Rotating bearing support

 An important, easily underestimated detail in the design of the pikchain® is the interface between the c-chain® and the slewing ring, or the rotary union. The c-chain® must be secured in such a manner that it does not bend or collapse at the point of directional rotation. igus® has designed a special component to address this issue. On the one hand, it gently guides the energy chain in the radius, and on the other, facilitates nearly friction-free rotation by using a PRT bearing from igus®, without generating significant torque. A hollow shaft then connects the slewing ring or the rotary union with this rotating bearing support.

 As I already wrote in one of my earlier papers, the devil is truly in the details.

 

 

 

 Back view PRT bearing

pikchain®: Driven by passion, part 3

Hello out there, 

Today I just want to come back to the following topic: The drive.

In one of my last Blogs from 10th of December I wrote you that we have changed the rear sprockets. At this time I could show you only a drawing of the new design. You remember? If not, just take a quick look of it again. 

[forcecaption]pikchain® with servo motor, which drives one of the rear sprocket via a shaft.

Today I add for you 2 photos which show the reality of the new drive system. This concept has very important advantages:

  • This drive system engages with the chain at many different places at the same time. So you have a very smooth start.
  • The belt can be retensioned.
  • Because of the innovative design the bending radius of the pikchain® doesn’t have any longer an influence to the size of the rear sprockets. Now you have one standard rear sprocket for every pikchain®-radius and you don’t have to think about pitches etc. anymore.

Of course there is still the other way to drive the pikchain®: One of the rear sprockets is connected directly to the servo motor, which is located at the backside of the pikchain®. See photo.  If you like to have detail drawings, please contact me. 

Of course you are free to drive the pikchain® directly by on e of the main pikchain® pulleys: See also my Blog “Driven by passion” But you need a special design for the pulleys. It has to have a profile that fits to the outer gliding elements of the pikchain® in this way, that the pulley is working like a sprocket. Again: If you wish detail drawings, don’t hesitate to contact me.

Don’t waste you time with the drive: Drive yourself to the real challenges to design your pikchain®.. If you have questions how to design the pikchain® drive:  Just call us! 

[forcecaption]You see here the drive sprocket and 2 other deflection sprockets.

[forcecaption]The other side: 2 deflection sprockets for the belt drive.

Connection hall sensor SS443A

The hall sensor Honeywell SS443A has an open collector output.
Switching a load or PLC requires a relay or optocoupler according to the following wiring diagram. The protective diode is necessary in the relay circuit.
Due to the low response times, we recommend the use of optocouplers (e.g. Weidmüller 8950760000).

[forcecaption]Optocoupler

[forcecaption]Relay 

Feedthrough of draw wires

For the series connection of joints, the 4 draw wires of the second (or upper) joint should be conducted through the first (or lower) joint. This feedthrough must be done in such a way that a movement of the lower joint does not alter the wire lengths of the feedthrough, which means Bowden cables are needed.

In the pictures you can see the schematic and actual feedthrough of the 4 draw wires by means of igus® plastic Bowden cables.

In the connecting rods of the joints (“skeleton”), the wires and cables are free in contrast. In total, a maximum of the following elements can be routed through an RL-50 joint:

4 draw wires plus 2 sensor cables (joint 1 and 2) plus 2 additional cables max. d4 (compressed air or electric).

[forcecaption]Diagram of wire arrangement in the feedthrough (white = rotate, yellow = pivot)

 

[forcecaption]Feedthrough: 1) compressed air hose d=4mm, 2) 4 draw wires, 3) sensor cable