Premium Essay

Ball Bearings Theory

Submitted By
Words 1168
Pages 5
In the literature, several models for ball bearings have been proposed to explain the gyroscopic effect and the centrifugal forces. Kurvinen et al. [5] improved the model provide by Sopanen and Mikkola [6, p. 201-211], [7, p. 213-223] and added the centrifugal forces and gyroscopic moment and contemplated the defect in the ball bearings. Kärkkäinen et al. [1, p. 606, 608] considered rotational inertia of the ball and inner ring and aerodynamic torque. In a recent pepper of the Halminen et al. [2, p. 692-705] the model for the cageless bearing is developed based on the available model for the bearing with the cage.

The friction between the rotor and inner race will affect the whirling motion of the rotor [1, p. 613], [8, p. 79-89]. As a result
…show more content…
267-269]. The accuracy of the results for both analytical and numerical method for calculating contact stress highly depends on the calculation of the loads exerted on the contact surface faces. Calculation of this load requires prior knowledge in the rotor dynamic and bearing model. Rolling contact stress is also imperative part of the analysis of the railroad industry and several studied has been done to model the contact stress and fatigue in rail road industry [16]. In addition, Ekberg et. all, [17, p. 899-909] considered effect of surface, subsurface stress, rolling contact and effect of defect in the contact surfaces to predict the rolling contact …show more content…
It is challenging to obtain the stress that is a consequent of the contact in an infinitesimal area. Although, the Hertzain stress model is an analytical method developed based on the theory of elasticity and can be applied to obtain the contact stress in the ball bearing. In this method the normal contact force should be known. Calculation of the normal force as a result of the contact of the ball on races is one the important step in investigating the maximum contact stress. In addition to the static force due to the weight of the rotor, the relative position of the rotor with respect to the bearing and penetration of the ball on races are essential for obtaining the normal force. In order to achieve above information, the detail model for ball bearing, simulation of the rotor during the dropdown should be taken into account. The calculation of the deformation of the race as a result of contact is critical data for determining the contact

Similar Documents

Free Essay


...Ball Bearing Drop Lab Bijay Gurung Nathan Wells September 21, 2014 Physics 2425 Purpose: The purpose of this lab is to calculate the gravity constant. Procedure: The materials needed for this experiments are standard mechanism which includes the time calculator, bearing, and a ruler. Student has to measure the distance of mechanism. Further we have to setup the mechanism by placing the bearing ball in the holding mechanism a distance h above the impact sensor. Once the bearing ball is released, an electronic timer will begin and finally halt once the steel ball has hit the impact plate. One student in a group records the time and repeats the trial for fifteen times. The free fall time, t, can then be used along with the distance h to calculate the acceleration of gravity. Theory: After obtaining the data, we have to convert the distance from cm to m. 1 cm=0.01m. The total height from where the bearing was drop is 173.7 cm=1.737m. We can find the acceleration due to gravity or g value by using the formula, g=2h/t^2, where ‘g’ is the acceleration due to gravity, ‘h’ is the height where bearing was drop from, & ‘t’ is time taken by bearing to hit the floor. For example, for the first trial we have the height of 1.737m, and time it takes was 0.5924s. We can calculate the ‘g’ value by, g=2h/t^2 g=2*1.737m/(0.5924s)^2=9.899 m/s^2 We can also use graphic calculator to find the time. In order to find the “g” by using graphic calculator, we have to......

