The door and window pulley is a small wheel with a groove around it, which can rotate around its axis. A simple machine that can rotate around a central axis. It consists of a grooved disc that can rotate around the central axis and a rope passing through the disc, called a pulley.
Door and window pulleys are widely used. Our sliding doors and windows need pulleys and sliding rails, and drawers also need pulleys. At present, the pulleys mainly include wooden pulleys, steel pulleys and engineering plastic pulleys. According to whether the position of the central axis of the pulley moves, the pulley can be divided into a crown block and a movable pulley. The characteristic of the crane is that it is effortless, but it can change the direction of power. It is essentially an equal-arm lever, and the movable pulley can save half of the force, but it cannot change the direction of the power, so it takes more distance. So there is a door and window pulley group, which can be assembled from a crown block and a movable pulley. The pulley block can not only save effort, but also change the direction of force.
Inferior door and window pulleys are harmful. Some inferior pulleys cannot reach the value advertised by the manufacturer. They are damaged and deformed after being used for a period of time, making them unusable. It needs to be replaced frequently, which is very troublesome. In addition, there are still problems such as high friction, unsmooth pushing and pulling, and loud noise in normal use. Some pulleys do not match the deformation of the slide rail after being used for a period of time, and are easy to derail during the pushing and pulling process, and the safety hazard is very dangerous.
First look at the material. The pulleys currently used are mainly made of plastics and alloys. Plastic pulleys are harder and cheaper, but they are easily damaged. Generally inferior to windows and doors because of low load-bearing capacity. On lighter cabinet doors, alloy pulleys are durable and not easily damaged. When we choose door and window pulleys, there are two kinds of ordinary and thickened ones, which can be selected according to the texture of the doors and windows. If the doors and windows are light in weight and small in size, small tracks can be used; otherwise, if the doors and windows are heavy, thicker tracks can be used, which is safe and durable.
When choosing, it depends on the quality of the pulley. If the quality of the door and window pulley is good, the door and window can be pushed and pulled smoothly. The quality of the pulley is mainly determined by its outer wheels and bearings. Commonly used outer wheels are made of nylon fiber and all-copper materials. The copper pulley is relatively strong, but there is a sound when it is pulled. When the nylon fiber material is pulled, there is no sound, but there is no copper pulley. Abrasion resistance
The pulley bearing is generally made of stainless steel, sliding without noise, and the height of some pulleys can be adjusted, which is very convenient to use. When choosing, pay attention to its manufacturing process.