Computer Aided Three-dimensional Interactive Application(CATIA)

CATIA stands for Computer Aided Three-dimensional Interactive Application and is one of the most widely known and used software systems in the CAD world that is marketed and technically supported by IBM. 

The software is very intricate and is used by some of the biggest names in the business world. Currently over 20,000 companies use it worldwide and the distinguished list of names that use the software are top names such as Goodyear, Ford, Toyota, Hyundai, Boeing, Porsche, and Lear Jet just to name a few. All these top companies and more take advantage of the powerful applications that the software has to offer in order to help develop and design their products.

If you are planning on getting into such careers as design, manufacturing, or architecture then learning CATIA software will most likely be required of you at some point in time.

10 Best Universities/Colleges for Mechanical Engineering

Mechanical engineering is the mother of all engineering disciplines. 

 Mass, motion, force, energy, design, and manufacturing – these comprises the world of mechanical engineering. It encompasses the research, design, development, construction and testing of tools, machines and other mechanical equipment. Education from a proper well recognized university, college or school of engineering is vital for all the mechanical engineers due to the highly technical nature of mechanical engineering. 

 According to the ranking of mechanical engineering universities, the top 10 best universities or colleges for mechanical engineering are MIT, Stanford university, UC Berkeley, University of Cambridge, California Institute of Technology (Caltech), Imperial College London, University of Tokyo, ETH Zurich (Swiss Federal Institute of Technology), University of Oxford and National University of Singapore (NUS).

1) MIT (Massachusetts Institute of Technology):

 MIT (Massachusetts Institute of Technology) is perhaps the most renowned and the top best Mechanical Engineering University in the world, and is well known for its cutting edge ideas and philosophies on engineering education. When we talk about mechanical engineering then MIT is the best institute for it. Their mechanical engineering department offers three different undergraduate programs, all with specific occupational trajectories in mind and eight different graduate programs, including doctorate of science. MechE attracts and features an extraordinarily rich diversity and quantity of talented individuals, including 400 undergraduates, 500 graduate students and about 75 faculty members.
Website: meche.mit.edu

2) Stanford University:

California’s Stanford University is another high ranked among top 10 best mechanical engineering university in the world. Mechanical engineering at Stanford University is best known all over the world for its entrepreneurially oriented engineering achievements. Department of mechanical engineering at Stanford university offers degrees at bachelor’s, master’s and doctorate levels. 

Website: me.stanford.edu

3) University of California, Berkeley (UCB) (UC Berkeley):

According to many reports and world rankings, UC Berkeley is another top mechanical engineering school in the world. UCB offers undergraduate as well as graduate programs in the field, with specializations and more focuses in ocean engineering, mechatronics, energy and environment, manufacturing, bioengineering, computation and MEMS and NANO.
Website: me.berkeley.edu

4) University of Cambridge:

University of Cambridge is one of the best mechanical engineering institutes in the world. The University of Cambridge is one of the oldest universities in the world and one of the largest in the United Kingdom. Its reputation for outstanding academic achievement is known world-wide and reflects the intellectual achievement of its students, as well as the world-class original research carried out by the staff of the University and the Colleges. They aim at providing young mechanical engineers with all the analytical, design and computing skills that underpin modern engineering practice, while encouraging the creativity and problem-solving skills that are so important to a good mechanical engineer.
Website: eng.cam.ac.uk

5) California Institute of Technology (Caltech):

California Institute of Technology (caltech) is well known best mechanical engineering university. Mechanical Engineering at Caltech has a century-long record of excellence. It brings together three simple elements: exceptionally talented individuals; an emphasis on fundamentals principles of thermal sciences, fluid and solid mechanics, and mechanical systems; and an atmosphere that inspires one to address the critical technological challenges of the day. their particular interests evolve with time, but their core mission of training the leaders of tomorrow and conducting fundamental research to address major technological roadblocks remains constant. Today, you will find students and faculty working on nano structured fuel cells, laboratory earthquakes, active ferroelectric materials and devices, neural prosthetics, debris flows, response of structures against accidental explosion, quantum mechanical origins of the strength of materials and genetic algorithms for design.
Website: me.caltech.edu

6) Imperial College London:

