What is a Saginaw screw?

The Saginaw design used a ball screw to transform rotation of the steering wheel into perpendicular linear motion of a rack. It featured a tube return. Actually, two tubes were employed to recirculate the several dozen balls on separate circuits. No pre-loading was necessary due to the coarse positioning requirements.

What is the difference between a lead screw and a ball screw?

The key difference between a ball screw and a lead screw is in the way the load is carried between the moving surfaces. A ball screw uses recirculating ball bearings to minimize friction and maximize efficiency while a lead screw depends on low coefficients of friction between sliding surfaces.

Who invented the ball screw?

H.M. Stevenson
The ball screw was invented independently by H.M. Stevenson and D. Glenn who were issued in 1898 patents 601,451 and 610,044 respectively. Early precise screwshafts were produced by starting with a low precision screwshaft, and then lapping the shaft with several spring-loaded nut laps.

What material are ball screws made of?

Materials. Ball screws are either made from plastic, metal or both. The shaft of the ball screw is always machined from steel or stainless steel, but the ball nuts may be made from plastic or metal, depending on the application.

When was the ball screw invented?

1874
Ball screws were first devised as a linear motion feeding mechanism for press machines. Such screws can be found in a U.S. patent filed in 1874, shown in Figure 5, as well as in a German patent filed in 1879.

Can you back drive a ball screw?

Lead screws and ball screws have different tendencies to back drive—lead screws typically have a very low chance of back driving, whereas ball screws are more likely to allow the load to fall. This disparity comes down to efficiency.

When would you use a ball screw?

Generally speaking, ball screws are better for applications that require smooth motion, efficiency, accuracy, precision, and prolonged continuous or high-speed movement. Traditional lead screws are more suitable for simple transfer applications for which speed, accuracy, precision, and rigidity are not as critical.

How do you check ball screw conditions?

Troubleshooting Ball Screws

1. Run a power check.
2. Measure the backlash between the screw and the nut.
3. Check for wipers on both ends of the nut assembly if possible.
4. Check the exposed screw for rust, pits, and chatter marks in the ball groove.
5. Check for heavy screw wear in areas where the nut travels the most.

What kind of Assembly is a ball screw drive?

The ball screw drive is an assembly that converts rotary motion to linear motion (or vice versa). It consists of a ball screw and a ball nut packaged as an assembly with recirculating ball bearings. The interface between the ball screw and the nut is made by ball bearings which roll in matching ball forms.

What’s the maximum load for a ball bearing screw?

Dynamic load rating is the maximum load which a ball bearing screw assembly can maintain for 1.0 million inches of travel (Inch Series) or 1.0 million revolutions (Metric Series). Overall length of the screw. Threaded length will be calculated based on the end support machining selected.

What makes a ball screw a ball nut?

It consists of a ball screw and a ball nut packaged as an assembly with recirculating ball bearings. The interface between the ball screw and the nut is made by ball bearings which roll in matching ball forms. With rolling elements, the ballscrew drive has a very low friction coefficient and is typically greater than 90% efficient.

What kind of screws are Thomson ball screws?

Thomson offers the widest range of ball screw products in the industry. The ball screw drive is an assembly that converts rotary motion to linear motion (or vice versa). It consists of a ball screw and a ball nut packaged as an assembly with recirculating ball bearings.