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Article
Publication date: 13 November 2017

Zhe Liu, Wei Chen, Desheng Li and Wenjing Zhang

In high-speed processing, the influence on the machining accuracy of a machine tool is greatly caused by the thermal deformation of the motorized spindle; a further study on the…

Abstract

Purpose

In high-speed processing, the influence on the machining accuracy of a machine tool is greatly caused by the thermal deformation of the motorized spindle; a further study on the thermal characteristics of the spindle is given in this paper. This study aims to reduce the thermal error and improve the performance of the machine tool by discussing the relationships between the temperature distributions and rotating accuracy caused by the thermal deformations of the spindle.

Design/methodology/approach

The paper opted for a method combining the theoretical analysis and the experimental study to study the thermal stability of the high-speed motorized spindle. First of all, a finite element model of the spindle was built with ANSYS, whereby temperature distributions and the thermal deformations were successively obtained at different speeds. And then, both the temperature field and the rotating accuracy of the motorized spindle were measured simultaneously by the thermal stability experiment. Finally, the experimental and theoretical results were compared and validated.

Findings

The thermal stability of the motorized spindle was studied in this paper, and some findings from the study were as follows: the spindle’s rotating accuracy maintained good in X direction but bad in Y and Z directions in terms of the deformations; the higher front-end temperature of the spindle which can significantly affect the rotating accuracy is needed to be controlled mainly; the recovery speed of the spindle deformation lagged behind the temperature’s fallback speed; the vibration graph about radial rotating sensitivity synthesized by X1 and X2 presented a trifoliate shape.

Originality/value

Based on a built test-bed which can synchronously measure the motorized spindle’s temperature distribution and rotating accuracy with five-point method, the coupling effects of the thermal deformation and temperature are embodied, and not only the vibration graph but also the thermal tilt angles can be gained. Therefore, considering the influence of the thermal deformation on the heat generated by the bearings, the paper fulfilled a study by which it was obtained that the front-end temperature of the spindle, which was higher and could significantly affect the rotating accuracy, needed to be controlled mainly.

Details

Industrial Lubrication and Tribology, vol. 69 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 8 January 2018

De-xing Zheng, Weifang Chen and Miaomiao Li

Thermal performances are key factors impacting the operation of angular contact ball bearings. Heat generation and transfer about angular contact ball bearings, however, have not…

Abstract

Purpose

Thermal performances are key factors impacting the operation of angular contact ball bearings. Heat generation and transfer about angular contact ball bearings, however, have not been addressed thoroughly. So far, most researchers only considered the convection effect between bearing housings and air, whereas the cooling/lubrication operation parameters and configuration effect were not taken into account when analyzing the thermal behaviors of bearings. This paper aims to analyze the structural constraints of high-speed spindle, structural features of bearing, heat conduction and convection to study the heat generation and transfer of high-speed angular contact ball bearings.

Design/methodology/approach

Based on the generalized Ohm’s law, the thermal grid model of angular contact ball bearing of high-speed spindle was first established. Next Gauss–Seidel method was used to solve the equations group by Matlab, and the nodes temperature was calculated. Finally, the bearing temperature rise was tested, and the comparative analysis was made with the simulation results.

Findings

The results indicate that the simulation results of bearing temperature rise for the proposed model are in better agreement with the test values. So, the thermal grid model established is verified.

Originality/value

This paper shows an improved model on forecasting temperature rise of high-speed angular contact ball bearings. In modeling, the cooling/lubrication operation parameters and structural constraints are integrated. As a result, the bearing temperature variation can be forecasted more accurately, which may be beneficial to improve bearing operating accuracy and bearing service life.

Details

Industrial Lubrication and Tribology, vol. 70 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 4 May 2010

Cheng‐Hsien Chen, Yuan Kang, Ding‐Wen Yang, Ren‐Ming Hwang and Shyh‐Shyong Shyr

The purpose of this paper is to study the influence of number of feeding holes on the performance of aerostatic bearings with spindle rotation. In traditional design of aerostatic…

Abstract

Purpose

The purpose of this paper is to study the influence of number of feeding holes on the performance of aerostatic bearings with spindle rotation. In traditional design of aerostatic bearings, the selection of hole numbers is dependent only on spindle size. However, when the hole numbers of air feeding are enough, the performance of the aerostatic bearing cannot be enhanced by increasing the hole numbers.

