-segment involute profile, the equation of the conjugate tooth profile and the engagement equation, are established based on the meshing theory. This new type of spherical gear drive has the potential to improve the load capacity and the performance of spherical gear transmission.

Positive Analysis of a New Type of Planar 3-DOF Parallel Mechanisms

2012 ◽  
Vol 522 ◽  
pp. 659-662
Author(s):  
Zhao Xin Meng ◽  
Xiao Gang Lei ◽  
Chao Mei Zhang
Keyword(s):  
Mathematical Model ◽  
Error Analysis ◽  
Positive Solution ◽  
Parallel Mechanism ◽  
Control Algorithm ◽  
Movement Analysis ◽  
Parallel Mechanisms ◽  
New Type ◽  
And Control ◽  
Polygon Method

The planar 3-DOF parallel mechanism was developed as a part of the pushing device for the wood sawing. Using closed vector polygon method to make positive movement analysis of the mechanism, establish the positive solution mathematical model. It provided the theory bases for the error analysis and control algorithm of the planar 3-DOF parallel mechanism.

The Optimum Design of a 6 DOF Fully-Parallel Micromanipulator for Enhanced Robot Accuracy

1989 ◽  
Author(s):  
C.-S. Han ◽  
D. Tesar ◽  
A. E. Traver
Keyword(s):  
Optimization Theory ◽  
Local Stress ◽  
Internal Force ◽  
Scale Model ◽  
Robot Accuracy ◽  
Cad Cam ◽  
Deflection Analysis ◽  
Motion Range ◽  
Critical Components ◽  
Velocity Transmission

Abstract The micromanipulator is a small amplitude, high resolution motion device to enhance robot accuracy by providing fine adjustments for precise error compensation and delicate force control. This paper addresses design objectives and optimization procedures for design of a unique 6 degree-of-freedom (DOF) fully-parallel micromanipulator. Using kinematic and dynamic modeling analysis, optimum geometric parameters are found which satisfy the desired motion range, effective force and velocity transmission and minimum input loading due to the bending of flexural joints. Computer simulations, optimization theory, and the finite element method are used to model, synthesize, and analyze micromanipulator components. Internal force analysis is performed to design the hardware components for critical load conditions. Using a CAD/CAM system, a full scale model of the mechanism has been created, and local stress and deflection analysis has been performed on the critical components.

Kinematic Design of a Large-Angular-Motion Constant-Velocity Coupling

1994 ◽  
Author(s):  
Stephen L. Canfield ◽  
Robert J. Salerno ◽  
Charles F. Reinholtz
Keyword(s):  
Range Of Motion ◽  
Mathematical Description ◽  
Constant Velocity ◽  
Solid Angle ◽  
Angular Motion ◽  
Joint Angles ◽  
Spatial Mechanism ◽  
Kinematic Design ◽  
New Type ◽  
Analytical Expressions

Abstract This paper describes a new type of constant-velocity coupling capable of producing solid joint angles greater than 180 degrees. Analytical expressions describing the range of motion are developed based on the kinematic closure equations of an equivalent spatial mechanism. This mathematical description is then used as a tool in the kinematic design and analysis of a constant-velocity coupling capable of producing a 240 degree solid angle output motion.

Structural Design and Simulation Optimization of New Type Telescoping Heavy Hydraulic Trailer Steering System

2012 ◽  
Vol 233 ◽  
pp. 47-50
Author(s):  
Rui Guo ◽  
Jing Yi Zhao ◽  
Yong Chang Wang ◽  
De Cai Han
Keyword(s):  
Power Consumption ◽  
Product Life Cycle ◽  
Simulation Optimization ◽  
Steering System ◽  
Front Axle ◽  
Steering Wheel ◽  
Pure Rolling ◽  
New Type ◽  
Turning Radius

The length variability of telescoping heavy hydraulic trailer wills casue friction and sliding, increasing drag torque and power consumption of steering, moreover, and reducing the security and reliability of steering, so the new type follow-up steering system is designed and studied. In order to reduce the turning radius and tire wear, the adjustable steering wheel structure and double front axle mechanism are designed. On this basis, the theoretical analysis of the steering system is carried out, and the mathematical model is established. The minimum error of actual and ideal angle is regarded as the optimization goal of pure rolling condition, and the simulation optimization and experimental research is done. The results show that: the steering structural optimization is feasible, the performance is optimal on the condition that the actual and ideal angle valves of inside and outside wheels of each axis are approximately equal in turning process, and can reflect the advantage of new follow-up steering system in lowering power consumption, improving product life cycle and other areas.

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