DESIGN AND ANALYSIS OF CAM MECHANISM WITH TRANSLATING FOLLOWER HAVING DOUBLE ROLLERS

2015 ◽  
Vol 39 (3) ◽  
pp. 397-406
Author(s):  
Jung-Fa Hsieh
Keyword(s):  
Kinematic Model ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Principal Curvatures ◽  
Surface Theory ◽  
Cam Mechanism ◽  
Pressure Angle ◽  
Straightforward Method ◽  
Cam Profile ◽  
Analytical Expressions

The pressure angle is one of the primary considerations in designing a cam mechanism since an inappropriate angle may cause excessive sliding loads on the follower. This paper presents a simple yet straightforward method for the design and analysis of a cam mechanism with a translating follower having double rollers. In the proposed approach, conjugate surface theory is employed to derive a kinematic model of the cam mechanism. Analytical expressions for the pressure angle and principal curvatures of the cam profile are then derived. The validity of the analytical expressions is confirmed by machining a designed cam using a 3-axis CNC machine tool.

Design of Cam Mechanisms with a Translating Follower Having Symmetrical Rollers

2015 ◽  
Vol 764-765 ◽  
pp. 233-238
Author(s):  
Jung Fa Hsieh
Keyword(s):  
Machine Tool ◽  
Kinematic Model ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Surface Theory ◽  
Cam Mechanism ◽  
Pressure Angle ◽  
Straightforward Method ◽  
Analytical Expressions

The pressure angle is one of the primary considerations in designing a cam mechanism since an inappropriate angle may cause excessive sliding loads on the follower. This paper presents a simple yet straightforward method for the design and analysis of a cam mechanism with a translating follower having double rollers. In the proposed approach, conjugate surface theory is employed to derive a kinematic model of the cam mechanism. Analytical expressions for the pressure angle is then derived. The validity of the analytical expressions is confirmed by machining a designed cam using a 3-axis CNC machine tool

DESIGN AND ANALYSIS OF CAM MECHANISM WITH NEGATIVE RADIUS ROLLER-FOLLOWER

2016 ◽  
Vol 40 (1) ◽  
pp. 89-100
Author(s):  
Jung-Fa Hsieh
Keyword(s):  
Angular Velocity ◽  
Design Methodology ◽  
Kinematic Model ◽  
Angular Acceleration ◽  
Principal Curvatures ◽  
Simple Method ◽  
Surface Theory ◽  
Cam Mechanism ◽  
Cam Profile ◽  
Analytical Expressions

This paper presents a simple method for the design and analysis of a cam mechanism with a negative radius roller-follower. In the proposed approach, conjugate surface theory is employed to derive a kinematic model of the cam mechanism. Analytical expressions for the pressure angle and principal curvatures of the cam profile are then derived. Finally, analytical expressions for the angular velocity and angular acceleration of the roller are derived. The validity of the proposed design methodology is demonstrated by machining a cam mechanism having a negative radius roller-follower with a radius of 100 mm.

DESIGN AND ANALYSIS OF OFFSET SLIDER-CRANK WITH TRANSLATING ROLLER-FOLLOWER

2011 ◽  
Vol 35 (3) ◽  
pp. 419-436 ◽  
Author(s):  
Jung-Fa Hsieh
Keyword(s):  
Kinematic Model ◽  
Transformation Method ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Principal Curvatures ◽  
Systematic Methodology ◽  
Cam Profile ◽  
Nc Data ◽  
Coordinate Transformation Method ◽  
Crank Mechanism

This paper presents a systematic methodology for the design and analysis of an offset slider-crank mechanism with a translating roller-follower. In the proposed approach, a generic kinematic model of the offset slider-crank and roller-follower is constructed using a homogenous coordinate transformation method and the slider cam profile are then derived using conjugate surface theory. The pressure angle and principal curvatures of the designed slider cam are analyzed based on the analytical expression of the cam profile. Finally, the NC data required to machine the slider cam are produced by equating the ability matrix of the 3-axis CNC machine tool with the desired tool location matrix.