Design/methodology/approach

The Reynolds equation is utilized to model the air film within bearing clearance at constant temperature and the state equation of adiabatic process is for air feeding within bearing clearance. The finite difference method with relaxation algorithm is utilized to determine the pressure distributions from discretized and coupled equations of flow continuity. The eccentricity, spindle speed, and the number and arrangement of feeding holes are considered in the analyses to determine the load capacity, attitude angle, and flow rate for the comparisons between various designs of aerostatic bearings.

Findings

It is seen from the simulation results that the aerostatic bearing designed with a small number of feeding holes and without locating at bearing bottom is most suitable for the spindle operating at high speed, while the bearing designed with a large number of feeding holes is suitable for the spindle operating at low speed, and the load capacity is increased with the increasing number of feeding holes for low journal speed.

Originality/value

The paper proposes an extensive database as a critical requirement in the design for number and arrangement of feeding holes of aerostatic bearings for the spindle operating at low or high speed.

Details

Industrial Lubrication and Tribology, vol. 62 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 11 April 2016

Qiyin Lin, Zhengying Wei, Ning Wang and Yubin Zhang

The purpose of this paper is to study the influences of recess configurations on the performances of high-speed hybrid journal bearing. Hybrid journal bearing earns increasing…

Abstract

Purpose

The purpose of this paper is to study the influences of recess configurations on the performances of high-speed hybrid journal bearing. Hybrid journal bearing earns increasing attention in high-speed machine tool spindle owing to its intrinsic outstanding performances of low temperature rise and high stability.

Design/methodology/approach

To investigate the coupled effects of temperature, turbulence and the interaction between lubricant and journal/bearing bush, a thermal fluid-structure interaction approach is presented and validated by the experimental results.

Findings

Ladder-type recess has excellent tribological characteristics in decreasing temperature rise, improving stability and inhibiting cavitation, which are all beneficial to improve the performances of high-speed spindle system.

Originality/value

This work can be a valuable guide for the future high-speed hybrid journal bearing design.

Details

Industrial Lubrication and Tribology, vol. 68 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 June 1956

S.F. CHISHOLM and R. COATS

SPINNING ROOM LUBRICATION. The detrimental effect of using incorrect oil, particularly for the lubrication of spindles and other high‐speed parts, far outweighs any consideration…

Abstract

SPINNING ROOM LUBRICATION. The detrimental effect of using incorrect oil, particularly for the lubrication of spindles and other high‐speed parts, far outweighs any consideration of the price of oil, since every slight inferiority in lubricating value is multiplied many thousand times in the multiplicity of lubricated bearings. Correct lubrication, therefore, is more important in this department than anywhere else in the mill, especially in so far as power consumption is concerned.

Details

Industrial Lubrication and Tribology, vol. 8 no. 6
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 11 April 2016

Qunfeng Zeng, Jinhua Zhang, Jun Hong and Cheng Liu

The purpose of this paper is to design an oil-air lubrication system with low temperature rise, vibration and noise simplifies the spindle configuration. The oil-air lubrication…

558

Abstract

Purpose

The purpose of this paper is to design an oil-air lubrication system with low temperature rise, vibration and noise simplifies the spindle configuration. The oil-air lubrication unit is a key component for high-speed grinding machine tools. The development of oil-air lubrication unit suitable for high/ultrahigh rotational speed is a daunting task owing to the lubrication challenges.

Design/methodology/approach

This paper emphasizes three main issues: the analysis of oil-air two-phase flow for tradition oil-air lubrication unit with the simulation method; the design of new oil-air lubrication unit for the high/ultrahigh-speed grinding machine tools and the comparative experiment research of tradition and new oil-air lubrication unit. The optimum structure parameters that create the optimum flow pattern and operating conditions resulting in low temperature increase, vibration and noise of oil-air lubricated spindle can be achieved by the simulation method and experiments.

Findings

The simulation and experimental results show that new oil-air lubrication unit lubricating a high speed electric spindle has a better performance with a small temperature increase and vibration, which means that our proposed method is an effective design method for oil-air lubrication system.

Originality/value

A design method suitable for high-speed oil-air lubrication unit is proposed. New oil-air lubrication unit is expected to apply for high/ultrahigh rotational speed grinding machine tools.

