The Performance of Ball Bearings With Silicon Nitride Ceramic Balls in High Speed Spindles for Machine Tools

1988 ◽  
Vol 110 (4) ◽  
pp. 693-698 ◽  
Author(s):  
Hirotoshi Aramaki ◽  
Yoshio Shoda ◽  
Yuka Morishita ◽  
Takeshi Sawamoto

Two types of angular contact ball bearings for machine tools having steel rings and silicon nitride balls were tested and the temperature rise was compared with that of conventional steel ball bearings with grease lubrication and oil-air lubrication as well. Experimental results indicated that the temperature rise of silicon nitride ball bearings was much lower than that of steel ball bearings at high speeds. Calculations made using a computer demonstrated that the reduction of gyroscopic moments and centrifugal forces acting on balls because of the low density of silicon nitride resulted in about 30 to 50 percent less frictional loss at high speeds even with low-cost lubrication such as grease or oil-air.

2021 ◽  
Author(s):  
Song Deng ◽  
Guiqiang Zhao ◽  
Dongsheng Qian ◽  
Hua Lin

Abstract To achieve effective cooling for high speed ball bearings, an investigation on the effect of bearing structure on oil-air flow and temperature inside bearing chamber is necessary. However, accurately defining boundary conditions of CFD model for high speed ball bearings has not been addressed completely. Adopting an improved dynamic model of bearings to calculate movements of balls and power loss to set the movement boundary and heat source of CFD model at high-low speeds and light-heavy loads. Then, rotational speed of cage and temperature of outer ring at various loads are tested to validate this proposed method. At high speeds, enlarging sealing degree of outlet not only reduces the temperature rise of bearings and improves the uniformity of temperature distribution, but also promotes the formation of oil-film on balls’ surfaces without increasing power loss. Yet it can reduce the temperature rise but can’t markedly improve the formation of oil-film at low and ultra-high speeds. Moreover, half birfield cage facing nozzle plays an important role in improving oil volume fraction inside the bearing cavity to reduce the temperature rise of bearings, and the next is birfield cage, they are again corrugated cage and half birfield cage back towards nozzle. These research results provide theoretical guidance for the improvement of bearing structure.


2019 ◽  
Vol 12 (3) ◽  
pp. 248-261
Author(s):  
Baomin Wang ◽  
Xiao Chang

Background: Angular contact ball bearing is an important component of many high-speed rotating mechanical systems. Oil-air lubrication makes it possible for angular contact ball bearing to operate at high speed. So the lubrication state of angular contact ball bearing directly affects the performance of the mechanical systems. However, as bearing rotation speed increases, the temperature rise is still the dominant limiting factor for improving the performance and service life of angular contact ball bearings. Therefore, it is very necessary to predict the temperature rise of angular contact ball bearings lubricated with oil-air. Objective: The purpose of this study is to provide an overview of temperature calculation of bearing from many studies and patents, and propose a new prediction method for temperature rise of angular contact ball bearing. Methods: Based on the artificial neural network and genetic algorithm, a new prediction methodology for bearings temperature rise was proposed which capitalizes on the notion that the temperature rise of oil-air lubricated angular contact ball bearing is generally coupling. The influence factors of temperature rise in high-speed angular contact ball bearings were analyzed through grey relational analysis, and the key influence factors are determined. Combined with Genetic Algorithm (GA), the Artificial Neural Network (ANN) model based on these key influence factors was built up, two groups of experimental data were used to train and validate the ANN model. Results: Compared with the ANN model, the ANN-GA model has shorter training time, higher accuracy and better stability, the output of ANN-GA model shows a good agreement with the experimental data, above 92% of bearing temperature rise under varying conditions can be predicted using the ANNGA model. Conclusion: A new method was proposed to predict the temperature rise of oil-air lubricated angular contact ball bearings based on the artificial neural network and genetic algorithm. The results show that the prediction model has good accuracy, stability and robustness.


2018 ◽  
Vol 70 (1) ◽  
pp. 15-22 ◽  
Author(s):  
De-xing Zheng ◽  
Weifang Chen ◽  
Miaomiao Li

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.


Author(s):  
Hyunwoo Hwang ◽  
Won-Sup Lee ◽  
No-Cheol Park ◽  
Hyunseok Yang ◽  
Young-Pil Park ◽  
...  

