• The Journal of the Acoustical Society of Korea
• /
• v.9 no.2
• /
• pp.14-24
• /
• 1990

A Study is made on shrink fit shaft in which its part is modelled and spring stiffness per unit length is estimated, then obtained transfer matrix. Transfer matrix of shaft is found by Myklestad's method and natural frequency is found by shrink fit tolerance on shrink fit shaft, too. In order to verify effectiveness of shrink fit effect, hollow shaft of the same size is compared with shrink fit shaft which will verified on experiment. As a result of this study, the more shrink fit tolerance increases, the more spring stiffness per unit length increases. It is obvious from the above results that shrink fit shaft due to shrink fit tolerances decreases natural frequency.

• Journal of the Korean Society for Precision Engineering
• /
• v.12 no.1
• /
• pp.29-37
• /
• 1995

In many metal forming processes, it is common to use stress rings for reducing elastic deformation and failures of forming dies. But, shrink fit of dies inner diameter of die insert, machining is reuqired after shrink fit processes. The reduction of inner diameter can be predicted by the analysis of elastic-plastic finite element method. The dimension of dies before shrink fit can be determined to minimize or remove machining after shrink fit processes by deformation analysis of die. The computation of contacting stresses along die surface was analyzied by rigid plasitic finite element method, and data were interpolated by the contact search algorithm. In this paper, we propose the analysis method of forging dies after shrink fit and forming to improve dimensional accuracy of final products.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.19 no.6
• /
• pp.889-894
• /
• 2010

Conventional shrink-fit tool holders have positive features, such as high accuracy, high strength, high stiffness and low sensitivity to centrifugal forces, but they require heavy investments for heating and cooling equipment. Generally the heating equipment has to heat the tool holder up to $200{\sim}300^{\circ}C$ for tool changes. This paper introduces a novel shrink-fit tool holder that is able to unclamp a tool at $40{\sim}50^{\circ}C$. This feature makes it possible to switch between the clamped and unclamped states by using a simple device, which has lower power, smaller size and lower cost than the heating equipment of the conventional shrink-fit tool holders. The proposed shrink-fit tool holder is able to expand its tool hole by using the shape memory alloys which are integrated in the tool holder body. Performances of the SMA shrink-fit tool holder were evaluated experimentally. The experimental results confirm that the proposed tool holder is feasible in aspects of clamping/unclamping operations, clamping force and repeatability of tool setup.

• Journal of the Korean Society for Precision Engineering
• /
• v.28 no.3
• /
• pp.301-307
• /
• 2011

In this paper, effects of major design parameters of cold forging dies on die mechanics are quantitatively investigated with emphasis on shrink fit using a thermoelastic finite element method. A ball-stud cold forging process found in a cold forging company is selected as a test process and the effects of die insert material, magnitude of shrink fit, dimension of shrink ring, number of shrink rings, partition of die insert and clamping force on effective stress and circumferential stress are analyzed. It has shown that the number of shrink rings, magnitude of shrink fit, and Young's modulus of die insert material have strong influence on compressive circumferential stress in die insert but that the influence of the other design parameters is relatively weak.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.11 no.4
• /
• pp.82-88
• /
• 2002

Copper bus-bar is made by drawing process and used in many part of industry. Ohen design drawing die for copper bus-bar, design factor is focused on the deformation of die-land by drawing force and shrink fit. In this paper it is analyzed to determine shrink fit value by shrink fit analysis program which is used with APDL/UIDL language in a commercial FEM package, ANSYS. The shrink fit analysis has been developed that enables optimal desist of the dies taking into account the elastic deflections. Elastic deflection is generated in shrink fitting the die inserts and that caused by the stresses generated using DEFORM software for drawing process analysis. This data can be processed as load input data fir a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the drawing die design. The stress analysis of the dies is used to determine optimized dimension of die-land.

• Journal of the Korean Society for Precision Engineering
• /
• v.27 no.9
• /
• pp.94-102
• /
• 2010

The spindle is the main component in machine tools. To develop high speed machine tools, a lot of studies have been carried out for high speed spindle. Bearing is very important part in spindle. The bearing clearance is influenced by shrink fit and thermal expansion during operation. The designer must take into account the reduction of shrink fits. The aims of this study are to grasp the shrink fits and behavior of a bearing which is a deeply connected with fatigue life of bearing and performance of spindle through FEM(Finite Element Method). This paper proposed optimum value of shrink fit considering deformation of spindle and stress of fitting area using design of experiments. Thus, the proposed formula can be used to obtain bearing internal clearance.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2009.10a
• /
• pp.119-123
• /
• 2009

In this paper, effects of major design parameters of cold forging dies on die mechanics are quantitatively investigated with emphasis on shrink fit using a thermoelastic finite element method. A ball-stud cold forging process found in a cold forging company is selected as a test process and the effects of die insert material, shrink fit, dimension of ring, partition of die inert and clamping force on effective stress and circumferential stress are analyzed.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2001.11a
• /
• pp.45-53
• /
• 2001

Copper bus-bar is made by drawing process and used in many part of industry. When design drawing die for copper bus-bar, design factor is focused on the deformation of die-land by drawing force and shrink fit. In this paper, to determine shrink fit value is analyzed by automatic shrink fit analysis program, APDL/UIDL language in a commercial FEM package, ANSYS, has been developed that enables optimal design of the dies taking into account the elastic deflections generated in shrink fitting the die inserts and that caused by the stresses generated in the process and by using DEFORM software for drawing process analysis. This data can be processed as load input data for a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the drawing die design. The stress analysis of the dies is used to determine optimized dimension of die-land.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2001.10a
• /
• pp.166-171
• /
• 2001

Copper bus-bar is made by drawing process and used in many part of industry. When design drawing die for copper bus-bar, design factor is focused on the deformation of die-land by drawing force and shrink fit. In this paper, to determine shrink fit value is analyzed by automatic shrink fit analysis program, APDL/UIDL language in a commercial FEM package, ANSYS, has been developed that enables optimal design of the dies taking into account the elastic deflections generated in shrink fitting the die inserts and that caused by the stresses generated in the process and by using DEFORM software for drawing process analysis. This data can be processed as load input data for a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the drawing die design. The stress analysis of the dies is used to determine optimized dimension of die-land.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.33 no.9
• /
• pp.963-968
• /
• 2009

This paper deals with shrink fit analysis of rotor by 2D cross-section, 2D axis-symmetry, and 3D FEM model. And this paper presents 2nd order approximation function of thermal expansion displacement by design variables (shape dimension, heating temperature, sleeve length, interference etc.), table of orthogonal array and RSM(response surface methodology). The possibility of the rotor with shrink fit is evaluated by thermal expansion displacement. If thermal expansion displacement is larger than interference, shrink fit enable to make the rotor. 2D axis-symmetry model and 3D model are more reasonable than 2D cross-section model, because stress and strain is different along length of shaft.