Words: 467 - Pages: 2

Free Essay

Over Heand Cane

...ABSTRACT Electric Overhead Travelling (EOT) Crane is one of the essential industrial equipment for material handling job. Indecent years little attention has been paid to the optimal design heavy electric overhead travelling bridges. The motive might be, but not limited to the availability of prevailing FEM, DIN, ISO, CMAA, BS, Chinese and now CEN standards for the design of cranes. Most of the crane manufacture has standardized the single dimensioned box section for multiple spans and duties of crane bridges for manufacturing simplicity. LIST OF TABLES Table No. | Table Description | Page No. | 1 Different cross section formula 2 Dimension for ramshorn hooks LIST OF FIGURES Figure No. Figure Description Page No. 1.1.1 Overhead crane 1.3.1 Standard crane 1.4.1 Free standing crane 1.5.1 Gear box 1.5.2 Electric brake motor 1.5.3 Rope guide 1.5.4 Load limiter 1.5.5 Low headroom trolley 1.6.1(A) Top Running Bridge Cranes 1.6.1(B) Under Running Bridge Crane 1.7.1 Top running vs. under running 1.9 Double girder crane hoist 1.9.1 Chain hoist 1.9.2 Wire rope hoist 3.1.1 Drawing of 160 ton hook, nut & Lock plate 3.2.1 CAD model of 160 ton hook 3.3.1 Different views of crane hook 3.3.2 Bending of a beam with larger Initial curvature 3.4.1 Modified cross section 3.5.1 Circular cross section 3.5.2 Rectangular cross......

Words: 5729 - Pages: 23

Free Essay

Hmt Bearings

...Introduction: HMT Bearings Ltd. ("HMTB") was incorporated in 1964 under the name of Indo Nippon Precision Bearings Limited. The Company was promoted as a state public sector company by the Government of Andhra Pradesh in technical collaboration with M/s Koyo Seiko Co. Ltd., Japan. It commenced commercial production in 1970. In 1980 the Company became a central public sector undertaking after it was made a subsidiary of HMT Limited ("HMTL"). The vision of the company is to produce & market bearings and other engineering components of world class excellence through total performance leadership. Company is strictly adhered to the standards, specifications stipulated in ISO-9001-2000. Objective: To explore the factors responsible for loss of company HMT Bearings Ltd. HMT Bearings began suffering a liquidity crisis in 1999-2000. It worsened 2002 and 2003, primarily due to a massive inventory buildup and accumulation of uncollected receivables. In mid-2002, the government and HMT Group explored shutting down HMT Bearings, taking the losses and pensioning off the employees. But that plan was rejected, out of concern for the impact on employment and high pension costs, and in the face of intense pressure by the Center of India Trade Union in Hyderabad. Rather than shut down HMT Bearings, government-funded bailouts were instituted, debt was converted to equity in order to eliminate the overwhelming interest expense. The key development in 2002 was the decision to seek a......

Words: 974 - Pages: 4

Free Essay


...As a manufacturing engineer , I also in charge on choosing the right material to be use on the car , for the wheels of the car , I decided to use teflon wheels as it is light , strong and helps in reducing during the rotation on the track . we use double ball bearing for each of the wheels. We used the treated ball bearings which we had produce during the innovation. The axle we use is the carbon fibre axle because it is very light . The colour that we use is metallic colour using spray paint . For the finishing process , we smoothen the car with differennt type of smoothness . we use the sandpaper that immersed into the water before sandblasting the car by using a sandpaper . this is to ensure the equal smooth on a surface of the car . After that ,,, the will be coated with a layer of car cement to repair the broken effects during the machining process on a denford CNC machine using my knowledge on CAM . it is used to cover the deformation that happened during the cutting process . NEXT , there will be next layer of of undercoat to coat the car . To ensure the perfect smoothness on the car surface, we sandblsting the car again that covered by the undercoat and to beautify and strenghten the car . It is the last finishing layer of the car before its paint using the pressure spray painting . Then , the car is sprayed by two layer of colour which are pink and thrn black . Lastly . we sprayed the clear layer to make the car surface looks shiny...

