If you need to convert rotary to linear motion chances are you are going to rely on the capabilities of a ball screw drive. This assembly consists of two major components:
1. Ball Nut
2. Ball Screw
Running along between the two components, creating an interface, are recirculating ball bearings.
The Ball Bearings
The purpose of ball bearings is to provide circular motion. They transfer the load between the screw and the nut with efficiency and precision in a variety of machinery. Well-constructed bearings perform three major actions. They
1. Support rotary parts
2. Reduce friction
3. Enable smooth rotation of an axis
This facilitates a smooth process.
To accomplish this, bearings consist of four major components:
• A large outer ring
• A small inner ring
• Balls in between the two rings
• A cage – this prevents the various ball bearings from striking one another
This structure dates as far back as the early 16th century – the inventor being the famous artist/inventor, Leonardo da Vinci (1452-1519).
Properties
The bearings of the ball nut and ball screw assembly come in different sizes. They can be infinitely small for wristwatches or incredibly large for applications inside a power plant. To achieve this, the material comprising the make-up of ball bearings must be durable. The manufacturer must form precise circular balls capable of performing their role with smoothness and accuracy.
The material most commonly employed in the production of quality bearings is steel. In particular, manufacturers utilize 52100 chrome steel. As a high carbon steel, it produces bearings with high strength, durability, and precision – perfect for resisting cracking and subsurface rolling contact fatigue.
The Ball Nut and Its Bearings
One high precision option for a linear application is the ball nut, ball screw assembly. In order to ensure this operates smoothly, converting rotary to linear motion, it is essential to have high-quality ball bearings. The right material and size will ensure the process flows smoothly and cost-effectively.