Another best college for mechanical engineering in the world is Imperial College London. It remains in the list of top ten mechanical engineering colleges of the world since many years. The Department of Mechanical Engineering at Imperial College London is one of the largest and most advanced departments in mechanical engineering in the UK and across the world. They were the top-rated Department of Mechanical Engineering in the recent Research Assessment Exercise 2008, held by the UK Government. The overall mission of the Department is to deliver world-class scholarship, education and research in Mechanical Engineering, with particular regard to their application in industry, healthcare and commerce. Imperial college offers mechanical degrees at undergraduate, graduate and doctorate levels.
Website: imperial.ac.uk/mechanicalengineering

7) University of Tokyo:

University of Tokyo has a long history of providing best mechanical engineering degrees hence producing highly outstanding and technical mechanical engineers in the world. University of Tokyo offers mechanical engineering degrees at undergraduate as well as graduate level.
Website: mech.t.u-tokyo.ac.jp/english

8) Zurich (Swiss Federal Institute of Technology):

Zurich (Swiss Federal Institute of Technology) has one of the best Department of Mechanical and Process Engineering. They offer best engineering degrees well recognized all over the world. The Department of Mechanical and Process Engineering educates students for excellence and leadership in science and industry through cutting edge research on an international platform to face the challenges of the Swiss and global society and economy by engineering innovation in its technology fields. Their vision is to Reach and maintain excellence and leadership in fulfilling its mission as recognized (e.g. among the top five departments worldwide) by students, industry, peers and the board of ETH Zurich.
Website: mavt.ethz.ch

9) University of Oxford:

Oxford is the oldest university in the English-speaking world and lays claim to nine centuries of continuous existence. As an internationally renowned centre for teaching and research, Oxford attracts students and scholars from across the globe, with almost a quarter of our students from overseas. More than 130 nationalities are represented among a student population of over 18,000. University of oxford produces world’s best mechanical engineers who are well appreciated and well recognized in all of the industries worldwide. So University of oxford is one of the best mechanical engineering university in the world.
Website: eng.ox.ac.uk

10) National University of Singapore (NUS):

Acknowledged as one of the finest universities in the world, National University of Singapore (NUS) is a comprehensive university offering a broad-based curriculum underscored by multi-disciplinary courses and cross-faculty enrichment. Department of mechanical engineering at National University of Singapore is known to be one of the best in the world. It remains in top ten best mechanical engineering colleges of the world since a long time. Besides undergraduate, a graduate and doctorate degree, NUS also offers mechanical engineering internships for mechanical engineers during summer vacations. These are research based internships for national as well as international students.
Website: me.nus.edu.sg

Laser Beam Welding

Laser Beam Welding setup:

Laser beam welding is a welding process that uses a laser beam to melt and vaporize material. A ruby laser rod is used for machining process. Here the lasing material is in the form of a solid ruby rod (doped with chromium) with the end faces made parallel to each other within (1 / 20) of the wavelength. One end of the rod is made totally reflective while the other end is partially reflective (about 80 percent). A number of Xenon flash lamps are placed around the laser rod for pumping it into the excited state. A highly reflective cylindrical enclosure surrounds both the rod and the flash lamps to restrict the light from the pumps into the rod.

Increasing the LASER power:

The frequency of the emitted light depends upon the difference in energy levels E2 – E1 and the Planck’s constant. If the photon of light so released comes into contact with another atom or molecule that has been similarly raised to the higher energy level, second atom or molecule is triggered to return to its stable energy level E1 releasing another photon of light.

The two photons so generated are identical in wave length, phase, direction and energy. This sequence of triggering is multiplied many fold to produce the laser beam. When the ruby crystal consisting of aluminium oxide into which 0.05 percent chromium has been introduced, is pumped into the excited state by the series of Xenon flash bulbs surrounding it, the chromium atoms are raised to the higher energy level, releasing a stream of photons, when they fall back to their stable lower energy level.

When this light is reflected from the end mirrors it triggers more atoms to their ground state leading to chain reaction of stimulated radiation. Some of this light escaping from the partially reflecting mirror on the right constitutes the laser. Because of lasers highly monochromatic nature this light can be easily focussed and concentrated with a lens to a very small diameter spot with a much higher intensity.

