| Author: | Fan, Yau-sun |
| Title: | Design of precision diamond turning lathe |
| Degree: | M.Sc. |
| Year: | 1995 |
| Subject: | Turning Lathes Machining Hong Kong Polytechnic University -- Dissertations |
| Department: | Multi-disciplinary Studies |
| Pages: | ix, 151 leaves : ill. ; 30 cm |
| Language: | English |
| Abstract: | During the last decades, the development in advanced technology has initialized the demand for extremely high precision components with contour accuracy in submicrometer range and surface finish of a few nanometres. Conventional means of machining these precision components include grinding, polishing and lapping. However, such machining methods are complicated in processes, expensive and time consuming in production. To cope with the increasing quality and quantity demand of precision components over a wide spectrum of industry, a number of new machining methods have been emerged. Single Point Diamond Turning is one of these alternatives to the conventional processes. Single Point Diamond turning is capable of machining a workpiece to profile accuracy of submicron range and roughness of nanometres yet in just one cutting. This kind of manufacturing technology greatly conforms to both the accuracy demand and cost-effective requirements and has exhibited a very potential prospect. In spite of its prospective future, the machine must conform to stringent requirements, these include the extremely high loop stiffness between the tool and the workpiece, the extremely smooth movement of the carriage, the capability of maintaining consistently a very small depths of cut, the control of temperature in the working space so that a thermal stability of the machine system can always be maintained, and the maintaining of a very low level of vibration. In this paper, the errors affecting the machining accuracy is first analyzed and evaluated, a small experimental oriented precision diamond turning lathe is then designed. Hydrostatic carriage system is implemented in this machine tool so that smooth/movement can always be obtained. A friction drive gear reduction mechanism is also designed such that a very fine resolution can be achieved. Laser interferometer is then applied for displacement measurement. Oil shower is utilized to reduce the thermal influence on the machining process and pneumatic isolators are used to isolate vibrations from external sources. A mathematical model using homogeneous transform matrix describing the structural loop of the machine system is also built, thus error budget can be made and the effect of individual error components can be estimated. From the calculation of error budget, it is found that Abbe offsets and thermal expansions are the dominating error sources in diamond turning. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b11829680.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 3.74 MB | Adobe PDF | View/Open |
Copyright Undertaking
As a bona fide Library user, I declare that:
- I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
- I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
- I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.
Please use this identifier to cite or link to this item:
https://theses.lib.polyu.edu.hk/handle/200/594