A study of thermal behavior of the machine tool spindle

The performances of high-speed machine tools depend not only on the speed, power, torque, dynamic and static stiffness, but also on the thermal behavior of the spindle. These parameters directly affect the productivity and quality of machining operations. This paper presents a 3-D finite element thermal model, which was based on the thermo mechanical bearing model and the numerical model of the spindle. Based on thermo mechanical analysis of bearings with angular contact, generated heat and thermal contact resistance are determined for each position of the ball. To provide the most accurate analysis possible in determining thermal contact resistance , bearings are divided into several zones based on the geometry of their cross-section. The aforementioned constraints have been applied to the 3-D FEM model which allowed for establishing temperature field distribution, and spindle thermal balance. In order to prove the efficacy of the proposed model, experimental measurements of spindle and bearing temperatures were done by using thermocouples and thermal imager.

Download Full-text

Thermal characteristic analysis of high-speed motorized spindle system based on thermal contact resistance and thermal-conduction resistance

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-014-6350-1 ◽

2014 ◽

Vol 76 (9-12) ◽

pp. 1913-1926 ◽

Cited By ~ 37

Author(s):

Zhifeng Liu ◽

Minghui Pan ◽

Aiping Zhang ◽

Yongsheng Zhao ◽

Yong Yang ◽

...

Keyword(s):

Contact Resistance ◽

Thermal Conduction ◽

High Speed ◽

Thermal Contact Resistance ◽

Thermal Contact ◽

Thermal Characteristic ◽

Characteristic Analysis ◽

Motorized Spindle ◽

Spindle System

Download Full-text

Thermal-Mechanical Analysis of Annular Target Design for High Volume Production of Molybdenum-99 Using Low-Enriched Uranium

Volume 9: Heat Transfer, Fluid Flows, and Thermal Systems, Parts A, B and C ◽

10.1115/imece2009-13238 ◽

2009 ◽

Cited By ~ 1

Author(s):

Kyler K. Turner ◽

Gary L. Solbrekken ◽

Charlie W. Allen

Keyword(s):

Contact Resistance ◽

Thermal Contact Resistance ◽

Nuclear Reactor ◽

Thermal Contact ◽

Cost Effective ◽

High Volume ◽

The United States ◽

Mechanical Analysis ◽

Effective Manner ◽

Enriched Uranium

Techenetium-99m is a diagnostic radioactive medical isotope that is currently used 30,000 times a day in the United States. All supplies of techenetium-99m’s parent isotope molybdenum-99 currently originate from nuclear reactor facilities located in foreign countries and use highly enriched uranium (HEU). In accordance with the Global Threat Reduction Initiative all uranium used in future molybdenum-99 production will use low enriched uranium (LEU). A design approach to using LEU in a cost-effective manner is to use a target that is based on LEU foil. A potential failure mode for the LEU foil based target is temperature excursion during irradiation due to poor thermal contact between the foil and the target cladding. The purpose of this study is to establish the theoretical basis for experimentally measuring the thermal contact resistance. Replicating in service heating conditions is nearly impossible when testing the thermal contact resistance as part of a study to establish LEU foil warpage tolerances, thus it is necessary to establish an alternate heating configuration that will allow a conservative estimate of the contact resistance. Thermal and mechanical analysis suggests that external heating of an annular target will place the interface into a state that will over-estimate the contact resistance relative to use conditions. Further, the magnitude of the heat load used for testing can be adjusted to control the degree of overestimation.

Download Full-text