This miniature precision motion control pulley is made of brass and is mounted to a double-shielded ball bearing made of 400-series hardened martensitic stainless steel. This miniature precision motion control pulley with a deep-groove ball bearing is designed for use with elastomer O-ring belts in applications requiring low torque, smooth operation, and low noise. The bearing has deep inner and outer races that conform to the balls that run in them, allowing higher speeds and creating lower friction than bearings with roller bearings, and the pulley has a single groove on the outer raceway’s surface that keeps the belt in place, preventing the belt from wearing down by rubbing against the sides of the pulley. The bearing has a metal shield on either side that is fastened to the outside ring and extends over the rolling elements. The shields assist in keeping out contaminants such as dirt and grime and also help to hold in lubricant applied during manufacturing. The inner and outer rings and balls are made of 400-series martensitic stainless steel hardened to a minimum of C58 on the Rockwell hardness scale, providing better resistance to corrosion and high temperatures than American Iron and Steel Institute (AISI) 52100 chrome steel, and higher hardness and wear resistance than plain stainless steel. This bearing has a stainless-steel cage to prevent the balls from coming into contact with each other during use, reducing friction, vibration, and noise. It can be used to a maximum operating temperature of 121 degrees C/250 degrees F. The ball bearing has a CN (normal) radial internal clearance designation, making it suitable for applications where the load and speeds do not result in thermal expansion. This clearance provides latitude for self-realignment and compensates for static and dynamic alignment errors. Manufactured to tight dimensional tolerances, this precision bearing is useful in applications that require high accuracy, high rotational speeds, and increased operating efficiency. It is for use in commercial and industrial applications including small appliances, drive systems, vending machines, toys, and small motors.
These pulleys spin freely on built-in bearings to maintain tension for reduced wear and vibration. They are often used with belt tensioners (sold separately). Ball bearings are double sealed to keep dirt out.
Brass pulleys are nonsparking and fit in extremely small spaces.