Application of homogenous transformation matrix to the design and machining of a Geneva mechanism with curved slots

2007 ◽  
Vol 221 (11) ◽  
pp. 1435-1443 ◽  
Author(s):  
J-F Hsieh
Keyword(s):  
Design Methodology ◽  
Kinematic Model ◽  
Cnc Machine ◽  
Principal Curvatures ◽  
Surface Theory ◽  
Comprehensive Method ◽  
Design And Manufacturing ◽  
Cost Efficient ◽  
Indexing Mechanism ◽  
Nc Data

The current paper presents a simple yet comprehensive method for the design and machining of a Geneva indexing mechanism with curved slots. In the proposed approach, a kinematic model of the Geneva mechanism is developed using homogenous coordinate transformation and conjugate surface theory. The pressure angle of Geneva mechanism and the principal curvatures of the curved slots are analysed using an analytical expression derived for the slot profile. The NC data required to machine the driven with curved slots are derived from the CNC link variables by equating the machine tool ability function and the tool location matrix. The proposed design methodology is verified by machining the designed curved slots using a three-axis CNC machine. The results confirm that the approach presented in this study enables the Geneva mechanism design and manufacturing tasks to be successfully integrated, thus making possible a flexible, automatic, cost efficient, and controllable production process.

DESIGN AND ANALYSIS OF CONSTANT-BREADTH CAM MECHANISM WITH OSCILLATING FLAT-FACED FOLLOWER

2017 ◽  
Vol 41 (2) ◽  
pp. 211-225
Author(s):  
Jung-Fa Hsieh
Keyword(s):  
Design Methodology ◽  
Sliding Velocity ◽  
Principal Curvatures ◽  
Surface Theory ◽  
Cam Mechanism ◽  
Contact Points ◽  
Comprehensive Method ◽  
Cam Follower ◽  
Cam Profile ◽  
Constant Breadth

A simple yet comprehensive method is presented for the design and analysis of a constant-breadth cam mechanism with an oscillating flat-faced follower. In the proposed approach, the kinematic characteristics of the cam mechanism are first derived. The cam profile is then designed using homogenous coordinate transformation and conjugate surface theory. Moreover, the sliding velocity at the cam-follower contact points is determined. Finally, the pressure angle of the constant-breadth cam mechanism and the principal curvatures of the cam are analyzed. The validity of the proposed design methodology is verified by means of motion simulations performed using CAD software.

DESIGN AND ANALYSIS OF GENEVA MECHANISM WITH CURVED SLOTS

2014 ◽  
Vol 38 (4) ◽  
pp. 557-567 ◽  
Author(s):  
Jung-Fa Hsieh
Keyword(s):  
Analytical Description ◽  
Singular Points ◽  
Principal Curvatures ◽  
Surface Theory ◽  
Double Points ◽  
Pressure Angle ◽  
Comprehensive Method ◽  
Analytical Formulae ◽  
Indexing Mechanism

A simple yet comprehensive method is proposed for the design of a Geneva indexing mechanism with curved slots. In the proposed approach, conjugate surface theory is used to derive an analytical description of the profile of the curved slots with and without an offset feature. Analytical formulae are then presented for the pressure angle of the Geneva mechanism and the principal curvatures of the curved slots. The effectiveness of an appropriate offset angle in eliminating the singular points and double-points on the curved slot profile is then demonstrated. Finally, a Geneva mechanism is fabricated in order to demonstrate the feasibility of the proposed approach.

Development of the Design and Fabrication System for Planar Cam Mechanisms

2020 ◽  
Vol 902 ◽  
pp. 114-125
Author(s):  
Pham Huy Hoang ◽  
Le Quang Ngoc
Keyword(s):  
Control System ◽  
Linear Optimization ◽  
Numerical Data ◽  
Control Program ◽  
Circuit Board ◽  
Cnc Machine ◽  
Cam Mechanism ◽  
Cam Design ◽  
Cam Profile ◽  
To Receive

