Development of System Machine with Multiple-Layred Spindle System

随着新的制造要求的到来，实现更高精度、更宽速度范围、多功能集成等先进系统机床(机床与制造系统兼容)至关重要。近年来，开发适合于系统机床的主轴结构变得必要和不可或缺。可以指出，这种新颖的主轴结构之一是多层独立驱动的，因此，在本研究项目中，提出了一种两层主轴系统，这是多层主轴的基本构型。采用滚动轴承支承两层主轴的主轴箱模型，对主轴结构的热行为进行了不同程度的研究，并提出了相应的设计方法。阐明了主轴的基本热行为，指出了内外主轴单元之间的相互影响。该冷却系统主要受主轴单元内部热源平衡的影响，并利用所提出的冷却系统对主轴单元内的气流，特别是封闭空间的冷却效果进行了验证。利用这种冷却系统来控制内外主轴单元之间的换热，基本上可以解决热变形的问题。在此基础上，用集总热容法对多层主轴系统的热行为进行了描述，并对系统中的相互影响进行了定性评价。为了简化多层结构，提出了无内圈滚动轴承支承的主轴系统。从整体上考察主轴结构的静动态性能的实验结果来看，该主轴结构具有令人满意的性能，适用于多层主轴系统。

It is basiccally important to realize advanced system machine (machine tool compatible with manufacturing system) with higher accuracy, wider range of speed, integrated multiple-function and so on., with advent of the new manufacturing requirement. The development of main spindle structure suitable for the system machine has recently become necessary and indispensable. It can be pointed out that one of such novel spindle structures is of multiple-layred and independent driving type.In this research project, therefore, a two-layred spindle system, which is basic configuration of multiple-layred type, has been proposed. The thermal behavior in the main spindle structure has been investigated to a various extent using the headstock model with a two-layred spindle supported by rolling bearings, finally aiming at the proposal of the due design methodology. The basic thermal behavior has been clarified, and also the mutural effects between inner and outer spindle units has been pointed out. It is considered to be mainly influenced by the balance between heat sources within them.The cooling effects of air flow in the spindle unit, especially the enclosed space has been ascertained using the proposed cooling system. The remedy of thermal deformation is basically possible using such a cooling system in the control of the heat transfer between the inner and outer spindle units.The thermal behavior of multiple-layred spindle system is furthermore represented with the lumped-heat-capacity method and this representation is proven as be effective when investigating the qualitative evaluation of the mutual effects in the system.The spindle system supported by rolling bearings without inner ring has been proposed aiming at the simplification of multiple-layred structure. From the experimental results for investigating static and dynamic behavior of the spindle structure as a whole, it has satisfactory performances and is applicable to the multiple-layred spindle system.