Table of Contents

工程适合 - 间隙，过渡，干扰合适

Introduction To Engineering Fit:

在特定类型的拟合中，孔尺寸和轴尺寸之间的差异称为余量。允许允许解释间隙合适与过盈配合之间的差异。正余量指定间隙适合，而拟合中的负余量指定干扰或力适合。两个部件，轴和孔之间存在的关系，它们将组装在组装之前的尺寸差异，称为拟合。当部件组装成子组件单元并且子组装单元组装到完整组件中时，不同部件的配合表面连接在一起以进行适当的功能要求。其中一个可以以关节或拟合的形式配合成另一个。配合可以具有合适程度的紧密性和自由度，用于配合部件之间所需的相对运动，以进行配合的特定功能要求。

The classification of fits is given in Fig.

Components are assembled to perform a specific function. The characteristic of the assembly is determined by the fit. Fit is the general term used to signify the relative degree of tightness or looseness of assembled parts, which decides the relative movement between mating parts. Particular type of fit results from the difference in the sizes of mating parts. Fig. shows the various types of fits. Two parts can fit each other in three ways, viz.

清关配合

Clearance fit is one in which two assembled parts are always free to move relative to each other in the assembly. In the clearance fit, the largest permitted shaft diameter is smaller than the diameter of the smallest hole. The difference between the size of the hole and the size of the shaft is defined as clearance. Clearance fits have limits of the size prescribed so that a clearance always results in a positive allowance, or air space is left between mating parts. The parts can be assembled by hand. Clearance fit is of two kinds namely sliding and running适合。
Examples of clearance fit are door hinges, wheel, and axle, shaft and bearing, etc. used in the assembly of parts.

清关配合可以分类如下：

Loose Fit

It is used between those mating parts where no precision is required. It provides minimum allowance and is used on loose pulleys, agricultural machineries, etc.

运行契合

对于运行架，轴的尺寸应该足够小以维持用于润滑的油薄膜。它用于轴承对等。可以使用每25毫米轴承直径的余量。

Slide Fit or Medium Fit

It is used on those mating parts where great precision is required. It provides medium allowance and is used in tool slides, slide valves, automobile parts, etc.

干涉合适

In the interference fit, mating parts in sub-assembly or main assembly are joined tightly together and no relative motion is possible. The minimum permitted diameter of the shaft is larger than the maximum allowable diameter of the hole. In this case, the shaft and the hole member in any sub-assembly or main assembly are to be attached permanently and used as a solid component but according to the application of this combination, this type of fit can be varied.Interference fit is used for permanent or semi-permanent assembly of parts, which require rigidity and alignment and no relative motion, such as dowel pins and bearings in casting.轴的尺寸与任何子组件或主组件中的孔的尺寸之间的差异称为干扰或负差或负余量。干扰拟合具有大小的限制，因此在组装配合部件时，干扰总是会导致干扰。过渡配合是两种，即驱动或压配合和收缩或力配合。组装，零件通常使用轴表压在一起

The interference fit can be sub-classified as follows :

收缩或重力配合

它指的是最大的负津贴。在孔和轴的组装中，孔通过加热膨胀，然后在其位置迅速冷却。它用于轮辋等的配件。

Medium Force Fit

这些配合有中等负津贴。需要相当大的压力来组装孔和轴。它用于车轮，发电机的电枢等。

紧身或压配合

一部分可以用手锤或轻度压力组装成另一个部分。在两个配合部件之间存在轻微的负余量（比拧紧配合）。它给出了半永久性配合，用在钥匙滑轮和轴，摇臂等上。

过渡契合

In this type of fit, the diameter of the largest allowable hole is greater than that of the smallest shaft, but the smallest hole is smaller than the largest shaft so that small positive or negative clearance between the shaft and hole member is employable. Thus, transition fit has limits of the size of the hole and shaft such that either a clearance or an interference fit may result when two specific parts from the lot are assembled. Here the tolerance zones of the hole and shaft overlap.Transition fits are a compromise between clearance and interference fit where a small amount of either clearance or interference is permissible.过渡配合是两种，即推合和键控配合。也就是说，有时轴略大于孔，有时略小于孔。Spigot in mating holes, coupling rings and recesses are the examples of transition fit.

Transition fit can be sub-classified as follows :

Push Fit

它是指零尺寸，在组装孔和轴时需要零压力（销等）。运动部件显示出这种类型的合适的最小振动。它也被称为舒适的贴合。

力适合或收缩配合

当两个配合部件刚性固定时使用力配合，使得一个不能在没有另一个的情况下移动。它要么需要高压以迫使轴进入孔或通过加热扩展的孔。它用于铁路车轮等。

绞合契合

在绞合拟合中的两个配合部件之间存在轻微的负余量。它需要压力迫使轴进入孔并提供光组件。它用于固定键，引脚等。

更多资源/文章