The large number of lasers that have been developed for welding generally fall into two main categories solid state lasers and gas lasers. Solid state lasers like ruby laser use solid crystal as lasering medium and are excited by Xenon or Krypton filled flash lamps. The output from these lasers is normally in pulses. The power rating of such units may be up to 2 KW. Gas lasers on the other hand use a glass tube through which a mixture of carbon dioxide, Helium or Nitrogen gas is flowing. Direct electrical energy is used with gas lasers for excitation. The gas flowing through the laser may be recirculated in some cases to reduce cost. Continuous wave gas lasers using carbon dioxide gas with power up to 20 KW are used for laser beam welding.

Welding is done with high power lasers with longer pulses so that metal can be heated to its melting point without vaporization. It may be done by conduction or by penetration. Conductive welding is carried out with the help of conductive heating of the joint and is limited to low depth welds. It uses low power intensity beams. Penetration will not be much and weld is obtained by welding of joint near the surface. As the power is increased the higher heat density obtained will cause the metal at the centre of the laser jet to be vaporized with a key hole being formed.

Some things to know about AutoCAD

   AutoCAD, created by Autodesk, is the most widely used technical drawing program wherewith over 1.25 million registered users. Autodesk is the fourth largest PC software company in the world. According to the Autodesk, and for Computer Aided Design (CAD), but can also stand for Computer Aided Drafting .

 The first version of AutoCAD came out in 1982 running under DOS. AutoCAD was the first significant CAD Program to run on a desktop computer. At the time most other technical drawing programs ran on high end workstations or even mainframes. AutoCAD success has been attributed to its famous open architecture. The support of Auto LISP a programming language designed especially for AutoCAD has also been a major factor in making AutoCAD the standard for serious technical drawing.

Although AutoCAD is primarily thought of as a CAD application used for 2D designs, it has a powerful 3D modelling engine that allows you to create 3D models of buildings or small parts used in a machine. 3D modelling in AutoCAD was introduced over a decade ago with AutoCAD R13 (and even before that as an add-on called Autodesk Modelling Extension for AutoCAD R12), but creating 3D models was very time consuming. In recent releases of AutoCAD, the 3D modelling features have been completely overhauled to allow conceptual designing in AutoCAD and to create high-quality presentation renderings with less effort.

AutoCAD not only gives you the 2D drafting tools that you’ve come to use everyday, but it also provides a robust set of tools for 3D modelling and visualizing the 3D models you can create.

Autodesk has created a program with unequalled features and capabilities, including 3D modelling and visualization access to external databases, intelligent dimensioning, importing and exporting of the file formats and many more.

Autodesk has developed a virtual corporation which includes programmers who create software designed to work with AutoCAD, dealers who provide technical support training and courses to over one million users each year.

Autodesk has expanded AutoCAD into a whole product line of programs with AutoCAD as a base and specialized, discipline-specific add-on built on top and included as one complete product.

The major disciplines that use AutoCAD are:

• Architectural
• Mechanical
• GIS (Geographical Information Systems)
• Facilities Management
• Electrical / Electronic
• Multimedia

These discipline specific flavour’s of AutoCAD include:

• Autodesk Architectural Desktop and Autodesk Building Systems (mechanical, electrical, and plumbing),
• Autodesk Mechanical Desktop,
• Autodesk Map,
• AutoCAD Land Desktop,
• Autodesk Survey, and
• Autodesk Civil Design.

Autodesk now offers Autodesk Revit and Autodesk Inventor, software applications that compete with Architectural Desktop and Mechanical Desktop, respectively. Revit and Inventor are not based on AutoCAD; they sacrifice AutoCAD compatibility in favour of a more fundamentally design- and 3D-oriented approach to CAD. Whether they ultimately will replace the traditional AutoCAD-based applications remains to be seen. Thus far, most companies seem to be sticking with AutoCAD and the AutoCAD-based Desktop applications.

However there are many other lesser known uses for AutoCAD, such as Pattern Making in the Garment Industry, Sign Making and so on.

Are we Mechanical Engineers under paid and overworked ?

I knew even before I entered this world of mechanical engineering that I’ll not be getting as handsomely paid as my colleagues in the Software/IT field. But I had hope that some time the world would recognize the worth of  mechanical engineers and start paying them more. And I believed money is not important – its personal satisfaction that matters the most! 

 I realized that the kind of money that my friends in the field of Information Technology and Management was much beyond what an average mech enggnr earns. The salary that a mechanical engineer earns at the end of his career is what the IT guy earns after just 4 or five years of experience.