Words: 267 - Pages: 2

Free Essay

International Human Resource Management

...│ CREDIT RESEARCH │ Wednesday │ 20 September │ 2006 Summary Financials (USD mn) 2003 Sales Gross Profit EBITDA Net Profit Fin Debt Equity Operating CF Free CF 160.3 32.8 14.8 8.4 9.7 43.4 12.3 (2.9) 2004 204.7 69.2 47.4 29.9 16.9 82.4 7.7 (11.3) 2005 249.7 82.8 52.1 30.9 50.7 96.3 21.1 2006E 279.6 94.0 61.0 34.8 153.9 129.2 45.4 No. 1 in the Russian ball bearing industry European Bearing Corporation (EBC) controls 37% of the Russian ball bearing market. EBC operates five ball bearing plants in Russia and one in Kazakhstan and produces more than 2,700 types of ball bearings for more than 500 customers. EBC controls 98% of Russia’s high-precision (aviation) ball bearing market and 95% of the railroad ball bearing market. These two business segments accounted for 65% of EBC’s revenues in 2005. Long-term relationship with Russian Railroads The company has a supply contract worth USD560 mn with Russian Railroads that secures EBC average annual revenue of USD100 mn to 2010. (23.2) 19.3 Source: Company data 2004 34% 23% 15% 0.4 35.0 2005 33% 21% 12% 0.9 13.7 Ratios 2003 Gross Margin EBITDA Margin Net Margin Debt/EBITDA EBITDA/Int. Expense Financial Debt/Equity 20% 9% 5% 0.7 22.8 0.22 Solid financial standing, moderate leverage In 2005, EBC reported revenues of USD250mn, up 22% y-o-y. EBITDA margin stood at 21%, while the debt/EBITDA ratio was only 0.9. Factoring in the planned CLN issue, debt/EBITDA should not exceed 2.5 at year-end 2006, and gradually......

Words: 13583 - Pages: 55

Free Essay

Automatic Forklift System

...CHAPTER 1 INTRODUCTION 1.1 History A forklift (also called a lift truck, a high/low, a stacker-truck, trailer loader, side loader or a fork hoist) is a powered industrial truck used to lift and transport materials. The modern forklift was developed in the 1920s by various companies including the transmission manufacturing company Clark and the hoist company Yale & Towne Manufacturing. The forklift has since become an indispensable piece of equipment in manufacturing and warehousing operations. The middle 19th century through the early 20th century saw the developments that led to today's modern forklifts. The Pennsylvania Railroad in 1906 introduced battery powered platform trucks for moving luggage at their Altoona, Pennsylvania train station. World War I saw the development of different types of material handling equipment in the United Kingdom by Ransomes, Sims and Jeffries of Ipswich. This was in part due to the labor shortages caused by the war. In 1917 Clark in the United States began developing and using powered tractor and powered lift tractors in their factories. In 1919 the Towmotor Company and Yale & Towne Manufacturing in 1920 entered the lift truck market in the United States. Continuing development and expanded use of the forklift continued through the 1920s and 1930s. World War II, like World War I before, spurred the use of forklift trucks in the war effort. Following the war, more efficient methods for storing products in warehouses were......

Words: 9017 - Pages: 37

Premium Essay

Fault Analysis of a Bearing

...ISSN: 2348 9510 International Journal Of Core Engineering & Management (IJCEM) Volume 1, Issue 9, December 2014 Fault Analysis of a Bearing Archit Upadhyay Bachelor of Engineering- Mechanical Engineering Acropolis Institute of Technology & Research, Indore, (M.P), India Contact Number: +91-9993099957 E-maid ID: Abstract The performance of a bearing which is dynamic in nature is very crucial to the working of a machine. The presence of defects in a bearing results in reduced efficiency or in some cases severe damage to the machine which is under consideration. Rolling element bearing is an indispensable part of any machine which finds widespread domestic and industrial applications. Different methods are used for detection and diagnosis of the bearing defects. This research is intended as a tutorial overview of bearing fault detection using vibration analysis. The advent of the microprocessor has enormously advanced the process of vibration data acquisition and analysis in recent years. Measurement that took hours only two decades ago can now be completed in minutes and better decisions made because of better data acquisition and presentation. However, the basic process of measurement and analysis have remained essentially unchanged, just like the machines from which vibrations is measured. The results of the measurement and data analysis need to be compared with known standards or guidelines and decisions made as to whether the machine is......

