Carriage Drift in Linear-Guideway Type Roller Bearings

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Hiroyuki Ohta ◽  
Taiki Kato ◽  
Soichiro Kato ◽  
Hideyuki Tajimi

This study deals with carriage drift (which is the differences of the carriage displacements or angular displacements at a certain position on a rail during a forward and return process) in linear-guideway type roller bearings. First, the displacements and angular displacements of the carriage of the “nonrecirculating” linear roller and ball bearings under a reciprocating operation were measured. The experimental results showed that carriage drift (in the horizontal, vertical, yaw, and pitch directions) occurred in the roller bearing and not in the ball bearing. Next, in relationship to roller skew, the generating mechanism of carriage drift in roller bearings was examined by a multibody analysis (MBA), then the generating mechanism of carriage drift was explained. Finally, to reduce carriage drift by restricting the roller skew, an antiskewing brace (ASB) was developed.

Author(s):  
J Dominy

This paper develops a simplified numerical technique for the analysis of heat generation and cage slip in high-speed axially loaded ball bearings. The model compares well with experimental results and has shown the characteristic slip behaviour associated with ball bearings. It has been possible to use the model to investigate the nature and causes of slip in lightly loaded ball bearings and it has been shown that the mechanism is primarily dependent upon the spin power, which falls rapidly as slip sets in. The characteristics of slip in ball bearings are shown to be quite different to those in roller bearings.


2006 ◽  
Vol 129 (1) ◽  
pp. 188-193 ◽  
Author(s):  
Hiroyuki Ohta ◽  
Yoshiki Kitajima ◽  
Soichiro Kato ◽  
Yutaka Igarashi

The effects of ball groupings on the pitching and yawing ball passage vibrations of linear guideway type ball bearings (linear ball bearings) under low-speed operation were studied. For this study, the test linear ball bearings (which can retain the ball grouping in operation) with three types of ball groupings were manufactured, and the pitching and yawing ball passage vibrations of each test linear ball bearing were measured using a laser autocollimator. Moreover, a calculation method of the ball passage vibrations for a linear ball bearing with an arbitrary ball grouping was presented. According to the presented method the ball passage vibrations for three types of ball groupings were calculated. The experimental and calculated results show that the occurrence of the pitching and yawing ball passage vibrations was affected by the ball groupings. For the occurrence, the wave forms, and the amplitude of the pitching and yawing ball passage vibrations for the ball groupings, the calculated results based on the presented method almost matched the experimental results.


2015 ◽  
Vol 137 (2) ◽  
Author(s):  
L. Houpert

Analytical relationships for calculating three rolling element bearing loads (Fx, Fy, and Fz) and two tilting moments (My and Mz) as a function of three relative race translations (dx, dy, and dz) and two relative race tilting angles (dθy and dθz) have been given in a previous paper. The previous approach was suggested for any rolling element bearing type, although it has been recognized that the assumption of a constant rolling element-race contact angle is not well supported by deep groove ball bearings (DGBB) or angular contact ball bearings (ACBB). The new approach described in this paper addresses the latter weaknesses by accounting for the variation of the contact angle on the most loaded ball and also shows that misalignment effects on spherical roller bearing (SRB) loads are negligible. Comparisons between the simplified approach (option 1) and the “enhanced” numerical approach (option 2, which requires a summation of the load components on each ball with the appropriate contact angle included) is made, showing a good correlation as long as the relative misalignment remains reasonable or occurs in the plane corresponding to maximum radial displacement. Option 2 can, however, be recommended since it is easy to program and quite accurate at any misalignment level. Other pros and cons of both options are described. As in the previous paper, a full coupling between all displacements and forces, as well as roller and raceway crown radii, are considered, meaning that Hertzian point contact stiffness is used in roller bearings at low load with a smooth transition toward Hertzian line contact as the load increases. This approach is particularly recommended for programming the rolling element bearing behavior in any finite element analysis or multibody system dynamic tool, since only two nodes are considered: one for the inner race (IR) center, usually connected to a shaft, and another node for the outer race (OR) center, connected to the housing.


2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Hiroyuki Ohta ◽  
Tomoya Sakaguchi ◽  
Masaharu Uchiumi

This paper deals with the load–displacement relationship of a ball bearing with axial, radial, and angular displacements for both the inner and outer rings. First, the expressions for the load–displacement relationship of ball bearings with any number of balls under the combined axial, radial, and moment loads were presented by using a system in which both the inner and outer rings are allowed to move in the axial, radial, and angular directions. Second, the presented expressions were compared with Jones' expressions (which are typical conventional expressions for the load–displacement relationship), then the range of application of Jones's expressions were elucidated. Third, the relative axial displacement, the relative radial displacement, and the relative angular displacement of a miniature ball bearing type 692 under the combined axial, radial, and moment loads were calculated. Finally, it was shown that the relative angular displacement in the case with no inner ring angular displacement is Ri/Ro times the relative angular displacement in the case with no outer ring angular displacement, in which Ri and Ro are the radii of the inner and outer race curvature center loci.


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.


1968 ◽  
Vol 10 (1) ◽  
pp. 1-12 ◽  
Author(s):  
H. F. Black

Where a rotor runs within a clearance space, the clearance being comparable with rotor mass unbalance, the synchronous whirling behaviour of the rotor may be considerably affected by intermittent interaction with the stator at the clearance position. Discontinuity and jump phenomena may occur: in general, behaviour will be different with increasing speed from that with decreasing speed, and in either case zones may exist in which rotor-stator interaction is possible but not certain. In the analysis here presented, rotor and stator are regarded as linear multi-degree-of-freedom systems including damping; dry friction at the clearance space is taken into account. Discussion is limited to cases with radial symmetry, and interaction is assumed limited to the position of the clearance space. Polar receptances are used to establish equilibrium conditions with interaction, and speed zones are defined within which interaction may occur. Some hypothetical cases are fully explored, demonstrating that rotor-stator interactions may occur in a variety of forms and circumstances. Interactions with dry friction counterwhirling are also considered. Some experimental results on counterwhirl within a ball bearing are given and qualitatively compared with theory.


2017 ◽  
Vol 866 ◽  
pp. 375-378
Author(s):  
Sathitbunanan Sumate ◽  
Wirote Ritthong

The ball bearings are the rotating components which are widely spread to moving parts for all machinery operation in general industry. This paper presents the ball bearing resistance tool which has a proper size and can handle the maximum load of 300 kg by using an electric power. The ball bearing resistance tool was used to test the bearings No. 6011 cm. The series of tests was performed in the ball bearings lubricated; engine oil SAE 10W/40, auto transmission fluid Dexron, and hydraulic oil. The rotational speeds for testing were vary; 500, 600 and 700 rpm respectively. At each speed, there were various weight; 50, 70, 90,110,130,150, and 170 kg respectively. The results show that the hydraulic oil generated the smallest coefficients of friction and energy efficiency for ball bearing operation.


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