Though one can argue that the satisfaction a mechanical engineer gets with his job is higher because he is doing something that he likes, the stark reality is that most mech enggnr who graduate out of college are not given pure technical or engineering jobs. They do techno-management works like managing the labour, placing order and maintaining supplies. The result is that they hardly use anything that they learrn in college. Thermodynamics, fluid mechanics, theory of machines, manufacturing sciences, industrial engineering – all get erased from the mind. They remain no more mechies but managers.  The only exception where people really do a bit of mechanical engineering is usually the product development & R&D departments.

This situation has to addressed.

List of International Mechanical Journals

I have given some of the standard International Journals on Mechanical Engineering. This list will be helpful for mechanical researcher's who look out for standard journals to publish there work.
(Names arranged based on alphabetical order)
1. Acoustics Research Letters Online (Acoustical Society of America)
2. Advances in Engineering Software
3. Applied Mathematical Modelling
4. Annals of the C.I.R.P.
5. ASME Journal of Dynamic Systems, Measurement & Control
6. ASME Journal of Energy Resource Technology
7. ASME Journal of Engineering for Industry
8. ASME Journal of Engineering Materials & Technology
9. ASME Journal of Fluids Engineering
10. ASME Journal of Manufacturing Science and Engineering
11. ASME Journal of Mechanical Design
12. ASME Journal of Solar Energy Engineering
13. ASME Journal of Tribology
14. ASME Journal of Vibration & Acoustics
15. Automatica
16. Australian Journal of Mechanical Engineering
17. Chinese Journal of Mechanical Engineering
18. Composite Structures
19. Computers in Industry
20. Computer Integrated Manufacturing Systems
21. Computers & Industrial Engineering
22. Computers & Operations Research
23. Control Engineering & Practice
24. Decision Sciences
25. Decision Support Systems
26. Design Studies (ELSEVIER)
27. Engineering Applications of Artificial Intelligence
28. Engineering Design & Automation Journal
29. Engineering Optimization
30. Ergonomics
31. European Journal of Operational Research
32. Evolutionary Computing
33. Expert Systems with Applications
34. Finite Element in Analysis Design
35. IEEE Manufacturing Engineer
36. IEEE Computer Aided Engineering Journal
37. IEEE Engineering Management Journal
38. IEEE Engineering Management Review
39. IEEE Expert
40. IEEE Journal of Micro Electro Mechanical Systems
41. IEEE Robotics & Automation Magazine
42. IEEE Transactions on Engineering Management
43. IEEE Transactions on Evolutionary Computing
44. IEEE Transactions on Man, Machine & Systems
45. IEEE Transactions on Manufacturing Technology
46. IEEE Transactions on Mechatronics
47. IEEE Transactions on Neural Networks
48. IEEE Transactions on Product Engineering & Production
49. IEEE Transactions on Robotics
50. IEEE Transactions on Robotics & Automation
51. IEEE Transactions on Software Engineering
52. IEEE Transactions on Systems, Man & Cybernetics
53. IIE transactions
54. IMechE Part B: Journal of Engineering Manufacture
55. Indian Academy of Sciences, Proceedings in Engineering Sciences
(Sadhana ISSN: 0256-2499)
56. Industrial Engineering Journal
57. Industrial Robot: An International Journal
58. INFORMS: The Journal of Computing
59. Integrated Computer Aided Engineering
60. International Communications in Heat & Mass Transfer (ELSEVIER)
61. Integrated Manufacturing Systems
62. International Journal for Manufacturing Technology & Research
 Department of Production Engineering
 Birla Institute of Technology, Mesra 835 215, Ranchi
63. International Journal of Advanced Manufacturing Technology
64. International Journal of Advanced Manufacturing System
65. International Journal of Agile Manufacturing
66. International Journal of Computational Methods in Engineering
67. International Journal of Computer Integrated Manufacturing
68. International Journal of Computers Applications in Technology
69. International Journal of Control
70. International Journal of Design Engineering
71. International Journal of Environmentally Conscious Design &
Manufacturing
72. International Journal of Engine Research IMechE
73. International Journal of Engineering Science
74. International Journal of Flexible Manufacturing Systems
75. International Journal of Fracture
76. International Journal of Heat and Mass Transfer
77. International Journal of High Performance Computing & Networking
78. International Journal of Industrial Ergonomics
79. International Journal of Industrial & System Engineering
80. International Journal of Intelligent Control and Systems
81. International Journal of Internet Manufacturing
82. International Journal of Interactive Design & Manufacturing
83. International Journal of Logistics Research & Applications
84. International Journal of Machine Tool & Manufacture
85. International Journal of Machine Tool Design and Research
86. International Journal of Machine Tools & Manufacturing