Words: 1834 - Pages: 8

Premium Essay


...Condition for Maximum Efficiency 2.12 Screw Jack 2.13 Pivot and Collar Friction 2.13.1 Flat Pivot 2.13.2 Conical Pivot 2.13.3 Collar Bearing 2.14 Clutch 2.15 Types of Clutches 2.15.1 Conical Clutch 2.15.2 Single Plate Clutch 2.15.3 Multi Plate Clutch 2.16 Journal Bearing 2.17 Rolling Friction 2.18 Ball and Roller Bearings 2.19 Summary 2.20 Key Words 2.21 Answers to SAQs 2.1 INTRODUCTION When a body moves or tends to move on another body, a force appears between the surfaces. This force is called force of friction and it acts opposite to the direction of motion. Its line of action is tangential to the contacting surfaces. The magnitude of this force depends on the roughness of surfaces. In engineering applications friction is desirable and undesirable. We can walk on the ground because of friction. Friction is useful in power transmission by belts. It is useful in appliances like brakes, bolts, screw jack, etc. It is undesirable in bearing and moving machine parts where it results in loss of energy and, thereby, reduces efficiency of the machine. In this unit, you will study screw jack, clutches and different type of bearings. 51 Theory of Machines Objectives After studying this unit, you should be able to      know application of friction force, know theory background of screw jack, know different type of bearings, analyse bearings, and know function of cluthes. 2.2 TYPES OF FRICTION There are two types of friction : (a) (b) Friction in......

Words: 6929 - Pages: 28

Premium Essay

Performance Financial

...THE COMPANY PROFILE 2.0 NATURE OF PROJECT IN TEAMS 2.1 QUALITIES OF LEADERSHIP & TOOLS USED 2.2 MOTIVATION to manage project teams 2.3 demonstration of the project management 3.0 CONCLUSION 4.0 REFERENCES 1.0 INTRODUCTION MARIAM Precision Bearing Manufacturing Co., Ltd Mariam Precision Bearing Manufacturing Co.Ltd. Is a manufacturer of high-grade bearing parts (green rings) as well as a wide range of ball and roller bearing products.  Through technology-sharing and production linkages with the world's leading bearing manufacturers, as well as progressive cooperation with partners in the domestic arena, Mariam has consistently elevated its manufacturing capability and is now recognized as one of the leading producers of high-grade finished bearings and components. To date, the company has 5 production facilities and affiliated plants, with a combined yearly output of almost 120million bearing units and auxiliary bearing parts. Under the Mariam Precision Bearing brand, Mariam has made headway into the domestic bearing market by supplying OEMs with cost-efficient products, together with value-added services encompassing the widest range of bearings available in any manufacturing company of its class. Its' roster of OEM customers are global brand names and market leaders in their respective industries. Complimenting this, Mariam has extensively developed its distribution arm which now...

Words: 4624 - Pages: 19

Premium Essay

Digital Media

...The media of mass communication have long played a fundamental role in people’s lives. The media informs, persuades, entertains, and even sells. For the most part; mass media is only owned by a few private companies, as we learned in the “media ownership” discussion. According to the “Telecommunications Act of 1996,”, this act was to spawn some competition the broadcast companies. It also eased the restrictions on the number of television stations one individual company can own. The media, controlled by power corporations and government organizations, has positioned itself to influence people in all manner of ways, but no one group controls the system as a whole. 90% of all television media is controlled by only six broadcast corporations. Media can provide companionship, shape perception. They are fundamental to an informed and educated public.(Pavlik, McIntosh 2004). “An important aspect of digitization is that the boundaries between different media have brought into question, and a presupposition has the developer that we are in an era of media convergence” (Storsul,Fagerjord (2008). Strosul and Fagerjord believe that “blurring the border between media does not have to mean convergence. There is also development toward stronger differentiation of media in which elements from earlier separate media and sectors are combined in new ways.” In communication, there are three forms of interpersonal,......

Words: 2211 - Pages: 9

Premium Essay


...Entrepreneurship Entrepreneurship is the act and art of being an entrepreneur or "one who undertakes innovations, finance and business acumen in an effort to transform innovations into economic goods". This may result in new organizations or may be part of revitalizing mature organizations in response to a perceived opportunity. The most obvious form of entrepreneurship is that of starting new businesses (referred as Startup Company); however, in recent years, the term has been extended to include social and political forms of entrepreneurial activity. When entrepreneurship is describing activities within a firm or large organization it is referred to as intra-preneurship and may include corporate venturing, when large entities spin-off organizations.[1] According to Paul Reynolds, entrepreneurship scholar and creator of the Global Entrepreneurship Monitor, "by the time they reach their retirement years, half of all working men in the United States probably have a period of self-employment of one or more years; one in four may have engaged in self-employment for six or more years. Participating in a new business creation is a common activity among U.S. workers over the course of their careers." [2] And in recent years has been documented by scholars such as David Audretsch to be a major driver of economic growth in both the United States and Western Europe. "As well, entrepreneurship may be defined as the pursuit of opportunity without regard to resources currently......

