combinations is [11]:The number of combinations of each group will be given
below case by case. The total number of combinations
over all groups is 60. From the design point of view this
is a more tractable number of alternatives to be con-
sidered.
4.2.1. R
R
machine
The two rotary axes carry the workpiece. The tool axis
can be fixed or carried by one (T), two (TT) or three
(TTT) linear axes.The number of possible designs is the sum of the fol-
lowing combinations:
(i) For the group G0/G5
the tool is fixed in space all
the five axes will carry the workpiece. The number
of different designs is 10 (NT
=3 and NR
=2), (Figs.
15 and 16).
(ii) For the group G1/G4
, NT+NR=1, so NT=1 and NR=0,
is the only possible choice for the tool kinematic
chain. Equation (3) gives NCOMB=6. The combi-
nations are: R
R
T
T
T; T
T
R
R
T; R
T
R
T
T;
T
R
T
R
T; R
T
T
R
T; T
R
R
T
T. Fig. 9 shows
these six designs.
(iii) For the group G2/G3
the tool axes are TT so NT
=1,
NR
=2, NT=2, NR=0 and Equation (2) gives NCOMB=3.
The three design combinations are: R
R
T
TT;
R
T
R
TT and T
R
R
TT. The group G2/G3
contains
three instances of the R
R
machine. These instances
are represented in Fig. 10.
(vi) If the tool axes are TTT the workpiece carrying axes
can only be R
R
. So only one design combination
is possible.
From the above-mentioned findings it can also be con-
cluded that the total number of R
R
five-axis machine
configurations is 20.
Machines with two axes on the clamping table can be
seen in Figs. 1, 3, 6 and 8. The advantages are:摘要：五轴数控加工中心在今天已经变得相当普遍。大多数机床的运动学分析是建立在直角笛卡儿坐标系基础上的。本文根据理论上可能的自由度组合对机床的可行性概念设计和实际应用情况进行了分类，定义了一些有用的定量参数，如工作空间的影响因素，机床空间的使用效率，空间定位指数和角度定位指数。分析比较了每种类型的优缺点，给出了选择和设计机床配置的相关标准。简要讨论了最近在工业上推出的基于Stewart平台的新概念机床。
关键词： 五轴联动；机床；运动链；工作空间；计算机数字控制；旋转轴
1.导言
机床的主要设计规范应遵循下列原则：
    运动学上应提供机床部件和刀具定向和定位足够的灵活性。
    定向和定位的速度应尽可能高。
    定向和定位的精度应尽可能高。
    刀具和工件能快速更换装夹。
    注意环境保护。
    尽可能高的材料去除率。 五轴铣削机床英文文献和中文翻译(4):http://www.youerw.com/fanyi/lunwen_5329.html