87. International Journal of Machine Tools & Manufacture (ELSEVIER)
88. International Journal of Manufacturing Research
89. International Journal of Mechanical Sciences
90. International Journal of Mechanical Engineering Education
91. International Journal of Mechanics and Materials Design
92. International Journal of Metrology
93. International Journal of Optomechatronics
94. International Journal of Plasticity
95. International Journal of Production Economics
96. International Journal of Production Research
97. International Journal of Precession Engineering & Manufacturing
98. International Journal of Refrigeration (ELSEVIER)
99. International Journal of Robotic Research
100. International Journal of System Science
101. International Journal of Technology and Design Education
102. International Transactions on Operational Research
103. Iron & Steel
104. Journal of Artificial Intelligence Research
105. Journal of the Brazilian Society of Mechanical Sciences &
Engineering
106. Journal of Computer Aided Design
107. Journal of Computing & Information Science in engineering
108. Journal of Design & Manufacturing
109. Journal of Energetic Materials
110. Journal of Energy Engineering
111. Journal of Energy Resources and Technology
112. Journal of Engineering Design
113. Journal of Engineering for Gas turbine and Power
114. Journal of Engineering Materials & Technology
115. Journal of Elasticity
116. Journal of Fluids Engineering
117. Journal of Intelligent Manufacturing
118. Journal of Intelligent and Robotic Systems
119. Journal of Japanese Society of Abrasive Technology
120. Journal of Japanese Society of Precision Engineering
121. Journal of Optimization Theory and Applications
122. Journal of Machining Science and Engineering
123. Journal of Machining Science and Technology
124. Journal of Manufacturing & Operations Management
125. Journal of Manufacturing Science & Engineering
126. Journal of Material Processing & Manufacturing Science
127. Journal of Materials Processing Technology
128. Journal of Maulana Azad National Institute of Technology,
BHOPAL - 462 007(INDIA)
129. Journal of Mechanical Design
130. Journal of Mechanical Working Technology
131. Journal of Mechanical Engineering (Institute of Materials and Machine
Mechanics) Slovak Academy of Sciences, Bratislava
132. Journal of Operations Research Society of Japan
133. Journal of Quality & Maintenance Engineering
134. Journal of Scheduling
135. Journal of Solar Energy Engineering
136. Journal of Sound & Vibrations
137. Journal of Sustainable Product Design
138. Journal of Vibrations and Acoustics
139. Journal of Strain Analysis for Engineering Design
140. Journal of The Chinese Institution of Industrial Engineers
141. Journal of the Indian Institute of Science, Bangalore
142. Journal of The Institution of Engineers (India), (Mechanical Engg.)
143. Journal of The Institution of Engineers (India), (Production Engg.)
144. Journal of The Operations Research Society
145. JSME, Journal of Advanced Mechanical Design, Systems and
Manufacturing
146. Leading Journal of Supply Chain Management
147. Machine Learning
148. Machining Science & Technology
149. Management Science
150. Manufacturing Engineering
151. Manufacturing Review
152. Manufacturing Technology & Management : Quarterly Journal of the
Indian Institution of Production Engineers
153. Manufacturing Technology Today : Journal of the Central
Manufacturing Technology Institute of India
154. Materials & Manufacturing Processes
155. Materials Science and Engineering: A
156. Mathematics of Operations Research
157. Mechanical Engineering
158. Mechanical Systems and Signal Processing
159. Mechanism and Machine Theory
160. Mechatronics
161. Measurement
162. Naval Research Logistics Quarterly
163. Non-Destructive Testing & Evaluation
164. Omega
165. Operation Research Letters
166. Operations Research
167. OPSEARCH, The Journal of Operations Research Society of India
168. OR Spectrum
169. ORSA Journal on Computing
170. Polymer-Plastics Technology & Engineering
171. Precision Metal
172. Proceedings of The Institution of Mechanical Engineering
173. Production & Inventory Management Journal
174. Production, Planning & Control
175. Production, Planning & Control: The Management of Operations
176. Productivity, National Productivity Council Journal
177. Quality Engineering
178. Quality & Reliability Engineering International
179. Reliability Engineering & System Safety
180. Robotics and Computer Integrated Manufacturing
181. Robotics and Autonomous Systems
182. SME Journal of Manufacturing Systems
183. Society for Industrial & Applied Mathematics’ Journal of Discrete
Mathematics
184. The Engineering Economist
185. The Open Mechanical engineering Journal
186. Transactions of Japanese Society of Mechanical Engineers
187. Transactions of the CSME
188. Tribology Transactions
189. UDYOG PRAGATI: The Journal for Practising Managers.
National Institute of Industrial Engineering ( NITIE )
Vihar Lake, Mumbai- 400 087.
190. Virtual & Physical Prototyping
191. Welding International

