机械类专业英语作文

My View about Mechanism

It is well known that the function of mechanism is to transmit or transform motion from one rigid body to another as part of the action of a machine.Gear system,cam system and plane and spatial linkages,which are considered as three types of common mechanical devices that can be used as basic elements of a mechanism.

A kinematics chain is a system of links,which are either jointed together or are in contact with one another in a manner that permits them to move relative to one another.A mechanism or linkage is a constrained kinematics chain,and is a mechanical device that has the purpose of transferring motion and/or force from a source to an output.

Mechanisms are used in a great variety of machines and devices.The simplest closed-loop linkage is the four-bar linkage,which has three moving links and four pin joints.The four-bar linkage has some special configurations created by making one or more links infinite in length,such as the slider-crank mechanism and its inversions.The first step in the motion analysis of more complicated mechanisms is to sketch the equivalent kinematics or skeleton diagram. The number of degree of freedom of the mechanism.The process of mechanisms are the first steps in both the kinematics analysis process.

The ability to visualize relative motion and the ability to improve on a particular design are marks of a successful kinematician.So we must

cultivate our ability of this in our daily life.Only in this way can we become a successful kinematician.

Introduction to Manufacture Because of the highly competitive nature of most manufacturing business,the question of finding ways to reduce cost is ever present. Low-cost manufacture dose not just happen.There is a close and interdependent relationship between the design of a product,selection of materials. Selection of process and equipment,and tooling selection and design.

A good starting point for cost reduction is in the design of the product.The design engineer should always keep in mind the possible alternatives available to him in making his design.The important way to reduce the cost in design is employing maximum acceptable tolerances and finishes. Specify surface roughness and accuracy no greater than that which is commensurate with the type of part or mechanism being designed and the production method or methods contemplated.A comprehensive study of the principle of interchangeability is essential for a thorough understanding and full appreciation of low-cost production techniques.

Many engineers have as their function the designing of products that are to be brought into reality through the processing or fabrication of materials. In this capacity they are a key faction in the material selection