modular-bearing

A lightweight, customizable and parametric bearing, manufacturable using 3D printing and CNC machining.

Description

The modular bearing is designed as an alternative for non-replaceable (or difficult to replace) bearings in robotic joints and actuators. It is customized using an OpenSCAD generator, and can be used in a wide number of designs. It can be swapped out without requiring any tools, depending on how it is integrated into a design.

Specifications

The following parameters of the modular bearing can be customized:

• Outer diameter (OD)
• Inner diameter (ID)
• Width
• Number of rolling elements
• Diameter of rolling elements
• Spacing of rolling elements in cage
• Tolerances of rolling and sliding surfaces
• Chamfer of rolling elements
• Inner and outer screw hole diameter
• Inner and outer screw hole count
• Edge distance of screw holes
• Optional secondary screw holes

Testing

Rotation tests have been performed by hand on the modular bearing, demonstrating smooth motion. Testing with the WOLF actuator will be conducted soon. Test video below (redirects to YouTube):

Bill of Materials

You will need the following:

Printed components:

• 1x inner ring
• 1x cage
• 1x outer ring, lower
• 1x outer ring, upper
• rolling elements (number will vary)

COTS components: The size and quantity of commercial fasteners will vary depending on the configuration of the bearing. The following components are recommended for use with the modular bearing:

• roll pins (to secure the outer ring halves together)
• countersunk bolts, to attach the bearing

Tools:

• 3D printer
• Tweezers (to assist with bearing assembly)
• PTFE lubricant (Super-Lube) for bearing races and rolling elements

Assembly Guide

The bearing shown below is configured for the WOLF actuator, however, the assembly procedure will apply to any modular bearing.

Step 1: Place the inner ring inside of the lower half of the outer ring.

Step 2: Place the cage in between the inner ring and lower half of the outer ring.

Step 3: Insert the rollers into the cage. Alternate orientation of the rollers as shown below.

Step 4: Apply PTFE lubricant (Super-Lube) to the rollers. Place the upper half of the outer ring on top of the lower.

Step 5: Secure the outer ring halves using 6 or 12 M3x10mm roll pins, by inserting them into the secondary holes of the rings.

Note: It is advised to use the secondary holes to the left or right of the middle one, as that hole will typically be used to secure loads.

Usage

The modular bearing can be integrated into a number of designs, including:

• robotic joints
• actuators
• motion platforms

Contribute

Contributions from the community are welcomed! Please send us a message if you are interested in collaborating.

License

Shield:

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Contact

If you have any questions or need support, please feel free to open an issue or contact us at:

Email: support@anthrobotics.ca

Website: anthrobotics

Twitter: @anthrobo