Cam Contour Research Articles

Design Calculation for Wedge Cam of Small Roller Centering Three-Jaw Jig

As wedge cam contour’s conventional equation of small roller centering three-jaw jig calculated by classic method is complex and difficult to be used for processing directly, a numerical calculation method for the wedge cam contour is proposed. Firstly, structure and working principle of centering small roller jig is introduced. Secondly, a new numerical calculation method sampling for wedge cam contour using equal step is presented, which can be obtained sampling points expression by numerical calculation model. Then,these samples points assignment will be fitting and interpolation in accordance with quadratic polynomial curve. The equation of quadratic polynomial interpolation on these sampling points these sampling will be obtained, which can be directly applied to NC programming. At last, through comparing fitted quadratic polynomial curve calculated by the numerical method with the theoretical curve calculated by classic method, it is found that the comparison tolerance is much smaller than conventional processing tolerance which is produced by using the theoretical curve for processing. The comparison tolerance is analyzed, refining the sampling step length and using piecewise fitting and interpolation loop calculation method is proposed,which can further improve numerical calculation accuracy to satisfy the requirement of higher and higher positioning. Therefore, it can be concluded that the numerical calculation method can effectively solve the difficult processing problem of wedge cam contour, which will produce better economic benefits.

A speed optimization algorithm based on the contour error model of lag synchronization for CNC cam grinding

In CNC cam grinding, the contour error will inevitably exceed the regular range when two axes have different lag caused by the high-speed grinding regardless of the dynamic characteristics of an individual system. To address this problem, a new speed algorithm is proposed in this paper, which is based on a new contour error model using the idea of lag synchronization and can improve the contour accuracy. In this work, a new concept of relative speed that is grinding carriage to the cam is first proposed, and the parametric equations of the relative speed are constructed. In comparison with the constant angular velocity grinding, it demonstrates that significant improvements in contouring accuracy can be realized through such an approach. Furthermore, two practical examples are given to verify the accuracy and reliability. The application results illustrate the cam contour error is less than 0.01 mm.

Computer Aided Design of Axial Piston Machines Having a Roller Piston Bearing

Swashplate axial piston machines are simple, compact and low price. This simplicity is at the expense of piston transverse forces which limits machine characteristics. The aim of this study is to propose more effective developed design using roller piston bearing. Ball bearing was proposed to reduce transverse forces acting on the piston end of the axial piston machines. The proposed roller bearing design will provide line contact bearing between roller and cam contour compared to point contact of ball bearing arrangement. The roller runs on a flat surface contour formed on the swashplate which is simpler in manufacturing process. The sliding friction between swashplate and slipper is replaced by a rolling friction between roller and runway of cam surface contour. Results show the feasibility of the developed design. The proposed design promises to increase the pressure limitation of the ball bearing arrangement. Parameters such as piston displacement, cam action angle are the same for both roller and ball piston bearing. A comparison analysis was also performed between two alternative cam contours, sinusoidal and linear piston displacement. The selection criterion was based on piston transverse torque. Results show that sinusoidal piston displacement is much better choice than the linear one.

The Cam Contour Control in Grinding Based on Repetitive Control and Error Compensation

The CNC cam grinding contour accuracy is influenced by the complexity of the cam profile and periodic disturbance caused by end effect and friction of the grinding system. In order to enhance the contouring performance, a contour error compensation is adopted. The repetitive learning control (RLC) and a cross-coupled controller (CCC) is combined to compensate the contour error. The repetitive control (RC) is employed for each individual axis to obtain a good tracking performance. Theoretical analyses and detailed simulation results show that the designed control system makes cam grinding system high performance of cam contour accuracy.

Inverse Modeling of Human Knee Joint Based on Geometry and Vision Systems for Exoskeleton Applications

Current trends in Robotics aim to close the gap that separates technology and humans, bringing novel robotic devices in order to improve human performance. Although robotic exoskeletons represent a breakthrough in mobility enhancement, there are design challenges related to the forces exerted to the users’ joints that result in severe injuries. This occurs due to the fact that most of the current developments consider the joints as noninvariant rotational axes. This paper proposes the use of commercial vision systems in order to perform biomimetic joint design for robotic exoskeletons. This work proposes a kinematic model based on irregular shaped cams as the joint mechanism that emulates the bone-to-bone joints in the human body. The paper follows a geometric approach for determining the location of the instantaneous center of rotation in order to design the cam contours. Furthermore, the use of a commercial vision system is proposed as the main measurement tool due to its noninvasive feature and for allowing subjects under measurement to move freely. The application of this method resulted in relevant information about the displacements of the instantaneous center of rotation at the human knee joint.

