Drive mechanism selection

Linear motion

Linear motion is motion in a straight line. It is usually achieved by converting rotational motion to linear motion - such is the case for belt drives, ball screws, etc. but not for linear motors.

To achieve linear motion, consider the following solutions in relation to the factors that are relevant to your application.

Application factors	Belt drives	Chain drives	Rack/Gear and pinion	Roller Pinon/rack	Leadscrews	Ballscrews	Linear Motors
Accuracy	Low	Low	Low-High	High	Low	Low-High	High
Backlash/Vibration	A consideration	A consideration	A consideration	Near Zero	A consideration	A consideration	Near Zero
Acceleration	Medium	Low	High	High	Low	Medium	High
Speed	Medium	Low	Medium	High	Low	Medium	High
Load capacity	Low	Medium	High	High	Low	High	Low
Length	Shorter	Shorter	Long	Long	Shorter	Shorter	Moderate
High wear and short life	A consideration	A consideration	A consideration	Long life	A consideration	A consideration	Long life
Maintenance	A consideration	A consideration	A consideration	Low to none	A consideration	A consideration	Low to none
Noise level	Medium	High	Medium	Low	High	Medium	Low
Dust and dirt emissions	High	High	Moderate	Low to none	Moderate	Moderate	Low to none

Rotary motion

For applications with heavy loads and slow turning, such as rotation of a crane, slewing bearings are suitable.

For applications with several, or several thousand, rotations per minute, rolling bearings are suitable.

Rolling bearings

Main article: Bearing selection

The table below shows level of suitability of different bearing types for different conditions.

This section is based on a table found in SKF handbooks and on the Engineers Edge website.

Image source: https://www.machinedesign.com/learning-resources/whats-the-difference-between/article/21831901/whats-the-difference-between-bearings