Pulley for blocks in AISI 316 and AISI 304 stainless steel.

What is pulley?

A pulley is a large wheel on which a rope turns, such as in a chairlift. In that application, the bullwheel that is attached to the prime mover is called the drive pulley, with the other known as the return pulley.

Inoxmare AISI 316 stainless steel pulleys have brass buckles. The brass is a material with a lower friction coefficient than steel.

AISI 304 pulleys. What are and how to use them? 

A pulley is a wheel on an axle or shaft that is designed to support movement and change of direction of a taut cable or belt along its circumference. Pulleys are used in a variety of ways to lift loads, apply forces, and to transmit power. In nautical contexts, the assembly of wheel, axle, and supporting shell is referred to as a “block”. A pulley may also be called a sheave or drum and may have a groove or grooves between two flanges around its circumference. The drive element of a pulley system can be a rope, cable, belt, or chain that runs over the pulley inside the groove or grooves. Pulleys are assembled to form a block and tackle in order to provide mechanical advantage to apply large forces. Pulleys are also assembled as part of belt and chain drives in order to transmit power from one rotating shaft to another.

A block is made from:

• Encasement:
  • The main part
  • Formed by 2 rounded parts.

• Pulley:
  • Ribbed circumference of wheel to house the cable.

• Pivot:
  • Steel cylinder
  • Passes through the encasement and the hole in the pulley

These are different types of pulley systems.

• Fixed pulley:
  • has an axle mounted in bearings attached to a supporting structure
  • changes the direction of the force on a rope or belt that moves along its circumference.

• Movable pulley:has an axle in a movable block.

• Compound:
  • a combination of fixed and a movable pulleys forms a block and tackle
  • can have several pulleys mounted on the fixed and moving axles, further increasing the mechanical advantage.

• Snatch block:
  • a type of pulley for blocks that opens on hinges to allow quick access to the rope.
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