Some mechanical terms worth knowing

Ball and Detent :
 A simple mechanical arrangement used to hold a moving part in a
temporarily fixed position relative to another part. The ball slides within a bored cylinder, against the
pressure of a spring, which pushes the ball against the detent, a hole of smaller diameter than the ball.
When the hole is in line with the cylinder, the ball falls partially into the hole under spring pressure,
holding the parts at that position. Additional force will push the ball back into its cylinder, compressing
the spring, and allowing the parts to move.
Bearing :
 The part of a machine within which a rotating or sliding
shaft is held. In some bearing types, balls or rollers are used between the bearing surfaces to reduce
rolling friction.

Bell crank:

 A pivoting double lever used to change the direction of applied motion. 

Boss : A cylindrical projection, as on a casting or a forging. Usually provides a contact surface 

around a hole. 

Broach:

To finish the inside of a hole to a shape other than round, as in a keyway (n) The tool for the 

process, which has serrated edges and is pushed or pulled through the hole to produce the required 

shape. 

Clevis :

A U-shaped piece with holes into which a link is inserted and through which a pin or bolt is 

run. It is used as a fastening device which allows rotational motion. 

Collar :

 A cylindrical feature on a part fitted on a shaft used to prevent sliding (axial) movement. 

Core:

 To form the hollow part of a casting, using a solid form placed in the mold (n) The 

solid form used in the coring process, often made of wood, sand, or metal. 

Counterbore:

 A cylindrical flat-bottomed hole, which enlarges the diameter of an existing pilot 

hole. The process used to create that feature.

Countersink  A conical depression added to an existing hole to accommodate and the conic head 

of a fastener recessing it below the surface of a face. The process used to create that feature.

Coupling :

 A device used to connect two shafts together at their ends for the purpose of 

transmitting power. May be used to account for minor misalignment or for mitigating shock loads. 

Die :

 One of a pair of hardened metal plates or impressing or forming desired shape. Also, a tool 

for cutting external threads. 

Face : 

 To machine a flat surface perpendicular to the axis of rotation of a piece.

Fillet :

 A rounded surface filling the internal angle between two intersection surfaces. Also Rounds

Fit :

 The class of contact between two machined surfaces, based upon their respective specified 

size tolerances (clearance, transitional, interference) 

Fixture :

A device used to hold a workpiece while manufacturing operations are performed upon 

that workpiece. 

Flange:

 A projecting rim or edge for fastening, stiffening or positioning. 

 Gage :

 A device used for determining the accuracy of specified manufactured parts by direct 

comparison..

Gage blocks :

 Precision machined steel blocks having two flat, parallel surfaces 

whose separation distance is fabricated to a guaranteed accuracy of a few millionths of an inch; 

Spotface :

 a round machine surface around a hole on a casting or forging, usually to provide a 

contact surface for a fastener or other mating component, the process used to create that feature 

Shim : 

A thin strip of metal inserted between two surfaces to adjust for fit. The process 

of inserting shims. 

Sheave :

 A grooved wheel used to accommodate a belt for the transmission of power. 

Sometimes referred to as a pulley sheave. 

Retaining Ring:

 A tool steel ring used in conjunction with a shaft groove or internal groove to 

located or control position of a component. 

Planetary Gears:

 A gearset characterized by one or more planet gear rotating 

around a sun gear. Epicyclic gearing systems include an outer ring gear (known as an annulas) with the 

planetary system.