Words: 6013 - Pages: 25

Free Essay


...10/29/13 Xerox PARC, Apple, and the Creation of the Mouse : The New Yorker ANNALS OF BUSINESS CREATION MYTH Xerox PARC, Apple, and the truth about innovation. by Malcolm Gladwell MAY 16, 2011 Print More Share Close Reddit Linked In Email The mouse was conceived by the computer scientist Douglas Engelbart, developed by Xerox PARC, and made marketable by Apple. I n late 1979, a twenty-four-year-old entrepreneur paid a visit to a research center in Silicon Valley called Xerox PARC. He was the co-founder of a small computer startup down the road, in Cupertino. His name was Steve Jobs. Xerox PARC was the innovation arm of the Xerox Corporation. It was, and remains, on Coyote Hill Road, in Palo Alto, nestled in the foothills on the edge of town, in a long, low concrete building, with enormous terraces looking out over the jewels of Silicon Valley. To the northwest was Stanford University’s Hoover Tower. To the north was Hewlett-Packard’s sprawling campus.¤tPage=all 1/12 10/29/13 Xerox PARC, Apple, and the Creation of the Mouse : The New Yorker All around were scores of the other chip designers, software firms, venture capitalists, and hardware-makers. A visitor to PARC, taking in that view, could easily imagine that it was the computer world’s castle, lording over the valley below—and, at the time, this wasn’t far from the truth. In 1970, Xerox had assembled......

Words: 6384 - Pages: 26

Premium Essay

Pierre Bourdieu Theory

...Pierre Bourdieu and the Distinctive Body Nadeem Fayaz For Pierre Bourdieu, the “natural body” is transformed into a “distinctive body”. A minority of people are able to profit from the use of their natural bodies, though the majority of people can only use their bodies for profit through projecting a distinctive body. To achieve this higher level of distinction perhaps is to treat the body as “a 'thing' separate from the self, a machine, to be tuned and serviced and improved wherever possible."[1] Though to treat the body as a machine, perhaps makes problematic the notion of the body as 'natural' because it is no longer just a biological entity, but a socially constructed product and ultimately, to gain distinction, a 'body for others.' The body for others “is the visible manifestation of the person, of the 'idea it wants to give of itself', its 'character', i.e. its values and capacities."[2] This manifestation of the body is influenced by the person's 'taste', social field and 'habitus'. Bourdieu defines taste as an incorporated principle of classification which governs all forms of incorporation, choosing and modifying everything that the body ingests and digests and assimilates, physiologically and psychologically.[3] Taste is thus determined by class, according to Bourdieu. This is significant because "People develop preferences for what is available to them."[4] These preferences are formed from a mixture of economic, social and cultural......

Words: 3122 - Pages: 13

Free Essay

Construction and Design of a Competitive Vex Robot

...designed to test the abilities of the robots. Each robot had to meet certain criteria, such as size of 18 inches or less and they had many constraints that the robot’s builders set in place. This gave the builders the freedom to create what they pleased, but within a set barrier put in place by the VEX company. The designers only used a manual to build the base, and then developed specific parts as modifications to the robot. Both robots were built to play defensively and offensively but responsible for different tasks. One robot was intended to move balls in low goals and the other for high goals. As a result, the team constructed two robots that were able to compete against teams from other schools. This research shows that robots could assist people with transporting objects in the dangerous environments. Introduction Robotics is the science or study of the technology associated with the design, fabrication, theory, and application of robots (What is robotics, 2013). Robots are machines that can be used to do jobs....

Words: 2354 - Pages: 10

Premium Essay

19th Century Research Paper

...could live without them. The top three scientific discoveries of the 19th centuries are Charles Darwin’s theory, Mendeleev’s periodic table, and the use of electricity. These three inventions led to many more. In the mid-nineteenth century, Charles Darwin formulated a major scientific theory in 1859. This theory of evolution, stating that all complex organisms developed from simple forms through the operation of...

Words: 1069 - Pages: 5