Details

Industrial Lubrication and Tribology, vol. 68 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 April 1956

S.F. CHISHOLM and R. COATS

Drawing Frames, Combers and Roving Frames. Drawing Frames (Fig. 3) are simple in construction, yet they must be in good mechanical condition and carefully maintained in order to…

Abstract

Drawing Frames, Combers and Roving Frames. Drawing Frames (Fig. 3) are simple in construction, yet they must be in good mechanical condition and carefully maintained in order to produce uniform, strong, high‐quality yarn. Roll bearings present an important lubrication problem. The weighting of the top rolls is distributed both to top‐roll and bottom‐roll bearings. Microscopic tenacious persistent films of lubricating oil must prevent metallic contact with the roll necks inorder to minimise friction, wear and power consumption. This must be accomplished with sparing application of correct oil if throw and spotting are to be prevented. It is the practice in some mills to use a fluid grease in order to minimise the possibility of oil creeping from the bearings and staining the slivers.

Details

Industrial Lubrication and Tribology, vol. 8 no. 4
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 24 November 2020

Pingping He, Feng Gao, Yan Li, Wenwu Wu and Dongya Zhang

The purpose of this paper is to research on optimization of spindle bearing preload based on efficiency coefficient method and provide theoretical guidance for variable preload of…

181

Abstract

Purpose

The purpose of this paper is to research on optimization of spindle bearing preload based on efficiency coefficient method and provide theoretical guidance for variable preload of intelligent spindle.

Design/methodology/approach

Based on an established thermo-mechanical coupling model of angular contact ball bearing with fix-position preload, temperature rise and axial stiffness of the bearing at different speeds and preload are analyzed, and life of the bearing is estimated by the improved L-P theory. The bearing temperature rise, axial stiffness and life data are standardized, and the preload is optimized by the efficiency coefficient method according to the requirements of operating conditions.

Findings

The optimized preload meets comprehensive requirements of the bearing temperature rise, axial stiffness and life under different operating conditions.

Originality/value

In the past studies, it is rarely reported that temperature rise, stiffness and life of the bearing under thermo-mechanical coupling effect are used as objective functions to optimize preload at different speeds.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2020-0205/

Details

Industrial Lubrication and Tribology, vol. 73 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 16 May 2019

Pingping He, Feng Gao, Yan Li, Wenwu Wu and Dongya Zhang

Under fix-position preload, the high rotation speed of the angular contact ball bearing exacerbates the frictional heat generation, which causes the increase of the bearing…

Abstract

Purpose

Under fix-position preload, the high rotation speed of the angular contact ball bearing exacerbates the frictional heat generation, which causes the increase of the bearing temperature and the thermal expansion. The high rotation speed also leads to the centrifugal expansion of the bearing. Under the thermal and centrifugal effect, the structural parameters of the bearing change, affecting the mechanical properties of the bearing. The mechanical properties of the bearing determine its heat generation mechanism and thermal boundary conditions. The purpose of this paper is to study the effect of centrifugal and thermal effects on the thermo-mechanical characteristics of an angular contact ball bearing with fix-position preload.

Design/methodology/approach

Because of operating conditions, elastic deformation occurs between the ball and the raceway. Assuming that the surfaces of the ball and channel are absolutely smooth and the material is isotropic, quasi-static theory and thermal network method are used to establish the thermo-mechanical coupling model of the bearing, which is solved by Newton–Raphson iterative method.

Findings

The higher the rotation speed, the greater the influence of centrifugal and thermal effects on the bearing dynamic parameters, temperature rise and actual axial force. The calculation results show that the effects of thermal field on bearing dynamic parameters are more significant than the centrifugal effect. The temperature rise and actual axial force of the bearing are measured. Comparing the calculation and the experimental results, it is found that the temperature rise and the actual axial force of the bearing are closer to reality considering thermal and centrifugal effects.

Originality/value

In the past studies, the thermo-mechanical coupling characteristics research and experimental verification of angular contact ball bearing with fix-position preload are not concerned. Research findings of this paper provide theoretical guidance for spindle design.

Details

Industrial Lubrication and Tribology, vol. 71 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Content available
Article
Publication date: 1 June 2002

406

Abstract

Details

Aircraft Engineering and Aerospace Technology, vol. 74 no. 3
Type: Research Article
ISSN: 0002-2667

Keywords

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