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MECHANISMS (Rotary motion mechanisms (Worm gear 3 (Z grooves=is the number…

- - - - Velocity remains constant
    - - velocity is reduced
    - - Velocity is increased
- - - - Class 2
        
        The effect of the effort applied is always multiplied (d>r)
        
        The resistance is between the fulcrum and the effort applied
      - Class 3
        
        The effect of the effort applied is always reduced (d<r)
        
        The effort applied is between the fulcrum and the resistance
      - Class 1
        
        The effect of the effort applied can be multiplied or reduced
        
        The fulcrum is between the effort applied and the resistance
    - - R- is the resistance or load which acts at the other end of the bar
      - d- is the distance from F to the fulcrum
      - r- is the distance from R to the fulcrum
      - F- is the force or effort applied at one end of the bar
    - - A lever is a rigid bar that is supported by a fulcrum
- - - - Are used to make permanent connections
        between axles and shafts
    - - Are used to connect shafts that can move
        along the axle or at an angle to each other.
      - Types
        
        Cardan joint
        
        Oldham joint
    - - Are mechanisms that allow axles or shafts to be connected
        or separated
      - Two types
        
        Clutches with teeth
        
        Friction clutches
  - - - By traction.
        
        The spring is stretched, in a bed frame for example.
      - By torsion.
        
        The spring is twisted, in a clothes peg for example
      - By compression.
        
        The spring is compressed, in a chair for example.
  - - - Be arings are made up of two concentric rings with balls or rollers between them.
      - In bushings the axle or the shaft is inserted in a plain circular piece that is placed inside a housing to provide a bearing surface.
  - - - Band brakess consist of a metal band that puts pressure on a drum attached to the axle of the object we want to slow down.
      - Drum brakes include one or two brake shoes that come into contact with the drum.
      - Disc brakes consist of pads and a disc attached to the object that we want to slow down.
- - - - A crankshaft transforms the rotary motion of an axle into a reciprocating motion with different connecting rods moving at different times.
      - It can also transform the reciprocating motion of the rods into a rotary motion of the axle.
      - This is a set of connecting rods attached to a jointed axle. Each of the joints of the axle acts as a crank.
    - - This is basically a rotating object that pushes a follower as it moves
      - We can change the shape and the usable profiles — the outside edge of the piece — that are more or less pointed to produce more complex movements.
      - A cern transforms rotary motion into reciprocating motion in the follower bar.
      - A set of cams fixed on the same axle is called a camshaft.
    - - This is composed of a crank and a rod called a connecting rod or link.
      - This rod has articulated Ioints at each end — one is connected to the crank and the other to the slider
      - This crank-link-slider system can work in reverse — it can transform reciprocating motion or oscillating motion into rotary motion.
      - This device was very important in the development of steam engines.
    - - This consists of a wheel with an off -centre rotation axle that doesn't coincidewith the centre of its circumference
      - It transforms the rotary motion of the wheel into reciprocating motion in the follower.
      - The distance between the centre of the circumference and the rotation axle is called eccentricity.
  - - - If the bolt rotates and the nut can't turn, the nut moves in a linear
        motion along the threaded axle.
      - If the nut rotates in a tixed position, the bolt will move in a linear motion.
      - This consists of a bolt or threaded bar and a nut that has the same interior diameter as the diameter of the bolt.
    - - F=is the force applied and R= the resistance
      - r= the radious of the winch and d= the length of the cranck handle
      - F·d=R·r--F=R·R·r/d
    - - L=is the velocity of the rack´s movement in millimetres per minute
      - P= is the distance between two consecutive teeht in millimetres
      - L=P·Z·N
      - Z= is the number of teeth in the pinion
      - N= is the number of rotation per minute of the pinion