Working With Linear Bushings Pt 4: Application Examples

The past few blog posts have been regarding the types of bushings and load capacity for the next few posts we will focus on application examples.  Linear bushings can be used in a variety of ways to carry out certain functions and move on a desired axis.  Many characteristics come into play.  Linear bushings are great for low cost solutions or for a more well-balanced linear guide design there are bearings.  Choosing bushing style helps narrow down what type of actuator to use, cylinder driven which is low in price or motor driven which is higher in price.  For vertical direction guidance, the drive center can be placed at the guide center enabling simple and compact mechanism structure.

In this post we will explain the usage and characteristics of linear bushings through application examples on simplified automation machinery.

XYZ Drive Mechanism

This application is called an XYZ Drive Mechanism.  It utilizes synchronous belt drives and a step motor.  Synchronous belt drives have various advantages such as quietness, light-weight, low cost, as well as not requiring lubrication maintenance. In 2-axis XY table designs, top Y axis weight is lightened to reduce the load on the bottom X axis. For this, synchronous belt drive is often used for Y-axis design.

[Fig.1] shows a typical 3-axis XYZ drive mechanism.  As you can see in the outlined drawing, linear guides are used on X-axis with the bearings being supported throughout the entire length of the axis.  On the Y and Z axis, linear bushings are used on linear shafts supported on both ends.  For driving, synchronous belts and a ball screw are used.  All movement is driven by the step motor on each axis converting rotary movement to linear movement via the synchronous belts.

xyz-drive

Pallet Transfer Machine, Y-Axis

Below is [Photo 1] which depicts an IC chip pallet transfer machine, a Y-axis application example. The Y-axis motion is converted into reciprocation motion with a synchronous belt, this is where you will see the linear bushings at work on the 2 supported shafts.

ic-chip-pallet

Single Axis Robot

single-axis-robot

[Fig.2] is an application example for a single axis robot.  The dual linear bushing guides are widely spaced for good load capacity and accuracy.  The synchronous belt drive has light weight and quiet operational characteristics.  Vertical inline orientation of the shaft and belt prevents the bushings from rotating, even for this one shaft structure design.

The traveling pulley arrangement in [Fig. 3] below is used for high motor power efficiency and precision positioning.

traveling-pulley

In order to lift the load (W) in [Fig. 3] by the distance of (S), the rope will need to be pulled up by twice the distance of (S).  This requires only half the force of the load (W).  If move distance is doubled, motor angular resolution is doubled and the positioning resolution improves.  Also, pulley backlash and lost motion is reduced by half.  Overall this improves precision.  If load is reduced by half, then the motor speed can be doubled for higher motor efficiency and a smaller motor can be used.  This improves efficiency.  Applying this principal to linear bushings will allow the designer to choose the correct types for high load, high speed or high accuracy.

These are a few of the simplest machines and applications linear bushings are used on.   More application examples using linear bushings will be covered in the next post!


Share this Story
Load More Related Articles
Load More By Carlicia Layosa
Load More In Featured Articles

Check Also

All Things FIRST®: Mechanical Paradox

For the last post of the FIRST® Robotics ...

Subscribe to our Channel

Follow Me @usa_misumi

Like us on Facebook

Find us on Google Plus

FOLLOW @ INSTAGRAM

  • Link up with #MISUMI's #chains. We have sizes from 11B to 80B as well as #sprockets to get your #gears going. 😉#powertransmission #rotary #engineering #puns #happyfriday
  • Congratulations to the drop a business card drawing winners at the 2017 PTS Trade Show! #winning #MISUMI #precision
  • Lookin' good Wash U Racing! 🏎️🏎️#fsae #michiganinternationalspeedway #engineering
  • Speed kills 🏁🏁 watching our favorite FSAE teams at the acceleration event! Need sponsorship for your team? DM for details! #fsae #michiganinternationalspeedway #formulasae
  • Behold! MISUMI has new #NAAMS configurable components for your #fixtures.  Check out our website for the latest! #automotive #goats #pinretainers #risers #Lblocks #shims #spacers
  • 3rd game into the season & the MISUMI Recreational #softball team is breaking team #records! Scoring 7 runs!  Go MISUMI! #teamwork #talent
  • Walking in the tracks of epic #robots. A glimpse of team pits, here teams show off and work on their robots. #FIRSTInspires #stemsquad #omgrobots #FRCChamps2017
  • Enjoying the team spirit this week at the #FIRST Robotics Championships in St. Louis! #stemsquad #FIRSTInspires #omgrobots #grizzlymascot