Reciprocating rotary-linear transformation

Crank and rod mechanisms 

This mechanisms was important for the first steam engines. Today we find cranks and rods in internal combustion engines, as well as windsceen wiper mechanisms.

Crankshaft mechanism 

We can connect multiple rods to one shaft. The rods are connected to cranks, and the cranks are connected to the crankshaft. We use crankshaft for combustion motors that use pistons. We also use them for sewing machines.

Cam mechanisms

A cam is an irregulary shaped device that rotates on a shaft. When the cam rotates, it pushes a special bar called a follower. The follower can move other parts or it can turn a switch on and off. In some mechanisms, a spring pushes the follower back to its original position. We can find camshaftsin toys, automatic tools and combustion motors. There are often eccentric cams in sewing machines and other devices that transform rotary motion to linear motion.

Rotary-linear transformation

Wheel

Wheels are essential parts of bicycles. They let us move more easily because they reduce our contact with the ground and decrease friction. However, if there isn't enought friction, the wheels can slide out of control.  

Rack and pinion mechanisms
A rack and pinion mechanisms has two parts. The rack is a bar with many teeth and the pinion is a gear with teeth that interlock with the rack. When the pinion rotates, the rack moves in a linear direction.If the mechanisms is reversible, the pinion also rotates when the rack moves..






Nut and bolt mechanism
A nut and bolt mechanisms transforms rotary motion  into linear motion. It has two parts: a bolt or a shaft with a spiral groove and a nut that turns around it. We can use a nut and bolt mechanism to lift loads because it funtions as a reducing system.








Whinch and crank mechanism 
A whinch is a cylinder that rotates around a horizontal axis. We attacha rope to the tothe winch and to a load. Then we turn the crank to rotate the winch. We use winches for lifting loads. We find them in cronstruction cranes and in the mechanism that raises window blinds in our homes.

Worm drive

A worm drive reduces the speed of a rotary system very effectively. A worm drive has two parts: a worm shaft and a worm gear. The saft has two, three or even more grooves.Each groove interlocks with one tooth of the worm gear.

                                     

Idler gear

In a simple two-gear system, the gears turn in opposite directions. If we want the gears to turn in the same direction, we put an idler gear between them. This gear changes the direction of rotation, but it doesn't change the ratio of tramsmission.

Rotary transmission

Rotary transmission systems put two rotating elements into contact. These mechanisms have two purposes:

• Transferring rotary force from an input location to another location.
• Changing the rotary speed by using rotating elements of different sizes.

We can perform these functions with various mechanisms, such as the following:

Pulleys and compound pulley systems

In a system of pulley, the equilibrium between the forces depends on the path that the rope follows.

Pulleys

 A pulley is a wheel that rotates around an axis and has a groove. We can divide pulleys into two basic types:

Compound pulley systems

Is a combination of fixed and movable pulleys. It ia also called a block and tackle system. We can combine the pulleys in various ways:

Linear transmission of motion - Levers

A lever is a rigidbar that turns around a point called a fulcrum. Various forces may act on the lever at the same time.

Each force produces a specific torque, which is the force multiplied by its distance from the fulcrum.

                                               Torque = Force x Distance
                                                   
                                                           F x d = R x r
                                            
Classes of levers 
We can divide levers into classes according to the locations of the fulcrum, force and resistance.

Classification of mecanisms

 We can classify mechanisms by the work that they do and how the funtion.

What is a mechanism?

Althought these mechanisms are quite different, they all have something in common. The make work easier because they transmit and transformation force and motion.

All of  these mechanismb requiere an input force and motion from some type of source.

Mechanisms transmit motion and force to receptors that finally perform the work.

This is the output force and motion.


          

Differences between the types of software

   
    We can aalso differentiate between the following types of software:

• Free software: Anyone can use, modify, copy and distribute this software. It is also open source. 

• Proprietary software: Users need special permision or a licence to use, modify, copy or distribute this software.
• Commercial software: The owner distributes and sells this sofware for a price.

• Freeware: This software does not cost anything. It can be copied and distributed, but it cannot be modified.
• Public domain sofware: The author makes this software avaible to everyone at no cost.

Wikis

     A wiki is a collection of web pages that visitors can edit, modify or expand. In this way, the content grows quickly with the contributions of the people working on it.

Like other web pages, wiki content must be stored on a server. Nomally, this would require playing for a hosting service, but many use free online service instead. The most popular examples are Wikispaces and PBWorks.

   

Vertical social networks

Vertical social networks: The users of vertical networks form communitiees who have similar reasons for using the appication.


Sharing professional information: Likendin is the most popular network for all kinds of professionals.

Sharing general ninformation: With FriendFeed, people can create private groups to share information about project, organise events and exchange photos or expeeriences with their friends.

Sharing photos: Instagram, Flick, Pinterest and picassa are popular.

Sharing videos:  YonTube, Dailymotion and Vimeo are common examples.



              

Live streaming: Skype, Twitch.tv, Livestream and upstream.tv are often used.

     

                                                       

Blogs

   Weblogs or blogs are a special type of web page. They were originally used as online diaries for people      to share their personal experiences.

   Blogs have the characteristics which made them interesting:

• The same blog can be shared by various bloggers working together as a team.
• Blogs can include hyperlinks to photos, audio recordings or videos.
• we can use blogs to make daily reports about a project and receive helpful feedback from other people.
• Businesses can use blogs to improve their customer service, by quickly responding to questions or complaints about their products.

     Some of the most popular blogging services are Blogger, Wordpress and Tumblr.