Recently, plasmonic nanolithography is studied by many researchers (1, 2 and 3). This presented a low-cost and high-throughput approach to maskless nanolithography technique that uses a metallic sharp-ridge nanoaperture with a high strong nanometer-sized optical spot induced by surface plasmon resonance. However, these nanometer-scale spots generated by metallic nanoapertures are formed in only the near-field region, which makes it very difficult to pattern above the photoresist surface at high-speeds.


2014 ◽  
Vol 658 ◽  
pp. 339-344
Author(s):  
Viorel Paleu ◽  
Ioan Damian ◽  
Cristel Stirbu

To monitor the friction torque evolution in tandems of angular contact ball bearings, a new testing device is developed. New partial hybrid bearings from 7206C series are obtained by combining 8 steel balls with 4 silicon nitride balls of the same diameter equally spaced in the cage, these bearings being denoted hereafter as 8S-4C type. For comparison, tests are carried-out also on conventional all-steel bearings and hybrid bearings with all the steel balls replaced by silicon nitride balls. The equilibrium temperature of the all-steel, hybrid and 8S-4C ball bearings is determined by tests. At high speed and light axial load, the 8S-4C ball bearings withstand to an oil shut-off test of one minute, while the similar all-steel bearings seized. The 8S-4C partial hybrid ball bearings can be an advantageous solution comparative to more expensive all hybrid bearings, avoiding the scuffing due to the self-healing effect induced by the higher hardness of the silicon nitride balls.


2018 ◽  
Vol 224 ◽  
pp. 01020 ◽  
Author(s):  
Georgi M. Martinov ◽  
Akram Al Khoury ◽  
Ahed Issa

Nowadays, there is a big demand on using small sized CNC machine tools, which have low price tag, wide range of implementations, low manufacturing costs and can be used for educational purposes. These machines can achieve casual manufacturing routines, like milling and drilling in applications, where there is no need for high speed performances and super quality of products. In this work, we proposed a model of CNC for these machines and analysed its components and efficiency. The model consists of three main layers: CNC system (application layer), ARM based microcomputer as CAN master and controller (connecting layer) and Servo-Drive Step Motors (actuating layer).


Author(s):  
C. H. Chen ◽  
K. W. Wang ◽  
Y. C. Shin

Abstract Experimental evidence [Shin, 1992] has shown that the natural frequencies of high speed spindles with angular contact ball bearings decrease with increasing rotational speed. A recent study [Wang, et al., 1991] illustrated that this phenomenon is caused by stiffness change of the bearings. A simplified approximation was used in the analysis to examine the bearing radial stiffness at high speeds. While the investigation explained the experimental observations in a qualitative sense, the analytical results so far are not sufficient to quantitatively describe the spindle behavior under high speed operations due to the approximations made in the modeling process. This paper presents an integrated approach toward the modelling of flexible spindles with angular contact ball bearings from basic principles. The local dynamics of the bearings are coupled with the global shaft motion. The model derived includes both the longitudinal and transverse vibrations of the shaft interacting with the nonlinear bearings. The influences of shaft speed on the bearing stiffness matrix and the system frequencies have been studied. It is shown that the spindle dynamic behavior can vary substantially as speed increases due to the bearing gyroscopic moment and centrifugal force. These effects have been ignored in most of the previous spindle models. Lab tests were conducted to validate the model. The analytical predictions are quantitatively verified by the experimental results.


2015 ◽  
Vol 1088 ◽  
pp. 711-715
Author(s):  
Gui Xi Jia ◽  
Jia Dong Chang ◽  
Xiao Lao Sun ◽  
Yun Peng Chang

The CrCN coatings was deposited on the substrate of GCr15 steel ball by closed field unbalanced magnetron sputter ion plating. The performances of vibration, temperature rise, rotational speed, load carrying ability and wear resistance of CrCN coatings steel ball bearing and uncoated steel ball bearing were tested by a bearing tester, and also comparatively analyzed. Results show that, compared to the uncoated bearing, the CrCN coatings steel ball bearing, in the case of rotational speeds higher than 5 000 rpm, have lower vibration values, especially above 6 000 rpm, the vibration values were significantly reduced, and the coated bearing has vibration stability performance. And the coated bearing has also slower temperature rise performance, excellent high-speed performance, good load carrying capacity characteristics and wear resistance performance etc.


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