Design of the Globoidal Cam Mechanism Based on MATLAB and CATIA

Working profile of Globoidal indexing cam is a complex surface. 2D mechanical drawing is difficult to describe it clearly. With the development of computer technology, the 3D design software such as CATIA, Pro-E, Solidworks, UG/NX, the solid and surface function of them make productions more excellent. Globoidal indexing cam profile equations firstly was studied, the geometric size of the globoidal indexing cam mechanism was calculate, and then use MATLAB to calculate the globoidal indexing cam contour surface 3D coordinates of points, finally completed the three-dimensional modeling of globoidal indexing cam in CATIA.

Reverse Engineering of Cam Design Based on BP NN

A three layer BP NN is created to design the cam. The data of cam contour ,which can be measured by CMM, has been used for the training where back propagation method is used.Advantage of solving nonliner problems gives BP netwok the ability to make out a more demand curve of cam. Taking advantage of its learning ability,NN model fits the actual cam contour gradually until the error fulfil the demand.Cam contour is ploted by Matlab,the result of which is better than cubic curve fitting,especially in the aspects of precise and velocity.

Research on Cam Contour Error of Grinding Machining

In order to obtain higher cam quality, the research on the cam contour error is studied. The cam is machined in the way of X-C biaxial linkage motions. The linear motor drives the grinding wheel mechanism to get the motion of X axis, and the motion of C axis is the rotating of cam driven by the torque motor. Because of the servo-system-lag of the two axes, the cam contour error is formed in the X-C biaxial linkage motions. Moreover, the following position error of X axis and C axis is not same as the cam contour error. The relationship between axis following position error and cam contour error is studied. The mathematical model of cam contour error is constructed, the relationship between the cam contour error and the following position error are obtained. At last, the conclusion which the cam contour error can be controlled is made, although the following position error exists at the same time. To design the contour error controller for higher quality cam is based on the above conclusion.

Integrated Design on CAD/CAM/CAPP/CNC for Cam Mechanism

In Pro/E environment, it gived the details about parameteric designs on cam contour curve. By 3D parameterized modeling, motion simulation and analysis of cam, the process planning and tool travel-paths generating were given. G-Codes program was automatically generated too. At last, the integrated design on CAM/CAPP/CNC for cam components is realized.

Disk Cam Contour Design Based on Inventor 2009

Taking disk cam mechanism with translating follower as an example, this paper introduces a method of rapid parameter design for disk cam contour through motion simulation platform Inventor 2009, by which the cam entity can be produced in accuracy. The function of motion simulation of Inventor 2009 is fully used to check the design, so that the efficiency of product design could be greatly improved.

Cutting Force Prediction of Disc Cam Contour Milling

Cutting force equation was established for milling with flat end cutter as feeding in straight-line path by means of discretization method. The model of milling force was conducted based on the manufacturing character of cylindrical surface. The milling force is continual change in manufacturing process, it’s not only influenced by milling parameter, but also related with the shape of cam’s contour. Milling force can result in vibration as machining. Milling force prediction is very useful for manufacturing accuracy control.

Application Research on a Curved CAM Surface Reconstruction Method

Globular indexing CAM mechanism is a good indexing mechanism. As the working curve of CAM contour surface is no extending curved surface, there is certain difficulty to design processing. It is new kinds of design method that reverse engineering apply in rapid modeling of curved CAM. In this way, designer can complete curve of CAM reverse modeling, and the rationality of the model is verified. At the same time, it also can reverse modeling and the subsequent development of other products to provide a reference.

Study on Control of the Cam Contour to Pressure Angle Base on MATLAB Modeling

In this paper, the mathematical model of eccentric follower cam contour and pressure angle was obtained from theoretical calculation, formulated the program diagram, and used MATLAB programming to realize the theoretical calculation. Through the analysis to influence of the base circle radius, eccentricity and lift angle to the maximum pressure angle of cam, proving that the maximum pressure angle could be controlled by the method of cam contour modeling based on MATLAB programming, and this method could realize the precise control to the maximum angle.

