英语原文共 7 页，剩余内容已隐藏，支付完成后下载完整资料

Mechanical Design

Abstract:

A machine is a combination of mechanisms and other components which

transforms, transmits. Examples are engines, turbines, vehicles, hoists, printing

presses, washing machines, and movie cameras. Many of the principles and methods

of design that apply to machines also apply to manufactured articles that are not true

machines. The term 'mechanical design' is used in a broader sense than 'machine

design' to include their design. the motion and structural aspects and the provisions

for retention and enclosure are considerations in mechanical design. Applications

occur in the field of mechanical engineering, and in other engineering fields as well,

all of which require mechanical devices, such as switches, cams, valves, vessels, and

mixers.

Keywords: Mechanical Design mechanisms Design Process

The Design Process

Designing starts with a need real.Existing apparatus may need improvements in

durability, efficiency, weight, speed, or cost. New apparatus may be needed to

perform a function previously

done by men, such as computation, assembly, or servicing. With the objective wholly

or partly

In the design preliminary stage, should allow to design the personnel fully to

display the creativity, not each kind of restraint. Even if has had many impractical

ideas, also can in the design early time, namely in front of the plan blueprint is

corrected. Only then, only then does not send to stops up the innovation the mentality.

Usually, must propose several sets of design proposals, then perform the comparison.

Has the possibility very much in the plan which finally designated, has used certain

not in plan some ideas which accepts.

When the general shape and a few dimensions of the several components become

apparent, analysis can begin in earnest. The analysis will have as its objective

satisfactory or superior performance, plus safety and durability with minimum weight,

and a competitive cost. Optimum proportions and dimensions will be sought for each

critically loaded section, together with a balance between the strengths of the several

components. Materials and their treatment will be chosen. These important objectives

can be attained only by analysis based upon the principles of mechanics, such as those

of static for reaction forces and for the optimum utilization of friction; of dynamics

for inertia, acceleration, and energy; of elasticity and strength of materials for stress

and deflection; of physical behavior of materials; and of fluid mechanics for

lubrication and hydrodynamic drives. The analyses may be made by the same

engineer who conceived the arrangement of mechanisms, or, in a large company, they

may be made by a separate analysis division or research group. Design is a reiterative

and cooperative process, whether done formally or informally, and the analyst can

contribute to phases other than his own. Product design requires much research and

development. Many Concepts of an idea must be studied, tried, and then either used

or discarded. Although the content of each engineering problem is unique, the

designers follow the similar process to solve the problems.

Product liability suits designers and forced in material selection, using the best

program. In the process of material, the most common problems for five (a) dont

understand or not use about the latest application materials to the best information, (b)

failed to foresee and consider the reasonable use material may (such as possible,

designers should further forecast and consider due to improper use products. In recent

years, many products liability in litigation, the use of products and hurt the plaintiff

accused manufacturer, and won the decision), (c) of the materials used all or some of

the data, data, especially when the uncertainty long-term performance data is so, (d)

quality control method is not suitable and unproven, (e) by some completely

incompetent persons choose materials.

Through to the above five questions analysis, may obtain these questions is does

not have the sufficient reason existence the conclusion. May for avoid these questions

to these questions research analyses the appearance indicating the direction. Although

uses the best choice of material method not to be able to avoid having the product

responsibility lawsuit, designs the personnel and the industry carries on the choice of

material according to the suitable procedure, may greatly reduce the lawsuit the

quantity.

May see from the above discussion, the choice material people should to the

material nature, the characteristic and the processing method have comprehensive and

the basic understanding.

Finally, a design based upon function, and a prototype may be built. If its tests are

satisfactory, the initial design will undergo certain modifications that enable it to be

manufactured in quantity at a lower cost. During subsequent years of manufacture and

service, the design is likely to undergo changes as new ideas are conceived or as

further analyses based upon tests and experience indicate alterations. Sales appeal.

Some Rules for Design

In this section it is suggested that, applied with a creative attitude, analyses can lead

to important improvements and to the conception and perfection of alternate, perhaps

more functional, economical,

and durable products.

To stimulate creative thought, the following rules are suggested for the designer

and analyst. The first six rules are parti

剩余内容已隐藏，支付完成后下载完整资料

资料编号：[452314]，资料为PDF文档或Word文档，PDF文档可免费转换为Word