Cam mechanisms are used as the control system in several industrial fields such as filling and canning, textiles, automotive. This paper introduces the development of a software for designing planar cam mechanism adapting the dynamic and kinematic requirements. The designed cam profile is then changed into numerical data used to generate the machine codes served for CNC-based fabrication. Traditional cam design is very complicated and has accumulated errors. The envelope theory and inverse method are utilized to perform constraint in pressure angle and motion. The smallest cam radius is then determined in a non-linear optimization adapting the constraints. The paper also presents the design of a CNC machine for cam profile fabrication. The design includes the control system and the circuit board. The CNC control program is built to receive numerical data from cam design section, to simulate the cam profile fabrication and then to fabricate. The optimal design and fabrication are applied to the cam mechanisms with knife-edge/roller reciprocating/oscilating followers. The verification shows that the designed and fabricated cam adapts the requirement of accuracy.

Design and machining of cylindrical cam with meshing indexing disc

2007 ◽  
Vol 221 (3) ◽  
pp. 341-351 ◽  
Author(s):  
J Hsieh
Keyword(s):  
Kinematic Model ◽  
Cnc Machine ◽  
Cam Design ◽  
Comprehensive Method ◽  
Design And Manufacturing ◽  
Machine Elements ◽  
Cam Profile ◽  
Profile Design ◽  
Cost Efficient ◽  
Nc Data

Cams are fundamentally important machine elements, which provide a simple means of generating virtually any follower motion. This paper presents a simple yet comprehensive method for the design and machining of a cylindrical cam with a meshing indexing disc. In the proposed methodology, homogenous coordinate transformation and conjugate surface theory are employed to develop a kinematic model for the cam profile design. The pressure angle and the principal curvature of the designed cam are analysed using the analytical expression derived for the profile. The required NC data equations are obtained by solving the CNC link variables by equating the machine tool ability function with the tool location matrix. The proposed methodology is verified by machining the designed cylindrical cam using a 4-axis CNC machine. The inspection results obtained from a 4-axis CMM show that the profile measurements of the machining cam are in excellent agreement with those of the designed profile. The results confirm that the methodology presented in this study enables the cam design and manufacturing tasks to be successfully integrated. As a result, the production process is flexible, automatic, cost efficient, and controllable.

Effect of Offset Tolerance on Motion Characteristics of Reciprocating Cam-Followers

1966 ◽  
Vol 181 (1) ◽  
pp. 331-337
Author(s):  
R. G. Fenton
Keyword(s):  
Cam Mechanism ◽  
Pressure Angle ◽  
Cam Profile ◽  
Manufacturing Tolerances ◽  
Motion Characteristics

The actual follower offset of a cam mechanism is affected by the manufacturing tolerances, deflections and clearances, and it is generally different from the nominal offset for which the cam profile has been designed to actuate a prescribed follower motion. The change in follower offset results in changes of follower motion characteristics. The actual values of follower displacement, stroke, velocity, acceleration, and pressure angle are derived in this paper, and the relationships between actual and nominal values of follower motion characteristics in terms of the effective follower offset tolerance are established.

DESIGN OF A PITCH-ROLL JOYSTICK BASED ON A THREE-LOBE SPHERICAL CAM MECHANISM

2016 ◽  
Vol 40 (2) ◽  
pp. 113-124
Author(s):  
Debal Saha ◽  
Jorge Angeles ◽  
Jozsef Kövecses
Keyword(s):  
High Pressure ◽  
Contact Ratio ◽  
Cam Mechanism ◽  
Bevel Gears ◽  
Pressure Angle ◽  
Frictional Losses ◽  
Transmission Mechanisms ◽  
Cam Profile ◽  
Selection Of

A pitch-roll joystick based on a spherical cam mechanism is proposed that can be implemented as a haptics device. Spherical cams can replace the bevel gears that are conventionally used in transmission mechanisms involving shafts with intersecting axes to achieve lower backlash, lower frictional losses and higher stiffness. Such a spherical cam mechanism is essentially composed of multi-lobe-cams and conical rollers. Undercutting is a deterrent to the generation of smooth cam surfaces, which calls for the synthesis of a singularity-free spherical cam profile. The issues of high pressure angle and high contact ratio are addressed by means of a multilobe cam. The design of the cam profile and the assembly of the joystick are described. The criteria for the selection of the numbers of lobes and rollers are also explained.

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