Design and Movement Simulation to the Cam of the Testing Device for Capacitor Encapsulation Equipment

In this paper, in order to design a cam mechanism be up to the mustard, a set of methods are put forward that using the Visual Basic programming language based on solidworks to draw cam contour line and then get its 3D models and generate the cam motion simulation by the solidworks motion. In the end, it’s proved that the cam designed though this method met the requirement.

Calculation of Nodes and the Application of CNC Welding Machine by Equal-Error Method to Approach Plane Curve of Cam Contour with Helix

Based on the characteristics of the welding of equal linear velocity of CNC welding machine, this article expounds the calculation of nodes by equal-error method to approach plane curve of cam contour with helix, and some characteristics of the method in the Welding process. Calculating by VC++ Program, we can find the distribution of maximum error and the nodes of plane curve of Cam Contour with CNC welding system of this method. With the system, the program can simulate the trajectory of the soldering point.

Parametric Design and Motion Simulation of Disc Cam Profile Curve Based on the UG NX

This paper presents a parametric design method of the cam profile curve with UG NX, created the cam curves with law of the curve command, conducted curve continuity analysis with Curve Continuity Analysis command, and the results show that all adjacent curves are tangent continuous. This ensures the design accuracy. The velocity curve and the displacement curve were got through the cam motion simulation, and the motion analysis is consistent with the results of theoretical design. Expressions were changed, and the motion analysis show that the parametric design of the cam contour is reasonable.

Design and Performance Analysis of Yielding Anchor Bolt with Large Deformation

According to the principle of the spring constant support device, a kind of large deformation yielding anchor bolt with three elongation properties has been designed. This paper analyzes the performance of the dynamically-pressured soft rock roadway surrounding rock and support mechanism of yielding anchor, carries out the force analysis of the anchor head, derives equation of the knife-type cam and uses Matlab programming to solve the knife -shaped cam contour curve. In the condition of keeping certain anchoring force, the anchor head can produce large displacement along the anchor body in order to decrease the pressure. And after the pressure of surrounding rock relief, the anchor head can move back to add pressure to form a “Loose - support”cycle of flexible supporting.

On the improvement design of dynamic characteristics for the roller follower of a variable-speed plate cam mechanism

Without modifying the cam contour, a cam mechanism with a variable input speed trajectory offers an alternative solution to flexibly achieve kinematic and dynamic characteristics, and then decrease the follower’s residual vibration. Firstly, the speed trajectory of cam is derived by employing Bezier curve, and motion continuity conditions are investigated. Then the motion characteristics between the plate cam and its roller follower are derived. To analyze the residual vibration, a single degree of freedom dynamic model of the elastic cam-follower system is introduced. Based on the motion equation derived from the dynamic model, the residual vibration of the follower is yielded. The design procedure to improve the kinematic and dynamic motion characteristics is presented and two design examples with discussions are provided. Finally, the simulations of the kinematic and dynamic models by ADAMS are carried out and verified that the design models as well as the performances of the mechanism are feasible.

Research on Error Sources Caused by Servo Feed in Cam Grinding

With the development of auto industry, the cam quality requirements higher and higher. In order to illustrate the effect of servo lag upon cam Contour error, X-C servo axis Trajectory coordinates have been acquired in real-time with dual-channel mode during cam grinding. By comparing the Trajectory coordinates detected and the interpolation contour, the errors caused by servo feed lags were verified, and the mechanism that how axis feed acceleration impact on cam Contour errors was proposed. Based on data acquisition and product test, the error compensation method based on servo lag is proved reasonable.

Reverse Design of Cam Contour Curve Based on BP Neural Network

To improve precision of reverse design in cam contour curve, method of using BP neural network was presented. The theory and algorithm of BP neural network were introduced, the principle and process of BP neural network modeling used in the reverse design of cam contour curve were expounded, and the actualize method of reverse design with modeled network was afforded. Experiment indicates that this method is suitable to reverse the contour curve of cam, and has high approach precision. At last, disadvantages of the method were discussed.